Water-based processed and alkoxide-based processed indium oxide thin-film transistors at different annealing temperatures

摘要

In this study, indium oxide (In2O3) thin-film transistors (TFTs) are fabricated by two kinds of low temperature solution-processed technologies (Ta≤300 ?C), i.e., water-based (DIW-based) process and alkoxide-based (2-ME-based) process. The thickness values, crystallization properties, chemical structures, surface roughness values, and optical prop-erties of In2O3 thin-films and the electrical characteristics of In2O3 TFTs are studied at different annealing temperatures. Thermal annealing at higher temperature leads to an increase in the saturation mobility (μsat) and a negative shift in the threshold voltage (VTH). The DIW-based processed In2O3-TFT annealed at 300?C exhibits excellent device performance, and one annealed at 200 ?C exhibits an acceptable μsat of 0.86 cm2/V·s comparable to that of a-Si:H TFTs, whereas the 2-ME-based TFT annealed at 300?C exhibits an abundant μsat of 1.65 cm2/Vs and one annealed at 200?C is inactive. The results are attributed to the fact that the DIW-based process induces a higher degree of oxidation and less defect states than the 2-ME-based process at the same temperature. The DIW-based process for fabricating the In2O3 TFT opens the way for the development of nontoxic, low-cost, and low-temperature oxide electronics.