Rajan:

Are you etching silicon or silicon dioxide? HF by itself is not that good of a
silicon etcher but does wonders on silicon dioxide. If you are trying to etch
silicon dioxide then I would suggest a buffered oxide etch with a ratio of about
6:1. If that is the case then a hardbake at 110 degrees C at 30 minutes in a box
oven or 1-2 minutes on a hot plate should give you good resistance to lifting of
the photoresist. It is common practice to use HMDS prior to photoresist coating
as this really helps with adhesion of photo to oxide. You might want to contact
Bill Moffet at Yield Engineering for more details. They are located in N.
California. Bob Henderson