[labnetwork] Silane Installation below grade

Fri Dec 8 23:25:39 EST 2017

Hi All,
I am sorry to hear that someone provided a design that could not work for you, James.
AGI participated in the Harvard LISE Nanofab design and more  recently in the U of Chicago WERC Nanofab  and  USC MCB Nanofab Designs of the H occupancy cleanrooms below grade. In general, although these were all covered by different codes, the following allowed them to be constructed with the full approval of the Authorities having jurisdiction. We have had success with this approach on both level and sloped sites. Duke University FCIEMAS and the UC Berkeley Nanofab use similar techniques due to their unique locations on a sloped site.

1-     The HPM (H-2/4 and H-3/4) storage and dispense rooms (gas cabinet and bottle location) were located AT Grade, even though the H-5 occupancy for the Nanofab is  below grade. The gases were piped down to the cleanroom in stainless steel tubing (double wall in the required cases) with gas monitoring,  via properly separated shafts with firestopping etc. This worked very well and did not require hazardous gas bottles such as those for Highly toxic or pyrophoric gases to travel anyplace but a few feet from the loading dock or outdoors, directly to HPM rooms at grade. These HPM rooms have exposed outside walls (25% of perimeter), doors to outside, explosion venting, explosion proof lighting  etc….  Only the tubing with a very small amount of hazardous gas at much lower pressure travels to the Cleanroom and labs below for use in process tools.

2-     Note that there is a calculation in the code to establish exactly where the “grade plane” is, and how much of the floor is “below grade”. Thus , the Harvard HPM rooms are NOT actually located Below grade according to the calculation at that time. However, a variance was also obtained related to the canopy over the loading dock. .

3-     Fire department approach and egress of occupants are provided by a large Areaway and stair from the Lower level cleanroom to allow for proper egress from the H-5 Occupancy below grade. Fire departments have varying ideas of how they would like those areaways and access stairs to be configured, based on their equipment and local codes. It is essential to configure the areaway to meet their needs.

4-     In all cases a few conversations with the local fire department, building officials and other authorities having jurisdiction are strongly suggested to be done early!  Often a variance is required, which has not been denied,  after a collaborative design, in our experience. Our experience with this continues to the present day all over the USA and abroad. The use of SEMs and EBeam lithography as well as TEMs, and other vibration sensitive tools to support Nanofabrication efforts in clean or close to clean environments,  have pushed nanofabs in urban or otherwise vibration and EMI  prone settings, to want the cleanrooms below grade where abatement of disturbances occurs, and  better tool performance is possible.

Best Regards,

Abbie Gregg
President
Abbie Gregg, Inc.
1130 East University Drive, Suite 105
Tempe, Arizona 85281
Phone 480 446-8000 x 107
Cell 480-577-5083
FAX 480-446-8001
email agregg at abbiegregg.com<mailto:agregg at abbiegregg.com>
website www.abbiegregg.com<http://www.abbiegregg.com>

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From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of James C. Sturm
Sent: Friday, December 8, 2017 6:39 AM
To: Paul, Jack <Jack.Paul at hdrinc.com>; Michael Hume <michael.hume at ualberta.ca>; labnetwork at mtl.mit.edu
Subject: Re: [labnetwork] Silane Installation below grade

One other note we ran up against in Princeton about 10-15 years ago:    The Harvard lab (built perhaps 15-20 years ago) is below grade, but on one side the ground was somewhat excavated to let some minimal daylight in, so you might claim it is not below grade.     As a result, they were able to either store (maybe) or use (that I’m fairly sure about) silane in the lab.    We were designing a new building in a tight space, with  some highly-paid consultants and architects who were supposedly experts on lab design and fire codes.    They  came up for us with something similar following the Harvard approach.   After the design was done (and we had paid them), it turned out we found out that the national code  (IBC, IFC??) that had allowed the Harvard approach had changed (which our “experts” were not at all aware of), so their design (and all the time we sunk into it) was worthless, and we had to start over (with new consultants.)   I don’t recall the exact technical details about H use and B use  (are those the right terms?) but that is the gist of the story.    )#)$#&*$(#&#$(#*(#&@!!
So Beware (and be safe)
Jim Sturm

********************************************
Prof. James C. Sturm
     Stephen R. Forrest Professor in Electrical Engineering
     Princeton University
     B410 E-Quad, Olden St.
    Princeton, NJ  08540
    609-258-5610, fax:  609-258-1177
    sturm at princeton.edu<mailto:sturm at princeton.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 Paul, Jack
Sent: Thursday, December 07, 2017 8:37 PM
To: Michael Hume <michael.hume at ualberta.ca<mailto:michael.hume at ualberta.ca>>; labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
Subject: Re: [labnetwork] Silane Installation below grade

Michael,
The building and fire codes in your jurisdiction (Edmonton) are probably different than the International Building and Fire Codes, but the general approach of those codes (IBC and IFC) is to restrict hazardous materials in basements because a) it is extremely difficult to fight fires at basement level, and b) basements are harder to exit, and c) typically basements cannot have explosion venting (as John Schott noted they had at Stanford).

As a pyrophoric gas, silane deflagrates extremely fast – almost fast enough to be officially labeled an “explosion” and thus when it is stored indoors it is often required to have an explosion vent (this is the lightly fastened roof structure that John mentioned in his email).

The IBC and IFC restrict the quantity of any pyrophoric material allowable in a single control area (i.e. one floor, or one fire-wall isolated area of a floor) to maximum of 4 lbs or 50 cu ft in storage, and 10 cu ft in “use-closed system”.  As I noted, your jurisdiction in Canada probably has not adopted the IBC and IFC, but my guess is that whatever code applies in your municipality, it will have similar restrictions.  Additionally, it may also refer to CGA G13 (as does the IFC) for design requirements for silane systems, thus adopting CGA-13 by reference.

In short – you may be violating building and fire code restrictions by placing the silane in the basement level.  Your campus architect or fire marshal should be able to provide guidance, or alternatively a friendly architect or lab planner.

Jack Paul, RA, LEED AP BD+C
D 602.474.3940  M 602.369.2086
hdrinc.com/follow-us<http://hdrinc.com/follow-us>

From: labnetwork-bounces at mtl.mit.edu<mailto:labnetwork-bounces at mtl.mit.edu> [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Michael Hume
Sent: Thursday, December 7, 2017 11:05 AM
To: labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
Subject: [labnetwork] Silane Installation below grade

Hello Colleagues,

We are in the process if installing a new PECVD system which will use 100% SiH4. In reviewing CGA-G13, it states:

7.2 Indoor storage and use
Buildings, rooms, or areas used for silane storage shall be constructed in accordance with the requirements of the local AHJ. Silane shall not be stored in locations below grade and silane bulk sources shall not be located indoors. For transfilling exceptions, see Section 18.

In our case, an installation below grade may be preferred. I am wondering if anyone can provide any insight into the reasoning behind this. Does anybody store/use Silane below grade?

Thank-you,
-Mike.

--

PLEASE NOTE MY PHONE NUMBER HAS CHANGED: 780-953-5081

Michael Hume

Operations Manager

University of Alberta - nanoFAB

W1-060 ECERF Building

9107 - 116 Street

Edmonton, Alberta

Canada T6G 2V4
www.nanofab.ualberta.ca<http://www.nanofab.ualberta.ca/> Ph: 780-953-5081* (New)
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