Etching of very thin layer of SiO2

Pegasus 3 is not meant to be used as an SiO2 etcher. Please do not develop nice SiO2 recipes on this machine. Often SIO2 etch recipes are very polymerizing and that can disturb the chamber conditions for the silicon etching recipes.

The recipe developed here is only for etching through a very thin SiO2 layer and does not have a high selectivity to silicon to avoid the recipe to become too polymerizing. So when it is used for etching down to silicon it will