Partially and fully silicided gate stacks

摘要

Metal-oxide semiconductor (MOS) devices and techniques for the fabrication thereof are provided. In one aspect, a metal-oxide semiconductor device is provided comprising a substrate; and at least one n-channel field effect transistor (NFET) having a gate stack over the substrate. The NFET gate stack comprises an NFET gate stack metal gate layer; a first NFET gate stack silicon layer over the NFET gate stack metal gate layer; a second NFET gate stack silicon layer over a side of the first NFET gate stack silicon layer opposite the NFET gate stack metal gate layer, wherein an interface is defined between the first NFET gate stack silicon layer and the second NFET gate stack silicon layer; and an NFET gate stack silicide region that extends through the interface between the first NFET gate stack silicon layer and the second NFET gate stack silicon layer.