The structural and morphological properties of InN epilayers grown on Si(111) substrates by plasma-assisted molecular beam epitaxy were studied. The mosaic characteristics such as grain size, twist and tilt angles were extracted by performing symmetric and asymmetrical rocking curves and reciprocal space mapping. According to X-ray diffraction analysis, the dislocation densities reduced from 1011 to 2.27 x 1010/cm2, when the substrate temperature was increased from 440 to 525C. Edge-type dislocation densities estimated both by fitting the FWHM of ω-scans of various lattice planes based on cosine theorem of spherical trigonometry and by grazing incidence (11•0) diffraction agree with plan-view transmission electron microscopy results. Surface morphology revealed grains with flat or terrace-like features separated by deep trenches. Faceted pits associated with screw-type threading dislocations were observed and their densities were in good consistence with the results obtained from X-ray diffraction. Improved film quality was achieved by applying highest growth temperature within InN dissociation limit.

Defect Structure Study of Epitaxial InN Films by Transmission Electron Microscopy and X-Ray Diffraction. W.L.Chen, Y.H.Wang, M.F.Chen, M.F.Huang, J.C.Fan: Physica E, 2010, 42[5], 1463-8