Patent ID: 7067868

Claim:
A semiconductor device, comprising: a semiconductor layer; a first gate dielectric adjacent a first side of a first portion of the semiconductor layer; a first gate electrode adjacent the first gate dielectric; a second gate dielectric adjacent a second side of the first portion of the semiconductor layer; a second gate electrode adjacent the second gate dielectric; means for encapsulating at least one of (i) the first gate electrode and the first gate dielectric and (ii) the second gate electrode and the second gate dielectric; a strained channel region having first and second heterojunctions adjacent opposite ends of the strained channel region and within the first portion of the semiconductor layer; and a semiconductor material selectively grown overlying a second portion of the semiconductor layer outside the first portion, wherein the semiconductor material comprises a material different from a material of the semiconductor layer, and wherein the semiconductor material is used as a diffusion source by controlling an amount of diffusion of the semiconductor material into the strained channel region of the first and second portions of the semiconductor layer.