Patent ID: 8629037

Claim:
A method of fabricating a semiconductor device, comprising: forming a first dielectric layer over a first surface and a second surface of a silicon substrate, the first and second surfaces being opposite surfaces, wherein a first portion of the first dielectric layer covers the first surface of the substrate, and a second portion of the first dielectric layer covers the second surface of the substrate; forming openings that extend into the substrate from the first surface; filling the openings with a second dielectric layer; removing the first portion of the first dielectric layer without removing the second portion of the first dielectric layer; forming a first III-V family layer over the first surface of the substrate and covering the second dielectric layer; forming a second III-V family layer over the first III-V family layer and over the second dielectric layer, wherein the second III-V family layer is comprised of a different III-V family material than the first III-V family layer; forming a gate structure over the second III-V family layer; and forming a first source/drain region and a second source/drain region in the second III-V family layer and partially in the first III-V family layer.