Design and Analysis of Polarity Controlled Electrically Doped Tunnel FET With Bandgap Engineering for Analog/RF Applications

Abstract

In this paper, we investigate a polarity controlled electrically doped tunnel FET (ED-TFET) based on the bandgap engineering for analog/RF applications. The proposed device exhibits a heavily doped n-type Si-channel with two distinctive gate: 1) control gate (CG) and 2) polarity gate (PG). First, the work function of 4.72 eV is considered for CG and PG to convert the layer beneath CG and PG of intrinsic type. Further, a bias of −1.2 V is applied at PG terminal to induce a p+ region, so that, it follows the similar trend as like a n+-i-p+ gated structure of conventional TFET. To improve the ON-state current of the proposed device, we investigate an interfacing of III–V with IV group material for heterojunction. It shows higher ON-state current in the order of $10^{-4}$ A/ $\mu \text{m}$ , ${I}_{ \mathrm{\scriptscriptstyle ON}}/{I}_{ \mathrm{\scriptscriptstyle OFF}}$ ratio (in the order of $10^{12}$ ) at ${V}_{\sf DS} = 0.7$ V. Further, its higher transconductance ${g} _{m}\approx 1.02$ mS and different RF performance parameters in the range of terahertz, enables its potential for analog/RF applications. However, linearity parameters are analyzed to give the assurance of the device for high-frequency applications. Moreover, a nonquasi-static RF model is adopted to analyze the behavior of the proposed ED-TFET in high frequency region. Based on this, the small-signal parameters were extracted and verified upto 500 GHz. The modeled result shows excellentmatching with the Y-parameters upto 500 GHz.