Optoelectronic component, semiconductor structure, and methods related thereto

Abstract

To provide an optoelectronic component which enhances quantum well intermixing.SOLUTION: A semiconductor structure comprises an n-doped first layer, a p-doped second layer doped with a first dopant, and an active layer arranged between the n-doped first layer and the p-doped second layer and having at least one quantum well. The active layer of the semiconductor structure is divided into a multiplicity of first optically active regions, at least one second region, and at least one third region. In this case, the plurality of first optically active regions are arranged at a distance from one another in a hexagonal pattern. The at least one quantum well in the active region has a greater band gap in the at least one second region than in the multiplicity of first optically active regions and the at least one third region. The band gap is modified by quantum well intermixing, in particular. The at least one second region encloses the multiplicity of first optically active regions.SELECTED DRAWING: Figure 6A

Description

[Technical field]

[0001] This patent application claims the priority of German Patent Application Publication No. 102019125349.7, filed September 20, 2019, German Patent Application Publication No. 102019127425.7, filed October 11, 2019, and International Application No. PCT / EP2020 / 052191, filed January 29, 2020, the disclosures of which are incorporated herein by reference.

[0002] Background technology The present invention relates to the fabrication of semiconductor structures for improving the low current efficiency of optoelectronic lighting devices, and to methods for their manufacture.The present invention further relates to optoelectronic component structures.

[0003] For various applications, optoelectronic components, i.e. so-called light-emitting diodes, must have sufficient brightness, i.e. be able to withstand relatively high current densities, while at the same time being highly or even highly efficient at low currents.

[0004] One measure to improve low-current operation is quantum well intermixing, which is used in various domains. In this case, the band gap of an active layer configured as a quantum well is changed by exchanging lattice atoms between this region and the barrier material surrounding it. This exchange process can be made particularly efficient if suitable impurity atoms, in particular doping atoms, are introduced into the semiconductor.

[0005] Such localized impurity diffusion and / or quantum well intermixing by impurities is an established technique for improving the performance of optoelectronic components, for example to reduce contact resistance, create transparent window regions for lasers, or reduce surface recombination in optoelectronic components.

[0006] However, it has been found that optoelectronic components with quantum well intermixing by impurities exhibit significant degradation, i.e. a clear decrease in output power even at low current intensities after short periods of operation, which is surprising since such degradation does not occur at comparable current intensities in components without quantum well intermixing.

[0007] Also, localized impurity diffusion and / or quantum well intermixing with impurities has been used to improve the low current efficiency of LEDs (light emitting diodes) in the InGaAIP material system (indium-gallium-aluminium-phosphide), which is limited to square geometries. It has been observed that the effectiveness of these barriers, together with the penetration of impurities, has a strong influence on the aging behavior of structural elements and devices, especially at high load current densities, especially when smaller structural elements are affected.

[0008] It would therefore be desirable to develop semiconductor structures and related methods that alleviate the above-mentioned problems.

[0009] The inventors have realized that, to date, geometric approaches to improving performance have only been undertaken in the area of ​​a single LED, and no steps have yet been taken to improve this effect by geometrically arranging LEDs on a wafer basis or in groups of LEDs during the manufacture of the semiconductor structure.

[0010] Summary of the Invention Aspects for improving quantum well intermixing, both for single optoelectronic component elements and for combinations, for example on a wafer, are presented in the following way.

[0011] For this purpose, a method for producing semiconductor components, in particular optoelectronic components or LEDs, is proposed, in which in a first step a semiconductor structure is provided. This semiconductor structure can in particular be produced by growing differently doped layers and / or layers of different material composition, in particular having a first n-doped layer, a second p-doped layer and an active layer with at least one quantum well arranged between them. In this case, the p-doped layer is provided with a first dopant for doping.

[0012] In a second step, a mask is applied and patterned on the semiconductor structure, in particular on the p-type doped layer, in order to protect the partial areas of the active layer intended for the generation of electromagnetic radiation from the penetration of the second dopant. In this case, the mask material may be made of either a dielectric material (silicon oxide, silicon nitride, etc.), a metal (Ti, etc.) or a semiconductor material.

[0013] The p-type doped layer not covered by the patterned mask is then doped with a second dopant such that quantum well intermixing occurs in areas of the active layer not covered by the patterned mask. In this regard, for example, doping of the p-type doped layer with the second dopant may be performed by vapor phase diffusion using a precursor having the second dopant.

[0014] In other methods, in this case precursors are pyrolyzed in a gas phase reaction, where the dopants are absorbed at the semiconductor surface and diffuse into the semiconductor, resulting in quantum well intermixing. All these sub-processes have different temperature dependencies, so the temperature range in which efficient quantum well intermixing can be achieved is very limited (typically 520+ / -20°C for InP or GaAs based semiconductors).

[0015] The proposed principle therefore defines the steps of dopant application using precursors and in-diffusion, thus establishing a process sequence for efficient quantum well intermixing by gas-phase diffusion, which allows the optimization of the process sequence for widening the process window and thus realizing aging-resistant optoelectronic components.

[0016] This defined process sequence may, in some aspects, include: - depositing a second dopant on the surface of the p-type doped layer, the precursor being decomposed at a first temperature selected such that the second dopant does not substantially diffuse into the p-type doped layer; and - diffusing the deposited second dopant into the p-type doped layer at a second temperature higher than the first temperature. It has.

[0017] The inventors have recognized that the process control of doping with a second dopant has a significant impact on reducing the charge carrier concentration in regions where long term impurity degradation of luminous efficiency occurs, particularly due to the increased dopant barrier that can be achieved through the process control in the active layer below the edges of the mask.

[0018] In addition, for process control according to the proposed concept, the step of diffusing the dopant-containing precursor in the vapor phase may, in some embodiments, include: - depositing a decomposition product containing the second dopant on a surface of the semiconductor structure; and - diffusing a second dopant into the semiconductor structure; It can be divided into:

[0019] This separation allows the temperature to be freely selected in the diffusion step with the occurrence of quantum well intermixing, in particular to be increased to values ​​(above 520° C.) at which surface occupation by the second dopant is no longer possible due to excessive desorption, which can be advantageously used to improve the aging behavior of optoelectronic components.

[0020] Here, the second dopant is of the same dopant type as the first dopant, e.g., Zn, Mg, etc. The amount of the deposited second dopant may be selected to diffuse substantially completely into the p-type doped layer during the diffusion process at the second temperature, thus providing only an amount sufficient for diffusion and quantum well intermixing to occur, and no more.

[0021] In another embodiment, the deposition amount of the second dopant herein is selected, for example, to form a barrier to lateral diffusion of charge carriers in areas of the active layer not covered by areas of the patterned mask, the barrier consisting of a barrier created by the second dopant and a barrier caused by quantum well intermixing.

[0022] In a development of this embodiment, the amount of the second dopant is selected such that in areas of the active layer not covered by the patterned mask, a barrier to lateral diffusion of charge carriers created by the second dopant is greater than the barrier caused by quantum well intermixing. Furthermore, the amount of the second dopant may be selected such that a band gap of the active layer in areas under the patterned mask is smaller than a band gap of the active layer not covered by the patterned mask.

[0023] In another embodiment, the doping process is followed by a final temperature step at a third temperature higher than the second temperature. In some embodiments, the semiconductor is subjected to an annealing step at this third temperature without further application of the second dopant. This downstream annealing step is configured at a higher temperature and without the use of a second dopant such that the significant improvement in low current efficiency achieved in the doping process is maintained over a longer period of operation.

[0024] The inventors have realized that the process of providing a second dopant at a first temperature and diffusing the second dopant at a second temperature is important in that it is causally related to the occurrence of quantum well intermixing as well as the subsequent degradation. In this case, atoms of the second dopant diffuse into the semiconductor layer stack and the active layer (or quantum well) where they can replace atoms of the original crystal lattice. These are atoms of the first dopant as well as atoms of the actual lattice material. The atoms displaced to interstitial sites are mobile and are presumed to have a major impact on the degradation of the optoelectronic component. An additional annealing step at a simultaneous higher third temperature, during which no further dopant is provided, reduces the subsequent efficiency loss.

[0025] In another aspect, suitable environmental conditions are provided for the annealing step by providing a supporting pressure with an element that forms a crystal lattice (for example by providing a suitable further precursor). By appropriately selecting this element, the lattice atoms displaced by the second dopant are provided with the ability to react at the surface of the semiconductor, thereby preventing the free movement of these atoms. If the displaced lattice atoms are, for example, group III atoms, the process can be initiated by a supporting pressure, preferably with a group V element. Accordingly, the interstitial atoms generated in the diffusion process diffuse to the surface during the annealing step according to the invention and are bonded there. By reducing the number of interstitial atoms involved in the degradation mechanism, the life of the component is significantly increased.

[0026] Thus, according to this embodiment, the annealing process comprises the steps of providing a further precursor comprising an element of the fifth main group, in particular P or As, and / or forming a layer of a III-V semiconductor material on the surface of the p-type doped layer.

[0027] In the annealing step, the precursor may be added from the beginning or only after the second process parameter is reached, and the concentration of the precursor may be varied during the annealing step so that sufficient precursor material is available to saturate the lattice atoms displaced by the dopant.

[0028] In another embodiment, this further precursor may specifically comprise the elements phosphorus or arsenic, primarily in compounds such as PH3, ASH3, TBA or TBP.

[0029] Another aspect concerns the process parameters that can be selected differently for each of the deposition, diffusion and annealing steps. In one embodiment, the parameters include at least one of the following parameters, or a combination thereof: temperature during one of the aforementioned steps, temperature change in a defined period of time, pressure during one of the aforementioned steps, pressure change in a defined period of time, composition and flow rate of the gases, especially the precursors, and duration of the annealing step.

[0030] For example, the process parameters include a defined first temperature during the supply of the second dopant, selected so that the second dopant does not substantially diffuse into the p-type doped layer when the second dopant is deposited in the p-type doped layer, a second temperature during the diffusion process of the second dopant, e.g., higher than the first temperature, and a third temperature during the annealing step, higher than the second temperature. In other words, the temperature during the annealing step is higher than the two temperatures during which quantum well intermixing occurs. Also, the durations of the supply of the second dopant, the diffusion process and the annealing may be different.

[0031] In other embodiments, a second dopant different from the first dopant is used. For example, Zn or Mg may be used as the second dopant. For example, a III-V semiconductor material is used as the material system of the semiconductor structure. It may have at least one of the following combinations: InP, AlP, GaP, GaAlP, InGaP, InAlP, GaAlP or InGaAlP. Similarly, the material system may be combined with other III-V semiconductors, such as As.

[0032] Another aspect relates to an optoelectronic component. It includes a semiconductor structure with III-V semiconductor material. The semiconductor structure includes an n-doped layer, a p-doped layer, and an active layer with at least one quantum well disposed therebetween. The p-doped layer includes a first dopant. The component further includes a light generating region, in particular a central region of the active layer, which is laterally surrounded by a second region of the active layer. This is because a second dopant is introduced into the second region, which causes quantum well intermixing in at least one quantum well of the active layer in the second region, such that the band gap of the second region is larger than the band gap of the central region.

[0033] Since this local quantum well intermixing by impurities takes place in the second region, and not in the first region, a barrier is formed in the active layer, and the lateral movement of charge carriers in the quantum wells of the active layer of the optoelectronic component is limited to this first region of the active layer. This prevents, for example, the current for operating the optoelectronic component from flowing in the peripheral region of the optoelectronic component, i.e., through the second region surrounding the first region, as much as possible. This reduces the non-radiative recombination of charge carriers caused by non-radiative recombination centers or high non-radiative surface recombination in the second region, which therefore leads to an improved performance of the component.

[0034] In another embodiment, a patterned mask is disposed on the p-doped layer to cover a first subregion of the p-doped layer, and a second dopant is introduced into the subregion of the p-doped layer not covered by the mask to generate quantum well intermixing in the active layer disposed below the subregion, the size of the mask being substantially the same as the size of the first subregion.

[0035] By selecting the support pressure during the annealing step according to the invention, the material displaced by the second dopant to the interstitial sites is converted into a layer covering a portion of the surface. A diffusion process during annealing removes the material from the interstitial sites, which is believed to result in no non-radiative recombination centers in the quantum well, so that the efficiency of the optoelectronic component does not decrease even over time. Accordingly, a layer is formed at the surface of the mixed partial region of the p-type doped layer, which consists of III-valent material of the III-V semiconductor material and elements of the precursor material, in particular P or As.

[0036] Besides process modifications leading to improved performance in the area of ​​individual light-emitting diodes, measures are provided for bringing about improvements in quantum well intermixing at wafer level. Usually, optoelectronic components are manufactured at wafer level as a large number of such structures. In this case, the manufacturing can be monolithic or the components can be singulated at a later time. In the first case, the quantum well intermixing also serves as a barrier against electrical crosstalk, in the second case, it can already be used during manufacturing to modify the area that will later form the edge.

[0037] In one embodiment, a semiconductor structure is presented, which comprises an n-type doped first layer, a p-type doped second layer doped with a first dopant, and an active layer. The latter is arranged between the n-type doped first layer and the p-type doped second layer and has at least one quantum well. According to the invention, the active layer can be divided into a plurality of first regions, in particular optically active regions, and at least one second region. In this case, in particular, the plurality of first optically active regions and the at least one second region are adjacent to each other. Furthermore, the plurality of first regions are arranged spaced apart from each other in a hexagonal pattern and are surrounded by at least one second region with quantum well intermixing. The quantum well intermixing can be generated in a manner similar to the process described above.

[0038] Here, each one of the plurality of first, in particular optically active, regions of the semiconductor structure can form, for example, each one of the parts of an optoelectronic component. The semiconductor structure can thus be formed from a number of individual optoelectronic components, which can be subsequently singulated, for example by an etching process or laser cutting through the epitaxial layer and subsequent removal of the substrate.

[0039] For example, the first regions are circular in shape. The lack of corners results in more uniform impurity penetration and quantum well intermixing along the borders of the subsequent light-emitting diodes, as compared to a square-shaped structural element. This also means that non-radiative recombination in the peripheral regions of the second regions of the structural element can be reduced, and accordingly the performance of each individual optoelectronic structural element can be improved. Nevertheless, advantageously, the manufacturing is performed at wafer level.

[0040] A circular shape in this context means that polygons with 6 or more sides are also possible, i.e. for example with 8, 10 or more sides, since positive effects for improving the performance of the optoelectronic component can already be observed for this shape. Likewise, the term circular shape can also include ovals, as well as ellipses or other rounded convex shapes.

[0041] The semiconductor structure is locally masked and, for example by means of a diffusion process, the second dopant penetrates region by region into the active layer, where quantum well intermixing occurs in the corresponding regions where quantum wells are present. The regions where quantum well intermixing occurs form at least one second region. The semiconductor structure thus comprises a second dopant, in particular a dopant different from the first dopant arranged in the p-type doped second layer, which dopant is arranged substantially uniformly in the at least one second region.

[0042] On the other hand, in the first regions, the application of the mask prevents quantum well intermixing as much as possible. More precisely, quantum well intermixing does not occur in the first regions. Accordingly, after the diffusion process, the second dopant is substantially not disposed in the first regions, and thus the second dopant is not disposed in the regions of the first portions in the quantum wells of the active layer.

[0043] Due to the division into the first and second regions and the associated quantum well intermixing, the first region can be used as an optically active region in the subsequent operation of the structural element, in particular a light-emitting diode, and therefore in the following the first region will be referred to as the first optically active region.

[0044] Such local quantum well intermixing by impurities takes place in the second region, rather than in the first optically active regions, and thus creates an electronic barrier in the active layer through a change in the band structure, restricting the charge carriers of the quantum wells in the active layer of the semiconductor structure from moving laterally to the first optically active regions of the active layer. This prevents, as far as possible, for example, the current for operating an optoelectronic component from flowing in the peripheral region of the optoelectronic component, i.e. through the second region surrounding the first region. Since non-radiative recombination centers are often present in the peripheral region of the singulated structure, charge carriers are kept away from the peripheral region, which therefore leads to an improved performance of the component.

[0045] However, in practice, the penetration of the impurities and thus the quantum well intermixing depends on the size of the open area into which the material to be diffused is introduced. Thus, if on a semiconductor structure a number of first optically active regions are arranged in a hexagonal shape, then in the spaces between each of the three first optically active regions arranged in a triangle, local maxima are formed that are larger in area, i.e. with a higher impurity concentration, than in the area between two adjacent first optically active regions. These maxima result from the fact that the diffusion process proceeds more efficiently in the large area regions where the second dopant is added than in the small spaces between the two first optically active regions, which are covered, for example, by a mask. This effect is undesirable in some circumstances, since it is important to achieve a very homogeneous diffusion pattern in the semiconductor structure in order to improve the low-current efficiency of the optoelectronic component.

[0046] Thus, in another embodiment, a semiconductor structure is presented, comprising an n-type doped first layer, a p-type doped second layer doped with a first dopant, and an active layer. The latter is arranged between the n-type doped first layer and the p-type doped second layer and has at least one quantum well. According to the invention, the active layer can be divided into a plurality of first regions, in particular optically active regions, and at least one second region. In this case, in particular, the plurality of first optically active regions and the at least one second region are adjacent to each other. Furthermore, the plurality of first optically active regions are arranged spaced apart from each other in a hexagonal pattern and are surrounded by at least one second region with quantum well intermixing. Furthermore, at least one third region is arranged in the space between the plurality of first optically active regions and the second region, in this case, in particular, adjacent to the at least one second region.

[0047] Unlike the previous embodiment, in this case the active layer is divided into a plurality of first optically active regions and at least one second region as well as at least one third region.

[0048] Here, the at least one third region is arranged in such a way that the regions where local maxima of high impurity concentration occur according to the aforementioned embodiment are inaccessible to quantum well intermixing, for example by applying a mask, and that also in these regions quantum well intermixing thus occurs as little as possible, as in the plurality of first optically active regions, so that after the diffusion process as little of the second dopant is arranged in the at least one third region as in the plurality of first optically active regions.

[0049] Furthermore, the at least one second region surrounds the multiple first optically active regions such that each of the multiple first optically active regions is individually concentrically surrounded by a portion of the at least one second region or by one of the multiple second regions. Thus, the at least one second region may result, for example, from a continuous annular segment each disposed around one of the multiple first optically active regions, or from a plurality of annular patches each disposed concentrically around one of the multiple first optically active regions. Similarly, the term annular may include circular, elliptical, as well as oval or other rounded convex shapes that are substantially concentrically disposed around and completely surround the multiple first optically active regions.

[0050] In this regard, at least one third region is adjacent to at least one second region. Thus, the at least one third region may have a continuous mesh-like area arranged around the plurality of annular second regions. However, in another embodiment, the plurality of third regions may each at least approximately reproduce the shape of a deltoid curve. This may be formed, for example, by exactly three second regions each arranged in a triangle, these regions having at least approximately a circular or annular shape. Similarly, the plurality of third regions may have a circular shape and may each be arranged in the center of three triangularly arranged first regions, these regions having at least approximately a circular shape.

[0051] What is important in the arrangement of the at least one third region is, for example, to reduce local maxima with higher impurity concentrations in the second regions during the diffusion process, for example by applying a mask, such as a dielectric or a photoresist mask, and thus to achieve a diffusion pattern of the semiconductor structure that is as homogeneous as possible.

[0052] Quantum well intermixing can occur by doping the second region with a second dopant, such as, for example, magnesium, zinc, cadmium (Mg, Zn, Cd), although this is not intended to be an exclusive choice of dopants and any other dopant of the same type that can be devised by one skilled in the art can be used for doping.

[0053] In another embodiment, the diffusion process for producing quantum well intermixing in the at least one second region may result in the second dopant being at least partially formed not only in the active layer in the second region, but also in the second p-doped layer and also in the region of the n-doped layer adjacent to the active layer, although this should not necessarily be understood as the region of the second p-doped layer and the first n-doped layer in which the second dopant is formed being coincident with the at least one second region of the active layer, although they may be.

[0054] In another embodiment, a semiconductor structure is proposed in which at least one second region has a substantially uniform bandgap produced by quantum well intermixing, meaning that in this region the bandgap energy has as constant a value as possible, and only towards the periphery of the region the bandgap becomes larger or smaller.

[0055] On the other hand, the at least one quantum well in the plurality of first optically active regions and the at least one third region has a smaller band gap than the quantum well in the at least one second region. Accordingly, a barrier produced according to one of the above aspects occurs between the plurality of first optically active regions and the second region, and between the at least one third region and the second region. In this case, the transition between the band gaps can be a step with a sharp edge or a smoothly flowing transition.

[0056] In another embodiment, the plurality of first optically active regions and the at least one third region have substantially the same band gap, in particular because the at least one quantum well of the plurality of first optically active regions and the at least one third region are substantially free of quantum well intermixing, and thus substantially free of the second dopant, in these regions.

[0057] According to another embodiment, the semiconductor structure, which may be formed from a number of individual optoelectronic components, is singulated into a number of optoelectronic components, for example by an etching process or laser cutting through an epitaxial layer and subsequent removal of the substrate. In this case, the cutout of each of the optoelectronic components is, for example, circular and comprises at least one of the first optically active regions and a portion of at least one second region, where the first optically active region and the second region are in particular arranged concentrically in the circular cutout. The at least one third region of the semiconductor structure is therefore not part of the number of individual optoelectronic components and thus in particular represents a reject of the singulation process. [Brief description of the drawings]

[0058] The present invention will now be described in detail with reference to exemplary configurations and to the drawings. [Figure 1A] FIG. 1 illustrates one configuration having various process steps for fabricating a semiconductor structure by quantum well intermixing in accordance with some aspects of the presented concepts. [Figure 1B] FIG. 1 illustrates one configuration having various process steps for fabricating a semiconductor structure by quantum well intermixing in accordance with some aspects of the presented concepts. [Figure 1C] FIG. 1 illustrates one configuration having various process steps for fabricating a semiconductor structure by quantum well intermixing in accordance with some aspects of the presented concepts. [Figure 1D]FIG. 1 illustrates one configuration having various process steps for fabricating a semiconductor structure by quantum well intermixing in accordance with some aspects of the presented concepts. [Figure 1E] FIG. 1 illustrates one configuration having various process steps for fabricating a semiconductor structure by quantum well intermixing in accordance with some aspects of the presented concepts. [Figure 1F] FIG. 1 illustrates one configuration having various process steps for fabricating a semiconductor structure by quantum well intermixing in accordance with some aspects of the presented concepts. [Diagram 2] FIG. 1 shows an exemplary time course of various process parameters during the execution of a method according to the proposed principle. [Diagram 3] 1A-1C are diagrams illustrating a portion of a semiconductor structure to illustrate various considerations of the presented concepts. [Figure 4] FIG. 10 illustrates the barrier height as a function of operating current for various dopants to explain the presented concept. [Diagram 5] FIG. 11 is a further diagram demonstrating the quantum efficiency at different barrier heights to explain the presented concept. [Figure 6A] 1 illustrates a plan view of a first configuration of a semiconductor structure suitable for emitting light in accordance with some aspects of proposed concepts. [Figure 6B] 1A-1C show relevant cross-sectional profiles of the band gap of a semiconductor structure in accordance with some aspects of proposed concepts. [Figure 7A] 1A-1C show plan views of further configurations of semiconductor structures suitable for emitting light in accordance with some aspects of proposed concepts. [Figure 7B] FIG. 2 illustrates an associated cross-sectional profile of the bandgap in accordance with some aspects of the proposed concepts. [Figure 8A] FIG. 13 shows a plan view of a third configuration in accordance with some configurations of the proposed concept. [Figure 8B]1A-1C show relevant cross-sectional profiles of the band gap according to several configurations of the proposed concept. [Figure 9A] FIG. 2 illustrates a plan view of a fourth configuration of a semiconductor structure implemented in various embodiments. [Figure 9B] 1A-1C show relevant cross-sectional profiles of the band gap of semiconductor structures implemented in various embodiments. [Figure 10A] 1A-1D illustrate a layer structure and a method of fabrication of one or more optoelectronic components, in particular μ-LEDs, according to some embodiments of the presented concepts. [Figure 10B] 1A-1D illustrate a layer structure and a method of fabrication of one or more optoelectronic components, in particular μ-LEDs, according to some embodiments of the presented concepts. [Figure 10C] 1A-1D illustrate a layer structure and a method of fabrication of one or more optoelectronic components, in particular μ-LEDs, according to some embodiments of the presented concepts. [Figure 11] FIG. 1 illustrates a bandgap representation of a semiconductor structure according to a proposed concept.

[0059] Detailed Description 1A-1F show the individual steps of the manufacturing process, where the quantum well intermixing can be further improved by a suitable selection of process parameters. In this regard, it was recognized that the dopants diffuse into the active layer under the mask by application with simultaneous diffusion, but there is no quantum well intermixing. Therefore, the active layer under the mask intended for light emission remains highly doped, which accelerates the aging process and deteriorates the properties.

[0060] 1A-1C show the semiconductor structure 1 undergoing further process steps. In FIG. 1A, a growth substrate 10, for example a GaAs substrate, is provided and prepared for further growth steps. These further steps may include deposition of sacrificial layers, passivation layers or conformal layers to different crystal structures. Similarly, the substrate may already contain or be prepared for leads, contacts or circuitry.

[0061] Subsequently, an n-type doped layer 20 based on a III-V material system is deposited on the prepared substrate 10. This deposition is carried out in an MOCVD reactor, but other methods disclosed in the present application can also be used for this purpose. For example, In, Ga, Al or combinations thereof with phosphorus P are used as materials. The exemplary InGaAlP layer 20 is n-type doped, and further layers and / or dopants (not shown in detail here) may also be provided to ensure good conductive contacts and low sheet resistance in the n-type doped layer 20.

[0062] In FIG. 1B, the active layer 30 is then applied. The active layer 30 contains at least one quantum well, which during operation of the completed component structure takes place, radiative recombination resulting in the generation of light. The at least one quantum well in the active layer 30 also contains a combination of layers of III-V semiconductor systems, which may for example consist of InGaAlP layers with different Al contents. A p-doped layer 40 is then produced on the active layer 30. For this purpose, a first dopant is used, for example Mg or Zn. This doping can be carried out, as for the n-doped layer 20, by adding the desired concentration of dopant during the manufacturing process. This allows a doping profile to be generated in the layer during the growth stage, which allows better adjustment of the desired electrical properties, while also offering the advantage of reduced impurities through a more uniform crystal growth.

[0063] After providing the semiconductor structure 1 in the previous steps, the p-type doped layer is now provided with a mask 50 in FIG. 1C and patterned accordingly. As shown, the patterned mask 50 covers a partial area on the surface of the p-type doped layer, and therefore also on a first partial area 33 of the active layer. An adjacent partial area 34 of the active layer is not covered by the mask 50. After patterning of the mask 50, doping of the p-type doped layer with a second dopant is performed by gas-phase diffusion using a precursor having first and second process parameters. Here, the second dopant is formed, for example, from Zn, for example from an organic Zn compound.

[0064] The process parameters of this second step include, in particular, the temperature, the pressure and the concentration of the second dopant, which may also vary during a given period of time. The parameters are selected in such a way that the second dopant is first deposited as a layer 45 on the surface of the semiconductor structure after decomposition of the precursor, forming a thin layer there, but does not or only very little diffuses into the p-type doped layer. For this purpose, for example, a lower temperature is selected than for the subsequent diffusion process. To provide the second dopant, the dopant is obtained from the decomposition of the precursor in the gas phase. This is carried out in an MOCVD or MOPVD reactor. The advantage of such a step is that the wafer remains in the reactor during the individual process steps and does not have to be transported. As a result, the structure obtained is shown in FIG. 1D with a thin layer of Zn or other material as the second dopant.

[0065] According to FIG. 1E, after the dopant is applied to the surface, a separate diffusion process is performed. This diffusion process is controlled by process parameters so that the second dopant diffuses through the layer 40 into the active layer and the quantum wells. In some cases, the second dopant may also diffuse slightly into the boundary region of the n-type doped layer. During this process, the second dopant reaches the region under the mask (in a stochastic distribution) by diffusion in the layer 40. On the other hand, the first partial region 33 of the active layer under the mask is free of dopant. Instead, a sharp edge is formed there, which surprisingly substantially coincides with the protrusion of the mask 50 into the active layer.

[0066] The process parameters are selected such that the diffusion causes intermixing in the quantum wells of the second subregion of the active layer, increasing the energy gap of the quantum wells, and in the boundary region between the first and second subregions, a relatively steep energy barrier is formed, due to which the quantum well intermixing decreases rapidly over a short distance.

[0067] Separating the application of the dopant from the subsequent diffusion step allows for better control of the individual processes. The deposition of the dopant is usually carried out at a lower temperature than the subsequent diffusion. This allows, on the one hand, a better adjustment of the amount of dopant provided and, on the other hand, the diffusion does not rely on gas phase reactions. In the later separate diffusion step, a suitable temperature profile is set so that a doping profile is constructed in which the diffusion barrier of the charge carriers generated by the dopant is close to the energy barrier generated by the quantum well intermixing.

[0068] Completion of this procedure is followed by an optional annealing step, shown in FIG. 1F. In this step, third process parameters are set, which in this example configuration include, in particular, a higher temperature and the addition of further precursors 70. This aspect is explained in detail in the present application. Due to the aforementioned diffusion process, the diffused Zn displaces other atoms of the crystal lattice and occupies their places. The displaced atoms may remain in interstitial sites. These atoms remain mobile thereafter and probably form recombination centers for non-radiative recombination. By their migration, these atoms thus migrate to the first partial region 33 and may significantly reduce the efficiency of the structural element there. This is supported by the observation that the efficiency decreases early even at low current densities.

[0069] By increasing the temperature and, optionally, by appropriate selection of precursors, the lattice atoms displaced during the diffusion step are bound to the surface. As a result, the surface acts as a sink for interstitial atoms. In short, by modifying the process parameters, it is possible to diffuse the displaced atoms, preferably from the active layer through the p-doped layer to the surface, reducing the potential non-radiative concentration in the active layer. It was found that the lifetime was significantly increased by using precursors with main group V materials, such as phosphorus P or arsenic As.

[0070] Fig. 2 qualitatively shows the time course of the process parameters, in particular the temperature T, the gas flow of the second dopant and the gas flow of the further precursor during the annealing stage. Between periods t1 and t2, on the one hand, the temperature is maintained at the first temperature T1 and further dopants are added so that they can be deposited on the surface of the semiconductor structure. The temperature T1 is selected such that no diffusion of the dopant into the semiconductor body occurs or occurs only to a very small extent. During this time, no further precursors are added. At time t2, the dopant is switched off and the temperature T1 is maintained until a slightly later time t3.

[0071] After a time t3, the temperature is increased to a value of T2. This temperature increase initiates a diffusion process, i.e. the dopants deposited on the surface diffuse into the p-doped layer. In the present configuration example, the temperature profile is kept substantially constant, but non-constant temperature profiles are also conceivable. Thus, depending on the temperature profile, the dopant profile is set. Then, in a next step, annealing is performed, i.e. the atoms replaced by the dopants are removed from the p-doped layer or the active layer and the quantum wells over time at a third temperature T3. For this, in addition to the temperature increase, further precursors are added, whose decomposition products combine with the replaced atoms at the surface. A concentration gradient of mobile replaced atoms is created, which removes them from the quantum wells of the active layer and binds them to the surface.

[0072] Figure 3 gives an overview of the aspects necessary to be able to explain the proposed principle. During dopant diffusion, an additional concentration of dopant material is formed in the p-type doped layer. When this dopant material is incorporated into the crystal lattice, atoms of the original semiconductor (e.g. trivalent components) migrate to interstitial sites. These interstitial atoms cause quantum well intermixing in the active layer, thus increasing the band gap. Here, the local area of ​​quantum well intermixing is predetermined by the mask, i.e., no quantum well intermixing occurs in the region of the quantum well under the mask, as shown in Figure 3. However, due to dopant diffusion, the doping is also increased in the region marked "Region II", so that a barrier to the lateral diffusion of charge carriers in the quantum well is formed. This barrier is already partially under the mask, so it is locally offset with respect to the boundary of the quantum well intermixing. Thus, there are two barriers that reduce the lateral diffusion of charge carriers: one due to increased doping and one due to quantum well intermixing.

[0073] As shown in FIG. 3, the boundary 36 of the quantum well intermixing and the boundary 37 of the additional p-type doping are locally offset, i.e. they do not coincide. From the point of view of charge carrier diffusion, the increase in the barrier also occurs gradually. The separation of the dopant deposition and diffusion allows the diffusion profile to be modified by freely choosing a suitable temperature profile during the diffusion process. Thus, for example, the boundary 37 can be pushed towards the boundary 36. This leads to a steeper barrier for charge carrier diffusion at the boundary of the mask 50. Similarly, the impurity concentration due to the substitution of atoms in the diffused material or in the active layer is also lowered by the precision of the process parameters. Additionally or alternatively, the electrical activation of the second dopant and thus the barrier caused by the additional p-type doping can be increased by optimizing the process parameters during the diffusion process, leading to a stronger reduction in the lateral charge carrier diffusion.

[0074] Figure 4 shows a simulation of the doping barrier height in a light-emitting diode as a function of doping concentration at low current. A significant increase of the doping barrier, nearly doubling it, is shown with increasing doping. Thus, charge carriers are not only effectively kept away from the edge regions, but also from the regions where the number of impurities is increased by the introduction of the second dopant.

[0075] This leads to a higher internal quantum efficiency. Figure 5 shows a graph of this, plotting the internal quantum efficiency versus current for different dopant concentrations. It can be clearly seen that for currents in the range of about 0.1 mA, the maximum value improves at higher concentrations.

[0076] The proposed principle and various measures improve both the low-current and high-current efficiency of optoelectronic components. Impurities in the optically active region of the active layer are reduced. At the same time, the diffusion barrier is increased in the edge regions of the component (or around the active layer), which allows charge carriers to be pushed away from the edges of the component, thereby reducing the proportion of non-radiative surface recombination.

[0077] In addition to geometric considerations for performance improvement in the area of ​​a single LED, examples of quantum well intermixing improvement at the wafer level are given below. Multiple structures of optoelectronic components are fabricated at the wafer level, whether they are subsequently used in a single component or monolithically. Measures such as the Zn diffusion mentioned above can reduce the impurity concentration in the subsequent active layer area and persistently bind or saturate the impurity atoms, improving low and high current efficiency.

[0078] 6A shows a plan view of a cross section of a first configuration of a semiconductor structure 0 and an associated cross-sectional profile of the energy of the band gap of the semiconductor structure along a cross-sectional axis AA. The semiconductor structure 0 has a plurality of first optically active regions 2a and second regions 2b formed therein, where the first optically active regions 2a are spaced apart from one another in a hexagonal pattern, and a second region 2b surrounds the first optically active regions 2a and is disposed in the spaces between them.

[0079] Furthermore, each one of the plurality of first optically active regions 2a of the semiconductor structure 0 forms part of each of the plurality of optoelectronic structural elements 1. In this respect, the optoelectronic structural elements are considered as light-emitting diodes. The plurality of first optically active regions 2a may be formed, for example, by applying a mask or, for example, by applying mask segments, possibly having the same or similar shape and size. A second dopant b is then added to the exposed second regions 2b around the mask or mask segments, so that quantum well intermixing can occur in this region. In the second regions, the diffusion of the second dopant and the associated quantum well intermixing changes the energy of the band gap compared to regions where no quantum well intermixing occurs.

[0080] Furthermore, Fig. 6A shows a cross-section of the semiconductor structure 0 and the resulting progression of the band gap energy along the cross-sectional axis AA, which shows the progression of the band gap energy in the regions 2a, 2b. It can be seen from this figure that the band gap energy of the second region 2b is greater than that of the first optically active region 2a. From the second region 2b to the first optically active region 2a, the band gap energy decreases, and conversely, this decrease is accompanied by an increase in the band gap energy from the first optically active region 2a to the second region 2b.

[0081] However, these transitions and similar transitions below are considered as qualitative transitions only and do not represent absolute values ​​or ratios of the band gap energies in the first optically active regions 2a and the second regions 2b. Similarly, the transition region between the second optically active regions and the first optically active regions may vary and may be somewhat flat or steep. The only important point is that the transition region from the first optically active regions 2a to the second regions 2b has a substantially sharp edge and that the band gap energy in the first optically active regions 2a is smaller than the band gap energy in the second regions 2b.

[0082] As a result, in other words, the dopant concentration of the second dopant b in the second region 2b is greater than the dopant concentration of the second dopant b in the plurality of first optically active regions 2a.

[0083] 6A, it can be seen that the bandgap energy in the second regions 2b does not have a constant value, but has a local maximum value of the bandgap energy in the region where the distance between the first regions 2a is greatest, because the diffusion process and therefore the quantum well intermixing proceeds more efficiently in the larger surface region where the second dopant b is added than in the smaller space between the two first optically active regions 2a, which is covered by a mask, for example.

[0084] Furthermore, the cross section of the semiconductor structure 0 shown in FIG. 6B and the resulting progression of the band gap energy along the cross section axis (BB) show the progression of the band gap energy along the perimeter of the optoelectronic component 1. This cross section axis passes through the second region 2b. In accordance with the above explanation, the band gap energy in the second region 2b does not have a constant value, but has a maximum value in the region where the distance between the first regions 2a is maximum, and has a minimum value in the region where the distance between the first regions 2a is minimum. In FIG. 6B, the region where the band gap energy of the semiconductor structure is locally maximum is exemplarily represented by Y, and the region where the band gap energy of the semiconductor structure is locally minimum is exemplarily represented by X and Z.

[0085] In practice, however, it is desirable to achieve a bandgap energy that is as uniform and constant as possible in the second region 2b of the semiconductor structure 0 and, correspondingly, along the perimeter of the optoelectronic component 1. Three configurations are therefore presented in particular (FIGS. 7A and 7B, 8A and 8B, 9A and 9B) in order to counteract the effects of local maxima in the bandgap energy of the semiconductor structure 0. Each of FIGS. 7A and 7B, 8A and 8B and 9A and 9B shows a plan view of one configuration of the semiconductor structure 0 according to the invention and the associated cross-sectional profile of the energy of the bandgap of the semiconductor structure along the cross-sectional axes AA and BB.

[0086] 6A and 6B, in addition to the first optically active regions 2a and at least one second region 2b, at least one further third region 2c is formed, which is also arranged in the spaces between the first optically active regions 2a.

[0087] More precisely, FIG. 7A shows a cross section of a semiconductor structure 0 having a plurality of first optically active regions 2a, a second region 2b and a plurality of third regions 2c. The plurality of first optically active regions 2a are arranged at a distance from one another in a hexagonal pattern as described above. The second region 2b surrounds the plurality of first optically active regions 2a such that each one of the plurality of first optically active regions 2a is surrounded in annular and / or concentric manner by the second region 2b. Thereby, the second region 2b is divided, for example, into annular segments and is connected, for example only in a point-like manner, with the next adjacent annular segment of the second region 2b. The plurality of third regions 2c are in each case formed in a deltoid curve by three of the annular segments of the second region 2b.

[0088] Here, the plurality of first optically active regions 2a and third regions 2c may be formed, for example, by applying a mask, for example, by applying mask segments, possibly of the same or similar shape and size, and then a second dopant b is added to the exposed second regions 2b around the mask or mask segments, so that quantum well intermixing can occur in this region.

[0089] Furthermore, Fig. 7A shows a cross section of the semiconductor structure 0 and its energy of the band gap along the cross section axis AA, which shows the energy of the band gap in the regions 2a, 2b and 2c. It can be seen from this figure that the band gap of the second region 2b is larger than the band gap of the first optically active region 2a and the third region 2c. In the regions where the axis AA crosses the second region 2b, respectively, a local increase in the band gap is observed. Depending on the area of ​​the second region 2b that crosses the axis AA, the energy of the band gap is respectively at a higher or lower value.

[0090] However, this transition is considered to be a qualitative transition and does not represent absolute values ​​or ratios of the band gap energies of the first optically active regions 2 a, the second regions 2 b, and the third regions 2 c. Similarly, the transition regions between the first optically active regions, the second regions 2 b, and the third regions 2 c may vary and may be somewhat flat or steep.

[0091] The only important point is that the transition regions from the first optically active regions 2a to the second regions 2b and from the third regions 2c to the second regions 2b have substantially sharp edges and that the band gap energy in the first optically active regions 2a and the third regions 2c is smaller than the band gap energy in the second regions 2b, which in turn means that the dopant concentration of the second dopant b in the second regions 2b is greater than the dopant concentration of the second dopant b in the first optically active regions 2a and the third regions 2c.

[0092] Furthermore, the cross section of the semiconductor structure 0 shown in FIG. 7B and the resulting progression of the band gap energy along the cross section axis BB show the progression of the band gap energy along the circumference of the optoelectronic component 1. This cross section axis passes through the second region 2b. In contrast to the depiction in FIG. 7B, the band gap energy in the second region 2b does not have a significant change. By introducing the third regions 2c, it is realized that in the spatial regions between the respective three regions of the first optically active regions 2a, the local maxima of the band gap energy of the semiconductor structure 0 are less pronounced. A more uniform band gap energy can therefore be realized in the second regions 2b. This in itself leads to an improved performance of the optoelectronic component 1.

[0093] A further configuration of the semiconductor structure 0 according to the invention and the resulting progression of the energy of the band gap in the semiconductor structure 0 along the cross-sectional axes AA and BB are shown in FIGS. 8A and 8B.

[0094] There, the third regions 2c are each circular and are arranged in the center of three of the first optically active regions 2a. Similarly, the term circular can include oval, elliptical or other rounded convex shapes. This arrangement of the third regions 2c is used to reduce local maxima of the applied second dopant b on the semiconductor structure 0 in order to achieve a substantially uniform dopant concentration in the second regions 2b, similar to that shown in Figures 7A and 7B. The circular third regions 2c shown in Figure 8A are arranged in the center of three of the first optically active regions 2a, already showing an improvement in the performance of the optoelectronic component 1. The second regions 2b therefore do not occur as continuous annular segments, but fill the space between the first optically active regions 2a and the third regions 2c.

[0095] The plurality of first optically active regions 2a and third regions 2c may be formed, for example, by applying a mask, for example, by applying mask segments, possibly of the same or similar shape and size, and further, a second dopant b is added to the exposed second regions 2b around the mask or mask segments, such that quantum well intermixing can occur in this region.

[0096] Furthermore, Fig. 8A shows a cross section of the semiconductor structure 0 and the resulting course of the band gap energy along the cross section axis AA, which shows the band gap energy in the regions 2a, 2b and 2c. It can be seen from this figure that the band gap energy of the second region 2b is greater than the band gap energy of the first optically active region 2a and the third region 2c. A local increase in the band gap is observed in the region where the axis AA crosses the second region 2b, respectively. Similarly, the transition regions between the first region, the second region 2b and the third region 2c may vary and may be somewhat flat or steep.

[0097] The only important point is that the transition regions from the first optically active regions 2a to the second regions 2b and from the third regions 2c to the second regions 2b have substantially sharp edges and that the band gap energy in the first optically active regions 2a and the third regions 2c is smaller than the band gap energy in the second regions 2b, which in turn means that the dopant concentration of the second dopant b in the second regions 2b is greater than the dopant concentration of the second dopant b in the first optically active regions 2a and the third regions 2c.

[0098] Furthermore, Fig. 8B shows a cross-section of the semiconductor structure 0 and the progression of the band gap energy along a cross-sectional axis indicated by an arrow leading therefrom, which shows the progression of the band gap energy along the periphery of the optoelectronic component 1. This cross-sectional axis passes through the second region 2b. As depicted in Fig. 7B, the band gap energy in the second region 2b also has a substantially constant value.

[0099] Since each of the third regions 2c occupies a smaller area than the third regions 2c of the configuration in Fig. 7A, there will be more pronounced local maxima in the regions where the distance from the first regions 2a and the third region 2c is greatest. Correspondingly, there will also be local minima in the regions where the distance between the first regions 2a and the third region is smallest. In Fig. 8B, the regions of local maxima of the band gap energy of the semiconductor structure are exemplarily represented by X and Z, and the regions of local minima of the band gap energy of the semiconductor structure are exemplarily represented by Y.

[0100] 6A, the introduction of the third regions 3c reduces the magnitude of the local maxima of the band gap energy of the semiconductor structure 0, and a relatively uniform and constant energy of the band gap prevails along the perimeter of the optoelectronic component 1 or within the second regions 2b of the semiconductor structure 0. This in itself already leads to an improvement in the performance of the optoelectronic component 1.

[0101] Furthermore, as shown in FIG. 8B, each one of the first optically active areas 2a of the semiconductor structure 0 forms part of a respective one optoelectronic component 1.

[0102] A further configuration of the semiconductor structure 0 according to the invention and the resulting progression of the energy of the band gap in the semiconductor structure 0 are shown in FIGS. 9A and 9B along the cross-sectional axes AA and BB.

[0103] Here, each of the first optically active regions 2a is concentrically surrounded by a second region 2b. Thus, there are a plurality of second regions 2b, each of which is arranged in an annular or circular shape around one of the first optically active regions 2a. Similarly, the terms annular or circular may include oval, elliptical or other rounded convex shapes.

[0104] Furthermore, the semiconductor structure 0 has a third region 2c arranged in the space between the plurality of first optically active regions 2a and the second region 2b. The plurality of first optically active regions 2a and the third region 2c may be formed, for example, by applying a mask, for example, by applying mask segments, possibly of the same or similar shape and size. Furthermore, a second dopant b is added to the exposed second region 2b around the mask or mask segments, so that quantum well intermixing can occur in this region.

[0105] The arrangement of the second regions 2b in an annular shape around each one of the first optically active regions 2a and the third region 2c prevents local maxima of the applied second dopant b from forming in the spatial regions between the three first optically active regions 2a. A substantially uniform dopant concentration can thus be achieved in the second regions 2b. A substantially uniform quantum well intermixing can also occur in the second regions 2b, which leads to an improved performance of the optoelectronic component 1.

[0106] Furthermore, the progression of the band gap energy along the cross-sectional axis AA shown in Figure 9A shows that the band gap energy in the second region 2b is larger than the band gap energy in the first optically active region 2a and the third region 2c. A local increase in the band gap is observed in each region where the axis AA intersects with the second region 2b.

[0107] However, this transition is considered to be a qualitative transition and does not represent the absolute values ​​of the band gap energies of the first optically active regions 2 a, the second regions 2 b and the third regions 2 c or their ratios. Similarly, the transition regions between the first optically active regions 2 a, the second regions 2 b and the third regions 2 c may vary and may be somewhat flat or steep.

[0108] The only important point is that there are substantially sharp edges in the transition regions from the first optically active regions 2a to the second regions 2b and from the third regions 2c to the second regions 2b, and that the band gap energy in the first optically active regions 2a and the third regions 2c is smaller than the band gap energy in the second region 2b.

[0109] As a result, in other words, the dopant concentration of the second dopant b in the second region 2b is greater than the dopant concentration of the second dopant b in the plurality of first optically active regions 2a and in the third region 2c.

[0110] 9B shows a cross-section of the semiconductor structure 0 and the resulting profile of the energy of the band gap along a cross-sectional axis BB, which shows the profile of the energy of the band gap along the periphery of the optoelectronic component 1. This cross-sectional axis passes through the second region 2b.

[0111] As depicted in Figures 6B, 7B and 8B, the band gap energy in the second regions 2b has a substantially constant value. By introducing the third regions 2c, the formation of local maxima of the applied second dopant b in the spatial regions between the three first optically active regions 2a, respectively, is avoided, and thus the local maxima of the band gap energy in the semiconductor structure 0 also do not occur. Thus, a substantially uniform band gap energy can be achieved in the second regions 2b.

[0112] 10A, 10B and 10C show the layer structure and corresponding fabrication of a semiconductor structure 0 as shown in FIGS. 7A, 8A and 9A. Here, the semiconductor structure 0 comprises an n-doped first layer 5, a p-doped second layer 6 doped with a first dopant, and an active layer 2 arranged between the n-doped first layer 5 and the p-doped second layer 6 and having at least one quantum well. These layers are, for example, epitaxially deposited on a carrier substrate, which is not shown here. In addition to the layers shown here, further layers, contact layers, sacrificial layers etc. may also be provided.

[0113] Figure 10B shows the next step in which a patterned mask 7 is applied, which has holes in it, into which the dopant b is introduced, in which case the diffusion of the second dopant b into the active layer 2 causes the quantum well intermixing described above.

[0114] By applying a mask or mask segments 7, for example a dielectric mask or a photoresist mask, to the surface of the p-doped second layer 6 and a subsequent diffusion process, the structure shown in FIG. 10C is formed. This shows, under the mask 7, a number of optically active areas surrounded by a second area 2b and at least one third area 2c. This structure and configuration results from the patterning of the applied mask 7, as described above. The second dopant b diffuses through the p-doped second layer 6 into the active layer 2 and forms therein the areas 2a, 2b and 2c. The areas 2a, 2b and 2c in the active layer 2 are thus the projection of the mask or mask segments 7 applied to the surface of the p-doped second layer 6 onto the active layer 2.

[0115] The plurality of first optically active regions 2a and at least one third region 2c are located in direct projection under the mask or mask segments 7 and result as regions into which the second dopant b does not substantially diffuse due to the mask or mask segments 7.

[0116] At least one second region 2b therefore arises as a region located as a free surface around the mask or mask segment 7 in direct projection beneath the region to which the second dopant b is applied. As a result, in the at least one second region 2b, the second dopant b diffuses into the second p-doped layer 6, into the active layer 2 and, depending on the doping profile and the process parameters, also partially into the region of the n-doped layer 5 bordering the active layer 2.

[0117] From this it can be seen that at least one second region 2b comprises a second dopant b and thus quantum well intermixing.

[0118] 11 shows the layer structure of the semiconductor structure 0 after application of a mask or mask segments 7 and diffusion of a second dopant b, as well as the band gap of at least one quantum well in the active layer 2. The energy of the band gap E in the vertical direction of the figure is shown across a cross section of the semiconductor structure 0 in the horizontal direction of the figure.

[0119] Here, the energy of the band gap E, seen from left to right, is substantially constant in the third region 2c and increases in the defined transition region from the third region 2c to the second region 2b. In the second region 2b, the energy of the band gap E again has a constant value and then decreases in the defined transition region from the second region 2b to the first optically active region 2a, the energy of the band gap E of the first optically active region 2a being constant. Conversely, following this progression, the energy of the band gap E of the defined transition region from the first optically active region 2a to the second region 2b increases and the energy of the band gap E of the defined transition region from the second region 2b to the third region 2c decreases.

[0120] However, the illustrated energy progression of the band gap E may vary and does not represent the absolute values ​​or ratios of the energy of the band gap E in the first optically active region 2a, the at least one second region 2b and the at least one third region 2c. Similarly, the transition regions between the at least one second region 2b and the first optically active region 2a and between the at least one second region 2b and the at least one third region 2c may also vary and may be somewhat flat or steep.

[0121] The only important point is that the energy of the band gap E of the first optically active region 2a and the at least one third region 2c is smaller than the energy of the band gap E of the at least one second region 2b, and that the energy of the band gap E of each of the first optically active region 2a and the at least one second region 2b is substantially constant along the perimeter of region 2a.

Claims

1. A method for producing an optoelectronic component, in particular a light-emitting diode, said method comprising the steps of: providing a semiconductor structure including a first n-type doped layer, a second p-type doped layer, and an active layer having at least one quantum well disposed therebetween, the p-type doped layer having a first dopant; applying and patterning a mask onto the semiconductor structure; doping the p-type doped layer with a second dopant to produce quantum well intermixing in areas of the active layer not covered by areas of the patterned mask; Including, doping the p-type doped layer with the second dopant is carried out by vapor phase diffusion using a precursor having the second dopant; The method further comprises: depositing the second dopant on a surface of the p-type doped layer by decomposing the precursor at a first temperature selected to substantially prevent diffusion of the second dopant into the p-type doped layer; diffusing the deposited second dopant into the p-type doped layer at a second temperature higher than the first temperature; A method comprising:

2. The method of claim 1 , wherein the second dopant comprises Zn or Mg and has the same dopant type as the first dopant.

3. 3. The method of claim 1, wherein the amount of the deposited second dopant is selected to diffuse substantially completely into the p-type doped layer during said diffusion.

4. 4. The method of claim 1, wherein the amount of the second dopant is selected such that in areas of the active layer not covered by areas of a patterned mask, a barrier to lateral diffusion of charge carriers generated by the second dopant is greater than the barrier caused by quantum well intermixing.

5. doping the p-type doped layer with a second dopant; annealing the semiconductor structure at a third temperature, the third temperature being greater than the second temperature, after diffusing the second dopant into the p-type doped layer. The method according to any one of claims 1 to 4, comprising:

6. 6. The method according to claim 1, wherein the mask is locally formed by a suitable layer of the semiconductor structure by a patterning step.

7. The annealing step comprises: Providing a further precursor comprising an element of the fifth main group, in particular P or As, and / or forming a layer of III-V semiconductor material on a surface of the p-type doped layer; The method of claim 5 or 6, comprising:

8. During said steps of deposition, diffusion and annealing, at least one of the following parameters is controlled: a change in temperature over a defined period of time during one of the preceding steps; pressure; the change in pressure during one of the preceding steps over a defined period of time; Gas composition; Combinations of these; 8. The method according to claim 1, wherein:

9. The semiconductor structure is made of at least one of the following material systems: InP; GaP; InGaP; InAlP; GaAlP; and InGaAlP; The method of any one of claims 1 to 8, further comprising forming a semiconductor layer comprising a group III-V semiconductor material comprising:

10. An optoelectronic component, in particular a light-emitting diode, comprising a semiconductor structure comprising a III-V semiconductor material, the active layer having an n-type doped layer, a p-type doped layer, and at least one quantum well disposed therebetween, the p-type doped layer having a first dopant; a central first semiconductor region of the active layer, the central region being laterally surrounded by a second semiconductor partial region of the active layer having a larger band gap than the first semiconductor region; Including, a second dopant is introduced into the second partial region, the second dopant causing quantum well intermixing in the at least one quantum well of the active layer located in the second partial region; An optoelectronic structure, wherein a barrier to lateral diffusion of charge carriers is formed in a defined region of the active layer, the barrier consisting of a barrier created by the second dopant and a barrier caused by quantum well intermixing.

11. 11. An optoelectronic component according to claim 10, wherein the defined areas are formed by a patterned mask applied during manufacture.

12. 11. An optoelectronic component according to claim 10, characterized in that the doping barrier created by the second dopant is greater than the barrier caused by the quantum well intermixing.

13. 13. An optoelectronic component as claimed in claim 10, further comprising a patterned mask arranged on a first partial region of the p-doped layer located above a central region of the active layer.

14. 14. An optoelectronic component according to claim 10, wherein the size of the mask substantially corresponds to the size of the central area.

15. 15. The optoelectronic component according to claim 10, wherein a layer of a III-valent material of the III-V semiconductor material and an element of a precursor material, in particular P or As, is formed on the surface of a partial region of the p-doped layer which is located above the defined region.

16. 1. A semiconductor structure comprising: an n-type doped first layer; a p-type doped second layer doped with a first dopant; an active layer having at least one quantum well disposed between the n-doped first layer and the p-doped second layer; Including, the active layer of the semiconductor structure is divided into a plurality of first optically active regions, at least one second region, and at least one third region; the plurality of first optically active regions are spaced apart from one another in a hexagonal pattern; at least one quantum well of the active region has a larger band gap in the at least one second region than in the plurality of first optically active regions and in the at least one third region, in particular the band gap being modified by quantum well intermixing; the at least one second region surrounds the plurality of first optically active regions; The at least one third region is disposed in a space between the plurality of first optically active regions.

17. 20. The semiconductor structure of claim 16, wherein said plurality of first optically active regions are formed at least approximately circular.

18. 18. The semiconductor structure of claim 16 or 17, wherein a plurality of second regions concentrically surround each of the plurality of first optically active regions.

19. 19. The semiconductor structure of claim 16, wherein the plurality of second regions are formed in at least a substantially circular shape.

20. 20. The semiconductor structure of claim 16, wherein a plurality of third regions are arranged such that each of the plurality of third regions is exactly centered on three of the first optically active regions.

21. 21. The semiconductor structure of claim 16, wherein each of the plurality of third regions is formed at least approximately circular.

22. 22. The semiconductor structure of claim 21, wherein each of the plurality of third regions at least approximately replicates a deltoid curve shape formed by exactly three of the plurality of second regions each formed at least approximately circular.

23. 23. The semiconductor structure according to any one of claims 16 to 22, wherein each optically active region of the plurality of first optically active regions forms part of a respective optoelectronic component.

24. 24. The semiconductor structure of claim 16, further comprising a second dopant substantially uniformly disposed in the at least one second region.

25. the second dopant in the at least one second region is the second p-type doped layer, and / or the active layer, and / or 25. The semiconductor structure of claim 16, wherein the semiconductor structure is formed at least partially in a region of an n-type doped layer adjacent to the active layer.

26. 26. The semiconductor structure of any one of claims 16 to 25, wherein the at least one second region has a substantially uniform bandgap modified by quantum well intermixing.

27. 27. The semiconductor structure of claim 16, wherein the plurality of first optically active regions and the at least one third region have substantially the same bandgap.

28. 28. The semiconductor structure of claim 16, wherein the plurality of first optically active regions are substantially free of quantum well intermixing.

29. 29. The semiconductor structure of any one of claims 16 to 28, wherein the at least one third region is substantially free of quantum well intermixing.

30. 30. The semiconductor structure of claim 16, wherein quantum well intermixing is reduced in a defined transition region from the at least one second region to the plurality of first optically active regions.

31. 31. The semiconductor structure of claim 16, wherein the second dopant is different from the first dopant.

32. 32. The semiconductor structure of any one of claims 16 to 31, wherein the second dopant is formed from the group comprising at least one of the following materials: Mg, Zn, Cd.

33. 13. An LED arrangement comprising a semiconductor structure according to any one of the preceding or following claims.

34. 1. A method of manufacturing a semiconductor structure, comprising: Providing a semiconductor structure having an n-type doped first layer, a p-type doped second layer doped with a first dopant, and an active layer disposed therebetween; applying a mask to the p-type doped second layer to define a plurality of first optically active regions in the active layer surrounded by at least one second region of the active layer and to define at least one third region disposed in a space between the plurality of first optically active regions; generating quantum well intermixing in at least one second region of the active layer; A method comprising:

35. the step of generating quantum well intermixing further comprising: Diffusing a second dopant into the p-type doped second layer, into the active layer in the at least one second region, and into a region of the n-type doped layer at least partially adjacent to the active layer.

35. The method of manufacturing a semiconductor structure of claim 34, comprising:

36. 36. The method of claim 34 or 35, wherein quantum well intermixing occurs only in the at least one second region by applying the mask to the p-type doped second layer and diffusing the first dopant into the p-type doped second layer, the active layer in the at least one second region, and at least partially into a region of the n-type doped layer adjacent to the active layer.

37. The mask may be a dielectric (e.g., SiO ２ , Si ３ N ４ 37. A method for manufacturing a semiconductor structure according to any one of claims 34 to 36, wherein the semiconductor structure is formed by a mask of the following formula:

38. 38. The method for manufacturing a semiconductor structure of any one of claims 34 to 37, wherein the second dopant is different from the first dopant.

39. 39. The method for manufacturing a semiconductor structure according to any one of claims 34 to 38, wherein said second dopant is formed from the group comprising at least one of the following elements: Mg, Zn, Cd.

40. A method for producing an optoelectronic component from a semiconductor structure according to any one of the preceding claims, comprising the steps of: Singulating the individual optoelectronic components, in particular by an etching process. A method comprising:

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