Patent ID: 6765217
Filing Date: 2004-07-20
Classification: G01N,H01J

Abstract:
A charged-particle-beam mapping projection-optical system, comprising:(a) an irradiation optical system that directs an irradiation charged particle beam along a first axis from an irradiation-beam source; (b) an ExB beam separator configured and situated to receive the irradiation beam from the irradiation optical system and to direct the irradiation beam downstream of the ExB beam separator; (c) an objective optical system configured and situated to receive the irradiation beam from the ExB beam separator, direct the irradiation beam to be incident on a surface of a specimen located at a position downstream of the objective optical system, receive an observation charged particle beam generated by impingement of the irradiation beam on the specimen surface, and direct the observation beam to the ExB beam separator, wherein the ExB beam separator causes the observation beam to propagate along a second axis having a direction different than the first axis; (d) an imaging optical system configured and situated to receive the observation beam from the ExB beam separator and to direct the observation beam from the ExB beam separator to a detector; and (e) an adjustment-beam source configured to emit an adjustment charged particle beam, the adjustment-beam source being situatable at the specimen position so as to direct the adjustment beam, in place of the observation beam, through the objective and imaging optical systems to the detector.