Band alignment of indium-gallium-zinc oxide/β-Ga2O3 heterojunction determined by angle-resolved X-ray photoelectron spectroscopy

• Published in: Japanese Journal of Applied Physics Vol. 57; no. 10
• Main Authors: Huan, Ya-Wei, Wang, Xing-Lu, Liu, Wen-Jun, Dong, Hong, Long, Shi-Bing, Sun, Shun-Ming, Yang, Jian-Guo, Wu, Su-Dong, Yu, Wen-Jie, Horng, Ray-Hua, Xia, Chang-Tai, Yu, Hong-Yu, Lu, Hong-Liang, Sun, Qing-Qing, Ding, Shi-Jin, Zhang, David Wei
• Format: Journal Article
• Language: English
• Published: The Japan Society of Applied Physics 01.10.2018
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/JJAP.57.100312

The energy band offsets between indium-gallium-zinc oxide (IGZO) and β-Ga2O3 were examined by angle-resolved X-ray photoelectron spectroscopy (AR-XPS). The Ga 2p spectra from the heterojunction contributed by the upper IGZO film and the β-Ga2O3 substrate were deconvoluted into two sub-peaks with the binding energy difference of 0.3 eV, in good agreement with the theoretical model. Meanwhile, the bandgaps of IGZO and β-Ga2O3 were measured to be 3.44 ± 0.1 and 4.64 ± 0.1 eV from the ultraviolet-visible (UV-vis) transmittance spectra. The valence and conduction band offsets between the IGZO and β-Ga2O3 were consequently determined to be 0.49 ± 0.05 and 0.71 ± 0.1 eV, respectively. These findings reveal that IGZO is an attractive intermediate semiconductor layer (ISL) for reducing the electron barrier height at metal/Ga2O3 interfaces.