Focused ion beam device

A focused ion beam device comprising:

• an ion source generating an ion beam;
• a diaphragm member with at least one through-hole, which is selected to allow to pass a portion of the ion beam generated by the ion source through;
• a blocking member blocking a portion of the ion beam passing through the through-hole of the diaphragm member;
• a drive mechanism driving the blocking member;
• and
• an optics irradiating a sample with the ion beam passing through the through-hole,
• wherein the drive mechanism drives a switch between presence and absence of blocking of the ion beam passing through the through-hole of the diaphragm member by the blocking member in a state in which the optics maintains a predetermined optical condition,
• the drive mechanism drives a switch between presence and absence of blocking of the ion beam passing through the through-hole placed at a central portion of the ion beam by the blocking member,
• the through-hole of the diaphragm member has a circular outer shape,
• the blocking member has an end with an edge extending in a linear direction, and
• the drive mechanism switches a cross-sectional shape of the ion beam with respect to a beam axis between an arch or semi-circular shape and a circular shape by driving a switch between presence and absence of blocking of the ion beam passing through the through-hole by the end,
• the focused ion beam device further comprises a control device that controls movement of the ion source, the diaphragm member, the blocking member, and the drive mechanism,
• the control device is capable of performing a first operation,
• in the first operation, the control device forms the ion beam with a circular cross-sectional shape with respect to the beam axis by aligning a central portion of the through-hole of the diaphragm member to a central portion of the ion beam without blocking the ion beam with the blocking member and acquires images for observation by scanning the sample with the ion beam,
• next, the control device forms the ion beam with an arc-shaped or semi-circular cross-sectional shape with respect to the beam axis by blocking a portion of the ion beam with the blocking member while maintaining identical optical conditions in the optics to optical conditions when the images for observation are acquired and processes the sample.