# US 10,310,385 B2 · Optical system for producing lithographic structures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,385 B2 - Document ID: US10310385B2 - Status: Granted - Kind: B2 - Application number: 15/994,068 - Filed: 2018-05-31 - Published: 2018-09-27 - Granted: 2019-06-04 - Earliest claimed: 2014-10-06 - Assignees: Carl Zeiss AG - Applicants: Carl Zeiss AG - Inventors: Philipp Huebner; Gerhard Krampert; Stefan Richter; Timo Mappes - Web page: https://patentgrep.com/patent/US10310385B2 ## CPC - G03F 7/70383: {Direct write, i.e. pattern is written directly without the use of a mask by one or multiple beams (maskless lithography using a programmable mask G03F7/70291)} - G03F 7/70683: {Mark designs} - G03F 9/7007: {Alignment other than original with workpiece} - G03F 9/7011: {Pre-exposure scan; original with original holder alignment; Prealignment, i.e. workpiece with workpiece holder} - 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 An optical system for producing lithographic structures is disclosed. Also disclosed is a method for determining relative coordinates of a position of a writing field relative to a position of a preview field in such an optical system, and a method for producing lithographic structures using such an optical system. ## Claims ### Claim 1 A method of operating an optical system configured to produce lithographic structures, the optical unit comprising a projection optical unit, a preview optical unit and a substrate holder, the method comprising: recording a test object using the preview optical unit or the projection optical unit in an initial field; positioning the test object in the initial field so that the test object has a defined position in the initial field; carrying out, via the substrate holder, a coarse displacement of the test object between the initial field and a target field; registering coarse relative coordinates of the coarse displacement; recording the test object using the other of the two optical units from the optical group; finely positioning the test object in the target field so that the test object has a defined position in the target field; and registering changes in the coarse relative coordinates during the fine positioning and producing the relative coordinates from the coarse relative coordinates and the result of the registration. ### Claim 2 (depends on 1) The method of claim 1, wherein the initial field the preview field or the writing field. ### Claim 3 (depends on 2) The method of claim 2, wherein the target field is different from the initial field, and the target field is the preview field or the writing field. ### Claim 4 (depends on 1) The method of claim 1, further comprising, during the fine positioning, maximizing a correlation of the position of the test object in the initial field and in the target field. ### Claim 5 (depends on 1) The method of claim 1, further comprising, during the test object recording, producing an image stack by recording various images of the test object using the recording optical unit in various displacement positions of the recording optical unit relative to the test object in a displacement direction perpendicular to the substrate plane. ### Claim 6 (depends on 1) The method of claim 1, further comprising, during the determination, repeatedly performing a coarse displacement of the test object between the fields the field group. ### Claim 7 (depends on 1) The method of claim 1, further comprising: determining a writing target position on the substrate in the preview field; displacing the writing target position from the preview field into the writing field using the determined relative coordinates; and writing a predetermined structure into the writing field using the writing light beam. ### Claim 8 (depends on 7) The method of claim 7, further comprising, before the writing target position is displaced from the preview field into the writing field, aligning the writing target position in the preview field. ### Claim 9 A system comprising: one or more processing devices; and one or more machine-readable hardware storage devices comprising instructions that are executable by the one or more processing devices to perform operations comprising: recording a test object using a preview optical unit or a projection optical unit in an initial field, the preview optical unit and the projection optical unit being optical units of an optical system configured to produce lithographic structures; positioning the test object in the initial field so that the test object has a defined position in the initial field; carrying out, via a substrate holder of the optical system, a coarse displacement of the test object between the initial field and a target field; registering coarse relative coordinates of the coarse displacement; recording the test object using the other of the two optical units from the optical group; finely positioning the test object in the target field so that the test object has a defined position in the target field; and registering changes in the coarse relative coordinates during the fine positioning and producing the relative coordinates from the coarse relative coordinates and the result of the registration. ### Claim 10 One or more non-transitory machine-readable hardware storage devices comprising instructions that are executable by one or more processing devices to perform operations comprising: recording a test object using a preview optical unit or a projection optical unit in an initial field, the preview optical unit and the projection optical unit being optical units of an optical system configured to produce lithographic structures; positioning the test object in the initial field so that the test object has a defined position in the initial field; carrying out, via a substrate holder of the optical system, a coarse displacement of the test object between the initial field and a target field; registering coarse relative coordinates of the coarse displacement; recording the test object using the other of the two optical units from the optical group; finely positioning the test object in the target field so that the test object has a defined position in the target field; and registering changes in the coarse relative coordinates during the fine positioning and producing the relative coordinates from the coarse relative coordinates and the result of the registration. ### Claim 11 (depends on 1) The method of claim 1, wherein the optical system comprises: a projection optical unit configured to guide a structure-producing writing light beam into a writing focus in a region of a substrate surface in a substrate plane; a deflection device configured to deflect the writing focus of the writing light beam within a writing field in the region of the substrate surface; a preview optical unit configured to image a preview field in the region of the substrate surface, the preview field having an area at least 10 times greater than an area of the writing field, the projection optical unit and the preview optical unit being carried by a common frame; a substrate holder displaceable in a plane parallel to the substrate surface with two degrees of translational freedom; and a control unit comprising a memory configured to store coordinates of a position of the writing field relative to a position of the preview field. ### Claim 12 (depends on 11) The method of claim 11, further comprising a process camera configured to capture the writing field via the beam path of the writing light beam in the projection optical unit. ### Claim 13 (depends on 11) The method of claim 11, wherein the projection optical unit is displaceable relative to the preview optical unit in a direction perpendicular to the substrate plane. ### Claim 14 (depends on 11) The method of claim 11, further comprising an autofocusing device configured to determine a focal plane of: a) the projection optical unit; and/or b) the preview optical unit. ### Claim 15 (depends on 11) The method of claim 11, wherein the projection optical unit has an image-side numerical aperture which is greater than one. ### Claim 16 (depends on 11) The method of claim 11, wherein the preview optical unit has an image-side numerical aperture which is less than 0.1. ### Claim 17 (depends on 11) The method of claim 11, further comprising a light source configured to produce writing light. ### Claim 18 (depends on 11) The method of claim 11, further comprising the common frame. ### Claim 19 (depends on 11) The method of claim 11, wherein the projection optical unit has an image-side numerical aperture which is greater than one, and the preview optical unit has an image-side numerical aperture which is less than 0.1. ### Claim 20 (depends on 12) The method of claim 12, wherein the projection optical unit has an image-side numerical aperture which is greater than one, and the preview optical unit has an image-side numerical aperture which is less than 0.1.