A method for increasing the etch-rate ratio of oxides to nonoxides in inert-gas ion milling processes

The etch-rate ratio of oxides to nonoxides in inert gas ion milling systems can be increased by injecting a flux of halocarbon gas molecules onto the surface along with the inert-gas ion beam. In order for the halocarbon to be effective, it must adsorb on the surfaces of interest and the halogon must form a volatile reaction product with the surfaces. The system Ar+/ CCl4/Si and SiO2 is used to illustrate this method.