Highly Stable AlInZnSnO and InZnO Double-Layer Oxide Thin-Film Transistors With Mobility Over 50 $\text{cm}^{2}/\text{V} \cdot \text{s}$ for High-Speed Operation

We present high-mobility back channel etch Al-In-Zn-Sn-O/In-Zn-O (IZO) double-layer channel thin-film transistors (TFTs). The field-effect mobility of 53.2 cm
²
/V·s, threshold voltage of 0.5 V, and subthreshold swing of 0.15 V/decade were obtained with a thin IZO-inserted double-layer channel TFT. The positive bias stability was improved with an IZO-inserted double-layer channel. We fabricated 13-stage ring oscillators, which exhibited an oscillating frequency of 296 kHz at V
_DD
= 20. These results demonstrate that the proposed double-layer channel oxide TFT can be used for demanding applications such as backplane devices for ultrahigh resolution display.