Exposure apparatus and method

• US 20040233407A1
• Filed: 06/30/2004
• Published: 11/25/2004
• Est. Priority Date: 11/28/1996
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Nishi, Kenji, Ota, Kazuya
• Granted Patent: US 7,177,008 B2
• Time in Patent Office: Days
• US Class Current: 355/53
• CPC Class Codes: G03F 7/70216 Mask projection systems
• CPC Class Codes: G03F 7/70358 Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging
• CPC Class Codes: G03F 7/70425 Imaging strategies, e.g. for increasing throughput or resolution, printing product fields larger than the image field or compensating lithography- or non-lithography errors, e.g. proximity correction, mix-and-match, stitching or double patterning
• 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 9/70 for microlithography measuring printed patterns for monitoring overlay G03F7/70633 or focus G03F7/70641; projection system adjustment G03F7/70258; position control G03F7/70775
• CPC Class Codes: G03F 9/7003 Alignment type or strategy, e.g. leveling, global alignment
• CPC Class Codes: G03F 9/7015 Reference, i.e. alignment of original or workpiece with respect to a reference not on the original or workpiece
• CPC Class Codes: G03F 9/7026 Focusing
• CPC Class Codes: G03F 9/7088 Alignment mark detection, e.g. TTR, TTL, off-axis detection, array detector, video detection

Abstract

A scanning exposure apparatus exposes a sensitive substrate by projecting a pattern formed on a mask onto the sensitive substrate while moving the substrate. The apparatus includes a projection system, a stage system, a first detector and a control system. The projection system is disposed in a path of an exposure beam and projects a pattern image onto the substrate. The stage system is disposed on an image plane side of the projection system, and has first and second stages, each of which is movable independently in a plane while holding the substrate. The first detector detects focusing information of a vicinity of an outer circumference of the substrate during a detecting operation. The control system controls the stage system to perform the detecting operation with the first stage, while performing a first exposure operation with the second stage, the substrate held by the second stage being exposed in the first exposure operation. After finishing the first exposure operation, a second exposure operation for the substrate on the first stage is performed, in which a shot area in the vicinity of the outer circumference of the substrate held by the first stage is exposed by moving the first stage in a scanning direction while adjusting a surface position of the substrate held by the first stage based on the detected focusing information.

Claims

1. A scanning exposure apparatus in which a sensitive substrate is exposed by projecting a pattern formed on a mask onto the sensitive substrate while moving the sensitive substrate, the apparatus comprising:

a projection system, disposed in a path of an exposure beam, which projects a pattern image onto the sensitive substrate;

a stage system, disposed on an image plane side of the projection system, which has a first stage and a second stage, each of which is movable independently in a plane while holding the sensitive substrate;

a first detector, functionally associated with the stage system, which detects focusing information of a vicinity of an outer circumference of the sensitive substrate during a detecting operation;

a control system, functionally associated with the stage system, which controls the stage system to perform the detecting operation with the first stage, while performing a first exposure operation with the second stage, the sensitive substrate held by the second stage being exposed in the first exposure operation; and

wherein after finishing the first exposure operation, a second exposure operation for the sensitive substrate on the first stage is performed, in which a shot area in the vicinity of the outer circumference of the sensitive substrate held by the first stage is exposed by moving the first stage in a scanning direction while adjusting a surface position of the sensitive substrate held by the first stage on the basis of the detected focusing information.

2. The scanning exposure apparatus according to claim 1, wherein the shot area in the vicinity of the outer circumference of the sensitive substrate on the first stage is exposed by moving the first stage so that an exposure beam scans the sensitive substrate from the outside to the inside of the sensitive substrate.

3. The scanning exposure apparatus according to claim 2, wherein during the detecting operation, the focusing information is detected by the first detector while moving the first stage.

4. The scanning exposure apparatus according to claim 1, wherein during the detecting operation, the focusing information is detected by the first detector while moving the first stage.

5. The scanning exposure apparatus according to claim 1, further comprising:

a first measuring system, functionally associated with the stage system, which has a measuring axis and monitors the first stage during the detecting operation of the first stage; and

a second measuring system, functionally associated with the stage system, which has a measuring axis and monitors the second stage during the first exposure operation and the first stage during the second exposure operation.

6. The scanning exposure apparatus according to claim 5, wherein the first measuring system has a first interferometer system and the second measuring system has a second interferometer system, and

wherein the first interferometer system is capable of monitoring positional information, tilts and rotation of the first stage during the detecting operation, and the second interferometer system is capable of monitoring positional information, tilts and rotation of the second stage during the first exposure operation and is capable of monitoring positional information, tilts and rotation of the first stage during the second exposure operation.

7. A micro-device manufacturing method including a lithography process utilizing the scanning exposure apparatus defined in claim 1.

8. A scanning exposure method for exposing a sensitive substrate by projecting a pattern formed on a mask through a projection optical system onto the sensitive substrate while moving the sensitive substrate, the method comprising:

performing a detecting operation by using a first stage on which the sensitive substrate is held, while performing a first exposure operation for the sensitive substrate held on a second stage, each of the first and second stages is movable independently on a two-dimensional plane;

detecting focusing information of a vicinity of an outer circumference of the sensitive substrate on the first stage during the detecting operation; and

performing, after finishing the first exposure operation, a second exposure operation for the sensitive substrate on the first stage, in which a shot area in the vicinity of the outer circumference on the sensitive substrate held on the first stage is exposed by moving the first stage in a scanning direction while adjusting a surface position of the sensitive substrate held on the first stage based on the detected focusing information.

9. The scanning exposure method according to claim 8, wherein the shot area in the vicinity of the outer circumference of the sensitive substrate on the first stage is exposed by moving the first stage so that an exposure beam scans the sensitive substrate from the outside to the inside of the sensitive substrate.

10. The scanning exposure method according to claim 9, wherein during the detecting operation, the focusing information is detected while moving the first stage.

11. The scanning exposure method according to claim 8, wherein during the detecting operation, the focusing information is detected while moving the first stage.

12. The scanning exposure method according to claim 8, further comprising:

monitoring the first stage by using a first interferometer system which has a measuring axis and monitors the first stage during the detecting operation; and

monitoring the second stage by using a second interferometer system which has a measuring axis, monitors the second stage during the first exposure operation and monitors the first stage during the second exposure operation.

13. The scanning exposure method according to claim 12, wherein the first interferometer system is capable of monitoring positional information, tilts and rotation of the first stage during the detecting operation, and the second interferometer system is capable of monitoring positional information, tilts and rotation of the second stage during the first exposure operation and is capable of monitoring positional information, tilts and rotation of the first stage during the second exposure operation.

14. The scanning exposure method according to claim 8, further comprising:

detecting focusing information of the sensitive substrate on the second stage in the first exposure operation; and

detecting focusing information of the sensitive substrate on the first stage in the second exposure operation.

15. A micro-device manufacturing method including a lithography process utilizing the scanning exposure method defined in claim 8.