Traceable methods for vertical scale characterization of dynamic stroboscopic scanning white-light interferometer...

Area of Science:

• Optical metrology
• Nanotechnology
• Surface characterization

Background:

• Stroboscopic scanning white-light interferometry (SSWLI) is valuable for 3D imaging of oscillating samples with nanometer precision.
• Traceability of vertical displacement measurements is crucial for SSWLI, especially for dynamic measurements where frequency response introduces errors.
• Existing calibration methods for static SSWLI measurements are insufficient for characterizing dynamic performance.

Purpose of the Study:

• To develop and present a method for traceable characterization of dynamic SSWLI measurements.
• To address the need for accurate motion standards in calibrating SSWLI under dynamic conditions.
• To establish uncertainty budgets for dynamic SSWLI measurements.

Main Methods:

• Utilizing dynamic transfer standards for SSWLI calibration.
• Characterizing dynamic transfer standards using a laser interferometer traceable to the SI meter.
• Performing dynamic SSWLI measurements across a frequency range from subkilohertz to 10.7 kHz with micrometer displacement.

Main Results:

• Successfully characterized dynamic SSWLI measurements up to 10.7 kHz.
• Achieved an expanded uncertainty (k=2) of 9.6 nm for a 766 nm displacement at 10.7 kHz.
• Demonstrated the methodology's applicability up to the frequency limits of SSWLI with appropriate samples.

Conclusions:

• The presented method enables traceable dynamic measurements using SSWLI.
• This approach is suitable for characterizing SSWLI performance in dynamic scenarios.
• The methodology can be extended to higher frequencies within the SSWLI's operational range.