Journal of Electronic Materials

, Volume 37, Issue 5, pp 641–645

Structural Characterization of Homoepitaxial Blue GaInN/GaN Light-Emitting Diodes by Transmission Electron Microscopy

  • M. Zhu
  • Y. Xia
  • W. Zhao
  • Y. Li
  • J. Senawiratne
  • T. Detchprohm
  • C. Wetzel
Article

DOI: 10.1007/s11664-008-0392-9

Cite this article as:
Zhu, M., Xia, Y., Zhao, W. et al. Journal of Elec Materi (2008) 37: 641. doi:10.1007/s11664-008-0392-9

We perform a transmission electron microscopy (TEM) characterization of blue light-emitting diode epiwafers grown homoepitaxially on a c-plane GaN substrate and compare with such grown on sapphire. We find a threading dislocation (TD) density as low as 2 × 108 cm−2 in homoepitaxial growth, which is 1/30 of that in sapphire-based material. A unique type of inverted pyramid defect with diameter ∼650 nm was observed. It originates from the homo-interface in edge-type TDs. TDs were also found to be generated within the quantum wells without a precursor TD defect. Otherwise, high-resolution TEM suggests extremely homogeneous quantum wells and barriers in terms of composition and well width. Besides plan-view TEM, wet chemical etching on n-type GaN was carried out in hot phosphoric acid to evaluate the TD density more quickly. The two methods prove to be equivalent with respect of determined TD densities.

Keywords

Homoepitaxybulk GaNGaInN/GaNtransmission electron microscopythreading dislocationinverted pyramid defectetch pit density

Copyright information

© TMS 2008

Authors and Affiliations

  • M. Zhu
    • 1
  • Y. Xia
    • 1
  • W. Zhao
    • 1
  • Y. Li
    • 1
  • J. Senawiratne
    • 1
  • T. Detchprohm
    • 1
  • C. Wetzel
    • 1
  1. 1.Future Chips Constellation and Department of Physics, Applied Physics, and AstronomyRensselaer Polytechnic InstituteTroyUSA