NOISE REDUCTION ELECTRON BEAM DEVICE, AND ELECTRON BEAM NOISE REDUCTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide an electron beam device and method capable of reducing noise in an image signal caused by emission noise to form an image with high SN-ratio.SOLUTION: A part of an electron beam is shielded by an objective aperture 5 arranged below a condenser lens 2, and the generated reflection electron beam 6 is detected by an MCP 4 to calculate a noise reduction signal. A phase and an amplitude of the noise reduction signal are adjusted by a noise reduction device 25 so that an SN ratio of an image signal by a secondary electron 21 generated from a sample by electron beam scanning becomes the maximum.