| AVS 65th International Symposium & Exhibition | |
| Thin Films Division | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Film Poster Session |
| Presenter: | Jintaek Park, Seoul National University, Republic of Korea |
| Authors: | J. Park, Seoul National University, Republic of Korea K.-H. Lim, Seoul National University, Republic of Korea S.-E. Lee, Seoul National University, Republic of Korea J.-E. Huh, Seoul National University, Republic of Korea J. Lee, Seoul National University, Republic of Korea E.G. Lee, Seoul National University, Republic of Korea C.I. Im, Seoul National University, Republic of Korea Y.S. Kim, Seoul National University, Republic of Korea |
| Correspondent: | Click to Email |
Solution-processed thin-film transistors (TFTs) have received great attention as a next generation display manufacturing method, because they do not require cumbersome equipment compared to the vacuum process and can be applied to the roll-to-roll process. Therefore, oxide semiconductors such as InOx using aqueous route method have been studied in a simple and inexpensive process. However, most of the research is confined to the semiconductor thin film, and the research on the gate insulating film which is indispensable for the constitution of the TFT device is insufficient.
In general, high-k materials such as AlOx, HfOx, and TaOx have been used as dielectric layers because they can provide large gate capacitance without significantly increasing gate leakage current. Among all high-k dielectric materials, AlOx is widely used because of its low deposition temperature, low cost, and good compatibility with oxide semiconductors.
In this study, AlOx using aqueous route method was deposited by a solution process and its characteristics were evaluated. Characteristic changes through atmospheric-pressure plasma treatment were observed by measurement of capacitance-frequency and breakdown voltage. It was observed that the frequency dependence of AlOx capacitance was reduced by atmospheric-pressure plasma treatment. In general, the frequency dependence of the AlOx capacitance is because of the ions in the layer limit the polarization response time. Thus, the changes of binding relationship according to plasma treatment time were analyzed by X-ray photoelectron spectroscopy (XPS). In addition, TFTs were fabricated by depositing a solution-processed InOx with a semiconductor film, and the characteristics were evaluated. It was observed that field-effect mobility increased from 6.7 to 15.1 compared to the untreated samples. The surface roughness of the AlOx films was investigated by atomic force microscopy (AFM). Semiconductor and gate dielectric fabrication, and plasma processing were performed in a non-vacuum environment and the process temperature was below 250 ℃.