Spectroscopic Ellipsometry

Spectroscopic ellipsometry operates by analyzing the change in the polarization state of light upon interaction with a sample surface. A light source, such as a monochromatic or broadband light source, generates polarized light which is directed towards the sample surface at a specific angle of incidence. Upon reflection or transmission through the sample, the polarization state of the light is altered due to the interaction with the sample’s surface and any thin films present.

An analyzer or detector then measures this change in polarization, quantified by two fundamental parameters known as Δ (Delta) and Ψ (Psi). These ellipsometric parameters are directly related to the optical properties of the sample, including film thickness, refractive index, and extinction coefficient. Mathematical models and algorithms are employed to relate the measured Δ and Ψ values to the desired sample properties.

The key aspect that distinguishes spectroscopic ellipsometry is that it measures these ellipsometric parameters over a range of wavelengths, rather than at just a single wavelength. This provides additional information about the dispersion characteristics of the sample, allowing for more accurate and comprehensive characterization of the optical properties and material composition. The spectroscopic data is collected by a spectrometer or array detector, enabling simultaneous measurement across the entire wavelength range of interest.

• Characterization of thin films used in semiconductor manufacturing (e.g., oxides, nitrides, metals)
• Monitoring of deposition processes and film growth
• Determination of film thickness, composition, and optical properties

• Measurement of anti-reflective, reflective, and optical coatings
• Characterization of dielectric and metallic coatings
• Analysis of multilayer thin-film structures

• Characterization of thin-film transistors and display materials
• Analysis of transparent conductive oxides and thin-film solar cells
• Monitoring of thin-film deposition processes

• Characterization of biological thin films (e.g., proteins, lipids, cells)
• Analysis of surface modifications and biocompatible coatings
• Monitoring of biomolecular interactions and adsorption processes

• Non-destructive and non-invasive: The technique does not damage or alter the sample, making it suitable for in-line monitoring and quality control.
• High sensitivity: Ellipsometry is highly sensitive to ultra-thin films and small changes in material properties.
• Quantitative and accurate: It provides precise quantitative measurements of film thickness, optical constants, and material properties.
• In-situ and real-time analysis: Ellipsometry can be performed in various environments (e.g., vacuum, controlled atmosphere) and can monitor processes in real-time.
• Broad wavelength range: Spectroscopic ellipsometry covers a wide range of wavelengths, providing comprehensive information about the sample.

• Sample Size: Maximum 3 mm x 1.2 cm.
• Maximum Sample Thickness: ~15 mm.