Gate stacks with multiple high-κ dielectric layers

Abstract

A first semiconductor device includes an interfacial layer over a substrate, a first high-κ dielectric layer over the interfacial layer, a second high-κ dielectric layer over the first high-κ dielectric layer, a Ti—Si mixing layer over the second high-κ dielectric layer, and a gate electrode layer over the Ti—Si mixing layer. A second semiconductor device includes an interfacial layer over a substrate, a first high-κ dielectric layer over the interfacial layer, a Ti—Si mixing layer over the first high-κ dielectric layer, a second high-κ dielectric layer over the Ti—Si mixing layer, and a gate electrode layer over the second high-κ dielectric layer. The method includes forming an interfacial layer over a substrate, forming a first high-κ dielectric layer over the interfacial layer, forming a second high-κ dielectric layer over the first high-κ dielectric layer, and forming a gate electrode layer over the second high-κ dielectric layer.

Dependencies are inferred from the claim text.