Hi all

I am wondering if someone can suggest me a good plasma chemistry to
get a very good selectivity between SiO2 and Si

I am using Trion's minilock phanthom III series ICP RIE etch system. I
have access to Ar, N2, O2, BCl3, Cl2, CF4 gases.

CF4 is etching both Si and SiO2, even Cl2/BCl3 combination is etching both.

Thanks a lot
Satish