Optimization of unknown defect rejection for automatic defect classification
First Claim
1. A method for defect classification comprising:
- storing a definition of a region in a feature space, wherein the definition is associated with a defect class and comprises a kernel function, wherein the kernel function comprises a kernel parameter that is associated with a plurality of parameter values, wherein each of the parameter values for the kernel parameter is used to determine a different shape of the region based on the kernel function and corresponds to a different desired rejection rate for automatic classification of a plurality of unclassified defects for the defect class;
receiving, by a processing device, a confidence threshold that corresponds to a desired rejection rate for automatic classification of at least one defect associated with the defect class;
selecting, by the processing device, one of the parameter values of the plurality of parameter values for the kernel parameter that determines the shape of the region and corresponds to the desired rejection rate associated with the confidence threshold for automatic classification of the plurality of unclassified defects;
receiving, by the processing device, inspection data for the plurality of unclassified defects detected in one or more wafer samples under inspection;
automatically classifying, by the processing device, the plurality of unclassified defects for the defect class using the kernel function and the selected one of the plurality of parameter values of the kernel parameter that determines the shape of the region and corresponds to the desired rejection rate for the plurality of unclassified defects to generate a first plurality of classification results, wherein the plurality of unclassified defects are classified with a class label associated with the region based on a location of the unclassified defects in the region with the shape determined from the kernel parameter with the one of the plurality of parameter values that is selected based on the confidence threshold that corresponds to the desired rejection rate;
obtaining a second plurality of classification results for one or more of the plurality of unclassified defects for the defect class; and
combining the first plurality of classification results and the second plurality of classification results.
1 Assignment
0 Petitions
Accused Products
Abstract
A method for defect classification includes storing, in a computer system, a definition of a region in a feature space. The definition is associated with a class of defects and comprises a kernel function comprising a parameter. The parameter determines a shape of the region. A confidence threshold for automatic classification of at least one defect associated with the class is received. A value of the parameter associated with the confidence threshold is selected. Inspection data for a plurality of defects detected in one or more samples under inspection is received. The plurality of defects for the class are automatically classified using the kernel function and the selected value of the parameter.
72 Citations
21 Claims
-
1. A method for defect classification comprising:
-
storing a definition of a region in a feature space, wherein the definition is associated with a defect class and comprises a kernel function, wherein the kernel function comprises a kernel parameter that is associated with a plurality of parameter values, wherein each of the parameter values for the kernel parameter is used to determine a different shape of the region based on the kernel function and corresponds to a different desired rejection rate for automatic classification of a plurality of unclassified defects for the defect class; receiving, by a processing device, a confidence threshold that corresponds to a desired rejection rate for automatic classification of at least one defect associated with the defect class; selecting, by the processing device, one of the parameter values of the plurality of parameter values for the kernel parameter that determines the shape of the region and corresponds to the desired rejection rate associated with the confidence threshold for automatic classification of the plurality of unclassified defects; receiving, by the processing device, inspection data for the plurality of unclassified defects detected in one or more wafer samples under inspection; automatically classifying, by the processing device, the plurality of unclassified defects for the defect class using the kernel function and the selected one of the plurality of parameter values of the kernel parameter that determines the shape of the region and corresponds to the desired rejection rate for the plurality of unclassified defects to generate a first plurality of classification results, wherein the plurality of unclassified defects are classified with a class label associated with the region based on a location of the unclassified defects in the region with the shape determined from the kernel parameter with the one of the plurality of parameter values that is selected based on the confidence threshold that corresponds to the desired rejection rate; obtaining a second plurality of classification results for one or more of the plurality of unclassified defects for the defect class; and combining the first plurality of classification results and the second plurality of classification results. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. An apparatus comprising:
-
a memory to store a definition of a region in a feature space, wherein the definition is associated with a defect class and comprises a kernel function, wherein the kernel function comprises a kernel parameter that is associated with a plurality of parameter values, wherein each of the parameter values for the kernel parameter is used to determine a different shape of the region based on the kernel function and corresponds to a different desired rejection rate for automatic classification of a plurality of unclassified defects for the defect class; and a processor, operatively coupled with the memory, to; receive a confidence threshold that corresponds to a desired rejection rate for automatic classification of at least one defect associated with the defect class; select one of the parameter values of the plurality of parameter values for the kernel parameter that determines the shape of the region and corresponds to the desired rejection rate associated with the confidence threshold for automatic classification of the plurality of unclassified defects; receive inspection data for the plurality of unclassified defects detected in one or more wafer samples under inspection; automatically classify the plurality of unclassified defects for the defect class using the kernel function and the selected one of the plurality of parameter values of the kernel parameter that corresponds to the desired rejection rate for the plurality of unclassified defects to generate a first plurality of classification results; obtain a second plurality of classification results for one or more of the plurality of unclassified defects for the class; and combine the first plurality of classification results and the second plurality of classification results, wherein the plurality of unclassified defects are classified with a class label associated with the region based on a location of the unclassified defects in the region with the shape determined from the kernel parameter with the one of the plurality of parameter values that is selected based on the confidence threshold that corresponds to the desired rejection rate. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. A non-transitory computer readable storage medium having instructions that, when executed by a processing device, cause the processing device to perform operations comprising:
-
storing a definition of a region in a feature space, wherein the definition is associated with a defect class and comprises a kernel function, wherein the kernel function comprises a kernel parameter that is associated with a plurality of parameter values, wherein each of the parameter values for the kernel parameter is used to determine a different shape of the region based on the kernel function and corresponds to a different desired rejection rate for automatic classification of a plurality of unclassified defects for the defect class; receiving a confidence threshold that corresponds to a desired rejection rate for automatic classification of at least one defect associated with the defect class; selecting one of the parameter values of the plurality of parameter values for the kernel parameter that determines the shape of the region and corresponds to the desired rejection rate associated with the confidence threshold for automatic classification of the plurality of unclassified defects; receiving inspection data for the plurality of unclassified defects detected in one or more wafer samples under inspection; automatically classifying the plurality of unclassified defects for the class using the kernel function and the selected one of the plurality of parameter values of the kernel parameter that determines the shape of the region and corresponds to the desired rejection rate for the plurality of unclassified defects to generate a first plurality of classification results, wherein the plurality of unclassified defects are classified with a class label associated with the region based on a location of the unclassified defects in the region with the shape determined from the kernel parameter with the one of the plurality of parameter values that is selected based on the confidence threshold that corresponds to the desired rejection rate; obtaining a second plurality of classification results for one or more of the plurality of unclassified defects for the class; and combining the first plurality of classification results and the second plurality of classification results. - View Dependent Claims (16, 17, 18, 19, 20, 21)
-
Specification