DEVICE FOR DETECTING SECONDARY ELECTRON IN A SCANNING ELECTRON MICROSCOPE

摘要

Pipe electrodes are incorporated along the optical axis of the objective lens between the objective lens and the detecting means, so that the primary electron beam irradiating the specimen is not adversely affected by the detecting means. A mesh electrode maintained at positive potential against the specimen is incorporated at the bottom end of the pipe electrode, so that almost all the secondary electrons from the specimen are attracted toward the detecting means.