Reverse engineering of e-beam deposited optical filters based on multi-sample photometric and ellipsometric data

Area of Science:

• Materials Science
• Optical Physics
• Metrology

Background:

• Accurate post-production characterization of multilayer (ML) materials is crucial for quality control and performance prediction.
• Traditional methods may require complex sample preparation or in-situ monitoring, limiting practical application.
• Spectral photometric and ellipsometric techniques offer non-destructive analysis capabilities.

Purpose of the Study:

• To propose and validate a post-production characterization approach for multilayer samples.
• To determine the reliability of different characterization strategies using ex-situ measurements.
• To identify the most practical and effective characterization method for real-world applications.

Main Methods:

• Utilized spectral photometric and ellipsometric data from specially prepared single-layer (SL) and multilayer (ML) sample sets.
• Performed ex-situ measurements on both building-block SL samples and the final ML sample.
• Compared the accuracy and reliability of various ex-situ characterization strategies applied to the final ML sample.

Main Results:

• Successfully determined reliable thicknesses and refractive indices for the final ML samples.
• Demonstrated the effectiveness of the proposed ex-situ characterization approach.
• Evaluated and compared the performance of different characterization strategies.

Conclusions:

• The proposed post-production characterization method provides reliable material property determination.
• Ex-situ analysis of the final ML sample is a viable and practical alternative to extensive sample preparation.
• This approach offers a valuable tool for optimizing material characterization in industrial settings.