METHOD FOR MEASURING OVERLAY AND MEASURING APPARATUS, SCANNING ELECTRON MICROSCOPE, AND GUI

A method for measuring overlay at a semiconductor device on which circuit patterns are formed by a plurality of exposure processes is characterized in including an image capturing step for capturing images of a plurality of areas of the semiconductor device, a reference image setting step for setting a reference image based on a plurality of the images captured in the image capturing step, a difference quantifying step for quantifying a difference between the reference image set in the reference image setting step and the plurality of images captured in the image capturing step, and an overlay calculating step for calculating the overlay based on the difference quantified in the difference quantifying step.