Analog/RF performance of L- and U-shaped channel tunneling field-effect transistors and their application as digital inverters

Abstract

The inverter performance comparisons of L- and U-shaped channel tunneling field-effect transistors (LTFET and UTFET) are investigated by using Sentaurus TCAD tool. The RF figures of merit for these two TFETs are analyzed in terms of transconductance (gm), output conductance (gds), gate capacitance (Cgg), gate-to-source capacitance (Cgs), gate-to-drain capacitance (Cgd), unit-gain cut-off frequency (fT), the maximum frequency of oscillation (fMAX) and gain bandwidth product (GBW). The simulation results reveal that LTFET and UTFET have the similar DC characteristic due to the identical tunneling process. And the better RF performance LTFET provides due to it has the much smaller Cgd than UTFET. Meanwhile, this work uses mixed device-circuit simulations to predict the performance of inverter circuit implemented with LTFET and UTFET for the first time. And the calculated results demonstrate LTFET is more optimization for inverter circuit design in the novel generation transistors. And all the simulation results in this paper can be used as a reference to choose the characteristic parameters of novel TFETs for inverter applications.