This paper reports an InGaZnO thin-film transistor involving a wide bandgap gate dielectric of ZrO2 and IGZO/TiOx channel stack. According to our experimental results, the IGZO TFT with a thin TiOx channel capping layer shows good device integrity of a low threshold voltage of 0.37 V, a small sub-threshold swing of 77 mV/decade, and a high mobility of 33 cm(2)/V.s under a low drive voltage of < 2 V. We also demonstrate that the significantly improved electrical property is mainly contributed by the enhanced channel electric field after TiOx capping, associated with maximizing charge accumulated capability. The favorable high-temperature transfer characteristics are also obtained in IGZO/TiOx TFT, indicating a weak Fermi-level pinning in IGZO/TiOx channel structure. With the operating temperature increasing further, the thermal activated effect shall dominate IGZO channel property beyond percolation conduction.
- Indium-gallium-zinc oxide (IGZO); thin-film transistor (TFT); titanium oxide (TiOx); zirconium oxide (ZrO2)
- FILM; TRANSISTORS; TFT
Hsu, H-H., Cheng, C-H., Chiou, P., Chiu, Y. C., Yen, S. S., Tung, C-H., & Chang, C-Y. (2015). Temperature-Dependent Transfer Characteristics of Low Turn-On Voltage InGaZnO Metal-Oxide Devices With Thin Titanium Oxide Capping Layers. IEEE/OSA Journal of Display Technology, 11(6), 512-517. https://doi.org/10.1109/JDT.2014.2355876