Energy filter, and energy analyzer and charged particle beam device provided with same

Abstract

A decelerating electrode of an energy filter includes an electrode pair that has an opening and a cavity portion provided in a rotationally symmetrical manner with the center of the opening as the optical axis. Voltages with electric potentials that are substantially the same as that of a charged particle beam are independently applied to both sides of the decelerating electrode. When an electrical field protrudes into the cavity portion, a saddle point having the same electric potential as that of incident charged particles is formed inside the decelerating electrode. The saddle point acts as a high pass filter for incident charged particles at an energy resolution of 1 mV or less. By analyzing charged particles which have been energy-separated, it is possible to measure the energy spectrum and ΔE at the high resolution of 1 mV or less and to obtain an SEM/STEM image with a high resolution.

Dependencies are inferred from the claim text.