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US5245384A Expired / Lapsed US ⏱️ 0.0 years remaining

Illuminating optical apparatus and exposure apparatus having the same

Assignee: Nikon Corp
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Filing: 1992-06-16
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Granted: 1993-09-14
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Expires: 2012-06-16
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Abstract

Abstract An illuminating optical apparatus adapted to eliminate the occurrence of any exposure light quantity loss and maintain an uniform exposure condition even if the σ value of an illuminating system is varied in response to changing of the pattern of a reticle to be exposed and an exposure apparatus having such illuminating optical apparatus. The illuminating optical apparatus includes an elliptical mirror for condensing an illuminating light from a light source, a collimating optical system for collimating the condensed illuminating light, an optical integrator for forming a plurality of secondary light sources from the coliminated illuminating light, and an afocal zoom optical system arranged in an optical path between the collimating optical system and the optical integrator to vary the secondary light sources in size. An image of an opening of the elliptical mirror is formed at an entrance surface of the optical integrator or in the vicinity thereof.

Inventors

  • 👤 Takashi Mori

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 12:46
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70058

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 154 words
An illuminating optical apparatus comprising: light source means for supplying an illuminating light; an elliptical mirror for condensing the illuminating light from said light source means; a collimating optical system for collimating the illuminating light condensed by said elliptical mirror; an optical integrator for forming a plurality of secondary light sources from the collimated light from said collimating optical system; a condenser optical system for condensing a plurality of light beams from said secondary light sources to illuminate in a superposing manner a surface to be irradiated; and an afocal zoom optical system arranged in an optical path between said collimating optical system and said optical integrator to vary said secondary light sources in size, said collimating optical system and said afocal zoom optical system being adapted so that an image of an opening of said elliptical mirror is formed at an entrance surface of said optical integrator or at a position near thereto.
Claim 2
Dependent Claim 154 words
An illuminating optical apparatus comprising: light source means for supplying an illuminating light; an elliptical mirror for condensing the illuminating light from said light source means; a collimating optical system for collimating the illuminating light condensed by said elliptical mirror; an optical integrator for forming a plurality of secondary light sources from the collimated light from said collimating optical system; a condenser optical system for condensing a plurality of light beams from said secondary light sources to illuminate in a superposing manner a surface to be irradiated; and an afocal zoom optical system arranged in an optical path between said collimating optical system and said optical integrator to vary said secondary light sources in size, said collimating optical system and said afocal zoom optical system being adapted so that an image of an opening of said elliptical mirror is formed at an entrance surface of said optical integrator or at a position near thereto.
Claim 3
Dependent Claim 50 words
An illuminating optical apparatus according to claim 1, wherein said afocal zoom optical system includes a plurality of lens group, and wherein at least one of said plurality of lens groups is moved in the direction of an optical axis thereof to vary the size of said secondary light sources.
Claim 4
Dependent Claim 49 words
An illuminating optical apparatus according to claim 1, further comprising stop means arranged at an exit-side focal position of said optical integrator or in the vicinity thereof to regulate the size of said secondary light sources varying in response to a zooming operation of said afocal zoom optical system.
Claim 5
Dependent Claim 36 words
An illuminating optical apparatus according to claim 1, further comprising wavelength extracting means arranged between said collimating optical system and said afocal zoom optical system for extracting light of a predetermined wavelength from said illuminating light.
Claim 6
Dependent Claim 31 words
An illuminating optical apparatus according to claim 2, wherein the entrance surface of said optical integrator and said surface to be irradiated are adapted to be substantially conjugate to each other.
Claim 7
Dependent Claim 148 words
An illuminating optical apparatus comprising: a light source for supplying an illuminating light; an elliptical mirror for condensing the illuminating light from said light source; a collimating optical system for collimating the illuminating light condensed by said elliptical mirror; an optical integrator for forming a plurality of secondary light sources from the collimated light beam from said collimating optical system; a condenser optical system for condensing a plurality of light beams from said secondary light sources to illuminate in a superposing manner a surface to be irradiated; and an afocal zoom optical system arranged in an optical path between said collimating optical system and said optical integrator to vary said secondary light sources in size; an opening of said elliptical mirror being arranged to be substantially conjugate to an entrance surface of said optical integrator with respect to said collimating optical system and said afocal zoom optical system.
Claim 8
Dependent Claim 148 words
An illuminating optical apparatus comprising: a light source for supplying an illuminating light; an elliptical mirror for condensing the illuminating light from said light source; a collimating optical system for collimating the illuminating light condensed by said elliptical mirror; an optical integrator for forming a plurality of secondary light sources from the collimated light beam from said collimating optical system; a condenser optical system for condensing a plurality of light beams from said secondary light sources to illuminate in a superposing manner a surface to be irradiated; and an afocal zoom optical system arranged in an optical path between said collimating optical system and said optical integrator to vary said secondary light sources in size; an opening of said elliptical mirror being arranged to be substantially conjugate to an entrance surface of said optical integrator with respect to said collimating optical system and said afocal zoom optical system.
Claim 9
Dependent Claim 54 words
An illuminating optical apparatus according to claim 6, wherein said afocal zoom optical system includes at least one movable lens group adapted for movement along an optical axis direction thereof whereby said at least one movable lens group is moved in said optical axis direction to vary the size of said secondary light sources.
Claim 10
Dependent Claim 40 words
An illuminating optical apparatus according to claim 7, wherein a condensing position of said illuminating light by said elliptical mirror and a position of an exit surface of said optical integrator are adapted to be substantially conjugate to each other.
Claim 11
Dependent Claim 31 words
An illuminating optical apparatus according to claim 8, wherein the entrance surface of said optical integrator and said surface to be irradiated are adapted to be substantially conjugate to each other.
Claim 12
Dependent Claim 36 words
An illuminating optical apparatus according to claim 9, further comprising wavelength extracting means arranged between said collimating optical system and said afocal zoom optical system to extract light having a predetermined wavelength from said illuminating light.
Claim 13
Dependent Claim 160 words
An exposure apparatus for transferring a circuit pattern on a reticle onto a wafer through a projection optical system, said apparatus comprising: light source means for supplying an illuminating light; an elliptical mirror for condensing the illuminating light from said light source means; a collimating optical system for collimating the illuminating light condensed by said elliptical mirror; an optical integrator for forming a plurality of secondary light sources from the collimated light beam from said collimating optical system; a condenser optical system for condensing a plurality of light beams from said secondary light sources to uniformly illuminate said reticle; and an afocal zoom optical system arranged in an optical path between said collimating optical system and said optical integrator to vary said secondary light sources in size; an opening of said elliptical mirror being adapted to be substantially conjugate to an entrance surface of said optical integrator with respect to said collimating optical system and said afocal zoom optical system.
Claim 14
Dependent Claim 160 words
An exposure apparatus for transferring a circuit pattern on a reticle onto a wafer through a projection optical system, said apparatus comprising: light source means for supplying an illuminating light; an elliptical mirror for condensing the illuminating light from said light source means; a collimating optical system for collimating the illuminating light condensed by said elliptical mirror; an optical integrator for forming a plurality of secondary light sources from the collimated light beam from said collimating optical system; a condenser optical system for condensing a plurality of light beams from said secondary light sources to uniformly illuminate said reticle; and an afocal zoom optical system arranged in an optical path between said collimating optical system and said optical integrator to vary said secondary light sources in size; an opening of said elliptical mirror being adapted to be substantially conjugate to an entrance surface of said optical integrator with respect to said collimating optical system and said afocal zoom optical system.
Claim 15
Dependent Claim 53 words
An exposure apparatus according to claim 11, wherein said afocal zoom optical system includes a plurality of lens groups, and wherein at least one of said plurality of lens groups is moved in the direction of an optical axis of said afocal zoom optical system to vary said secondary light sources in size.
Claim 16
Dependent Claim 27 words
An exposure apparatus according to claim 12, wherein the entrance surface of said optical integrator and said reticle are arranged to be substantially conjugate to each other.
Claim 17
Dependent Claim 102 words
An exposure apparatus according to claim 12, further comprising: a first variable aperture stop arranged on an exit side of said optical integrator; a second variable aperture stop arranged at a pupil position of said projection optical system; input means for inputting information necessary for obtaining a predetermined optimum illumination condition; drive means for moving at least one of the lens groups within said afocal zoom optical system in the optical axis direction thereof; and control means responsive to the input information from said input means to control said first variable aperture stop, said second variable aperture stop and said drive means.
Claim 18
Dependent Claim 63 words
An exposure apparatus according to claim 14, wherein a condensing position of said illuminating light by said elliptical mirror and a position of the exit surface of said optical integrator are adapted to be substantially conjugate to each other, and wherein the exit surface of said optical integrator and said second variable aperture stop are adapted to be substantially conjugate to each other.
Claim 19
Dependent Claim 113 words
An exposure apparatus according to claim 12, further comprising: a first variable aperture stop arranged on an exit side of said optical integrator; a second variable aperture stop arranged at a pupil position of said projection optical system; mark detecting means for detecting a mark formed on said reticle, said mark including information necessary for obtaining predetermined optimum illumination conditions; drive means whereby at least one of the lens groups within said afocal zoom optical system is moved in the optical axis direction thereof; and control means responsive to the detected information from said mark detecting means to control said first variable aperture stop, said second variable aperture stop and said drive means.
Claim 20
Dependent Claim 63 words
An exposure apparatus according to claim 16, wherein a condensing position of the illuminating light by said elliptical mirror and a position of an exit surface of said optical integrator are adapted to be substantially conjugate to each other, and wherein the exit surface of said optical integrator and said second variable aperture stop are adapted to be substantially conjugate to each other.

References Cited (Backward Citations)

US4497015A Cited
JPS59155843A Cited
US4668077A Cited
US4739373A Cited
US4851882A Cited
US4939630A Cited
US4851978A Cited
US5121160A Cited
US5160962A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-09-13 1997-03-15 1997-09-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-09-13 2001-03-15 2001-09-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-09-13 2005-03-15 2005-09-14 $7700.00 Window Closed / Lapsed

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