Novel attributes of steep-slope staggered type heterojunction p-channel electron-hole bilayer tunnel field effect transistor

Abstract

In this paper, the electrical characteristics and sensitivity analysis of staggered type <em>p</em>-channel heterojunction electron-hole bilayer tunnel field effect transistor (HJ-EHBTFET) are thoroughly investigated via simulation study. The minimum lattice mismatch between InAs/GaAs_0.1Sb_0.9 layers besides low carrier effective mass of materials provides high probability of tunneling current that eventually boosts the device performance. Unlike the conventional lateral tunnel field effect transistor (TFET), band to band tunneling (BTBT) in HJ-EHBTFET occurs in the electrically doped intrinsic channel and in the vertical direction which may considerably improve the on-state current. Due to the abrupt BTBT and steep transition from the off-state to on-state, subthreshold swing of 2mV/dec with on/off current ratio of 3.85×10¹³ is obtained. The sensitivity of main electrical parameters is computed via calculating their related standard deviation and mean values with respect to the variation of device critical design parameters. The 2D variation matrix of threshold voltage is computed as a function of top and bottom gate workfunction for determining an optimum value aiming towards competent electrical characteristics. In addition, the sensitivity analysis reveals that the electrical parameters are rarely susceptible to the source doping density, which may considerably solve the limit of dopant solubility in III-V materials. Moreover, HJ-EHBTFET is dramatically unaffected by the variation of gate overlap length and drain voltage, which makes the device have efficient performance in nanoscale regime.