Performance investigation of asymmetric double‐gate doping less tunnel FET with Si/Ge heterojunction

Abstract

Tunnel field effect transistors (TFETs) have been exhibiting an enticing performance to succeed in metal–oxide–semiconductor technology. However, TFET also possesses several challenges such as low drive current, ambipolarity, and requirement of abrupt doping profiles for the occurrence of band-to-band tunnelling (BTBT) conduction mechanism at the junction. To overcome these challenges, the authors propose a heterojunction doping less tunnel field-effect transistor with an asymmetric double gate (HJ ADG DLTFET). This device employs a low bandgap material at the source region, which increases the BTBT rate at the channel–source interface leading to enhanced drive current while maintaining low off-current. Consequently, an increment of one order for ION (∼1.5 × 10−5 A/µm) compared to the conventional ADG DLTFET has been provided by this device. Additionally, the comparative analysis of the proposed device and conventional one has been performed to reveal the advantages of the proposed structure in terms of transfer characteristics, transconductance, gate-to-drain capacitance, cut-off frequency, gain–bandwidth product, device efficiency, and transconductance frequency product. Moreover, the effect of gate length and drain voltage variations has been analysed for HJ ADG DLTFET concerning the aforementioned characteristics.