METHOD FOR PRODUCING FACET MIRRORS AND PROJECTION EXPOSURE APPARATUS
The disclosure relates to methods for producing mirrors, in particular facet mirrors, and projection exposure apparatuses equipped with the mirrors.
1 . An apparatus, comprising:
a carrying element;
a mirror element carried by the carrying element; and
coolant lines connected to cavities defined by a region between the mirror element and the carrying element,
wherein:
the carrying element comprises a material having a thermal conductivity of at least 100 W/(mK);
the mirror element comprises an optically polishable material having a surface roughness of less than 0.5 nm rms in the high spatial frequency range;
the mirror element has a thickness within the range of 0.2 mm to 5 mm; and
the apparatus is an EUV projection exposure apparatus.
2 . The apparatus of claim 1 , wherein the surface roughness of the optically polishable materials is 0.2 nm rms in the high spatial frequency range.
3 . The apparatus of claim 2 , wherein the material having the thermal conductivity of at least 100 W/mK is a metallic material.
4 . The apparatus of claim 3 , wherein the mirror element has a thickness within the range of one mm to three mm.
5 . The apparatus of claim 4 , wherein the cavities are grooves.
6 . The apparatus of claim 1 , wherein the material having the thermal conductivity of at least 100 W/mK is a metallic material.
7 . The apparatus of claim 1 , wherein the mirror element has a thickness within the range of one mm to three mm.
8 . The apparatus of claim 1 , wherein the cavities are grooves.
9 . The apparatus of claim 1 , wherein the apparatus comprises an illumination system, the illumination system comprises a facet mirror, and the mirror element is a mirror facet of the facet mirror.
10 . The apparatus of claim 1 , wherein the mirror element comprises silicon.
11 . The apparatus of claim 1 , wherein the mirror element comprises a nickel-coated steel body.
12 . The EUV apparatus of claim 1 , further comprising a carrier body on which the carrying element is arranged, wherein the carrying element is movable relative to the carrier body.
13 . The apparatus of claim 12 , wherein the carrying element and the carrier body are formed from the same material.
14 . The EUV apparatus of claim 1 , further comprising a carrier body on which the carrying element is arranged, wherein the carrying element is tiltable relative to the carrier body.
15 . The apparatus of claim 14 , wherein the carrying element and the carrier body are formed from the same material.
16 . The apparatus of claim 1 , wherein the carrying element comprises a material selected from the group consisting of Invar, copper and aluminum.
17 . The apparatus of claim 1 , further comprising solder which connects the mirror element and the carrying element.
18 . The apparatus of claim 1 , further comprising an inorganic material which connects the mirror element and the carrying element, wherein the inorganic material comprises silicon oxide bridges.
19 . The apparatus of claim 1 , wherein the mirror element is wedge-shaped or spherical.
20 . The apparatus of claim 1 , wherein the mirror element is a substantially circular lamina having a diameter within the range of between 2 mm and 15 mm.
21 . The apparatus of claim 1 , wherein the mirror element is a substantially circular lamina having a diameter within the range of between 8 mm 12 mm.
22 . The apparatus of claim 1 , further comprising a connecting material which connects the mirror element and the carrying element, wherein the connecting material has a modulus of elasticity of less than 70 MPa.
23 . An apparatus, comprising:
a carrying element; and
a mirror element carried by the carrying element,
wherein:
the carrying element comprises a material having a thermal conductivity of at least 100 W/(mK);
the mirror element comprises an optically polishable material having a surface roughness of less than 0.5 nm rms in the high spatial frequency range;
the mirror element has a thickness within the range of 0.2 mm to 5 mm;
cavities define by a region between the mirror element and the carrier element;
the cavities are configured to be connected to coolant lines; and
the apparatus is an EUV projection exposure apparatus.
24 . A system, comprising:
a facet mirror comprising a mirror facet; and
a carrying element which carries the mirror facet,
wherein:
the carrying element comprises a material having a thermal conductivity of at least 100 W/(mK);
the mirror facet comprises an optically polishable material having a surface roughness of less than 0.5 nm rms in the high spatial frequency range;
the mirror facet has a thickness within the range of 0.2 mm to 5 mm;
cavities define by a region between the mirror facet and the carrier element;
the cavities are configured to be connected to coolant lines; and
the system is an EUV illumination system.