Stress relaxation in Si-doped GaN studied by Raman spectroscopy

In-Hwan Lee, In Hoon Choi, Cheul Ro Lee, Eun Joo Shin, Dongho Kim, Sam Kyu Noh, Sung Jin Son, Ki Yong Lim, Hyung Jae Lee

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We report the Si-doping-induced relaxation of residual stress in GaN epitaxial layers grown on (0001) sapphire substrate by the metalorganic vapor phase epitaxy technique. Micro-Raman spectroscopy is used to assess stress situation in the films with systematically modulated doping concentration from 4.0×10 17 up to 1.6×10 19 cm -3 . As the Si-doping concentration increases, a monotonie decrease of the E 2 phonon frequency is observed, which signifies gradual relaxation of the stress in the film. The layers are fully relaxed when electron concentration exceeds 1.6 ×10 19 cm -3 . The linear coefficient of shift in Raman frequency (ω) induced by the in-plane biaxial compressive stress (σ ) is estimated to be Δω/Δσ =7.7 cm -1 /GPa. We suggest that Si doping increases density of misfit dislocation, judging from linewidth of x-ray rocking curve.

Original languageEnglish
Pages (from-to)5787-5791
Number of pages5
JournalJournal of Applied Physics
Issue number11
Publication statusPublished - 1998 Jun 1


ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Lee, I-H., Choi, I. H., Lee, C. R., Shin, E. J., Kim, D., Noh, S. K., Son, S. J., Lim, K. Y., & Lee, H. J. (1998). Stress relaxation in Si-doped GaN studied by Raman spectroscopy. Journal of Applied Physics, 83(11), 5787-5791.