Patent ID: 6744057
Filing Date: 2004-06-01
Classification: G01N,H01J

Abstract:
A convergent charged particle beam apparatus comprising:an electron beam system which emits a converged electron beam; a vacuum chamber which is connected to the electron beam system and which has an exhausting unit to maintain an inside of the vacuum chamber at a predetermined vacuum atmosphere; a stage which mounts a specimen and moves at least in one direction inside of the vacuum chamber; an electron beam image observation unit which observes an electron beam image of a surface of the specimen mounted on the stage by irradiation of the electron beam emitted from the electron beam system and scanned over the surface of the specimen; a height detector which optically detects a height of the specimen mounted on the stage by illuminating the surface of said specimen with light at an incident angle of at least 60 degree and by detecting a reflected light of the illumination reflected from the surface of the specimen; and a controller which controls a focus position of the electron beam in accordance with an output from the height detector while the stage is moving at least in one direction.