Pattern Evaluation Apparatus and Computer Program
The present invention is intended to provide a pattern evaluation apparatus and a computer program aimed at achieving defect inspection with high efficiency and high precision while allowing manufacturing variations that are dissimilar depending on the sites of a circuit. In order to achieve the above object, proposed are a computer program and an inspection system having a means of performing statistical processing of measurement data of a plurality of inspection target patterns having similar or same design pattern shape used for manufacturing the inspection target patterns, and performing adjustment of a defect determination threshold in accordance with a distribution state of measurement data.
1 . A pattern evaluation apparatus comprising an arithmetic processing device that detects a defect of a pattern on the basis of a comparison between a measurement value of the pattern and a predetermined threshold,
the apparatus further comprising a storage medium that stores the measurement value of the pattern,
wherein the arithmetic processing device obtains an index value indicating variations of a plurality of measurement values of a same pattern on design data stored in the storage medium, and sets the threshold in accordance with the index value.
2 . The pattern evaluation apparatus according to claim 1 ,
wherein the arithmetic processing device obtains a statistical value of the plurality of measurement values of the same pattern on the design data, and obtains the index value from the statistical value.
3 . The pattern evaluation apparatus according to claim 2 ,
wherein the arithmetic processing device sets the threshold on the basis of standard deviation of the index value.
4 . The pattern evaluation apparatus according to claim 1 ,
wherein the arithmetic processing device uses the design data to classify the plurality of measurement values for each of types of sites of the pattern.
5 . The pattern evaluation apparatus according to claim 1 ,
wherein the arithmetic processing device assigns identification information corresponding to the site of the pattern to the measurement value, and obtains the index value for the measurement value having the same identification information.
6 . The pattern evaluation apparatus according to claim 1 ,
wherein the measurement value is at least one of dimension, a difference between reference data and contour data, curvature of a portion of the pattern, a major axis of a circular pattern, a minor axis of a circular pattern, and an area of a circular pattern.
7 . The pattern evaluation apparatus according to claim 6 ,
wherein the curvature is obtained by statistical calculation of curvatures of a plurality of sites constituting the pattern.
8 . The pattern evaluation apparatus according to claim 1 ,
wherein the arithmetic processing device classifies the pattern into a site including a top of the pattern and a site not including the top of the pattern, and obtains the variation in units of the classified sites.
9 . The pattern evaluation apparatus according to claim 1 ,
wherein the arithmetic processing device divides an edge of the pattern into a plurality of regions, and performs statistical processing of the measurement values in units of the divided regions.
10 . The pattern evaluation apparatus according to claim 1 ,
wherein, in a case where two or more peaks exist in a histogram of the measurement value, the arithmetic processing device defines a measurement value belonging to the peak including a measurement value relatively diverging from a design standard out of the two or more peaks, as a systematic defect.
11 . A computer program causing a computer to execute comparison operation of a measurement value of a pattern with a predetermined threshold to detect a defect in the pattern,
the program causing the computer to obtain an index value indicating variations of a plurality of measurement values of a same pattern on design data stored in a storage medium and causing the computer to set the threshold in accordance with the index value.