Patterning semiconductor materials using surface modification techniques

Abstract

A method includes forming a mask over a semiconductor layer. The method includes first patterning the mask to form a first opening that exposes a first portion of the semiconductor layer. The method includes performing a plasma treatment to form a surface modification layer over the exposed first portion. The method includes second patterning the mask to form a second opening that exposes a second portion of the semiconductor layer, thereby forming a patterned mask that defines the first and second openings. The method includes performing an etching process to the semiconductor layer through the patterned mask to form a first trench extending from the first opening and a second trench extending from the second opening. The etching process removes the first portion at a first rate and the second portion at a second rate that is greater than the first rate.

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