chemical approval

Mary Tang mtang at
Wed Nov 14 13:59:30 PST 2007

Hi all --

I agree, we should not allow VM-651 if we cannot be told what it is.  I 
suspect, however, that it's a CYA sort of approach that HD Micro is 

1-methoxy-2-propanol is a propylene glycol ether similar to PGMEA 
(propylene glycol monomethyl ether acetate -- same as the previous, but 
with the acetate group added.)  Both are considered "safe" alternatives 
to the older ethylene glycol ethers linked to reproductive problems in 
the semiconductor industry.  PGMEA is the dominant solvent (along with 
ethyl lactate) for resist and polymer products..  Well, unless it's 
NMP.  The PEL of 1-methoxy-2-propanol is 100 ppm.  The TWA of PGMEA is 
100 ppm.  So, I think VM-652 is OK. 

By the way, Kevin O'Sullivan (tdo) and Matthew Buynowski from Nanosys 
(working with ericp and jsuarez) also requested polyimides and adhesion 
promoters from HD Micro.  Matt asks for PI2610 and VM652.  Kevin asks 
for PI2525.  It would be worth getting these people to talk with each other.

Also, I think there are enough requests that we ought to post a generic 
recommended process on the web (maybe in the litho processes section.)  
In general, Mahnaz and I propose the following:

1.  Spin coating only on headway2.  Fresh polyimide can be cleaned up 
with NMP or excess acetone.  Spin chuck and parts should be cleaned up 
as soon as possible after coating.  Personal or dedicated wafer handling 
tools must be used (do NOT used the general, shared litho cassettes.)

2.  If photosensitive polyimide is used, it must be manually developed.  
Polyimide exposure is not approved (yet) for the steppers.

3.  Blue M oven can be used for controlled curing of the resin.  Do NOT 
use the singe or YES ovens.  A hot plate bake of about 5 minutes is 
recommended prior to placing in the Blue M if only to drive off excess 
solvent.  Do not use the hot plates for curing resins at temperatures 
above 200C.

4.  Only cured polyimide is allowed in tools in the white area of the 
lab.  A specmat request must be submitted to process wafers with cured 
polyimide in tools other than gold-contaminated equipment.

Any suggestions, changes, comments?


Ed Myers wrote:
> All,
> The P!-2610 and T-9036 might be OK (NMP based, if I understand the 
> language).  The MSDS for both the VM-651 and VM-652 seem more 
> concerning.  The VM-652 is 1-Methoxy-2-Propanol.  This reads pretty 
> bad, but I don't know if anyone has any experience.
> There is no information on the VM-651 as what are it's components.  
> The MSDS also reads pretty bad, so I think we should say no to this 
> chemical.
> Comments,
> Ed
> At 11:27 AM 11/14/2007, Elizabeth Edwards wrote:
>> Hi,
>> I don't know who to send these MSDS forms to for approval. I would
>> like to purchase at least the PI-2610 to use in the Stanford
>> NanoFacility (in CIS). If you are the right person - can you please
>> let me know which of these chemicals (I've attached the MSDS sheets) I
>> can purchase?
>> Thanks,
>> Liz
>> ---------- Forwarded message ----------
>> From: Elizabeth Edwards <ehe at>
>> Date: Nov 5, 2007 3:32 PM
>> Subject: HD Microsystems polyimide MSDS
>> To: Mary Tang <mtang at>
>> Hi Mary,
>> I wanted to check with you before purchasing these 4 chemicals that
>> they are permitted inside SNF.
>> MSDS attached for HD Microsystems products:
>> PI-2610 polyimide
>> T-9039 polyimide thinner
>> VM-651 and VM-652 (one is concentrated) adhesion promoters
>> -Liz
>> Content-Type: application/pdf; name="PI-2610 MSDS.pdf"
>> X-Attachment-Id: 0.2
>> Content-Disposition: attachment; filename="PI-2610 MSDS.pdf"
>> Content-Type: application/pdf; name="T-9039 MSDS.pdf"
>> X-Attachment-Id: 0.3
>> Content-Disposition: attachment; filename="T-9039 MSDS.pdf"
>> Content-Type: application/pdf; name="VM-651 MSDS.pdf"
>> X-Attachment-Id: 0.4
>> Content-Disposition: attachment; filename="VM-651 MSDS.pdf"
>> Content-Type: application/pdf; name="VM-652 MSDS.pdf"
>> X-Attachment-Id: 0.5
>> Content-Disposition: attachment; filename="VM-652 MSDS.pdf"

Mary X. Tang, Ph.D.
Stanford Nanofabrication Facility
CIS Room 136, Mail Code 4070
Stanford, CA  94305
mtang at

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