Lam Research Corporation
Selective self-aligned patterning of silicon germanium, germanium and type III/V materials using a sulfur-containing mask

Abstract:

A method for patterning a substrate including multiple layers using a sulfur-based mask includes providing a substrate including a first layer and a second layer arranged on the first layer. The first layer includes a material selected from a group consisting of germanium, silicon germanium and type III/V materials. The method includes depositing a mask layer including sulfur species on sidewalls of the first layer and the second layer by exposing the substrate to a first wet chemistry. The method includes removing the mask layer on the sidewalls of the second layer while not completely removing the mask layer on the sidewalls of the first layer by exposing the substrate to a second wet chemistry. The method includes selectively etching the second layer relative to the first layer and the mask layer on the sidewalls of the first layer by exposing the substrate to a third wet chemistry.