Optoelectronic component and method for producing optoelectronic component

Abstract

In at least one embodiment, the optoelectronic component (1) has at least one optoelectronic semiconductor chip (2), at least one optical element (3) and an intermediate layer (4) between the at least one optoelectronic semiconductor chip (2) and the at least one optical element (3). The at least one optoelectronic semiconductor chip (2) is configured to emit radiation in a first wavelength range. The at least one optical element (3) is formed by means of a material which is transmissive to radiation in the second wavelength range (6). The intermediate layer (4) comprises a material that is transmissive to radiation from the first wavelength range and that is absorptive to radiation from the second wavelength range (6). The first wavelength range comprises a different wavelength than the second wavelength range (6).

Description

Technical Field

[0001] An optoelectronic component is provided. Furthermore, a method for producing an optoelectronic component is provided. Summary of the Invention

[0002] The object to be solved is, in particular, to specify an optoelectronic component which is characterized by a high light extraction efficiency and a long service life. Another object to be solved is, in particular, to specify a method for producing such a component.

[0003] This object is achieved by the subject matter having the features of independent claim 1 or by a method having the features of independent claim 10. Advantageous embodiments and developments are the subject matter of the respective dependent claims.

[0004] According to at least one embodiment of the optoelectronic component, the optoelectronic component comprises at least one optoelectronic semiconductor chip configured to emit radiation in a first wavelength range.

[0005] The at least one optoelectronic semiconductor chip comprises, for example, a semiconductor layer sequence having an active region for generating or absorbing electromagnetic radiation. The active region is formed, for example, using a III-V compound semiconductor material.

[0006] In principle, it is possible to generate electromagnetic radiation in the blue, green, or red spectral range, in the UV range, or in the IR range in the active region during normal operation. Preferably, radiation in the UV range, in particular radiation in the so-called UVC range of the electromagnetic spectrum, is generated during normal operation of the active region. In particular, the radiation generated in the active region during operation is radiation in the first wavelength range.

[0007] The at least one optoelectronic semiconductor chip further comprises, for example, a chip substrate. A semiconductor layer sequence is arranged on a main side of the chip substrate. The chip substrate is, for example, a growth substrate for the semiconductor layer sequence. The chip substrate preferably comprises sapphire or is formed from sapphire. Preferably, the at least one optoelectronic semiconductor chip is a volume emitter, in particular a sapphire chip.

[0008] Contact locations for contacting the semiconductor layer sequence and supplying electrical current thereto are provided on that side of the semiconductor layer sequence which faces away from the chip substrate. Preferably, the optoelectronic semiconductor chip is a flip chip.

[0009] Preferably, the optoelectronic semiconductor chip is in particular a light emitting diode, or LED for short. Alternatively, it is possible for the optoelectronic semiconductor chip to be a laser diode, for example an edge emitter or surface emitting semiconductor laser diode, also referred to as VCSEL for short.

[0010] According to at least one embodiment, the optoelectronic component includes at least one optical element. The at least one optical element is configured, for example, for beam shaping of radiation from a first wavelength range. The at least one optical element is, for example, a lens, a prism, or a metalens structure. The optical element enables radiation emitted by the at least one semiconductor chip to be directed during normal operation, for example, in a main emission direction. The main emission direction is preferably perpendicular to a main extension direction of the semiconductor layer sequence or of the active zone and is the direction in which the radiation from the first wavelength range emitted by the optoelectronic component during operation has its intensity maximum.

[0011] According to at least one embodiment, an optoelectronic component includes an intermediate layer, which is arranged between at least one optoelectronic semiconductor chip and at least one optical element. The intermediate layer serves, for example, as an adhesion promoter to secure the at least one optical element to the at least one semiconductor chip. Preferably, the intermediate layer is in direct contact with the at least one semiconductor chip and with the at least one optical element. The intermediate layer has, for example, a thickness of 1 μm to 5 μm inclusive. Roughness of the surface of the at least one optoelectronic semiconductor chip and / or the at least one optical element, on which the intermediate layer is arranged, can advantageously be compensated by means of the intermediate layer.

[0012] For example, the intermediate layer is arranged on the main emission surface of at least one optoelectronic semiconductor chip. During normal operation, a majority of the radiation generated in the active region, for example, at least 50% or at least 75%, is emitted via the main emission surface. If the at least one optoelectronic semiconductor chip is, for example, a sapphire chip, the main emission surface is, in particular, the surface of the chip substrate opposite the semiconductor layer sequence. Conversely, if the optoelectronic semiconductor chip is, for example, a laser diode, the main emission surface is preferably a facet of the laser diode.

[0013] According to at least one embodiment of the optoelectronic component, at least one optical element is formed from a material that is transmissive to radiation from the second wavelength range. For example, the material of the optical element includes glass. Alternatively or additionally, it is possible to form the optical element from sapphire and / or quartz. When a material or element is referred to as being "transmissive" for a specific radiation, in particular, it has a transmittance of at least 80%, at least 90%, or at least 95% with respect to that radiation.

[0014] According to at least one embodiment of the optoelectronic component, the intermediate layer includes a material that is transmissive for radiation from a first wavelength range and absorptive for radiation from a second wavelength range. If a material or element is referred to here and hereinafter as "absorptive" for a specific radiation, it in particular has a reflectivity with respect to this radiation of at least 80%, at least 90%, or at least 95%.

[0015] The intermediate layer comprises, for example, glass. The intermediate layer is designed, for example, to have high transmittance at a wavelength of 275 nm and absorbency at shorter wavelengths. The material of the intermediate layer is particularly designed to be insensitive to radiation from the first wavelength range. This means that the intermediate layer is not decomposed or damaged by radiation from the first wavelength range. If, for example, the semiconductor chip is a sapphire chip that emits radiation in the UVC range during operation, i.e., the first wavelength range is the UVC region, the intermediate layer is preferably UV-stabilized.

[0016] In particular, the intermediate layer does not contain any organic material. Preferably, the intermediate layer consists entirely of inorganic material. The material of the intermediate layer is adapted, for example, so that the intermediate layer can be heated by radiation from the second wavelength range.

[0017] According to at least one embodiment of the optoelectronic component, the first wavelength range has different wavelengths than the second wavelength range. For example, the first wavelength range and the second wavelength range are each non-overlapping, continuous ranges. This means, in particular, that every wavelength in the first wavelength range is not contained in the second wavelength range, and vice versa.

[0018] In at least one embodiment, an optoelectronic component includes at least one optoelectronic semiconductor chip, at least one optical element, and an intermediate layer between the at least one optoelectronic semiconductor chip and the at least one optical element. The at least one optoelectronic semiconductor chip is configured to emit radiation in a first wavelength range. The at least one optical element is formed using a material that is transmissive to radiation in a second wavelength range. The intermediate layer includes a material that is transmissive to radiation from the first wavelength range and absorptive to radiation from the second wavelength range. The first wavelength range includes wavelengths that differ from the second wavelength range.

[0019] Current optoelectronic components are based on the following technical considerations. Currently, for components comprising a semiconductor chip, particularly one emitting in the UVC range, and a lens, a fluoropolymer lens is typically applied directly to the semiconductor chip by casting or molding. This presents a challenge in selecting process conditions that avoid damaging the semiconductor chip and other materials while ensuring sufficient component stability. Delamination and reduced material service life are particularly problematic. This is primarily due to the high temperatures encountered during curing of the fluoropolymer lens, which can also damage the semiconductor chip.

[0020] An alternative concept is a glass lens that is applied to an optical carrier and fixed, for example, relative to the semiconductor chip. However, this results in a disadvantageous material transition from the semiconductor chip to air, followed by a material transition from air to glass and another material transition from glass to air, for light extraction efficiency in the emission direction. Due to the total internal reflection that occurs here, the lens effect is also counteracted, in addition to the efficiency loss.

[0021] An additional possibility is to apply the glass lens to a so-called fusion bond. However, this places very high demands on the roughness and cleanliness of the surfaces of the semiconductor chip and the glass lens. Typically, the roughness Ra needs to be less than 1 nm, where Ra represents the average roughness value. This can only be achieved with the help of special production processes. For example, with this process, only artificial wafers for the glass lens and semiconductor chip must be produced, in which the lens is embedded in the matrix material in order to subsequently achieve the required surface quality. After the fusion bonding process, the semiconductor chip must be detached from the matrix material together with the lens. This is very costly, which leads to very high process and development costs.

[0022] In the optoelectronic component of the present invention, the optical element is attached to the optoelectronic semiconductor chip via an intermediate layer. The use of the intermediate layer avoids air gaps between the optical element and the optoelectronic semiconductor chip. This improves optical outcoupling. Applying a lens to the front side of the semiconductor chip enables beam shaping in the forward direction. Advantageously, this significantly improves the light extraction efficiency of the optoelectronic component. At the same time, total internal reflection caused by, for example, material transitions to air when coupling radiation out of the optoelectronic component can be reduced. Consequently, the service life of the optoelectronic component can be advantageously increased.

[0023] According to at least one embodiment of the optoelectronic component, at least one optical element is configured for beam shaping of radiation from the first wavelength range and / or the second wavelength range. The at least one optical element is, for example, a lens, in particular a converging lens. During normal operation, radiation from the first wavelength range emitted by the optoelectronic semiconductor chip is directed, for example, in a main emission direction by means of the optical element.

[0024] Alternatively or additionally, the optical element serves as a lens for radiation in the second wavelength range, which is directed onto the intermediate layer, for example, during the production of the optoelectronic component. The optical element focuses the radiation, for example, onto the intermediate layer.

[0025] Alternatively, the at least one optical element can be a prism. By means of the prism, for example, the main emission direction of the optoelectronic component can be influenced. This can be advantageous in particular when the at least one optoelectronic semiconductor chip is a laser diode.

[0026] According to at least one embodiment of the optoelectronic component, at least one optical element and at least one optoelectronic semiconductor chip are cohesively connected to one another by means of an intermediate layer. This means, in particular, that no other materials are provided between the at least one optoelectronic semiconductor chip and the intermediate layer, and between the intermediate layer and the at least one intermediate element. The intermediate layer preferably directly adjoins the at least one optoelectronic semiconductor chip and the at least one optical element. Advantageously, this avoids material transitions to a low-refractive-index material between the at least one optoelectronic semiconductor chip and the at least one optical element, thereby increasing the efficiency of light extraction from the optoelectronic component.

[0027] According to at least one embodiment of the optoelectronic component, the first wavelength range lies in the UV range of the electromagnetic spectrum and includes wavelengths greater than or equal to 250 nm. For example, the first wavelength range includes wavelengths up to 380 nm, 300 nm, or 280 nm, inclusive. For example, during normal operation, the optoelectronic component emits radiation with a peak wavelength of 275 nm. The peak wavelength is the wavelength at which the emission spectrum of the optoelectronic component has its maximum intensity. The at least one optoelectronic semiconductor chip is therefore, in particular, a UV chip, for example, a UV sapphire chip.

[0028] According to at least one embodiment of the optoelectronic component, the first wavelength range lies in the UV range of the electromagnetic spectrum and includes wavelengths greater than or equal to 200 nm. For example, the first wavelength range includes wavelengths up to 380 nm, 300 nm, or 280 nm, inclusive. For example, during normal operation, the optoelectronic component emits radiation with a peak wavelength of 230 nm. The at least one optoelectronic semiconductor chip is therefore, in particular, a UV chip, for example, a UV sapphire chip.

[0029] According to at least one embodiment of the optoelectronic component, the second wavelength range includes wavelengths between 180 nm and 230 nm or between 150 nm and 200 nm, limit values ​​included. The second wavelength range is particularly in the UVC range of the electromagnetic spectrum. The second wavelength range preferably includes shorter wavelengths than the first wavelength range.

[0030] Alternatively, it is possible that the second wavelength range includes wavelengths that are greater than wavelengths from the first wavelength range. For example, the second wavelength range includes wavelengths from the IR range of the electromagnetic spectrum.

[0031] According to at least one embodiment of the optoelectronic component, at least one optical element has a higher melting point than the intermediate layer. For example, the melting point of the at least one optical element is twice, 1.5 times, or 1.3 times higher than the melting point of the intermediate layer. As a result, the intermediate layer between the at least one optoelectronic semiconductor chip and the at least one optical element can be at least partially melted by heating without damaging the optical element. The melting point of the intermediate layer is, for example, between 700° C. and 800° C. inclusive. The melting point of the optical element is, for example, greater than 1500° C.

[0032] According to at least one embodiment of the optoelectronic component, the intermediate layer includes a matrix material into which filler particles are introduced. The filler particles are formed, in particular, from a material that is transmissive or reflective for radiation from a first wavelength range and absorptive for radiation from a second wavelength range. The matrix material is preferably transmissive for radiation from both the first and second wavelength ranges. The matrix material is, for example, a fluoropolymer. The filler particles are, for example, silicon dioxide particles, also known as fused silica.

[0033] According to at least one embodiment of the optoelectronic component, the at least one optical element is a sapphire lens. If the at least one optoelectronic semiconductor chip is a sapphire chip, a sapphire lens is particularly advantageous as the at least one optical element, since the at least one optical element is adapted to the chip substrate of the semiconductor chip, for example, with respect to the coefficient of thermal expansion and / or the refractive index.

[0034] According to at least one embodiment of the optoelectronic component, the coefficients of thermal expansion of the at least one optical element, the at least one optoelectronic semiconductor chip, and the intermediate layer differ from one another by at most 0.5 ppm / K. If the at least one optoelectronic semiconductor chip is, for example, a sapphire chip and the at least one optical element is simultaneously a sapphire lens, they have the same coefficient of thermal expansion. In this case, the coefficient of thermal expansion of the at least one optoelectronic semiconductor chip and the at least one optical element is, for example, 7.9 ppm / K. Advantageously, the intermediate layer is then configured such that its coefficient of thermal expansion differs from that of the at least one optoelectronic semiconductor chip and the at least one optical element by at most 0.5 ppm / K. In this case, for example, the coefficient of thermal expansion of the intermediate layer is 7.7 ppm / K.

[0035] By matching the coefficients of thermal expansion of the at least one optoelectronic semiconductor chip, the at least one optical element and the intermediate layer, thermal stresses in the optoelectronic component can be reduced.

[0036] According to at least one embodiment, the optoelectronic component comprises a plurality of optoelectronic semiconductor chips in a chip array. Furthermore, the optoelectronic component comprises a plurality of optical elements in a lens array. The chip array and the lens array are connected to each other in a material-fitting manner by means of an intermediate layer.

[0037] According to at least one embodiment, at least one optoelectronic semiconductor chip is arranged on a carrier substrate. A connection layer is provided between the carrier substrate and the at least one optoelectronic semiconductor chip. The carrier substrate is formed, for example, by means of ceramic. The connection layer is preferably a solder layer, which electrically connects the at least one optoelectronic semiconductor chip to the carrier substrate. The connection layer comprises, for example, gold and / or tin. In particular, the connection layer can be formed by means of AuSn. On the side facing the at least one optoelectronic semiconductor chip, the carrier substrate preferably comprises a connection portion, via which the at least one optoelectronic semiconductor chip can be contacted and energized. On the side opposite the connection portion, the carrier substrate comprises, for example, a metallization. In particular, the connection portion is electrically connected to the metallization via a through-contact portion passing through the carrier substrate. It is feasible that the connection portion, the through-contact portion, and the metallization are formed integrally and each comprise at least one metal, such as copper.

[0038] According to at least one embodiment, an optoelectronic component includes a frame on a carrier substrate. The frame surrounds at least one optoelectronic semiconductor chip in a lateral direction. The frame is formed, for example, using a polymer and / or an epoxy, or alternatively comprises silicon. The lateral direction is, for example, a direction extending perpendicular to the main emission direction.

[0039] The frame is preferably provided with a reflective coating on the surface facing the optoelectronic semiconductor chip. The surface facing at least one optoelectronic semiconductor chip is preferably inclined. That is, the surface forms an acute angle with respect to the main extension plane of the active region. The reflective coating is reflective for radiation in the first wavelength range and preferably comprises at least one metal, such as aluminum. Advantageously, the frame and the reflective coating can deflect radiation emitted laterally by the semiconductor chip during normal operation in a main emission direction.

[0040] Furthermore, a method for producing an optoelectronic component is proposed. By means of this method, in particular, the optoelectronic component described here can be produced. This means that all features disclosed for the method are also disclosed for the component, and vice versa.

[0041] In at least one embodiment of the method, at least one optical element is provided in step A). ​​An intermediate layer is applied to a main surface of the at least one optical element in step B). The intermediate layer is applied, for example, by means of metered dispensing. Alternatively, the material for the intermediate layer can be applied, for example, as a thin plate, powder, or paste and subsequently melted. It is also possible to apply the material for the intermediate layer by means of sputtering, vapor deposition, coating, or spraying. At least one optoelectronic semiconductor chip is positioned on a side of the intermediate layer facing away from the at least one optical element.

[0042] In step C) of the method, at least one optoelectronic semiconductor chip is placed on the side of the intermediate layer facing away from the at least one optical element. In particular, the at least one optical element is placed on the at least one optoelectronic semiconductor chip via the intermediate layer. An adhesion promoter, such as glycerol, can be used to prevent the at least one semiconductor chip from slipping relative to the at least one optical element. In a further method step, the adhesion promoter is preferably removed again, for example by evaporation.

[0043] In a further step D), at least one optoelectronic semiconductor chip is connected to at least one optical element by irradiating the intermediate layer with radiation from a second wavelength range. The at least one optical element is preferably formed from a material that is transmissive to radiation from the second wavelength range. The radiation from the second wavelength range is absorbed in the intermediate layer, causing it to heat, at least locally, to a temperature above its melting point. The intermediate layer advantageously acts like a solder, for example, a glass solder.

[0044] In particular, the intermediate layer comprises a material which is absorptive for radiation from the second wavelength range and transmissive for radiation from the first wavelength range. Radiation of the first wavelength range is emitted, for example, by at least one optoelectronic semiconductor chip during normal operation.

[0045] Advantageously, heat is introduced only locally at the intermediate layer during the method, thereby keeping the thermal load relatively low during the method. In particular, the at least one optoelectronic semiconductor chip is only slightly heated during this process. The reduced thermal load can increase the overall service life of the optoelectronic component and reduce the risk of premature damage to the at least one semiconductor chip during component manufacturing. This can increase the service life of the optoelectronic component.

[0046] According to at least one embodiment of the method, in step D), the intermediate layer is irradiated with radiation from the second wavelength range through an optical element. The at least one optical element is configured, for example, for beam shaping of the radiation from the second wavelength range. By irradiating the intermediate layer through the at least one optical element, the radiation from the second wavelength range can be focused specifically onto the intermediate layer. This reduces the thermal load on the at least one optoelectronic semiconductor chip and the at least one optical element.

[0047] According to at least one embodiment of the method, laser radiation with a wavelength between 100 nm and 250 nm, preferably between 120 nm and 230 nm inclusive, is used in step D). The light source of this laser radiation is, for example, an F2 laser, a Xe2 laser, a KrCl laser, a KrF laser, or preferably an ArF laser. It is possible for the light source to be pulsed.

[0048] According to at least one embodiment of the method, the at least one optical element has a lateral extension greater than the beam width of the laser radiation when observing the main surface. The beam width of the laser radiation is, for example, measured perpendicularly to the propagation direction of the laser radiation. The lateral extension is, for example, the maximum extension of the at least one optical element in a lateral direction. The lateral extension of the at least one optical element is, for example, between 1000 μm and 6000 μm, for example, approximately 2500 μm or 5000 μm. Preferably, in this embodiment or in all embodiments, the at least one optical element has a lateral extension at least as large as the lateral extension of the main emission surface of the at least one optoelectronic semiconductor chip. In this case, in particular when observing the main emission surface, the main emission surface is completely covered by the at least one optical element. The beam width of the laser radiation is, for example, approximately 1740 μm. In particular, the at least one optical element is configured for beam shaping of the laser radiation. The laser radiation is focused onto the intermediate layer by the at least one optical element. This can reduce the thermal load on the at least one optoelectronic semiconductor chip and the at least one optical element.

[0049] According to at least one embodiment of the method, in step D), the intermediate layer is uniformly irradiated with laser radiation. This means, in particular, that the laser radiation has a width in the region of the intermediate layer that is equal to or greater than the lateral extent of the intermediate layer. The lateral extent of the intermediate layer is measured perpendicular to the propagation direction of the laser radiation. Advantageously, this allows the intermediate layer to be heated using a single irradiation process, and allows efficient connection of the at least one optical element to the at least one optoelectronic semiconductor chip.

[0050] Alternatively, it is possible that the laser radiation has a beam width in the region of the intermediate layer that is smaller than the lateral extension of the intermediate layer. In this case, the intermediate layer can be irradiated with the laser radiation in a grid-like manner.

[0051] According to at least one embodiment of the method, in step B), the at least one optical element is heated to a temperature above the melting temperature of the intermediate layer, so that the material of the intermediate layer is evenly distributed over the main surface. The at least one optical element is heated, for example, to at least 700°C or at least 800°C and up to 900°C or up to 1000°C. For example, the at least one optical element is heated using a hot plate. For example, the at least one optical element is provided on a hot plate. Preferably, the at least one optical element has a higher melting temperature than the intermediate layer. This prevents partial melting of the optical element.

[0052] According to at least one embodiment of the method, at least one optoelectronic semiconductor chip is applied to a carrier substrate before step C). During step D), the connection layer between the carrier substrate and the at least one optoelectronic semiconductor chip is heated to a maximum of 250° C. The connection layer is, for example, a solder layer. The connection layer may, for example, contain gold and / or tin or be formed using AuSn.

[0053] According to at least one embodiment of the method, a plurality of optical elements are provided in a lens array. An intermediate layer is applied to the lens array. The lens array is connected to a chip array comprising a plurality of optoelectronic semiconductor chips, such that each optoelectronic semiconductor chip is associated with at least one optical element. It is possible for each optoelectronic semiconductor chip to be associated with exactly one optical element.

[0054] According to at least one embodiment of the method, the composite of the lens array and the chip array is divided into a plurality of optical components. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Further advantages, advantageous embodiments, and improvements of the optoelectronic components and methods are apparent from the following exemplary embodiments illustrated in conjunction with the schematic diagrams. Identical, similar, and identically functioning elements are provided with the same reference numerals in the figures. The figures and the size relationships of the elements illustrated therein relative to one another should not, in principle, be regarded as true to scale. Rather, individual elements may be illustrated exaggeratedly for improved clarity and / or understanding.

[0056] The accompanying drawings show:

[0057] Figure 1 、 2 4 and 4 show cross-sectional views of embodiments of an optoelectronic device,

[0058] Figure 3 A detail view showing a cross-sectional view of an intermediate layer according to one embodiment,

[0059] Figures 5 to 11 sectional views showing different method stages of a method for producing an optoelectronic component according to two exemplary embodiments,

[0060] Figure 12 、 13 , 15 and 17 show graphical views of material properties of a material for an intermediate layer according to one embodiment,

[0061] Figure 14 shows simulation results for the outcoupling efficiency of the optoelectronic device described here,

[0062] Figure 16 A graphical view showing the material properties of materials used for optical components. DETAILED DESCRIPTION

[0063] Figure 1 The optoelectronic component 1 comprises an optoelectronic semiconductor chip 2 and an optical element 3. An intermediate layer 4 is arranged between the semiconductor chip 2 and the optical element 3.

[0064] The optoelectronic semiconductor chip 2 includes a semiconductor layer sequence 22. The semiconductor layer sequence 22 is based on a III-V compound semiconductor material. The semiconductor layer sequence 22 includes an active region (not shown). During proper operation, electromagnetic radiation is generated in the active region. During normal operation, this electromagnetic radiation is emitted by the optoelectronic semiconductor chip 2 and, therefore, by the optoelectronic component 1. The radiation is radiation from the first wavelength range 5.

[0065] The radiation in the first wavelength range 5 is electromagnetic radiation from the UV range of the electromagnetic spectrum, in particular the UVC range. For example, the optoelectronic component 1 emits radiation with a peak wavelength of 275 nm during normal operation. The peak wavelength is the wavelength at which the emission spectrum of the optoelectronic component 1 has its maximum intensity.

[0066] The optoelectronic semiconductor chip 2 further comprises a chip substrate 21 . A semiconductor layer sequence 22 is applied on the chip substrate 21 . The chip substrate 21 is a sapphire substrate. The semiconductor chip 2 is therefore a sapphire chip, in particular a volume emitter.

[0067] Contact locations 23 for electrically contacting the semiconductor layer sequence 22 are provided on that side of the semiconductor layer sequence 22 which faces away from the chip substrate 21. During normal operation, the semiconductor layer sequence 22 can be electrically supplied via the contact locations 23. The optoelectronic semiconductor chip 2 is thus a flip chip.

[0068] The intermediate layer 4 is arranged on the side of the chip substrate 21 facing away from the semiconductor layer sequence 22. The intermediate layer 4 comprises a matrix material 41 in which filler particles 42 are embedded. In the present exemplary embodiment, the matrix material 41 is formed by means of a fluoropolymer. The filler particles 42 are currently silicon dioxide particles (see Figure 3 ).

[0069] The intermediate layer 4 is transmissive to radiation from a first wavelength range 5. The intermediate layer 4 is designed to be absorptive to radiation from a second wavelength range 6, which includes wavelengths different from those of the first wavelength range 5. The second wavelength range 6, for example, includes shorter wavelengths than the first wavelength range 5. For example, the second wavelength range 6 is UV radiation with a wavelength of less than 230 nm. Alternatively, however, it is also possible for the second wavelength range to have longer wavelengths than the first wavelength range 5. Thus, the second wavelength range 6 can include radiation in the IR range, for example.

[0070] By irradiating the intermediate layer 4 with radiation in the second wavelength range 6, the optical element 3 can be fastened to the semiconductor chip 2. In this case, the intermediate layer 4 is heated by absorbing the radiation in the second wavelength range 6, so that a positive connection is produced between the semiconductor chip 2 and the optical element 3 (see also Figure 9 ).

[0071] The intermediate layer 4 has a thickness between 1 μm and 5 μm inclusive. The thickness of the intermediate layer 4 is selected in such a way that roughness on the side of the semiconductor chip 2 and / or the optical element 3 facing the intermediate layer 4 is compensated.

[0072] The optical element 3 is configured for beam shaping of radiation in the first wavelength range 5. The radiation can be directed in the direction of a main emission direction 10 by the optical element 3. The main emission direction 10 is preferably perpendicular to the main extension direction of the semiconductor layer sequence 22. It is also possible that the optical element 3 is configured for beam shaping of radiation from the second wavelength range 6 (see Figure 11 ).

[0073] In this embodiment, the optical element 3 is a lens. In this embodiment, the optical element 3 is formed using sapphire. Using sapphire for the optical element 3 and the chip substrate 21 can reduce thermal stresses in the optical device 1. The optical element 3 is designed to be transmissive to radiation in the first and second wavelength ranges 5 and 6. The optical element 3 preferably has a maximum lateral extension of 5000 μm. This lateral extension is measured in a direction parallel to the main extension plane of the semiconductor layer sequence 22.

[0074] Figure 2 An optoelectronic component 1 according to a second exemplary embodiment is shown. Figure 2 Optoelectronic devices 1 and Figure 1 The optoelectronic device 1 is distinguished in that, Figure 1 The optoelectronic component 1 is applied to a carrier substrate 7. The carrier substrate 7 includes a connection site 71 on the side facing away from the semiconductor chip 2 and a metallization 73 on the side opposite the connection site 71. The metallization 73 electrically connects the connection site 71 to the carrier substrate 7 via a plated-through contact 72. The carrier substrate 7 is formed using ceramic. The connection site 71, the plated-through contact 72, and the metallization 73 each include at least one metal, for example, copper. The optoelectronic component 1 can be externally contacted and electrically supplied via the metallization 73. The connection site, the plated-through contact, and the metallization 73 can be manufactured in one piece.

[0075] During normal operation, the semiconductor layer sequence 22 can be electrically energized via the contact locations 23, which are electrically conductively connected to the connection locations 71 by means of the connection layer 8. The connection layer 8 is a solder layer which comprises, in particular, AuSn.

[0076] Figure 2 The optoelectronic component 1 further comprises a frame 9. The frame is applied to the main side of the carrier substrate 7 and surrounds the semiconductor chip 2 and the optical element 3 in a lateral direction. The lateral direction is a direction perpendicular to the main emission direction 10. The frame 9 is formed, for example, using a polymer. For example, the frame is an epoxy casting. Alternatively, the frame 9 is a silicon frame adhesively bonded to the carrier substrate 7.

[0077] The frame is provided with a coating 91 on the surface facing the semiconductor chip 2. This surface is inclined and has an acute angle with respect to the main extension direction of the semiconductor layer sequence 22. The coating 91 is designed to be reflective for radiation from the first wavelength range 5. The coating 91 preferably comprises a metal such as, for example, aluminum. Due to the frame having the reflective coating 91, radiation from the first wavelength range 5 emitted by the optoelectronic component 1 during normal operation is directed in the main emission direction 10.

[0078] In an alternative embodiment, the optoelectronic component 10 does not have a frame 9. In this case, the optoelectronic semiconductor chip 2 is applied to the carrier substrate 7 without the frame 9 surrounding it. In this embodiment, the beam shaping and / or the alignment of the radiation in the main emission direction 10 occurs largely or completely via the optical element 3. In all other respects, this embodiment is identical to the embodiment of the present invention. Figure 2 The embodiment is consistent with .

[0079] Figure 4 Optoelectronic devices 1 and Figure 1 The difference between the optoelectronic components is that the intermediate layer is formed by means of glass. The glass is designed to be transparent to radiation from the first wavelength range 5 and absorbent to radiation from the second wavelength range. Therefore, with regard to the connection between the optoelectronic semiconductor chip 2 and the optical element 3, Figure 4 The middle layer 4 has the Figure 1 and Figure 2 The same functions and characteristics of the middle layer 4.

[0080] Intermediate layer 4 is formed using this glass so that the coefficient of thermal expansion of intermediate layer 4 differs from the coefficients of thermal expansion of chip substrate 21 and optical element 3 by less than 0.5 ppm / K. When chip substrate 21 and optical element 3 are made of sapphire, the coefficient of thermal expansion of chip substrate 21 and optical element 3 is, for example, 7.9 ppm / K. For example, glass having a coefficient of thermal expansion of 7.7 ppm / K is used for intermediate layer 4. The matching coefficient of thermal expansion of intermediate layer 4 can reduce thermal stresses in optoelectronic component 1.

[0081] also, Figure 4 Optoelectronic devices 1 and Figure 1 The optoelectronic device 1 is distinguished in that, Figure 4 The optoelectronic component is applied on a carrier substrate 7. The carrier substrate 7 has in particular Figure 2 The carrier substrate 7 has the same features.

[0082] In accordance with Figures 5 to 11 In a first method step of the method for producing an optoelectronic device 1, an optical element 3 ( Figure 5 ). The optical element 3 has, for example, Figure 1The optical element 3 has the same features as the optical element 3. The optical element 3 is provided on the heating plate 101.

[0083] In a subsequent method step, the material of the intermediate layer 40 is applied to the main surface 31 of the optical element 3 ( Figure 6 ). The material of the intermediate layer 40 is applied by means of a quantitative dispensing glue. Here, a glue dispenser 102 is used. Alternatively, the material of the intermediate layer 40 can also be applied as a glass sheet or as a paste or as a powder. It is also possible that the material of the intermediate layer 40 is applied by means of sputtering, evaporation, coating or spraying.

[0084] In a further method step, the material of the intermediate layer 40 is distributed uniformly on the main surface 31 of the optical element 3 and forms the intermediate layer 4 ( Figure 7 ). In this method step, the optical element 3 is heated by means of a heating plate 101. The optical element 3 is heated to a temperature above the melting temperature of the intermediate layer 4. For example, the optical element 3 is heated to 800° C. The intermediate layer 4 preferably has Figure 4 The same features as the middle layer 4.

[0085] In a subsequent step, the optical element 3 is connected to the semiconductor chip 2 by means of the intermediate layer 4. The semiconductor chip 2 has, for example, Figure 1 The semiconductor chip 2 is provided, for example, on a carrier substrate 7. The carrier substrate 7 preferably has the same Figure 4 The carrier substrate 7 has the same features.

[0086] In order to connect the optical element 3 to the semiconductor chip 2, the optical element 3 is placed opposite to the semiconductor chip 2. Here, the optical element 3 is placed above the semiconductor chip 2 by means of a transfer device 103 ( Figure 8 ). For placing the optical element 3, an adhesion promoter (not shown), such as glycerol, can be used. In a process step not shown, the adhesion promoter can be removed again. For example, the adhesion promoter is evaporated.

[0087] Subsequently, the intermediate layer 4 is irradiated with radiation from the second wavelength range 6 ( Figure 9 The radiation from the second wavelength range 6 is laser radiation 60. The laser radiation 60 is emitted by a light source 62. The intermediate layer 4 is irradiated through the optical element 3. The light source 62 is, for example, an ArF laser that emits the laser radiation 60 at a wavelength of 193.3 nm.

[0088] For example, the laser radiation 60 has a beam width 62 of 1740 μm. The optical element 3 has, for example, a lateral expansion of 2500 μm. Both the beam width 62 and the lateral expansion of the optical element 3 are measured perpendicular to the propagation direction of the laser radiation 60. The optical element 3 forms a beam shaping ( Figure 10 ).

[0089] The laser radiation 60 is absorbed in the intermediate layer 4. As a result, the intermediate layer 4 is heated above its melting temperature and melts. After the intermediate layer 4 cools down after the irradiation with the laser radiation 60, the optoelectronic semiconductor chip 2 and the optical element 3 are connected to each other in a form-fitting manner.

[0090] The laser radiation 60 is focused in the intermediate layer 4 by the optical element 3 ( Figure 10 ). The laser radiation 60 irradiates the region of the intermediate layer 4 that, in a plan view of the optoelectronic semiconductor chip 2, covers the semiconductor chip 2. This means that the intermediate layer 4 is uniformly irradiated with the laser radiation 60 in its region adjacent to the semiconductor chip 2. Thus, the intermediate layer 4 is irradiated in a single irradiation step, and a form-fitting connection is achieved between the semiconductor chip 2 and the optical element 3.

[0091] This avoids an air gap between the semiconductor chip 2 and the optical element 3. Furthermore, no large jump in the refractive index occurs between the substrate 21 and the optical element 3, whereby the outcoupling efficiency of the optoelectronic component 1 can be increased.

[0092] exist Figure 11 In the method steps shown in Figures 5 to 10 The method is carried out differently as follows: a lens array 30 is provided, onto which an intermediate layer 4 is applied. The lens array 30 comprises a plurality of optical elements 3. Subsequently, a chip array 20 is applied to the intermediate layer 4 on the side facing away from the lens array 30. The chip array 20 comprises a plurality of optoelectronic semiconductor chips 2.

[0093] Subsequently, a reflective coating 91 is applied to the side of the intermediate layer 4 facing away from the lens array 30 and to the side surfaces of the optoelectronic semiconductor chip 2. The reflective coating 91 comprises at least one metal, such as, for example, aluminum.

[0094] Subsequently, the optoelectronic semiconductor chip 2 is enclosed by means of a molding method, so that a carrier substrate 7 is produced.

[0095] In a further method step, the lens array 30 and the chip array 20 are singulated along separation lines 75. The separation lines 75 extend between the optical elements 3 of the lens region 30. After singulation, exactly one optical element 3 is associated with each optoelectronic semiconductor chip 2.

[0096] Alternatively, the singulation step of producing the optoelectronic component 1 comprising a plurality of optical elements 3 and optoelectronic semiconductor chips 2 can also be omitted.

[0097] Figure 12 and Figure 13The material properties of the glass that can be used for the intermediate layer 4 are shown. For example, such glass is used according to Figure 4 The intermediate layer 4 of the optoelectronic component 1 is formed.

[0098] Glasses 11 to 15 each have a transmittance 50 that approaches zero when the wavelength 51 is less than 200 nm. Thus, glasses 11 to 15 are not light-transmitting but rather absorbent within the wavelength range. Figure 12 In the wavelength range of wavelengths 51 greater than 400 nm, all glasses 11 to 15 have a transmittance of greater than 85% to greater than 90%. In particular, glass 11 already exhibits a transmittance 50 of approximately 90% at a wavelength 51 of approximately 250 nm. This makes glass 11 particularly suitable for the intermediate layer 4 because it is transmissive at the peak wavelength of the optoelectronic semiconductor chip 2. At the same time, glass 11 exhibits an absorptivity of nearly 100% at a wavelength of 193-90 nm, which is, for example, the second wavelength range 6.

[0099] The thermal expansion coefficient 53 of the glasses 11 to 15 is matched to the thermal expansion coefficient 53 of sapphire ( Figure 13 The difference between the thermal expansion coefficient 53 of the glasses 11 to 15 and that of sapphire is only 0.2 ppm / K. In contrast, the difference in thermal expansion coefficient between quartz glass and sapphire is greater than 7 ppm / K. The glasses 11 to 15 are therefore particularly suitable as intermediate layers in order to reduce thermal stresses in the optoelectronic component 1 .

[0100] Figure 14 The simulation results are shown, showing the outcoupling efficiency as a function of the refractive index and maximum lateral extension of the optical element. In principle, the best results are achieved with a lateral extension of 2500 μm for the optical element 3. The maximum outcoupling efficiency is achieved with lenses whose material has a refractive index of 1.8. Therefore, a suitable material for the optical element 3 is sapphire, which has a refractive index of 1.8.

[0101] Figure 15 The transmittance 50 is shown for a fluoropolymer which is used, for example, as matrix material 41 for the intermediate layer 4 . Figure 15 The different curves in FIG relate to different fluoropolymer variants, such as the so-called Cytop_CTL-A, CTX-A, and CTX-S variants. It shows that for short-wave radiation with a wavelength 52 of less than 3.5 μm, the transmittance 50 for all variants is approximately 90%. Fluoropolymers are therefore suitable as matrix materials 41 because they are transmissive to radiation from both the first wavelength range and the second wavelength range 6.

[0102] Figure 16The transmittance 50 of sapphire is shown in % as a function of wavelength 52 for different thicknesses. It is shown that the transmittance 50 is greater than 60% for wavelengths 52 greater than 0.2 μm for all thicknesses and greater than 90% for wavelengths 52 greater than 0.25 μm for all thicknesses. Sapphire is therefore suitable as a material for optical element 3 because it is substantially transmissive for radiation from both the first wavelength range and the second wavelength range 6.

[0103] Figure 17 The transmittance 50 of the silicon dioxide granules is shown in % as a function of the wavelength 52 in μm. It is shown that for wavelengths below 0.2 μm, the transmittance 50 decreases, thereby increasing the absorptivity. Furthermore, at a wavelength 52 of approximately 2.6 μm, the transmittance 50 has a local minimum, thereby increasing the absorptivity at this wavelength 52. Therefore, silicon dioxide granules are suitable as filler particles 42 in the matrix material 41 for the intermediate layer 4, because the absorption of the silicon dioxide granules allows for targeted heat input into the intermediate layer at specific wavelengths.

[0104] The invention is not restricted to the exemplary embodiments by the description thereof. Rather, the invention encompasses any novel feature and any combination of features, which in particular includes any combination of features in the claims, even if the feature or combination itself is not described in detail in the claims or exemplary embodiments.

[0105] This patent application claims the priority of German patent application 10 2023 104 440.0, the disclosure content of which is incorporated herein by reference.

[0106] List of reference numerals:

[0107] 1 Optoelectronic devices

[0108] 2 Optoelectronic semiconductor chips

[0109] 3 Optical components

[0110] 4 Middle Layer

[0111] 5 First wavelength range

[0112] 6 Second wavelength range

[0113] 7 Carrier substrate

[0114] 8 Connection Layer

[0115] 9 Framework

[0116] 10 Main radiation direction

[0117] 11…15 glass

[0118] 20-chip array

[0119] 21 Chip substrate

[0120] 22 Semiconductor layer sequence

[0121] 23 Contact Areas

[0122] 30 lens array

[0123] 31 Main surface of optical element

[0124] 40 Middle layer material

[0125] 41 Matrix material

[0126] 42 Filling particles

[0127] 50 Transmittance in %.

[0128] 51 Wavelength in nm

[0129] 52 Wavelength in μm

[0130] 53 Coefficient of thermal expansion in ppm / K

[0131] 54 Refractive Index

[0132] 55 Coupling output efficiency

[0133] 60 Laser Radiation

[0134] 61 Beam Width

[0135] 62 light sources

[0136] 71 connection parts

[0137] 72 Through contact

[0138] 73 Metallization

[0139] 75 separation line

[0140] 91 cladding

[0141] 101 Heating Plate

[0142] 102 Dispenser

[0143] 103 Transfer Equipment

Claims

1. An optoelectronic device (1), comprising: at least one optoelectronic semiconductor chip (2) configured to emit radiation in a first wavelength range (5), - at least one optical element (3), and an intermediate layer (4) between the at least one optoelectronic semiconductor chip (2) and the at least one optical element (3), in the intermediate layer (4) is configured to fasten the at least one optoelectronic semiconductor chip (2) to the at least one optical element (3), the at least one optical element (3) is formed by means of a material which is transmissive for radiation from the second wavelength range (6), - the intermediate layer (4) comprises a material which is transmissive for radiation from the first wavelength range (5) and absorptive for radiation from the second wavelength range (6), and - The first wavelength range (5) comprises different wavelengths than the second wavelength range (6).

2. The optoelectronic device (1) according to claim 1, The at least one optical element (3) is designed for beam shaping of radiation from the first wavelength range (5) and / or the second wavelength range (6).

3. The optoelectronic component (1) according to claim 1, wherein By means of the intermediate layer (4), the at least one optical element (3) and the at least one optoelectronic semiconductor chip (2) are connected to one another in a form-fitting manner.

4. The optoelectronic component (1) according to claim 1, wherein - said first wavelength range (5) comprises wavelengths in the UV range of the electromagnetic spectrum, wherein the wavelength is greater than or equal to 250 nm, and - said second wavelength range (6) comprises wavelengths between 180 nm and 230 nm, limit values ​​included.

5. The optoelectronic device (1) according to any one of claims 1 to 3, wherein - said first wavelength range (5) comprises wavelengths in the UV range of the electromagnetic spectrum, wherein the wavelength is greater than or equal to 200 nm, and - said second wavelength range (6) comprises wavelengths between 150 nm and 200 nm, limit values ​​included.

6. The optoelectronic component (1) according to any one of the preceding claims, wherein The at least one optical element (3) has a higher melting point than the intermediate layer (4).

7. The optoelectronic component (1) according to any one of the preceding claims, wherein - the intermediate layer (4) comprises a matrix material (41) into which filler particles (42) are introduced, The filler particles (42) are formed from a material that is transmissive to radiation from the first wavelength range (5) and absorptive to radiation from the second wavelength range (6).

8. The optoelectronic component (1) according to claim 1, wherein The at least one optical element (3) is a sapphire lens.

9. The optoelectronic component (1) according to claim 1, wherein The thermal expansion coefficients of the at least one optical element (3), the at least one optoelectronic semiconductor chip (2) and the intermediate layer (4) differ from one another by at most 0.5 ppm / K.

10. The optoelectronic device (1) according to any one of the preceding claims, further comprising: - a plurality of optoelectronic semiconductor chips (2) in a chip array (20), - a plurality of optical elements (3) in a lens array (30), in The chip array (20) and the lens array (30) are connected to each other in a form-fitting manner by means of the intermediate layer (4).

11. A method for manufacturing an optoelectronic device (1), further comprising the steps of: A) providing at least one optical element (3), B) applying an intermediate layer (4) to a main surface (31) of the at least one optical element (3), C) placing at least one optoelectronic semiconductor chip (2) on a side of the intermediate layer (4) facing away from the at least one optical element (3), D) connecting the at least one optical element (3) to the at least one optoelectronic semiconductor chip (2) by irradiating the intermediate layer (4) with radiation from a second wavelength range (6), wherein the at least one optical element (3) is formed by means of a material which is transmissive for radiation from the second wavelength range (6), and - Radiation from the second wavelength range (6) is absorbed in the intermediate layer (4), so that the intermediate layer (4) is heated at least locally to a temperature above the melting temperature of the intermediate layer (4).

12. The method according to claim 11, wherein In step D), the intermediate layer (4) is irradiated by means of radiation from the second wavelength range (6) via the optical element (3).

13. The method according to claim 12, wherein - in step D), using laser radiation (60) with a wavelength between 120 nm and 230 nm, limit values ​​included, - the at least one optical element (3) has a lateral extension when observing the main surface (31) that is greater than the beam width (61) of the laser radiation (60), and The at least one optical element (3) is configured for beam shaping of the laser radiation (60).

14. The method according to claim 13, wherein In step D), the intermediate layer (4) is irradiated uniformly with the laser radiation (60).

15. The method according to any one of claims 11 to 14, wherein In step B), the at least one optical element (3) is heated to a temperature above the melting temperature of the intermediate layer (4), so that the material of the intermediate layer (4) is evenly distributed on the main surface (31).

16. The method according to any one of claims 11 to 15, wherein Before step C), the at least one optoelectronic semiconductor chip (2) is applied to a carrier substrate (7), and During step D), the connection layer (8) between the carrier substrate (7) and the at least one optoelectronic semiconductor chip (2) is heated to a maximum of 250° C.

17. The method according to any one of claims 11 to 16, wherein - providing a plurality of optical elements (3) in a lens array (30), - applying the intermediate layer (4) on the lens array (30), The lens array (30) is connected to a chip array (20) comprising a plurality of optoelectronic semiconductor chips (2), so that at least one optical element (3) is associated with each optoelectronic semiconductor chip (2).

18. The method according to claim 17, The composite component composed of the lens array (30) and the chip array (20) is divided into a plurality of optical devices (1).

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