Focused Ion beam thinning (FIB thinning)
Focused Ion beam thinning is used to produce electron transparent thin slice (lamella) of constant thickness. FIB uses a focused beam of ions. Most widespread are instruments using gallium ion sources. These ions are then accelerated to an energy of 5-50 keV , and then focused onto the sample.
Method: drawing of parallel trenches delimitating the defined area by sputtering under a focused ion beam (FIB). The resulting ‘wall’ or lamellae constitutes the thin parallel sided slice, either ready for observation or requiring further extraction from the bulk material.
The nanometer-scale resolution of the FIB allows the exact thin region to be chosen. Almost any kind of material can be FIB thinned.