Selective etching between silicon-and-germanium-containing materials with varying germanium concentrations

Abstract

Exemplary semiconductor processing methods may include providing a pre-treatment precursor to a processing region of a semiconductor processing chamber. A first layer of silicon-and-germanium-containing material and a second layer of silicon-and-germanium-containing material may be disposed on a substrate housed within the processing region. A native oxide may be present on the first layer and the second layer. The methods may include contacting the substrate with the pre-treatment precursor to remove the native oxide. The methods may include providing an oxygen-containing precursor to the processing region. The methods may include contacting the substrate with the oxygen-containing precursor to oxidize at least a portion of the second layer. The methods may include providing an etchant precursor to the processing region. The methods may include contacting the substrate with the etchant precursor to selectively etch the first layer of silicon-and-germanium-containing material.