High resolution transmission electron microscopy study on the microstructures of aluminum nitride and hydrogenated aluminum nitride films prepared by radio frequency reactive sputtering

Abstract

Aluminum nitride (AlN) and hydrogenated aluminum nitride (AlN:H) films on Si substrate have been deposited by the radio frequency reactive magnetron sputtering. The microstructures of the two films have been examined and compared by transmission electron microscopy (TEM) and high-resolution TEM. In the growth of the AlN:H film, it has been observed that the amorphous phase is formed at the initial stage of deposition, and c-axis oriented crystallite nucleates at the amorphous layer. The lattice mismatch between the film and substrate and the stress in the film are reduced, and the film surface is smooth due to this amorphous phase. A schematic model explaining the growth of AlN and AlN:H films is proposed, and the reason for the easy formation of the amorphous phase in AlN:H film is discussed.