Amorphous oxide semiconductors (AOSs) are of great current interest for thin-film transistor (TFT) channel layer applications. In particular, indium gallium zinc oxide (IGZO) is under intense development for commercial applications because of its demonstrated high performance at low processing temperatures. The objective of the research presented in this book is to provide detailed assessments of device stability, temperature dependence, and related phenomena for IGZO- based TFTs processed at temperatures between 200 C and 300 C.