Glass composite for use in extreme ultra violet lithography

Patent metadata

Field	Value
Publication number	US-10427974-B2
Application number	US-201615559958-A
Country	US
Kind code	B2
Filing date	Mar 22, 2016
Priority date	Mar 26, 2015
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

A glass composite for use in Extreme Ultra-Violet Lithography (EUVL) is provided. The glass composite includes a first silica-titania glass section. The glass composite further includes a second doped silica-titania glass section mechanically bonded to a surface of the first silica-titania glass section, wherein the second doped silica-titania glass section has a thickness of greater than about 1.0 inch.

First claim

What is claimed is:

1. A glass composite for use in Extreme Ultra-Violet Lithography (EUVL), the glass composite comprising:
a first silica-titania glass section; and
a second doped silica-titania glass section mechanically bonded to a surface of the first silica-titania glass section,
wherein the second doped silica-titania glass section has a thickness of greater than about 1.0 inch.

2. The glass composite of claim 1 , wherein the first silica-titania glass section comprises between about 5.0 wt. % and about 16 wt. % titania.

3. The glass composite of claim 1 , wherein the titania of the first silica-titania glass section comprises a crystalline form, wherein the crystalline form is predominantly anatase.

4. The glass composite of claim 1 , wherein the second doped silica-titania glass section comprises between about 5.0 wt. % and about 12 wt. % titania.

5. The glass composite of claim 1 , wherein the second doped silica-titania glass section comprises between about 1.0 wt. % and about 10.0 wt. % of at least one dopant.

6. The glass composite of claim 5 , wherein the at least one dopant is selected from the group consisting of boron, fluorine, chlorine, phosphorous, hydroxyl groups and mixtures thereof.

7. The glass composite of claim 1 , wherein the second doped silica-titania glass section comprises a slope of coefficient of thermal expansion (CTE) versus temperature at 20° C. of less than about 1.6 ppb/K 2 .

8. The glass composite of claim 1 , wherein the second doped silica-titania glass section comprises a curvature machined into a surface of the second doped silica-titania glass section.

9. The glass composite of claim 1 , wherein the first silica-titania glass portion comprises between about 50% and about 95% of the thickness of the bonded glass composite.

10. The glass composite of claim 1 comprising a mass greater than about 20 kg.

11. The glass composite of claim 1 , wherein the first silica-titania glass section and the second doped silica-titania glass section comprise a near-zero CTE.

12. A method for forming a glass composite for use in Extreme Ultra-Violet Lithography (EUVL), the method comprising:
forming a first silica-titania glass section;
forming a second silica-titania glass section;
doping the second silica-titania glass section to form a doped silica-titania glass section; and
mechanically bonding the doped silica-titania glass section to a surface of the first silica-titania glass section,
wherein the doped silica-titania glass section has a thickness of greater than about 1.0 inch.

13. The method of claim 12 , further comprising heat treating the first silica-titania glass section to form a crystalline form of titania, wherein the crystalline form is predominantly anatase.

14. The method of claim 13 , wherein heat treating the first silica-titania glass section comprises modifying the coefficient of thermal expansion (CTE) and the slope of CTE versus temperature of the first silica-titania glass section to substantially match the CTE and the slope of CTE versus temperature of the doped silica-titania glass section.

15. The method of claim 12 , further comprising annealing the doped silica-titania glass section.

16. The method of claim 12 , wherein forming the second silica-titania glass section comprises pressing soot particles to form a soot compact.

17. The method of claim 12 , wherein the bonding step comprises fusion bonding the doped silica-titania glass section to a surface of the first silica-titania glass section.

18. The method of claim 12 , wherein the bonding step comprises frit bonding the doped silica-titania glass section to a surface of the first silica-titania glass section.

19. The method of claim 12 , wherein the bonding step comprises low temperature sol-gel bonding the doped silica-titania glass section to a surface of the first silica-titania glass section comprises.

20. The method of claim 12 , further comprising forming a curved reflective surface on a surface of the doped silica-titania glass section.

Assignees

• Corning Inc

Inventors

• Annamalai Sezhian

Classifications

• G02B5/0891

  Ultraviolet [UV] mirrors (apparatus for microlithography exposure G03F7/70; X-ray multilayer structures G21K1/06) · CPC title

• G02B1/00

  Optical elements characterised by the material of which they are made; Optical coatings for optical elements · CPC title

• C03B2201/06

  Doped silica-based glasses · CPC title

• B32B2551/00

  Optical elements · CPC title

• B32B2307/416

  Reflective · CPC title