High aspect ratio AFM Probe processing by helium-ion-beam induced deposition

Area of Science:

• Nanotechnology
• Materials Science
• Surface Science

Background:

• Atomic Force Microscopy (AFM) requires high-aspect-ratio probes for imaging complex surfaces.
• Scanning Helium Ion Microscopy (SHIM) offers sub-nanometer resolution and nanoscale fabrication capabilities.

Purpose of the Study:

• To fabricate high-aspect-ratio probe tips for AFM using SHIM.
• To improve AFM's ability to image highly uneven and concavo-convex surfaces.

Main Methods:

• Utilized SHIM with a gas injection system for ion-beam induced deposition.
• Deposited platinum (Pt) nano-pillars onto commercial AFM probe tips using a helium ion beam.
• Controlled nano-pillar length by adjusting helium ion beam irradiation time.

Main Results:

• Successfully fabricated Pt nano-pillars with ~40nm diameter and up to ~2000nm length.
• Probes with Pt nano-pillars demonstrated improved access to narrow trenches in AFM measurements.
• Achieved better imaging of features with reduced salient and enhanced reentrant characteristics compared to conventional probes.

Conclusions:

• SHIM-based ion-beam induced deposition is effective for creating high-aspect-ratio AFM probe tips.
• The fabricated Pt nano-pillar probes significantly enhance AFM's capability for high-resolution imaging of challenging surfaces.
• This method offers a pathway for developing advanced AFM probes for nanoscale metrology and characterization.