Patent ID: 7767560

Claim:
A method of forming a semiconductor device on an Si substrate, said method comprising: forming a Si fin structure on said Si substrate, by protecting with photoresist a portion of said Si substrate where said Si fin structure is to be formed and etching away adjacent regions of said Si substrate; growing a layer of oxide on said Si fin structure and said Si substrate; exposing at least a portion of said Si fin structure by mechanically or chemically polishing said oxide layer to a top surface of said Si fin structure and recessing said oxide layer adjacent said Si fin structure; epitaxially growing a Si 1-x Ge x layer on said exposed portion of said Si fin structure wherein said Si 1-x Ge x layer has a first Ge concentration, x; and preferentially oxidizing Si from said Si 1-x Ge x layer and from said Si fin structure into SiO 2 wherein Si is predominantly consumed and Ge is forced into said Si fin structure resulting in a Si 1-w Ge w fin structure having a maximum second Ge concentration, w, and a width.