CMOS gates with solid-solution alloy tunable work functions

摘要

Gates of at least one of NMOS transistors and PMOS transistors of a CMOS integrated circuit are formed with a solid-solution alloy of at least two metals. The work function of the gate electrode is tunable by controlling the selection of the metals or the relative proportion of the metals that form a layer of the solid-solution alloy. In one embodiment, a layer of each metal is deposited onto the gate area of a MOS transistor. At least one metal is deposited using atomic layer deposition. The solid-solution alloy is formed by annealing subsequent to the deposition of the metals.