A FIB induced boiling mechanism for rapid nanopore formation

Area of Science:

• Materials Science
• Nanotechnology
• Computational Physics

Background:

• Focused Ion Beam (FIB) technology is a key method for creating nanopores in solid-state membranes.
• These nanopores are crucial for applications like high-throughput DNA sequencing due to their thermomechanical properties.
• Understanding the nanopore formation process is essential for optimizing fabrication.

Purpose of the Study:

• To investigate the mechanism of nanopore formation using large-scale molecular dynamics simulations.
• To identify the critical ion delivery rate that alters the nanopore formation process.
• To explore methods for accelerating nanopore fabrication for DNA sequencing.

Main Methods:

• Large-scale molecular dynamics simulations were employed to model the FIB nanopore formation process.
• The simulations analyzed the effect of varying ion delivery rates on the target material.
• The study focused on the transition in formation mechanisms at different ion fluxes.

Main Results:

• A threshold ion delivery rate was identified, above which the nanopore formation mechanism changes.
• At low rates, formation is sputter-limited and slow.
• At higher rates, a thermally dominated process, akin to explosive boiling, leads to rapid mass rearrangement via bubble growth and coalescence, significantly speeding up formation.

Conclusions:

• The mechanism of FIB-induced nanopore formation transitions from sputtering-limited to a thermally dominated explosive boiling process at a critical ion flux.
• This explosive boiling mechanism offers a pathway to substantially accelerate the fabrication of nanopores.
• Optimizing ion delivery rates based on these findings can enhance the efficiency of nanopore fabrication for applications such as DNA sequencing.