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.