Semiconductor device having metal gate and manufacturing method thereof

Abstract

A semiconductor device having metal gate includes a substrate, a first metal gate positioned on the substrate, and a second metal gate positioned on the substrate. The first metal gate includes a first p-work function metal layer, an n-work function metal layer, and a gap-filling metal layer. The second metal gate includes a second p-work function metal layer, the n-work function metal layer, and the gap-filling metal layer. The first p-work function metal layer and the second p-work function metal layer include a same p-typed metal material. A thickness of the first p-work function metal layer is larger than a thickness of the second p-work function metal layer. The first p-work function metal layer, the second p-work function metal layer, and the n-work function metal layer include a U shape.

What is claimed is: 
     
         1 . A semiconductor device having metal gate comprising:
 a substrate;   a first metal gate positioned on the substrate, the first metal gate comprising a first p-work function metal layer, an n-work function metal layer, and a gap-filling metal layer; and   a second metal gate positioned on the substrate, the second metal gate comprising a second p-work function metal layer, the n-work function metal layer, and the gap-filling metal layer, wherein   the first p-work function metal layer and the second p-work function metal layer comprise a same p-typed metal material, a thickness of the first p-work function metal layer is larger than a thickness of the second p-work function metal layer, and the first p-work function metal layer, the second p-work function metal layer and the n-work function metal layer comprise a U shape.   
     
     
         2 . The semiconductor device having metal gate according to  claim 1 , further comprising a high-k gate dielectric layer formed in between the first metal gate and the substrate, and between the second metal gate and the substrate. 
     
     
         3 . The semiconductor device having metal gate according to  claim 2 , wherein the high-k gate dielectric layer comprises a U shape. 
     
     
         4 . The semiconductor device having metal gate according to  claim 2 , wherein the high-k gate dielectric layer comprises a flat shape. 
     
     
         5 . The semiconductor device having metal gate according to  claim 2 , further comprises an interfacial layer positioned between the high-k gate dielectric layer and the substrate.