# US 12,525,425 B2 · Pattern inspection apparatus, and method for acquiring alignment amount between outlines > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,525,425 B2 - Document ID: US12525425B2 - Status: Granted - Kind: B2 - Application number: 18/148,588 - Filed: 2022-12-30 - Published: 2023-05-11 - Granted: 2026-01-13 - Earliest claimed: 2020-07-29 - Assignees: NuFlare Technology, Inc. - Applicants: NuFlare Technology, Inc. - Inventors: Shinji Sugihara - Web page: https://patentgrep.com/patent/US12525425B2 ## CPC - H01J 37/222: {Image processing arrangements associated with the tube} - G01N 21/956: Inspecting patterns on the surface of objects {(contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} - G01N 23/2251: using incident electron beams, e.g. scanning electron microscopy [SEM] - G06T 1/00: General purpose image data processing - G06T 7/001: {using an image reference approach} - G06T 7/337: {involving reference images or patches} - H01J 37/244: Detectors; Associated components or circuits therefor - G01N 2223/401: image processing - G06T 2207/30148: Semiconductor; IC; Wafer - H01J 37/09: Diaphragms; Shields associated with electron or ion-optical arrangements; Compensation of disturbing fields - H01J 37/28: with scanning beams {(H01J37/268, H01J37/292, H01J37/2955 take precedence)} - H01J 2237/0453: multiple apertures - H01J 2237/221: Image processing - H01J 2237/226: Image reconstruction - H01J 2237/2617: Comparison or superposition of transmission images; Moiré - H01J 2237/28: Scanning microscopes - H01J 2237/2817: Pattern inspection - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract A pattern inspection apparatus includes an actual outline image generation circuit to generate an actual outline image of a predetermined region defined by a function, where the gray scale value of each pixel in the predetermined region including plural actual image outline positions on an actual image outline of a figure pattern in an inspection image is dependent on a distance from the center of a pixel concerned to the closest actual image outline position in the plural actual image outline positions, and a reference outline image generation circuit to generate a reference outline image of the predetermined region defined by the function, where a gray scale value of each pixel in the predetermined region is dependent on a distance from the center of a pixel concerned to the closest reference outline position in plural reference outline positions on a reference outline to be compared with the actual image outline. ## Claims ### Claim 1 A pattern inspection apparatus comprising: an image acquisition mechanism configured to acquire an inspection image of a substrate on which a figure pattern is formed; an actual outline image generation circuit configured to generate an actual outline image of a predetermined region defined by a predetermined function, in which the predetermined function defines a gray scale value of each pixel in the predetermined region including a plurality of actual image outline positions on an actual image outline of the figure pattern in the inspection image is dependent on a distance from a center of a pixel concerned to a closest actual image outline position in the plurality of actual image outline positions; a reference outline image generation circuit configured to generate a reference outline image of the predetermined region defined by the predetermined function, in which the predetermined function defines a gray scale value of each pixel in the predetermined region is dependent on a distance from a center of a pixel concerned to a closest reference outline position in a plurality of reference outline positions on a reference outline to be compared with the actual image outline; an alignment amount calculation circuit configured to calculate an alignment amount for performing alignment between the actual outline image and the reference outline image by using a gray scale difference between the actual outline image and the reference outline image; and a comparison circuit configured to compare the actual image outline with the reference outline by using the alignment amount, wherein a derivative of the predetermined function is substantially continuous. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein the alignment amount calculation circuit shifts at least one of the actual outline image and the reference outline image while changing a shift amount between the actual outline image and the reference outline image, and calculates the shift amount, as the alignment amount, that makes a sum of squared differences between a gray scale value of the actual outline image and a gray scale value of the reference outline image in each shift amount smaller than others. ### Claim 3 (depends on 1) The apparatus according to claim 1, wherein the predetermined function is a Gaussian function. ### Claim 4 (depends on 1) The apparatus according to claim 1 further comprising: an actual image outline position extraction circuit configured to extract, for each predetermined region, the plurality of actual image outline positions of each figure pattern in the inspection image concerned. ### Claim 5 A method for acquiring an alignment amount between outlines comprising: acquiring an inspection image of a substrate on which a figure pattern is formed; generating an actual outline image of a predetermined region defined by a predetermined function, in which the predetermined function defines a gray scale value of each pixel in the predetermined region including a plurality of actual image outline positions on an actual image outline of the figure pattern in the inspection image is dependent on a distance from a center of a pixel concerned to a closest actual image outline position in the plurality of actual image outline positions; generating a reference outline image of the predetermined region defined by the predetermined function, in which the predetermined function defines a gray scale value of each pixel in the predetermined region is dependent on a distance from a center of a pixel concerned to a closest reference outline position in a plurality of reference outline positions on a reference outline to be compared with the actual image outline; and calculating an alignment amount for performing alignment between the actual outline image and the reference outline image by using a gray scale difference between the actual outline image and the reference outline image, and outputting a result, wherein a derivative of the predetermined function is substantially continuous. ### Claim 6 (depends on 5) The method according to claim 5 further comprising: shifting at least one of the actual outline image and the reference outline image while changing a shift amount between the actual outline image and the reference outline image, and calculating the shift amount, as the alignment amount, that makes a sum of squared differences between a gray scale value of the actual outline image and a gray scale value of the reference outline image in each shift amount smaller than others. ### Claim 7 (depends on 5) The method according to claim 5, wherein the predetermined function is a Gaussian function. ### Claim 8 (depends on 5) The method according to claim 5 further comprising: extracting, for each predetermined region, the plurality of actual image outline positions of each figure pattern in the inspection image concerned.