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Projection optical system, exposure apparatus, and exposure method

a projection optical system and exposure apparatus technology, applied in the field of projection optical systems, exposure apparatuses, exposure methods, etc., can solve the problems of increasing reflection loss occurring at the optical surface, and the projection optical system cannot obtain a large effective numerical aperture at the image side, so as to achieve high accuracy, reduce the accuracy of alignment, and improve the effect of accuracy

Inactive Publication Date: 2009-02-19
NIKON CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention relates to a projection optical system for an exposure apparatus used in the manufacturing of microdevices. The system needs to have a higher resolution and a larger effective numerical aperture (NA) than the conventional system to improve the resolution of the projection optic. However, the conventional system cannot achieve this because it is limited by the refractive index of the liquid used for exposure. To solve this problem, the invention provides a projection optic with a catadioptric and off-axis structure that reduces the portion of the image space filled with liquid, allowing for a micropattern to be projected and exposed with high accuracy without enlarging the substrate stage or lowering the accuracy of the alignment optic.

Problems solved by technology

This increases reflection loss occurring at an optical surface.
As a result, the projection optical system cannot obtain a large effective numerical aperture at its image side.

Method used

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  • Projection optical system, exposure apparatus, and exposure method
  • Projection optical system, exposure apparatus, and exposure method
  • Projection optical system, exposure apparatus, and exposure method

Examples

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first example

[0060]FIG. 4 shows a lens structure of a projection optical system according to a first example of the present embodiment. As shown in FIG. 4, the first imaging optical system G1 included in the projection optical system PL of the first example includes a plane parallel plate P1, a biconvex lens L11, a positive meniscus lens L12 having a convex surface at its reticle side, a biconvex lens L13, a biconcave lens L14 having an aspherical concave surface at its reticle side, a positive meniscus lens L15 having a convex surface at its reticle side, a positive meniscus lens L16 having a concave surface at its reticle side, a negative meniscus lens L17 having a concave surface at its reticle side, a positive meniscus lens L18 having an aspherical concave surface at its reticle side, a positive meniscus lens L19 having a concave surface at its reticle side, a biconvex lens L110, and a positive meniscus lens L111 having an aspherical concave surface at its wafer side, which are arranged sequ...

second example

[0067]FIG. 6 shows a lens structure for a projection optical system according to a second example of the present embodiment. As shown in FIG. 6, the first imaging optical system G1 in the projection optical system PL of the second example includes a plane parallel plate P1, a biconvex lens L11, a positive meniscus lens L12 having a convex surface at its reticle side, a positive meniscus lens L13 having a convex surface at its reticle side, a biconcave lens L14 having an aspherical concave surface at its reticle side, a positive meniscus lens L15 having a convex surface at its reticle side, a positive meniscus lens L16 having a concave surface at its reticle side, a negative meniscus lens L17 having a concave surface at its reticle side, a positive meniscus lens L18 having an aspherical concave surface at its reticle side, a positive meniscus lens L19 having a concave surface at its reticle side, a biconcave lens L110, and a positive meniscus lens L111 having an aspherical concave su...

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Abstract

An immersion projection optical system having, for example, a catadioptric and off-axis structure, reduces the portion of an image space filled with liquid (immersion liquid). The projection optical system, which projects a reduced image of a first plane onto a second plane through the liquid, includes a refractive optical element (Lp) arranged nearest to the second plane. The refractive optical element includes a light emitting surface (Lpb) shaped to be substantially symmetric with respect to two axial directions (XY-axes) perpendicular to each other on the second plane. The light emitting surface has a central axis (Lpba) that substantially coincides with a central axis (40a) of a circle (40) corresponding to a circumference of a light entering surface (Lpa) of the refractive optical element. The central axis of the light emitting surface is decentered in one of the two axial directions (Y-axis) from an optical axis (AX).

Description

TECHNICAL FIELD[0001]The present invention relates to a projection optical system, an exposure apparatus, and an exposure method, and more particularly, to a projection optical system optimal for an exposure apparatus used to manufacture microdevices, such as semiconductor devices and liquid crystal display devices, through a photolithography process.BACKGROUND ART[0002]An exposure apparatus projects and exposes an image of a pattern of a mask (or a reticle) on a photosensitive substrate (e.g., wafer or a glass plate coated by a photoresist). More specifically, the exposure apparatus uses a projection optical system to project and expose the image in a photolithography process, in which semiconductor devices or the like are manufactured. The projection optical system is required to have a higher resolution due to the increasing level of integration of semiconductor devices or the like manufactured with the exposure apparatus.[0003]To improve the resolution of the projection optical ...

Claims

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Application Information

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Patent Type & Authority Applications(United States)
IPC IPC(8): G03B27/54
CPCG02B1/06G02B17/0892G02B21/33G03F7/702G03F7/70341G02B17/08G03F7/70225G03F7/2041G03F7/70275H01L21/0273H01L21/0274G03F7/70725
Inventor OMURA, YASUHIROOKADA, TAKAYANAGASAKA, HIROYUKI
Owner NIKON CORP
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