US Patent 11784054 Etching method and substrate processing system

An etching method for performing side-etching of silicon germanium layers of a substrate having alternating silicon layers and the silicon germanium layers formed thereon is provided. The method includes modifying surfaces of residuals by supplying a plasmarized gas containing hydrogen to the residuals on exposed end surfaces of the silicon germanium layers, and performing side-etching on the silicon germanium layers by supplying a fluorine-containing gas to the silicon germanium layers.