Effect of Hydrogen Gas on c-Axis Oriented AlN Films Prepared by Reactive Magnetron Sputtering

AlN films were deposited on glass substrates by reactive dc magnetron sputtering in an atmosphere of pure nitrogen gas or a mixed gas of hydrogen and nitrogen. The AlN films deposited in the nitrogen gas had a c-axis perpendicular to the substrate surface. On the other hand, the film deposited in the gas with hydrogen added showed a c-axis parallel to the substrate surface. Optical transmittance of the parallel oriented films was better than that of the perpendicularly oriented films and there was a great difference in the microstructure of the film surface between these two films.