INTEGRATED CIRCUIT HAVING PLURAL TRANSISTORS WITH WORK FUNCTION METAL GATE STRUCTURES

摘要

The present invention provides an integrated circuit including a substrate, a first transistor, a second transistor and a third transistor. The first transistor has a first metal gate including a first bottom barrier layer, a first work function metal layer and a first metal layer. The second transistor has a second metal gate including a second bottom barrier layer, a second work function metal layer and a second metal layer. The third transistor has a third metal gate including a third bottom barrier layer, a third work function metal layer and a third metal layer. The first transistor, the second transistor and the third transistor has the same conductive type. A nitrogen concentration of the first bottom barrier layer>a nitrogen concentration of the second bottom barrier layer>a nitrogen concentration of the third bottom barrier layer.

主权项

1. An integrated circuit having plural transistors with different threshold voltages, comprising:
a substrate; a first transistor with a first metal gate disposed on the substrate, wherein the first metal gate comprises a first bottom barrier layer, a first work function metal (WFM) layer and a first metal layer; a second transistor with a second metal gate disposed on the substrate, wherein the second metal gate comprises a second bottom barrier layer, a second WFM layer and a second metal layer; and a third transistor with a third metal gate disposed on the substrate, wherein the third metal gate comprises a third bottom barrier layer, a third WFM layer and a third metal layer, wherein the first transistor, the second transistor and the third transistor have the same conductive type, and a nitrogen concentration of the first bottom barrier layer>a nitrogen concentration of the second bottom barrier layer>a nitrogen concentration of the third bottom barrier layer.