中国物理B ›› 2012, Vol. 21 ›› Issue (10): 108101-108101.doi: 10.1088/1674-1056/21/10/108101

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Quantum dots-templated growth of strain-relaxed GaN on a c-plane sapphire by radio-frequency molecular beam epitaxy

郭浩民, 文龙, 赵志飞, 步绍姜, 李新化, 王玉琦   

  1. Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
  • 收稿日期:2012-03-30 修回日期:2012-04-18 出版日期:2012-09-01 发布日期:2012-09-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 1179042).

Quantum dots-templated growth of strain-relaxed GaN on a c-plane sapphire by radio-frequency molecular beam epitaxy

Guo Hao-Min (郭浩民), Wen Long (文龙), Zhao Zhi-Fei (赵志飞), Bu Shao-Jiang (步绍姜), Li Xin-Hua (李新化), Wang Yu-Qi (王玉琦)   

  1. Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
  • Received:2012-03-30 Revised:2012-04-18 Online:2012-09-01 Published:2012-09-01
  • Contact: Li Xin-Hua E-mail:xinhuali@issp.ac.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 1179042).

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摘要： We investigated the quantum dots-templated growth of a (0001) GaN film on a c-plane sapphire substrate. The growth was carried out in a radio-frequency molecular beam epitaxy system. The enlargement and coalescence of grains on the GaN quantum dots template was observed in the atom force microscopy images, as well as the more ideal surface morphology of the GaN epitaxial film on the quantum dots template compared with the one on the AlN buffer. The Ga polarity was confirmed by the reflected high energy electron diffraction patterns and the Raman spectra. The significant strain relaxation in the quantum dots-templated GaN film was calculated based on the Raman spectra and the X-ray rocking curves. Meanwhile, the threading dislocation density in the quantum dots-templated film was estimated to be 7.1×107 cm-2, which was significantly suppressed compared with that of the AlN-buffered GaN film. The room-temperature Hall measurement showed an electron mobility of up to 1860 cm2/V·s in the two-dimensional electron gas at the interface of the Al0.25Ga0.75N/GaN heterojunction.

关键词: III-V semiconductor, radio-frequency molecular beam epitaxy, dislocation

Abstract: We investigated the quantum dots-templated growth of a (0001) GaN film on a c-plane sapphire substrate. The growth was carried out in a radio-frequency molecular beam epitaxy system. The enlargement and coalescence of grains on the GaN quantum dots template was observed in the atom force microscopy images, as well as the more ideal surface morphology of the GaN epitaxial film on the quantum dots template compared with the one on the AlN buffer. The Ga polarity was confirmed by the reflected high energy electron diffraction patterns and the Raman spectra. The significant strain relaxation in the quantum dots-templated GaN film was calculated based on the Raman spectra and the X-ray rocking curves. Meanwhile, the threading dislocation density in the quantum dots-templated film was estimated to be 7.1×107 cm-2, which was significantly suppressed compared with that of the AlN-buffered GaN film. The room-temperature Hall measurement showed an electron mobility of up to 1860 cm2/V·s in the two-dimensional electron gas at the interface of the Al0.25Ga0.75N/GaN heterojunction.

Key words: III-V semiconductor, radio-frequency molecular beam epitaxy, dislocation

中图分类号:  (III-V semiconductors)

  • 81.05.Ea
81.15.Hi (Molecular, atomic, ion, and chemical beam epitaxy) 61.72.Hh (Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.))