POSITIONING STAGE SYSTEM AND POSITION MEASURING METHOD

• US 20020003629A1
• Filed: 04/07/1999
• Published: 01/10/2002
• Est. Priority Date: 04/08/1998
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: MATSUI, SHIN
• Granted Patent: US 6,404,505 B2
• Time in Patent Office: Days
• US Class Current: 356/614
• CPC Class Codes: G03F 7/70691 Handling of masks or workpieces
• CPC Class Codes: G03G 17/02 with electrolytic development
• CPC Class Codes: G03G 17/04 using photoelectrophoresis
• CPC Class Codes: G03G 17/06 Apparatus therefor
• CPC Class Codes: G03G 17/08 using an electrophoto-adhesive process, e.g. manifold imaging
• CPC Class Codes: G03G 17/10 using migration imaging, e.g. photoelectrosolography G03G17/04 takes precedence

Abstract

A positioning stage system includes a first stage movable at least in one of a rotational direction and a tilt direction, a second stage movable at least in X and Y directions, a measurement mirror system fixed to the second stage, a reference mirror system disposed on the first stage, and a measuring system for measuring displacement of the measurement mirror system in the X or Y direction, while using the reference mirror system as a positional reference, wherein the reference mirror system is arranged so that laser light incident on the reference mirror system is reflected in the same direction as the incidence, substantially constantly.

Claims

1. A stage system, comprising:

a first stage movable at least in one of a rotational direction and a tilt direction;

a second stage movable at least in X and Y directions;

a measurement mirror system fixed to said second stage;

a reference mirror system disposed on said first stage; and

a measuring system for measuring displacement of said measurement mirror system in the X or Y direction, while using said reference mirror system as a positional reference;

wherein said reference mirror system is arranged so that laser light incident on said reference mirror system is reflected in the same direction as the incidence, substantially constantly.

2. A stage system according to claim 1, wherein said reference mirror system includes retroreflectors.

3. A stage system according to claim 2, wherein said retroreflectors comprise a corner cube or a cat'"'"'s-eye optical system.

4. A stage system according to claim 1, wherein said reference mirror system includes mirrors and correcting means for changing postures of the mirrors with respect to said first stage.

5. A stage system according to claim 4, wherein said correcting means controls the posture of said mirrors so that the posture of said mirrors with respect to laser light, impinging thereto, is maintained substantially constant.

6. A stage system according to claim 5, wherein said mirrors are mounted on said first stage through said correcting means.

7. A stage system according to claim 5, wherein said correcting means includes driving means for controlling postures of said mirrors, respectively.

8. A stage system according to claim 1, wherein said measuring system detects displacement information related to said measurement mirror system, with respect to each of the X and Y directions, on the basis of interference between laser light coming via said reference mirror system and laser light coming via said measurement mirror system.

9. A stage system according to claim 1, wherein said measuring system includes a laser interferometer to be associated with said reference mirror system and a laser interferometer to be associated with said measurement mirror system.

10. A stage system according to claim 1, wherein said first stage comprises a mask stage for holding a mask and being movable at least in one of a rotational direction along the mask surface and a tilt direction to the mask surface, and wherein said second stage comprises a substrate stage for holding a substrate and being movable in X and Y directions along an X-Y plane parallel so the substrate surface.

11. A stage system according to claim 10, wherein said reference mirror system is mounted on one of the mask and said mask stage.

12. A position measuring method, comprising the steps of:

mounting a reference mirror system on a first stage which is movable at least in one of a rotational direction and a tilt direction, wherein the reference mirror system is arranged so that laser light incident on the reference mirror system is reflected in the same direction as the incidence substantially constantly;

fixedly mounting a measurement mirror system on a second stage which is movable at least in X and Y directions;

measuring displacement of the measuring mirror system in X and Y directions while using the reference mirror system as a positional reference, on the basis of laser interference.

13. A method according to claim 12, wherein, with respect to each of the X and Y directions, the laser light impinging on the reference mirror system is reflected in the same direction as the incidence substantially constantly, on the basis of use of retroreflectors in the reference mirror system or of relatively changing posture of mirrors with respect to the first stage.

14. An exposure apparatus, comprising:

a mask stage for holding a mask and being movable at least in one of a rotational direction along the mask surface and a tilt direction to the mask surface;

a substrate stage for holding a substrate, to be exposed, and being movable in X and Y directions along an X-Y plane parallel to the substrate surface;

a measurement mirror system fixed to said substrate stage;

a reference mirror system disposed on said mask stage; and

a measuring system for measuring displacement of said measurement mirror system in the X or Y direction, while using said reference mirror system as a positional reference, and on the basis of laser interference;

wherein the substrate on said substrate stage can be aligned with respect to the mask on the basis of the measurement by said measuring system, and a pattern of the aligned mask can be transferred and printed onto the substrate; and

wherein said reference mirror system is arranged so that laser light incident on said reference mirror system is reflected in the same direction as the incidence, substantially constantly.

15. An apparatus according to claim 14, wherein the pattern transfer is made by use of X-rays.

16. An apparatus according to claim 14, wherein information related to a positional error, in X and Y directions, of said reference mirror system due to rotation or a change in tilt of the mask stage is detected beforehand in relation to a drive amount of said mask stage, and wherein said measuring system has a function for correcting a measured value in accordance with the drive amount of said mask stage.

17. An apparatus according to claim 14, wherein said mask stage performs mask drive for mask positioning, and wherein said measuring system measures displacement of said measurement mirror after completion of the mask drive.

18. A device manufacturing method, comprising the steps of:

transferring, by exposure, a pattern of a mask onto a substrate by use of an exposure apparatus including (i) a mask stage for holding the mask and being movable at least in one of a rotational direction along the mask surface and a tilt direction to the mask surface, (ii) a substrate stage for holding the substrate, to be exposed, and being movable in X and Y directions along an X-Y plane parallel to the substrate surface, (iii) a measurement mirror system fixed to the substrate stage, (iv) a reference mirror system disposed on the mask stage, and (v) a measuring system for measuring displacement of the measurement mirror system in the X or Y direction, while using the reference mirror system as a positional reference, and on the basis of laser interference, wherein the substrate on the substrate stage can be aligned with respect to the mask on the basis of the measurement by the measuring system, and a pattern of the aligned mask can be transferred and printed onto the substrate, and wherein the reference mirror system is arranged so that laser light incident on the reference mirror system is reflected in the same direction as the incidence, substantially constantly; and

developing the exposed substrate, whereby a device can be produced from the substrate.