A low-temperature method for improving the performance of sputter-deposited ZnO thin-film transistors with supercritical fluid.

A low-temperature method, supercritical CO₂ (SCCO₂) fluid technology, is employed to improve the device properties of ZnO TFT at 150 °C. In this work, the undoped ZnO films were deposited by sputter at room temperature and treated by SCCO₂ fluid which is mixed with 5 ml pure H₂O. After SCCO₂ treatment, the on/off current ratios and threshold voltage of the device were improved significantly. From x-ray photoelectron spectroscopy analyses, the enhancements were attributed to the stronger Zn–O bonds, the hydrogen-related donors, and the reduction in dangling bonds at the grain boundary by OH passivation. [ABSTRACT FROM AUTHOR]