[labnetwork] updated survey

Thu May 18 10:58:13 EDT 2017

Hi Steven,

Like you, I have worked as a fab rat for numerous years and have observed the same diversity you mention.  Intel has studied the effects of different gowns, hoods, boots, gloves and wipe-down methods to exhaustion.  None of our nano-facilities, however, will need to meet the expectations Intel has with their processor business in the next two decades.  I have also worked in classes 1 through 10000, and in the 1k and 10k spaces I have seen and used the booties, hairnets and lab coats you mention.  Most of them had high flow HEPA regions directly over the areas operators introduced material (like a mini-environment).  Most experienced lint, occasionally, on final product... trapped under a film.  The majority of these were due to long-sleeved shirts and sweaters of personnel as they reached in to remove their gowns from the hangar.  The lint would transfer to adjacent gowns, and then get blown on to the product during production activity.  This can be avoided by banning sweaters, and by allowing hangars to be removed from their positions in the rack so that one’s arm does not need to reach in to retrieve it.  If a user was laying down a critical film, and lint was an issue…it would be an issue whether they were wearing a lab coat or a full gown… the source of the lint would likely have originated in the gown room, and that’s where the control needs to take place.

Even with our full gown protocols, we still occasionally need to reemphasize to the user group the importance of not wearing particle generating items (cosmetics, colognes, dangling earrings, scarves and sweaters), and to fully cover their hair and beards.  Poor hygiene itself can lead to significant particle generation.

As for the benefit, well there are other costs to argue besides full- versus partial-gowns.  The cleaning of horizontal surfaces in a modern CR of Class 10/100, with a recirculating system and a small amount of makeup air, has proven here to be of high importance; the cost of keeping the CR clean must also be assessed.  If gowns were not to be used, there would likely be a higher amount of particulate being filtered and, therefore, higher filter replacement frequency, and a more frequent need to wipe surfaces, etc. and all of these activities are cost intensive.  Especially if the staff were doing the work, because now their time would be pulled away from equipment and process activities.

The aforementioned are my thoughts and observations and I’ve been shown wrong before, but I think their may be cost benefits to wearing gowns if all costs are accounted for.

We are planning on doing a study and analysis on this subject once we are completed with our move to the new facility.

I’m sure there might be some data available, however, from Intel’s studies of these issues…

Best regards,

________________________________________________________________

Mark Weiler
Fab Equipment Manager
CMU Nanofabrication Facility
Dept. of Electrical & Computer Engineering
5000 Forbes Avenue
Pittsburgh, PA 15213
P:  412-268-2471
F:  412-268-4323
www.ece.cmu.edu<http://www.ece.cmu.edu>

[cid:2D2E01E3-CEC1-4F48-A845-224D8D7CED12 at wv.cc.cmu.edu] <https://www.linkedin.com/in/marksbasics>
<https://www.linkedin.com/in/marksbasics>
On May 17, 2017, at 3:09 PM, Paolini, Steven <spaolini at cns.fas.harvard.edu<mailto:spaolini at cns.fas.harvard.edu>> wrote:

Not to start a national debate but has anybody ever seen a comprehensive study of the benefits of full gowning versus the expense and trouble? As a former Field service engineer and long time fab rat, I have visited many sites and no two follow the same protocol. The interesting part of this is that every site believes that theirs is the best. How can something that’s fairly scientific be so subjective? I do notice that all of these sites are of the “wrap em’ up”  method, but my perennial question is “at what expense?” Is the ten minutes lost to dash out of the clean room to retrieve an item worth whatever benefit full gowning provides? Has anyone ever estimated if the loss of working time because of the added activity is worth the effort? I am a firm believer in that higher air changes per hour is the best contributor to a clean room’s performance. I do doubt however, that the obstacle of full gowning in a clean room class 100 or dirtier offers little, if any, contribution to the overall room performance.
After donning bunny suits for more than 35 years, I have yet to find a comprehensive study on this subject. I have seen many a paper written that emphasizes high particle counts on personnel that aren’t fully gowned but that’s half of the equation, If loss of productivity and general work habit change is factored in, does it become a “non value add” activity? Wouldn’t it be nice if you could just wear booties, a hairnet, and lab coat without any detrimental effects to your space?
I think the microelectronic and nanofabrication community has been influenced by the larger fabs in that whatever they do must be the right thing. It’s been many years since we have been gowning up to enter a clean space but maybe it’s time to determine if the trouble and expense equate to the benefit. Other industries that are under constant expense pressure have altered their methods to lower costs. The food packaging business for example has moved from providing a clean general space to mini environments in which critical process steps are done in a high HEPA flow area directed at the product.
 Is there anyone in this network that questions this practice and has access to a good scientific study that might help settle this (my) dispute? Is there anyone here that can support my claim of full gowning to be high cost/low benefit ?
Thanks for listening.

Steve Paolini
Principal Equipment Engineer
Harvard University Center for Nanoscale Systems
11 Oxford St.
Cambridge, MA 02138
617- 496- 9816
spaolini at cns.fas.harvard.edu<mailto:spaolini at cns.fas.harvard.edu>
www.cns.fas.harvard.edu<http://www.cns.fas.harvard.edu/>

From: labnetwork-bounces at mtl.mit.edu<mailto:labnetwork-bounces at mtl.mit.edu> [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Ferraguto, Thomas
Sent: Wednesday, May 17, 2017 12:45 PM
To: labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
Subject: [labnetwork] updated survey

Here’s the updated flash survey for ERP Systems and Interlocks.

On a side note, I did a video audit of our “Honor System” run lab and we did not book 31% of the Activity.

Institution

System

FTE's

Interlocks

Total

52% Home Grown

0.60

83.3%

UC Davis

Badger

0.25

Yes

University of Houston

Home Grown

0.0025

No

Stanford

Badger

0

Yes

University of Utah

Coral

1

Yes

University of Freiburg

Home Grown/w Coral

1

Yes

MIT

Coral

1

Yes

Delft University

Phoenix

2

Yes

University of Delaware

FOM

0.1

Yes

UNC

Home Grown

0.1

No

UC San Diego

FOM

0.25

Yes

University of Louisville

FOM

0.1

Yes

UMass Lowell

FOM

0.2

No

Purdue

Ilab

2

Yes

EPFL-Lausanne-Switzerland:

Home Grown

1

Yes

Cal-Tech

Home Grown/Labrunr

0.3

Yes

University of Texas

Home Grown

0.2

Yes

Harvard

Home Grown

0.1

Yes

Berkeley

Home Grown

0.75

Yes

UCSB

Home Grown/SignupMonkey

0.125

No

Washington Nanofabrication Facility (WNF)

Home Grown/w Coral

1

Yes

Georgia Tech

Home Grown SUMS

2

Yes

Columbia University

Badger

0

Yes

University of Alberta

Home Grown LMACS

0.5

Yes

University of Florida

Home Grown

0.5

Yes

Best Regards

Tom

Thomas S. Ferraguto
Saab ETIC Nanofabrication Laboratory Director
Saab ETIC Building Director
1 University Avenue
Lowell MA 01854
Mobile 617-755-0910
Land 978-934-1809
Fax 978-934-1014

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