Optical element, optical assembly and production method
An optical element for transmitting radiation includes: a first surface region surrounding an optically used area of the optical element; and a second surface region that adjoins the first surface region. A circumferential edge is formed between the first and second surface regions. The optical element further includes a one-piece film which covers the first surface region, the edge and the second surface region. The film includes a hydrophobic material at least on its side facing away from the first and the second surface regions. An optical assembly includes at least one such optical element. A method produces such an optical element.
1. An article configured to transmit radiation, the article comprising:
an optical element comprising an optically used region, a first surface region surrounding the optically used region, and a second surface region adjoining the first surface region so that a peripheral edge is present between the first and second surface regions;
a first adhesive layer; and
a one-piece film covering the first surface region, the peripheral edge and the second surface region,
wherein:
the first adhesive layer is between the optical element and the one-piece film;
the first adhesive layer connects the one-piece film to the first and second surface regions of the optical element;
the one-piece film comprises a hydrophobic material at least on a side of the one-piece film facing away from the first and second surface regions; and
the one-piece film is preformed.
2. The article of claim 1 , wherein the one-piece film has a bend in a region of the peripheral edge.
3. The article of claim 1 , wherein:
the first adhesive layer comprises first and second portions;
the first portion of the first adhesive layer connects the one-piece film to the first surface region; and
the second portion of the first adhesive layer connects the one-piece film to the second surface region.
4. The article of claim 1 , wherein the first adhesive layer comprises an adhesive tape.
5. The article of claim 1 , further comprising a heat-conducting component between the one-piece film and at least one region selected from the group consisting of the first surface region and the second surface region.
6. The article of claim 5 , wherein the heat-conducting component comprises a heat-conducting layer.
7. The article of claim 5 , wherein the heat-conducting component extends into the first and second surface regions.
8. The article of claim 5 , further comprising a second adhesive layer, wherein the heat-conducting component is between the first and second adhesive layers.
9. The article of claim 5 , wherein the heat-conducting component does not extend to an edge of the one-piece film in at least one region selected from the group consisting of the first surface region and the second surface region.
10. The article of claim 5 , wherein the heat-conducting component comprises a material having a thermal conductivity greater than 100 W m −1 K −1 .
11. The article of claim 1 , wherein the one-piece film has a thermal conductivity of more than 100 W m −1 K −1 .
12. The article of claim 1 , wherein the hydrophobic material of the one-piece film comprises at least one material selected from the group consisting of polyolefins, polyacrylates, (poly)vinylchlorides, polystyrenes, polysiloxanes, polycarbonates and epoxy polymers.
13. The article of claim 1 , wherein the hydrophobic material is roughened on the side of the one-piece film that faces away from the first and second surface regions.
14. The article of claim 1 , wherein the hydrophobic material comprises a coating on the side of the one-piece film facing away from the first and second surface regions.
15. The article of claim 1 , wherein the one-piece film has a thickness of less than 500 μm.
16. The article of claim 1 , further comprising a radiation-protection layer on at least one region selected from the group consisting of the first surface region and the second surface region.
17. The article of claim 1 , wherein the first surface region defines a peripheral lateral surface of a conical volume region of the optical element.
18. The article of claim 17 , wherein the second surface region is planar and surrounds the first surface region in an annular manner.
19. The article of claim 1 , wherein the second surface region is planar and surrounds the first surface region in an annular manner.
20. An apparatus, comprising:
an article according to claim 1 , wherein
the apparatus is an immersion lithography projection exposure apparatus.
21. The optical assembly of claim 20 , further comprising an immersion fluid, wherein an end face of the article is at least partially immersed in the immersion fluid.
22. The article of claim 1 , wherein the first adhesive layer is adhered directly to the optical element, and the one-piece film is adhered directly to the first adhesive layer.
23. The article of claim 1 , wherein:
the first adhesive layer comprises a double-sided tape which comprises first and second sides;
the first side of the adhesive tape is adhered directly to the optical element; and
the second side of the adhesive tape is adhered directly to the one-piece film.