Method of measuring the position of a mask surface along the height direction, exposure device, and exposure method

• US 20060187456A1
• Filed: 12/21/2005
• Published: 08/24/2006
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Tanaka, Keiichi, Hirayanagi, Noriyuki
• Granted Patent: US 7,433,017 B2
• Time in Patent Office: Days
• US Class Current: 356/423
• CPC Class Codes: G03F 7/70358 Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging
• CPC Class Codes: G03F 7/70783 Handling stress or warp of chucks, masks or workpieces, e.g. to compensate for imaging errors or considerations related to warpage of masks or workpieces due to their own weight
• CPC Class Codes: G03F 9/7026 Focusing
• CPC Class Codes: G03F 9/7034 Leveling

Abstract

A method to measure the height-direction position of a mask M in an exposure device having a function to irradiate the mask M with light emitted from a light source and transfer a pattern formed on the mask M onto a photosensitive substrate such as a wafer by a projection optical system, a mask surface height-direction position measurement method characterized by moving, before measuring the height-direction position of the mask M, an exposure area defining member 1 which is arranged between the mask M and the projection optical system and defines an exposure area at the time of exposure.

Claims

1. A method of measuring the height-direction position of a mask in an exposure device, the exposure device being configured to emit light from a light source onto the mask and transfer a pattern formed on the mask onto a photosensitive substrate using a projection optical system, the method comprising:

moving, before measuring the height-direction position of the mask, an exposure area defining member placed between the mask and the projection optical system, the exposure area defining member defining an exposure area; and

measuring the height-direction position of the mask.

2. The mask surface height-direction position measurement method described in claim 1 wherein the exposure area defining member is fixed in its position at the time of exposure.

3. The mask surface height-direction position measurement method described in claim 1 wherein the exposure area defining member is moved, before measurement, to a position which does not obstruct the mechanism of a height measurement device.

4. The mask surface height-direction position measurement method described in claim 3 wherein the mask surface height-direction position measurement is performed as intermittently changing the relative position between the mask and the exposure area defining member.

5. The mask surface height-direction position measurement method described in claim 1 wherein the exposure area defining member has an opening through which exposure light can pass, and the height-direction position measurement is performed through the opening.

6. The mask surface height-direction position measurement method described in claim 1, further comprising moving a mask stage which supports the mask while measuring the height-direction position of the mask.

7. The mask surface height-direction position measurement method described in claim 1 wherein the exposure area defining member is a slit substrate.

8. The mask surface height-direction position measurement method described in claim 1 wherein the mask height-direction position measurement is performed using an optical measurement device having at least a measurement light source and a detector to detect a light flux which is emitted from the measurement light source and reflected by the mask.

9. The mask surface height-direction position measurement method described in claim 1, further comprising measuring a height-direction position of a mask stage, and correcting the measured mask surface height-direction position with the measured mask stage height-direction position.

10. The mask surface height-direction position measurement method described in claim 1, further comprising measuring a height direction position of a no pattern region of the mask, which surrounds a pattern region.

11. The mask surface height-direction position measurement method described in claim 1, further comprising returning the exposure area defining member to a position which defines the exposure area at the time of exposure.

18. The mask surface height-direction position measurement method described in claim 1, further comprising the step of correcting the height-direction position of the mask, at the time of exposure, based on the measured height-direction position data of the mask surface.

19. The mask surface height-direction position measurement method described in claim 1, further comprising the step of correcting the height-direction position of the mask based on the measured height-direction position data of the mask surface.

12. A method of measuring the height-direction position of a mask in an exposure device, the exposure device being configured to emit light from a light source onto the mask and transfer a pattern formed on the mask onto a photosensitive substrate using a projection optical system, the method comprising:

providing a mask stage height position measurement device to measure the height-direction position of a mask stage which holds the mask, and obtaining the height-direction position of the mask surface from data measured by the mask stage height position measurement device.

20. The mask surface height-direction position measurement method described in claim 12, further comprising the step of correcting the height-direction position of the mask based on based on the height-direction position of the measured mask surface and the measured height-direction position of the mask stage at the time of exposure.

13. A method of measuring the height-direction position of a mask surface from a reference plane by a height measurement device in an exposure device, the exposure device being configured to emit light from a light source onto the mask and transfer a pattern formed on the mask onto a photosensitive substrate using a projection optical system, the method comprising:

providing an exposure area defining member for defining an exposure area at the time of exposure, and measuring the height-direction position of the mask surface at a position in which a height measurement device is not obstructed by the exposure area defining member.

14. (canceled)

15. (canceled)

16. An exposure device for exposing a photosensitive substrate with a reflection mask pattern, comprising:

a projection optical system for projecting the reflection mask pattern, a measurement means for measuring the height-direction position of the reflection mask, a measurement means for measuring the height-direction position of the photosensitive substrate, a means for adjusting the height-direction position of the reflection mask based on the measured height-direction position of the reflection mask, and a means for adjusting the height-direction position of the photosensitive substrate based on the measured height-direction position of the photosensitive substrate.

17. An exposure device for exposing a mask with light emitted from a light source and for transferring a pattern formed on the mask onto a photosensitive substrate, comprising:

a projection optical system, height-direction position measurement means for measuring the height-direction position of the mask, an exposure area defining member which is provided between the mask and the projection optical system for defining an exposure area, a movement means for moving the exposure area defining member, and a control means for controlling the movement means so as to fix the exposure area defining member at the time of exposure and move the exposure area defining member at the time of measuring the height-direction position.

21. A method of exposing a photosensitive substrate with a pattern on a mask, the method comprising:

moving an exposure area defining member;

measuring a height-direction position of the mask after moving the exposure area defining member;

correcting the height-direction position of the mask based on the measured height-direction position data of the mask;

emitting light onto the mask in a corrected height-direction position; and

transferring the pattern on the mask to the photosensitive substrate.