# US 8,771,906 B2 · Method and system for forming a pattern using charged particle beam lithography with multiple exposure passes which expose different surface area > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,906 B2 - Document ID: US8771906B2 - Status: Granted - Kind: B2 - Application number: 13/947,242 - Filed: 2013-07-22 - Published: 2013-11-21 - Granted: 2014-07-08 - Earliest claimed: 2009-12-26 - Assignees: D2S, Inc. - Applicants: D2S, Inc. - Inventors: Harold Robert Zable; Akira Fujimura - Web page: https://patentgrep.com/patent/US8771906B2 ## CPC - G03F 7/2061: {Electron scattering (proximity) correction or prevention methods} - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - B82Y 40/00: Manufacture or treatment of nanostructures - G03F 1/36: Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes - G03F 1/78: by charged particle beam [CPB], e.g. electron beam patterning of masks - G03F 7/2063: {for the production of exposure masks or reticles} - G06F 30/00: Computer-aided design [CAD] - H01J 37/3026: {Patterning strategy} - H01J 37/3174: {Particle-beam lithography, e.g. electron beam lithography} - H01J 37/3175: {Projection methods, i.e. transfer substantially complete pattern to substrate} - H01J 2237/31764: Dividing into sub-patterns - H01J 2237/31776: Shaped beam - Y10S 430/143: Electron beam - 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) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract In the field of semiconductor production using charged particle beam lithography, a method and system for fracturing or mask data preparation or proximity effect correction is disclosed, in which the union of shots from one of a plurality of exposure passes is different than the union of shots from a different exposure pass. Methods for manufacturing a reticle and manufacturing an integrated circuit are also disclosed, in which the union of shots from one of a plurality of charged particle beam exposure passes is different than the union of shots from a different exposure pass. ## Claims ### Claim 1 A method for fracturing or mask data preparation or proximity effect correction for charged particle beam lithography comprising: determining a plurality of shaped beam shots for each of the plurality of exposure passes of a shaped beam charged particle beam system, wherein the union of the plurality of shaped beam shots for any exposure pass in the plurality of exposure passes is different than the union of the pluralities of shaped beam shots for all of the exposure passes. ### Claim 2 (depends on 1) The method of claim 1 wherein shots in the plurality of shaped beam shots for each of the plurality of exposure passes have assigned shot dosages. ### Claim 3 (depends on 1) The method of claim 1 wherein a shaped beam shot in the plurality of shaped beam shots for an exposure pass is square. ### Claim 4 (depends on 3) The method of claim 3 wherein all shaped beam shots for all the exposure passes are square. ### Claim 5 (depends on 1) The method of claim 1 wherein the shaped beam charged particle beam system comprises a charged particle beam source and an aperture plate, wherein the aperture plate comprises a single aperture which the charged particle beam source illuminates. ### Claim 6 (depends on 1) The method of claim 1 wherein the shaped beam charged particle beam system comprises a charged particle beam source and an aperture plate, wherein the aperture plate comprises a plurality of apertures which the charged particle beam source illuminates. ### Claim 7 (depends on 1) The method of claim 1 wherein shots in a subset of the plurality of shaped beam shots in at least one of the plurality of exposure passes overlap each other. ### Claim 8 (depends on 1) The method of claim 1 wherein for an exposure pass in the plurality of exposure passes, shots in the plurality of shaped beam shots are disjoint. ### Claim 9 (depends on 1) The method of claim 1 wherein the determining comprises using charged particle beam simulation. ### Claim 10 (depends on 9) The method of claim 9 wherein the charged particle beam simulation includes at least one of the group consisting of forward scattering, backward scattering, resist diffusion, Coulomb effect, etching, fogging, loading and resist charging. ### Claim 11 (depends on 1) The method of claim 1 wherein the determining is performed using a computing hardware processor. ### Claim 12 A method for forming a set of patterns on a surface using a shaped beam charged particle beam system, the method comprising: exposing a plurality of shaped beam shots for each of a plurality of exposure passes, wherein the union of the plurality of shaped beam shots for any exposure pass in the plurality of exposure passes is different than the union of the pluralities of shaped beam shots for all of the exposure passes. ### Claim 13 (depends on 12) The method of claim 12 wherein in the exposing, shots in the plurality of shaped beam shots for the exposure pass have assigned shot dosages. ### Claim 14 (depends on 12) The method of claim 12 wherein a shaped beam shot in the plurality of shaped beam shots for an exposure pass is square. ### Claim 15 (depends on 14) The method of claim 14 wherein all shaped beam shots for all the exposure passes are square. ### Claim 16 (depends on 12) The method of claim 12 wherein the shaped beam charged particle beam system comprises a charged particle beam source and an aperture plate, wherein the aperture plate comprises a single aperture which the charged particle beam source illuminates. ### Claim 17 (depends on 12) The method of claim 12 wherein the shaped beam charged particle beam system comprises a charged particle beam source and an aperture plate, wherein the aperture plate comprises a plurality of apertures which the charged particle beam source illuminates. ### Claim 18 (depends on 12) The method of claim 12 wherein in the exposing, shots in a subset of the plurality of shaped beam shots overlap each other, for at least one of the exposure passes. ### Claim 19 (depends on 12) The method of claim 12 wherein the surface is a semiconductor wafer, the method further comprising using the set of patterns on the wafer to manufacture an integrated circuit. ### Claim 20 A method for manufacturing an integrated circuit using an optical lithographic process, the optical lithographic process using a reticle, the method comprising: a) providing a shaped beam charged particle beam system; b) setting a base dosage level for an exposure pass; c) exposing a plurality of shaped beam shots for the exposure pass using the set base dosage level; and d) repeating b) and c) for at least one additional exposure pass, wherein the sum of the pluralities of shots for all of the exposure passes forms a set of desired patterns on the reticle, and wherein the union of the plurality of shaped beam shots for any exposure pass is different than the union of the pluralities of shaped beam shots for all of the exposure passes. ### Claim 21 (depends on 20) The method of claim 20 wherein the shaped beam charged particle beam system comprises a charged particle beam source and an aperture plate, wherein the aperture plate comprises a single aperture which the charged particle beam source illuminates. ### Claim 22 (depends on 20) The method of claim 20 wherein the shaped beam charged particle beam system comprises a charged particle beam source and an aperture plate, wherein the aperture plate comprises a plurality of apertures which the charged particle beam source illuminates. ### Claim 23 (depends on 20) The method of claim 20 wherein a shaped beam shot in the plurality of shaped beam shots for an exposure pass is square. ### Claim 24 A method for fracturing or mask data preparation or proximity effect correction for shaped beam charged particle beam lithography comprising: determining a plurality of shaped beam shots for each of a plurality of exposure passes of a shaped beam charged particle beam system, wherein a shaped beam shot in one exposure pass overlaps a shaped beam shot in a different exposure pass, and wherein a shaped beam shot in each exposure pass covers area uniquely covered in that exposure pass only. ### Claim 25 (depends on 24) The method of claim 24 wherein the determining comprises using charged particle beam simulation. ### Claim 26 (depends on 24) The method of claim 24 wherein the shaped beam charged particle beam system comprises a charged particle beam source and an aperture plate, wherein the aperture plate comprises a plurality of apertures which the charged particle beam source illuminates. ### Claim 27 A method for forming a set of patterns on a surface using a shaped beam charged particle beam system, the method comprising: exposing a plurality of shaped beam shots for each of a plurality of exposure passes, wherein a shaped beam shot in one exposure pass overlaps a shaped beam shot in a different exposure pass, and wherein a shot in each exposure pass covers area uniquely covered in that exposure pass only. ### Claim 28 (depends on 27) The method of claim 27 wherein the shaped beam charged particle beam system comprises a charged particle beam source and an aperture plate, wherein the aperture plate comprises a plurality of apertures which the charged particle beam source illuminates. ### Claim 29 A system for fracturing or mask data preparation or proximity effect correction for use with shaped beam charged particle beam lithography comprising: an input device configured to receive a set of patterns to be formed on a surface; a computation device configured to determine a set of shaped beam shots that can be used to form the set of patterns using a plurality of exposure passes, wherein the set of shaped beam shots comprises a plurality of shaped beam shots for each of a plurality of exposure passes, and wherein the union of the plurality of shaped beam shots for any exposure pass in the plurality of exposure passes is different than the union of the pluralities of shaped beam shots for all of the exposure passes; and an output device configured to output the determined set of shaped beam shots. ### Claim 30 (depends on 29) The system of claim 29 wherein a shaped beam shot in the set of shaped beam shots is square. ### Claim 31 (depends on 30) The system of claim 30 wherein all shaped beam shots in the set of shaped beam shots are square. ### Claim 32 (depends on 29) The system of claim 29 wherein the computation device is configured to determine a set of shaped beam shots for a shaped beam charged particle beam system which comprises a charged particle beam source and an aperture plate, wherein the aperture plate comprises a plurality of apertures which the charged particle beam source illuminates.