Patent ID: 7755776

Claim:
An inspection system for inspecting a heightwise variation in a sample, comprising: holding means for holding a first sample; charging means for charging the first sample held by the holding means voltage application means for applying a voltage to the first sample held by the holding means; an electro-optic system that radiates an electron beam to the first sample applied with the voltage by the voltage application means and images a mirror electron returning near a surface of first the sample; and an image processing means for processing a first mirror image acquired by imaging the mirror electron, wherein the image processing means outputs information corresponding to a difference between the first mirror image acquired by the mirror electron and a second mirror image of a second sample used as a standard for determining a heightwise variation of the first sample, wherein the image processing means performs a first process for Fourier-transforming the first mirror image acquired by imaging the mirror electron to generate a first Fourier transform image; wherein the image processing means performs a second process for synthesizing the first Fourier transform image with a filter pattern for removing information about an elevation difference from a second Fourier transform image for the second mirror image to generate a composite image; and wherein the image processing means performs a third process for performing an inverse Fourier transform on the composite image to generate an inverse Fourier transform image and outputting the inverse Fourier transform image as the information corresponding to the difference.