Fig. 2. (a)–(d) Transfer characteristics after 50 nm thickness Al₂O₃ deposition at coating temperatures of 100 °C, 130 °C, 140 °C and 150 °C, respectively. (e)–(h) Transfer characteristics after the Al₂O₃ deposition at 140 °C with coating thicknesses of 50 nm, 100 nm, 150 nm and 200 nm, respectively.