# US 11,029,614 B2 · Level sensor apparatus, method of measuring topographical variation across a substrate, method of measuring variation of a physical parameter related to a lithographic process, and lithographic apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,614 B2 - Document ID: US11029614B2 - Status: Granted - Kind: B2 - Application number: 16/318,388 - Filed: 2017-06-22 - Published: 2019-08-08 - Granted: 2021-06-08 - Earliest claimed: 2016-07-26 - Assignees: ASML Netherlands B.V. - Applicants: Asml Netherlands B.V. - Inventors: Wim Tjibbo Tel; Frank Staals; Martin Jules Marie-Emile De Nivelle; Tanbir Hasan - Web page: https://patentgrep.com/patent/US11029614B2 ## CPC - G03F 9/7034: {Leveling} - G05B 19/4097: characterised by using design data to control NC machines, e.g. CAD/CAM (G05B19/4093 takes precedence) - G05B 2219/45028: Lithography - G05B 2219/45031: Manufacturing semiconductor wafers - 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) - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) ## Abstract A method of determining topographical variation across a substrate on which one or more patterns have been applied. The method includes obtaining measured topography data representing a topographical variation across a substrate on which one or more patterns have been applied by a lithographic process; and combining the measured topography data with knowledge relating to intra-die topology to obtain derived topography data having a resolution greater than the resolution of the measured topography data. Also disclosed is a corresponding level sensor apparatus and lithographic apparatus having such a level sensor apparatus, and a more general method of determining variation of a physical parameter from first measurement data of variation of the physical parameter across the substrate and intra-die measurement data of higher resolution than the first measurement data and combining these. ## Claims ### Claim 1 A method comprising: obtaining first measurement data of variation of a physical parameter across a substrate on which one or more patterns have been applied by a lithographic process; obtaining second measurement data, wherein the second measurement data comprises intra-die measurement data of higher resolution than the first measurement data, and wherein the second measurement data is referenced to reference measurement data, the reference measurement data separate from the first measurement data and the reference measurement data having a common frame of reference with the first measurement data; and combining, by a hardware computer system, the first measurement data with the second measurement data to obtain derived measurement data having a resolution greater than the resolution of the first measurement data. ### Claim 2 (depends on 1) The method of claim 1, wherein the first measurement data is measured using a first metrology tool and the second measurement data is measured using a second metrology tool. ### Claim 3 (depends on 2) The method of claim 2, further comprising performing a calibration which comprises simultaneously measuring a portion of a substrate using respectively the second metrology tool and a reference metrology tool being the same as and/or having a common frame of reference with the first metrology tool. ### Claim 4 (depends on 2) The method of claim 2, wherein the physical parameter is topography, wherein the first metrology tool comprises an optical level sensor apparatus and wherein the common frame of reference is to that of a gas pressure differential level sensor apparatus to which the optical level sensor apparatus is referenced. ### Claim 5 (depends on 4) The method of claim 4, wherein the reference metrology tool comprises the gas pressure differential level sensor apparatus. ### Claim 6 (depends on 2) The method of claim 2, wherein the second metrology tool is an electron beam metrology tool. ### Claim 7 (depends on 2) The method of claim 2, wherein the physical parameter is a pattern shift error and the first metrology tool comprises an alignment sensor apparatus and the common frame of reference is to that of an overlay metrology apparatus to which the alignment sensor apparatus is referenced. ### Claim 8 (depends on 7) The method of claim 7, wherein the reference metrology tool comprises the alignment sensor apparatus or an overlay metrology apparatus. ### Claim 9 (depends on 2) The method of claim 2, wherein the physical parameter is critical dimension or other parameter relating to size of a structure, and the first metrology tool comprises a first critical dimension (CD) metrology apparatus and the common frame of reference is to that of a second CD metrology apparatus to which the first CD metrology apparatus is referenced. ### Claim 10 (depends on 9) The method of claim 9, wherein the first CD metrology apparatus comprises a scatterometer based metrology apparatus and the second CD metrology apparatus comprises a scanning electron microscope. ### Claim 11 (depends on 10) The method of claim 10, wherein the reference metrology tool comprises the scatterometer based metrology apparatus. ### Claim 12 A computer program product comprising a non-transitory computer-readable medium having instructions therein, the instructions, upon execution by a computer system, configured to cause the computer system to at least: obtain first measurement data of variation of a physical parameter across a substrate on which one or more patterns have been applied by a lithographic process; obtain second measurement data, wherein the second measurement data comprises intra-die measurement data of higher resolution than the first measurement data, and wherein the second measurement data is referenced to reference measurement data, the reference measurement data separate from the first measurement data and the reference measurement data having a common frame of reference with the first measurement data; and combine the first measurement data with the second measurement data to obtain derived measurement data having a resolution greater than the resolution of the first measurement data. ### Claim 13 (depends on 12) The computer program product of claim 12, wherein the first measurement data is measured using a first metrology tool and the second measurement data is measured using a second metrology tool. ### Claim 14 (depends on 13) The computer program product of claim 13, wherein the instructions are further configured to cause the computer system to perform a calibration which uses a simultaneous measurement of a portion of a substrate using respectively the second metrology tool and a reference metrology tool being the same as and/or having a common frame of reference with the first metrology tool. ### Claim 15 (depends on 13) The computer program product of claim 13, wherein the physical parameter is topography, wherein the first metrology tool comprises an optical level sensor apparatus and wherein the common frame of reference is to that of a gas pressure differential level sensor apparatus to which the optical level sensor apparatus is referenced. ### Claim 16 (depends on 13) The computer program product of claim 13, wherein the physical parameter is a pattern shift error and the first metrology tool comprises an alignment sensor apparatus and the common frame of reference is to that of an overlay metrology apparatus to which the alignment sensor apparatus is referenced. ### Claim 17 A computer program product comprising a non-transitory computer-readable medium having instructions therein, the instructions, upon execution by a computer system, configured to cause the computer system to at least: obtain first measurement data of variation of a physical parameter across a substrate on which one or more patterns have been applied by a lithographic process; obtain second measurement data, wherein the second measurement data comprises intra-die measurement data of higher resolution than the first measurement data, and wherein the second measurement data is referenced to reference measurement data having a common frame of reference with the first measurement data; and combine the first measurement data with the second measurement data to obtain derived measurement data having a resolution greater than the resolution of the first measurement data, the derived measurement data being values of the first measurement data modified to new values by the second measurement data or being values of the second measurement data modified to new values by the first measurement data. ### Claim 18 (depends on 17) The computer program product of claim 17, wherein the first measurement data is measured using a first metrology tool and the second measurement data is measured using a second metrology tool. ### Claim 19 (depends on 18) The computer program product of claim 18, wherein the instructions are further configured to cause the computer system to perform a calibration which uses a simultaneous measurement of a portion of a substrate using respectively the second metrology tool and a reference metrology tool being the same as and/or having a common frame of reference with the first metrology tool. ### Claim 20 (depends on 18) The computer program product of claim 18, wherein the physical parameter is topography, wherein the first metrology tool comprises an optical level sensor apparatus and wherein the common frame of reference is to that of a gas pressure differential level sensor apparatus to which the optical level sensor apparatus is referenced.