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Alpha 2.0
J.A. Woollam
The alpha 2.0 is a budget-friendly option for routine measurements of thin film thickness and refractive index.
A compact footprint and simple design make the alpha 2.0 easy to use while harnessing the power of spectroscopic ellipsometry. It was designed for ease-of-use: simply place the sample on the stage, choose the model that matches your film, click "measure", and you will have results within seconds.
Applications
Transparent FilmsSelf-Assembled Monolayers
Absorbing Films
Materials:
• a-Si
• poly-Si
• Diamond-like carbon
• Organic materials
• Organic LED films
• SiC
• Photoresist
• Display color filters
• Metals
Models:
• Lorentz
• Gaussian
• Drude
• Tauc-Lorentz
• B-Spline
Features
Dual-Rotation™ Technology
The alpha 2.0 is equipped with Dual-Rotation ellipsometry technology, featuring a rotating compensator on the source unit and rotating analyzer on the detector unit. This technology provides access to high accuracy and Mueller matrix measurements in a single optical cycle.
CCD Detection System
The alpha 2.0 uses a CCD detector for simultaneous measurement of 190 wavelengths. This allows measurement from 400 nm to 1000 nm in less than a second.
Compact
Everything contained in one small package to fit easily on your benchtop. Easy connection to your computer via USB.
Auto Alignment
Alignment is integrated into the data acquisition routine. Automated Z-translation alignment for easy data acquisition. Simply place your sample on the stage and the Alpha 2.0 does the rest.
CompleteEASE® Software
CompleteEASE is the world's leading ellipsometry software. Includes prebuilt models for beginners, comprehensive measurement capabilities, and advanced data analysis features.
Specifications
System Configuration (in order)• Light source
• Fixed polarizer
• Rotating compensator
• Sample
• Rotating analyzer
• Fixed analyzer
• Spectrometer and detector
Angles of Incidence
• Manual adjustment
• 65°, 70°, 75° (off-sample)
• 90° (straight-through)
Spectral Range
• 400nm to 1000nm (190 wavelengths)
Light Source
• Quartz Tungsten Halogen (QTH)
Data Acquisition Rate
• 5-10 seconds for full spectrum (typical)
Beam Diameter
• Focused, <1 mm.
Sample Size
• Max. sample diameter: 200 mm
• Max. substrate thickness: 11 mm (65° AOI), 16 mm (70° AOI), 21 mm (75° AOI)
Measurable Quantities
• Ellipsometry: ? (0°-90°) and A (0°-360°)
• Intensity: % Transmission and % Reflection
• Depolarization: % Depolarization
Mueller Matrix: 11 normalized elements of the Mueller Matrix (normalized to m11). Useful for samples that are both anisotropic and depolarizing.
Typical Accuracy
• Straight-through measurement of empty beam, met by 98% of wavelengths from 400nm to 1000nm with ten second averaging time:
? = 45°± 0.2
A=0°±0.2
Typical Repeatability
• Thirty consecutive measurements of native oxide (nominally 2nm) or thermal oxide (nominally 25nm) on silicon with a warm system at 70° angle and ten second averaging with fixed sample:
?thickness <0.01nm
