US Patent 6905543 Methods of forming tungsten nucleation layer

The nucleation delay in the formation of a tungsten layer on a substrate is reduced or eliminated by alternative processes. In one process the substrate is exposed to atomic hydrogen before the tungsten nucleation layer is formed. In the other process the substrate is exposed to a boron hydride such as diborane (B2H6) before the nucleation layer is formed. The process works effectively to reduce or eliminate the tungsten nucleation delay on a variety of surfaces, including silicon, silicon dioxide, silicon nitride and titanium nitride.