Patent ID: 7705300

Claim:
A charged particle beam apparatus comprising: a charged particle beam source; an objective lens for focusing a charged particle beam emitted from said charged particle beam source so as to irradiate a specimen with the charged particle beam; a deflector for deflecting the charged particle beam from an optical axis of said objective lens to cause said objective lens to deliver the charged particle beam to the specimen from a direction different from the optical axis of said objective lens towards the optical axis of said objective lens; a detector for detecting charged particles emitted from the specimen; a stigmator for correcting an astigmatic aberration of the charged particle beam; and a controller for automatically controlling said stigmator, objective lens and deflector such that when the charged particle beam is tilted, astigmatism correction and focus adjustment of the charged particle beam and FOV (Field of View) shift correction are conducted on the basis of the charged particles detected by said detector; and wherein said controller is configured for selectively inhibiting at least one of the astigmatism correction, focus adjustment and FOV shift correction from being carried out, when the charged particle beam is irradiated to the specimen on a tilt; and wherein said controller is further configured to: acquire a first image before tilting the charged particle beam with a first magnification for acquiring a required tilt image; acquire a second image before tilting the charged particle beam with a second magnification lower than the first magnification after the first image is acquired; tilt the charged particle beam by said deflector to irradiate the specimen with the tilted charged particle beam from a direction different from the optical axis after the second image is acquired; acquire a third image with the second magnification after the charged particle beam is tilted; perform a first FOV shift correction by comparing the third image with the second image, adjust an optical condition of the charged particle beam after the first FOV shift correction is performed, acquire a fourth image after tilting the charged particle beam with the first magnification after the adjustment of the optical condition; and perform a second FOV shift correction by comparing the fourth image with the first image.