Focused ion beam system

A focused ion beam system including a differentially-pumped vacuum unit, and a focused ion beam column,

• wherein the differentially-pumped vacuum unit has a head adapted to face a region within a surface to be processed of a substrate to be processed;
• exhaust grooves that are cut into the head from that surface which is adapted to face the surface to be processed and run in a way that surround the center of the head, and an orifice within a region that is radially inward of the exhaust grooves and forms a part of a processing vacuum region, which allows a processing to be performed in the region within the surface to be processed, with the result that the exhaust grooves provide an outlet of air evacuated from the processing vacuum region while, with the facing surface of the head facing the surface to be processed, vacuum evacuation works to create a high vacuum inside the processing vacuum region, and
• wherein the focused ion beam column has a chamber placed near the surface of the head opposite to the facing surface of the head and connected to the orifice for communication with the processing vacuum region, and a focused ion beam optical system built in the chamber to emit a focused ion beam in a way that passes through the orifice,
• wherein the focused ion beam system comprises:
• a vacuum pad, of a porous material, with a suction surface being exposed in a way that surrounds the outer edge of the substrate;
• a substrate support on which the substrate and vacuum pad are placed, and
• a vacuum pump for vacuum evacuation using the vacuum pad, to provide an arrangement in which, while the head of the differentially-pumped vacuum unit partially falls out of the outer edge of the substrate, the suction surface allows an input of air evacuated from a region between the suction surface and the head to maintain the high vacuum inside the processing vacuum region.