Long-term stability of the wavelength method of height scale calibration for interference microscopy

Danette Fitzgerald; Peter de Groot

doi:10.1117/12.2528155

Translator Disclaimer

3 September 2019 Long-term stability of the wavelength method of height scale calibration for interference microscopy

Danette Fitzgerald, Peter de Groot

Author Affiliations +

Proceedings Volume 11102, Applied Optical Metrology III; 111020K (2019) https://doi.org/10.1117/12.2528155
Event: SPIE Optical Engineering + Applications, 2019, San Diego, California, United States

Abstract

An important characterization for surface topography instruments is a traceable calibration of the height scale. We calibrate our coherence scanning interference microscopes using a natural spectral emission line in place of a sequence of material measures such as step-height specimens. The uncertainty budget for our approach includes estimates for several error sources associated with long term drift. Here we summarize results collected over 3 years’ experience from our laboratories to provide statistical support for confirming and refining these uncertainty contributions. We find that the source wavelength stability is < 0.005% RMS and the stability of the height scaling factor (the amplification coefficient) is < 0.02% RMS over 900 days. Both values are better than our original estimates. We also show < 0.13% RMS reproducibility of the complete traceable process using acceptance test data for over 100 manufactured instruments. Finally, we report results of 3 years of experience in certifying step-height specimens using the traceable wavelength method.

Conference Presentation

Citation Download Citation

Danette Fitzgerald and Peter de Groot "Long-term stability of the wavelength method of height scale calibration for interference microscopy", Proc. SPIE 11102, Applied Optical Metrology III, 111020K (3 September 2019); https://doi.org/10.1117/12.2528155

ACCESS THE FULL ARTICLE