Waveguide sidewall roughness measurement on full wafers by SEM-based stereoscopy

Area of Science:

• Photonics and Materials Science
• Nanotechnology and Surface Metrology

Background:

• Integrated optical devices are crucial for modern telecommunications.
• Precise control over waveguide sidewall quality is essential for device performance.
• Existing methods for sidewall roughness measurement can be limited in resolution or applicability.

Purpose of the Study:

• To introduce a novel technique for quantifying sidewall roughness in silica waveguides.
• To demonstrate the application of scanning electron microscopy (SEM) for high-resolution surface topography analysis.
• To provide practical insights into implementing this measurement method.

Main Methods:

• Utilizing a scanning electron microscope (SEM) for high-resolution imaging.
• Applying principles of stereoscopy to reconstruct 3D sidewall topography from 2D SEM images.
• Developing specific sample preparation and imaging protocols for optical waveguides.

Main Results:

• Successfully retrieved detailed sidewall topography of silica waveguides.
• Demonstrated the capability of the technique to measure surface roughness parameters.
• Presented initial results showcasing the effectiveness and resolution of the method.

Conclusions:

• The presented stereoscopy-based SEM technique offers a viable approach for accurate sidewall roughness measurement.
• This method can contribute to improved fabrication processes and performance optimization of integrated optical devices.
• Further refinement could enable routine quality control in optical waveguide manufacturing.