Patent ID: 7776732

Claim:
A method to form a metal high dielectric constant (MHK) transistor, comprising: providing a MHK stack disposed on a substrate, the MHK stack comprising a layer of high dielectric constant material and an overlying layer comprised of a metal, the MHK stack having an overlying layer comprised of silicon; selectively removing only the overlying layer comprised of silicon and the overlying layer comprised of metal, without removing the layer of high dielectric constant material, to form an upstanding portion of a MHK gate structure comprised of an underlying portion of the layer comprised of metal, and an overlying portion of the layer comprised of silicon; forming a single sidewall layer comprised of amorphous silicon or polycrystalline silicon on sidewalls of the upstanding portion of the MHK gate structure; removing a portion of the layer of high dielectric constant material to form exposed surfaces of the layer of high dielectric constant material, wherein the removing the portion is performed directly after forming the single sidewall layer; and forming an offset spacer layer over the single sidewall layer and over the exposed surfaces of the layer of high dielectric constant material.