UVISEL Phase Modulated Ellipsometer Performance Qualified

Ellipsometric accuracy for cases where Δ is close to 0°: Straight-Through Air measurements

The only material for which the ellipsometric parameters are absolutely known is air: an ellipsometric measurement in the straight-through configuration should by definition return Ψ = 45° and Δ = 0°.

Straight-through ellipsometric measurements of air performed on

Ellipsometer accuracy and repeatability

Standard Reference Materials

The accuracy and repeatability measurements of the UVISEL ellipsometer were performed using a standard reference materials (SRM) supplied by the National Institute of Standards Technology (NIST). Standards consist of thermal oxide on silicon and the NIST 100 nm was used.

The NIST 100 nm gives the following certified values (for a one layer model):

  • Thickness: 973.00 Å
  • Refractive index: 1.465


The repeatability is defined as the standard deviation of 10 static measurements made at the same spot location. The accuracy is the difference between the average value of the sample properties (thicknesses and refractive index) over 10 measurements and the NIST nominal value.