Stress State of GaN Epilayer Grown on Sapphire and 6H-SiC Substrates

    Volume 41, Issue 5 (September 2013)

    ISSN: 0090-3973

    CODEN: JTEOAD

    Published Online: 1 July 2013

    Page Count: 6


    Zhang, Kexiong
    School of Physics and Optoelectronic Engineering, Dalian Univ. of Technology, Dalian,

    Liang, Hongwei
    School of Physics and Optoelectronic Engineering, Dalian Univ. of Technology, Dalian,

    State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai,

    Song, Shiwei
    School of Physics and Optoelectronic Engineering, Dalian Univ. of Technology, Dalian,

    Yang, Dechao
    State Key Laboratory on Integrated Optoelectronics, School of Electronic Science and Engineering, Jilin Univ., Changchun,

    Shen, Rensheng
    School of Physics and Optoelectronic Engineering, Dalian Univ. of Technology, Dalian,

    Liu, Yang
    School of Physics and Optoelectronic Engineering, Dalian Univ. of Technology, Dalian,

    Xia, Xiaochuan
    School of Physics and Optoelectronic Engineering, Dalian Univ. of Technology, Dalian,

    Luo, Yingmin
    School of Physics and Optoelectronic Engineering, Dalian Univ. of Technology, Dalian,

    Du, Guotong
    School of Physics and Optoelectronic Engineering, Dalian Univ. of Technology, Dalian,

    State Key Laboratory on Integrated Optoelectronics, School of Electronic Science and Engineering, Jilin Univ., Changchun,

    (Received 13 July 2012; accepted 20 March 2013)

    Abstract

    The stress states and influence of two opposite stress types under similar stress intensities on the structural and optical properties of GaN films grown on sapphire and 6H-SiC substrates via metalorganic chemical vapor deposition were investigated. The E2 (high) phonon shifts of Raman spectra show that tensile stresses exist in the GaN epilayer grown on 6H-SiC, whereas compressive stresses appear in the film grown on sapphire, indicating that the thermal mismatch between the epilayers and the substrates plays a major role in determining the residual stresses in GaN films. Narrower full widths at half-maximum of E2 (high) phonon and double crystal X-ray diffraction peaks and the higher E2 (high) phonon intensity are visible for the GaN film grown on sapphire, illustrating that under almost equivalent stress intensities, tensile stresses have a much more negative influence on the crystalline quality of GaN epilayers. Finally, a numerical relationship between the luminescent band gap and the biaxial stresses of the GaN films is obtained at 10 K.


    Paper ID: JTE20120231

    DOI: 10.1520/JTE20120231

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    Author
    Title Stress State of GaN Epilayer Grown on Sapphire and 6H-SiC Substrates
    Symposium , 0000-00-00
    Committee F01