Compact Modeling of Charge, Capacitance, and Drain Current in III–V Channel Double Gate FETs

In this paper, we present a surface potential based compact modeling of terminal charge, terminal capacitance, and drain current for III-V channel double gate field-effect transistor (DGFET) including the effect of conduction band nonparabolicity. The proposed model is developed accounting for the two-dimensional density of states and includes the effect of quantum capacitance associated with the low density of states channel material. In addition, model incorporates contribution of the first two sub-bands and efficiently captures the step like behavior appearing in the gate capacitance and transconductance with population of the higher sub-bands. The behavior of bias-dependent terminal capacitances and drain current is verified with the numerical simulation data of InGaAs channel DGFET and shows a close agreement with the simulation data.