Patent ID: 6867101

Claim:
A method of fabricating a semiconductor device, having a nitride/high-k material/nitride gate dielectric stack, comprising: initiating formation of the nitride/high-k material/nitride gate dielectric stack by: depositing a first ultra-thin nitride film on a semiconductor substrate, wherein the first ultra-thin nitride film is deposited by using an atomic layer deposition (ALD) technique; depositing a high-k material on the first ultra-thin nitride film, wherein the high-k material comprises a thin metal film, and wherein the thin metal film comprises at least one material selected from a group consisting essentially of zirconium (Zr), hafnium (Hf), and titanium (Ti); and depositing a second ultra-thin nitride film on the high-k material, thereby forming a sandwich structure, wherein the second ultra-thin nitride film is deposited using an atomic layer deposition (ALD) technique; depositing a gate material on the second ultra-thin nitride film, wherein said gate material comprises polysilicon-germanium (poly-SiGe); completing formation of the nitride/high-k material/nitride gate dielectric stack from the sandwich structure; and completing fabrication of the device; wherein the first and second ultra-thin nitride films prevent the at least one material selected from the group consisting essentially of zirconium (Zr), hafnium (Hf), and titanium (Ti) from diffusing into the semiconductor substrate and the gate material, respectively.