In order to achieve AlN bulk growth, HTCVD chlorinated process is investigated. High growth rate and high crystalline quality are targeted for AlN films grown on (0001) 4H SiC at 1750°C. The precursors used are ammonia NH3 and aluminium chlorides AlClx species formed in situ by action of Cl2 on high purity Al wire. Influences of N/Al ratio in the gas phase on growth rate, crystalline state and microstructure are presented. Growth rates of up to 200 µm/h have been reached for polycrystalline layers. Thermodynamic calculations were carried out and correlated to the experimental results. As-grown AlN layers were characterized by SEM and X-ray Diffraction. Surface morphology is studied by SEM and FEG-SEM and crystallographic orientations were obtained by X-ray diffraction on θ/2θ.