Multilayer structure offering improved impermeability to gases

19:

• The multilayer structure according to claim 18, wherein z is strictly less than a ratio (x+y)/10.

20:

• The multilayer structure according to claim 18, wherein the value of x decreases from an interface between the SiOxNyHz type layer and the SiO2 layer towards the substrate, and the value of y increases from the interface between the SiOxNyHz type layer and the SiO2 layer towards the substrate.

21:

• The multilayer structure according to claim 20, wherein x varies from 2 to 0, y varies from 0 to 1, or both.

22:

• The multilayer structure according to claim 18, wherein a material of the SiO2 layer has a Young's modulus of greater than or equal to 30 GPa, and a material of the SiOxNyHz type layer has a Young's modulus of less than or equal to 20 GPa.

23:

• The multilayer structure according to claim 18, wherein the stack has a refractive index of greater than 1.5.

24:

• The multilayer structure according to claim 22, wherein the stack is obtained by conversion of an inorganic precursor of a perhydropolysilazane type, 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 inorganic precursor of the perhydropolysilazane type before conversion, measured by infrared reflectance spectrometry in the case of a substrate made of polymer material.

25:

• The multilayer structure according to claim 24, 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 type before conversion, measured by infrared reflectance spectrometry in the case of a substrate made of polymer material.

26:

• The multilayer structure according to claim 22, wherein the stack is obtained by conversion of an inorganic precursor of a perhydropolysilazane type, 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 type before conversion, measured by infrared transmission spectrometry in the case of a silicon substrate.

27:

• The multilayer structure according to claim 26, 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 inorganic precursor of the perhydropolysilazane type before conversion, measured by infrared transmission spectrometry in the case of a silicon substrate.

28:

• The multilayer structure according to claim 18, wherein the SiO2 layer and the SiOxNyHz type layer are made of amorphous materials.

29:

• The multilayer structure according to claim 18, wherein the substrate is made of a polymer material.

30:

• The multilayer structure according to claim 18, further comprising a layer of polymer material on the SiO2 layer of the first stack on a face opposite the one in contact with the SiOxNyHz type layer.

32:

• The multilayer structure according to claim 31, wherein zi is strictly less than a ratio (xi+yi)/10, where xi, yi and zi may or may not be identical for different values of i.

33:

• The multilayer structure according to claim 32, comprising at least one layer made of polymer material positioned between the (SiO2)i layer of a stack and the the SiOxiNyiHzi type layer of the stack which follows directly.

34:

• The multilayer structure according to claim 33, comprising n−1 layers made of polymer material, where each of the layers made of polymer material is positioned between two stacks.

36:

• The method according to claim 35, further comprising further depositing a layer of polymer material after the converting.

37:

• The method according to claim 35, further comprising repeating the depositing and converting, or repeating the depositing, converting, and further depositing.

39:

• The multilayer structure according to claim 23, wherein the stack is obtained by conversion of an inorganic precursor of a perhydropolysilazane type, 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 inorganic precursor of the perhydropolysilazane type before conversion, measured by infrared reflectance spectrometry in the case of a substrate made of polymer material.

The multilayer structure according to claim 23, wherein the stack is obtained by conversion of an inorganic precursor of a perhydropolysilazane type, 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 inorganic precursor of the perhydropolysilazane type before conversion, measured by infrared transmission spectrometry in the case of a silicon substrate.