The microscopic crystalline structure (MCS) such as domain texturing, lattice tilting fluctuation and strain fluctuation in thick AIN films grown on trench patterned AIN/alpha-Al2O3 templates was clarified by utilizing position dependent X-ray microdiffraction measurements in combination with transmission electron microscopy observations. The results clearly demonstrate that the trench patterned templates have a strong influence on the MCS in the thick AlN films. The MCS is anisotropic between the [11 (2) over bar0] and [1 (1) over bar 00] directions. Periodic domain texturing was observed along the [11 (2) over bar0] direction, corresponding to the periodicity of the patterning pitch of the template. Submicron crystal domains arc tilted at different angles to the [11 (2) over bar0] direction, and the crystal domain tilting becomes larger in the void containing trench regions than in the terrace regions. This generates the periodicity in lattice tilting fluctuation and strain fluctuation along the [11 (2) over bar0] direction. These were found to be caused primarily by two factors; one of which being the elastic strain relaxation that depends on the growth direction in the terrace regions, and the other being the inhomogeneity in distribution and morphology of dislocations that have Burgers vectors with a screw component in the void containing trench regions. (C) 2014 Elsevier B.V. All rights reserved.