Si/Ge Hetero Tunnel Field-Effect Transistor with Junctionless Channel Based on Nanowire.

Abstract

A Si/Ge hetero tunnel field-effect transistor (TFET) with junctionless channel based on nanowire (JLNW-TFET) is proposed, and its electrical performance and dependency of natural parameters are investigated. The JLNW-TFET is operated by compensating each demerit of the following two mechanisms: thermionic generation of junctionless field-effect transistor (JLFET) and band to band tunneling (BTBT) generation of tunnel field-effect transistor (TFET). Although the on-current Ion of JLNW-TFET decreases approximately ten times as much as that of the conventional TFET, its subthreshold swing SS is three times steeper than that of the conventional TFET and ambipolar current Iambipolar does not appear as a result of the structural characteristics. Ioff increases due to Shockley-Read-Hall (SRH) recombination when the density of traps increases; however, an increase in SS is not observed. At temperatures higher than room temperature, Ioff increases slightly and SS and Ion are almost constant. Furthermore, quantum confinement and trap assisted tunneling do not significantly affect the performance of the devices except for increasing Ioff and slightly decreasing Ion.