Cyclic etch of silicon oxide and polysilicon

Abstract

Exemplary semiconductor processing methods may include providing one or more first etchant precursors to a processing region of a semiconductor processing chamber. A substrate may be housed within the processing region. A plurality of pairs of silicon oxide material and polysilicon material may be disposed on the substrate. The methods may include forming plasma effluents of the one or more first etchant precursors and contacting the substrate with the plasma effluents of the one or more first etchant precursors to selectively etch silicon oxide material. The methods may include providing one or more second etchant precursors to the processing region, forming plasma effluents of the one or more second etchant precursors, and contacting the substrate with the plasma effluents of the one or more second etchant precursors to selectively etch polysilicon material. A temperature within the processing region may be greater than or about 0° C.

Dependencies are inferred from the claim text.