Reduction of threshold voltage deviation in Damascene metal gate MOSFETs

The Damascene metal gate transistors are found to exhibit characteristics superior to those of the conventional polysilicon gate transistors with respect to the threshold voltage deviation (/spl Delta/V/sub th/) and the subthreshold swing (S-factor) when the metal gate work function deviation (crystal orientation deviation) is suppressed by using the inorganic CVD technique. The mechanisms of the gate length dependence of /spl Delta/V/sub th/ and S-factor in the Damascene metal gate transistors can be explained by metal gate work function deviation in the channel region.