Patent ID: 9362179
Filing Date: 2016-06-07
CPC Classification: H01L

Claim Text:
1. A method of forming a semiconductor structure, said method comprising: forming a silicon fin precursor in an nFET device region of a substrate, and a fin stack comprising alternating material portions, and, from bottom to top, of silicon and a silicon germanium alloy in a pFET device region of said substrate; performing a thermal anneal to convert said fin stack into a silicon germanium alloy fin precursor having a first germanium content; and performing a thermal oxidation to convert said silicon fin precursor into a silicon fin, and to convert said silicon germanium alloy fin precursor into a silicon germanium alloy fin having a second germanium content that is greater than said first germanium content, wherein said silicon fin has a width that is less than a width of said silicon fin precursor and said silicon germanium alloy fin has a width less than a width of said silicon germanium alloy fin precursor.