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-x
Al
_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-x
Al
_x
and DSS technology. Saturation drive current enhancement of 94% for NiSi
_2-x
Al
_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 V
_GS
-V
_T
=V
_DS
= 1.2 V was achieved for NiSi
_2-x
Al
_x
DSS MuGFETs with 55 nm gate length.