High Performance Metal Gate CMOS with High-K Gate Dielectric

摘要

A CMOS structure is disclosed in which both type of FET devices have gate insulators containing high-k dielectrics, and gates containing metals. The threshold of the two type of devices are adjusted in separate manners. One type of device has its threshold set by exposing the high-k dielectric to oxygen. During the oxygen exposure the other type of device is covered by a stressing dielectric layer, which layer also prevents oxygen penetration to its high-k gate dielectric. The high performance of the CMOS structure is further enhanced by adjusting the effective workfunctions of the gates to near band-edge values both NFET and PFET devices.