Performance comparison between p–i–n and p–n junction tunneling field-effect transistors

Abstract

In this study, we investigated the direct-current (DC) and radio-frequency (RF) performances of p–i–n and p–n junction tunneling field-effect transistors (TFETs). Compared to the p–i–n junction TFET, the p–n junction TFET exhibited higher on-state current (Ion) because the channel formation mechanism of the p–n junction TFET resulted in a narrower tunneling barrier and an expanded tunneling area. Further, the reduction of Ion of the p–n junction TFET by the interface trap was smaller. Moreover, the p–n junction TFET exhibited lower gate-to-drain capacitance (Cgd) because a depletion capacitance (Cgd,dep) was formed by the depletion region under gate dielectric. Consequently, the p–n junction TFET achieved an improvement of cut-off frequency (fT) and intrinsic delay time (τ), which are related to the current performance and total gate capacitance (Cgg). We confirmed the enhancement of device performances in terms of Ion, fT, and τ by the conduction mechanism of the p–n junction TFET.