Polarization-Engineered III-Nitride Heterojunction Tunnel Field-Effect Transistors

Abstract

The concept and simulated device characteristics of tunneling field-effect transistors (TFETs) based on III-nitride heterojunctions are presented for the first time. Through polarization engineering, interband tunneling can become significant in III-nitride heterojunctions, leading to the potential for a viable TFET technology. Two prototype device designs, inline and sidewall-gated TFETs, are discussed. Polarization-assisted p-type doping is used in the source region to mitigate the effect of the deep Mg acceptor level in p-type GaN. Simulations indicate that TFETs based on III-nitride heterojunctions can be expected to achieve ON/ OFF ratios of $10^{6}$ or more, with switching slopes well below 60 mV/decade, ON-current densities approaching 100 $\mu \text{A}/\mu \text{m}$ , and energy delay products as low as 67 aJ-ps/ $\mu \text{m}$ .