Modeling of Current Mismatch and 1/f Noise for Halo-Implanted Drain-Extended MOSFETs

Drain-extended MOSFET (DEMOS) with halo implant induced laterally asymmetric channel doping shows anomalous characteristics across bias and temperature that cannot be captured by existing models. The transconductance ( ${g}_{m}$ ) maxima in the linear region is found to be not only a function of the peak mobility but also the halo doping density. In the saturation region, the ${g}_{m}$ characteristics show a nonmonotonic “hump” induced by the halo-region/channel-region junction barrier. Another key care-about for analog design - the drain current ( ${I}_{D}$ ) mismatch, also exhibits unique characteristics with excess mismatch in the weak-inversion (WI) region, in particular at low temperature. In addition, the anomalous flicker noise ( ${1}/{f}$ noise) trends in the presence of high-trap density in the halo region of halo-implanted DEMOS are also discussed. In this work, we propose an analytical model based on the equivalent conductance and impedance field theory to capture these effects. The proposed model is in good agreement with measurements and numerical device simulations using technology computer-aided design (TCAD) of DEMOS across a different oxide thickness, geometry, bias, and temperature.