High Aspect Ratio Nanoscale Pores through BCP-Based Metal Oxide Masks and Advanced Dry Etching

Area of Science:

• Materials Science
• Nanotechnology
• Surface Engineering

Background:

• Surface modification is vital for creating functional materials.
• Porous topographies offer advantages like high surface area and specific properties (e.g., hydrophobicity).
• Fabricating controlled porous structures, especially with high aspect ratios, remains a challenge.

Purpose of the Study:

• To introduce a new fabrication technique for creating high-aspect-ratio porous silicon.
• To demonstrate the combination of self-assembled block-copolymer masks and deep reactive ion etching (DRIE).
• To evaluate the suitability of these porous structures for applications requiring high light absorption and thermal management.

Main Methods:

• Utilized nanoscale self-assembled block-copolymer-based metal oxide masks.
• Employed optimized deep reactive ion etching (DRIE) of silicon.
• Characterized fabricated structures using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM).

Main Results:

• Successfully fabricated porous silicon topographies with aspect ratios up to 50.
• Demonstrated precise control over pore and topography development.
• Evaluated the performance of fabricated features for light absorption and thermal management.

Conclusions:

• The combined block-copolymer masking and DRIE technique is effective for creating high-aspect-ratio porous silicon.
• The fabricated porous structures show promise for applications in optics and thermal engineering.
• This method offers a reliable route for advanced surface functionalization.