Etching of silicon dioxide selectively to silicon nitride and polysilicon

A method of non-selectively etching silicon dioxides, comprising the step of:

• exposing a substrate with at least two different oxide types to reactive radicals, said oxide types being selected from the group consisting of thermal oxides and deposited oxides, whereby said exposing consumes said oxide types at a substantially equal rate, the consumed oxides forming product layers.

A method of non-selectively etching oxides, comprising the step of:

• exposing a substrate with at least two different oxide types to reactive radicals, said oxide types being selected from the group consisting of thermal oxides and deposited oxides, whereby said exposing consumes said oxide types at a substantially equal rate, the consumed oxides forming product layers, and wherein said reactive radicals are formed by exciting a gas mixture selected from the group consisting of the combination of NH.sub.3 and NF.sub.3 and the combination of CF.sub.4, O.sub.2, H.sub.2 and N.sub.2, whereby said exposing consumes said oxide types at a substantially equal rate, the consumed oxides forming product layers.

A method of non-selectively etching oxides, comprising the steps of:

• exposing a substrate with at least two different oxide types to reactive radicals, said oxide types being selected from the group consisting of thermal oxides and deposited oxides, whereby said exposing consumes said oxide types at a substantially equal rate, the consumed oxides forming product layers;
• and
• removing said product layers.