Patent ID: 9559120
Date: 2017-01-31
CPC Classifications: H01L

Claim:
1. A method for forming complementary metal oxide semiconductor devices, comprising: masking a first portion of a tensile-strained silicon layer of a silicon on insulator substrate with a hard mask; doping a second portion of the tensile-strained silicon layer outside the first portion; removing the hard mask; growing an undoped silicon layer on the doped portion and the first portion, wherein the undoped silicon layer becomes a tensile-strained undoped silicon layer; relaxing strain in the undoped silicon layer over the doped portion by converting the doped portion to a porous silicon to form a relaxed silicon layer; converting the porous silicon to an oxide; growing a SiGe layer on the relaxed silicon layer; oxidizing the SiGe layer to convert the relaxed silicon layer to a compressed SiGe layer; and etching fins in the first portion from the tensile-strained silicon layer and the undoped silicon layer and in the second portion from the compressed SiGe layer.