FIB‐induced damage in silicon

Abstract

SummaryThe damage created in silicon transmission electron microscope specimens prepared using a focused ion beam miller is assessed using cross-sections of trenches milled under different beam conditions. Side-wall damage consists of an amorphous layer formed by direct interaction with the energetic gallium ion beam; a small amount of implanted gallium is also detected. By contrast, bottom-wall damage layers are more complex and contain both amorphous films and crystalline regions that are richer in implanted gallium. More complex milling sequences show that redeposition of milled material, enriched in gallium, can occur depending on the geometry of the mill employed. The thickness of the damage layers depends strongly on beam energy, but is independent of beam current. Monte Carlo modelling of the damage formed indicates that recoil silicon atoms contribute significantly to the damaged formed in the specimen.

Fabrication and convergent X-ray nanobeam diffraction characterization of submicron-thickness SrTiO3 crystalline sheets

“…12 The ion-lattice collisions can displace atoms from lattice sites, creating vacancies and interstitials, which can coalesce to form dislocation. 6,13 The resulting microstructure is described using a mosaic model and yields an increased angular width of x-ray reflections. 14 In addition, vacancies in STO result in a well-known lattice expansion.…”

“…The transverse straggle of ions creates such an amorphous region with a depth of tens of nanometers and changes the chemistry and functional properties of material outside the region being milled. 13,16,17 Structural features introduced during milling, including mosaic blocks, strain, point defects, and curvature, result in an increase in the angular width of x-ray rocking curves. 18,19 The intensity and width of the (002) Bragg reflection in Ga-ion-milled BiFeO 3 thin films, for example, are reduced and broadened as a result of the electric fields of surface charges and defects.…”

Direct characterization of focusing light by negative refraction in a photonic crystal flat lens

“…Of course, there are drawbacks for FIB. Notably, for microfabrication of crystal silicon using FIB, the specimens inevitably suffering a certain amount of damages, such as ion implanting, material re-deposition, and sidewall amorphognosia, which are responsible for relatively high optical loss in the fabricated waveguide [14,15]. In order to minimize optical losses, a few fabrication strategies have been established such as high temperature annealing, use of a protective mask, gas-assisted etching and baking treatment in N 2 atmosphere [16,17].…”

Focused Ion Beam System—a Multifunctional Tool for Nanotechnology

“…Firstly, bombardment with Ga + ions will likely result in some level of gallium Figure 32. The structure of (a) the side-wall and (b) bottom-wall of the trench milled using a 10 keV beam energy and a 250 pA ion beam current [49].…”

“…They experimented with different beam energies, and noted that a reduction from 30 keV to 10 keV cut the thickness of the damage layer in half. In more complex milling patterns, redeposition often occurred [49].…”