Light-emitting diode chip, and method for manufacturing a light-emitting diode chip

Abstract

The invention relates to a light-emitting diode chip comprising: - a p-contact region (40) which is formed of GaP, - a p-type semiconductor region (4), - an n-type semiconductor region (3), - an active region (2) between the n-type semiconductor region (3) and the p-type semiconductor region (4), - an outer side surface (14) which laterally delimits the p-contact region (40), the p-type semiconductor region (4), the n-type semiconductor region (3), and the active region (2), and - an intermixing region (1) at least in the area of the active region (2) at the outer side surface (14) and / or at an inner side surface (19) in an open region (18). The light-emitting diode chip may be, inter alia, a micro-LED.

Description

[0001] Description

[0002] LED chip and method for manufacturing an LED chip

[0003] A light-emitting diode chip and a method for manufacturing a light-emitting diode chip are described.

[0004] The German patent DE 102010026518 Al describes a light-emitting diode chip and a method for its manufacture.

[0005] One task to be solved is to specify a light-emitting diode chip that can be operated particularly efficiently.

[0006] Another task to be solved is to specify a method for manufacturing such a light-emitting diode chip.

[0007] According to at least one embodiment of the LED chip, the LED chip comprises a p-contact area formed with GaP. The p-contact area can contain GaP or consist entirely of GaP. The material with which the p-contact area is formed is doped with a p-type dopant.

[0008] The p-contact area is used for p-side contacting of the LED chip. For example, it is in direct contact with a contact metal.

[0009] The p-contact region is located on the p-side outer surface of a semiconductor body of the LED chip. The p-contact region can extend over a major surface of the semiconductor body of the LED chip. This major surface, for example, runs at least partially parallel to a major extension plane of the LED chip.

[0010] The p-contact region can completely cover the main area. Alternatively, it is possible that the p-contact region is structured and does not completely cover the main area.

[0011] According to at least one embodiment of the LED chip, the LED chip comprises a p-type semiconductor region. This p-type semiconductor region is doped, at least locally, with a p-type dopant. For example, the p-type semiconductor region borders directly on the p-type contact region. The p-type semiconductor region can comprise several layers, such as barrier layers, cladding layers, and buffer layers, stacked on top of each other in a growth direction.

[0012] According to at least one embodiment of the LED chip, the LED chip comprises an n-type semiconductor region. This n-type semiconductor region is doped, at least in some areas, with an n-type dopant. The n-type semiconductor region can comprise several regions, such as barrier layers, cladding layers, and / or buffer layers, stacked on top of each other in a growth direction.

[0013] According to at least one embodiment of the LED chip, the LED chip comprises an active region located between the n-type semiconductor region and the p-type semiconductor region. The active region is, for example, arranged along a growth direction of the semiconductor body of the LED chip between the n-type and p-type semiconductor regions. The regions of the LED chip are, for example, stacked on top of each other along the growth direction and each extends, at least partially, parallel to the main plane of extension of the LED chip.

[0014] The active area comprises, for example, alternating quantum well layers and barrier layers and is intended for the generation of electromagnetic radiation during the operation of the light-emitting diode chip.

[0015] According to at least one embodiment of the LED chip, the LED chip comprises a side surface that bounds the p-contact region, the p-type semiconductor region, the n-type semiconductor region, and the active region in a lateral direction. This side surface runs, for example, perpendicular or transverse to the main plane of extension of the LED chip. The side surface can be an outer and / or an inner surface.

[0016] The side surface, for example, represents the outer boundary surface of the semiconductor body of the LED chip; that is, an outer side surface that connects a top surface of the semiconductor body with a bottom surface of the semiconductor body. Depending on its shape, the LED chip can have one or more outer side surfaces. If the LED chip is cuboid, for example, it has four outer side surfaces.

[0017] Furthermore, it is possible that the LED chip was open.

[0018] The chip has areas within its outer boundaries where internal surfaces, i.e., inner surfaces, are also formed. In this case, at least one mixing region is formed within the LED chip.

[0019] According to at least one embodiment of the LED chip, the LED chip has a mixing area at least in the area of ​​the active area on the outer side surface and / or on an inner side surface in an open area.

[0020] In the mixing region, the LED chip contains a mixing substance. For example, the quantum well layers and the barrier layers of the active region are mixed in the mixing region.

[0021] This means that the mixing agent induces a mixing of crystal components within the areas of the LED chip, particularly the quantum well layers and barrier layers in the active region. This mixing occurs, for example, at a temperature significantly above room temperature and also above the intended operating temperature of the finished LED chip. The mixing can be homogeneous across all quantum well layers in the active region. Alternatively, the mixing can be inhomogeneous. The mixing area preferably extends completely through the active region and can also encompass the adjacent semiconductor regions, such as the p-type semiconductor region, the n-type semiconductor region, and / or the p-contact region. The LED chip can have no, one, or several open regions.In the open area(s), inner surfaces are formed that border the semiconductor body. These open areas can be used, for example, as vias for through-hole plating. It is possible for the mixing areas to be formed only on the inner surfaces and not on the outer surfaces of the LED chip. This is particularly advantageous for large LED chips. However, it is also possible for the mixing area to be formed only on the outer surfaces. This is particularly advantageous for small LED chips.

[0022] The opened area(s) are, for example, designed as blind holes, which can have a round or square cross-section.

[0023] According to at least one embodiment of the LED chip, an LED chip is specified as follows:

[0024] - a p-contact region formed with GaP ,

[0025] - a p-type semiconductor region,

[0026] - an n-type semiconductor region,

[0027] - an active region between the n-type semiconductor region and the p-type semiconductor region,

[0028] - a side surface which limits the p-contact region, the p-conducting semiconductor region, the n-conducting semiconductor region, and the active region in a lateral direction, and

[0029] - a mixing zone, at least in the region of the active area on the outer side surface and / or on an inner side surface in an open area. The LED chip described here is based, among other things, on the understanding that forming a mixing zone on a side surface of the LED chip, particularly in the region of the active area, makes non-radiative recombination less likely and thus increases the efficiency of the LED chip. Therefore, under the same operating conditions, the LED chip exhibits higher brightness than an LED chip without such a mixing zone. This proves particularly advantageous for LED chips with a p-contact area formed with GaP.

[0030] Furthermore, a method for manufacturing a light-emitting diode (LED) chip is described. In particular, the LED chip described herein can be manufactured using this method, such that all features of the LED chip described herein are also of the method described herein, and vice versa.

[0031] According to at least one embodiment of the process, a growth substrate is first provided. This growth substrate is, for example, a wafer on which a large number of LED chips are fabricated. The growth substrate is, for example, a semiconductor body made of GaAs or SiC. The subsequent areas of the LED chip are then epitaxially deposited onto a growth surface of the growth substrate.

[0032] According to at least one embodiment of the process, the n-type semiconductor region, the active region, the p-type semiconductor region, and the p-contact region, formed with GaP, are grown on the growth substrate. A masking layer is applied to the side of the p-contact region facing away from the p-type semiconductor region. The masking layer can be applied in the same epitaxial reactor as the other regions. Alternatively, the masking layer can be applied in a separate, subsequent process step. The masking layer has numerous openings through which the p-contact region is exposed and freely accessible.

[0033] According to at least one embodiment of the process, the formation of a multitude of diffusion regions is achieved by introducing a mixing agent, at least in the active region, through the openings of the masking layer. To form the diffusion regions, for example, the entire assembly is heated to temperatures above room temperature and above the subsequent operating temperature of the LED chips to be manufactured.

[0034] According to at least one embodiment of the process, singulation is carried out through at least some of the diffusion regions and / or the creation of open areas within at least some of the diffusion regions to generate outer and / or inner side surfaces, in which a mixing region is formed on each of the outer and / or inner side surfaces, at least in the region of the active area. The mixing region is created by separating the individual LED chips along the diffusion regions through the openings in the masking layer and / or by forming open areas in the semiconductor body. It is possible that the masking layer is removed before or after singulation or remains in the finished LED chip.

[0035] According to at least one embodiment of the process for manufacturing a light-emitting diode chip, the process comprises the following steps:

[0036] - Providing a growth substrate,

[0037] - Creating an n-type semiconductor region, an active region, a p-type semiconductor region and a p-contact region formed with GaP, and a masking layer on the growth substrate,

[0038] - Forming a large number of diffusion zones by introducing a mixing agent, at least in the active area, through openings in the masking layer,

[0039] - Separation through at least some of the diffusion areas and / or creation of open areas within at least some of the diffusion areas to create outer and / or inner side surfaces, in which a mixing area is formed on each of the outer and / or inner side surfaces at least in the area of ​​the active area.

[0040] The method described here makes it possible to produce the light-emitting diode chips described here particularly cost-effectively.

[0041] The following section provides a more detailed explanation of the implementation forms of the LED chips and methods described herein. All implementation forms can refer to both the LED chips and the methods described herein. According to at least one implementation form, at least one of the following areas of the LED chip is based on a phosphide compound semiconductor material: p-type semiconductor region, n-type semiconductor region, active region. In particular, it is possible that all of these areas are based on a phosphide compound semiconductor material.

[0042] In this context, “based on phosphide compound semiconductor material” means that the semiconductor regions, or at least a part thereof, particularly preferably at least the active region and / or a growth substrate for the regions, preferably Al n Ga m Initiative n-m P or As n Ga m Initiative n-m P comprises , where 0 < n < 1, 0 < m < 1 and n+m < 1. This material does not necessarily have to have a mathematically exact composition according to the formula above. Rather, it may contain one or more dopants as well as additional components. For the sake of simplicity, however, the formula above only includes the essential components of the crystal lattice (Al or As, Ga, In, P), even though these may be partially replaced by small amounts of other substances.

[0043] The light-emitting diode chip can then be configured in particular to generate electromagnetic radiation from the wavelength range of IR radiation and / or red light during operation; preferably, the light-emitting diode chip is configured to emit red light during operation.

[0044] According to at least one embodiment of the LED chip, the mixing area forms an electrical passivation on the outer and / or inner side surface, and / or the electrical conductivity on the outer and / or inner side surface of the LED chip is reduced. This means that, in addition to the property that the rate of non-radiative recombination is reduced due to the mixing area, the mixing area can also form an electrical passivation on the outer and / or inner side surface of the LED chip. This makes it possible to provide an LED chip with increased ESD resistance.

[0045] In this case, it is particularly possible that the mixing zone of the LED chip is present across its entire surface. This means that the mixing agent is detectable in all areas of the LED chip, on both the outer and / or inner surfaces.

[0046] According to at least one embodiment of the LED chip, the mixing region has a thickness of at least 10 nm and at most 100 pm from the side surface, preferably 1–5 pm. The mixing region is located where the interface between the quantum film and the barrier is recognizably thicker than in the non-mixed region.

[0047] The method described here can be used, in particular, for LED chips of different sizes. It is possible, for example, to use the method in the production of micro-LEDs, but also for LED chips with a base area of ​​100 pm. 2 , 500 pm 2 or more. In this case, for example, the thickness of the mixing area can be chosen to be thicker than for LED chips with smaller edge lengths. This can be achieved, for example, by the size of the openings of the

[0048] Masking layer can be set.

[0049] According to at least one embodiment of the light-emitting diode chip, the mixing area includes the mixing substance, which is formed, for example, by zinc and / or magnesium.

[0050] According to at least one embodiment, the masking layer remains on a side of the p-contact area facing away from the p-type semiconductor region and / or within the p-contact area of ​​the LED chip. This means that the masking layer is not removed, but rather the p-contact area is at least partially covered by the masking layer. The masking layer can, for example, contribute to protecting the p-contact area during further processing steps or serve as a masking material for subsequent process steps, such as the application of mirrors or contact layers. Furthermore, it is possible that the masking layer serves as a contact layer in the finished LED chip.

[0051] According to at least one embodiment, the masking layer comprises GaAs and / or AlGaAs or consists of one of these materials. In particular, a masking layer formed with GaAs can be applied directly in the epitaxial assembly, where the other areas of the LED are also manufactured. Alternatively, the masking layer can be applied subsequently, outside of the epitaxial assembly. The masking layer can, for example, also comprise two or more layers, alternating between GaAs and AlGaAs. Such a masking layer containing GaAs and / or AlGaAs can be selectively removed from the p-contact region, which is formed with GaP, particularly by wet chemistry. For example, H₂O₂, NH₄OH, H₂O, BOE, and / or HF can be used for this purpose.

[0052] According to at least one embodiment, the masking layer comprises at least one of the following materials: TCO material, SiON, SiO2, SiN, Al12O3, HfO

[0053] If the masking layer is formed with a TCO material such as ITO, ZnO, InZnO or the like, the masking layer can remain in the finished LED chip as a contact layer or current expansion layer.

[0054] The other materials mentioned can, for example, remain in the finished LED chip as part of a mirror layer and / or as diffusion barriers for a solder material.

[0055] According to at least one embodiment, the light-emitting diode chip is a micro-LED.

[0056] In the following, the term micro-LED refers in the broadest sense to any light-emitting diode (LED) – usually not a laser – with particularly small dimensions.

[0057] Dimensions are referred to. In particular, in micro-LEDs, a growth substrate is removed, so that typical heights of such micro-LEDs are, for example, in the range of 0.1 pm to 10 pm.

[0058] In principle, a micro-LED does not necessarily have to have a rectangular emission surface. Generally, for example, an LED with an emission surface where, in a top view of the layers of the layer stack, each lateral extent of the emission surface is less than or equal to 100 pm or less than or equal to 70 pm, can be referred to as a micro-LED.

[0059] For example, for rectangular micro-LEDs, an edge length - especially in top view of a top surface of the micro-LED - of less than or equal to 70 pm or less than or equal to 50 pm is possible.

[0060] Most of these micro-LEDs are provided on wafers with holding structures that can be removed without damaging the micro-LEDs.

[0061] Currently, micro-LEDs are primarily used in displays. Here, the micro-LEDs form pixels or subpixels and emit light of a defined color. Due to their small pixel size and high density at close range, micro-LEDs are suitable for small monolithic displays for AR applications, particularly smart glasses. Furthermore, other applications are possible, especially for data communication or pixelated lighting applications. Various notations for micro-LED can be found in the literature, e.g., pLED, p-LED, uLED, u-LED, or Micro Light Emitting Diode.

[0062] According to at least one embodiment, the mixing agent is introduced into the active area from a side of the active area facing away from the growth substrate. For this purpose, the mixing agent, for example in the form of a solution, is applied to the masking material and penetrates the semiconductor body through the openings in the masking layer. It is possible that the mixing agent also extends into the growth substrate. The growth substrate can be removed before or after singulation, or it can remain in the finished LED chip.

[0063] The following section provides a more detailed explanation of the light-emitting diode and the method described here, using exemplary embodiments and the corresponding figures.

[0064] Based on the schematic sectional views of Figures 1A, 1B, IC, ID, IE , 1F, IG, 1H, the process steps of an exemplary embodiment of a process described here are explained in more detail.

[0065] Based on the schematic sectional representation of Figures 1H, 2, 3, examples of the light-emitting diodes described here are explained in more detail.

[0066] Identical, similar, or similarly effective elements are marked with the same reference symbols in the figures. The figures and the relative sizes of the elements depicted within them are not to be considered to scale. Rather, individual elements may be exaggerated for clarity and / or to improve representation.

[0067] According to an exemplary embodiment of a method described herein, a growth substrate 10 is first provided, Figure 1A. The growth substrate 10 is, for example, at least partially composed of GaAs and has at least one growth surface 10a which is composed of GaAs.

[0068] In a subsequent process step, Figure 1B, an n-type semiconductor region 3, an active region 2, a p-type semiconductor region 4, and a p-contact region 40 formed with GaP are grown on the growth substrate 10. These regions can, for example, comprise various sublayers and follow one another directly in the sequence shown. The growth of these regions on the growth substrate is carried out epitaxially.

[0069] In a subsequent process step, Figure IC, a masking layer 12 is produced on the side of the p-contact region 40 facing away from the growth substrate 10. The masking layer 12 can, for example, be produced in the same epitaxial reactor as the other regions. The masking layer 12 is formed, for example, with GaAs.

[0070] Openings 16 are created in the masking layer 12, Figure ID, in which material from the masking layer 12 has been removed and the p-contact area 40 is freely accessible at the bottom surface. For example, the openings 16 can be created lithographically. In a subsequent process step, Figure IE, a plurality of diffusion areas 11 are formed by introducing a mixing agent, at least in the active area 2, through the openings 16 of the masking layer 12. For example, the mixing agent can penetrate all areas 2, 3, 4 and, if necessary, also the growth substrate 10.

[0071] For example, the n-type semiconductor region 3, the active region 2, and the p-type semiconductor region 4 are based on a phosphide compound semiconductor material. The p-contact region 40, for example, consists of GaP. The mixing material is, for example, zinc.

[0072] In a subsequent process step, Figure 1F, the masking layer 12 can be removed. Furthermore, the growth substrate 10 can be removed and the epitaxially produced semiconductor layer sequence is electrically connected to a support 5 via a p-contact layer.

[0073] In a subsequent process step, Figure IG, the particles are separated along the separation lines 13, which are imaginary lines, through the diffusion regions 11, thereby generating outer side surfaces 14 of LED chips. On each of the LED chips, a mixing region 1 is formed on at least the active region 2 of the outer side surfaces 14. The LED chip can also include one or more open regions 18. Side surfaces, namely inner side surfaces 19, are also formed in the open region(s) 18, bordering the semiconductor body. The open region(s) 18 can, for example, be used as vias for through-hole plating.

[0074] It is possible that the mixing region 1 is formed only on the inner side surfaces 19 and not on the outer side surface 14 of the LED chip. This is particularly advantageous for large LED chips. However, it is also possible that the mixing region 1 is formed only on the outer side surfaces 14. This is particularly advantageous for small LED chips.

[0075] The singulation also takes place through the support 5, Figure IG. Alternatively, it is possible for the growth substrate 10 to remain and no rebonding onto a support 5 takes place.

[0076] The schematic sectional view of Figure 1H shows a light-emitting diode chip described here according to a first embodiment. The light-emitting diode chip comprises the p-contact area 40, which is formed with GaP and borders the p-contact layer 6, via which it is connected to the carrier 5. The carrier 5 can, for example, be electrically conductive.

[0077] The LED chip further comprises the p-type semiconductor region 4, the active region 2, and the n-type semiconductor region 3. The mixing region 1 is located on the outer side surface 14, which laterally borders the p-contact region 40, the p-type semiconductor region 4, the n-type semiconductor region 3, and the active region 2. The n-contact layer 9 is located on the side of the n-type semiconductor region 3 facing away from the support 5.

[0078] The embodiment of the LED chip described in conjunction with Figure 1H is a vertical LED chip with n- and p-contacts on opposite sides. Alternatively, it is also possible for the LED chip to be contactable from only one side, for example, from the top or the bottom. In this case, the p-contact layer 6 and the n-contact layer 9 are arranged on the same side of the LED chip. For example, vias extend, for example, in the open areas 18 (see Figure IG), through the areas of the LED chip, in particular through the active area, to electrically connect at least one of the semiconductor areas 3, 4. The LED chip is then configured, for example, as a flip chip or UX:3 chip.

[0079] In conjunction with the schematic sectional view of Figure 2, a further embodiment of a light-emitting diode (LED) chip described herein is explained in more detail. Unlike the LED chip described in conjunction with Figure 1H, the masking layer 12 is not removed in this case. For example, the masking layer 12 remains as a contact layer in the LED chip. In this case, the masking layer 12 is formed, for example, by a TCO material.

[0080] Furthermore, it is possible that the masking layer 12 is formed with an electrically insulating material such as SiON, SiC>2, SiN, Al2O3, or HfO. In this case, the masking layer 12 can have vias to the contact layer 6. The masking layer 12 can, for example, be configured as a dielectric mirror.

[0081] In conjunction with the schematic sectional view of Figure 3, a further embodiment of a light-emitting diode chip described herein is explained in more detail. In this embodiment, the light-emitting diode chip comprises a reflective layer 7, which is arranged between the contact layer 6 and the p-contact area 40. This reflective layer can, for example, be electrically conductive and is formed, for example, with a metal. The reflective layer can, for example, comprise or consist of gold.

[0082] Furthermore, the p-contact region 40 and, if applicable, the p-conducting semiconductor region 4 comprise structures 17, which are, for example, designed as prisms. These structures 17, which extend into the semiconductor body, reduce the probability of total internal reflection on the side of the semiconductor chip facing the support 5 and thus increase the efficiency of the LED chip. In addition, the structures 17 reduce the thickness of any potentially absorbing semiconductor layer, which also leads to improved efficiency.

[0083] The features and embodiments described in connection with the figures can be combined with one another according to further embodiments, even if not all combinations are explicitly described. Furthermore, the embodiments described in connection with the figures can alternatively or additionally exhibit further features according to the embodiments described in the general part.

[0084] This patent application claims priority from German patent application 10 2024 115 430 . 6, the disclosure content of which is hereby incorporated by reference. The invention is not limited to the description by reference to the exemplary embodiments. Rather, the invention encompasses every new feature as well as every combination of features, which in particular includes every combination of features in the patent claims, even if this feature or combination itself is not explicitly specified in the patent claims or exemplary embodiments.

[0085] Reference character list

[0086] 1 Mixing area

[0087] 2 active areas

[0088] 3 n-conducting semiconductor region

[0089] 4 p-type semiconductor region

[0090] 40 p contact area

[0091] 5 carriers

[0092] 6 p-contact layer

[0093] 7 mirrors

[0094] 9 n-contact layer

[0095] 10 Growth substrate

[0096] 10a Growth area

[0097] 11 Di f fusion area

[0098] 12 masking layer

[0099] 13 dividing lines

[0100] 14 outer side surface

[0101] 16 openings

[0102] 17 Structuring

[0103] 18 open area

[0104] 19 inner side surface

Claims

Patent claims 1. Light-emitting diode chip with - a p-contact region (40) formed with GaP, - a p-type semiconductor region (4) , - an n-conducting semiconductor region (3) , - an active region (2) between the n-conducting semiconductor region (3) and the p-type semiconductor region (4) , - an outer side surface (14) which limits the p-contact region (40), the p-conducting semiconductor region (4), the n-conducting semiconductor region (3) and the active region (2) in a lateral direction, and - a mixing area (1) at least in the area of ​​the active area (2) on the outer side surface (14) and / or on an inner side surface (19) in an open area (18) .

2. Light-emitting diode chip according to the preceding claim, wherein at least one of the following areas is based on a phosphide compound semiconductor material: p-type semiconductor area (4), n-type semiconductor area (3), active area (2).

3. Light-emitting diode chip according to one of the preceding claims, wherein the mixing area (1) forms an electrical passivation on the outer and / or inner side surface (14,19) and / or reduces the electrical conductivity on the outer and / or inner side surface (14,19).

4. Light-emitting diode chip according to one of the preceding claims, wherein the mixing area (1) is formed on the entire outer and / or inner side surface (14, 19).

5. Light-emitting diode chip according to one of the preceding claims, wherein the mixing area (1) from the outer and / or inner side surface (14,19) has a thickness of at least 10 nm and at most 100 pm.

6. Light-emitting diode chip according to one of the preceding claims, wherein at least one mixing area (1) is formed within the light-emitting diode chip.

7. Light-emitting diode chip according to one of the preceding claims, wherein the mixing area (1) is generated by using a mixing agent which is zinc and / or magnesium.

8. Light-emitting diode chip according to one of the preceding claims, comprising a masking layer (12) on a side of the p-contact area (40) facing away from the p-conducting semiconductor area (4) and / or in the p-contact area (40).

9. Light-emitting diode chip according to the preceding claim, wherein the masking layer (12) comprises GaAs and / or AlGaAs .

10. Light-emitting diode chip according to one of the two preceding claims, wherein the masking layer (12) comprises at least one of the following materials: TCO material, SiON, SiO2, SiN, A12O3, HfO.

11. Light-emitting diode chip according to one of the preceding claims, wherein the light-emitting diode chip is a micro-LED.

12. Method for manufacturing a light-emitting diode chip comprising the following steps: - Providing a growth substrate (10) , - Generating an n-type semiconductor region (3), an active region (2), a p-type semiconductor region (4) and a p-contact region (40) formed with GaP, and a masking layer (12) on the growth substrate (10), - Forming a multitude of diffusion zones (11) by introducing a mixing agent at least in the active zone (2) through openings (16) in the masking layer (12) , - Separation through at least some of the diffusion areas (11) and / or creation of open areas (18) within at least some of the diffusion areas to create outer and / or inner side surfaces (14,19) in which a mixing area (1) is formed on each of the outer and / or inner side surfaces (14,19) at least in the area of ​​the active area (2).

13. Method according to the previous claim, wherein the mixing agent is introduced into the active region (2) from a side of the active region facing away from the growth substrate.

14. Method according to one of the preceding claims, wherein the masking layer (12) is removed after the introduction of the mixing agent.

15. Method according to one of the preceding claims, wherein a light-emitting diode chip is manufactured according to one of the preceding claims.

Images