Performance improvement in electrospun InGaZnO nanofibres field-effect-transistors using low thermal budget microwave calcination and Ar/O2 mixed-plasma surface treatment

In this study, we present a low thermal budget microwave annealing (MWA) method for calcination of electrospun In-Ga-ZnO (IGZO) nanofibres and demonstrate an improvement in the performance of IGZO nanofibre field-effect transistors (FETs) by Ar/O-2 mixed-plasma surface treatment. The IGZO nanofibres were fabricated by electrospinning method and calcined using MWA method. This process allowed for a significant reduction in the heat treatment temperature and time. Subsequently, plasma surface treatment using various ratios of Ar/O-2 gas mixtures was carried out. The surface morphology and chemical composition of MWA-calcined and plasma-treated IGZO nanofibres were studied by SEM and XPS analysis. In order to investigate the effects of MWA calcination combined with Ar/O-2 mixed-plasma treatment on the electrical properties and the reliability of nanofibres-based transistors, IGZO nanofibres FETs were fabricated and applied to resistor-loaded inverters. Our results show that the O-2 plasma treatment significantly improves the performance of IGZO nanofibres FETs and the resistor-loaded inverters based on IGZO nanofibres FETs, whereas Ar plasma treatment degrades the performance of these devices. The instability tests using positive bias temperature stress (PBTS) and negative bias temperature stress (NBTS) revealed that the O-2 plasma treatment contributed to the stability of IGZO nanofibres FETs. Our results suggest that the MWA calcination combined with the Ar/O-2 mixed-plasma surface treatment is a promising technique for the fabrication of high performance IGZO nanofibres FETs with low thermal budget processes.