Surface roughness of III-V fin formed on silicon sidewall by implementing sacrificial buffers

摘要

A method for use in forming a fin of a field-effect transistor includes: patterning a mandrel into a substrate at least by recessing portions of the substrate; forming dielectric material at least on the recessed portions of the substrate, wherein the dielectric material partially covers exterior sidewalls of the mandrel; forming a first buffer at least on a portion of the exterior sidewalls of the mandrel not covered by the dielectric material; forming a second buffer at least on exterior sidewalls of the first buffer; forming a semiconductor channel at least on the dielectric material, wherein at least the second buffer is between the channel and the mandrel; exposing interior sidewalls of at least the first buffer at least by removing the mandrel; and removing the first buffer and the second buffer without removing the channel.