Hello all,

I have some questions about depositing teflon(or teflon-like)

1. If there are some cavites  on silicon substrate.  I want to deposit teflon on
Si surface but not on Si3N4
  (Si3N4 is in the cavity, as the figure).
   How do I remove the teflon on Si3N4 easily after the CVD teflon process(or
other teflon deposit process)??
   I know that the adhesion between teflon and Si3N4 is bad, may I immerse the
wafer in acetone(or something else)
   to remove the teflon on Si3N4??
   I can't use photolithography process, because the height of Si3N4 patterns
are  much lower than Si. PR can't coater well on it.

Si                        Si
——
——
     ╲                ／
       ╲            ／
         ╲        ／
            — ——
              Si3N4

2. After removing the teflon on Si3N4,  I will use RIE(CF4) to remove Si3N4.
   Will CF4 plasma attack teflon (I need the hydrophobic property of teflon)???

Thanks for your advices.