Aluminum nitride (AlN) bulk single crystals up to 45 mm in diameter and 10 mm in thickness have been successfully grown on 6H-SiC(0001) substrates by the sublimation method. Moreover, high growth rate of 200μm/h has been achieved by high temperature homo-epitaxial AlN growth on AlN(0001) substrate. The Raman spectrum indicates that the polytype of the grown AlN single crystals is a Wurtzite-2H type structure, and the crystals do not include any impurity phases. In both the hetero- and homo-epitaxial AlN bulk single crystal growth, the quality at the top of the crystal improves as the crystal thickness increases along the <;0001> direction during the growth: low etch pit density 7 × 104 cm-2 and 1 × 104 cm-2 have been achieved at a thickness of 8 mm and 2 mm in the hetero- and homo-epitaxial growth, respectively.