CHANNEL PROFILE ENGINEERING FOR MOSFETS WITH 100-NM CHANNEL LENGTHS

Effective inversion electron mobility and several short-channel effect s are examined for different channel doping profiles in NMOSFET's with L(eff) near 100 nm using device simulators. For given threshold volta ge, the effective mobility depends on the doping profile shape when th e ionized dopant impurity scattering near the surface is nonnegligible as may be the case with the high doping required for proper scaling t o L(eff) less than or equal to 100 mm. In this regime, super-steep ret rograde profiles result in higher effective mobility values than conve ntional step doping profiles while allowing deeper drain/source juncti ons.