METHOD FOR PRODUCING AN OPTOELECTRONIC SEMICONDUCTOR COMPONENT AND OPTOELECTRONIC SEMICONDUCTOR COMPONENT

Abstract

The invention relates to a method for producing an optoelectronic semiconductor component (10) that comprises structuring (S100) of a masking material (105) over a growth substrate (100), such that a pattern of exposed surface regions (106) is created, and epitaxially growing (S110) a first semiconductor material over the exposed surface regions (106), wherein pillars (108) are formed in a region facing the growth substrate (100), and a continuous first semiconductor layer (110) of a first conductivity type is formed in a region facing away from the growth substrate (100). The method further comprises forming (S120) an active zone (115) over the first semiconductor layer (110) and the pillars (108), wherein the active zone (115) is suitable for emitting or absorbing electromagnetic radiation (20), and epitaxially growing (S130) a second semiconductor layer (120) of a second conductivity type over the active zone (115). A modal value M(d) of a distance d between centres of the exposed regions (106) fulfils the following condition: M(d) ≤ 1.5*λ, wherein λ denotes the average wavelength of the electromagnetic radiation in the first semiconductor material.

Description

[0001] METHOD FOR PRODUCING AN OPTOELECTRONIC SEMICONDUCTOR COMPONENT AND OPTOELECTRONIC SEMICONDUCTOR COMPONENT

[0002] DESCRIPTION

[0003] Light-emitting diodes ("LEDs") are semiconductor devices with a semiconductor layer stack comprising a sequence of a first semiconductor layer of a first conductivity type, for example n-type, and a second semiconductor layer of a second conductivity type, for example p-type. When a voltage is applied to the semiconductor layer stack, photons are emitted due to the recombination of electrons and holes. In general, an LED represents a Lambertian emitter that emits electromagnetic radiation via a main surface of the semiconductor layer stack. The intensity of the emitted electromagnetic radiation changes depending on an emission angle.

[0004] For many applications, a point-like light source with the smallest possible dimensions in the pm range is desired. Therefore, concepts are being developed that can be used to produce improved optoelectronic semiconductor devices.

[0005] The present invention is based on the object of providing an improved method for producing an optoelectronic semiconductor component and an improved optoelectronic semiconductor component.

[0006] According to embodiments, the object is achieved by the subject matter of the independent patent claims. Advantageous further developments are defined in the dependent claims. A method for producing an optoelectronic semiconductor component comprises structuring a masking material over a growth substrate so that a pattern of exposed surface regions is produced and epitaxially growing a first semiconductor layer over the exposed surface regions, wherein pillars are formed in a region facing the growth substrate and a continuous first semiconductor layer of a first conductivity type is formed in a region facing away from the growth substrate.The method further comprises forming an active zone over the first semiconductor layer and the pillars, the active zone being suitable for emitting or absorbing electromagnetic radiation, and epitaxially growing a second semiconductor layer of a second conductivity type over the active zone. A modal value M(d) of a distance d between centers of the exposed regions satisfies the following condition: M(d) < 1.5*, where X denotes the mean wavelength of the electromagnetic radiation in the first semiconductor material.

[0007] The term "mode value" used in the present disclosure refers to a most frequently occurring value within the existing distances between the centers. For example, the following relationship may apply to the mode value M ( d) of the distance: 0 . 4 * X < M ( d) < 0 . 6 * X .

[0008] The semiconductor material may, for example, contain InGaN. For example, the In content of the semiconductor material may increase with increasing distance from the growth substrate. For example, the refractive index of InGaN may range from 2.2 to 2.4, and the refractive index of AlN may range from 2.0 to 2.2, depending on the manufacturing process. Accordingly, taking this refractive index range into account, the following relationship may apply to the modal value M(d) of the distance: M(d) < 0.625 * X' or

[0009] 0.16 * M(d) < X' < 0.3 * M(d) , where X' is the wavelength in vacuum.

[0010] The term "average wavelength in a semiconductor material" refers to an effective wavelength averaged over different refractive indices. The effective wavelength depends on a refractive index in the propagation medium. If the refractive index changes due to a spatially changing composition ratio, the average is taken over the different refractive indices or the different effective wavelengths.

[0011] According to embodiments, the first semiconductor material can be grown in such a way that a refractive index of the first semiconductor material is changed. For example, the refractive index of the first semiconductor material can change periodically. A period p within which the refractive index changes periodically can satisfy the following relationship: 0.4 * X < p < 0.6 * X, where X corresponds to the wavelength within the first semiconductor material.

[0012] For example, the first semiconductor material may be doped with dopants of a first conductivity type. According to further embodiments, the first semiconductor material may be undoped in the region where pillars are formed and doped with dopants of the first conductivity type in the region where the continuous first semiconductor layer is formed.

[0013] According to embodiments, the method may further comprise applying a carrier substrate over the second semiconductor layer and detaching the growth substrate such that the pillars are arranged in the region of a first main surface of a resulting device or workpiece.

[0014] The pillars can be removed from a part of the optoelectronic semiconductor component. For example, the pillars can be removed from a region of the optoelectronic semiconductor component that does not horizontally overlap the active region. For example, the pillars can be removed from the entire region or from a part of the region of the optoelectronic semiconductor component that does not horizontally overlap the active region.

[0015] According to further embodiments, the pillars can be removed from a region of the optoelectronic semiconductor component that horizontally overlaps the active region. For example, the pillars can be removed from the entire region or from a part of the region of the optoelectronic semiconductor component that horizontally overlaps the active region.

[0016] The method may further comprise forming a first contact element in a region from which the pillars have been removed. For example, the pillars may be undoped.

[0017] Furthermore, the method may comprise applying a contact layer of the first conductivity type over the growth substrate, wherein the masking layer is applied over the contact layer, and the first semiconductor material of the first conductivity type is grown over the contact layer. For example, the first semiconductor material may be doped. For example, the growth substrate may be stripped after applying the carrier substrate over the second semiconductor layer; furthermore, at least a portion of the contact layer may be removed after stripping the growth substrate.

[0018] According to embodiments, an optoelectronic semiconductor component comprises a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and an active zone suitable for emitting electromagnetic radiation between the first and the second semiconductor layer, wherein the first semiconductor layer, the active zone and the second semiconductor layer are arranged to form a semiconductor layer stack and the active zone adjoins a second main surface of the first semiconductor layer. The optoelectronic semiconductor component further comprises an ordered photonic structure above a first main surface of the first semiconductor layer, wherein the ordered photonic structure directly adjoins the first semiconductor layer, is arranged above the active zone and comprises pillars containing a material of the first semiconductor layer.A modal value M ( d) of a distance d between centers of the columns satisfies the following condition : M ( d) < 1 , 5 * , where X denotes the wavelength of the electromagnetic radiation in the first semiconductor layer .

[0019] For example, the following condition may be met:

[0020] 0.4*X<M(d)<0.6*X.

[0021] For example, a semiconductor material of the first semiconductor layer may contain InGaN. The In content of the semiconductor material of the pillars may decrease with increasing distance from the first semiconductor layer. Furthermore, a defect density within the pillars may increase with increasing distance from the first semiconductor layer.

[0022] For example, the pillars may be removed from a part of the optoelectronic semiconductor device.

[0023] For example, a part of the optoelectronic semiconductor component in which columns are present may be smaller than a horizontal extension of the active zone.

[0024] The optoelectronic semiconductor component may further comprise a first contact element which is electrically connected to the first semiconductor layer, wherein the first contact element is arranged in the part of the optoelectronic semiconductor component from which the pillars are removed.

[0025] The accompanying drawings are intended to provide an understanding of embodiments of the invention. The drawings illustrate embodiments and, together with the description, serve to explain the same. Further embodiments and many of the intended advantages will be apparent from the following detailed description. The elements and structures shown in the drawings are not necessarily to scale. Like reference numerals refer to like or corresponding elements and structures.

[0026] Figures 1A to 1C illustrate steps for fabricating an optoelectronic semiconductor component.

[0027] Figures 2A to 2C illustrate further steps for fabricating a semiconductor device. Figure 2D shows a semiconductor device according to embodiments.

[0028] Figure 3 shows components of an optoelectronic semiconductor device according to further embodiments.

[0029] Figure 4 shows components of an optoelectronic semiconductor device according to further embodiments.

[0030] Figure 5 shows components of an optoelectronic semiconductor device according to further embodiments.

[0031] Figure 6A shows a cross-sectional view of an optoelectronic semiconductor device according to embodiments.

[0032] Figure 6B shows a plan view of the optoelectronic semiconductor device shown in Figure 6A.

[0033] Figure 6C shows an arrangement of semiconductor devices according to embodiments.

[0034] Figure 7 shows a schematic view of an electrical device according to embodiments.

[0035] Figure 8 summarizes a method according to embodiments.

[0036] In the following detailed description, reference is made to the accompanying drawings, which form a part of the disclosure, and in which specific embodiments are shown for purposes of illustration. In this context, directional terminology such as "top", "bottom", "front", "back", "over", "on", "in front of", "behind", "fore", "rear", etc., refers to the orientation of the figures just described. Since the components of the embodiments can be positioned in different orientations, the directional terminology is for the purpose of explanation only and is in no way limiting.

[0037] The description of the embodiments is not limiting, as other embodiments exist and structural or logical changes may be made without departing from the scope defined by the claims. In particular, elements of embodiments described below may be combined with elements of other described embodiments, unless the context indicates otherwise.

[0038] The terms "wafer" or "semiconductor substrate" used in the following description can encompass any semiconductor-based structure having a semiconductor surface. Wafer and structure are to be understood as including doped and undoped semiconductors, epitaxial semiconductor layers, optionally supported by a base support, and other semiconductor structures. For example, a layer of a first semiconductor material can be grown on a growth substrate of a second semiconductor material, for example a GaAs substrate, a GaN substrate, or a Si substrate, or of an insulating material, for example a sapphire substrate.

[0039] Depending on the intended use, the semiconductor can be based on a direct or an indirect semiconductor material. Examples of semiconductor materials particularly suitable for generating electromagnetic radiation include, in particular, nitride semiconductor compounds, which can be used to generate ultraviolet, blue, or longer-wavelength light, for example, such as GaN, InGaN, AlN, AlGaN, AlGaNN, AlGaNBN, phosphide semiconductor compounds, which can be used to generate green or longer-wavelength light, for example, such as GaAsP, AlGaNP, GaP, AlGaP, as well as other semiconductor materials such as GaAs, AlGaAs, InGaAs, AlInGaAs, SiC, ZnSe, ZnO, Ga2O3, diamond, hexagonal BN, and combinations of the materials mentioned. The stoichiometric ratio of the compound semiconductor materials can vary. Further examples of semiconductor materials can include silicon, silicon-germanium, and germanium.In the context of this description, the term "semiconductor" also includes organic semiconductor materials.

[0040] The term "substrate" generally includes insulating, conductive, or semiconductor substrates.

[0041] The term "vertical," as used in this description, is intended to describe an orientation that is substantially perpendicular to the first surface of a substrate or semiconductor body. The vertical direction may, for example, correspond to a growth direction during layer growth.

[0042] The terms "lateral" and "horizontal," as used in this description, are intended to describe an orientation or alignment that is substantially parallel to a first surface of a substrate or semiconductor body. This can be, for example, the surface of a wafer or a chip (die).

[0043] The horizontal direction can, for example, lie in a plane perpendicular to a growth direction when growing layers.

[0044] The term "column" used in the present disclosure refers to a structure having any cross-section, such as round, oval, or square, that extends in a vertical direction. It is intended that the diameter of a column changes only insignificantly along the vertical direction. For example, a difference between the maximum and minimum diameters of a column is smaller than a minimum diameter of a column.

[0045] As shown in Figure 1A, a structured masking layer 105 is created over a suitable growth substrate 100, which may be, for example, a silicon substrate or a sapphire substrate. For example, as shown in Figure 1A, a contact layer, for example, an n-doped contact layer 102, may first be applied over the growth substrate 100, for example, in direct contact with the growth substrate 100. According to an embodiment, the contact layer 102 may be an InGaN contact layer.

[0046] A masking layer, for example made of silicon oxide or silicon nitride, is then formed and structured. For example, the structuring can comprise a photolithographic process, for example using a stepper or electron beam lithography. For example, the structuring can produce a region-wise regular, for example hexagonal, pattern of, for example, round holes in the masking layer. For example, the masking layer can be further structured by etching. The result is a structured masking material 105, wherein a pattern of exposed surface regions 106 is produced. The exposed surface regions 106 are not covered with the masking material 105.

[0047] For example, in a case such as in Figure 1A, in which an n-contact layer is provided, surface regions of the n-contact layer 102 may be exposed. The centers of the exposed regions 106 may, for example, have a distance d.

[0048] Thereafter, a first semiconductor material is grown epitaxially over the exposed surface regions 106. In the process, pillars 108 form, as shown in Figure 1B. According to embodiments, a material of the first semiconductor layer can be InGaN. In order to achieve a desired wavelength range of the emitted electromagnetic radiation, the In concentration is increased step by step during the growth of the first semiconductor layer, for example, in order to finally achieve the desired In concentration in the subsequently growing first semiconductor layer. Due to lattice mismatches, defects 107 arise that grow out to the side of the resulting pillars 108. This is indicated in Figure 1B.For example, according to the embodiments described in the present application, a diameter of the columns may be smaller than (0.75*d) or smaller than (0.5*d), where d corresponds to the distance between column centers. Thereafter, the growth conditions are changed so that, after reaching a low defect density, the columns coalesce, forming a continuous first semiconductor layer 110.

[0049] For example, the first semiconductor material may be doped with dopants of a first conductivity type, for example n-type. According to further embodiments, the first semiconductor material may be undoped in a region in which the pillars 108 are formed. In the region in which the continuous first semiconductor layer 110 is formed, the first semiconductor material may be doped with dopants of the first conductivity type. For example, the resulting first semiconductor layer 110 may have an x Gai- xN-layer with a high In content. For example, x can be greater than 0.3. For example, the pillars 108 can be applied such that the region in which the pillars are present has a layer thickness of at least 0.5 pm. For example, a maximum thickness of the region in which the pillars 108 are present can be 2 to 3 pm. In the layer region with coalesced pillars, the composition is selected such that a lattice constant is adapted to the lattice constant of the active zone to be applied. In this way, the defect density can be minimized and the efficiency of the component can be increased.

[0050] As further shown in Figure 1C, an active zone 115 and a second semiconductor layer of a second conductivity type, for example p-type, can then be formed over the active zone 115. The material of the second semiconductor layer can also be InGaN, for example In y Gai-y N be .

[0051] The active zone can, for example, have a pn junction, a double heterostructure, a single quantum well (SQW), or a multi-quantum well (MQW) structure for radiation generation. The term "quantum well structure" has no significance with regard to the dimensionality of the quantization. It thus encompasses, among other things, quantum wells, quantum wires, and quantum dots, as well as any combination of these layers.

[0052] In the described method, a modal value M ( d) of a distance d between the centers of the exposed regions 106 can satisfy the following condition: M ( d) < 0 , 625 * X ' , or 0.16 * X' < M(d) < 0.5 * X' or 0.2 * X' < M(d) < 0.3 * X', where X' denotes the wavelength of the electromagnetic radiation in a vacuum.

[0053] Figure 1C shows a cross-sectional view of a resulting workpiece 118.

[0054] As shown in Figure 2A, a mesa structure 122 may subsequently be defined, for example, by etching. For example, a portion of the active zone 115 and a portion of the second semiconductor layer 120 may be removed. As a result, a portion of a surface of the first semiconductor layer 110 may be exposed.

[0055] Subsequently, as shown in Figure 2B, a second contact region 123 can be applied and patterned. For example, a metal of the second contact region can have a high reflectivity. According to further embodiments, a transparent conductive oxide ("ITO", indium tin oxide, or "TCO", transparent conductive oxide) or a combination of such an oxide and a metal can be used instead of a metal. Furthermore, an insulating layer 124, for example, an insulating oxide or silicon nitride, can be applied. Subsequently, a continuous mirror layer 125 can be formed. The mirror layer 125 can, for example, cover a part of the first semiconductor layer 110, a side flank of the mesa 122, as well as the second contact region 123 and the second semiconductor layer 120.A material of the mirror layer can, for example, have a high reflectivity and can comprise gold, silver or aluminum. The mirror layer can have further layers for connection to a subsequent solder layer. Figure 2B shows a cross-sectional view of a resulting workpiece 118. The workpiece 118 can then be applied to a carrier substrate 130 and soldered, for example using a suitable solder material 127. Alternatively, an electrically conductive adhesive can also be used instead of the solder material 127. After connection to the carrier substrate 130, the growth substrate 100 can be removed, for example by a laser lift-off method. Figure 2C illustrates this method step.

[0056] After turning the workpiece 118 over, a first contact region 112 can be formed. For example, the generated electromagnetic radiation can be emitted via the first contact region 112. Accordingly, the first contact region 112 can be formed as a transparent contact region. The transparent first contact region 112 can, for example, comprise a transparent oxide, optionally in combination with a very thin metal layer or a metal layer formed as non-contiguous, very small metallizations, and can have a transmittance of at least 50%. As further shown in Figure 2D, an insulation layer 114 can be applied beneath a first contact element 113 for connection to a power source. The insulation layer 114 prevents or reduces injection of charge carriers into a region outside the active region of the optoelectronic semiconductor component 10.Figure 2D shows a cross-sectional view of an example of a correspondingly manufactured optoelectronic semiconductor component 10.

[0057] Figure 2D shows a schematic cross-sectional view of an optoelectronic semiconductor component 10 according to embodiments. The optoelectronic semiconductor component 10 has a semiconductor layer stack comprising a first semiconductor layer 110 of a first conductivity type, for example n-conducting, a second semiconductor layer 120 of a second conductivity type, for example p-conducting, and an active zone 115. The active zone 115 is suitable for emitting electromagnetic radiation. The active zone 115 is arranged between the first and the second semiconductor layer 110, 120. The active zone 115 adjoins a second main surface 121 of the first semiconductor layer 110. An ordered photonic structure 109 is arranged above a first main surface 111 of the first semiconductor layer 110. The ordered photonic structure 109 directly adjoins the first semiconductor layer 110 and is arranged above the active zone 115.The ordered photonic structure comprises pillars 108 containing a material of the first semiconductor layer 110. A modal value M ( d) of a distance d between centers of the pillars 108 satisfies the following condition:.

[0058] M ( d) < 1 , 5 * X or

[0059] 0.4 * X < M ( d) < 0.6 * X, where X denotes the wavelength of the electromagnetic radiation emitted by the active zone 115 in the semiconductor material. Furthermore, according to the embodiments described in the context of the present application, a diameter of the columns 108 can be smaller than ( 0.75 * d) or smaller than ( 0.5 * d).

[0060] Furthermore, according to the embodiments described in the context of the present application, a height of the columns, i.e., for example, a distance between the adjacent horizontal surface regions of the adjacent semiconductor layers, for example, the first semiconductor layer 110 and the semiconductor contact layer 102 of the first conductivity type, can be greater than 200 nm, for example, greater than 300 nm, or greater than 500 nm. For example, with a distance greater than 200 nm, for example, greater than 300 nm or greater than 500 nm across the continuously formed first semiconductor layer 110, the diameter of the columns can be at least 25% or at least 50% of the distance d between adjacent columns.

[0061] In the context of the present disclosure, the term "ordered photonic structure" means a structure whose structural elements are arranged at predetermined locations. The arrangement pattern of the structural elements is subject to a specific order. The functionality of the ordered photonic structure results from the arrangement of the structural elements. The structural elements are arranged, for example, in such a way that diffraction effects occur. The structural elements can, for example, be arranged periodically, so that a photonic crystal is realized. According to further embodiments, the structural elements can also be arranged such that they represent deterministic aperiodic structures, for example Vogel spirals. According to further embodiments, the structural elements can also be arranged such that they realize a quasi-periodic crystal, for example an Archimedean lattice.According to further embodiments, the term "ordered photonic structure" also includes periodic structures with larger periods, so that, for example, a complete photonic band gap is not achieved. Such periodic structures can still have useful influences on light propagation.

[0062] The ordered photonic structure 109 is arranged above the active zone 115. More precisely, the ordered photonic structure 109 is arranged along a vertical emission direction of electromagnetic radiation. Accordingly, the ordered photonic structure 109 overlaps with the active zone 115 in the horizontal direction. As can also be seen in Figure 2D, the ordered photonic structure 109 is arranged above a first main surface of the first semiconductor layer 110. The first main surface 111 can have depressions. These depressions can be caused, for example, by an overgrowth of the pillars 108 during the epitaxy process. The ordered photonic structure 109 or the pillars 108 that form the ordered photonic structure 109 directly border the first semiconductor layer 110.For example, the pillars 108 in a region of the interface with the first semiconductor layer 110 may have a similar or identical composition ratio and an identical or similar dopant concentration as the first semiconductor layer 110. However, the composition ratio and dopant concentration may also be different. For example, the pillars 108 may be doped with dopants of the first conductivity type.

[0063] For example, the semiconductor material may include InGaN. For example, an In content of the semiconductor material within the pillars 108 may decrease with increasing distance from the first semiconductor layer 110. A first contact region 112 may be arranged adjacent to and connected to the contact layer 102 or to the ordered photonic structure. A second contact region 123 may be arranged adjacent to the second semiconductor layer 120. The second contact region 123 is electrically connected to the second semiconductor layer 120.

[0064] If an electrical voltage is applied between the first contact region 112 and the second contact region 123, current flows through the active zone 115, whereby electromagnetic radiation corresponding to the band gap of the active zone 115 is generated. The periodically arranged pillars 108 form an ordered photonic structure 109 and, according to embodiments, modify the optical modes within the waveguide structure formed by the first and second semiconductor layers 110, 120 and the active zone 115. The modification is, for example, such that the generation of light in laterally guided modes is suppressed and the generation of light in free-beam modes, i.e. modes that can be coupled out and propagate essentially vertically, is increased. According to further embodiments, the strength of the light generation in certain modes is only slightly influenced by the pillar structure 108.However, in this case the column structure can ensure efficient light extraction of the generated light.

[0065] Due to the small thickness of the active layer, which corresponds to a maximum of several wavelengths of the emitted radiation, the number of modes can be limited. This enables a selection of the free-jet modes that couple with the active zone 115. As a result, improved directionality is achieved compared with a Lambertian radiator. The described mechanisms can occur depending on the selection of the respective layer thicknesses. For example, both mechanisms can also occur in parallel.

[0066] The described optoelectronic semiconductor component 10 can, for example, be a micro-LED (pLED) with an edge length of less than 10 pm, for example less than 5 pm. The edge length can, for example, be greater than 1 pm or 2 pm.

[0067] Figure 3 shows a cross-sectional view of an optoelectronic semiconductor component according to further embodiments. The individual components in Figure 3 are identical or similar to those shown in Figure 2D. In contrast to the optoelectronic semiconductor component shown in Figure 2D, the contact layer 102 has been partially removed. The region from which the contact layer 102 has been removed overlaps with the active zone 115 in the horizontal direction. With the optoelectronic semiconductor component 10 shown, improved light coupling can be achieved since no optical losses can occur due to absorption in the contact layer 102 or due to unintentional coupling into the waveguide formed by a continuous n-contact layer 102. As also shown in Figure 3, the contacting is made laterally here.This means that the first contact element 113 is arranged in a region that only slightly overlaps the active zone 115 horizontally. Accordingly, a series resistance may be added here by lateral current spreading. For example, the first contact element 113 may be laterally displaced relative to the second contact region 123. For example, the first contact element 113 may only slightly overlap the second contact region horizontally or not at all.

[0068] Figure 4 shows a cross-sectional view of an optoelectronic semiconductor component according to further embodiments. The optoelectronic semiconductor component shown in Figure 4 is similar to that shown in Figure 3. In contrast to the optoelectronic semiconductor component shown in Figure 3, the first contact element 113 directly adjoins the first semiconductor layer 110. This means that in the region of the first contact element 113, the pillars 108 are completely removed. If this variant is used, the semiconductor contact layer 102 of the first conductivity type can be dispensed with, for example in the method described in Figure 1A. For example, in this case the first semiconductor layer 110 can be highly doped in order to achieve contact via the first contact element 113. Furthermore, the pillars 108 can be undoped or only slightly doped.For example, undoped layers exhibit higher light absorption than doped layers. Accordingly, the optical properties can be improved when using undoped columns 108.

[0069] Figure 5 shows a schematic cross-sectional view of an optoelectronic semiconductor component according to further embodiments. Components of the optoelectronic semiconductor component 10 shown in Figure 5 are identical or similar to those of the optoelectronic semiconductor component shown in Figure 4. Deviating from this, a so-called Bragg mirror structure is implemented within the pillars 108. The embodiment of the pillars 108 shown in Figure 5 with a Bragg mirror structure can also be implemented in all other embodiments. For example, the pillars 108 can have first and second layer regions 103, 104. A refractive index in a first layer region 103 can be different from a refractive index in the second layer region 104. Furthermore, the first layer region 103 and the second layer region 104 can be arranged periodically.A period p within which the refractive index changes periodically can satisfy the following relationship:.

[0070] 0 , 4 * X <p <0 , 6 * X, wobei X der Wellenlänge innerhalb des dotierten Halbleitermaterials entspricht .

[0071] The periodic change in the refractive index can be brought about, for example, by changing the concentration of the components of the respective semiconductor layers. For example, when producing an InGaN layer, additional aluminum can be added in a variable proportion. In this way, changes in the refractive index are achievable. In addition, a variation in the dopant concentration can be used. The Bragg structure amplifies the effect of the ordered photonic structure on the optical modes. As a result, the light outcoupling can be increased, which can cause a further improvement in directionality.A combination of the embodiments of the pillars 108 shown in Figure 5 with a Bragg mirror structure and the arrangement of the first contact element 113 in direct contact with the first semiconductor layer 110 leads to a reduction in the electrical resistance between the first contact element 113 and the first semiconductor layer 110 compared to a structure in which the first contact element 113 is connected to the first semiconductor layer 110 via the pillars 108. In the arrangement shown in Figure 5, current conduction through the pillars 108 can be avoided. For example, an electrical conductivity of the pillars can be reduced by generating the Bragg structure. According to further embodiments, the pillars 108 can be undoped or only slightly doped.

[0072] Figure 6A shows a schematic cross-sectional view of an optoelectronic semiconductor component in which the pillars 108 have been removed from a part of the optoelectronic semiconductor component 10. More precisely, the pillars 108 can only extend over a smaller area than the area of ​​the active zone 115. Accordingly, a lateral extent of the region of the pillars 108 is smaller than the lateral extent of the active zone 115. Furthermore, the first contact element 113 is arranged in an edge region of the optoelectronic semiconductor component 10. For example, the first contact element 113 only overlaps with the active zone 115 to a small extent. The electromagnetic radiation which is generated in the active zone in these regions is guided to a large extent in the waveguide formed by the active zone and the surrounding layers and is only coupled out to a small extent in this region.The ordered photonic structure 109 remains only in a partial area of ​​the lateral surface of the active zone 115. The majority of the light extraction occurs in the area of ​​the ordered photonic structure 109. This allows the emission of electromagnetic radiation from the optoelectronic semiconductor component to be concentrated onto a very small area, for example, less than 2, 3, or 5 pm. The emitted electromagnetic radiation can, for example, be better collimated by additional optics, such as microlenses. For example, the pillars 108 can be doped, undoped, or only slightly doped.

[0073] Figure 6B shows a top view of the optoelectronic semiconductor component. As can be seen, the region in which the ordered photonic structure 109 is arranged occupies only a small area. The active zone 115 has a larger lateral extent than the ordered photonic structure 109.

[0074] Figure 6C shows an arrangement of optoelectronic semiconductor components 10 above a common carrier substrate 130. The optoelectronic semiconductor components 10 can be designed as shown in Figures 6A or 6B. Figure 6C further shows microlenses 133 for generating collimated or largely collimated light emission. The emitted electromagnetic radiation 20 has a very small beam cross-section. Such small beam cross-sections are suitable, for example, for use in AR / VR ("Augmented Reality, Virtual Reality"). According to further embodiments, the optoelectronic semiconductor component 10 shown in Figures 2D, 3, 4 and 5 can also be used in the arrangement shown in Figure 6C.

[0075] Figure 7 shows an electronic device according to embodiments. The electronic device 30 comprises one or more optoelectronic semiconductor components 10 as described above. For example, the electronic device may comprise an arrangement or an array of optoelectronic semiconductor components 10. For example, the optoelectronic semiconductor components 10 may be implemented as micro-LEDs. The electronic device 30 may, for example, be an AR / VR device or a display.

[0076] Figure 8 summarizes a method according to embodiments. A method for producing an optoelectronic semiconductor component comprises structuring (S 100) a masking material over a growth substrate so as to produce a pattern of exposed surface regions and epitaxially growing (S 110) a first semiconductor material over the exposed surface regions, wherein pillars are formed in a region facing the growth substrate and a continuous first semiconductor layer of a first conductivity type is formed in a region facing away from the growth substrate.The method further comprises forming (S 120) an active zone over the first semiconductor layer and the pillars, the active zone being suitable for emitting or absorbing electromagnetic radiation, and epitaxially growing (S 130) a second semiconductor layer of a second conductivity type over the active zone. A modal value M (d) of a distance d between centers of the exposed regions satisfies the following condition: dd 1 . 5 * , where X denotes the mean wavelength of the electromagnetic radiation in the first semiconductor material.

[0077] The described manufacturing method makes it possible to produce an optoelectronic semiconductor component with improved luminous efficacy and improved directionality of the light emission. When the optoelectronic semiconductor component is arranged in a pixel array, crosstalk to neighboring pixels is reduced. Furthermore, the light output area is limited. More precisely, in the embodiment shown in Figure 6A or 6B, for example, one luminous area per pixel is reduced. As a result, the emitted electromagnetic radiation can be better collimated by additional optics, for example, microlenses.

[0078] Although specific embodiments have been illustrated and described herein, those skilled in the art will recognize that a variety of alternative and / or equivalent embodiments may be substituted for the specific embodiments shown and described without departing from the scope of the invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, the invention is limited only by the claims and their equivalents.

[0079] LIST OF REFERENCE SYMBOLS optoelectronic semiconductor component emitted electromagnetic radiation electronic device growth substrate semiconductor contact layer of the first conductivity type first layer region of the column second layer region of the column structured masking material exposed surface region defect column ordered photonic structure first semiconductor layer first main surface of the first semiconductor layer first contact region first contact element insulation layer active zone workpiece second semiconductor layer second main surface of the first semiconductor layer mesa structure second contact region insulation layer mirror layer solder material carrier substrate lens

Claims

CLAIMS 1. Method for producing an optoelectronic Semiconductor component (10) comprising: Structuring (S100) a masking material (105) over a growth substrate (100) so that a pattern of exposed surface regions (106) is created; epitaxially growing (S110) a first semiconductor material over the exposed surface regions (106), wherein pillars (108) are formed in a region facing the growth substrate (100), and a continuous first semiconductor layer (110) of a first conductivity type is formed in a region facing away from the growth substrate (100); Forming (S120) an active zone (115) over the first semiconductor layer (110) and the pillars (108), wherein the active zone (115) is suitable for emitting or absorbing electromagnetic radiation (20); and epitaxially growing (S130) a second semiconductor layer (120) of a second conductivity type over the active zone (115), Applying a carrier substrate (130) over the second semiconductor layer (120); and Detaching the growth substrate (100) so that the columns (108) are arranged in the region of a first main surface of a resulting workpiece (118), wherein a modal value M(d) of a distance d between centers of the exposed regions (106) satisfies the following condition: M(d) < 1.5 * , where X is the mean wavelength of the electromagnetic radiation in the first semiconductor material .

2. The method of claim 1, wherein the semiconductor material contains InGaN.

3. The method according to claim 2, wherein an In content of the semiconductor material increases with increasing distance from the growth substrate (100).

4. Method according to one of the preceding claims, wherein the following relationship applies to the modal value M(d): 0.4 * X < M (d) < 0.6 * .

5. The method according to any one of the preceding claims, wherein the first semiconductor material is grown such that a refractive index of the doped semiconductor material is changed.

6. The method of claim 5, wherein the refractive index of the first semiconductor material changes periodically.

7. The method according to claim 6, wherein a period p within which the refractive index changes periodically satisfies the following relationship: 0.4 * X <p <0, 6 * X, wobei X der Wellenlänge innerhalb des ersten Halbleitermaterials entspricht.

8. The method according to any one of the preceding claims, further comprising removing the pillars (108) from a portion of the optoelectronic semiconductor device (10).

9. The method according to claim 8, wherein the columns (108) consist of a region of the optoelectronic semiconductor component, which does not overlap horizontally with the active area (115) must be removed.

10. The method according to claim 8 or 9, wherein the columns (108) are removed from a region of the optoelectronic semiconductor component which horizontally overlaps with the active region (115).

11. The method according to any one of claims 8 to 10, further comprising forming a first contact element (113) in a region from which the pillars (108) have been removed.

12. The method according to any one of the preceding claims, further comprising depositing a contact layer (102) of the first conductivity type over the growth substrate (100), wherein the masking layer (105) is deposited over the contact layer (102) and the first semiconductor material is grown over the contact layer (102).

13. The method of claim 12, wherein the growth substrate (100) is removed after applying the carrier substrate (130) over the second semiconductor layer (120), further comprising removing at least a portion of the contact layer (102) after removing the growth substrate (100).

14. Optoelectronic semiconductor component (10), comprising: a first semiconductor layer (110) of a first conductivity type; a second semiconductor layer (120) of a second conductivity type, and an active zone (115) suitable for emitting electromagnetic radiation between the first and the second semiconductor layer (110, 120), wherein the first Semiconductor layer (110), the active zone (115) and the second semiconductor layer (120) are arranged to form a semiconductor layer stack and the active zone (115) borders on a second main surface (121) of the first semiconductor layer, and an ordered photonic structure (109) above a first main surface (111) of the first semiconductor layer (110), wherein the ordered photonic structure (109) directly borders on the first semiconductor layer (110), is arranged above the active zone (115) and comprises pillars (108) containing a semiconductor material of the first semiconductor layer (110), wherein a modal value M(d) of a distance d between centers of the pillars (108) satisfies the following condition: dd 1.5 * , where X denotes the mean wavelength of the electromagnetic radiation (20) in the semiconductor material of the first semiconductor layer (110).

15. Optoelectronic semiconductor component (10) according to claim 14, wherein the semiconductor material contains InGaN.

16. Optoelectronic semiconductor component (10) according to claim 15, wherein an In content of the semiconductor material of the pillars decreases with increasing distance from the first semiconductor layer (110).

17. Optoelectronic semiconductor component (10) according to one of claims 14 to 16, wherein the following relationship applies to the modal value M(d) of the distance d: 0.4 * X < dd 0.6 * .

18. Optoelectronic semiconductor component (10) according to one of claims 14 to 17, wherein a defect density in the columns (108) increases with increasing distance from the first semiconductor layer (110).

19. Optoelectronic semiconductor component (10) according to one of claims 14 to 18, wherein the pillars (108) are removed from a part of the optoelectronic semiconductor component.

20. Optoelectronic semiconductor component (10) according to claim 19, wherein a part of the optoelectronic semiconductor component present in the columns (108) is smaller than a horizontal extent of the active zone (115).

21. Optoelectronic semiconductor component (10) according to claim 19 or 20, further comprising a first contact element (113) electrically connected to the first semiconductor layer (110), wherein the first contact element (113) is arranged in the part of the optoelectronic semiconductor component (10) from which the pillars (108) are removed.