Fine laminar barrier protective layer

• US 20090142524A1
• Filed: 12/19/2005
• Published: 06/04/2009
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Inventors: Moelle, Christoph, Kuepper, Thomas, Hamel, Margareta, Mehrtens, Andree
• Granted Patent: US 8,435,650 B2
• Time in Patent Office: Days
• US Class Current: 428/34.400
• CPC Class Codes: C03C 17/245 by deposition from the vapour phase
• CPC Class Codes: C03C 2218/153 by plasma-enhanced cvd
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: C03C 2218/345 Surface crystallisation
• CPC Class Codes: C03C 23/007 by thermal treatment
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/45523 Pulsed gas flow or change of composition over time
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/131 Glass, ceramic, or sintered, fused, fired, or calcined metal oxide or metal carbide containing [e.g., porcelain, brick, cement, etc.]
• CPC Class Codes: Y10T 428/24744 Longitudinal or transverse tubular cavity or cell

Abstract

In order to provide a thermostable and highly effective barrier coating on a substrate, and to protect the substrate against the effect of harmful gas components even at high temperatures, the invention provides a coated substrate comprising a barrier coating having a multiplicity of consecutive individual layers respectively of a kind differing from or similar to a neighboring individual layer, the individual layers exhibiting a layer thickness of respectively at most 50 nanometers.

Claims

1. A coated substrate defined by a coating having a multiplicity of consecutive individual layers respectively of a kind differing from or similar to a neighboring individual layer, the individual layers exhibiting a layer thickness of respectively at most 50 nanometers, wherein the substrate is a tube that is hot Pinched after coating with the formation of a sealed cavity.

2. The coated substrate as claimed in claim 1, wherein at least one of the individual layers exhibit a layer thickness of at most 10 nanometers.

3. The coated substrate as claimed in claim 1, wherein at least one of the individual layers exhibit a layer thickness of at most 2 nanometers.

4. The coated substrate as claimed in claim 1, wherein at least one individual layer of the coating differs from a neighboring individual layer in its chemical composition.

5. The coated substrate as claimed in claim 1, wherein at least one of the individual layers exhibits crystalline structure.

6. The coated substrate as claimed in claim 5, defined by a layer having a number of consecutive, similar crystalline layers.

7. The coated substrate as claimed in claim 1, wherein at least one individual layer of the coating differs from a neighboring individual layer in its morphology.

8. The coated substrate as claimed in claim 7, wherein the individual layer differs from a neighboring individual layer by its crystal structure.

9. The coated substrate as claimed in claim 1, wherein the coating comprises at least one partial layer packet having individual layers of the same composition but different morphology.

10. The coated substrate as claimed in claim 1, wherein the individual layers differ from one another in their growth mode.

11. The coated substrate as claimed in claim 1, wherein at least one of the individual layers exhibits an amorphous or at least partially amorphous structure.

12. The coated substrate as claimed in claim 11, defined by a layer having a number of consecutive, similar, at least partially amorphous layers.

13. The coated substrate as claimed in claim 1, wherein the coating comprises at least one partial layer packet having alternating layers of a different nature.

14. The coated substrate as claimed in claim 1, wherein the coating comprises at least one partial layer packet having amorphous and neighboring, at least partially crystalline layers.

15. The coated substrate as claimed in claim 1, wherein the coating comprises at least one partial layer packet having two at least partially crystalline layers of a different composition, between which respectively one amorphous layer is arranged.

16. The coated substrate as claimed in claim 1, wherein the coating is transparent.

17. The coated substrate as claimed in claim 1, defined by a transparent substrate.

18. The coated substrate as claimed in claim 16, wherein the transparency of the coating corresponds to the transparency of the substrate.

19. The coated substrate as claimed in claim 16, wherein the light transmission through a coated substrate deviates in the visible spectral region by at most 5% from the transmission of a substrate without the coating.

20. The coated substrate as claimed in claim 1, wherein the refractive index of the coating corresponds to the refractive index of the substrate surface, or deviates therefrom by at most 5%.

21. The coated substrate as claimed in claim 1, defined by an antireflection layer system having the coating, the entire layer system acting in an antireflective fashion and at least one layer of the antireflection layer system comprising a partial layer packet that has a multiplicity of thin consecutive layers with an average thickness of the individual layers of at most 50 nanometers, and whose effective refractive index is dimensioned such that the antireflection layer system acts overall in an antireflective fashion.

22. The coated substrate as claimed in claim 1, wherein at least one of the individual layers contain inorganic oxides.

23. The coated substrate as claimed in claim 1, wherein at least one of the individual layers contains at least one of the oxides TiO₂, ZrO₂, SiO₂, Al₂O₃, Nb₂O₅, Ta₂O₅, HfO₂.

24. The coated substrate as claimed in claim 1, wherein the substrate comprises at least one of the materials of glass, glass ceramic, ceramic, metal, semiconductor, a crystalline material.

25. The coated substrate as claimed in claim 1, wherein the substrate is hollow.

26. The coated substrate as claimed in claim 1, wherein the substrate is tubular.

27. The coated substrate as claimed in claim 25, wherein the substrate is internally coated.

29. The coated substrate as claimed in claim 1, wherein the coating is catalytically active.

30. The coated substrate as claimed in claim 29, distinguished by titanium oxide-containing photocatalytically active individual layers.

31. A catalyst comprising a substrate as claimed in claim 1.

28. (canceled)

32. A method for producing a coating, on a substrate comprising:

depositing a multiplicity of consecutive individual layers respectively of a kind differing from or similar to a neighboring individual layer and whose layer thickness is respectively at most 50 nanometers, wherein a tubular substrate is coated and is heated up and pinched after the coating.

33. The method as claimed in claim 32, wherein at least one of the individual layers are deposited with a layer thickness of at most 10 nanometers.

34. The method as claimed in claim 32, wherein at least one of the individual layers of the coating are deposited with a layer thickness of at most 2 nanometers.

35. The method as claimed in claim 32, wherein the individual layers are deposited by means of at least one vacuum deposition method.

36. The method as claimed in claim 35, wherein at least one portion of the individual layers is deposited with the aid of plasma-pulse-supported vapor phase deposition.

37. The method as claimed in claim 35, wherein at least one portion of the individual layers is sputtered on.

38. The method as claimed in claim 32, wherein consecutive layers of different morphology are deposited by changing the process parameters from one layer to a subsequent layer.

39. The method as claimed in claim 38, wherein individual layers of different growth mode are deposited by changing the process parameters.

40. The method as claimed in claim 32, wherein at least one amorphous individual layer is deposited.

41. The method as claimed in claim 32, wherein at least one at least partially crystalline individual layer is deposited.

42. The method as claimed in claim 32, wherein at least one partial layer packet of the coating is deposited having alternating layers of a different kind.

43. The method as claimed in claim 32, wherein at least one partial layer packet of the coating is deposited having two at least partially crystalline layers of a different composition between which an amorphous layer is respectively arranged.

44. The method as claimed in claim 32, wherein a gas composition other than that which is used for the coating operation is introduced between the coating steps for coating the individual layers, and then the morphology of a previously grown individual layer is influenced by using a plasma treatment to input energy.

45. The method as claimed in claim 44, wherein a gas composition including a reactive gas is introduced for the plasma treatment.

46. The method as claimed in claim 45, wherein a gas composition including oxygen gas is introduced for the plasma treatment.

47. The method as claimed in claim 44, wherein pulsed electromagnetic energy is used for generating the plasma during the plasma treatment.

48. The method as claimed in claim 44, wherein the individual layer is brought to partial or complete crystallization by means of the plasma treatment.

49. The method as claimed in claim 44, wherein a crystalline individual layer is deposited and is converted into an at least partially amorphous individual layer by means of the plasma treatment.

50. The method as claimed in claim 44, wherein a crystalline individual layer is deposited and is converted into a layer of another crystalline phase or morphology by means of the plasma treatment.

51. The method as claimed in claim 32, in which the steps of the deposition of an individual layer and the plasma treatment of this individual layer are repeated several times in order to produce thicker layers from different or similar individual layers with layer thicknesses of up to at most 50 nanometers.

52. The method as claimed in claim 32, wherein a hollow tubular substrate is coated.

53. The method as claimed in claim 52, wherein a lamp bulb is coated.

54. The method as claimed in claim 52, wherein the substrate is internally coated.

56. The method as claimed in claim 32, wherein a lamp bulb is produced by means of the pinching.

57. The method as claimed in claim 32, wherein photocatalytically active individual layers are deposited.

58. The method as claimed in claim 32, wherein photocatalytically active titanium oxide-containing individual layers are deposited.

59. The method as claimed in claim 32 for plasma-supported CVD coating of substrates, in the case of which the substrate is arranged in a reactor, the gas for the plasma coating or plasma treatment being fed to the reactor space via a branch line that is connected to a main line through which a gas supply system provides the gas or gas mixture for the CVD coating, and that exhibits a lower flow resistance in comparison to the branch line with reactor and substrate held therein, and a plasma for the coating or plasma treatment being generated in the process gas in the reactor by means of irradiating electromagnetic energy, and the main line and branch line being pumped out via at least one pump.

60. The method as claimed in claim 59, wherein pressure is controlled by a pressure measuring device and a control valve, connected in the main line, for setting the pressure in the main line to a desired value as a function of the measured pressure values recorded with the pressure measuring device.

61. The method as claimed in claim 60, wherein the pressure is controlled by means of a control valve arranged downstream of the junction of the branch line.

55. (canceled)

62. An apparatus for CVD coating of substrates, apparatus comprising:

a gas supply having a number of gas reservoirs connected by means of controllable valves to a main line connected to a pump; and

a reactor for CVD coating connected, via a branch line branching off from the main line, to the gas supply with the number of gas reservoirs and to the pump, in order to evacuate the reactor and to exchange the process gas, the reactor being for irradiating electromagnetic energy into a reactor space in order to generate a plasma, and the main line exhibiting a lower flow resistance in comparison to the branch line with reactor and substrate held therein.

63. The apparatus as claimed in claim 62, wherein the device for irradiating electromagnetic energy into the reactor space is designed for irradiating pulsed electromagnetic energy.

64. The apparatus as claimed in claim 62, defined by a reactor for internally coating hollow substrates.

65. The apparatus as claimed in claim 62, defined by pressure control by a pressure measuring device and a control valve, connected in the main line, for setting the pressure in the main line to a desired value as a function of the measured pressure values recorded with the pressure measuring device.

66. The apparatus as claimed in claim 63, wherein the control valve is arranged downstream of the junction of the branch line in the flow direction.

67. An amorphous SiO₂ substrate having a barrier layer, the substrate exhibiting an amorphous structure, wherein a barrier layer with crystallized silicon oxide of the substrate is arranged on at least one surface of the substrate, the crystallites of the barrier layer exhibiting an average size of at most 50 nanometers.

68. The substrate as claimed in claim 67, wherein the crystallites of the barrier layer exhibit an average size of at most 10 nanometers.

69. The substrate as claimed in claim 67, wherein the crystallites of the barrier layer exhibit an average size of at most 2 nanometers.

70-71. -71. (canceled)

72. A method for producing a substrate having a barrier layer in the case of which a substrate with amorphous structure is provided and on at least one surface of the substrate a barrier layer is produced, the method comprising:

crystallizing the substrate material with crystallites of an average size of at most 50 nanometers, wherein a barrier layer is produced by crystallizing amorphous silicon oxide.

73. The method as claimed in claim 72, wherein a barrier layer is produced by crystallizing the substrate material with crystallites of an average size of at most 10 nanometers.

74. The method as claimed in claim 72, wherein a barrier layer is produced by crystallizing the substrate material with crystallites of an average size of at most 2 nanometers.

77. The method as claimed in claim 72, wherein crystallizing the substrate material comprises superficially heating up the surface of the substrate.

78. The method as claimed in claim 72, wherein crystallizing the substrate material comprises plasma treatment of the surface of the substrate.

79. The method as claimed in claim 72, wherein crystallizing the substrate material comprises reactive plasma etching of the surface of the substrate.

75-76. -76. (canceled)