Multistage-connected multipole, multistage multipole unit, and charged particle beam device

A multistage multipole unit comprising:

• a plurality of multistage-connected multipoles;
• a housing in a cylindrical shape with which the multistage-connected multipoles are connected,
• wherein the multistage-connected multipole includes:
• a plurality of poles disposed along an optical axis direction of a charged particle beam and having notches in opposed surfaces;
• and a pillar disposed between the poles and comprised of an insulator, the pole and the pillar being joined with each other in the notches via a joining material,
• wherein the housing includes grooves disposed at predetermined intervals in the circumferential direction of the cylindrical shape and parallel in the optical axis direction, and
• wherein the multistage-connected multipoles are fit into the grooves.

A charged particle beam device comprising:

• a charged particle source ejecting a charged particle;
• a charged particle beam optical system focusing the charged particle;
• and
• a multistage multipole unit as an aberration corrector included in the charged particle beam optical system,
• wherein the multistage multipole unit includes a plurality of multistage-connected multipoles, and
• wherein the multistage-connected multipoles include:
• a plurality of poles disposed along an optical axis direction of a charged particle beam and having notches in opposed surfaces;
• and a pillar disposed between the poles and comprised of an insulator, the pole and the pillar being joined with each other in the notches via a joining material.