Patent Number: 
Section: claims

1. An EUV lithography apparatus comprising:an EUV source;an optical system coupled to the EUV source; anda curved honeycomb article made using the process described below placed operatively between the EUV source and the optical system, such that a substantial fraction of the EUV radiation generated by the EUV source propagates through the channels of the curved honeycomb article;said process comprising the steps of:providing a honeycomb body having a first face, a second face, and a honeycomb structure having a plurality of substantially parallel channels formed from the first face to the second face;filling the channels of the honeycomb body with a filler material, thereby forming a filled honeycomb composite;molding the filled honeycomb composite to form a curved filled honeycomb composite; andfinishing the curved filled honeycomb composite into the curved honeycomb article,wherein during the step of molding, the filler material has a plastic deformation behavior compatible with that of the honeycomb body. 2. A curved honeycomb article having a first face, a second face, and a plurality of channels formed from the first face to the second face, each channel having a channel axis;said curved honeycomb article defining and occluded area when projected upon a plane perpendicular to its channel axis at the geometrical center;wherein the curved honeycomb article has a width of at least about 15 cm in at least one direction in the plane normal to a channel axis at its geometrical center, and each channel has a virtual channel extension associated therewith, the virtual channel extensions defining a convergence area substantially smaller than the occluded area of the curved honeycomb article; andwherein one of said faces is a concave face and one of said faces is a convex face, and said convergence area is formed in a plane on the concave side of said honeycomb article, andwherein the convergence area has at least one dimension less than about 2 cm in length. 3. The curved honeycomb article of claim 2, wherein the convergence area has at least two mutually perpendicular dimensions less than 5 mm in length. 4. The curved honeycomb article of claim 2, wherein the curved honeycomb article has a thickness of at least about 3 mm. 5. The curved honeycomb article of claim 2, wherein the convergence area is within about 60 cm of a surface on the concave side of the curved honeycomb article. 6. The curved honeycomb article of claim 2, wherein the honeycomb structure has a channel density of at least about 1.5 channels per square cm. 7. The curved honeycomb article of claim 2, wherein the honeycomb structure has a geometrical transparency of at least about 50% as viewed radially from the convergence area. 8. An EUV apparatus comprising:an EUV source;an optical system coupled to the EUV source; andthe curved honeycomb article of claim 2; wherein the curved honeycomb article is operatively positioned between the source and the optical system, such that a substantial fraction of the EUV radiation generated by the EUV source propagates through the channels of the curved honeycomb article. 9. The curved honeycomb article of claim 2, wherein the curved honeycomb article is formed as an essentially spherical shell segment or an essentially cylindrical shell segment. 10. The curved honeycomb article of claim 9, wherein curved honeycomb article subtends an angle of at least about 70 degrees in at least one direction. 11. The curved honeycomb article of claim 9, wherein the curved honeycomb article has a radius of curvature of less than about 38 cm.