METHOD TO FABRICATE FULLY SILICIDED N-POLYSILICON AND P-POLYSILICON IN A CMOS PROCESS FLOW

摘要

An improved method of forming a fully suicided (FUSI) gate in both NMOS and PMOS transistors of the same MOS device is disclosed. In one example, the method comprises forming a first suicide in at least a top portion of a gate electrode of the PMOS devices and not over the NMOS devices. The method further comprises concurrently forming a second silucide in at least a top portion of a gate electrode of both the NMOS and PMOS devices, and forming a FUSI gate suicide of the gate electrodes. In one embodiment, the thickness of the second suicide is greater than the first suicide by an amount which compensates for a difference in the rates of suicide formation between the NMOS and PMOS devices.