[labnetwork] HPM gas survey

[Iulian Codreanu]

Hi Michael,

Please see below for a summary of hat I have:
-I run all hazardous gases (3 or more on the fire diamond) in coaxial 
lines; both the inner and outer tube are 316L SS.
-The coaxial lines do not use any preformed directional changes; both 
the inner and outer tubes are welded; the bend radius is 10 diameters.
-The coaxial space is either under vacuum or pressure (on the lines I 
warm up) and the vacuum/pressure is monitored; any change leads to valve 
closure and notifications.
-The only hazardous gas cylinder I have in the cleanroom is BCl3 because 
I wanted it close to the etcher; I may put future low vapor pressure 
hazardous cylinders in the cleanroom. I warm up the line that runs from 
the gas cabinet to the etcher. I also warm up the cylinder and the 
manifold inside the gas cabinet.
-I do not have a pressure regulator in the BCl3 cabinet.
-All my gas cabinets are single-panel, dual output; I am using only one 
output for now.
-I use 4-stick VMBs (except for BCl3; the cabinet is connected directly 
to the etcher).
-I have a Gas Room that houses the corrosive gas cabinets and some 
"non-hazardous" cylinders outside of gas cabinets; the space is 
monitored for O2 concentration.
-I have a Bunker that houses the flammable and pyrophoric gases in 
cabinets; any future GeH4, PH3, B2H6 will go in there; the space is 
monitored for O2 concentration.
-The exhaust from the gas cabinets and VMBs is sampled for hazardous gases.
-The flammable gas cabinets and VMBs have UV/IR sensors that get power 
from and report to the Fire Alarm System (FAS). The FAS is connected to 
the TGMS and the TGMS can close valves in the gas cabinets, VMBs, and tools.
-All gas cabinets and VMBs are sprinklered.
-My C4F8 panel has two outputs; one is currently used and one is for the 
future. They tee off downstream of the pressure regulator.

I hope this helps and I wish you the best of luck,

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 12/6/2016 10:17 AM, Michael Khbeis wrote:
> Dear Colleagues,
>
> Once again, I am pitted against my capital projects group. This time 
> regarding HPM gas infrastructure. Thanks to your prior input, we were 
> able to obtain a proper toxic gas monitoring system. However, now I am 
> in a code interpretation debate with their process piping consultants 
> on the use of VMBs for multi-tool feeds and coaxial lines. They don't 
> want either in our project. They specified hastelloy for Chlorine and 
> BCl3 but single walled 316ss (after much debate that 304 was not 
> sufficient) for all our other gasses. In ALL my prior sites we always 
> used coaxial lines as a secondary containment for HPMs, but currently 
> this project has no coax specified.
>
> I am also in debate on whether or not 100% hydrogen (large 330cf 
> cylinders) can be in the Cleanroom without a cabinet vs a bunker in a 
> cabinet. Their interpretation is that an H-5 facility can store 
> 9000cf; however, I believe they are ignoring the vented enclosure 
> requirements.
>
> We will have the following HPM gasses:
> 100% Silane
> 100% Hydrogen
> Ammonia
> Chlorine
> Boron Trichloride
> Phosphine
> Diborane
>
> Can you please weigh in on your sites use of:
>
> 1) coaxial lines, which gasses and if any HPMs are excluded or use 
> single hastelloy
>
> 2) use of valve manifold boxes / vented enclosures for distributing 
> HPMs to multiple tools (or anywhere else there's a mechanical connection)
>
> 3) location and enclosure or not for 100% hydrogen
>
> And on a non-safety related note, we asked for panels with multi-stick 
> feeds to each tool; however, the process piping designer just teed all 
> of our lines from a single point and put a regulator at each tool 
> instead to "save money". I am very concerned about LP gasses (e.g 
> C4F8) being starved when multiple tools are running. We distinctly had 
> issues with past lab with shared C4F8 bottles. Their recommendation is 
> to ONLY heat the cylinder to increase vapor pressure, but given my 
> limited knowledge, I believe with high flow rate and lacking heating 
> of the panel and lines we will have gas condensation issues. To date, 
> my input is still being dismissed so please state:
>
> 4) how you handle LP gas distribution to multiple tools
>
> I thank you so much for taking the time out of your busy schedules to 
> provide this input. This community/forum has been such a blessing.
>
> Most gratefully,
>
> Dr. Michael Khbeis
> Washington Nanofab Facility
> University of Washington
> Fluke Hall, Box 352143
> (O) 206.543.5101 <tel:206.543.5101>
> (C) 443.254.5192 <tel:443.254.5192>
> khbeis at uw.edu <mailto:khbeis at uw.edu>
>
>
> _______________________________________________
> 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: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20161208/9c5a2b04/attachment.html>