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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 (gm) 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 gm characteristics show a nonmonotonic “hump” induced by the halo-region/channel-region junction barrier. Another key care-about for analog design - the drain current (ID) 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/ƒ 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. [ABSTRACT FROM AUTHOR]

We present an analytical modeling approach for drain current (${I}_{D}$) mismatch in lateral nonuniformly doped (NUD) MOSFETs. The model uses the carrier number fluctuation theory to include the effect of random dopant fluctuations (RDFs) on inversion charge fluctuation (ICF) in different operating regions. Our analysis shows that the conventional models for uniformly doped device underestimate the ${I}_{D}$ mismatch by one-to-two orders of magnitude at low gate voltages in NUD devices. We have also considered the effect of RDF on mobility fluctuation (MF), which shows its significant role in strong inversion (SI). To investigate the physical mechanism leading to such a behavior, extensive technology computer-aided design simulations are performed for various conditions of bias, doping profiles, and temperature. Using the impedance field method to calculate the relative contributions of RDF to ICF and MF, we show that our model can successfully capture the drain current mismatch across subthreshold to SI in the NUD device. [ABSTRACT FROM AUTHOR]

We present an analytical model that accurately captures anomalous matching characteristics of drain current in a halo-implanted MOSFET across bias, geometry, and temperature. It is shown that the variation in drain current in different gate bias regimes results from the random-dopant fluctuations (RDFs) in different spatial regions across the channel of the device with nonuniform channel doping. Such effects cannot be captured by existing compact models. Using the impedance field method to calculate the relative contributions of the RDF in the higher doped halo region and the lower doped channel region, we demonstrate, for the first time, an analytical model that can successfully capture the drain current mismatch from subthreshold to strong inversion. We also report for the first time the unique temperature dependence of matching of the drain current in halo-implanted devices and propose a model to capture this behavior. The model is validated using extensive technology computer-aided design analysis and experimental data and is can be extended to the framework of the industry standard BSIM-BULK (formerly BSIM6) MOS model. [ABSTRACT FROM AUTHOR]

We present a phenomenological model for subsurface leakage current in MOSFETs biased in accumulation. The subsurface leakage current is mainly caused by source–drain coupling, leading to carriers surmounting the barrier between the source and the drain. The developed model successfully takes drain-to-source voltage ( V\mathrm{ DS}) , gate-to-source voltage ( V\mathrm{ GS}) , gate length ( LG) , substrate doping concentration ( N\mathrm{ sub}) , and temperature ( $T$ ) dependence into account. The presented analytical model is implemented into the BSIM6 bulk MOSFET model and is in good agreement with technology-CAD simulation data. [ABSTRACT FROM AUTHOR]