If you hard bake the resist at 150 or 170 deg. C it should be fairly
impervious to KOH or TMAH. Deep UV treatment would prevent reflow if
that would be a problem. Vacuum hard bake makes a very hard baked. Of
course you would have to worry about removal and might need plasma O2.

However, the positive resist Novalak system is design to be balanced
between insoluability and soluability with alkali solutions. So if you
want no baking and still lots of resistance resistance, I think you
would have to go with a negative resist and a reversed mask.

Then there are more exotic solutions like some bilayer combination.

I am not sure what the constraints you have.

Ed

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Nitin Shukla
Sent: Monday, October 01, 2007 12:37 PM
To: [email protected]
Subject: [mems-talk] Photoresist as etch mask!

Hi,
  I would appreciate if anyone could suggest me a photoresist that would
not be etched by TMAH or KOH.