REFLECTIVE OPTICAL ELEMENT FOR GRAZING INCIDENCE IN THE EUV WAVELENGTH RANGE

• US 20150009480A1
• Filed: 07/01/2014
• Published: 01/08/2015
• Est. Priority Date: 07/08/2013
• Status: Active Grant

• Current Assignee: CARL Zeiss SMT GmbH (Carl-Zeiss-Stiftung)
• Original Assignee: Carl Zeiss Laser Optics Gmbh (Carl-Zeiss-Stiftung)
• Inventors: Shklover, Vitaliy
• Granted Patent: US 9,703,209 B2
• Time in Patent Office: Days
• US Class Current: 355/67
• CPC Class Codes: G02B 5/0808 having a single reflecting layer G02B5/0883, G02B5/0891 take precedence
• CPC Class Codes: G02B 5/0891 Ultraviolet [UV] mirrors apparatus for microlithography exposure G03F7/70; X-ray multilayer structures G21K1/06
• CPC Class Codes: G03F 7/70316 Details of optical elements, e.g. of Bragg reflectors, extreme ultraviolet [EUV] multilayer or bilayer mirrors or diffractive optical elements
• CPC Class Codes: G03F 7/70958 Optical materials or coatings, e.g. with particular transmittance, reflectance or anti-reflection properties

Abstract

An optical element comprises a reflecting coating on a substrate. The reflecting coating contains boron and can have a thickness of more than 50 nm.

Claims

1. An optical element, comprising:

a substrate; and

a reflecting coating supported by the substrate,

wherein the reflecting coating comprises boron, and the reflecting coating has a thickness of more than 50 nm.

2. The optical element of claim 1, wherein the optical element is a grazing incidence optical element.

3. The optical element of claim 2, wherein the optical element is configured to be used in the extreme ultraviolet wavelength.

4. The optical element of claim 1, wherein the optical element is configured to be used in the extreme ultraviolet wavelength.

5. The optical element of claim 1, wherein the reflecting coating comprises a boride.

6. The optical element of claim 1, wherein the reflecting coating comprises a metal boride.

7. The optical element of claim 1, wherein the reflecting coating comprises a mixed boride.

8. The optical element of claim 7, wherein the mixed boride is a binary metal boride or ternary metal boride.

9. The optical element of claim 1, wherein the reflecting coating comprises a metal boride comprising at least one metal selected from the group consisting of molybdenum, ruthenium, niobium, zirconium, rhodium, rhenium, palladium, gold, platinum, nickel, tantalum, tungsten, osmium, iridium, titanium, hafnium, magnesium, calcium and strontium.

10. The optical element of claim 1, wherein the reflecting coating comprises a boride having a stoichiometry which varies over the thickness of the reflecting coating.

11. The optical element of claim 1, wherein the substrate comprises a material which comprises a material selected from the group consisting of a metal, a metal alloy, a glass, a glass ceramic, a ceramic, a monocrystalline semiconductor, a polycrystalline semiconductor, and a composite material.

12. The optical element of claim 1, further comprising an adhesion promoter layer between the substrate and the reflecting coating.

13. The optical element of claim 1, further comprising an adhesion promoter layer between the substrate and the reflecting coating, wherein the reflecting coating comprises a metal boride, and the adhesion promoter layer comprises a metal of the metal boride.

14. The optical element of claim 1, further comprising an adhesion promoter layer between the substrate and the reflecting coating, wherein the reflecting coating comprises a mixed metal boride, and the adhesion promoter layer comprises a metal of the mixed metal boride.

15. The optical element of claim 1, wherein the thickness of the reflecting coating is more than 100 nm.

16. The optical element of claim 1, wherein the thickness of the reflecting coating is more than 10000 nm.

17. The optical element of claim 1, wherein the reflecting coating comprises only one boron-containing layer.

18. The optical element of claim 1, wherein the reflecting coating consists of one boron-containing layer.

19. The optical element of claim 1, wherein the optical element is a collector mirror.

20. An optical system, comprising:

an optical element, comprising;

a substrate; and

a reflecting coating supported by the substrate,

wherein the reflecting coating comprises boron, the reflecting coating has a thickness of more than 50 nm, and the optical system is an EUV lithography optical system.

21. The optical system of claim 20, wherein the optical element is a grazing incidence optical element.

22. The optical system of claim 20, wherein the system is an EUV lithography illumination system.

23. A device, comprising:

an illumination system; and

a projection objective,

wherein;

the device comprises an optical element;

the optical element comprises a substrate and a reflecting layer supported by the substrate;

the reflecting coating comprises boron;

the reflecting coating has a thickness of more than 50 nm; and

the device is an EUV lithography device.

24. The device of claim 23, wherein the illumination system comprises the optical element.