Abstract: A process for etching of silicon oxide such as silicon dioxide, or oxynitride. The process includes etching a silicon oxide layer to expose an underlying electrically conductive titanium silicide layer and provide a contact opening extending through the silicon oxide layer to the electrically conductive titanium silicide layer. The etching is performed by exposing the silicon oxide layer to an etching gas in an ionized state in a reaction chamber of a plasma generating device. The etching gas includes a fluoride-containing gas and a passivating nitrogen gas which is present in an amount effective to suppress a removal rate of the electrically conductive titanium silicide layer when it is exposed to the etching gas during the etching step. The fluoride-containing gas can be CF.sub.4, CHF.sub.3, C.sub.2 F.sub.6, CH.sub.2 F.sub.2, SF.sub.6, other Freons and mixtures thereof. The etching gas can also include a carrier gas such as Ar, He, Ne, Kr or mixtures thereof.

Abstract: A process for etching of silicon oxide/nitride such as silicon dioxide, silicon nitride or oxynitride. The process includes etching a silicon oxide/nitride layer to expose an underlying electrically conductive layer and provide a via extending through the silicon oxide/nitride layer to the electrically conductive layer. The etching is performed by exposing the silicon oxide/nitride layer to an etching gas in an ionized state in a reaction chamber of a plasma generating device. The etching gas includes a fluoride-containing gas and a passivating gas which is present in an amount effective to suppress sputtering of the electrically conductive layer when it is exposed to the etching gas during the etching step. The passivating gas can be nitrogen gas and the fluoride-containing gas can be CF.sub.4, CHF.sub.3, C.sub.2 F.sub.6, CH.sub.2 F.sub.2, SF.sub.6, other Freons and mixtures thereof. The etching gas can also include a carrier gas such as Ar, He, Ne, Kr or mixtures thereof.