Nitrogen oxide plasma treatment for reduced nickel silicide bridging

摘要

Bridging between nickel silicide layers on a gate electrode and source/drain regions along silicon nitride sidewall spacers is prevented by treating the exposed surfaces of the silicon nitride sidewall spacers with a nitrogen oxide plasma to create a surface region having reduced free silicon. Embodiments include treating the silicon nitride sidewall spacers with a nitrogen plasma to reduce the refractive index of the surface region to less than about 1.95.