APPLICATION OF THE EFFECTIVE IMPEDANCE METHOD FOR IN SITU ELLIPSOMETRIC ANALYSIS OF MAGNETIC FILMS

Abstract

The technique of effective surface impedance is proposed and applied as useful tool for non-destructive in situ characterisation of optical and magneto-optical parameters of magnetic heterostructures. Standard ellipsometry analysis requires the model response to be calculated from every layer in the structure. For any ellipsometry investigations a proper choice of a physical model is important for solving the inverse problem by a regression method. Reasonable approximations used for in situ ellipsometry monitoring are assumptions of a constant rate of layer growth and stable optical parameters. In this case a method of a pseudosubstrate is used which approximates the underlying structure as a single interface (so called virtual interface), rather than tracking the entire sample history. The virtual interface is placed at some level and growth is modelled on this interface with no knowledge retained for the underlying structure.Magneto-optical spectra were detected in the configuration of equatorial Kerr effect which is fully compatible with the ellipsometry measurements. The method is successfully used to analyse Co, Fe/Si/glass films.

Keywords

• effective impedance
• in situ ellipsometry
• magnetic films
• kerr effect
• magneto- ellipsometry
• multilayers
• pseudosubstrate
• virtual interface