Low-temperature deposition of α-Al₂O₃ film using Al+α-Al₂O₃ composite target by radio frequency magnetron sputtering

The realization of low temperature deposition of α-Al₂O₃ films is important for expanding its application in cutting tools, diffusion barrier and anti-oxidization coating. Here, the alumina films were deposited on Si(100) substrates by radio frequency magnetron sputtering using various targets of Al, α-Al₂O₃, and Al + 15 wt% α-Al₂O₃ composite. The elemental composition, phase constitution, microstructure, morphology and mechanical property of the as-deposited films were characterized by various techniques. The results show that the film deposited from the α-Al₂O₃ target is composed of amorphous and α-Al₂O₃, while the single phase α-Al₂O₃ film was successfully deposited by reactively sputtering the composite target at a substrate temperature of 550 °C. The hardness of the α-Al₂O₃ film deposited from Al+α-Al₂O₃ composite target was measured as ∼23.8 GPa. (paper)