Metal Gates of PMOS Devices Having High Work Functions

摘要

A semiconductor structure includes a refractory metal silicide layer; a silicon-rich refractory metal silicide layer on the refractory metal silicide layer; and a metal-rich refractory metal silicide layer on the silicon-rich refractory metal silicide layer. The refractory metal silicide layer, the silicon-rich refractory metal silicide layer and the metal-rich refractory metal silicide layer include same refractory metals. The semiconductor structure forms a portion of a gate electrode of a metal-oxide-semiconductor device.