Abstract: A defect detection method includes acquiring a reference image; selecting a target region of the reference image; identifying, based on a matching metric, one or more comparative regions of the reference image corresponding to the target region; acquiring a test image; masking the test image with the target region of the reference image and the one or more comparative regions of the reference image; defining a defect threshold for the target region in the test image based on the one or more comparative regions in the test image; and determining whether the target region of the test image contains a defect based on the defect threshold.

Abstract: Methods and systems for detecting defects on a specimen are provided. One system includes a storage medium configured for storing images for a physical version of a specimen generated by an inspection system. At least two dies are formed on the specimen with different values of one or more parameters of a fabrication process performed on the specimen. The system also includes computer subsystem(s) configured for comparing portions of the stored images generated at locations on the specimen at which patterns having the same as-designed characteristics are formed with at least two of the different values. The portions of the stored images that are compared are not constrained by locations of the dies on the specimen, locations of the patterns within the dies, or locations of the patterns on the specimen. The computer subsystem(s) are also configured for detecting defects at the locations based on results of the comparing.

Abstract: A defect inspection system includes an inspection sub-system and a controller communicatively coupled to the detector. The inspection sub-system includes an illumination source configured to generate a beam of illumination, a set of illumination optics to direct the beam of illumination to a sample, and a detector configured to collect illumination emanating from the sample. The controller includes a memory device and one or more processors configured to execute program instructions. The controller is configured to determine one or more target patterns corresponding to one or more features on the sample, define one or more care areas on the sample based on the one or more target patterns and design data of the sample stored within the memory device of the controller, and identify one or more defects within the one or more care areas of the sample based on the illumination collected by the detector.

Abstract: A defect detection method includes acquiring a reference image; selecting a target region of the reference image; identifying, based on a matching metric, one or more comparative regions of the reference image corresponding to the target region; acquiring a test image; masking the test image with the target region of the reference image and the one or more comparative regions of the reference image; defining a defect threshold for the target region in the test image based on the one or more comparative regions in the test image; and determining whether the target region of the test image contains a defect based on the defect threshold.

Abstract: A defect inspection system includes an inspection sub-system and a controller communicatively coupled to the detector. The inspection sub-system includes an illumination source configured to generate a beam of illumination, a set of illumination optics to direct the beam of illumination to a sample, and a detector configured to collect illumination emanating from the sample. The controller includes a memory device and one or more processors configured to execute program instructions. The controller is configured to determine one or more target patterns corresponding to one or more features on the sample, define one or more care areas on the sample based on the one or more target patterns and design data of the sample stored within the memory device of the controller, and identify one or more defects within the one or more care areas of the sample based on the illumination collected by the detector.

Abstract: Methods and systems for detecting defects on a specimen are provided. One system includes a storage medium configured for storing images for a physical version of a specimen generated by an inspection system. At least two dies are formed on the specimen with different values of one or more parameters of a fabrication process performed on the specimen. The system also includes computer subsystem(s) configured for comparing portions of the stored images generated at locations on the specimen at which patterns having the same as-designed characteristics are formed with at least two of the different values. The portions of the stored images that are compared are not constrained by locations of the dies on the specimen, locations of the patterns within the dies, or locations of the patterns on the specimen. The computer subsystem(s) are also configured for detecting defects at the locations based on results of the comparing.

Abstract: Systems and methods for classifying defects on a wafer are provided. One method includes dilating an extended bounding box (EBB) surrounding a defect position on a wafer in two dimensions in proportion to a width and height of a pattern of interest (POI) for a hot spot closest to the defect position. The method also includes determining if polygons in the POI match polygons in the dilated bounding box. If the polygons in the POI do not match the polygons in the dilated bounding box, the defect is classified as a non-hot spot defect. If the polygons in the POI match the polygons in the dilated bounding box, the defect is classified as a hot spot defect if the area of the EBB intersects the area of interest associated with the hot spot and a non-hot spot defect if the EBB area does not intersect the area of interest.

Abstract: Systems and methods for determining a position of output of an inspection system in design data space are provided. One method includes merging more than one feature in design data for a wafer into a single feature that has a periphery that encompasses all of the features that are merged. The method also includes storing information for the single feature without the design data for the features that are merged. The information includes a position of the single feature in design data space. The method further includes aligning output of an inspection system for the wafer to the information for the single feature such that positions of the output in the design data space can be determined based on the position of the single feature in the design data space.

Abstract: Systems and methods for classifying defects on a wafer are provided. One method includes dilating an extended bounding box (EBB) surrounding a defect position on a wafer in two dimensions in proportion to a width and height of a pattern of interest (POI) for a hot spot closest to the defect position. The method also includes determining if polygons in the POI match polygons in the dilated bounding box. If the polygons in the POI do not match the polygons in the dilated bounding box, the defect is classified as a non-hot spot defect. If the polygons in the POI match the polygons in the dilated bounding box, the defect is classified as a hot spot defect if the area of the EBB intersects the area of interest associated with the hot spot and a non-hot spot defect if the EBB area does not intersect the area of interest.