Patent ID: 8350214

Claim:
A charged particle beam applied apparatus comprising: a charged particle source that produces charged particles; a primary electron optical system that includes an illumination-system separation unit separating the charged particles produced by the charged particle source into a plurality of charged particle beams, one or more lenses used to apply the plurality of charged particle beams onto a specimen, and a scanning-beam deflector causing the plurality of charged particle beams to scan the specimen; a signal detecting unit that detects individual secondary charged particle beams produced at a plurality of positions on the specimen by illuminating the specimen with the plurality of charged particle beams; a secondary electron optical system that guides the secondary charged particle beams to the signal detecting unit; a movable stage on which the specimen is mounted; and a control unit that controls the switching times of charge-control beam illumination and signal-detection beam illumination, the charge-control beam illumination carried out for negatively charging the specimen by illuminating the specimen with a plurality of charge-control charged particle beams, and the signal-detection beam illumination carried out for detecting signals from the specimen by illuminating the specimen with a plurality of signal-detection charged particle beams, wherein the control unit controls optical conditions of the primary electron optical system to switch between the charge-control beam illumination and the signal-detection beam illumination, and wherein the primary electron optical system further includes a first deflector disposed between the charged particle source and the illumination-system separation unit, and the control unit controls the first deflector to deflect the charged particles so that the charged particles selectively pass through a part of the illumination-system separation unit to form the charge-control charged particle beams or the signal-detection charged particle beams.