Patent ID: 7239735
Filing Date: 2007-07-03
Classification: G01N,G01R,G06T

Abstract:
1. A pattern inspection method which scans an inspected pattern formed on a substrate according to design data with a laser beam and receives light passed through said substrate with a light receiving device and, from pattern information obtained by said light receiving device, generates an image of the inspected pattern and, for coincidence between this image and reference data obtained by imaging of said design data, corrects said reference data to generate a reference image and compares the image of said inspected pattern and the reference image to detect any defects of the inspected pattern wherein, said reference image generation comprising: provision to each pixel of sub-pixels dividing the pixel to form a matrix and calculation of a gray level of the pixel based on the number of sub-pixels belonging to a pattern developed in each pixel, calculation of a pattern width for the reference data by treating a number obtained by dividing said gray level by a gray level step count as the width of the pattern developed in that pixel, determination of an edge boundary condition showing the gray level corresponding to the pattern edge position through convolution operation of an optical point spread function corresponding to a strength of the laser beam and said inspected pattern image, detection of the edge position in said inspected pattern by the unit of sub-pixels according to said edge boundary condition, calculation of the pattern width for said inspected pattern according to the detected edge position, and calculation of the correction width of the pattern width for said reference data in the unit of sub-pixels from the difference between the pattern width of said inspected pattern and the pattern width of the reference data.