Patent ID: 7493577
Filing Date: 2009-02-17
Classification: G03F

Abstract:
1. A method for automatically recognizing geometric points of features in a target design for OPC mask quality calculation, comprising; for each feature in the target design, traversing x, y points comprising the feature and connecting each neighboring pair of points to define respective segments, wherein a set of contiguous segments form a step if the x values of the segments/points all increase or decrease and the same is true for the y values; determining physical characteristics of the segments of the respective features by comparing lengths of the segments to one another and to threshold values, wherein the threshold values comprise a first threshold value for identifying jog segments of a feature, a second threshold value for identifying short segments of a feature, a third threshold value for identifying long segments of a feature, and a fourth threshold value for measuring the length difference between segments; determining locations of quality measuring points along particular ones of the segments based on the physical characteristics; and outputting the quality measuring points into quality measuring groups, including a Critical Dimension (CD) group having CD points, an End-of-line (EOL) group having EOL points, and a Space group having points to measure spaces between features.