Catadioptric imaging systems for digital scanner

• US 10,488,638 B2
• Filed: 07/05/2017
• Issued: 11/26/2019
• Est. Priority Date: 11/22/2013
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Williamson, David M.
• Primary Examiner(s): Deherrera, Kristina M
• Application Number:
  US15/642,116
• Publication Number:
  US 20170307863A1
• Time in Patent Office: 874 Days
• Field of Search: 359355
• CPC Class Codes: G02B 17/0816 off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements
• CPC Class Codes: G02B 17/0892 specially adapted for the UV
• CPC Class Codes: G02B 27/0031 for scanning purposes
• CPC Class Codes: G03F 7/70225 Optical aspects of catadioptric systems, i.e. comprising reflective and refractive elements

Abstract

Projection optical system for forming an image on a substrate and including an illumination relay lens and a projection lens each of which is a catadioptric system. The projection lens may include two portions in optical communication with one another, the first of which is dioptric and the second of which is catadioptric. In a specific case, the projection optical system satisfies

$4<\frac{{\beta }_I}{{\beta }_T}<30,$
where β_I and β_T are magnifications of the first portion and the overall projection lens. Optionally, the projection lens may be structured to additionally satisfy

$6<\frac{{\beta }_{\mathrm{II}}}{{\beta }_T}<20,$
where β_II is a magnification of the second portion. A digital scanner including such projection optical system and operating with UV light having a spectral bandwidth on the order of 1 picometer. Method for forming an image with such projection optical system.

Claims

1. A projection optical system configured to form an image on an image plane, comprising:

a first optical system having a concave mirror, said first optical system configured to form an intermediate optical image;

a second optical system configured as a dioptric optical system disposed to form an image of the intermediate image on the image plane;

said first and second optical systems aggregately configured to satisfy a condition of

2. A projection optical system according to claim 1, further comprising a catadioptric illumination relay lens and a spatial light modulator (SLM) positioned to receive light from the catadioptric illumination relay lens and reflect said light towards the first and second optical systems.

3. A projection optical system according to claim 1,

wherein said projection optical system is configured to satisfy a condition of

4. A projection optical system according to claim 1,

wherein said projection optical system is configured to satisfy a condition of |β

_II|<

|β

_I|, wherein β

_II denotes a magnification of the first optical system.

5. A projection optical system according to claim 1,

wherein said first optical system is configured such that said light directed through the projection optical system towards the image plane passes through a first group of lenses including a first negative lens, then through a second group of lenses, and then is reflected with a concave mirror to form a reflected beam transmitted through the second group of lenses.

6. A projection optical system according to claim 5, wherein the second group of lenses includes second and third negative lenses immediately adjacent to one another, a concave surface of the second negative lens facing away from the concave mirror, a concave surface of the third negative lens facing the concave mirror.

7. A projection optical system according to claim 6, wherein the second group of lenses further comprises a positive lens between the first group of lenses and the third negative lens.

8. A projection optical system according to claim 1, wherein the second optical system comprises at least two positive lenses disposed immediately adjacent to one another such as to receive light directly from the intermediate image.

9. A projection optical system according to claim 8, wherein the second optical system further comprises at least two negative lenses disposed immediately adjacent to one another between said at least two positive lenses and the image plane.

10. A projection optical system according to claim 9, wherein the second optical system further comprises a light-condensing lens unit between the at least two negative lenses and the image plane.

11. A projection optical system according to claim 10, wherein every lens of the light-condensing lens-unit is a positive lens.

12. A projection optical system according to claim 1, characterized, in operation with light having a central wavelength of about 193.3 nm and a spectral bandwidth of about 1 picometer, a first Strehl ratio at the central wavelength and a second Strehl ratio across the spectral bandwidth, both the first and second Strehl ratios exceeding 0.95.

13. A projection optical system according to claim 1, configured to form the image with a reduction ratio of at least 50.

14. An exposure apparatus configured to expose a substrate to light delivered thereto through liquid from an object, said exposure apparatus comprising:

a stage configured to support a substrate defining an image plane; and

a projection optical system comprising;

a first optical system having a concave mirror, said first optical system configured to form an intermediate optical image;

a second optical system configured as a dioptric optical system disposed to form an image of the intermediate image on the image plane;

said first and second optical systems aggregately configured to satisfy a condition of

15. An exposure apparatus according to claim 14, further comprising an illumination relay lens disposed to illuminate the object with the light passing therethrough.

16. An exposure apparatus according to claim 15, wherein said illumination relay lens includes a catadioptric illumination relay lens.

17. A method for manufacturing a device, the method comprising:

exposing a substrate with light delivered thereto from an object through liquid with the use of the projection optical system that comprises

a first optical system having a concave mirror, said first optical system configured to form an intermediate optical image;

a second optical system configured as a dioptric optical system disposed to form an image of the intermediate image on the image plane;

wherein said first and second optical systems are aggregately configured to satisfy a condition of

18. A projection optical system configured to form an image on an image plane, the projection optical system comprising:

a first optical system including a concave mirror positioned to form an intermediate optical image;

a second optical system configured as a dioptric optical system and disposed to form an image of the intermediate image on the image plane;

said first and second optical systems aggregately configured to satisfy a condition of

19. A projection optical system according to claim 18, further comprising a catadioptric illumination relay lens and a spatial light modulator (SLM) positioned to receive light from the catadioptric illumination relay lens and reflect said light towards the first and second optical systems.

20. A projection optical system according to claim 18, wherein said projection optical system is configured to satisfy a condition

21. A projection optical system according to claim 20, wherein said projection optical system is configured to satisfy a condition of |β

_II|<

|β

_I|.

22. A projection optical system according to claim 18, characterized, in operation with light having a central wavelength of about 193.3 nm and a spectral bandwidth of about 1 picometer, a first Strehl ratio at the central wavelength and a second Strehl ratio across the spectral bandwidth, both the first and second Strehl ratios exceeding 0.95.