Patent ID: 6972224

Claim:
A method of fabricating a semiconductor device, the method comprising: providing a semiconductor substrate having a surface and having a first area and a second area; forming a gate dielectric on the surface over the first area and over the second area; forming a sacrificial layer over the gate dielectric, wherein the sacrificial layer comprises silicon oxide; patterning the sacrificial layer so that the gate dielectric over the first area is exposed and a remaining portion of the sacrificial layer protects the gate dielectric over the second area; depositing a first metal gate conductor material over exposed gate dielectric and over the remaining portion of the sacrificial layer; patterning the first metal gate conductor material so that the remaining portion of the sacrificial layer is exposed; after patterning the first metal gate conductor material, removing the remaining portion of the sacrificial layer so as to expose the gate dielectric over the second area using a wet chemical etch; and depositing a second metal gate conductor material over the patterned first metal gate conductor material and directly on the gate dielectric that was exposed over the second area as a result of removing the remaining sacrificial layer.