The 82nd JSAP Autumn Meeting 2021

Presentation information

Oral presentation

21 Joint Session K "Wide bandgap oxide semiconductor materials and devices" » 21.1 Joint Session K "Wide bandgap oxide semiconductor materials and devices"

[12p-N206-1~19] 21.1 Joint Session K "Wide bandgap oxide semiconductor materials and devices"

Sun. Sep 12, 2021 1:00 PM - 6:15 PM N206 (Oral)

Mutsumi Sugiyama(Tokyo Univ. of Sci.), Katayama Tsukasa(Hokkaido Univ), Riena Jinno(Univ of Tokyo)

1:00 PM - 1:15 PM

[12p-N206-1] Conversion of Solution-processed Amorphous Gallium Oxide Insulator to Semiconductor through Hydrogen Incorporation

〇(D)Diki Purnawati1, Juan Paolo Bermundo1, Michael Paul Jallorina1, Yukiharu Uraoka1 (1.NAIST)

Keywords:Conversion, Gallium Oxide, Hydrogen Incorporation

Amorphous Gallium Oxide (a-GaOx) is a fascinating material owing to its ultra-wide bandgap (UWB) (~4.8 eV), excellent device stability, high transparency, smooth surface, and compatibility with solution process. Moreover, a-GaOx have been proposed to improve device stability. Nevertheless, a-GaOx-based TFT shows poor mobility due to its low carrier concentration. With relatively few-research on solution-processed UWB a-GaOx TFTs and with most studies employing GaOx with crystalline structure processed at high temperatures (>600°C), this work on solution processed a-GaOx TFT is promising and interesting to report. The a-GaOx TFT was successfully converted into their semiconducting state after H2 annealing. Simultaneously, high RH ambient evidently improves the saturation mobility (μsat) from 6.0×10-4 to 1.0×10-2 cm2V-1s-1. This suggest that both H2-annealing and high RH contributed to high amount of hydrogen concentrations which incorporated into the a-GaOx channel during the treatments. Furthermore, H-incorporated contributed as shallow donor states which increase the μsat. The increased carrier concentration correlated well to the Fermi level energy (Ef) of each condition. The Ef shifted closer to the CBM implying higher electron concentration which leads to increase mobility. Thus, by maintaining the amorphous structure, insulator-to-semiconductor conversion of the a-GaOx channel has been successfully shown through the observed TFT switching obtained after hydrogenation. Moreover, we expect that this remarkable effect will remain robust.