中国物理B ›› 2007, Vol. 16 ›› Issue (9): 2786-2790.doi: 10.1088/1009-1963/16/9/048

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GaN layers with different polarities prepared by radio frequency molecular beam epitaxy and characterized by Raman scattering

钟飞, 李新化, 邱凯, 尹志军, 姬长建, 曹先存, 韩奇峰, 陈家荣, 王玉琦   

  1. Key Laboratory of Material Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
  • 收稿日期:2006-12-11 修回日期:2007-02-15 出版日期:2007-09-20 发布日期:2007-09-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 10574130).

GaN layers with different polarities prepared by radio frequency molecular beam epitaxy and characterized by Raman scattering

Zhong Fei(钟飞), Li Xin-Hua(李新化), Qiu Kai(邱凯), Yin Zhi-Jun(尹志军), Ji Chang-Jian(姬长建), Cao Xian-Cun(曹先存), Han Qi-Feng(韩奇峰), Chen Jia-Rong(陈家荣), and Wang Yu-Qi(王玉琦)   

  1. Key Laboratory of Material Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
  • Received:2006-12-11 Revised:2007-02-15 Online:2007-09-20 Published:2007-09-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 10574130).

摘要: GaN layers with different polarities have been prepared by radio-frequency molecular beam epitaxy (RF-MBE) and characterized by Raman scattering. Polarity control are realized by controlling Al/N flux ratio during high temperature AlN buffer growth. The Raman results illustrate that the N-polarity GaN films have frequency shifts at $A_{1}$(LO) mode because of their high carrier density; the forbidden $A_{1}$(TO) mode occurs for mixed-polarity GaN films due to the destroyed translation symmetry by inversion domain boundaries (IDBS); Raman spectra for Ga-polarity GaN films show that they have neither frequency shifts mode nor forbidden mode. These results indicate that Ga-polarity GaN films have a better quality, and they are in good agreement with the results obtained from the room temperature Hall mobility. The best values of Ga-polarity GaN films are 1042 cm$^{2}$/Vs with a carrier density of 1.0$\times $10$^{17}$~cm$^{ - 3}$.

关键词: polarity, gallium nitride, Raman scattering

Abstract: GaN layers with different polarities have been prepared by radio-frequency molecular beam epitaxy (RF-MBE) and characterized by Raman scattering. Polarity control are realized by controlling Al/N flux ratio during high temperature AlN buffer growth. The Raman results illustrate that the N-polarity GaN films have frequency shifts at $A_{1}$(LO) mode because of their high carrier density; the forbidden $A_{1}$(TO) mode occurs for mixed-polarity GaN films due to the destroyed translation symmetry by inversion domain boundaries (IDBS); Raman spectra for Ga-polarity GaN films show that they have neither frequency shifts mode nor forbidden mode. These results indicate that Ga-polarity GaN films have a better quality, and they are in good agreement with the results obtained from the room temperature Hall mobility. The best values of Ga-polarity GaN films are 1042 cm$^{2}$/Vs with a carrier density of 1.0$\times $10$^{17}$ cm$^{ - 3}$.

Key words: polarity, gallium nitride, Raman scattering

中图分类号:  (Molecular, atomic, ion, and chemical beam epitaxy)

  • 81.15.Hi
63.20.-e (Phonons in crystal lattices) 68.55.A- (Nucleation and growth) 78.30.Fs (III-V and II-VI semiconductors) 78.66.Fd (III-V semiconductors)