Method of adjusting metal gate work function of NMOS device

摘要

A method of adjusting a metal gate work function of an NMOS device comprises: depositing a layer of metal nitride film or metal film on a high K dielectric as a metal gate electrode by a physical vapor deposition process; implanting elements such as Tb, Er, Yb or Sr into the metal gate electrode by an ion implantation process; performing a high temperature annealing so that the doped metal ions are driven to and accumulate on the interface between the metal gate electrode and the high K gate dielectric, or form dipoles by an interface reaction on the interface between the high K gate dielectric and SiO₂. The method is capable of adjusting the metal gate work function, and is well-compatible with CMOS process.