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US 2004/0169835 A1Published application
Light condenser
AssigneeIntel Corporation
InventorMichael Goldstein
Life of this patent
Estimating the term…
Abstract
A light condenser suitable for EUV lithography that includes reflective rings concentric to an optical axis. Each ring has a reflective surface to reflect light rays emanating from a light source so that the light rays converge towards a mask to produce Köhler illumination on the mask. The reflective surface has a curve segment that includes a section of a parabolic curve that is rotated relative to an optical axis and has a focal point at the light source.
Claims30
A lithography system comprising:
- a light condenser having reflective surfaces concentric to an optical axis, each reflective surface to reflect light from a light source to produce an annular illumination that projects onto a mask to form a uniformly illuminated region on the mask, each reflective surface to reflect the light towards the mask with a predefined convergence angle, the convergence angle equal to the angle between the optical axis and a propagation direction of the light, the reflective surfaces collectively to reflect light towards the mask with more than one convergence angle.
An apparatus comprising:
- a first reflective surface to reflect light rays emanating from a point, the first reflective surface having a curvature such that substantially all of the reflected light rays propagate at a first angle relative to an axis that passes through the point and converge towards a region to produce uniform illumination at the region.
An apparatus comprising:
- a reflective surface positioned relative to an optical axis to reflect light rays emanating from a location on the optical axis so that the light rays converge towards a region on a plane perpendicular to the optical axis, the reflective surface having a curve segment that comprises a section of a parabolic curve having a focal point at the location and rotated an angle relative to the optical axis.
A lithography system comprising:
- a light source;
- a light condenser having reflective surfaces concentric to an optical axis, each reflective surface to reflect light from the light source to produce an annular illumination that projects onto a mask to form a uniformly illuminated region on the mask, each reflective surface to reflect the light towards the mask with a predefined convergence angle, the convergence angle equal to the angle between the optical axis and a propagation direction of the light, the reflective surfaces collectively to reflect light towards the mask with more than one convergence angle;
- projection optics to project an image reflected from the mask onto a substrate;
- and
- a stepper to move the mask and the substrate, the movement of the substrate correlated to the movement of the mask.
2 more elements
A method comprising:
- generating light rays from a location on an optical axis;
- reflecting the light rays with a first reflective surface having a curvature such that substantially all of the reflected light rays propagate with a first convergence angle relative to the optical axis, the light rays converging toward a region to produce uniform illumination at the region.
A method comprising:
- providing a first reflective surface to reflect light rays emanating from a location, the first reflective surface having a curvature such that reflected light rays propagate in a direction at a first angle with an axis and converge toward a region to produce uniform illumination at the region;
- and
- providing a second reflective surface to reflect light rays emanating from the location, the second reflective surface having a curvature such that reflected light rays propagate in a direction at a second angle with the axis and converge toward the region, the second angle different from the first angle.
A method of lithography comprising:
- generating light rays having wavelengths less than 300 nm;
- reflecting the light rays with a light condenser having a reflective surface with a curvature such that the reflected light rays converge relative to an optical axis towards a mask having a pattern to produce a uniformly illuminated region on the mask, the angle between the optical axis and the propagation direction of reflected light rays all being substantially the same;
- focusing an image of a portion of the pattern illuminated by the light rays onto a photo-resist on a substrate;
- and
- producing the pattern on the substrate.
2 more elements
Dependencies are inferred from the claim text.