Nanopillar fabrication with focused ion beam cutting

Area of Science:

• Materials Science
• Nanotechnology
• Surface Engineering

Background:

• Fabricating high-aspect-ratio micro-/nanopillars is crucial for various applications.
• Existing methods often result in tapered structures or surface damage.
• Focused ion beam (FIB) milling is a powerful nanofabrication technique.

Purpose of the Study:

• To develop a versatile method for fabricating taper-free micro-/nanopillars with large aspect ratios.
• To overcome limitations of existing FIB milling techniques regarding tapering and surface damage.
• To establish a reliable procedure for cross-sectional analysis of fabricated pillars.

Main Methods:

• Utilized focused ion beam (FIB) cutting with a 90° incident angle relative to the pillar's long axis.
• Employed a stepwise reduction of the FIB current during milling.
• Developed a precise method for determining the cross-section of each micro-/nanopillar.

Main Results:

• Successfully fabricated taper-free micro-/nanopillars with large aspect ratios.
• The 90° milling angle effectively prevented pillar tapering.
• Stepwise current reduction minimized gallium (Ga) ion radiation damage on the milled surfaces.
• Accurate cross-sectional determination confirmed pillar integrity.

Conclusions:

• The developed FIB cutting method offers a versatile and precise approach for fabricating high-quality, taper-free micro-/nanopillars.
• This technique is suitable for applications requiring tall, slender nanostructures with minimal surface damage.
• The established cross-section determination procedure enhances the reliability of nanofabrication characterization.