Extrapolation of critical thickness of GaN thin films from lattice constant data using synchrotron X-ray

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

Research output: Contribution to journalConference article

2 Citations (Scopus)


In some materials, Van der Merwe's equilibrium theory of strain relief is believed to explain the sudden transition from pseudomorphic growth of a thin film to a progressively relaxed state. We show, for the first time for GaN, how an accurate estimate of the critical thickness of a thin film can be extrapolated from suitable measurements of lattice constants as a function of film thickness using synchrotron X-ray. We do this both for an elementary elastic energy function, in which the interactions between the dislocations are ignored, and for a more realistic energy estimate due to Kasper. The method is found to work quantitatively for thin films of GaN on AlN. The critical thickness is determined to be 29±4 angstroms.

Original languageEnglish
Pages (from-to)557-561
Number of pages5
JournalMaterials Research Society Symposium - Proceedings
Publication statusPublished - 1996 Dec 1
EventProceedings of the 1996 MRS Spring Symposium - San Francisco, CA, USA
Duration: 1996 Apr 81996 Apr 12


All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this