Superior High-Temperature Electrical Characteristics of ALD Ultrathin In2O3 Transistors

In this work, we report an effective method to improve the high-temperature reliability of atomic-layer-deposited (ALD) ultrathin (3 nm) indium oxide (In2O $_{{3}}\text {)}$ transistors. A high field-effect mobility ( $\mu _{\text {FE}}\text {)}$ of 80 cm2/V $\cdot $ s at 85 °C and an ultralow average rate of voltage shift of −0.8 mV/K were successfully demonstrated, which was attributed mainly to the efficient passivation of oxygen vacancies in the In2O3 channel by O3-based atomic layer deposition of HfO2, ultrathin channels, and high capacitance density. Excellent bias-thermal stability characteristics of In2O3 transistors were achieved. Low-frequency (1/ ${f}\text {)}$ noise is generated mainly in the channel region, and the noise level remains almost the same from 25 °C to 85 °C, indicating excellent interface quality and low trap density.