Optoelectronic semiconductor component and method for producing an optoelectronic semiconductor component

Abstract

The invention relates to an optoelectronic semiconductor component (1) comprising a micro-LED (100) and a conversion element (200). The micro-LED (100) is designed to emit a first electromagnetic radiation in the blue wavelength range. The conversion element (200) is designed to convert the first electromagnetic radiation into a second electromagnetic radiation. The conversion element (200) is in direct contact with the micro-LED (100). The invention also relates to a method for producing an optoelectronic semiconductor component (1).

Description

[0001] Description

[0002] OPTOELECTRONIC SEMICONDUCTOR COMPONENT AND METHOD FOR FABRICING AN OPTOELECTRONIC SEMICONDUCTOR COMPONENT

[0003] An optoelectronic semiconductor device and a method for fabricating an optoelectronic semiconductor device are described. The optoelectronic semiconductor device is preferably configured to emit electromagnetic radiation.

[0004] One task to be solved is to specify an optoelectronic semiconductor device with a particularly compact design.

[0005] Another task to be solved is to specify a method for manufacturing an optoelectronic semiconductor device with a particularly compact design.

[0006] These tasks are solved by a device and a method according to the independent claims. Advantageous embodiments and further developments of the device and the method are the subject of the dependent claims and are further described in the following description and figures.

[0007] According to at least one embodiment, the optoelectronic semiconductor device comprises a micro-LED and a conversion element.

[0008] A micro-LED can be, for example, any light-emitting diode (LED) with a particularly small lateral extent. Specifically, the growth substrate of the micro-LED is removed, so that the typical vertical extent of micro-LEDs is, for example, in the range of 1 pm to 10 pm. The micro-LED can have a rectangular emission surface. For example, rectangular micro-LEDs often have an edge length—especially when viewed from above, looking at the layers of the stack—of less than or equal to 100 pm or less than or equal to 50 pm. Various notations for micro-LED can be found in the literature, e.g., pLED, p-LED, uLED, u-LED, or Micro Light Emitting Diode.

[0009] The micro-LED is based in particular on a nitride compound semiconductor material. "Based on a nitride compound semiconductor material" in this context means that a semiconductor layer sequence or at least a part thereof, particularly preferably at least an active region and / or a growth substrate wafer, is a nitride compound semiconductor material, preferably AlnGamlnx-n- m N, where 0 < n < 1, 0 < m < 1, and n+m < 1. This material does not necessarily have to have a mathematically exact composition according to the formula above. Rather, it may, for example, contain one or more dopants as well as additional components. For the sake of simplicity, however, the formula above only includes the essential components of the crystal lattice (Al, Ga, In, N), even if these are partially replaced by small amounts.

[0010] Quantities of other substances may be replaced and / or added.

[0011] The micro-LED comprises, in particular, a metal reflector that directs electromagnetic radiation generated in the micro-LED into a principal emission direction. Preferably, the metal reflector has a lateral extent of at least 200 nm, and more preferably at least 500 nm, at a principal emission surface of the micro-LED. The metal reflector is preferably made of at least one of the following materials: aluminum, titanium, platinum.

[0012] Here and in the following, a lateral direction refers to a direction parallel to a principal extension direction of the semiconductor device. Here and in the following, a vertical direction refers to a direction parallel to a stacking direction of the semiconductor layers of the micro-LEDs and a direction transverse, in particular perpendicular to, the lateral direction.

[0013] The conversion element comprises, in particular, a matrix material and a plurality of conversion particles. The matrix material is, for example, formed with a radiolucent organic material. Preferably, the matrix material comprises a polysiloxane, a silicone, or an epoxy resin. The conversion element has, in particular, a thickness of at least 10 pm and at most 50 pm. Here and in the following, the thickness of the conversion element corresponds to its average extent in the vertical direction. The thickness is determined, among other things, by the material used, the desired application, and the transmission properties.

[0014] According to at least one embodiment of the optoelectronic semiconductor device, the micro-LED is configured to emit initial electromagnetic radiation in the blue wavelength range. The blue wavelength range includes, in particular, wavelengths between 400 nm and 485 nm. Short-wavelength blue radiation is especially well-suited for exciting conversion materials configured to emit green or red light, as well as for exciting conversion materials to generate white light.

[0015] According to at least one embodiment of the optoelectronic semiconductor device, the conversion element is configured to convert the first electromagnetic radiation into a second electromagnetic radiation. In particular, the conversion element comprises conversion particles formed with quantum dots and / or phosphors. Preferably, particles with a mean diameter of at most 2 pm, and more preferably at most 1 pm, are used as phosphors.

[0016] According to at least one embodiment of the optoelectronic semiconductor device, the conversion element is in direct contact with the micro-LED. In particular, the conversion element adheres to the micro-LED by means of the matrix material. Preferably, the semiconductor device is free of an adhesive layer between the conversion element and the micro-LED.

[0017] According to at least one embodiment, the optoelectronic semiconductor device comprises a micro-LED and a conversion element, wherein

[0018] - the micro-LED is set up to emit initial electromagnetic radiation in the blue wavelength range ,

[0019] - the conversion element is set up to convert the first electromagnetic radiation into a second electromagnetic radiation and

[0020] - the conversion element is in direct contact with the micro-LED. The following considerations underlie the optoelectronic module described here: To manufacture displays with micro-LEDs, micro-LEDs with different emission wavelengths are required. Such micro-LEDs have often featured different semiconductor materials, as combining micro-LEDs with wavelength conversion elements has been difficult to achieve. Conventional methods for applying conversion elements are too coarse and therefore cannot be applied to micro-LEDs on a smaller scale. Furthermore, conventional methods involve first separating the LEDs, and the conversion element is often only applied during the subsequent integration of the chip into a package. However, such a procedure is not suitable for micro-LEDs, as handling individual micro-LEDs is extremely complex.

[0021] The optoelectronic module described here utilizes, among other things, the idea of ​​applying a conversion layer to a plurality of micro-LEDs by lamination. Subsequently, the conversion layer can be separated into a plurality of individual conversion elements, thus enabling the simultaneous fabrication of a plurality of bondable semiconductor devices.

[0022] According to at least one embodiment of the optoelectronic semiconductor device, the side surfaces of the conversion element exhibit traces of an ablation process. These traces are, in particular, traces of an etching process, laser ablation, or sawing process. According to at least one embodiment of the optoelectronic semiconductor device, the conversion element is formed with a B-stage material. A B-stage material can be described as partially cured or, more accurately, as "pre-dried." Specifically, the material of the conversion element is only partially cross-linked before contact with the micro-LEDs. Only in a subsequent process step is the adhesive fully cured, for example, by the application of heat and / or irradiation with light or pressure. For example, the material of the conversion element comprises two different types of cross-linking.In other words, two different types of cross-linking exist in the molecular bonds of the material. According to another variant, the material of the conversion element contains chemically linked quantum dots, from which only solvent evaporated in a first step.

[0023] A method for manufacturing an optoelectronic semiconductor device is further described. The optoelectronic semiconductor device can be manufactured in particular using the method described here. That is to say, all features related to the optoelectronic semiconductor device described here also apply to the method for manufacturing an optoelectronic semiconductor device described here, and vice versa.

[0024] According to at least one embodiment of the method for manufacturing an optoelectronic semiconductor device, a plurality of micro-LEDs are provided on a primary substrate. The primary substrate is preferably mechanically self-supporting. For example, the primary substrate is formed with silicon.

[0025] According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, a conversion layer is laminated directly onto the micro-LEDs. Lamination, in particular, joins two planar components together in a single process step. Specifically, the components are joined under increased pressure and temperature. Advantageously, no additional adhesive layer is required.

[0026] According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, the conversion layer is separated into a plurality of conversion elements to form a plurality of semiconductor devices, each comprising a micro-LED and a conversion element. In particular, ablation traces are created on the side surfaces of the conversion elements by the separation of the conversion layer.

[0027] According to at least one embodiment, the method for manufacturing an optoelectronic semiconductor device comprises the following steps:

[0028] - Providing a plurality of micro-LEDs on a primary substrate,

[0029] - Laminating a conversion layer directly onto the micro-LEDs and

[0030] - Separating the conversion layer into a plurality of conversion elements to form a plurality of semiconductor devices, each comprising a micro-LED and a conversion element. According to at least one embodiment of the method for manufacturing an optoelectronic semiconductor device, the conversion layer is only partially crosslinked before contact with the micro-LEDs. Preferably, the degree of crosslinking of the conversion layer before contact with the micro-LEDs is between 50% and 90%, more preferably between 60% and 80%.

[0031] According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, a sacrificial layer is placed between the micro-LEDs and the primary substrate. In particular, the sacrificial layer is completely or partially removed in further process steps. The sacrificial layer is, for example, formed with silicon oxide.

[0032] According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, a compound layer is arranged between the sacrificial layer and the primary substrate. In particular, the compound layer is completely or partially removed in further process steps. The compound layer is preferably formed with an organic material, for example, benzocyclobutene. The compound layer serves in particular to planarize the micro-LEDs and preferably establishes a mechanical connection between the micro-LEDs and the primary substrate.

[0033] According to at least one implementation form of the procedure for

[0034] In the fabrication of an optoelectronic semiconductor device, the interconnect layer and the micro-LEDs are connected exclusively by means of a retention structure. Advantageously, the retention structure has a reduced contact area with the micro-LED. In other words, the lateral extent of the interconnect layer in the region of the retention structure is reduced compared to the lateral extent of the micro-LEDs. The retention structure comprises, in particular, a plurality of retention elements.

[0035] According to at least one embodiment of the method for manufacturing an optoelectronic semiconductor device, the conversion layer is separated into a plurality of conversion elements before the micro-LEDs are detached from the primary substrate. Preferably, the separation of the conversion layer is carried out using a plasma etching process, in particular with an ozone plasma.

[0036] According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, the conversion layer is separated by means of a plurality of separation grooves that provide access to the sacrificial layer. In other words, the separation grooves extend from a side of the conversion layer facing away from the micro-LEDs to at least the sacrificial layer. Advantageously, the separation grooves are created using one of the following methods: plasma etching, laser etching, sawing, or wet chemical etching. The use of a mask layer is particularly advantageous for plasma etching, wet chemical etching, and laser etching. The micro-LEDs can advantageously serve as a mask for a separation step. A mask layer can be omitted in a sawing process.According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, the sacrificial layer is removed after the separation grooves have been created. Specifically, the sacrificial layer is removed using gaseous hydrofluoric acid. After removal of the sacrificial layer, the micro-LEDs are only in direct contact with the interconnect layer via the retention structures. Advantageously, the semiconductor devices can then be easily mechanically detached from the interconnect layer.

[0037] According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, the conversion layer is separated after the micro-LEDs are detached from the primary substrate.

[0038] According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, the conversion layer is arranged on a secondary support. The secondary support is preferably radiolucent. For example, the secondary support is formed with quartz or sapphire. A separating layer is preferably arranged between the conversion layer and the secondary support. The separating layer is preferably formed with zinc oxide, cerium oxide, or aluminum nitride. The separating layer facilitates the detachment of the conversion layer from the secondary support in subsequent process steps.

[0039] According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, the conversion layer is optically characterized before being deposited onto the micro-LEDs. In particular, optical parameters of the conversion layer, such as the color and brightness of the emitted radiation, are spatially resolved and determined under blue light illumination. Advantageously, areas of the conversion layer that deviate too far from the desired optical parameters can then be discarded or omitted.

[0040] According to at least one embodiment of the method for manufacturing an optoelectronic semiconductor device, the semiconductor devices are detached from the secondary substrate by means of laser-induced forward transfer (LIFT).

[0041] According to at least one embodiment of the method for manufacturing an optoelectronic semiconductor device, the primary support and the interconnect layer are completely removed after the conversion layer has been applied to the micro-LEDs.

[0042] According to at least one embodiment of the method for manufacturing an optoelectronic semiconductor device, the sacrificial layer serves as an etch stop for the interconnect layer and as a hard mask for creating the separation grooves. In particular, the sacrificial layer extends completely between the interconnect layer and the microLEDs. The sacrificial layer is preferably formed with one of the following materials: SiO₂, Al₂O₃, TiO₂, nitrides, or organic material.

[0043] According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, recesses are formed laterally between the micro-LEDs in the interconnect layer before the conversion layer is applied. The recesses are formed, for example, by a plasma ashing process. The micro-LEDs preferably serve as masks for the ashing process. The recesses increase the distance between the conversion layer and the interconnect layer. This reduces or prevents unwanted adhesion of the conversion layer to the interconnect layer.

[0044] According to at least one embodiment of the method for manufacturing an optoelectronic semiconductor device, the depth of the recesses is at least 2 pm, preferably at least 5 pm, and particularly preferably at least 10 pm. The depth of the recesses corresponds to their extent in the vertical direction measured from a surface of the micro-LEDs.

[0045] The optoelectronic semiconductor device described here is particularly suitable for use in displays. The micro-LEDs form pixels or subpixels and emit light of a defined color. Due to their small pixel size and high density with close spacing, micro-LEDs are suitable, among other things, for small monolithic displays for AR applications, especially smart glasses, and also for televisions, vehicle displays, or vehicle exterior lighting, for example in taillights or brake lights.

[0046] Further advantages, beneficial designs, and further developments of the optoelectronic semiconductor device result from the following exemplary embodiments shown in the figures. These show:

[0047] Figures 1A to ID show schematic sectional views of an optoelectronic semiconductor device described herein in various steps of a method for its manufacture according to a first embodiment.

[0048] Figures 2A to 2E are schematic sectional views of an optoelectronic semiconductor device described here in various steps of a method for its manufacture according to a second exemplary embodiment.

[0049] Figures 3A to 3F are schematic sectional views of an optoelectronic semiconductor device described here in various steps of a method for its manufacture according to a third exemplary embodiment.

[0050] Figures 4A and 4B are schematic sectional views of an optoelectronic semiconductor device described herein in various steps of a method for its manufacture according to a fourth embodiment and

[0051] Figure 5 shows a detailed schematic sectional view of an optoelectronic semiconductor device described here.

[0052] Identical, similar, or similarly effective elements are marked with the same reference symbols in the figures. The figures and the relative sizes of the elements depicted within them are not to be considered to scale. Rather, individual elements may be exaggerated for clarity and / or to improve representation.

[0053] Figures 1A to ID show schematic sectional views of an optoelectronic semiconductor device 1 described herein in various steps of a method for its manufacture according to a first embodiment.

[0054] Figure 1A shows a first step of a method for fabricating an optoelectronic semiconductor device 1. A plurality of micro-LEDs 100 are provided on a primary support 110. The primary support 110 is preferably mechanically self-supporting. For example, the primary support 110 is formed with silicon.

[0055] The micro-LEDs 100 are each configured to emit initial electromagnetic radiation in the blue wavelength range. The blue wavelength range includes, in particular, wavelengths between 400 nm and 485 nm. Short-wavelength blue radiation is especially well-suited for exciting conversion materials configured to emit green or red light, as well as for exciting conversion materials to generate white light.

[0056] A sacrificial layer 40 is arranged between the micro-LEDs 100 and the primary support 110. In particular, the sacrificial layer 40 is completely or partially removed in further process steps. The sacrificial layer 40 is formed, for example, with silicon oxide. A compound layer 11 is arranged between the sacrificial layer 40 and the primary support 110. In particular, the compound layer 11 is completely or partially removed in further process steps. The compound layer 11 is preferably formed with an organic material, for example, benzocyclobutene. The compound layer 11 serves, in particular, to planarize the micro-LEDs 100 and preferably establishes a mechanical connection between the micro-LEDs 100 and the primary support 110.

[0057] The interconnect layer 11 and the micro-LEDs 100 are each connected to each other exclusively by means of a retaining structure 50. The retaining structure 50 advantageously has a reduced contact area with the micro-LED 100. In other words, the extent of the interconnect layer 11 in a lateral direction X in the region of the retaining structure 50 is reduced compared to the extent of the micro-LEDs 100 in the lateral direction X. The retaining structure 50 comprises, in particular, a plurality of retaining elements. A lateral direction X here and in the following refers to a direction parallel to a principal direction of extension of the semiconductor device. A vertical direction Y here and in the following refers to a direction parallel to a stacking direction of the semiconductor layers of the micro-LEDs 100 and a direction transverse, in particular perpendicular to, the lateral direction X. The interconnect layer 11 contacts the micro-LEDs 100 exclusively through the retaining structures 50.The sacrificial layer 40, with the exception of the holding structures 50, is arranged entirely between the micro-LEDs 100 and the interconnect layer 11. Figure IB shows a further step of a process for manufacturing an optoelectronic semiconductor device 1. A conversion layer 20 is laminated directly onto the micro-LEDs 100. In lamination, two planar devices are joined together in a single process step. In particular, the devices are joined together under increased pressure and temperature. Advantageously, no additional adhesive layer is required.

[0058] The conversion layer 20 is formed with a B-stage material. A B-stage material can be described as partially cured or, better yet, as "pre-dried." In particular, the material of the conversion layer 20 is only partially cross-linked before contact with the micro-LEDs 100. Only in a subsequent process step is the adhesive fully cured by the application of heat, and / or irradiation with light or under pressure. Preferably, the degree of cross-linking of the conversion layer 20 before contact with the micro-LEDs 100 is between 50% and 90%, more preferably between 60% and 80%.

[0059] The conversion layer 20 comprises, in particular, a matrix material and a plurality of conversion particles. The matrix material is, for example, formed with a radiolucent organic material. Preferably, the matrix material comprises a polysiloxane or an epoxy resin. The conversion layer 20 has, in particular, a thickness of at least 10 pm and at most 50 pm. The thickness of the conversion layer 20 corresponds here and in the following to an average extent of the conversion layer 20 in the vertical direction Y. The material of the conversion layer 20 is configured for converting the first electromagnetic radiation into a second electromagnetic radiation. In particular, the conversion layer 20 comprises conversion particles formed with quantum dots and / or phosphors. Preferably, particles with an average diameter of at most 2 pm, and more preferably of at most 1 pm, are used as phosphors.

[0060] The conversion layer 20 is in direct contact with the micro-LEDs 100. In particular, the conversion layer 20 adheres to the micro-LED 100 by means of the matrix material. Preferably, the semiconductor device 1 is free of an adhesive layer between the conversion layer 20 and the micro-LEDs 100.

[0061] Figure IC shows a further step of a process for manufacturing an optoelectronic semiconductor device 1. According to at least one embodiment of the process for manufacturing an optoelectronic semiconductor device, the conversion layer 20 is separated into a plurality of conversion elements 200 to form a plurality of semiconductor devices 1, each comprising a micro-LED 100 and a conversion element 200. In particular, ablation traces are created on the side surfaces 200A of the conversion elements 200 by separating the conversion layer 20.

[0062] The conversion layer 20 is separated into a plurality of conversion elements 200 before the micro-LEDs 100 are detached from the primary substrate 110. Preferably, the conversion layer 20 is separated using a plasma etching process, in particular with an ozone plasma. The separation of the conversion layer 20 is achieved by means of a plurality of separation grooves 31 that provide access to the sacrificial layer 40. In other words, the separation grooves 31 extend from a side of the conversion layer 20 facing away from the micro-LEDs 100 to at least the sacrificial layer 40. Advantageously, the separation grooves 31 are created using one of the following methods: plasma etching, laser cutting, sawing, or wet chemical etching. The use of a mask layer is particularly advantageous for plasma etching, wet chemical etching, and laser cutting. The micro-LEDs can advantageously serve as a mask for a singulation step.A mask layer can be omitted during a sawing process.

[0063] Figure ID shows a further step of a process for fabricating an optoelectronic semiconductor device 1. The sacrificial layer 40 is removed after the separation grooves 31 have been introduced. In particular, the sacrificial layer 40 is removed using gaseous hydrofluoric acid. After the removal of the sacrificial layer 40, the micro-LEDs 100 are only in direct contact with the interconnect layer 11 via the support structures 50.

[0064] Advantageously, the semiconductor components 1 can then be easily mechanically detached from the interconnect layer 11 and thus separated.

[0065] Figures 2A to 2E show schematic sectional views of an optoelectronic semiconductor device 1 described herein in various steps of a method for its fabrication according to a second embodiment. Figure 2A shows a first step of a method for fabricating an optoelectronic semiconductor device 1. A secondary support 120 is provided. The secondary support 120 is preferably radiolucent. For example, the secondary support 120 is formed with quartz or sapphire. A separating layer 121 is applied to the secondary support 120. The separating layer 121 is preferably formed with zinc oxide, cerium oxide, or aluminum nitride.

[0066] Figure 2B shows a further step of a process for fabricating an optoelectronic semiconductor device 1. A conversion layer 20 is laminated directly onto the separating layer 121. In subsequent process steps, the separating layer 121 simplifies the detachment of the conversion layer 20 from the secondary support 120.

[0067] Subsequently, the conversion layer 20 can be optically characterized before being applied to the micro-LEDs 100. In particular, optical parameters of the conversion layer 20, such as the color temperature and brightness of the emitted radiation, are spatially resolved and determined under blue light illumination. Advantageously, areas of the conversion layer 20 that deviate too far from the desired optical parameters can then be discarded or omitted.

[0068] Figure 2C shows a further step of a process for fabricating an optoelectronic semiconductor device 1. A plurality of micro-LEDs 100 are provided on a primary support 110. Subsequently, the conversion layer 20 is laminated onto the micro-LEDs 100. In particular, the material of the conversion layer 20 is only partially cross-linked prior to contact with the micro-LEDs 100.

[0069] The sacrificial layer 40 extends completely between the interconnect layer 11 and the micro-LEDs 100. The sacrificial layer 40 is not interrupted by any retaining structures 50. The sacrificial layer 40 is preferably formed with one of the following materials: SiO2, Al2O3, TSO2, nitrides, or organic material.

[0070] Figure 2D shows a further step in a process for fabricating an optoelectronic semiconductor device 1. The primary support 110 and the interconnect layer 11 are completely removed after the conversion layer 20 is applied to the micro-LEDs 100. The sacrificial layer 40 serves, for example, as an etch stop layer for the removal of the interconnect layer 11.

[0071] Figure 2E shows a further step of a process for manufacturing an optoelectronic semiconductor device 1. The conversion layer 20 is separated by means of a plurality of separation grooves 31. The separation grooves 31 extend from a side of the conversion layer 20 facing away from the secondary support 120 to at least the separation layer 121. The sacrificial layer 40 also serves, for example, as a hard mask for introducing the separation grooves 31.

[0072] In subsequent process steps, singulation can be achieved by detaching the individual semiconductor devices 1 from the secondary carrier 120, for example by means of laser-induced forward transfer. Figures 3A to 3F show schematic sectional views of an optoelectronic semiconductor device 1 described herein in various steps of a process for its fabrication according to a third embodiment.

[0073] Figure 3A shows a first step of a process for fabricating an optoelectronic semiconductor device 1. The provided micro-LEDs 100 on a primary substrate 110 correspond to the elements shown in Figure 1A.

[0074] Figure 3B shows a further step in a process for fabricating an optoelectronic semiconductor device 1. The sacrificial layer 40 is completely removed before the conversion layer 20 is laminated onto the micro-LEDs 100. After the removal of the sacrificial layer 40, the micro-LEDs 100 are only in direct contact with the interconnect layer 11 via the support structures 50.

[0075] Figure 30 shows a further step of a process for fabricating an optoelectronic semiconductor device 1. A conversion layer 20 provided on a secondary carrier 120 is laminated onto the micro-LEDs 100. The material of the conversion layer 20 is only partially cross-linked before contact with the micro-LEDs 100.

[0076] Figure 3D shows a further step in a process for manufacturing an optoelectronic semiconductor device 1. The primary support 110 and the interconnect layer 11 are mechanically detached from the micro-LEDs 100. For example, the weak remaining mechanical connection between the micro-LEDs 100 and the interconnect layer 11 via the retention structures 50 can be eliminated by the shrinkage of the matrix material of the conversion layer 20 during residual curing.

[0077] Figure 3E shows a further step of a process for manufacturing an optoelectronic semiconductor device 1. The conversion layer 20 is separated by means of a plurality of separation grooves 31. The separation grooves 31 extend from a side of the conversion layer 20 facing away from the secondary support 120 to at least the separation layer 121. The micro-LEDs 100 also serve, for example, as a hard mask for introducing the separation grooves 31.

[0078] Figure 3F shows a further step of a process for manufacturing an optoelectronic semiconductor device 1. The semiconductor devices 1 are detached from the secondary support 120 by means of a laser-induced forward transfer onto a target substrate 130. The separating layer 121 is illuminated with laser radiation E from a side of the secondary substrate 120 facing away from the semiconductor devices 1. This causes the semiconductor devices 1 to detach from the separating layer 121. Advantageously, the individual semiconductor devices 1 can thus be selectively transferred individually or in parallel onto the target substrate 130.

[0079] Figures 4A and 4B show schematic sectional views of an optoelectronic semiconductor device 1 described herein in various steps of a method for its fabrication according to a fourth embodiment. The steps shown in Figures 4A and 4B represent alternative embodiments of the steps shown in Figures 3B and 3C.

[0080] In the step shown in Figure 4A, recesses 32 are additionally formed laterally between the micro-LEDs 100 in the interconnect layer 11 before the conversion layer 20 is arranged. The recesses 32 are formed, for example, by means of a plasma ashing process. The micro-LEDs 100 preferably serve as masks for the ashing process.

[0081] Figure 4B clearly shows that the recesses 32 increase the distance between the conversion layer 20 and the bonding layer 11. This reduces or prevents unwanted adhesion of the conversion layer 20 to the bonding layer 11.

[0082] The depth 32Y of the recesses 32 is at least 2 pm, preferably at least 5 pm, and particularly preferably at least 10 pm. The depth 32Y of the recesses 32 corresponds to their extent in the vertical direction Y measured from a surface of the micro-LEDs 100.

[0083] Figure 5 shows a detailed schematic sectional view of an optoelectronic semiconductor device 1 described herein. For the sake of clarity, the details have been omitted in the remaining Figures 1 to 4. In particular, each semiconductor device 1 of the preceding Figures 1 to 4 has a structure according to the example of Figure 5. The micro-LED 100 comprises a first semiconductor region 101 of a first conductivity, a second semiconductor region 102 of a second conductivity, and an active region 103 configured for generating electromagnetic radiation. The active region 103 is arranged between the first semiconductor region 101 and the second semiconductor region 102 and comprises a pn junction. In particular, the first conductivity is a p-type conductivity and the second conductivity is an n-type conductivity.

[0084] A conversion element 200 is arranged on a side of the second semiconductor region 102 facing away from the active region 103. A contact layer 80 and an electrode 90 are arranged for electrical contacting the first region 101. The contact layer 80 is formed, for example, with indium tin oxide. The electrode 90 is preferably formed with nickel and gold. Electrical contacting of the second semiconductor region 102 is carried out separately and is not shown here.

[0085] The semiconductor device 1 further comprises a metal reflector 60 on a side of the first region 101 facing away from the conversion element 200 and on side faces of the semiconductor regions 101, 102, 103. The metal reflector 60 directs electromagnetic radiation generated in the micro-LED 100 into a principal emission direction. Preferably, the metal reflector 60 has a lateral extent 60X of at least 200 nm, preferably at least 500 nm, on a principal emission surface of the micro-LED 100. Such a large lateral extent of the metal reflector 60 simplifies the removal of the sacrificial layer 40 after the conversion layer 20 has been applied. The metal reflector 60 is at least partially embedded by an insulating layer 70. The insulating layer 70 is formed in particular by means of atomic layer deposition and prevents an electrical short circuit of the pn junction through the metal reflector 60.

[0086] The sacrificial layer 40 shown here is partially interrupted by holding structures 50. The holding structures 50 each comprise at least three holding elements.

[0087] The invention is not limited by the description based on the exemplary embodiments. Rather, the invention encompasses every new feature as well as every combination of features, which in particular includes every combination of features in the patent claims, even if this feature or combination itself is not explicitly specified in the patent claims or exemplary embodiments.

[0088] This patent application claims priority over German patent application 102024115785.2, the disclosure content of which is hereby incorporated by reference.

[0089] Reference character list

[0090] I optoelectronic semiconductor device

[0091] II Compound layer

[0092] 100 micro-LEDs

[0093] 101 First Semiconductor Area

[0094] 102 second semiconductor area

[0095] 103 active area

[0096] 20 Conversion layer

[0097] 200 conversion element

[0098] 200A Side surfaces of the conversion element

[0099] 31 Separation trench

[0100] 32 Exclusion

[0101] 32Y Depth of the recesses

[0102] 40 victim layer

[0103] 50 support structure

[0104] 60 metal reflector

[0105] 60X thickness of the metal reflector

[0106] 70 I insulation layer

[0107] 80 Contact layer

[0108] 90 electrode

[0109] 110 primary carriers

[0110] 120 secondary carriers

[0111] 121 Separation layer

[0112] 130 target substrate

[0113] E Laser radiation

Claims

Patent claims 1. Optoelectronic semiconductor device (1) comprising a micro-LED (100) and a conversion element (200) , wherein - the micro-LED (100) is set up to emit initial electromagnetic radiation in the blue wavelength range, - the conversion element (200) is set up to convert the first electromagnetic radiation into a second electromagnetic radiation, - the conversion element (200) is in direct contact with the micro-LED (100), and - the conversion element (200) is formed with a B-stage material.

2. Optoelectronic semiconductor device (1) according to the preceding claim, wherein - The side surfaces (200A) of the conversion element (200) show traces of a removal process.

3. Optoelectronic semiconductor device (1) according to the preceding claim, wherein the traces of an ablation process are traces of an etching process, a laser ablation or a sawing process.

4. Method for fabricating an optoelectronic semiconductor device (1) , comprising the steps: - Providing a plurality of micro-LEDs (100) on a primary substrate (110) , - Laminating a conversion layer (20) directly onto the micro-LEDs (100) , - Separating the conversion layer (20) into a plurality of conversion elements (200) to form a plurality of semiconductor devices (1) each comprising a micro-LED (100) and a conversion element (200) , and - the conversion layer (20) is only partially cross-linked before contact with the microLEDs (100).

5. Method for manufacturing an optoelectronic semiconductor device (1) according to the preceding claim, wherein the degree of crosslinking of the conversion layer (20) prior to contact with the micro-LEDs (100) is between 50% and 90%.

6. Method for manufacturing an optoelectronic semiconductor device (1) according to one of the preceding claims, wherein - a sacrificial layer (40) is arranged between the micro-LEDs (100) and the primary carrier (110).

7. Method for manufacturing an optoelectronic semiconductor device (1) according to one of the preceding claims, wherein - a connecting layer (11) is arranged between the sacrificial layer (40) and the primary carrier (110).

8. Method for manufacturing an optoelectronic semiconductor device (1) according to the preceding claim, wherein - the interconnect layer (11) and the micro-LEDs (100) are connected to each other exclusively by means of a holding structure (50).

9. Method for producing an optoelectronic semiconductor device (1) according to one of the preceding claims, whereby - the conversion layer (20) is separated into a plurality of conversion elements (200) before the microLEDs (100) are detached from the primary carrier (110).

10. Method for manufacturing an optoelectronic semiconductor device (1) according to the preceding claim, wherein - the separation of the conversion layer (20) by means of a plurality of separation trenches (31) which make the sacrificial layer (40) accessible.

11. Method for manufacturing an optoelectronic semiconductor device (1) according to the preceding claim, wherein - the sacrificial layer (40) is removed after the separation trenches have been dug.

12. Method for manufacturing an optoelectronic semiconductor device (1) according to one of the preceding claims, wherein - the conversion layer (20) is separated after the micro-LEDs (100) are detached from the primary carrier (110).

13. Method for manufacturing an optoelectronic semiconductor device (1) according to one of the preceding claims, wherein - the conversion layer (20) is arranged on a secondary support (120).

14. Method for manufacturing an optoelectronic semiconductor device (1) according to the preceding claim, wherein - the semiconductor components (1) are detached from the secondary support (120) by means of laser-induced forward transfer.

15. Method for manufacturing an optoelectronic semiconductor device (1) according to one of the preceding claims, wherein - the sacrificial layer (40) serves as an etching stop for the bonding layer (11) and as a hard mask for the insertion of the separating trenches (31).

16. Method for manufacturing an optoelectronic semiconductor device (1) according to one of the preceding claims, wherein - recesses (32) are formed laterally between the micro-LEDs (100) in the interconnect layer (11) before the conversion layer (20) is arranged.

17. Method for manufacturing an optoelectronic semiconductor device (1) according to the preceding claim, wherein - the depth (32Y) of the recesses (32) is at least 2 pm, preferably at least 5 pm and particularly preferably at least 10 pm.

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