EXPOSURE APPARATUS AND DEVICE MANUFACTURING METHOD

Abstract

An exposure apparatus for exposing a pattern of a reticle onto a substrate includes an illumination optical system configured to illuminate the reticle on a target plane to be illuminated using light from a light source, wherein the illumination optical system includes a computer-generated hologram configured to discretely form plural bright spots on a plane that has a Fourier transformation relationship with the target plane when the light that has no angular distribution is incident upon the computer-generated hologram, and an optical element configured to introduce the light that has an angular distribution to the computer-generated hologram.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic sectional view of a structure of an exposure apparatus according to one aspect of the present invention.

FIGS. 2A and 2B are views for explaining a conventional DOE.

FIGS. 3A and 3B are views for explaining a DOE in the exposure apparatus shown in FIG. 1.

FIGS. 4A and 4B are views for explaining a variation of the DOE in the exposure apparatus shown in FIG. 1.

FIGS. 5A and 5B are views for explaining another variation of the DOE in the exposure apparatus shown in FIG. 1.

FIG. 6 is a schematic sectional view showing a turret as one illustrative changer that changes a sectional shape of the light incident upon each point of the DOE in the exposure apparatus shown in FIG. 1.

FIG. 7 is a schematic sectional view showing a structure of a fly-eye lens arranged on the turret shown in FIG. 6.

FIGS. 8A and 8B are views for explaining a change of a size of a light intensity pattern formed by the DOE shown in FIGS. 5A and 5B.

FIG. 9 is a schematic sectional view showing one illustrative adjuster that adjusts a divergent angle of the light incident upon the DOE in the exposure apparatus shown in FIG. 1.

FIG. 10 is a flowchart for explaining a manufacture of a device.

FIG. 11 is a flowchart for a wafer process of step 4 shown in FIG. 10.

Claims

1. An exposure apparatus for exposing a pattern of a reticle onto a substrate, the exposure apparatus comprising an illumination optical system configured to illuminate the reticle on a target plane to be illuminated using light from a light source, wherein the illumination optical system includes: a computer-generated hologram configured to discretely form plural bright spots on a plane that has a Fourier transformation relationship with the target plane when the light that has no angular distribution is incident upon the computer-generated hologram; andan optical element configured to introduce the light that has an angular distribution to the computer-generated hologram.

2. An exposure apparatus according to claim 1, wherein when the optical element introduces the light having the angular distribution to the computer-generated hologram, a light intensity distribution on the plane that has the Fourier transformation relationship with the target plane becomes uniform.

3. An exposure apparatus according to claim 1, wherein the illumination optical system further includes a condenser optical system configured to condense the light from the computer-generated hologram, wherein the condenser optical system has a variable focal length.

4. An exposure apparatus according to claim 1, wherein the illumination optical system further includes a condenser optical system configured to condense the light from the computer-generated hologram, wherein d=2×f×tan γ is met where d is a minimum interval in the plural bright spots, γ is a divergent angle of the light incident upon the computer-generated hologram, and f is a focal length of the condenser optical system.

5. An exposure apparatus according to claim 1, wherein the illumination optical system further includes a changer configured to change a sectional shape of the light incident upon the computer-generated hologram with respect to a plane perpendicular to an optical axis of the illumination optical system.

6. An exposure apparatus according to claim 5, wherein the sectional shape is one of a circle, a rectangle, and a hexagon.

7. An exposure apparatus according to claim 1, wherein the illumination optical system further includes an adjuster configured to adjust a divergent angle of the light incident upon the computer-generated hologram.

8. An exposure apparatus according to claim 2, wherein the light intensity distribution has a multipole distribution.

9. An exposure apparatus according to claim 2, wherein the light intensity distribution is a continuous distribution that connects two adjacent light intensity distributions corresponding to two adjacent bright spots.

10. A device manufacturing method comprising the steps of: exposing a substrate using an exposure apparatus; anddeveloping the substrate that has been exposed, wherein the exposure apparatus includes an illumination optical system configured to illuminate the reticle on a target plane to be illuminated using light from a light source, wherein the illumination optical system includes:a computer-generated hologram configured to discretely form plural bright spots on a plane that has a Fourier transformation relationship with the target plane when the light that has no angular distribution is incident upon the computer-generated hologram; andan optical element configured to introduce the light that has an angular distribution to the computer-generated hologram.