System and method for integrating multiple metal gates for CMOS applications

Abstract

A dual-gate MOSFET with metal gates and a method for setting threshold voltage in such a MOSFET is provided. The method comprises: forming a gate oxide layer overlying first and second channel regions; forming a first metal layer having a first thickness overlying the gate oxide layer; forming a second metal layer having a second thickness overlying the first metal layer first thickness; selectively removing the second metal layer overlying the first channel region; forming a third metal layer; establishing a first MOSFET with a gate work function responsive to the thicknesses of the first and third metal layer overlying the first channel region; and, establishing a second MOSFET, complementary to the first MOSFET, with a gate work function responsive to the combination of the thicknesses of the first, second, and third metal layers overlying the second channel region.

Dependencies are inferred from the claim text.