High-energy proton-radiation tolerance in IGZO synaptic transistors

Abstract

Exposure to cosmic rays leads to partial degradation of the electronic devices. This study tested the resilience of bare indium-gallium-zinc-oxide synaptic transistors under 33 MeV high-energy proton irradiation. In the transistors tested, clear differences were observed before and after high-energy proton irradiation. The drive current was reduced by 10–30 %, showing degradation with high-energy radioactive irradiation in the drain-to-source current–gate-to-source voltage (IDS–VGS) transfer characteristics. Despite the structural damage, the transistor still exhibited reasonable switching behavior. To understand the effects of irradiation on the contact junction, the series resistance (RSD) was calculated; RSD increased from 361 to 546 kΩ. Potentiation and depression were measured for evaluating the performance of the neuromorphic device application. The plasticity synaptic current change (ΔPSC) was 37.7 and 22.8 nA before and after proton irradiation. When measuring the current values of the reservoir computing (RC) states, clear differences in states were observed post-proton irradiation.