# US 11,442,024 B2 · Defect classification device, inspection device, and inspection system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,024 B2 - Document ID: US11442024B2 - Status: Granted - Kind: B2 - Application number: 16/642,948 - Filed: 2017-09-11 - Published: 2020-08-13 - Granted: 2022-09-13 - Earliest claimed: 2017-09-11 - Assignees: Hitachi High-Technologies Corporation - Applicants: Hitachi High-Technologies Corporation - Inventors: Takanori Kondo; Toshifumi Honda; Akira Hamamatsu; Hideo Ota; Yoshio Kimoto - Web page: https://patentgrep.com/patent/US11442024B2 ## CPC - G01N 21/9501: {Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} - G01N 21/95607: {using a comparative method} - G01N 21/8851: {Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges (G01N21/8806 and G01N21/93 - G01N21/95692 take precedence; optical measurement of dimensions G01B11/00; optical scanning G02B26/10; image transformation G06T3/00; computerised image enhancement G06T5/00; image processing per se for flaw detection G06T7/0002)} - 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)} - H10P 74/203: {Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects} - H10P 74/23: {characterised by multiple measurements, corrections, marking or sorting processes} - G01N 2021/8438: {Mutilayers} - G01N 2021/8867: {using sequentially two or more inspection runs, e.g. coarse and fine, or detecting then analysing} - 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) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract In order to prevent an erroneous determination of an on-film defect, the sensitivity of the post-inspection is reduced so that a film swelling due to a minute defect would not be detected. Classification is performed to determine whether a defect is at least one of an on-film defect and a film swelling, by performing a coordinate correction on the result of a post-inspection by an actual-defect fine alignment using the result of a pre-inspection performed with two-stage thresholds, and by checking defects against each other. In addition, classification is performed to determine whether a defect is at least one of an on-film defect and a film swelling by, during the post-inspection, preparing instruction data from information of the refractive index and thickness of a film formed on a wafer and comparing the instruction data with a signal intensity ratio of a detection system. ## Claims ### Claim 1 A defect classification device comprising: a storage device; and a signal processing device configured to acquire a first detection signal obtained by irradiating a wafer before a film formation process with a light and a second detection signal obtained by irradiating the wafer after the film formation process with a light, classify a defect on the wafer using signal intensities of the first and second detection signals, and store a classification result in the storage device, wherein the signal processing device is configured to compare a first threshold value with a signal intensity of the first detection signal, and compare a second threshold value having a value smaller than the first threshold value with the signal intensity of the first detection signal, an inspection signal of the first threshold value or more being taken as a first result, and an inspection signal of the second threshold value or more and less than the first threshold value being taken as a second result; and classify the defect on the wafer by comparing the first result with the second detection signal, and the second result with the second detection signal. ### Claim 2 (depends on 1) The defect classification device according to claim 1, wherein the signal processing device specifies a defect deposited on a film generated on the wafer due to the film formation process. ### Claim 3 (depends on 1) The defect classification device according to claim 1, wherein the signal processing device classifies the defect into a film swelling in which a defect below a film generated on the wafer due to the film formation process is taken as a core, and an on-film defect above the film. ### Claim 4 (depends on 1) The defect classification device according to claim 1, wherein the signal processing device corrects a coordinate corresponding to the second detection signal using the first result, and compares the second detection signal after the coordinate correction with the first result and the second result. ### Claim 5 (depends on 1) The defect classification device according to claim 1, wherein the signal processing device acquires a plurality of first detection signals detected by a plurality of detection systems, adds the plurality of first detection signals to generate a first addition signal, acquires a plurality of second detection signals detected by the plurality of detection systems, adds the plurality of second detection signals to generate a second addition signal, and classifies the defect on the wafer by comparing the first threshold value with a signal intensity of the first addition signal, and the second threshold value with the signal intensity of the first addition signal to acquire the first result and the second result, and comparing the first result with the second addition signal, and the second result with the second addition signal. ### Claim 6 A defect classification device comprising: a storage device; and a signal processing device configured to acquire detection signals detected by a plurality of detection systems obtained by irradiating a wafer after a film formation process with a light, classify a defect on the wafer using signal intensities of the detection signals, and store a classification result in the storage device, wherein the signal processing device is configured to read out, from the storage device, instruction data for determining whether a signal obtained from a result of an inspection is a signal due to a defect, the instruction data being corresponding to film information of the wafer, compare the instruction data with a signal intensity ratio of the detection signals from at least two detection systems, and classify the defect on the wafer based on a result of the comparing, the instruction data is different for each film thickness included in the film information, and is data based on first signal intensity ratio data when the defect is a film swelling and based on second signal intensity ratio data when the defect is an on-film defect in the signal intensity ratio of at least two detection systems, and the signal processing device classifies the defect on the wafer according to a distance between the signal intensity ratio of the detection signals and the first signal intensity ratio data, and a distance between the signal intensity ratio of the detection signals and the second signal intensity ratio data. ### Claim 7 (depends on 1) An inspection device, comprising: an irradiation optical system configured to irradiate a wafer with an illumination light; a plurality of detection systems configured to detect a scattered light from the wafer; and the defect classification device according to claim 1. ### Claim 8 (depends on 6) An inspection device, comprising: an irradiation optical system configured to irradiate a wafer with an illumination light; a plurality of detection systems configured to detect a scattered light from the wafer; and the defect classification device according to claim 6. ### Claim 9 (depends on 7) An inspection system comprising: a plurality of inspection devices according to claim 7; and at least one server configured to store an inspection result and a defect classification result from the inspection devices, wherein a first inspection device executes an inspection before a film formation process on a wafer before the film formation process, acquires an inspection result before the film formation process, and transmits the inspection result before the film formation process to the server, the server receives the inspection result before the film formation process from the first inspection device, and transmits the inspection result before the film formation process to a second inspection device, and the second inspection device executes an inspection after the film formation process on the wafer after the film formation process, acquires an inspection result after the film formation process, classifies the defect using the inspection result before the film formation process and the inspection result before the film formation process, and transmits a defect classification result to the server. ### Claim 10 (depends on 1) An inspection system comprising: a plurality of inspection devices including a first inspection device and a second inspection device; and at least one server configured to classify a defect by using inspection results from the inspection devices including the defect classification device according to claim 1, wherein the inspection devices each include an irradiation optical system configured to irradiate the wafer with an illumination light, and a plurality of detection systems configured to detect a scattered light from the wafer, the first inspection device executes an inspection before a film formation process on the wafer before the film formation process, and transmits an inspection result before the film formation process to the server, the second inspection device executes an inspection after the film formation process on the wafer after the film formation process, and transmits an inspection result after the film formation process to the server, and the server classifies the defect by using the inspection result before the film formation process and the inspection result after the film formation process received from the first inspection device and the second inspection device. ### Claim 11 (depends on 1) An inspection system comprising: a plurality of inspection devices including a first inspection device and a second inspection device; the defect classification device according to claim 1; and at least one server configured to store an inspection result from the inspection device and a defect classification result from the defect classification device, wherein the inspection devices each include an irradiation optical system configured to irradiate the wafer with an illumination light, and a plurality of detection systems configured to detect a scattered light from the wafer, the first inspection device executes an inspection before a film formation process on the wafer before the film formation process, and transmits an inspection result before the film formation process to the server, the second inspection device executes an inspection after the film formation process on the wafer after the film formation process, and transmits an inspection result after the film formation process to the server, the server transmits the inspection result before the film formation process and the inspection result after the film formation process received from the first inspection device and the second inspection device to the defect classification device, and the defect classification device classifies the defect by using the inspection result before the film formation process and the inspection result after the film formation process.