Investigation of Energy Band at Atomic-Layer-Deposited ZnO/β-Ga2O3 ([Formula: see text]) Heterojunctions

Shun-Ming Sun; Wen-Jun Liu; Yi-Fan Xiao; Ya-Wei Huan; Hao Liu; Shi-Jin Ding; David Wei Zhang

doi:10.1186/s11671-018-2832-7

Investigation of Energy Band at Atomic-Layer-Deposited ZnO/β-Ga₂O₃ ([Formula: see text]) Heterojunctions

Nanoscale Res Lett. 2018 Dec 24;13(1):412. doi: 10.1186/s11671-018-2832-7.

Authors

Shun-Ming Sun¹, Wen-Jun Liu¹, Yi-Fan Xiao¹, Ya-Wei Huan¹, Hao Liu¹, Shi-Jin Ding¹, David Wei Zhang¹

Affiliation

¹ State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433 China.

Abstract

The energy band alignment of ZnO/β-Ga₂O₃ ([Formula: see text]) heterojunction was characterized by X-ray photoelectron spectroscopy (XPS). The ZnO films were grown by using atomic layer deposition at various temperatures. A type-I band alignment was identified for all the ZnO/β-Ga₂O₃ heterojunctions. The conduction (valence) band offset varied from 1.26 (0.20) eV to 1.47 (0.01) eV with the growth temperature increasing from 150 to 250 °C. The increased conduction band offset with temperature is mainly contributed by Zn interstitials in ZnO film. In the meanwhile, the acceptor-type complex defect V_zn + OH could account for the reduced valence band offset. These findings will facilitate the design and physical analysis of ZnO/β-Ga₂O₃ relevant electronic devices.

Keywords: ALD; Contacts; ZnO; β-Ga2O3.