Al_2O_3 coating with a Ni-based buffer layer: Preparation, characterization and electrical insulating properties

摘要

Al_2O_3 coatings, with a Ni-based buffer layer (Ni or NiAl), were deposited on a Cu substrate by electron beam evaporation (EBE). The Al_2O_3 coatings were amorphous of good stoicniometry and their surface was undulated and continuous. The Ni-based buffer layer played a key role on improving the adhesion of the Al_2O_3 coatings to the substrate. The diffusion of Cu from the substrate into the Al_2O_3 coating at high temperature was suppressed by the buffer layer. Excellent resistivity (10~(15) OMEGA cm) and high breakdown voltage (110 kV/mm) have been obtained.