Spectroscopic Ellipsometer VASE (J.A. Wollam Co. Inc.)

Ellipsometry is a very sensitive measurement technique that uses polarized light to characterize thin films, surfaces, and material microstructures. It derives its sensitivity from the determination of the relative phase change in a beam of reflected polarized light, exceeding the sensitivity of an intensity reflectance measurement. Ellipsometry measures the change in polarization state of light reflected from (or transmitted from) the surface of a sample. Ellipsometry is commonly used to characterize both thin films and bulk materials. The most common application is measurement of thin film thickness and optical constants.


Ellipsometry has been used to determine:

  • Optical constants
  • Thin film thickness (single of multiple layers)
  • Doping concentration
  • Surface and interfacial roughness
  • Alloy ration
  • Crystallinity
  • Optical anisotropy
  • Depth profile of material properties
  • Growth or Etch rate (in-situ)
  • Temperature (in-situ)