In-Ga-Zn-oxide Thin-film Transistors with Sb2TeOχ Gate Insulators Fabricated by Reactive Sputtering Using a Metallic SbTe Target

摘要

Using reactive sputtering, we made transparent amorphous Sb2TeOχ thin films from a metallic Sb2Te target in an oxidizing atmosphere. In-Ga-Zn-oxide thin-film transistors (IGZO TFTs) with Sb2TeOχ gate insulators deposited at room temperature showed a large hysteresis with a counterclockwise direction, which was caused by mobile charges in the gate insulators. The problems of the mobile charges was solved by using Sb2TeOχ films formed at 250 °C. After the IGZO TFT had been annealed at 200 °C for 1 hour in an O2 ambient, the mobility of the IGZO TFT was 22.41 cm2/Vs, and the drain current on-off ratio was ～108.