Aluminium nitride layers were grown by Low Pressure Chemical Vapour Deposition on off-cut 6H-SiC and 4H-SiC substrates, implanted or with an epilayer. Samples were annealed at the temperature of 1600 degreesC or 1650 degreesC. Depending of annealing temperature and nature of the substrate, the AlN layers were partially removed and the SiC substrates etched. AIN layers and SiC surfaces were characterized by X-ray diffraction and Scanning Electron Microscopy before and after annealing.