Impact of Metal Salt Precursor on Low-Temperature Annealed Solution-Derived Ga-doped In₂O₃ Semiconductor for Thin-Film Transistors

Abstract

Sol–gel-derived oxide semiconductors annealed at a low temperature have been of great interest recently in various thin-film transistor (TFT) applications. However, studies on the influence of metal salt precursor on sol–gel-derived oxide semiconductor annealed at a low temperature have not yet been reported. In this study, the impact of metal salt precursor on the chemical structure evolution of Ga-doped In2O3 (IGO) semiconductor and electrical performance of thin-film transistors with a corresponding oxide semiconductor is investigated. X-ray photoelectron spectroscopy (XPS)-based chemical structure analysis is carried out in conjunction with an understanding of the electrical performance of device. It is revealed that in addition to the thermally enhanced evolution of metal oxide chemical structure, the impurities due to the incomplete thermal decomposition of metal salt precursor do not only hinder the formation of metal oxide lattice, resulting in an electrically inactive oxide semiconductor, but also significantly deteriorate the electrical performance, such as field-effect mobility, subthreshold swing, and on/off current ratio, of thin-film transistor.