AUTOMATIC FOCUSING SYSTEM FOR SCANNING ELECTRON MICROSCOPE EQUIPPED WITH LASER DEFECT DETECTION FUNCTION

A scanning electron microscope equipped with a laser defect detection function has an automatic focusing function that performs the steps of: obtaining a deviation (offset) amount between focal positions of an optical microscope and a scanning electron microscope; detecting a defect by a laser dark-field image of the optical microscope; analyzing the dark-field image to readjust a focus of the optical microscope to adjust a height of the optical microscope; and automatically adjusting a focus of the scanning electron microscope by adding a readjusted amount of the focus of the optical microscope to the offset amount before an observation is conducted by the scanning electron microscope.