Applied Materials, Inc.
Formation of bottom isolation

Abstract:

A method may include forming a plasma of a fluorine-containing precursor and contacting a semiconductor substrate with plasma effluents. The semiconductor substrate may include a layer of a first silicon-containing material having a first germanium content formed over the semiconductor substrate, and alternating layers of a second silicon-containing material and a third silicon-containing material over the layer of the first silicon-containing material. The third silicon-containing material may have a second germanium content. The method may further include laterally recessing the third silicon-containing material relative to the first and second silicon-containing materials. The method may further include depositing a spacer material adjacent to the third silicon-containing material relative to the first and second silicon-containing materials. The method may also include etching the first silicon-containing material relative to the second silicon-containing material and the spacer material.