Patent ID: 6600170
Filing Date: 2003-07-29
Classification: H01L

Abstract:
A semiconductor device comprising:a semiconductor substrate comprising a silicon germanium (SiGe) layer formed on a base layer; a plurality of field effect transistors (FET) including at least one first FET and at least one second FET formed on the semiconductor substrate; wherein said first FET comprises a first channel region comprising a portion of said SiGe layer, a gate electrode formed over the first channel region, and a gate oxide layer interposed between the gate electrode and the first channel region, wherein the gate oxide layer is formed immediately adjacent to and in contact with the SiGe layer; and said second FET comprises a strained silicon layer formed on the SiGe layer, a second channel region comprising a portion of said strained silicon layer and a portion of said SiGe layer, a gate oxide layer formed on the second channel region, and a gate electrode formed on the gate oxide layer, wherein there is substantially no strained silicon in said first channel region.