Differential confocal measurement for surface topography with microstructures based on spiral scanning and wavelet...

Area of Science:

• Metrology
• Optical Measurement
• Surface Science

Background:

• Traditional raster-scanning methods face challenges with acceleration/deceleration, impacting efficiency and stability.
• Accurate measurement of microstructured surfaces is crucial for various scientific and industrial applications.

Purpose of the Study:

• To introduce a novel spiral-scanning laser differential confocal measurement method (SSLDCM).
• To enhance the speed, precision, and stability of surface topography measurement for microstructures.

Main Methods:

• Implemented spiral plane scanning to avoid acceleration/deceleration issues.
• Utilized a variable sampling rate for uniform point distribution and reduced 3D imaging time.
• Applied an adaptive wavelet threshold denoising method to filter measurement noise.

Main Results:

• Experimental platform demonstrated a linear region range of 13 µm with a slope of 164.15 mV/µm.
• Measurements of a silicon wafer showed high consistency with a commercial microscope, with deviations under 2.71%.
• The SSLDCM achieved efficient and stable measurement processes.

Conclusions:

• The SSLDCM provides a highly efficient and accurate noncontact method for surface topography measurement.
• This technique shows significant potential for applications requiring precise microstructured surface analysis.
• The method overcomes limitations of traditional scanning techniques, offering improved performance.