Abstract: AlN film is deposited on a nanorod ZnO template by metalorganic chemical vapor deposition.Scanning electron microscopy measurements reveal that this film forms a lying nanorod surface.The grazing incidence X-ray diffraction further proves that it is entirely a wurtzite AlN structure,and the average size of the crystallite grains is about 12nm,which is near the ZnO nanorod diameter (30nm).This means that the nanorod ZnO template can restrict the AlN lateral overgrowth.Additionally,by etching the ZnO template with H2 at high temperatures,we directly achieve epitaxial lift-off during the growth process.Eventually,free-standing AlN nanocrystals are achieved,and the undamaged area is near 1cm×1cm.We define the growth mechanism as a "grow-etch-merge" process.

Key words: metalorganic vapor phase epitaxy, nanomaterials, nitride