Flexible, Gallium Oxide (Ga2O3) Thin Film Transistors (TFTs) and Circuits for the Internet of Things (IoT)

Even though present advanced silicon-based devices and technology could be reaching their zenith of performance levels, still there are many orthogonal applications, which are yet far from their reach. Also, due to their high process temperatures, there are still a number of applications that are out-of-reach for silicon, namely direct integration into flexible and printed electronics, as opposed to a hybrid integration of adding a prefabricated integrated circuit. These can find usage in low-cost and disposable wearable medical technologies. Therefore, the low temperature-solution processed oxide semiconductors that are complimentary to the performance of silicon are prerequisite for the forthcoming printed, flexible and wearable electronics revolution. Here, solution processed, flexible gallium oxide (Ga2O3) thin film transistors (TFT) and inverter circuit are reported. The high-K aluminium oxide (Al2O3) for the gate dielectric, was deposited with the help of a room temperature anodization process. The gallium oxide TFTs show high performance, with extracted electron mobility (µ) 2.74 cm2/V.s, operating voltage as low as 3V and threshold voltage (Vth) 0.61 V. The on/off ratio 104 and subthreshold swing (SS) 0.5 V/dec, Hysteresis 0.1 V and transconductance, gm, is 64.8 µS.