Method for driving spatial light modulator, method for forming pattern for exposure, exposure method, and exposure apparatus

• US 9,599,906 B2
• Filed: 09/26/2011
• Issued: 03/21/2017
• Est. Priority Date: 09/27/2010
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Watanabe, Yoji
• Primary Examiner(s): Iacoletti, Michelle M
• Application Number:
  US13/825,948
• Publication Number:
  US 20130222781A1
• Time in Patent Office: 2,003 Days
• US Class Current: 1/1
• CPC Class Codes: G02B 26/06 for controlling the phase of light G02B26/08 takes precedence , measuring optical phase difference G01J9/00
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
• CPC Class Codes: G03F 7/70508 Data handling in all parts of the microlithographic apparatus, e.g. handling pattern data for addressable masks or data transfer to or from different components within the exposure apparatus

Abstract

A method for driving a spatial light modulator includes setting a plurality of mirror elements in a first region into a state of phase 0, setting a plurality of optical elements in a second region adjacent in a Y-direction to the first region into a state of phase π, and setting auxiliary pattern elements consisting of a plurality of mirror elements arranged at a pitch P over a resolution limit of a projection optical system in an X-direction in a boundary region extending in the X-direction between the first region and the second region, into the state of phase π. In projecting a pattern onto an object with use of the spatial light modulator having the array of optical elements, the pattern can be formed in position accuracy or shape accuracy finer than the width of images of the optical elements.

Claims

1. An exposure method for exposing an object with exposure light from a light source to project a pattern onto the object, comprising:

illuminating a plurality of reflective elements arranged on a predetermined surface with the exposure light from the light source;

directing the exposure light from the plurality of reflective elements to a projection optical system; and

exposing the object with the exposure light from the projection optical system,

wherein the illuminating includes;

setting first reflective elements of the plurality of reflective elements so as to reflect the exposure light in a first phase, wherein each of the first reflective elements is situated in a first region or a second region of the predetermined surface, wherein the first region is displaced from the second region along a first direction on the predetermined surface; and

setting second reflective elements of the plurality of reflective elements situated within a third region so as to reflect the exposure light in a second phase different from the first phase, the third region being located between the first region and the second region,

wherein a first boundary corresponding to a third-region-side edge of the first region is non-linear, the first boundary defined by edges of the first reflective elements that are arranged along the third-region-side edge of the first region, and

wherein the exposing the object includes exposing an edge of the pattern with the exposure light received from the first reflective elements of the first region that defines the first boundary.

2. The exposure method according to claim 1, wherein a second boundary corresponding to a third-region-side edge of the second region is non-linear, and the second boundary is defined by edges of reflective elements of the first reflective elements that are arranged along the third-region-side edge of the second region.

3. The exposure method according to claim 1, wherein each of the plurality of reflective elements has a size that the projection optical system cannot resolve.

4. The exposure method according to claim 3, wherein a phase difference between the exposure light reflected by the first reflective elements set to reflect at the first phase and the exposure light reflected by the second reflective elements set to reflect at the second phase is 180°

.

5. The exposure method according to claim 1, wherein a phase difference between the exposure light reflected by the first reflective elements set to reflect at the first phase and the exposure light reflected by the second reflective elements set to reflect at the second phase is 180°

.

6. The exposure method according to claim 1, wherein

the plurality of reflective elements are arranged at a predetermined pitch, and

the pattern is a line-and-space pattern having a pitch that is different from a value obtained by multiplying the predetermined pitch with a magnification of the projection optical system.

7. The exposure method according to claim 6, wherein the first boundary has a plurality of projecting portions each oriented toward the third region.

8. The exposure method according to claim 7, wherein the plurality of projecting portions are arranged at a first pitch along a direction along which an edge of the line-and-space pattern extends.

9. The exposure method according to claim 6, wherein the first boundary has a plurality of depressed portions each oriented away from the third region.

10. The exposure method according to claim 9, wherein the plurality of depressed portions are arranged at a first pitch along a direction along which an edge of the line-and-space pattern extends.

11. The exposure method according to claim 1, wherein the first boundary has a plurality of projecting portions each oriented toward the third region.

12. The exposure method according to claim 11, wherein one of the plurality of projecting portions is constituted by one of the first reflective elements.

13. The exposure method according to claim 1, wherein the first boundary has a plurality of depressed portions each oriented away from the third region.

14. The exposure method according to claim 13, wherein one of the plurality of depressed portions is constituted by one of the first reflective elements.

15. A device manufacturing method comprising:

forming a pattern of a photosensitive layer on a substrate, using the exposure method as defined in claim 1; and

processing the substrate with the pattern formed thereon.

16. An exposure apparatus configured to expose an object with exposure light from a light source to project a pattern onto the object, comprising:

a spatial light modulator having a plurality of reflective elements arranged on a predetermined surface;

a projection optical system configured to project the pattern onto the object using the exposure light routed through the plurality of reflective elements; and

a controller configured to drive the plurality of reflective elements in the spatial light modulator,

wherein the controller;

sets first reflective elements of the plurality of reflective elements situated in a first region or a second region so as to reflect exposure light in a first phase, the first region displaced from the second region along a first direction on the predetermined surface; and

sets second reflective elements of the plurality of reflective elements situated within a third region so as to reflect exposure light in a second phase different from the first phase, the third region being located between the first region and the second region,

wherein a first boundary corresponding to a third-region-side edge of the first region is non-linear, the first boundary defined by edges of reflective elements that are included in the first reflective elements and arranged along the third-region-side edge of the first region, and

wherein the exposing the object includes exposing an edge of the pattern with the exposure light received from the reflective elements defining the first boundary.

17. The exposure apparatus according to claim 16, wherein a second boundary corresponding to a third-region-side edge of the second region is non-linear, and the second boundary is defined by edges of reflective elements of the first reflective elements that are situated along the third-region-side edge of the second region.

18. The exposure apparatus according to claim 16, wherein each of the plurality of reflective elements has such a size that the projection optical system cannot resolve.

19. The exposure apparatus according to claim 18, wherein a phase-difference between the exposure light reflected by the first reflective elements in the first phase and the exposure light reflected by the second reflective elements in the second phase is 180°

.

20. The exposure apparatus according to claim 19, wherein each of the plurality of reflective elements is movable up and down.

21. The exposure apparatus according to claim 16, wherein a phase difference between the exposure light reflected by the first reflective elements in the first phase and the exposure light reflected by the second reflective elements in the second phase is 180°

.

22. The exposure apparatus according to claim 21, wherein each of the plurality of reflective elements is movable up and down.

23. The exposure apparatus according to claim 16, wherein

the plurality of reflective elements is arranged at a predetermined pitch, and

the pattern is a line-and-space pattern having a pitch that is different from a value obtained by multiplying the predetermined pitch with a magnification of the projection optical system.

24. The exposure apparatus according to claim 23, wherein the controller controls the plurality of reflective elements so that the first boundary has a plurality of projecting portions each oriented toward the third region.

25. The exposure apparatus according to claim 24, wherein the controller controls the plurality of reflective elements so that the plurality of projecting portions are arranged at a first pitch along a direction along which an edge of the line-and-space pattern extends.

26. The exposure apparatus according to claim 23, wherein the controller controls the plurality of reflective elements so that the first boundary has a plurality of depressed portions each oriented away from the third region.

27. The exposure apparatus according to claim 26, wherein the controller controls the plurality of reflective elements so that the plurality of depressed portions is arranged at a first pitch along a direction along which an edge of the line-and-space pattern extends.

28. The exposure apparatus according to claim 16, wherein the controller controls the plurality of reflective elements so that the first boundary has a plurality of projecting portions each oriented toward the third region.

29. The exposure apparatus according to claim 28, wherein one of the plurality of projecting portions is constituted by one of the first reflective elements.

30. The exposure apparatus according to claim 16, wherein the controller controls the plurality of reflective elements so that the first boundary has a plurality of depressed portions each oriented away from the third region.

31. The exposure apparatus according to claim 30, wherein one of the plurality of depressed portions is constituted by one of the first reflective elements.

32. A device manufacturing method comprising:

forming a pattern of a photosensitive layer on a substrate, using the exposure apparatus as defined in claim 16; and

processing the substrate with the pattern formed thereon.

33. An exposure method for exposing an object with exposure light from a light source to project a pattern onto the object, comprising:

illuminating a plurality of reflective elements arranged on a predetermined surface with the exposure light from the light source;

directing the exposure light from the plurality of reflective elements to a projection optical system; and

exposing the object with the exposure light from the projection optical system,

wherein the illuminating includes;

setting first reflective elements of the plurality of reflective elements to a first condition, wherein each of the first reflective elements is situated in a first region or a second region of the predetermined surface, wherein the first region is displaced from the second region along a first direction on the predetermined surface; and

setting second reflective elements of the plurality of reflective elements situated within a third region to a second condition different from the first condition, the third region being located between the first region and the second region,

wherein a first boundary corresponding to a third-region-side edge of the first region is non-linear, the first boundary defined by edges of the first reflective elements that are arranged along the third-region-side edge of the first region,

wherein the directing the exposure light includes directing exposure light reflected by the first reflective elements set at the first condition to the projection optical system in a first phase, and directing exposure light reflected by the second reflective elements set at the second condition to the projection optical system in a second phase different from the first phase, and

wherein the exposing the object includes exposing an edge of the pattern with the exposure light received from the first reflective elements of the first region that defines the first boundary.

34. An exposure apparatus configured to expose an object with exposure light from a light source to project a pattern onto the object, comprising:

a spatial light modulator having a plurality of reflective elements arranged on a predetermined surface;

a projection optical system configured to project the pattern onto the object using the exposure light routed through the plurality of reflective elements; and

a controller configured to drive the plurality of reflective elements in the spatial light modulator,

wherein the controller;

sets first reflective elements of the plurality of reflective elements situated in a first region or a second region to a first condition, the first region displaced from the second region along a first direction on the predetermined surface; and

sets second reflective elements of the plurality of reflective elements situated within a third region to a second condition different from the first condition, the third region being located between the first region and the second region,

wherein a first boundary corresponding to a third-region-side edge of the first region is non-linear, the first boundary defined by edges of reflective elements that are included in the first reflective elements and arranged along the third-region-side edge of the first region,

wherein the spatial light modulator is situated to direct the exposure light received from the light source to the projection optical system, wherein the light reflected by the first reflective elements set at the first condition has a first phase, light reflected by the second reflective elements set at the second condition has a second phase, different from the first phase, and

wherein the exposing the object includes exposing an edge of the pattern with the exposure light received from the reflective elements defining the first boundary.

35. An exposure method for exposing an object with exposure light from a light source to project a pattern onto the object, comprising:

illuminating a plurality of reflective elements arranged on a predetermined surface with the exposure light from the light source;

directing the exposure light from the plurality of reflective elements to a projection optical system; and

exposing the object with the exposure light from the projection optical system,

wherein the illuminating includes;

setting reflective elements in a first region and a second region so as to reflect exposure light in a first phase, wherein the first region is displaced from the second region along a first direction on the predetermined surface;

setting all reflective elements in a third region so as to reflect exposure light in a second phase different from the first phase, the third region being located between the first region and the second region,

wherein a first boundary corresponding to a third-region-side edge of the first region is non-linear, the first boundary defined by edges of the first reflective elements that are arranged along the third-region-side edge of the first region, and

wherein the exposing the object includes exposing an edge of the pattern with the exposure light received from the first reflective elements of the first region that defines the first boundary.

36. An exposure apparatus configured to expose an object with exposure light from a light source to project a pattern onto the object, comprising:

a spatial light modulator having a plurality of reflective elements arranged on a predetermined surface;

a projection optical system configured to project the pattern onto the object using the exposure light routed through the plurality of reflective elements; and

a controller configured to drive the plurality of reflective elements in the spatial light modulator,

wherein the controller;

sets reflective elements of the plurality of reflective elements situated in a first region or a second region so as to reflect exposure light in a first phase, the first region displaced from the second region along a first direction on the predetermined surface; and

sets all reflective elements in a third region so as to reflect exposure light in a second phase different from the first phase, the third region being located between the first region and the second region,

wherein a first boundary corresponding to a third-region-side edge of the first region is non-linear, the first boundary defined by edges of reflective elements that are included in the first reflective elements and arranged along the third-region-side edge of the first region, and

wherein the exposing the object includes exposing an edge of the pattern with the exposure light received from the reflective elements defining the first boundary.