Cho Seong-Kun, Cho Won-Ju
Department of Electronic Materials Engineering, Kwangwoon University, Seoul 139-701, Republic of Korea.
J Nanosci Nanotechnol. 2020 Jul 1;20(7):4163-4169. doi: 10.1166/jnn.2020.17781.
In this study, we propose a simplified-single-step microwave annealing (S₃-MWA) technique in an O₂ ambient, which is a low thermal budget heat treatment method, for the application in solutionprocessed amorphous indium-gallium-zinc oxide (-IGZO) thin films. For the application of solutionprocessed -IGZO films in electronic devices, a multi-step post deposition annealing (PDA) process, which involves baking at low temperatures to vaporize the solvent, and high temperature conventional thermal annealing to remove defects in the film, is essential. To simplify the multi-step PDA process, we studied the possibility of reducing the thermal process temperature and time by replacing it with a single-step PDA process using microwave equipment. The electrical properties were compared to investigate the effect of the annealing method and ambient on solution-processed -IGZO thin film transistors (TFTs). As a result, the S₃-MWA-processed -IGZO TFTs were found to exhibit superior electrical characteristics in comparison with the conventional PDA-processed devices. It was found that the O₂ ambient process not only shortened the annealing time of S₃-MWA but also improved the electrical properties. Furthermore, the S₃-MWA was superior to the conventional PDA in the evaluation of device reliability under a gate bias stress test. The S₃-MWA process in the O₂ ambient was also responsible for improving the reliability of solution-processed -IGZO TFTs. Therefore, we confirmed that the proposed S₃-MWA in the O₂ ambient is a more effective and promising technique than conventional PDA for the low thermal budget treatment of solution-processed -IGZO TFTs.
在本研究中，我们提出了一种在氧气环境中的简化单步微波退火（S₃-MWA）技术，这是一种低热预算热处理方法，用于溶液处理的非晶铟镓锌氧化物（-IGZO）薄膜。对于溶液处理的-IGZO薄膜在电子器件中的应用，多步沉积后退火（PDA）工艺至关重要，该工艺包括在低温下烘烤以蒸发溶剂，以及在高温下进行传统热退火以去除薄膜中的缺陷。为了简化多步PDA工艺，我们研究了用微波设备的单步PDA工艺替代它来降低热处理温度和时间的可能性。通过比较电学性能来研究退火方法和环境对溶液处理的-IGZO薄膜晶体管（TFT）的影响。结果发现，与传统PDA工艺处理的器件相比，经S₃-MWA工艺处理的-IGZO TFT表现出优异的电学特性。发现氧气环境工艺不仅缩短了S₃-MWA的退火时间，还改善了电学性能。此外，在栅极偏置应力测试下评估器件可靠性时，S₃-MWA优于传统PDA。氧气环境中的S₃-MWA工艺还提高了溶液处理的-IGZO TFT的可靠性。因此，我们证实，对于溶液处理的-IGZO TFT的低热预算处理，所提出的氧气环境中的S₃-MWA是一种比传统PDA更有效且有前景的技术。
