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. A method, comprising:
forming a one-piece film; and
after forming the one-piece film, connecting the one-piece film to: i) a first surface region of the optical element; and ii) a second surface region of the optical element,
wherein:
the first surface region surrounds the optically used region;
the second surface region adjoins the first surface region so that a peripheral edge is present between the first and second surface regions;
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 method further comprises disposing an adhesive layer between the optical element and the one-piece film so that the adhesive layer connects the one-piece film to the first and second surface regions of the optical element.
2. The method of claim 1 , further comprising:
forming a bend in the one-piece film in a region of the peripheral edge; and
after forming the bend, connecting the one-piece film to the first and second regions of the optical element.
3. The method of claim 1 , wherein the adhesive layer comprises an adhesive tape.
4. The method of claim 3 , wherein:
the adhesive layer comprises first and second portions;
the first portion of the adhesive layer connects the one-piece film to the first surface region; and
the second portion of the adhesive layer connects the one-piece film to the second surface region.
5. The method of claim 1 , further comprising disposing 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 method of claim 5 , wherein the heat-conducting component comprises a heat-conducting layer.
7. The method of claim 5 , wherein the heat-conducting component extends into the first and second surface regions.
8. The method of claim 5 , further comprising embedding the heat-conducting component between first and second adhesive layers.
9. The method 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 method 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 method of claim 1 , wherein the one-piece film has a thermal conductivity of more than 100 W m −1 K −1 .
12. The method 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 method 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 method 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 method of claim 1 , wherein the one-piece film has a thickness of less than 500 μm.
16. The method of claim 1 , further comprising disposing 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 method of claim 1 , wherein the first surface region defines a peripheral lateral surface of a conical volume region of the optical element.
18. The method of claim 17 , wherein the second surface region is planar and surrounds the first surface region in an annular manner.
19. The method of claim 1 , wherein the second surface region is planar and surrounds the first surface region in an annular manner.
20. The method of claim 1 , wherein the method forms an article, and the method further comprises incorporating into an immersion lithography projection exposure apparatus.
21. The method of claim 20 , an end face of the article is at least partially immersed in an immersion fluid in the immersion lithography projection exposure apparatus.