Abstract AlGaN/GaN heterostructures on vicinal sapphire substrates and just-oriented sapphire substrates (0001) are grown by the metalorganic chemical vapor deposition method. Samples are studied by high-resolution x-ray diffraction, atomic force microscopy, capacitance--voltage measurement and the Van der Pauw Hall-effect technique. The investigation reveals that better crystal quality and surface morphology of the sample are obtained on the vicinal substrate. Furthermore, the electrical properties are also improved when the sample is grown on the vicinal substrate. This is due to the fact that the use of vicinal substrate can promote the step-flow mode of crystal growth, so many macro-steps are formed during crystal growth, which causes a reduction of threading dislocations in the crystal and an improvement in the electrical properties of the AlGaN/GaN heterostructure.
Received: 09 January 2009
Revised: 12 April 2009
Accepted manuscript online:
PACS:
73.40.Kp
(III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions)
Fund: Project supported by the State Key
Program of National Natural Science Foundation of China (Grant No
60736033) and the National Key Science and Technology Special
Project (Grant No 2008ZX 0101002-003).
Cite this article:
Xu Zhi-Hao(许志豪), Zhang Jin-Cheng(张进成), Zhang Zhong-Fen(张忠芬), Zhu Qing-Wei(朱庆玮), Duan Huan-Tao(段焕涛), and Hao Yue(郝跃) The effects of vicinal sapphire substrates on the properties of AlGaN/GaN heterostructures 2009 Chin. Phys. B 18 5457
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