Projection optical system
First Claim
Patent Images
1. A projection exposure apparatus comprising:
- an illumination optical system including a light source for illuminating a patterning structure;
a projection optical system for projecting an image of the illuminated patterning structure onto a substrate;
the illumination optical system and the projection optical system each comprising a plurality of lenses;
wherein each of the lenses has a maximum design fluence value associated therewith, the maximum design fluence value representing a predetermined expected maximum fluence that the respective lens will be exposed to during a standard mode of operation of the projection exposure apparatus;
at least one lens being made of a lens material selected from a first group of lens materials wherein, after exposure to a given number of pulses of radiation of a given pulse length, each lens material of the first group has a characteristic transition point representative of a fluence value, wherein each lens material of the first group will have rarefied after exposure to the given number of pulses of radiation of the given pulse length having any fluence value below its transition point, and wherein each lens material of the first group will have densified after exposure to the given number of pulses of radiation of the given pulse length having any fluence value above its transition point; and
wherein the transition point of each lens material of the first group satisfies the following condition;
TRC<
0.8·
HD wherein TRC represents the transition point of the respective lens material, HD represents the design fluence value of the respective lens, and wherein at least one lens is made of a first fused silica material comprised in the first group of lens materials, wherein a transmittance of the first fused silica material obeys the relationship
T=10−
(ko+kind)·
l with T denoting the transmittance, k0 being an absorption coefficient of the first fused silica material before exposure to light of a wavelength of 193.4 nm, k0+kind being a total absorption coefficient after the first fused silica material has been exposed to 160 million pulses of radiation having a fluence of 5 mJ/cm2 and a wavelength of 193.4 nm, and l being a length of a path of light through the first fused silica material, and wherein the following condition is fulfilled;
kind<
10−
3 cm−
1.
1 Assignment
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Accused Products
Abstract
Radiation-induced damage to a lens material in a projection exposure system is reduced by selection of maximum design fluence values HD for lenses and at least one lens made of a material having a characteristic transition point TRC after exposure to a given amount of radiation, wherein, for instance, TRC<0.8. HD among other relationships and/or characteristics of the lenses.
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Citations
38 Claims
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1. A projection exposure apparatus comprising:
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an illumination optical system including a light source for illuminating a patterning structure;
a projection optical system for projecting an image of the illuminated patterning structure onto a substrate;
the illumination optical system and the projection optical system each comprising a plurality of lenses;
wherein each of the lenses has a maximum design fluence value associated therewith, the maximum design fluence value representing a predetermined expected maximum fluence that the respective lens will be exposed to during a standard mode of operation of the projection exposure apparatus;
at least one lens being made of a lens material selected from a first group of lens materials wherein, after exposure to a given number of pulses of radiation of a given pulse length, each lens material of the first group has a characteristic transition point representative of a fluence value, wherein each lens material of the first group will have rarefied after exposure to the given number of pulses of radiation of the given pulse length having any fluence value below its transition point, and wherein each lens material of the first group will have densified after exposure to the given number of pulses of radiation of the given pulse length having any fluence value above its transition point; and
wherein the transition point of each lens material of the first group satisfies the following condition;
TRC<
0.8·
HDwherein TRC represents the transition point of the respective lens material, HD represents the design fluence value of the respective lens, and wherein at least one lens is made of a first fused silica material comprised in the first group of lens materials, wherein a transmittance of the first fused silica material obeys the relationship
T=10−
(ko +kind )·
lwith T denoting the transmittance, k0 being an absorption coefficient of the first fused silica material before exposure to light of a wavelength of 193.4 nm, k0+kind being a total absorption coefficient after the first fused silica material has been exposed to 160 million pulses of radiation having a fluence of 5 mJ/cm2 and a wavelength of 193.4 nm, and l being a length of a path of light through the first fused silica material, and wherein the following condition is fulfilled;
kind<
10−
3 cm−
1. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. Projection exposure apparatus comprising:
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an illumination optical system including a light source for illuminating a patterning structure;
a projection optical system for projecting an image of the illuminated patterning structure onto a substrate;
the illumination optical system and the projection optical system each comprising a plurality of lenses;
wherein each location on a surface of each lens has a design fluence value associated therewith, the design fluence value representing a predetermined expected fluence that the respective location on the surface of the lens will be exposed to during a standard mode of operation of the projection exposure apparatus;
wherein each location on the surface of each lens has a design fluence gradient value associated therewith, the design fluence gradient value representing a predetermined expected change of the design fluence value per unit length;
and wherein each lens has a first location with a maximum design gradient product associated therewith, the maximum design gradient product representing a maximum product of the design fluence gradient value and the design fluence value at the location of the design fluence gradient value for the respective lens;
at least one lens being made of a lens material selected from a second group of lens materials wherein each lens of the second group has a characteristic transition point after exposure to a given number of pulses of radiation of a given pulse length, wherein each lens material will have rarefied after exposure to the given number of pulses of radiation of the given pulse length having any fluence value below the transition point, and wherein each lens material will densified after exposure to the given number of pulses of radiation of the given pulse length having any fluence value above the transition point;
wherein each lens material further has a characteristic minimum value associated therewith, the minimum value representing a fluence value causing the greatest extent of rarefaction in the lens material after exposure to the given number of pulses of radiation of the given pulse length, and wherein the minimum value Hmin of each lens material of the second group satisfies the following condition;
Hmin<
HGHmaxwherein HGHmax represents the design fluence value at the location with the maximum design gradient product, and Hmin represents the minimum value of the respective lens material, and wherein at least one lens is made of a first fused silica material comprised in the second group of lens materials, wherein a transmittance of the first fused silica material obeys the relationship
T=10−
(ko +kind )·
lwith T denoting the transmittance, k0 being an absorption coefficient of the first fused silica material before exposure to light of a wavelength of 193.4 nm, k0+kind being a total absorption coefficient after the first fused silica material has been exposed to 160 million pulses of radiation having a fluence of 5 mJ/cm2 and a wavelength of 193.4 nm, and l being a length of a path of light through the first fused silica material, and wherein the following condition is fulfilled;
kind<
10−
3 cm−
1. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A projection exposure apparatus comprising:
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an illumination optical system including a light source for illuminating a patterning structure;
a projection optical system for projecting an image of the illuminated patterning structure onto a substrate;
the illumination optical system and the projection optical system each comprising a plurality of lenses;
wherein each of the lenses has a maximum design fluence value associated therewith, the maximum design fluence value representing a predetermined expected maximum fluence that the respective lens will be exposed to during a standard mode of operation of the projection exposure apparatus;
at least one lens being made of a lens material selected from a first group of lens materials wherein, after exposure to a given number of pulses of radiation of a given pulse length, each lens material of the first group has a characteristic transition point representative of a fluence value, wherein each lens material of the first group will have rarefied after exposure to the given number of pulses of radiation of the given pulse length having any fluence value below its transition point, and wherein each lens material of the first group will have densified after exposure to the given number of pulses of radiation of the given pulse length having any fluence value above its transition point; and
wherein the transition point of each lens material of the first group satisfies the following condition;
TRC<
0.8·
HDwherein TRC represents the transition point of the respective lens material, HD represents the design fluence value of the respective lens, and wherein at least one lens is made of a first fused silica material comprised in the first group of lens materials, which first fused silica material comprises a fused silica material manufactured by depositing SiO2-particles to form a porous soot body, followed by vitrification, which first fused silica material has a H2-content of about 5·
1015 molecules/cm3 or more.
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32. A projection exposure apparatus comprising:
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an illumination optical system including a light source for illuminating a patterning structure;
a projection optical system for projecting an image of the illuminated patterning structure onto a substrate;
the illumination optical system and the projection optical system each comprising a plurality of lenses;
wherein each of the lenses has a maximum design fluence value associated therewith, the maximum design fluence value representing a predetermined expected maximum fluence that the respective lens will be exposed to during a standard mode of operation of the projection exposure apparatus;
at least one lens being made of a lens material selected from a first group of lens materials wherein, after exposure to a given number of pulses of radiation of a given pulse length, each lens material of the first group has a characteristic transition point representative of a fluence value, wherein each lens material of the first group will have rarefied after exposure to the given number of pulses of radiation of the given pulse length having any fluence value below its transition point, and wherein each lens material of the first group will have densified after exposure to the given number of pulses of radiation of the given pulse length having any fluence value above its transition point; and
wherein the transition point of each lens material of the first group satisfies the following condition;
TRC<
0.8·
HDwherein TRC represents the transition point of the respective lens material, HD represents the design fluence value of the respective lens, and wherein at least one lens is made of a first fused silica material comprised in the first group of lens materials, which first fused silica material comprises a fused silica material manufactured by depositing SiO2-particles to form a porous soot body, followed by vitrification, which first fused silica material has an OH-content of about 50 ppm by weight or less. - View Dependent Claims (33)
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34. Projection exposure apparatus comprising:
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an illumination optical system including a light source for illuminating a patterning structure;
a projection optical system for projecting an image of the illuminated patterning structure onto a substrate;
the illumination optical system and the projection optical system each comprising a plurality of lenses;
wherein each location on a surface of each lens has a design fluence value associated therewith, the design fluence value representing a predetermined expected fluence that the respective location on the surface of the lens will be exposed to during a standard mode of operation of the projection exposure apparatus;
wherein each location on the surface of each lens has a design, fluence gradient value associated therewith, the design fluence gradient value representing a predetermined expected change of the design fluence value per unit length;
and wherein each lens has a first location with a maximum design gradient product associated therewith, the maximum design gradient product representing a maximum product of the design fluence gradient value and the design fluence value at the location of the design fluence gradient value for the respective lens;
at least one lens being made of a lens material selected from a second group of lens materials wherein each lens of the second group has a characteristic transition point after exposure to a given number of pulses of radiation of a given pulse length, wherein each lens material will have rarefied after exposure to the given number of pulses of radiation of the given pulse length having any fluence value below the transition point, and wherein each lens material will densified after exposure to the given number of pulses of radiation of the given pulse length having any fluence value above the transition point;
wherein each lens material further has a characteristic minimum value associated therewith, the minimum value representing a fluence value causing the greatest extent of rarefaction in the lens material after exposure to the given number of pulses of radiation of the given pulse length, and wherein the minimum value Hmin of each lens material of the second group satisfies the following condition;
Hmin<
HGHmaxwherein HGHmax represents the design fluence value at the location with the maximum design gradient product, and Hmin represents the minimum value of the respective lens material, and wherein at least one lens is made of a first fused silica material comprised in the second group of lens materials, which first fused silica material comprises a fused silica material manufactured by depositing SiO2-particles to form a porous soot body, followed by vitrification, which first fused silica material has a H2-content of about 5·
1015 molecules/cm3 or more.
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35. Projection exposure apparatus comprising:
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an illumination optical system including a light source for illuminating a patterning structure;
a projection optical system for projecting an image of the illuminated patterning structure onto a substrate;
the illumination optical system and the projection optical system each comprising a plurality of lenses;
wherein each location on a surface of each lens has a design fluence value associated therewith, the design fluence value representing a predetermined expected fluence that the respective location on the surface of the lens will be exposed to during a standard mode of operation of the projection exposure apparatus;
wherein each location on the surface of each lens has a design fluence gradient value associated therewith, the design fluence gradient value representing a predetermined expected change of the design fluence value per unit length;
and wherein each lens has a second location with a maximum design gradient product associated therewith, the maximum design gradient product representing a maximum product of the design fluence gradient value and the design fluence value at the location of the design fluence gradient value for the respective lens;
at least one lens being made of a lens material selected from a second group of lens materials wherein each lens of the second group has a characteristic transition point after exposure to a given number of pulses of radiation of a given pulse length, wherein each lens material will have rarefied after exposure to the given number of pulses of radiation of the given pulse length having any fluence value below the transition point, and wherein each lens material will densified after exposure to the given number of pulses of radiation of the given pulse length having any fluence value above the transition point;
wherein each lens material further has a characteristic minimum value associated therewith, the minimum value representing a fluence value causing the greatest extent of rarefaction in the lens material after exposure to the given number of pulses of radiation of the given pulse length, and wherein the minimum value Hmin of each lens material of the second group satisfies the following condition;
Hmin<
HGHmaxwherein HGHmax represents the design fluence value at the location with the maximum design gradient product, and Hmin represents the minimum value of the respective lens material, and wherein at least one lens is made, of a first fused silica material comprised in the second group of lens materials, which first fused silica material comprises a fused silica material manufactured by depositing SiO2-particles to form a porous soot body, followed by vitrification, which first fused silica material has an OH-content of about 50 ppm by weight or less. - View Dependent Claims (36)
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37. A projection exposure apparatus comprising:
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an illumination optical system including a light source for illuminating a patterning structure;
a projection optical system for projecting an image of the illuminated patterning structure onto a substrate;
the illumination optical system and the projection optical system each comprising a plurality of lenses;
wherein each of the lenses has a maximum design fluence value associated therewith, the maximum design fluence value representing a predetermined expected maximum fluence that the respective lens will be exposed to during a standard mode of operation of the projection exposure apparatus;
wherein more than 50% of a total number of the plurality of lenses in at least one of the illumination optical system and the projection optical system are made of a lens material selected from a first group of lens materials wherein, after exposure to a given number of pulses of radiation of a given pulse length, each lens material of the first group has a characteristic transition point representative of a fluence value, wherein each lens material of the first group will have rarefied after exposure to the given number of pulses of radiation of the given pulse length having any fluence value below its transition point, and wherein each lens material of the first group will have densified after exposure to the given number of pulses of radiation of the given pulse length having any fluence value above its transition point; and
wherein the transition point of each lens material of the first group satisfies the following condition;
TRC<
0.8·
HDwherein TRC represents the transition point of the respective lens material, HD represents the design fluence value of the respective lens.
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38. Projection exposure apparatus comprising:
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an illumination optical system including a light source for illuminating a patterning structure;
a projection optical system for projecting an image of the illuminated patterning structure onto a substrate;
the illumination optical system and the projection optical system each comprising a plurality of lenses;
wherein each location on a surface of each lens has a design fluence value associated therewith, the design fluence value representing a predetermined expected fluence that the respective location on the surface of the lens will be exposed to during a standard mode of operation of the projection exposure apparatus;
wherein each location on the surface of each lens has a design fluence gradient value associated therewith, the design fluence gradient value representing a predetermined expected change of the design fluence value per unit length;
and wherein each lens has a first location with a maximum design gradient product associated therewith, the maximum design gradient product representing a maximum product of the design fluence gradient value and the design fluence value at the location of the design fluence gradient value for the respective lens;
wherein more than 50% of a total number of the plurality of lenses in at least one of the illumination optical system and the projection optical system are made of a lens material selected from a second group of lens materials wherein each lens of the second group has a characteristic transition point after exposure to a given number of pulses of radiation of a given pulse length, wherein each lens material will have rarefied after exposure to the given number of pulses of radiation of the given pulse length having any fluence value below the transition point, and wherein each lens material will densified after exposure to the given number of pulses of radiation of the given pulse length having any fluence value above the transition point;
wherein each lens material further has a characteristic minimum value associated therewith, the minimum value representing a fluence value causing the greatest extent of rarefaction in the lens material after exposure to the given number of pulses of radiation of the given pulse length, and wherein the minimum value Hmin of each lens material of the second group satisfies the following condition;
Hmin<
HGHmaxwherein HGHmax represents the design fluence value at the location with the maximum design gradient product, and Hmin represents the minimum value of the respective lens material.
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Specification