semiconductor chip

Abstract

semiconductor chip (1) comprising a semiconductor body (2) with a sequence of semiconductor layers, wherein - the semiconductor layer sequence comprises an n-type multilayer structure (21), a p-type semiconductor layer (22) and an active region (20) for generating radiation, which is arranged between the n-type multilayer structure (21) and the p-type semiconductor layer (22); - in the n-conducting multilayer structure (21) a doping profile is formed which has at least one doping tip (4), - the n-conducting multilayer structure (21) has a quantum structure with a plurality of quantum layers (211) arranged between barrier layers (212), - the doping profile has an additional doping tip (41), - a sub-region (216) of the quantum structure of the n-conducting multilayer structure (21) has a high doping concentration by means of the further doping tip (41), and - between the further doping tip (41) and the doping tip (4) a low n-conducting doped region (45) of the quantum structure is formed, wherein the low n-conducting doped region (45) contains at least one quantum layer (211) and at least one barrier layer (212).

Description

[0001] The present application relates to a semiconductor chip intended for generating radiation.

[0002] Semiconductor chips are known from the documents US 2004 / 0 004 223 A1, US 2008 / 0 149 918 A1, US 2007 / 0 063 207 A1 and DE 10 2007 022 947 A1.

[0003] LED semiconductor chips often have an active region with several quantum wells intended for radiation generation.

[0004] For InGaN quantum wells in the active region, it has been shown that the radiated power does not increase linearly with increasing current density. One reason for this is that charge carriers are often not injected efficiently into the quantum wells.

[0005] One task is to provide a semiconductor chip in which charge carriers can be efficiently injected into the active region.

[0006] This problem is solved by the subject matter of independent patent claim 1. Further embodiments and developments are the subject matter of the dependent patent claims.

[0007] The semiconductor chip comprises a semiconductor body with a semiconductor layer sequence, wherein the semiconductor layer sequence comprises an n-conducting multilayer structure, a p-conducting semiconductor layer, and an active region provided for generating radiation. The active region is arranged between the n-conducting multilayer structure and the p-conducting semiconductor layer. A doping profile having at least one doping peak is formed in the n-conducting multilayer structure.

[0008] The doping profile represents, in particular, a profile of the doping in the vertical direction, i.e., in a direction that runs along a deposition direction for the semiconductor layer sequence of the semiconductor body. In other words, the doping profile runs perpendicular to a main extension plane of the semiconductor layers of the semiconductor layer sequence of the semiconductor body.

[0009] For the purposes of this application, a doping tip is understood to be a region of a semiconductor material that has a high doping concentration compared to at least one adjacent region. The semiconductor material surrounding the doping tip, preferably on both sides, is preferably lightly doped, undoped, or intrinsically doped.

[0010] A high doping concentration is defined as a concentration of at least 2 * 10 18 cm -3 understood.

[0011] A low doping concentration is defined as a concentration of at least 1 * 10 16 cm -3 and at most 1 * 10 18 cm -3 understood.

[0012] It has been shown that a doping tip that is thin and highly doped, particularly compared to the rest of the n-conducting multilayer structure, leads to improved charge carrier injection into the active region of the semiconductor chip. Due to the high doping, the n-conducting multilayer structure exhibits a comparatively high transverse conductivity, i.e., high conductivity in the lateral direction, in the region of the doping tip, so that charge carriers can be injected particularly homogeneously into the active region in the lateral direction. The at least one doping tip also leads to a more laterally homogeneous current flow in the reverse direction, i.e., in the blocking direction of the active region. As a result, the semiconductor chips exhibit reduced sensitivity to electrostatic discharge (ESD).

[0013] In a preferred embodiment, the n-conducting multilayer structure has at least one region highly doped by means of the doping peak and a region doped with a low n-conducting conductivity. Preferably, the doping concentration in the at least one doping peak is at least five times, particularly preferably at least eight times, for example ten times, as high as in the low n-conducting doped region of the n-conducting multilayer structure.

[0014] The low n-conducting doped region can in particular be adjacent to the doping tip.

[0015] Preferably, the doping concentration in the doping tip is at least 4 * 10 18 cm -3 . High conductivity can be achieved through a high doping concentration.

[0016] Furthermore, the doping concentration in the doping tip is preferably at most 1 * 10 20 cm -3 , particularly preferably not more than 3 * 10 19 cm -3 .

[0017] Furthermore, the doping concentration in the, in particular adjacent, low n-conducting doped region is preferably at most 5 * 10 17 cm -3 , particularly preferably at most 2 * 10 17 cm -3 .

[0018] In a preferred embodiment, a doping concentration in the at least one doping peak is at least 4 * 10 18 cm -3 and in the low n-conducting doped region at most 8 * 10 17 cm -3 .

[0019] A vertical extension of the doping tip is preferably between 1 nm and 30 nm inclusive, particularly preferably between 2 nm and 20 nm inclusive. In particular, the vertical extension of the doping tip can be between 7 nm and 10 nm inclusive.

[0020] During operation of the semiconductor chip, the n-conducting multilayer structure serves primarily to inject electrons into the active region. For this purpose, the n-conducting multilayer structure does not necessarily have to be doped with n-conductivity throughout. Rather, the n-conducting multilayer structure can also have one or more layers in which the n-conducting multilayer structure is undoped or intrinsically doped.

[0021] Accordingly, the p-type semiconductor layer is specifically designed for hole injection into the active region. The p-type semiconductor layer can also be multilayered, with individual layers differing in doping and / or crystal composition.

[0022] The semiconductor body is preferably based on a compound semiconductor, in particular on a nitride compound semiconductor.

[0023] “Based on nitride compound semiconductors” in the present context means that the active epitaxial layer sequence or at least one layer thereof comprises a nitride III / V compound semiconductor material, preferably Al y Ga 1-x-y In x N, where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 and x + y ≤ 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 affect the characteristic physical properties of Al y Ga 1-x- y In x N material does not change significantly. For simplicity, however, the above formula only includes the essential components of the crystal lattice (Al, Ga, In, N), even if these may be partially replaced by small amounts of other substances.

[0024] The active region preferably has a plurality of quantum layers. The quantum layers are expediently arranged between barrier layers. The quantum layers and barrier layers can form a quantum structure.

[0025] For the purposes of this application, the term "quantum structure" encompasses, in particular, any structure in which charge carriers can experience quantization of their energy states through confinement. In particular, the term "quantum structure" does not specify the dimensionality of the quantization. It thus encompasses, among other things, quantum wells, quantum wires, and quantum dots, as well as any combination of these structures.

[0026] The n-type multilayer structure has a quantum structure. This quantum structure has a plurality of quantum layers.

[0027] The term quantum structure also refers in particular to both a multi-quantum well (MQW) structure and a superlattice structure. In contrast to a multi-well quantum structure, the distances between neighboring quantum layers in a superlattice are so small that the electron states of neighboring quantum layers quantum mechanically couple with each other and form shared electron states.

[0028] For example, barrier layers having a thickness of 5 nm or less, for example 2 nm, can be formed between the quantum layers of a superlattice.

[0029] In a preferred embodiment, a band gap of the quantum layer of the n-conducting multilayer structure is at least as large as a band gap of the quantum layer of the active region. Particularly preferably, the band gap of the quantum layer is larger than the band gap of the quantum layer of the active region. For example, in a semiconductor chip based on a nitride compound semiconductor, the quantum layers of the n-conducting multilayer structure can have a lower indium content x than the quantum layers of the active region.

[0030] In contrast to the quantum layers of the active region, the quantum layers of the n-conducting multilayer structure are not intended to generate radiation, but rather serve in particular for the efficient injection of electrons into the active region, where they can recombine with holes, emitting radiation.

[0031] The quantum layers of the active region are preferably intrinsic or undoped.

[0032] In a further preferred embodiment, the doping tip is arranged between the quantum layer of the n-conducting multilayer structure closest to the active region and the quantum layer of the active region closest to the n-conducting multilayer structure. This ensures good lateral current distribution near the active region.

[0033] Furthermore, a distance of the doping tip from the active region, in particular from the quantum layer of the active region closest to the n-conducting multilayer structure, is a distance between 1 nm and 30 nm inclusive, particularly preferably between 2 nm and 20 nm inclusive, in particular between 7 nm and 10 nm inclusive.

[0034] By means of this highly doped doping tip near the active region, charge carrier injection into the active region can be particularly efficient and, in particular, particularly homogeneous in the lateral direction. In the reverse direction, the at least one doping tip also results in improved utilization of many possible charge carrier paths due to the high transverse conductivity, which reduces the risk of ESD damage compared to a semiconductor chip that does not have doping tips in the n-type region of the semiconductor body.

[0035] The at least one doping peak is preferably configured such that the doping profile exhibits sharp transitions from a low doping concentration to a high doping concentration and vice versa. During the manufacture of the semiconductor chip, this can be achieved by a low growth rate, for example, a rate between 20 nm / h and 500 nm / h. Preferably, the deposition, in particular epitaxial deposition, is carried out, for example, by means of MOCVD.

[0036] In a preferred embodiment, a crystal structure of the n-conducting multilayer structure has V-shaped pits. Such pits, which can form during the deposition of the semiconductor layers, particularly along dislocation lines, are also referred to as "V-pits." Such V-shaped pits can form particularly at a comparatively low deposition temperature of the semiconductor material, approximately below 950°C. These V-shaped pits can lead to improved behavior of the semiconductor chips in the reverse direction.

[0037] The doping profile has at least one further doping peak. In particular, at least one quantum layer of the n-conducting multilayer structure can be arranged between the doping peak and the further doping peak. In other words, the doping profile can be configured such that a portion of the quantum layers of the n-conducting multilayer structure is highly n-doped, while the remaining portion of the quantum layers is comparatively lightly n-doped.

[0038] The doping profile may also have more than two doping peaks, in particular between one and five doping peaks, preferably between one and three doping peaks.

[0039] In a preferred embodiment of the semiconductor chip, a growth substrate for the semiconductor layer sequence of the semiconductor body is completely or at least partially removed. Such a semiconductor chip is also referred to as a thin-film semiconductor chip.

[0040] A thin-film semiconductor chip, such as a thin-film light-emitting diode chip, can further be characterized within the scope of the present invention by at least one of the following characteristic features: - on a first main surface of a semiconductor body facing a carrier element, which comprises a semiconductor layer sequence with an active region, in particular an epitaxial layer sequence, a mirror layer is applied or formed, for example integrated as a Bragg mirror in the semiconductor layer sequence, which reflects at least part of the radiation generated in the semiconductor layer sequence back into the latter; - the semiconductor layer sequence has a thickness in the range of 20 µm or less, in particular in the range of 10 µm; and / or - the semiconductor layer sequence contains at least one semiconductor layer with at least one surface which has a mixing structure which ideally leads to an approximately ergodic distribution of the light in the

[0041] semiconductor layer sequence, ie it exhibits as ergodic stochastic scattering behavior as possible.

[0042] A basic principle of a thin-film light-emitting diode chip is described, for example, in I. Schnitzer et al., Appl. Phys. Lett. 63 (16), October 18, 1993, 2174 - 2176.

[0043] Further features, embodiments and expediencies emerge from the following description of the embodiments in conjunction with the figures.

[0044] They show: Fig. 1A shows an embodiment of a semiconductor body with a semiconductor layer sequence in a schematic sectional view, Fig. 1B schematic representations of a conduction band edge profile E C and a doping profile along a deposition direction z for a section of a semiconductor body according to a second embodiment, Fig. 2 a first embodiment of a semiconductor chip in a schematic sectional view, Fig. 3 a second embodiment of a semiconductor chip in a schematic sectional view, and Fig. 4 a result of a measurement of a current I as a function of a reverse voltage U.

[0045] Identical, similar or similarly acting elements are provided with the same reference symbols in the figures.

[0046] The figures are schematic representations and therefore not necessarily to scale. Rather, comparatively small elements and, in particular, layer thicknesses may be exaggerated for clarity.

[0047] A first embodiment of a semiconductor body for a semiconductor chip is shown in Fig. 1A is shown schematically in a sectional view. The semiconductor body 2 has a semiconductor layer sequence that forms the semiconductor body. The semiconductor layer sequence has an active region 20 provided for generating radiation, which is arranged between an n-conducting multilayer structure 21 and a p-conducting semiconductor layer 22. The semiconductor layer sequence of the semiconductor body is preferably deposited epitaxially, in particular by means of MBE or MOCVD, on a growth substrate 29. In the case of a semiconductor body based on a nitride compound semiconductor, sapphire, silicon carbide, silicon, or gallium nitride, for example, is suitable as a growth substrate. A buffer layer can be formed between the n-conducting multilayer structure 21 and the growth substrate, which can be provided in particular to increase the crystal quality (not explicitly shown).

[0048] The active region 20 has a quantum structure formed by a plurality of quantum layers 201 and a plurality of barrier layers 202 arranged between the quantum layers. The active region here merely exemplifies a quantum structure with three quantum layers. However, a different number of quantum layers can also be provided, for example, only one or two quantum layers or more than three, for example up to 20 quantum layers, for example, five to eight quantum layers.

[0049] The p-conductive semiconductor layer 22 can also be formed in multiple layers, wherein the individual layers can differ from one another in particular by their material composition and / or by their doping.

[0050] The n-conducting multilayer structure 21 has a quantum structure with a plurality of quantum layers 211 arranged between barrier layers 212.

[0051] The position of a doping tip 4 in the vertical direction, i.e., in a plane perpendicular to a main extension plane of the semiconductor layers of the semiconductor body 2, is schematically illustrated by an arrow. The doping tip is located in the n-conducting multilayer structure 21, in particular between the quantum layer 211 of the n-conducting multilayer structure closest to the active region and the quantum layer 201 of the active region 20 closest to the n-conducting multilayer structure.

[0052] The doping tip 4 enables effective injection of electrons into the active region 20. In the reverse direction, the doping tip also improves current spreading, which leads to a reduced risk of ESD damage to the semiconductor chip formed by the semiconductor layer sequence. The reduced ESD sensitivity is thus already achieved during the deposition of the semiconductor layer sequence, thus reducing the risk of damage to the semiconductor chip in a subsequent manufacturing step.

[0053] A schematic representation of a conduction band edge E C and a silicon doping profile is in Fig. 1B is shown as a function in the z-direction for a second embodiment of a semiconductor body for a semiconductor chip. The z-direction corresponds to the deposition direction of the semiconductor layers of the semiconductor body 2 and runs perpendicular to a main extension plane of the semiconductor layers of the semiconductor body 2.

[0054] This second embodiment essentially corresponds to the one described in connection with Fig. 1A for a semiconductor body. In contrast, in this embodiment, a further doping tip 41 is formed.

[0055] The further doping tip 41 forms a highly doped subregion of the quantum structure of the n-conducting multilayer structure 21. Between the further doping tip and the doping tip 4, a low n-conducting doped region 45 of the quantum structure is formed.

[0056] In this embodiment, the semiconductor body 2, in particular the active region 20, is based on a nitride compound semiconductor material.

[0057] The active region 20 has a plurality of quantum layers 201. In this exemplary embodiment, the active region is intended for generating radiation in the blue spectral range. For this purpose, the quantum layers each have an indium content of x = 0.2. However, the active region can also be designed for the emission of radiation in a different spectral range.

[0058] The higher the indium content, the lower the band gap and thus the energy of the photons that can be generated in the active region. The indium content can therefore be varied within wide limits. For example, quantum layers with an indium content of x = 0.10 emit radiation in the ultraviolet spectral range during operation, and quantum layers with an indium content of x = 0.40 emit radiation in the green spectral range. GaN barrier layers 202 are arranged between the quantum layers.

[0059] In this embodiment, the doping profile for the n-conducting multilayer structure 21 is realized using silicon doping. However, another dopant may also be used.

[0060] The doping profile has a doping peak 4. In this embodiment, this doping peak has a width of approximately 5 nm. In the area of ​​the doping peak 4, the doping concentration is 1 * 10 19 cm -3, while the doping concentration in a low n-conducting doped region 45 adjacent to the doping tip 4 has a doping concentration of 1 * 10 17 cm -3 Furthermore, the doping profile has a further doping peak 41 with a width of 15 nm, in which the n-conducting multilayer structure with a doping concentration of 1 * 10 19 cm -3 is doped n-conducting.

[0061] The doping tips allow for particularly uniform charge carrier injection in the lateral direction. This results in efficient current spreading, especially directly beneath the quantum layers 201 of the active region.

[0062] The n-conducting multilayer structure 21 has, as in connection with Fig. 1A describes a quantum structure with a plurality of quantum layers 211, each arranged between barrier layers 212. The doping profile creates a low-doped subregion 215 of the quantum structure and a highly doped subregion 216 of the quantum structure. In these regions, the quantum layers and / or the barrier layers can each be doped. Preferably, the quantum layers and the barrier layers are highly doped, at least in the region of the at least one doping peak.

[0063] The n-conducting multilayer structure 21 thus has both a low-doped subregion of the quantum structure and a highly doped subregion of the quantum structure. The low-doped subregion 215 of the quantum layers runs between the doping tips 4, 41 and forms an electron reservoir during operation of the semiconductor chip. The doping tip 4 enables a particularly effective and laterally homogeneous injection of charge carriers from the n-conducting multilayer structure 21 into the quantum layers of the active region 20.

[0064] In this exemplary embodiment, the quantum layers of the n-conducting multilayer structure 21 have an indium content of x = 0.1. However, the indium content can also be selected differently. Preferably, the indium content is at most as high as the indium content of the quantum layers in the active region, so that the band gap of the quantum layers of the n-conducting multilayer structure 21 is larger than the band gap of the quantum layers in the active region 20 or corresponds to the band gap of the quantum layers in the active region.

[0065] The quantum structure of the n-conducting multilayer structure can be designed in particular as a quantum well structure or as a superlattice, for example with barrier layers of a thickness of less than 5 nm, for example of approximately 2 nm.

[0066] This simplifies efficient injection of charge carriers into the active region.

[0067] Of course, the material compositions of the active region 20 and the n-conducting multilayer structure 21 as well as the doping profile may also deviate from the embodiment shown.

[0068] Preferably, a doping concentration in at least one doping tip 4 is at least 4 * 10 18 cm -3 . Furthermore, the doping concentration in the doping tip is preferably at most 1 * 10 20 cm -3 , particularly preferably not more than 3 * 10 19 cm -3 .

[0069] In the low n-conducting doped region 45, the doping concentration is preferably at most 5 * 10 17 cm -3 , particularly preferably at most 2 * 10 17 cm -3 .

[0070] The doping concentration in the at least one doping peak is preferably at least five times, particularly preferably at least eight times, as high as in the low n-conducting doped region of the n-conducting multilayer structure.

[0071] A thickness, i.e. vertical extent, of the doping tip 4 and / or the further doping tip 41 is preferably between 1 nm and 30 nm inclusive, particularly preferably between 2 nm and 20 nm inclusive, most preferably between 7 nm and 10 nm inclusive.

[0072] The doping tip 4 is preferably at a small distance from the active region 20, particularly preferably a distance of at most 30 nm, in particular between 1 nm and 30 nm inclusive, preferably between 2 nm and 20 nm inclusive, most preferably between 7 nm and 10 nm inclusive.

[0073] Furthermore, deviating from the exemplary embodiments shown, more than two doping tips can also be provided, for example between one and five doping tips inclusive.

[0074] Furthermore, the n-conducting multilayer structure 21 can also, in contrast to the exemplary embodiments shown, comprise layers or sublayers that are undoped or intrinsically doped. In this case, the undoped or intrinsically doped layers are expediently so thin that the n-conducting multilayer structure 21 has a sufficiently high conductivity for electrons in the deposition direction.

[0075] In order to produce a doping profile that is as rectangular as possible in the region of the doping tips 4, 41, the deposition is preferably carried out at a low growth rate, for example at a rate between 20 nm / h and 500 nm / h.

[0076] Furthermore, a crystal structure of the n-conducting multilayer structure preferably has V-shaped grooves, which form increasingly along dislocations, particularly at low deposition temperatures, such as below 950°C. These V-shaped grooves can lead to improved behavior of the semiconductor chips when a voltage is applied in the reverse direction.

[0077] A first embodiment of a semiconductor chip 1 is shown in Fig. 2, wherein the semiconductor body 2 is shown as an example in connection with Fig. 1A is described.

[0078] The semiconductor chip 1 is designed as a thin-film LED semiconductor chip, in which the growth substrate 29 ( Fig. 1A) for the semiconductor layer sequence of the semiconductor body 2. The active region 20 is intended for generating incoherent radiation during operation.

[0079] The semiconductor body 2 is arranged on a carrier 5. The carrier 5 serves in particular to mechanically stabilize the semiconductor body, so that the growth substrate is not required for this purpose.

[0080] A semiconductor material, such as silicon, gallium arsenide or germanium, or a ceramic, such as aluminum nitride, is suitable as a carrier material.

[0081] The carrier 5 is mechanically stable and further electrically conductively connected to the semiconductor body by means of a connecting layer 8.

[0082] For example, a solder or an electrically conductive adhesive is suitable as a connecting layer.

[0083] A mirror layer 62 is formed between the carrier 5 and the semiconductor body 2. By means of the mirror layer, radiation generated in the active region 20 during operation of the semiconductor body 2, which is emitted in the direction of the carrier 5, can be reflected in the direction of the radiation exit surface 200 and thus exit the semiconductor chip.

[0084] On the side of the semiconductor body 2 facing away from the carrier 5, the semiconductor body has a first contact 31. On the opposite side of the semiconductor chip, i.e., on the side of the carrier 5 facing away from the semiconductor body 2, a second contact 32 is formed.

[0085] The first contact and / or the second contact preferably contain a metal, for example gold, silver, platinum, aluminum, nickel, chromium or copper or an alloy with at least one of the materials mentioned.

[0086] By means of the first contact 31 and the second contact 32, charge carriers can be injected into the active region 20 from different sides during operation of the semiconductor chip 1 and can recombine there with the emission of radiation.

[0087] The electrons injected via the first contact 31 are efficiently distributed in the lateral direction in the n-conducting multilayer structure 21 in the region of the at least one doping tip 4 and homogeneously coupled into the quantum layers 201 of the active region 20.

[0088] The mirror layer 62 is preferably metallic and furthermore preferably has a high reflectivity for the radiation generated in the active region. For example, a metal such as aluminum, silver, gold, palladium, or rhodium, or a metallic alloy comprising at least one of the aforementioned metals, is suitable for the mirror layer.

[0089] A second embodiment of a semiconductor chip 1 is shown in Fig. 3 is shown schematically in a sectional view. The semiconductor body 2 is again as in connection with Fig. 1A. In contrast to the semiconductor chip according to the Fig. In the first exemplary embodiment described in FIG. 2, the semiconductor body 2 has a recess 24 that extends from a side facing the carrier 5 through the p-conducting semiconductor layer 22 and through the active region 20 into the n-conducting multilayer structure 21. The recess penetrates the quantum layers 211 of the n-conducting multilayer structure. The side surfaces of the recess are covered by an insulating layer 27, which protects the semiconductor body 2 from an electrical short circuit in the active region 20.

[0090] A contact layer 65 is formed in the recess 24, which serves to electrically contact the active region from the side facing away from the p-conductive semiconductor layer 22.

[0091] The carrier 5 has a first connection area 51 and a second connection area 52, wherein the first connection area 51 is electrically connected to the n-conducting multilayer structure 21 via the contact layer 65, and the second connection area 52 is electrically connected to the p-conducting semiconductor layer 22 via the mirror layer 62. The first connection area 51 and the second connection area 52 are arranged on the same side of the carrier 5.

[0092] The recess 24 thus allows electrical contact to be made with the n-conducting multilayer structure 21 arranged on the side of the active region 20 facing away from the carrier 5, so that the radiation exit surface 200 can be designed free of an external electrical contact. This prevents shadowing of the radiation exit surface by a non-radiation-permeable contact.

[0093] The carrier 5 has openings 55, which extend from a first main surface 501 of the carrier facing the semiconductor body 2 to a second main surface 502 opposite the first main surface. The first connection surface 51 is electrically connected to the first contact 31 and the second connection surface 52 is electrically connected to the second contact 32 via these openings, so that the semiconductor chip 1 can be externally electrically contacted from an underside of the semiconductor chip facing away from the radiation exit surface 200. Furthermore, the semiconductor body 2 has a structuring 7 on the side of the radiation exit surface 200. The structuring serves to reduce total reflection of radiation generated in the active region within the semiconductor chip and thus to increase the coupling-out efficiency. Of course, such a structuring can also be used in the case of the Fig. 2 described first embodiment of the semiconductor chip may be provided.

[0094] In Fig. Figure 4 shows the behavior of the reverse current I as a function of the voltage in the reverse direction, i.e., in the blocking direction of the active region 20. Curve 99 shows measurements on a semiconductor layer sequence from which the semiconductor bodies for the semiconductor chips are produced during subsequent processing. The semiconductor layer sequence is, as in connection with Fig. 1B described.

[0095] In comparison, a curve shows 98 measurements on a semiconductor layer sequence in which a conventional n-conducting region without doping tips is used.

[0096] An arrow 97 illustrates that, by means of the described design of the n-conducting multilayer structure 21, the current curve initially increases more slowly for low voltages and only shows a steep increase in current at very high voltage values. The measurement curve thus exhibits a significantly more pronounced kink-like curve.

[0097] The description of the exemplary embodiments was provided merely by way of example based on the description of an LED semiconductor chip. However, the described configuration of the n-conducting multilayer structure 21 and the doping profile with at least one doping peak 4 can also be used for a coherent or at least partially coherent radiation-emitting component, for example, for a surface-emitting or edge-emitting semiconductor laser chip or for an RCLED (resonant cavity light-emitting diode).

Claims

[1] Semiconductor chip (1) comprising a semiconductor body (2) with a semiconductor layer sequence, wherein - the semiconductor layer sequence comprises an n-conducting multilayer structure (21), a p-conducting semiconductor layer (22) and an active region (20) provided for generating radiation, which is arranged between the n-conducting multilayer structure (21) and the p-conducting semiconductor layer (22); - a doping profile is formed in the n-conducting multilayer structure (21) which has at least one doping peak (4), - the n-conducting multilayer structure (21) has a quantum structure with a plurality of quantum layers (211) arranged between barrier layers (212), - the doping profile has a further doping peak (41), - a partial region (216) of the quantum structure of the n-conducting multilayer structure (21) has a high doping concentration by means of the further doping tip (41), and - a low n-conductively doped region (45) of the quantum structure is formed between the further doping tip (41) and the doping tip (4), wherein the low n-conductively doped region (45) contains at least one quantum layer (211) and at least one barrier layer (212). [2] Semiconductor chip (1) according to claim 1, wherein a doping concentration in the at least one doping tip (4) is at least five times as high as in the low n-conductively doped region (45) of the n-conductive multilayer structure (21). [3] Semiconductor chip (1) according to claim 2, wherein the doping concentration in the at least one doping tip (4) is at least 4 * 10 18 cm -3 and in the low n-conducting doped region (45) at most 8 * 10 17 cm -3 amounts. [4] Semiconductor chip (1) according to one of claims 1 to 3, wherein the doping tip (4) has a vertical extent of between 1 nm and 30 nm inclusive. [5] Semiconductor chip (1) according to one of claims 1 to 4, wherein the doping tip (4) has a vertical extension between 5 nm and 20 nm inclusive. [6] Semiconductor chip (1) according to one of claims 1 to 5, wherein the doping tip (4) has a distance of between 2 nm and 20 nm inclusive from the active region (20). [7] Semiconductor chip (1) according to claim 6, wherein the active region (20) has a plurality of quantum layers (201), wherein the doping tip (4) is arranged between the quantum layer (211) of the n-conductive multilayer structure (21) closest to the active region (20) and the quantum layer (201) of the active region (20) closest to the n-conductive multilayer structure (21). [8] Semiconductor chip (1) according to claim 7, wherein a band gap of the quantum layer (211) of the n-conducting multilayer structure (21) is at least as large as a band gap of the quantum layer (201) of the active region (20). [9] Semiconductor chip (1) according to one of claims 1 to 8, wherein at least one quantum layer (211) of the n-conducting multilayer structure (21) is arranged between the doping tip (4) and the further doping tip (41). [10] Semiconductor chip (1) according to one of claims 1 to 9, wherein the active region (20) is based on a nitride compound semiconductor material. [11] Semiconductor chip (1) according to one of claims 1 to 10, wherein a crystal structure of the n-conductive multilayer structure (21) has V-shaped grooves. [12] Semiconductor chip (1) according to one of claims 1 to 11, in which a growth substrate for the semiconductor layer sequence of the semiconductor body (2) is removed. [13] Semiconductor chip (1) according to claim 1, in which - a doping concentration in the at least one doping tip (4) is at least five times as high as in a region of the n-conducting multilayer structure (21) adjacent to the doping tip (4); - the active region (20) has a quantum structure with at least one quantum layer (201); and - a band gap of the quantum layer (211) of the n-conducting multilayer structure (21) is larger than a band gap of the quantum layer (201) of the active region (20).

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