Low-temperature and rapid photo-annealing process for metal-oxide thin-film transistors using combined excimer deep-ultraviolet and intensely pulsed light irradiation

Abstract

The fabrication of high-performance metal-oxide-based thin-film transistors (TFTs) on flexible and transparent polymer substrates by solution processes has garnered substantial interest, particularly for manufacturing flex-ible electronics. However, the annealing conditions for metal oxides, which require a high annealing temperature and prolonged annealing time, have been a crucial barrier to fabricate metal-oxide TFTs on polymer substrates. In this study, using a photo-annealing method based on combined excimer deep ultraviolet (EDUV) and intensely pulsed light (IPL) treatments. The EDUV has a peak at 172 nm and irradiates energy with an intensity of 65 mW/ cm(2) onto the target material. A Xenon lamp was used for IPL treatment with an irradiation energy fluence of 1.8 J/cm(2) when applied for one pulse duration. The total applied energy was controlled by the number of treatment pulses. The previous results of annealing temperature and annealing time of 140 ?C and 15 min were reduced to 130 ?C and 10 min, respectively. Moreover, a mobility of 5.35 cm(2)/Vs and on-off ratio of 106 were achieved. The optimal processing conditions determined in this study are applicable to polymer substrates and are expected to contribute to the production of transparent electronic devices on high-performance, large-area flexible substrates through continuous roll-to-roll printing.