Integration of dual workfunction metal gate CMOS devices

摘要

A dual work function CMOS metal gate device provides a composite metal gate electrode structure. The composite metal gate structure includes a bulk metal and a thin metal layer having an appropriate work function for the transistor type and desired threshold voltage, V_T. Both N-channel and P-channel transistors are formed to have distinct threshold voltages by incorporating the metal material having the appropriate work function for the desired V_T into the composite metal gate electrode. The two different electrodes of the N-channel and P-channel transistors are electrically connected by means of the bulk metal.