We have grown AlN films on Ru(0001) substrates using a low-temperature growth technique with pulsed laser deposition. We found that AlN(0001) grows epitaxially on Ru(0001) with an in-plane epitaxial relationship of AlN[1120]//Ru[1120]. Electron backscattering diffraction observations revealed that neither 30 degrees rotational domains nor cubic phase domains were present in the AlN films and the full-width at half-maximum of the distribution in the AlN[0001] crystalline orientation was 0.56 degrees. Spectroscopic ellipsometry measurements showed that the AlN/Ru hetero-interface was quite abrupt, which is important for fabrication of high-frequency film bulk acoustic resonators. (c) 2006 Elsevier B.V. All rights reserved.