Reflective optical element for EUV lithography device
First Claim
1. A reflective optical element configured for an operating wavelength in at least one of the soft x-ray and extreme ultraviolet wavelength range, comprising:
- a multilayer system comprising;
at least two alternating layers of respective materials having differing real parts of the index of refraction at the operating wavelength, andat least two additional layers of further material, the at least two additional layers adjoining each other, and situated adjoining at least one of the two alternating layers,wherein the two additional layers differ respectively at a transition from the layer having a lower real part of the index of refraction to the layer having a higher real part of the index of refraction and at a transition from the layer having a higher real part of the index of refraction to the layer having a lower real part of the index of refraction.
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Accused Products
Abstract
A reflective optical element exhibits an increase in the maximum reflectivity at operating wavelengths in the extreme ultraviolet or soft x-ray wavelength range. A first additional intermediate layer (23a, 23b) and a second additional intermediate layer (24a, 24b) are provided between the absorber layer (22) and the spacer layer (21), wherein the first additional intermediate layer increases the reflectivity and the second additional intermediate layer (24a,b) prevents chemical interaction between the first additional intermediate layer (23a,b) and the adjoining spacer layer (21) and/or the absorber layer (22).
19 Citations
21 Claims
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1. A reflective optical element configured for an operating wavelength in at least one of the soft x-ray and extreme ultraviolet wavelength range, comprising:
a multilayer system comprising; at least two alternating layers of respective materials having differing real parts of the index of refraction at the operating wavelength, and at least two additional layers of further material, the at least two additional layers adjoining each other, and situated adjoining at least one of the two alternating layers, wherein the two additional layers differ respectively at a transition from the layer having a lower real part of the index of refraction to the layer having a higher real part of the index of refraction and at a transition from the layer having a higher real part of the index of refraction to the layer having a lower real part of the index of refraction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A reflective optical element configured for an operating wavelength in at least one of the soft x-ray and extreme ultraviolet wavelength range, comprising:
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a multilayer system comprising; at least two alternating layers of respective materials having differing real parts of the index of refraction at the operating wavelength, and at least two additional layers of further material situated adjoining at least one of the two alternating layers, wherein the two additional layers differ respectively at a transition from the layer having a lower real part of the index of refraction to the layer having a higher real part of the index of refraction and at a transition from the layer having a higher real part of the index of refraction to the layer having a lower real part of the index of refraction; and wherein a sequence of the two additional layers at a transition from the layer having the lower real part of the index of refraction to the layer having the higher real part of the index of refraction differs from a sequence of the two additional layers at a transition from the layer having the higher real part of the index of refraction to the layer having the lower real part of the index of refraction.
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14. A reflective optical element configured for an operating wavelength in at least one of the soft x-ray and extreme ultraviolet wavelength range, comprising:
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a multilayer system comprising; at least two alternating layers of respective materials having differing real parts of the index of refraction at the operating wavelength, and at least two additional layers of further material situated adjoining at least one of the two alternating layers, wherein the two additional layers differ respectively at a transition from the layer having a lower real part of the index of refraction to the layer having a higher real part of the index of refraction and at a transition from the layer having a higher real part of the index of refraction to the layer having a lower real part of the index of refraction; and wherein a first of the at least two additional layers of a further material is situated on at least one transition between the two alternating layers, which results in an increase of the maximum reflectivity of the multilayer system at the operating wavelength in comparison to the reflectivity without the additional layer, and a second of the at least two additional layers of another further material is situated on the at least one transition, which acts as a barrier between the adjoining layers.
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15. A reflective optical element configured for an operating wavelength in at least one of the soft x-ray and extreme ultraviolet wavelength range, comprising:
a multilayer system comprising; at least two alternating layers of respective materials having differing real parts of the index of refraction at the operating wavelength, and at least two additional layers of further respective materials situated adjoining at least one of the two alternating materials, wherein a first of the additional layers of a first of the further materials is situated on at least one transition between the two alternating layers, which results in an increase of the maximum reflectivity of the multilayer system at the operating wavelength in comparison to the reflectivity without the additional layer, and a second of the additional layers of a second of the further materials is situated on the at least one transition, which acts as a barrier between the adjoining layers. - View Dependent Claims (16, 17, 18, 19, 20, 21)
Specification