Theoretical investigations on metal/high-k interfaces

We have found that effective work functions of high-work function gate metals (p-metals) become small and Fermi level pinning of gate metals occurs after high temperature treatment as the same in the case in p+poly-Si gates. On the contrary, intrinsic hybridization between metal and high-k wave function at the interface is crucial factor to determine effective work function of gate metals after low temperature treatment. As discussed above, metal/high-k interface properties are much different each other after high- and low-temperature treatment.