System and method for positioning an object

• US 20070023684A1
• Filed: 06/23/2005
• Published: 02/01/2007
• Est. Priority Date: 06/23/2005
• Status: Active Grant

• Current Assignee: George Lewis, Zelimir Krokar
• Original Assignee: George Lewis, Zelimir Krokar
• Inventors: Lewis, George, Krokar, Zelimir
• Granted Patent: US 7,298,495 B2
• Time in Patent Office: Days
• US Class Current: 250/442.110
• CPC Class Codes: H01J 2237/20292 Means for position and/or orientation registration
• CPC Class Codes: H01J 37/20 Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support

Abstract

A motion system includes a first stage that is configured to rotate about a first axis and a second stage coupled to the first stage that includes an object carrier adapted to position an object in at least one other axis. The motion system has a novel arrangement of laser interferometer elements and axes of motion. The arrangement permits accurate and precise measurement of a position of the object carrier in up to three (or more) axes of motion even as the first stage of the motion system is tilted through relatively large angles. The novel arrangement of the axes of motion also enables very precise control of the position of the object carrier even at high tilt angles.

Claims

1. A system for positioning an object, comprising:

a structural support member;

a first stage including (i) at least one rotational element coupled to the structural support member and (ii) a frame coupled to the at least one rotational element operable to rotate about a first axis through use of the at least one rotational element;

a second stage coupled to the first stage, the second stage having an object carrier adapted to move an object in a second axis; and

a laser metrology system configured (i) to direct a laser beam in a direction substantially on and parallel to the first axis and (ii) to measure a position of the object carrier.

2. The system according to claim 1 wherein the laser metrology system is further configured to direct the laser beam through the structural support member.

3. The system according to claim 1 wherein the second stage includes an X-stage and a Y-stage and wherein the laser metrology system includes optical elements that direct the laser beam to measure a position of the object carrier in respective X- and Y-axes.

4. The system according to claim 1 further including at least one Z-control mechanism that moves the first stage in a Z-axis direction and wherein the laser metrology system is adapted to direct the laser beam in a direction substantially on and parallel to the first axis for all first stage positions on the Z-axis.

5. The system according to claim 1 wherein an aggregate center of gravity of the first stage and the second stage is within 1 inch of the first axis.

6. The system according to claim 1 wherein the first stage includes a first rotational element and a second rotational element, and wherein the first rotational element is fixedly coupled to the structural support member and the second rotational element is variably coupled to the structural support member.

7. The system according to claim 1 wherein the first stage is adapted to rotate greater than one degree.

8. The system according to claim 1 further including an immobilization mechanism coupled to the first stage to restrict motion of the first stage.

9. The system according to claim 1 further including an alignment sensor adapted to detect an orientation of the object on the object carrier.

10. The system according to claim 1 further including at least one motion control processor coupled to the second stage that causes the second stage to move in a desired manner and wherein the at least one motion control processor receives feedback of the position of the object carrier from the laser metrology system.

11. The system according to claim 10 further including at least one other metrology system to measure a position of the object carrier or object, and wherein the at least one motion control processor receives feedback from the at least one other metrology system for use in controlling the position of the object carrier or object.

12. The system according to claim 1 used in an electron beam system, vacuum chamber, ion beam system, laser beam system, or automated manufacturing process.

13. A method of positioning an object, comprising:

directing a laser beam in a direction substantially on and parallel to a first axis about which a first stage rotates; and

measuring, through use of the laser beam, a position of an object carrier of a second stage, coupled to the first stage, adapted to move an object in a second axis.

14. The method according to claim 13 wherein directing the laser beam includes directing the laser beam through a structural support member to which the first stage is coupled.

15. The method according to claim 13 wherein measuring the position of the object carrier includes measuring the position of the object carrier in X- and Y-axes.

16. The method according to claim 13 further including moving the first stage in a Z-axis direction and wherein measuring the position of the object carrier includes directing the laser beam in a direction substantially on and parallel to the first axis for all first stage positions on the Z-axis.

17. The method according to claim 13 wherein an aggregate center of gravity of the first stage and the second stage is within 1 inch of the first axis.

18. The method according to claim 13 further including adjusting a coupling of the first stage to a structural support member at one of two locations at which the first stage is coupled to the structural support member.

19. The method according to claim 13 further including rotating the first stage greater than one degree.

20. The method according to claim 13 further including immobilizing the first stage to restrict motion of the first stage.

21. The method according to claim 13 further including detecting an orientation of the object on the object carrier.

22. The method according to claim 13 further including feeding back a position of the object carrier and causing the second stage to move in a desired manner based on feedback of the position of the object carrier.

23. The method according to claim 22 further including measuring a position of the object carrier or object separate from the feeding back of the position of the object carrier and controlling the position of the object carrier or object based on the measured position.

24. The method according to claim 13 used in an electron beam system, vacuum chamber, ion beam system, laser beam system, or automated manufacturing process.

25. A system for positioning an object, comprising:

means for directing a laser beam in a direction substantially on and parallel to a first axis about which a first stage rotates; and

means for measuring, through use of the laser beam, a position of an object carrier of a second stage, coupled to the first stage, adapted to move an object in a second axis.