[12a-N206-1~9] 21.1 Joint Session K "Wide bandgap oxide semiconductor materials and devices"

[12a-N206-7] Hard x-ray photoemission spectroscopy on InGaZnO₄ bulk single crystals

〇Yunosuke Takahashi¹, Goro Shibata¹, Mario Okawa¹, Akira Yasui², Yasumasa Takagi², Yusuke Kawamura¹, Naoki Kase¹, Nobuaki Miyakawa¹, Tomohiko Saitoh¹ (1.Tokyo Univ.of Sci., 2.JASRI/SPring-8)

Keywords:IGZO, photoemission spectroscopy, single crystal

NBIS reported in amorphous IGZO(a-IGZO) thin film transistors is a challenging problem to be solved for stabilizing its behavior. Its origin is considered to be attributed to subgap states located just above the valence band. We performed HX-PES measurements on InGaZnO₄ bulk single crystals and concluded that the subgap states are not attributed to oxygen vacancies but crystallinity.