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US 8,558,988 B2Granted
Thin film continuous spatially modulated grey attenuators and filters
AssigneeASML Holding N.V.
InventorsYuli Vladimirsky, Lev Ryzhikov, Ronald A. Wilklow
Life of this patent
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Abstract
A system and method for use of a lithography apparatus having a substrate and an absorbing film formed on the substrate. A thickness of the absorbing film is spatially modulated across at least a part of the substrate to reduce a non-uniform intensity of a radiation beam transmitted through the substrate.
Claims19
A lithography apparatus, comprising:
- a substrate;
- an absorbing film formed on the substrate;
- a wavefront compensator configured to compensate for a refractive effect of the absorbing film and formed on the substrate,
- wherein a thickness of the absorbing film is spatially modulated across at least a part of the substrate to reduce a non-uniform intensity of a radiation beam transmitted through the substrate, and
- wherein a thickness of the wavefront compensator is inversely proportional to the spatially modulated thickness of the absorbing film across at least a part of the substrate.
2 more elements
A lithography apparatus, comprising:
- an illumination system configured to condition a beam of radiation;
- a patterning device configured to pattern the beam of radiation;
- a projection system configured to project the patterned beam onto a target area of a workpiece;
- and
- an attenuator to condition the beam of radiation including
- a substrate,
- an absorbing film located on the substrate, and
- a wavefront compensator configured to compensate for a refractive effect of the absorbing film and formed on the substrate,
- wherein a thickness of the absorbing film is spatially modulated across at least a part of the substrate to reduce a non-uniform intensity of the radiation beam, and
- wherein a thickness of the wavefront compensator is inversely proportional to the thickness of the absorbing film across at least a part of the substrate.
7 more elements
A method, comprising:
- transmitting a radiation beam through a wavefront compensator located on a substrate to reduce wavefront non-uniformity of the radiation beam;
- and
- transmitting the radiation beam through an absorbing film located on the substrate, wherein the absorbing film has a thickness that is spatially modulated across at least a part of the substrate to reduce a non-uniform intensity of the radiation beam, and wherein a thickness of the wavefront compensator is inversely proportional to the thickness of the absorbing film across at least a part of the substrate.
Dependencies are inferred from the claim text.