# US 12,181,792 B2 · Optical proximity correction method and method of manufacturing extreme ultraviolet mask by using the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,792 B2 - Document ID: US12181792B2 - Status: Granted - Kind: B2 - Application number: 17/651,627 - Filed: 2022-02-18 - Published: 2022-12-29 - Granted: 2024-12-31 - Earliest claimed: 2021-06-29 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Narak Choi; Dongwon Kang - Web page: https://patentgrep.com/patent/US12181792B2 ## CPC - G03F 1/36: Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes - G03F 7/70308: {Optical correction elements, filters or phase plates for manipulating imaging light, e.g. intensity, wavelength, polarisation, phase or image shift} - 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 proximity correction (OPC) method of effectively imitating a mask topography effect for a mask having a curvilinear pattern includes generating a library for edge filters of a near field by using an electromagnetic field simulation; generating an any-angle edge filter by using the library; for a mask having a curvilinear pattern, generating a first mask image by using thin mask approximation; determining whether the curvilinear pattern satisfies a reference; when the curvilinear pattern satisfies the reference, performing skewed Manhattanization on the curvilinear pattern and then generating a second mask image by applying the any-angle edge filter to edges of the curvilinear pattern. ## Claims ### Claim 1 An optical proximity correction (OPC) method, comprising: generating a library for edge filters of a near field by using an electromagnetic field simulation; generating an any-angle edge filter by using the library; for a mask having a curvilinear pattern, generating a first mask image by using thin mask approximation; determining whether the curvilinear pattern satisfies a reference; and when the curvilinear pattern satisfies the reference, performing skewed Manhattanization on the curvilinear pattern and then generating a second mask image by applying the any-angle edge filter to edges of the curvilinear pattern. ### Claim 2 (depends on 1) The OPC method of claim 1, wherein the skewed Manhattanization comprises: rotating the curvilinear pattern in a first direction by an azimuthal angle difference of a chief-ray between a center of a mask slit and a periphery of the mask slit; performing Manhattanization on the curvilinear pattern; and rotating edges of the curvilinear pattern generated by the Manhattanization in a second direction, opposite the first direction, by the azimuthal angle difference, wherein, in the generating of the second mask image, the any-angle edge filter is applied to the rotated edges. ### Claim 3 (depends on 2) The OPC method of claim 2, wherein, in the performing of the Manhattanization, the edges of the curvilinear pattern are divided into straight edges, wherein, in the rotating in the second direction, the straight edges are rotated in the second direction by the azimuthal angle difference, and wherein the rotated straight edges are perpendicular to or parallel with an azimuthal angle of the chief-ray on the periphery of the mask slit. ### Claim 4 (depends on 2) The OPC method of claim 2, wherein the reference is a size of the curvilinear pattern, an angle between adjacent edges, or a curvature of the curvilinear pattern, or any combination thereof. ### Claim 5 (depends on 2) The OPC method of claim 2, wherein the azimuthal angle of the chief-ray at the center of the mask slit is about 270°, azimuthal angles of the chief-ray at outermost portions on both sides of the mask slit are about 250° and about 290°, respectively, and wherein the azimuthal angle difference is within a range of about −20° to about 20°. ### Claim 6 (depends on 1) The OPC method of claim 1, wherein the any-angle edge filter is generated as a combination of a vertical filter with a horizontal filter. ### Claim 7 (depends on 1) The OPC method of claim 1, wherein the near field comprises a near field of extreme ultraviolet (EUV) light, and wherein a polar angle of the chief-ray is about 6°. ### Claim 8 (depends on 1) The OPC method of claim 1, wherein the electromagnetic field simulation comprises a finite difference time domain (FDTD) simulation. ### Claim 9 (depends on 1) The OPC method of claim 1, further comprising: after the generating of the second mask image, generating a final mask image by adding the second mask image to the first mask image; and generating an optical OPC model by using the final mask image. ### Claim 10 (depends on 1) The OPC method of claim 1, further comprising: when the curvilinear pattern does not satisfy the reference, generating the second mask image by applying the any-angle edge filter to the edges of the curvilinear pattern. ### Claim 11 A method of manufacturing an extreme ultraviolet (EUV) mask, comprising: generating a library for edge filters of a near field by using an electromagnetic field simulation; generating an any-angle edge filter by using the library; generating a first mask image by applying a thin mask approximation to a mask of a curvilinear pattern; determining whether the curvilinear pattern satisfies a reference; when the curvilinear pattern satisfies the reference, performing skewed Manhattanization to the curvilinear pattern and then generating a second mask image by applying the any-angle edge filter to edges of the curvilinear pattern; generating a final mask image by adding the second mask image to the first mask image; and exposing an EUV mask substrate by using the final mask image. ### Claim 12 (depends on 11) The method of claim 11, wherein the skewed Manhattanization comprises: rotating the curvilinear pattern in a first direction by an azimuthal angle difference of a chief-ray between a center of a mask slit and a periphery of the mask slit; performing Manhattanization on the curvilinear pattern; and rotating edges of the curvilinear pattern generated by the Manhattanization in a second direction, opposite the first direction, by the azimuthal angle difference, wherein, in the generating of the second mask image, the any-angle edge filter is applied to the rotated edges. ### Claim 13 (depends on 12) The method of claim 12, wherein, in the performing of the Manhattanization, the edges of the curvilinear pattern are divided into straight edges, wherein, in the rotating in the second direction, the straight edges are rotated in the second direction by the azimuthal angle difference, and wherein the rotated straight edges are perpendicular to or parallel with an azimuthal angle of the chief-ray on the periphery of the mask slit. ### Claim 14 (depends on 12) The method of claim 12, wherein the reference is a size of the curvilinear pattern, an angle between adjacent edges, or a curvature of the curvilinear pattern or any combination thereof. ### Claim 15 (depends on 12) The method of claim 12, wherein the near field comprises a near field of extreme ultraviolet (EUV) light, wherein a polar angle of the chief-ray is about 6°, wherein the azimuthal angle of the chief-ray at the center of the mask slit is about 270°, and the azimuthal angles of the chief-ray at outermost portions on both sides of the mask slit are about 250° and about 290°, respectively. ### Claim 16 A method of manufacturing an extreme ultraviolet (EUV) mask, comprising: generating a library for edge filters of a near field by using an electromagnetic field simulation; generating an any-angle edge filter by using the library; generating a first mask image by applying a thin mask approximation to a mask of a curvilinear pattern; determining whether the curvilinear pattern satisfies a reference; when the curvilinear pattern satisfies the reference, performing a skewed Manhattanization on the curvilinear pattern and then generating a second mask image by applying the any-angle edge filter to edges of the curvilinear pattern; generating a final mask image by adding the second mask image to the first mask image; and performing a simulation by reflecting data of the final mask image to an optical proximity correction (OPC) model; transferring design data obtained by the simulation as mask tape-out (MTO) design data; preparing mask data based on the MTO design data; and exposing an EUV mask substrate based on the mask data. ### Claim 17 (depends on 16) The method of claim 16, wherein the skewed Manhattanization comprises: rotating the curvilinear pattern in a first direction by an azimuthal angle difference of a chief-ray between a center of a mask slit and a periphery of the mask slit; performing Manhattanization on the curvilinear pattern; and rotating edges of the curvilinear pattern generated by the Manhattanization in a second direction, opposite the first direction, by the azimuthal angle difference, wherein the rotated edges are perpendicular to or parallel with an azimuthal angle of the chief-ray on the periphery of the mask slit. ### Claim 18 (depends on 17) The method of claim 17, wherein, in the performing of the Manhattanization, the edges of the curvilinear pattern are divided into vertical and horizontal edges, wherein, in the rotating in the second direction, the vertical and horizontal edges are rotated in the second direction by the azimuthal angle difference, wherein, in the applying of the any-angle edge filter, the any-angle edge filter is applied to the rotated vertical and horizontal edges. ### Claim 19 (depends on 17) The method of claim 17, wherein the reference is a size of the curvilinear pattern, an angle between adjacent edges, or a curvature of the curvilinear pattern, or any combination thereof. ### Claim 20 (depends on 17) The method of claim 17, wherein the near field comprises a near field of extreme ultraviolet (EUV) light, wherein a polar angle of the chief-ray is about 6°, wherein the azimuthal angle of the chief-ray at the center of the mask slit is about 270°, and the azimuthal angles of the chief-ray at outermost portions on both sides of the mask slit are about 250° and about 290°, respectively.