Optimizing the precision of a multichannel three-polarizer spectroscopic ellipsometer

Area of Science:

• Optical Physics
• Materials Science
• Metrology

Background:

• Spectroscopic ellipsometry is a powerful technique for characterizing thin films and surfaces.
• Achieving high precision in measurements is crucial for accurate material property determination.
• Existing methods may have limitations in precision and accuracy.

Purpose of the Study:

• To develop a multichannel three-polarizer spectroscopic ellipsometer with an optimized data acquisition algorithm.
• To enhance the precision and accuracy of spectroscopic ellipsometry measurements.
• To establish a method for identifying optimal data reduction techniques for rotating-element ellipsometers.

Main Methods:

• Development of a multichannel three-polarizer spectroscopic ellipsometer.
• Implementation of a data acquisition algorithm for precise measurement of unnormalized Fourier coefficients.
• Wavelength-independent offset angle determination using regression calibration.
• Calculation of sample parameters using derived data reduction functions.
• Error analysis of sample parameters based on Fourier coefficient correlation coefficients.

Main Results:

• The developed algorithm achieves accurate and precise measurement of unnormalized Fourier coefficients.
• Wavelength-independent offset angles were successfully obtained through regression calibration.
• A comparison of different data reduction methods identified the most precise approach.
• The study provides a framework for optimizing precision in spectroscopic ellipsometry.

Conclusions:

• The novel spectroscopic ellipsometer and its associated algorithm significantly improve measurement precision.
• The methodology allows for accurate determination of sample parameters and their associated errors.
• This approach offers a valuable tool for advancing materials characterization and metrology.
• The developed precision optimization strategy is applicable to other rotating-element ellipsometers.