Patent ID: 9105623
Filing Date: 2015-08-11
Classification: H01L

Abstract:
1. A semiconductor device having metal gate comprising: a substrate; a first metal gate positioned on the substrate, the first metal gate having a high-k gate dielectric layer, a first metal layer comprising a first work function, a filling metal layer, and an etch stop layer formed between the first metal layer and the filling metal layer; and a second metal gate positioned on the substrate, the second metal gate having the high-k gate dielectric layer, a second metal layer comprising the first work function, a third metal layer formed between the high-k gate dielectric layer and the second metal layer and comprising a second work function, an etch stop layer formed between the second metal layer and the third metal layer, and the filling metal layer, the second metal layer having materials the same with the first metal layer, but a thickness of the second metal layer is smaller than a thickness of the first metal layer, wherein the first work function and the second work function are different from each other.