Breaking the Trade‐Off Between Mobility and On–Off Ratio in Oxide Transistors

Abstract

Amorphous oxide semiconductors (AOS) are pivotal for next‐generation electronics due to their high electron mobility and excellent optical properties. However, In2O3, a key material in this family, encounters significant challenges in balancing high mobility and effective switching as its thickness is scaled down to nanometer dimensions. The high electron density in ultra‐thin In2O3 hinders its ability to turn off effectively, leading to a critical trade‐off between mobility and the on‐current (Ion)/off‐current (Ioff) ratio. This study introduces a mild CF4 plasma doping technique that effectively reduces electron density in 10 nm In2O3 at a low processing temperature of 70 °C, achieving a high mobility of 104 cm2 V⁻¹ s⁻¹ and an Ion/Ioff ratio exceeding 10⁸. A subsequent low‐temperature post‐annealing further improves the critical reliability and stability of CF4‐doped In2O3 without raising the thermal budget, making this technique suitable for monolithic three‐dimensional (3D) integration. Additionally, its application is demonstrated in In2O3 depletion‐load inverters, highlighting its potential for advanced logic circuits and broader electronic and optoelectronic applications.