Patent ID: 9116136
Filing Date: 2015-08-25
Classification: G01B,G01N

Abstract:
1. An inspection method comprising: placing a sample, which has a mesa portion having a pattern thereon, on a table; irradiating light to the mesa portion through an optical system, and receiving light reflected by the mesa portion for measuring a height of the mesa portion; creating a height map of the mesa portion based on a height of corner positions of the mesa portion; correcting a height of the mesa portion using the height map based on an amount of difference between a height data of the height map of the mesa portion and a target value, and a temporal variation of a focal position of light irradiated to the mesa portion; obtaining an optical image of the pattern while controlling a height of a position of the table based on the corrected height of the mesa portion; and comparing the optical image with a reference image and determining a defect when a difference value between the optical image and the reference image is more than a predetermined threshold value.