Wafer fixing unit for focused ion beam apparatus

A wafer fixing unit for securing a wafer in a focused ion beam apparatus, comprising:

• a fixed frame in a horizontal plane, having a pair of side plates and a forward plate;
• a first member disposed rearward of the forward plate in the horizontal plane, having a flat rectangular plate shape and a rectangular depression in a forward section thereof, the first member being movably disposed between the pair of side plates;
• a second member having a T-shape defining a narrow end and a wide end, arranged substantially parallel to and above the horizontal plane, wherein the narrow end of the T-shape is placed in the rectangular depression and connected to the first member, the second member being movably disposed above the forward plate, the second member further including a plurality of projecting parts extending substantially perpendicular to the horizontal plane, each of the plurality of projecting parts having a vertical contact surface substantially perpendicular to the horizontal plane for contacting and securing a wafer;
• and
• a pair of springs disposed on opposite sides of the second member, between and parallel to the side plates, for connecting the first member to the forward plate and for allowing movement of the first member to and from a rest position and a wafer securing position.