Method of fabricating a gate stack integration of complementary MOS device

摘要

A method of forming an integrated circuit structure includes providing a substrate comprising a first device region and a second device region; forming an oxide cap over the substrate and in the first device region and the second device region; forming a first metal layer over the oxide cap, wherein the first metal layer has a first portion in the first device region and a second portion in the second device region; forming a mask to cover the second portion of the first metal layer, wherein the first portion of the first metal layer is exposed; removing the first portion of the first metal layer and the oxide cap from the first device region; removing the mask; and forming a second metal layer in the first device region and the second device region, wherein the second metal layer in the second device region is over the second portion of the first metal layer.