Novel epitaxial nickel aluminide-silicide with low Schottky-Barrier and series resistance for enhanced performance of dopant-segregated source/drain N-channel MuGFETs

Abstract

We have developed a novel epitaxial nickel-aluminide suicide (NiSi 2-x Alx) to reduce the Schottky-Barrier height (SBH) and series resistance in n-channel MuGFETs with dopant-segregated Schottky-Barrier source/drain (DSS). 10% substitutional incorporation of Al in the Si matrix at the silicide-Si interface leads to a 37% reduction in the intrinsic SBH of nickel suicide. A further 42% effective reduction in the DSS SBH was attained with the combination of NiSi2-xAlx and DSS technology. Saturation drive current enhancement of 94 % for NiSi2-xAl x DSS MuGFETs over NiSi DSS MuGFETs was achieved, attributed to SBH lowering, series resistance reduction and possibly silicide strain effects. As a result, an excellent drive current of 882 μA/μm at VGS-V, Vτ = 1.2 V was achieved for NiSÍ2-x,Al x DSS MuGFETs with 55 nm gate length.