In this paper, we present the unique features exhibited by a modiﬁed asymmetrical double-gate (DG) silicon-on-insulator (SOI) MOSFET. The proposed structure is similar to that of the asymmetrical DG SOI MOSFET with the exception that the front gate consists of two materials. The resulting modiﬁed structure, i.e., a dual-material double-gate (DMDG) SOI MOSFET, exhibits signiﬁcantly reduced short-channel effects (SCEs) when compared with the DG SOI MOSFET. SCEs in this structure have been studied by developing an analytical model. The model includes the calculation of the surface potential, electric ﬁeld, threshold voltage, and drain-induced barrier lowering. A model for the drain current, transconductance, drain conductance, and voltage gain is also discussed. It is seen that SCEs in this structure are suppressed because of the perceivable step in the surface-potential proﬁle, which screens the drain potential. We further demonstrate that the proposed DMDG structure provides a simultaneous increase in the transconductance and a decrease in the drain conductance when compared with the DG structure. The results predicted by the model are compared with those obtained by two-dimensional simulation to verify the accuracy of the proposed analytical model.
Index Terms—Double gate (DG), drain-induced barrier lowering (DIBL), dual-material gate (DMG), IV model, silicon-on-insulator (SOI) MOSFET, two-dimensional (2-D) modeling.
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