The most recent generation of imaging ellipsometers, the EP4, combines microscopy with ellipsometry. All structures inside the optical system’s range of vision can be simultaneously measured with the microscopic part. Traditional ellipsometers must concentrate on the measurement spot while measuring spot by spot with inferior lateral resolution.
The microscopic part of the EP4 allows microscopic images to be produced with an ellipsometric-enhanced contrast. The camera’s live view can show minute variations in thickness or refractive index.
This enables the identification of areas of interest for ellipsometric studies to determine thickness (0.1 nm–10 µm) and refractive index values. A single measurement can capture 3D maps of the lateral variation in thickness and/or refractive index.
It is possible to combine complementary techniques, such as AFM, QCM-D, reflectometry, and Raman, to observe the same region. Additional accessories can increase measuring options under regulated environmental conditions or temperature variations.
Sophisticated Modeling Software
The modular EP4 software allows direct control and parallel or offline analysis. The instrument is controlled by the EP4 control. In the live view, regions for measurements can be chosen. It is possible to automatically organize and measure several samples.
The recorded data can be processed using DataStudio. The intricacies of the samples can be substantially studied through histogram analysis and line profiles.
The samples can be modeled using the EP4Model. Its user-friendly interface makes it easy to design thin film sample configurations that range from simple to sophisticated. It provides data on the sample’s thickness and refractive indices. Acquiring other physical parameters, such as the bandgap or the volume fraction of a mixed material layer is also possible.
Key Features
- Modular setup: Simple configuration changes from BAM to complete spectroscopic ellipsometer for single wave, multiwave, and BAM
- Spectroscopic imaging ellipsometry from 190/250/360 nm to 1000/1700/2700 nm
- The ability to measure the thickness and refractive index on microstructures with a 1 µm highest lateral ellipsometric resolution
- Ellipsometric enhanced contrast images for live visualization of the sample
- First identify, then measure: Intuitive selection of measurement region by drawing region in live view
- Parallel measurement of multiple regions within the selected field of view
- Patented knife-edge illumination that suppresses distracting backside reflections without causing damage
- Increase the measurement options by adding further components, such as cells, temperature control, or liquid handling
- Quality Control: Also available as OEM version for QC in product lines

Image Credit: Park Systems
nanofilm_ep4: Imaging Ellipsometer