Abstract
Atomic‐layer‐deposited SnO2 is used as a gate electrode to replace indium tin oxide (ITO) in thin‐film transistors and circuits for the first time. The SnO2 films deposited at 200 °C show low electrical resistivity of ≈3.1 × 10−3 Ω cm with ≈93% transparency in most of the visible range of the electromagnetic spectrum. Thin‐film transistors fabricated with SnO2 gates show excellent transistor properties including saturation mobility of 15.3 cm2 V−1 s−1, a low subthreshold swing of ≈130 mV dec−1, a high on/off ratio of ≈109, and an excellent electrical stability under constant‐voltage stressing conditions to the gate terminal. Moreover, the SnO2‐gated thin‐film transistors show excellent electrical characteristics when used in electronic circuits such as negative channel metal oxide semiconductor (NMOS) inverters and ring oscillators. The NMOS inverters exhibit a low propagation stage delay of ≈150 ns with high DC voltage gain of ≈382. A high oscillation frequency of ≈303 kHz is obtained from the output sinusoidal signal of the 11‐stage NMOS inverter‐based ring oscillators. These results show that SnO2 can effectively replace ITO in transparent electronics and sensor applications.
Atomic‐layer‐deposited SnO2 is used as a gate electrode for thin‐film‐transistor devices and circuits. The electrical properties of the SnO2‐gated devices and circuits show very good and comparable performance to devices and circuits using ITO electrodes. These results show that SnO2 has the potential to replace indium tin oxide as the gate‐electrode material in transparent electronics applications.