Atomic arrangement at the AlN/ZrB2 interface

R. Liu, A. Bell, Fernando Ponce, S. Kamiyama, H. Amano, I. Akasaki

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Abstract

Low-dislocation-density GaN films (∼108cm-2) have been grown on closely lattice-matched ZrB2 substrates by metalorganic vapor phase epitaxy using low-temperature AlN as a buffer layer. High-resolution electron microscopy images of the AlN/ZrB2 interface region reveal that the AlN buffer layer does not grow directly on the ZrB 2 substrate. Instead, the existence of an unintentional intermediate cubic-phase layer (approximately 2 nm thick) has been observed. Misfit dislocations are evident at both interfaces of the intermediate layer. Our analysis indicates that the intermediate layer has a lattice constant a=4.6Å, and that it is a ternary alloy of ZrxB yNz, which should result from a transformation from the hexagonal phase of ZrB2 due to interdiffusion of nitrogen and boron at the elevated temperature required for growth of GaN. This intermediate cubic-phase layer of ZrxByNz appears to have been so far unavoidable in the growth of high-quality GaN epilayers on ZrB 2 substrates by our technique.

Original languageEnglish (US)
Pages (from-to)3182-3184
Number of pages3
JournalApplied Physics Letters
Volume81
Issue number17
DOIs
StatePublished - Oct 21 2002

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ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Liu, R., Bell, A., Ponce, F., Kamiyama, S., Amano, H., & Akasaki, I. (2002). Atomic arrangement at the AlN/ZrB2 interface. Applied Physics Letters, 81(17), 3182-3184. https://doi.org/10.1063/1.1516876