Transparent Oxide Thin-Film Transistors Composed of Al and Sn-doped Zinc Indium Oxide

We have fabricated the transparent bottom gate thin-film transistors (TFTs) using Al and Sn-doped zinc indium oxide (AT-ZIO) as an active layer. The AT-ZIO active layer was deposited by RF magnetron sputtering at room temperature, and the AT-ZIO TFT showed a field effect mobility of 15.6 cm
²
/Vs even before annealing. The mobility increased with increasing the In
₂
O
₃
content and postannealing temperature up to 250
^deg
C. The AT-ZIO TFT exhibited a field effect mobility of 30.2 cm
²
/Vs, a subthreshold swing of 0.17 V/dec, and an on/off current ratio of more than 10
⁹
.