Ultra-high aspect ratio replaceable AFM tips using deformation-suppressed focused ion beam milling.

Area of Science:

• Nanotechnology
• Materials Science
• Surface Science

Background:

• Atomic Force Microscopy (AFM) relies on high-aspect-ratio (HAR) tips for nanoscale imaging.
• Conventional on-axis focused ion beam (FIB) milling has limitations in tip customization and shape control.
• Lateral FIB milling offers greater flexibility but has been hindered by beam-induced deformation.

Purpose of the Study:

• To develop a method for fabricating exchangeable and customizable ultra-high aspect ratio AFM tips.
• To overcome the challenge of beam-induced deformation in lateral FIB milling for HAR structures.
• To demonstrate the assembly and performance of these novel AFM tips.

Main Methods:

• Utilized lateral focused ion beam (FIB) milling for tip fabrication.
• Implemented a deformation-suppressing writing strategy to enable HAR structure definition.
• Developed techniques for assembling the HAR tips onto custom probes.

Main Results:

• Achieved ultra-high aspect ratios of up to 45.
• Fabricated tips with diameters as small as 9 nm.
• Successfully demonstrated the assembly and initial AFM scanning with the fabricated tips.

Conclusions:

• Lateral FIB milling, with a deformation-suppressing strategy, enables the fabrication of customizable ultra-high aspect ratio AFM tips.
• This advancement overcomes previous limitations, offering enhanced flexibility in tip design and performance.
• The developed tips show promise for advanced AFM applications requiring high resolution and specific tip geometries.