Illumination system for illuminating a mask in a microlithographic exposure apparatus
First Claim
1. A diffractive optical element configured to be inserted into a light beam path of an illumination system of a microlithographic projection exposure apparatus so that, during use of the illumination system, the diffractive optical element produces an intensity distribution in a pupil surface of the illumination system,wherein:
- a Fourier transform of an angular distribution produced by the diffractive optical element differs from the intensity distribution;
the diffractive optical element comprises a plurality of gratings; and
the gratings are configured so that, during use of the diffractive optical element, each ray of light incident on the gratings is deflected so that rays of the light emerging from the gratings diverge from each other.
2 Assignments
0 Petitions
Accused Products
Abstract
An illumination system of a micro-lithographic projection exposure apparatus is provided, which is configured to illuminate a mask positioned in a mask plane. The system includes a pupil shaping optical subsystem and illuminator optics that illuminate a beam deflecting component. For determining a property of the beam deflecting component, an intensity distribution in a system pupil surface of the illumination system is determined. Then the property of the beam deflecting component is determined such that the intensity distribution produced by the pupil shaping subsystem in the system pupil surface approximates the intensity distribution determined before. At least one of the following aberrations are taken into account in this determination: (i) an aberration produced by the illuminator optics; (ii) an aberration produced by the pupil shaping optical subsystem; (iii) an aberration produced by an optical element arranged between the system pupil surface and the mask plane.
21 Citations
27 Claims
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1. A diffractive optical element configured to be inserted into a light beam path of an illumination system of a microlithographic projection exposure apparatus so that, during use of the illumination system, the diffractive optical element produces an intensity distribution in a pupil surface of the illumination system,
wherein: -
a Fourier transform of an angular distribution produced by the diffractive optical element differs from the intensity distribution; the diffractive optical element comprises a plurality of gratings; and the gratings are configured so that, during use of the diffractive optical element, each ray of light incident on the gratings is deflected so that rays of the light emerging from the gratings diverge from each other. - View Dependent Claims (2, 3, 4, 5, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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6. A method, comprising:
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determining an angular distribution to be produced by a diffractive optical element configured to be inserted in an illumination system of a microlithographic projection exposure apparatus so that, during use of the illumination system, the diffractive optical element produces together with a pupil shaping system, which is between the diffractive optical element and a pupil surface of the illumination system, an intensity distribution in the pupil surface of the illumination system that approximates a desired intensity distribution, wherein; the diffractive optical element comprises a plurality of gratings; the gratings are configured so that, during use of the diffractive optical element, each ray of light incident on the gratings is deflected so that rays of the light emerging from the gratings diverge from each other; a Fourier transform of an angular distribution produced by the diffractive optical element differs from the desired intensity distribution; and the determination comprises taking into account at least one of the following; an aberration produced by illuminator optics which are configured to illuminate the diffractive optical element; and an aberration produced by the pupil shaping optical subsystem. - View Dependent Claims (7, 8)
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20. An illumination system, comprising:
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a diffractive optical element configured to be inserted into a light beam path of the illumination system so that, during use of the illumination system, the diffractive optical element produces an intensity distribution in a pupil surface of the illumination system; a zoom lens group having a front focal plane; and an optical raster element between the zoom lens group and the pupil surface of the illumination system, wherein; the diffractive optical element is disposed in the front focal plane of the zoom lens group; a Fourier transform of an angular distribution produced by the diffractive optical element differs from the intensity distribution; and the illumination system is a microlithographic illumination system. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27)
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Specification