Hybrid layers for use in coatings on electronic devices or other articles

• US 7,968,146 B2
• Filed: 10/31/2007
• Issued: 06/28/2011
• Est. Priority Date: 11/01/2006
• Status: Active Grant

• Current Assignee: Princeton University
• Original Assignee: The Trustees of Princeton University (Princeton University)
• Inventors: Wagner, Sigurd, Mandlik, Prashant
• Primary Examiner(s): Meeks; Timothy H
• Assistant Examiner(s): MILLER, JR, JOSEPH ALBERT
• Application Number:
  US11/931,939
• Publication Number:
  US 20080237181A1
• Time in Patent Office: 1,336 Days
• Field of Search: None
• US Class Current: 427/248.1
• CPC Class Codes: C23C 16/0245 by etching with a plasma
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/22 characterised by the deposition of inorganic material, other than metallic material
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/509 using internal electrodes
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: H01L 31/18 Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
• CPC Class Codes: H10K 50/8426 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 85/40 Organosilicon compounds, e.g. TIPS pentacene
• CPC Class Codes: Y10T 428/239 Complete cover or casing
• CPC Class Codes: Y10T 428/24331 including nonapertured component
• CPC Class Codes: Y10T 428/24612 Composite web or sheet
• CPC Class Codes: Y10T 428/24752 Laterally noncoextensive components
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A method for forming a coating over a surface is disclosed. The method comprises depositing over a surface, a hybrid layer comprising a mixture of a polymeric material and a non-polymeric material. The hybrid layer may have a single phase or comprise multiple phases. The hybrid layer is formed by chemical vapor deposition using a single source of precursor material. The chemical vapor deposition process may be plasma-enhanced and may be performed using a reactant gas. The precursor material may be an organo-silicon compound, such as a siloxane. The hybrid layer may comprise various types of polymeric materials, such as silicone polymers, and various types of non-polymeric materials, such as silicon oxides. By varying the reaction conditions, the wt % ratio of polymeric material to non-polymeric material may be adjusted. The hybrid layer may have various characteristics suitable for use with organic light-emitting devices, such as optical transparency, impermeability, and/or flexibility.

Claims

1. A method for forming a coating over a surface, comprising:

using a source of precursor material;

transporting the precursor material to a reaction location adjacent a surface to be coated;

and

depositing a hybrid layer over the surface by chemical vapor deposition using the source

of precursor material, wherein the hybrid layer consists essentially of a mixture of polymeric

silicon and inorganic silicon, wherein the weight ratio of polymeric silicon to inorganic silicon is in the range of 95;

5 to 5;

95, and wherein the polymeric silicon and the inorganic silicon are created from the same source of precursor material;

wherein at least an 0.1 μ

m thickness of the hybrid layer is deposited under the same

reaction conditions for all the reaction conditions in the deposition process;

wherein the water vapor transmission rate is less than 10<sup>−

6</sup> g/m²/day through the at least 0.1 μ

m thickness of the hybrid layer.

2. The method of claim 1, wherein the precursor material is hexamethyl disiloxane or dimethyl siloxane.

3. The method of claim 1, wherein the precursor material comprises a single organo-silicon compound.

4. The method of claim 1, wherein the precursor material comprises a mixture of organo-silicon compounds.

5. The method of claim 1, wherein the chemical vapor deposition is plasma-enhanced.

6. The method of claim 5, further comprising providing a reactant gas and wherein the chemical vapor deposition takes place in the presence of the reactant gas.

7. The method of claim 6, wherein the reactant gas is oxygen.

8. The method of claim 1, wherein the weight ratio of polymeric silicon to inorganic silicon is in the range of 90:

10 to 10;

90.

9. The method of claim 1, wherein the weight ratio of polymeric silicon to inorganic silicon is in the range of 25:

75 to 10;

90.

10. The method of claim 1, wherein at least a 1,600 Å

thickness of the hybrid layer is deposited under the same reaction conditions for all the reaction conditions in the deposition process.

11. The method of claim 1, wherein a 1,600-60,000 Å

thickness of the hybrid layer is deposited under the same reaction conditions for all the reaction conditions in the deposition process.

12. The method of claim 1, wherein the precursor material is hexamethyl disiloxane or dimethyl siloxane;

and wherein the chemical vapor deposition is plasma-enhanced.

13. The method of claim 1, further comprising depositing an unmixed polymeric silicon layer over the surface using the source of precursor material prior to depositing the hybrid layer.

14. The method of claim 1, further comprising depositing an unmixed inorganic silicon layer over the surface using the source of precursor material prior to depositing the hybrid layer.

15. The method of claim 1, further comprising depositing an unmixed polymeric silicon layer over the surface using the source of precursor material after depositing the hybrid layer.

16. The method of claim 1, further comprising depositing an unmixed inorganic silicon layer over the surface using the source of precursor material after depositing the hybrid layer.

17. The method of claim 1, wherein the hybrid layer, as deposited, has a wetting contact angle of a water droplet in the range of 36°

to 60°

.

18. The method of claim 1, wherein the hybrid layer is optically transparent.

19. The method of claim 18, wherein the hybrid layer has greater than 90% transmittance from the near-UV to the near-IR spectrum.

20. The method of claim 1, wherein the surface is pretreated prior to depositing the hybrid layer to improve the interfacial cohesion between the surface and the hybrid layer.

21. The method of claim 20, wherein the step of pretreating the surface comprises a chemical treatment.

22. The method of claim 20, wherein the step of pretreating the surface comprises a physical-chemical treatment.

23. The method of claim 22, wherein the physical-chemical treatment is a plasma treatment.

24. The method of claim 20, wherein the step of pretreating comprises disposing an intervening layer on the surface prior to depositing the hybrid layer.

25. The method of claim 24, wherein the intervening layer comprises a material that serves to increase the interfacial cohesion between the surface and the hybrid layer.

26. The method of claim 1, wherein the thickness of the hybrid layer deposited under the same reaction conditions is in a range from 0.1-10 μ

m.

27. The method of claim 1, further comprising:

depositing a plurality of hybrid layers over the surface by chemical vapor deposition using the source of precursor material, wherein each hybrid layer independently consists essentially of a mixture of polymeric silicon and inorganic silicon, wherein the weight ratio of polymeric silicon to inorganic silicon is in the range of 95;

5 to 5;

95, and wherein the polymeric silicon and the inorganic silicon are created from the same source of precursor material;

wherein for each of the plurality of hybrid layers, at least an 0.1 μ

m thickness of the hybrid layer is deposited under the same reaction conditions for all the reaction conditions in the deposition process.

28. The method of claim 27, wherein the plurality of hybrid layers are created by sequentially changing one or more of the reaction conditions in the chemical vapor deposition process.

29. The method of claim 28, further comprising providing a reactant gas, wherein the chemical vapor deposition takes place in the presence of the reactant gas, and wherein the plurality of hybrid layers are created by sequentially changing the amount of reactant gas in the chemical vapor deposition process.

30. The method of claim 27, wherein the amount of polymeric silicon in one hybrid layer differs by at least 10 weight % from the amount of polymeric silicon in another hybrid layer.

31. The method of claim 28, wherein the chemical vapor deposition is plasma-enhanced, and wherein the plurality of hybrid layers are created by sequentially changing the plasma power level in the plasma-enhanced chemical vapor deposition process.

32. The method of claim 27, wherein the overall internal stress in the multi-layered coating is controlled by tuning the internal stress in each hybrid layer.

33. The method of claim 32, wherein the internal stress in each hybrid layer is tuned by controlling the deposition conditions used to deposit each hybrid layer.

34. The method of claim 33, wherein the internal stress in each of the hybrid layers is tuned by controlling at least two deposition conditions which have an effect on the internal stress.

35. The method of claim 33, wherein each hybrid layer is deposited by plasma-enhanced chemical vapor deposition (PE-CVD), and wherein the deposition conditions being controlled are selected from the group consisting of:

deposition pressure, deposition power, gas flow rates, and electrode distance.

36. The method of claim 32, wherein the internal stress in each hybrid layer is tuned such that the overall internal stress in the multi-layered coating is balanced.

37. The method of claim 36, wherein the overall internal stress in the multi-layered coating is zero or nearly zero.

38. The method of claim 32, wherein at least one hybrid layer closer to the surface has a lower internal stress than at least one hybrid layer farther from the surface.

39. The method of claim 24, wherein the intervening layer is optically transparent.

40. The method of claim 24, wherein the intervening layer comprises an inorganic material.

41. The method of claim 40, wherein the inorganic material is chromium or silicon nitride.

42. The method of claim 27, wherein the precursor material is hexamethyl disiloxane or dimethyl siloxane;

and wherein the chemical vapor deposition is plasma-enhanced.

43. The method of claim 27, wherein for each of the plurality of hybrid layers, the thickness of the hybrid layer deposited under the same reaction conditions is in a range from 0.1-10 μ

m.