| 초록 |
Thin-film diodes (TFDs) have been studied in various designs to show small, light, transparent, and stable rectification characteristics for application to next-generation devices. Schottky diodes, formed by the junction of a semiconductor with a metal and MIM diodes of a metal-insulator-metal structure, are examples of conventional TFDs. However, there are limitations that the Schottky diode has a narrow operating voltage range, and the MIM diode exhibits a low rectification ratio. Recently, MIOS (metal-insulator-oxide semiconductor) TFDs have been studied as a next-generation diode due to their wide operating voltage and high rectification ratio. In particular, MIOS TFDs have the advantage of being able to selectively change the operating voltage range by adjusting the thickness of the insulator. Nevertheless, for the diversity of MIOS TFDs, it is necessary to have a technology that can selectively change the diode's turn-on voltage as well as the operating voltage range. Herein, we propose a new method to adjust the turn-on voltage of MIOS TFDs. We deposited a-IGZO (amorphous indium-gallium-zinc-oxide) as an oxide semiconductor layer of MIOS TFDs using a radio frequency magnetron sputtering system. When depositing a-IGZO, the oxygen vacancy could be easily changed by adjusting the oxygen partial pressure compared to argon inside the vacuum chamber. The difference in oxygen vacancies has a direct effect on the electrical properties of the carrier flowing through the defects in the silicon dioxide, which in turn causes for the diode turn-on voltage change. The results of precisely controlling the turn-on voltage of MIOS TFDs are expected to have a positive impact on securing diversity and industrial application of the next-generation diodes. |
