Widest spectral range ellipsometer VASE
From Woollam Co.
The VASE is our most accurate and versatile ellipsometer for research on all types of materials: semiconductors, dielectrics, polymers, metals, multi-layers and more.
|Ex-situ spectroscopic ellipsometer|
|Wide spectral range from 193 to 3200 nm|
|Maximum data accuracy|
|High spectral resolution and perfect R&D flexibility|
It combines high accuracy and precision with a wide spectral range from 193 to 3200 nm. Variable wavelength and angle of incidence allow flexible measurement capabilities including:
- Reflection and transmission ellipsometry
- Generalized ellipsometry
- Reflectance (R) intensity
- Transmittance (T) intensity
- Cross-polarized R/T
- Mueller matrix
Maximum data accuracy
The VASE features a rotating analyzer ellipsometer (RAE) combined with our patented AutoRetarder for unparalleled data accuracy.
High-precision wavelength selection
The HS-190TM scanning monochromator is designed specifically for spectroscopic ellipsometry. It optimizes speed, wavelength accuracy, and light throughput, while automatically controlling selection of wavelengths and spectral resolution.
The VASE features a vertical sample mount to accommodate a large variety of measurement geometries including reflection, transmission, and scattering.
- vertical sample mount
- computer-controlled angle of incidence goniometer 20° - 90°
- single or double chamber monochromator
- spectral range 250 - 1100 nm (standard)
- DUV from 193nm
- NIR to 1700 nm, 2500nm or 3200nm
- computer-controlled mapping unit: 50mm XY or 150mm XY
- computer controlled sample rotator
- manual 50 mm XY translation
- 200 µm focused beam option
- cryostat (4.2 to 500 K or 4.2 to 800 K)
- heat cell (RT to 300 °C or -80 °C to +600 °C)
Bandgap, electronic transitions and critical points can be measured for semiconductor materials such as GaN, InP, SiGe, CdTe, etc. Good wavelength resolution and ability to measure depolarization ensure accurate optical constants.
For thicker films (>5 μm), good spectral resolution is needed to resolve the interference oscillation features of Ψ/Δ data. Operator defined monochromator step size and narrow bandwidth help resolve fine spectral features.
The monochromator is positioned before the sample, so only low intensity monochromatic light strikes the sample. This prevents exposure of photosensitive samples.