Snapshot angle-resolved channeled spectroscopic micro-ellipsometry for thin-film characterization.

Area of Science:

• Materials Science
• Optical Physics
• Spectroscopy

Background:

• Ellipsometry is crucial for thin film characterization.
• Existing methods may face limitations in precision and spectral range.
• Need for advanced spectroscopic techniques for accurate optical property determination.

Purpose of the Study:

• To introduce and validate a novel angle-resolved channeled spectroscopic micro-ellipsometry (ACSE) system.
• To demonstrate the system's capability in accurately measuring thin film parameters.
• To enhance precision in ellipsometric measurements through advanced signal processing.

Main Methods:

• Development of an ACSE system with near-normal incidence and line-scan spectroscopy.
• Analysis of spectral interference envelopes to separate DC and AC signal components.
• Application of Hilbert transform for calibrating spectral amplitude and phase errors.

Main Results:

• The ACSE system operates in the 480-680 nm visible range with incidence angles from 0° to 60°.
• Accurate separation of low-frequency (baseline) and high-frequency (modulation) signal components.
• Successful measurement of SiO2 thin film thicknesses (10-1500 nm) and refractive indices, validated against a commercial ellipsometer.

Conclusions:

• The developed ACSE system offers a precise and reliable method for thin film characterization.
• The signal processing techniques significantly improve the accuracy of retrieved ellipsometric parameters.
• This technology provides a valuable tool for materials science and optical metrology.