Patent ID: 7970200

Claim:
A pattern inspection apparatus comprising: means for magnifying and taking a color image including a plurality of pixels, wherein the color image includes a contact hole over a substrate, and the contact hole overlaps at least two of the plurality of pixels; a generator for generating a first color information of each of the plurality of pixels, wherein the first color information includes three color coordinate components, red (R), green (G), and blue (B), of an RGB color space; a converter for converting the first color information of each of the plurality of pixels into a second color information including first, second and third color coordinate components; a generator for generating a gray-scale image in accordance with the first color coordinate component; a generator for generating a binary image from the gray-scale image by regarding one of the plurality of pixels having the first color coordinate component of less than a predetermined threshold as black pixel and another one of the plurality of pixels having the first color coordinate component of more than the predetermined threshold as a white pixel; means for detecting the contact hole from the binary image to obtain coordinate data of at least two of the plurality of pixels overlapped by the contact hole; means for calculating a mean value of the second color coordinate component of at least two of the plurality of pixels overlapped by the contact hole; and means for comparing the mean value of the second color coordinate component in each contact hole with preset non-defective reference color information, and judging the contact hole.