I agree with Bill. We have had resist lifting problems with HF, but it
goes away with a good vapor prime. Although HF will eventually
penetrate the resist surface, the most likely culprit is HF diffusing
sideways and lifting the resist.

Also, I have also found that excessive hard baking will create small
voids in the resist film that increases HF penetration. For HF I don't
generally do hard baking.


On Thu, Nov 18, 2010 at 4:13 PM, Bill Moffat
 wrote:
> Use vacuum vapor prime for resist adhesion.  Good adhesion for 20 minutes of
HF etching.
>
> Bill Moffat