Investigation of defects in ultra-thin Al2O3 films deposited on pure copper by the atomic layer deposition technique

摘要

Al2O3 films with various thicknesses were deposited by the atomic layer deposition (ALD) technique on pure copper at temperatures of 100-200 degrees C. Oxidation trials were conducted in air at 200 degrees C to investigate the defects in these films. The analytic results show that the defects have a looser micro-structure compared to their surroundings, but do not directly expose the substrate, like pinholes. The film's crystallinity, mechanical properties and oxidation resistance could also be affected by these defects. Superficial contamination particles on the substrate surface are confirmed to be nucleation sites of the defects. A model for the mechanism of defect formation is proposed in this study. (C) 2015 Elsevier B.V. All rights reserved.