Strained silicon MOSFETs having NMOS gates with work functions for compensating NMOS threshold voltage shift

摘要

The threshold voltage shift exhibited by strained silicon NMOS devices is compensated with respect to the threshold voltages of PMOS devices formed on the same substrate by increasing the work function of the NMOS gates. The NMOS gate work function exceeds the PMOS gate work function so as to compensate for a difference in the respective NMOS and PMOS threshold voltages. The NMOS gates are preferably fully silicided while the PMOS gates are partially silicided.