FR3082662A1 - Method of manufacturing an optoelectronic device with self-aligned light confinement walls - Google Patents

Abstract

The manufacture of an optoelectronic device (10) involves the formation of light-emitting diodes (11) each of which has a wire shape, the formation of spacer walls (14) made of a first dielectric material and transparent to light radiation (16) from the diodes (11). The lateral sides (111) of each diode (11), over its entire height (H), are surrounded by at least one of the spacing walls (14). Light confinement walls (17) are formed in a second material capable of blocking the light radiation (16) coming from the diodes (11). The light confining walls (17) directly cover the lateral flanks (141) of the spacing walls (14) while being in contact with them. The radiation (16) coming from each diode (11) and directed towards the adjacent diodes (11) is blocked by the confinement wall (17). The upper edges (112) of the diodes (11) are covered by the light confinement material so as to ensure light extraction by the rear face of the optoelectronic device (10). An optoelectronic device (10) as such is also described. Figure 14

Description

Title of the invention: Method for manufacturing an optoelectronic device with self-aligned light confinement walls Technical field of the invention The present invention relates to a method for manufacturing an optoelectronic device comprising a matrix of light emitting diodes.

The invention also relates to an optoelectronic device as such.

The invention finds application in particular in display screens or image projection systems.

STATE OF THE ART [0004] By optoelectronic device is meant here a device adapted to effect the conversion of an electrical signal into electromagnetic radiation to be emitted, in particular light.

There are optoelectronic devices comprising light emitting diodes, also known by the acronym LED for "light-emitting diode" according to the English terminology devoted, formed on a substrate.

It is known that each light-emitting diode comprises an active material exploiting quantum wells, a semiconductor portion doped according to a first type of doping to play the role of P-doped junction and a semiconductor portion doped according to a second type of doping to play the role of N doped junction

Each light emitting diode can be formed on the basis of three-dimensional semiconductor elements, themselves at least partially obtained by growth by epitaxy. Light-emitting diodes are typically formed from a semiconductor material comprising, for example, elements from column III and column V of the periodic table, such as a III-V compound, especially gallium nitride (GaN), indium and gallium nitride (InGaN) or aluminum and gallium nitride (AlGaN).

There are optoelectronic devices comprising a matrix of light-emitting diodes having a certain emission surface through which is transmitted the light radiation emitted by the light-emitting diodes. Such optoelectronic devices can in particular be used in the constitution of display screens or image projection systems, where the matrix of light-emitting diodes in fact defines a matrix of light pixels where each pixel comprises one or more light-emitting diodes.

One of the difficulties is to achieve that the light radiation emitted by a light-emitting diode does not mix with the light radiation emitted by the adjacent light-emitting diodes in order to improve the contrasts. In particular, one problem is to succeed in avoiding color excitations of the diaphotia type between the sub-pixels, a phenomenon also known as “cross-talk” in the technical field concerned. However, this problem proves increasingly difficult to solve given the increasing miniaturization of light emitting diodes.

A known solution is to form light confinement walls capable of blocking the transmission of light radiation emitted by one or more given light-emitting diode (s) to one or more light-emitting diode (s) ) adjacent.

A known technique for forming such light confinement walls consists in depositing a layer of resin on the light-emitting diodes, the resin being photolithographed while respecting a pattern guaranteeing the presence of trenches intended to be then filled with a material, by example by a growth or deposition technique, capable of blocking light radiation or even of ensuring a reflection thereof.

This technique has the drawback that it is difficult to comply with precise alignment between the confinement walls and the light-emitting diodes. This problem is all the more present given the increasing miniaturization of light-emitting diodes in order to obtain high resolution in the end.

In this context, there is a need to have a method for manufacturing a simple, efficient optoelectronic device which makes it possible to increase the resolution while optimizing the contrast.

OBJECT OF THE INVENTION The aim of the present invention is to propose a method of manufacturing an optoelectronic device comprising a matrix of light emitting diodes which makes it possible to obtain optoelectronic devices with high resolution and high contrast.

This object can be achieved by implementing a process for manufacturing an optoelectronic device comprising an array of light-emitting diodes, comprising the following steps:

formation of the matrix of light-emitting diodes on a support face of a substrate, this step being carried out so that each light-emitting diode has an elongated wire shape along a longitudinal axis extending in a transverse direction of the optoelectronic device oriented transversely to the substrate support side,

- formation of spacer walls made of a first dielectric material transparent to light radiation coming from the light-emitting diodes, the spacer walls formed being such that the lateral flanks of each light-emitting diode, over its entire height counted in the transverse direction , are surrounded by at least one of the spacing walls,

- formation of light confinement walls formed in a second material capable of blocking the light radiation coming from light-emitting diodes, the light confinement walls formed directly covering the lateral flanks of the spacing walls by being in contact, so that the light radiation from each light-emitting diode and directed towards the adjacent light-emitting diodes is blocked by the light confinement wall which covers the spacer wall which surrounds said light-emitting diode.

Some preferred but non-limiting aspects of this manufacturing process are as follows.

The step of forming the spacing walls comprises a step of depositing a thin layer of the first material, implemented so that the deposited thin layer covers the lateral flanks and the upper edge of the light-emitting diodes.

After the step of depositing the thin layer of the first material, the step of forming the spacer walls comprises a step of etching the thin layer of the first material previously deposited located at the upper edges of the light emitting diodes. and at the level of the zones between the light-emitting diodes.

The second material used in the step of forming the light confinement walls is such that the light confinement walls are reflective for the light radiation coming from the light-emitting diodes.

The step of forming the light confinement walls comprises a step of depositing a thin layer of the second material used so that this thin layer of the second material directly covers the lateral flanks of the spacing walls by being in contact with them and covers the upper edge of the light-emitting diodes and the step of depositing the thin layer of the second material comprises a step of filling, by said thin layer of the second material, the empty spaces delimited between the spacing walls at the level areas between the light emitting diodes.

At the end of the step of forming the light confinement walls, the upper edge of each light-emitting diode is not covered by the second material so that the light radiation from the light-emitting diodes is emitted out of the device optoelectronics by an emitting surface of the optoelectronic device located, with respect to the light-emitting diodes, on the side of the upper edges of the light-emitting diodes in the transverse direction.

At the end of the step of forming the light confinement walls, the upper edge of each light-emitting diode is covered by a light confinement wall so that after the implementation of a step of removing the substrate , the light radiation coming from the light-emitting diodes is emitted out of the optoelectronic device by an emitting surface of the optoelectronic device located, with respect to the light-emitting diodes, on the side opposite to the upper edges of the light-emitting diodes in the transverse direction.

The step of forming the spacer walls is implemented so that the spacer walls formed have an outer face of convex shape, in particular frustoconical, and the light confinement walls formed have an inner face having a concave shape complementary to said convex shape and turned towards the light-emitting diode whose light radiation it confines.

The first material used for the formation of the spacer walls comprises photoluminescent particles which are in the form of quantum dots.

The invention also relates to an optoelectronic device comprising:

- a matrix of light-emitting diodes in which each light-emitting diode has an elongated wire shape along a longitudinal axis extending in a transverse direction of the optoelectronic device,

- spacer walls made of a first dielectric material and transparent to light radiation coming from light-emitting diodes and arranged so that the lateral flanks of each light-emitting diode, over its entire height counted in the transverse direction, are surrounded by at minus one of the spacer walls,

- and light confinement walls formed in a second material capable of blocking the light radiation coming from light-emitting diodes, the light confinement walls directly covering the lateral flanks of the spacing walls by being in contact with them, the light radiation coming from of each light emitting diode and directed towards the adjacent light emitting diodes being blocked by the light confinement wall which covers the spacer wall which surrounds said light emitting diode.

Some preferred but non-limiting aspects of this optoelectronic device are as follows.

The light confinement walls cover the upper edge of the light emitting diodes and the light radiation from the light emitting diodes is emitted outside the optoelectronic device by an emitting surface of the optoelectronic device located, with respect to the light emitting diodes, on the opposite side. at the upper edges of the light-emitting diodes in the transverse direction.

The second material is such that the light confinement walls are reflective for the light radiation coming from the light-emitting diodes and the spacing walls have an external face of convex shape and the light confinement walls have an internal face having a concave shape complementary to said convex shape and turned towards the light-emitting diode whose light radiation it confines.

The optoelectronic device comprises a lower electrode layer formed in an electrically conductive material and transparent to light radiation, said lower electrode layer being in electrical contact with the lower edges of the light-emitting diodes in order to fulfill a function of first electrode common to several light-emitting diodes.

Each light emitting diode is of the core-shell type and the optoelectronic device comprises an upper electrode layer formed in an electrically conductive material and transparent to light radiation, the upper electrode layer directly covering the lateral flanks and the upper edge. light-emitting diodes being in contact with them so as to fulfill a second electrode function common to several light-emitting diodes, the spacer walls directly covering the side blanks and the upper edge of the upper electrode layer being in contact with them and the upper electrode layer being in electrical contact with at least one of the light confinement walls.

The light confinement walls do not cover the upper edge of the light emitting diodes and the light radiation from the light emitting diodes is emitted outside the optoelectronic device by an emitting surface of the optoelectronic device located, relative to the light emitting diodes, of the side of the upper edges of the light-emitting diodes in the transverse direction.

SUMMARY DESCRIPTION OF THE DRAWINGS Other aspects, aims, advantages and characteristics of the invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of nonlimiting example, and made with reference to the accompanying drawings in which:

[Fig-1] illustrates a step in a first example of implementation of a manufacturing process according to the invention.

[Fig.2] illustrates another step of the first example of implementation of a manufacturing process according to the invention.

[Fig.3] illustrates another step of the first example of implementation of a manufacturing process according to the invention.

[Fig.4] illustrates another step of the first example of implementation of a manufacturing process according to the invention.

[Fig.5] illustrates another step of the first example of implementation of a manufacturing process according to the invention.

[Fig.6] illustrates a variant of Figure 5.

[Fig.7] shows, in top view, an example of optoelectronic device manufactured by the implementation of the manufacturing process of Figures 1 to 5.

[Fig.8] shows, in top view, another example of optoelectronic device manufactured by the implementation of the manufacturing process of Figures 1 to 5.

[Fig. 9] shows, in longitudinal section, another example of an optoelectronic device which can be obtained by implementing a manufacturing process according to the invention.

[Fig. 10] shows, in longitudinal section, yet another example of an optoelectronic device which can be obtained by implementing a manufacturing process according to the invention.

[Fig.l 1] illustrates a step in a second example of implementation of a manufacturing process according to the invention.

[Fig. 12] illustrates another step of the second example of implementation of a manufacturing process according to the invention.

[Fig. 13] illustrates a variant of FIG. 12.

[Fig. 14] shows, in longitudinal section, another example of an optoelectronic device which can be obtained by implementing a manufacturing process according to the invention.

Detailed description In the figures and in the following description, the same references represent the same or similar elements. In addition, the different elements are not shown to scale so as to favor the clarity of the figures. Furthermore, the different embodiments and variants are not mutually exclusive and can be combined with one another.

The invention relates firstly to a method of manufacturing an optoelectronic device 10 comprising a matrix of light-emitting diodes 11. It also relates to an optoelectronic device 10 as such, comprising the matrix of light-emitting diodes 11.

Thanks to the arrangement of such a matrix of light-emitting diodes 11, a particularly targeted application is the supply of an image display screen or of an image projection device.

For this purpose, the matrix of light emitting diodes 11 may have a certain emission surface through which is transmitted the light radiation coming from the light emitting diodes 11. The matrix of light emitting diodes 11 in practice defines a matrix of pixels luminous where each pixel comprises one or more light-emitting diodes 11. In particular, each pixel can comprise:

- at least one sub-pixel formed by at least one light-emitting diode 11 capable of directly generating, or transmitting, via a suitable light converter, blue light,

- at least one sub-pixel formed by at least one light-emitting diode 11 capable of directly generating, or transmitting, via a suitable light converter, green light,

- at least one sub-pixel formed by at least one light-emitting diode 11 capable of directly generating, or transmitting via a suitable light converter, red light.

Figures 1 to 5 illustrate different stages of a first example of implementation of a manufacturing process according to the invention.

Referring first to Figure 1, the manufacturing process includes a step of forming the matrix of light emitting diodes 11 on a support face 12 of a substrate 13.

To facilitate understanding, we define here and for the remainder of the description a three-dimensional direct coordinate system (X, Y, Z) where the plane (X, Y) corresponds to the main plane of the optoelectronic device 10 in which the light-emitting diodes 11 are distributed and where Z corresponds to the transverse direction of the optoelectronic device oriented transversely to the plane (X, Y). In other words, the directions X and Y are generally oriented parallel to the general plane of the support face 12 of the substrate used for the manufacture of the optoelectronic device 10 and the transverse direction Z is oriented transversely to the support face 12 of the substrate 13.

During this step, each light-emitting diode 11 formed advantageously has an elongated wire shape along a longitudinal axis extending in the transverse direction Z of the optoelectronic device 10.

The organization of each light emitting diode 11 in the form of a wire is very advantageous for optoelectronic devices 10 with high resolution and high contrast while not generating any limitation as to the materials and techniques used in the steps following of the manufacturing process and by conferring all the known advantages as to the use of such wired light-emitting diodes 11, in particular in terms of cost and efficiency.

The techniques used to form the wired light-emitting diodes 11 are not limiting as regards the manufacturing process described in this document so that to implement this step of forming light-emitting diodes 11, ΓMan of the Trade may use all known techniques.

Not illustrated in detail, each light-emitting diode 11 comprises semiconductor elements including a first doped portion, an active part and a second doped portion. The semiconductor elements are arranged in a wire form, according to micrometric or nanometric dimensions.

Each light emitting diode 11 in the form of a wire can either be of the heart-shell type or alternatively may have an axial structure where the first doped portion, the active part and the second doped portion are stacked in the transverse direction Z All the techniques known for these purposes can be used, in particular by exploiting the known principles of epitaxial growth.

The cross section of the wired light-emitting diodes 11, taken in any plane parallel to the plane (X, Y), can have different shapes such as, for example, an oval, circular or polygonal shape (for example square, rectangular, triangular or hexagonal).

For example in the case of a heart-shell type organization, each light-emitting diode 11 comprises a wire forming the first doped portion, whether it is of type N or of type P, extending transversely to the plane of the support face 12 of the substrate 13, and a shell covering at least the upper part of this wire. The shell may comprise a stack of several layers of semiconductor materials, in particular at least one layer forming the active part covering at least the upper part of the wire and a layer forming the second doped portion and covering the layer forming the active part.

By way of example, the constituent wires of the first doped portion can be, at least in part, formed from semiconductor materials mainly comprising a III-V compound, for example III-N compounds. Examples of group III include gallium, indium or aluminum. Examples of III-N compounds are GaN, AIN, InGaN or AlInGaN. Other group V elements can also be used, for example, phosphorus, arsenic or antimony. Generally, the elements in compound III-V can be combined with different molar fractions. It should be pointed out that the wires can equally be formed from semiconductor materials mainly comprising a compound II-VI. The dopant can be chosen, in the case of a III-V compound, from the group comprising a P type dopant of group II, for example magnesium, zinc, cadmium or mercury, a P type dopant of group IV for example carbon, or an N type dopant of group IV, for example silicon, germanium or selenium.

The active part is the layer from which the majority of the radiation supplied by the light-emitting diode 11 is emitted. It may include means for confining the carriers of electric charge, such as quantum wells. It is, for example, made up of alternating layers of GaN and InGaN. The GaN layers can be doped. Alternatively, the active layer can consist of a single layer of InGaN.

The layer forming the second doped portion, P-type doped if the wires are N-type doped or N-type doped if the wires are P-type doped, may correspond to a semiconductor layer or to a stack of semiconductor layers allowing the formation of a PN or PIN junction.

In general, the first doped portion of the light emitting diodes 11 is in electrical contact with a first lower electrode and the second doped portion of the light emitting diodes 11 is in electrical contact with a second upper electrode. These considerations will be deepened in the following only by way of example.

The manner of forming the first lower electrode and the second upper electrode are not limiting and all known techniques, and suitable for the implementation of the subsequent steps which will be described in the following description, may on the contrary be considered by the skilled person. For example, the first lower electrode can be formed by the substrate 13 itself or by a conductive layer formed on the support face 12 of the substrate 13. The first lower electrode can also be formed after the substrate 13 has been removed.

It is therefore emphasized that the terms “formation of the matrix of light-emitting diodes 11 on the support face 12” means either that the light-emitting diodes 11 are directly formed on the support face 12 by means of mechanical and electrical contact, or that the light-emitting diodes 11 are indirectly formed on the support face 12 by interposing at least the conductive layer intended to ensure the function of the first lower electrode.

The substrate 13 can therefore be at least partially formed in a highly doped conductive or semiconductor material so as to have good electrical conductivity properties, for example made of preferably monocrystalline silicon.

The substrate 13 can also be formed from sapphire or even from a III-V semiconductor material, for example GaN.

It can alternatively be a silicon on insulator or "SOI" type substrate for "Silicon On Insulator" according to the English terminology used.

Alternatively, the substrate 13 can be formed from a semiconductor or electrically insulating material.

It appears from the above that the first lower electrode can be formed by the substrate 13 itself or by a lower electrode layer 21, formed on the substrate 13 in an electrically conductive material and in electrical contact with the lower edges of the light-emitting diodes 11 in order to fulfill a function of first electrode common to several light-emitting diodes 11.

In the case where an emission of light will be sought on the rear face of the optoelectronic device 10, as is for example the case in the embodiments of FIGS. 9 and 10, the lower electrode layer 21 can be transparent to light radiation 16 coming from light-emitting diodes 11 (it is specified that in this embodiment, the substrate 13 on which the light-emitting diodes 11 are formed is removed and the lower electrode layer 21 is formed after the substrate has been removed 13). However, it is specified that this condition of transparency of the layer 21 to the light radiation 16 is not compulsory, in particular in the case where it is desired that the emission of light takes place on the side of the front face of the optoelectronic device 10 .

It is possible to provide a layer of electrically insulating material between the substrate 13 and the lower electrode layer 21, for example depending on the nature of the substrate 13, such a layer of electrically insulating material remaining optional, however.

The lower electrode layer 21 may comprise a nucleation layer or a stack of nucleation layers formed in a material suitable for the growth, on said material, of the semiconductor elements of the light-emitting diodes 11.

For example, the material making up a nucleation layer may be a nitride, a carbide or a boride of a transition metal from column IV, V or VI of the periodic table of the elements or a combination of these compounds. By way of example, the nucleation layer may be made of aluminum nitride, aluminum oxide, boron, boron nitride, titanium, titanium nitride, tantalum, tantalum nitride, hafnium , in hafnium nitride, in niobium, in niobium nitride, in zirconium, in zirconium boride, in zirconium nitride, in silicon carbide, in nitride and tantalum carbide, or in magnesium nitride in the MgxNy form, where x is approximately equal to 3 and y is approximately equal to 2, for example magnesium nitride in the form Mg3N2. The nucleation layer can be doped with the same type of conductivity as that of the semiconductor elements intended to grow, and have a thickness for example between 1 nm and 200 nm, preferably between 10 nm and 50 nm. The nucleation layer can be composed of an alloy or a stack of one or more materials mentioned in the list above.

The lower electrode layer 21 may comprise, in addition to the nucleation layer (s) or in place of the nucleation layer (s), a conductive layer or a stack of conductive layers, in particular of a metallic nature.

In the case where it will be sought to emit light from the side of the front face of the optoelectronic device 10, the conductive layer or layers can cover the nucleation layer (s) between the light-emitting diodes 11 but without extending over light emitting diodes 11. The conductive material used for such conductive layers is for example: aluminum, copper, gold, ruthenium, silver, zinc, titanium, nickel. It may in particular be sought for properties enabling it to play a role of reflector for reflecting outwards the light radiation 16 initially emitted by the light-emitting diodes 11 in the direction of the substrate 13.

In the case where it will be sought an emission of light from the side of the rear face of the optoelectronic device 10, the conductive material used for such conductive layers may have characteristics of transparency to the light emitted by the light emitting diodes 11 The material used can for example be chosen from all the transparent conductive oxides known to Γ Man of the Trade, also known by the acronym “TCO” for “Transparent Conductive Oxide” in English. Provision may in particular be made for forming the conductive layer or layers, for example by deposition, after a step of removing the substrate 13 and removing the one or more nucleation layers.

The manufacturing method then comprises, with reference to FIG. 3, a step of forming spacer walls 14 made of a first material which is both dielectric and transparent to light radiation 16 (this light radiation being shown diagrammatically by arrows undergoing a reflection in FIG. 5) coming from the light-emitting diodes 11. The spacing walls 14 are formed so that the lateral flanks 111 of each light-emitting diode 11, over its entire height H counted in the transverse direction Z, are surrounded by at least one of the spacing walls 14. By way of example, the height H of the light-emitting diodes 11 is between 0.1 and 100 μm, preferably between 0.5 and 20 μm.

The first material used for the formation of the spacer walls 14 therefore has transparency properties at the wavelengths provided for the light radiation 16 coming from the active parts of the light-emitting diodes 11 and at the same time properties of electrical insulation. It may for example be an oxide, a nitride or even for example a silicon oxynitride. Other materials may also be suitable, such as organic materials, certain resins or silicones, TiO2 or HfO2.

The first material used for the formation of the spacer walls 14 may comprise photoluminescent particles, suitable for converting the light radiation 16 emitted by the light-emitting diodes 11 in terms of wavelengths, in order to ultimately modify the color. light emitted from the optoelectronic device 10. This solution can be used to obtain pixels or subpixels of different colors without having to resort to other additional color converters.

Preferably, the photoluminescent particles are in the form of quantum dots (or “quantum dots” according to the appropriate English terminology), that is to say in the form of semiconductor nanocrystals whose confinement quantum is substantially three-dimensional. The average size of the quantum dots can then be between 0.2 nm and 50 nm, for example between 1 nm and 30 nm. The quantum dots can be formed from at least one semiconductor compound, which can be chosen from cadmium selenide (CdSe), indium phosphorus (InP), gallium and indium phosphorus (InGaP), sulfide cadmium (CdS), zinc sulfide (ZnS), cadmium oxide (CdO) or zinc (ZnO), zinc and cadmium selenide (CdZnSe), zinc selenide (ZnSe) for example with copper or manganese, graphene or among other semiconductor materials which may be suitable. The size and composition of the photoluminescent particles are chosen according to the desired luminescence wavelength. It can be heart-shell structures as well.

In general, any technique can be envisaged by the skilled person to form such spacing walls 14.

At the end of their training stage, depending on the general organization sought for the optoelectronic device 10, the spacer walls 14 can be arranged so as not to cover the upper edges 112 of the light-emitting diodes 11 as shown in the examples in FIGS. 5, 6, 9 and 10, or alternatively the spacer walls 14 can be arranged so as to cover them as shown in the examples in FIGS. 13 and 14.

According to a particular embodiment of the nonlimiting manufacturing process, with reference to FIG. 2, the step of forming the spacer walls 14 comprises a step of depositing a thin layer 15 of the first material , implemented so that the thin layer 15 deposited covers the lateral flanks 111 and the upper edge 112 of the light-emitting diodes 11. The thin layer 15 can directly cover the lateral flanks 111 and the upper edges 112 of the light-emitting diodes 11 while being at their contact. Alternatively, the thin layer 15 can cover them indirectly by interposing at least one intermediate layer such as at least one thin layer of conductive material transparent to light radiation 16 intended to fulfill the role of the second upper electrode. These provisions are for example shown in Figure 9 with the presence of the layer marked 22 which will be described in more detail in the following description.

The thin layer 15 can be deposited by chemical vapor deposition (or "Chemical Vapor Deposition", in English), for example by atomic thin layer deposition (or "Atomic Layer Deposition", in English), or even by physical vapor deposition (or “Physical Vapor Deposition”, in English), for example by electron beam, by sputtering, or other.

The thin layer 15 can be deposited according to a conformal deposition technique (case of Figures 3 and 4 for example), or by a deposition technique where the thickness of the deposited thin layer 15 is not constant like this is shown in Figures 11 to 13.

By "conformal deposition" means the deposition of a thin layer 15 on the light emitting diodes 11 so that it extends locally substantially parallel to the surface it covers. The thin layer 15 conformally deposited has a substantially homogeneous thickness. The local thickness can however vary between a minimum value at the level for example of a surface substantially orthogonal to the plane (X, Y) and a maximum value at the level for example of a surface substantially parallel to the plane (X, Y). By way of illustration only, for a conformal deposition of a thin layer of 1 μm, the thickness of the thin layer 15 can vary between a value of 500 nm at the level of the lateral flanks 111 of the light-emitting diodes 11 and a value of 1 μm at the upper edges 112 of the light-emitting diodes 11.

In general, the thin layer 15 has an average thickness (this average thickness being substantially homogeneous in the particular embodiment providing a conformal deposition of material) which can be between 100 nm and 10 μm, and preferably between 500 nm and 5 pm, for example between 1 pm and 2 pm, at the lateral flanks 111 of the light-emitting diodes 11.

The thickness of the thin layer 15 may in particular result from a compromise between its function of self-alignment of the light confinement walls 17 described below, and the provision of the best possible resolution.

Thus, as can be seen in FIG. 2, the thin layer 15 can continuously cover the lateral flanks 111 of the light-emitting diodes 11, their upper edges 112 and the zones 18 between the light-emitting diodes 11.

In the second example of implementation of the manufacturing process shown in Figures 11 and 12, the deposition of the thin layer 15 is carried out in a non-conforming manner, in the sense that the thickness of the thin layer 15 has , after deposit, large variations. In particular, the thickness of the thin layer 15 gradually decreases as it approaches the connection zone between the light-emitting diodes 11 and the substrate 13, that is to say at their lower edges. This progressive reduction takes place both along the lateral flanks 111 of the light-emitting diodes 11 and along the zones separating the light-emitting diodes 11 from one another.

According to a particular non-limiting mode of implementation of the manufacturing process, in order to achieve for example the temporary configuration of FIG. 3, after the step of depositing the thin layer 15 of the first material, the step of forming the spacing walls 14 comprises an optional step of etching the thin layer 15 of first material previously deposited, this etching being located at the upper edges 112 of the light-emitting diodes 11 and at the areas 18 between the light-emitting diodes 11.

Thus, the parts of the thin layer 15 not located at the lateral flanks 111 of the light-emitting diodes 11 are etched. This removes the parts of the thin layer 15 which cover the upper edges 112 of the light-emitting diodes and the zones 18. located between the light-emitting diodes 11. In other words, the spacer walls 14 cover the lateral flanks 111 of the light-emitting diodes 11 continuously, which facilitates the subsequent formation of the light confinement walls 17 directly in contact with them.

This etching step can be carried out by dry etching, for example by plasma etching (RIE, ICP..Dry etching being highly anisotropic, only remain the parts of the thin layer 15 covering the lateral flanks 111 of the light emitting diodes 11, thus forming spacer walls 14 which surround the light-emitting diodes 11 in a plane parallel to the plane (X, Y), as can be seen in FIG. 3.

However, this etching step is optional so that the spacing walls 14 can completely cover directly or indirectly the upper edges of the light-emitting diodes 11, as is the case for example in FIGS. 11 to 14. In the case where this etching of the thin layer 15 is not performed after the deposition of the thin layer 15, the spacing walls 14 will correspond essentially to the thin layer 15 formed. In the case where this etching of the thin layer 15 is carried out, the spacing walls 14 will essentially correspond to the remainders of the thin layer 15 after etching.

The manufacturing process then comprises, with reference for example to FIG. 5, a step of forming light confinement walls 17 formed in a second material capable of blocking the light radiation 16 coming from the light-emitting diodes 11. By " block the light radiation ”, it is understood either that the material absorbs the incident light radiation so that it does not pass through this material, or that the material has properties of reflection of the incident light radiation on this material.

The light confinement walls 17 formed directly cover the lateral flanks 141 of the spacing walls 14 while being in contact with them, so that the light radiation 16 coming from each light-emitting diode 11 and directed towards the light-emitting diodes 11 adjacent is blocked (by absorption or reflection) by the light confinement wall 17 which covers the spacer wall 14 which surrounds this light-emitting diode 11.

By “light radiation 16 from light emitting diodes 11”, it is meant that it is light radiation directly emitted by light emitting diodes 16, that is to say light radiation converted by possible color converters, for example by means of photoluminescent particles in the first material used for the formation of the spacer walls 14.

The presence of such light confinement wall 17 prevents light radiation 16 from light emitting diodes 11 from mixing together from one light emitting diode 11 to the other in order to be able to have a strong contrast.

In other words, if it is possible to provide that the second material used in the step of forming the light confinement walls 17 is only opaque vis-à-vis the light radiation 16 from the light emitting diodes 11, it It is very advantageous to guarantee that this second material is such that the light confining walls 17 are reflective for the light rays 16 coming from the light-emitting diodes 11. This makes it possible to increase the efficiency of the assembly and possibly to fake an emission of the light radiation 16 outside the optoelectronic device 10 on the side of the rear face after removal of the substrate 13.

The second material having such reflective properties with respect to light radiation 16 can be formed from the same reflective material or from a plurality of different materials deposited on each other. The reflective materials can be chosen from aluminum, silver, nickel, platinum, or any other suitable material.

In general, any technique can be envisaged by those skilled in the art to form such light confinement walls 17.

According to a particular non-limiting mode of implementation of the manufacturing process, with reference to Figure 4, the step of forming the light confinement walls 17 comprises a step of depositing a thin layer 19 of the second material implemented so that this thin layer 19 of the second material covers not only the lateral flanks 141 of the spacing walls 14 by being in direct contact but also, by being in contact with it or not (for example in the case where the upper edges 112 are already covered by the layer forming the second upper electrode and / or by a portion of spacing walls 14), the upper edge 112 of the light-emitting diodes 11.

As illustrated in FIG. 4, the step of depositing the thin layer 19 of the second material may for example comprise a step of filling, by this thin layer 19 of the second material, the empty spaces delimited between the spacer walls 14 at the zones 18 between the light-emitting diodes 11.

The deposition of the thin layer 19 can however be carried out by any technique known to those skilled in the art, the choice being able for example to depend on the nature of the material deposited, on its thickness or on the voids externally separating the spacing walls. 14. The thickness of the thin layer 19 deposited may be greater than the height H of the light-emitting diodes 11 sufficiently to ensure, if necessary, that the second material can cover the upper edges 112 of the light-emitting diodes 11, in the case where a reflection of the light rays 16 is desired at this location. But as shown in FIG. 9, it is possible to achieve that the thin layer intended to form the light confinement walls 17 covers the upper edges 112 of the diodes 11 despite a thickness of this thin layer clearly less than H.

The second example of implementation of the manufacturing process illustrated in Figures 11 and 12 also provides for the deposition of the thin layer 19 (Figure 11) between and on the spacer walls 14 previously formed by a deposit promoting thickness irregular as already explained. In contact with the spacing walls 14, the thin layer 19 has a shape complementary to the spacing walls 14 by matching their external shapes. It follows that it will be the same for the light confinement walls 17 obtained following the deposition of the thin layer 19. The thin layer 19 then covers the lateral flanks and the upper edges of the spacing walls 14 which cover themselves the upper edges 112 and the lateral flanks 111 of the light-emitting diodes 11.

When the extraction of the emitted light is sought by the front face of the optoelectronic device 10, that is to say on the side opposite to the substrate 13 used for manufacturing, the manufacturing process will be carried out so that 'at the end of the step of forming the light confinement walls 17, the upper edge 112 of each light-emitting diode 11 is not covered by the second material so that the light radiation 18 coming from the light-emitting diodes 11 is emitted out of the optoelectronic device 10 by an emitting surface of the optoelectronic device 10 located, with respect to the light-emitting diodes 11, on the side of the upper edges 112 of the light-emitting diodes 11 in the transverse direction Z.

Thus, after the step of depositing the thin layer 19 of the second material, the step of forming the light confinement walls 17 may include, to achieve the configuration of Figure 5 or the configuration of Figures 12 at 14, an optional etching step and / or a chemical mechanical polishing step of the thin layer 19 of the second material previously deposited, on the side opposite to the substrate 13 in the transverse direction Z. This etching and / or polishing step Mechanochemical can be implemented by any technique known to those skilled in the art. The objective of this step is in particular, when desired, to ensure that the light confinement walls 17 do not cover the upper edges 112 of the light-emitting diodes 11, in particular in order to allow the emission of light radiation 16 out of the optoelectronic device 10 from the front panel.

If FIG. 12 illustrates an example in which planarization of the thin layer 19 previously deposited is carried out by etching or by chemical mechanical polishing until all the second material is removed above the upper edges 112 of the light-emitting diodes 11 , these upper edges 112 remaining covered by the first material corresponding to the spacer wall 14 (the light confinement walls 17 covering only the lateral flanks of the spacer walls 14), FIG. 13 shows diagrammatically the variant of FIG. 12 which corresponds to the particular case where the step of etching the thin layer 19 is selective etching, in the sense that only the second material is etched and the first material remains substantially intact (in other words, the shape of the spacing walls 14 is identical at the level of the upper edges 112 of the light-emitting diodes 11, whether before or after said etching step of the thin layer 19.

In the manufacturing process which has just been described, the spacing walls 14 on which the light confinement walls 17 are directly formed very advantageously provide an alignment function for the luminous confinement walls 17 formed. As the spacer walls 14 are themselves formed in alignment with respect to the light-emitting diodes 11 which they surround, this results in an advantageous phenomenon of self-alignment of the light confinement walls 17 with respect to the light-emitting diodes 11. This makes it possible to obtain light confinement walls 17 aligned very precisely even in the case of light-emitting diodes 11 spaced apart at a very small pitch in the plane (X, Y). This results in the possibility of providing an optoelectronic device 10 having both a high contrast (thanks to the presence of the light confinement walls 17) and a high resolution, and this in a simple and economical manner.

Referring to Figure 6 which shows a variant of Figure 5, at the end of the step of forming the spacer walls 14, each spacer wall 14 has, on the side of the support face 12 of the substrate 13, a thickness counted transversely to the longitudinal axis of the light-emitting diode 11 which it surrounds which decreases progressively as it approaches the support face 12 of the substrate 13 in the transverse direction Z. Such a decreasing thickness of the walls spacing 14 on the side of the substrate 13 can be obtained by a suitable control of the conditions of the deposition of the first material in a more or less consistent manner in this zone. The advantage of this embodiment is that the light confining walls 17 formed on such spacing walls 14 have a complementary shape in the area 171, which can approach, for example, a form of pseudo-parabola, in order to to improve the extraction of the light emitted from the optoelectronic device 10 by the front face.

Figures 7 and 8 show, in top view, partially two examples of optoelectronic devices 10 manufactured by the implementation of the manufacturing process of Figures 1 to 5. If Figure 7 shows that the containment walls luminous 17 formed can be such that the light emitting diodes 11 are separated and made individual, FIG. 8 illustrates that the control of the thickness of the spacing walls 14 formed at the level of the lateral flanks 112 of the light emitting diodes 11 and the control of the pitch between the light-emitting diodes 11 make it possible to produce light confinement walls 17 for sub-pixels with several light-emitting diodes 11. In particular, by locally adapting the pitch between the light-emitting diodes 11 in a suitable manner, it is possible to obtain a coalescence of the spacing walls 14 therebetween for certain light-emitting diodes 11, comm e this is visible in Figure 8 unlike Figure 7.

Optionally, after the step of forming the light confining walls 17, the method comprises a step of removing the first material having served for the temporary constitution of the spacer walls 14. If, once this removal has taken place, the voids created can optionally be left empty, it is conceivable to provide an additional step consisting in filling the voids created by the removal of the first material with a third filling material. The third filling material may for example be constituted by a silicone material or by a material capable of ensuring a light converter function. Any material suitable for this function can be considered by the skilled person.

When the extraction of the emitted light is sought by the rear face of the optoelectronic device 10, that is to say on the side of the base of the light emitting diodes 11 opposite their upper edges 112, the manufacturing process is made so that at the end of the step of forming the light confining walls 17, the upper edge 112 of each light-emitting diode 11 is also covered (directly as is the case in FIG. 10; or indirectly as c 'is the case in Figure 9) by a light confinement wall 17 so that after the implementation of a step of removing the substrate 13, the light radiation 16 from the light emitting diodes 11 is emitted from the device optoelectronics 10 by an emitting surface 20 of the optoelectronic device 10 located, with respect to the light-emitting diodes 11, on the side opposite to the upper edges 112 light-emitting diodes 11 in the transverse direction Z. These are, for example, the configurations of FIGS. 9 and 10.

In each of FIGS. 9 and 10, in which a single pixel is shown purely by way of illustration, the optoelectronic device 10 therefore comprises:

a matrix of light-emitting diodes 11 where each light-emitting diode 11 has the wire form described above, that is to say elongated along a longitudinal axis extending in the transverse direction Z of the optoelectronic device 10,

- The spacer walls 14 made of the first material as described above, arranged such that the lateral flanks 111 of each light-emitting diode 11, over its entire height H, are surrounded by at least one of these walls d '' spacing 14,

- And the light confinement walls 17 formed in the second material as described above, and directly covering the lateral flanks 141 of the spacer walls 14 while being in contact with them and covering the upper edge 112 of the light-emitting diodes 11.

In each of the examples of FIGS. 9 and 10, the light confinement walls which cover the lateral flanks 111 of the light-emitting diodes 11 allow the light radiation 16 coming from each light-emitting diode 11 and directed towards the adjacent light-emitting diodes 11 either blocked by the light confinement wall 17 which covers the spacer wall 14 which surrounds this light-emitting diode 11. At the same time, by the fact that the light confinement walls 17 also cover the upper edges 112 of the light-emitting diodes 11, the light radiation 16 coming from the light-emitting diodes 11 is emitted out of the optoelectronic device 10 by an emitting surface 20 of the optoelectronic device 10 situated, with respect to the light-emitting diodes 11, on the side opposite to the upper edges 112 of the light-emitting diodes 11 along the trans direction versal Z.

In each of the examples of Figures 9 and 10, the lower electrode layer 21, already mentioned, formed after removal of the substrate 13, is transparent to light radiation 16 from the light emitting diodes 11. The lower electrode layer 21 is in electrical contact with the lower edges of the light-emitting diodes 11 so that the first lower electrode is common to several light-emitting diodes 11. Thus, following the formation of the light-emitting diodes 11, the spacing walls 14 and the walls containment 17, the manufacturing process comprises a step of removing the substrate 13 and then a step of forming the lower electrode layer 21, typically by deposition, on the face released after the removal of the substrate 13. The material used for the formation of the lower electrode layer 21 may for example be chosen from all the transparent oxides known to those skilled in the art, also known by the acronym "TCO" for "Transparent Conductive Oxide" in English.

To obtain the optoelectronic device 10 of FIG. 9, at least one insulating layer 23 is formed on the upper face of the substrate 13 before the formation of light-emitting diodes 11, said at least one insulating layer 23 making it possible to avoid contact electric between the lower electrode layer 21 and the upper electrode layer 22.

In FIG. 9, each light-emitting diode 11 is of the core-shell type. These light-emitting diodes 11 are, for example, obtained via epitaxial growth from a continuous nucleation layer or from nucleation pads distributed on the substrate 13, in the insulating layer 23. The optoelectronic device 10 also comprises the upper electrode layer 22 formed in an electrically conductive material transparent to the light radiation emitted by the light-emitting diodes 11. The upper electrode layer 22, the material of which can be chosen from all the transparent conductive oxides TCO known to those skilled in the art, directly covers the lateral flanks 111 and the upper edge 112 of the light-emitting diodes 11 while being in contact with them so as to constitute a second upper electrode common to several light-emitting diodes 11. The spacing walls 14 then directly cover the side blanks and the upper edge of the layer d upper electrode 22 being in contact therewith. Then the light confinement walls 17 are formed. The upper electrode layer 22 is in electrical contact with at least one of the light confinement walls 17 which are formed on the spacing walls 14, in particular in their upper part. The substrate 13 is removed and then the lower electrode layer 21 is formed on said at least one insulating layer 23 and to be in contact with the lower edges of the light-emitting diodes. The offset marked 24 makes it possible to illustrate the etching undergone by the second material by its front face, to isolate the second upper electrodes from one sub-pixel to the other. The light confinement walls 17 are embedded externally in a first insulating layer 25, on which the supply and control device 26 is formed by means of an electrical contact between this device 26 and the upper parts of the light confinement walls 17. The supply and control device 26 is itself embedded in a second insulating layer 27. All known techniques for forming the supply and control device 26, the first insulating layer 25 and the second insulating layer 27, can be considered.

It is understood that in the optoelectronic device 10 of FIG. 9, the light confinement walls 17, thanks to their conductive properties, enter into the constitution of the second upper electrode in addition to the upper electrode layers 22 which, as for them, are directly in contact with the second doped portions of the shell of the light-emitting diodes 11. They participate in the electrical connection with respect to the supply and control device 26.

The optoelectronic device 10 of FIG. 10 is substantially identical to that of FIG. 9 with the difference that each light-emitting diode 11 here has an axial structure and that the upper electrode layer 22 is absent due to the axial structure light-emitting diodes 11. The electrically insulating layer 23 formed on the lower electrode layer 21 here makes it possible to avoid electrical contact between the lower electrode layer 21 and the light confinement walls 17 which alone fulfill the function second upper electrode. These are the second doped portions of the light-emitting diodes 11 which are in direct contact with the light confinement walls 17, at the level of the upper edges 112 of the light-emitting diodes 11.

The step of forming the spacer walls 14 can optionally be implemented, in particular in the case where the second material is such that the light confinement walls 17 are reflective for the light radiation 16 coming from the light-emitting diodes. 11, so that the spacer walls 14 formed have an external face of convex shape. The light confinement walls 17 then advantageously have an internal face 172 having a concave shape complementary to the convex shape delimited by the spacer wall 14 which it covers. The concave shape formed by the internal face 172 faces the light-emitting diode 11 of which it confines the light radiation 16.

The convex shapes delimited by the spacing walls 14 can, for example, be parabolic, so that the light confining walls 17 then have a complementary concave parabolic shape, as is the case on each. of FIGS. 9 and 10. It is then very advantageous, in the case of light-emitting diodes 11 having an axial structure, to ensure, by suitable control of the conditions of formation of the spacing walls 14, that this concave parabola is shaped so that the active part of the light-emitting diode 11 [0125] [0126] [0127] [0128] [0129] capable of emitting light radiation 16 is located at the focal point of the concave parabola.

However, the spacing walls 14 may have convex shapes of other natures, such as for example a frustoconical shape, so that the light confining walls 17 then have a complementary frustoconical shape.

These arrangements can prove to be advantageous when it is desired that the light emitted undergoes collimation in a reduced cone, such as for example a light beam opening characterized by a value NA (for “Numerical Aperture”, in English) of l '' order of 0.3. The effect of such concave shapes of the reflecting internal faces 172 is all the more effective for a light-emitting diode 11 of wire form in order to ensure the collimation of the light emitted so as to be emitted partly parallel to the axis of the first doped wire-shaped portions of the light emitting diodes 11, while such light emitting diodes 11 intrinsically have a heart-shaped far field.

In the example of optoelectronic device 10 of FIG. 14, unlike the provisions of FIGS. 9 and 10, the light confinement walls 17 do not cover the upper edge of the light-emitting diodes 11 so that the light radiation 16 coming from the diodes light emitting 11 is emitted from the optoelectronic device 10 by an emitting surface of the optoelectronic device 10 located, relative to the light emitting diodes 11, on the side of the upper edges 112 of the light emitting diodes 11 in the transverse direction Z.

In FIG. 14, in which only two light-emitting diodes 11 are shown purely by way of illustration, the optoelectronic device 10 therefore comprises:

a matrix of light-emitting diodes 11 where each light-emitting diode 11 has the wire form described above, that is to say elongated along a longitudinal axis extending in the transverse direction Z of the optoelectronic device 10,

- The spacer walls 14 made of the first material as described above, arranged so that the lateral flanks of each light-emitting diode 11, over its entire height H, are surrounded by at least one of these walls of spacing 14,

- And the light confinement walls 17 formed in the second material as described above, and directly covering the lateral flanks 141 of the spacer walls 14 while being in contact with them but not covering the upper edge of the light-emitting diodes 11.

In the example of FIG. 14, the first lower electrode is formed by the substrate 13 itself. The lower edges of the light-emitting diodes 11 are in contact with the substrate 13, for example through the nucleation layer or the nucleation pads, to establish the electrical contact. The substrate 13 integrates in its thickness electrical insulation elements 30 extending through the substrate 13 and delimiting two by two of the portions of the substrate 13 electrically isolated from each other. The electrical insulation elements 30 may comprise trenches each extending over the entire thickness of the substrate 13 and filled with an electrically insulating material, for example an oxide, in particular silicon oxide, or a insulating polymer. Alternatively, as illustrated in Figure 14, the walls of each trench are covered with an insulating layer 31, the rest of the trench being filled with a semiconductor or conductive material 32, for example polycrystalline silicon. According to another variant, the electrical insulation elements 30 comprise doped regions of a type of polarity opposite to the substrate 13. By way of example, each trench has a width greater than 1 micron. The electrical insulation elements 30 may comprise a first series of such trenches oriented in the lateral direction Y and thus staggered along the longitudinal direction X and a second series of such trenches oriented in the longitudinal direction X and therefore staggered along the lateral direction Y. This makes it possible to achieve a matrix organization of the light-emitting diodes 11 in the plane of the substrate 13.

It is specified here that such electrical insulation elements 30 can completely be implemented even in the case where the substrate 13 is formed in a semiconductor or electrically insulating material, for reasons of thermal resistance.

Electrical contacts 33 necessary for the pixelation of the optoelectronic device 10 are formed on the rear face of the optoelectronic device 10. More specifically, the electrical contacts 33 are formed so as to be in electrical contact with the rear face of the substrate 13.

To obtain the optoelectronic device 10 of FIG. 14, at least one insulating layer 23 is formed on the upper face of the substrate 13 before the formation of light-emitting diodes 11, said at least one insulating layer 23 making it possible to avoid contact electric between the substrate 13 and the upper electrode layer 22.

In FIG. 14, each light-emitting diode 11 is for example obtained via epitaxial growth from a continuous nucleation layer or from nucleation pads distributed on the substrate 13, in openings of the insulating layer 23. The optoelectronic device 10 also comprises the upper electrode layer 22 formed from an electrically conductive material and transparent to the light radiation emitted by light-emitting diodes 11. The upper electrode layer 22, the material of which can be chosen from all the transparent conductive oxides TCO known to those skilled in the art, directly covers the lateral flanks 111 and the upper edge 112 of the light-emitting diodes 11 while being in contact with them so as to constitute a second upper electrode common to several light-emitting diodes 11. The spacing walls 14 then directly cover the side blanks and the upper edge of the upper electrode layer 22 being in contact with them. Then the light confinement walls 17 are formed. The upper electrode layer 22 is in electrical contact with at least one of the light confinement walls 17 which are formed on the spacer walls 14, in the interface zone marked 28 between the upper electrode layer 22 and the light confinement walls 17. The confinement walls 17 are discontinuous, in particular in the form of recesses obtained by etching the second material by its front face, to isolate the second upper electrodes from one sub-pixel to the other . An electrically insulating material 29 can be added in these recesses.

In a variant not illustrated in FIG. 14, where the first lower electrode is no longer formed by the substrate 13 itself, the substrate 13 is removed and then a lower electrode layer is formed on said at least the insulating layer 23 previously formed on the substrate 13, this lower electrode layer being in contact with the lower edges of the light-emitting diodes 11. Then the electrical contacts necessary for the pixelation of the optoelectronic device 10 are formed on the rear face of the optoelectronic device 10 More specifically, the electrical contacts are then formed so as to be in electrical contact with the rear face of the lower electrode layer.

Claims (1)

[Claim 1] claims Method for manufacturing an optoelectronic device (10) comprising an array of light-emitting diodes (11), comprising the following steps: - Formation of the matrix of light-emitting diodes (11) on a support face (12) of a substrate (13), this step being carried out so that each light-emitting diode (11) has an elongated wire shape along a longitudinal axis s' extending in a transverse direction (Z) of the optoelectronic device (10) oriented transversely to the support face (12) of the substrate (13), - formation of spacer walls (14) made of a first dielectric material transparent to light radiation (16) coming from light-emitting diodes (11), the spacer walls (14) formed being such that the lateral flanks (111 ) of each light-emitting diode (11), over its entire height (H) counted in the transverse direction (Z), are surrounded by at least one of the spacing walls (14), - formation of light confinement walls (17) formed in a second material capable of blocking light radiation (16) coming from light-emitting diodes (11), the light confinement walls (17) formed directly covering the lateral flanks (141) spacer walls (14) being in contact therewith, so that the light radiation (16) from each light emitting diode (11) and directed towards the adjacent light emitting diodes (11) is blocked by the confinement wall luminous (17) which covers the spacer wall (14) which surrounds said light-emitting diode (11), characterized in that at the end of the stage of formation of the luminous confinement walls (17), the upper border ( 112) of each light-emitting diode (11) is covered by a light confinement wall (17) so that after the implementation of a step of removing the substrate (13), the light radiation (16) coming from the light-emitting diodes (11) is emitted out of the optoelectronic device (10) by an emitting surface (20) of the optoelectronic device (10) located, relative to the light-emitting diodes (11), on the side opposite to the upper edges (112) of the light-emitting diodes (11) in the transverse direction (Z). [Claim 2] Manufacturing method according to claim 1, characterized in that the step of forming the spacer walls (14) is carried out so that the spacer walls (14) formed have an outer face of convex shape and that the light confinement walls (17) formed have an internal face (172) having a concave shape complementary to said convex shape and facing the light-emitting diode (11) whose light radiation it confines (16). [Claim 3] Manufacturing method according to one of claims 1 or 2, characterized in that the step of forming the spacer walls (14) comprises a step of depositing a thin layer (15) of the first material, implemented so that the thin layer (15) deposited covers the lateral flanks (111) and the upper edge (112) of the light-emitting diodes (11). [Claim 4] Manufacturing method according to claim 3, characterized in that after the step of depositing the thin layer (15) of the first material, the step of forming the spacer walls (14) comprises a step of etching the thin layer (15) of the first previously deposited material located at the upper edges (112) of the light-emitting diodes (11) and at the level of the zones (18) between the light-emitting diodes (11). [Claim 5] Manufacturing method according to any one of claims 1 to 4, characterized in that the second material used in the step of forming the light confinement walls (17) is such that the light confinement walls (17) are reflective for light radiation (16) from the light emitting diodes (11). [Claim 6] Manufacturing method according to any one of claims 1 to 5, characterized in that the step of forming the light confinement walls (17) comprises a step of depositing a thin layer (19) of the second material used so that this thin layer (19) of the second material directly covers the lateral flanks (141) of the spacing walls (14) while being in contact with them and covers the upper edge (112) of the light-emitting diodes (11) and in this that the step of depositing the thin layer (19) of the second material comprises a step of filling, with said thin layer (19) of the second material, the empty spaces delimited between the spacing walls (14) at the level of the zones (18) between the light emitting diodes (11). [Claim 7] Manufacturing method according to any one of claims 1 to 6, characterized in that the first material used for the formation of the spacer walls (14) comprises photoluminescent particles which are in the form of quantum dots. [Claim 8] Optoelectronic device (10) comprising: - an array of light emitting diodes (11) where each light emitting diode (11) has an elongated wire shape along a longitudinal axis extending in a transverse direction (Z) of the optoelectronic device (10), - spacer walls (14) made of a first dielectric material transparent to light radiation (16) coming from the light-emitting diodes (11) and arranged so that the lateral flanks (111) of each light-emitting diode (11) , over its entire height (H) counted in the transverse direction (Z), are surrounded by at least one of the spacing walls (14), - And light confinement walls (17) formed in a second material capable of blocking the light radiation (16) coming from light-emitting diodes (11), the light confinement walls (17) directly covering the lateral flanks (141) of the spacer walls (14) being in contact with them, the light radiation (16) coming from each light-emitting diode (11) and directed in the direction of the adjacent light-emitting diodes (11) being blocked by the light confinement wall (17) which covers the spacer wall (14) which surrounds said light-emitting diode (11), characterized in that the light confinement walls (17) cover the upper edge (112) of the light emitting diodes (11) and in that the light radiation (16) coming from the light emitting diodes (11) is emitted outside the optoelectronic device ( 10) by an emitting surface (20) of the optoelectronic device (10) located, with respect to the light-emitting diodes (11), on the side opposite to the upper edges (112) of the light-emitting diodes (11) in the transverse direction (Z) . [Claim 9] Optoelectronic device (10) according to claim 8, characterized in that the second material is such that the light confining walls (17) are reflective for the light radiation (16) coming from the light-emitting diodes (11) and in that the spacer walls (14) have an outer face of convex shape and the light confinement walls have an internal face (172) having a concave shape complementary to said convex shape and turned towards the light-emitting diode (11) of which it confines the light radiation (16). [Claim 10] Optoelectronic device (10) according to one of claims 8 or 9, characterized in that it comprises a lower electrode layer (21) formed in an electrically conductive material and transparent to light radiation (16), said lower electrode layer (21) being in electrical contact with the lower edges of the light emitting diodes (11) in order to fulfill a function of first electrode common to several light emitting diodes (11). [Claim 11] Optoelectronic device (10) according to one of claims 8 to 10, characterized in that each light-emitting diode (11) is of the core-shell type and in that it comprises an upper electrode layer (22 ) formed of an electrically conductive material transparent to light radiation (16), the upper electrode layer (22) directly covering the lateral flanks (111) and the upper edge (112) of the light-emitting diodes (11) being at their contact so as to fulfill a function of second electrode common to several light-emitting diodes (11), the spacing walls (14) directly covering the side blanks and the upper edge of the upper electrode layer (22) being at their contact and the upper electrode layer (22) being in electrical contact with at least one of the light confinement walls (17).