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Ringfield lithography

Assignee: Nokia Bell Labs
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Filing: 1991-07-19
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Granted: 1994-05-24
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Expires: 2011-07-19
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Abstract

Abstract Ringfield projection apparatus using x-ray radiation e.g. of 1.30 ANGSTROM wavelength is suitable for lithographic patterning in the fabrication of integrated circuits at design rules of 0.25 mu m and below. The design permits reduction from an enlarged mask as well as substantial throughput, the latter due to unexpectedly large slit width. Incorporation of a folding mirror improves fabrication expediency by moving the device being fabricated to the other side of the system from the mask.

Inventors

  • 👤 Tanya E. Jewell
  • 👤 Kevin Thompson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 15:36
CPC Classifications
G; G02; G02B; G02B17/00; G02B17/02; G02B17/06; G02B17/0647; G02B17/0657; H; H10; H10P; H10P34/00; B; B82; B82Y; B82Y10/00; G03; G03F; G03F7/00; G03F7/20; G03F7/2037; G03F7/2039; G03F7/70; G03F7/70008; G03F7/70033; G03F7/70058; G03F7/70066; G03F7/70216; G03F7/70233; G03F7/70283; G03F7/70358

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 109 words
Scanning ringfield reduction projection apparatus for lithographic patterning with x-ray radiation in the wavelength range of from 300 Å to 40 Å, the optics of the apparatus being all-reflective and comprising Distributed Bragg Reflectors, characterized in that the apparatus includes a scanning arcuate slit of constant radius from the optic axis along its length and of width in the scanning direction of at least 0.5 mm, the focusing optics consisting of four coaxial, spherical elements, which as viewed from object to image are, in succession, concave, convex, concave and concave, the third element providing an accessible stop, at least two elements having aspheric departures, and all elements being coaxial.
Claim 2
Dependent Claim 109 words
Scanning ringfield reduction projection apparatus for lithographic patterning with x-ray radiation in the wavelength range of from 300 Å to 40 Å, the optics of the apparatus being all-reflective and comprising Distributed Bragg Reflectors, characterized in that the apparatus includes a scanning arcuate slit of constant radius from the optic axis along its length and of width in the scanning direction of at least 0.5 mm, the focusing optics consisting of four coaxial, spherical elements, which as viewed from object to image are, in succession, concave, convex, concave and concave, the third element providing an accessible stop, at least two elements having aspheric departures, and all elements being coaxial.
Claim 3
Dependent Claim 23 words
Apparatus of claim 1 in which the width of the slit decreases from a central maximum value to compensate for otherwise-increased curvature-induced exposure.

References Cited (Backward Citations)

US3748015A Cited
US4240707A Cited
US4733955A Cited
US5153898A Cited
US4747678A Cited
US5063586A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-05-23 1997-11-22 1998-05-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-05-23 2001-11-22 2002-05-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-05-23 2005-11-22 2006-05-24 $7700.00 Window Closed / Lapsed

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