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

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 (I_on) 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 I_on of the p-n junction TFET by the interface trap was smaller. Moreover, the p-n junction TFET exhibited lower gate-to-drain capacitance (C_gd) because a depletion capacitance (C_gd,dep) was formed by the depletion region under gate dielectric. Consequently, the p-n junction TFET achieved an improvement of cut-off frequency (f_T) and intrinsic delay time (τ), which are related to the current performance and total gate capacitance (C_gg). We confirmed the enhancement of device performances in terms of I_on, f_T, and τ by the conduction mechanism of the p-n junction TFET.