Foreign object height measurement method and charged particle beam device

A charged particle beam device comprising:

• a sample stage on which a sample is placed and which is capable of rotating and inclining;
• a charged particle optical system configured to irradiate the sample with a charged particle beam;
• a detection system configured to detect a signal electron generated by irradiating the sample with the charged particle beam;
• a control unit configured to control the sample stage, the charged particle optical system, and the detection system and acquire a charged particle image based on the signal electron detected by the detection system;
• and
• an image processing unit configured to measure a height of a foreign object on the sample from the charged particle image, wherein
• the image processing unit is configured to store in advance dependence data indicating a dependence of a calculated value of a height of a foreign object calculated from a foreign object image, which is an image of the foreign object extracted from the charged particle image, on an orientation of the foreign object,
• the image processing unit is configured to extract a measurement target foreign object image, which is an image of a measurement target foreign object, from the charged particle image and output a measurement value of a height of the measurement target foreign object along with a warning regarding reliability or measuring the height of the measurement target foreign object from a charged particle image acquired by rotating the sample stage and changing an orientation of the measurement target foreign object detected from the measurement target foreign object image when it is determined that the orientation of the measurement target foreign object does not satisfy an acceptable error range based on the dependence data, and
• the orientation of the foreign object is defined by an angle defined by a longest line segment among line segments that connect contact points between a contour of the foreign object image and inclination direction lines, which are two parallel straight lines extending in an inclination direction of the sample stage, and a reference line perpendicular to the inclination direction lines.