Growth structure for a radiation-emitting semiconductor device and radiation-emitting semiconductor device

Abstract

Growth structure (1) for a radiation-emitting semiconductor component (10) comprising - a semiconductor substrate (2) which - contains a material based on arsenide compound semiconductors, - a buffer structure (3) which - is arranged on the semiconductor substrate (2), - contains a material based on arsenide compound semiconductors and - a buffer layer (4) with at least one n-doped layer (5), wherein - the n-doped layer (5) contains a material based on arsenide compound semiconductors and oxygen and a molar fraction of oxygen in the n-doped layer (5) is between 10 15 cm -3 and 10 19 cm -3 amounts, - the buffer structure (3) has at least one further buffer layer (8, 9) which contains a material based on arsenide compound semiconductors, is n-doped and contains oxygen, - the further buffer layer (8, 9) serves as an etching stop layer when the semiconductor substrate (2) or the growth structure (1) is detached from a luminescence diode structure (11), and - one of the at least two buffer layers (4, 8, 9) is a bulk layer and the other of the at least two buffer layers (4, 8, 9) consists of a superlattice having a plurality of n-doped, oxygen-free layers (6) and a plurality of n-doped, oxygen-containing layers (5) arranged alternately.

Description

[0001] A growth structure for a radiation-emitting semiconductor component is specified, which in particular contains a material based on arsenide compound semiconductors.

[0002] Growth substrates made of GaAs are known to suffer from the problem of a comparatively high dislocation density. While silicon wafers usually have a very low dislocation density of less than 100 cm -2 , the dislocation density of GaAs wafers is 10 5 cm -2. Dislocations occurring in the GaAs substrate can migrate into the overlying layers of a grown semiconductor structure. In a radiation-emitting semiconductor component with such a semiconductor structure or a light-emitting diode structure, this can result in spontaneous failures and increased aging during operation. The buffer layers or ELOG (Epitaxial Lateral Overgrowth) masking layers used to date (see, for example, Fig. 1 and Fig. 2) cannot prevent this problem or can only do so with considerable effort.

[0003] Furthermore, documents US 2010 / 0 166 033 A1, US 2006 / 0 255 367 A1, and US 6 355 951 B1 describe growth structures each comprising a buffer structure on a substrate. According to document US 2010 / 0 166 033 A1, the growth structure can be removed. According to documents US 2006 / 0 255 367 A1 and US 6 355 951 B1, the buffer structure can contain oxygen.

[0004] One problem to be solved here is to provide a growth structure or a radiation-emitting semiconductor component with improved crystal quality while maintaining acceptable manufacturing costs. This problem is solved, inter alia, by a growth structure or a radiation-emitting semiconductor component having the features of the independent subject claims.

[0005] Advantageous further developments of the growth structure or of the radiation-emitting semiconductor component are the subject of the dependent claims.

[0006] A growth structure for a radiation-emitting semiconductor component is specified. The growth structure is particularly suitable for a laser diode. According to at least one embodiment, the growth structure comprises a semiconductor substrate containing a material based on arsenide compound semiconductors. Furthermore, the growth structure has a buffer structure arranged on the semiconductor substrate and containing a material based on arsenide compound semiconductors.

[0007] “Based on arsenide compound semiconductors” in this context means that a structure so designated or a part of this structure preferably contains Al n Ga m In 1-n-mAs, 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 above formula. Rather, it can contain one or more dopants as well as additional components that do not substantially change the physical properties of the material.

[0008] According to at least one embodiment, a semiconductor substrate consisting of GaAs is used for the growth structure. Semiconductor substrates or growth structures based on arsenide compound semiconductors are particularly suitable for the production of radiation-emitting semiconductor components based on arsenide or phosphide compound semiconductors.

[0009] The buffer structure comprises a buffer layer having at least one n-doped layer containing oxygen. The at least one n-doped layer therefore contains oxygen. The mole fraction of oxygen in the n-doped layer is between 10 15 cm -3 and 10 19 cm -3 In particular, the mole fraction of oxygen in the n-doped layer is greater than 10 15 cm -3 and is a maximum of 10 19 cm -3 The oxygen can be incorporated into the crystal structure of the n-doped layer, for example, as a dopant. The oxygen in the n-doped layer advantageously contributes to compensating the dislocation density of the semiconductor substrate.

[0010] In a preferred embodiment, the molar fraction of oxygen in the n-doped oxygen-containing layer is between 10 17 cm -3 and 10 18 cm-3 In other words, the mole fraction can be a minimum of 100 ppm and a maximum of 20,000 ppm. Here, too, deviations of up to 10% are quite tolerable. With a mole fraction within the specified ranges, it is possible that a large portion of the dislocation lines will be bent, preventing them from reaching a surface of the growth substrate intended for the growth of the LED structure.

[0011] Preferably, the buffer layer or buffer structure as a whole is n-doped, which ensures the electrical conductivity of the buffer layer or buffer structure during operation of the radiation-emitting semiconductor component. In particular, several layers contained in the buffer structure are n-doped with the same dopant.

[0012] According to at least one embodiment, the buffer structure, or layers contained in the buffer structure, are grown on the semiconductor substrate. This can be achieved by epitaxial deposition, for example, using MOCVD ("Metal-Organic Chemical Vapor Deposition"), MBE ("Molecular Beam Epitaxy"), or LPE ("Liquid Phase Epitaxy"). Compared to the production of a growth structure, in which an ELOG masking layer is created on the semiconductor substrate, the complex structuring of the masking layer is eliminated.

[0013] The aforementioned dislocation density refers to the total length of all dislocation lines per unit volume in a crystalline solid. In conventional semiconductor devices, the dislocation lines extend from the growth substrate into the LED structure, where they lead to defects. This problem is solved in particular by means of the buffer layer.

[0014] According to at least one embodiment, the semiconductor substrate has dislocation lines that continue into the buffer structure and are bent by the buffer layer. The inventors have discovered that, in particular, the oxygen used in the buffer layer causes the dislocation lines of the semiconductor substrate to bend, so that they largely cannot penetrate into the LED structure, and the LED structure is therefore largely dislocation-free or the dislocation density reaches an insignificant level.

[0015] According to at least one embodiment, the at least one n-doped oxygen-containing layer contains AlGaAsO. Since AlGaAs or AlGaAsO has almost the same lattice constant as GaAs, the less frequently occurring gallium can advantageously be at least partially replaced by the more frequently occurring aluminum. The molar fraction of aluminum is preferably between 1% and 100%, particularly preferably between 1% and 60%. In other words, the at least one n-doped layer (5) contains Al m Ga 1-m As:O, where 0.01 ≤ m ≤ 1, particularly preferably 0.01 ≤ m ≤ 0.6. Deviations of up to 10% are quite tolerable. For example, the oxygen is introduced into a GaAs material using a complex aluminum compound, forming AlGaAsO. In particular, the at least one n-doped oxygen-containing layer consists of AlGaAsO.

[0016] Furthermore, the at least one n-doped oxygen-containing layer is preferably free of indium.

[0017] According to at least one embodiment, the buffer layer consists of an n-doped, oxygen-containing layer. In this case, the buffer layer is a so-called "bulk layer." In other words, the buffer layer is largely homogeneous, i.e., made of only a single material, and comparatively thick or stable. For example, the n-doped, oxygen-containing layer or buffer layer can have a thickness of between 50 nm and 800 nm inclusive. AlGaAsO, i.e., AlGaAs mixed with oxygen, is preferably considered as the material for the n-doped oxygen-containing layer or buffer layer. Furthermore, the n-doped layer can be n-doped with dopants such as Te and / or Si. Furthermore, the buffer layer is, in particular, largely uninterrupted.

[0018] According to at least one embodiment, the buffer layer has at least one n-doped, oxygen-free layer, i.e., a layer without oxygen, and at least one n-doped, oxygen-containing layer, which are arranged one above the other. In particular, the buffer layer has a plurality of n-doped, oxygen-free layers and a plurality of n-doped, oxygen-containing layers, which are arranged alternately. The at least one oxygen-containing layer can be formed from AlGaAsO. GaAs is preferably considered for the at least one oxygen-free layer. According to at least one embodiment, the buffer layer consists of a superlattice, i.e., a sequence of thin layers that repeat periodically. For example, the superlattice can have 5 to 20 repetitions. The at least one oxygen-free layer can be thicker than the at least one oxygen-containing layer.The at least one oxygen-free layer is preferably formed with a thickness of between 0.5 nm, which corresponds to a monolayer, preferably 2 nm, and 10 nm, inclusive. Furthermore, the thickness of the at least one oxygen-containing layer can be between 0.5 nm, preferably 1 nm, and 5 nm. Deviations of up to 10% are entirely tolerable. For example, tellurium, silicon, or sulfur can be used as the n-dopant for the at least one oxygen-free layer. The same n-dopant can be used to dope both the oxygen-containing and the oxygen-free layers.

[0019] According to at least one unclaimed variant, the buffer structure consists of the buffer layer, i.e. the buffer structure has no further layers apart from the buffer layer.

[0020] According to at least one embodiment, the buffer structure has at least one further buffer layer. The further buffer layer is arranged, for example, on a side of the above-described first buffer layer facing the semiconductor substrate. The further, second buffer layer can contain GaAs and be n-doped. For example, tellurium, silicon, or sulfur can be used as the n-dopant for the further buffer layer. In particular, the second buffer layer is at least not completely free of oxygen. If the buffer structure has a further buffer layer, the first buffer layer can be made thinner. In this case, a thickness of approximately 10 nm may already be sufficient.

[0021] Additionally or alternatively, the buffer structure may have a further buffer layer on a side of the first buffer layer facing away from the semiconductor substrate. This buffer layer may also contain GaAs and be doped with an n-type dopant such as tellurium, silicon, or sulfur, and may at least not be completely free of oxygen.

[0022] According to at least one embodiment, the buffer structure comprises a first buffer layer consisting of a superlattice having the above-mentioned properties, as well as a second and / or third buffer layer, which are (each) formed as a “bulk layer” having the above-mentioned properties.

[0023] The additional buffer layer(s) can further improve the crystal quality of the growth structure. Furthermore, the lattice constant of the growth structure can be brought closer to the lattice constant of the semiconductor substrate.

[0024] According to at least one embodiment, it is provided that the buffer structure comprises a first buffer layer which is designed as a “bulk layer” with the above-mentioned properties, and furthermore has a second and / or third buffer layer which (each) consist of a superlattice with the above-mentioned properties.

[0025] According to at least one embodiment, the at least one further buffer layer serves as an etching stop layer when the semiconductor substrate or the growth structure is detached from the luminescence diode structure.

[0026] A radiation-emitting semiconductor component is specified, which has a growth structure as described above. In particular, the growth structure comprises a semiconductor substrate containing a material based on arsenide compound semiconductors. Furthermore, the growth structure comprises a buffer structure arranged on the semiconductor substrate, which contains a material based on arsenide compound semiconductors and which has a buffer layer with at least one n-doped layer containing oxygen.

[0027] Furthermore, the radiation-emitting semiconductor component comprises a light-emitting diode structure based on arsenide or phosphide compound semiconductors, which has a first region of a first conductivity type, a second region of a second conductivity type, and an active region for generating radiation arranged between the first and second regions, wherein the light-emitting diode structure is grown on the growth structure. Preferably, the first region is an n-conducting region and the second region is a p-conducting region. Particularly preferably, the first region is arranged on a side of the active region facing the growth structure, while the second region is located on a side of the active region facing away from the growth structure.

[0028] “Based on arsenide or phosphide compound semiconductors” in this context means that a structure so designated or a part of this structure preferably contains Al n Ga m In 1-n-m Ace or Al n Ga m In 1-n-m P, 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 above formula. Rather, it can contain one or more dopants as well as additional components that do not essentially change the physical properties of the material. For the sake of simplicity, however, the above formula only includes the essential components of the crystal lattice (Al, Ga, In, P), even if these may be partially replaced by small amounts of other substances.

[0029] For example, the light-emitting diode structure can be grown epitaxially on the growth structure using MOCVD (“Metal-Organic Chemical Vapour Deposition”), MBE (“Molecular Beam Epitaxy”) or LPE (“Liquid Phase Epitaxy”).

[0030] The arsenide or phosphide compound semiconductor-based light-emitting diode structure, or rather its active region, is particularly suitable for generating radiation with a wavelength in the red (InxGayAl1-x-yP) to infrared (InxGayAl1-x-yAs) spectral range. In particular, the radiation-emitting semiconductor component emits radiation with a wavelength between 750 nm and 1200 nm during operation.

[0031] The active region of the light-emitting diode structure preferably has a pn junction, a double heterostructure, a single quantum well (SQW) structure, or a multiple quantum well (MQW) structure for radiation generation. For the purposes of this application, the term "quantum well structure" encompasses, in particular, any structure in which charge carriers can experience quantization of multiple energy states through confinement. In particular, the term "quantum well structure" does not specify the dimensionality of the quantization. It thus encompasses, among other things, quantum wells, quantum wires, and quantum dots, and any combination of these structures.

[0032] The n-type region, the active region and the p-type region can each have one or more layers.

[0033] According to at least one embodiment, the radiation-emitting semiconductor component is a laser diode, i.e., a coherent emitter. In particular, the laser diode is a high-power laser diode that delivers a radiation output of 20 W up to and including 300 W at a current between 20 A and 300 A. To achieve such a radiation output, the light-emitting diode structure of the semiconductor component can be designed as a laser bar and have a plurality of adjacent strip-shaped regions that are electrically operated in parallel. The semiconductor component, in particular, has at least ten adjacent strip-shaped regions.

[0034] According to a preferred embodiment, the radiation-emitting semiconductor component is an edge emitter. This means that the radiation generated by the active region exits at least one side surface of the semiconductor component. The side surfaces delimit the semiconductor component in lateral directions, i.e., in directions that run transversely, in particular perpendicularly, to a growth direction of the LED structure. The growth direction indicates the direction in which the layers of the LED structure are successively applied to the growth structure.

[0035] Alternatively, the radiation-emitting component can be a surface emitter. In this case, the radiation generated in the active region exits at a main surface of the semiconductor component. The main surface defines the semiconductor component's outer boundary on a side of the LED structure facing away from the growth structure. Although the radiation output achievable with a surface emitter is generally lower than with an edge emitter, surface emitters often exhibit better beam quality.

[0036] Overall, the application of the radiation-emitting semiconductor component determines whether it is designed as an edge emitter or a surface emitter. While edge emitters are used as pump lasers, for example, surface emitters are used as optical transmitters for fiber optic data transmission and also for laser printers.

[0037] Further advantages, preferred embodiments and developments of the growth structure and the radiation-emitting semiconductor component will become apparent from the following explanations in conjunction with the Fig. 1 to 4.

[0038] They show: Fig. 1 a schematic representation of a TEM image of a conventional semiconductor structure based on nitride compound semiconductors (source: dissertation “Metallorganic gas phase epitaxy of group III nitride-based LED structures on silicon”, page 136, figure 5.36, 07.07.1982, Sebastian Drechsel), Fig. 2 a schematic cross-sectional view of a radiation-emitting semiconductor component according to a comparative example, Fig. 3 shows a schematic cross-sectional view of an exemplary radiation-emitting semiconductor component on which a radiation-emitting semiconductor component according to a first embodiment is based, Fig. 4 a schematic cross-sectional view of a radiation-emitting semiconductor component according to a second embodiment.

[0039] Identical, similar or similarly acting elements are provided with the same reference symbols in the figures.

[0040] The Fig. Figures 1 to 4 are schematic representations and therefore not necessarily to scale. Rather, comparatively small elements, and especially layer thicknesses, may be exaggerated for clarity.

[0041] Fig. 1 shows a conventional semiconductor structure 15 based on nitride compound semiconductors.

[0042] In the present context, “based on nitride compound semiconductors” means that the active epitaxial layer sequence or at least one layer thereof comprises a nitride III / V compound semiconductor material.

[0043] The semiconductor structure 15 has a growth structure 1 and a semiconductor layer sequence 17 grown thereon. The growth structure 1 comprises a semiconductor substrate 2 and an ELOG (“Epitaxial Lateral Overgrowth masking layer 16, which is applied to the semiconductor substrate 2. The ELOG masking layer 16 is provided to reduce the dislocation density in the semiconductor structure 15. The masking layer 16 is formed from SiN, while the semiconductor substrate 2 is made of sapphire.

[0044] The ELOG masking layer 16 has a plurality of recesses (not marked) through which the semiconductor layer sequence 17 is formed by epitaxial growth on the semiconductor substrate 2. Since dislocations can only propagate through the recesses, the growth structure 1 has a reduced dislocation density on a side facing the semiconductor layer sequence 17 compared to the semiconductor substrate 2.

[0045] As from Fig. As can be seen in Figure 1, breakthroughs 18 of defects still occur. Furthermore, the production of the recesses in the ELOG masking layer 16, for example, by photolithographic structuring, is comparatively complex.

[0046] Fig. 2 shows a comparative example of a radiation-emitting semiconductor component 10. The radiation-emitting semiconductor component 10 comprises a growth structure 1 and a light-emitting diode structure 11 arranged thereon, which is intended to generate radiation, preferably in the infrared range.

[0047] The growth structure 1 comprises a semiconductor substrate 2 made of GaAs with a comparatively high dislocation density. To reduce the dislocation density, the growth structure 1 contains a buffer layer 4 arranged on the semiconductor substrate 2 and on which the light-emitting diode structure 11 is grown.

[0048] Buffer layer 4 is an n-doped GaAs layer that is free of oxygen. For example, tellurium is used as an n-type dopant.

[0049] The light-emitting diode structure 11 is deposited on the growth structure 1. The light-emitting diode structure 11 contains materials based on arsenide compound semiconductors. Adjacent to the growth structure 1, the light-emitting diode structure 11 has a first, n-conducting region 12, which is followed in a growth direction A by an active region 13 for generating radiation. Following the active region 13 in the growth direction A is a second, p-conducting region 14.

[0050] Although the buffer layer 4 contained in the growth structure 1 can be formed largely without dislocations, the buffer layer 4 cannot sufficiently prevent a migration of the dislocation lines 7 from the semiconductor substrate 2 into the light-emitting diode structure 11 during the growth of the light-emitting diode structure 11 or later during the operation of the component. Fig. 2, the dislocation lines 7 extend from the semiconductor substrate 2 through the first region 12 and the active region 13 into the second region 14 and thereby reduce the crystal quality of the radiation-emitting semiconductor component 10.

[0051] Overall, therefore, neither the combined with Fig. 1 described masking layer 16 nor by the in connection with Fig. 2 described buffer layer 4, a crystal quality of sufficient quality can be achieved with acceptable manufacturing effort.

[0052] The situation is different with the following in connection with the Fig. 3 and Fig. 4 described embodiments.

[0053] The Fig. The radiation-emitting semiconductor component 10 shown in Figure 3 has a growth structure 1 and a luminescence diode structure 11 arranged thereon for generating radiation.

[0054] The growth structure 1 is a composite component comprising a semiconductor substrate 2 and a buffer structure 3 arranged on the semiconductor substrate 2. The semiconductor substrate 2 forms, in particular, a growth substrate suitable for growing both the buffer structure 3 and the light-emitting diode structure 11. Furthermore, the semiconductor substrate 2 advantageously forms a self-supporting, stable base body and can serve as a carrier body in the finished radiation-emitting semiconductor component 10. Alternatively, the semiconductor substrate 2 can be removed or at least thinned and replaced, for example, with another carrier.

[0055] Both the semiconductor substrate 2 and the buffer structure 3 are formed from materials based on arsenide compound semiconductors. Preferably, the semiconductor substrate 2 is made of GaAs.

[0056] The light-emitting diode structure 11 may also contain materials based on arsenide compound semiconductors. Alternatively, the light-emitting diode structure 11 may contain materials based on phosphide compound semiconductors.

[0057] Suitable methods for producing the buffer and light-emitting diode structure 3, 11 are, for example, MOCVD (“Metal-Organic Chemical Vapour Deposition”), MBE (“Molecular Beam Epitaxy”) or LPE (“Liquid Phase Epitaxy”).

[0058] In the Fig. In the embodiment shown in Figure 3, the buffer structure 3 consists of a buffer layer 4 having a superlattice. The buffer layer 4 comprises several n-doped, oxygen-free layers 6 and several n-doped, oxygen-containing layers 5, which are arranged one on top of the other in an alternating sequence. A particularly suitable material system for the oxygen-containing layers 5 is AlGaAsO. The molar fraction of aluminum is preferably between 1% and 100%, in particular between 1% and 60%. In other words, the n-doped, oxygen-containing layers 5 each contain Al m Ga 1-m As:O, where 0.01 ≤ m ≤ 1, particularly preferably 0.01 ≤ m ≤ 0.6. Preferably, the mole fraction of oxygen is greater than 10 15 cm -3 and is a maximum of 10 19 cm -3. Particularly preferably, the mole fraction of oxygen in the n-doped layers 5 is between 10 17 cm -3 and 10 18 cm -3 In other words, the molar fraction can be at least 100 ppm and at most 20,000 ppm. GaAs is particularly suitable for the oxygen-free layers 6. Deviations of up to 10% are quite tolerable for the specified molar fractions. The same n-type dopant can be used for doping both the oxygen-containing and the oxygen-free layers 6 and 5.

[0059] The oxygen-free layers 6 are preferably provided with a thickness D1 between and including 0.5 nm, preferably 2 nm, and 10 nm inclusive. Furthermore, the thickness D2 of the oxygen-containing layers 5 is in particular between 0.5 nm, preferably 1 nm, and 5 nm. Deviations of up to 10% are entirely tolerable.

[0060] The light-emitting diode structure 11 has a first region 12 of a first conductivity type, a second region 14 of a second conductivity type, and an active region 13 for generating radiation arranged between the first and second regions 14. Preferably, the first region 12 is an n-conducting region, and the second region 14 is a p-conducting region.

[0061] Furthermore, the first region 12 is arranged on a side of the active region 13 facing the growth structure 1, while the second region 14 is located on a side of the active region 13 facing away from the growth structure 1.

[0062] As from Fig. As can be seen in Figure 3, dislocation lines 7 originate from the semiconductor substrate 2 and extend into the buffer structure 3 or buffer layer 4. By means of the buffer structure 3 or buffer layer 4, the dislocation lines 7 are largely bent, so that they do not migrate further into the LED structure 11. The inventors have discovered that, in particular, the oxygen used in the n-doped layers 5 causes the dislocation lines to bend, so that they largely cannot penetrate into the LED structure 11.

[0063] This effect can also be achieved in a buffer structure 3 according to a first exemplary embodiment, which does not consist of only one buffer layer 4 as in the illustrated example, but has at least one further buffer layer (not illustrated). A further buffer layer can be arranged on a side of the buffer layer 4 facing the semiconductor substrate 2 or on a side of the buffer layer 4 facing away from the semiconductor substrate 2. Two further buffer layers can also be provided, between which the buffer layer 4 is then arranged. The at least one further buffer layer can contain GaAs, be free of oxygen and, moreover, be n-doped. For example, tellurium can be used as the n-dopant. According to the first exemplary embodiment, it is provided that the at least one further buffer layer is designed as a “bulk layer” with the properties described below in connection with Fig. 4 described properties.

[0064] The radiation-emitting semiconductor component 10 is designed as a laser diode, which emits radiation in particular in the infrared range with a wavelength between 750 nm and 1200 nm. Furthermore, the radiation-emitting semiconductor component 10 shown is an edge emitter, which emits the radiation generated by the active region 13 at a side surface of the semiconductor component 10 arranged parallel to the image plane. The side surfaces 10A and the side surfaces (not shown) arranged parallel to the image plane delimit the semiconductor component 10 in lateral directions, i.e., in directions that run transversely, in particular perpendicularly, to a growth direction A of the LED structure. The growth direction A indicates the direction in which the regions 12, 13, 14 of the LED structure 11 are successively applied to the growth structure 1.

[0065] In particular, the radiation-emitting component 10 is a high-power laser diode which provides a radiation power of 20 W up to and including 300 W at a current between 20 A and 300 A. In order to achieve such a radiation power, the luminescence diode structure 11 of the semiconductor component 10 can be designed as a laser bar and can comprise a plurality of adjacent strip-shaped regions, each of which has a Fig. 3 have the structure shown.

[0066] The Fig. The embodiment of a radiation-emitting semiconductor component 10 shown in Figure 4 has a similar structure to that shown in Fig. 3. In this respect, reference is made to the above explanations. Differences exist in the buffer structure 3, which will be discussed in more detail below.

[0067] The radiation-emitting semiconductor component 10 comprises a growth structure 1 and a light-emitting diode structure 11 arranged thereon for generating radiation. Both structures 1, 11 can contain materials based on arsenide compound semiconductors. Alternatively, the light-emitting diode structure 11 can be formed from materials based on phosphide compound semiconductors.

[0068] The growth structure 1 comprises a semiconductor substrate 2, preferably a GaAs substrate, and a buffer structure 3, which is grown in particular on the semiconductor substrate 2.

[0069] The buffer structure 3 has a first buffer layer 4 consisting of an n-doped, oxygen-containing layer 5. The buffer layer 4 comprises AlGaAs mixed with oxygen as its material system. The buffer layer 4 is thus formed from AlGaAsO. The buffer layer 4 is a so-called "bulk layer." In other words, the buffer layer 4 is largely homogeneous, i.e., composed of only a single material system, and is comparatively thick and stable.

[0070] In the Fig. In the embodiment shown in Figure 4, the buffer structure 3 has two further buffer layers 8, 9, between which the first buffer layer 4 is arranged. In this case, the first buffer layer 4 can be formed comparatively thin, with a thickness D of approximately 10 nm.

[0071] The second and third buffer layers 8, 9 may each contain GaAs and be n-doped, with tellurium being used as the n-dopant, for example. For example, the buffer layers 8, 9 may be free of oxygen. Alternatively, the second and third buffer layers 8, 9 according to the second embodiment may each consist of a superlattice, as described in connection with the Fig. 3 described buffer layer 4.

[0072] Furthermore, it is also conceivable in the second embodiment that the buffer structure 3 has only one further buffer layer, which is arranged on a side of the first buffer layer 4 facing or facing away from the semiconductor substrate 2.

[0073] It is also possible for the buffer structure 3 to consist only of the buffer layer 4. In this case, the buffer layer 4 is comparatively thick, with a preferred thickness D between 50 nm and 150 nm, whereby deviations of up to 10% are tolerable.

[0074] The radiation-emitting component 10 is preferably an edge-emitting laser diode with the features already described in connection with Fig. 3. However, the radiation-emitting semiconductor component 10 can also be a surface-emitting laser diode in which the radiation is coupled out at a main surface 10B of the semiconductor component 10.

[0075] Overall, the crystal quality of the light-emitting diode structures 11 can be improved by means of the buffer structures 3 described here, so that fewer failures occur in the semiconductor components 10 and the operating life can be extended.

[0076] The invention is not limited by the description based on the exemplary embodiments. Rather, the invention encompasses any novel feature and any combination of features, including, in particular, any combination of features in the patent claims, even if this feature or combination itself is not explicitly stated in the patent claims or exemplary embodiments.

[0077] This patent application claims priority from German patent application 102019106521.6, the disclosure of which is hereby incorporated by reference. List of reference symbols 1 Growth structure 2 Semiconductor substrate 3 Buffer structure 4 Buffer layer 5 oxygen-containing layer 6 oxygen-free layer 7 Dislocation line 8, 9 additional buffer layer 10 Radiation-emitting semiconductor component 10A side surface 10B Main Area 11 Light-emitting diode structure 12 first area 13 active area 14 second area 15 Semiconductor structure 16 Masking layer 17 Semiconductor layer sequence 18 Breakthrough A Growth direction D, D1, D2 thickness

Claims

[1] Growth structure (1) for a radiation-emitting semiconductor component (10) comprising - a semiconductor substrate (2) which - contains a material based on arsenide compound semiconductors, - a buffer structure (3) which - is arranged on the semiconductor substrate (2), - contains a material based on arsenide compound semiconductors and - a buffer layer (4) with at least one n-doped layer (5), wherein - the n-doped layer (5) contains a material based on arsenide compound semiconductors and oxygen and a molar fraction of oxygen in the n-doped layer (5) is between 10 15 cm -3 and 10 19 cm -3 amounts, - the buffer structure (3) has at least one further buffer layer (8, 9) which contains a material based on arsenide compound semiconductors, is n-doped and contains oxygen, - the further buffer layer (8, 9) serves as an etching stop layer when the semiconductor substrate (2) or the growth structure (1) is detached from a luminescence diode structure (11), and - one of the at least two buffer layers (4, 8, 9) is a bulk layer and the other of the at least two buffer layers (4, 8, 9) consists of a superlattice having a plurality of n-doped, oxygen-free layers (6) and a plurality of n-doped, oxygen-containing layers (5) arranged alternately. [2] Growth structure (1) according to the preceding claim, wherein the semiconductor substrate (2) has dislocation lines (7) which continue into the buffer structure (3) and are bent by means of the buffer layer (4). [3] Growth structure (1) according to one of the preceding claims, wherein the at least one n-doped layer (5) contains AlGaAsO. [4] Growth structure (1) according to the preceding claim, wherein the at least one n-doped layer (5) Al m Ga 1-m Contains As:O and 0.01 ≤ m ≤ 1. [5] Growth structure (1) according to one of the two preceding claims, wherein the at least one n-doped layer (5) consists of AlGaAsO. [6] Growth structure (1) according to one of the preceding claims, wherein a molar fraction of oxygen in the n-doped layer (5) is at least 100 ppm and at most 20,000 ppm. [7] Growth structure (1) according to one of the preceding claims, wherein the buffer layer (4) consists of an n-doped oxygen-containing layer (5). [8] Growth structure (1) according to one of the preceding claims, wherein the at least one oxygen-free layer (6) has a thickness between 0.5 nm and 10 nm. [9] Growth structure (1) according to one of the preceding claims, wherein the at least one oxygen-containing layer (5) has a thickness between 0.5 nm and 5 nm. [10] Growth structure (1) according to one of the preceding claims, wherein the oxygen-free layer (6) contains GaAs. [11] Growth structure (1) according to one of the preceding claims, wherein the semiconductor substrate (2) consists of GaAs. [12] Radiation-emitting semiconductor component (10) comprising - a growth structure (1) according to one of the preceding claims, and - a luminescence diode structure (11) based on arsenide or phosphide compound semiconductors, which has a first region (12) of a first conductivity type, a second region (14) of a second conductivity type and an active region (13) for generating radiation arranged between the first and second regions (12, 14), where the luminescence diode structure (11) is grown on the growth structure (1).

Images