Semiconductor device and method of fabricating metal gate of the same

摘要

Provided is a semiconductor device that comprises a metal gate having a low sheet resistance characteristic and a high diffusion barrier characteristic and a method of fabricating the metal gate of the semiconductor device. The semiconductor device includes a metal gate formed on a gate insulating film, wherein the metal gate is formed of a metal nitride that contains Al or Si and includes upper and lower portions where the content of Al or Si is relatively high and a central portion where the content of Al or Si is relatively low.