MEASUREMENT METHOD AND APPARATUS, EXPOSURE APPARATUS, EXPOSURE METHOD, AND ADJUSTING METHOD

Abstract

A measurement method for measuring a position of an aperture stop in an optical system includes the steps of measuring a light intensity distribution of light that passes the aperture stop, at a position that is optically conjugate with a pupil position in the optical system, and determining a position of the aperture stop in the optical system based on a diffraction fringe of the light intensity distribution measured by the measuring step.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a light intensity distribution at an aperture stop's edge.

FIG. 2 illustrates diffraction at the aperture stop's edge.

FIG. 3 is a schematic sectional view showing a structure of an exposure apparatus according to one aspect of the present invention.

FIG. 4 is a flowchart for explaining a measurement method according to one aspect of the present invention.

FIG. 5 is a schematic sectional view showing a structure of the exposure apparatus according to one aspect of the present invention.

FIG. 6 is a schematic sectional view showing a structure of a mask shown in FIG. 5.

FIG. 7 is a schematic sectional view showing a structure of a measuring part shown in FIG. 5.

FIG. 8 is a schematic sectional view showing a structure of the exposure apparatus according to one aspect of the present invention.

FIG. 9 is a flowchart for explaining an exposure method according to one aspect of the present invention.

FIG. 10 is a flowchart for explaining a fabrication of a device (a semiconductor device and a liquid crystal display device).

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

FIG. 12 is a schematic diagram showing a pattern formed on a photosensitive substrate.

Claims

1. A measurement method for measuring a position of an aperture stop in an optical system, said measurement method comprising the steps of: measuring a light intensity distribution of light that passes the aperture stop, at a position that is optically conjugate with a pupil position in the optical system; anddetermining a position of the aperture stop in the optical system based on a diffraction fringe of the light intensity distribution measured by the measuring step.

2. A measurement method according to claim 1, wherein the determining step includes the steps of: calculating an integral curve relative to a radial direction of the aperture stop based on a rotational integration from a center of outline of the light intensity distribution;calculating one or more extreme values in the integral curve; andcalculating a numerical aperture of the aperture stop based on the one or more extreme values.

3. A measurement method according to claim 1, wherein the determining step includes the steps of: calculating an integral curve relative to a radial direction of the aperture stop based on a rotational integration from a center of outline of the light intensity distribution;calculating one or more extreme values in the integral curve from each of plural section curves that pass the center of outline of the light intensity distribution; andcalculating a shape of the aperture stop based on the one or more extreme values.

4. A measurement method according to claim 1, wherein the determining step calculates a positional offset of the aperture stop in an optical axis direction.

5. A measurement method according to claim 1, wherein the determining step includes the steps of: calculating an integral curve relative to a radial direction of the aperture stop based on a rotational integration from a center of outline of the light intensity distribution;calculating at least one local maximum or minimum value from a leading edge of the integral curve to an n-th leading or trailing edge where n is an integer of 0 or greater; andcalculating a position of the aperture stop in a radial direction or a positional offset of the aperture stop in an optical axis direction based on the at least one local maximum or minimum value.

6. A measurement apparatus for measuring a position of an aperture stop in an optical system, said measurement apparatus comprising: a measurement unit arranged at a position that is optically conjugate with a pupil position in the optical system, the measurement unit measuring a light intensity distribution of light that has passed the aperture stop; anda controller for controlling the position of the aperture stop in the optical system based on a diffraction fringe of the light intensity distribution measured by the measurement unit.

7. A measurement apparatus according to claim 6, further comprising a mask that has an aperture part that transmits the light, and a diffusion part that diffuses the light, the mask being located at a position that is optically conjugate with an object plane of the optical system.

8. An exposure apparatus comprising: a projection optical system for projecting a pattern of a reticle onto a substrate;a mask that has an aperture part that transmits the light, and a diffusion part that diffuses the light, the mask being located at a position that is substantially optically conjugate with an object plane of the projection optical system;a measurement unit arranged at a position that is optically conjugate with a pupil position in the projection optical system, the measurement unit measuring a light intensity distribution of light that has passed the aperture stop; anda controller for controlling a position of the aperture stop in the projection optical system based on a diffraction fringe of the light intensity distribution measured by the measurement unit.

9. An exposure method for exposing a pattern of a reticle onto a substrate via a projection optical system, said exposure method comprising the steps of: exposing a mask pattern of a mask onto a substrate at plural different exposure doses, the mask having an aperture part that transmits the light, and a diffusion part that diffuses the light, the mask being located at or near a position optically conjugate with an object plane of the projection optical system, and apart from an image plane of the projection optical system; anddetermining a position of the aperture stop in the projection optical system based on the mask pattern exposed on the substrate.

10. An adjusting method comprising the steps of: measuring a position of an aperture stop in an optical system using a measurement method according to claim 1; andadjusting the aperture stop in the optical system based on a measurement result of the measuring step.

11. An adjusting method comprising the steps of: measuring a position of an aperture stop in an optical system using a measurement apparatus according to claim 6; andadjusting the aperture stop in the optical system based on a measurement result of the measuring step.