Thermal stress in the semiconductor device adjustment

The present invention provides a method of adjusting thermal stress in a semiconductor device, comprising: a first epitaxial layer of silicon germanium to grow on the semiconductor substrate; to grow a second epitaxial silicon layer on a silicon germanium layer; and performing a first oxide layer is silicon germanium oxide, germanium oxide, wherein generating the first silicon region. Performing stress relief operation to relieve stress caused by the first silicon germanium oxide regions. Forming a gate dielectric on a top surface and sidewalls of the silicon layer. A gate electrode formed on the gate electrode over the dielectric substance.