Use of spectroscopic ellipsometry to study Zr/Ti films on Al

Spectroscopic ellipsometry in the spectral range between the near-ultraviolet and the near-infrared (250-1700 nm) (SE) and the mid-infrared (2-23 mum) (IR-SE) have been used for the characterization of various thin coatings on aluminium. Both SE and IR-SE provide information concerning the morphological features of the coating, but owing to the presence of characteristic absorptions IR-SE also reveals the chemical composition. This paper discusses the application of the developed optical models for the characterization of the more complex Zr/Ti-based passivation coatings. The results obtained indicate that these coatings consist of a complex hydrated Zr/Ti/Al oxyfluoride. Copyright (C) 2002 John Wiley Sons, Ltd.