Illumination optical system, exposure apparatus having the same, and device fabricating method

• US 20030197847A1
• Filed: 04/23/2003
• Published: 10/23/2003
• Est. Priority Date: 04/23/2002
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Shinoda, Kenichiro
• Granted Patent: US 6,894,764 B2
• Time in Patent Office: Days
• US Class Current: 355/67
• 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 7/70183 Zoom systems for adjusting beam diameter

Abstract

An illumination optical system for illuminating a reticle using light from a light source includes an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the reticle while making variable a ratio of a light amount between a first area and a second area different from the first area, the first and second areas being on the, plane.

Claims

1. An illumination optical system for illuminating a reticle using light from a light source, said illumination optical system comprising an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the reticle while making variable a ratio of a light amount between a first area and a second area different from the first area, the first and second areas being on the plane.

2. An illumination optical system according to claim 1, wherein light from the first area substantially illuminates the reticle to resolve a desired pattern on the reticle, and light from the second area substantially illuminates the reticle to restrain an auxiliary pattern on the reticle from resolving.

3. An illumination optical system according to claim 1, wherein the illumination-light generating mechanism includes a prism or diffraction optical element.

4. An illumination optical system for illuminating an object surface using light from a light source, said illumination optical system comprising an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially-Fourier conversion relationship with the object surface,

wherein said illumination-light generating mechanism includes:

a first light transmission element that is arranged at a side of the light source and forms a first light division part for diving the light on a surface of the first light transmission element; and

a second light transmission element that is arranged at a side of the object surface and forms a second light division part for diving the light on a surface of the second light transmission element, and

wherein the first and second light division parts have non-parallel sectional shapes that include an optical axis.

5. An illumination optical system according to claim 4, wherein the first and second light transmission elements move in an optical-axis direction relative to each other,

wherein one of the first and second light transmission elements has a polyhedral incidence or exit end, and the other of the first and second light transmission elements has a cone incidence or exit surface.

6. An illumination optical system according to claim 4, wherein the first light transmission element has a concave polyhedral or cone incidence end and a plane exit end, while the second light transmission element has a convex plane incidence end and a polyhedral or cone exit end.

7. An illumination optical system according to claim 4, wherein the first light transmission element has a convex plane incidence end and a polyhedral or cone exit end, while the second light transmission element has a concave polyhedral or cone incidence end and a plane exit end.

8. An illumination optical system according to claim 5, wherein the polyhedral end of the first and/or second light transmission elements has a pyramid shape.

9. An illumination optical system for illuminating an object surface using light from a light source, said illumination optical system comprising a prism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the object surface,

wherein said prism having an incidence surface has a polygonal pyramid shape, and a cone exit surface.

10. An illumination optical system for illuminating an object surface using light from a light source, said illumination optical system comprising an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the object surface,

wherein said illumination-light generating mechanism includes:

a first prism that receives the light from the light source; and

a second prism that receives light from the first prism, and

wherein one of the first and second prisms has a polyhedral incidence or exit end, and the other of the first and second prisms has a cone incidence or exit surface.

11. An illumination optical system according to claim 10, wherein at least one of the first and second prisms are adapted to be movable in an optical-axis direction.

12. An illumination optical system according to claim 10, wherein at least one of the first and second prisms are rotatable around an optical axis.

13. An exposure method comprising the step of illuminating a reticle using an illumination optical system with light from a light source,

wherein the illumination optical system includes an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the reticle while making variable a ratio of a light amount between a first area and a second area different from the first area, the first and second areas being on the plane, and

wherein light from the first area substantially contributes to a resolution of a desired pattern on the reticle, and light from the second area substantially contributes to a restraint of an auxiliary pattern from resolving.

14. An exposure apparatus comprising:

an illumination optical system that includes an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with a reticle while making variable a ratio of a light amount between a first area and a second area different from the first area, the first and second areas being on the plane; and

a projection optical system for projecting light from the reticle onto an object to be exposed.

15. An exposure apparatus comprising:

an illumination optical system that includes an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the object surface, wherein said illumination-light generating mechanism includes a first light transmission element that is arranged at a side of the light source and forms a first light division part for diving the light on a surface of the first light transmission element, and a second light transmission element that is arranged at a side of the object surface and forms a second light division part for diving the light on a surface of the second light transmission element, and wherein the first and second light division parts have non-parallel sectional shapes that include an optical axis; and

a projection optical system for projecting light from the reticle onto an object to be exposed.

16. An exposure apparatus comprising:

an illumination optical system that includes a prism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the object surface, wherein said prism having an incidence surface having a polygonal pyramid shape, and a cone exit surface; and

a projection optical system for projecting light from the reticle onto an object to be exposed.

17. An exposure apparatus comprising:

an illumination optical system that includes an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the object surface, wherein said illumination-light generating mechanism includes a first prism that receives the light from the light source, and a second prism that receives light from the first prism, and wherein one of the first and second prisms has a polyhedral incidence or exit end, and the other of the first and second prisms has a cone incidence or exit surface; and

a projection optical system for projecting light from the reticle onto an object to be exposed.

18. A device fabricating method comprising the steps of:

exposing an object using an exposure apparatus; and

performing a predetermined process for the object that has been exposed,

wherein the exposure apparatus includes;

an illumination optical system that includes an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the reticle while making variable a ratio of a light amount between a first area and a second area different from the first area, the first and second areas being on the plane; and

a projection optical system for projecting light from the reticle onto an object to be exposed.

19. A device fabricating method comprising the steps of:

exposing an object using an exposure apparatus; and

performing a predetermined process for the object that has been exposed,

wherein the exposure apparatus includes;

an illumination optical system that includes an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the object surface, wherein said illumination-light generating mechanism includes a first light transmission element that is arranged at a side of the light source and forms a first light division part for diving the light on a surface of the first light transmission element, and a second light transmission element that is arranged at a side of the object surface and forms a second light division part for diving the light on a surface of the second light transmission element, and wherein the first and second light division parts have non-parallel sectional shapes that include an optical axis; and

a projection optical system for projecting light from the reticle onto an object to be exposed.

20. A device fabricating method comprising the steps of:

exposing an object using an exposure apparatus; and

performing a predetermined process for the object that has been exposed,

wherein the exposure apparatus includes;

an illumination optical system that includes a prism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the object surface, wherein said prism having an incidence surface having a polygonal pyramid shape, and a cone exit surface; and

a projection optical system for projecting light from the reticle-onto an object to be exposed.

21. A device fabricating method comprising the steps of:

exposing an object using an exposure apparatus; and

performing a predetermined process for the object that has been exposed,

wherein the exposure apparatus includes;

an illumination optical system that includes an illumination-light generating mechanism for generating a light amount distribution on a plane that has a substantially Fourier conversion relationship with the object surface, wherein said illumination-light generating mechanism includes a first prism that receives the light from the light source, and a second prism that receives light from the first prism, and wherein one of the first and second prisms has polyhedral incidence or exit ends, and the other of the first and second prisms has cone incidence or exit surfaces; and

a projection optical system for projecting light from the reticle onto an object to be exposed.