Atomic layer etching 3D structures: Si and SiGe and Ge smoothness on horizontal and vertical surfaces

摘要

Methods and apparatuses for etching semiconductor material on substrates using atomic layer etching by chemisorption, by deposition, or by both chemisorption and deposition mechanisms in combination with oxide passivation are described herein. Methods involving atomic layer etching using a chemisorption mechanism involve exposing the semiconductor material to chlorine to chemisorb chlorine onto the substrate surface and exposing the modified surface to argon to remove the modified surface. Methods involving atomic layer etching using a deposition mechanism involve exposing the semiconductor material to a sulfur-containing gas and hydrogen to deposit and thereby modify the substrate surface and removing the modified surface.