Patent ID: 12224269

DETAILED DESCRIPTION OF THE DRAWINGS

In the figures and in the remainder of the description, the same reference numerals represent identical or similar elements. In addition, the different elements are not represented to scale so as to enhance clarity of the figures. Moreover, the different embodiments and variants do not exclude one another and may be combined together.

In the following description, unless indicated otherwise, the terms «substantially», «about» and «in the range of» mean «within 10%».

For exclusively illustration purposes, but without any limitation, each of the accompanying figures represents only an assembly comprising a few light-emitting diodes111,121,131. The number of light-emitting diodes per sub-pixel11a,11b,11cand the number of pixels, are however in no way limited.

The disclosure relates firstly to an optoelectronic device10, comprising a plurality of pixels11each comprising at least one primary sub-pixel11acomprising at least one primary light-emitting diode111adapted to emit a first light radiation substantially having a first wavelength and formed on a support face110of a substrate101.

Thanks to the arrangement of three-dimensional light-emitting diodes of the disclosure, a particularly targeted application is the provision of an image display screen or of an image projection device.

It is also clear that the manufacturing methods can concern other applications, in particular the detection or measurement of electromagnetic radiations or else photovoltaic applications.

The optoelectronic device10is obtained starting from a substrate101, having a support face110, which is an element common to the various embodiments.

The substrate101is consisting for example, by a stack of a monolithic layer (not represented), of a lower electrode layer (not represented) which can be a seed layer or called a conductive nucleation layer and of a first electrically insulating layer (not represented). Those skilled in the art could refer, for example, to document FR-A1-3053530 for the provision of such a substrate101.

The support face110of the substrate101is formed, for example, by the exposed face of said first electrically insulating layer or of the nucleation layer.

The monolithic layer can be formed from a semiconductor material doped or not, for example Al2O3or silicon or even germanium, and more particularly monocrystalline silicon. It 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 type substrate or «SOI». Alternatively, the monolithic layer can be formed in an electrically insulating material.

The lower electrode layer can serve as a seed layer for the growth of light-emitting diode portions. The lower electrode layer can be continuous or discontinuous. The material composing the lower electrode layer may be a nitride, carbide or boride of a transition metal from column IV, V or VI of the periodic table of the elements or a combination of these compounds. For example, the lower electrode layer can be made of aluminum nitride, aluminum oxide, boron, boron nitride, titanium, titanium nitride, tantalum, tantalum nitride, hafnium, hafnium nitride, niobium, niobium nitride, zirconium, zirconium boride, zirconium nitride, silicon carbide, tantalum nitride and carbide, or magnesium nitride under the formula MgxNy, where x is approximately equal to 3 and y is approximately equal to 2, for example magnesium nitride under the formula Mg3N2. The lower electrode layer can be doped and of the same type of conductivity as that of the semiconductor elements intended to grow, and have a thickness for example comprised between 1 nm and 200 nm, preferably comprised between 10 nm and 50 nm. The lower electrode layer can consist of an alloy or a stack of at least one material mentioned in the above list.

Said first electrically insulating layer may comprise a first intermediate insulating layer which covers said lower electrode layer. It forms a growth mask authorizing the epitaxial growth, for example, of the various light-emitting diodes111,121,131from through openings emerging locally on the surfaces of the lower electrode layer. Said first electrical insulation layer also participates in providing electrical insulation between the first lower electrodes (not represented) and the second upper electrodes (not represented). The first intermediate insulating layer is made of at least one dielectric material(s) such as, for example, a silicon oxide (for example SiO2or SiON) or a silicon nitride (for example Si3N4or SiN), or even a silicon oxynitride, an aluminum oxide (for example Al2O3) or a hafnium oxide (for example HfO2). The thickness of the first intermediate insulating layer may be comprised between 5 nm and 1 μm, preferably comprised between 20 nm and 500 nm, for example equal to approximately 100 nm.

Said first layer of electrically insulating material may further include a second intermediate electrically insulating layer (not represented) which covers the first lower electrodes and participates in providing electrical insulation between the first lower electrodes and the second upper electrodes. Said second electrically intermediate insulating layer may also cover the growth mask formed by the first intermediate insulating layer. The second intermediate insulating layer can be made of a dielectric material identical to or different from that of the growth mask, such as, for example, a silicon oxide (for example SiO2) or a silicon nitride (for example Si3N4or SiN), or even a silicon oxynitride, an aluminum oxide (for example Al2O3) or a hafnium oxide (for example HfO2). The thickness of the second intermediate insulating layer may be comprised between 5 nm and 1 μm, preferably comprised between 20 nm and 500 nm, for example equal to approximately 100 nm.

At least one light-emitting diode111adapted to emit a first light radiation having substantially a first wavelength is formed on the substrate101. Each light-emitting diode111has a substantially wired shape elongated along a longitudinal axis A extending in a first direction111agenerally perpendicular to the support face110of the substrate101.

Each light-emitting diode111comprises at least one first primary semiconductor portion112electrically connected to a first electrode. Generally, each light-emitting diode is connected to a first lower electrode, formed in the substrate (not represented and which may be the seed layer), which is continuous or not. Those skilled in the art will be able to refer to patent FR3053530 to produce the substrate101containing the appropriate lower electrodes. The first primary semiconductor portion112is doped according to a first doping type selected among a N-type doping and a P-type doping. The first primary semiconductor portion112has a generally wired shape elongated along the longitudinal axis A extending in a first direction111agenerally perpendicular to the support face110of the substrate101. The first primary semiconductor portion112is therefore of three-dimensional shape, according to micrometric or nanometric dimensions. Preferably, the first primary semiconductor portion112has a substantially wired, conical or frustoconical shape. In the text, the terms «three-dimensional» or «wired» or «frustoconical» or «conical» are equivalent. The first primary semiconductor portion112includes a top end112aopposite a proximal end of the first primary semiconductor portion112facing towards the support face110of the substrate101.

In the description and in the figures, the embodiments are described for wired light-emitting diodes111,121,131.

By way of example, the first primary semiconductor portion112, but this is also valid for the first secondary and tertiary semiconductor portions122and132, can be, at least in part, formed from group IV semiconductor materials such as silicon or germanium or else mainly including a III-V compound, for example III-N compounds. Examples of Group III comprise gallium, indium or aluminum. Examples of compounds III-N are GaN, AlN, InGaN or AlInGaN. Other elements of group V can also be used, for example, phosphorus, arsenic or antimony. Generally, the elements in compound III-V can be combined with different mole fractions. It should be noted that the first primary semiconductor portion112can indifferently be formed from semiconductor materials mainly comprising a compound II-VI. The dopant can be selected, in the case of a compound III-V, among 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 a N-type dopant from group IV, for example silicon, germanium, selenium, sulfur, terbium or tin.

The right section of the first primary semiconductor portion112, but this is also valid for the first secondary and tertiary semiconductor portions122and132, may have different shapes such as, for example, an oval, circular or polygonal shape (for example square, rectangular, triangular, hexagonal) shape.

In general, the various layers or sub-layers making up the light-emitting diodes111,121,131can be obtained by any technique of those skilled in the art such as for example: chemical vapor deposition (CVD), an atomic layer deposition (ALD), or physical vapor deposition (PVD) but preferably by epitaxy (for example MBE, MOVPE).

As illustrated inFIGS.1and2, each light-emitting diode111comprises at least one primary lattice parameter accommodation layer113arranged at least on, and in contact with, the top end112aof the first primary semiconductor portion112.

As illustrated inFIGS.1and2, each light-emitting diode111comprises at least a second primary active semiconductor portion114formed by epitaxial growth from the primary lattice parameter accommodation layer113. This second primary active semiconductor portion114is arranged at least on, and in contact with, the primary lattice parameter accommodation layer113.

As illustrated inFIGS.1,2and9, each light-emitting diode111comprises at least one third primary semiconductor portion115electrically connected to a second electrode. This third primary semiconductor portion115is doped according to a second doping type opposite to the first doping type. It is arranged at least on, and in contact with, the second primary active semiconductor portion114. This third primary semiconductor portion115is, in one example, identical for at least all the primary and secondary and tertiary light-emitting diodes consisting at least one sub-pixel. This third primary semiconductor portion115can be formed from group IV semiconductor materials such as silicon or germanium or mainly including a compound III-V, for example compounds III-N. Examples of group III comprise gallium, indium or aluminum. Examples of compounds III-N are GaN, AlN, InGaN or AlInGaN. Other elements of group V can also be used, for example, phosphorus, arsenic or antimony. Generally, the elements in compound III-V can be combined with different mole fractions. It should be noted that the first primary semiconductor portion112can indifferently be formed from semiconductor materials mainly including a compound II-VI. The dopant can be selected, in the case of a compound III-V, 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 a N-type dopant from group IV, for example silicon, germanium, selenium, sulfur, terbium or tin.

The second electrode is preferentially transparent and can be formed in one example of a transparent conductive oxide such as doped tin oxide or even doped zinc oxide covered or not partially covered by a metal electrode layer.

The second primary active semiconductor portion114is configured so as to emit said first light radiation when at least one of the first and second electrodes is powered. The color emitted or in other words the wavelength emitted from the second primary active semiconductor portion114is in particular dependent on its indium concentration. The second primary active semiconductor portion114may include means for confining the electric charge carriers, such as single or multiple quantum wells. It consists for example of an alternation of layers of GaN and InGaN having respective thicknesses of 5 to 20 nm (for example 8 nm) and of 1 to 15 nm (for example 2.5 nm). The GaN layers can be doped, for example of N or P type. According to another example, the active layer can comprise a single layer of InGaN, for example with a thickness greater than 10 nm.

The primary lattice parameter accommodation layer113has, at least at its interface with the second primary active semiconductor portion114, a first difference in primary lattice parameter comprised between 2.32% and 0.93% relative to the second primary active semiconductor portion114.

The primary lattice parameter accommodation layer113thus configured allows serving as a basis for the epitaxial growth of a second primary active semiconductor portion114whose indium concentration will be at least in part determined by the first difference in primary lattice parameter of the primary lattice parameter accommodation layer113relative to the second primary active semiconductor portion114. This is in particular due to the general fact that a change in indium concentration in a second primary active semiconductor portion114involves a change of lattice parameter of said second primary active semiconductor portion114. Thus, during the epitaxial formation of the second primary active semiconductor portion114, the atomic species having lattice parameters too far away from the lattice parameters of the primary lattice parameter accommodation layer113will be immediately desorbed. Thus, only the alloy forming the second primary active semiconductor portion114having the selected indium concentration will be able to grow and form in a perennial manner on the primary lattice parameter accommodation layer113.

Advantageously, this allows to obtain second primary active semiconductor portions114emitting a wavelength independently selected to the diameter of the primary light-emitting diodes111.

Advantageously, this also allows to obtain in the same reactor, in a single phase, second active semiconductor portions having different indium contents and therefore emitting at different wavelengths.

Thus, in one example, the primary lattice parameter accommodation layer113is formed in a material having a difference in lattice parameters comprised between 2% and 2.5% relative to a second primary active semiconductor portion114whose indium proportion is comprised between 13% and 20%. A second primary active semiconductor portion114thus obtained is able to emit a first radiation comprised between 440 and 500 nm and corresponding to a light radiation which is generally blue-colored.

In another example, the primary lattice parameter accommodation layer113is formed in a material having a difference in lattice parameters comprised between 1.5% and 2% relative to a second primary active semiconductor portion114whose indium proportion is comprised between 20% and 27%. A second primary active semiconductor portion114obtained by epitaxy from this primary lattice parameter accommodation layer113is adapted to emit radiation comprised between 500 and 570 nm and corresponding to a light radiation which is generally green-colored.

In another example, the primary lattice parameter accommodation layer113is formed from a material having a difference in lattice parameters comprised between 1% and 1.5% relative to a second primary active semiconductor portion114whose indium proportion is comprised between 27% and 40%. A second primary active semiconductor portion114obtained by epitaxy from this primary lattice parameter accommodation layer113is adapted to emit a radiation comprised between 570 and 680 nm and corresponding to a light radiation which is generally red-colored. The primary lattice parameter accommodation layer113may have, in one example, at least at its interface with the first primary semiconductor portion112, a second difference in primary lattice parameter comprised between 1.07% and 2.17% relative to the first primary semiconductor portion112. In this example, the second difference in primary lattice parameters of 1.07% corresponds to a difference in lattice parameters between GaN and Al0.1Ga0.9N and the second difference in primary lattice parameter of 2.17% corresponds to a difference in lattice parameter between GaN and In0.2Ga0.8N. This can be advantageous so that the primary lattice parameter accommodation layer113does not exhibit any or few defects during its formation from the first primary semiconductor portion112. To allow the first and second primary lattice parameter difference conditions explained above to coexist, it may be advantageous to create an atomic concentration gradient in the primary lattice parameter accommodation layer113. Thus, in one example, it is possible to vary the proportion of gallium or aluminum or indium in the primary lattice parameter accommodation layer113in a decreasing manner in the first direction111aand in a direction opposite to the top end112aof the first primary semiconductor portion112, that is to say a direction tending to move away from the top end112a. Advantageously, this allows to gradually adapt the lattice parameters between the first primary semiconductor portion112through the primary lattice parameter accommodation layer113up to the second primary active semiconductor portion114. The stresses are thus reduced and the dislocations avoided.

In this document, the «primary» notion refers only to a first sub-pixel of a given pixel, this first sub-pixel being intended to emit light according to a first color. The «secondary» notion refers only to a second sub-pixel of the pixel, this second sub-pixel being intended to emit light according to a second color different from the first color. The «tertiary» notion refers only to a third sub-pixel of the pixel, this third sub-pixel being intended to emit light according to a third color different from the first color and from the second color. In other words, the terms «primary», «secondary» and «tertiary» induce no notion on the order of manufacture or on the order of importance between the different sub-pixels.

In a second embodiment illustrated inFIG.3, the primary lattice parameter accommodation layer113includes at least one lattice parameter accommodation primary sub-layer of a first nature113a. It is configured so that the second primary active semiconductor portion114, formed on and in contact with said lattice parameter accommodation primary sub-layers of a first nature113a, is able to emit a first light radiation, generally blue-colored by consisting of light rays having essentially wavelengths comprised between a first minimum value equal to 440 nm and a first maximum value equal to 500 nm.

In one example, the lattice parameter accommodation primary sub-layer of a first nature113ahas, at least at its interface with the first primary semiconductor portion112, a third difference in primary lattice parameters comprised between 1.07% and 0.65% relative to the lattice parameters of the first primary semiconductor portion112.

In one example, the lattice parameter accommodation primary sub-layer of a first nature113acontains a first alloy of aluminum, gallium, indium and nitrogen, in particular containing a gallium proportion decreasing in the first direction111aand in a direction opposite to the top end112aof the first primary semiconductor portion112.

In a third embodiment illustrated inFIG.4, the primary lattice parameter accommodation layer113includes at least one lattice parameter accommodation primary sub-layer of a second nature113b. The latter is configured so that the first light radiation capable of being emitted by the second primary active semiconductor portion114formed on, and in contact with, said lattice parameter accommodation primary sub-layer of a second nature113bis generally green-colored by consisting of light rays having essentially wavelengths comprised between a second minimum value equal to 500 nm and a second maximum value equal to 570 nm.

In one example, the lattice parameter accommodation primary sub-layer of a second nature113bis arranged at least on, and in contact with, the lattice parameter accommodation primary sub-layer of a first nature113a. The lattice parameter accommodation primary sub-layer of a second nature113bhas, at least at its interface with the lattice parameter accommodation primary sub-layer of a first nature113a, a fourth difference in primary lattice parameters comprised between 1.71% and 3.22% relative to the lattice parameters of the lattice parameter accommodation primary sub-layer of a first nature113a.

In another example, the lattice parameter accommodation primary sub-layer of a second nature113bcontains a second alloy of gallium, indium and nitrogen, in particular containing an indium proportion decreasing in the first direction111aand in the direction opposite to the top end112aof the first primary semiconductor portion112.

In a fourth embodiment illustrated inFIG.5, the primary lattice parameter accommodation layer113includes at least one lattice parameter accommodation primary sub-layer of a third nature113c. The second primary active semiconductor portion114formed on, and in contact with the lattice parameter accommodation primary sub-layer of a third nature113c, preferably by epitaxy, is adapted to emit the first light radiation so that it is generally red-colored by consisting of light rays having essentially wavelengths comprised between a third minimum value equal to 570 nm and a third maximum value equal to 680 nm.

In one example, the lattice parameter accommodation primary sub-layer of a third nature113cis arranged at least on, and in contact with, the lattice parameter accommodation primary sub-layer of a second nature113b. The lattice parameter accommodation primary sub-layer of a third nature113cthen has, at least at its interface with the lattice parameter accommodation primary sub-layer of a second nature113b, a fifth difference in primary lattice parameters comprised between 1.25% and 1.75% relative to the lattice parameters of the lattice parameter accommodation primary sub-layer of a second nature113b.

In another example, the lattice parameter accommodation primary sub-layer of a third nature113ccontains a third alloy of gallium, indium and nitrogen.

In a fifth embodiment, each pixel11includes at least one secondary sub-pixel11bcomprising at least one secondary light-emitting diode121adapted to emit a second light radiation having substantially a second wavelength different from the first wavelength and formed on the support face110of the substrate101. Each secondary light-emitting diode121comprises:at least a first secondary semiconductor portion122offset relative to the first primary semiconductor portion112in a general plane parallel to the support face110, electrically connected to a first electrode and doped according to a first doping type selected among a N-type doping and a P-type doping, the first secondary semiconductor portion122having a generally wired shape elongated along a longitudinal axis A extending in the first direction111a, the first secondary semiconductor portion122including a top end122aopposite to a proximal end of the first secondary semiconductor portion122facing towards the support face110of the substrate101,at least one secondary lattice parameter accommodation layer123arranged at least on, and in contact with, the top end122aof the first secondary semiconductor portion122,a second secondary active semiconductor portion124formed by epitaxial growth from the secondary lattice parameter accommodation layer123, the second secondary active semiconductor portion124being arranged at least on, and in contact with, the secondary lattice parameter accommodation layer123,a third secondary semiconductor portion125electrically connected to a second electrode and doped according to a second doping type opposite to the first doping type and arranged at least on, and in contact with, the second secondary active semiconductor portion124.
The second secondary active semiconductor portion124is configured so as to emit said second light radiation when at least one of the first and second electrodes is powered.
The secondary lattice parameter accommodation layer123has, at least at its interface with the second secondary active semiconductor portion124, a first difference in secondary lattice parameters comprised between 3.51% and 0.30% relative to the second secondary active semiconductor portion124.

In a sixth embodiment illustrated inFIG.9at least one secondary lattice parameter accommodation layer123comprises at least one of the following sub-layers:a lattice parameter accommodation secondary sub-layer of a first nature123aconfigured so that the second light radiation capable of being emitted by the second secondary active semiconductor portion124formed on, and in contact with, said lattice parameter accommodation secondary sub-layer of a first nature123ais generally blue-colored by consisting of light rays having essentially wavelengths comprised between the first minimum value equal to 440 nm and the first maximum value equal to 500 nm,a lattice parameter accommodation secondary sub-layer of a second nature123bconfigured so that the second light radiation capable of being emitted by the second secondary active semiconductor portion124formed on, and in contact with, said lattice parameter accommodation secondary sub-layer of a second nature123bis generally green-colored by consisting of light rays having essentially wavelengths comprised between the second minimum value equal to 500 nm and the second maximum value equal to 570 nm,a lattice parameter accommodation secondary sub-layer of a third nature123cconfigured so that the second light radiation capable of being emitted by the second secondary active semiconductor portion124formed on, and in contact with, said lattice parameter accommodation secondary sub-layer of a third nature123bis generally red-colored by consisting of light rays having essentially wavelengths comprised between the third minimum value equal to 570 nm and the third maximum value equal to 680 nm.

Preferably, the lattice parameter accommodation secondary sub-layer of a third nature123cis of the same composition and/or formed at the same time as the lattice parameter accommodation primary sub-layer of a third nature113c.

Preferably, the lattice parameter accommodation secondary sub-layer of a first nature123ais of the same composition and/or formed at the same time as the lattice parameter accommodation primary sub-layer of a first nature113a.

Preferably, the lattice parameter accommodation secondary sub-layer of a second nature123bis of the same composition and/or formed at the same time as the lattice parameter accommodation primary sub-layer of a second nature113b.

In a seventh embodiment illustrated inFIG.9, each pixel11includes at least one tertiary sub-pixel11ccomprising at least one secondary light-emitting diode131adapted to emit a third light radiation having substantially a third wavelength different from the first wavelength and from the second wavelength and formed on the support face110of the substrate101. Each tertiary light-emitting diode131comprises:at least one first tertiary semiconductor portion132offset relative to the first primary semiconductor portion112and relative to the first secondary semiconductor portion122in a general plane parallel to the support face110electrically connected to a first electrode and doped according to a first doping type selected among a N-type doping and a P-type doping, the first tertiary semiconductor portion132having a generally wired shape elongated along a longitudinal axis A extending in the first direction111a, the first tertiary semiconductor portion132including a top end132aopposite to a proximal end of the first tertiary semiconductor portion132facing towards the support face110of the substrate101,at least one tertiary lattice parameter accommodation layer133arranged at least on, and in contact with, the top end132aof the first tertiary semiconductor portion132,a second tertiary active semiconductor portion134formed by epitaxial growth from the tertiary lattice parameter accommodation layer133, the second tertiary active semiconductor portion134being arranged at least on, and in contact with, the tertiary lattice parameter accommodation layer133,a third tertiary semiconductor portion135electrically connected to a second electrode and doped according to a second doping type opposite to the first doping type and arranged at least on, and in contact with, the second tertiary active semiconductor portion134.
In this embodiment, the second tertiary active semiconductor portion134is configured so as to emit said third light radiation when at least one of the first and second electrodes is powered.
In this embodiment, the tertiary lattice parameter accommodation layer133has, at least at its interface with the second tertiary active semiconductor portion134, a first difference in tertiary lattice parameters comprised between 4.39% and 1.21% relative to the second tertiary active semiconductor portion134.

In one example, at least one tertiary lattice parameter accommodation layer133comprises at least one of the following sub-layers:a lattice parameter accommodation tertiary sub-layer of a first nature133aconfigured so that the third light radiation capable of being emitted by the second tertiary active semiconductor portion134formed on, and in contact with, said the lattice parameter accommodation tertiary sub-layer of a first nature133ais generally blue-colored by consisting of light rays having essentially wavelengths comprised between the first minimum value equal to 440 nm and the first maximum value equal to 500 nm,a lattice parameter accommodation tertiary sub-layer of a second nature133bconfigured so that the third light radiation capable of being emitted by the second tertiary active semiconductor portion134formed on, and in contact with, said lattice parameter accommodation tertiary sub-layer of a second nature133bis generally green-colored by consisting of light rays having essentially wavelengths comprised between the second minimum value equal to 500 nm and the second maximum value equal to 570 nm,a lattice parameter accommodation tertiary sub-layer of a third nature133cconfigured so that the third light radiation capable of being emitted by the second tertiary active semiconductor portion134formed on, and in contact with, said lattice parameter accommodation tertiary sub-layer of a third nature133cis globally red-colored by consisting of light rays having essentially wavelengths comprised between the third minimum value equal to 570 nm and the third maximum value equal to 680 nm.

Preferably, the lattice parameter accommodation tertiary sub-layer of a third nature133cis of the same composition and/or formed at the same time as the lattice parameter accommodation primary sub-layer of a third nature113c.

Preferably, the lattice parameter accommodation tertiary sub-layer of a first nature133ais of the same composition and/or formed at the same time as the lattice parameter accommodation primary sub-layer of a first nature113a.

Preferably, the lattice parameter accommodation tertiary sub-layer of a second nature133bis of the same composition and/or formed at the same time as the lattice parameter accommodation primary sub-layer of a second nature113b.

An optoelectronic device11obtained with primary, secondary and tertiary light-emitting diodes111,121,131as described beforehand advantageously makes it possible to obtain light-emitting diodes of different colors without using light converters, which is less expensive.

Advantageously, this allows to obtain light-emitting diodes with a larger diameter and therefore to improve the light intensity, in particular for blue light-emitting diodes.

Another advantage arises from the fact that a single active layer growth step may be used to manufacture multiple active layer compositions if different accommodation layers of different natures are used for different light-emitting diodes.

The disclosure also covers a method for manufacturing an optoelectronic device10, some steps of which are illustrated inFIGS.6to9.

The optoelectronic device10includes a plurality of pixels11, in which the formation of said plurality of pixels11comprises the implementation of a first phase consisting, for each pixel11, in forming at least one primary sub-pixel111acomprising at least one primary light-emitting diode111adapted to emit a first light radiation having substantially a first wavelength and formed on a support face110of a substrate101. The first phase comprises the following steps:a) formation, on the support face110of the substrate101, of at least one first primary semiconductor portion112intended to be electrically connected to a first electrode and doped according to a first doping type selected among a N-type doping and a P-type doping, the first primary semiconductor portion112having a generally wired shape elongated along a longitudinal axis A extending in a first direction111agenerally perpendicular to the support face110of the substrate101, the first primary semiconductor portion112including a top end112aopposite to a proximal end of the first primary semiconductor portion112facing towards the support face110of the substrate101;b) formation of at least one primary lattice parameter accommodation layer113at least on, and in contact with, the top end112aof the first primary semiconductor portion112formed in step a);c) formation of a second primary active semiconductor portion114by epitaxial growth from the primary lattice parameter accommodation layer113formed in step b), the second primary active semiconductor portion114being arranged on, and in contact with, the primary lattice parameter accommodation layer113;d) formation of a third primary semiconductor portion115intended to be electrically connected to a second electrode and doped according to a second doping type opposite to the first doping type, at least on, and in contact with, the second primary active semiconductor portion114.

The second primary active semiconductor portion114formed in step c) is configured so as to emit said first light radiation when at least one of the first and second electrodes is powered. The primary lattice parameter accommodation layer113formed in step b) has, at least at its interface with the second primary active semiconductor portion114formed in step c), a first difference in primary lattice parameters comprised between 2.12% and 0.93% relative to the second primary active semiconductor portion114.

In one example, step b) includes at least one of the following sub-steps:b1) formation of at least one lattice parameter accommodation primary sub-layer of a first nature113aconfigured so that the first light radiation capable of being emitted by the second primary active semiconductor portion114formed in step c) on, and in contact with, said lattice parameter accommodation primary sub-layer of a first nature113ais generally blue-colored by consisting of light rays having essentially wavelengths comprised between a first minimum value equal to 440 nm and a first maximum value equal to 500 nm;b2) formation of a lattice parameter accommodation primary sub-layer of a second nature113b, the lattice parameter accommodation primary sub-layer of second nature113bconfigured so that the first light radiation capable of being emitted by the second primary active semiconductor portion114formed in step c) on, and in contact with, said lattice parameter accommodation primary sub-layer of a second nature113bis generally green-colored by consisting of light rays having essentially wavelengths comprised between a second minimum value equal to 500 nm and a second maximum value equal to 570 nm;b3) formation of at least one lattice parameter accommodation primary sub-layer of a third nature113cconfigured so that the first light radiation capable of being emitted by the second primary active semiconductor portion114formed in step c) on, and in contact with, said lattice parameter accommodation primary sub-layer of a third nature113bis generally red-colored by consisting of light rays having essentially wavelengths comprised between a third minimum value equal to 570 nm and a third maximum value equal to 680 nm.

In another example, the formation of said plurality of pixels11comprises the implementation of a second phase essentially simultaneously with the first phase and consisting, for each pixel11, in forming at least one secondary sub-pixel11bcomprising at least one secondary light-emitting diode121adapted to emit a second light radiation having substantially a second wavelength different from the first wavelength and formed on the support face110of the substrate101. The second phase comprises the following steps:e) formation, on the support face110of the substrate101, of a first secondary semiconductor portion122offset relative to the first primary semiconductor portion112in a general plane parallel to the support face110, intended to be electrically connected to a first electrode and doped according to a first doping type selected among a N-type doping and a P-type doping, the first secondary semiconductor portion122having a generally wired shape elongated along a longitudinal axis A extending in the first direction111a, the first secondary semiconductor portion122including a top end122aopposite to a proximal end of the first secondary semiconductor portion122facing towards the support face110of the substrate101, step e) being carried out at the same time and with the same technique as step a);f) formation of at least one secondary lattice parameter accommodation layer123at least on, and in contact with, the top end122aof the first secondary semiconductor portion122formed in step e);g) formation of a second secondary active semiconductor portion by epitaxial growth from the secondary lattice parameter accommodation layer123formed in step f), the second secondary active semiconductor portion124being arranged on, and in contact with, the secondary lattice parameter accommodation layer123, step g) being carried out at the same time and with the same technique as step c);h) formation of a third secondary semiconductor portion125intended to be electrically connected to a second electrode and doped according to a second doping type opposite to the first doping type, at least on, and in contact with, the second secondary active semiconductor portion124.

The second secondary active semiconductor portion124formed in step g) is configured so as to emit said second light radiation when at least one of the first and second electrodes is powered.

The secondary lattice parameter accommodation layer123formed in step f) has, at least at its interface with the second secondary active semiconductor portion124formed in step g), a first difference in secondary lattice parameters comprised between 3.51% and 0.30% relative to the second secondary active semiconductor portion124.

In one example, step f) includes at least one of the following sub-steps:f1) formation of at least one lattice parameter accommodation secondary sub-layer of a first nature123aconfigured so that the second light radiation capable of being emitted by the second secondary active semiconductor portion124formed in step g) on, and in contact with, said lattice parameter accommodation secondary sub-layer of a first nature123ais generally blue-colored by consisting of light rays having essentially wavelengths comprised between the first minimum value equal to 440 nm and the first maximum value equal to 500 nm, the lattice parameter accommodation secondary sub-layer of a first nature123abeing similar in composition and thickness to the lattice parameter accommodation primary sub-layer of a first nature113aand step f1) being carried out at the same time and by the same technique as step b1);f2) formation of a lattice parameter accommodation secondary sub-layer of a second nature123bconfigured so that the second light radiation capable of being emitted by the second secondary active semiconductor portion124formed in step g) on, and in contact with, said lattice parameter accommodation secondary sub-layer of a second nature123bis generally green-colored by consisting of light rays having essentially wavelengths comprised between the second minimum value equal to 500 nm and the second maximum value equal to 570 nm, the lattice parameter accommodation secondary sub-layer of a second nature123bbeing similar in composition and in thickness to the lattice parameter accommodation primary sub-layer of a second nature113band step f2) being carried out at the same time and by the same technique as step b2);f3) formation of at least one lattice parameter accommodation secondary sub-layer of a third nature123cconfigured so that the second light radiation capable of being emitted by the second secondary active semiconductor portion124formed in step g) on, and in contact with, said lattice parameter accommodation secondary sub-layer of a third nature123cis generally red-colored by consisting of light rays having essentially wavelengths comprised between the third minimum value equal to 570 nm and the third maximum value equal to 680 nm. The lattice parameter accommodation secondary sub-layer of a third nature123cis similar in composition and in thickness to the lattice parameter accommodation primary sub-layer of a third nature113c. Step f3) is carried out at the same time and by the same technique as step b3).

In another example, the formation of said plurality of pixels11comprises the implementation of a third phase essentially simultaneously with the first phase and with the second phase and consisting, for each pixel11, in forming at least one tertiary sub-pixel11ccomprising at least one tertiary light-emitting diode131adapted to emit a third light radiation having substantially a third wavelength different from the first wavelength and from the second wavelength and formed on the support face110of the substrate101. The third phase comprises the following steps:i) formation, on the support face110of the substrate101, of a first tertiary semiconductor portion132offset relative to the first primary semiconductor portion112and relative to the first secondary semiconductor portion122in a general plane parallel to the support face110, intended to be electrically connected to a first electrode and doped according to a first doping type selected among a N-type doping and a P-type doping, the first tertiary semiconductor portion132having a generally wired shape elongated according to a longitudinal axis A extending in the first direction111a, the first tertiary semiconductor portion122including a top end132aopposite to a proximal end of the first tertiary semiconductor portion132facing towards the support face110of the substrate101, step i) being carried out in the same time and with the same technique as step a) and as step e);j) formation of at least one tertiary lattice parameter accommodation layer133at least on, and in contact with, the top end132aof the first tertiary semiconductor portion132formed in step i);k) formation of a second tertiary active semiconductor portion134by epitaxial growth from the tertiary lattice parameter accommodation layer133formed in step j), the second tertiary active semiconductor portion134being arranged on, and in contact with, the tertiary lattice parameter accommodation layer133, step k) being carried out at the same time and with the same technique as step c) and as step g);l) formation of a third tertiary semiconductor portion135intended to be electrically connected to a second electrode and doped according to a second doping type opposite to the first doping type, at least on, and in contact with, the second tertiary active semiconductor portion134.

In this example, the second tertiary active semiconductor portion134formed in step k) being configured so as to emit said third light radiation when at least one of the first and second electrodes is powered;

In addition, the tertiary lattice parameter accommodation layer133formed in step j) has, at least at its interface with the second tertiary active semiconductor portion134formed in step k), a first difference in tertiary lattice parameters comprised between 4.39% and 1.21% relative to the second secondary active semiconductor portion124.

In a complementary example, step j) includes at least one of the following sub-steps:j1) formation of at least one lattice parameter accommodation tertiary sub-layer of a first nature133aconfigured so that the third light radiation capable of being emitted by the second tertiary active semiconductor portion134formed in step k) on, and in contact with, said lattice parameter accommodation tertiary sub-layer of a first nature133ais generally blue-colored by consisting of light rays having essentially wavelengths comprised between the first minimum value equal to 440 nm and the first maximum value equal to 500 nm, the lattice parameter accommodation tertiary sub-layer of a first nature133abeing similar in composition and in thickness to the lattice parameter accommodation primary sub-layer of a first nature113aand to the lattice parameter accommodation secondary sub-layer of a first nature123aand step j1) being carried out at the same time and by the same technique as step b1) and as step f1);j2) formation of a lattice parameter accommodation tertiary sub-layer of a second nature133bconfigured so that the third light radiation capable of being emitted by the second tertiary active semiconductor portion134formed in step k) on, and in contact with, said lattice parameter accommodation tertiary sub-layer of a second nature133bis generally green-colored by consisting of light rays having essentially wavelengths comprised between the second minimum value equal to 500 nm and the second maximum value equal to 570 nm, the lattice parameter accommodation tertiary sub-layer of a second nature133bbeing similar in composition and in thickness to the lattice parameter accommodation primary sub-layer of a second nature113band to the lattice parameter accommodation secondary sub-layer of a second nature123band step j2) being carried out at the same time and by the same technique as step b2) and as step f2);j3) formation of at least one lattice parameter accommodation tertiary sub-layer of a third nature133cconfigured so that the third light radiation capable of being emitted by the second tertiary active semiconductor portion134formed in step k) on, and in contact with, said lattice parameter accommodation tertiary sub-layer of a third nature133cis generally red-colored by consisting of light rays having essentially wavelengths comprised between the third minimum value equal to 570 nm and the third maximum value equal to 680 nm. The lattice parameter accommodation tertiary sub-layer of a third nature133cis similar in composition and in thickness to the lattice parameter accommodation primary sub-layer of a third nature113cand to the lattice parameter accommodation secondary sub-layer of a third nature123c. Step j3) is carried out at the same time and by the same technique as step b3) and as step f3).

Before carrying out step c), it may be necessary to carry out etching operations of the lattice parameter accommodation primary sub-layers of a third nature113cand the lattice parameter accommodation primary sub-layers of a second nature113b. The etching may be carried out, for example, by plasma or by a wet process, or even by using mechanical-chemical polishing.

Likewise, before carrying out step g), it may be necessary to carry out operations for etching the lattice parameter accommodation secondary sub-layers of a third nature123cin order to expose the lattice parameter accommodation secondary sub-layer of a second nature123b. The etching may be carried out, for example, by plasma or by a wet process, or even by using mechanical-chemical polishing.

The illustrated figures refer to axial or “core-shell” type structures, the disclosure may indifferently concern the two types of light-emitting diode structures.

The first and second electrodes are intentionally not represented and the person skilled in the art will be able to use his knowledge to produce them.

Of course, the disclosure is not limited to the embodiments represented and described above, but on the contrary covers all the variants and combinations thereof.