Multilayer structure offering improved impermeability to gases

Patent metadata

Field	Value
Publication number	US-9771654-B2
Application number	US-201214346890-A
Country	US
Kind code	B2
Filing date	Sep 24, 2012
Priority date	Sep 26, 2011
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A multilayer structure including a substrate and a first stack of a layer of SiO 2 and a layer of material of the SiO x N y H z type positioned between the substrate and the layer of SiO 2 , in which the layer of SiO 2 and the layer of material of the SiO x N y H z type have thicknesses (e B , e A ) such that the thickness of the layer of SiO 2 is less than or equal to 60 nm, the thickness of the layer of material of the SiO x N y H z type (e B ) is more than twice the thickness (e A ) of the layer of SiO 2 , and the sum of the thicknesses of the layer of SiO 2 and of the layer of material of the SiO x N y H z type is between 100 nm and 500 nm, and in which z is strictly less than the ratio (x+y)/5, and advantageously z is strictly less than the ratio (x+y)/10.

First claim

The invention claimed is:

1. A multilayer structure, comprising a substrate, and a first stack of a SiO 2 layer and a SiO x N y H z layer positioned between the substrate and SiO 2 layer,
wherein
the SiO 2 layer has a thickness of less than or equal to 60 nm,
the SiO x N y H z layer has a thickness of more than twice the thickness of the SiO 2 layer,
the thicknesses of the SiO 2 layer and the SiO x N y H z layer total from 100 nm to 500 nm, and
z is strictly positive and is strictly less than a ratio (x+y)/5,
wherein the value of x decreases from an interface between the SiO x N y H z layer and the SiO 2 layer towards the substrate, and the value of y increases from the interface between the SiO x N y H z layer and the SiO 2 layer towards the substrate,
wherein x varies from 2 to 0 and y varies from 0 to 1, and
wherein the SiO 2 layer and the SiO x N y H z layer are made of amorphous materials.

2. The multilayer structure according to claim 1 , wherein z is strictly less than a ratio (x+y)/10.

3. The multilayer structure according to claim 1 , wherein a material of the SiO 2 layer has a Young's modulus of greater than or equal to 30 GPa, and a material of the SiO x N y H z layer has a Young's modulus of less than or equal to 20 GPa.

4. The multilayer structure according to claim 1 , wherein the stack has a refractive index of greater than 1.5.

5. The multilayer structure according to claim 3 , wherein the stack is obtained by conversion of a liquid containing a perhydropolysilazane, where the stack has a transmittance corresponding to a Si—H bond of greater than 80% of a transmittance of the Si—H bond of the liquid containing the perhydropolysilazane before conversion, measured by infrared reflectance spectrometry in the case of a substrate made of polymer material.

6. The multilayer structure according to claim 5 , wherein the stack has a transmittance corresponding to the Si—H bond of greater than 90% of the transmittance of the Si—H bond of the inorganic precursor of the perhydropolysilazane before conversion, measured by infrared reflectance spectrometry in the case of a substrate made of polymer material.

7. The multilayer structure according to claim 3 , wherein the stack is obtained by conversion of an inorganic precursor of a perhydropolysilazane, where the stack has an absorbance corresponding to a Si—H bond of less than 20% of an absorbance of the Si—H bond of the inorganic precursor of the perhydropolysilazane before conversion, measured by infrared transmission spectrometry in the case of a silicon substrate.

8. The multilayer structure according to claim 7 , wherein the stack has an absorbance corresponding to the Si—H bond of less than 10% of the absorbance of the Si—H bond of the liquid containing the perhydropolysilazane before conversion, measured by infrared transmission spectrometry in the case of a silicon substrate.

9. The multilayer structure according to claim 1 , wherein the substrate is made of a polymer material.

10. The multilayer structure according to claim 1 , further comprising a layer of polymer material on the SiO 2 layer of the first stack on a face opposite the one in contact with the SiO x N y H z layer.

11. The multilayer structure according to claim 1 , comprising n stacks, wherein
n is a positive integer greater than or equal to 1,
each stack comprises a (SiO 2 ) i layer and a SiO xi N yi H zi layer,
i is a positive integer of between 1 and n,
the (SiO 2 ) i layers of each stack have a thickness of less than or equal to 60 nm,
the SiO xi N yi H zi layers of each stack have a thickness of more than twice the thickness of the (SiO 2 ) i layers,
the thicknesses of the (SiO 2 ) i layers and the SiO xi N yi H zi layers total from 100 nm to 500 nm, and
z i is strictly less than a ratio (x i +y i )/5.

12. The multilayer structure according to claim 11 , wherein z i is strictly less than a ratio (x i +y i )/10, where x i , y i and z i may or may not be identical for different values of i.

13. The multilayer structure according to claim 12 , comprising at least one layer made of polymer material positioned between the (SiO 2 ) i layer of a stack and the SiO xi N yi H zi layer of the stack which follows directly.

14. The multilayer structure according to claim 13 , comprising n−1 layers made of polymer material, where each of the layers made of polymer material is positioned between two stacks.

15. The multilayer structure according to claim 4 , wherein the stack is obtained by conversion of a liquid containing a perhydropolysilazane, where the stack has a transmittance corresponding to a Si—H bond of greater than 80% of a transmittance of the Si—H bond of the liquid containing the perhydropolysilazane before conversion, measured by infrared reflectance spectrometry in the case of a substrate made of polymer material.

16. The multilayer structure according to claim 4 , wherein the stack is obtained by conversion of a liquid containing a perhydropolysilazane, where the stack has an absorbance corresponding to the Si—H bond of less than 20% of an absorbance of the Si—H bond of the liquid containing the perhydropolysilazane before conversion, measured by infrared transmission spectrometry in the case of a silicon substrate.

17. The multilayer structure according to claim 13 , wherein the substrate is a polymer material of a polyester selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate.

18. The multilayer structure according to claim 13 , wherein the substrate is a polymer material of a polyolefin selected from the group consisting of polyethylene and polypropylene.

19. The multilayer structure according to claim 13 , wherein the substrate is a polymer material of a polyamide.

20. The multilayer structure according to claim 1 , wherein the SiO 2 layer and the SiO x N y H z layer are in close contact along their entire surfaces and wherein each of the layers contains only one material.

21. The multilayer structure according to claim 1 , wherein the thicknesses of the SiO 2 layer and the SiO x N y H z layer total from 100 nm to 250 nm.

22. A method for producing a multilayer structure according to claim 1 ,
the method comprising:
depositing a liquid containing a perhydropolysilazane on a substrate; and
converting by irradiation by VUV radiation with a wavelength of less than or equal to 220 nm and an ultraviolet radiation with a wavelength of greater than or equal to 220 nm in an atmosphere with an oxygen content of greater than 10 ppm and less than 500 ppm and a water content of less than or equal to 1,000 ppm, so as to form a stack of a SiO 2 layer and a SiO x N y H z layer.

23. The method according to claim 22 , further comprising further depositing a layer of polymer material after the converting.

24. The method according to claim 22 , further comprising repeating the depositing and converting.

25. A method for producing a multilayer structure according to claim 1 ,
the method comprising:
depositing a liquid containing perhydropolysilazane on a substrate;
converting by irradiation by ultraviolet radiation with a wavelength of greater than 220 nm in an atmosphere having an oxygen content and a water content of less than 10 ppm to obtain a converted layer;
depositing a liquid containing the perhydropolysilazane on the converted layer; and
converting by irradiation by VUV radiation with a wav

Assignees

• Commissariat A L'Energie Atomique Et Aux Ene Alt
• Commissariat Energie Atomique

Inventors

• Cros Stephane
• Alberola Nicole
• Garandet Jean-Paul
• Morlier Arnaud

Classifications

• H10P14/6689

  the compound being a silazane · CPC title

• C23C18/143

  Radiation by light, e.g. photolysis or pyrolysis · CPC title

• Y10T428/24975

  No layer or component greater than 5 mils thick · CPC title

• Y10T428/2495

  Thickness [relative or absolute] · CPC title

• C23C18/1225 Primary

  Deposition of multilayers of inorganic material · CPC title