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US 2006/0076516 A1Published application
Reflective optical element, optical system and EUV lithography device
OwnerMarco Wedowskiinventor
Life of this patent
Estimating the term…
Abstract
In order to obtain optimal reflectivity on optical elements for the EUV and the soft X-ray range, multilayers constructed of a number of layers are used. Contamination or degradation of the surface leads to imaging defects and transmission losses. In the prior art, it has been attempted to counter a negative change in the surface by providing a cover layer system on the surface of the reflective optical element that should protect the surface. The invention renders the influence of the surface degradation manageable by a targeted selection of the distribution of thickness of the cover layer system, whereby at least one layer of the cover layer system has a gradient that is not equal to zero.
Claims40
A reflective optical element for the extreme ultraviolet and/or soft x-ray wavelength range comprising:
- a cover layer system having at least one layer to protect the surface, whose spatial structure can be described in a Cartesian system of coordinates (x, y, z) with z=z(x, y), wherein a thickness distribution d=d(x, y) of at least one layer of the cover layer system as a function of its spatial coordinates has a gradient not equal to zero.
A reflective optical element for the extreme ultraviolet and/or soft x-ray range, comprising:
- a cover layer system having at least one layer to protect the surface, whose spatial structure can be described in a Cartesian system of coordinates (x, y, z) with z=z(x, y), wherein the cover layer system has at least one outer layer and a layer lying underneath, and a thickness distribution d=d(x, y) of at least the layer of the cover layer system lying underneath, as a function of its spatial coordinates, has a gradient not equal to zero.
A reflective optical element, comprising:
- a multilayer system for the extreme ultraviolet and/or soft x-ray range with a cover layer system having at least one layer to protect the surface, whose spatial structure can be described in a Cartesian system of coordinates (x, y, z) with z=z(x, y), wherein the gradient of the thickness distribution d=d(x, y) of at least one layer of the cover layer system at the location (x, y) is not equal to the gradient of the thickness distribution of at most ten individual layers of the multilayer system immediately adjacent to the cover layer system.
A reflective optical element, comprising:
- a multilayer system for the extreme ultraviolet and/or soft x-ray wavelength range with a cover layer system having at least one layer to protect the surface, whose spatial structure can be described in a Cartesian system of coordinates (x, y, z) with z=z(x, y), wherein the cover layer system has at least one outer layer and a layer lying underneath, and the gradient of the thickness distribution d=d(x, y) of at least the layer of the cover layer system lying underneath at the location (x,y) is not equal to the gradient of the thickness distribution of at most ten individual layers of the multilayer system immediately adjacent to the cover layer system.
An optical system, comprising:
- at least two reflective optical elements for the extreme ultraviolet and/or soft x-ray wavelength range each with a cover layer system, wherein the cover layer systems have different materials, or different thickness distributions in the z-direction as a function of the x or y-coordinates, or x and y-coordinates, or a combination thereof, and the thickness distribution of at least one layer of one cover layer system has a gradient not equal to zero.
An optical system, comprising:
- at least two reflective optical elements for the extreme ultraviolet and/or soft x-ray wavelength range each with a cover layer system, wherein the cover layer systems have different materials, or different thickness distributions in the z-direction as a function of the x or y-coordinates, or x and y-coordinates, or a combination thereof, and the cover layer system has at least one outer layer and a layer lying underneath, and the thickness distribution d=d(x, y) of at least the layer of the cover layer system lying underneath has a gradient not equal to zero.
An optical system comprising:
- at least two reflective optical elements for the extreme ultraviolet and/or soft x-ray wavelength range each with a cover layer system, wherein the cover layer systems have different materials, or different thickness distributions in the z-direction as a function of the x or y-coordinates, or x and y-coordinates, or a combination thereof, and the gradient of the thickness distribution d=d(x, y) of at least one layer of one cover layer system at the location (x, y) is unequal to all gradients of at most ten individual layers of the multilayer system immediately adjacent to the cover layer system.
An optical system, comprising:
- at least two reflective optical elements for the extreme ultraviolet and/or soft x-ray wavelength range each with a cover layer system, wherein the cover layer systems have different materials, or different thickness distributions in the z-direction as a function of the x or y-coordinates, or x and y-coordinates, or combinations thereof, and the gradient of the thickness distribution d=d(x, y) of at least the layer of one cover layer system lying underneath at the location (x, y) is unequal to all gradients of at most ten individual layers of the multilayer system immediately adjacent to the cover layer system.
An EUV lithography appliance, comprising:
- at least two reflective optical elements for the extreme ultraviolet and/or soft x-ray wavelength range with at least one cover layer system, wherein the cover layer systems have different materials, or different thickness distributions in the z-direction as a function of the x or y-coordinates, or x and y-coordinates, or a combination thereof, and the thickness distribution of at least one layer of one cover layer system has a gradient not equal to zero.
An EUV lithography appliance, comprising:
- at least two reflective optical elements for the extreme ultraviolet and/or soft x-ray wavelength range with at least one cover layer system, wherein the cover layer system has at least one outer layer and one layer lying underneath, and the cover layer systems have different materials, or different thickness distributions in the z-direction as a function of the x or y-coordinates, or x and y-coordinates, or a combination thereof, and the thickness distribution of at least the layer of a cover layer system lying underneath has a gradient not equal to zero.
Dependencies are inferred from the claim text.