Patent ID: 7456948

Claim:
A particle/defect detecting method comprising: an inspection object moving stage nearly continuously moved in both main scan and sub-scan directions for providing a rotational motion in main scan and a translational motion in sub-scan; a light source; illumination means for illuminating a surface of an object to be inspected with light from the light source as an illustrated spot of a predetermined size; scattered/diffracted/reflected light detecting means for detecting light of the illuminated light scattered/diffracted/reflected at said illustrated spot and converting the detected light to an electric signal; A/D converting means for converting said electric signal to digital data; inspection coordinate detecting means for detecting a position on the surface of the object during inspection as inspection coordinate data at a time corresponding to said converted digital data; particle/defect determining means for determining presence of a particle or a defect on the surface of the inspection object or in an interior of the inspection object close to its surface on the basis of said electric signal or said digital data; particle diameter calculating means for calculating a size of said determined particle or defect on the basis of the digital data; and particle/defect coordinate calculating means for calculating a position coordinate value of said particle or defect on the surface of the inspection object on the basis of information received from the inspection coordinate detecting means, wherein said A/D converting means includes a digital data table for storing or saving a plurality of said digital data continuously obtained by continuously sampling said electric signal at intervals of a predetermined time on a main scan locus over a period of time corresponding at least 2 turns of the inspection object moving stage, said A/D converting means also includes an illustrated-spot illumination-distribution data table for storing or saving a relative illumination distribution of the illuminated light within said illustrated spot on the surface of said inspection object in a two-dimensional Cartesian coordinate system having a y axis corresponding to a direction of a straight line connected from a rotational center of said inspection object moving stage to a center of said illustrated spot and having an x axis perpendicular to said y axis as two-dimensional matrix data having data divisions divided at intervals of a first spacing in an x axis direction and at intervals of a second spacing in a y axis direction, and said particle/defect coordinate calculating means calculates a position coordinate value X, Y of said determined particle or defect using a result of comparison between said digital data table and said illustrated-spot illumination-distribution data table in a two-dimensional Cartesian coordinate system (X,Y) having a Y axis corresponding to a direction of a linear symmetric axis on the surface of the inspection object and having an X axis perpendicular to said Y axis.