Confocal pore size measurement based on super-resolution image restoration

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Nuclear track-etched membranes (NTEMs) are crucial in filtration and separation.
• Accurate characterization of submicrometer pores is essential for NTEM performance.
• Existing pore size measurement methods can be time-consuming or lack sufficient resolution.

Purpose of the Study:

• To develop a fast and accurate confocal pore size measurement technique for NTEMs.
• To enable online inspection of pore size evolution during the etching process.
• To enhance the lateral resolution for precise pore edge detection.

Main Methods:

• Utilizing confocal microscopy combined with super-resolution image restoration.
• Implementing a circle edge-setting criterion of 0.2408 for accurate pore edge detection.
• Performing theoretical analysis, edge response simulation, and experimental validation.

Main Results:

• Achieved significant improvement in lateral resolution for NTEM imaging.
• Demonstrated precise pore edge detection with a minimum measurable diameter of 0.19 μm.
• Obtained a root mean square residual of 1.4 nm and an edge response better than 80 nm.
• Measurement results showed excellent agreement with scanning electron microscopy (SEM) data.

Conclusions:

• The proposed super-resolution confocal pore size measurement method is fast, accurate, and reliable for NTEMs.
• This technique facilitates online monitoring of pore size during etching.
• The method offers a viable alternative to traditional characterization techniques like SEM for NTEM pore analysis.