Self-aligned coplanar amorphous indium zinc oxide thin-film transistors with high performance

Abstract

Self-aligned coplanar amorphous indium zinc oxide thin-film transistors (a-IZO TFTs) were fabricated. The a-IZO TFTs had a field-effect mobility of μFE=24.4cm2V−1s−1, a subthreshold slope of 180mV/dec, and an on/off ratio of 109. As the channel length decreased, the threshold voltage VTH shifted to more negative voltages, and μFE increased due to the diffused carriers from the contact regions. The intrinsic field-effect mobility was estimated to be 15.05cm2V−1s−1 in the linear mode and 13.28cm2V−1s−1 in saturation mode. Under positive/negative bias–temperature–illumination stress, the shift in VTH was less than ±0.7V after 11,000s.