US Patent 11031291 Semiconductor structure and method of forming the same

A semiconductor structure includes a substrate including a first region and a second region, a first channel layer disposed in the first region and a second channel layer disposed in the second region, a first dielectric layer disposed on the first channel layer and a second dielectric layer disposed on the second channel layer, and a first gate electrode disposed on the first dielectric layer and a second gate electrode disposed on the second dielectric layer. The first channel layer in the first region includes Ge compound of a first Ge concentration, the second channel layer in the second region includes Ge compound of a second Ge concentration. The first Ge concentration in the first channel layer is greater than the second Ge concentration in the second channel layer.