Patent ID: 7531427

Claim:
A method for providing a homogeneous distribution of germanium in an SiGe layer when oxidizing a surface region thereof, which comprises directly oxidizing the surface region of the SiGe layer by: conducting a first phase of directly oxidizing the SiGe layer to form an oxidized surface region which is sufficiently thick to act as a capping oxide to protect the SiGe layer from pitting during further heating while also forming a Ge-enriched region which is located within the SiGe layer immediately beneath the oxidized surface region and a remaining part of the SiGe layer, wherein the oxidized surface region is sufficiently thin to be below a threshold thickness range that would generate dislocations within the SiGe layer due to a lattice parameter mismatch between the Ge-enriched region and the remaining part of the SiGe layer, and conducting a second phase of high temperature annealing in an inert atmosphere of the capping oxide, Ge-enriched region and remaining part of the SiGe layer for a time and at a temperature sufficient to allow diffusion of Ge from the Ge-enriched region into the remaining of the SiGe layer to provide the homogeneous distribution of germanium within the remaining SiGe layer.