Strain Relaxation in GaN/AlN Films Grown on Vicinal and On-Axis SiC Substrates


Article Preview

Strain relaxation in the GaN/AlN/6H-SiC epitaxial system grown by vicinal surface epitaxy (VSE) is investigated and compared with that in on-axis epitaxy. High resolution x-ray diffraction (HRXRD) measurements show that GaN films grown by VSE have improved crystalline quality. High resolution transmission electron microscope (HRTEM) studies reveal that there are two types of misfit dislocations (MDs) at AlN/6H-SiC interfaces: 60˚ complete dislocations along <1120 > directions with Burgers vector 1/3<1120 > and 60˚ Shockley partials along <10 10 > directions with Burgers vector 1/3<10 10 >. The latter are usually geometrical partial misfit dislocations (GPMDs) that are dominant in VSE to accommodate the lattice mismatch and stacking sequence mismatch simultaneously. In VSE, it is the high-density GPMDs formed at the vicinal surface steps that facilitate rapid strain relaxation at the initial stage of deposition and hence lead to superior crystalline quality of the subsequently grown GaN films.



Materials Science Forum (Volumes 527-529)

Edited by:

Robert P. Devaty, David J. Larkin and Stephen E. Saddow




J. Bai et al., "Strain Relaxation in GaN/AlN Films Grown on Vicinal and On-Axis SiC Substrates", Materials Science Forum, Vols. 527-529, pp. 1513-1516, 2006

Online since:

October 2006




[1] Jun-ichi Kato, Satoru Tanaka, Satoshi Yamada, and Ikuo Suemune: Appl. Phys. Lett. Vol. 83 (2003), p.1569.

[2] M. Benyoucef, M. Kuball, D. D. Koleske, A. E. Wickenden, R. L. Henry, M. Fatemi and M. E. Twigg: Mater. Sci. Eng. Vol. B93 (2002), p.15.

[3] P. A. Grudowski, A. L. Holmes, C. J. Eiting and R. D. Dupuis: Appl. Phys. Lett. Vol. 69 (1996), p.3626.

[4] P. Vermaut, P. Ruterana, G. Nouet and H. Morkoç: Phil. Mag. A Vol. 75 (1997), p.239.

[5] J. Bai, X. Huang, M. Dudley, B. Wagner, R. F. Davis, L. Wu, E. Sutter, Y. Zhu, and B. J. Skromme: J. Appl. Phys. Vol. 98 (2005), p.063510.

[6] P. Pirouz and J. W. Yang: Ultramicroscopy Vol. 51 (1993), p.189.

[7] P. Pirouz and F. Ernst: Metal-ceramic Interfaces (Pergamon Press, Oxford 1990), pp.199-221.

[8] B. Moran, F. Wu, A. E. Romanov, U. K. Mishra, S. P. Denbaars, and J. S. Speck: J. Cryst. Growth Vol. 273 (2004), p.38.

[9] X. R. Huang, J. Bai, M. Dudley, B. Wagner, R. F. Davis, and Y. Zhu: Phys. Rev. Lett. Vol. 95 (2005), p.086101.

Fetching data from Crossref.
This may take some time to load.