Patent ID: 11107655

Abstract:
In order to optimize defect contrast in a charged particle beam device that inverts charged particles directly above a sample and observes the electrons, this charged particle beam device is provided with a charged particle source, an electron gun control device which applies a first voltage to the charged particle source, a substrate voltage control device which applies a second voltage to a sample, an image forming optical system which includes an imaging lens for imaging charged particles incident from the direction of the sample, a detector which includes a camera for detecting the charged particles, and an image processing device which processes the detected signal, wherein the imaging optical system is configured so as not to image secondary electrons emitted from the sample, but forms an image with mirror electrons bounced back by the electric field formed on the sample by means of the potential difference between the first and the second voltages. The image processing device generates a control signal for controlling the potential difference on the basis of the acquired signal, and optimizes defect contrast by controlling the reflection surface of the mirror electrons.