Exposure apparatus, method for manufacturing therof, method for exposing and method for manufacturing microdevice

• US 6,811,953 B2
• Filed: 05/22/2001
• Issued: 11/02/2004
• Est. Priority Date: 05/22/2000
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Hatada, Hitoshi, Iguchi, Masahiro, Kato, Masaki, Shirasu, Hiroshi, Koyama, Motoo
• Primary Examiner(s): McPherson, John A.
• Assistant Examiner(s): Chacko-Davis, Deborah
• Application Number:
  US09/861,698
• Publication Number:
  US 20020005940A1
• Time in Patent Office: 1,260 Days
• Field of Search: 430/311-397, 355/53-69
• US Class Current: 430/311
• CPC Class Codes: G03F 7/70275 Multiple projection paths, e.g. array of projection systems, microlens projection systems or tandem 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 9/7026 Focusing

Abstract

The memory unit stores the correlation of the positional change in the image planes of the projection optical modules in the focusing direction and the light quantity change. The image plane position determination unit finds the positional change value of the image planes of the projection optical modules based on the correlation information that is stored in the memory unit and the information on changes in the amount of light that is emitted to the projection optical modules. The compensation value calculating unit calculates the compensation value corresponding to the change in the amount of curvature in the image planes of the projection optical modules. The compensating unit compensates the change value in conformity with the compensation value. The focus compensation optical system is driven based on the change value that is compensated.

Claims

1. A microdevice manufacturing method, comprising:

an exposure step of using an exposure apparatus, comprising;

an illumination optical system, which illuminates a mask with a predetermined pattern;

a projection optical system, which includes a plurality of projection optical modules arrayed in a predetermined direction in order to form partially overlapping exposure regions on a photosensitive substrate, and projects the pattern of said mask onto said photosensitive substrate; and

, a focusing adjustment unit, which aligns each respective image plane of said plurality of projection optical modules with respect to said photosensitive substrate in a certain focusing direction;

wherein said focusing adjustment unit sets at a substantially same position in said certain focusing direction, certain portions that contribute to formation of said partially overlapping exposure regions on image planes of projection optical modules that are next to each other, to expose a pattern of said mask to said photosensitive substrate;

a developing step of developing said substrate that is exposed; and

an adjusting step of detecting a change amount of an image positioned in said partially overlapping exposure regions projected by said projection optical modules, in said certain focusing direction, by said exposure step to adjust said focusing adjusting units respectively provided in said projection optical modules to align the image planes of said projection optical modules in said certain focusing direction.

2. An exposure apparatus manufacturing method, which exposes a pattern of a mask onto a photosensitive substrate using a projection optical system having a plurality of projection optical modules arrayed in a predetermined direction in order to form partially overlapping exposure regions on said photosensitive substrate, and an illumination optical system that illuminates said mask with a predetermined pattern;

said exposure apparatus manufacturing method comprising;

a setting step of setting focus adjusting means in said projection optical modules, said focus adjusting means moving images projected by said projection optical modules in a certain focusing direction;

a measurement step of measuring position of image planes of said plurality of projection optical modules in said certain focusing direction; and

an adjustment step of adjusting so that portions that contribute to said partially overlapping exposure regions of image planes of projection optical modules that are next to each other have substantially the same position in said certain focusing direction by said focus adjusting means, by using measurement information that is obtained in said measurement step.

3. An exposure apparatus manufacturing method, which exposes a pattern of a mask onto a photosensitive substrate using a projection optical system that has a plurality of projection optical modules arrayed in a predetermined direction and an illumination optical system that illuminates said mask with a predetermined pattern;

said exposure apparatus manufacturing method comprising;

a calculation step of pre-calculating a maximum positional change amount for image plane of every said plurality of projection optical modules in a certain focusing direction, which are caused by exposure to said photosensitive substrate; and

a setting step of setting initial reference image planes of said plurality of projection optical modules based on calculated results of said calculation step.

4. The exposure apparatus manufacturing method according to claim 3, wherein said setting step further comprises an adjustment step of adjusting such that portions that contribute to formation of partially overlapping exposure region in image plane of projection modules that are next to each other have a nearly same position in said certain focusing position.

5. A micro-device manufacturing method, comprising:

an exposure step of using an exposure apparatus comprising;

an illumination system for illuminating each of respective plurality of regions in a predetermined direction, said regions are included in a pattern formed on a mask; and

a projection optical system, which comprises a plurality of projection optical units arrayed corresponding to said plurality of regions on a mask, and projects the pattern that is formed on said mask to a photosensitive substrate;

wherein said illumination system forms a secondary light source at a position substantially optically conjugate with each respective pupil plane on said plurality of projection optical units, and has a function for introducing said light from said secondary light source into said mask, and said illumination system comprises, in order to actually control changes in each respective optical characteristic of said plurality of projection optical units by optical illumination, a setting unit that sets said secondary light source for an optical intensity distribution that is actually higher intensity in the peripheral portion therein than in a center portion therein, to set said secondary light source for an optical intensity distribution that is actually higher intensity in a peripheral portion therein than in the center portion therein so as to suppress changes in each respective optical characteristic of said plurality of projection optical units, and expose said pattern image of said mask onto said photosensitive substrate; and

a development step of developing said substrate exposed.

6. An exposure method, which illuminates a plurality of regions, which are positioned in a given direction on a mask with a pattern, and then projection exposes said pattern formed on said mask onto a photosensitive substrate through a projection optical system with a plurality of projection optical units positioned corresponding to said plurality of regions on said mask;

said exposure method comprising;

an illumination step of illuminating a plurality of regions on said mask by forming a secondary light source in a position nearly optically conjugate with the pupil plane of each of said plurality of projection optical units, and then guiding light from said secondary light source to said mask; and

a setting step of setting the optical intensity distribution of said secondary light source where its peripheral portion has a practically higher intensity than that of its center portion, as to suppress the change in the optical characteristics of each of said plurality of projection optical units.

7. The exposure method according to claim 6, further comprising:

an additional setting step of setting the outer diameter of said secondary light source when it is converted to a value on said pupil plane, to greater than a given ratio times the clear aperture of said pupil plane.

8. The exposure method according to claim 6, further comprising:

an exposure step of moving in a scanning direction on that crosses said given direction said mask and said photosensitive substrate against said projection optical system, and then scan exposing said pattern formed on said mask onto said photosensitive substrate via said projection optical system.

9. An exposure method according to claim 6, wherein said projection optical unit comprises a catadioptric optical system.

10. An exposure method, which illuminates a plurality of regions, which are positioned in a given direction on a mask, on which a pattern to be transferred is formed, and then projection exposes said pattern formed on said mask onto a photosensitive substrate through a projection optical system with a plurality of projection optical units positioned corresponding to said plurality of regions on said mask;

said exposure method comprising;

an illumination step of illuminating a plurality of regions on said mask by forming a secondary light source in a position nearly optically conjugate with the pupil plane of each of said plurality of projection optical units, and then guiding light from said secondary light source to said mask; and

a setting step of setting the outer diameter of said secondary light source when it is converted to a value on said pupil plane, to greater than 0.7 times the clear aperture of said pupil so that change in the optical characteristics of each of said plurality of projection optical units, which is caused by irradiation of light, can be practically suppressed.

11. The exposure method according to claim 10, further comprising:

an exposure step of moving in a scanning direction on that crosses said given direction said mask and said photosensitive substrate against said projection optical system, and then scan exposing said pattern formed on said mask onto said photosensitive substrate via said projection optical system.

12. An exposure method according to claim 10, wherein said projection optical unit comprises a catadioptric optical system.

13. An exposure method comprising:

an illumination step of illuminating a mask using an illumination optical system; and

a transcription step of transcribing a pattern that is formed on said mask onto a photosensitive substrate;

wherein;

said illumination step includes a step of making an optical intensity distribution at pupil of said illumination optical system higher at a peripheral portion than at a center portion; and

said transcription step comprising;

a first exposure step, which forms a first exposure region on said photosensitive substrate while making said optical intensity distribution at pupil of said illumination optical system higher at said peripheral portion than at said center portion with practically suppressing change in optical characteristics of each of a plurality of projection optical units, which is caused by irradiation of light; and

a second exposure step, which forms on said photosensitive substrate a second exposure region that partially overlaps said first exposure region while making said optical intensity distribution at pupil of said illumination optical system higher at said peripheral portion than at said center portion with practically suppressing change in the optical characteristics of each of said plurality of projection optical units, which is caused by irradiation of light.

14. The exposure method according to claim 13, wherein said transcription step comprises a step of projecting the pattern of said mask onto said photosensitive substrate using a projection optical system.

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

a scanning step of moving said mask and said photosensitive substrate relative to said projection optical system.

16. The exposure method according to claim 15, wherein:

said first exposure step comprises a step of forming a first exposure region on said photosensitive substrate while moving said mask and said photosensitive substrate relative to said projection optical system in said scanning step; and

said second exposure step comprises a step of forming a second exposure region on said photosensitive substrate while moving said mask and said photosensitive substrate relative to said projection optical system in said scanning step.

17. A microdevice manufacturing method, comprising:

an exposure step of using an exposure apparatus comprising;

an illumination optical system, which illuminates a mask with a predetermined pattern;

a projection optical system, which includes a plurality of projection optical modules that are arrayed in a predetermined direction, and projects the pattern of said mask onto a photosensitive substrate;

a first adjusting unit, which compensates a change of a first optical characteristic in accordance with time passage with respect to at least one projection optical module of said plurality of projection optical modules; and

a second adjusting unit, which compensates a second optical characteristic that differs from said first optical characteristic and is caused by said first adjusting unit, to expose a pattern of said mask;

a developing step of developing said substrate that is exposed; and

an adjusting step of, by performing said exposure step, performing adjustment, using said first adjusting unit which compensates change of a first optical characteristic in accordance with time passage with respect to at least one projection optical module of said plurality of projection optical modules, and said second adjusting unit.

18. A microdevice manufacturing method, comprising:

an exposure step of using an exposure apparatus comprising;

an illumination optical system, which illuminates a mask with a predetermined pattern;

a projection optical system, which includes a plurality of projection optical modules arrayed in a predetermined direction, and projects the pattern of said mask onto a photosensitive substrate;

a first adjusting unit, which compensates a chance of an optical characteristic with respect to at least one of said plurality of projection optical modules that develop due to heat deformation of at least one optical component that is included in each of respective said plurality of projection optical modules; and

a second adjusting unit, which compensates a change of an optical characteristic with respect to said plurality of projection optical modules that develop due to heat deformation of at least one deflecting member included in each of respective said plurality of projection modules to expose a pattern of said mask to said photosensitive substrate;

a developing step of developing said substrate that is exposed; and

an adjusting step of performing adjustment by performing said exposure step, using said first adjusting unit which compensate the change of a first optical characteristic that develops due to heat deformation of at least one optical component that is included in each of respective said plurality of projection optical modules or said second adjusting unit.

19. A microdevice manufacturing method, comprising:

an exposure step of using an exposure apparatus, comprising;

an illumination optical system, which illuminates a mask with a predetermined pattern; and

a projection optical system, which comprises a plurality of projection optical modules that are irradiated with light from said illumination optical system through said mask and arrayed in a predetermined direction, and projects the pattern of said mask onto a photosensitive substrate;

wherein, in order to form a partially overlapping exposure region onto said photosensitive substrate, image planes of said plurality of projection optical modules have a portion that contributes to the formation of said overlapping exposure regions; and

moreover, in order to make position of portions that contribute to formation of said overlapping exposure regions that are next to each other substantially the same in a certain focusing direction, further comprising a focus adjustment unit that performs adjustment of position in said certain focusing direction of image plane of each of said plurality of projection optical modules, to expose a pattern of said mask to said photosensitive substrate;

a developing step of developing said substrate that is exposed; and

an adjusting step of detecting change amount of an image positioned in said overlapping exposure regions projected by said projection optical modules, in said certain focusing direction, by said exposure step to adjust said focusing adjusting units respectively provided in said projection optical modules to align the image planes of said projection optical modules in said certain focusing direction.

20. A microdevice manufacturing method, comprising:

an exposure step of using an exposure apparatus, comprising;

an illumination system for illuminating each of respective plurality of regions in a predetermined direction, said regions are included in a pattern formed on a mask; and

a projection optical system, which comprises a plurality of projection optical units arrayed corresponding to said plurality of regions on a mask, and projects the pattern that is formed on said mask to a photosensitive substrate;

wherein said illumination system forms a secondary light source at a position substantially optically conjugate with each respective pupil plane on said plurality of projection optical units, and has a function for introducing said light from said secondary light source into said mask; and

said illumination system comprises, in order to actually control changes in each respective optical characteristic of said plurality of projection optical units by optical illumination, a setting unit that sets said secondary light source for an optical intensity distribution that is actually higher intensity at a peripheral portion therein than in center portion therein, to set said secondary light source for an optical intensity distribution that is actually higher intensity at the peripheral portion therein than in center portion therein so as to suppress changes in each respective optical characteristic of said plurality of projection optical units, and expose said pattern image of said mask onto said photosensitive substrate; and

a developing step of developing said substrate that is exposed.

21. A microdevice manufacturing method, comprising:

an exposure step of using an exposure apparatus, comprising;

an exposure step of using an exposure apparatus, comprising;

an illumination system, which illuminates each of a plurality of regions positioned in a given direction on a mask with a pattern, and a projection optical system, which has a plurality of projection optical units positioned corresponding to said plurality of regions on said mask, and which projects said pattern formed on said mask onto a photosensitive substrate;

wherein;

said illumination system has a function to form a secondary light source in a position substantially optically conjugate with the pupil plane of each of said plurality of projection optical units, and to guide light from said secondary light source to said mask; and

said illumination system comprises a setting unit, which sets the outer diameter of said secondary light source when it is converted to a value on said pupil plane, to greater than 0.7 times the clear aperture of said pupil plane, so that a change in the optical characteristics of each of said plurality of projection optical units, which is caused by irradiation of light, can be controlled for the most part, to set the outer diameter of said secondary light source when it is converted to a value on said pupil plane, to greater than 0.7 times the clear aperture of said pupil plane, so as to suppress the change in the optical characteristics of each of said plurality of projection optical units and expose a pattern of said mask to said photosensitive substrate; and

a developing step of developing said substrate that is exposed.

22. A microdevice manufacturing method, comprising:

an exposure step of using an exposure apparatus, comprising;

an illumination system, which illuminates a mask with a pattern; and

a projection optical system, which projects said pattern on said mask onto a photosensitive substrate, wherein;

said illumination system comprises;

a formation unit, which forms a secondary light source in a position substantially conjugate with the pupil plane of said projection optical system, and an adjustment unit, which adjusts the optical intensity distribution of said secondary light source dependent upon a change in the optical characteristics of said projection optical system, to adjust the optical intensity distribution of said secondary light source, so as to suppress the change in the optical characteristics of said projection optical system and to expose a pattern of said mask to said photosensitive substrate; and

a developing step of developing said substrate that is exposed.

23. A microdevice manufacturing method, comprising:

an exposure step of using an exposure apparatus, which exposes a photosensitive substrate through a mask on which a pattern to be transferred is formed on a plurality of regions in a given direction;

said exposure apparatus comprising;

a projection optical system, which has a plurality of projection optical units respectively positioned corresponding to said plurality of regions, and which projects said pattern onto a photosensitive substrate; and

an illumination system, which forms a secondary light source in a position substantially optically conjugate with the pupil plane of each of said plurality of projection optical units, and which illuminates said mask with light from said secondary light source;

wherein said illumination system, includes a setting unit, which sets an optical intensity distribution where a peripheral portion of said secondary light source has a higher intensity than that of a center portion, so that change in the optical characteristics of each of said plurality of projection optical units, which is caused by light from the secondary light source, can be controlled, to set an optical intensity distribution where a peripheral portion of said secondary light source has a higher intensity than that of a center portion so as to suppress the chance in the optical characteristics of each of said plurality of projection optical units and expose a pattern of said mask to said photosensitive substrate; and

a developing step of developing said substrate that is exposed.