Effect of Soft Baking Temperature on Solution-Processed In-Ga-Zn-O Thin-Film-Transistor at Low Temperature

We fabricated solution-processed In-Ga-Zn-O (IGZO) thin-film-transistors (TFTs) at soft baking temperatures ranging from 160 to 250 degrees C. In general, soft heat treatments should be conducted at low temperatures in order to ensure adhesion and chemical stability. This process is characterized by low-temperature primary chemical reactions. The relationship between these reactions and the electrical performance of the TFT were investigated on the basis of the chemical and electronic characteristics. The devices were subjected to identical post deposition annealing (microwave irradiation). However, the electrical characteristics (field effect mobility, threshold swing, and hysteresis) varied significantly with the prior softbaking temperature (160-250 degrees C, 10 min). This suggests that, owing to the removal of impurities, low softbaking temperatures are conducive for achieving excellent electrical characteristics.