Photovoltaic device and method of manufacturing the same

Abstract

The present invention relates to a photoelectric device comprising a three-dimensional (3D) structural part (1) including a pyramid (21) made of a first InGaN-based material formed from substrates (2, 2a, 2b), wherein the three-dimensional (3D) structural part (1) comprises a wire (24) made of a second GaN-based material different from the first material, and the wire (24) extends in a longitudinal direction perpendicular to the plane of the substrates (2, 2a, 2b) between the substrates (2, 2a, 2b) and the base (210) of the InGaN-based pyramid (21), so that the three-dimensional (3D) structural part has a general pencil shape. The present invention also relates to such a three-dimensional structural part and a method for manufacturing a photovoltaic device based on a plurality of such three-dimensional structural parts.

Description

Technology Field

[0001] The present invention relates to the field of optoelectronics. It finds particularly advantageous applications in the field of light-emitting diodes based on gallium nitride (GaN) having a three-dimensional structure. Background Technology

[0002] Light-emitting diodes (LEDs) generally include a region called an active region where radiative recombination of electron-hole pairs occurs, which enables the generation of optical radiation with a major wavelength.

[0003] For display applications, LEDs can be configured to generate light radiation with primary wavelengths of blue, green, or red.

[0004] This primary wavelength depends particularly on the composition of the active region. To generate light radiation in green or red, the active region can generally be based on InGaN. The higher the concentration of indium [In], the greater the wavelength. Therefore, to obtain an LED that emits red light, it may be necessary to include a concentration of indium [In] ≥ 10 at%.

[0005] GaN-based LEDs are generally manufactured according to a technique called planar technology, which involves forming a two-dimensional (2D) layer stack in a direction perpendicular to the base plane on the base plane of a substrate.

[0006] This stack may generally include a GaN buffer region, an N-doped GaN region, an active InGaN-based region, and a P-doped GaN region from the substrate.

[0007] For example, by rear-structuring this stack by a lithography / etching step, a plurality of LEDs or micro-LEDs can be formed, each having a mesa structure that typically includes a top surface and a sidewall (Fig. 1).

[0008] However, in the case of high indium concentration, for example [In] ≥ 10 at%, the mismatch in lattice parameters between the GaN-based region and the InGaN-based active region (22) ultimately causes mechanical stress that leads to the creation of structural defects through plastic relaxation. These structural defects affect the radiation efficiency of LEDs or micro LEDs. In particular, it is especially difficult to obtain red LEDs with good radiation efficiency.

[0009] Another disadvantage of this type of mesa structure is related to the rear structure. The sidewall (200) obtained by etching generally has defects that promote the appearance of non-radiative surface recombination. The radiation efficiency of the LED is further reduced.

[0010] One solution to reduce sidewall defects is to directly form a GaN-based three-dimensional (3D) structure. This three-dimensional structure may be pyramidal, as illustrated in FIG. 2. To further limit plastic stress relaxation phenomena, this pyramid may include a bulk InGaN region located beneath the active region (22). The document “Nanoscale selective area growth of a thick, dense, uniform, In-rich, InGaN nanostructure array on a GaN / sapphire template, S. Sundaram et al., Journal of Applied Physics 116, 163105 (2014)” discloses, for example, a bulk InGaN pyramidal region. This bulk InGaN pyramidal region (21) is hereinafter referred to as the “InGaN pyramid.”

[0011] The growth of the InGaN pyramid can be performed by epitaxy from a GaN layer (11) partially covered with a masking layer (12).

[0012] The disadvantage of the InGaN pyramid (21) formed in this way is that it may have many structural defects. Therefore, the crystal quality of the bulk InGaN region is not sufficient to manufacture photovoltaic devices, especially LEDs, with satisfactory performance.

[0013] To improve the crystalline quality of epitaxial InGaN pyramids (21), one solution consists of growing these pyramids (21) from a GaN buffer layer (11). This buffer layer (11) is particularly thicker than conventional thin layers. The buffer layer (11) allows structural defects to be confined to the lower portion of the layer (11), for example, at the interface with the underlying support (10) made of silicon. As the concentration of these structural defects generally decreases along the thickness of the layer, the GaN buffer layer (11) has improved crystalline quality on its upper portion. However, the use of such a thick GaN buffer layer (11) causes curvature issues for the silicon support (10) in the form of a wafer. Such a buffer layer is more expensive to produce.

[0014] Another disadvantage of this type of pyramid structure is that the inclusion of indium in the bulk InGaN region (21) remains limited even in the GaN buffer layer (11). In particular, it is difficult to form an InGaN pyramid (21) with an indium concentration [In] ≥ 10 at% with satisfactory crystal quality. Therefore, this three-dimensional pyramidal InGaN-based structure cannot form a micro LED that emits red light with satisfactory radiation efficiency. The problem to be solved

[0015] The present invention aims to overcome at least some of the aforementioned drawbacks in part.

[0016] In particular, the objective of the present invention is to provide a three-dimensional structure comprising an InGaN pyramid having improved crystal quality.

[0017] Another objective of the present invention is to provide a method for forming an InGaN pyramid that can reduce the manufacturing cost of the InGaN pyramid and / or improve the crystal quality.

[0018] Another objective of the present invention is to provide a photovoltaic device comprising an InGaN pyramid that emits red or green light with improved radiant efficiency, in particular a GaN-based three-dimensional LED.

[0019] Other objects, features, and advantages of the present invention will become apparent from the following description and the accompanying drawings. It is understood that other advantages may be incorporated. means of solving the problem

[0020] To achieve the above-mentioned purpose, the present invention provides, according to a first embodiment, a three-dimensional (3D) structure for optoelectronics comprising a pyramid made of a first InGaN-based material formed from a planar substrate.

[0021] Advantageously, the three-dimensional structure comprises a wire made of a second GaN-based material different from the first material, said wire extending in a longitudinal direction perpendicular to the plane of the substrate between the substrate and the base of the InGaN-based pyramid, so that the three-dimensional structure has a general pencil shape.

[0022] Therefore, GaN-based wires serve as three-dimensional substrates for InGaN-based pyramids. These wire-shaped three-dimensional substrates advantageously replace planar substrates in the form of thick GaN buffer layers. In particular, these wire-shaped substrates have better crystal quality than thick GaN planar substrates and are more economical to produce.

[0023] It is preferable to obtain these GaN-based wires by growing them from bottom to top using a "bottom-up" approach, rather than by etching from top to bottom using a reverse approach known as "top-down." This "bottom-up" growth limits the emergence of mechanical stress within the GaN, particularly because free surfaces exist on the wire walls during growth. This restricts the occurrence of structural defects within the wire, thereby improving the crystalline quality of the GaN-based wires. Furthermore, unlike the "top-down" approach, which promotes the emergence of such surface defects, this allows for the limitation or elimination of surface defects on the wire walls.

[0024] Furthermore, wire-shaped growth offers better efficiency than bulk layer growth. The surface area to volume ratio of a wire is actually larger than that of a planar layer. Since growth is limited by surface phenomena, wire-shaped growth exhibits higher growth efficiency. This allows for reduced manufacturing costs by dislocating conventional GaN-based substrates into a wire shape.

[0025] These wire-shaped substrates can also be advantageously formed on large-dimensional silicon wafers, such as 8-inch or 12-inch ones, the latter of which do not suffer from curvature issues. Mechanical stress associated with the difference in lattice parameters between silicon and GaN-based materials is significantly relieved by the growth of this material in wire form compared to the growth of this material in layer form—for the same layer thickness and wire height.

[0026] A second aspect of the present invention relates to a gallium nitride (GaN)-based photovoltaic device comprising a plurality of three-dimensional (3D) structures according to a first aspect of the present invention.

[0027] The three-dimensional structures are advantageously spaced apart from each other by a spacing distance (ds) of 650 nm or less, preferably 600 nm or less.

[0028] The development leading to the present invention has made it possible to identify that high GaN-based wire density promotes the growth of InGaN-based structures on the top of the wire rather than on the walls of the wire. According to technical bias, growth by vapor phase epitaxy using organometallic precursors (MOVPE) creates substantially conformal layers on the substrate surface, regardless of whether they are structured. Therefore, according to this bias, MOVPE deposition of InGaN on GaN-based wires forms a structure called a radial three-dimensional structure having continuous layers of InGaN on the walls and on the top of the wire.

[0029] Conversely, within the framework of the development of the present invention, such MOVPE deposition of InGaN on a series of GaN-based wires sufficiently close to each other was shown to enable obtaining a structure called an axial three-dimensional structure, where the InGaN-based material is mainly located on top of the wires.

[0030] Furthermore, unexpectedly, these InGaN-based superstructures grow into pyramids rather than wire-like layers. One possible explanation is that the proximity of the superstructures disrupts the equilibrium of the thermodynamic system, leading to the formation of these pyramids.

[0031] According to one specific example, by periodically depositing InGaN wells and AlGaN barriers on a substrate in the form of GaN-based wires spaced apart by about 200 nm, bulk InGaN-based pyramids can ultimately be obtained on top of the wires.

[0032] Under these conditions of high wire density, when the spacing distance (ds) between wires is 650 nm or less, indium is uniformly distributed while forming the upper pyramid structure.

[0033] Obtaining such bulk InGaN-based pyramids advantageously allows for the growth of active InGaN-based regions with improved crystal quality and / or increased indium concentration.

[0034] InGaN-based pyramids can advantageously have slopes corresponding to semipolar planes. These semipolar planes are, for example, of the {10-11} type. These semipolar planes promote the integration of indium compared to nonpolar planes in the wire walls. Thus, the upper InGaN pyramid can have a sufficient indium concentration, such as [In] ≥ 10 at%, to form an LED configured to emit green or red light with enhanced radiation efficiency.

[0035] A third aspect of the present invention relates to a method for manufacturing a plurality of three-dimensional (3D) structures for optoelectronics, each comprising an InGaN-based pyramid.

[0036] This method includes the following steps:

[0037] - A step of providing a substrate comprising at least one surface layer that allows nucleation and growth of GaN based on, for example, GaN, AlN and / or other metal nitrides,

[0038] - A step of depositing a masking layer on a GaN-based substrate, the masking layer including an opening in which a surface layer is exposed,

[0039] - Forming GaN-based wires extending from the base to the top, respectively, in a longitudinal direction substantially perpendicular to the surface layer by epitaxy from an exposed area of ​​the surface layer, wherein the base is connected to the surface layer through an opening, and

[0040] - A step of forming an InGaN-based pyramid on top of a GaN-based wire by epitaxy.

[0041] Therefore, this method enables the formation of InGaN-based pyramids from an advantageously thin surface layer, also known as a nucleation layer. Epitaxial wires have higher crystal quality than bulk layers of the same thickness. Therefore, these wires advantageously form a 3D GaN-based substrate of excellent crystal quality for the growth of InGaN-based pyramids. Consequently, the crystal quality of the InGaN-based pyramids is improved.

[0042] GaN-based wire epitaxy is also more efficient and consumes less precursor than GaN-based bulk layer epitaxy. Therefore, this method can ultimately reduce the manufacturing cost of InGaN-based pyramids.

[0043] According to favorable possibilities, the apertures of the masking layer are regularly distributed in an array form with a pitch of 700 nm or less, for example, between 50 nm and 650 nm. This pitch partially determines the spacing distance (ds) between the wires. Thus, after the growth of the GaN-based wires, they are relatively close to each other. This allows for the axial growth of InGaN on top of the wires in a pyramidal shape.

[0044] It should be understood that the features and advantages of one embodiment of the present invention can be converted into other embodiments of the present invention by making only slight modifications to the necessary parts. Brief explanation of the drawing

[0045] The intent, purpose, features, and advantages of the present invention will become more apparent from the detailed description of the latter embodiments illustrated by the following accompanying drawings: Figure 1 illustrates a three-dimensional LED structure having a mesa structure according to the prior art. FIG. 2 illustrates a three-dimensional LED structure including an InGaN-based pyramid according to the prior art. FIG. 3 illustrates a three-dimensional structure including an InGaN-based pyramid according to one embodiment of the present invention. FIG. 4a is a scanning transmission electron microscope (STEM) image of a three-dimensional structure according to one embodiment of the present invention. FIG. 4b is an enlarged view of the image of FIG. 4a illustrating an upper pyramid of a three-dimensional structure according to one embodiment of the present invention. FIG. 4c is the EDX mapping of FIG. 4b showing the distribution of indium within the upper pyramid of a three-dimensional structure according to one embodiment of the present invention. FIG. 5 is a scanning electron microscope (SEM) image of a photovoltaic device including a plurality of three-dimensional structures according to one embodiment of the present invention. FIG. 6 is a scanning electron microscope (SEM) image of a photovoltaic device including a plurality of three-dimensional structures according to another embodiment of the present invention. FIG. 7a shows the wavelength (λ) in the red light region in the plan view of the photovoltaic device shown in FIG. 6. R This is a cathode emission image formed for ). Fig. 7b is an image of Fig. 7a with an increased dynamic range of brightness, showing the wavelength (λ) of the upper InGaN-based pyramid. R Emphasizes the difference in emission intensity in ). FIG. 7c is a hyperspectral image showing the cathodic emission spectrum associated with each point of the spatial profile shown in FIG. 7b. Figure 8 is the photoluminescence spectrum of the photoelectric device shown in Figure 6. FIG. 9 is a photoluminescence spectrum of a photoelectric device including a plurality of three-dimensional structures according to another embodiment of the present invention. FIG. 10a is a scanning electron microscope (SEM) image of a photovoltaic device including a plurality of three-dimensional structures according to another embodiment of the present invention. Figure 10b is the photoluminescence spectrum of the photoelectric device shown in Figure 10a. The drawings are provided as examples and do not limit the invention. The drawings constitute a schematic representation of the principles to facilitate understanding of the invention and are not necessarily drawn to the actual applicable scale. In particular, the dimensions of various elements of the three-dimensional structure do not necessarily represent the actual state. Specific details for implementing the invention

[0046] Before beginning a detailed review of the embodiments of the present invention, it is recalled that the present invention according to the first aspect includes the following optional features which may be used particularly in combination or alternatively.

[0047] According to one example, the wire has a height of 150 nm or more.

[0048] According to one example, the wire has a diameter of 30 nm or more and / or 500 nm or less.

[0049] According to one example, an InGaN-based pyramid has a base diameter, and the wire diameter is less than or equal to the base diameter.

[0050] According to one example, the base of an InGaN-based pyramid is substantially parallel to the plane of the substrate.

[0051] According to one example, a GaN-based wire comprises a base placed on a planar substrate and a top supporting the base of an InGaN-based pyramid, said top being surrounded by an InGaN-based collar.

[0052] According to one example, an InGaN-based pyramid includes a plane tilted at an angle of about 30° with respect to the longitudinal direction, and this tilted plane substantially corresponds to a {10-11} type semipolar plane.

[0053] According to one example, the three-dimensional structure further includes an active InGaN-based region on at least one face of an InGaN-based pyramid, said active region configured to emit or receive optical radiation.

[0054] According to one example, an InGaN-based pyramid has an indium level [In] ≥ 10%.

[0055] According to one example, an InGaN-based pyramid has a height of 50 nm or more and / or 500 nm or less.

[0056] In one example, the diameter of the wire is larger than the diameter of the opening of the masking layer.

[0057] The present invention according to a second embodiment comprises the following optional features which may be used particularly in combination or alternatively:

[0058] According to one example, at least part of the three-dimensional structure of the photovoltaic device is configured to emit optical radiation having a principal wavelength, and the principal wavelength varies depending on the diameter (φ) of the wire of the three-dimensional structure and the separation distance (ds) separating two adjacent three-dimensional structures among the three-dimensional structures.

[0059] According to one example, a plurality of three-dimensional structures have the same spacing distance (ds) and the same wire diameter (φ), and said three-dimensional structures are configured to emit optical radiation having a principal wavelength (λ) partially determined by the diameter (φ) and spacing distance (ds) for a green three-dimensional structure of the same plate (same growth conditions, particularly an active layer).

[0060] According to one example, the photoelectric element comprises at least first, second, and third plurality of three-dimensional structures having first, second, and third separation distances (ds1, ds2, ds3) and first, second, and third diameters (φ1, φ2, φ3) of a wire, respectively, wherein ds1 <ds2 <ds3 및 φ1>φ2 > φ3, and the first, second, and third plurality of three-dimensional structures each have different first, second, and third wavelengths (λ1, λ2, λ3), preferably λ1 > λ2 > λ3.

[0061] According to one example, a photovoltaic device is ds1<ds2 및 φ1> It includes a plurality of first and second three-dimensional structures having first and second separation distances (ds1, ds2) and first and second diameters (φ1, φ2) of a wire, respectively, such that φ2 is equal to φ2, and the first and second plurality of three-dimensional structures emit optical radiation having first and second wavelengths (λ1, λ2) respectively, which are different from each other and preferably λ1 > λ2.

[0062] According to one example, the photoelectric element comprises at least a first plurality of three-dimensional structures having a first separation distance (ds1) and a first diameter (φ1) of a wire, and the three-dimensional structures emit optical radiation having a first wavelength (λ1) belonging to the spectrum of red light.

[0063] According to one example, the photoelectric element comprises at least a second plurality of three-dimensional structures having a second separation distance (ds2) and a second diameter (φ2) of a wire, and the three-dimensional structures emit light radiation having a second wavelength (λ2) that belongs to the spectrum of green light.

[0064] According to one example, the photoelectric element comprises at least a third plurality of three-dimensional structures having a third separation distance (ds3) and a third diameter (φ3) of a wire, and the three-dimensional structures emit optical radiation having a third wavelength (λ3) belonging to the spectrum of blue light.

[0065] According to one example, ds1 <ds2 <ds3 및 / 또는 φ1>φ2 > φ3.

[0066] According to one example, the first wavelength (λ1) is greater than 600 nm.

[0067] According to one example, the second wavelength (λ2) is between 500 nm and 600 nm.

[0068] According to one example, the third wavelength (λ3) is less than 500 nm.

[0069] According to one example, the dominant wavelength (λ) of the optical radiation is 400 nm or more and / or 700 nm or less.

[0070] According to one example, the main wavelength (λ) of optical radiation falls between 500 nm and 650 nm.

[0071] The present invention according to a third embodiment comprises the following optional features which may be used particularly in combination or alternatively:

[0072] According to one example, this method includes the following steps:

[0073] - A step of providing a substrate comprising at least one surface layer that allows nucleation and growth of GaN based on, for example, GaN, AlN and / or other metal nitrides,

[0074] - A step of depositing a masking layer including an opening in which a surface layer is exposed on a substrate,

[0075] - Forming GaN-based wires extending from the base to the top, respectively, in a longitudinal direction substantially perpendicular to the surface layer by epitaxy from an exposed area of ​​the surface layer, wherein the base is connected to the surface layer through an opening, and

[0076] - A step of forming an InGaN-based pyramid on top of a GaN-based wire by epitaxy.

[0077] According to one example, the surface layer has a thickness of 1 nm to 200 nm, preferably 10 nm to 200 nm.

[0078] According to one example, the formation of InGaN-based pyramids and / or GaN-based wires is carried out by metal-organic vapor phase epitaxy (MOVPE).

[0079] According to one example, the openings of the masking layer are spaced apart by a pitch between 50 nm and 700 nm.

[0080] According to one example, the aperture of the masking layer is 4μm -2 Above and / or 400μm -2 It is distributed to have a surface density of the following.

[0081] According to one example, the formation of an InGaN-based pyramid is configured such that the InGaN-based pyramid has an indium level [In] ≥ 10 at%.

[0082] According to one example, the formation of InGaN-based pyramids occurs at temperatures above 780°C.

[0083] According to one example, the masking layer comprises at least first, second, and third plurality of openings having first, second, and third pitches (p1, p2, p3) and first, second, and third opening diameters (φo1, φo2, φo3), respectively, wherein p1 < p2<p3 및 φo1> A plurality of first, second, and third three-dimensional structures are simultaneously formed, configured to emit optical radiation such that φo2 > φo3, each having different first, second, and third wavelengths (λ1, λ2, λ3), preferably such that λ1 > λ2 > λ3.

[0084] According to one example, the masking layer comprises a plurality of first and second openings, each having first and second pitches (p1, p2) and first and second opening diameters (φo1, φo2), wherein p1<p2 및 φo1> By making it φo2, a plurality of first and second three-dimensional structures are simultaneously formed, each having different first and second wavelengths (λ1, λ2) and preferably emitting light radiation such that λ1 > λ2.

[0085] Unless they are compatible, it should be understood that the three-dimensional structure, manufacturing method, and optoelectronic device may include any of the above features by making only slight modifications to the necessary parts.

[0086] In the present invention, a three-dimensional structure including an InGaN-based pyramid is particularly dedicated to the manufacture of three-dimensional LEDs.

[0087] The present invention can be more widely implemented for various optoelectronic devices having a three-dimensional structure, particularly devices including an active region.

[0088] The active region of a photovoltaic device refers to the region where most of the light supplied by the device is emitted or where most of the light received by the device is captured.

[0089] Therefore, the present invention can also be implemented in relation to a laser or photovoltaic device.

[0090] Unless explicitly stated otherwise, the relative arrangement of the third layer interposed between the first layer and the second layer in the context of the present invention does not necessarily mean that the layers are in direct contact with each other, but rather means that the third layer is in direct contact with the first layer and the second layer, or is separated from them by at least one other layer or at least one other element.

[0091] The stage of forming various elements is understood in a broad sense. It can be performed in multiple sub-stages that are not strictly sequential.

[0092] The diameter of the wire or the base of the pyramid refers to the largest transverse dimension. In the present invention, the wire does not necessarily have to have a circular cross-section. Particularly in the case of a GaN-based wire, this cross-section may be hexagonal. Then, the diameter corresponds to the distance separating the two opposite upper ends of the hexagonal section. Alternatively, the diameter may correspond to the average diameter calculated from the diameter of the circle inscribed in the polygon of the cross-section and the diameter of the circle circumscribed in the polygon. The diameter of the three-dimensional structure is approximately equal to the diameter of the wire of this three-dimensional structure.

[0093] The pencil shape refers to a shape comprising a cylindrical body and a tapered tip at one end of the body. The barrel is preferably a straight cylinder. The barrel may have a hexagonal or polygonal cross-section. In this patent application, the cross-section is nearly constant along the height of the cylinder. Nevertheless, it may vary slightly, for example, by 5% or 10% of the surface, without questioning the definition of the cylindrical body mentioned above. The cylindrical body corresponds to the GaN-based wire of this patent application. The tapered tip is positioned at one end of the cylindrical body. It preferably has the same base as the cylinder and preferably extends continuously to converge toward a point or upper region. The tapered tip may optionally include one or more angles. The tapered tip corresponds to the upper InGaN-based pyramid of this patent application.

[0094] A wire refers to a three-dimensional structure with an elongated shape in the longitudinal direction. In the drawing, the longitudinal dimension of the wire along z is larger than, and preferably much larger than, the transverse dimension of the wire in the xy plane in the drawing. The longitudinal dimension is, for example, at least 5 times, and preferably at least 10 times, larger than the transverse dimension.

[0095] The surface density of a three-dimensional structure depends on the separation distance (ds) separating two adjacent three-dimensional structures. The surface density of a three-dimensional structure is particularly k / ds where k is a proportionality constant. 2 Depending on this, it can be inversely proportional to this distance (ds).

[0096] In this patent application, the terms "concentration," "level," and "content" are synonyms.

[0097] More specifically, concentration is expressed in relative units such as moles or atomic fractions (at%) or the number of atoms per cubic centimeter (at.cm). -3 It can be expressed in absolute units such as ).

[0098] In the following, concentration is an atomic fraction expressed in at% unless otherwise indicated.

[0099] In this patent application, the terms "light-emitting diode," "LED," or simply "diode" are used as synonyms. "LED" may also be understood as "micro LED."

[0100] In the following, the following abbreviations related to material M are used optionally:

[0101] Mi represents material M that is inherently or unintentionally doped, according to the terminology commonly used in the field of microelectronics for the suffix -i.

[0102] Mn represents material M doped with N, N+, or N++, according to the terminology commonly used in the field of microelectronics for the suffix -n.

[0103] Mp represents a material M doped with P, P+, or P++, according to the terminology commonly used in the field of microelectronics for the suffix -p.

[0104] A substrate, layer, or device "based" on material M means a substrate, layer, or device comprising only this material M or comprising this material M and possible other materials, e.g., alloying elements, impurities, or doping elements. Thus, a gallium nitride (GaN)-based wire may comprise, for example, gallium nitride (GaN or GaN-i) or doped gallium nitride (GaN-p, GaN-n). A pyramid based on gallium-indium nitride (InGaN) may comprise, for example, gallium nitride-aluminum (AlGaN) or gallium nitride with different aluminum and indium (GaInAlN) contents. In the context of the present invention, material M is generally crystalline.

[0105] A reference mark, preferably a normal orthogonal one including the axes (x, y, z), is shown on the attached drawing.

[0106] In this patent application, it is desirable to consider the thickness of the layer and the height of the device. The thickness is taken in a direction perpendicular to the main extension plane of the layer, and the height is taken perpendicular to the base plane (xy) of the substrate. Accordingly, the buffer layer or surface layer typically has a thickness according to z, and the wire has a height according to z.

[0107] Dimensional values ​​match within manufacturing and measurement tolerances. Therefore, theoretically, two identical separation distances (ds) or two wire diameters may actually have slight dimensional variations.

[0108] The terms "substantially," "approximately," and "of the order of" mean "within 10%" of a value when in relation to a value, or "within 10°" of an angle direction when in relation to an angle direction. Therefore, a direction substantially perpendicular to a plane means a direction having an angle of 90±10° with respect to the plane.

[0109] To determine the geometry, crystallographic orientation, and configuration of the three-dimensional structure and various elements of this three-dimensional structure (especially wires, pyramids, collars, and active regions), scanning electron microscopy (SEM), transmission electron microscopy (TEM), or scanning transmission electron microscopy (STEM) analysis may be performed.

[0110] The crystallographic orientation of various elements can be directly estimated from TEM or SEM images, or accurately determined, for example, by microdiffraction within TEM.

[0111] TEM or STEM is also suitable for observing and identifying structural defects, particularly dislocations within InGaN pyramids. Various techniques listed below can be implemented in a non-comprehensive manner: dark-field and bright-field, weak beam, and high-angle diffraction (HAADF) imaging.

[0112] The chemical composition of various elements can be determined using the well-known EDX or X-EDS method (an abbreviation for "energy dispersive x-ray spectroscopy").

[0113] This method is suitable for analyzing the configuration of small devices such as 3D LEDs. This can be implemented in metallurgical sections within a scanning electron microscope (SEM) or thin sections within a transmission electron microscope (TEM).

[0114] The optical properties of various elements, in particular the major emission wavelengths of InGaN-based pyramids and / or InGaN-based active regions, can be determined by spectroscopy.

[0115] Cathode emission (CL) and photoluminescence (PL) spectroscopy are suitable for optically characterizing the three-dimensional structure described in the present invention.

[0116] The technique mentioned above makes it possible to determine whether a photovoltaic device having a three-dimensional structure, in particular, includes an InGaN-based pyramid formed on top of a GaN-based wire as described in the present invention. The possibility of the presence of a collar can also be easily observed using this technique.

[0117] A first embodiment of a three-dimensional structure according to the present invention will now be described with reference to FIGS. 3 and FIGS. 4a to 4c.

[0118] FIG. 3 illustrates a plurality of adjacent three-dimensional structures (1) distributed on the same substrate (2a). The following description regarding one of these three-dimensional structures naturally extends to these plurality of other three-dimensional structures which are considered to be substantially identical to one another.

[0119] The three-dimensional structure (1) comprises at least one wire (24) and one pyramid (21) on top of the wire (24). Preferably, the three-dimensional structure is formed directly from a substrate (2a). This substrate (2a) may be in the form of a stack comprising a support (10) in the z-direction, a surface layer (13) called a nucleation layer, and a masking layer (12). The substrate (2a) is substantially planar and parallel to the plane (xy).

[0120] The support (10) may be made of sapphire to limit lattice parameter mismatch with GaN, or may be made of silicon to reduce costs and address technical compatibility issues. In the latter case, the substrate may be in the form of a wafer with a diameter of 200 mm or 300 mm. In particular, the substrate serves as a support for the three-dimensional structure.

[0121] The nucleation layer (13) is preferably based on AlN. Alternatively, it may be based on other metal nitrides such as GaN or AlGaN. This nucleation layer (13) may be any layer that allows for the nucleation and growth of GaN known to those skilled in the art. It may be formed on a silicon support (10) by epitaxy, preferably by metal-organic vapor phase epitaxy (MOVPE). Advantageously, it has a thickness of 200 nm or less, preferably 100 nm or less, for example, about 50 nm. This allows for limiting mechanical stress induced by this layer (13) on the support (10). This allows for avoiding harmful curvature of the support (10). Such a thickness also allows for limiting the appearance of structural defects in the nucleation layer (13). In particular, the growth of this nucleation layer (13) can be pseudomorphic, that is, the stress of epitaxy (particularly related to the difference in lattice parameters between Si and AlN, GaN or AlGaN) can be elastically relieved during growth. Thus, the crystal quality of this nucleation layer (13) can be optimized.

[0122] The masking layer (12) is preferably made of a dielectric material, for example, silicon nitride Si3N4. The masking layer may be deposited on the nucleation layer (13) by chemical vapor deposition (CVD). The masking layer includes circular openings (120) that partially mask the nucleation layer (13) and preferably expose an area of ​​the nucleation layer (13). These openings (120) typically have dimensions, a diameter (φ0) or average diameter ranging from 30 nm to 500 nm. The openings (120) may be evenly distributed within the masking layer (12), for example, in the form of an aligned array. The pitch, i.e., the distance separating the centers of two adjacent openings (120), is preferably 700 nm or less. The distance may be configured between 50 nm and 650 nm. The openings (120) are advantageously 4 µm -2 It has a greater surface density. This ultimately enables obtaining a densely distributed three-dimensional structure on the substrate (2a). These openings (120) can be created, for example, by UV or DUV (abbreviation for Deep UV) lithography, electron beam lithography, or NIL (abbreviation for Nanoimprint lithography). Thus, the formation of the masking layer (12) typically involves the deposition of a dielectric material followed by the formation of the openings (120) typically by lithography. Such a masking layer (13) enables local growth of the three-dimensional structure in each opening (120). In particular, during a preliminary growth step called budding, a GaN-based seed (20) is formed in the opening (120) and then fills the opening (120). Subsequent growth of the wire (24) then occurs locally from this seed (20).

[0123] The wire (24) is based on GaN. Preferably, it is oriented parallel to z in the crystallographic direction

[0001] corresponding to the axis (c) of the hexagonal crystallographic structure.

[0124] GaN-based wires (24) can be formed by epitaxy, preferably by metal-organic-vapor-phase epitaxy (MOVPE) as defined in Publication WO2012136665. The gallium source in the form of an organometallic precursor (precursor III) can generally be trimethyl gallium (TMGa) or triethyl gallium (TEGa). The nitrogen source can generally be ammonia (NH3) (precursor V). The growth temperature is preferably greater than 700°C, for example, around 1000°C. The gas pressure in the growth reactor is, for example, about 425 Torr. Growth is preferably carried out under a neutral and / or reducing atmosphere, typically by adding nitrogen N2 and / or dihydrogen H2. The flow of various gases can be adjusted in a manner known to those skilled in the art, particularly depending on the volume of the reactor.

[0125] The formation of the wire (24) can alternatively be performed by molecular beam epitaxy (MBE), vapor phase epitaxy using a chlorinated gas precursor HVPE (short for "Hydride Vapor Phase Epitaxy"), chemical vapor deposition (CVD) and MOCVD (short for "MetalOrganic Chemical Vapor Deposition").

[0126] Optionally, conventional surface preparation steps (chemical cleaning, heat treatment) of the seed (20) may be performed before the epitaxial growth of the wire (24).

[0127] The wire (24) may include an N-doped GaN-based region. In a known manner, this N-doped region may be the result of growth, injection, and / or activation annealing. N-doping may be obtained directly from a silicon or germanium source during growth, particularly by adding, for example, silane or disilane or germanium vapor. The growth conditions required for the formation of such a wire (24) are widely known.

[0128] The wire (24) has a diameter (φ) of 30 nm or more and / or 500 nm or less. This diameter (φ) may be larger than the diameter of the opening (120) and the seed (20) that generates the wire (24). In this case, the base (240) of the wire (24) supports the masking layer (12) of the substrate (2a). In the plane (xy), the cross-section of the wire (24) may typically have a somewhat regular hexagonal shape. The wire (24) also has a height (h) of 150 nm or more. The top (241) of the wire (24) is preferably substantially flat and parallel to the plane (xy) to accommodate the base (210) of the pyramid (21). The wire (24) preferably has an aspect ratio (h / φ) greater than 1, and preferably greater than 5. This improves the crystal quality of the wire (24) at its top (241). This also allows the upper part (241) to move away from the flat substrate (2a) below. Thus, the local environment of the upper part (241) is not obstructed by the flat substrate (2a) below. Therefore, the formation of the InGaN pyramid (21) on the upper part (241) of the wire (24) is not affected by the flat substrate (2a).

[0129] The pyramid (21) is based on InGaN. It is preferably oriented in the same crystallographic direction as the wire (24). The formation of the InGaN-based pyramid (21) can be carried out by epitaxy, preferably metal-organic vapor phase epitaxy (MOVPE). The growth conditions required for the formation of the pyramid (21) are different from the conditions required for the formation of the wire (24). The InGaN-based material is grown by adding it to a source of indium in the form of an organometallic precursor, e.g., trimethylindium (TMIn) or triethylindium (TEIn), particularly gallium (TEGa), trimethylgallium (TMGa), and a source of nitrogen (NH3). The ratio of the indium precursor element (TMIn, TEIn) to all precursor III (TEGa, TMGa, and TMIn, TEIn...) can be approximately 0.3. The growth temperature can be about 800°C. The gas pressure in the growth reactor is, for example, about 100 Torr. The V / III or In / III ratio, pressure, and growth temperature can be adjusted according to the design of the epitaxy reactor and the target emission wavelength.

[0130] According to one possibility, the Ga / N elemental ratio can be greater than 100. This promotes the growth of this InGaN-based material in a pyramidal shape.

[0131] According to one possibility, the growth of the wire (24) is configured to obtain Ga polarity at the top (241) of the wire (24). This polarity also promotes a pyramidal growth shape.

[0132] The immediate environment at the top (241) of the wire (24) can also affect the growth pattern. In particular, the proximity of other wires (24) and other adjacent tops (241) can locally modify the growth conditions of the InGaN-based material. In relation to the development of the present invention, high density on the substrate (2a), particularly 4 μm -2It was found that larger wires promote a pyramidal growth pattern. Additionally, it was found that as the surface density of the wire (24) increases, the concentration of indium [In] contained in the pyramid (21) increases.

[0133] The growth temperature of the pyramid (21) is preferably greater than 700°C, preferably greater than 750°C, and advantageously around 780°C. This allows for the improvement of the crystalline quality of the pyramid (21). The formation of the InGaN-based pyramid (21) and the formation of the wire (24) can be advantageously performed in a single growth frame.

[0134] FIGS. 4a and 4b are STEM-HAADF images of the three-dimensional structure obtained from MOVPE. These images show that there are substantially no structural defects in the wire (24) in particular, and the pyramid (21) also has very good crystal quality.

[0135] Structurally, the pyramid (21) comprises a base (210) that rests on the upper part (241) of the wire (24) and an upper part (211) opposite the base (210) along z. The upper part (211) of the pyramid (21) may form a tip. It may be somewhat truncated or flat (Fig. 4a). The base (210) of the pyramid (21) has a diameter (φp) greater than the diameter (φ) of the wire (24). This base (210) generally has a regular hexagonal shape that is nearly identical to the cross-section of the wire (24). The pyramid (21) extends from the base (210) to the upper part (211) while maintaining a cross-section that is typically somewhat regular hexagonal in the plane (xy). Thus, the pyramid (21) includes an inclined surface or face (212) that extends from the base (210) to the upper part (211). In particular, there may be six such faces (212). The pyramid (21) has a height (hp). This height (hp) may be approximately the height (h) of the wire (24), preferably at least 2 times smaller than the height (h) of the wire (24), preferably at least 5 times smaller, and for example, about 10 times smaller. The pyramid (21) preferably has an aspect ratio (hp / φp) of about 1. This corresponds to an inclination of the plane (212) of approximately 60° with respect to the plane (xy). This plane (212) may advantageously correspond to a {10-11} type plane. This allows for the integration of indium into the active region (22) formed on the pyramid (21) or this plane (212). According to another possibility, the plane (212) may be inclined at an angle of approximately 80° with respect to the plane (xy). The inclination of this plane (212) corresponds almost to a {20-21} type semipolar plane.

[0136] The pyramid (21) may extend below the base (210) around the upper part (241) of the wire (24) in the shape of a collar (26), for example (Fig. 4b). This collar (26) may include a facet (262) as a continuation of the face (212) of the pyramid (21). This collar (26) typically forms a cap covering the upper part (241) of the wire (24) together with the pyramid (21). The collar (26) enhances mechanical cohesion, for example, between the wire (24) and the pyramid (21). The collar (26) may have a substantial height, for example, about one-third or half the height of the pyramid. It may also extend toward the base (240) of the wire (24) in the form of a thin layer of several nanometers, for example, about 1 to 5 nm, covering the vertical wall of the wire (24). The collar (26) may include an irregular ring continuous along z. Therefore, this continuous irregular ring can form a castle-shaped cross-section along zx to form a step or level. The collar (26) does not necessarily have to be continuous with the pyramid (21). The collar can be independent.

[0137] The InGaN-based pyramid (21) preferably has an indium concentration of 10 at% or more. Indium is distributed throughout the volume of the pyramid (21), as shown by the EDX mapping of the indium element shown in FIG. 4c. Preferably, it is distributed homogeneously within the pyramid (21) and, if appropriate, within the collar (26).

[0138] To create a photovoltaic device that emits or receives light radiation, the three-dimensional structure (1) may include an active region (22) on the side (212) of a pyramid (21) and a GaN-based region (23) on the active region (22), particularly as shown in FIG. 3.

[0139] In the case of an LED, the active region (22) may include a plurality of quantum wells configured to emit optical radiation at a major wavelength (λ). These quantum wells are based, for example, on InGaN. They can typically be separated from each other by an AlGaN-based barrier.

[0140] The region (23) may be based on GaN, particularly P-doped GaN. This typically covers the active region (22) and allows carriers to be injected into the active region (22). Growth of the region (23) over the active region (22) is preferably performed to obtain a conformal layer. The thickness of this layer is preferably limited to tens of nanometers, e.g., less than 100 nm or even less than 50 nm, to limit the reabsorption of optical radiation emitted by the active region (22). The edges of the layer forming the region (23) may have straight sides parallel to z, as shown in FIG. 3. Alternatively, these sides are inclined and extend from one side of the three-dimensional structure. The sides of the region (23) of a given three-dimensional structure may optionally be combined with at least one side of the region (23) of an adjacent three-dimensional structure. In this case, a single region (23) in the form of a substantially continuous layer may be formed on a plurality of adjacent three-dimensional structures.

[0141] The main wavelength of the light radiation emitted by the active region (22) depends particularly on the indium concentration of the quantum well. As the indium content increases, the main wavelength increases toward the red light region of the visible spectrum. In particular, an indium concentration exceeding 15 at% or 20 at% can emit red light having a main wavelength of 600 nm or more.

[0142] For such emission to be satisfactory in relation to the LED, the radiating efficiency must be sufficiently high, for example, about 20%. To achieve this efficiency, the crystallinity of the active region (22) must be good.

[0143] The three-dimensional InGaN-based pyramid (21) advantageously forms a transition region between the GaN-based wire (24) and the active InGaN-based region (22). Thus, the concentration of integrated indium can be increased gradually, for example, stepwise from the pyramid (21) to the active region (22). This allows the appearance of structural defects in the active region (22) to be limited. The concentration of indium required to emit red light radiation in the active region (22) can therefore be achieved without degrading the crystal quality of the active region. Thus, this three-dimensional structure comprising the GaN-based wire (24), the InGaN-based pyramid (21), the In(Al)GaN-based active region (22), and the GaN-p-based region (23) can advantageously emit red light radiation with high radiation efficiency.

[0144] FIG. 5 illustrates a plurality of three-dimensional structures as described above, dispersed in a dense array. In this example, the three-dimensional structures have a diameter of approximately 200 nm and a surface density of 20 μm -2 It is at that level.

[0145] According to another exemplary embodiment, FIG. 6 shows a diameter of approximately 100 nm and 25 μm -2 Multiple three-dimensional structures having a surface density of a certain degree are illustrated. InGaN-based pyramids (21) are not covered in this example.

[0146] Figures 7a through 7c show some optical properties obtained by cathodic emission spectroscopy within a SEM on the three-dimensional structure exemplified in Figure 6. Figure 7A specifically shows the mapping of cathodic emission intensity at an acquisition wavelength of approximately 610 nm in a top view of this three-dimensional structure. It is evident that most InGaN-based pyramids emit light at this wavelength when stimulated by electron beam scanning of the SEM. Figure 7b takes data from Figure 7a and provides increased contrast intensity dynamics. Different emission intensity thresholds of the pyramids are indicated at wavelength λ ≈ 620 nm. The data profiles indicated in the map of Figure 7b are extracted and displayed in Figure 7c. Each point in the profile corresponds to a wavelength spectrum acquired in the range of approximately 250 nm to 750 nm. These spectra are collected in Figure 7c. The emission spectra of the pyramids all appear to be concentrated at wavelength λ ≈ 620 nm. The width of the emission peaks is also considerably small, at the level of tens of nanometers. This spectral purity implies that the crystalline quality of the pyramids is particularly good.

[0147] Figure 8 shows the photoluminescence spectra associated with these multiple three-dimensional structures. The most intense emission peak is concentrated around λ ≈ 610 nm. At half the height of this peak, the width is approximately 45 nm. This peak corresponds to the InGaN pyramid of the three-dimensional structure.

[0148] The measured radiant efficiency for this pyramid is about 20%. This confirms that the three-dimensional pyramid structure obtained according to the above-described embodiment has crystal quality suitable for the production of red LEDs.

[0149] Therefore, these multiple three-dimensional structures can be advantageously implemented within a red three-dimensional LED.

[0150] Fig. 9 shows a diameter of approximately 100 nm and a surface density of 6 μm -2Another example of a photoluminescence spectrum obtained for a three-dimensional structure (not shown) is presented. Here, the surface density of the three-dimensional structure is divided by approximately 2 compared to the previous example. In this example, the most intense emission peak corresponding to the InGaN pyramid of the three-dimensional structure is concentrated around λ ≈ 480 nm (blue light range). At half the height of this peak, the width is approximately 20 nm. Therefore, multiple such three-dimensional structures can be advantageously implemented in blue three-dimensional LEDs. Another example of a three-dimensional structure is shown in Fig. 10a.

[0151] Figure 10b shows the photoluminescence spectrum associated with the three-dimensional structure of this example. The most intense emission peak is concentrated around λ ≈ 515 nm (green light range). At half the height of this peak, the width is approximately 20 nm. This peak corresponds to the InGaN pyramid of the three-dimensional structure shown in Figure 10a. Therefore, multiple such three-dimensional structures can be advantageously implemented within a green three-dimensional LED.

[0152] Therefore, these various examples show that reducing the surface density of a three-dimensional structure for a given diameter shifts the main emission peak of the three-dimensional structure toward a smaller wavelength. The width of this peak also decreases at its mid-height.

[0153] Conversely, for a given surface density, increasing the diameter of the three-dimensional structure shifts the main emission peak of the three-dimensional structure toward a larger wavelength.

[0154] Therefore, a wide range of wavelength settings can be obtained by changing the surface density and / or diameter of the three-dimensional structure.

[0155] Accordingly, the three-dimensional structure according to the present invention can be advantageously implemented in different types of optoelectronic devices, particularly red three-dimensional LEDs, green three-dimensional LEDs, and blue three-dimensional LEDs, by adapting the surface density and diameter of these three-dimensional structures.

[0156] Three-dimensional structures with different diameters (φ) and different spacing distances (ds) of wires (24) can be advantageously distributed on the same substrate (2a) to form regions that emit light radiation at different major wavelengths. For example, a photoelectric device is:

[0157] - A first region comprising a three-dimensional structure having a first diameter (φ1) and a first separation distance (ds1), wherein the three-dimensional structure emits optical radiation at a first wavelength (λ1) greater than, for example, 600 nm (red light range),

[0158] - A second region comprising a three-dimensional structure having a second diameter (φ2) and a second separation distance (ds2), wherein the second region emitting light radiation at a second wavelength (λ2) included, for example, in the range of 500 nm to 600 nm (green light range),

[0159] - A third region comprising a three-dimensional structure having a third diameter (φ3) and a third separation distance (ds3), wherein the three-dimensional structure emits light radiation at a third wavelength (λ3) of, for example, less than 500 nm (blue light range).

[0160] These first, second, and third regions can be partially embedded in each other, so there exist multiple first, second, and third subsets configured to emit in the red, green, and blue light ranges, respectively.

[0161] The present invention also relates to a method for manufacturing a three-dimensional LED as described in the preceding exemplary embodiments.

[0162] According to an advantageous embodiment, the method allows for the simultaneous formation of first, second, and third regions of a three-dimensional structure configured to emit optical radiation having first, second, and third wavelengths (λ1, λ2, λ3), respectively. In particular, these first, second, and third regions of the three-dimensional structure may be formed from a masking layer (12) deposited on a substrate (2b) comprising a plurality of first, second, and third openings (120) having first, second, and third pitches (p1, p2, p3), respectively, and first, second, and third opening diameters (φo1, φo2, φo3), so that p1 <p2 <p3 및 / 또는 φo1>Make φo2 > φo3.

[0163] The present invention is not limited to the aforementioned embodiments but extends to all embodiments covered by the claims.

Claims

Claim 1 A gallium nitride (GaN)-based optoelectronic device comprising first and second plurality of three-dimensional (3D) structural members (1), wherein each of the first and second plurality of three-dimensional (3D) structural members (1) comprises an InGaN-based pyramid (21) made of a first InGaN-based material formed from a planar substrate (2, 2a, 2b), and a GaN-based wire (24) made of a second GaN-based material different from the first InGaN-based material, wherein the GaN-based wire (24) extends in a longitudinal direction perpendicular to the plane of the planar substrate (2, 2a, 2b) between the planar substrate (2, 2a, 2b) and the base (210) of the InGaN-based pyramid (21), so that each of the three-dimensional structural members has a general pencil shape, and the first and second plurality of three-dimensional structural members each have first and second spacing distances ds1, ds2, between the wires A photoelectric device having first and second diameters Φ1 and Φ2 of wires, ds1 < ds2 and Φ1 > Φ2, wherein the first and second plurality of three-dimensional structures emit optical radiation having first and second wavelengths λ1 and λ2 respectively such that λ1 > λ2, and wherein the GaN-based wire (24) comprises a base (240) placed on a planar substrate (2, 2a, 2b) and a top (241) supporting the base (210) of an InGaN-based pyramid (21), wherein the top (241) is surrounded by an InGaN-based collar (26), and the InGaN-based collar (26) forms a cap covering the top (241) of the GaN-based wire (24) together with the InGaN-based pyramid (21). Claim 2 A photoelectric device according to claim 1, wherein the InGaN-based pyramid comprises faces, and the collar comprises faces that are in a continuous line with the faces of the InGaN-based pyramid. Claim 3 In claim 1 or 2, the base (210) of the InGaN-based pyramid (21) is substantially parallel to the plane of the planar substrate (2, 2a, 2b), of the photoelectric device. Claim 4 An optoelectronic device according to claim 1 or 2, wherein the InGaN-based pyramid (21) has a base diameter Φp, the GaN-based wire (24) has a diameter Φ, and the diameter Φ of the GaN-based wire (24) is less than or equal to the base diameter Φp. Claim 5 In claim 1 or 2, each three-dimensional structural part further comprises an active InGaN-based region (22) on at least one face (212) of an InGaN-based pyramid (21), said active InGaN-based region (22) is configured to emit or receive light radiation, a photoelectric device. Claim 6 A photoelectric device according to claim 1 or 2, wherein the first plurality of three-dimensional (3D) structural parts are spaced apart from each other by a spacing distance ds1 of 650 nm or less, and the second plurality of three-dimensional (3D) structural parts are spaced apart from each other by a spacing distance ds2 of 650 nm or less. Claim 7 The photoelectric element according to claim 1 or 2, wherein the photoelectric element comprises at least three first, second, and third plurality of three-dimensional (3D) structural members, each of the first, second, and third plurality of three-dimensional (3D) structural members has first, second, and third separation distances ds1, ds2, ds3 between wires and first, second, and third diameters φ1, φ2, φ3 of the wires, ds1 < ds2 < ds3 and φ1 > φ2 > φ3, and the first, second, and third plurality of three-dimensional (3D) structural members (1) emit optical radiation having first, second, and third wavelengths λ1, λ2, λ3, respectively, where λ1 > λ2 > λ3. Claim 8 A method for manufacturing a gallium nitride (GaN)-based optoelectronic device comprising first and second plurality of three-dimensional (3D) structural members (1), wherein each three-dimensional (3D) structural member (1) comprises an InGaN-based pyramid (21) and a GaN-based wire (24), and the method comprises: providing a substrate (2b) comprising at least one surface layer (13) that allows nucleation and growth of GaN based, for example, GaN, AlN, and / or other metal nitrides; forming a masking layer (12) on the substrate (2b) that includes an opening (120) through which the surface layer (13) is exposed; forming GaN-based wires (24) that extend from a base (240) to a top (241), respectively, in a longitudinal direction substantially perpendicular to the surface layer (13) from the exposed area of ​​the surface layer (13) through the opening (120); and of the GaN-based wire (24). Step of forming an InGaN-based pyramid (21) on the upper part (241);The masking layer (12) is formed with at least first and second plurality of openings (120) having first and second pitches p1, p2 and first and second opening diameters φo1, φo2, respectively, and p1 < p2 and φo1 > φo2, and first and second plurality of three-dimensional (3D) structural parts (1) are simultaneously formed having first and second separation distances ds1, ds2 between wires and first and second diameters φ1, φ2 of wires, respectively, and ds1 < ds2 and Φ1 > Φ2, and the first and second plurality of three-dimensional (3D) structural parts (1) are configured to emit optical radiation having first and second wavelengths λ1, λ2, respectively, where λ1 > λ2, and the base (240) is a planar substrate (2, 2a, 2b) A manufacturing method in which the upper portion (241) is placed on top, the upper portion (241) supports the base (210) of the InGaN-based pyramid (21), the upper portion (241) is surrounded by an InGaN-based collar (26), and the InGaN-based collar (26) forms a cap that covers the upper portion (241) of the GaN-based wire (24) together with the InGaN-based pyramid (21).; Claim 9 In claim 8, the manufacturing method wherein the surface layer (13) has a thickness included in 1 nm to 200 nm. Claim 10 A manufacturing method according to claim 8 or 9, wherein the formation of the InGaN-based pyramid (21) and / or the formation of the GaN-based wire (24) is performed by metal-organic vapor phase epitaxy (MOVPE). Claim 11 A manufacturing method according to claim 8 or 9, wherein the openings (120) of the masking layer (12) are spaced apart by a pitch between 50 nm and 700 nm. Claim 12 In claim 8 or 9, the opening (120) of the masking layer (12) is 4 μm -2 Above and / or 400μm -2 A manufacturing method distributed to have the following surface density. Claim 13 A manufacturing method according to claim 8 or 9, wherein the formation of the InGaN-based pyramid (21) is configured such that the InGaN-based pyramid (21) has an indium level [In] ≥ 10 at%. Claim 14 In claim 8 or 9, the formation of the InGaN-based pyramid (21) is carried out at a temperature of 780°C or higher, in a manufacturing method. Claim 15 In claim 8 or 9, the masking layer (12) further comprises a third plurality of openings (120) having a pitch p3 and a third opening diameter φo3, p1 < p2 < p3 and φo1 > φo2 > φo3, and simultaneously forms first, second, and third plurality of three-dimensional (3D) structural members (1) having first, second, and third separation distances ds1, ds2, ds3 and first, second, and third diameters φ1, φ2, φ3 of the wires, respectively, and such that ds1 < ds2 < ds3 and / or φ1 > φ2 > φ3, the first, second, and third plurality of three-dimensional (3D) structural members each have a first, second, and third wavelength such that λ1 > λ2 > λ3. A manufacturing method configured to emit optical radiation having λ1, λ2, and λ3.

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