If you use a non-multiplexed etch with an etchant containing sufficient
carbon, a polymer will be left on the sidewalls.  This will happen, for
example, with equal parts of SF6, CHF3 and O2.

Roger Shile

-----Original Message-----
Hi all,

         Does anyone know any etchant that will etch Silicon alone
leaving Teflon like fluoropolymer which we get from the passivation
stage of bosch process?

Thanks in advance!

Arun