Optical films and methods of making the same

• US 8,808,972 B2
• Filed: 01/22/2010
• Issued: 08/19/2014
• Est. Priority Date: 04/15/2004
• Status: Active Grant

• Current Assignee: Ushio Denki Kabushiki Kaisha (Ushio Incorporated)
• Original Assignee: Polarization Solutions, Llc
• Inventors: Wang, Jian Jim, Sciortino, Paul Jr., Deng, Xuegong, Nikolov, Anguel N.
• Primary Examiner(s): ANGEBRANNDT, MARTIN J
• Application Number:
  US12/692,193
• Publication Number:
  US 20100265571A1
• Time in Patent Office: 1,670 Days
• Field of Search: None
• US Class Current: 430/321
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 5/1857 using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation

Abstract

Films for optical use, articles containing such films, methods for making such films, and systems that utilize such films, are disclosed.

Claims

1. A method of manufacturing a polarizer for a selected wavelength of light, comprising:

providing a surface of a layer of a first material of an article, said surface comprising a series of trenches having widths of about 100 nm or less, and depths of at least 50 nm, and filling the trenches to at least 10% of their volumes by sequentially forming a plurality of monolayers of a second material different from the first material within the trenches, and conformally coating the surfaces of the trenches by providing at least one monolayer disposed in the trenches by atomic layer deposition (ALD), and wherein

the first and second materials and the trench widths and depths are selected such that the layer transmits about 50% or more of light of the selected wavelength having a first polarization state incident on the layer along a path, and blocks about 80% or more of light of the selected wavelength having a second polarization state incident on the layer along the path, where the first and second polarization states are orthogonal; and

the selected wavelength is in the ultraviolet range.

2. The method of claim 1, wherein the trench is formed by etching a continuous layer of the first material.

3. The method of claim 2, wherein etching the first layer comprises reactive ion etching.

4. The method of claim 1, wherein the trench is formed lithographically.

5. The method of claim 4, wherein the trench is formed using nanoimprint lithography.

6. The method of claim 5, wherein the nano-imprint lithography includes forming a pattern in a thermoplastic material.

7. The method of claim 5, wherein the nano-imprint lithography includes forming a pattern in a UV curable material.

8. The method of claim 4, wherein the trench is formed using holographic lithography.

9. The method of claim 8, wherein the holographic lithography comprises immersing a layer of the first material in a fluid having a refractive index higher than a refractive index of air.

10. The method of claim 8, wherein the holographic lithography comprises exposing a layer of a resist material to an interference pattern formed from radiation having a wavelength of about 400 nm or less.

11. The method of claim 1, wherein the first material comprises at least one metal selected from the group consisting of Au and Ag.

12. The method of claim 1, wherein the trench has a width of about 70 nm or less.

13. The method of claim 1, wherein the trench has a width of about 40 nm or less.

14. The method of claim 1, wherein the trench has a depth of about 200 nm or more.

15. The method of claim 1, wherein the trench has a depth of about 130 nm or more.

16. The method of claim 1, further comprising forming one or more monolayers of a third material within the trench, wherein the third material is different from the first and second materials.

17. The method of claim 16, wherein the monolayers of the second and third materials form a nanolaminate material.

18. The method of claim 1, wherein the layer of the first material and the second material form a continuous layer.

19. The method of claim 1, wherein forming the plurality of monolayers of the second material comprises depositing a monolayer of a precursor and exposing the monolayer of the precursor to a reagent to provide a monolayer of the second material.

20. The method of claim 19, wherein the reagent chemically reacts with the precursor to form the second material.

21. The method of claim 20, wherein the reagent oxidizes the precursor to form the second material.

22. The method of claim 19, wherein depositing the monolayer of the precursor comprises introducing a first gas comprising the precursor into a chamber housing the article.

23. The method of claim 22, wherein a pressure of the first gas in the chamber is about 0.01 to about 100 Torr while the monolayer of the precursor is deposited.

24. The method of claim 22, wherein exposing the monolayer of the precursor to the reagent comprises introducing a second gas comprising the reagent into the chamber.

25. The method of claim 24, wherein a third gas is introduced into the chamber after the first gas is introduced and prior to introducing the second gas.

26. The method of claim 25, wherein the third gas is inert with respect to the precursor.

27. The method of claim 25, wherein the third gas comprises at least one gas selected from the group consisting of helium, argon, nitrogen, neon, krypton, and xenon.

28. The method of claim 22, wherein a pressure of the second gas in the chamber is about 0.01 to about 100 Torr while the monolayer of the precursor is exposed to the reagent.

29. The method of claim 19, wherein the precursor comprises at least one precursor selected from the group consisting of tris(tert-butoxy)silanol, (CH₃)₃Al, TiCl₄, SiCl₄, SiH₂Cl₂, TaCl₃, AlCl₃, Hf-ethoxide and Ta-ethoxide.

30. The method of claim 1, wherein the second material comprises at least one material selected from a group consisting of SiO₂, SiN_x, Si, Al₂O₃, ZrO₂, Ta₂O₅, TiO₂, HfO₂, Nb₂O₅, and MgF₂.

31. The method of claim 1, wherein the layer of the first material comprises additional trenches formed in the surface of the layer.

32. The method of claim 31, wherein the trenches are separated by rows of the first material.

33. The method of claim 1, wherein the layer of the first material forms a surface relief grating.

34. The method of claim 33, wherein the surface relief grating has a grating period of about 200 nm or less.

35. The method of claim 33, wherein the surface relief grating has a grating period of about 130 nm or less.

36. The method of claim 1, further comprising forming an anti-reflection film on a surface of the article.

37. The method of claim 1, wherein the article further comprises a substrate supporting the layer of the first material.

38. The method of claim 37, wherein the substrate comprises a layer of an inorganic glass material.

39. A polarizer, comprising:

a first material having a surface, said surface comprising a trench having a width of less than 150 nm and a depth of at least 50 nm, and a plurality of monolayers of a second material different from the first material formed within the trench to a depth of at least 10%, wherein at least one monolayer is disposed in the trench by atomic layer deposition (ALD) to conformally coat the surface of the trench, wherein the first and second materials, and the trench width and depth selected such that the polarizer transmits about 50% or more of light of a selected wavelength having a first polarization state incident on the layer along a path, and blocks about 80% or more of light of the selected wavelength having a second polarization state incident on the layer along the path, where the first and second polarization states are orthogonal; and

the selected wavelength is in the ultraviolet range.

40. The polarizer of claim 39, wherein the trench has a width of about 70 nm or less.

41. The polarizer of claim 39, wherein the trench has a width of about 40 nm or less.

42. The polarizer of claim 39, wherein the trench has a depth of about 100 nm or more.

43. The polarizer of claim 39, wherein the trench has a depth of about 150 nm or more.

44. The polarizer of claim 39, wherein the trench has a depth of about 300 nm or more.

45. The polarizer of claim 39, further comprising forming one or more monolayers of a third material within the trench, wherein the third material is different from the first and second materials.

46. The polarizer of claim 45, wherein the monolayers of the second and third materials form a nanolaminate material.

47. The polarizer of claim 39, wherein the layer of the first material and the second material form a continuous layer.

48. The polarizer of claim 39, wherein the second material comprises at least one material selected from a group consisting of SiO₂, SiN_x, Si, Al₂O₃, ZrO₂, Ta₂O₅, TiO₂, HfO₂, Nb₂O₅, and MgF₂.

49. The polarizer of claim 39, wherein the layer of the first material comprises additional trenches formed in the surface of the layer.

50. The polarizer of claim 49, wherein the trenches are separated by rows of the first material.

51. The polarizer of claim 39, wherein the layer of the first material forms surface relief grating.

52. The polarizer of claim 51, wherein the surface relief grating has a grating period of about 500 nm or less.

53. The polarizer of claim 51, wherein the surface relief grating has a grating period of about 200 nm or less.

54. The polarizer of claim 39, further comprising forming an anti-reflection film on a surface of the article.

55. The polarizer of claim 39, wherein the article further comprises a substrate supporting the layer of the first material.

56. The polarizer of claim 55, wherein the substrate comprises a layer of an inorganic glass material.

57. The polarizer of claim 39, further comprising a grating element width of 200 nm or less.

58. The polarizer of claim 39, further comprising a grating element width of 100 nm or less.