Charged particle beam device and charged particle beam measurement method

A charged particle beam measurement method in a charged particle beam device having a charged particle source that generates a primary charged particle beam, a stage on which a sample is put, an acceleration voltage setting unit that sets the acceleration voltage of the primary charged particle beam, an objective lens that focuses the primary charged particle beam onto a sample, a detector that detects secondary charged particles emitted from the sample, a detection controller configured to extract detected signals obtained by the detector, and a trigger signal controller configured to transmit a trigger signal to the detection controller, the method comprising:

• a step of starting the extraction of the detected signals using a first trigger signal generated by the trigger signal controller;
• a step of completing the extraction of the detected signals using a second trigger signal generated by the trigger signal controller;
• a step of sampling the detected signals N times using N (N is a natural number) third trigger signals that are generated by the trigger signal controller and that equally divide an interval time T between the first trigger signal and the second trigger signal;
• and
• a step of measuring the secondary charged particles by integrating and averaging the signals sampled in respective division times ΔT obtained by equally dividing the interval time T, and
• the division time ΔT is controlled in such a manner that the measured number of secondary charged particles becomes larger than the minimum number of charged particles satisfying ergodicity.