National Physical Laboratory

Variable Angle Spectroscopic Ellipsometry



This is used to characterise thin films and bulk materials.

  • Most commonly used for thin film thickness measurement and optical constants.
  • For many samples it is sensitive to film thickness on a sub-monolayer level and is the primary technique for determining optical constants in the UV, visible and IR wavelength ranges.
  • Ideal for a large variety of applications, including measurements of dielectrics, polymers, semiconductors, metal, etc.
  • A spectral range from 193nm to 1700nm covers critical points in semiconductors, making it useful for measuring and controlling compound semiconductor alloy ratios.
  • A broad range of film thicknesses (sub-nanometer to 10¬†microns) can be measured.

Variable angle spectroscopic ellipsometry has the advantage over fixed angle measurements in that it acquires large amounts of data and can be optimised for particular film thicknesses or optical parameters.


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Last Updated: 5 Mar 2012
Created: 29 May 2009