Process integration of Si1-xGex CMOS with Si1-xGex relaxation after STI formation

摘要

A method of forming a CMOS device includes preparing a silicon substrate, including forming plural device regions on the substrate; epitaxially forming a strained SiGe layer on the substrate, wherein the SiGe layer has a germanium content of between about 20% and 40%; forming a silicon cap layer epitaxially on the SiGe layer; depositing a gate oxide layer; depositing a first polysilicon layer; implanting H+ ions to a depth below the SiGe layer; forming a trench by shallow trench isolation which extends into the substrate; annealing the structure at a temperature of between about 700° C. to 900° C. for between about five minutes to sixty minutes; depositing an oxide layer and a second polysilicon layer, thereby filling the trench; planarizing the structure to the top of the level of the portion of the second polysilicon layer which is located in the trench; and completing the CMOS device.