Design and investigation of doping-less gate-all-around TFET with Mg₂Si source material for low power and enhanced performance applications

Abstract

The MOSFET faces the major problem of being unable to achieve a subthreshold swing (SS) below 60 mV/dec. As device dimensions continue to reduce and the demand for high switching ratios for low power consumption increases, the TFETs (Tunnel Field Effect Transistors) appears to be a viable device, displaying promising characteristic as an answer to the shortcomings of the traditional MOSFETs. So far, TFET designing has been a task of sacrificing higher ON state currents for low subthreshold swing (and vice versa), and a device that displays both while maintaining structural integrity and operational stability lies in the nascent stages of popular research. This work presents a comprehensive analysis of a heterojunction plasma doped gate-all-around TFET (HPD-GAA-TFET) with a comparison between Mg2Si and Si as source material. Charge plasma technique has been employed to induce doping in an intrinsic silicon wafer with the help of suitable electrodes. A low-energy bandgap material, i.e., Magnesium Silicide has been incorporated as source material to form a heterojunction between source and silicon-based channel. A rigorous performance comparison between Si-based GAA-TFET and HPD-GAA-TFET has been drawn with respect to electrical, RF, linearity, and distortion parameters. It is observable that HPD-GAA-TFET outperforms conventional Si-based GAA-TFET presenting an ON-state current (ION), SS, threshold voltage (Vth), and current switching ratio as 0.377 mA, 12.660 mV/dec, 0.214 V, and 2.985×1012,respectively. Moreover, HPD-GAA-TFET holds faster switching in contrast to Si-based device and is also more reliable. Therefore, HPD-GAA-TFET shows suitable candidature for low-power applications.

GaAs-on-insulator based vertical heterojunction tunnel FET: proposal and analysis for VLSI circuit applications

“…Figure 9(b) shows the f T variation with V GS for both the proposed devices. f T shows the maximum frequency that can be escalated by a discrete device and is expressed as [44]:…”

“…g m should be constant with V GS to attain high linearity; however, it varies for TFETs thus reflecting non-linearity. In order to investigate the linearity and distortion performance of the device, several metrics like higher order transconductances (g m2 and g m3 ), second and third order voltage intercept points (VIP2 and VIP3), third-order input intercept point (IIP3), and second-order harmonic distortion (HD2) are evaluated using the expressions mentioned below [44] for both the proposed devices:…”