# US 10,372,045 B2 · Method of calibrating a reluctance actuator assembly, reluctance actuator and lithographic apparatus comprising such reluctance actuator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,372,045 B2 - Document ID: US10372045B2 - Status: Granted - Kind: B2 - Application number: 14/428,287 - Filed: 2013-08-26 - Published: 2015-08-20 - Granted: 2019-08-06 - Earliest claimed: 2012-09-19 - Assignees: ASML Netherlands B.V. - Applicants: ASML Netherlands B.V. - Inventors: Johannes Antonius Gerardus Akkermans; Bas Pieter Lemmen; Sjoerd Martijn Huiberts; Joeri Lof; Petrus Theodorus Rutgers; Sven Antoin Johan Hol; Harmeet Singh; Peter Michel Silvester Maria Heijmans - Web page: https://patentgrep.com/patent/US10372045B2 ## CPC - G03F 7/70725: {control} - G03F 7/22: Exposing sequentially with the same light pattern different positions of the same surface {(G03F7/70 takes precedence)} - G03F 7/70758: {Drive means, e.g. actuators, motors for long- or short-stroke modules or fine or coarse driving} - H01F 7/081: {Magnetic constructions} - H01F 7/1646: {Armatures or stationary parts of magnetic circuit having permanent magnet} - H02K 11/20: for measuring, monitoring, testing, protecting or switching (rectifiers H02K11/04; power electronics H02K11/33) - H02K 41/025: Asynchronous motors - H02K 41/03: Synchronous motors; Motors moving step by step; Reluctance motors (H02K41/035 takes precedence) - H02K 41/033: {with armature and magnets on one member, the other member being a flux distributor} - H02P 6/16: Circuit arrangements for detecting position - H02P 25/034: Voice coil motors (voice coil motors driven by DC H02P7/025) - H02P 25/06: Linear motors - H02P 25/08: Reluctance motors - H02P 25/092: Converters specially adapted for controlling reluctance motors - 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) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A reluctance actuator assembly comprising a reluctance actuator, a flux sensor to measure a magnetic flux in a gap of the reluctance actuator, and a flux amplifier to drive an actuator coil of the reluctance actuator based on a flux set point and the flux measured by the flux sensor. A method comprising providing to the flux amplifier a flux setpoint, the flux setpoint comprising a time constant component and a sinusoidally varying component at an excitation frequency, measuring a force generated by the reluctance actuator in response to the flux setpoint, and calibrating the reluctance actuator assembly from the measured force. ## Claims ### Claim 1 A linear reluctance actuator comprising: a stator comprising: a stator yoke forming a closed magnetic path around a center space, a plurality of teeth in an X axis and Y axis of the linear reluctance actuator, each tooth of the plurality of teeth projecting from the stator yoke into the center space, and a plurality of coils, each coil of the plurality of coils being configured to generate a magnetic flux in respective ones of the teeth; and a mover arranged in the center space and displaceable relative to the stator yoke in the X axis and in the Y axis, the mover comprising a plurality of faces, each face of the plurality of faces facing a respective one of the teeth to form a gap between the mover and the respective one of the teeth, wherein each face of the plurality of faces has a surface facing a surface of the respective one of the plurality of teeth and the surfaces are substantially planar, wherein actuation of at least one coil results in a force in at least one of the X axis and Y axis of the linear reluctance actuator, thereby displacing the mover relative to the stator yoke in the at least one of the X and Y axis. ### Claim 2 (depends on 1) The linear reluctance actuator according to claim 1, further comprising a flux sensor per tooth, the flux sensor being provided in the gap between the mover and the tooth. ### Claim 3 (depends on 2) The linear reluctance actuator according to claim 2, further comprising a flux amplifier configured to drive the coils of the linear reluctance actuator based on a flux set point and the flux measured by the flux sensors. ### Claim 4 (depends on 1) The linear reluctance actuator according to claim 1, wherein each coil of the plurality of coils is positioned around a respective one of the teeth. ### Claim 5 (depends on 1) The linear reluctance actuator according to claim 1, wherein each coil of the plurality of coils is positioned around a respective part of the stator yoke between neighboring teeth. ### Claim 6 (depends on 1) The linear reluctance actuator according to claim 1, comprising four teeth and four coils. ### Claim 7 A lithographic apparatus arranged to transfer a pattern from a patterning device onto a substrate, the lithographic apparatus comprising: a movable object; and a reluctance actuator configured to move the movable object, the reluctance actuator comprising: a stator comprising: a stator yoke forming a closed magnetic path around a center space, a plurality of teeth in an X axis and Y axis of the reluctance actuator, each tooth of the plurality of teeth projecting from the stator yoke into the center space, and a plurality of coils, each coil of the plurality of coils being configured to generate a magnetic flux in respective ones of the teeth; and a mover arranged in the center space and displaceable relative to the stator yoke in the X axis and in the Y axis, the mover comprising a plurality of faces, each face of the plurality of faces facing a respective one of the teeth to form a gap between the mover and the respective one of the teeth, wherein actuation of at least one coil results in a force in at least one of the X axis and Y axis of the reluctance actuator, thereby displacing the mover relative to the stator yoke in the at least one of the X and Y axis. ### Claim 8 (depends on 7) The lithographic apparatus according to claim 7, wherein the reluctance actuator comprises at least four teeth and four coils. ### Claim 9 (depends on 8) The lithographic apparatus according to claim 8, wherein each of the four teeth of the reluctance actuator is oriented at an angle of substantially 45 degrees with respect to a scanning direction of the movable object. ### Claim 10 (depends on 7) The lithographic apparatus according to claim 7, wherein the reluctance actuator further comprises a flux sensor per tooth, the flux sensor being provided in the gap between the mover and the tooth. ### Claim 11 (depends on 7) The lithographic apparatus according to claim 7, wherein the reluctance actuator further comprises a flux amplifier configured to drive the coils of the reluctance actuator based on a flux set point and the flux measured by the flux sensors. ### Claim 12 (depends on 7) The lithographic apparatus according to claim 7, wherein each coil of the plurality of coils is positioned around a respective one of the teeth. ### Claim 13 (depends on 7) The lithographic apparatus according to claim 7, wherein each coil of the plurality of coils is positioned around a respective part of the stator yoke between neighboring teeth.