As channel length of metal-oxide-semiconductor field-effect transistors (MOSFETs) is deeply scaled down, enhancing the carrier mobility in the channel is desired for improving the performance of complementary MOS (CMOS) circuit. SiGe is a promising channel material because of its high electron and hole mobility. Higher Ge content in SiGe film makes higher mobility of both electrons and holes, and the oxidation process of SiGe is an easy way to achieve higher Ge content. In this study, various oxidation conditions were performed of SiGe film, and a conventional p-type thin-film-transistor (TFT) was fabricated on it. I-V characteristics were measured to investigate the influence on electrical properties of the various oxidation conditions. It is found that the devices of higher oxidation temperature, longer oxidation time, and higher oxygen flow show better electrical performance. It is also found that devices under lower oxidation rate have lower leakage current and then induce higher On/Off ratio.