Patent ID: 6559459
Filing Date: 2003-05-06
Classification: G01N,H01J

Abstract:
A convergent charged particle beam apparatus comprising:an electron beam source; electron optical system which converges and focuses an electron beam emitted from said electron beam source; a vacuum chamber; a stage arranged inside of said vacuum chamber so as to mount a specimen under inspection thereon and to move said specimen in at least one plane; an electron beam image observation arrangement which observes an electron beam image of a surface of said specimen mounted on said stage when the electron beam converged by said electron optical system is irradiated and scanned over the surface of said specimen and secondary charged particles produced from said specimen are detected so as to provide electron image data of the surface of said specimen; a height detector which optically detects a surface height of said specimen by irradiating light from outside of said vacuum chamber onto said specimen and detecting light received from said specimen by the irradiation of the light with a light detector disposed outside of said vacuum chamber; a controller which controls a focal point of the electron beam converged and focused by said electron optical system in accordance with the output from said height detector; and a display which displays the electron image of the surface of said specimen observed by said electron beam image observation arrangement when the focal point of the electron beam irradiating the surface of said specimen is controlled by said controller.