Patent ID: 9698060
Date: 2017-07-04
CPC Classifications: H01L

Claim:
1. A method comprising: forming a first germanium-containing fin higher than top surfaces of Shallow Trench Isolation (STI) regions, wherein the STI regions are on opposite sides of the first germanium-containing fin and extend into a silicon substrate, and the first germanium-containing fin has a first germanium atomic percentage, wherein the first germanium-containing fin extends below top surfaces of the STI regions to physically contact the silicon substrate; forming a first gate stack on a middle portion of the first germanium-containing fin, with an end portion of the first germanium-containing fin exposed; etching the end portion of the first germanium-containing fin to form a recess; and re-growing a first source/drain region in the recess, wherein the first source/drain region has a second germanium atomic percentage lower than the first germanium atomic percentage.