Patent ID: 7825011

Claim:
A method of manufacturing a semiconductor device comprising: forming at least one semiconductor element in a substrate and a semiconductor body; wherein forming the at least one semiconductor element includes, forming a silicon-germanium layer on the substrate, the silicon-germanium layer including a mixed crystal of silicon and germanium, the silicon-germanium layer having a lower surface close to the substrate and an upper surface more remote from the substrate, and subjecting the silicon-germanium layer to an oxidizing treatment at a surface of the silicon-germanium layer while the other surface of the silicon-germanium layer is protected against the oxidizing treatment by a blocking layer, the blocking layer formed on the upper surface of the silicon-germanium layer, the method further comprising, forming a cavity in the semiconductor body below the silicon-germanium layer, and through the cavity, subjecting the lower surface of the silicon-germanium layer to an oxidizing treatment.