Method of calibrating a reluctance actuator assembly, reluctance actuator and lithographic apparatus comprising such reluctance actuator

Patent metadata

Field	Value
Publication number	US-10372045-B2
Application number	US-201314428287-A
Country	US
Kind code	B2
Filing date	Aug 26, 2013
Priority date	Sep 19, 2012
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

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.

First claim

What is claimed is:

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.

2. 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.

3. 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.

4. 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.

5. 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.

6. The linear reluctance actuator according to claim 1 , comprising four teeth and four coils.

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.

8. The lithographic apparatus according to claim 7 , wherein the reluctance actuator comprises at least four teeth and four coils.

9. 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.

10. 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.

11. 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.

12. The lithographic apparatus according to claim 7 , wherein each coil of the plurality of coils is positioned around a respective one of the teeth.

13. 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.

Assignees

• Asml Netherlands Bv

Inventors

• Akkermans Johannes Antonius Gerardus
• Lemmen Bas Pieter
• Huiberts Sjoerd Martijn
• Lof Joeri
• Rutgers Petrus Theodorus
• Hol Sven Antoin Johan
• Singh Harmeet
• Heijmans Peter Michel Silvester Maria

Classifications

• H02K11/20

  for measuring, monitoring, testing, protecting or switching (rectifiers H02K11/04; power electronics H02K11/33) · CPC title

• G03F7/70725 Primary

  control · CPC title

• H02P25/034

  Voice coil motors (voice coil motors driven by DC H02P7/025) · CPC title

• G03F7/70758

  Drive means, e.g. actuators, motors for long- or short-stroke modules or fine or coarse driving · CPC title

• H02P6/16

  Circuit arrangements for detecting position · CPC title