中国物理B ›› 2011, Vol. 20 ›› Issue (5): 57801-057801.doi: 10.1088/1674-1056/20/5/057801

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Optical and structural investigation of a-plane GaN layers on r-plane sapphire with nucleation layer optimization

张金风, 许晟瑞, 张进成, 郝跃   

  1. School of Microelectronics, Xidian University, Xi'an 710071, China; Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi'an 710071, China
  • 收稿日期:2010-11-17 修回日期:2010-12-27 出版日期:2011-05-15 发布日期:2011-05-15
  • 基金资助:
    Project supported by the National Key Science &

Optical and structural investigation of a-plane GaN layers on r-plane sapphire with nucleation layer optimization

Zhang Jin-Feng (张金风), Xu Sheng-Rui (许晟瑞), Zhang Jin-Cheng (张进成), Hao Yue (郝跃)   

  1. School of Microelectronics, Xidian University, Xi'an 710071, China; Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi'an 710071, China
  • Received:2010-11-17 Revised:2010-12-27 Online:2011-05-15 Published:2011-05-15
  • Supported by:
    Project supported by the National Key Science & Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2008ZX01002-002) and the Major Program and the Key Program of the National Natural Science Foundation of China (Grant Nos. 60890191 and 60736033).

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摘要： Nonpolar a-plane GaN epilayers are grown on several r-plane sapphire substrates by metal organic chemical vapour deposition using different nucleation layers: (A) a GaN nucleation layer deposited at low temperature (LT); (B) an AlN nucleation layer deposited at high temperature; or (C) an LT thin AlN nucleation layer with an AlN layer and an AlN/AlGaN superlattice both subsequently deposited at high temperature. The samples have been characterized by X-ray diffraction (XRD), atomic force microscopy and photoluminescence. The GaN layers grown using nucleation layers B and C show narrower XRD rocking curves than that using nucleation layer A, indicating a reduction in crystal defect density. Furthermore, the GaN layer grown using nucleation layer C exhibits a surface morphology with triangular defect pits eliminated completely. The improved optical property, corresponding to the enhanced crystal quality, is also confirmed by temperature-dependent and excitation power-dependent photoluminescence measurements.

关键词: a-plane GaN, metal organic chemical vapour deposition, AlN/AlGaN superlattice, photoluminescence

Abstract: Nonpolar a-plane GaN epilayers are grown on several r-plane sapphire substrates by metal organic chemical vapour deposition using different nucleation layers: (A) a GaN nucleation layer deposited at low temperature (LT); (B) an AlN nucleation layer deposited at high temperature; or (C) an LT thin AlN nucleation layer with an AlN layer and an AlN/AlGaN superlattice both subsequently deposited at high temperature. The samples have been characterized by X-ray diffraction (XRD), atomic force microscopy and photoluminescence. The GaN layers grown using nucleation layers B and C show narrower XRD rocking curves than that using nucleation layer A, indicating a reduction in crystal defect density. Furthermore, the GaN layer grown using nucleation layer C exhibits a surface morphology with triangular defect pits eliminated completely. The improved optical property, corresponding to the enhanced crystal quality, is also confirmed by temperature-dependent and excitation power-dependent photoluminescence measurements.

Key words: a-plane GaN, metal organic chemical vapour deposition, AlN/AlGaN superlattice, photoluminescence

中图分类号:  (III-V semiconductors)

  • 78.55.Cr
81.15.Kk (Vapor phase epitaxy; growth from vapor phase)