Microscopic imaging ellipsometer is an instrument that combines optical microscopy imaging and ellipsometry technology, mainly used to measure parameters such as film thickness, refractive index, absorption coefficient, and obtain the three-dimensional morphology distribution of the sample surface.
Microscopic imaging ellipsometer is based on the principle of elliptical polarization. By analyzing the polarization state changes of incident polarized light after reflection or transmission by the sample, combined with optical microscopy imaging technology, it obtains the three-dimensional morphology distribution of the sample surface and optical parameters such as film thickness and refractive index.
The process includes:
Light source and polarization control: The light emitted by the light source is converted into linearly polarized light through a polarizer, and then adjusted to a specific polarization state (such as elliptically polarized light) through a compensator.
Sample interaction: Polarized light is incident on the surface of the sample and undergoes reflection or transmission with the sample. The polarization state changes due to the characteristics of the sample, such as film thickness and refractive index.
Detection and analysis: Polarizers measure the polarization state of reflected or transmitted light (usually described by ellipsoidal angles PSI and Δ), and use physical models (such as thin film optical theory) to invert and calculate parameters such as sample thickness and refractive index. At the same time, the CCD imaging system obtains ellipsoidal parameters at different positions on the sample surface, forming three-dimensional morphology and thickness distribution images.
Operation precautions
Sample preparation:
The surface of the sample should be flat and clean to avoid dust or scratches affecting polarized light reflection.
For multi-layer film samples, it is necessary to establish a reasonable physical model to improve measurement accuracy.
Environmental control: Environmental factors such as temperature, vibration, and stray light may affect measurement stability and require operation on a constant temperature, shock resistant optical platform.
Data processing:
Fit experimental data and theoretical models using built-in algorithms, calculate sample parameters, and visualize results.
For complex samples, multiple analytical techniques need to be combined to obtain more accurate results.