Actuator System Using Multiple Piezoelectric Actuators

• US 20100026976A1
• Filed: 07/24/2009
• Published: 02/04/2010
• Est. Priority Date: 07/30/2008
• Status: Active Grant

• Current Assignee: ASML Holding NV
• Original Assignee: ASML Holding NV
• Inventors: Scipione, Fred Joseph, Meehan, Michael F.
• Granted Patent: US 8,446,562 B2
• Time in Patent Office: Days
• US Class Current: 355/55
• CPC Class Codes: G02B 7/005 Motorised alignment
• CPC Class Codes: G03F 7/70258 Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system
• CPC Class Codes: G03F 7/70825 Mounting of individual elements, e.g. mounts, holders or supports workpiece or mask holders G03F7/707

Abstract

A positioning system adjusts a position of an optical element within an optical device, such as a variable-zoom lens system. A frame supports the optical element, and an elongated surface of each of one or more elongated support structures supports the frame. The frame also supports one or more piezoelectric actuators that, respectively, engage one of the elongated support structures. A controller supplies a control signal to activate each of the one or more actuator modules. Upon activation, a piezoelectric element of each of the activated actuator modules applies a combination of a first force and a second force to an elongated surface of the respective elongated support structures to position the frame along the elongated surface. The combination of forces applied by the piezoelectric element advances the piezoelectric actuator module along the elongated support structure.

Claims

1. A system for positioning an optical element within an optical device, comprising:

a frame configured to support the optical element;

one or more elongated support structures, wherein each of the one or more elongated support structures comprises at least one elongated surface configured to support the frame;

one or more actuator modules, wherein each of the one or more actuator modules is supported by the frame and configured to engage a respective one of the one or more elongated support structures, each of the one or more actuator modules comprises at least one piezoelectric element configured to (i) apply a first force to the at least one elongated surface of the respective one of the one or more elongated support structures in a direction substantially perpendicular to the at least one elongated surface and (ii) apply a second force to the at least one elongated surface of the respective one of the one or more elongated support structures in a direction substantially parallel to the at least one elongated surface; and

a controller configured to supply a control signal to activate each of the one or more actuator modules,

whereby the at least one piezoelectric element of each activated one of the one or more actuator modules applies a combination of the first and second forces to the at least one elongated surface of the respective one of the one or more elongated support structures to position the frame along the at least one elongated surface.

2. The system of claim 1, wherein each of the one or more elongated support structures has one of a prismatic cross section, a cylindrical cross section, or a semi-cylindrical cross section.

3. The system of claim 1, wherein each of the one or more elongated support structures has a triangular cross section.

4. The system of claim 1, wherein:

the one or more elongated support structures comprises three elongated support structures; and

an elongated axis of each of the three elongated support structures is substantially parallel to an optical axis of the optical device.

5. The system of claim 1, wherein the at least one piezoelectric element of each activated one of the one or more actuator modules sequentially applies the first and second forces to the at least one elongated surface of the respective one of the one or more elongated support structures.

6. The system of claim 1, wherein the at least one piezoelectric element of each activated one of the one or more actuator modules applies an identical combination of the first and second forces to the at least one elongated surface of the respective one of the one or more elongated support structures.

7. The system of claim 1, wherein:

the frame comprises a linear encoder configured to measure a position of the frame along a corresponding one or the elongated support structures; and

the control signal provided to each of the one or more actuator modules is based on measurements made by the linear encoder module.

8. The system of claim 1, further comprising:

one or more additional frames respectively configured to support a corresponding additional optical element, wherein each of the one or more additional frames is supported by the one or more elongated support structures; and

one or more additional actuator modules, wherein each of the one or more additional actuator modules is supported by a respective one of the one or more additional frames and configured to engage a respective one of the elongated support.

9. The system of claim 1, wherein the controller supplies an identical respective one of the control signal to each of the one or more actuator modules.

10. The system of claim 1, wherein the optical element is a lens element and the optical device is a set of telescoping zoom optics.

11. A lithographic apparatus, comprising:

a support structure configured to support a pattern device that is configured to pattern a beam of radiation from an illumination system;

a projection system configured to project the patterned beam towards a substrate support configured to support a substrate, the projection system comprising a system for positioning an optical element, the system comprising;

a frame configured to support the optical element;

one or more elongated support structures, wherein each of the one or more elongated support structures comprises at least one elongated surface configured to support the frame;

one or more actuator modules, wherein each of the one or more actuator modules is supported by the frame and configured to engage a respective one of the one or more elongated support structures, each of the one or more actuator modules comprises at least one piezoelectric element configured to (i) apply a first force to the at least one elongated surface of the respective one of the one or more elongated support structures in a direction substantially perpendicular to the at least one elongated surface and (ii) apply a second force to the at least one elongated surface of the respective one of the one or more elongated support structures in a direction substantially parallel to the at least one elongated surface; and

a controller configured to supply a control signal to activate each of the one or more actuator modules,

whereby the at least one piezoelectric element of each activated one of the one or more actuator modules applies a combination of the first and second forces to the at least one elongated surface of the respective one of the one or more elongated support structures to position the frame along the at least one elongated surface.

12. The lithographic apparatus of claim 11, wherein each of the one or more elongated support structures has one of a prismatic cross section, a cylindrical cross section, or a semi-cylindrical cross section.

13. The lithographic apparatus of claim 11, wherein each of the one or more elongated support structures has a triangular cross section.

14. The lithographic apparatus of claim 11, wherein the at least one piezoelectric element of each activated one of the one or more actuator modules sequentially applies the first and second forces to the at least one elongated surface of the respective one of the one or more elongated support structures.

15. The lithographic apparatus of claim 11, wherein the at least one piezoelectric element of each activated one of the one or more actuator modules applies an identical combination of the first and second forces to the at least one elongated surface of the respective one of the one or more elongated support structures.

16. The lithographic apparatus of claim 11, wherein:

the frame comprises a linear encoder configured to measure a position of the frame along a corresponding one or the elongated support structures; and

the control signal provided to each of the one or more actuator modules is based on measurements made by the linear encoder module.

17. The lithographic apparatus of claim 11, further comprising:

one or more additional frames respectively configured to support a corresponding additional optical element, wherein each of the one or more additional frames is supported by the one or more elongated support structures; and

one or more additional actuator modules, wherein each of the one or more additional actuator modules is supported by a respective one of the one or more additional frames and configured to engage a respective one of the elongated support.

18. The lithographic apparatus of claim 11, wherein the controller supplies an identical respective one of the control signal to each of the one or more actuator modules.

19. The lithographic apparatus of claim 11, wherein the optical element is a lens element and the optical device is a set of telescoping zoom optics.

20. A method for positioning an optical element within an optical device, comprising:

measuring one or more of a longitudinal position of the optical element, a lateral position of the optical element, and a rotation of the optical element;

applying a combination of a first force and a second force to at least one elongated surface of a respective one of a plurality of elongated support structures in response to the measured one or more of the longitudinal position, lateral position, and rotation, the plurality of elongated support structures being configured to support the optical element within the optical device; and

adjusting one or more of the longitudinal position, the lateral position, and the rotation of the optical element using at least the applied combination of the first force and the second force.

21. The method of claim 20, further comprising:

generating a control signal based on the measured longitudinal position, lateral position, and rotation; and

applying a combination of a first force and a second force to the at least one elongated surface based on at least the generated control signal.

22. The method of claim 20, wherein the applying step comprises:

applying the first force in a direction substantially perpendicular to the at least one elongated surface; and

applying the second force being in a direction substantially parallel to the at least one elongated surface.

23. The method of claim 20, wherein the measuring step comprises:

measuring the longitudinal position of the optical element in a direction substantially parallel to an optical axis of the optical device;

measuring the lateral position of the optical element in a direction substantially perpendicular to the optical axis of the optical device; and

measuring the rotation of the optical device about any axis substantially perpendicular to the optical axis of the optical device.