Exposure method and apparatus

• US 20050151942A1
• Filed: 12/22/2004
• Published: 07/14/2005
• Est. Priority Date: 12/26/2003
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Kawashima, Haruna
• Granted Patent: US 7,145,635 B2
• Time in Patent Office: Days
• US Class Current: 355/30
• CPC Class Codes: G03B 27/52 Details
• CPC Class Codes: G03F 7/70341 Details of immersion lithography aspects, e.g. exposure media or control of immersion liquid supply chemical composition of immersion liquids G03F7/2041
• CPC Class Codes: G03F 7/70916 Pollution mitigation, i.e. mitigating effect of contamination or debris, e.g. foil traps

Abstract

An exposure apparatus includes a projection optical system for projecting a pattern on a mask onto an object to be exposed, a final surface of the projection optical system and a surface of the object being immersed in a fluid, and a plane-parallel plate arranged between the projection optical system and the object, wherein the plane-parallel plate includes a first surface and a second surface that serves as a back surface of the first surface and opposes to the object, both the first and second surfaces being immersed in the fluid.

Claims

1. An exposure apparatus comprising:

a projection optical system for projecting a pattern on a mask onto an object to be exposed, a final surface of said projection optical system and a surface of the object being immersed in a fluid; and

a plane-parallel plate arranged between said projection optical system and the object,

wherein said plane-parallel plate includes a first surface and a second surface that serves as a back surface of the first surface and opposes to the object, both the first and second surfaces being immersed in the fluid.

2. An exposure apparatus according to claim 1, wherein said projection optical system includes an optical element that is closest to said plane-parallel plate, and a medium that contacts a surface of the optical element at a side opposite to the plane-parallel plate is gas.

3. An exposure apparatus according to claim 1, wherein said projection optical system includes an optical element that is closest to said plane-parallel plate, and the optical element has a plane surface at the side of said plane-parallel plate.

4. An exposure apparatus according to claim 3, wherein an incident angle of light upon the optical element is maintained below the Brewster angle.

5. An exposure apparatus according to claim 3, wherein a distance between the first surface and the optical element is longer than a distance between the second surface and the object.

6. An exposure apparatus according to claim 1, wherein said plane-parallel plate has an antireflection coating that is designed according to incident light at an angle corresponding to a numerical aperture of the projection optical system.

7. An exposure apparatus according to claim 1, wherein said plane-parallel plate has a quartz substrate.

11. A device manufacturing method comprising the steps of:

exposing an object using an exposure apparatus according to claim 1;

and

developing an object that has been exposed.

8. An exposure method for immerses, in a fluid, a surface of an object to be exposed, and a final surface of a projection optical system, and for projecting a pattern on a mask onto the object via the projection optical system, said exposure method comprising the steps of:

immersing, in the fluid, a first surface of a plane-parallel plate arranged between the projection optical system and the object;

immersing, in the fluid, a second surface of the plane-parallel plate which serves as a back surface of the first surface and opposes to the object; and

projecting the pattern on the object via the plane-parallel plate.

9. An exposure method according to claim 8, further comprising the step of inserting the plane-parallel plate between the projection optical system and the object.

10. An exposure method according to claim 8, wherein said projection optical system includes an optical element that is closest to the plane-parallel plate,

wherein said exposure method further comprises the step of separating a first medium as a fluid that fills a space between the plane-parallel plate and the object, from a second medium as a fluid that fills a space between the plane-parallel plate and the optical element, and for independently controlling circulations of the first medium and the second medium.