Effect of silicon substrate hydrogenation treatment on nickel silicide formation

Nickel silicide is being considered as a replacement for the currently used class of silicides-for contacts to the source, drain and gate regions in CMOS circuits. In this work, the effect of substrate hydrogenation by a hydrogen plasma treatment prior to nickel deposition and silicidation was studied. The sheet resistance of the silicide film was observed to decrease with hydrogenation at silicidation temperatures below 600°C. However, defects are seen near the interface at the lower processing temperatures, while at higher temperatures greater in-diffusion of Ni into the hydrogenated Si samples is observed.