Complementary metal oxide semiconductor metal gate transistors may be formed by depositing a metal layer in trenches formerly inhabited by patterned gate structures. The patterned gate structures may have been formed of polysilicon in one embodiment. The metal layer may have a workfunction most suitable for forming one type of transistor, but is used to form both the n and p-type transistors. The workfunction of the metal layer may be converted, for example, by ion implantation to make it more suitable for use in forming transistors of the opposite type.