Nitrogen-rich silicon nitride sidewall spacer deposition

摘要

Salicide processing is implemented with nitrogen-rich silicon nitride sidewall spacers that allow a metal silicide layer e.g., NiSi, to be formed over the polysilicon gate electrode and source/drain regions using salicide technology without associated bridging between the metal silicide layer on the gate electrode and the metal silicide layers over the source/drain regions.Bridging between a metal silicide e.g., nickel silicide, layer on a gate electrode and metal silicide layers on associated source/drain regions is avoided by forming nitrogen-rich silicon nitride sidewall spacers with increased nitrogen, thereby eliminating free Si available to react with the metal subsequently deposited and thus avoiding the formation of metal silicide on the sidewall spacers.