Spacer Dielectric Engineering for Enhanced Analog/RF Performance in Dual-Metal Double Gate GaAs/Si1-xGex TFETs

Abstract

The present study provides an investigation DMDG GaAs/Si1 − xGex tunnel field-effect transistor device (TFET) with dielectric spacer based on its ana- log and RF performance metrics. The device performance is assessed for varying spacer dielectric medium (εr = 1, 3.9, 7.5, 9, 25). For precise device modeling and electrostatic control, all simulations are conducted using the 2D TCAD sim- ulation platform. The study reveals that by using the high-k spacers the device parameters i.e., transconductance, cut-off frequency, and gain bandwidth product, substantially increased whereas the threshold voltage decreased. However, use of low-k spacers suppresses the parasitic capacitances but lowers ON-state current (ION). The incorporated spacer modulation indicates that εr = 9 offers an opti- mized device DC and RF characteristic and obtains a higher ION/IOFF ratio. These findings emphasize the significance of dielectric spacer selection as a significant design element for energy-efficient and high-speed nanoelectronic circuits.