# US 12,007,701 B2 · Determining a mark layout across a patterning device or substrate > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,007,701 B2 - Document ID: US12007701B2 - Status: Granted - Kind: B2 - Application number: 17/294,503 - Filed: 2019-10-21 - Published: 2022-01-13 - Granted: 2024-06-11 - Earliest claimed: 2018-11-26 - Assignees: ASML Netherlands B.V. - Applicants: Asml Netherlands B.V. - Inventors: Pavel Smal; Inez Marlena Sochal; Gautam Sarma - Web page: https://patentgrep.com/patent/US12007701B2 ## CPC - G03F 7/70616: {Monitoring the printed patterns} - G03F 9/7046: {Strategy, e.g. mark, sensor or wavelength selection} - G03F 7/70625: {Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness} - 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} - G03F 7/70683: {Mark designs} - 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 A method for determining a layout of mark positions across a patterning device or substrate, the method including: obtaining a model configured to model data associated with measurements performed on the patterning device or substrate at one or more mark positions; obtaining an initial mark layout including initial mark positions; reducing the initial mark layout by removal of one or more mark positions to obtain a plurality of reduced mark layouts, each reduced mark layout obtained by removal of a different mark position from the initial mark layout; determining a model uncertainty metric associated with usage of the model for each reduced mark layout out of the plurality of reduced mark layouts; and selecting one or more reduced mark layouts based on its associated model uncertainty metric. ## Claims ### Claim 1 A method for determining a layout of mark positions across a patterning device or substrate, the method comprising: obtaining a computer model configured to model data associated with measurements performed on the patterning device or substrate at one or more mark positions; obtaining an initial mark layout comprising initial mark positions; reducing the initial mark layout by removal of one or more mark positions to obtain a plurality of reduced mark layouts, each reduced mark layout obtained by removal of a different mark position from the initial mark layout; determining a model uncertainty metric associated with usage of the computer model for each reduced mark layout out of the plurality of reduced mark layouts; and selecting one or more reduced mark layouts based on the model uncertainty metric associated with the plurality of reduced mark layouts. ### Claim 2 (depends on 1) The method of claim 1, wherein only the reduced mark layout is selected which has the lowest model uncertainty metric among the plurality of reduced mark layouts. ### Claim 3 (depends on 1) The method of claim 1, further comprising: a) obtaining the initial mark layout from a selected reduced mark layout out of the one or more selected reduced mark layouts and repeating the reducing, determining, and selecting; and b) repeating step a) for all selected one or more reduced mark layouts. ### Claim 4 (depends on 3) The method of claim 3, wherein the steps a) and b) are repeated until the reduced mark layout comprises a pre-defined number of mark positions. ### Claim 5 (depends on 4) The method of claim 4, wherein the pre-defined number of mark positions is based on an acceptable measurement time associated with measuring the number of mark positions. ### Claim 6 (depends on 3) The method of claim 3, wherein the steps a) and b) are repeated until the model uncertainty metric exceeds a threshold. ### Claim 7 (depends on 4) The method of claim 4, wherein the pre-defined number of mark positions is based on the model uncertainty. ### Claim 8 (depends on 1) The method of claim 1, wherein the initial mark layout or a reduced mark layout of the plurality of reduced mark layouts is a layout of one or more selected from: alignment mark positions, overlay mark positions, focus mark positions or critical dimension mark positions. ### Claim 9 (depends on 1) The method of claim 1, wherein the computer model is a six-parameter model describing an alignment or overlay parameter of a substrate, the substrate being a wafer. ### Claim 10 (depends on 1) The method of claim 1, wherein the model uncertainty metric is associated with a G-optimality criterion. ### Claim 11 (depends on 1) The method of claim 1, wherein the mark positions are distributed across a field on a substrate. ### Claim 12 (depends on 1) The method of claim 1, wherein the mark positions are distributed across an entire substrate. ### Claim 13 (depends on 1) An apparatus specifically configured to carry out the method of claim 1, the apparatus configured as a lithographic apparatus operable to perform a lithographic process on the substrate. ### Claim 14 A computer program product comprising a non-transitory computer-readable medium having computer readable instructions therein, the instructions, when run on a suitable computer apparatus, configured to cause the computer apparatus to at least: obtain a computer model configured to model data associated with measurements performed on a patterning device or substrate at one or more mark positions across the patterning device or substrate; obtain an initial mark layout comprising initial mark positions; reduce the initial mark layout by removal of one or more mark positions to obtain a plurality of reduced mark layouts, each reduced mark layout obtained by removal of a different mark position from the initial mark layout; determine a model uncertainty metric associated with usage of the computer model for each reduced mark layout out of the plurality of reduced mark layouts; and select one or more reduced mark layouts based on the model uncertainty metric associated with the plurality of reduced mark layouts. ### Claim 15 (depends on 14) The computer program product of claim 14, wherein only the reduced mark layout is selected which has the lowest model uncertainty metric among the plurality of reduced mark layouts. ### Claim 16 (depends on 14) The computer program product of claim 14, wherein the instructions are further configured to cause the computer apparatus to: a) obtain the initial mark layout from a selected reduced mark layout out of the one or more selected reduced mark layouts and repeat the reducing, determining, and selecting; and b) repeat a) for all selected one or more reduced mark layouts. ### Claim 17 (depends on 14) The computer program product of claim 14, wherein a) and b) are repeated until the reduced mark layout comprises a pre-defined number of mark positions. ### Claim 18 (depends on 14) The computer program product of claim 14, wherein a) and b) are repeated until the model uncertainty metric exceeds a threshold. ### Claim 19 (depends on 14) The computer program product of claim 14, wherein the initial mark layout or a reduced mark layout of the plurality of reduced mark layouts is a layout of one or more selected from: alignment mark positions, overlay mark positions, focus mark positions or critical dimension mark positions. ### Claim 20 (depends on 14) The computer program product of claim 14, wherein the model uncertainty metric is associated with a G-optimality criterion.