Patent ID: 7906761

Claim:
A charged particle beam apparatus having a function to inspect or measure a sample by generating a charged particle beam by unit of a single charged particle beam source, separating the charged particle beam into a plurality of primary beams, irradiating the primary beams on the sample, detecting generated secondary beams, and processing the detected signals that are obtained thereof, the charged particle beam apparatus comprising: a primary optical system, wherein it forms the plurality of primary beams to scan on the sample; a secondary optical system, wherein it separately detects the secondary beams generated by irradiating the plurality of primary beams on the sample; and an aperture array having a plurality of apertures which divides the charged particle beam into the plurality of primary beams; a beam selection aperture having one or more openings through which the selected at least one of the plurality of primary beams can pass; means for determining an allowable range of beam diameters in view of the property of the sample to be inspected; means for selecting at least one of the plurality of primary beams to scan on the sample based on the determined allowable range of the beam diameters; and means for controlling positioning of the beam selection aperture so that only the selected primary beams scan on the sample.