| 摘要 |
An apparatus and method for electron beam inspection with projection electron microscopy, is constructed so as to allow correction of changes in focus offsets due to changes in the electrically charged state particularly during inspection. The apparatus includes: a focus measure sensor unit; a focus measure calculation unit which calculates focus measure from the multiple image signals converted by the focus measure sensor unit; a focus position calculation unit which calculates the height of a confocal plane conjugate to the plane of convergence of a planar electron beam by an objective lens, on the basis of the calculated focus measure, and then calculates the focus position of the objective lens on the basis of the calculated height of the confocal plane; and a focus position correction unit which corrects the focus position of the objective lens according to the calculated focus position of the objective lens.
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