Orientation of aluminum nitride films grown with hyperthermal molecular beams

Abstract Unskimmed, pulsed hyperthermal molecular beams of trimethylaluminum (TMA) and ammonia were used to grow films of aluminum nitride. The crystal structure of the films was determined by X-ray diffraction (XRD). AlN was deposited on Si(1 0 0) and AlN–Si. The AlN–Si samples consist of 1 μm layer of MOCVD-grown polycrystalline AlN on Si(1 0 0) substrates. The resulting film orientation on Si(1 0 0) is with the AlN( 1 0 1 0 ) plane parallel to the substrate plane. On AlN–Si substrates, the AlN( 1 0 1 0 ) plane is still prevalent. The effect of varying the precursors’ azimuthal angle of incidence, α , was also investigated. AlN was grown on Si(1 0 0) at α =0, 30, 60°. For α >0, the AlN( 1 0 1 0 ) and AlN( 1 0 1 1 ) planes are present. At α =60°, weak X-ray diffraction peaks indicate the films have short-range order. For the α examined, the average growth rate is approximately 0.35 μm/h. AES was used for chemical analysis of films.