中国物理B ›› 2008, Vol. 17 ›› Issue (4): 1360-1363.doi: 10.1088/1674-1056/17/4/034

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Effect of double AlN buffer layer on the qualities of GaN films grown by radio-frequency molecular beam epitaxy

李新化, 钟飞, 邱凯, 尹志军, 姬长建   

  1. Key Laboratory of Material Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
  • 收稿日期:2007-02-07 修回日期:2007-08-30 出版日期:2008-04-20 发布日期:2008-04-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 10574130).

Effect of double AlN buffer layer on the qualities of GaN films grown by radio-frequency molecular beam epitaxy

Li Xin-Hua(李新化), Zhong Fei(钟飞), Qiu Kai(邱凯), Yin Zhi-Jun(尹志军), and Ji Chang-Jian(姬长建)   

  1. Key Laboratory of Material Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China
  • Received:2007-02-07 Revised:2007-08-30 Online:2008-04-20 Published:2008-04-01
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 10574130).

摘要: This paper reports that the GaN thin films with Ga-polarity and high quality were grown by radio-frequency molecular beam epitaxy on sapphire (0001) substrate with a double AlN buffer layer. The buffer layer consists of a high-temperature (HT) AlN layer and a low-temperature (LT) AlN layer grown at 800\du\ and 600\du, respectively. It is demonstrated that the HT-AlN layer can result in the growth of GaN epilayer in Ga-polarity and the LT-AlN layer is helpful for the improvement of the epilayer quality. It is observed that the carrier mobility of the GaN epilayer increases from 458 to 858\,cm$^{2}$/V$\cdot $s at room temperature when the thickness of LT-AlN layer varies from 0 to 20\,nm. The full width at half maximum of x-ray rocking curves also demonstrates a substantial improvement in the quality of GaN epilayers by the utilization of LT-AlN layer.

关键词: Gallium Nitride, buffer layer, carrier mobility, polarity

Abstract: This paper reports that the GaN thin films with Ga-polarity and high quality were grown by radio-frequency molecular beam epitaxy on sapphire (0001) substrate with a double AlN buffer layer. The buffer layer consists of a high-temperature (HT) AlN layer and a low-temperature (LT) AlN layer grown at 800℃ and 600℃, respectively. It is demonstrated that the HT-AlN layer can result in the growth of GaN epilayer in Ga-polarity and the LT-AlN layer is helpful for the improvement of the epilayer quality. It is observed that the carrier mobility of the GaN epilayer increases from 458 to 858 cm$^{2}$/V$\cdot $s at room temperature when the thickness of LT-AlN layer varies from 0 to 20 nm. The full width at half maximum of x-ray rocking curves also demonstrates a substantial improvement in the quality of GaN epilayers by the utilization of LT-AlN layer.

Key words: Gallium Nitride, buffer layer, carrier mobility, polarity

中图分类号:  (Thin film structure and morphology)

  • 68.55.-a
73.50.Dn (Low-field transport and mobility; piezoresistance) 73.61.Ey (III-V semiconductors) 81.15.Hi (Molecular, atomic, ion, and chemical beam epitaxy)