Focused Ion Beam, (FIB), is a technique commonly used in the semiconductor industry but also material science for site-specific analysis, deposition and ablation of materials.

Primary use for FIB in the semiconductor industry is circuit editing on the chip. FIB is used as a micro-nano machining tool able to modify circuitry at nano scale. This is done by a finely focused gallium (Ga+) ion beam along with different injected gases to precisely image, etch and cut various material electrical connections, or deposit conductive material for making connections between metal traces, or even deposit SiO glass for isolation.

When an IC designer identifies a design flaw or encounters problems at simulation or prototyping stage , they may apply FIB circuit editing to their process of debugging and validation, making necessary modifications before going on to the next phase. FIB circuit edit helps optimizes the design functionality, development cycle as well as reduces potential errors and design costs.

Information resources:  https://en.wikipedia.org/wiki/Focused_ion_beam,  ISTFA November 12, 2006/ Focused Ion Beam: A Design Repair / Fault Isolation Tool