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US4856905A Expired / Lapsed US ⏱️ 0.0 years remaining

Projection exposure apparatus

Assignee: Nikon Corp
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Filing: 1988-05-10
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Granted: 1989-08-15
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Expires: 2008-05-10
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Abstract

Abstract A projection exposure apparatus capable of improving the precision of baseline measurement has an objective optical system whose chromatic aberration has been corrected for a first wavelength and a second wavelength and which is used for introducing the lights of first and second wavelengths into an imging optical system through a mask, a first illuminating system for focusing the light of the first wavelength at a plane of the mask and a plane of a substrate through the objective optical system, a second illuminating system for focusing the light of the second wavelength at a plane of the mask and a plane of the substrate through the objective optical system, and deflecting means for commonly deflecting the lights of first and second wavelengths entering the objective optical system in such a manner that the lights of first and second wavelengths respectively scan alignment marks formed on the mask and substrate at the same time.

Inventors

  • 👤 Kenji Nishi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 09:29
CPC Classifications
G; G03; G03F; G03F9/00; G03F9/70; G03F9/7065

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 171 words
A projection exposure apparatus comprising: an imaging optical system for projecting the image of an object placed on a first plane onto a second plane, wherein said first and second planes are mutually conjugate for a first wavelength with respect to said imaging optical system; first and second alignment mark means respectively formed on said first and second planes; means for supplying a first radiation beam of said first wavelength; means for supplying a second radiation beam of a second wavelength different from said first wavelength; optical means for focusing, through a common light path, said first and second radiation beams on said first plane in the vicinity of said first alignment mark means, and further focusing said beams through said imaging optical system on said second plane in the vicinity of said second alignment mark means; and deflection means for simultaneously varying the direction of said first and second radiation beams in such a manner that said first and second radiation beams scan said first and second alignment mark means.
Claim 2
Dependent Claim 171 words
A projection exposure apparatus comprising: an imaging optical system for projecting the image of an object placed on a first plane onto a second plane, wherein said first and second planes are mutually conjugate for a first wavelength with respect to said imaging optical system; first and second alignment mark means respectively formed on said first and second planes; means for supplying a first radiation beam of said first wavelength; means for supplying a second radiation beam of a second wavelength different from said first wavelength; optical means for focusing, through a common light path, said first and second radiation beams on said first plane in the vicinity of said first alignment mark means, and further focusing said beams through said imaging optical system on said second plane in the vicinity of said second alignment mark means; and deflection means for simultaneously varying the direction of said first and second radiation beams in such a manner that said first and second radiation beams scan said first and second alignment mark means.
Claim 3
Dependent Claim 19 words
A projection exposure apparatus according to claim 1, wherein said deflection means is provided on said common light path.
Claim 4
Dependent Claim 42 words
A projection exposure apparatus according to claim 1, wherein said optical means comprises multiple focus optical means for focusing a part of said second radiation beam onto said first plane and another part of said second radiation beam onto said second plane.
Claim 5
Dependent Claim 41 words
A projection exposure apparatus according to claim 1, further comprising alignment means for determining the relative positions of said first and second alignment mark means, based on said first and second radiation beams illuminating said first and second alignment mark means.

References Cited (Backward Citations)

US4795244A Cited
US4798962A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-08-14 1993-02-13 1993-08-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-08-14 1997-02-13 1997-08-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-08-14 2001-02-13 2001-08-15 $7700.00 Window Closed / Lapsed

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