Method for Forming Dual Fully Silicided Gates and Devices with Dual Fully Silicided Gates

摘要

A method for manufacturing CMOS devices with fully silicided (FUSI) gates is described. A metallic gate electrode of an NMOS transistor and a metallic gate electrode of a pMOS transistor have a different work function. The work function of each transistor type is determined by selecting a thickness of a corresponding semiconductor gate electrode and a thermal budget of a first thermal step such that, during silicidation, different silicide phases are obtained on the nMOS and the pMOS transistors. The work function of each type of transistor can be adjusted by selectively doping the semiconductor material prior to the formation of the silicide.