From rmorrison at draper.com Tue Mar 3 06:21:13 2015 From: rmorrison at draper.com (Morrison, Richard H., Jr.) Date: Tue, 03 Mar 2015 11:21:13 +0000 Subject: [labnetwork] resist fluoresce Message-ID: Hi Everyone, I am trying to figure out what wavelength I need for a Microscope to see positive resist fluoresce during an inspection step? Looking for scum and really thin resist on the surface after development. Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From sbhas at uchicago.edu Tue Mar 3 11:52:07 2015 From: sbhas at uchicago.edu (Shivakumar Bhaskaran) Date: Tue, 3 Mar 2015 16:52:07 +0000 Subject: [labnetwork] resist fluoresce In-Reply-To: References: Message-ID: I use yellow filter in my microscope. Our users inspect the photoresists coated wafer with yellow filters. http://www.olympusmicro.com/primer/photomicrography/ccfilters/ccyellow.html --Shiva Shivakumar Bhaskaran, Ph.D. Searle CleanRoom Manager The University of Chicago 5735 S.Ellis, Room 032 Chicago-60637 Ph:773-795-2297 https://searle-cleanroom.uchicago.edu/ From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Morrison, Richard H., Jr. Sent: Tuesday, March 03, 2015 5:21 AM To: labnetwork at mtl.mit.edu Subject: [labnetwork] resist fluoresce Hi Everyone, I am trying to figure out what wavelength I need for a Microscope to see positive resist fluoresce during an inspection step? Looking for scum and really thin resist on the surface after development. Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From rmorrison at draper.com Wed Mar 4 07:08:00 2015 From: rmorrison at draper.com (Morrison, Richard H., Jr.) Date: Wed, 04 Mar 2015 12:08:00 +0000 Subject: [labnetwork] Need help with RIE process Message-ID: Hi everyone, I have a strange problem that I need some help with. We have an Ulvac NE-550 RIE system with an electrostatic chuck. The wafer is a double sided polish with 1um of SiO2. One side has an AZ4620 resist pattern 8um thick to etch the 1um of oxide. Because the process runs hot we break the etch into 9 different steps and move into the LL after every step. On the polished side that is down on the ESC check we have craters on the surface that look like a lightning strike or meteor strike, this is fairly deep several microns. I have attached a photo of the damage. Have any of you seen anything like this? I need to fix the issue because the side that is down ends up being the frontside of the wafer and that is a killer defect. We think the oxide is charging and when the lift pins come up (at ground potential) we get a discharge. Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: FL1_LOWER LEFT AND RIGHT_STEP25A_2_BULLET HOLES.JPG Type: image/jpeg Size: 176113 bytes Desc: FL1_LOWER LEFT AND RIGHT_STEP25A_2_BULLET HOLES.JPG URL: From vito.logiudice at uwaterloo.ca Wed Mar 4 10:51:41 2015 From: vito.logiudice at uwaterloo.ca (Vito Logiudice) Date: Wed, 4 Mar 2015 15:51:41 +0000 Subject: [labnetwork] Need help with RIE process In-Reply-To: Message-ID: Hi Rick, I think you've nailed the source of the problem. I've seen damage like this on a CMOS production line where further analysis confirmed the cause to be electrostatic discharges. SEM analysis showed spectacular, deep craters surrounded by obvious debris much like in the photo you sent. This might not be feasible and I'm not entirely sure it would help reduce/eliminate the problem but can you perhaps get away with fastening the wafer to another, bare carrier wafer via the use of an acceptable adhesive (the same resist being used as your etch mask perhaps)? Good luck Vito -- Vito Logiudice P.Eng. Director of Operations, Quantum NanoFab University of Waterloo Lazaridis QNC 1207 200 University Avenue West Waterloo, ON Canada N2L 3G1 Tel.: (519) 888-4567 ext. 38703 Email: vito.logiudice at uwaterloo.ca Website: https://fab.qnc.uwaterloo.ca From: , "", "Jr." > Date: Wednesday, 4 March, 2015 7:08 AM To: "labnetwork at mtl.mit.edu" > Subject: [labnetwork] Need help with RIE process Hi everyone, I have a strange problem that I need some help with. We have an Ulvac NE-550 RIE system with an electrostatic chuck. The wafer is a double sided polish with 1um of SiO2. One side has an AZ4620 resist pattern 8um thick to etch the 1um of oxide. Because the process runs hot we break the etch into 9 different steps and move into the LL after every step. On the polished side that is down on the ESC check we have craters on the surface that look like a lightning strike or meteor strike, this is fairly deep several microns. I have attached a photo of the damage. Have any of you seen anything like this? I need to fix the issue because the side that is down ends up being the frontside of the wafer and that is a killer defect. We think the oxide is charging and when the lift pins come up (at ground potential) we get a discharge. Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From bob.henderson at etchedintimeinc.com Wed Mar 4 10:49:11 2015 From: bob.henderson at etchedintimeinc.com (Bob Henderson) Date: Wed, 4 Mar 2015 08:49:11 -0700 Subject: [labnetwork] Need help with RIE process In-Reply-To: References: Message-ID: <000001d05692$c26446f0$472cd4d0$@henderson@etchedintimeinc.com> Rick: Holy lightning bolt you do seem to have a discharge problem. You didn't say if the wafer has oxide on both sides but assuming it does I would suggest stripping the oxide on the chuck side to avoid the charging problem you seem to have. An electrostatic chuck works much better if you have a conductive material or in this case a semiconductor material than a dielectric. Assuming you also helium backside cooling with your E-chuck this should also allow you to etch the oxide that is patterned without the need to run multiple cycles. Depending on the RF power you might have to lower it a bit to avoid reticulation of the photo resist. I also don't understand why you are using 8 microns of resist as 1-2 microns should suffice assuming the resist: oxide selectivity is around 3:1. If you care to share your process recipe I might be able to help out some more. Bob Henderson From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Morrison, Richard H., Jr. Sent: Wednesday, March 04, 2015 5:08 AM To: labnetwork at mtl.mit.edu Subject: [labnetwork] Need help with RIE process Hi everyone, I have a strange problem that I need some help with. We have an Ulvac NE-550 RIE system with an electrostatic chuck. The wafer is a double sided polish with 1um of SiO2. One side has an AZ4620 resist pattern 8um thick to etch the 1um of oxide. Because the process runs hot we break the etch into 9 different steps and move into the LL after every step. On the polished side that is down on the ESC check we have craters on the surface that look like a lightning strike or meteor strike, this is fairly deep several microns. I have attached a photo of the damage. Have any of you seen anything like this? I need to fix the issue because the side that is down ends up being the frontside of the wafer and that is a killer defect. We think the oxide is charging and when the lift pins come up (at ground potential) we get a discharge. Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 _____ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. _____ -------------- next part -------------- An HTML attachment was scrubbed... URL: From hathaway at cns.fas.harvard.edu Wed Mar 4 12:38:19 2015 From: hathaway at cns.fas.harvard.edu (Mac Hathaway) Date: Wed, 4 Mar 2015 12:38:19 -0500 Subject: [labnetwork] Need help with RIE process In-Reply-To: References: Message-ID: <54F7430B.1040408@cns.fas.harvard.edu> Hi Rick, That's definitely arcing. Question is, when is it occurring... It's been a while since I worked with electrostatic chucks, but as I recall, you can build up static charges on fully covered wafers, during plasma processes. The problems we used to see were that the wafer would stick along one edge when the lifter pins came up, and I think we could even see the arcing at the point of contact when the wafer finally "unstuck". Do these wafers have oxide on both sides?.... Also, is there a window where you can watch the wafer during de-chucking? What we used to do, if I remember correctly, was to run a weak argon (?) plasma at the end of the etch, which we called the "dechuck" step. It took a bit of tuning to get it right. You could even try keeping it on while the pins are coming up, to allow a discharge path behind the wafer, but that will be a function of your software, and hardware interlocks. Lastly, sometimes this problem goes away if you just give the dechuck step more time, to allow excess static charge to bleed off. As I say, it was a while ago, so there may be more recent approaches to incomplete dechucking that I'm not aware of. Mac Mac Hathaway Senior Process and Systems Engineer Harvard Center for Nanoscale Systems 11 Oxford St. Cambridge, MA02138 617-495-9012 On 3/4/2015 7:08 AM, Morrison, Richard H., Jr. wrote: > > Hi everyone, > > I have a strange problem that I need some help with. We have an Ulvac > NE-550 RIE system with an electrostatic chuck. The wafer is a double > sided polish with 1um of SiO2. One side has an AZ4620 resist pattern > 8um thick to etch the 1um of oxide. Because the process runs hot we > break the etch into 9 different steps and move into the LL after every > step. On the polished side that is down on the ESC check we have > craters on the surface that look like a lightning strike or meteor > strike, this is fairly deep several microns. > > I have attached a photo of the damage. Have any of you seen anything > like this? I need to fix the issue because the side that is down ends > up being the frontside of the wafer and that is a killer defect. We > think the oxide is charging and when the lift pins come up (at ground > potential) we get a discharge. > > Rick > > Draper Laboratory > > Principal Member of the Technical Staff > > Group Leader Microfabrication Operations > > 555 Technology Square > > Cambridge Ma, 02139-3563 > > www.draper.com > > rmorrison at draper.com > > W 617-258-3420 > > C 508-930-3461 > > ------------------------------------------------------------------------ > Notice: This email and any attachments may contain proprietary (Draper > non-public) and/or export-controlled information of Draper Laboratory. > If you are not the intended recipient of this email, please > immediately notify the sender by replying to this email and > immediately destroy all copies of this email. > ------------------------------------------------------------------------ > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From nclay at seas.upenn.edu Wed Mar 4 15:56:09 2015 From: nclay at seas.upenn.edu (Noah Clay) Date: Wed, 4 Mar 2015 15:56:09 -0500 Subject: [labnetwork] Need help with RIE process In-Reply-To: <000001d05692$c26446f0$472cd4d0$@henderson@etchedintimeinc.com> References: <000001d05692$c26446f0$472cd4d0$@henderson@etchedintimeinc.com> Message-ID: <0E336913-FC4E-4D88-9264-C9222A684464@seas.upenn.edu> Rick, Are you running a lower power Ar plasma before/while de-chucking? Have a look at this: http://www.google.com/patents/US20110151669 To summarize, here?s a cut-and-paste from the patent: As part of the de-chuck process, an argon de-chuck is performed, wherein argon is introduced into chamber 42 and a radio frequency (RF) power, for example, about 400 watts, is applied to ionize argon and generate argon plasma. The RF energy may be applied for about 10 seconds. It is expected that by applying the argon plasma, the accumulated charges built up in wafer 100 are at least partially neutralized. The argon de-chuck is part of the de-chuck process because it also has the effect of releasing wafer 100. During or after the period when the argon plasma is in chamber 42, a reverse de-chuck voltage is applied to ESC 16 to de-chuck (release) wafer 100. In an embodiment, the reverse de-chuck voltage (referred to as a high reverse de-chuck voltage hereinafter) is between about ?650V and about ?975V. Experiments have found that, advantageously, by limiting the reverse de-chuck voltage in this range, the JTAG failure that may occur to wafer 100 in the via-etching is significantly reduced. This range of the reverse de-chuck voltage is likely to be less negative than the low reverse de-chuck voltages that are also used for de-chuck, which low reverse de-chuck voltages may be about ?1300V, for example. The reverse de-chuck voltage may be applied, for example, about 2 seconds, although a longer or shorter time may also be used. After the de-chuck process, lift pins 14 are raised to lift up wafer 100. Lift pins 14 are grounded and contact the backside of wafer 100. Accordingly, charges that are accumulated in the exposed conductive features may be discharged through the backside of wafer 100. Advantageously, due to the use of the high reverse de-chuck voltage, which has a magnitude of about 50 percent to about 75 percent of the low reverse de-chuck voltage, the JTAG failure is significantly reduced. Experiments performed on wafers have demonstrated that if a low reverse de-chuck voltage of ?1300V (which was used in conventional via-etching processes) is used, after the formation of opening 22 (FIG. 3) and the subsequent photo resist ashing, the voltage potentials on the respective wafers range between about 6.5V and about ?0.1V, with the difference being about 6.6V. As a comparison, when a high reverse de-chuck voltage of ?975V (an embodiment of the present invention) is used, after the etching and ashing process of opening 22, the voltage potentials on the respective wafers range between about ?1.3V and about ?3.9V, with the difference being only about 2.6V. The significant reduction in the differences of voltage potentials on a same wafer indicates better charge neutralization in the embodiments of the present invention than in conventional methods, which results in lower JTAG failure rates. Best, Noah > On Mar 4, 2015, at 10:49 AM, Bob Henderson wrote: > > Rick: > > Holy lightning bolt you do seem to have a discharge problem. You didn?t say if the wafer has oxide on both sides but assuming it does I would suggest stripping the oxide on the chuck side to avoid the charging problem you seem to have. An electrostatic chuck works much better if you have a conductive material or in this case a semiconductor material than a dielectric. Assuming you also helium backside cooling with your E-chuck this should also allow you to etch the oxide that is patterned without the need to run multiple cycles. Depending on the RF power you might have to lower it a bit to avoid reticulation of the photo resist. I also don?t understand why you are using 8 microns of resist as 1-2 microns should suffice assuming the resist: oxide selectivity is around 3:1. If you care to share your process recipe I might be able to help out some more. Bob Henderson > > From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Morrison, Richard H., Jr. > Sent: Wednesday, March 04, 2015 5:08 AM > To: labnetwork at mtl.mit.edu > Subject: [labnetwork] Need help with RIE process > > Hi everyone, > > I have a strange problem that I need some help with. We have an Ulvac NE-550 RIE system with an electrostatic chuck. The wafer is a double sided polish with 1um of SiO2. One side has an AZ4620 resist pattern 8um thick to etch the 1um of oxide. Because the process runs hot we break the etch into 9 different steps and move into the LL after every step. On the polished side that is down on the ESC check we have craters on the surface that look like a lightning strike or meteor strike, this is fairly deep several microns. > > I have attached a photo of the damage. Have any of you seen anything like this? I need to fix the issue because the side that is down ends up being the frontside of the wafer and that is a killer defect. We think the oxide is charging and when the lift pins come up (at ground potential) we get a discharge. > > Rick > > > Draper Laboratory > Principal Member of the Technical Staff > Group Leader Microfabrication Operations > 555 Technology Square > Cambridge Ma, 02139-3563 > > www.draper.com > rmorrison at draper.com > W 617-258-3420 > C 508-930-3461 > > Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From pinsesearch at pitt.edu Fri Mar 6 13:45:52 2015 From: pinsesearch at pitt.edu (Vidic, Brian A) Date: Fri, 6 Mar 2015 18:45:52 +0000 Subject: [labnetwork] Open Position - Technical Director, Univ of Pittsburgh Nanotechnology Center Message-ID: <25a83c62c90343d38851dde6c7e576d8@pitt-prodx-10.univ.pitt.edu> Colleagues: The University of Pittsburgh's Petersen Institute for NanoScience and Engineering (PINSE) has opened recruitment for a Technical Director to lead the Institute's Nanoscale Fabrication and Characterization Facility. I look forward to your consideration and your sharing of this posting with your colleagues. My thanks in advance. Best Brian Brian Vidic Director of Technology Interim Director of Operations, PINSE-NFCF Swanson School of Engineering University of Pittsburgh 3700 O'Hara St Suite 148 Benedum Hall Pittsburgh, PA 15261 *: 412/624-8101 | 7: 412/624-2027 | *: vidicba at pitt.edu -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: PINSE Technical Director.pdf Type: application/pdf Size: 68727 bytes Desc: PINSE Technical Director.pdf URL: From Loik.gence at cetuc.puc-rio.br Mon Mar 16 10:36:18 2015 From: Loik.gence at cetuc.puc-rio.br (=?windows-1252?Q?Lo=EFk_GENCE?=) Date: Mon, 16 Mar 2015 11:36:18 -0300 Subject: [labnetwork] Thermal load in cleanrooms ISO 5/6 In-Reply-To: <54F7430B.1040408@cns.fas.harvard.edu> References: <54F7430B.1040408@cns.fas.harvard.edu> Message-ID: <5506EA62.9000008@cetuc.puc-rio.br> Hi Everyone, I am working on the design of a small cleanroom facility (70m2) ISO 5/6. Right now, I am dealing with the problem of thermal load, Which is crucial here in Rio, where the average outside temperature is of 30 deg C with a relative humidity of 75-80 %. I would like to have your help and/or comments on several points: Most of the manufacturers do not provide a value for the thermal load (why?). Assuming 2 or max 3 people working simultaneously in the cleanrooms, and usual cleanroom value: 22 deg C - 55% humidity. The main issue is: how can I estimate the cooling power required for the Air Conditioning System (ACS)? I have the list of equipments we'll have and the corresponding electrical power. I assumed the heat generated by 2 users and added the total electrical power dissipated as heat inside of the cleanroom, using a simultaneity factor of 0.75 (all equipments won't be turned on at the same time) and neglected the heat produced by the filter fan and lightning. *** ** - Is it reasonable for dimensioning the ACS cooling power ? * Also most of the equipments have a cooling water circuit. But the cooling power needed is well described in the installation manual provided with the equipments. * - Should I subtract from the **ACS cooling power**value, **the cooling po**wer **from the chillers?* - *Do you think a central and unique chiller (placed outside of the building) is preferred to several smaller chillers placed closer to the equipment?* I thank you very much for your kind help or comments. regards, Lo?k. -- __________________________________________ Dr. Lo?k Gence PUC-RIO/CETUC-LABSEM End Rua Marques de S?o Vicente, 225-Gavea CEP:22451-900 Rio de Janeiro, RJ-Brasil (Telefone) +55 (021) 3527-2193 (Mobile) +55 (021) 99156-5558 loik.gence at cetuc.puc-rio.br __________________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From myoung6 at nd.edu Mon Mar 16 11:55:11 2015 From: myoung6 at nd.edu (Mike Young) Date: Mon, 16 Mar 2015 11:55:11 -0400 Subject: [labnetwork] Thermal load in cleanrooms ISO 5/6 In-Reply-To: <5506EA62.9000008@cetuc.puc-rio.br> References: <54F7430B.1040408@cns.fas.harvard.edu> <5506EA62.9000008@cetuc.puc-rio.br> Message-ID: Hi, Lo?k. Welcome to the group. I would caution you about neglecting the heat contribution of the cleanroom lighting and the fan filter units. Make sure they are really, truly, negligible, because it is not difficult for them to dominate the total cleanroom heat load under some conditions! In addition, we find that almost all of our equipment is in operation almost all of the time, so before you use the .75 diversity factor, make sure it is realistic. The ACS has to be designed to meet the worst-case heat load, which will be worst-case weather conditions, plus everything turned on and running, plus maximum personnel heat load, under conditions of worst-case (maximum) makeup air flow. Getting all of this right is one of the most challenging problems in cleanroom design. Good luck! --Mike > On Mar 16, 2015, at 10:36 AM, Lo?k GENCE wrote: > > Hi Everyone, > > I am working on the design of a small cleanroom facility (70m2) ISO 5/6. Right now, I am dealing with the problem of thermal load, > Which is crucial here in Rio, where the average outside temperature is of 30 deg C with a relative humidity of 75-80 %. > > I would like to have your help and/or comments on several points: > > Most of the manufacturers do not provide a value for the thermal load (why?). Assuming 2 or max 3 people working simultaneously in the cleanrooms, and usual cleanroom value: 22 deg C - 55% humidity. The main issue is: how can I estimate the cooling power required for the Air Conditioning System (ACS)? > > I have the list of equipments we'll have and the corresponding electrical power. I assumed the heat generated by 2 users and added the total electrical power dissipated as heat inside of the cleanroom, using a simultaneity factor of 0.75 (all equipments won't be turned on at the same time) and neglected the heat produced by the filter fan and lightning. > > - Is it reasonable for dimensioning the ACS cooling power ? > > Also most of the equipments have a cooling water circuit. But the cooling power needed is well described in the installation manual provided with the equipments. > > - Should I subtract from the ACS cooling power value, the cooling power from the chillers? > > - Do you think a central and unique chiller (placed outside of the building) is preferred to several smaller chillers placed closer to the equipment? > > > I thank you very much for your kind help or comments. > > > regards, > > Lo?k. > > -- > __________________________________________ > Dr. Lo?k Gence > > PUC-RIO/CETUC-LABSEM > > End Rua Marques de S?o Vicente, 225-Gavea > CEP:22451-900 Rio de Janeiro, RJ-Brasil > > (Telefone) +55 (021) 3527-2193 > > (Mobile) +55 (021) 99156-5558 > > loik.gence at cetuc.puc-rio.br > __________________________________________ > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -- Michael P. Young (574) 631-3268 (office) Nanofabrication Specialist (574) 631-4393 (fax) Department of Electrical Engineering (765) 637-6302 (cell) University of Notre Dame mike.young at nd.edu B-38 Stinson-Remick Hall Notre Dame, IN 46556-5637 -------------- next part -------------- An HTML attachment was scrubbed... URL: From Jack.Paul at hdrinc.com Mon Mar 16 12:01:37 2015 From: Jack.Paul at hdrinc.com (Paul, Jack) Date: Mon, 16 Mar 2015 16:01:37 +0000 Subject: [labnetwork] Thermal load in cleanrooms ISO 5/6 In-Reply-To: <5506EA62.9000008@cetuc.puc-rio.br> References: <54F7430B.1040408@cns.fas.harvard.edu> <5506EA62.9000008@cetuc.puc-rio.br> Message-ID: Hello Lo?k, I am an architect with HDR Architecture, Inc. and engineering and architectural firm who design cleanrooms. We have a few comments on your notes below: - As you have already done, start with your equipment list. It is safe to assume that all power consumed by equipment is converted to heat (very little "mechanical" energy). However, your 75% simultaneity factor is probably high. We tend to see it much closer to 25% (we usually call this "diversity") which assumes that at any point in a working day, about 25% of the equipment is actually running. - If you have data from manufacturers for how much heat is dissipated to cooling water, then you can subtract that heat load from your total equipment load. - We would normally account for the load for lighting. If you do not have data on the lighting fixtures, it is safe to assume about 10 watts per m2. This load would not have any diversity. - We would also account for the heat load for the fan filter units. It can be significant. The fan-filter unit manufacturer should be able to provide data, but if not you can use as a placeholder roughly 50% of the power consumed by the unit, and again this load would not have any diversity applied to it. - Each person is a relatively small load (100 - 125 watts/person) ? The sum of these items is a good estimate for your cooling load in the cleanroom. - A central cooling water loop is generally most energy efficient. A series of separate smaller chillers consume power and reject the heat into the cleanroom airstream where it then must be removed by the ACS. Water is a better thermal energy conductor than air. o A recirculating loop with a heat exchanger and pumps, dedicated to the equipment will typically provide the best performance. o The primary side of the heat exchanger can be chilled water from your ACS or a central plant (whatever you have available in your new cleanroom facility) o The secondary side would feed the loop and be routed through the cleanroom to individual tools. It can be a closed loop so you have complete control of the quality of the water. Hope this helps. Let us know if you have additional questions. Regards, Jack Paul From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Lo?k GENCE Sent: Monday, March 16, 2015 7:36 AM To: labnetwork at mtl.mit.edu Subject: [labnetwork] Thermal load in cleanrooms ISO 5/6 Hi Everyone, I am working on the design of a small cleanroom facility (70m2) ISO 5/6. Right now, I am dealing with the problem of thermal load, Which is crucial here in Rio, where the average outside temperature is of 30 deg C with a relative humidity of 75-80 %. I would like to have your help and/or comments on several points: Most of the manufacturers do not provide a value for the thermal load (why?). Assuming 2 or max 3 people working simultaneously in the cleanrooms, and usual cleanroom value: 22 deg C - 55% humidity. The main issue is: how can I estimate the cooling power required for the Air Conditioning System (ACS)? I have the list of equipments we'll have and the corresponding electrical power. I assumed the heat generated by 2 users and added the total electrical power dissipated as heat inside of the cleanroom, using a simultaneity factor of 0.75 (all equipments won't be turned on at the same time) and neglected the heat produced by the filter fan and lightning. - Is it reasonable for dimensioning the ACS cooling power ? Also most of the equipments have a cooling water circuit. But the cooling power needed is well described in the installation manual provided with the equipments. - Should I subtract from the ACS cooling power value, the cooling power from the chillers? - Do you think a central and unique chiller (placed outside of the building) is preferred to several smaller chillers placed closer to the equipment? I thank you very much for your kind help or comments. regards, Lo?k. -- __________________________________________ Dr. Lo?k Gence PUC-RIO/CETUC-LABSEM End Rua Marques de S?o Vicente, 225-Gavea CEP:22451-900 Rio de Janeiro, RJ-Brasil (Telefone) +55 (021) 3527-2193 (Mobile) +55 (021) 99156-5558 loik.gence at cetuc.puc-rio.br __________________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From khbeis at uw.edu Mon Mar 16 12:10:36 2015 From: khbeis at uw.edu (Michael Khbeis) Date: Mon, 16 Mar 2015 09:10:36 -0700 Subject: [labnetwork] Need help with RIE process In-Reply-To: <54F7430B.1040408@cns.fas.harvard.edu> References: <54F7430B.1040408@cns.fas.harvard.edu> Message-ID: <3C825B15-3FC4-4DD3-9E07-326A24906D92@uw.edu> Rick I second Mac on adding a dechuck step. You can use N2 plasma too. Dr. Michael Khbeis Washington Nanofab Facility University of Washington Fluke Hall, Box 352143 (O) 206.543.5101 (C) 443.254.5192 khbeis at uw.edu > On Mar 4, 2015, at 9:38 AM, Mac Hathaway wrote: > > Hi Rick, > > That's definitely arcing. Question is, when is it occurring... It's been a while since I worked with electrostatic chucks, but as I recall, you can build up static charges on fully covered wafers, during plasma processes. The problems we used to see were that the wafer would stick along one edge when the lifter pins came up, and I think we could even see the arcing at the point of contact when the wafer finally "unstuck". > > Do these wafers have oxide on both sides?.... Also, is there a window where you can watch the wafer during de-chucking? > > What we used to do, if I remember correctly, was to run a weak argon (?) plasma at the end of the etch, which we called the "dechuck" step. It took a bit of tuning to get it right. You could even try keeping it on while the pins are coming up, to allow a discharge path behind the wafer, but that will be a function of your software, and hardware interlocks. Lastly, sometimes this problem goes away if you just give the dechuck step more time, to allow excess static charge to bleed off. > > As I say, it was a while ago, so there may be more recent approaches to incomplete dechucking that I'm not aware of. > > > Mac > > Mac Hathaway > Senior Process and Systems Engineer > Harvard Center for Nanoscale Systems > 11 Oxford St. > Cambridge, MA 02138 > 617-495-9012 > > >> On 3/4/2015 7:08 AM, Morrison, Richard H., Jr. wrote: >> Hi everyone, >> >> I have a strange problem that I need some help with. We have an Ulvac NE-550 RIE system with an electrostatic chuck. The wafer is a double sided polish with 1um of SiO2. One side has an AZ4620 resist pattern 8um thick to etch the 1um of oxide. Because the process runs hot we break the etch into 9 different steps and move into the LL after every step. On the polished side that is down on the ESC check we have craters on the surface that look like a lightning strike or meteor strike, this is fairly deep several microns. >> >> I have attached a photo of the damage. Have any of you seen anything like this? I need to fix the issue because the side that is down ends up being the frontside of the wafer and that is a killer defect. We think the oxide is charging and when the lift pins come up (at ground potential) we get a discharge. >> >> Rick >> >> >> Draper Laboratory >> Principal Member of the Technical Staff >> Group Leader Microfabrication Operations >> 555 Technology Square >> Cambridge Ma, 02139-3563 >> >> www.draper.com >> rmorrison at draper.com >> W 617-258-3420 >> C 508-930-3461 >> >> Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. >> >> >> _______________________________________________ >> labnetwork mailing list >> labnetwork at mtl.mit.edu >> https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From khbeis at uw.edu Mon Mar 16 12:26:00 2015 From: khbeis at uw.edu (Michael Khbeis) Date: Mon, 16 Mar 2015 09:26:00 -0700 Subject: [labnetwork] Thermal load in cleanrooms ISO 5/6 In-Reply-To: <5506EA62.9000008@cetuc.puc-rio.br> References: <54F7430B.1040408@cns.fas.harvard.edu> <5506EA62.9000008@cetuc.puc-rio.br> Message-ID: <58156CB3-D8D3-4F19-A46C-BE921FEAFC64@uw.edu> Loik I think that having the electrical load converted to heat load and having the diversity factor is sufficient. You can subtract the heat load dissipated through chilled water but that is presumably also being fed by your primary chiller. I would err on the side of being conservative since cleanrooms always end up being packed to a maximum density of equipment and people during their lifespans - give yourself a 20% margin at the least. I also would not discount the impact of the filter fan unit heat dissipation. Since you are recycling most of the air several times the joule heating from the FFUs will cause a noticeable temperature rise. Given the class of your Cleanroom the FFU density will not be as high but I would add them into the load calc. Finally, regarding central chiller vs multiple point of use units - much easier to keep spare parts on hand and do PMs on a central chiller unit as these are usually handled by the building facilities folks. In my opinion, multiple point of use chillers are a maintenance nightmare and you often end up buying something quickly to replace or augment a failing unit. It is nearly impossible to keep multiple point of use units running consistently if you don't have dedicated maintenance staff. The exception to this is if your tools all required different or special temperatures and you end up needing multiple water-to-water heat exchangers then point of use chillers may make sense. Best, Dr. Michael Khbeis Washington Nanofab Facility University of Washington Fluke Hall, Box 352143 (O) 206.543.5101 (C) 443.254.5192 khbeis at uw.edu > On Mar 16, 2015, at 7:36 AM, Lo?k GENCE wrote: > > Hi Everyone, > > I am working on the design of a small cleanroom facility (70m2) ISO 5/6. Right now, I am dealing with the problem of thermal load, > Which is crucial here in Rio, where the average outside temperature is of 30 deg C with a relative humidity of 75-80 %. > > I would like to have your help and/or comments on several points: > > Most of the manufacturers do not provide a value for the thermal load (why?). Assuming 2 or max 3 people working simultaneously in the cleanrooms, and usual cleanroom value: 22 deg C - 55% humidity. The main issue is: how can I estimate the cooling power required for the Air Conditioning System (ACS)? > > I have the list of equipments we'll have and the corresponding electrical power. I assumed the heat generated by 2 users and added the total electrical power dissipated as heat inside of the cleanroom, using a simultaneity factor of 0.75 (all equipments won't be turned on at the same time) and neglected the heat produced by the filter fan and lightning. > > - Is it reasonable for dimensioning the ACS cooling power ? > > Also most of the equipments have a cooling water circuit. But the cooling power needed is well described in the installation manual provided with the equipments. > > - Should I subtract from the ACS cooling power value, the cooling power from the chillers? > > - Do you think a central and unique chiller (placed outside of the building) is preferred to several smaller chillers placed closer to the equipment? > > > I thank you very much for your kind help or comments. > > > regards, > > Lo?k. > > -- > __________________________________________ > Dr. Lo?k Gence > > PUC-RIO/CETUC-LABSEM > > End Rua Marques de S?o Vicente, 225-Gavea > CEP:22451-900 Rio de Janeiro, RJ-Brasil > > (Telefone) +55 (021) 3527-2193 > > (Mobile) +55 (021) 99156-5558 > > loik.gence at cetuc.puc-rio.br > __________________________________________ > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From codreanu at udel.edu Mon Mar 16 13:41:38 2015 From: codreanu at udel.edu (Iulian Codreanu) Date: Mon, 16 Mar 2015 13:41:38 -0400 Subject: [labnetwork] Thermal load in cleanrooms ISO 5/6 In-Reply-To: <5506EA62.9000008@cetuc.puc-rio.br> References: <54F7430B.1040408@cns.fas.harvard.edu> <5506EA62.9000008@cetuc.puc-rio.br> Message-ID: <550715D2.7010907@udel.edu> Loik, Another thing to keep in mind is the heat that is "taken away from the equipment" via exhaust. The heat generated by a piece of equipment can: -Be dissipated into the room -Be "taken away" by the cooling water. -Be "taken way" by exhaust. If a piece of equipment is not cooled and does not have exhaust then all the heat gets dissipated into the room. If the piece of equipment is cooled and exhausted only part of the heat generated will end up in the room. If you know how much heat is taken away by the cooling water and/or exhaust that is great. If you do not, I saw engineers using factor such as (PCW stands for process cooling water): 100% of the power into the room if no PCW and no exhaust 50% of the power into the room is no PCW but exhaust 40% of the power into the room if PCW but no exhaust 20% of the power into the room if both PCW and exhaust I prefer the "unique chiller (placed outside of the building)" approach for cooling the equipment. If you can run the water from the unique chiller directly through the equipment, you do not have to deal with the heat generated by the "small chillers". Iulian iulian Codreanu, Ph.D. Director of Operations, UD NanoFab 163 ISE Lab 221 Academy Street Newark, DE 19716 302-831-2784 http://udnf.udel.edu On 3/16/2015 10:36 AM, Lo?k GENCE wrote: > Hi Everyone, > > I am working on the design of a small cleanroom facility (70m2) ISO > 5/6. Right now, I am dealing with the problem of thermal load, > Which is crucial here in Rio, where the average outside temperature is > of 30 deg C with a relative humidity of 75-80 %. > > I would like to have your help and/or comments on several points: > > Most of the manufacturers do not provide a value for the thermal load > (why?). Assuming 2 or max 3 people working simultaneously in the > cleanrooms, and usual cleanroom value: 22 deg C - 55% humidity. The > main issue is: how can I estimate the cooling power required for the > Air Conditioning System (ACS)? > > I have the list of equipments we'll have and the corresponding > electrical power. I assumed the heat generated by 2 users and added > the total electrical power dissipated as heat inside of the cleanroom, > using a simultaneity factor of 0.75 (all equipments won't be turned on > at the same time) and neglected the heat produced by the filter fan > and lightning. > *** > ** - Is it reasonable for dimensioning the ACS cooling power ? * > > Also most of the equipments have a cooling water circuit. But the > cooling power needed is well described in the installation manual > provided with the equipments. > > * - Should I subtract from the **ACS cooling power**value, > **the cooling po**wer **from the chillers?* > > - *Do you think a central and unique chiller (placed outside > of the building) is preferred to several smaller chillers placed > closer to the equipment?* > > > I thank you very much for your kind help or comments. > > > regards, > > Lo?k. > > -- > __________________________________________ > Dr. Lo?k Gence > > PUC-RIO/CETUC-LABSEM > > End Rua Marques de S?o Vicente, 225-Gavea > CEP:22451-900 Rio de Janeiro, RJ-Brasil > > (Telefone) +55 (021) 3527-2193 > > (Mobile) +55 (021) 99156-5558 > > loik.gence at cetuc.puc-rio.br > __________________________________________ > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From Loik.gence at cetuc.puc-rio.br Mon Mar 16 15:04:01 2015 From: Loik.gence at cetuc.puc-rio.br (=?windows-1252?Q?Lo=EFk_GENCE?=) Date: Mon, 16 Mar 2015 16:04:01 -0300 Subject: [labnetwork] Thermal load in cleanrooms ISO 5/6 In-Reply-To: References: <54F7430B.1040408@cns.fas.harvard.edu> <5506EA62.9000008@cetuc.puc-rio.br> Message-ID: <55072921.6040308@cetuc.puc-rio.br> Thank you all for your messages. It helps! I'll introduced ligthning and FF units in the thermal load calculation. I can see that the /a priori/ estimation of the diversity factor seems to be difficult. Overestimating the thermal load is comfortable, but, here, I really have to minimize the cost of the HVAC system choosing a proper size/power of the HVAC because of our limited budget... Thanks again! Lo?k. On 16/03/2015 12:55, Mike Young wrote: > Hi, Lo?k. Welcome to the group. > > I would caution you about neglecting the heat contribution of the > cleanroom lighting and the fan filter units. Make sure they are > really, truly, negligible, because it is not difficult for them to > dominate the total cleanroom heat load under some conditions! In > addition, we find that almost all of our equipment is in operation > almost all of the time, so before you use the .75 diversity factor, > make sure it is realistic. > > The ACS has to be designed to meet the worst-case heat load, which > will be worst-case weather conditions, plus everything turned on and > running, plus maximum personnel heat load, under conditions of > worst-case (maximum) makeup air flow. Getting all of this right is one > of the most challenging problems in cleanroom design. > > Good luck! > > --Mike > > >> On Mar 16, 2015, at 10:36 AM, Lo?k GENCE > > wrote: >> >> Hi Everyone, >> >> I am working on the design of a small cleanroom facility (70m2) ISO >> 5/6. Right now, I am dealing with the problem of thermal load, >> Which is crucial here in Rio, where the average outside temperature >> is of 30 deg C with a relative humidity of 75-80 %. >> >> I would like to have your help and/or comments on several points: >> >> Most of the manufacturers do not provide a value for the thermal load >> (why?). Assuming 2 or max 3 people working simultaneously in the >> cleanrooms, and usual cleanroom value: 22 deg C - 55% humidity. The >> main issue is: how can I estimate the cooling power required for the >> Air Conditioning System (ACS)? >> >> I have the list of equipments we'll have and the corresponding >> electrical power. I assumed the heat generated by 2 users and added >> the total electrical power dissipated as heat inside of the >> cleanroom, using a simultaneity factor of 0.75 (all equipments won't >> be turned on at the same time) and neglected the heat produced by the >> filter fan and lightning. >> *** >> ** - Is it reasonable for dimensioning the ACS cooling power ? * >> >> Also most of the equipments have a cooling water circuit. But the >> cooling power needed is well described in the installation manual >> provided with the equipments. >> >> * - Should I subtract from the **ACS cooling power**value, >> **the cooling po**wer **from the chillers?* >> >> - *Do you think a central and unique chiller (placed outside >> of the building) is preferred to several smaller chillers placed >> closer to the equipment?* >> >> >> I thank you very much for your kind help or comments. >> >> >> regards, >> >> Lo?k. >> >> -- >> __________________________________________ >> Dr. Lo?k Gence >> >> PUC-RIO/CETUC-LABSEM >> >> End Rua Marques de S?o Vicente, 225-Gavea >> CEP:22451-900 Rio de Janeiro, RJ-Brasil >> >> (Telefone) +55 (021) 3527-2193 >> >> (Mobile) +55 (021) 99156-5558 >> >> loik.gence at cetuc.puc-rio.br >> __________________________________________ >> _______________________________________________ >> labnetwork mailing list >> labnetwork at mtl.mit.edu >> https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork > > -- > Michael P. Young (574) 631-3268 (office) > Nanofabrication Specialist (574) 631-4393 (fax) > Department of Electrical Engineering (765) 637-6302 (cell) > University of Notre Dame mike.young at nd.edu > B-38 Stinson-Remick Hall > Notre Dame, IN 46556-5637 > -- __________________________________________ Dr. Lo?k Gence LABSEM ? PUC-RIO End Rua Marques de S?o Vicente, 225-G?vea CEP:22451-900 ? Rio de Janeiro, RJ-Brasil (Telefone) +55 (021) 3527-2193 (Mobile) +55 (021) 99156 5558 loik.gence at cetuc.puc-rio.br __________________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From michael.rooks at yale.edu Mon Mar 16 16:07:25 2015 From: michael.rooks at yale.edu (Michael Rooks) Date: Mon, 16 Mar 2015 16:07:25 -0400 Subject: [labnetwork] Thermal load in cleanrooms ISO 5/6 In-Reply-To: <58156CB3-D8D3-4F19-A46C-BE921FEAFC64@uw.edu> References: <54F7430B.1040408@cns.fas.harvard.edu> <5506EA62.9000008@cetuc.puc-rio.br> <58156CB3-D8D3-4F19-A46C-BE921FEAFC64@uw.edu> Message-ID: <550737FD.3010207@yale.edu> I have a different opinion about chillers: A single central unit creates a single point of failure for the entire facility, and maintenance requires everything to be shut down at once. I would rather have the (several small) chillers where I can see them, and I don't trust facilities people to do the maintenance properly. Same advice for UPS. Out of sight, out of mind. Also, if you have numerous chillers then you should keep a spare handy, just as you would for vacuum pumps. -------------------------------- Michael Rooks Yale Institute of Nanoscience and Quantum Engineering nano.yale.edu On 03/16/2015 12:26 PM, Michael Khbeis wrote: > Loik > > I think that having the electrical load converted to heat load and > having the diversity factor is sufficient. You can subtract the heat > load dissipated through chilled water but that is presumably also > being fed by your primary chiller. I would err on the side of being > conservative since cleanrooms always end up being packed to a maximum > density of equipment and people during their lifespans - give yourself > a 20% margin at the least. I also would not discount the impact of the > filter fan unit heat dissipation. Since you are recycling most of the > air several times the joule heating from the FFUs will cause a > noticeable temperature rise. Given the class of your Cleanroom the FFU > density will not be as high but I would add them into the load calc. > > Finally, regarding central chiller vs multiple point of use units - > much easier to keep spare parts on hand and do PMs on a central > chiller unit as these are usually handled by the building facilities > folks. In my opinion, multiple point of use chillers are a maintenance > nightmare and you often end up buying something quickly to replace or > augment a failing unit. It is nearly impossible to keep multiple point > of use units running consistently if you don't have dedicated > maintenance staff. The exception to this is if your tools all required > different or special temperatures and you end up needing multiple > water-to-water heat exchangers then point of use chillers may make sense. > > Best, > > Dr. Michael Khbeis > Washington Nanofab Facility > University of Washington > Fluke Hall, Box 352143 > (O) 206.543.5101 > (C) 443.254.5192 > khbeis at uw.edu > > On Mar 16, 2015, at 7:36 AM, Lo?k GENCE > wrote: > >> Hi Everyone, >> >> I am working on the design of a small cleanroom facility (70m2) ISO >> 5/6. Right now, I am dealing with the problem of thermal load, >> Which is crucial here in Rio, where the average outside temperature >> is of 30 deg C with a relative humidity of 75-80 %. >> >> I would like to have your help and/or comments on several points: >> >> Most of the manufacturers do not provide a value for the thermal load >> (why?). Assuming 2 or max 3 people working simultaneously in the >> cleanrooms, and usual cleanroom value: 22 deg C - 55% humidity. The >> main issue is: how can I estimate the cooling power required for the >> Air Conditioning System (ACS)? >> >> I have the list of equipments we'll have and the corresponding >> electrical power. I assumed the heat generated by 2 users and added >> the total electrical power dissipated as heat inside of the >> cleanroom, using a simultaneity factor of 0.75 (all equipments won't >> be turned on at the same time) and neglected the heat produced by the >> filter fan and lightning. >> *** >> ** - Is it reasonable for dimensioning the ACS cooling power ? * >> >> Also most of the equipments have a cooling water circuit. But the >> cooling power needed is well described in the installation manual >> provided with the equipments. >> >> * - Should I subtract from the **ACS cooling power**value, >> **the cooling po**wer **from the chillers?* >> >> - *Do you think a central and unique chiller (placed outside >> of the building) is preferred to several smaller chillers placed >> closer to the equipment?* >> >> >> I thank you very much for your kind help or comments. >> >> >> regards, >> >> Lo?k. >> >> -- >> __________________________________________ >> Dr. Lo?k Gence >> >> PUC-RIO/CETUC-LABSEM >> >> End Rua Marques de S?o Vicente, 225-Gavea >> CEP:22451-900 Rio de Janeiro, RJ-Brasil >> >> (Telefone) +55 (021) 3527-2193 >> >> (Mobile) +55 (021) 99156-5558 >> >> loik.gence at cetuc.puc-rio.br >> __________________________________________ >> _______________________________________________ >> labnetwork mailing list >> labnetwork at mtl.mit.edu >> https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork >> > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://urldefense.proofpoint.com/v2/url?u=https-3A__www-2Dmtl.mit.edu_mailman_listinfo.cgi_labnetwork&d=AwICAg&c=-dg2m7zWuuDZ0MUcV7Sdqw&r=apnDUg1OD9ejswcjrIvVgS28NpQ7-FGy7Sl7_YPlupc&m=hBL35UTQaOURuTrkXiNi1rZCy7Gy_rS075IrmahPX18&s=ZF7WKY75a9SR06b7Ulb31qeww2Hm1AcHRtLpSb5eXJA&e= -------------- next part -------------- An HTML attachment was scrubbed... URL: From james.beall at nist.gov Mon Mar 16 16:25:03 2015 From: james.beall at nist.gov (Beall, James A.) Date: Mon, 16 Mar 2015 20:25:03 +0000 Subject: [labnetwork] Thermal load in cleanrooms ISO 5/6 In-Reply-To: <550715D2.7010907@udel.edu> References: <54F7430B.1040408@cns.fas.harvard.edu> <5506EA62.9000008@cetuc.puc-rio.br> <550715D2.7010907@udel.edu> Message-ID: <614FCF45-FCFE-4B0B-B085-F2FCA4619E2E@nist.gov> Loic, I agree with the caution about accounting for the heat from the FFU; it is significant. In our fabs we use a large external Process Chilled Water unit which provides cooling for 40-50 tools. Some of the equipment (like cryopump compressors and larger pumps which typically have larger => 3/8? diameter), cooling lines can be directly cooled by the PCW loop. Many other tools like electron gun evaporators and sputter guns have smaller cooling lines and you may have trouble directly connecting them to the PCW loop and achieving the required flows and pressures. We end up with many small heat exchangers each set up for the particular needs of our tools. Some run distilled water, some DI water, some glycol and some high temperature thermal fluids. The pumps are the weak point in these units. When connecting tools across your PCW loop be careful to include balancing or flow setting valves as you will have many connections in parallel. Also I prefer to use a non-closed system, i.e., one with an atmospheric pressure return tank. This can be automatically refilled with treated water as needed to account for leaks and losses. Having your return water dump into a non-pressurized tank creates much less back pressure than the closed loop pressurized systems. The back pressure can be a killer with many parallel connected tools with different impedances. - Jim On Mar 16, 2015, at 11:41 AM, Iulian Codreanu > wrote: Loik, Another thing to keep in mind is the heat that is "taken away from the equipment" via exhaust. The heat generated by a piece of equipment can: -Be dissipated into the room -Be "taken away" by the cooling water. -Be "taken way" by exhaust. If a piece of equipment is not cooled and does not have exhaust then all the heat gets dissipated into the room. If the piece of equipment is cooled and exhausted only part of the heat generated will end up in the room. If you know how much heat is taken away by the cooling water and/or exhaust that is great. If you do not, I saw engineers using factor such as (PCW stands for process cooling water): 100% of the power into the room if no PCW and no exhaust 50% of the power into the room is no PCW but exhaust 40% of the power into the room if PCW but no exhaust 20% of the power into the room if both PCW and exhaust I prefer the "unique chiller (placed outside of the building)" approach for cooling the equipment. If you can run the water from the unique chiller directly through the equipment, you do not have to deal with the heat generated by the "small chillers". Iulian iulian Codreanu, Ph.D. Director of Operations, UD NanoFab 163 ISE Lab 221 Academy Street Newark, DE 19716 302-831-2784 http://udnf.udel.edu On 3/16/2015 10:36 AM, Lo?k GENCE wrote: Hi Everyone, I am working on the design of a small cleanroom facility (70m2) ISO 5/6. Right now, I am dealing with the problem of thermal load, Which is crucial here in Rio, where the average outside temperature is of 30 deg C with a relative humidity of 75-80 %. I would like to have your help and/or comments on several points: Most of the manufacturers do not provide a value for the thermal load (why?). Assuming 2 or max 3 people working simultaneously in the cleanrooms, and usual cleanroom value: 22 deg C - 55% humidity. The main issue is: how can I estimate the cooling power required for the Air Conditioning System (ACS)? I have the list of equipments we'll have and the corresponding electrical power. I assumed the heat generated by 2 users and added the total electrical power dissipated as heat inside of the cleanroom, using a simultaneity factor of 0.75 (all equipments won't be turned on at the same time) and neglected the heat produced by the filter fan and lightning. - Is it reasonable for dimensioning the ACS cooling power ? Also most of the equipments have a cooling water circuit. But the cooling power needed is well described in the installation manual provided with the equipments. - Should I subtract from the ACS cooling power value, the cooling power from the chillers? - Do you think a central and unique chiller (placed outside of the building) is preferred to several smaller chillers placed closer to the equipment? I thank you very much for your kind help or comments. regards, Lo?k. -- __________________________________________ Dr. Lo?k Gence PUC-RIO/CETUC-LABSEM End Rua Marques de S?o Vicente, 225-Gavea CEP:22451-900 Rio de Janeiro, RJ-Brasil (Telefone) +55 (021) 3527-2193 (Mobile) +55 (021) 99156-5558 loik.gence at cetuc.puc-rio.br __________________________________________ _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From cknollen at stanford.edu Mon Mar 16 19:14:34 2015 From: cknollen at stanford.edu (Clifford F Knollenberg) Date: Mon, 16 Mar 2015 16:14:34 -0700 (PDT) Subject: [labnetwork] Cleaning heavy metals off chamber liners- is there any place that does this? In-Reply-To: <734469853.1932812.1426547564829.JavaMail.zimbra@stanford.edu> Message-ID: <410704885.1942814.1426547674894.JavaMail.zimbra@stanford.edu> We have heavy metal residues on the chamber liners of our Ar Ion Mill that we would like to get removed. The heavy metals include Hg, Cd, and Te, mixed in with a large amount of non-toxic metals (Fe, Si, Au, etc). We would like to get them cleaned (bead blasted) at a facility capable of handling heavy metal residues safely. We do not need the chamber liners completely clean of the heavy metals, but want to reduce the metal build-up on the surface. Any advice would be helpful. Regards, Cliff -- Clifford Knollenberg Cleanroom Science and Engineering Associate- Stanford Nano Center Email: cknollen at stanford.edu Tel: 650-723-1675 From mheiden at engr.ucr.edu Mon Mar 16 20:22:30 2015 From: mheiden at engr.ucr.edu (Mark Heiden) Date: Tue, 17 Mar 2015 00:22:30 +0000 Subject: [labnetwork] AFM Holder Parts Message-ID: Has anyone had to replace these little AFM probe holders with the vertical pins? (From a Veeco AFM) Ours got bent and broken (likely dropped) and the vendor won't sell us the parts individual mounts, only the entire stage. They could be easily cut off and new once glued on if we just had a vendor. I've looked all over the "interweb" but have not found them. Thanks, Mark Heiden NanoFab Cleanroom Manager Center for Nanoscale Science and Engineering University of California, Riverside 951-827-2551 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Stage AFM.jpg Type: image/jpeg Size: 868789 bytes Desc: Stage AFM.jpg URL: From nclay at seas.upenn.edu Mon Mar 16 21:35:57 2015 From: nclay at seas.upenn.edu (Noah Clay) Date: Mon, 16 Mar 2015 21:35:57 -0400 Subject: [labnetwork] Cleaning heavy metals off chamber liners- is there any place that does this? In-Reply-To: <410704885.1942814.1426547674894.JavaMail.zimbra@stanford.edu> References: <410704885.1942814.1426547674894.JavaMail.zimbra@stanford.edu> Message-ID: <34165F36-8014-47A4-9F9F-5477FD9A1098@seas.upenn.edu> Cliff, If you can afford the downtime, I would consider reclaiming through a company like Materion (search: "metal reclaim materion"). There are many similar outfits, but it's likely worth a call to understand their services, restrictions, etc. As you probably know, there may be money paid to Stanford if sufficient precious metals are reclaimed, but service charges tend to negate this. I can't vouch for how they handle Hg, Cd and Te...if they process these at all. In any event, l pasted a link below. Best of luck, Noah Clay Quattrone Nanofabrication Facility University of Pennsylvania Philadelphia, PA http://materion.com/Services/MaterialRecyclingandReclamation/PreciousMetalRefiningandRecycling.aspx On March 16, 2015 7:14:34 PM EDT, Clifford F Knollenberg wrote: >We have heavy metal residues on the chamber liners of our Ar Ion Mill >that we would like to get removed. The heavy metals include Hg, Cd, >and Te, mixed in with a large amount of non-toxic metals (Fe, Si, Au, >etc). We would like to get them cleaned (bead blasted) at a facility >capable of handling heavy metal residues safely. We do not need the >chamber liners completely clean of the heavy metals, but want to reduce >the metal build-up on the surface. > >Any advice would be helpful. > >Regards, > >Cliff > >-- >Clifford Knollenberg >Cleanroom Science and Engineering Associate- Stanford Nano Center >Email: cknollen at stanford.edu >Tel: 650-723-1675 > > >_______________________________________________ >labnetwork mailing list >labnetwork at mtl.mit.edu >https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. -------------- next part -------------- An HTML attachment was scrubbed... URL: From Loik.gence at cetuc.puc-rio.br Tue Mar 17 10:13:33 2015 From: Loik.gence at cetuc.puc-rio.br (=?windows-1252?Q?Lo=EFk_GENCE?=) Date: Tue, 17 Mar 2015 11:13:33 -0300 Subject: [labnetwork] Thermal load in cleanrooms ISO 5/6 In-Reply-To: <614FCF45-FCFE-4B0B-B085-F2FCA4619E2E@nist.gov> References: <54F7430B.1040408@cns.fas.harvard.edu> <5506EA62.9000008@cetuc.puc-rio.br> <550715D2.7010907@udel.edu> <614FCF45-FCFE-4B0B-B085-F2FCA4619E2E@nist.gov> Message-ID: <5508368D.5060307@cetuc.puc-rio.br> Dear Jim, I like the idea of a single external Chiller. This should be fine for most of our tools. However a few equipments are more sensitive demanding higher flow and or pressure... The combination an external chiller and a few smaller ones line could be the best solution for us, having a small backup chiller in case of urgent need... I am curious to know the number of technicians you have in a facility with 40-50 tools... Here, ww can afford only one ;-/ best, Lo?k. Le 16/03/2015 17:25, Beall, James A. a ?crit : > Lo?k, > > I agree with the caution about accounting for the heat from the FFU; > it is significant. > > In our fabs we use a large external Process Chilled Water unit which > provides cooling for 40-50 tools. Some of the equipment (like cryopump > compressors and larger pumps which typically have larger => 3/8? > diameter), cooling lines can be directly cooled by the PCW loop. Many > other tools like electron gun evaporators and sputter guns have > smaller cooling lines and you may have trouble directly connecting > them to the PCW loop and achieving the required flows and pressures. > > We end up with many small heat exchangers each set up for the > particular needs of our tools. Some run distilled water, some DI > water, some glycol and some high temperature thermal fluids. The pumps > are the weak point in these units. > > When connecting tools across your PCW loop be careful to include > balancing or flow setting valves as you will have many connections in > parallel. > > Also I prefer to use a non-closed system, i.e., one with an > atmospheric pressure return tank. This can be automatically refilled > with treated water as needed to account for leaks and losses. Having > your return water dump into a non-pressurized tank creates much less > back pressure than the closed loop pressurized systems. The back > pressure can be a killer with many parallel connected tools with > different impedances. > > > - Jim > > > > On Mar 16, 2015, at 11:41 AM, Iulian Codreanu > wrote: > >> Loik, >> >> Another thing to keep in mind is the heat that is "taken away from >> the equipment" via exhaust. >> >> The heat generated by a piece of equipment can: >> -Be dissipated into the room >> -Be "taken away" by the cooling water. >> -Be "taken way" by exhaust. >> >> If a piece of equipment is not cooled and does not have exhaust then >> all the heat gets dissipated into the room. >> >> If the piece of equipment is cooled and exhausted only part of the >> heat generated will end up in the room. >> >> If you know how much heat is taken away by the cooling water and/or >> exhaust that is great. If you do not, I saw engineers using factor >> such as (PCW stands for process cooling water): >> 100% of the power into the room if no PCW and no exhaust >> 50% of the power into the room is no PCW but exhaust >> 40% of the power into the room if PCW but no exhaust >> 20% of the power into the room if both PCW and exhaust >> >> I prefer the "unique chiller (placed outside of the building)" >> approach for cooling the equipment. If you can run the water from >> the unique chiller directly through the equipment, you do not have to >> deal with the heat generated by the "small chillers". >> >> Iulian >> >> >> >> iulian Codreanu, Ph.D. >> Director of Operations, UD NanoFab >> 163 ISE Lab >> 221 Academy Street >> Newark, DE 19716 >> 302-831-2784 >> http://udnf.udel.edu >> On 3/16/2015 10:36 AM, Lo?k GENCE wrote: >>> Hi Everyone, >>> >>> I am working on the design of a small cleanroom facility (70m2) ISO >>> 5/6. Right now, I am dealing with the problem of thermal load, >>> Which is crucial here in Rio, where the average outside temperature >>> is of 30 deg C with a relative humidity of 75-80 %. >>> >>> I would like to have your help and/or comments on several points: >>> >>> Most of the manufacturers do not provide a value for the thermal >>> load (why?). Assuming 2 or max 3 people working simultaneously in >>> the cleanrooms, and usual cleanroom value: 22 deg C - 55% humidity. >>> The main issue is: how can I estimate the cooling power required for >>> the Air Conditioning System (ACS)? >>> >>> I have the list of equipments we'll have and the corresponding >>> electrical power. I assumed the heat generated by 2 users and added >>> the total electrical power dissipated as heat inside of the >>> cleanroom, using a simultaneity factor of 0.75 (all equipments won't >>> be turned on at the same time) and neglected the heat produced by >>> the filter fan and lightning. >>> *** >>> ** - Is it reasonable for dimensioning the ACS cooling power ? * >>> >>> Also most of the equipments have a cooling water circuit. But the >>> cooling power needed is well described in the installation manual >>> provided with the equipments. >>> >>> * - Should I subtract from the **ACS cooling power**value, >>> **the cooling po**wer **from the chillers?* >>> >>> - *Do you think a central and unique chiller (placed outside >>> of the building) is preferred to several smaller chillers placed >>> closer to the equipment?* >>> >>> >>> I thank you very much for your kind help or comments. >>> >>> >>> regards, >>> >>> Lo?k. >>> >>> -- >>> __________________________________________ >>> Dr. Lo?k Gence >>> >>> PUC-RIO/CETUC-LABSEM >>> >>> End Rua Marques de S?o Vicente, 225-Gavea >>> CEP:22451-900 Rio de Janeiro, RJ-Brasil >>> >>> (Telefone) +55 (021) 3527-2193 >>> >>> (Mobile) +55 (021) 99156-5558 >>> >>> loik.gence at cetuc.puc-rio.br >>> __________________________________________ >>> >>> >>> _______________________________________________ >>> labnetwork mailing list >>> labnetwork at mtl.mit.edu >>> https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork >> >> _______________________________________________ >> labnetwork mailing list >> labnetwork at mtl.mit.edu >> https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork > > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -- __________________________________________ Dr. Lo?k Gence PUC-RIO/CETUC-LABSEM End Rua Marques de S?o Vicente, 225-Gavea CEP:22451-900 Rio de Janeiro, RJ-Brasil (Telefone) +55 (021) 3527-2193 (Mobile) +55 (021) 99156-5558 loik.gence at cetuc.puc-rio.br __________________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From carsen at stanford.edu Wed Mar 18 12:07:18 2015 From: carsen at stanford.edu (Carsen Kline) Date: Wed, 18 Mar 2015 09:07:18 -0700 Subject: [labnetwork] Automated N2 shutoff for dry pumps Message-ID: <5509A2B6.4050501@stanford.edu> Hello all, The topic of nitrogen cost is a common thread within this group, and many of you have found creative solutions to reduce N2 usage on dry pump purges. It is my understanding from reading your comments and from talking to a dry pump repair outfit that continuous N2 feed is not necessary in many of our applications and in some cases can be comfortably converted to CDA. For those pumps that require nitrogen, but have an active process duty that doesn't justify the amount of N2 they consume, we're looking for an automated solution to switch off or reduce N2 flow during system idle time. It's been recommended to me by one vendor that N2 should flow for 30 minutes following process, but after this could be shut off or reduced. Rather than reinvent the wheel that some of you may already have in service, I'd like to ask if anyone could share a design for such a timed system with a provision for tying it to an enable/disable system (such as Badger/Coral/FOM). I'd be interested in detailed plans or even complete units that we could purchase outright. My contact information is listed below. Many thanks, I look forward to your feedback. Carsen -- Carsen Kline Stanford Nanofabrication Facility Paul G. Allen Bldg 141, Mail Code 4070 Stanford, CA 94305 (650)724-8214 carsen at stanford.edu http://snf.stanford.edu From kurt.kupcho at wisc.edu Wed Mar 18 15:58:42 2015 From: kurt.kupcho at wisc.edu (Kurt Kupcho) Date: Wed, 18 Mar 2015 19:58:42 +0000 Subject: [labnetwork] Pre-oxidation furnace clean Message-ID: Hi everyone - For a traditional thermal oxidation furnace, for things like building gate oxides, the general practice is to do a pre-furnace clean using piranha, RCA 1, RCA 2, and HF in successive cleanings beforehand. I was wondering for other academic cleanrooms following this practice what rules do you have in place for once the students clean their samples and how long they can store these samples before putting into the oxidation furnace. Let's assume that the students redo the HF dip to remove the native oxide layer that has reformed, and they stored the samples in a clean container in a N2 dry box inside the cleanroom. Do you require them to put the sample in the oxidation furnace immediately after pre-furnace clean? 1 day? 1 week? Also, if you do have a specific rule for this do you have any cleanliness data to back it up? Thank you ahead of time for your insightful responses! Best, Kurt --------------------------------------------------- Kurt Kupcho Microelectronics Engineer WCAM 1550 Engineering Drive ECB Room 3110 Madison, WI 53706 E: kurt.kupcho at wisc.edu T: 608-262-2982 F: 608-265-2614 [http://wcam.engr.wisc.edu/logos/pics/wcam420x80.png] -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image002.png Type: image/png Size: 23961 bytes Desc: image002.png URL: From anava at tauex.tau.ac.il Mon Mar 23 05:30:06 2015 From: anava at tauex.tau.ac.il (Nava Ariel- Sternberg) Date: Mon, 23 Mar 2015 09:30:06 +0000 Subject: [labnetwork] Ni evaporation Message-ID: Hi all, We've came across some issues with Ni e-beam evaporation and thought of consulting the network: Which crucible are you using for Ni e-beam evaporation? We've tried Al2O3 and Vitreous carbon, both recommended by the material/crucible suppliers. Any tips with respect to melting the material or the evaporation process itself? Thanks, Nava Nava Ariel-Sternberg, Ph.D. Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing Director MNCF Manager Phone: 03-640-5619 Mobile: 054-9984959 Email: anava at tauex.tau.ac.il -------------- next part -------------- An HTML attachment was scrubbed... URL: From dongshin at brandeis.edu Sun Mar 22 22:59:11 2015 From: dongshin at brandeis.edu (Dongshin Kim) Date: Sun, 22 Mar 2015 22:59:11 -0400 Subject: [labnetwork] 2015 Brandeis MRSEC Summer Course Announcement Message-ID: Dear Colleagues, We announce the opening of registration for our annual, one??week summer course, ?Introduction to Microfluidics Technology? to be held at Brandeis University, near Boston, MA. The microfluidics course is a hands-?on laboratory course sponsored by the National Science Foundation?s Bioinspired Soft Materials Research Science and Engineering Center (MRSEC) at Brandeis. It will be offered during the week of June 22 ?? 26, 2015. It is intended for graduate students, post docs, faculty and industrial scientists and engineers interested in utilizing microfluidic technology in their work, in both physical sciences and life sciences, and does not assume any specific prerequisites. ?Introduction to Microfluidics Technology? (June 22 ? 26, 2015) will be taught by Dr. Dongshin Kim http://goo.gl/9a6y7Z. A $750 fee will cover the course and housing in double-?occupancy rooms with on-?site breakfast and lunch from Monday through Friday. Single rooms are not available. Local students who do not need housing will pay a non-?resident fee of $400. Please bring this course to the attention of any appropriate scientists and engineers. See the attached information for a detailed course description. Best regards, Dongshin Kim Director of Microfluidics MRSEC/Physics Brandeis University 415 South St. MS 057 Waltham, MA 02454 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: 2015 Brandeis MRSEC Summer Course and syllabus_extended.pdf Type: application/pdf Size: 185651 bytes Desc: not available URL: From Vincent.Luciani at nist.gov Mon Mar 23 09:08:07 2015 From: Vincent.Luciani at nist.gov (Luciani, Vincent) Date: Mon, 23 Mar 2015 13:08:07 +0000 Subject: [labnetwork] Ni evaporation In-Reply-To: References: Message-ID: Hello Nava, Dr. Gerard Henein is our PVD expert and responsible for our evaporators. He uses a copper crucible for Ni. Gerard is copied if you want to follow up with him. Best, Vince From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Nava Ariel- Sternberg Sent: Monday, March 23, 2015 5:30 AM To: labnetwork at mtl.mit.edu Subject: [labnetwork] Ni evaporation Hi all, We've came across some issues with Ni e-beam evaporation and thought of consulting the network: Which crucible are you using for Ni e-beam evaporation? We've tried Al2O3 and Vitreous carbon, both recommended by the material/crucible suppliers. Any tips with respect to melting the material or the evaporation process itself? Thanks, Nava Nava Ariel-Sternberg, Ph.D. Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing Director MNCF Manager Phone: 03-640-5619 Mobile: 054-9984959 Email: anava at tauex.tau.ac.il -------------- next part -------------- An HTML attachment was scrubbed... URL: From nnelsonfitzpatrick at uwaterloo.ca Mon Mar 23 09:18:42 2015 From: nnelsonfitzpatrick at uwaterloo.ca (Nathan Nelson - Fitzpatrick) Date: Mon, 23 Mar 2015 13:18:42 +0000 Subject: [labnetwork] Ni evaporation Message-ID: Hi Nava, We have also experienced problems in our lab with Ni e-beam evaporation in VC or Al2O3 crucibles. We found that the VC crucibles would break down after a few deposition cycles (and would ?tarnish? the Ni melt) and the one time we tried Al2O3 as a crucible liner it broke immediately upon removal from our E-beam hearth. We have settled on using Tungsten crucibles for our Ni e-beam evaporation. We have not observed any notable problems with this process and our first W crucible lasted for over two years before we needed to retire it. Best regards, -Nathan -- Nathan Nelson-Fitzpatrick PhD Nanofabrication Process Engineer Quantum NanoFab University of Waterloo 200 University Avenue West Waterloo, ON Canada N2L 3G1 Ph: +1 519-888-4567 ext. 31796 From: Nava Ariel- Sternberg > Date: Monday, March 23, 2015 at 5:30 AM To: "labnetwork at mtl.mit.edu" > Subject: [labnetwork] Ni evaporation Hi all, We've came across some issues with Ni e-beam evaporation and thought of consulting the network: Which crucible are you using for Ni e-beam evaporation? We've tried Al2O3 and Vitreous carbon, both recommended by the material/crucible suppliers. Any tips with respect to melting the material or the evaporation process itself? Thanks, Nava Nava Ariel-Sternberg, Ph.D. Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing Director MNCF Manager Phone: 03-640-5619 Mobile: 054-9984959 Email: anava at tauex.tau.ac.il -------------- next part -------------- An HTML attachment was scrubbed... URL: From hft at ncsu.edu Mon Mar 23 10:03:35 2015 From: hft at ncsu.edu (Henry Taylor) Date: Mon, 23 Mar 2015 10:03:35 -0400 Subject: [labnetwork] Ni evaporation In-Reply-To: References: Message-ID: Hello Nava, In my lab we do not use a crucible. We put the Ni pellets directly in the hearth. The Ni melts into a ball. It does not stick to the hearth. Best, Henry Taylor Senior Hardware Engineer NNF at NCSU On Mon, Mar 23, 2015 at 5:30 AM, Nava Ariel- Sternberg < anava at tauex.tau.ac.il> wrote: > Hi all, > > > > We've came across some issues with Ni e-beam evaporation and thought of > consulting the network: > > > > Which crucible are you using for Ni e-beam evaporation? We've tried Al2O3 > and Vitreous carbon, both recommended by the material/crucible suppliers. > > Any tips with respect to melting the material or the evaporation process > itself? > > > > Thanks, > > > > Nava > > > > > > Nava Ariel-Sternberg, Ph.D. > > Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing > Director > > MNCF Manager > > Phone: 03-640-5619 > > Mobile: 054-9984959 > > Email: anava at tauex.tau.ac.il > > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork > > -------------- next part -------------- An HTML attachment was scrubbed... URL: From bfuchs at chtm.unm.edu Mon Mar 23 11:10:24 2015 From: bfuchs at chtm.unm.edu (Beth Fuchs) Date: Mon, 23 Mar 2015 09:10:24 -0600 Subject: [labnetwork] Ni evaporation In-Reply-To: References: Message-ID: <55102CE0.1030500@chtm.unm.edu> For quite some time we used vitreous carbon and found that the crucible will crack unless the beam current is ramped up and down VERY slowly (I think we ramp at about 2mA/min compared to 25mA/min for other metals). We finally dedicated a pocket in our indexer for Ni without a crucible liner and have had no problems since. The Ni does not adhere to the copper hearth so we can remove it easily for cleaning. Beth On 3/23/2015 3:30 AM, Nava Ariel- Sternberg wrote: > Hi all, > > We've came across some issues with Ni e-beam evaporation and thought of > consulting the network: > > Which crucible are you using for Ni e-beam evaporation? We've tried > Al2O3 and Vitreous carbon, both recommended by the material/crucible > suppliers. > > Any tips with respect to melting the material or the evaporation process > itself? > > Thanks, > > Nava > > Nava Ariel-Sternberg, Ph.D. > > Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing > Director > > MNCF Manager > > Phone: 03-640-5619 > > Mobile: 054-9984959 > > Email: anava at tauex.tau.ac.il > > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork > -- Beth Fuchs Database Administrator Center for High Tech Materials 1313 Goddard SE Albuquerque, NM 87106-4343 (505) 272-7801 (fax) From mondol at mit.edu Mon Mar 23 12:44:28 2015 From: mondol at mit.edu (Mark K Mondol) Date: Mon, 23 Mar 2015 12:44:28 -0400 Subject: [labnetwork] Ni evaporation In-Reply-To: References: Message-ID: <551042EC.7080207@mit.edu> I agree, never had a problem with Ni sticking. It is also fun to note the change in the beam shape when the Ni source goes above its Curie point. Regards, Mark K Mondol On 3/23/2015 10:03 AM, Henry Taylor wrote: > Hello Nava, > > In my lab we do not use a crucible. We put the Ni pellets directly in > the hearth. The Ni melts into a ball. It does not stick to the hearth. > > Best, > Henry Taylor > Senior Hardware Engineer > NNF at NCSU > -- Mark K Mondol Assistant Director NanoStructures Laboratory And Facility Manager Scanning Electron Beam Lithography Facility Bldg 38 Room 177 www.rle.mit.edu/sebl mondol at mit.edu office - 617-253-9617 cell - 617-224-8756 From rmorrison at draper.com Mon Mar 23 13:42:52 2015 From: rmorrison at draper.com (Morrison, Richard H., Jr.) Date: Mon, 23 Mar 2015 17:42:52 +0000 Subject: [labnetwork] Ni evaporation In-Reply-To: References: Message-ID: Hi, Here is info from Draper laboratory PVD engineer, Joseph Louis: We used a FABMATE crucible from Lesker because of its surface properties: http://www.lesker.com/newweb/evaporation_sources/ebeam_crucibles_fabmate.cfm?pgid=0 Even with its property benefits, one can really only use it for one, maybe two runs before it cracks (especially for the thick runs we were attempting). I believe I did staggered pre-melting for this material, that is, one row of pellets, melt, second row of pellets, melt and actual run. If I recall correctly, when I tried any more than that I got voids in the melt and/or early cracking. One process issue of note is stress especially for thicker films (e.g. 1[um]+). Lower dep rates seemed to help (~0.5[ang/sec]) but a better method is Ion Assisted Deposition if the system is capable. Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Nava Ariel- Sternberg Sent: Monday, March 23, 2015 5:30 AM To: labnetwork at mtl.mit.edu Subject: [labnetwork] Ni evaporation Hi all, We've came across some issues with Ni e-beam evaporation and thought of consulting the network: Which crucible are you using for Ni e-beam evaporation? We've tried Al2O3 and Vitreous carbon, both recommended by the material/crucible suppliers. Any tips with respect to melting the material or the evaporation process itself? Thanks, Nava Nava Ariel-Sternberg, Ph.D. Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing Director MNCF Manager Phone: 03-640-5619 Mobile: 054-9984959 Email: anava at tauex.tau.ac.il ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From julia.aebersold at louisville.edu Mon Mar 23 13:52:36 2015 From: julia.aebersold at louisville.edu (julia.aebersold at louisville.edu) Date: Mon, 23 Mar 2015 17:52:36 +0000 Subject: [labnetwork] Ni evaporation In-Reply-To: References: Message-ID: I really like this idea for we have cracking crucibles all the time. Running without a crucible scares me if the beam were to melt the hearth and puncture the water jacket. Nathan, what was your price difference between Tungsten and Al2O3 crucibles. Cheers! Julia Aebersold, Ph.D. Cleanroom Manager Micro/Nano Technology Center University of Louisville Shumaker Research Building, Room 233 2210 South Brook Street Louisville, KY 40292 502-852-1572 http://louisville.edu/micronano/ From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Nathan Nelson - Fitzpatrick Sent: Monday, March 23, 2015 9:19 AM To: Nava Ariel- Sternberg; labnetwork at mtl.mit.edu Subject: Re: [labnetwork] Ni evaporation Hi Nava, We have also experienced problems in our lab with Ni e-beam evaporation in VC or Al2O3 crucibles. We found that the VC crucibles would break down after a few deposition cycles (and would "tarnish" the Ni melt) and the one time we tried Al2O3 as a crucible liner it broke immediately upon removal from our E-beam hearth. We have settled on using Tungsten crucibles for our Ni e-beam evaporation. We have not observed any notable problems with this process and our first W crucible lasted for over two years before we needed to retire it. Best regards, -Nathan -- Nathan Nelson-Fitzpatrick PhD Nanofabrication Process Engineer Quantum NanoFab University of Waterloo 200 University Avenue West Waterloo, ON Canada N2L 3G1 Ph: +1 519-888-4567 ext. 31796 From: Nava Ariel- Sternberg > Date: Monday, March 23, 2015 at 5:30 AM To: "labnetwork at mtl.mit.edu" > Subject: [labnetwork] Ni evaporation Hi all, We've came across some issues with Ni e-beam evaporation and thought of consulting the network: Which crucible are you using for Ni e-beam evaporation? We've tried Al2O3 and Vitreous carbon, both recommended by the material/crucible suppliers. Any tips with respect to melting the material or the evaporation process itself? Thanks, Nava Nava Ariel-Sternberg, Ph.D. Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing Director MNCF Manager Phone: 03-640-5619 Mobile: 054-9984959 Email: anava at tauex.tau.ac.il -------------- next part -------------- An HTML attachment was scrubbed... URL: From nnelsonfitzpatrick at uwaterloo.ca Mon Mar 23 14:22:20 2015 From: nnelsonfitzpatrick at uwaterloo.ca (Nathan Nelson - Fitzpatrick) Date: Mon, 23 Mar 2015 18:22:20 +0000 Subject: [labnetwork] Ni evaporation In-Reply-To: References: Message-ID: Hi Julia, I don?t recall what we paid for the Al2O3 crucibles. I do recall that the Tungsten crucible was about 3-4x more expensive than the comparably sized VC crucible. Best, -Nathan -- Nathan Nelson-Fitzpatrick PhD Nanofabrication Process Engineer Quantum NanoFab University of Waterloo 200 University Avenue West Waterloo, ON Canada N2L 3G1 Ph: +1 519-888-4567 ext. 31796 From: "julia.aebersold at louisville.edu" > Date: Monday, March 23, 2015 at 1:52 PM To: Nathan Nelson - Fitzpatrick >, Nava Ariel- Sternberg >, "labnetwork at mtl.mit.edu" > Subject: RE: [labnetwork] Ni evaporation I really like this idea for we have cracking crucibles all the time. Running without a crucible scares me if the beam were to melt the hearth and puncture the water jacket. Nathan, what was your price difference between Tungsten and Al2O3 crucibles. Cheers! Julia Aebersold, Ph.D. Cleanroom Manager Micro/Nano Technology Center University of Louisville Shumaker Research Building, Room 233 2210 South Brook Street Louisville, KY 40292 502-852-1572 http://louisville.edu/micronano/ From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Nathan Nelson - Fitzpatrick Sent: Monday, March 23, 2015 9:19 AM To: Nava Ariel- Sternberg; labnetwork at mtl.mit.edu Subject: Re: [labnetwork] Ni evaporation Hi Nava, We have also experienced problems in our lab with Ni e-beam evaporation in VC or Al2O3 crucibles. We found that the VC crucibles would break down after a few deposition cycles (and would ?tarnish? the Ni melt) and the one time we tried Al2O3 as a crucible liner it broke immediately upon removal from our E-beam hearth. We have settled on using Tungsten crucibles for our Ni e-beam evaporation. We have not observed any notable problems with this process and our first W crucible lasted for over two years before we needed to retire it. Best regards, -Nathan -- Nathan Nelson-Fitzpatrick PhD Nanofabrication Process Engineer Quantum NanoFab University of Waterloo 200 University Avenue West Waterloo, ON Canada N2L 3G1 Ph: +1 519-888-4567 ext. 31796 From: Nava Ariel- Sternberg > Date: Monday, March 23, 2015 at 5:30 AM To: "labnetwork at mtl.mit.edu" > Subject: [labnetwork] Ni evaporation Hi all, We've came across some issues with Ni e-beam evaporation and thought of consulting the network: Which crucible are you using for Ni e-beam evaporation? We've tried Al2O3 and Vitreous carbon, both recommended by the material/crucible suppliers. Any tips with respect to melting the material or the evaporation process itself? Thanks, Nava Nava Ariel-Sternberg, Ph.D. Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing Director MNCF Manager Phone: 03-640-5619 Mobile: 054-9984959 Email: anava at tauex.tau.ac.il -------------- next part -------------- An HTML attachment was scrubbed... URL: From elliscd at auburn.edu Mon Mar 23 16:14:41 2015 From: elliscd at auburn.edu (Charles Ellis) Date: Mon, 23 Mar 2015 20:14:41 +0000 Subject: [labnetwork] Ni evaporation Message-ID: Nava, We have run Ni directly in the copper hearth (i.e. no crucible) for 20 years or more without an issue. Just make sure you properly cool your hearth and it will be almost impossible to punch a hole in it. I agree with Rick, Ni is high stress and thick films have been known to pull chucks of silicon from my wafers. A slow rate <0.5A/sec has been our standard for Ni ? to reduce the stress. Charles Ellis Auburn University From: Nava Ariel- Sternberg > Date: Monday, March 23, 2015 at 4:30 AM To: "labnetwork at mtl.mit.edu" > Subject: [labnetwork] Ni evaporation Hi all, We've came across some issues with Ni e-beam evaporation and thought of consulting the network: Which crucible are you using for Ni e-beam evaporation? We've tried Al2O3 and Vitreous carbon, both recommended by the material/crucible suppliers. Any tips with respect to melting the material or the evaporation process itself? Thanks, Nava Nava Ariel-Sternberg, Ph.D. Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing Director MNCF Manager Phone: 03-640-5619 Mobile: 054-9984959 Email: anava at tauex.tau.ac.il -------------- next part -------------- An HTML attachment was scrubbed... URL: From ncrews at latech.edu Mon Mar 23 17:11:58 2015 From: ncrews at latech.edu (Niel Crews) Date: Mon, 23 Mar 2015 16:11:58 -0500 Subject: [labnetwork] Job opening in Louisiana - cleanroom manager In-Reply-To: References: Message-ID: <5510819E.8020008@latech.edu> We are looking to hire an Associate Director of Operations to oversee our cleanroom operations and equipment. Of course we are flexible, but I envision the ideal candidate to be a US citizen, maybe 5 years out of a M.S. degree in some engineering field, and currently working as a cleanroom technician/engineer in industry or a larger university facility. The link to the job listing is: https://www.tinytechjobs.com/cgi-bin/details?job_id=1703. I also take email inquiries directly at ncrews at latech.edu Thanks, Niel Crews Director, Institute for Micromanufacturing Louisiana Tech University On 3/23/2015 12:52 PM, julia.aebersold at louisville.edu wrote: > > I really like this idea for we have cracking crucibles all the time. > Running without a crucible scares me if the beam were to melt the > hearth and puncture the water jacket. Nathan, what was your price > difference between Tungsten and Al2O3 crucibles. > > Cheers! > > Julia Aebersold, Ph.D. > > Cleanroom Manager > > Micro/Nano Technology Center > > University of Louisville > > Shumaker Research Building, Room 233 > > 2210 South Brook Street > > Louisville, KY 40292 > > 502-852-1572 > > http://louisville.edu/micronano/ > > *From:*labnetwork-bounces at mtl.mit.edu > [mailto:labnetwork-bounces at mtl.mit.edu] *On Behalf Of *Nathan Nelson - > Fitzpatrick > *Sent:* Monday, March 23, 2015 9:19 AM > *To:* Nava Ariel- Sternberg; labnetwork at mtl.mit.edu > *Subject:* Re: [labnetwork] Ni evaporation > > Hi Nava, > > We have also experienced problems in our lab with Ni e-beam > evaporation in VC or Al2O3 crucibles. We found that the VC crucibles > would break down after a few deposition cycles (and would ?tarnish? > the Ni melt) and the one time we tried Al2O3 as a crucible liner it > broke immediately upon removal from our E-beam hearth. We have > settled on using Tungsten crucibles for our Ni e-beam evaporation. We > have not observed any notable problems with this process and our first > W crucible lasted for over two years before we needed to retire it. > > Best regards, > > -Nathan > > -- > > Nathan Nelson-Fitzpatrick PhD > > Nanofabrication Process Engineer > > Quantum NanoFab > > University of Waterloo > > 200 University Avenue West > > Waterloo, ON Canada N2L 3G1 > > Ph: +1 519-888-4567 ext. 31796 > > *From: *Nava Ariel- Sternberg > > *Date: *Monday, March 23, 2015 at 5:30 AM > *To: *"labnetwork at mtl.mit.edu " > > > *Subject: *[labnetwork] Ni evaporation > > Hi all, > > We've came across some issues with Ni e-beam evaporation and thought > of consulting the network: > > Which crucible are you using for Ni e-beam evaporation? We've tried > Al2O3 and Vitreous carbon, both recommended by the material/crucible > suppliers. > > Any tips with respect to melting the material or the evaporation > process itself? > > Thanks, > > Nava > > Nava Ariel-Sternberg, Ph.D. > > Tel-Aviv University Center for Nanoscience and Nanotechnology, > Managing Director > > MNCF Manager > > Phone: 03-640-5619 > > Mobile: 054-9984959 > > Email: anava at tauex.tau.ac.il > > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From bernard at mtl.mit.edu Mon Mar 23 17:41:48 2015 From: bernard at mtl.mit.edu (Bernard Alamariu) Date: Mon, 23 Mar 2015 17:41:48 -0400 Subject: [labnetwork] Ni evaporation In-Reply-To: References: Message-ID: <5510889C.2060300@mtl.mit.edu> Hello Nava, You must use a crucible. Even the Ni melt does not stick to the hearth, the Cu from the hearth will massively diffuse into the Ni melt and it will end on the wafers. Thanks, Bernard The On 3/23/15 10:03 AM, Henry Taylor wrote: > Hello Nava, > > In my lab we do not use a crucible. We put the Ni pellets directly in > the hearth. The Ni melts into a ball. It does not stick to the hearth. > > Best, > Henry Taylor > Senior Hardware Engineer > NNF at NCSU > > On Mon, Mar 23, 2015 at 5:30 AM, Nava Ariel- Sternberg > > wrote: > > Hi all, > > We've came across some issues with Ni e-beam evaporation and > thought of consulting the network: > > Which crucible are you using for Ni e-beam evaporation? We've > tried Al2O3 and Vitreous carbon, both recommended by the > material/crucible suppliers. > > Any tips with respect to melting the material or the evaporation > process itself? > > Thanks, > > Nava > > Nava Ariel-Sternberg, Ph.D. > > Tel-Aviv University Center for Nanoscience and Nanotechnology, > Managing Director > > MNCF Manager > > Phone: 03-640-5619 > > Mobile: 054-9984959 > > Email: anava at tauex.tau.ac.il > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork > > > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From anava at tauex.tau.ac.il Tue Mar 24 02:28:12 2015 From: anava at tauex.tau.ac.il (Nava Ariel- Sternberg) Date: Tue, 24 Mar 2015 06:28:12 +0000 Subject: [labnetwork] Ni evaporation In-Reply-To: References: Message-ID: Dear all, Thank you all for the many helpful responses I got. Many suggested using the Ni directly in the copper hearth. Aren't you worried of Ni contamination? Other crucibles, wafers during other depositions? Thanks again, Nava Nava Ariel-Sternberg, Ph.D. Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing Director MNCF Manager Phone: 03-640-5619 Mobile: 054-9984959 Email: anava at tauex.tau.ac.il From: Charles Ellis [mailto:elliscd at auburn.edu] Sent: Monday, March 23, 2015 10:15 PM To: Nava Ariel- Sternberg; labnetwork at mtl.mit.edu Subject: Re: [labnetwork] Ni evaporation Nava, We have run Ni directly in the copper hearth (i.e. no crucible) for 20 years or more without an issue. Just make sure you properly cool your hearth and it will be almost impossible to punch a hole in it. I agree with Rick, Ni is high stress and thick films have been known to pull chucks of silicon from my wafers. A slow rate <0.5A/sec has been our standard for Ni - to reduce the stress. Charles Ellis Auburn University From: Nava Ariel- Sternberg > Date: Monday, March 23, 2015 at 4:30 AM To: "labnetwork at mtl.mit.edu" > Subject: [labnetwork] Ni evaporation Hi all, We've came across some issues with Ni e-beam evaporation and thought of consulting the network: Which crucible are you using for Ni e-beam evaporation? We've tried Al2O3 and Vitreous carbon, both recommended by the material/crucible suppliers. Any tips with respect to melting the material or the evaporation process itself? Thanks, Nava Nava Ariel-Sternberg, Ph.D. Tel-Aviv University Center for Nanoscience and Nanotechnology, Managing Director MNCF Manager Phone: 03-640-5619 Mobile: 054-9984959 Email: anava at tauex.tau.ac.il -------------- next part -------------- An HTML attachment was scrubbed... URL: From rmorrison at draper.com Tue Mar 24 11:59:24 2015 From: rmorrison at draper.com (Morrison, Richard H., Jr.) Date: Tue, 24 Mar 2015 15:59:24 +0000 Subject: [labnetwork] follow up to etch tool damage Message-ID: Hi everyone, Just wanted to update you on what we have found out about the damage to the Substrates from the RIE tool we have. Again the tool is an Ulvac NE-550 high density RIE tool. First of all we confirmed that we do not have an electrostatic chuck, but it is ceramic chuck with helium backside cooling and stainless lift pins going through the chuck to lift the wafer. We tried to run Argon plasma before lifting and it did not solve the issue. We have also tried a long wait 5 minutes before we de-chuck. The arc damage is only seen after we run a SiO2 etch using CHF3/CF4 gas ratio 55sccm/6sccm operating pressure is 2.66Pa, antenna power 500watts, RF bias at 100w. We ran other wafers using a poly etch recipe SF6/O2 10sccm/10sccm 5Pa pressure, antenna power 800w, RF Bias 50 watts We are still working with the manufacturer to figure this out. Any more ideas? Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From rmorrison at draper.com Tue Mar 24 12:03:55 2015 From: rmorrison at draper.com (Morrison, Richard H., Jr.) Date: Tue, 24 Mar 2015 16:03:55 +0000 Subject: [labnetwork] LN2 vs N2 generation on site Message-ID: Hi everyone, I am paying >$220K per year for LN2 to generate Nitrogen for my fab. Have any of you guys switched to onsite Nitrogen generator? Looking for ideas on: Cost of system Maintenance cost of system Quality of the Nitrogen. Operating cost per CuFt of Nitrogen Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From tribble at fas.harvard.edu Tue Mar 24 16:31:10 2015 From: tribble at fas.harvard.edu (Tribble, Thomas) Date: Tue, 24 Mar 2015 20:31:10 +0000 Subject: [labnetwork] LN2 vs N2 generation on site In-Reply-To: References: Message-ID: <2FA135939A3C9644A89D6AF332BE5FD6018D7AC3C8@harvandmbx05.fasmail.priv> Richard, We haven't switched to onsite generation for the fab, but we (Harvard) have looked at it. The Harvard fab has a 9000 gallon LN2- 3? storage that gets re-filled approximately once a week. The storage facility occupies approximately 300 GSF, and there is no more real estate available for this purpose. Based upon a much smaller on-site generator recently completed, on-site generation to replace the fab storage facility would require more real estate than is available. Part of the demand for space is the self-imposed requirement for N+1 redundancy. This also affects the capital budget. But if saving money is your focus, I suggest that your discussion should be focused on the purity of your gas requirements. Locally generated 1? gas is inexpensive cheap to produce. Locally generated 3? gas is moderately expensive to produce. Locally generated 6? gas is very expensive to produce. From the refinery, 3? gas is all that is produced and transported. What we at Harvard use is 6? gas (3? gas run through a purifier). An unofficial audit has shown that less than 10% of our usage actually demands 6? purity. Want to save money? Figure out your demand by purity and segregate the flows (piping). Provide your pump and gas cabinet purges with on-site generated 1? gas. Your facility will save. Tom Tribble From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Morrison, Richard H., Jr. Sent: Tuesday, March 24, 2015 12:04 PM To: labnetwork at mtl.mit.edu Subject: [labnetwork] LN2 vs N2 generation on site Hi everyone, I am paying >$220K per year for LN2 to generate Nitrogen for my fab. Have any of you guys switched to onsite Nitrogen generator? Looking for ideas on: Cost of system Maintenance cost of system Quality of the Nitrogen. Operating cost per CuFt of Nitrogen Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From vamsinittala at gmail.com Wed Mar 25 00:08:40 2015 From: vamsinittala at gmail.com (N P VAMSI KRISHNA) Date: Wed, 25 Mar 2015 09:38:40 +0530 Subject: [labnetwork] follow up to etch tool damage In-Reply-To: References: Message-ID: Hi Rick, The issue may have been developing over a period of time and it appeared during CHF3 plasma. >From our experience: 1. Please chk if there were any long only polymer (C4F8) based plasma runs done with out proper chamber cleans in between. If so, you may not observe any abnormalities inside the chamber, in fact the chamber looks polished. (not the combination of SF6 and C4F8 - Si etch recipe) 2. Near the ICP/antenna Coil on the top of the tool there will be a shielding ring, check that once. If the tool is nearing the maintenance that could have damaged and shorted. Which results in arcing. 3.Check the coolant that is going to the ICP/antenna, coolant should not have particles. If you see any clean the lines (with N2 blowing) and replace with fresh coolant. 4. Unplug the RF connectors from the RF generator and the tool, check if there is any abnormal black color. Hope it helps. Thanks & best regards, vamsi On Tue, Mar 24, 2015 at 9:29 PM, Morrison, Richard H., Jr. < rmorrison at draper.com> wrote: > Hi everyone, > > > > Just wanted to update you on what we have found out about the damage to > the Substrates from the RIE tool we have. Again the tool is an Ulvac NE-550 > high density RIE tool. > > > > First of all we confirmed that we do not have an electrostatic chuck, but > it is ceramic chuck with helium backside cooling and stainless lift pins > going through the chuck to lift the wafer. > > > > We tried to run Argon plasma before lifting and it did not solve the > issue. We have also tried a long wait 5 minutes before we de-chuck. > > > > The arc damage is only seen after we run a SiO2 etch using CHF3/CF4 gas > ratio 55sccm/6sccm operating pressure is 2.66Pa, antenna power 500watts, RF > bias at 100w. > > > > We ran other wafers using a poly etch recipe SF6/O2 10sccm/10sccm 5Pa > pressure, antenna power 800w, RF Bias 50 watts > > > > We are still working with the manufacturer to figure this out. Any more > ideas? > > > > Rick > > > > > > Draper Laboratory > > Principal Member of the Technical Staff > > Group Leader Microfabrication Operations > > 555 Technology Square > > Cambridge Ma, 02139-3563 > > > > www.draper.com > > rmorrison at draper.com > > W 617-258-3420 > > C 508-930-3461 > > > ------------------------------ > Notice: This email and any attachments may contain proprietary (Draper > non-public) and/or export-controlled information of Draper Laboratory. If > you are not the intended recipient of this email, please immediately notify > the sender by replying to this email and immediately destroy all copies of > this email. > ------------------------------ > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork > > -- -- Thanks & Best Regards, ----------------- *N.P.Vamsi Krishna* Center for Nano Science and Engineering (CeNSE), Indian Institute of Science(IISc), Bangalore. INDIA-560012 *A bird sitting on the branch of a tree is not afraid of the branch shaking or breaking, because it trusts not the branches but its OWN WINGS.* -------------- next part -------------- An HTML attachment was scrubbed... URL: From john.nibarger at nist.gov Wed Mar 25 08:53:24 2015 From: john.nibarger at nist.gov (Nibarger, John) Date: Wed, 25 Mar 2015 12:53:24 +0000 Subject: [labnetwork] LN2 vs N2 generation on site Message-ID: We also found our LN2 to be an expensive proposition. We have a 6000 gallon LN2 tank shared with an MBE. Cleanroom use was about 900 gallons per day while the MBE was about 200 gallons per day. The N2 generator we purchased system consists of a large compressor with filters and dryers to make CDA (-40 C dew point and very low hydrocarbons) which feed a PSA type N2 generator. We provide 110 psi N2 at 99.5% purity at ~ 2000 scfh. We've had the system online now for only 6 months. We expect a cost recovery on the system in less than two years. Maintenance is mostly keeping the compressor working well and following it's proper PM schedule. We'll need to replace the dryer material every 3 years or so and expect to replace the PSA carbon molecular sieve every 5-10 years. It's one thing to get some cheaper low quality N2, the hard part is where to use it. Our fab is relativity new (~ 18,000 sqft which we moved into the summer of 2012) so our tooling hasn't migrated too far and all of the toxic gas tools and furnaces are in the same quadrant of the fab. We've kept our high purity LN2 evaporate plumbed to that quadrant (and used filters to improve quality further). We've used the low quality N2 generator gas in the rest of the fab as our N2 generator capacity allows. Any tools that need high purity N2 (99.999%) for processing have gas from dedicated cylinders. We also made provisions for intended or unintended shutdowns of the N2 generator by installing an automatic switchover to the LN2 evaporate so the fab stays up. Overall, we're pretty happy with our system and is has made an noticeable savings on our LN2 costs. Users have not reported any issues. I'd say it's too early to put an operating cost on the system since we don't fully know the PM costs (largely driven by how long our PSA carbon molecular sieves last for). From a cost perspective we spent about $130,000 for the system including new piping and staff time over 5 years at 2000 scfh (93.11 standard cubic feet (scfh) of gaseous N2 = 1 gallon LN2) gives about $0.14/gallon LN2. The saving will be larger over longer times too. If you have access to large amounts of CDA from facilities services, which we didn't at the time of installation, you can forgo the cost of the compressor/dryer/filter part of the system and save even more. Cheers, John John P. Nibarger, Ph.D. Manager, Boulder Micro-Fabrication Facility National Institute of Standards and Technology 325 Broadway, MS 817.03 Boulder, CO 80305 303-497-4575 (phone) 303-497-3042 (fax) john.nibarger at nist.gov From: , "", "Jr." > Date: Tuesday, March 24, 2015 at 10:03 AM To: "labnetwork at mtl.mit.edu" > Subject: [labnetwork] LN2 vs N2 generation on site Hi everyone, I am paying >$220K per year for LN2 to generate Nitrogen for my fab. Have any of you guys switched to onsite Nitrogen generator? Looking for ideas on: Cost of system Maintenance cost of system Quality of the Nitrogen. Operating cost per CuFt of Nitrogen Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: From colwib2 at rpi.edu Wed Mar 25 10:44:17 2015 From: colwib2 at rpi.edu (Bryant Colwill) Date: Wed, 25 Mar 2015 10:44:17 -0400 Subject: [labnetwork] Employment Opportunities at Rensselaer Polytechnic Message-ID: <5512C9C1.2050402@rpi.edu> Colleagues, Rensselaer Polytechnic Institute (RPI) currently has _two_ cleanroom positions available. A design/process engineer responsible for guiding our users throughout their design and fabrication efforts. The second is an applications engineer leading our microscopy research core. For more a more detailed description of each, please refer to the PDF attachment. If anyone is interested in formally applying, the HR postings can be found at: https://rpijobs.rpi.edu/postings/search?utf8=%E2%9C%93&query=&query_v0_posted_at_date=&2141=2&commit=Search Thanks for your time, Bryant Bryant Colwill MNCR General Manager Rensselaer Polytechnic Institute 110 8th Street, CII 6015 Troy, NY 12180 Ph:518-276-3946 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Process Engineer and Sr. Applications Engineer.pdf Type: application/pdf Size: 389034 bytes Desc: not available URL: From vito.logiudice at uwaterloo.ca Wed Mar 25 14:46:41 2015 From: vito.logiudice at uwaterloo.ca (Vito Logiudice) Date: Wed, 25 Mar 2015 18:46:41 +0000 Subject: [labnetwork] Pre-oxidation furnace clean In-Reply-To: Message-ID: Hi Kurt, If I recall correctly from my experience working in a CMOS industrial fab many years ago, critical thermal oxidation runs (i.e.., gate oxides) had to begin within 30 minutes of the preceding RCA clean/HF dip step. Beyond 30 minutes, an additional HF dip (10:1) was required, with no repeat of the RCA clean step deemed necessary. This could only be performed a limited number of times (3?) before the affected production lot required special attention from engineering. I also coordinated several extended production plant shutdowns which lasted anywhere from a few days up to 1.5 weeks. In all cases, production lots at critical production steps had to be "parked" at specific process locations and always in dry boxes with constant N2 purges. We never permitted wafer batches to be parked with exposed silicon. Specifically, wafers could not be parked before a gate oxidation run: the gate oxide had to be grown before the shutdown. Hope this helps. Best regards, Vito -- Vito Logiudice P.Eng. Director of Operations, Quantum NanoFab University of Waterloo Lazaridis QNC 1207 200 University Avenue West Waterloo, ON Canada N2L 3G1 Tel.: (519) 888-4567 ext. 38703 Email: vito.logiudice at uwaterloo.ca Website: https://fab.qnc.uwaterloo.ca From: Kurt Kupcho > Date: Wednesday, 18 March, 2015 3:58 PM To: "labnetwork at mtl.mit.edu" > Subject: [labnetwork] Pre-oxidation furnace clean Hi everyone ? For a traditional thermal oxidation furnace, for things like building gate oxides, the general practice is to do a pre-furnace clean using piranha, RCA 1, RCA 2, and HF in successive cleanings beforehand. I was wondering for other academic cleanrooms following this practice what rules do you have in place for once the students clean their samples and how long they can store these samples before putting into the oxidation furnace. Let?s assume that the students redo the HF dip to remove the native oxide layer that has reformed, and they stored the samples in a clean container in a N2 dry box inside the cleanroom. Do you require them to put the sample in the oxidation furnace immediately after pre-furnace clean? 1 day? 1 week? Also, if you do have a specific rule for this do you have any cleanliness data to back it up? Thank you ahead of time for your insightful responses! Best, Kurt --------------------------------------------------- Kurt Kupcho Microelectronics Engineer WCAM 1550 Engineering Drive ECB Room 3110 Madison, WI 53706 E: kurt.kupcho at wisc.edu T: 608-262-2982 F: 608-265-2614 [http://wcam.engr.wisc.edu/logos/pics/wcam420x80.png] -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image002.png Type: image/png Size: 23961 bytes Desc: image002.png URL: From Kolin.Brown at mail.wvu.edu Wed Mar 25 15:21:41 2015 From: Kolin.Brown at mail.wvu.edu (Kolin Brown) Date: Wed, 25 Mar 2015 19:21:41 +0000 Subject: [labnetwork] E-beam evaporator of Molybdenum Oxide Message-ID: To all, We have a request to add molybdenum oxide to our e-beam evaporator dedicated to oxide material deposition. Currently we only deposit silicon oxide, aluminum oxide and ITO I our system. Does anyone have any experience in e-beam evaporator of molybdenum oxide, or any information if the material may cause contamination problems? / Kolin S. Brown Cleanroom Manager, Shared Research Facilities West Virginia University (304)293-9683 ksbrown at mail.wvu.edu ? -------------- next part -------------- An HTML attachment was scrubbed... URL: From shott at stanford.edu Fri Mar 27 11:54:57 2015 From: shott at stanford.edu (John Shott) Date: Fri, 27 Mar 2015 08:54:57 -0700 Subject: [labnetwork] LN2 vs N2 generation on site In-Reply-To: <2FA135939A3C9644A89D6AF332BE5FD6018D7AC3C8@harvandmbx05.fasmail.priv> References: <2FA135939A3C9644A89D6AF332BE5FD6018D7AC3C8@harvandmbx05.fasmail.priv> Message-ID: <55157D51.2060805@stanford.edu> Rick: This is an excellent question and I thank Tom Tribble and John Nibarger for their initial contributions to this topic ... and others that will undoubtedly soon follow. First, let me get my remedial class question out of the way: Tom, you've got me feeling like a rank beginner. I must confess to being unfamiliar with the 1?, 3?, and 6? notation for gas purity. Is this the equivalent of what I know as dot notation? In other words, so they correspond to 1-, 3-, and 6-nines purity that is 1.0, 3.0, and 6.0 in dot notation? Where 99.5% purity is 2.5? Or is ? notation something different? I would like to add confirmation of your "unofficial audit" that found that 10% of your usage demands high purity. We also have a 9000 gallon LN2 tank (which, sadly, gets filled every fourth day). We have two sets of vaporizers on it: the big set supplies the copper-piped "house N2" and the smaller vaporizers that also go through a switchable set of purifiers and then feed our stainless-piped "UHP N2" system. Nouse N2 usage is dominated by pump purge. We have totalizing flow meters on each main line and typically observe that the UHP N2 consumption is 130-200 SLM and the house N2 consumption is 2500-2800 SLM. In other words our total nitrogen flow is very close to 3000 SLM (or about 4.5M - 5.0M SCF per month!). In other words, our high-purity consumption is in the range of 5-7% of our total consumption. Note: we actually use the house nitrogen for our SRDs ... if we moved that intermittent high-flow to UHP N2, it probably gets us close to, but no higher than, 10%. My question to the labnetwork community is what level of nitrogen purity would you want for pump purges of some of our nastier processes? For example, things like DCS and ammonia for LPCVD nitride? Hydrogen, germane, silane, plus dopants for an epitaxial process? is 1.0 nitrogen good enough? The way that I look at it, that is only a 50% reduction of oxygen as compared to what you find in air. How about 2.0 nitrogen (99%), good enough? And one question to John Nibarger: is the moisture content of your generated nitrogen controlled by the moisture content of your feed CDA? In other words, with your incoming CDA dew point of -40C is the dew point of your generated nitrogen also approximately -40C? If the incoming CDA were drier (say -55C to -60C) do you expect that your generated nitrogen would also be that much drier? I ask because for pumps running corrosives such as HCl, Cl2, BCl3, and HBr it would seem that dryness of the purge gas would be more important than the background oxygen content. Thank you all, John On 3/24/2015 1:31 PM, Tribble, Thomas wrote: > > Richard, > > We haven?t switched to onsite generation for the fab, but we (Harvard) > have looked at it. The Harvard fab has a 9000 gallon LN2- 3? storage > that gets re-filled approximately once a week. The storage facility > occupies approximately 300 GSF, and there is no more real estate > available for this purpose. Based upon a much smaller on-site > generator recently completed, on-site generation to replace the fab > storage facility would require more real estate than is available. > Part of the demand for space is the self-imposed requirement for N+1 > redundancy. This also affects the capital budget. > > But if saving money is your focus, I suggest that your discussion > should be focused on the purity of your gas requirements. Locally > generated 1? gas is inexpensive cheap to produce. Locally generated 3? > gas is moderately expensive to produce. Locally generated 6? gas is > *very* expensive to produce. From the refinery, 3? gas is all that is > produced and transported. What we at Harvard use is 6? gas (3? gas > run through a purifier). An unofficial audit has shown that less than > 10% of our usage actually demands 6? purity. > > Want to save money? Figure out your demand by purity and segregate > the flows (piping). Provide your pump and gas cabinet purges with > on-site generated 1? gas. Your facility will save. > > Tom Tribble > > *From:*labnetwork-bounces at mtl.mit.edu > [mailto:labnetwork-bounces at mtl.mit.edu] *On Behalf Of *Morrison, > Richard H., Jr. > *Sent:* Tuesday, March 24, 2015 12:04 PM > *To:* labnetwork at mtl.mit.edu > *Subject:* [labnetwork] LN2 vs N2 generation on site > > Hi everyone, > > I am paying >$220K per year for LN2 to generate Nitrogen for my fab. > Have any of you guys switched to onsite Nitrogen generator? > > Looking for ideas on: > > Cost of system > > Maintenance cost of system > > Quality of the Nitrogen. > > Operating cost per CuFt of Nitrogen > > Rick > > Draper Laboratory > > Principal Member of the Technical Staff > > Group Leader Microfabrication Operations > > 555 Technology Square > > Cambridge Ma, 02139-3563 > > www.draper.com > > rmorrison at draper.com > > W 617-258-3420 > > C 508-930-3461 > > ------------------------------------------------------------------------ > > Notice: This email and any attachments may contain proprietary (Draper > non-public) and/or export-controlled information of Draper Laboratory. > If you are not the intended recipient of this email, please > immediately notify the sender by replying to this email and > immediately destroy all copies of this email. > > ------------------------------------------------------------------------ > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From rmorrison at draper.com Fri Mar 27 14:08:13 2015 From: rmorrison at draper.com (Morrison, Richard H., Jr.) Date: Fri, 27 Mar 2015 18:08:13 +0000 Subject: [labnetwork] LN2 vs N2 generation on site In-Reply-To: <55157D51.2060805@stanford.edu> References: <2FA135939A3C9644A89D6AF332BE5FD6018D7AC3C8@harvandmbx05.fasmail.priv> <55157D51.2060805@stanford.edu> Message-ID: Hi Everyone, I would like to share with you some details. We have 2 3000 gallon tanks. Tank one feeds the Microfabrication Laboratory and is filled every other day. The 2nd tank feeds 3 different labs, Assembly, MCM and 5th Floor and is filled every 4th day, this systems is all SS from the tank to point if use. We do not use purifiers so I expect that even though the LN2 is 99.999% I have something less at the point of use. The Microfab is mostly dry boxes, N2 guns, purge for pumps, purge for 3 furnace tubes (oxidation) and 3 LPCVD system, poly, nitride and SiC. We run all dry pumps and have not had any problems using this gas stream. We shut of the SRD at night and weekend to save gas but I am still at a high flow. From the tank to the Microfab loop is all SS, the Microfab loop is oxygen free EP Copper silver soldered. Microfab runs 23 cuft to 34cuft/min (SRD dependant) MCM runs 3-6 cuft/min depending on tools usage Assembly 1-16 cuft/min depending on tool usage 5th Floor 1-5 cuft/min depending on tool usage The MCM, Assembly and 5th floor need oxygen free Nitrogen with no moisture; so my guess here 99.99% Nitrogen or 99.9%? The Microfabrication should be 99.99% or does it need 99.999%. We have never had our existing system analyzed, any ideas here? [cid:image002.png at 01D06897.7677FDB0] [cid:image004.png at 01D06897.7677FDB0] Thanks for your comments so far and I looked forward to more discussion. BTW after fees and surcharges I pay $1.23 per 100cuft and I use 1.45million cuft per month (data from flow meters). The company delivers the equivalent of 2.6million cuft so I lose to evaporation and cooling 1million cuft per month, does this sound right or do I have a big leak some place? Rick From: John Shott [mailto:shott at stanford.edu] Sent: Friday, March 27, 2015 11:55 AM To: Tribble, Thomas; Morrison, Richard H., Jr.; labnetwork at mtl.mit.edu; Nibarger, John Subject: Re: [labnetwork] LN2 vs N2 generation on site Rick: This is an excellent question and I thank Tom Tribble and John Nibarger for their initial contributions to this topic ... and others that will undoubtedly soon follow. First, let me get my remedial class question out of the way: Tom, you've got me feeling like a rank beginner. I must confess to being unfamiliar with the 1?, 3?, and 6? notation for gas purity. Is this the equivalent of what I know as dot notation? In other words, so they correspond to 1-, 3-, and 6-nines purity that is 1.0, 3.0, and 6.0 in dot notation? Where 99.5% purity is 2.5? Or is ? notation something different? I would like to add confirmation of your "unofficial audit" that found that 10% of your usage demands high purity. We also have a 9000 gallon LN2 tank (which, sadly, gets filled every fourth day). We have two sets of vaporizers on it: the big set supplies the copper-piped "house N2" and the smaller vaporizers that also go through a switchable set of purifiers and then feed our stainless-piped "UHP N2" system. Nouse N2 usage is dominated by pump purge. We have totalizing flow meters on each main line and typically observe that the UHP N2 consumption is 130-200 SLM and the house N2 consumption is 2500-2800 SLM. In other words our total nitrogen flow is very close to 3000 SLM (or about 4.5M - 5.0M SCF per month!). In other words, our high-purity consumption is in the range of 5-7% of our total consumption. Note: we actually use the house nitrogen for our SRDs ... if we moved that intermittent high-flow to UHP N2, it probably gets us close to, but no higher than, 10%. My question to the labnetwork community is what level of nitrogen purity would you want for pump purges of some of our nastier processes? For example, things like DCS and ammonia for LPCVD nitride? Hydrogen, germane, silane, plus dopants for an epitaxial process? is 1.0 nitrogen good enough? The way that I look at it, that is only a 50% reduction of oxygen as compared to what you find in air. How about 2.0 nitrogen (99%), good enough? And one question to John Nibarger: is the moisture content of your generated nitrogen controlled by the moisture content of your feed CDA? In other words, with your incoming CDA dew point of -40C is the dew point of your generated nitrogen also approximately -40C? If the incoming CDA were drier (say -55C to -60C) do you expect that your generated nitrogen would also be that much drier? I ask because for pumps running corrosives such as HCl, Cl2, BCl3, and HBr it would seem that dryness of the purge gas would be more important than the background oxygen content. Thank you all, John On 3/24/2015 1:31 PM, Tribble, Thomas wrote: Richard, We haven?t switched to onsite generation for the fab, but we (Harvard) have looked at it. The Harvard fab has a 9000 gallon LN2- 3? storage that gets re-filled approximately once a week. The storage facility occupies approximately 300 GSF, and there is no more real estate available for this purpose. Based upon a much smaller on-site generator recently completed, on-site generation to replace the fab storage facility would require more real estate than is available. Part of the demand for space is the self-imposed requirement for N+1 redundancy. This also affects the capital budget. But if saving money is your focus, I suggest that your discussion should be focused on the purity of your gas requirements. Locally generated 1? gas is inexpensive cheap to produce. Locally generated 3? gas is moderately expensive to produce. Locally generated 6? gas is very expensive to produce. From the refinery, 3? gas is all that is produced and transported. What we at Harvard use is 6? gas (3? gas run through a purifier). An unofficial audit has shown that less than 10% of our usage actually demands 6? purity. Want to save money? Figure out your demand by purity and segregate the flows (piping). Provide your pump and gas cabinet purges with on-site generated 1? gas. Your facility will save. Tom Tribble From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Morrison, Richard H., Jr. Sent: Tuesday, March 24, 2015 12:04 PM To: labnetwork at mtl.mit.edu Subject: [labnetwork] LN2 vs N2 generation on site Hi everyone, I am paying >$220K per year for LN2 to generate Nitrogen for my fab. Have any of you guys switched to onsite Nitrogen generator? Looking for ideas on: Cost of system Maintenance cost of system Quality of the Nitrogen. Operating cost per CuFt of Nitrogen Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image002.png Type: image/png Size: 41506 bytes Desc: image002.png URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image004.png Type: image/png Size: 38783 bytes Desc: image004.png URL: From spaolini at cns.fas.harvard.edu Fri Mar 27 16:15:19 2015 From: spaolini at cns.fas.harvard.edu (Paolini, Steven) Date: Fri, 27 Mar 2015 20:15:19 +0000 Subject: [labnetwork] LN2 vs N2 generation on site In-Reply-To: References: <2FA135939A3C9644A89D6AF332BE5FD6018D7AC3C8@harvandmbx05.fasmail.priv> <55157D51.2060805@stanford.edu> Message-ID: Some great info on this thread. I have nothing to add to Tom Tribble?s input except a sincere thank you for supplying me with a non- interruptive, constant N2 source. As a sort of side note, I would like to mention a way to save some N2 in wet process tools. Certain brands of SRD?s, SST?s and SAT?s are specified to have a nitrogen connection to an ?insurance? venturi. This venturi keeps the bowl seal under a negative pressure for when it fails in an effort to control particle distribution of the seal material. Some brands have a separate connection and others are fed from a common point. The units with a separate connection can be fed with CDA and others that are connected commonly will require some modification to split off the venturi feed from the rest of the n2 purge, dry, etc. Doing so can save an average of 1-2 LPM constant flow which can, and will add up. Steve Paolini Equipment Dood Harvard University Center for Nanoscale Systems From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Morrison, Richard H., Jr. Sent: Friday, March 27, 2015 2:08 PM To: John Shott; labnetwork at mtl.mit.edu Subject: Re: [labnetwork] LN2 vs N2 generation on site Hi Everyone, I would like to share with you some details. We have 2 3000 gallon tanks. Tank one feeds the Microfabrication Laboratory and is filled every other day. The 2nd tank feeds 3 different labs, Assembly, MCM and 5th Floor and is filled every 4th day, this systems is all SS from the tank to point if use. We do not use purifiers so I expect that even though the LN2 is 99.999% I have something less at the point of use. The Microfab is mostly dry boxes, N2 guns, purge for pumps, purge for 3 furnace tubes (oxidation) and 3 LPCVD system, poly, nitride and SiC. We run all dry pumps and have not had any problems using this gas stream. We shut of the SRD at night and weekend to save gas but I am still at a high flow. From the tank to the Microfab loop is all SS, the Microfab loop is oxygen free EP Copper silver soldered. Microfab runs 23 cuft to 34cuft/min (SRD dependant) MCM runs 3-6 cuft/min depending on tools usage Assembly 1-16 cuft/min depending on tool usage 5th Floor 1-5 cuft/min depending on tool usage The MCM, Assembly and 5th floor need oxygen free Nitrogen with no moisture; so my guess here 99.99% Nitrogen or 99.9%? The Microfabrication should be 99.99% or does it need 99.999%. We have never had our existing system analyzed, any ideas here? [cid:image001.png at 01D068A9.1C7D9BA0] [cid:image002.png at 01D068A9.1C7D9BA0] Thanks for your comments so far and I looked forward to more discussion. BTW after fees and surcharges I pay $1.23 per 100cuft and I use 1.45million cuft per month (data from flow meters). The company delivers the equivalent of 2.6million cuft so I lose to evaporation and cooling 1million cuft per month, does this sound right or do I have a big leak some place? Rick From: John Shott [mailto:shott at stanford.edu] Sent: Friday, March 27, 2015 11:55 AM To: Tribble, Thomas; Morrison, Richard H., Jr.; labnetwork at mtl.mit.edu; Nibarger, John Subject: Re: [labnetwork] LN2 vs N2 generation on site Rick: This is an excellent question and I thank Tom Tribble and John Nibarger for their initial contributions to this topic ... and others that will undoubtedly soon follow. First, let me get my remedial class question out of the way: Tom, you've got me feeling like a rank beginner. I must confess to being unfamiliar with the 1?, 3?, and 6? notation for gas purity. Is this the equivalent of what I know as dot notation? In other words, so they correspond to 1-, 3-, and 6-nines purity that is 1.0, 3.0, and 6.0 in dot notation? Where 99.5% purity is 2.5? Or is ? notation something different? I would like to add confirmation of your "unofficial audit" that found that 10% of your usage demands high purity. We also have a 9000 gallon LN2 tank (which, sadly, gets filled every fourth day). We have two sets of vaporizers on it: the big set supplies the copper-piped "house N2" and the smaller vaporizers that also go through a switchable set of purifiers and then feed our stainless-piped "UHP N2" system. Nouse N2 usage is dominated by pump purge. We have totalizing flow meters on each main line and typically observe that the UHP N2 consumption is 130-200 SLM and the house N2 consumption is 2500-2800 SLM. In other words our total nitrogen flow is very close to 3000 SLM (or about 4.5M - 5.0M SCF per month!). In other words, our high-purity consumption is in the range of 5-7% of our total consumption. Note: we actually use the house nitrogen for our SRDs ... if we moved that intermittent high-flow to UHP N2, it probably gets us close to, but no higher than, 10%. My question to the labnetwork community is what level of nitrogen purity would you want for pump purges of some of our nastier processes? For example, things like DCS and ammonia for LPCVD nitride? Hydrogen, germane, silane, plus dopants for an epitaxial process? is 1.0 nitrogen good enough? The way that I look at it, that is only a 50% reduction of oxygen as compared to what you find in air. How about 2.0 nitrogen (99%), good enough? And one question to John Nibarger: is the moisture content of your generated nitrogen controlled by the moisture content of your feed CDA? In other words, with your incoming CDA dew point of -40C is the dew point of your generated nitrogen also approximately -40C? If the incoming CDA were drier (say -55C to -60C) do you expect that your generated nitrogen would also be that much drier? I ask because for pumps running corrosives such as HCl, Cl2, BCl3, and HBr it would seem that dryness of the purge gas would be more important than the background oxygen content. Thank you all, John On 3/24/2015 1:31 PM, Tribble, Thomas wrote: Richard, We haven?t switched to onsite generation for the fab, but we (Harvard) have looked at it. The Harvard fab has a 9000 gallon LN2- 3? storage that gets re-filled approximately once a week. The storage facility occupies approximately 300 GSF, and there is no more real estate available for this purpose. Based upon a much smaller on-site generator recently completed, on-site generation to replace the fab storage facility would require more real estate than is available. Part of the demand for space is the self-imposed requirement for N+1 redundancy. This also affects the capital budget. But if saving money is your focus, I suggest that your discussion should be focused on the purity of your gas requirements. Locally generated 1? gas is inexpensive cheap to produce. Locally generated 3? gas is moderately expensive to produce. Locally generated 6? gas is very expensive to produce. From the refinery, 3? gas is all that is produced and transported. What we at Harvard use is 6? gas (3? gas run through a purifier). An unofficial audit has shown that less than 10% of our usage actually demands 6? purity. Want to save money? Figure out your demand by purity and segregate the flows (piping). Provide your pump and gas cabinet purges with on-site generated 1? gas. Your facility will save. Tom Tribble From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Morrison, Richard H., Jr. Sent: Tuesday, March 24, 2015 12:04 PM To: labnetwork at mtl.mit.edu Subject: [labnetwork] LN2 vs N2 generation on site Hi everyone, I am paying >$220K per year for LN2 to generate Nitrogen for my fab. Have any of you guys switched to onsite Nitrogen generator? Looking for ideas on: Cost of system Maintenance cost of system Quality of the Nitrogen. Operating cost per CuFt of Nitrogen Rick Draper Laboratory Principal Member of the Technical Staff Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork ________________________________ Notice: This email and any attachments may contain proprietary (Draper non-public) and/or export-controlled information of Draper Laboratory. If you are not the intended recipient of this email, please immediately notify the sender by replying to this email and immediately destroy all copies of this email. ________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.png Type: image/png Size: 41506 bytes Desc: image001.png URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image002.png Type: image/png Size: 38783 bytes Desc: image002.png URL: From savitha.p at ece.iisc.ernet.in Mon Mar 30 05:49:04 2015 From: savitha.p at ece.iisc.ernet.in (savitha.p) Date: Mon, 30 Mar 2015 15:19:04 +0530 Subject: [labnetwork] Smoke detectors in the clean room Message-ID: Hi! We had a fire recently inside the cleanroom and our smoke detectors did not give any warning even though the fire was burning for ~5min before it was put out. We currently have smoke detectors, a VESDA system installed inside the room with 3 detectors, one at the plenum level, one in the room and one under the raised floor (room is square shaped with ~700 sq.ft area, Class 1000). We were wondering how the other fabs handle these kind of situations. What is the ideal distance between smoke detectors and how do you ensure that the smoke is driven over the detectors no matter what the location of the fire is. Please let us know your thoughts on this matter. Thanks and regards, Savitha ____________________________________________ Dr.Savitha P, Technology Manager National Nanofabrication Centre, Centre for Nanoscience and Engineering Indian Institute of Science Bangalore - 560012 India. Ph: +91 80 2293 3254 www.cense.iisc.ernet.in -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. From myoung6 at nd.edu Mon Mar 30 09:26:12 2015 From: myoung6 at nd.edu (Mike Young) Date: Mon, 30 Mar 2015 09:26:12 -0400 Subject: [labnetwork] Smoke detectors in the clean room In-Reply-To: References: Message-ID: <43D7E05E-0266-439E-8A13-8F787DA34C20@nd.edu> Unless I am missing something, in most jurisdictions, this is determined entirely by the applicable building and/or fire code(s). Cleanroom management generally have no say in the matter. --Mike > On Mar 30, 2015, at 5:49 AM, savitha.p wrote: > > Hi! > > We had a fire recently inside the cleanroom and our smoke detectors did not give any warning even though the fire was burning for ~5min before it was put out. We currently have smoke detectors, a VESDA system installed inside the room with 3 detectors, one at the plenum level, one in the room and one under the raised floor (room is square shaped with ~700 sq.ft area, Class 1000). > > We were wondering how the other fabs handle these kind of situations. What is the ideal distance between smoke detectors and how do you ensure that the smoke is driven over the detectors no matter what the location of the fire is. > > Please let us know your thoughts on this matter. > > Thanks and regards, > > Savitha > > ____________________________________________ > > > Dr.Savitha P, > Technology Manager > National Nanofabrication Centre, > Centre for Nanoscience and Engineering > Indian Institute of Science > Bangalore - 560012 > India. > Ph: +91 80 2293 3254 > www.cense.iisc.ernet.in > > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -- Michael P. Young (574) 631-3268 (office) Nanofabrication Specialist (574) 631-4393 (fax) Department of Electrical Engineering (765) 637-6302 (cell) University of Notre Dame mike.young at nd.edu B-38 Stinson-Remick Hall Notre Dame, IN 46556-5637 -------------- next part -------------- An HTML attachment was scrubbed... URL: From mfcchung at ust.hk Mon Mar 30 09:57:24 2015 From: mfcchung at ust.hk (mfcchung) Date: Mon, 30 Mar 2015 21:57:24 +0800 Subject: [labnetwork] =?utf-8?b?5Zue5b6p77yaUmU6ICBTbW9rZSBkZXRlY3RvcnMg?= =?utf-8?q?in_the_clean_room?= Message-ID: An HTML attachment was scrubbed... URL: From Thomas_Ferraguto at uml.edu Mon Mar 30 09:32:44 2015 From: Thomas_Ferraguto at uml.edu (Ferraguto, Thomas) Date: Mon, 30 Mar 2015 13:32:44 +0000 Subject: [labnetwork] Free Vacuum Training with Kurt Lesker Message-ID: Colleagues You are invited to a free Training Session conducted by Kurt J. Lesker Company at the UMass Lowell Saab Emerging Technology and Innovation Center. Kurt J. Lesker is a leading component and equipment manufacture for thins films and semi-conductor processing equipment. The Course will cover: Vacuum Basics, Physical Vapor Deposition and Atomic Layer Deposition Basics Lunch will be served to registered attendees. Attendance is limited. **E-Mail Thomas_ferraguto at uml.edu if you would like to attend** The Event will be held in the Saab ETIC Atrium, April 9th 2015, 10:00 AM - 3:00 PM Thomas S. Ferraguto Saab ETIC Nanofabrication Laboratory Director University of Massachusetts Lowell 1 University Avenue Lowell MA 01854-5120 978-934-1809 land 617-755-0910 mobile 978-934-1014 fax [cid:image003.png at 01D06ACC.7928E420] -------------- next part -------------- A non-text attachment was scrubbed... Name: 15-062 KJLC-ShortCourseDatasheet-UMASS - FINAL.pdf Type: application/octet-stream Size: 675514 bytes Desc: not available URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image003.png Type: application/octet-stream Size: 57996 bytes Desc: not available URL: From myoung6 at nd.edu Mon Mar 30 12:30:49 2015 From: myoung6 at nd.edu (Mike Young) Date: Mon, 30 Mar 2015 12:30:49 -0400 Subject: [labnetwork] Free Vacuum Training with Kurt Lesker In-Reply-To: References: Message-ID: <0D214406-7DA5-49D3-A87D-3959D9FDD4ED@nd.edu> KJL gave a similar presentation here (at Notre Dame) a few weeks ago. I did not personally attend, but staff who did attend reported that it was time well spent. --Mike > On Mar 30, 2015, at 9:32 AM, Ferraguto, Thomas wrote: > > Colleagues > > You are invited to a free Training Session conducted by Kurt J. Lesker Company at the UMass Lowell Saab Emerging Technology and Innovation Center. > Kurt J. Lesker is a leading component and equipment manufacture for thins films and semi-conductor processing equipment. > The Course will cover: Vacuum Basics, Physical Vapor Deposition and Atomic Layer Deposition Basics > Lunch will be served to registered attendees. Attendance is limited. > **E-Mail Thomas_ferraguto at uml.edu if you would like to attend** > The Event will be held in the Saab ETIC Atrium, April 9th 2015, 10:00 AM - 3:00 PM > > > Thomas S. Ferraguto > Saab ETIC Nanofabrication Laboratory Director > University of Massachusetts Lowell > 1 University Avenue > Lowell MA 01854-5120 > 978-934-1809 land > 617-755-0910 mobile > 978-934-1014 fax > -- Michael P. Young (574) 631-3268 (office) Nanofabrication Specialist (574) 631-4393 (fax) Department of Electrical Engineering (765) 637-6302 (cell) University of Notre Dame mike.young at nd.edu B-38 Stinson-Remick Hall Notre Dame, IN 46556-5637 -------------- next part -------------- An HTML attachment was scrubbed... URL: From julia.aebersold at louisville.edu Mon Mar 30 20:14:40 2015 From: julia.aebersold at louisville.edu (julia.aebersold at louisville.edu) Date: Tue, 31 Mar 2015 00:14:40 +0000 Subject: [labnetwork] Smoke detectors in the clean room In-Reply-To: <43D7E05E-0266-439E-8A13-8F787DA34C20@nd.edu> References: , <43D7E05E-0266-439E-8A13-8F787DA34C20@nd.edu> Message-ID: I bet Abbie Gregg has a good response for the code standards here in the US. Cheers! Julia Aebersold, Ph.D. MNTC Cleanroom Manager University of Louisville 2210 South Brook Street Shumaker Research Building, Room 233 Louisville, KY 40292 (502) 852-1572 http://louisville.edu/micronano/ ________________________________ From: labnetwork-bounces at mtl.mit.edu [labnetwork-bounces at mtl.mit.edu] on behalf of Mike Young [myoung6 at nd.edu] Sent: Monday, March 30, 2015 9:26 AM To: Labnetwork Subject: Re: [labnetwork] Smoke detectors in the clean room Unless I am missing something, in most jurisdictions, this is determined entirely by the applicable building and/or fire code(s). Cleanroom management generally have no say in the matter. --Mike On Mar 30, 2015, at 5:49 AM, savitha.p > wrote: Hi! We had a fire recently inside the cleanroom and our smoke detectors did not give any warning even though the fire was burning for ~5min before it was put out. We currently have smoke detectors, a VESDA system installed inside the room with 3 detectors, one at the plenum level, one in the room and one under the raised floor (room is square shaped with ~700 sq.ft area, Class 1000). We were wondering how the other fabs handle these kind of situations. What is the ideal distance between smoke detectors and how do you ensure that the smoke is driven over the detectors no matter what the location of the fire is. Please let us know your thoughts on this matter. Thanks and regards, Savitha ____________________________________________ Dr.Savitha P, Technology Manager National Nanofabrication Centre, Centre for Nanoscience and Engineering Indian Institute of Science Bangalore - 560012 India. Ph: +91 80 2293 3254 www.cense.iisc.ernet.in _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -- Michael P. Young (574) 631-3268 (office) Nanofabrication Specialist (574) 631-4393 (fax) Department of Electrical Engineering (765) 637-6302 (cell) University of Notre Dame mike.young at nd.edu B-38 Stinson-Remick Hall Notre Dame, IN 46556-5637 -------------- next part -------------- An HTML attachment was scrubbed... URL: From shott at stanford.edu Tue Mar 31 09:26:04 2015 From: shott at stanford.edu (John Shott) Date: Tue, 31 Mar 2015 06:26:04 -0700 Subject: [labnetwork] LN2 vs N2 generation on site In-Reply-To: References: <2FA135939A3C9644A89D6AF332BE5FD6018D7AC3C8@harvandmbx05.fasmail.priv> <55157D51.2060805@stanford.edu> Message-ID: <551AA06C.8030505@stanford.edu> Rick: In an earlier message, you had commented about the large volume difference between what you use and what gets delivered. To me, something seems strange if you are getting 2.6M cuft per month but are using only a bit more than half of that. I believe that large LN2 tanks are noticeably more efficient than that for gaseous usage and would expect that the amount that you use to be at least 90% of what is delivered. Here is my understanding ... and I've tried to check these numbers out with our LN2 supplier: A big tank that is just sitting there (that is with little or no usage) would lose something like 0.5-1.0% per day due to heat transfer and gas that ends up getting vented but not used. However, for any system that is using a significant volume of product per day ... and yours clearly is ... I would expect that venting losses would be very close to zero. When you are using a significant volume of product, that would tend to reduce the pressure in the tank, the pressure building circuit kicks in ... but that doesn't result in any loss because the liquid that is vaporized to build pressure goes into your tank. There is certainly a significant loss anytime that you have a delivery ... and, if your vendor is like ours, you pay for all of that nitrogen. I believe that the largest fraction of that consumption is the nitrogen that is "depressurized" from the tanker following your fill to reduce the tanker pressure from above your tank pressure down to the legal limit for them to drive again on the highways which is, I think, 10 PSIG. The nitrogen consumed during your fill that never goes into your tank including pre- and post-fill purges and this tanker "blow down" is significant. Others may have a better number than I, but I count on losing at least 20,000 cuft of gas per delivery. On average, we get 8 deliveries per month of 600,000 cuft per delivery for a total delivered volume of about 4.8M cuft. So, losing 20,000 cuft per delivery is only a 3% loss. Of course, with a smaller tank, the per-fill loss percentage goes up assuming that they are still filling with a 53' trailer. Note: you will have higher losses if you are using liquid withdrawal to any degree because there is a fair volume of nitrogen that is "lost" as gaseous nitrogen for every liquid gallon that you extract. If your tank pressure is set up for gaseous usage with a tank pressure of 120-150 PSIG, then any liquid usage is probably not terribly efficient because of flash losses, etc. ... basically the gas that is vaporized in the process of getting things cooled down so that you get good liquid extraction. I don't have much experience in that area so can't really offer a precise number for loss during liquid withdrawal but that is likely to be significantly lower than the 90% number that I think you should expect for gaseous withdrawal. However, if your system is predominantly used as a source of gaseous nitrogen, I would expect that your overall efficiency should be closer to 90%. How well are your flow meters calibrated? Do you have flow meters on all possible usage? Are your flow meters fully temperature compensated or are you measuring gas that is noticeably colder than room temperature? Anecdotally, we just sent our two main flow meters out for calibration: when they came back, they are now giving readings that indicate that we are consuming more nitrogen than our vendor is supplying. In short, I'm not sure that I trust the absolute readings that I get off these big flow meters for an absolute reading. In short, if your tank is used predominantly for gaseous nitrogen, I would expect that your overall tank efficiency should be closer to 90% and would look carefully at whether I was monitoring all usage and whether my usage flow meters were giving me believable results. If your liquid withdrawal and usage are significant everything that I have said may be off base because I expect that liquid withdrawal is an inherently lower efficiency process. I trust that my colleagues will correct me if they believe that I've badly misstated things here. Good luck, John On 3/27/2015 11:08 AM, Morrison, Richard H., Jr. wrote: > Thanks for your comments so far and I looked forward to more > discussion. BTW after fees and surcharges I pay $1.23 per 100cuft and > I use 1.45million cuft per month (data from flow meters). The company > delivers the equivalent of 2.6million cuft so I lose to evaporation > and cooling 1million cuft per month, does this sound right or do I > have a big leak some place? -------------- next part -------------- An HTML attachment was scrubbed... URL: From len.olona at ou.edu Tue Mar 31 10:37:35 2015 From: len.olona at ou.edu (Olona, Leonard E.) Date: Tue, 31 Mar 2015 14:37:35 +0000 Subject: [labnetwork] Free Vacuum Training with Kurt Lesker In-Reply-To: <0D214406-7DA5-49D3-A87D-3959D9FDD4ED@nd.edu> References: <0D214406-7DA5-49D3-A87D-3959D9FDD4ED@nd.edu> Message-ID: KJL just finished a presentation here at OU. It was excellent. We had a very nice turn out from across the board. Physics, Mechanical, Electrical Engineering. -Len Leonard E. Olona Facility Manager RIL Cleanroom Manager University of Oklahoma web: http://arrc.ou.edu/ web: http://cleanroom.ou.edu/ voice: +1- 405- 325-4374 From: Mike Young > Date: Monday, March 30, 2015 11:30 AM To: "labnetwork at mtl.mit.edu" > Subject: Re: [labnetwork] Free Vacuum Training with Kurt Lesker KJL gave a similar presentation here (at Notre Dame) a few weeks ago. I did not personally attend, but staff who did attend reported that it was time well spent. --Mike On Mar 30, 2015, at 9:32 AM, Ferraguto, Thomas > wrote: Colleagues You are invited to a free Training Session conducted by Kurt J. Lesker Company at the UMass Lowell Saab Emerging Technology and Innovation Center. Kurt J. Lesker is a leading component and equipment manufacture for thins films and semi-conductor processing equipment. The Course will cover: Vacuum Basics, Physical Vapor Deposition and Atomic Layer Deposition Basics Lunch will be served to registered attendees. Attendance is limited. **E-Mail Thomas_ferraguto at uml.edu if you would like to attend** The Event will be held in the Saab ETIC Atrium, April 9th 2015, 10:00 AM - 3:00 PM Thomas S. Ferraguto Saab ETIC Nanofabrication Laboratory Director University of Massachusetts Lowell 1 University Avenue Lowell MA 01854-5120 978-934-1809 land 617-755-0910 mobile 978-934-1014 fax -- Michael P. Young (574) 631-3268 (office) Nanofabrication Specialist (574) 631-4393 (fax) Department of Electrical Engineering (765) 637-6302 (cell) University of Notre Dame mike.young at nd.edu B-38 Stinson-Remick Hall Notre Dame, IN 46556-5637 -------------- next part -------------- An HTML attachment was scrubbed... URL: From pestal at eecs.berkeley.edu Tue Mar 31 14:00:17 2015 From: pestal at eecs.berkeley.edu (Danny Pestal) Date: Tue, 31 Mar 2015 11:00:17 -0700 Subject: [labnetwork] LN2 vs N2 generation on site In-Reply-To: <551AA06C.8030505@stanford.edu> References: <2FA135939A3C9644A89D6AF332BE5FD6018D7AC3C8@harvandmbx05.fasmail.priv> <55157D51.2060805@stanford.edu> <551AA06C.8030505@stanford.edu> Message-ID: All, To add some information on liquid nitrogen boil-off / loss: In 2007 the UC Berkeley Microlab did a survey of our nitrogen usage in order to confirm the accuracy of our metrology before moving to a recharge model for nitrogen use in labs not directly associated with the Microlab. >From this analysis we discovered an 8% discrepancy between the amount of nitrogen we were consuming versus the amount of nitrogen we were being delivered. This number is from a 9000 gallon tank, with purely gaseous use, that was being drawn on at the time at about 1800 L/m. Danny Pestal Facilities Manager Marvell NanoLab University of California, Berkeley 510-809-8600 On Tue, Mar 31, 2015 at 6:26 AM, John Shott wrote: > Rick: > > In an earlier message, you had commented about the large volume difference > between what you use and what gets delivered. To me, something seems > strange if you are getting 2.6M cuft per month but are using only a bit > more than half of that. > > I believe that large LN2 tanks are noticeably more efficient than that for > gaseous usage and would expect that the amount that you use to be at least > 90% of what is delivered. > > Here is my understanding ... and I've tried to check these numbers out > with our LN2 supplier: > > A big tank that is just sitting there (that is with little or no usage) > would lose something like 0.5-1.0% per day due to heat transfer and gas > that ends up getting vented but not used. However, for any system that is > using a significant volume of product per day ... and yours clearly is ... > I would expect that venting losses would be very close to zero. When you > are using a significant volume of product, that would tend to reduce the > pressure in the tank, the pressure building circuit kicks in ... but that > doesn't result in any loss because the liquid that is vaporized to build > pressure goes into your tank. > > There is certainly a significant loss anytime that you have a delivery ... > and, if your vendor is like ours, you pay for all of that nitrogen. I > believe that the largest fraction of that consumption is the nitrogen that > is "depressurized" from the tanker following your fill to reduce the tanker > pressure from above your tank pressure down to the legal limit for them to > drive again on the highways which is, I think, 10 PSIG. The nitrogen > consumed during your fill that never goes into your tank including pre- and > post-fill purges and this tanker "blow down" is significant. Others may > have a better number than I, but I count on losing at least 20,000 cuft of > gas per delivery. On average, we get 8 deliveries per month of 600,000 > cuft per delivery for a total delivered volume of about 4.8M cuft. So, > losing 20,000 cuft per delivery is only a 3% loss. Of course, with a > smaller tank, the per-fill loss percentage goes up assuming that they are > still filling with a 53' trailer. > > Note: you will have higher losses if you are using liquid withdrawal to > any degree because there is a fair volume of nitrogen that is "lost" as > gaseous nitrogen for every liquid gallon that you extract. If your tank > pressure is set up for gaseous usage with a tank pressure of 120-150 PSIG, > then any liquid usage is probably not terribly efficient because of flash > losses, etc. ... basically the gas that is vaporized in the process of > getting things cooled down so that you get good liquid extraction. I don't > have much experience in that area so can't really offer a precise number > for loss during liquid withdrawal but that is likely to be significantly > lower than the 90% number that I think you should expect for gaseous > withdrawal. However, if your system is predominantly used as a source of > gaseous nitrogen, I would expect that your overall efficiency should be > closer to 90%. > > How well are your flow meters calibrated? Do you have flow meters on all > possible usage? Are your flow meters fully temperature compensated or are > you measuring gas that is noticeably colder than room temperature? > Anecdotally, we just sent our two main flow meters out for calibration: > when they came back, they are now giving readings that indicate that we are > consuming more nitrogen than our vendor is supplying. In short, I'm not > sure that I trust the absolute readings that I get off these big flow > meters for an absolute reading. In short, if your tank is used > predominantly for gaseous nitrogen, I would expect that your overall tank > efficiency should be closer to 90% and would look carefully at whether I > was monitoring all usage and whether my usage flow meters were giving me > believable results. If your liquid withdrawal and usage are significant > everything that I have said may be off base because I expect that liquid > withdrawal is an inherently lower efficiency process. > > I trust that my colleagues will correct me if they believe that I've badly > misstated things here. > > Good luck, > > John > > > On 3/27/2015 11:08 AM, Morrison, Richard H., Jr. wrote: > > Thanks for your comments so far and I looked forward to more discussion. > BTW after fees and surcharges I pay $1.23 per 100cuft and I use 1.45million > cuft per month (data from flow meters). The company delivers the equivalent > of 2.6million cuft so I lose to evaporation and cooling 1million cuft per > month, does this sound right or do I have a big leak some place? > > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork > > -------------- next part -------------- An HTML attachment was scrubbed... URL: From spaolini at cns.fas.harvard.edu Tue Mar 31 16:26:22 2015 From: spaolini at cns.fas.harvard.edu (Paolini, Steven) Date: Tue, 31 Mar 2015 20:26:22 +0000 Subject: [labnetwork] Convectron gauges Message-ID: Greeting fellow Nanofabbers, Has anyone experienced frequent failures of convectron style vacuum gauges in a Xenon Difluoride etcher? I chose to use this style because it is important for us to observe vacuum over a wide range for this process, but within 10 hours of running time, the readout displays "bad sensor" or the gauge will not read above 3 Torr. I have been using a major vacuum component supplier's version of a popular manufacturer's gauge and we have an isolation valve that closes during process. I suspect residual XeF2 is the culprit but I would like to hear from the community if there have been similar failures. Thanks! Steve Paolini Principal Equipment Engineer Harvard University Center for Nanoscale Systems 617- 496- 9816 spaolini at cns.fas.harvard.edu www.cns.fas.harvard.edu -------------- next part -------------- An HTML attachment was scrubbed... URL: