Spectroscopic ellipsometer for Vacuum Ultra Violet: VUV-VASE

From Woollam Co.

The VUV-VASE variable angle spectroscopic ellipsometer is the standard in optical characterization of materials used in lithography applications. Its measurement range spans vacuum ultraviolet (VUV) to near infrared (NIR). This provides incredible versatility to characterize numerous types of materials: semiconductors, dielectrics, polymers, metals, multilayers and now liquids such as immersion fluids.

VUV ellipsometry
Spectral range 146 to 1700 nm
Sample purge
Full automation

Wide spectral range

Available 146 nm to 1700 nm spectral range with the NIR upgrade.

High accuracy

The patented AutoRetarder features precise measurements of Delta over the full range (0-360 degrees) including near 0 and 180 degrees. This ensures the best measurement of any sample type.

Convenient sample loading

The VUV-VASE uses a load lock chamber to load and purge the sample chamber with ease.

Protect your samples

The VUV-VASE is designed with the monochromator before the sample to minimize the light that probes your sample. This helps protect photo-sensitive materials.

  • Spectral range: 146 to 1100 nm
  • NIR extension: to 1700 nm or 2500 nm
  • Verticale sample mount
  • Motorized angle of incidence goniometer: 25° to 90°
  • AutoRetarder
  • Ellipsometry, transmittance and reflectance
  • Large sample load lock cell: 300 mm wafer, 6"" photo-masks
  • XY sample mapping

Measure film thickness and refractive index (n and k) at 157 nm, 193 nm, 248 nm.

Electronical transitions


Bandgap, electronic transitions and critical points of semiconductor materials could be measured in the VUV spectral range with a stand-alone instrument, which normally requires access to a synchrotron beam line.


Advanced anisotropic measurements (generalized SE) provide additional information to help fully characterize uniaxial (two sets of optical constants) and biaxial (three sets of optical constants) anisotropic materials.

The VUV-VASE can measure in both reflection and transmission ellipsometry modes. The graphs show ordinary and extraordinary dielectric functions of 4H SiC measured with VUV-VASE.

Antireflex coatings
Stepper optics
Follow us: twitter linkedin facebook
European offices
© LOT Quantum Design 2016