Patent ID: 6545370
Filing Date: 2003-04-08
Classification: H01L

Abstract:
A semiconductor device comprising:a gate electrode, having opposing side surfaces and an upper surface, on a semiconductor substrate with a gate insulating layer therebetween; a composite silicon nitride sidewall spacer on each opposing side surfaces of the gate electrode, the composite silicon nitride sidewall spacer comprising: an inner layer of silicon nitride, having a first refractive index and a thickness of about 450 Ã¥ to about 550 Ã¥, on one of the opposing side surfaces of the gate electrode; and an outer layer of silicon nitride, having a refractive index less than the first refractive index and less than about 1.95 and a thickness of about 350 Ã¥ to about 450 Ã¥, on the inner layer of silicon nitride; a layer of nickel silicide on the upper surface of the gate electrode; and a layer of nickel silicide on the substrate surface adjacent each silicon nitride sidewall spacer.