关键词: subthreshold, Mg₂Si, heterojunction, charge plasma, gate-all-around (GAA)

Abstract: Metal-oxide-semiconductor field-effect transistor (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 tunnel field-effect transistor (TFET) appears to be a viable device, displaying promising characteristic as an answer to the shortcomings of the traditional MOSFET. So far, TFET designing has been a task of sacrificing higher ON state current 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) by making a comparison between Mg$_{2}$Si and Si which serve as source materials. Charge plasma technique is employed to implement doping in an intrinsic silicon wafer with the help of suitable electrodes. A low-energy bandgap material, i.e. magnesium silicide is incorporated as source material to form a heterojunction between source and silicon-based channel. A rigorous comparison of performance between Si-based GAA-TFET and HPD-GAA-TFET is conducted in terms of electrical, radio frequency (RF), linearity, and distortion parameters. It is observable that HPD-GAA-TFET outperforms conventional Si-based GAA-TFET with an ON-state current ($I_{\rm ON}$), subthreshold swing (SS), threshold voltage ($V_{\rm th}$), and current switching ratio being 0.377 mA, 12.660 mV/dec, 0.214 V, and $2.985\times 10^{12}$, respectively. Moreover, HPD-GAA-TFET holds faster switching and is more reliable than Si-based device. Therefore, HPD-GAA-TFET is suitable for low-power applications.

Key words: subthreshold, Mg₂Si, heterojunction, charge plasma, gate-all-around (GAA)