TCAD Simulation of Single-Event-Transient Effects in L-Shaped Channel Tunneling Field-Effect Transistors

Abstract

Tunnel field-effect transistors (TFETs) have promising structures for future ultrascaled devices thanks to their capability in reducing swing threshold and short channel effects. In this paper, Si-based L-shaped channel TFETs (LTFETs) with buried oxide layers subjected to heavy-ion irradiation are scrutinized using Technology Computer-Aided Design simulation for the first time. The effects of linear energy transfer and voltage bias on single-event effects (SEEs) are investigated. Results show that the peak value of drain current in LTFET reaches up to 2.59 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> A at 10 MeV · cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /mg, which is much higher than the on-state current at Vd = 0.5 V. Moreover, it indicates that LTFET is more sensitive to SEE than fully depleted silicon-on-insulator MOSFET with back-plane layer. Meanwhile, overall analysis shows that the charge collection process in LTFET device is mainly due to the drift-diffusion mechanism and the bipolar amplification effect can be eliminated. A part of the hole produced by ion strikes will diffuse from the body into the drain region and help reduce the duration of transient. Moreover, by simulating heavy-ion strike in the lateral and vertical channels in LTFETs, the tunneling junction was first confirmed as the most sensitive part of the TFET against heavy-ion impacts, where the highest electric field in the device is found. These findings give a new insight into the SEE in TFETs, which can provide guidelines for the future radiation-hardened applications for TFET-based circuits.