Vertical Channel ZnO Thin-Film Transistors Using an Atomic Layer Deposition Method

Vertical channel ZnO thin-film transistors (TFTs) were fabricated on glass and flexible substrates. Conformally deposited thin films prepared using atomic layer deposition were used for the active layer, gate insulator, and gate electrode. Owing to the very short channel (0.5 μm) and very thin (20 nm) gate insulator layer, the ON-current of the vertical channel ZnO TFT was 57 μA at the gate and drain voltages of 3 and 4 V, respectively. Vertical channel oxide TFTs may be promising for device applications with low power consumption.