Deconvolution of local surface response from topography in nanometer profilometry with a dual-scan method

Area of Science:

• Surface Metrology
• Nanotechnology
• Optical Microscopy

Background:

• Profilometry is crucial for characterizing surface topography.
• Distinguishing surface heterogeneity from topography is challenging.
• Existing methods lack sufficient resolution or versatility.

Purpose of the Study:

• To introduce and validate a dual-scan method for separating surface heterogeneity from topographic signals.
• To demonstrate the efficacy of differential confocal microscopy for high-resolution profilometry.
• To assess the applicability of the dual-scan method to various profilometric techniques.

Main Methods:

• Implementing a dual-scan technique with a fixed vertical offset in profilometric measurements.
• Utilizing a newly developed open-loop nanometer profilometric technique: differential confocal microscopy.
• Testing the method on composite samples to evaluate performance.

Main Results:

• Successfully separated surface heterogeneity signals from topographic signals.
• Achieved a depth resolution of 10 nanometers using differential confocal microscopy.
• Demonstrated the method's potential for high-resolution surface analysis.

Conclusions:

• The dual-scan method effectively differentiates surface heterogeneity and topography.
• Differential confocal microscopy offers a promising approach for nanometer-scale profilometry.
• This technique holds potential for broader application in advanced surface characterization techniques like AFM and STM.