Low-aberration ExB deflector optics for scanning electron microscopy.

To suppress aberrations in the signal electron optics of a scanning electron microscope, we propose ExB deflector (deflector with superimposed electric and magnetic fields) optics that cancel the aberrations generated during large-angle deflection. This improves the resolution of the angle or position of the signal electrons on the sample surface, allowing them to be discriminately detected. The proposed optics consist of two ExB deflectors and a transfer system with two 4-f systems, or systems that have four times the focal length, placed between them.