<i>In situ</i> nitrogen doping enables highly stable InSnZnON thin-film transistors

Abstract

This study proposes a coupling strategy combining co-sputtering and in situ nitrogen doping, which is used to fabricate nitrogen-doped indium-tin-zinc-oxide (ITZON) thin-film transistors (TFTs) that possess both high electrical performance and excellent stability. The ITZON channel layer was successfully fabricated through co-sputtering of ITO and ZnO targets in the Ar/N2 atmosphere. Comprehensive material characterization combined with technology computer aided design simulations reveals that the enhanced performance and stability originate from nitrogen doping effectively passivating oxygen vacancies, improving interface quality, and optimizing carrier transport pathways enabled by nitrogen incorporation. The optimized ITZON TFTs exhibit outstanding overall performance with the field-effect mobility (μFE) of 48.65 cm2/V s, the subthreshold swing of 0.34 V/dec, the threshold voltage (VTH) of −0.41 V, and minimal hysteresis of 0.09 V. Under positive/negative gate bias stress and positive/negative bias illumination stress tests, the devices demonstrate exceptional stability with threshold voltage shifts (ΔVTH) of +0.26 V, −0.73 V, +1.55 V, and −1.09 V, respectively. The strategy provides a simple and process-friendly solution for achieving high-performance multicomponent oxide TFTs.