Monte Carlo simulation of nanoscale material focused ion beam gas-assisted etching: Ga and Ne etching of SiO in the presence of a XeF precursor gas.

Elucidating energetic particle-precursor gas-solid interactions is critical to many atomic and nanoscale synthesis approaches. Focused ion beam sputtering and gas-assisted etching are among the more commonly used direct-write nanomachining techniques that have been developed. Here, we demonstrate a method to simulate gas-assisted focused ion beam (FIB) induced etching for editing/machining materials at the nanoscale.

Simulating advanced focused ion beam nanomachining: a quantitative comparison of simulation and experimental results.

A simulation study of focused ion beam (FIB) sputtering in SiO is presented. The basis of this study is an enhanced version of the EnvizION Monte Carlo simulation program for FIB processing, which previously was restricted to targets composed of a single atom. A Monte Carlo method is presented for the simulation of FIB sputtering in SiO in three-dimensions, with ion implantation, to elucidate the complex dynamics of nanoscale milling of compound targets.

Monte Carlo simulations of nanoscale Ne ion beam sputtering: investigating the influence of surface effects, interstitial formation, and the nanostructural evolution.

We present an updated version of our Monte-Carlo based code for the simulation of ion beam sputtering. This code simulates the interaction of energetic ions with a target, and tracks the cumulative damage, enabling it to simulate the dynamic evolution of nanostructures as material is removed. The updated code described in this paper is significantly faster, permitting the inclusion of new features, namely routines to handle interstitial atoms, and to reduce the surface energy as the structure would otherwise develop energetically unfavorable surface porosity.

Laser-Assisted Focused He Ion Beam Induced Etching with and without XeF Gas Assist.

Focused helium ion (He) milling has been demonstrated as a high-resolution nanopatterning technique; however, it can be limited by its low sputter yield as well as the introduction of undesired subsurface damage. Here, we introduce pulsed laser- and gas-assisted processes to enhance the material removal rate and patterning fidelity. A pulsed laser-assisted He milling process is shown to enable high-resolution milling of titanium while reducing subsurface damage in situ.

In Situ Mitigation of Subsurface and Peripheral Focused Ion Beam Damage via Simultaneous Pulsed Laser Heating.

Focused helium and neon ion (He(+)/Ne(+)) beam processing has recently been used to push resolution limits of direct-write nanoscale synthesis. The ubiquitous insertion of focused He(+)/Ne(+) beams as the next-generation nanofabrication tool-of-choice is currently limited by deleterious subsurface and peripheral damage induced by the energetic ions in the underlying substrate. The in situ mitigation of subsurface damage induced by He(+)/Ne(+) ion exposures in silicon via a synchronized infrared pulsed laser-assisted process is demonstrated.

Observation of synchronized atomic motions in the field ion microscope.

For over half a century, the field ion microscope (FIM) has been used to visualize atomic structures at the apex of a sharpened needle by way of the ion beams which are created at the most protruding atoms. In this paper we used a conventional FIM to study the emission characteristics of the neon ion beams produced within the FIM. The neon emission pattern is observed to be relatively short lived and subject to temporal and angular fluctuations.

The prospects of a subnanometer focused neon ion beam.

The success of the helium ion microscope has encouraged extensions of this technology to produce beams of other ion species. A review of the various candidate ion beams and their technical prospects suggest that a neon beam might be the most readily achieved. Such a neon beam would provide a sputtering yield that exceeds helium by an order of magnitude while still offering a theoretical probe size less than 1-nm.