Zoom illumination system for use in photolithography
First Claim
1. An illumination system for photolithography, comprising:
- an illumination source and an optical integrator that together produce a plurality of incident source images;
a condenser that receives a plurality of incident beams from the plurality of incident source images and forms an illumination field at an illumination plane using the incident beams, the condenser including a Zoom Array Integrator (ZAI) having fixed and movable lens components arranged to controllably vary a size of the illumination field throughout a zoom range of the ZAI and to maintain telecentric illumination at a substantially fixed numerical aperture at the illumination plane throughout the zoom range, whereby the illumination field is scattered by an optical element and then telecentrically imaged to a reticle with a substantially fixed reticle numerical aperture at the reticle throughout the zoom range.
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Accused Products
Abstract
The present invention provides an illumination system for varying the size of an illumination field incident to a scattering optical element. The illumination field is subsequently imaged to a reticle in a photolithographic process. The illumination system includes, in series along an optical axis of the illumination system, an optical source, a beam conditioner, a first optical integrator, a first or input collimating lens, a zoom array integrator (ZAI), a second or output collimating lens, the optical scattering element, a relay lens, and the reticle. The ZAI includes an assembly of fixed and moveable lens components arranged to vary the size of the illumination field throughout a zoom range of the ZAI while maintaining telecentric illumination at a substantially fixed numerical aperture. Illumination telecentricity and substantially fixed numerical apertures are maintained at both the scattering optical element and the reticle throughout the zoom range.
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Citations
24 Claims
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1. An illumination system for photolithography, comprising:
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an illumination source and an optical integrator that together produce a plurality of incident source images;
a condenser that receives a plurality of incident beams from the plurality of incident source images and forms an illumination field at an illumination plane using the incident beams, the condenser including a Zoom Array Integrator (ZAI) having fixed and movable lens components arranged to controllably vary a size of the illumination field throughout a zoom range of the ZAI and to maintain telecentric illumination at a substantially fixed numerical aperture at the illumination plane throughout the zoom range, whereby the illumination field is scattered by an optical element and then telecentrically imaged to a reticle with a substantially fixed reticle numerical aperture at the reticle throughout the zoom range. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A Zoom Array Integrator (ZAI) for providing an illumination field useable in a photolithographic system, comprising:
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at least one fixed lens component; and
a plurality of moveable lens components, wherein the fixed and moveable lens components are arranged to controllably vary a size of the illumination field throughout a zoom range of the ZAI and to maintain telecentric illumination at a substantially fixed numerical aperture at the illumination field throughout the zoom range, whereby the illumination field is scattered by an optical element and then telecentrically imaged to a reticle with a substantially fixed reticle numerical aperture at the reticle throughout the zoom range.
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23. A Zoomable Array Integrator (ZAI) for providing an illumination field useable in a photolithographic system, comprising, in series along an optical axis of the ZAI:
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a fixed first X lens array having optical power in an X-direction;
a fixed first Y lens array having optical power in a Y-direction perpendicular to the X-direction;
a moveable second Y lens array having optical power in the Y-direction;
a fixed second X-array; and
a moveable third Y lens array, wherein the moveable second and third Y-arrays are moved along the optical axis to vary a size of the illumination field without a loss of optical energy at the illumination field. - View Dependent Claims (24)
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Specification