Patent ID: 9536795
Date: 2017-01-03
CPC Classifications: H01L

Claim:
1. A method comprising: providing a silicon-germanium-on-insulator (SGOI) substrate, the SGOI substrate includes (from bottom to top) a substrate, an insulator layer, and a SiGe layer; forming a patterned hardmask on the SiGe layer; forming a plurality of fins in the SiGe layer by etching a trench through the SiGe layer, the trench exposes a top surface of the insulator layer, the patterned hardmask protects a top surface of the plurality of fins, the plurality of fins includes a first fin and a second fin, the first fin has a first width and the second fin has a second width, and the first width is similar to the second width; trimming the second fin to a third width by etching sidewalls of the second fin, the top of the second fin is protected by the patterned hardmask, and the first fin is protected by a first fin mask; modulating the germanium fraction of the first and second fin using a Ge-condensation process, the patterned hardmask protects the top surface of the plurality of fins, the first fin has a fourth width and the second fin has a fifth width, and the first fin has a lower germanium concentration than the second fin; and trimming the first fin to a sixth width, the sixth width is similar to the fifth width.