SYSTEM AND METHOD FOR MAKING A GRADED BARRIER COATING

• US 20090110892A1
• Filed: 12/01/2008
• Published: 04/30/2009
• Est. Priority Date: 06/30/2004
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Yan, Min, Scherer, Brian Joseph, Tandon, Sheila, Duggal, Anil, ERLAT, Ahmet Gun
• Application Number:
  US12/325,905
• Publication Number:
  US 20090110892A1
• Time in Patent Office: Days
• US Class Current: 428/213
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/45523 Pulsed gas flow or change of composition over time
• CPC Class Codes: C23C 16/50 using electric discharges generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34
• CPC Class Codes: H01L 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
• CPC Class Codes: H10K 2101/80 Composition varying spatially, e.g. having a spatial gradient
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 50/8445 multilayered coatings having a repetitive structure, e.g. having multiple organic-inorganic bilayers
• CPC Class Codes: H10K 59/873 Encapsulations
• CPC Class Codes: H10K 59/8731 multilayered coatings having a repetitive structure, e.g. having multiple organic-inorganic bilayers
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]

Abstract

Methods and apparatus are disclosed relating to graded-composition barrier coatings comprising first and second materials in first and second zones. The compositions of one or both zones vary substantially continuously across a thickness of the zone in order to achieve improved properties such as barrier, flexibility, adhesion, optics, thickness and tact time. The graded-composition barrier coatings find utility in preventing exposure of devices such as organic electro-luminescent devices (OLEDs) to reactive species found in the environment.

Claims

1. An assembly comprising:

a device; and

a graded-composition barrier coating disposed on a surface of said device, said coating comprising;

a first zone defined by a first thickness comprising a first material and a second material wherein a composition of said first zone varies substantially continuously across said first thickness and wherein a first percent composition of said first material is greater than or equal to a first percent composition of said second material; and

a second zone defined by a second thickness comprising said first material and said second material wherein a composition of said second zone varies substantially continuously across said second thickness and wherein a second percent composition of said second material is greater than or equal to a second percent composition of said first material.

2. The assembly of claim 1, wherein said first material is organic and said second material is inorganic.

3. The assembly of claim 1, wherein said first material and said second material are each inorganic.

4. The assembly of claim 1, wherein said first material is different from said second material.

5. The assembly of claim 1, wherein a percent atomic Carbon in said first zone does not exceed approximately 90%.

6. The assembly of claim 1, wherein a percent atomic Carbon in said second zone does not exceed approximately 5%.

7. The assembly of claim 1, wherein said first thickness is between approximately 5 nm and approximately 1000 nm.

8. The assembly of claim 1, wherein said coating comprises a material selected from the group consisting of:

organic, inorganic, ceramic, and combinations thereof.

9. The assembly of claim 8, wherein the inorganic and ceramic materials are selected from the group consisting of:

oxide, nitride, carbide, boride, and combinations thereof of elements of Groups IIA, IIIA, IVA, VA, VIA, VIIA, IB, and IIB, metals of Groups IIIB, IVB, and VB, and rare-earth metals.

10. The assembly of claim 8, wherein said organic material comprises a material selected from the group consisting of:

a polymer, parylene, an acrylic, a siloxane, xylene, an alkene, styrene, an organosilane, an organosilazane, an organosilicone, and combinations thereof.

11. The assembly of claim 8, wherein the inorganic material comprises a material selected from the group consisting of:

metal oxide, metal nitride, silicon oxide, silicon nitride, metal oxynitride, silicon oxynitride, and combinations thereof.

12. The assembly of claim 1, wherein said coating is substantially transparent.

13. The assembly of claim 1 wherein said device is selected from the group consisting of:

an electrochromic device, a liquid crystal display, an organic light emitting diode, a light emitting diode, a photovoltaic device, a radiation detector, an integrated circuit, a sensor, a component of a medical diagnostic system and combinations thereof.

14. The assembly of claim 1 further comprising a substrate upon which said device is disposed.

15. The assembly of claim 14, wherein said substrate is substantially flexible.

16. The assembly of claim 14, wherein said substrate is substantially transparent.

17. The assembly of claim 14, wherein said substrate comprises a material selected from the group consisting of:

plastic, glass and metal.

18. The assembly of claim 1 further comprising a substrate upon which said coating is disposed.

19. The assembly of claim 1, wherein said device is encapsulated by said coating or by said coating and a substrate.

20. The assembly of claim 1, wherein said coating has an oxygen transmission rate less than approximately 0.01 cm³/(m²day), as measured at 25°

C. with a gas containing approximately 21 volume-percent oxygen.

21. The assembly of claim 1, wherein said coating has a water vapor transmission rate less than approximately 0.0001 g/(m²day), as measured at 25°

C. with a gas having approximately 100-percent relative humidity.

22. The assembly of claim 1, wherein said first zone and said second zone are contiguous.

23. The assembly of claim 1, wherein said device is a substrate.

24. A method of forming a barrier coating, the method comprising:

providing a device having a surface; and

depositing on said surface a graded-composition barrier coating comprising;

a first zone defined by a first thickness comprising a first material and a second material wherein a composition of said first zone varies substantially continuously across said first thickness and wherein a first percent composition of said first material is greater than or equal to a first percent composition of said second material; and

a second zone defined by a second thickness comprising said first material and said second material wherein a composition of said second zone varies substantially continuously across said second thickness and wherein a second percent composition of said second material is greater than or equal to a second percent composition of said first material.

25. The method of claim 24, wherein said first material is organic and said second material is inorganic.

26. The method of claim 24, wherein said first material and said second material are each inorganic.

27. The method of claim 24, wherein said first material is different from said second material.

28. The method of claim 24, wherein a percent atomic Carbon in said first zone does not exceed approximately 90%.

29. The method of claim 24, wherein a percent atomic Carbon in said second zone does not exceed approximately 5%.

30. The method of claim 24, wherein said coating is deposited using a method selected from the group consisting of:

sputtering, reactive sputtering, evaporation, plasma-enhanced chemical vapor deposition, reactive ion etching plasma-enhanced chemical vapor deposition, radio-frequency plasma-enhanced chemical-vapor deposition, expanding thermal-plasma chemical-vapor deposition, electron-cyclotron-resonance plasma-enhanced chemical-vapor deposition, inductively-coupled plasma-enhanced chemical-vapor deposition, and combinations thereof.

31. The method of claim 24, wherein said coating has optical properties that are substantially uniform along an axis of light transmission, said axis oriented substantially perpendicular to the surface of the coating.

32. The method of claim 24, wherein said first thickness is between approximately 5 nm and approximately 1000 nm.

33. The method of claim 24, wherein said coating comprises a material selected from the group consisting of:

organic, inorganic, ceramic, and combinations thereof.

34. The method of claim 33, wherein the inorganic and ceramic materials are selected from the group consisting of:

oxide, nitride, carbide, boride, and combinations thereof of elements of Groups IIA, IIIA, IVA, VA, VIA, VIIA, IB, and IIB, metals of Groups IIIB, IVB, and VB, and rare-earth metals.

35. The method of claim 33, wherein said organic material comprises a material selected from the group consisting of:

a polymer, parylene, an acrylic, a siloxane, xylene, an alkene, styrene, an organosilane, an organosilazane, an organosilicone, and combinations thereof.

36. The method of claim 33, wherein the inorganic material comprises a material selected from the group consisting of:

metal oxide, metal nitride, silicon oxide, silicon nitride, metal oxynitride, silicon oxynitride, and combinations thereof.

37. The method of claim 24, wherein said coating is substantially transparent.

38. The method of claim 24, wherein said device is selected from the group consisting of:

an electrochromic device, a liquid crystal display, an organic light emitting diode, a light emitting diode, a photovoltaic device, a radiation detector, an integrated circuit, a sensor, a component of a medical diagnostic system and combinations thereof.

39. The method of claim 24 further comprising a substrate upon which said device is disposed.

40. The method of claim 39, wherein said substrate is substantially flexible.

41. The method of claim 39, wherein said substrate is substantially transparent.

42. The method of claim 39, wherein said substrate comprises a material selected from the group consisting of:

plastic, glass and metal.

43. The method of claim 24 further comprising a substrate upon which said coating is disposed.

44. The method of claim 24, wherein said device is encapsulated by said coating or by said coating and a substrate.

45. The method of claim 24, wherein said coating has an oxygen transmission rate less than approximately 0.01 cm³/(m² day), as measured at 25°

C. with a gas containing approximately 21 volume-percent oxygen.

46. The method of claim 24, wherein said coating has a water vapor transmission rate less than approximately 0.0001 g/(m²day), as measured at 25°

C. with a gas having approximately 100-percent relative humidity.

47. The method of claim 24, wherein said first zone and said second zone are contiguous.

48. The method of claim 24, wherein said device is a substrate.