Roger,
      I think a vacuum vapor prime with HMDS will help you with adhesion.  I am
not familiar with Microposit LOR 10A, but you are trying to stick an organic
onto a non organic.  A molecule that constitutes an inorganic/organic mix can
only help.  Good news a vacuum vapor prime once applied is not affected by the
moisture in the air.  This means I can prime the samples here and ship them back
with better adhesion.  Can you send me some samples.  Bill Moffat

-----Original Message-----
From: Roger Shile [mailto:[email protected]]
Sent: Monday, March 10, 2003 2:33 PM
To: General MEMS discussion
Subject: [mems-talk] Liftoff on Pyrex


I am attempting to pattern Cr/Au films on Pyrex by liftoff.  However the I am
getting unacceptable results due to poor adhesion of the liftoff resist.
my process is as follows:

Clean Pyrex in Piranha, DI rinse, blow dry.
Dehydration bake 30 minutes ~ 200 degC
Spin on Microposit LOR 10A
Bake 30 min 150-190 degC
Spin on S1813 resist
Bake 30 min at 90 degC
Expose and develop
Bake 30 min at 90 degC (to avoid outgassing during sputter)
Sputter 100A Cr + 1 Micron Au

My understanding was that HMDS prime isn't necessary prior to application of LOR
or LOL.  I had good results with the above process on Si.
Would a HMDS prime improve LOR adhesion to Pyrex?  If so what is an ideal prime
e.g. resulting contact angle for water drop?

Is there some other technique to improve LOR/LOL adhesion to Pyrex?

Roger Shile
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