Channel profile engineering for MOSFET's with 100 nm channel lengths

The effective inversion electron mobility and several short-channel effects are examined for different channel doping profiles in NMOSFETs with L/sub eff/ near 100 nm using device simulators. For given threshold voltage, the effective mobility depends on the doping profile shape when the ionized dopant impurity scattering near the surface is nonnegligible as may be the case with the high doping required for proper scaling to L/sub eff//spl les/100 nm. In this regime, super-steep retrograde profiles result in higher effective mobility values than conventional step doping profiles while allowing deeper drain/source junctions.<
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