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Interferometric measurement of phase change on reflection.
Kate M Medicus1, Marcus Chaney, John E Brodziak
1Department of Physics and Optical Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA. k.medicus@mitutoyo.nl
Applied Optics
|March 27, 2007
Summary
This study presents an interferometric method to measure phase change, removing sample height effects. The technique achieves +/-3.8 degree uncertainty, crucial for precise interferometric radius measurements.
Area of Science:
- Optical Metrology
- Interferometry
- Surface Characterization
Background:
- Accurate phase change measurement is critical in optical metrology.
- Traditional methods can be complicated by sample height variations.
- Understanding phase change effects is vital for precision measurements.
Purpose of the Study:
- To develop and demonstrate an interferometric method for measuring phase change.
- To quantify the uncertainty associated with the phase change measurement.
- To investigate the impact of phase change on interferometric radius measurements.
Main Methods:
- Utilized an interferometric technique employing sample backreflection.
- Developed a background subtraction method to isolate phase change.
- Analyzed the theoretical error introduced by phase change in radius measurements.
Main Results:
- Successfully measured phase change, intrinsically removing sample height.
- Achieved a phase change measurement uncertainty of +/-3.8 degrees.
- Determined a theoretical worst-case error of 30 nm in radius measurement due to phase change.
Conclusions:
- The developed interferometric method provides a robust way to measure phase change.
- Background subtraction is the primary source of uncertainty in phase change measurement.
- Phase change significantly impacts interferometric radius measurements, with a quantifiable error.
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