中国物理B ›› 2009, Vol. 18 ›› Issue (7): 2998-3001.doi: 10.1088/1674-1056/18/7/063

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Degradation mechanism of two-dimensional electron gas density in high Al-content AlGaN/GaN heterostructures

张进成, 郑鹏天, 张娟, 许志豪, 郝跃   

  1. Laboratory of Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071, China
  • 收稿日期:2008-11-21 修回日期:2009-01-01 出版日期:2009-07-20 发布日期:2009-07-20
  • 基金资助:
    Project supported by the Major Program and State Key Program of National Natural Science of China (Grant Nos 60890191 and 60736033) and the National Key Science {\&} Technology Special Project (Grant No 2008ZX 01002).

Degradation mechanism of two-dimensional electron gas density in high Al-content AlGaN/GaN heterostructures

Zhang Jin-Cheng(张进成), Zheng Peng-Tian(郑鹏天), Zhang Juan(张娟), Xu Zhi-Hao(许志豪), and Hao Yue(郝跃)   

  1. Laboratory of Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071, China
  • Received:2008-11-21 Revised:2009-01-01 Online:2009-07-20 Published:2009-07-20
  • Supported by:
    Project supported by the Major Program and State Key Program of National Natural Science of China (Grant Nos 60890191 and 60736033) and the National Key Science {\&} Technology Special Project (Grant No 2008ZX 01002).

摘要: This paper finds that the two-dimensional electron gas density in high Al-content AlGaN/GaN heterostructures exhibits an obvious time-dependent degradation after the epitaxial growth. The degradation mechanism was investigated in depth using Hall effect measurements, high resolution x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy. The results reveal that the formation of surface oxide is the main reason for the degradation, and the surface oxidation always occurs within the surface hexagonal defects for high Al-content AlGaN/GaN heterostructures.

Abstract: This paper finds that the two-dimensional electron gas density in high Al-content AlGaN/GaN heterostructures exhibits an obvious time-dependent degradation after the epitaxial growth. The degradation mechanism was investigated in depth using Hall effect measurements, high resolution x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy. The results reveal that the formation of surface oxide is the main reason for the degradation, and the surface oxidation always occurs within the surface hexagonal defects for high Al-content AlGaN/GaN heterostructures.

Key words: degradation mechanism, two-dimensional electron gas, AlGaN/GaN heterostructures, surface oxidation

中图分类号:  (Electronic transport in nanoscale materials and structures)

  • 73.63.-b
73.40.Kp (III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions) 72.20.My (Galvanomagnetic and other magnetotransport effects) 79.60.Jv (Interfaces; heterostructures; nanostructures) 81.65.Mq (Oxidation)