Optical characterization of thin Al₂O₃ layers deposited by magnetron sputtering technique at industrial conditions for applications in glazing

In this study, thin Al₂O₃ films (11 nm – 82 nm) were deposited by means of a recently developed pulse gas injection magnetron sputtering method and investigated by means of atomic force microscopy, spectroscopic ellipsometry and spectrophotometry. Quite low values of optical constants (1.581 to 1.648 at λ = 550 nm) of the alumina films are directly associated with specific growth conditions (pulse injection of the reactive or reactive + inert gas) in the pulse gas injection magnetron sputtering process. The light transmittance of Al₂O₃/glass systems (86 % to 90 %) is only a few percent lower than that calculated for glass (93 %).