special materials request

Mary Tang mtang at snf.stanford.edu
Fri Jan 23 08:37:11 PST 2004

Hi Charles --

I'm sorry, but we don't seem to have a record of Tze Wee ever submitting a request
for PVA, at least not to specmat at snf -- I hope this has not caused a serious delay in
your experiments...

PVA has been approved for use in the lab, but we still like to see requests and MSDS
sheets since, as you know, there are so many formulations and some are not as benign
as yours.

Also, I still have a couple of questions regarding your process flow, and if you
could correct/clarify, it would be much appreciated.  I take it that your process is:

headway spin/cure on a hotplate
etch substrate in drytek2
analyze on nanospec, ellipsometer, semhitachi
do you plan on stripping the PVA?  I take it that this will be at wbgeneral?

If this is, indeed the case, then I take it that we will not have to worry about
disposal (waste from the headway will be taken up in foil and disposed of in the
hazardous waste can; if you strip at wbgeneral, presumably the PVA will be so dilute
it will not pose a hazard.)  The concern is that although your PVA formulation is
pretty benign by Palo Alto waste standards, our drains at SNF are used for oxidizing
chemicals (which are neutralized in the AWN.)  PVA and the diluting alcohols are
flammables and should not come into contact with oxidizers.  However, if the amounts
you are using are very small (i.e., whatever is cured on top of a wafer), then it
shouldn't be a problem (one pint down the drain might be, however.)

The final concern would be that the PVA should not outgas in the semhitachi (it
should be subject to the same softbake required for resists.)

If this is the case, and there are no additional concerns from the other specmat
members, then I'd say your PVA is approved.  Please see Mahnaz about getting a yellow
sticker to store your PVA.


Charles D Schaper wrote:

> Tze Wee Chen submitted an application around Aug, 2002, to use
> the material in the attached MSDS, a mixture of alcohols.  Another
> student, Hiro, would also like to use this material, but we didn't
> see it listed in the data base of accepted materials.  We would
> like to conduct the experiments as soon as possible, and would
> appreciate your attention to this matter.  We will repeat the
> application just in case Tze Wee's application was misplaced, but
> I believe there was some communication approving the material:
> 1.  Requestor name: Tetsuhiro Hatogai
> 2.  Phone number: 650-799-5366
> 3.  email address: hatogai at stanford.edu
> 4.  Requstors PI: Professor R. Fabian W. Pease
> 5.  Name of new chemical: Partall Film #10
> 6.  No other materials
> 7.  Name of vendor: Fiberlay, Inc.
> 8.  www.fiberlay.com
> 9.  2425 NW Market St., Seattle WA 98107 1-800-942-0660
> 10. Surface coating that is water soluble
> 11. No other material exists that can form as strong soluble films
> 12. Drytek2, headway, nanospec, ellipsometer, semhitachi
> 13. 1 pint
> 14. liquid
> 15. No chemical is needed to mix it
> 16. Please see attached
> 17. Will not be used in the clean area
> 18. Storage group identifier = L, Main Hazard Class = 6
> 19. Should be enough room
> 20. Material is water soluble and can be poured down drain
> 21. Process Flow: (1) Spin-coat on a silicon wafer using headway,
>     (2) Detach dried film from silicon wafer,
>     (3) Spin-coat resist onto dried film
>     (4) Etch resist and dried film in drytek2
>     (5) Measure film thickness using nanospec, ellipsometer
>     (6) Measure cross section in semhitachi
>   ------------------------------------------------------------------------
>                                  Name: PartallFilm254Q.pdf
>    PartallFilm254Q.pdf           Type: Portable Document Format (APPLICATION/PDF)
>                              Encoding: BASE64
>                       Download Status: Not downloaded with message

Mary X. Tang, Ph.D.
National Nanofabrication Users' Network
Stanford Nanofabrication Facility
CIS Room 136, Mail Code 4070
Stanford, CA  94305
mtang at stanford.edu

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