# US 12,183,541 B2 · Charged particle beam system and overlay misalignment measurement method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,183,541 B2 - Document ID: US12183541B2 - Status: Granted - Kind: B2 - Application number: 17/634,501 - Filed: 2019-08-28 - Published: 2022-09-22 - Granted: 2024-12-31 - Earliest claimed: 2019-08-28 - Assignees: Hitachi High-Tech Corporation - Applicants: Hitachi High-Tech Corporation - Inventors: Takuma Yamamoto - Web page: https://patentgrep.com/patent/US12183541B2 ## CPC - H01J 37/28: with scanning beams {(H01J37/268, H01J37/292, H01J37/2955 take precedence)} - G03F 7/70633: {Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching} - H01J 37/222: {Image processing arrangements associated with the tube} - H01J 37/244: Detectors; Associated components or circuits therefor - H01J 37/265: {Controlling the tube; circuit arrangements adapted to a particular application not otherwise provided, e.g. bright-field-dark-field illumination} - H01J 2237/24475: Scattered electron detectors - H01J 2237/2448: Secondary particle detectors - H01J 2237/24592: Inspection and quality control of devices - H01J 2237/2817: Pattern inspection - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) ## Abstract In the present invention, an overlay misalignment is quickly measured. An image generation unit generates an image on the basis of signals from a detector. A matching processing unit identifies, by means of matching processing with a template image, the position of an overlay measurement pattern in the image generated by the image generation unit. A line profile generation unit generates, by scanning the overlay pattern, a first line profile pertaining to a secondary electron signal and a second line profile pertaining to a backscattered electron signal. An overlay misalignment measurement unit identifies the position of a first pattern in the overlay measurement pattern from the first line profile, identifies the position of a second pattern in the overlay measurement pattern from the second line profile, and measures an overlay misalignment in a sample on the basis of the position of the first pattern and the position of the second pattern. ## Claims ### Claim 1 A charged particle beam system comprising: a charged particle beam irradiation unit irradiating a sample with a charged particle beam; a detector detecting a secondary electron signal or a backscattered electron signal from the sample; and a computer system controlling the charged particle beam irradiation unit and measuring the amount of overlay misalignment in the sample, wherein the computer system includes an image generation unit generating an image based on a signal of the detector, a matching processing unit specifying a position of an overlay measurement pattern by matching processing in relation to a template image in the image generated by the image generation unit, a line profile generation unit generating a first line profile regarding the secondary electron signal and generating a second line profile regarding the backscattered electron signal by selectively scanning a portion of the overlay measurement pattern at the position specified by the matching processing unit, and an overlay misalignment measurement unit specifying a position of a first pattern in the overlay measurement pattern from the first line profile, specifying a position of a second pattern in the overlay measurement pattern from the second line profile, and measuring the overlay misalignment in the sample based on the position of the first pattern and the position of the second pattern. ### Claim 2 (depends on 1) The charged particle beam system according to claim 1, wherein the line profile generation unit corrects a position where the scanning is executed based on the position of the overlay measurement pattern specified by the matching processing unit. ### Claim 3 (depends on 1) The charged particle beam system according to claim 1, comprising a display unit displaying the image generated by the image generation unit and the first line profile or the second line profile. ### Claim 4 (depends on 1) The charged particle beam system according to claim 1, wherein the line profile generation unit is configured to be capable of designating a scanning area for line profile generation on the image generated by the image generation unit. ### Claim 5 (depends on 4) The charged particle beam system according to claim 4, wherein the line profile generation unit is configured to be capable of designating a first scanning area where a first direction is a longitudinal direction and a second scanning area where a second direction intersecting with the first direction is a longitudinal direction. ### Claim 6 (depends on 1) The charged particle beam system according to claim 1, wherein a measurement cursor or a line template image corresponding to the first line profile or the second line profile are pre-registered, and wherein the overlay misalignment measurement unit adjusts a position of the measurement cursor based on a result of matching processing between the line template image and the first line profile or the second line profile. ### Claim 7 (depends on 1) The charged particle beam system according to claim 1, wherein the line profile generation unit generates the first line profile or the second line profile by adding a signal obtained by charged particle beam scanning along different directions. ### Claim 8 An overlay misalignment measurement method for measuring the amount of overlay misalignment between different layers of a sample based on a signal detected by a detector by irradiating the sample with a charged particle beam, the method comprising: a step of generating an image based on output of the detector; a step of specifying a position of an overlay measurement pattern by matching processing between the image and a template image; a step of generating a first line profile regarding a secondary electron signal and generating a second line profile regarding a backscattered electron signal by selectively scanning a portion of the overlay measurement pattern at the position of the overlay measurement pattern; a step of specifying a position of a first pattern in the overlay measurement pattern from the first line profile and specifying a position of a second pattern in the overlay measurement pattern from the second line profile; and a step of measuring the overlay misalignment in the sample based on the position of the first pattern and the position of the second pattern. ### Claim 9 (depends on 8) The overlay misalignment measurement method according to claim 8, wherein a position where the scanning is executed is corrected based on the position of the overlay measurement pattern specified by the matching processing in a case where the first line profile or the second line profile is generated. ### Claim 10 (depends on 8) The overlay misalignment measurement method according to claim 8, further comprising a step of designating a scanning area in a case where the first line profile or the second line profile is generated. ### Claim 11 (depends on 10) The overlay misalignment measurement method according to claim 10, wherein the scanning area includes a first scanning area where a first direction is a longitudinal direction and a second scanning area where a second direction intersecting with the first direction is a longitudinal direction. ### Claim 12 (depends on 8) The overlay misalignment measurement method according to claim 8, wherein a measurement cursor or a line template image corresponding to the first line profile or the second line profile are pre-registered, further comprising a step of adjusting a position of the measurement cursor based on a result of matching processing between the line template image and the first line profile or the second line profile. ### Claim 13 (depends on 8) The overlay misalignment measurement method according to claim 8, wherein the first line profile or the second line profile is generated by adding a signal obtained by charged particle beam scanning along different directions in a case where the first line profile or the second line profile is generated.