Evanescent-Mode Analysis of Short-Channel Effects in MOSFETs

The short channel effects (SCE) of bulk MOSFETs with super-steep retrograded channels (SSR), fully-depleted SOI, and double-gate MOSFETs have been analyzed using device simulations and a scaling-length (λ) analysis. It is found that the minimum channel length should be larger than 5λ and that the depletion thickness of the SSR should be around 30 nm in order to be applicable to 70-nm CMOS technology. A high-kappa dielectric shows a limitation in scaling due to the drain-field penetration through the dielectric unless the equivalent SiO ₂ thickness is very thin. The SSR gives the smallest SCE of the three structures considered.