METHOD FOR PROCESSING AN ARRANGEMENT WITH μLEDS AND ARRANGEMENT

Abstract

The invention relates to a method for processing an arrangement with a plurality of microLEDs, comprising the following steps: providing a plurality of vertical microLEDs on a support substrate, wherein the microLEDs have a contact surface on a top surface opposite the support substrate, and embedding the plurality of vertical microLEDs in a photoactive material, wherein the photoactive material covers spaces between adjacent microLEDs of the plurality of optoelectronic components and their top surface. Portions of the photoactive material above the top surface, which at least partially contain the contact surface, are exposed and developed, thereby removing portions of the photoactive material so that a portion of the top surface, which at least partially contains the contact surface, is exposed.A conductive transparent layer is applied to the remaining photoactive material and the exposed part of the top surface to electrically contact the contact area.

Description

[0001] The present invention relates to a method for processing an optoelectronic component, in particular a µLED, and an optoelectronic arrangement with a plurality of µLEDs. BACKGROUND

[0002] Simultaneous testing of multiple microLEDs at different stages of their manufacturing process is necessary to avoid large batches of defective components and to increase production yield. While it is possible to perform some tests directly at the wafer level, it is also common to use dedicated test setups, known as test vehicles.

[0003] To prepare such test vehicles, a large number of microLEDs are extracted from the production wafer and applied to a suitable test substrate. This large number of microLEDs is then further processed to implement the test vehicle, which is subsequently used for a variety of electrical and optical tests. However, the preparation and implementation of such test vehicles, which consist of arrays with a large number of microLEDs, is prone to errors.

[0004] In particular, the step of applying dielectric material as SOG (spin-on-glass) to the substrate and the individual microLEDs creates a step around the microLEDs. Any conductive layer, such as ITO, that is applied and sputtered onto the SOG material is prone to cracking due to this step around the microLEDs. Subsequent stress tests during the testing procedure, where the assembly is subjected to real-world scenarios, can lead to fractures in the conductive layer. These problems affect not only test vehicles but also assemblies with a large number of microLEDs, such as displays, light projectors, and the like.

[0005] In conventional methods, the surface of microLEDs is opened by a dry etching process that removes the SOG material from the top surface. However, due to various tolerances such as the thickness of the microLEDs, slight tilt during deposition of the microLEDs onto the substrate, the thickness of the solder, and other factors, the top surfaces of many microLEDs are typically uneven. The etching process to remove the SOG material, which exposes all surfaces, therefore also etches the SOG material between the microLEDs, complicating a defined and reproducible process for depositing a conductive material for testing and other purposes.

[0006] Consequently, there is a desire to improve an arrangement with a large number of µLEDs, resulting in a less error-prone structure with higher reproducibility. SUMMARY OF THE INVENTION

[0007] This and other objectives are addressed by the subject matter of the independent claims. Features and further aspects of the proposed principles are set forth in the dependent claims.

[0008] The inventors propose modifying the process steps for manufacturing an array of microLEDs by embedding the array of microLEDs in a planarized material that is photoactive and therefore easily structured without dry etching. Consequently, areas of such a photoactive material can be developed using a photomask layer or a direct laser exposure device, thereby exposing contact surfaces for connecting the array of microLEDs.

[0009] The newly proposed steps eliminate the need for back-etching or mechanical grinding to remove the spin-on-glass material, requiring only a much simpler removal of a portion of the photoactive material. The photoactive polymerization material remains on the array in which the optoelectronic components or microLEDs are embedded. This reduces the risk of damaging the microLEDs during processing due to the aforementioned tolerances and enables improved process control. Furthermore, several steps required in conventional processing techniques can be omitted, resulting in a faster manufacturing process, particularly suitable for arrays used for testing purposes.

[0010] Several aspects concern a method for processing an arrangement with a plurality of optoelectronic components, and in particular microLEDs. Such a method comprises the step of providing a plurality of vertical components, and in particular vertical microLEDs, on a substrate. The vertical optoelectronic components each comprise a contact area on the top surface facing the substrate.

[0011] In this context, the term "vertical optoelectronic component" refers to an optoelectronic component comprising two contact surfaces on opposite sides. According to the proposed principle, such vertical optoelectronic components are arranged on the substrate, with their respective lower contact surfaces connected to corresponding contact surfaces on the substrate. The opposite contact surface is located on the top side of the optoelectronic component.

[0012] The term "µLED" refers to an optoelectronic component, which can be a bulk or surface emitter, with a length or width of less than 70 µm and up to a few micrometers. Typical µLEDs have a length of approximately 4 µm to 20 µm, for example, 15 µm, 10 µm, or 8 µm. Due to their size, these µLEDs are usually implemented as vertical optoelectronic components.

[0013] The numerous vertical optoelectronic components are embedded in the photoactive material according to the proposed principle. The photoactive material fills the space between the adjacent vertical optoelectronic components as well as their top surface. The material forms a more or less flat surface on the substrate and the components, while the optoelectronic components may exhibit small curved protrusions in the form of small bumps on the plane of the photoactive material. Therefore, the photoactive material may not be perfectly flat, but slightly uneven, with the roughness in most cases being less than 1 µm or less than 0.5 µm, and certainly less than the height of the vertical optoelectronic components.

[0014] Parts of the photoactive material positioned above the top surface and containing at least part of the contact area of ​​the respective optoelectronic components are then exposed and thus developed. The developed parts can then be removed, leaving the undeveloped parts behind. Alternatively, this step can be reversed, i.e., the photoactive material not positioned above the top surface, which contains at least part of the contact area of ​​the respective optoelectronic components, can be exposed and developed, and then the undeveloped parts above the top surface can be removed.

[0015] In both cases, the subsequent removal exposes a portion of the top surface that at least partially contains the contact area.

[0016] Subsequently, a conductive transparent layer is applied to the remaining photoactive material and to the exposed areas of the top side of the vertical optoelectronic components in order to electrically contact the contact area of ​​the respective optoelectronic components.

[0017] As stated, the proposed principle protects the optoelectronic components from potential damage by embedding them in the photoactive material, while the respective top surface remains exposed and can then be contacted without additional etching steps. Furthermore, potential edges between the optoelectronic components and the spin-on-glass material, which arise due to differing etch rates in conventional techniques, are reduced or completely avoided. Advantages such as the highly precise positioning of photomask layers or the direct laser exposure process are retained.

[0018] In some further aspects, a structured mask layer is applied to the photoactive material, exposing a portion of the top surface that contains at least part of the contact area. This structured mask layer can comprise a variety of transparent elements, such as holes or lenses. These transparent elements are positioned over the portion of the top surface that contains at least part of the contact area. The photoactive material over these areas is then exposed to light for removal in a subsequent, simplified washing step, without the need for etching the photoactive material.

[0019] Instead of a structured photomask layer, a direct laser exposure unit can be used. First, the position of the top surface of the multiple optoelectronic components on the substrate is determined. After determining these positions, the direct laser exposure unit is used to expose the areas of the photoactive material above the top surface that at least partially contain the contact area of ​​the vertical optoelectronic components. This particular method has the advantage that the position of each top surface of the multiple optoelectronic components can be determined after these components have been placed on the substrate, but before they are embedded in the photoactive material. Therefore, tolerances or inclinations during the positioning or arrangement process of the multiple optoelectronic components on the substrate can be compensated for.

[0020] In some other aspects, the step of developing the photoactive material includes the step of removing illuminated areas, leaving unilluminated areas of the photoactive layer on the substrate. However, this specific step can also be reversed, so that the step of developing the protective material includes the step of removing unilluminated areas, leaving illuminated areas of the photoactive layer on the substrate.

[0021] The latter step is evidently useful in cases where the support substrate is further processed within a multitude of optoelectronic components to create a display or other arrangement, and where the photoactive material remains on the support substrate during normal operation of such an arrangement. In such circumstances, it can be beneficial to protect the photoactive material from oxygen or other degrading substances.

[0022] Several further aspects relate to the step of providing a structured mask layer. This step can involve providing a structured mask layer containing a variety of transparent areas such as holes, lenses, and the like. The structured mask layer is positioned over the photoactive layer material so that each or all of the transparent areas are positioned over the respective structured areas of the top surface, which at least partially contain the contact area. However, the transparent areas in the structured mask layer are somewhat smaller than the area of ​​the top surface. Consequently, during the subsequent exposure step, not the entire photoactive layer on the top surface is exposed, but only a portion of it, leaving the material at the periphery edges undeveloped.

[0023] Consequently, after removing the developed areas, a small section of the photoactive material may remain at the circumferential edges of the top surface of the respective optoelectronic components. In this respect, the multiple transparent areas can be circular or rectangular in shape. Alternatively, an oval or polygonal shape can also be used for the multiple transparent areas. After removing the exposed photoactive material, the resulting recess, which exposes the contact area, can have the same shape.

[0024] Several steps involve embedding the numerous vertical optoelectronic components in the photoactive material. In some cases, the photoactive material can be sputtered onto the substrate, thereby covering the optoelectronic components and their top surfaces. Alternatively, the photoactive material can be centrifugally deposited onto the substrate and the numerous optoelectronic components.

[0025] As another alternative, the photoactive material can be applied to the substrate, and in particular between the spaces between adjacent optoelectronic components of the plurality of vertical optoelectronic components. In some cases, sections of the photoactive material can also be applied to the top surface of some of the plurality of vertical optoelectronic components. Alternatively, the photoactive material can be sprayed onto the substrate, and in particular between the spaces between adjacent optoelectronic components. The photoactive material can also be sprayed onto the top surface of some or all of the plurality of vertical optoelectronic components.

[0026] In this respect, the development step can involve etching the exposed or developed areas of the photoactive material. Alternatively, the unexposed areas (corresponding to the undeveloped areas) of the photoactive material can be etched. However, such an etching process differs from an etching process of the spin-on-glass material as in conventional techniques and is similar to simply removing the photoactive material using solvents suitable for material removal. These solvents are generally non-aggressive and do not affect or damage the optoelectronic components or the inactivated areas of the photoactive material.

[0027] After removal of the photoactive material, heat treatment can be performed before or after the development step. For example, the photoactive material remaining after the development and removal process can be baked to further improve stabilization and prevent delamination in subsequent steps. In this respect, the coefficient of thermal expansion (CTE) can be selected to be similar to that of the surrounding material for the temperature ranges used during operation of the setup.

[0028] The conductive transparent layer can include ITO and can be sputtered onto the remaining photoactive material and the top surface of the optoelectronic components, extending over the edge between the photoactive material and the exposed contact areas of the top surface. In this respect, the thickness of the conductive transparent layer, or simply the amount of sputtered material, is sufficient to seamlessly connect the thickness on the exposed contact areas of the top surface with the conductive transparent material on the photoactive layer surrounding these exposed contact areas.

[0029] Another aspect relates to an arrangement with a plurality of optoelectronic components. The arrangement comprises a substrate with a plurality of contact lines. A plurality of vertical optoelectronic components, in particular microLEDs, are arranged on the substrate and, more specifically, on the plurality of contact lines. The arrangement is configured such that the first contact area of ​​each of the plurality of vertical optoelectronic components is connected to a corresponding contact line on the substrate. Furthermore, each of the plurality of vertical optoelectronic components comprises a second contact area opposite the first contact area.

[0030] According to the proposed principle, a non-conductive, inactivated photoactive material is arranged on the substrate, in which the plurality of vertical optoelectronic components is embedded. A portion of the inactivated photoactive material extends to the top surface of each plurality of vertical optoelectronic components, leaving at least a portion of the secondary contact area exposed. For example, the portions of the top surface covered by the inactivated photoactive material can include the peripheral edge regions of the plurality of vertical optoelectronic components. A conductive transparent layer covers the inactivated photoactive material as well as the exposed contact area of ​​the plurality of vertical optoelectronic components, thus establishing an electrical contact.

[0031] Since the thickness of the inactivated photoactive material extending across the top surface is significantly less, the step transition between the exposed contact area and the photoactive material is thin enough for the transparent conductive layer to form a stable, well-defined, and controllable contact. In particular, this step transition is not located along the sidewalls of the optoelectronic components, as in conventional methods, thus avoiding the risk of breakage or rupture of the conductive transparent material due to thermal stress. In some cases, the thickness of such a step can range from a few nm to approximately 500 nm, and in any case, is less than 1 µm. Therefore, in some cases, the transparent conductive material can have a thickness greater than that of a step of the photoactive material extending across the top surface.

[0032] In some aspects, the exposed area of ​​the top can have the shape of a circle, a rectangle, a polygon, or an oval.

[0033] Several aspects concern the shape and structure of the portion of the inactivated photoactive material that extends across the top surfaces of the vertical optoelectronic components. As mentioned previously, the inactivated photoactive material extends along the circumferential edges of the respective optoelectronic component. In some cases, the surface of the inactivated photoactive material may exhibit curvature, such that the thickness of the photoactive material is partially increased towards the exposed contact area. Therefore, the thickness of the photoactive material may increase towards the center of the respective optoelectronic component.

[0034] These properties are adjusted and, to a certain extent, controlled by the amount of material applied, as well as by the application technique. For example, centrifugal casting of the photoactive material can result in a different surface shape than sputtering, creating protrusions and bumps due to obstacles formed by the optoelectronic components. Consequently, the portion of the inactivated photoactive material extending onto the top surface may exhibit curvature in a cross-sectional view, with an increasing inclination towards the exposed contact areas. However, the surface roughness of the photoactive material (i.e., the distance between the lowest and highest points) is likely to be less than 1 µm and, in particular, less than 500 nm. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Further aspects and embodiments according to the proposed principle will become clear with reference to the various embodiments and examples, which are described in detail in connection with the accompanying drawings, in which Fig. 1A to 1D show a method for processing an order; Fig. Figures 2A to 2D illustrate a method for processing an arrangement according to some aspects of the proposed principle; Fig. Three alternative process steps during the processing of an order according to some aspects of the proposed principle are shown; Fig. Figures 4A to 4C show a top view of an optoelectronic component during the processing of an arrangement according to some aspects of the proposed principle; Fig. 5 represents an arrangement with an optoelectronic component embedded in such a material. DETAILED DESCRIPTION

[0036] The following embodiments and examples reveal various aspects and their combinations according to the proposed principle. The embodiments and examples are not always to scale. Likewise, various elements may be enlarged or reduced to highlight individual aspects. It is understood that the individual aspects of the embodiments and examples shown in the figures can readily be combined without contradicting the principle of the invention. Some aspects have a regular structure or shape. It should be noted that in practice, minor differences and deviations from the ideal form may occur without contradicting the inventive concept.

[0037] Furthermore, the individual figures and aspects are not necessarily depicted in the correct size, nor do the proportions between the individual elements have to be essentially correct. Some aspects are emphasized by being enlarged. However, terms such as "above," "over," "below," "under," "larger," "smaller," and the like are correctly represented in relation to the elements within the figures. Thus, it is possible to deduce such relationships between the elements from the figures.

[0038] Fig. Figure 1 shows an arrangement with an optoelectronic component, in particular a microLED. The microLED has a very small diameter of less than 70 µm or even smaller, for example, but not limited to less than 20 or even less than 10 µm. The optoelectronic component and the microLED are in Fig. Figure 1A is shown as a vertical optoelectronic component with a bottom surface 22 and a top surface 21 opposite the bottom surface. The bottom and top surfaces each comprise a contact area which, in this case, extends over the entire respective surface. The optoelectronic component 20 is arranged with its bottom surface 22 and its contact surface on a respective contact plane 15, which is located on a support 10.

[0039] The contact surface 15 establishes an electrical contact with the optoelectronic component and is further connected to contact lines arranged within the support 10. The support 10 can be a substrate, a wafer structure, or another suitable rigid element on which the optoelectronic components are mounted. A transparent dielectric material layer 10a is applied to the surface of the support 10 during subsequent processing steps. The dielectric material of layer 10a also covers the side walls and the top surface 21 of the optoelectronic component. The dielectric material 10a consists of SiO2 or another suitable material. It is sputtered onto the respective surface to achieve better wetting and contact of the spin-coated spin-on-glass material or the dielectric material 30a, which is applied to the dielectric material layer 10a in a subsequent step.

[0040] The in Fig. The spin-on process shown in Figure 1B results in a protrusion 35a of some spin-coated material on the surface 21 of the optoelectronic component. The protrusion 35a arises from the spinning of the spin-on-glass material 30a, since the total amount used for the spinning process is slightly larger than the actual available volume between the optoelectronic components on the substrate. Furthermore, the spinning process itself and other surface effects between the dielectric material 10a and the spin-on-glass material 30a can cause some material to be deposited on the top surface.

[0041] In any case, it is necessary to remove the excess material from the top surface. For this purpose, a plasma etching process is carried out, which is related to the process described in Fig. The structure shown in Figure 1C leads to the opening of the top surface 21 of the optoelectronic component 10. However, the plasma etching process also removes parts of the material 30a adjacent to the optoelectronic component, as well as parts of the dielectric material 10a. Since the etching rate of the dielectric material 10a is slower than the etching rate of the spin-on-glass material 30a, an edge or step typically forms between the optoelectronic component 20 and the dielectric material 10a, as well as between the dielectric material 10a and the spin-on-glass material 30a.

[0042] Consequently, during the subsequent sputtering process of the conductive transparent layer, for example using ITO, the adhesion between the spin-on-glass material and the conductive transparent material is reduced near the edge regions of the optoelectronic component. This is also partly due to the exposed dielectric material 10a, which can lead to delamination between the three different materials 30a, 10a, and 40. Furthermore, the step between the optoelectronic components 20 and the conductive transparent layer 40 can also lead to breakage or damage of the conductive transparent layer 40, especially since the material used is typically brittle and breaks easily.

[0043] As a result, the inventors propose a new planarization embedding material for an arrangement with a large number of optoelectronic components, which is easier to process and has a lower risk of delamination or breakage of the transparent conductive layer material.

[0044] Fig. Figure 5 shows a corresponding arrangement with an optoelectronic component embedded in such a material. The µLED 20 comprises a layer stack with two differently doped layers 26 and 27, between which an active region 25 is arranged. The two differently doped layers 26 and 27 can include various current distribution and current transport sublayers as well as cladding sublayers (not shown here) adjacent to the active region 25. Various semiconductor materials, including a III-V semiconductor material such as GaN, GaP, or GaAs, are suitable, although other material systems, including ternary or quaternary systems such as InGaN, AlGaN, AlGaP, InGaP, InAlGaN, InGaAlP, or combinations thereof, can also be used. The optoelectronic component is designed as a vertical µLED with two opposing surfaces 21 and 22, each surface comprising an electrical contact.In addition, the surface 21, which forms the top surface, is roughened to achieve improved light transmission.

[0045] The µLED 20 is arranged with its underside 22 on a contact surface 15, which is located on the substrate 10. The element 15 is connected to a contact line in an intermediate layer 11, which is located within the substrate 10.

[0046] According to the proposed principle, the optoelectronic component is embedded in an inactivated photoactive material 30, which extends from the surface of the support substrate 10 to a height corresponding to the top surface 21 of the optoelectronic component. The term “inactivated photoactive material” refers to a photoactive material that has been processed in such a way that illumination of the material no longer affects its properties.

[0047] A small portion of the inactivated photoactive material 30 extends slightly onto the top surface around the edges of the optoelectronic component. The thickness of this additional material is small and can range from less than 1 µm to less than 300 nm or even less than 100 nm. A conductive transparent layer 40 is deposited onto the inactivated photoactive material 30 and the top surface and contact area of ​​the optoelectronic component. The thickness of this conductive transparent layer 40 is greater than the thickness of the projection 32 of the inactivated photoactive material extending onto the top surface. As a result, only a very small or no significant step is formed in the conductive transparent layer 40, thus reducing the risk of breakage or delamination.

[0048] The Fig. Figures 2A to 2D illustrate an embodiment of a method for processing an arrangement with a plurality of optoelectronic components. The method comprises the step of providing a carrier substrate 10 with a plurality of contact lines and contact elements 15 arranged in a specific structure on the surface of the carrier substrate. For example, the respective contact elements 15 can be arranged in rows and columns with a predetermined spacing between them. Using various transfer methods, several optoelectronic components are applied to the respective contact elements 15 on the carrier substrate.

[0049] The underside 22 of the optoelectronic components is slightly smaller than the respective contact elements 15 on which the optoelectronic components are arranged, as shown in Fig. Figure 2A shows this. This allows small tolerances or misalignments of the various components to be compensated for during the transfer process and ensures that the contact surface on the underside of each of the optoelectronic components is in electrical contact with the respective contact elements 15. The underside with the contact surface is attached to the contact elements using solder.

[0050] In a subsequent process step, a photoactive material 30 is applied to the surface of the support substrate 10 and to the space between the optoelectronic components. The amount of photoactive material used is adjusted so that the total volume is slightly larger than the available volume, causing parts of the photoactive material to form small protrusions 35 on the optoelectronic components 20. More precisely, these protrusions 35 now resemble small hillocks that follow the position of the optoelectronic components and completely cover the top surfaces 21.

[0051] Photoactive material is defined as a material that can be easily photostructured without requiring additional etching steps to produce the structured layer. A typical example is MERCK Silicon Organic Glass, which is described at https: / / www.merckgroup.com / research / science-space / presentations / 2017-10-Micro-LED-Proposed-PPT-V3.pdf

[0052] According to the proposed principle, a photomask structure 50 is now arranged over the arrangement of optoelectronic components on the support substrate, as shown in Fig. Figure 2B shows the photomask structure 50, which comprises a multitude of transparent sections 51 configured like lenses or simply transparent windows and positioned opposite the top surfaces 21 of the respective optoelectronic components. The diameter of each transparent section 51 is slightly smaller than that of the top surface 21 to compensate for potential misalignments during the assembly process of the optoelectronic components, which could lead to minor spacing differences between adjacent components. Furthermore, using a smaller diameter prevents light from penetrating the photoactive material adjacent to the optoelectronic components, which could result in the removal of the developed photoactive material between the components.

[0053] Nevertheless, the transparent sections 51 are large enough to cover the contact surfaces on the top surface 21 even with slight misalignment. The photoactive material 30 is illuminated with light 55 of a specific wavelength, thereby exposing and developing parts 36 of the photoactive material relative to the transparent sections 51. As shown in Fig. As shown in 2B, the development results in the developed photoactive material 36 covering part of the top surfaces 21, while edge areas 32 of the photoactive material may remain undeveloped.

[0054] The developed areas are then removed using a simple removal method for the photoactive material 30, such as a solvent or a mild etching step. Removing the exposed and developed areas 36 creates depressions 33 and openings in the photoactive material on the top surface 21 of the respective optoelectronic components, as shown in Fig. Figure 2C shows that, however, small material sections 32 remain at the circumferential edge of the optoelectronic components 20. The size of these material sections 32 is relatively small, and their thickness can range from a few tens to a few hundred nm. Furthermore, due to the centrifugal process, these parts 32 may exhibit a slight curvature or an inclined surface, resulting in an increasing thickness towards the center of the exposed top surface 21. It should be noted, however, that the curvature and the increase in thickness are significantly exaggerated in the drawing.

[0055] In other words, the thickness of these material sections is small, but can vary slightly and may increase from the edges towards the center of the top surface 21. However, the overall height difference in the thickness of the photoactive material between two adjacent devices (i.e., in the middle between two components) and the top surface 21 of these components is very small and can range from a few nanometers to about 400 nm. Typically, the height difference is less than the thickness of the conductive layer that is subsequently deposited onto the surface of the photoactive material 30 and the top surfaces of the optoelectronic components. The resulting structure is in Fig. 2D representation.

[0056] A conductive transparent layer 60, consisting of ITO, is sputtered onto the top surface of the photoactive material 30, resulting in a substantially uniform thickness across the entire assembly. The thickness is approximately 50 nm to 300 nm in regions 61 and 63, but may be smaller or larger depending on the overall size of the optoelectronic components and the thickness of the overlapping regions 32 on the top surface. However, the thickness is sufficiently small that no steps or edges are formed during the sputtering process. In this context, [the following appears to be a separate, unrelated section:] Fig. 2D shows the total height difference to illustrate the sputtering process.

[0057] The proposed principle enables the provision of an arrangement comprising a multitude of optoelectronic components on a support substrate, utilizing a photoactive material and a conductive transparent layer deposited thereon. The photoactive material does not delaminate from the sidewalls of the optoelectronic components due to thermal or mechanical stress, thus providing a surface onto which the conductive transparent layer can be deposited. Furthermore, no significant step transition occurs between the sidewall edges of the optoelectronic components and the photoactive material that could lead to breakage or damage of the conductive transparent layer. Instead, the conductive transparent layer can be deposited on a smooth and flat surface of both the photoactive material and the top surfaces of the optoelectronic components.In some additional processing steps, the photoactive material can be inactivated or otherwise processed to stabilize the material and make it resistant to oxygen or other gases or liquids.

[0058] In the present method, the structured photomask was used to expose portions of the photoactive layer and subsequently remove them from the optoelectronic components. However, this process can also be reversed, whereby the photoactive material 30 is exposed between the optoelectronic components (i.e., above the support substrate), and subsequently, unexposed material is removed from the top surface 21 of the optoelectronic components. The variation of this process step can depend on the photoactive material used and the subsequent stability after completion of the fabrication and processing of the assembly.

[0059] Furthermore, due to the fixed arrangement between the transparent sections 51, the photomask layer may be subject to possible misalignment with respect to the position of the optoelectronic components on the substrate.

[0060] Therefore, in some respects it makes sense to refrain from using a structured photomask, as in Fig. 2B shows that it deviates. Rather, it shows Fig. 3 an alternative embodiment in which a direct laser exposure device is used to selectively expose certain areas of the photoactive material 30.

[0061] More precisely, the exact position of the optoelectronic components 20 arranged on the support substrate 10 is determined in a prior step, and in particular before the photoactive material is applied to the support substrate. Any misalignment of some of the optoelectronic components is identified. Evaluating the respective positions of the optoelectronic components allows the subsequent illumination process to be realigned to ensure proper illumination of the areas 36 of the photoactive material directly above the contact area. Thus, any misalignment of the optoelectronic components during the arrangement step is compensated for. After the position has been determined and evaluated, a laser direct exposure device is used to expose the areas 36 of the photoactive material, as shown in Fig. Figure 3 shows. Similar to the previous embodiment, small areas 32 of the material 30 can remain unexposed, covering the edges of the optoelectronic component.

[0062] The Fig. Figures 4A to 4C show a top view of the respective process steps according to the proposed principle. In this embodiment, the optoelectronic component 20 is formed by a rectangular shape with a top surface 21, as shown in Fig. Figure 4A shows the photoactive material 30 completely surrounding the optoelectronic component 20 and also covering the top surface.

[0063] Fig. Figure 4B shows the result of the exposure process of the photoactive material using a photomask structure (not shown here) whose transparent section 51 is positioned directly above the central section of the top surface 21 of the optoelectronic component 20. In this particular embodiment, the transparent section of the photomask structure has an oval shape and is subsequently exposed to develop the underlying photoactive material.

[0064] The resulting developed photoactive material sections 36 also have the oval shape and are subsequently removed to expose the underlying top surface. Fig.Figure 4C shows the final result, in which a small recess 33, exposing the top surface 21 of the optoelectronic component 20, is formed in the photoactive material 30. Furthermore, small circumferential sections 32 remain on the top surface of the optoelectronic component. REFERENCE MARK LIST 10 Carrier substrate 10a dielectric material layer 11 Intermediate shift 15 contact element 20 optoelectronic component 21 upper surface 22 Underside 25 active area 26-layer dotted 27-layer dotted 30 photoactive material 30a Spin-on glass material 32 Edge area 33 recess 35, 35a advantage 36 developed section 40 conductive transparent layer 50 photomask structure 51 transparent section 55 light 60 conductive transparent layer 61, 63 area

Claims

[1] Method for processing an arrangement with a plurality of optoelectronic components, in particular µLEDs, comprising the following steps: - Providing a plurality of vertical optoelectronic components on a support substrate, wherein the optoelectronic components have a contact surface on a top side opposite the support substrate; - Embedding the plurality of vertical optoelectronic components in a photoactive material, wherein the photoactive material covers the spaces between adjacent optoelectronic components of the plurality of vertical optoelectronic components and their top surface; - Illuminating parts of the photoactive material above the top surface that at least partially contain the contact area; - Developing the photoactive material, thereby removing parts of the photoactive material so that part of the top surface, which at least partially contains the contact area, is exposed; - Providing a conductive transparent layer on the remaining photoactive material and the exposed section of the top surface to electrically contact the contact area. [2] Method according to claim 1, wherein the step of illuminating areas comprises the following step: - Providing a structured mask layer on the photoactive material so that a portion of the photoactive material above the top surface, which at least partially contains the contact area, can be exposed for exposure; - Exposing the exposed parts of the photoactive material; [3] Method according to claim 1, wherein the step of illuminating areas comprises the following step: - Providing a direct laser exposure device; - Determining the position of the top side of the multiple optoelectronic components on the substrate; - Illumination of parts of the photoactive material above the top surface, which at least partially contains the contact area, by the direct laser imaging device. [4] Method according to any of the preceding claims, wherein the development step comprises the step of removing the exposed areas so that the unexposed areas of the photoactive layer remain on the substrate; or wherein the development step comprises the step of removing unexposed areas so that exposed areas of the photoactive material remain on the substrate. [5] Method according to any of the preceding claims, wherein the step of providing a structured mask layer comprises the step - Providing a structured mask layer that includes a variety of transparent areas; - Arranging the structured mask layer over the photoactive material such that each transparent section of the multiple transparent sections is positioned over a respective section of the top surface that at least partially contains the contact area, wherein an area of ​​a transparent section is smaller than an area of ​​the top surface. [6] Method according to claim 3 above, wherein the multiple transparent sections each have the shape of a circle, a rectangle, a polygon or an oval. [7] Method according to any of the preceding claims, wherein the step comprises embedding the plurality of vertical optoelectronic components in a photoactive material: - Applying the photoactive material so that it forms curved protrusions over the positions of the plurality of vertical optoelectronic components; optionally leaving some of the curved protrusions on the top side after the development step. [8] Method according to any one of the preceding claims, wherein the step of embedding the plurality of vertical optoelectronic components comprises one of the following: - Rotation of the photoactive material; - Sputtering of the photoactive material; - the dosing of the photoactive material, in particular onto the top surface of the multitude of vertical optoelectronic components; to spray the photoactive material, in particular onto the top surface of the multitude of vertical optoelectronic components; - Heat treatment of the applied photoactive material, especially after the development step. [9] Method according to any of the preceding claims, wherein the development step comprises: - Etching of the exposed areas of the photoactive material; - Etching of the unexposed areas of the photoactive material; - Supports the remaining photoactive material. [10] Method according to any of the preceding claims, wherein the conductive transparent layer comprises ITO and is sputtered onto the remaining photoactive material so that it extends over the edge between the photoactive material and the exposed contact areas on the top surface. [11] Arrangement, comprehensive: - a carrier substrate with a large number of contact lines; - a plurality of vertical optoelectronic components, in particular µLEDs, arranged on the substrate such that a first contact area of ​​each of the plurality of vertical optoelectronic components is connected to a respective of the plurality of contact lines, wherein each of the plurality of vertical optoelectronic components comprises a second contact area opposite the first contact area; - a non-conductive inactivated photoactive material on the support substrate, embedding the plurality of vertical optoelectronic components, wherein part of the inactivated photoactive material extends to a top surface of the respective plurality of vertical optoelectronic components and the second contact area is partially exposed; - a conductive transparent layer covering the inactivated photoactive material and the exposed contact area of ​​the multitude of vertical optoelectronic components. [12] Arrangement according to claim 11, wherein the inactivated photoactive material comprises at least one of the following elements: - TiO2; - SiO2; - Siloxane filler; and - Graphite. [13] Arrangement according to one of claims 11 to 12, wherein the portion of the inactivated photoactive material extending onto a top surface has a curvature such that the thickness of the photoactive material partially increases in the direction of the exposed contact area; or wherein the portion of the inactivated photoactive material extending onto a top surface has a curvature with an increasing inclination in the direction of the exposed contact area when viewed in section. [14] Arrangement according to any one of claims 11 to 13, wherein the exposed area on the top side has one of the following shapes: - a circle; - a rectangle; - a polygon; and - an oval. [15] Arrangement according to any one of claims 11 to 14, wherein the transparent conductive material has a thickness greater than a step of the inactivated photoactive materials extending over the top surface. [16] Arrangement according to one of claims 11 to 15, further comprising a dielectric layer arranged on parts of the support substrate and along the side walls and the plurality of vertical optoelectronic components.

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