# US 8,570,535 B2 · Pattern generators, calibration systems and methods for patterning workpieces > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,535 B2 - Document ID: US8570535B2 - Status: Granted - Kind: B2 - Application number: 13/064,067 - Filed: 2011-03-03 - Published: 2011-09-15 - Granted: 2013-10-29 - Earliest claimed: 2010-03-03 - Assignees: Micronic Mydata AB - Applicants: Anders Svensson; Fredrik Jonsson - Inventors: Anders Svensson; Fredrik Jonsson - Web page: https://patentgrep.com/patent/US8570535B2 ## CPC - G03F 9/7019: {Calibration} - G03F 7/70775: {Position control, e.g. interferometers or encoders for determining the stage position} - G03F 7/7085: {Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load} - G03F 9/7049: {Technique, e.g. interferometric} - G03F 9/7076: {Mark details, e.g. phase grating mark, temporary mark} - 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 pattern generator includes: a writing tool and a calibration system. The writing tool is configured to generate a pattern on a workpiece arranged on a stage. The calibration system is configured to determine a correlation between a coordinate system of the writing tool and a coordinate system of a calibration plate on one of the stage and the workpiece. The calibration system is also configured to determine the correlation at least partly based on an optical correlation signal, or pattern, in a form of at least one optical beam being reflected from at least one reflective pattern on the surface of the calibration plate. ## Claims ### Claim 1 A pattern generator comprising: a writing tool configured to generate a pattern on a workpiece arranged on a stage; and a calibration system configured to determine a correlation between a coordinate system of the writing tool and a coordinate system of a calibration plate on one of the stage and the workpiece; wherein the calibration system is further configured to determine the correlation at least partly based on an optical correlation signal, or pattern, in a form of at least one optical beam reflected from at least one reflective pattern on a surface of the calibration plate; wherein the at least one reflective pattern has areas of differing reflectance, and the calibration plate is configured to reflect an optical beam for calibrating the spatial position, focus and dose of the optical beam. ### Claim 2 (depends on 1) The pattern generator of claim 1, wherein the calibration system is configured to determine the correlation while the writing tool is generating the pattern on the workpiece, and wherein the pattern generator is configured to perform real-time alignment of the pattern generated on the workpiece based on the correlation between the coordinate system of writing tool and the coordinate system of the calibration plate. ### Claim 3 (depends on 1) The pattern generator of claim 1, wherein the correlation between the coordinate system of the writing tool and the coordinate system of the calibration plate is determined at least partly prior to generating the pattern on the workpiece. ### Claim 4 (depends on 3) The pattern generator of claim 3, wherein the calibration system is a separate measurement system configured to emit, toward the calibration plate, at least one optical beam arranged in a pattern matching at least one reflective pattern on the calibration plate, and wherein the at least one optical beam reflected from the at least one reflective pattern on the calibration plate is further used to determine the correlation between the coordinate system of the writing tool and the coordinate system of the calibration plate. ### Claim 5 (depends on 1) The pattern generator of claim 1, wherein the correlation between the coordinate system of the writing tool and the coordinate system of the calibration plate is determined at least partly during the generating of the pattern on the workpiece. ### Claim 6 (depends on 1) The pattern generator of claim 1, wherein the correlation between the coordinate system of the writing tool and the coordinate system of the calibration plate is determined at least partly in between strokes of at least one writing unit of the writing tool generating the pattern on the workpiece. ### Claim 7 (depends on 4) The pattern generator of claim 4, wherein the correlation is determined at least partly in between writing sweeps of one rotor arm. ### Claim 8 (depends on 4) The pattern generator of claim 4, wherein the correlation is determined at least partly in between writing sweeps of two separate rotor arms. ### Claim 9 (depends on 1) The pattern generator of claim 1, wherein the calibration system is further configured to emit, toward the calibration plate, at least one optical beam arranged in a pattern matching at least one reflective pattern on the calibration plate, and wherein the at least one optical beam reflected from the at least one reflective pattern on the calibration plate is further used by the calibration system to determine the correlation between the coordinate system of the writing tool and the coordinate system of the calibration plate. ### Claim 10 (depends on 1) The pattern generator of claim 1, further comprising: a separate measurement system configured to emit an optical beam arranged in a pattern matching at least one reflective pattern on the calibration plate, and wherein the at least one optical beam reflected from the at least one reflective pattern on the calibration plate is used by the calibration system to determine the correlation between the coordinate system of the writing tool and the coordinate system of the calibration plate. ### Claim 11 (depends on 1) The pattern generator of claim 1, wherein while generating the pattern on the workpiece, the pattern generator is configured to perform real-time alignment of the pattern based on the correlation between the coordinate system of writing tool and the coordinate system of the calibration plate. ### Claim 12 (depends on 11) The pattern generator of claim 11, wherein the optical beam includes a line image, and the at least one reflective pattern is configured to match the line image of the optical beam. ### Claim 13 (depends on 12) The pattern generator of claim 12, wherein the optical beam includes a plurality of ray pencils arranged in a pattern matching the at least one reflective pattern. ### Claim 14 (depends on 12) The pattern generator of claim 12, wherein the line image is an SLM line image. ### Claim 15 (depends on 12) The pattern generator of claim 12, further comprising: at least one optical detector configured to sample the reflected optical beam. ### Claim 16 (depends on 12) The pattern generator of claim 12, wherein the at least one reflective pattern and matching line image are configured to provide a single peak in a resulting correlation signal. ### Claim 17 (depends on 12) The pattern generator of claim 12, wherein the at least one reflective pattern is configured according to a Barker or Barker-like coding scheme. ### Claim 18 (depends on 12) The pattern generator of claim 12, wherein the optical beam includes a set of ray pencils arranged in a one-dimensional pattern. ### Claim 19 (depends on 18) The pattern generator of claim 18, wherein the calibration plate further comprises: a plurality of horizontal reflective patterns matching the one-dimensional pattern of the optical beam; and a plurality of sets of vertical reflective bars having a set of slanted reflective patterns interlaced between each pair of adjacent set of vertical reflective bars, each set of slanted reflective patterns including a plurality of slanted bars arranged to match the one-dimensional pattern of the optical beam. ### Claim 20 (depends on 19) The pattern generator of claim 19, wherein the calibration plate further comprises: a plurality of diffuse pads for calibrating focus sensors by measuring a surface topology of the calibration plate; a chirped raster for calibration of focus by measuring a modulation of the reflected optical beam; a plurality of verification pads for verifying a calibration and verification of timing of pattern exposure; a plurality of lines arranged in a fan-like pattern, for measurement of the angular orientation of the calibration plate; and a plurality of offset calibration areas for calibrating a timing offset of the calibration plate. ### Claim 21 (depends on 19) The pattern generator of claim 19, wherein the plurality of slanted reflective patterns and the plurality of sets of vertical reflective bars are interlaced along a trajectory traversed by the optical beam. ### Claim 22 (depends on 12) The pattern generator of claim 12, wherein the writing tool is a rotor including at least one rotor arm, the system further comprising: a laser source configured to emit the optical beam; a rotating prism configured to direct the optical beam to the at least one rotor arm; and a reflector configured to reflect the optical signal toward the calibration plate. ### Claim 23 (depends on 1) The pattern generator of claim 1, wherein the stage is a cylindrical stage. ### Claim 24 (depends on 1) The pattern generator of claim 1, wherein the writing tool is a helix writing tool. ### Claim 25 (depends on 1) The pattern generator of claim 1, wherein the pattern is generated on the workpiece by roll-to-roll printing. ### Claim 26 (depends on 1) The pattern generator of claim 1, wherein separate optical beams are used for generating the pattern on the workpiece and for performing real-time alignment of the pattern on the workpiece.