Lithographic apparatus and device manufacturing method
First Claim
1. A lithographic apparatus comprising:
- an illumination system to provide a projection beam of radiation, the illumination system defining an intensity distribution in a pupil plane, the illumination system comprising a first optical element constructed and arranged to deflect the projection beam over a first range of directions with a direction dependent intensity distribution determined by the optical element;
a support structure to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern;
a substrate table to hold a substrate; and
a projection system to project the patterned beam onto a target portion of the substrate;
a second optical element optically following said first optical element in a path of the projection beam, the first optical element and the second optical element each being arranged to pass a major part of the projection beam substantially without deflection, the second optical element deflecting a portion of the major part of the projection beam passed by the first optical element over a second range of directions with a direction dependent intensity distribution; and
a transmission blocking element to block transmission to the substrate of the part of intensity of the projection beam passed undeflected by both the optical element and the second optical element.
1 Assignment
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Accused Products
Abstract
A projection beam PB is projected onto a substrate W via a mask MA. The direction dependence of the intensity of the beam at the substrate W is controlled by passing the beam through a series of optical elements 120a-b in front of a pupil plane 14. The intensity distribution as a function of position in the pupil plane 14 determines the angle dependence at the substrate W. The optical elements 120a-b, which are preferably arrays of microlenses (or more particularly DOE'"'"'s: Diffractive Optical Elements) each define an angle dependence of the intensity of the beam PB. The optical elements 120a-b are each arranged to pass a major part of the beam PB substantially without deflection and a minor part with a deflection angle dependent intensity. The major part of the beam is blocked out of the beam behind the series of optical elements 120a-b. As a result an addition of the effects of upon the intensity in the pupil plane 14 is realized.
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Citations
18 Claims
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1. A lithographic apparatus comprising:
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an illumination system to provide a projection beam of radiation, the illumination system defining an intensity distribution in a pupil plane, the illumination system comprising a first optical element constructed and arranged to deflect the projection beam over a first range of directions with a direction dependent intensity distribution determined by the optical element;
a support structure to support a patterning device, the patterning device serving to pattern the projection beam according to a desired pattern;
a substrate table to hold a substrate; and
a projection system to project the patterned beam onto a target portion of the substrate;
a second optical element optically following said first optical element in a path of the projection beam, the first optical element and the second optical element each being arranged to pass a major part of the projection beam substantially without deflection, the second optical element deflecting a portion of the major part of the projection beam passed by the first optical element over a second range of directions with a direction dependent intensity distribution; and
a transmission blocking element to block transmission to the substrate of the part of intensity of the projection beam passed undeflected by both the optical element and the second optical element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A device manufacturing method comprising:
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providing a substrate that is at least partially covered by a layer of radiation-sensitive material;
providing a projection beam of radiation using an illumination system;
deflecting a projection beam of radiation with a first optical element over a range of directions with a direction dependent intensity distribution determined by the optical element and passing a major part of the beam substantially without deflection;
patterning the projection beam with a pattern in its cross-section; and
projecting the patterned beam of radiation onto a target portion of a layer of radiation-sensitive material on a substrate;
deflecting the passed portion of the projection beam over a further range of directions with a direction dependent intensity distribution with a second optical element and passing a major part of the projection beam substantially without deflection; and
blocking transmission to the substrate of the part of the projection beam passed undeflected by both the first optical element and the second optical element. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. An illumination optical system for use in a lithographic projection apparatus, comprising:
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a first optical element constructed and arranged to deflect a portion of a beam of radiation over a first range of directions with a direction dependent intensity distribution determined by the first optical element, such that a first deflected portion of the beam has less energy than a first undeflected portion of the beam;
a second optical element optically following said first optical element in a path of the projection beam and constructed and arranged to deflect a portion of the first undeflected portion of the beam from the first optical element, and producing a second direction dependent intensity distribution determined by the second optical element, such that a second deflected portion of the beam has less energy than a second undeflected portion of the beam; and
a blocking element to block transmission to the substrate of the second undeflected portion.
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Specification