Wafer Defect Discovery

Abstract

Systems and methods for discovering defects on a wafer are provided. One method includes detecting defects on a wafer by applying a threshold to output generated by a detector in a first scan of the wafer and determining values for features of the detected defects. The method also includes automatically ranking the features, identifying feature cut-lines to group the defect into bins, and, for each of the bins, determining one or more parameters that if applied to the values for the features of the defects in each of the bins will result in a predetermined number of the defects in each of the bins. The method also includes applying the one or more determined parameters to the output generated by the detector in a second scan of the wafer to generate a defect population that has a predetermined defect count and is diversified in the values for the features.

What is claimed is: 
     
         1 . A system configured to discover defects on a wafer, comprising:
 an inspection subsystem comprising at least an energy source and a detector, wherein the energy source is configured to generate energy that is directed to and scanned over a wafer, and wherein the detector is configured to detect energy from the wafer and to generate output responsive to the detected energy; and   a computer subsystem configured for:
 detecting defects on the wafer by applying a threshold to the output generated by the detector in a first scan of the wafer; 
 determining values for features of the detected defects; 
 based on the values for the features, automatically ranking the features and identifying feature cut-lines to group the defects into bins; 
 for each of the bins, determining one or more parameters that if applied to the values for the features of the defects in said each of the bins will result in a predetermined number of the defects in said each of the bins; and 
 applying the one or more determined parameters to the output generated by the detector in a second scan of the wafer to generate a defect population, wherein the defect population has a predetermined defect count and is diversified in the values for the features.