Exposure method and apparatus, and method for fabricating device with light amount distribution having light larger in first and second pairs of areas

• US 8,675,177 B2
• Filed: 09/20/2007
• Issued: 03/18/2014
• Est. Priority Date: 04/09/2003
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Kudo, Takehito, Hirukawa, Shigeru
• Primary Examiner(s): Liu, Chia-how Michael
• Application Number:
  US11/902,277
• Publication Number:
  US 20080024747A1
• Time in Patent Office: 2,371 Days
• Field of Search: 355/71, 355/67, 355/53
• US Class Current: 355/71
• CPC Class Codes: G03B 27/42 for automatic sequential copying of the same original G03B27/34, G03B27/53 take precedence
• CPC Class Codes: G03F 7/70091 Illumination settings, i.e. intensity distribution in the pupil plane or angular distribution in the field plane; On-axis or off-axis settings, e.g. annular, dipole or quadrupole settings; Partial coherence control, i.e. sigma or numerical aperture [NA]
• CPC Class Codes: G03F 7/701 Off-axis setting using an aperture
• CPC Class Codes: G03F 7/70108 Off-axis setting using a light-guiding element, e.g. diffractive optical elements [DOEs] or light guides
• CPC Class Codes: G03F 7/70158 Diffractive optical elements
• CPC Class Codes: G03F 7/70191 Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like
• CPC Class Codes: G03F 7/70566 Polarisation control

Abstract

An exposure method and apparatus simultaneously transfer patterns with various pitches with high resolution. On the pupil surface of an illumination system, at least first and second pairs of areas are set. The distribution of intensity of light over the pupil surface is set so that the intensities of light of the second pair of areas is smaller than that of the first pair of areas.

Claims

1. An exposure method for illuminating a pattern with an illumination system to expose a substrate through a projection system, the method comprising:

illuminating the pattern with illumination light having a light amount distribution which is set such that an amount of light is larger in each of two first areas than in a third area and an amount of light is larger in each of two second areas than in the third area, the third area being an area other than the two first areas and the two second areas on a pupil plane of the illumination system, the two first areas being in line so that a first straight line interconnecting the two first areas passes through an optical axis and the two first areas are located approximately at the same distance from the optical axis along the first straight line, the two second areas being in line so that a second straight line orthogonal to the first straight line at the optical axis interconnects the two second areas and passes through the optical axis and the two second areas are located approximately at the same distance from the optical axis along the second straight line; and

projecting an image of the illuminated pattern onto the substrate by the projection system,

wherein the light amount distribution is generated by a formation optical system which is provided on an incident side of the pupil plane in the illumination system,

the third area includes the optical axis on the pupil plane,

each of the two first areas is surrounded by the third area and each of the two second areas is surrounded by the third area,

distances from the two second areas to the optical axis are smaller than distances from the two first areas to the optical axis,

an amount of light is smaller in each of the two second areas than in each of the two first areas, and

the first straight line passes through only the two first areas and the third area without passing through any of the second areas.

2. The exposure method according to claim 1, wherein

the two first areas are approximately symmetrically arranged with respect to the optical axis on the pupil plane.

3. The exposure method according to claim 2, wherein

the two first areas are arranged on the first straight line passing through the optical axis and being parallel to a first direction on the pupil plane.

4. The exposure method according to claim 2, wherein

the two second areas are approximately symmetrically arranged with respect to the optical axis on the pupil plane.

5. The exposure method according to claim 4, wherein

a size of each of the two second areas is smaller than a size of each of the two first areas.

6. The exposure method according to claim 1, wherein

the illumination light distributed in the two first areas is substantially linearly polarized light.

7. The exposure method according to claim 6, wherein

a direction of the linearly polarized light approximately coincides with a tangent direction.

8. The exposure method according to claim 1, wherein

the light amount distribution is used in an illumination for the pattern which is periodical in one of two directions orthogonal to each other and isolated in the other of the two directions, and the one of the two directions orthogonal to each other corresponds to a first direction.

9. A device manufacturing method, comprising:

exposing the substrate by the exposure method as recited in claim 1;

developing the exposed substrate; and

processing the developed substrate.

10. An exposure apparatus, comprising:

an illumination system which illuminates a pattern;

a projection system which projects the pattern onto a substrate; and

a formation optical system which changes a light amount distribution of illumination light on a pupil plane of the illumination system and which generates a light amount distribution in which an amount of light is larger in each of two first areas than in a third area and an amount of light is larger in each of two second areas than in the third area, the third area being an area other than the two first areas and the two second areas on the pupil plane of the illumination system, the two first areas being in line so that a first straight line interconnecting the two first areas passes through an optical axis and the two first areas are located approximately at the same distance from the optical axis along the first straight line, the two second areas being in line so that a second straight line orthogonal to the first straight line at the optical axis interconnects the two second areas and passes through the optical axis and the two second areas are located approximately at the same distance from the optical axis along the second straight line,

wherein the formation optical system is provided on an incident side of the pupil plane in the illumination system,

the third area other than the two first areas and the two second areas includes the optical axis on the pupil plane,

each of the two first areas is surrounded by the third area and each of the second areas is surrounded by the third area,

distances from the two second areas to the optical axis are smaller than distances from the two first areas to the optical axis, and an amount of light is smaller in each of the two second areas than in each of the two first areas, and

the first straight line passes through only the two first areas and the third area without passing through any of the second areas.

11. The exposure apparatus according to claim 10, wherein

the two first areas are approximately symmetrically arranged with respect to the optical axis on the pupil plane.

12. The exposure apparatus according to claim 11, wherein

the two first areas are arranged on the first straight line passing through the optical axis and are parallel to a first direction on the pupil plane.

13. The exposure apparatus according to claim 11, wherein

the two second areas are approximately symmetrically arranged with respect to the optical axis on the pupil plane.

14. The exposure apparatus according to claim 13, wherein

a size of each of the two second areas is smaller than a size of each of the two first areas.

15. The exposure apparatus according to claim 14, wherein

the formation optical system can change the light amount distribution by at least one of movement of an optical element and exchange of optical elements.

16. The exposure apparatus according to claim 10, wherein

the illumination light distributed in the first areas is substantially linearly polarized light.

17. The exposure apparatus according to claim 16, wherein

a direction of the linearly polarized light approximately coincides with a tangent direction.

18. The exposure apparatus according to claim 10, wherein

the light amount distribution in which the amount of light is made larger in the two first areas and the two second areas is used in an illumination for the pattern which is periodical in one of two directions orthogonal to each other and that is isolated in the other of the two directions, and the one of the two directions orthogonal to each other corresponds to a first direction.

19. A device manufacturing method, comprising:

exposing the substrate with the exposure apparatus as recited in claim 10;

developing the exposed substrate; and

processing the developed substrate.