Patent ID: 7655567

Claim:
A method of forming a tungsten layer on a partially fabricated semiconductor substrate comprising: depositing a tungsten (W) nucleation layer on the semiconductor substrate by a combined PNL-CVD nucleation layer process, said combined PNL-CVD nucleation layer process comprising sequentially exposing the substrate to a reducing agent and a tungsten-containing precursor in one or more PNL cycles and, after the one or more PNL cycles, depositing at least a portion of a tungsten (W) nucleation layer by a chemical vapor deposition (CVD) process; wherein the CVD portion of the combined PNL-CVD nucleation layer process uses silane and hydrogen as reducing agents, wherein the PNL portion of the combined PNL-CVD nucleation layer process is performed at a substrate temperature of less than about 350 C and the CVD portion of the PNL-CVD nucleation layer process is performed at a substrate temperature of at least about 400 C; and depositing a tungsten (W) bulk layer on the tungsten (W) nucleation layer using a CVD process, wherein the CVD bulk deposition uses hydrogen as a reducing agent; wherein the tungsten (W) nucleation layer facilitates the formation of the tungsten (W) bulk layer.