Projection exposure method and apparatus

• US 6,590,636 B2
• Filed: 09/27/2001
• Issued: 07/08/2003
• Est. Priority Date: 01/27/1997
• Status: Expired due to Fees

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Nishi, Kenji
• Primary Examiner(s): NGUYEN, HUNG
• Application Number:
  US09/963,541
• Publication Number:
  US 20020036762A1
• Time in Patent Office: 649 Days
• Field of Search: 355/53-55, 355/67, 355/77, 355/72-76, 356/399-401, 250/548
• US Class Current: 355/53
• CPC Class Codes: G03F 7/2022 Multi-step exposure, e.g. hybrid; backside exposure; blanket exposure, e.g. for image reversal; edge exposure, e.g. for edge bead removal; corrective exposure
• CPC Class Codes: G03F 7/701 Off-axis setting using an aperture
• CPC Class Codes: G03F 7/70358 Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging
• CPC Class Codes: G03F 7/70466 Multiple exposures, e.g. combination of fine and coarse exposures, double patterning or multiple exposures for printing a single feature stitching G03F7/70475
• CPC Class Codes: G03F 7/70716 Stages
• CPC Class Codes: G03F 7/70733 Handling masks and workpieces, e.g. exchange of workpiece or mask, transport of workpiece or mask
• CPC Class Codes: G03F 7/70741 Handling masks outside exposure position, e.g. reticle libraries

Abstract

A scanning exposure method moves a mask and a substrate synchronously. A first mask and a second mask are provided for a mask stage. The mask stage has a reflective surface extending in a scanning direction, and the first and second masks are arranged along the scanning direction. Surface curvature data is prepared on the reflective surface in relation to positions of the first and second masks. Positional information of the mask stage is detected by irradiating the reflective surface with a measuring beam. Then, the mask stage is moved based on the surface curvature data and the detected positional information in a direction other than the scanning direction.

Claims

1. A scanning exposure method in which a mask and a substrate are moved synchronously, the method comprising:

providing a first mask and a second mask for a mask stage, the mask stage having a reflective surface extending in a scanning direction and the first and second masks being arranged along the scanning direction;

preparing surface curvature data on the reflective surface in relation to positions of the first and second masks to be provided;

detecting positional information of the mask stage by irradiating the reflective surface with a measuring beam; and

moving the mask stage based on the surface curvature data and the detected positional information in a direction other than the scanning direction.

2. A method according to claim 1, further comprising:

providing a substrate on a first stage; and

providing a substrate on a second stage, the first and second stages being movable independently on a base.

3. A method according to claim 2, wherein an exposure operation of the first stage is performed during a detecting operation of the second stage.

4. A method according to claim 3, further comprising:

monitoring the first stage by a first interferometer system during the exposure operation; and

monitoring the second stage by a second interferometer system during the detecting operation.

5. A method according to claim 4, wherein the first and second interferometer systems have five measuring axes respectively to monitor positions, rotation, and tilts of the first and second stages.

6. A method according to claim 5, wherein the first interferometer system has a first measuring axis in a predetermined direction;

the second interferometer system has a second measuring axis in the predetermined direction;

the first stage is controlled without the second measuring axis during the exposure operation; and

the second stage is controlled without the first measuring axis during the detecting operation.

7. A method according to claim 6, further comprising:

detecting a first positional relationship between a mark formed on the first mask and a reference on the second stage through a projection system in order to align a plurality of shot areas of the substrate held on the second stage with the first mask, the second stage being monitored with the first measuring axis at the time of the detection of the first positional relationship.

8. A method according to claim 7, further comprising:

detecting a second positional relationship between a mark formed on the second mask and the reference on the second stage through the projection system in order to align the plurality of shot areas of the substrate held on the second stage with the second mask, the second stage being monitored with the first measuring axis at the time of the detection of the second positional relationship.

9. A method according to claim 7, further comprising:

detecting a surface information of the substrate held on the second stage during the detecting operation.

10. A method according to claim 9, further comprising:

detecting the surface information of the substrate held on the second stage during an exposure operation of the second stage.

11. A micro-device manufacturing method comprising a lithography process which utilizes the method defined in claim 1.

12. A scanning exposure method comprising:

providing a first mask to a first mask stage;

providing a second mask to a second mask stage;

moving the first mask stage and the second mask stage independently on a guide;

performing a first scanning exposure operation in which each of a plurality of areas on a substrate is exposed by moving the first mask stage; and

performing at least one of a mask changing operation and a mask mark detecting operation by using the second mask stage, while performing the first scanning exposure using the first mask stage.

13. A scanning exposure method according to claim 12, further comprising:

performing, prior to the first scanning exposure operation, an alignment operation for the first mask by using a reference on a substrate stage on which the substrate is held.

14. A scanning exposure method according to claim 12, wherein the first scanning exposure operation is performed in a first station and at least one of the mask changing operation and the mask mark detecting operation is performed in a second station;

and

wherein the first station and the second station are apart from each other in a predetermined direction.

15. A scanning exposure method according to claim 14, further comprising:

monitoring the first and second mask stages by using a plurality of interferometric measuring axes which are apart from each other in the predetermined direction.

16. A scanning exposure method according to claim 15, wherein the plurality of interferometric measuring axes include a first measuring axis which is used for monitoring one of the stages in the first station, and a second measuring axis which is used for monitoring the other of the stages in the second station.

17. A scanning exposure method according to claim 14, further comprising:

moving, after finishing the scanning exposure operation, the second mask stage to the first station in order to perform a second scanning exposure operation by using the second mask held by the second mask stage.

18. A scanning exposure method according to claim 12, further comprising:

moving, after finishing the scanning exposure operation, the first mask stage to a third station in order to perform at least one of a mask chaning operation and a mask mark detecting operation by using the first mask stage.

19. A scanning exposure method according to claim 18, wherein the third station is located on the opposite side of the second station with respect to the first station.

20. A scanning exposure method according to claim 14, wherein during the first scanning exposure operation, the first mask stage is moved in a direction parallel to the predetermined direction in order to expose each of the plurality of areas on the substrate held by the first mask stage.

21. A scanning exposure method according to claim 12, further comprising:

providing the substrate on a first substrate stage; and

providing a substrate on a second substrate stage, the first and second stages being movable independently.

22. A scanning exposure method according to claim 21, further comprising:

determining, prior to the first scanning exposure operation, a relationship between the plurality of areas on the substrate held by the first substrate stage and a reference on the first substrate stage; and

performing, prior to the first scanning exposure operation, an alignment operation of the first mask held by the first mask stage by using the reference on the first substrate stage.

23. A scanning exposure method according to claim 22, further comprising:

performing at least one of a substrate changing operation and a detecting operation by using the second substrate stage, while the first scanning exposure operation is performed for the substrate held on the first substrate stage.

24. A scanning exposure method according to claim 23, further comprising:

detecting a surface information of the substrate held on the second substrate stage during the detecting operation.

25. A scanning exposure method according to claim 24, further comprising:

detecting surface information of the substrate held on the first substrate stage during the first scanning exposure operation.

26. A micro-device manufacturing method comprising a lithography process which utilizes the method defined in claim 12.