MgO epitaxy on GaN (0002) surfaces by molecular beam epitaxy

H. S. Craft, J. F. Ihlefeld, M. D. Losego, R. Collazo, Z. Sitar, J. P. Maria

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We report on the epitaxial deposition of magnesium oxide films with [111] crystallographic orientation on (0002) GaN by molecular beam epitaxy. Specifically, we use an adsorption controlled growth mechanism to initiate the growth process. Electron diffraction shows a spotty intense pattern without intensity fluctuations during growth and evidence of in-plane twinning. X-ray diffraction reveals the films to be epitaxial with full width at half maximum values of 0.3°, 0.5°, and 1° in 2θ, φ, and circles, respectively. Wet etching of the GaN surface with a HCl:HF mixture prior to growth is critical for achieving high crystalline quality. Epitaxial growth is observed between room temperature and 650 °C, with negligible changes in crystalline quality with increased temperature. Atomic force microscopy analysis shows grainy surfaces with feature sizes near 10 nm and rms roughness values of 1.4 Å over 1 μ m2 areas. X-ray diffraction analysis suggests MgO film stability up to 850 °C in ex situ air annealing.

Original languageEnglish (US)
Article number212906
JournalApplied Physics Letters
Issue number21
StatePublished - May 21 2006


All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

Cite this

Craft, H. S., Ihlefeld, J. F., Losego, M. D., Collazo, R., Sitar, Z., & Maria, J. P. (2006). MgO epitaxy on GaN (0002) surfaces by molecular beam epitaxy. Applied Physics Letters, 88(21), [212906].