Novel Epitaxial Nickel Aluminide-Silicide with Low Schottky-Barrier and Series Resistance for Enhanced Performance of Dopant-Segregated Source/Drain N-channel MuGFETs

We have developed a novel epitaxial nickel-aluminide silicide (NiSi_2-xAl_x) 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 silicide. A further 42% effective reduction in the DSS SBH was attained with the combination of NiSi_2-xAl_x and DSS technology. Saturation drive current enhancement of 94% for NiSi_2-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 muA/mum at V_GS-V_T =V_DS = 1.2 V was achieved for NiSi_2-xAl_xDSS MuGFETs with 55 nm gate length.