Accurion EP4 is a high-end system for Imaging Spectroscopic Ellipsometry, combining spectroscopic ellipsometry and optical microscopy in a single instrument. It enables spatially resolved, parallel measurement of film thickness and refractive index on micro-structured samples with lateral resolution down to 1 µm, featuring live ellipsometric contrast imaging and direct selection of regions of interest for quantitative analysis.
The Microscopic Way of Doing Ellipsometry
Simultaneous Ellipsometry on Every Pixel
In the EP4, imaging spectroscopic ellipsometry is performed in parallel across the entire field of view. No scanning or sequential single-point measurements are required.
Highest Lateral Ellipsometric Solution
With lateral ellipsometric resolution down to 1 µm, the EP4 enables precise film thickness and refractive index measurements on even the smallest inhomogeneous and micro-structured features.
First Identify, then Measure
The principle “First identify, then measure” enables intuitive selection of regions of interest directly from the live ellipsometric image.
Continuous Spectroscopic Imaging
Continuous spectroscopic imaging from UV to NIR ensures comprehensive optical characterization across the relevant spectral range.
Key Features
- Microscopic lateral resolution down to 1 µm, enabling precise determination of film thickness and refractive index on micro-structured samples.
- Sub-nanometer vertical sensitivity for highly sensitive detection of ultra-thin layers, including mono- and sub-monolayers.
- Imaging Spectroscopic Ellipsometry (across UV–VIS–NIR), with a configurable spectral range from 190 nm to 1700 nm.
- True parallel multi-pixel measurement, performing spectroscopic ellipsometry simultaneously on every pixel within the field of view.
- ROI-based measurement workflow (“First identify, then measure”), allowing intuitive selection of measurement regions directly in the live ellipsometric view.
- Live ellipsometric contrast imaging for real-time visualization of thickness and optical inhomogeneities.
- Automated sample stage control with large-area stitching, enabling measurements over extended sample areas.
- Knife-edge illumination for non-destructive suppression of backside reflections on transparent substrates.
- Modular optical design with interchangeable objective lenses, allowing adaptation to different measurement tasks.
- User-friendly EP4 software suite (EP4Control, DataStudio, EP4Model) for instrument control, data analysis, and optical modeling.
- Active vibration isolation ensuring superior mechanical stability for high-precision measurements.

