Spectral purity filter for multi-layer mirror, lithographic apparatus including such multi-layer mirror, method for enlarging the ratio of desired radiation and undesired radiation, and device manufacturing method
First Claim
1. A multi-layer mirror, comprising:
- a multi-layer stack, the multi-layer stack comprising a plurality of alternating layers with a multi-layer stack top layer and a spectral filter top layer arranged on the multi-layer stack, the spectral filter top layer comprisinga first spectral purity enhancement layer comprising a first material and having a first layer thickness d1;
an intermediate layer comprising a second material and having a second layer thickness d2; and
a second spectral purity enhancement layer comprising a third material and having a third layer thickness d3, the second spectral purity enhancement layer being arranged on the multi-layer stack top layer, wherein the first material is selected from Si3N4, SiO2, ZnS, Te, diamond, CsI, Se, SiC, amorphous carbon, MgF2, CaF2, TiO2, Ge, PbF2, ZrO2, BaTiO3, LiF or NaF, the third material is selected from Si3N4, SiO2, ZnS, Te, diamond, CsI, Se, SiC, amorphous carbon, MgF2, CaF2, TiO2, Ge, PbF2, ZrO2, BaTiO3, LiF or NaF, the second material comprises a material different from the first and third materials, and d1+d2+d3 has a thickness between 2.5 and 40 nm, and wherein the first, second and third materials and the first, second and third layer thicknesses are configured to minimize absorption and/or destructive interference of radiation having a wavelength selected from a first wavelength range of 5-20 nm, and maximize absorption and/or destructive interference of radiation having a wavelength selected from a second wavelength range of 100-400 nm.
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Abstract
A multi-layer mirror includes on top of the multi-layer mirror a spectral purity enhancement layer, for example for application in an EUV lithographic apparatus. This spectral purity enhancement layer includes a first spectral purity enhancement layer, but between the multi-layer mirror and first spectral purity enhancement layer there may optionally be an intermediate layer or a second spectral purity enhancement layer and intermediate layer. Hence, multi-layer mirrors with the following configurations are possible: multi-layer mirror/first spectral purity enhancement layer; multi-layer mirror/intermediate layer/first spectral purity enhancement layer; and multi-layer mirror/second spectral purity enhancement layer/intermediate layer/first spectral purity enhancement layer. The spectral purity of normal incidence radiation may be enhanced, such that DUV radiation is diminished relatively stronger than EUV radiation.
22 Citations
18 Claims
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1. A multi-layer mirror, comprising:
a multi-layer stack, the multi-layer stack comprising a plurality of alternating layers with a multi-layer stack top layer and a spectral filter top layer arranged on the multi-layer stack, the spectral filter top layer comprising a first spectral purity enhancement layer comprising a first material and having a first layer thickness d1; an intermediate layer comprising a second material and having a second layer thickness d2; and a second spectral purity enhancement layer comprising a third material and having a third layer thickness d3, the second spectral purity enhancement layer being arranged on the multi-layer stack top layer, wherein the first material is selected from Si3N4, SiO2, ZnS, Te, diamond, CsI, Se, SiC, amorphous carbon, MgF2, CaF2, TiO2, Ge, PbF2, ZrO2, BaTiO3, LiF or NaF, the third material is selected from Si3N4, SiO2, ZnS, Te, diamond, CsI, Se, SiC, amorphous carbon, MgF2, CaF2, TiO2, Ge, PbF2, ZrO2, BaTiO3, LiF or NaF, the second material comprises a material different from the first and third materials, and d1+d2+d3 has a thickness between 2.5 and 40 nm, and wherein the first, second and third materials and the first, second and third layer thicknesses are configured to minimize absorption and/or destructive interference of radiation having a wavelength selected from a first wavelength range of 5-20 nm, and maximize absorption and/or destructive interference of radiation having a wavelength selected from a second wavelength range of 100-400 nm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A lithographic apparatus comprising a multi-layer mirror, the multi-layer mirror comprising a multi-layer stack, the multi-layer stack comprising a plurality of alternating layers with a multi-layer stack top layer and a spectral filter top layer arranged on the multi-layer stack, the spectral filter top layer comprising
a first spectral purity enhancement layer comprising a first material and having a first layer thickness d1; -
an intermediate layer comprising a second material and having a second layer thickness d2; and a second spectral purity enhancement layer comprising a third material and having a third layer thickness d3, the second spectral purity enhancement layer being arranged on the multi-layer stack top layer, wherein the first material is selected from Si3N4, SiO2, ZnS, Te, diamond, CsI, Se, SiC, amorphous carbon, MgF2, CaF2, TiO2, Ge, PbF2, ZrO2, BaTiO3, LiF or NaF, the third material is selected from Si3N4, SiO2, ZnS, Te, diamond, CsI, Se, SiC, amorphous carbon, MgF2, CaF2, TiO2, Ge, PbF2, ZrO2, BaTiO3, LiF or NaF,the second material comprises a material different from the first and third materials, and d1+d2+d3 has a thickness between 2.5 and 40 nm, and wherein the first, second and third materials and the first, second and third layer thicknesses are configured to minimize absorption and/or destructive interference of radiation having a wavelength selected from a first wavelength range of 5-20 nm, and maximize absorption and/or destructive interference of radiation having a wavelength selected from a second wavelength range of 100-400 nm. - View Dependent Claims (15)
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16. A method for enlarging the ratio of radiation having a wavelength selected from a first wavelength range of 5-20 nm and radiation having a wavelength selected from a second wavelength range of 100-400 nm in a beam of radiation of a source emitting radiation in both wavelength ranges, the method comprising reflecting at least part of the beam of radiation on a multi-layer mirror comprising a multi-layer stack, the multi-layer stack comprising a plurality of alternating layers with a multi-layer stack top layer and a spectral filter top layer arranged on the multi-layer stack, the spectral filter top layer comprising a first spectral purity enhancement layer comprising a first material and having a first layer thickness d1;
- an intermediate layer comprising a second material and having a second layer thickness d2; and
a second spectral purity enhancement layer comprising a third material and having a third layer thickness d3, the second spectral purity enhancement layer being arranged on the multi-layer stack top layer, wherein the first material is selected from Si3N4, SiO2, ZnS, Te, diamond, CsI, Se, SiC, amorphous carbon, MgF2, CaF2, TiOF2, Ge, PbF2, ZrOF2, BaTiOF3, LiF or NaF, the third material is selected from Si3N4, SiO2, ZnS, Te, diamond, CsI, Se, SiC, amorphous carbon, MgF2, CaF2, TiOF2, Ge, PbF2, ZrOF2, BaTiOF3, LiF or NaF, the second material comprises a material different from the first and third materials, and d1+d2+d3 has a thickness between 2.5 and 40 nm, and wherein the first, second and third materials and the first, second and third layer thicknesses are configured to minimize absori,tion and/or destructive interference of radiation having a wavelength selected from the first wavelength range, and maximize absorption and/or destructive interference of radiation having a wavelength selected from the second wavelength range. - View Dependent Claims (17)
- an intermediate layer comprising a second material and having a second layer thickness d2; and
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18. A device manufacturing method, comprising:
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providing a beam of radiation; patterning the beam of radiation; projecting the patterned beam of radiation onto a target portion of the substrate; enlarging the ratio of radiation having a wavelength selected from a first wavelength range of 5-20 nm and radiation having a wavelength selected from a second wavelength range of 100-400 nm in a beam of radiation of a source emitting radiation in both wavelength ranges by reflecting at least part of the beam of radiation on a multi-layer mirror comprising a multi-layer stack, the multi-layer stack comprising a plurality of alternating layers with a multi-layer stack top layer and a spectral filter top layer arranged on the multi-layer stack, the spectral filter top layer comprising a first spectral purity enhancement layer comprising a first material and having a first layer thickness dl;
an intermediate layer comprising a second material and having a second layer thickness d2; and
a second spectral purity enhancement layer comprising a third material and having a third layer thickness d3, the second spectral purity enhancement layer being arranged on the multi-layer stack top layer, wherein the first material is selected from Si3N4, SiO2, ZnS, Te, diamond, CsI, Se, SiC, amorphous carbon, MgF2, CaF2, TiOF2, Ge, PbF2, ZrOF2, BaTiOF3, LiF or NaF, the third material is selected from Si3N4, SiO2, ZnS, Te, diamond, CsI, Se, SiC, amorphous carbon, MgF2, CaF2, TiOF2, Ge, PbF2, ZrOF2, BaTiOF3, LiF or NaF, the second material comprises a material different from the first and third materials, and d1+d2+d3 has a thickness between 2.5 and 40 nm, and wherein the first, second and third materials and the first, second and third layer thicknesses are configured to minimize absorption and/or destructive interference of radiation having a wavelength selected from the first wavelength range, and maximize absorption and/or destructive interference of radiation having a wavelength selected from the second wavelength range.
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Specification