Systems and methods for imaging secondary charged particle beams using adaptive secondary charged particle optics

摘要

PROBLEM TO BE SOLVED: To provide a method of imaging a secondary charged particle diverging from a sample upon collision of a primary charged particle beam.SOLUTION: In the present method, while a first operation parameter selected from the group containing the incident energy of a primary charged particle beam incident onto a sample, the strength of extraction field for extracting a secondary charged particle beam at the position of the sample, the intensity of magnetic field of an objective lens for focusing the primary charged particle beam on the sample, and the operation distance from the sample to the objective lens is set to a first value, the excitation of a first lens and a second lens is controlled to map the secondary charged particle beam on a first area which overlaps a first aperture of a diaphragm plate on the diaphragm plate and a second aperture of the diaphragm plate. In addition, the first operation parameter is set to a second value, and the excitation of the first lens and the second lens is controlled to map the secondary charged particle beam onto the first area on the diaphragm plate.SELECTED DRAWING: Figure 13a