Epitaxial growth of AlN on single-crystal Ni(111) substrates

Abstract

We grew AlN thin films on Ni(111) at room temperature using pulsed laser deposition. In situ reflection high-energy electron diffraction observations showed sharp streak patterns, revealing that the AlN films grew epitaxially and were of high quality, even when grown at room temperature. Electron backscatter diffraction measurements showed that the in-plane epitaxial relationship between the film and Ni was AlN[11-20]∥Ni[01-1] with no 30° rotational domains. Grazing incidence angle x-ray reflectivity measurements determined that the interfacial layer was less than 1.2nm thick, if present. This indicates that the heterointerface between the AlN film and Ni substrate is atomically abrupt and that the AlN films serve as an excellent barrier layer for Ni atoms. Furthermore, the refractive index of a 60-nm-thick AlN film was 2.15 at 3.1eV and 2.08 at 1.6eV. These results demonstrate that the AlN films grown on Ni substrates at room temperature are of high quality from the perspective of their structural and optical properties.