公开(公告)号：US20200303152A1

公开(公告)日：2020-09-24

申请号：US16089281

申请日：2016-03-29

Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION

Inventor： Takashi OHSHIMA ,  Hiroyuki MINEMURA ,  Yumiko ANZAI ,  Momoyo ENYAMA ,  Yoichi OSE ,  Toshihide AGEMURA

IPC: H01J37/073 ,  H01J37/22

Abstract: To provide an electron microscope capable of performing the switching-over between normal illumination and annular illumination, wide-area irradiation, an interference pattern as desired or normal illumination in an expeditious and readily manner or achieving a better S/N ratio, the electron microscope comprises a photocathode 101 with negative electron affinity in use; an excitation optical system to excite the photocathode; and an electron optics system to irradiate an electron beam 13 generated from the photocathode by excitation light 12 irradiated through the excitation optical system onto a sample, the excitation optical system including a light source device 107 for the excitation light; and an optical modulation means 108 which is disposed in an optical path of the excitation light to perform spatial phase modulation to the excitation light.