Critical thickness of GaN thin films on sapphire (0001)

Chinkyo Kim, I. K. Robinson, Jaemin Myoung, Kyuhwan Shim, Myung Cheol Yoo, Kyekyoon Kim

Research output: Contribution to journalArticle


Synchrotron x-ray diffraction was employed to measure the lattice constants a and c of GaN films grown with an AlN buffer layer on sapphire (0001) over a thickness range of 50 Å to 1 μm. We used multiple reflections and a least-squares fit method for high reliability. As the thickness increased, the lattice constant a increased from 3.133 Å to 3.196 Å and c decreased from 5.226 Å to 5.183 Å. The expected trend was fitted to an equilibrium theory, allowing the critical thickness of GaN on AlN to be estimated at 29 Å ± 4 Å in good agreement with a theoretical prediction.

Original languageEnglish (US)
Pages (from-to)2358-2360
Number of pages3
JournalApplied Physics Letters
Issue number16
StatePublished - Oct 14 1996

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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  • Cite this

    Kim, C., Robinson, I. K., Myoung, J., Shim, K., Yoo, M. C., & Kim, K. (1996). Critical thickness of GaN thin films on sapphire (0001). Applied Physics Letters, 69(16), 2358-2360.