Aluminum nitride films synthesized by dual ion beam sputtering

Aluminum nitride films were deposited by varying the voltages of argon ion beams from 400 to 1200 V in dual ion beam sputtering. The crystal structure, microstructure, and elemental distributions of the aluminum nitride films were analyzed by x-ray diffraction, field emission scanning electron microscopy, and secondary ion mass spectroscopy, respectively. The aluminum nitride films exhibited the 〈002〉 preferred orientation at an optimal ion beam voltage of 800 V. The orientation changed to a mixture of {100} and {002} planes above 800 V, accounting for radiation damage. The thickness of the film increases with increasing ion beam voltage, reaching a steady state value of 210 nm at an ion beam voltage of 1200 V. Under optimal condition (800 V), the c-axis orientation of the aluminum nitride 〈002〉 film was obtained with a dense and high-quality crystal structure.