A compound metal comprising HfSiN which is a n-type metal having a workfunction of about 4.0 to about 4.5, preferably about 4.3, eV which is thermally stable on a gate stack comprising a high k dielectric and an interfacial layer. Furthermore, after annealing the stack of HfSiN/high k dielectric/interfacial layer at a high temperature (on the order of about 1000° C.), there is a reduction of the interfacial layer, thus the gate stack produces a very small equivalent oxide thickness (12 Å classical), which cannot be achieved using TaSiN.