| 摘要 |
Provided is an electrostatic lens for charged particle radiation with a lens performance relatively comparable to that of a magnetic type lens. A plurality of electrodes arranged on the incident side of charged particles form a first electric field area, wherein orbit radii of the charged particles are reduced without exceeding, on the way, the initial orbit radii that are orbit radii at the incident time, and a second electric field area, wherein force in the direction advancing in parallel with a central axis is applied to the charged particles that have passed through the first electric field area. A plurality of electrodes arranged on the projection side form a third electric field area, wherein the orbit radii of the charged particles do not exceed the initial orbit radii on the way and are curved to intersect with a central axis at angles larger than orbit angles defined with respect to the central axis of when the charged particles are projected from the second electric field area. |
