Titanium doped zinc oxide thin film transistors fabricated by cosputtering technique

Highlights: • TiZO TFTs were fabricated successfully by the cosputtering of Ti and ZnO targets. • Effects of sputtering power on the performance of TiZO TFTs were investigated. • TiZO thin films were characterized using XRD, AFM and SEM, which agreed well with the variation of device performance. • The optimal electrical performance was obtained at 60 W of ZnO sputtering power and 80 W of Ti sputtering power. • The TiZO material, as a kind of In-free oxide semiconductor, shows huge potential to be the active layer of TFTs. Titanium doped zinc oxide (TiZO) thin-film transistors (TFTs) were fabricated with the active layer deposited by the cosputtering of Ti and ZnO targets. We fabricated TiZO TFTs under various sputtering powers, effects of which on the performance of TiZO TFTs were investigated. The results suggest that the effective Ti doping concentration is significant for excellent electrical properties. The optimal electrical performance was obtained at 60 W of ZnO sputtering power and 80 W of Ti sputtering power. The changes in the crystalline structure, surface morphology and optical transmittance of TiZO thin films were examined according to the sputtering power, which agreed well with the variation of device performance.