Analytical model of surface potential profiles and transfer characteristics for hetero stacked tunnel field-effect transistors

Abstract

An analytical model of surface potential profiles and transfer characteristics for hetero stacked tunnel field-effect transistors (HS-TFETs) is presented for the first time, where hetero stacked materials are composed of two different bandgaps. The bandgap of the underlying layer is smaller than that of the upper layer. Under different device parameters (upper layer thickness, underlying layer thickness, and hetero stacked materials) and temperature, the validity of the model is demonstrated by the agreement of its results with the simulation results. Moreover, the results show that the HS-TFETs can obtain predominant performance with relatively slow changes of subthreshold swing (SS) over a wide drain current range, steep average subthreshold swing, high on-state current, and large on-off state current ratio.

An accurate analytical surface potential model of heterojunction tunnel FET

“…There have been many reported surface potential models for TFETs. [15][16][17][18][19][20][21][22][23] Some of these models assume that the channel is depleted, [15,16] which renders them inapplicable when the device is biased in the drain-control region. Although some models take the effect of the inversion charge into account, they ignore the effects of source depletion, [17][18][19] meaning the models cannot predict the influence of source doping, which is a key parameter to be designed.…”