The focused ion beam (FIB) instrument is used particularly in the semiconductor and materials science fields for site-specific analysis, deposition, and ablation of materials. The FIB instrument uses a focused beam of ions, e.g., Ga ions, and is incorporated in a system with both electron and ion beam columns, allowing the same feature to be investigated using either or both beams. Source ions are then accelerated to an energy of 5-50 keV (kiloelectronvolts), and focused onto the sample by electrostatic lenses. When the high-energy gallium ions strike the sample, they will sputter atoms from the surface. Because of the sputtering capability, the FIB is used as a micro-machining tool, to modify or machine materials at the micro- and nanoscale. The common smallest beam size is 2.5-6 nm.