Charged Particle Beam Device and Charged Particle Beam Measurement Method

摘要

An object of the present invention is to realize both of the accuracy of measuring the amount of secondary electron emissions and the stability of a charged particle beam image in a charged particle beam device. In a charged particle beam device, extraction of detected signals is started by a first trigger signal, the extraction of the detected signals is completed by a second trigger signal, the detected signals are sampled N times using N (N is a natural number) third trigger signals that equally divide an interval time T between the first trigger signal and the second trigger signal, secondary charged particles are measured 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.

主权项

1. A charged particle beam device comprising:
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 to a sample; a detector that detects secondary charged particles emitted from the sample; a detection control unit that extracts detected signals obtained by the detector; and a trigger signal control unit that transmits a trigger signal to the detection control unit, wherein the detection control unit: controls to start the extraction of the detected signals using a first trigger signal generated by the trigger signal control unit; controls to complete the extraction of the detected signals using a second trigger signal generated by the trigger signal control unit; controls to sample the detected signals N times using N (N is a natural number) third trigger signals that are generated by the trigger signal control unit and that equally divide an interval time T between the first trigger signal and the second trigger signal; and controls to measure 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 number of primary charged particles contained in the division time ΔT becomes larger than the minimum number of charged particles satisfying ergodicity.