Design and realization of resonant tunneling permeable base transistors

Abstract

Tunneling-based devices are promising in circuit applications due to low-power, high speed and high functionality. A new type of tunneling transistor, the Resonant Tunneling Permeable Base Transistor (RT-PBT) has recently been demonstrated 111. In this device, an embedded metallic gate is used to adjust the potential in an adjacent double barrier via Schottky depletion. As will be shown in this paper, the introduction of the current-limiting double barrier heterostnrcture changes the optimization of the device as compared to the Permeable Base Transistor (PBT) [2]. In particular, the gate is more effective at lower doping levels without a loss in transconductance. the transconductance is limited by the tunneling current density, and the capacitance shows only a modest dependence on the doping. The speed of the device, fT. is determined by the transwnductance, g, . and the total gate capacitance, CO, . To estimate these parameters, simulations were carried out based on a drift and d i is ion model. We used a single barrier to emulate the behavior (limit the current) of the double barrier and the barrier height was adjusted to match a typical tunneling current at peak bias (Vc=0.5 V and Jp=40 Wcm'or V,=1 .O V and Jp=140 Wcm').