The Quantization Impact of Accumulated Carriers in Silicide-Gated MOSFETs

We studied the electrical behavior of MOSFETs in both accumulation and inversion regions when the poly doping concentration was increased up to a level emulating the metallic limit for silicides. Our Poisson-Schrodinger simulations reveal a lower capacitance in the case of the silicided gate when compared with the ideal metal gate; as a consequence, the assumption that silicided gates behave like ideal metals leads to an overestimate of the extracted physical thickness of the insulator. We also showed that accumulation/depletion effects are still present in actual metal gates. Gate quantization produces a shift of the flatband voltage when compared with the classical value. This quantum shift increases as the polysicon doping increases, which is up to . However, for higher dopings, this flatband shift decreases and tends to disappear.