Patent ID: 6873051

Claim:
A semiconductor device comprising: a gate electrode, having opposing side surfaces and an upper surface, on an upper surface of semiconductor substrate with a gate dielectric layer therebetween; source/drain regions in the semiconductor substrate on opposite sides of the gate electrode; dielectric sidewall spacers on the opposite sides of the gate electrode; a nitrogen-containing diffusion modulating layer, which impedes nickel diffusion, on the source/drain regions and on the upper surface of the gate electrode; and a layer of nickel silicide on the nitrogen-containing diffusion modulating layer, wherein the nitrogen-containing diffusion modulating layer contains nitrided titanium silicide, a mixture of nitrided titanium silicide and nitrided nickel silicide, nitrided tantalum silicide, or a mixture of nitrided tantalum silicide and nitrided nickel silicide.