Photo-Electrical Properties of MgZnO Thin-Film Transistors With High- ${k}$ Dielectrics

In this letter, magnesium zinc oxide (MgZnO) was deposited to fabricate a thin-film transistor (TFT) by radio-frequency magnetron sputtering. We used alumina as MgZnO TFT gate insulator layer via an atomic layer deposition method. The MgZnO TFT with Al
₂
O
₃
insulator could exhibit a mobility of 7.73 cm
²
/Vs, threshold voltage of 4.2 V, and subthreshold swing of 0.29 V/decade. Compared with our previous published study, the current switching ratio was improved by nearly two orders of magnitude. Furthermore, the hysteresis phenomenon had been investigated and the results showed that the high-k gate insulator could improve the interface state caused by the traps.