Characterization of nanotextured AIN thin films by x-ray absorption near-edge structures

AlN thin films have been grown on c-cut sapphire substrates by pulsed-laser deposition. The film epitaxially grown at 1073 K under vacuum of 5 x 10(-4) Pa was used to examine the crystallographic orientation dependence of Al K-edge x-ray absorption near-edge structures (XANES), which satisfactorily agrees with theoretical spectra obtained by first-principles calculations. The film grown at 1073 K with N-2 backfill of 7 x 10(-2) Pa shows nanotextured structure with its c plane parallel to the substrate. Although the nanotexture is not evident by x-ray diffraction, XANES can unambiguously indicate the texturing. Cross-sectional high-resolution electron microscopy provides the evidence of the nanostructure. (c) 2005 American Institute of Physics.