Measuring method and measuring apparatus of pupil transmittance distribution, exposure method and exposure apparatus, and device manufacturing method

• US 9,389,519 B2
• Filed: 01/21/2011
• Issued: 07/12/2016
• Est. Priority Date: 02/25/2010
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Kita, Naonori
• Primary Examiner(s): Kreutzer, Colin
• Application Number:
  US13/011,320
• Publication Number:
  US 20110205514A1
• Time in Patent Office: 1,999 Days
• Field of Search: 355/67, 355/68, 355/77, 356/124, 356/124.5
• US Class Current: 1/1
• CPC Class Codes: G01M 11/02 Testing optical properties
• CPC Class Codes: G03F 7/70133 Measurement of illumination distribution, in pupil plane or field plane
• CPC Class Codes: G03F 7/70591 Testing optical components
• CPC Class Codes: G03F 7/706 Aberration measurement
• CPC Class Codes: G03F 7/70941 Stray fields and charges, e.g. stray light, scattered light, flare, transmission loss

Abstract

A measuring apparatus for measuring a pupil transmittance distribution of an optical system to be examined has a diffraction grating mounted on a first surface in an optical Fourier transform relation with a pupil of the optical system, an illumination optical system which makes a beam inclined relative to the optical axis, incident to a predetermined position on the first surface so that a +first-order diffracted beam, generated through the diffraction grating, passes through a first pupil partial region in an effective region of the pupil and so that a −first-order diffracted beam, generated through the diffraction grating, passes through a second pupil partial region, and a measuring unit which measures an intensity of the +first-order diffracted beam, and an intensity of the −first-order diffracted beam, and determines a ratio of a pupil transmittance in the first and second pupil partial region regions.

Claims

1. A measuring method of measuring a pupil transmittance distribution of an optical system to be examined which forms an image of a first surface, comprising:

supplying a first beam and a second beam in at least a partially overlapping manner at predetermined positions on the first surface, inclinations of the first and second beams relative to an optical axis of the optical system to be examined being different from each other;

generating a positive order diffracted beam and a negative order diffracted beam by diffracting the first beam on the first surface;

generating a positive order diffracted beam and a negative order diffracted beam by diffracting the second beam on the first surface;

letting the positive order diffracted beam of the first beam, the negative order diffracted beam of the first beam, the positive order diffracted beam of the second beam, and the negative order diffracted beam of the second beam be incident on the optical system to be examined; and

determining the pupil transmittance distribution by using a measured value of an intensity of the positive order diffracted beam of the first beam having passed through the optical system to be examined, a measured value of an intensity of the negative order diffracted beam of the first beam having passed through the optical system to be examined, a measured value of an intensity of the positive order diffracted beam of the second beam having passed through the optical system to be examined, and a measured value of an intensity the negative order diffracted beam of the second beam having passed through the optical system to be examined.

2. The measuring method according to claim 1,

wherein the positive order diffracted beam of the first beam incident on the optical system to be examined passes through a first pupil partial region in an effective region of the pupil of the optical system to be examined, and

the negative order diffracted beam of the first beam incident on the optical system to be examined passes through a second pupil partial region apart from the first pupil partial region in the effective region.

3. The measuring method according to claim 2,

wherein one of the positive order diffracted beam and the negative order diffracted beam of the second beam incident on the optical system to be examined passes through the first pupil partial region.

4. The measuring method according to claim 2,

wherein the positive order diffracted beam of the second beam incident on the optical system to be examined passes through a third pupil partial region apart from the first and second pupil partial regions in the effective region, and

the negative order diffracted beam of the second beam passes through a fourth pupil partial region apart from the first to third pupil partial regions in the effective region.

5. The measuring method according to claim 4,

wherein the positive order diffracted beam of the first beam, generated through the diffracting the first beam, is a +first-order beam, and the negative order diffracted beam of the first beam, generated through the diffracting the first beam, is a −

first-order beam.

6. The measuring method according to claim 5,

wherein the first beam and the second beam are incident simultaneously to the predetermined position so that ±

third-order diffracted beams of the first beam pass through pupil partial regions apart from the first to fourth pupil partial regions on the pupil, the ±

third-order diffracted beams of the first beam being generated through the diffracting the first beam.

7. The measuring method according to claim 2,

wherein the determining the pupil transmittance distribution includes determining a relationship between a pupil transmittance in the first pupil partial region and a pupil transmittance in the second pupil partial region.

8. The measuring method according to claim 1,

wherein said diffracting the first and second beams comprises imparting a first phase value to light passing through a first phase region on the first surface and imparting a second phase value different from the first phase value to light passing through a second phase region adjacent to the first phase region.

9. The measuring method according to claim 8,

wherein the first and second phase regions are alternately arranged on the first surface, and

the second phase value is different by it from the first phase value.

10. The measuring method according to claim 8,

wherein the first and second phase regions comprise the first phase regions of a rectangular shape and the second phase regions of a rectangular shape arranged in a checkered pattern.

11. The measuring method according to claim 9,

wherein the generating the positive order diffracted beam and the negative order diffracted beam, comprises:

imparting the first phase value to light passing through the first phase region on the first surface; and

diffracting the second beam by imparting the second phase value to light passing through the second phase region.

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

supplying a calibration beam through the first surface and the optical system to be examined, to a predetermined position on a second surface on which the image is formed;

diffracting the calibration beam by imparting a third phase value to light passing through a third phase region on the second surface and imparting a fourth phase value different from the third phase value to light passing through a fourth phase region adjacent to the third phase region; and

measuring an intensity of a positive order diffracted beam of the calibration beam and an intensity of a negative order diffracted beam of the calibration beam, the positive order diffracted beam of the calibration beam being generated through the diffracting the calibration beam, the negative order diffracted beam of the calibration beam being generated through the diffracting the calibration beam.

13. The measuring method according to claim 12,

wherein the calibration beam is not diffracted by the first surface.

14. The measuring method according to claim 12, further comprising:

letting the positive order diffracted beam of the calibration beam and the negative order diffracted beam of the calibration beam be incident on a measuring optical system, the positive order diffracted beam of the calibration beam having traveled via the first pupil partial region and the optical system to be examined, the negative order diffracted beam of the calibration beam having traveled via the second pupil partial region and the optical system to be examined,

wherein the intensities of the positive order diffracted beam of the calibration beam and the negative order diffracted beam of the calibration beam are measured after passage through the measuring optical system.

15. The measuring method according to claim 14,

wherein the intensity of the positive order diffracted beam of the calibration beam and the intensity of the negative order diffracted beam of the calibration beam are measured, the positive order diffracted beam of the calibration beam having been generated through the diffracting the calibration beam and having traveled through the measuring optical system, the negative order diffracted beam of the calibration beam having been generated through the diffracting the calibration beam and having traveled through the measuring optical system.

16. The measuring method according to claim 15,

wherein a calculation result of the pupil transmittance distribution is calibrated by using measured values of the intensities of the positive order diffracted beam and the negative order diffracted beam of the calibration beam, the positive order diffracted beam and the negative order diffracted beam of the calibration beam having been generated through the diffracting the calibration beam and having traveled through the measuring optical system.

17. A controlling method of controlling an exposure apparatus which comprises an illumination optical system of illuminating a predetermined pattern, and a projection optical system of forming an image of the predetermined pattern on a photosensitive substrate, comprising:

changing an illumination condition for illumination of the predetermined pattern, based on a measurement result of a pupil transmittance distribution of the projection optical system measured by the measuring method according to claim 1.

18. The controlling method according to claim 17,

wherein the illumination condition is at least one of an illuminance distribution on the first surface by the illumination optical system and a pupil luminance distribution on a pupil of the illumination optical system.

19. An exposure method comprising illuminating a predetermined pattern, and performing exposure to transfer the predetermined pattern onto a photosensitive substrate by a projection optical system, comprising:

changing an illumination condition for illumination of the predetermined pattern, based on a measurement result of a pupil transmittance distribution of the projection optical system measured by the measuring method according to claim 1.

20. An exposure method comprising illuminating a predetermined pattern, and performing exposure to transfer the predetermined pattern onto a photosensitive substrate by a projection optical system, comprising:

using a pattern produced based on a measurement result of a pupil transmittance distribution of the projection optical system measured by the measuring method according to claim 1.

21. A device manufacturing method, comprising:

performing exposure to transfer the predetermined pattern onto the photosensitive substrate, using the exposure method according to claim 19;

developing the photosensitive substrate with the predetermined pattern transferred thereon, and forming a mask layer in a shape corresponding to the predetermined pattern on a surface of the photosensitive substrate; and

processing the surface of the photosensitive substrate through the mask layer.

22. A device manufacturing method, comprising:

performing exposure to transfer the predetermined pattern onto the photosensitive substrate, using the exposure method according to claim 20;

developing the photosensitive substrate with the predetermined pattern transferred thereon, and forming a mask layer in a shape corresponding to the predetermined pattern on a surface of the photosensitive substrate; and

processing the surface of the photosensitive substrate through the mask layer.