中国物理B ›› 2009, Vol. 18 ›› Issue (11): 4970-4975.doi: 10.1088/1674-1056/18/11/059

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Influence of dislocations in the GaN layer on the electrical properties of an AlGaN/GaN heterostructure

高志远, 郝跃, 张进城, 李培咸, 谷文萍   

  1. Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071, China
  • 收稿日期:2008-08-13 修回日期:2009-03-25 出版日期:2009-11-20 发布日期:2009-11-20
  • 基金资助:
    Project supported by the National Key Basic Research and Development Program (973 Program) of China (Grant Nos 2002CB3119 and 513270407).

Influence of dislocations in the GaN layer on the electrical properties of an AlGaN/GaN heterostructure

Gao Zhi-Yuan(高志远),Hao Yue(郝跃)†, Zhang Jin-Cheng(张进城), Li Pei-Xian(李培咸), and Gu Wen-Ping(谷文萍)   

  1. Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071, China
  • Received:2008-08-13 Revised:2009-03-25 Online:2009-11-20 Published:2009-11-20
  • Supported by:
    Project supported by the National Key Basic Research and Development Program (973 Program) of China (Grant Nos 2002CB3119 and 513270407).

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摘要： This paper reports on a comparative study of the spatial distributions of the electrical, optical, and structural properties in an AlGaN/GaN heterostructure. Edge dislocation density in the GaN template layer is shown to decrease in the regions of the wafer where the heterostructure sheet resistance increases and the GaN photoluminescence band-edge energy peak shifts to a high wavelength. This phenomenon is found to be attributed to the local compressive strain surrounding edge dislocation, which will generate a local piezoelectric polarization field in the GaN layer in the opposite direction to the piezoelectric polarization field in the AlGaN layer and thus help to increase the two-dimensional electron gas concentration.

Abstract: This paper reports on a comparative study of the spatial distributions of the electrical, optical, and structural properties in an AlGaN/GaN heterostructure. Edge dislocation density in the GaN template layer is shown to decrease in the regions of the wafer where the heterostructure sheet resistance increases and the GaN photoluminescence band-edge energy peak shifts to a high wavelength. This phenomenon is found to be attributed to the local compressive strain surrounding edge dislocation, which will generate a local piezoelectric polarization field in the GaN layer in the opposite direction to the piezoelectric polarization field in the AlGaN layer and thus help to increase the two-dimensional electron gas concentration.

Key words: GaN, edge dislocation, piezoelectric polarization, two-dimensional electron gas

中图分类号:  (III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions)

  • 73.40.Kp
78.55.Cr (III-V semiconductors) 61.72.Hh (Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)) 77.65.Bn (Piezoelectric and electrostrictive constants) 62.20.F- (Deformation and plasticity)