1. Locally non-uniform oxidation in selfterminating thermal oxidation assisted wet etching technique for AlGaN/GaN heterostructure.
- Author
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Jingqian Liu, Jinyan Wang, Zhe Xu, Haisang Jiang, Zhenchuan Yang, Maojun Wang, Min Yu, Bing Xie, Wengang Wu, Xiaohua Ma, Jincheng Zhang, and Yue Hao
- Subjects
OXIDATION ,THERMAL oxidation (Materials science) ,ALUMINUM gallium nitride ,TRANSMISSION electron microscopes ,ENERGY dispersive X-ray spectroscopy - Abstract
The oxidation mechanism in self-terminating wet etching technique with thermal oxidation of AlGaN layer followed by etching in KOH solution is investigated. Spike-shape remnants of oxidised AlGaN are observed at the initial stage of wet etching in KOH solution, which could be completely etched away after enough etching time. Transmission electron microscope/energy dispersive spectroscopy analysis indicates the existence of crystalline AlGaN inside the remnants. Finally, a possible explanation is given that the oxide channels from AlGaN surface towards AlGaN/GaN interface generated during thermal oxidation are firstly etched away at the initial stage of KOH wet etching, then after enough time these remnants with non-c axis crystal orientation surfaces exposed to KOH solution could be completely etched away leaving GaN layer beneath unaffected, which realises self-terminating etching. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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