Epitaxial growth of aluminum nitride films on sapphire by reactive evaporation

Single−crystal films of AlN were fabricated on sapphire substrates by reactive evaporation of aluminum in ammonia gas. Films obtained have smooth and flat surfaces and there is no observed cracking. On the (0001) plane of sapphire, the c axis of AlN is aligned normal to the substrate surface, while on sapphire (011̄2), the c axis of AlN is inclined at about 28° to the film normal.