18/01/2024
What is Ellipsometric Film Thickness Measurement System?
An ellipsometric film thickness measurement system is a tool used to measure the thickness of thin films on a surface. It works by using polarized light to interact with the film and then analyzing the changes in the light’s polarization to determine the film’s thickness.
Ellipsometric film thickness measurement system
Here’s how it works:
- Polarized light source: The system emits a beam of polarized light, which means that the electric field of the light wave is oscillating in a single plane.
- Sample interaction: The polarized light is directed at the sample with the thin film. As the light interacts with the film, it undergoes a change in its polarization due to the optical properties of the film and the underlying substrate.
- Detector: The reflected light is then captured by a detector that measures the changes in the polarization state.
- Data analysis: The measured changes in polarization are used to calculate the thickness of the film using a complex mathematical model that takes into account the optical properties of the film and the substrate.
Ellipsometry has several advantages over other methods for measuring thin film thickness:
- Non-destructive: It is a non-destructive technique, which means that it does not damage the sample.
- High precision: It can measure film thickness with very high precision, often down to a few angstroms (Å).
- Wide range of materials: It can be used to measure the thickness of a wide variety of materials, including metals, semiconductors, dielectrics, and polymers.
- Multi-layer films: It can be used to measure the thickness of multiple layers in a film stack.
Ellipsometry is a powerful tool for characterizing thin films in a variety of applications, including:
- Semiconductor device fabrication: Measuring the thickness of gate oxide layers and other critical layers in transistors.
- Solar cell production: Measuring the thickness of anti-reflection coatings and other layers in solar cells.
- Optical coatings: Measuring the thickness of coatings on lenses, mirrors, and other optical components.
- Biomedical research: Measuring the thickness of protein layers on surfaces.