Evaluation of Nd-Al doped indium-zinc oxide thin-film transistors by a μ-PCD method

摘要

In this work, we investigated the effect of deposition conditions such as sputtering power, oxygen ratio and sputtering pressure on the properties of Nd-Al doped indium-zinc oxide (NAIZO) thin-film transistors based on copper (Cu) electrodes. The quality of deposited films was evaluated by introducing a microwave photoconductivity decay (mu-PCD) measurement. The results showed strong connection between sputtering conditions and mu-PCD results, which reveal that sputtering process was vital for film quality control. In addition, the tendency of obtained Peak value and D value from mu-PCD was in highly consistent with the final devices performance especially the saturation mobility. As a result, the optimized devices showed a saturation mobility of 21.4 cm(2)V(-1)S(-1), threshold voltage about 1.0 V, subthreshold swing about 0.18 V/decade and I-on/I-off ratio about 9.9 x 10(7). The non-destructive and efficient mu-PCD method offers a convenient way to optimize the deposition procedure for metal oxide semiconductors.