Charged particle beam apparatus

Abstract

The charged particle beam apparatus includes a charged particle source generating a charged particle beam, a deflector deflecting the charged particle beam, a detector detecting secondary electrons emitted from an irradiation target in response to irradiation with the charged particle beam, and a processor system. The processor system (A) acquires a first time-series change in secondary electron detection-related quantity by repeatedly performing the following (A1) and (A2), (A1) directly or indirectly, maintains or changes the control amount applied to the deflector to a first control amount, and (A2) acquires the secondary electron detection-related quantity based on an output from the detector, and (B) acquires a time-series change in variation of the beam diameter of the charged particle beam based on the first time-series change.

Dependencies are inferred from the claim text.