Plated metal transistor gate and method of formation

Abstract

Using plating, metal gates for N channel and P channel transistors are formed of different materials to achieve the appropriate work function for these N and P channel transistors. The plating is achieved with a seed layer consistent with the growth of the desired layer. The preferred materials are selected from the platinum metals, which comprise ruthenium, ruthenium oxide, iridium, palladium, platinum, nickel, osmium, and cobalt. These are attractive metals because they are relatively high conductivity, can be plated, and provide a good choice of work functions for forming P and N channel transistors.