OPTOELECTRONIC SEMICONDUCTOR DEVICE AND ITS MANUFACTURING PROCESS

Abstract

Optoelectronic semiconductor device (10), comprising: one carrier (100); a first semiconductor layer (110) of a first conductivity type; a second semiconductor layer (120) of a second conductivity type, wherein the first and second semiconductor layers (110, 120) are stacked on top of each other, such that the second semiconductor layer (120) is arranged between the first semiconductor layer (110) and the support (100); a first contact structure (105); a contact layer (109) which is arranged over a side of the first semiconductor layer (110) facing away from the second semiconductor layer (120) and is connected to the first semiconductor layer (110); a separating layer (108) arranged above a side of the contact layer (109) facing away from the first semiconductor layer (110); and a current expansion layer (107) arranged above a side of the separating layer (108) facing away from the contact layer (109), wherein the first contact structure (105) is connected to the contact layer (109) via the current expansion layer (107) and the separation layer (108), the separating layer (108) is present as a continuous layer in a region between the contact layer (109) and the current expansion layer (107) and the separating layer (108) has a lower conductivity than the current expansion layer, and a layer stack containing the contact layer (109), the separating layer (108) and the current expansion layer (107) exhibits anisotropic conductivity.

Description

[0001] This patent application claims priority from German patent application DE 10 2019 100 799.2, the disclosure of which is hereby incorporated by reference.

[0002] A light-emitting diode (LED) is a light-emitting device based on semiconductor materials. For example, an LED contains a pn junction. When electrons and holes recombine in the region of the pn junction, for example, when a corresponding voltage is applied, electromagnetic radiation is generated.

[0003] Further light-emitting diodes are known from the documents US 2012 / 0 305 061 A1, WO 2008 / 082 244 A1, DE 10 2013 101 529 A1, US 2005 / 0 139 825 A1 and DE 10 2005 046 190 A1.

[0004] In general, concepts are being researched that can improve current supply to the semiconductor layers. Furthermore, concepts that make optoelectronic semiconductor components less complex to manufacture are being explored.

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

[0006] According to the present invention, the object is achieved by the subject matter and method of the independent patent claims. Advantageous further developments are defined in the dependent patent claims. SUMMARY

[0007] An optoelectronic semiconductor component comprises a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type, wherein the first and second semiconductor layers are stacked one above the other. The optoelectronic semiconductor component further comprises a first contact structure and a contact layer arranged over a side of the first semiconductor layer facing away from the second semiconductor layer and connected to the first semiconductor layer. The optoelectronic semiconductor component further contains a separation layer arranged over a side of the contact layer facing away from the first semiconductor layer, and a current spreading layer arranged over a side of the separation layer facing away from the contact layer. The first contact structure is connected to the contact layer via the current spreading layer and the separation layer.A layer stack containing the contact layer, the separation layer, and the current-spreading layer exhibits anisotropic conductivity. The separation layer is present as a continuous layer in a region between the contact layer and the current-spreading layer.

[0008] For example, the separation layer can be an insulating layer with a layer thickness of less than 10 nm. In particular, the layer thickness of the separation layer can be in a range of 0.5 to 5 nm.

[0009] According to further embodiments, the separation layer may comprise a dielectric layer with a conductive additive.

[0010] Furthermore, the separating layer can comprise a dielectric layer with locally increased electrical conductivity.

[0011] According to further embodiments, an optoelectronic semiconductor component may comprise a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type, wherein the first and second semiconductor layers are stacked one above the other. The optoelectronic semiconductor component further comprises a first contact structure and a contact layer arranged over a side of the first semiconductor layer facing away from the second semiconductor layer and connected to the first semiconductor layer. The optoelectronic semiconductor component further includes a separation layer arranged over a side of the contact layer facing away from the first semiconductor layer, and a current spreading layer arranged over a side of the separation layer facing away from the contact layer.The first contact structure is connected to the contact layer via the current spreading layer and the separation layer. A layer stack containing the contact layer, the separation layer, and the current spreading layer exhibits anisotropic conductivity. The separation layer comprises a conductive transparent oxide with a conductivity that is lower than the conductivity of the material of the current spreading layer.

[0012] According to embodiments, a specific resistance of the separation layer may be greater than 10, 100, or 1000 times the specific resistance of the current spreading layer. For example, a material of the separation layer may be selected from metal atom-doped TiO2, β-Ga2O3, undoped or doped ZnO, undoped or doped SnO2, NbO, MnO, MoO, or combinations of these materials.

[0013] According to further embodiments, an optoelectronic semiconductor component comprises a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type, wherein the first and second semiconductor layers are stacked one above the other. The optoelectronic semiconductor component further comprises a first contact structure and a contact layer arranged over a side of the first semiconductor layer facing away from the second semiconductor layer and connected to the first semiconductor layer. The optoelectronic semiconductor component further contains a separation layer arranged over a side of the contact layer facing away from the first semiconductor layer, and a current spreading layer arranged over a side of the separation layer facing away from the contact layer. The first contact structure is connected to the contact layer via the current spreading layer and the separation layer.A layer stack containing the contact layer, the separation layer, and the current spreading layer exhibits anisotropic conductivity. The separation layer comprises a dielectric layer, wherein a plurality of pores are arranged in the dielectric layer, and the pores are at least partially filled with a conductive material.

[0014] For example, the pores can have a largest dimension of less than 0.5 µm. The pore spacing can be less than 10 µm, for example, less than 1 µm.

[0015] A method for producing an optoelectronic semiconductor component comprises forming a semiconductor layer stack having a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type, and forming a contact layer after forming the first semiconductor layer, wherein the contact layer is connected to the first semiconductor layer. The method further comprises forming a separation layer after forming the contact layer and forming a current spreading layer after forming the separation layer. A first contact structure is connected to the contact layer via the current spreading layer and the separation layer. A layer stack containing the contact layer, the separation layer, and the current spreading layer has anisotropic conductivity.The separation layer is present as a continuous layer in an area between the contact layer and the current spreading layer.

[0016] For example, forming the separation layer may include performing an ALD process to form a dielectric layer.

[0017] According to embodiments, the separation layer may be formed at a shallow angle. For example, the separation layer may be formed using a GLAD (glanced angle deposition) process. For example, forming the separation layer may include forming a conductive transparent oxide with a conductivity lower than the conductivity of the current spreading layer material.

[0018] For example, the separation layer can be formed as a dielectric layer. Subsequently, the conductivity of the dielectric layer can be locally increased by laser irradiation.

[0019] According to all embodiments described here, a layer thickness of the current spreading layer can be greater than a layer thickness of the contact layer. For example, the layer thickness of the contact layer can be 5 to 25 nm. The layer thickness of the current spreading layer can be, for example, 30 to 150 nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings 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 become apparent from the following detailed description. The elements and structures shown in the drawings are not necessarily drawn to scale. Like reference numerals refer to like or corresponding elements and structures. Fig. 1A shows a cross-sectional view of an optoelectronic semiconductor device according to embodiments. Fig. 1B shows an enlarged cross-sectional view of a portion of the optoelectronic semiconductor device. Fig. 2A shows a schematic cross-sectional view of a portion of an optoelectronic semiconductor device according to embodiments. Fig. 2B shows a schematic cross-sectional view of a portion of an optoelectronic semiconductor device according to embodiments. Fig. Figure 2C shows a schematic cross-sectional view of a portion of an optoelectronic semiconductor device. Fig. 3A shows a schematic layout of an optoelectronic semiconductor device according to embodiments. Fig. 3B shows a cross-sectional view of the optoelectronic semiconductor device according to embodiments. Fig. 3C shows a schematic layout of an optoelectronic semiconductor device according to further embodiments. Fig. 4 summarizes a method according to embodiments. DETAILED DESCRIPTION

[0021] 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 not limiting in any way.

[0022] The description of the embodiments is not limiting, as other embodiments exist and structural or logical changes may be made. In particular, elements of embodiments described below may be combined with elements of other described embodiments, unless the context indicates otherwise.

[0023] 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 understood to include 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 or of an insulating material, for example, on a sapphire substrate. Other examples of growth substrate materials include glass, silicon dioxide, quartz, or a ceramic.

[0024] Depending on the intended use, the semiconductor can be based on a direct or indirect semiconductor material. Examples of semiconductor materials particularly suitable for generating electromagnetic radiation include, in particular, nitride semiconductor compounds, which can generate ultraviolet, blue, or longer-wavelength light, for example, such as GaN, InGaN, AlN, AlGaN, AlGaInN, AlGaInBN; phosphide semiconductor compounds, which can generate green or longer-wavelength light, for example, such as GaAsP, AlGaInP, GaP, AlGaP; and other semiconductor materials such as GaAs, AlGaAs, InGaAs, AlInGaAs, SiC, ZnSe, ZnO, Ga2O3, diamond, hexagonal BN, and combinations of the aforementioned materials. 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.

[0025] The term “substrate” generally includes insulating, conductive or semiconductor substrates.

[0026] 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).

[0027] The horizontal direction can, for example, lie in a plane perpendicular to a growth direction when growing layers.

[0028] 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.

[0029] Where the terms "have," "contain," "comprise," "have," and the like are used here, these are open terms that indicate the presence of the elements or characteristics in question, but do not exclude the presence of further elements or characteristics. The indefinite and definite articles include both the plural and the singular, unless the context clearly indicates otherwise.

[0030] In the context of this description, the term "electrically connected" means a low-resistance electrical connection between the connected elements. The electrically connected elements do not necessarily have to be directly connected to each other. Additional elements can be arranged between the electrically connected elements.

[0031] The term “electrically connected” also includes tunnel contacts between the connected elements.

[0032] Fig. 1A shows a vertical cross-sectional view of an optoelectronic semiconductor device according to embodiments. Fig. The optoelectronic semiconductor component 10 shown in Figure 1A can be, for example, a light-emitting diode (LED). A first semiconductor layer 110 and a second semiconductor layer 120 are arranged above a suitable carrier 100. For example, the first semiconductor layer 110 can be doped with a first conductivity type, for example, p-type, and the second semiconductor layer 120 can be of a second conductivity type, for example, n-type. For example, the first and second semiconductor layers 110, 120 are based on a nitride compound semiconductor material. An active zone 115 can be arranged between the first semiconductor layer 110 and the second semiconductor layer 120.

[0033] The active zone can, for example, contain 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" has no bearing on 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.

[0034] For example, the second semiconductor layer 120 can be arranged between the first semiconductor layer 110 and a suitable carrier 100. For example, the carrier 100 can be a growth substrate for the semiconductor layer sequence. Suitable materials for the growth substrate or the carrier can include, for example, sapphire, silicon carbide, or gallium nitride. A contact layer 109 made of an electrically conductive material can be arranged above the first semiconductor layer 110. For example, the contact layer 109 can be composed of a conductive oxide, a so-called "TCO ("Transparent Conductive Oxide"). Examples include, in particular, ITO (indium tin oxide), IZO (indium zinc oxide), or another transparent conductive material. The contact layer 109 can, for example, directly adjoin the first semiconductor layer 110.

[0035] A separation layer 108 is arranged on a side of the contact layer 109 facing away from the first semiconductor layer 110. A current spreading layer 107 is arranged above a side of the separation layer 108 facing away from the contact layer 109. The layer stack containing the contact layer 109, the separation layer 108, and the current spreading layer 107 has anisotropic conductivity. For example, the resistivity of the layer stack is smaller in a horizontal direction than in a vertical direction. According to embodiments, the layer stack may consist of the contact layer 109, the separation layer 108, and the current spreading layer. According to further embodiments, the layer stack may be bounded by the contact layer 109 and the separation layer 108. The layer stack thus has a greater transverse conductivity than vertical conductivity.For example, this can be realized by having the separation layer 108 with a lower conductivity than the current spreading layer 107.

[0036] Specific realizations of the separation layer 108 are described below with reference to the Fig. 1B and 2A to 2C. According to embodiments, the separation layer may be constructed from one or more layers.

[0037] According to embodiments, the separating layer 108 is present as a continuous layer in a region between the contact layer 109 and the current spreading layer 107. For example, no special via openings can be formed in this region, via which electrical contact can be established between the contact layer 109 and the current spreading layer 107.

[0038] Furthermore, the Fig. The optoelectronic semiconductor component 10 shown in Figure 1A has a first contact structure 105. The first contact structure 105 is connected to the contact layer 109 via the current spreading layer 107 and the separation layer 108.

[0039] The current spreading layer 107 is constructed of a transparent conductive material, for example a conductive metal oxide such as ITO or IZO.

[0040] According to all embodiments described here, a layer thickness of the current spreading layer 107 may be greater than a layer thickness of the contact layer 109. For example, the layer thickness of the contact layer 109 may be 5 to 25 nm. The layer thickness of the current spreading layer 107 may be, for example, 30 to 150 nm.

[0041] In the Fig. In the optoelectronic semiconductor component illustrated in Figure 1A, the functions of current distribution and electrical contact are separated from one another. More precisely, a thin contact layer 109 is arranged in contact with the first semiconductor layer 110 over the entire surface or a large area. Due to its smaller layer thickness, the thin contact layer 109 has a reduced transverse conductivity. Conversely, less electromagnetic radiation is absorbed due to the smaller layer thickness. The thicker current spreading layer 107 results in improved transverse conductivity. Radiation losses can be reduced, for example, via the separating layer 108, as described with reference to Fig. 2A and Fig. 2B will be explained.

[0042] For example, the semiconductor layer stack can be structured into a mesa 121. Accordingly, a part of a first main surface 119 of the second semiconductor layer 120 can be exposed. A second electrical contact element 126 can, for example, contact the second semiconductor layer 120 in the region of an exposed first main surface 119. For example, the second contact element 126 can be connected to the second semiconductor layer 120 via a conductive material 124. An insulating material 129 can be arranged between the second contact element 126 and the underlying semiconductor material 120. For example, in the case of the Fig. 1A, the part located to the left of the second contact element 126 may be continued on the right side of the second contact element 126.

[0043] By applying a voltage between the first contact structure 105 and the second contact element 126, a current can be impressed into the optoelectronic semiconductor component. This can cause the emission of electromagnetic radiation 20, for example, via a first main surface 102 of the first semiconductor layer 110. In general, the more uniform this current is, the higher the achievable light yield.

[0044] The optoelectronic semiconductor component 10 may further comprise a passivation layer 103, which may, for example, be arranged over the current spreading layer 107. The passivation layer may, for example, also be arranged over the sidewalls 122 of the mesa 121 and may be arranged completely over the first main surface 102 of the first semiconductor layer 110 and over exposed regions of the second semiconductor layer 120. The passivation layer may be formed from a material with a lower refractive index than the refractive index of the current spreading layer 107. For example, the passivation layer may contain silicon oxide.

[0045] According to embodiments, the separation layer 108 can be realized by a very thin insulating layer with a lower conductivity than the current spreading layer. Fig. 1B shows a schematic cross-sectional view of the layer stack comprising contact layer 109, separation layer 108, and current spreading layer 107. For example, separation layer 108 can be only a few monolayers thick. Possible materials for the separation layer include, for example, Al2O3, SiO2, Si3N4, TiO2, TaO, Nb2O5, or combinations of these materials, wherein the stoichiometric ratios can also be different than specified. For example, in this case, the separation layer can have a layer thickness of less than 10 nm. For example, the insulating layer can have a layer thickness greater than 0.5 nm. According to embodiments, this separation layer 108 can be deposited using an ALD (atomic layer deposition) method. The thickness can be adjusted very precisely, even for very thin layers. Furthermore, surface roughnesses above contact layer 109 can be well molded over.As a result, a separation layer 108 is provided that is uniformly insulating or uniformly low-conductivity in the vertical direction. For example, charge carriers can tunnel through the thin insulating layer 108. As a result, the separation layer 108 has a lower conductivity than the contact layer 109 and the current spreading layer 107. Accordingly, the layer stack comprising contact layer 109, separation layer 108, and current spreading layer 107 has anisotropic conductivity, i.e., a significantly greater transverse conductivity than vertical conductivity.

[0046] According to further embodiments, the separation layer 108 can be designed such that, in addition to the electrical property of low conductivity, it also has an optical function. The main objective here is to reduce absorption, essentially through the total reflection of flat rays in the separation layer. A further objective is to increase transmission in a relevant angular range. This can be achieved, for example, by the separation layer 108 having a minimum layer thickness and a refractive index that is adapted, for example, to the refractive index of the passivation layer 103. For example, a minimum layer thickness of the separation layer can be 20 nm. The separation layer 108 can have several individual layers with different refractive indices and layer thicknesses.

[0047] Fig. 2A shows a cross-sectional view through the layer stack of contact layer 109, separation layer 108, and current spreading layer 107 according to further embodiments. As in Fig. 2A, the separation layer 108 has a minimum thickness d3 of, for example, 20 to 800 nm. For example, the separation layer can comprise a conductive transparent oxide with a conductivity that is lower than the conductivity of the current spreading layer 107, for example indium tin oxide. Furthermore, in this case, the material of the separation layer can have a lower absorption capacity than the current spreading layer 107 and the contact layer 109. For example, the separation layer can contain TiO2 doped with metal atoms. For example, the TiO2 can be doped with niobium. According to further embodiments, the separation layer 108 can contain β-Ga2O3, undoped or doped ZnO, undoped or doped SnO2, NbO, MnO, or MoO.

[0048] According to embodiments, in these cases the refractive index or refractive index profile can be adjusted or reduced by deposition at shallow angles (oblique angle deposition or glazing angle deposition (GLAD)). As a result, the total internal reflection of flat rays can be achieved in an improved manner. In this method, the surface of a workpiece over which the layer is to be deposited is arranged at a specific angle relative to the direction of incidence of the material to be grown. For example, the material can be deposited at a shallow angle of less than 45° relative to the horizontal surface of the semiconductor layers. With such a geometry, for example, shadowing effects can occur due to grown regions. As a result, a layer is not deposited continuously but in a columnar manner. Defects or pores can form between adjacent columns.As a result, the deposited layer has a lower refractive index than the bulk material. This type of separation layer 108 is described below with reference to FIG. Fig. 2B will be shown in more detail.

[0049] Alternatively, the separation layer 108 can also be constructed from a dielectric, insulating material in which defects or pores are formed. The dielectric, insulating material can contain, for example, silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, or combinations of these materials. The pores are partially filled with a conductive material, for example, a transparent conductive oxide. For example, only some of the pores, for example, pores with a certain minimum diameter, can be filled with conductive material. For example, pores can also be incompletely filled. For example, ITO, which is deposited using an ALD process, can be used as the conductive material. According to further embodiments, doped or undoped SnO2, which is deposited, for example, using a CVD process, can also be used.Subsequently, for example, the current spreading layer 107 can also be deposited using an ALD process or a PVD (“Physical Vapor Deposition”) process.

[0050] For example, the pores can have a largest horizontal dimension of less than 0.5 µm. The pore spacing can be less than 10 µm, for example, less than 1 µm.

[0051] According to further embodiments, the separation layer 108 may comprise a dielectric layer, for example as mentioned above, with a conductive additive.

[0052] Fig. Figure 2B shows a cross-sectional view of the layer stack of contact layer 109, isolation layer 108, and current spreading layer 107 over a semiconductor body comprising the first semiconductor layer and the second semiconductor layer. Here, isolation layer 108 is deposited by shallow-angle deposition. Fig. 2B shows the columnar structures 113 resulting from this type of deposition, separated from each other by defects or pores 112.

[0053] This results in a reduced optical refractive index for the separation layer compared to a separation layer without columnar structures 113. As a result, the separation layer 108 may be suitable for reflecting electromagnetic radiation 20 emitted by the semiconductor layer stack, which would be emitted at shallow angles, back into the semiconductor layer stack.

[0054] According to further embodiments, it is possible to locally increase the conductivity of the separation layer 108.

[0055] Fig. 2C shows a schematic cross-sectional view of the layer stack of contact layer 109, separation layer 108 and current distribution layer 107. According to Fig. 2C, the conductivity of the separation layer 108 is locally increased in region 123. For example, this post-treatment can comprise local laser irradiation. As a result, for example, a portion of the current spreading or contact layer can diffuse into the separation layer 108 and lead to a local current path there. According to further embodiments, for example, if a material of the separation layer 108 comprises a transparent conductive oxide, the material of the separation layer can be locally annealed, thereby increasing the conductivity. Furthermore, the material of the separation layer 108 can be modified by the local treatment. For example, the stoichiometry of the material of the separation layer 108 can be locally modified.

[0056] As described, the special design of the separation layer provides a separation layer with a high but defined resistance. As a result, the layer stack comprising contact layer 109, separation layer 108, and current spreading layer 107 has a high conductivity in the lateral direction. Furthermore, the layer stack has a limited conductivity in the vertical direction. In this way, it is possible to prevent so-called current crowding in the region of the contact structure 105. More precisely, the presence of the separation layer spreads the current over a larger horizontal area and does not concentrate it solely in the area immediately adjacent to the first contact structure 105. As a result, current injection and thus light emission can be homogenized.Because the separation layer 108 has a finite conductivity in the vertical direction, electrical contact between the current distribution layer 107 and the contact layer 109 can be achieved without increased technological complexity. In addition, it is possible for the separation layer 108 to fulfill an optical function, as described.

[0057] Fig. 3A shows a schematic layout of an optoelectronic semiconductor component 10 according to embodiments. Here, for example, the first contact structure 105 is formed as a contact finger. The contact finger can be rectangular, annular, or arcuate. However, any other configurations of this contact finger are possible. For example, it can be comb-shaped or similar to the veining of a leaf. Furthermore, the first contact structure 105 can have a plurality of contact fingers, which can be identical or different from one another. The first contact structure 105 can be electrically connected via a first contact element 106. Furthermore, the optoelectronic semiconductor component 10 comprises a second contact element 126.

[0058] According to Fig. 3A, for example, a first contact structure 105 for electrically contacting the first semiconductor layer 110 and a second contact structure (not shown in Fig. 3A) in the vertical direction one above the other. This is explained with reference to Fig. 3B. The second contact element 126 can, for example, be arranged at a corner position of the rectangle, diagonally opposite the first contact element 106. For example, the contacting of the second semiconductor layer can occur at a location that is surrounded on both sides by the first semiconductor layer 110.

[0059] Fig. Figure 3B shows a schematic cross-sectional view of the optoelectronic semiconductor device between I and I', as shown in Fig. 3A. The second semiconductor layer 120 and the first semiconductor layer 110 and, if applicable, the active zone 115 are arranged above the carrier 100. A part of the first semiconductor layer 110 and of the active zone 115 is removed in places, so that a part of the first surface 119 of the second semiconductor layer 120 is exposed. A second contact structure 125 is arranged in this region. Parts of the first and second semiconductor layers 110, 120 are each arranged on both sides of the second contact structure 125. The second contact structure 125 is enclosed, for example, on three sides by an insulating material 129, so that the second contact structure 125 is electrically insulated from the adjacent current spreading layer 107 and the adjacent first semiconductor layer 110. For example, the second contact structure 125 contains a metal.The first contact structure 105 can be arranged vertically above the second contact structure 125. In this way, absorption losses of the emitted electromagnetic radiation by the contact structures can be reduced. The first semiconductor layer 110 is electrically connected to the current spreading layer 107 and the first contact structure 105 via the contact layer 109 and the isolation layer 108.

[0060] Fig. 3C shows a schematic layout of a portion of an optoelectronic semiconductor device according to further embodiments. As in Fig. 3C, the first contact structure 105 and the second contact structure 125 can also be implemented in spatially separated regions, wherein, for example, the semiconductor layer stack comprising the first semiconductor layer 110 and the second semiconductor layer 120 is structured into a mesa. In this case, a part of the first main surface 119 of the second semiconductor layer 120 is exposed, as also shown in Fig. 1A. As shown in Fig. For example, as shown in Figure 3C, the first contact structure 105 may be electrically connected via a first contact element 106. The second contact structure 125 may be electrically connected via a second contact element 126.

[0061] Fig.4 illustrates a method for producing an optoelectronic semiconductor component. The method comprises forming (S100) a semiconductor layer stack comprising a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type. The method further comprises forming (S110) a contact layer after forming the first semiconductor layer, wherein the contact layer is connected to the first semiconductor layer. The method further comprises forming a separation layer (S120) after forming the contact layer and forming (S130) a current spreading layer after forming (S120) the separation layer. In this case, a first contact structure is connected to the contact layer via the current spreading layer and the separation layer. Furthermore, a layer stack containing the contact layer, the separation layer, and the current spreading layer has anisotropic conductivity.The separating layer (108) is present as a continuous layer in a region between the contact layer (109) and the current spreading layer (107).

[0062] For example, forming the separation layer may include performing an ALD process to form a dielectric layer. For example, the dielectric layer may be formed with a layer thickness of 0.5 to 5 nm.

[0063] As described, the described method can achieve a more homogeneous electrical contact with the first semiconductor layer without requiring complex technological processes, such as defining contact holes in the separation layer. Accordingly, the manufacturing process for the optoelectronic semiconductor component can be simplified. LIST OF REFERENCE SYMBOLS 10 Optoelectronic semiconductor component 15 Optoelectronic semiconductor component 20 emitted electromagnetic radiation 25 optoelectronic device 100 carriers 102 first main surface of the first semiconductor layer 103 Passivation layer 105 first contact structure 106 first contact element 107 Current spreading layer 108 Separating layer 109 Contact layer 110 first semiconductor layer 112 pores 113 columnar structure 115 active zone 119 first main surface of the second semiconductor layer 120 second semiconductor layer 121 Mesa 122 Side wall of the mesa 123 Area with increased conductivity 124 conductive material 125 second contact structure 126 second contact element 129 insulating material

Claims

[1] Optoelectronic semiconductor component (10), comprising: a carrier (100); a first semiconductor layer (110) of a first conductivity type; a second semiconductor layer (120) of a second conductivity type, wherein the first and second semiconductor layers (110, 120) are stacked one above the other such that the second semiconductor layer (120) is arranged between the first semiconductor layer (110) and the carrier (100); a first contact structure (105); a contact layer (109) arranged over a side of the first semiconductor layer (110) facing away from the second semiconductor layer (120) and connected to the first semiconductor layer (110); a separating layer (108) arranged over a side of the contact layer (109) facing away from the first semiconductor layer (110); and a current spreading layer (107) arranged over a side of the separating layer (108) facing away from the contact layer (109), wherein the first contact structure (105) is connected to the contact layer (109) via the current spreading layer (107) and the separating layer (108), the separating layer (108) is present as a continuous layer in a region between the contact layer (109) and the current spreading layer (107) and the separating layer (108) has a lower conductivity than the current spreading layer, and a layer stack containing the contact layer (109), the separation layer (108) and the current spreading layer (107) has an anisotropic conductivity. [2] Optoelectronic semiconductor component (10) according to claim 1, wherein the separating layer (108) is an insulating layer with a layer thickness of less than 10 nm. [3] Optoelectronic semiconductor component (10) according to claim 2, wherein a layer thickness of the separating layer (108) is in a range of 0.5 to 5 nm. [4] Optoelectronic semiconductor component (10) according to one of the preceding claims, in which no via openings are formed in the separation layer (108). [5] Optoelectronic semiconductor component (10) according to claim 1, wherein the separation layer (108) comprises a dielectric layer with a conductive additive. [6] Optoelectronic semiconductor component (10) according to claim 1, wherein the separation layer (108) comprises a dielectric layer with locally increased electrical conductivity. [7] Optoelectronic semiconductor component (10), comprising: a carrier (100); a first semiconductor layer (110) of a first conductivity type; a second semiconductor layer (120) of a second conductivity type, wherein the first and second semiconductor layers (110, 120) are stacked one above the other such that the second semiconductor layer (120) is arranged between the first semiconductor layer (110) and the carrier (100); a first contact structure (105); a contact layer (109) arranged over a side of the first semiconductor layer (110) facing away from the second semiconductor layer (120) and connected to the first semiconductor layer (110); a separating layer (108) arranged over a side of the contact layer (109) facing away from the first semiconductor layer (110); and a current spreading layer (107) arranged over a side of the separating layer (108) facing away from the contact layer (109), wherein the first contact structure (105) is connected to the contact layer (109) via the current spreading layer (107) and the separating layer (108), the separation layer (108) comprises a dielectric layer, wherein a plurality of pores (112) are arranged in the dielectric layer and the pores (112) are at least partially filled with a conductive material, and a layer stack containing the contact layer (109), the separation layer (108) and the current spreading layer (107) has an anisotropic conductivity. [8] Optoelectronic semiconductor component (10) according to claim 7, wherein the pores (112) have a largest dimension which is less than 0.5 µm. [9] Optoelectronic semiconductor component (10) according to claim 7 or 8, wherein the pores (112) have a spacing of less than 10 µm. [10] Optoelectronic semiconductor component (10) according to one of the preceding claims, wherein a layer thickness of the current spreading layer (107) is greater than the layer thickness of the contact layer (109). [11] Optoelectronic semiconductor component (10) according to one of the preceding claims, wherein the layer thickness of the contact layer (109) is 5 to 25 nm. [12] Optoelectronic semiconductor component (10) according to one of the preceding claims, wherein the layer thickness of the current spreading layer (107) is 30 to 150 nm. [13] Method for producing an optoelectronic semiconductor component (10) with Forming (S100) a semiconductor layer stack comprising a first semiconductor layer (110) of a first conductivity type and a second semiconductor layer (120) of a second conductivity type over a carrier (100) such that the second semiconductor layer (120) is arranged between the first semiconductor layer (110) and the carrier (100); Forming (S110) a contact layer (109) after forming the first semiconductor layer (110), wherein the contact layer (109) is connected to the first semiconductor layer (110); Forming (S120) a separating layer (108) after forming the contact layer; and Forming a current spreading layer (107) after forming the separation layer (108), wherein a first contact structure (105) is connected to the contact layer (109) via the current spreading layer (107) and the separating layer (108) and a layer stack containing the contact layer (109), the separating layer (108) and the current spreading layer (107), has an anisotropic conductivity and the separating layer (108) is present as a continuous layer in a region between the contact layer (109) and the current spreading layer (107) and the separating layer (108) has a lower conductivity than the current spreading layer. [14] The method of claim 13, wherein forming the separation layer (108) comprises performing an ALD process to form a dielectric layer. [15] Method according to claim 14, wherein the separating layer (108) is formed by a GLAD process (“glanced angle deposition”). [16] The method of any one of claims 13 to 15, wherein forming the separation layer (108) comprises forming a conductive transparent oxide having a conductivity lower than the conductivity of the material of the current spreading layer (107). [17] Method according to claim 13, wherein the separating layer (108) is formed as a dielectric layer and subsequently a conductivity of the dielectric layer is locally increased by means of laser irradiation.

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