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

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 (I-on)/off-current (I-off) 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 degrees C, achieving a high mobility of 104 cm(2) V-1 s(-1) and an I-on/I-off ratio exceeding 10(8). 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.