LIGHT EMISSIONING ELEMENT

Abstract

A light-emitting element comprising: a semiconductor structure comprising a first semiconductor layer of a first conductivity type, an active layer located below the first semiconductor layer, and a second semiconductor layer of a second conductivity type located below the active layer; a cover made of an insulating material and located on the upper surface of the first semiconductor layer; a metal layer located within the cover; a light-transmitting electrode located on the upper surface of the cover and the upper surface of the first semiconductor layer;a first electrode comprising an external connection region located on the upper surface of the light-transmitting electrode and an extension region extending from the external connection region, and a second electrode located on the second semiconductor layer. At least one region of the extension region overlaps the cover portion and the metal layer in a top view.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] This application claims priority over Japanese patent application No. 2024-168693, filed on September 27, 2024, the entire contents of which are hereby incorporated by reference. BACKGROUND Technical area

[0002] The present disclosure relates to a light-emitting element. State of the art

[0003] Japanese patent publication No. 2018-113442 discloses a light-emitting element comprising a first electrode electrically connected to a semiconductor layer of a first conductivity type, and a second electrode positioned on a transparent electrode layer, which is itself arranged on a semiconductor layer of a second conductivity type and electrically connected to the transparent electrode layer. It also discloses the structure in which the second electrode includes a second electrode pad and a second electrode extension area extending from the second electrode pad, and a second reflective layer is arranged between the second electrode and the transparent electrode layer to improve light extraction efficiency. OVERVIEW

[0004] Such a light-emitting element must exhibit higher output and higher reliability. One objective of the present disclosure is to provide a light-emitting element with higher reliability that is capable of achieving higher output.

[0005] A light-emitting element according to one embodiment of the present invention comprises: a semiconductor structure comprising a first semiconductor layer of a first conductivity type, an active layer arranged below the first semiconductor layer, and a second semiconductor layer of a second conductivity type arranged below the active layer; a cover element made of an insulating material and arranged on the upper surface of the first semiconductor layer; a metal layer arranged within the cover element; and a light-transmitting electrode arranged on the upper surface of the cover element and the upper surface of the first semiconductor layer.A first electrode comprising an external connection region located on the upper surface of the light-transmitting electrode and an extension region extending from the external connection region, and a second electrode located on the second semiconductor layer. At least one region of the extension region overlaps the cover portion and the metal layer in a plan view. The external connection region comprises a first region that, in a plan view, overlaps the cover portion but does not overlap the metal layer.

[0006] A light-emitting element according to a further embodiment of the present invention comprises: a semiconductor structure comprising a first semiconductor layer of a first conductivity type, an active layer arranged below the first semiconductor layer, and a second semiconductor layer of a second conductivity type arranged below the active layer; a cover element arranged on the upper surface of the first semiconductor layer and comprising one or more elements selected from Zr, Si, V, Nb, Hf, Ta, Al, Ce, In, Sb, and Zn, and either one or both of oxygen and nitrogen; a metal layer arranged within the cover element; a light-transmitting electrode arranged on the upper surface of the cover element and the upper surface of the first semiconductor layer;A first electrode comprising an external connection region located on the top surface of the light-transmitting electrode and an extension region extending from the external connection region; and a second electrode located on the second semiconductor layer. At least one region of the extension region overlaps the cover portion and the metal layer in plan view. The external connection region includes a first region that overlaps the cover portion in plan view but does not overlap the metal layer.

[0007] A light-emitting element according to an embodiment of the present disclosure can achieve higher output and higher reliability. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1A is a schematic top view showing an example of a light-emitting element according to embodiment 1. Fig. 1B is a schematic cross-sectional view, taken along line 1b-1b in Fig. 1A. Fig. 1C is a schematic partial cross-sectional view, taken along line 1c-1c in Fig. 1A. Fig. 1D is a schematic partial cross-sectional view, taken along the line 1d-1d in Fig. 1A. Fig. Figure 1E is a schematic top view showing another example of a light-emitting element according to embodiment 1. Fig. Figure 1F is a schematic, partially enlarged cross-sectional view of the structure directly below the extent area in a light-emitting element according to embodiment 1. Fig. Figure 1G is a schematic partial cross-sectional view of the structure around the extent area in a light-emitting element according to embodiment 1-1. Fig. Figure 1H is a schematic partial cross-sectional view of the structure around the external connection area in a light-emitting element according to embodiment 1-2. Fig. Figure 1I is a schematic partial cross-sectional view of the structure around the extent area in the light-emitting element according to embodiment 1-2. Fig. Figure 1J is a schematic partial cross-sectional view of the structure around the external connection area in a light-emitting element according to embodiment 1-3. Fig. Figure 1K is a schematic partial cross-sectional view of the structure around the external connection area in a light-emitting element according to embodiment 1-4. Fig. 2A is a schematic top view of a light-emitting element according to embodiment 2. Fig. 2B is a schematic cross-sectional view, taken along line 2b-2b in Fig. 2A. Fig. 2C is a schematic partial cross-section, recorded along the line 2c-2c in Fig. 2A. Fig. 2D is a schematic, partially enlarged cross-sectional view showing another example of the structure directly below the external connection area in a light-emitting element according to embodiment 2. Fig. Figure 2E is a schematic partial cross-sectional view showing yet another example of the structure directly below the external connection area in a light-emitting element according to embodiment 2. Fig. Figure 3A is a schematic top view of a light-emitting element according to embodiment 3. Fig. 3B is a schematic cross-sectional view, taken along line 3b-3b in Fig. 3A. Fig. 3C is a schematic partial cross-section, recorded along the line 3c-3c in Fig. 3A. Fig. Figure 4 is a schematic top view illustrating a method for determining the boundary between the external connection area and an extent area of ​​the first electrode in a light-emitting element. DETAILED DESCRIPTION

[0008] Certain embodiments of light-emitting elements according to the present invention are described below. The drawings referenced in the following description are schematic representations of the present invention. Accordingly, the scale, intervals, or positional relationships of the components may be exaggerated, or components may be partially omitted. There may be cases in which the scale or intervals of components do not correspond between a top view and a cross-sectional view. In the following description, the same designations and reference numerals generally denote the same or similar components, for which a detailed description may be omitted.

[0009] In this specification, terms such as "on," "above," "top," "below," "below," "bottom," and the like are used to indicate the relative positions of components in a drawing referenced for explanatory purposes. These terms are not intended to indicate absolute positions unless specifically stated otherwise.

[0010] The inventor conducted his research to provide a light-emitting element with higher output and reliability, and conceived the idea of ​​placing a metal layer between an electrode and a semiconductor structure to reduce light absorption by the electrode and increase the output of the light-emitting element. As a result of the inventor's further investigations, it was discovered for the first time that, in the case of a light-emitting element incorporating a metal layer, a wire connection in the external connection area of ​​the electrode makes the electrode more susceptible to separation from the semiconductor layer.Based on these findings, the present inventor has completed a light-emitting element that can increase the output by providing a metal layer, while reducing the chances of electrode separation during wire connection.

[0011] Light-emitting elements according to embodiments 1 to 3 of the present invention are described below. Design 1

[0012] Fig. Figure 1A is a schematic top view of a light-emitting element 10A according to embodiment 1. Fig. 1B is a schematic cross-sectional view, taken along line 1b-1b in Fig. 1A. Fig. 1C is a schematic partial cross-sectional view, taken along line 1c-1c in Fig. 1A, which primarily shows the structure around the external connection area 16a of the first electrode 16. Fig. 1D is a schematic partial cross-sectional view, taken along the line 1d-1d in Fig. 1A, which primarily shows the structure around the extension area 16b of the first electrode 16.

[0013] The light-emitting element 10A according to this embodiment comprises a semiconductor structure 12, a cover part 21, a metal layer 13, a light-transmitting electrode 15, a first electrode 16, and a second electrode 17. The light-emitting element 10A preferably includes a protective layer 20 that covers the semiconductor structure 12, the light-transmitting electrode 15, the first electrode 16, and the second electrode 17. The in Fig. The light-emitting element 10A shown in Figure 1A is in the state in which no protective layer 20 is present. The light-emitting element 10A can include a substrate 11 below the semiconductor structure 12 for supporting the semiconductor structure 12.

[0014] The semiconductor structure 12 comprises a first semiconductor layer 12a of a first conductivity type, an active layer 12c located below the first semiconductor layer 12a, and a second semiconductor layer 12b of a second conductivity type located below the active layer 12c. The cover 21 is made of an insulating material and is located on the upper surface of the first semiconductor layer 12a. The metal layer 13 is located within the cover 21. A light-transmitting electrode 15 is located on the upper surface of the cover 21 and on the upper surface of the first semiconductor layer 12a. The first electrode 16 includes an external connection area 16a and an extension area 16b that extends from the external connection area 16a to the upper surface of the light-transmitting electrode 15.The second electrode 17 is arranged on the second semiconductor layer 12b.

[0015] In a top view of the light-emitting element 10A, at least one area of ​​the extension area 16b overlaps the cover part 21 and the metal layer 13.

[0016] In this specification, the term "top view" refers to a view of the light-emitting element 10A from the side of the first electrode 16. In the Fig. In the example shown in Figure 1A of the light-emitting element 10A, the metal layer 13 is localized in the areas indicated by hatching and partially overlaps each of the three extent areas 16b.

[0017] How Fig. 1B and Fig. As can be seen from 1D, at least a portion of the light traveling from the active layer 12c to the extension regions 16b is reflected by the metal layer 13 before reaching the extension regions 16b and can thus be extracted by the light-emitting element 10A. This can reduce light absorption by the extension regions 16b, thereby improving the output of the light-emitting element 10A.

[0018] The metal layer 13 can be arranged such that a region of each extension region 16b does not overlap the metal layer 13. In the Fig. In the example shown in Figure 1A, the extension areas 16b do not overlap the metal layer 13 in the vicinity of the external connection area 16a, which is essentially circular in a top view. This is advantageous in order to further enhance the effect of reducing the separation of the external connection area 16a, as described below.

[0019] From the perspective of further increasing the effect of the output of the light-emitting element 10A, it is preferred that substantially the entire extent areas 16b overlap the metal layer 13 in a top view, as in the one shown in Fig. 1E light-emitting element 10A1 shown.

[0020] As in Fig. 1B and Fig. As shown in Figure 1C, the external connection area 16a in a top view of the light-emitting element 10A includes a first region 161 that overlaps the cover part 21 but not the metal layer 13. Such a structure allows separation of the external connection area 16a to be prevented during wire joining, as described below.

[0021] If a metal layer 13 is located directly beneath the external interconnection area 16a, the metal layer 13 would be subjected to an impact when a wire is connected to the external interconnection area 16a. This would cause the metal layer 13 to detach from the cover part 21 at the interface between the metal layer 13 and the cover part 21 directly beneath the external interconnection area 16a. This is assumed to be caused by the weak adhesion between the metal layer 13 and the cover part 21, which is due to the properties of the materials used for the metal layer 13 and the cover part 21. This separation can lead to the separation of the external interconnection area 16a from the semiconductor structure 12. The separation of the external interconnection area 16a can result in a decrease in the reliability of the light-emitting element.For example, the adhesion between the metal layer 13 and the cover part 21 is weaker than the adhesion between the semiconductor structure 12 and the cover part 21.

[0022] In the light-emitting element 10A according to this embodiment, the metal layer 13 is arranged such that the external connection area 16a includes a first region 161 directly below which the metal layer 13 is absent. That is, in a region between the external connection area 16a and the semiconductor structure 12, the interface area, which is a weak adhesion region, between the metal layer 12 and the cover part 21 is reduced, thus preventing the external connection area 16a from being separated from the semiconductor structure 12 during wire joining. This can increase the reliability of the light-emitting element 10A.

[0023] In the Fig. In the light-emitting element 10A shown in Figure 1A, the external interconnection region 16a does not overlap the metal layer 13 at all in a top view. In other words, the entirety of the external interconnection region 16a constitutes a first region 161. Furthermore, the extension regions 16b, which are adjacent to the external interconnection region 16a in a top view, do not overlap the metal layer 13. With this structure, it is less likely that the external interconnection region 16a will be separated from the semiconductor structure 12. However, the amount of light from the active layer 12c reaching the extension region 16b can be increased, such that the effect of increasing the output of the light-emitting element 10A can be reduced.

[0024] Each component is described in detail below. Semiconductor structure 12

[0025] A semiconductor structure 12 comprises a first semiconductor layer 12a of a first conductivity type, an active layer 12c located below the first semiconductor layer 12a, and a second semiconductor layer 12b of a second conductivity type located below the active layer 12c. In other words, the semiconductor structure 12 has a first semiconductor layer 12a, a second semiconductor layer 12b, and an active layer 12c positioned between the first semiconductor layer 12a and the second semiconductor layer 12b. The semiconductor structure 12 can be arranged on the top surface of a substrate 11. The shape of the semiconductor structure 12 in a top view is, for example, rectangular. In the case where the semiconductor structure 12 has a rectangular shape in a top view, the length of one side is 100 µm to 2000 µm.

[0026] The first conductivity type is either p-type or n-type. The second conductivity type differs from the first conductivity type, i.e., it is either n-type or p-type. In this embodiment, the first conductivity type is p-type and the second conductivity type is n-type. The active layer 12c emits light when a voltage is applied across the first electrode 16, which is electrically connected to the first semiconductor layer 12a, and the second electrode 17, which is located on and electrically connected to the second semiconductor layer 12b.

[0027] The semiconductor structure 12 can have regions where the first semiconductor layer 12a and the active layer 12c are not present, i.e., it can have recesses formed in a surface of the first semiconductor layer 12a, comprising a first exposed area 12d1 and a second exposed area 12d2, each of which is an area where the second semiconductor layer 12b is exposed at the bottom of one of the respective recesses.

[0028] In the Fig. In the example shown in Figure 1A, a first exposed region 12d1 and a second exposed region 12d2 are provided along the periphery of the light-emitting element 10A in a top view. Specifically, in a top view, a strip-shaped first exposed region 12d1 is provided along the four sides of the light-emitting element 10A, and a semi-elliptical second exposed region 12d2, connected to the first exposed region 12d1, is provided essentially at the center of one of the sides of the light-emitting element 10A. A second electrode 17 is arranged on the semi-elliptical second exposed region 12d2. The position and shape of the second exposed region 12d2 can be modified appropriately based on the other structural characteristics of the light-emitting element.In the present specification, the first exposed area 12d1 and the second exposed area 12d2 can be referred to collectively as the exposed area 12d.

[0029] For the first semiconductor layer 12a, the second semiconductor layer 12b and the active layer 12c, nitride semiconductors such as In are used. x Al y Ga 1-x-y N (0≤X, 0≤Y, X+Y<1) is used. Cover part 21

[0030] The cover part 21 is arranged on the upper surface of the first semiconductor layer 12a and partially covers the upper surface of the first semiconductor layer 12a.

[0031] As in Fig. As shown in Figure 1A, in a top view, the outer edges of the cover part 21 are preferably located outside the outer edges of the first electrode 16. The distance between the outer edges of the cover part 21 and the outer edges of the first electrode 16, i.e., the width of a region of the cover part 21 located outside the first electrode 16, is, for example, 2 µm to 7 µm.

[0032] The cover part 21 is made of an insulating material, preferably a light-transmitting insulating material. Alternatively, the cover part 21 is made of a material containing one or more elements selected from Zr, Si, V, Nb, Hf, Ta, Al, Ce, In, Sb and Zn, as well as either one or both of oxygen and nitrogen.

[0033] The cover part 21, which is made of such a material, makes it possible to reduce the probability that the metal layer 13 arranged in the cover part 21 will be electrically connected to the light-transmitting electrode 15, thereby further improving the reliability of the light-emitting element 10A.

[0034] Examples of materials that can be suitablely used for the cover part 21 include oxides, nitrides, or oxynitrides of Zr, Si, V, Nb, Hf, Ta, Al, Ce, In, Sb, Zn, or the like, particularly preferably SiO2, SiN, SiON, or the like. The material for the cover part 21 is preferably selected taking into account the characteristics that are particularly important for the purpose, such as increased moisture resistance, increased output, and the like.

[0035] For example, from the point of view of increasing moisture resistance, a highly moisture-resistant material, e.g. SiON, is preferably used for the cover part 21, such that the moisture does not reach the metal layer 13 arranged in the cover part 21.

[0036] On the other hand, from the perspective of increasing output, a material with a lower refractive index than that of the first semiconductor layer 12a is preferably used for the cover part 21 to facilitate effective light extraction from the semiconductor structure 12. The refractive indices in this specification refer to the refractive indices for the peak wavelength of the light emitted by the semiconductor structure 12, unless otherwise specifically stated. Preferably, a material with a higher refractive index than that of the light-transmitting electrode 15 is used for the cover part 21, such that the light from the semiconductor structure 12 can be effectively transmitted through the light-transmitting electrode 15 described below.

[0037] An example is described below in which the semiconductor structure 12 is made of nitride semiconductors and the active layer 12c emits light with a peak wavelength of 455 nm. In this case, the refractive index of the first semiconductor layer 12a is approximately 2.4, and the refractive index of the light-transmitting electrode 15, if made of indium tin oxide (ITO), is approximately 1.97. Accordingly, the cover 21 is preferably made of SiN, which has a refractive index of approximately 2.01. This can reduce the reflection of light at the interface between the cover 21 and the light-transmitting electrode 15, allowing for more efficient extraction of the light traveling from the semiconductor structure 12 to the cover 21.

[0038] The thickness of the cover part 21, for example, is in a range of approximately 100 nm to 300 nm.

[0039] As in Fig. As shown in 1F, the cover part 21 can consist of a plurality of layers.

[0040] Fig. Figure 1F is a schematic, partially enlarged cross-sectional view, primarily showing the metal layer 13, which is located directly below an extension area 16b and the surrounding cover part 21. The in Fig. The example of the cover part 21 shown in Figure 1F includes a first layer 21a located below the metal layer 13, a second layer 21b located above the metal layer 13, and a third layer 21c that covers the second layer 21b and is in contact with the upper surface of the first semiconductor layer 12a. The first layer 21a, the second layer 21b, and the third layer 21c are made of a material similar to that of the cover part 21 described above.

[0041] When the cover part 21 is formed from the first layer 21a, the second layer 21b and the third layer 21c, the metal layer 13 covered in the cover part 21 can be isolated both from the first semiconductor layer 12a positioned below the metal layer 13 and from the light-transmitting electrode 15 located on the upper and lateral side of the metal layer 13.

[0042] The first layer 21a, the second layer 21b, and the third layer 21c can be made of different materials; two of these layers can be made of the same material and one of these layers of a different material; or all of these layers can be made of the same material. In the case where two or more of the first layer 21a, the second layer 21b, and the third layer 21c are made of the same material, it might be difficult to distinguish them from one another. In such a case, these layers can be treated as an integral body and considered as the “covering part 21,” as described in Fig. It is shown in 1D.

[0043] The thickness of the first layer 21a can be set to, for example, 80 nm or more and 300 nm or less. Setting the thickness of the first layer 21a to 80 nm or more allows for more secure isolation of the metal layer 13 from the first semiconductor layer 12a and enables effective reflection at the interface between the first layer 21a and the first semiconductor layer 12a. Setting the thickness of the first layer 21a to 300 nm or less prevents the cover 21, which contains the first layer 21a, from becoming excessively thick, thereby reducing the likelihood of discontinuities in the light-transmitting electrode 15 formed on the cover 21. In this specification, the thickness of a component refers to the greatest thickness of the component in a cross-sectional area.

[0044] The thickness of the second layer 21b can be set, for example, to 80 nm or more and 120 nm or less. Setting the thickness of the second layer 21b to 80 nm or more allows for more reliable insulation of the metal layer 13 from the light-transmitting electrode 15. Setting the thickness of the second layer 21b to 120 nm or less prevents the cover part 21, which contains the second layer 21b, from becoming excessively thick, thereby reducing the likelihood of a break in the light-transmitting electrode 15 formed on the cover part 21.

[0045] The thickness of the third layer 21c can be adjusted, for example, to 100 nm or more and 500 nm or less. At the location directly below the external connection area 16a, the third layer 21c reflects the light emitted by the active layer 12c, thus reducing light absorption by the external connection area 16a. Adjusting the thickness of the third layer 21c within this range allows for a reduction in the amount of light absorbed by the external connection area 16a. Metal layer 13

[0046] As in Fig. 1B and Fig. As shown in Figure 1D, the metal layer 13 is arranged within the cover part 21, which is positioned between the first semiconductor layer 12a and the extension regions 16b of the first electrode 16. As shown in Fig. As shown in Figure 1F, in the case where the cover part 21 consists of a first layer 21a, a second layer 21b, and a third layer 21c, the metal layer 13 is arranged within the cover part 21 by being positioned between the first layer 21a and the second layer 21b and further covered by the third layer 21c. The first layer 21a is in contact with the lower surface of the metal layer 13, the second layer 21b is in contact with the upper surface of the metal layer 13, and the third layer 21c is in contact with the lateral surfaces of the metal layer 13.

[0047] The metal layer 13 allows light that was not reflected at the interface between the cover part 21 (the first layer 21a in the case of a three-layer structure) and the first semiconductor layer 12a, and which entered the cover part 21 (the first layer 21a), to be reflected by the metal layer 13 towards the first semiconductor layer 12a. This allows the output of the light-emitting element 10A to be increased compared to a case in which the metal layer 13 is not included in the cover part 21.

[0048] In this embodiment, as in Fig. 1B and Fig. As shown in Figure 1C, the metal layer 13 is not located in a region of the cover area 21 between the first semiconductor layer 12a and the external connection area 16a of the first electrode 16. This can reduce the occurrence of separation of the external connection area 16a, which is due to the metal layer 13, when a wire connection is made to the external connection area 16a.

[0049] The reflectance of the metal layer 13 for the peak wavelength of the light from the active layer 12c is higher than the reflectance of the first electrode 16 for the peak wavelength of the light from the active layer 12c. The metal layer 13 is made of a metallic material that has a high reflectance for the peak wavelength of the light from the active layer 12c. For example, the metal layer 13 is made of a metallic material that has a reflectance of 70% or more, preferably 80% or more, for the peak wavelength of the light from the active layer 12c. For example, Al, Ag, or an alloy containing these metals can be used for the metal layer 13.

[0050] From the perspective of preventing the dissolution of the metal layer 13 in the solution used for sampling after the formation of the metal layer 13, AlCu is preferably used for the metal layer 13, as it is more corrosion-resistant than Al. The thickness of the metal layer can be adjusted, for example, to 80 nm or more and 120 nm or less. Light-transmitting electrode 15

[0051] A light-transmitting electrode 15 is arranged on the upper surface of the cover part 21 and on the region of the upper surface of the first semiconductor layer 12a that is not covered by the cover part 21. The light-transmitting electrode 15 is electrically connected to the first semiconductor layer 12a. A portion of the light-transmitting electrode 15 is located between the first electrode 16 and the cover part 21. The light-transmitting electrode 15, which substantially covers the entire upper surface of the first semiconductor layer 12a, can diffuse the current supplied to the first electrode 16 over a wider region of the first semiconductor layer 12a.

[0052] The material for the light-transmitting electrode 15 is preferably a metal oxide that exhibits conductivity. The light-transmitting electrode 15 is, for example, an oxide containing at least one of the elements selected from the group consisting of Zn, In, Sn, Ga, and Ti. For example, ITO, zinc oxide (ZnO), indium oxide (In₂O₃), tin oxide (SnO₂), or indium zinc oxide (IZO) can be used for the light-transmitting electrode 15. ITO is particularly preferred for the light-transmitting electrode 15, which covers substantially the entire upper surface of the first semiconductor layer 12a, because it exhibits high transmittance for visible light and high conductivity.

[0053] From the perspective of reducing light absorption, the thickness of the light-transmitting electrode 15 is preferably smaller. The thickness of the light-transmitting electrode 15 can, for example, be set to 30 nm or more and 100 nm or less, preferably 35 nm or more and 80 nm or less. First electrode 16

[0054] A first electrode 16 includes an external connection area 16a and an extension area 16b that extends from the external connection area 16a, which is located on the upper surface of the light-transmitting electrode 15. The external connection area 16a can be located on the upper surface of the light-transmitting electrode 15.

[0055] The external connection area 16a is a region for external connection by wire connection or the like. In a plan view, the external connection area 16a has, for example, a substantially circular, quadrilateral, or semi-elliptical shape. In the Fig. In the example shown in Figure 1A, the shape of the external connection area 16a is essentially circular in a top view.

[0056] The extension area 16b is an auxiliary electrode for the efficient diffusion of the current supplied to the light-transmitting electrode 15 via the external connection area 16a. In a top view, the width of the extension area 16b is smaller than the width of the external connection area 16a.

[0057] There are cases where the external connection area 16a can be easily distinguished from the extension areas 16b, and cases where it cannot be easily distinguished.

[0058] In the case where the boundary 16c between the external connection area 16a and an extension area 16b can be clearly determined, as in the case of the in Fig. The external connection area 16a of the light-emitting element 10A shown in 1A can be distinguished from the extension area 16b using the boundary 16c as a reference.

[0059] In the Fig. In the example shown in 1A, the boundary 16c between the external connection area 16a and each extension area 16b can be uniquely determined, since each extension area 16b, which has a substantially constant width, extends in a plan view from the external connection area 16a.

[0060] In the case of the in Fig. In the light-emitting element 10D shown in Figure 4, it is difficult to uniquely determine the boundary 16c between the external connection area 16a and an extension area 16b. In the Fig. In the example shown, it is difficult to determine the boundary 16c between the external connection area 16a and each of the extension areas 16b, since the width of each extension area 16b extending from the external connection area 16a is not constant in a plan view. In such a case, the boundary 16c between the external connection area 16a and an extension area 16b can be determined by the process described below.

[0061] In the Fig. The 4 light-emitting element 10D shown includes extension areas 16b, a curved extension area 16b1 and a straight extension area 16b2, and the tip of each extension area is rounded in a top view.

[0062] In a curved extension area 16b1, the width is measured at a position near the apex where the edges of the extension area 16b1 become essentially parallel, which is called the reference width W. 16b1 for the extension area 16b1. As used herein, the term "width" of the extension area 16b1 is the dimension orthogonal to the extension direction of the extension area 16b1 in a plan view.

[0063] The width of the extension area 16b1 can then be measured at several locations from the apex of the extension area 16b1 towards the external connection area 16a. The position at which the measured width is equal to 1.5 times the reference width W 16b1The boundary 16c between the external connection area 16a and the extension area 16b1 is designated as boundary 16c. Instead of measuring the width of the extension area 16b1, a device can be used to determine whether the width at a position is 1.5 times the reference width W. 16b1 whether it corresponds or not. For example, two parallel lines spaced so that their width is equal to 1.5 times the reference width W can 16b1 (1.5×W 16b1 ) are drawn on a transparent sheet and are used as a device to identify the position where the width is equal to 1.5 times the reference width W. 16b1 is.

[0064] Similarly, with respect to the straight extension area 16b2, the width is measured near the apex of the extension area 16b2, where the edges become essentially parallel, which is known as the reference width W. 16b2for the extension area 16b2.

[0065] The width of the extension area 16b2 can then be measured at several locations from the apex of the extension area 16b2 towards the external connection area 16a. The position at which the measured width is 1.5 times the reference width W 16b2 The boundary 16c is defined as the boundary between the external connection area 16a and the extension area 16b2. The boundary 16c can be identified using a device to determine whether the width is 1.5 times the reference width W. 16b2 It corresponds or it does not.

[0066] In the light-emitting element 10A according to this embodiment, a cover element 21, made of an insulating material, is arranged between the first electrode 16 (the external connection area 16a and the extension areas 16b) and the first semiconductor layer 12a of the semiconductor structure 12. In other words, the first electrode 16 is not in direct contact with the first semiconductor layer 12a. The first electrode 16 is electrically connected to the first semiconductor layer 12a via the light-transmitting electrode 15. With this arrangement of a cover element 21, it is less likely that current will flow from the first electrode 16 to the semiconductor structure 12 located directly below the first electrode. This can reduce the light emission of the semiconductor structure 12 directly below the first electrode 16, thereby reducing the light absorption by the first electrode 16.Furthermore, the current flow to the semiconductor structure 12 can be increased in the area other than the region directly below the electrode 16, thereby allowing the light-emitting element 10A to emit light efficiently.

[0067] For the external connection area 16a of the first electrode 16, for example, copper, gold, or an alloy containing these metals as main components can be used, as these are suitable for external connection by wire joining or the like. The external connection area 16a and the extension areas 16b of the first electrode 16 can be made of the same material.

[0068] In a top view of the light-emitting element 10A, the extension regions 16b overlap the cover part 21 and the metal layer 13 at least partially. In other words, the metal layer 13 is located directly beneath at least some regions of the extension regions 16b. A portion of the light traveling from the active layer 12c toward the first electrode 16 is reflected by the metal layer 13. Accordingly, the absorption of light by the first electrode 16 can be reduced, thus increasing the output of the light-emitting element 10A.

[0069] In a top view of the light-emitting element 10A, the external connection area 16a also includes a first region 161 that overlaps the cover part 21 but not the metal layer 13. There is no interface between the cover part 21 and the metal layer 13 directly below the first region 161.

[0070] The weak adhesion between the cover part 21 and the metal layer 13 could allow interface separation directly below the external connection area 16a during wire joining. This interface separation can lead to separation between the semiconductor structure 12 and the external connection area 16a.

[0071] To reduce such interface separation between the cover part 21 and the metal layer 13, the metal layer 13 is arranged such that the external interconnection area 16a includes a first region 161 that has no interface between the cover part 21 and the metal layer 13. With this structure, it is less likely that the external interconnection area 16a will be separated from the semiconductor structure 12 when a wire connection is made to the external interconnection area 16a.

[0072] From the perspective of preventing the separation of the external connection area 16a, the external connection area 16a is preferably the first region 161 in its entirety, as shown in Fig. 1C shown.

[0073] The dimensions of the first electrode 16 can be adjusted appropriately, taking into account the dimensions of the light-emitting element 10A.

[0074] As an example, the external connection area 16a of the first electrode 16 has a maximum dimension of 50 µm to 100 µm and a region of 1950 µm 2 up to 7850 µm 2 The extension areas 16b are, viewed from above, 2 µm to 10 µm wide. The thickness of the first electrode 16 is, for example, 0.5 µm to 4 µm. The thickness of the external connection area 16a and the thicknesses of the extension areas 16b can be the same or different from each other. Second electrode 17

[0075] A second electrode 17 is arranged on the second semiconductor layer 12b. The second electrode 17 is arranged on the upper surface of the second semiconductor layer 12b, which is exposed at the bottom of the second exposed region 12d2, which in a top view has a substantially semi-elliptical shape.

[0076] For the second electrode 17, for example Cu, Au or an alloy containing these metals as main components can be used to make it suitable for external connection by wire connection or the like. Protective layer 20

[0077] A protective layer 20 is optionally included in the light-emitting element 10A to essentially cover and protect the entire upper surface of the light-emitting element 10A.

[0078] In the case where a protective layer 20 is included in the light-emitting element 10A, the protective layer 20 has an opening in which an area of ​​the upper surface of the external connection area 16a of the first electrode 16 is exposed, as shown in Fig. 1B and Fig. Figure 1C shows a wire connection to the external connection area 16a, which is made on the upper surface of the external connection area 16a exposed at the opening of the protective layer 20. The protective layer 20 need not cover the lateral surfaces and a portion of the upper surface (near the outer edge) of the external connection area 16a. In other words, the lateral surfaces and the upper surface of the external connection area 16a may be exposed by the protective layer 20.

[0079] For the protective layer 20, a material with light transmissivity and insulating properties is preferably used. For example, SiO2 or SiON can be used for the protective layer 20. Substrate 11

[0080] The light-emitting element 10A optionally includes a substrate 11 for supporting the semiconductor structure 12. The substrate 11 can serve as a growth substrate for epitaxial growth of the semiconductor structure 12. For example, if nitride semiconductors are used for the semiconductor structure 12, a sapphire (Al₂O₃) substrate can be used for the substrate 11. Manufacturing process

[0081] An example of a process for manufacturing a light-emitting element 10A is explained.

[0082] A semiconductor structure 12, comprising a second semiconductor layer 12b, an active layer 12c, and a first semiconductor layer 12a, and having an exposed region 12d in which the second semiconductor layer 12b is exposed, is provided on the upper surface of a substrate 11. The semiconductor structure 12 can be formed, for example, by MOCVD (metal-organic vapor deposition).

[0083] A metal layer 13 is formed in a cover part 21 at predetermined locations on the upper surface of the first semiconductor layer 12a (positions corresponding to the in Fig. (corresponding to the extent areas 16b of the first electrode 16 shown in Figure 1). A metal layer 13, which is covered in the cover part 21, can be formed, for example, by two methods described below.

[0084] In a first process, a metal layer 13 is formed within the cover part 21, which includes a first layer 21a, a second layer 21b and a third layer 21c, as shown in Fig. Figure 1F shows that a stacked structure is formed by successively forming a first layer 21a, made of an insulating material, a metal layer 13, and a second layer 21b, also made of an insulating material, at predetermined positions (positions corresponding to the extent regions 16b) on the upper surface of the first semiconductor layer 12a. Subsequently, a third layer 21c, also made of an insulating material, is formed to cover the upper and lateral surfaces of the stacked structure. This creates a metal layer 13 located within the covering portion 21.

[0085] In a second process, a metal layer 13 is placed between the two layers made of an insulating material of the cover part 21.

[0086] First, a first insulating layer is formed at predetermined positions on the top surface of the first semiconductor layer 12a (positions corresponding to the extent regions 16b). Then, a metal layer 13 is formed at a location within the outer periphery of the first insulating layer in a top view of the top surface of the first insulating layer. Subsequently, a second insulating layer, having substantially the same dimensions as the first insulating layer, is formed to cover the top surface and the lateral surfaces of the metal layer 13.

[0087] The metal layer 13 can be formed by a known film formation process, such as sputtering, chemical vapor deposition (CVD) or the like.

[0088] The cover part 21 can be formed, for example, by sputtering, chemical vapor deposition or the like.

[0089] A light-transmitting electrode 15 is formed on the top surface and lateral surfaces of the cover part 21 and on the top surface of the first semiconductor layer 12a that is not covered by the cover part 21. The light-transmitting electrode 15 can be formed, for example, by sputtering. Subsequently, a first electrode 16 is formed at a predetermined location on the top surface of the light-transmitting electrode 15, and a second electrode 17 is formed at a predetermined location on the top surface of the second semiconductor layer 12b, which is exposed at the second exposed area 12d2. The first electrode 16 and the second electrode 17 can be formed, for example, by sputtering.

[0090] A protective layer 20, made of an insulating material, is then formed to cover the semiconductor structure 12, the light-transmitting electrode 15, the extension areas 16b of the first electrode 16, the first exposed area 12d1, and the second exposed area 12d2. The protective layer 20 can be formed, for example, by sputtering, chemical vapor deposition, or the like. The protective layer 20 can partially cover the lateral and top surfaces of the first electrode 16 and the second electrode 17 to such an extent that it does not interfere with the wire connections of the external connection area 16a of the first electrode 16 and the second electrode 17.

[0091] Designs comprising the light-emitting element 10A according to this embodiment are described in detail below. Light-emitting elements 10A2 to 10A5 of embodiments 1-1 to 1-4 are described, focusing on the differences from the light-emitting element 10A of embodiment 1, while the description of similar features is omitted. Design 1-1

[0092] Fig. Figure 1G is a schematic cross-sectional view of a light-emitting element 10A2 according to embodiment 1-1, primarily showing the structure of the extension regions 16b of the first electrode 16 and its surroundings. The first layer 21a, the second layer 21b, and the metal layer 13 of the Fig. The light-emitting element 10A of embodiment 1 shown in Figure 1F has essentially a constant thickness at both lateral ends and in its central region in cross-section. In contrast, in the first variation, the thicknesses of these layers vary laterally. Fig. 1G is a schematic cross-section corresponding to the one along 1d-1d in Fig. 1A corresponds to this.

[0093] In the light-emitting element 10A2 of embodiment 1-1, the thicknesses of the first layer 21a, the second layer 21b, and the metal layer 13 are smaller in cross-section at both lateral ends and larger in the central region. Since the thickness of the metal layer 13 is less at both ends than in the central region, the first layer 21a and the second layer 21b are able to easily cover the end regions of the metal layer 13. With this structure, the metal layer 13 is less likely to be affected by the external environment and thus less likely to be modified or degraded, thereby improving the reliability of the light-emitting element 10A2. Design 1-2

[0094] Fig. 1H and Fig. Figure 1I shows schematic cross-sectional views of a light-emitting element 10A3 according to embodiment 1-2. Fig. 1H represents the structure around the external connection area 16a of the first electrode 16, and Fig. 1I represents the structure around an extension area 16b of the first electrode 16.

[0095] As in Fig. As shown in Figure 1H, the first electrode 16 of the light-emitting element 10A3 according to embodiment 1-2 includes a reflective electrode 22a located between the light-transmitting electrode 15 and the external connection area 16a. The reflective electrode 22a has a higher reflectance for the peak wavelength of the light emitted by the active layer 12c than the external connection area 16a.

[0096] In a top view of the light-emitting element 10A3, the first region 161, which overlaps the cover part 21 but not the metal layer 13, of the external connection area 16a overlaps the reflective electrode 22a. Since the first region 161 does not overlap the metal layer 13, the light traveling from the active layer 12c towards the first region 161 of the external connection area 16a cannot be reflected by the metal layer 13. The light-emitting element 10A3 according to the second variation includes a reflective electrode 22 in a position that overlaps the first region 161, allowing the reflective electrode 22 to reflect the light traveling from the active layer 12c towards the first region 161. This can reduce the absorption of light by the external connection area 16a, thereby further increasing the output of the light-emitting element 10A3.The reflectance of the reflecting electrode 22a for the peak wavelength of the light emitted by the active layer 12c may be lower than the reflectance of the metal layer 13 for the peak wavelength of the light emitted by the active layer 12c. Conversely, the adhesion between the reflecting electrode 22a and the cover part 21 may be higher than the adhesion between the metal layer 13 and the cover part 21.

[0097] In a top view of the light-emitting element 10A3, the outer edges of the reflecting electrode 22a are preferably located outside the outer edges of the external connection area 16a. In other words, in a top view, the reflecting electrode 22a is preferably larger than the external connection area 16a and completely overlaps the external connection area 16a. In a cross-sectional view, such as Fig. 1H, the width W22a of the reflecting electrode 22a is greater than the width W16a of the external connection area 16a. This relationship between the width W22a of the reflecting electrode 22a and the width W16a of the external connection area 16a is established in the same cross-section, regardless of the relationship between the width W22a of the reflecting electrode 22a in one cross-section and the width W16a of the external connection area 16a in another cross-section.

[0098] The “width” of the reflecting electrode 22a in a cross-section refers to a dimension in the direction orthogonal to the thickness direction of the reflecting electrode 22a, and the “width” of the external connection area 16a in a cross-section refers to a dimension in the direction orthogonal to the thickness direction of the external connection area 16a.

[0099] In this configuration, the reflecting electrode 22a can be localized along the entire path of the light rays moving from the active layer 12c towards the first region 161 of the external connection area 16a, further increasing the output of the light-emitting element 10A3.

[0100] The reflective electrode 22a is made of a conductive material, for example, a single or multilayer structure composed of a metal or alloy. An example of a multilayer structure is one that stacks an Rh-Cr alloy layer and a Pt layer on the side facing the light-transmitting electrode 15. The reflective electrode 22a can have a light-reflecting function and a function to ensure good contact with the light-transmitting electrode 15.

[0101] As in Fig. As shown in Figure 1I, the reflective electrode 22b is preferably also provided between the light-transmitting electrode 15 and the extension regions 16b. As shown in Fig. As shown in Figure 1I, the width W13 of the metal layer 13 is preferably larger than the width W22b of the reflecting electrode 22b if both the metal layer 13 and the reflecting electrode 22b are located directly below the extension regions 16b. The "width" of the metal layer 13 and the "width" of the extension regions 16b are dimensions orthogonal to the direction in which they extend in a top view. Fig. 1I is a cross-sectional view taken along a plane that is orthogonal to the extension direction of an extension area 16b, and the width W13 of the metal layer 13 and the width 22b of the reflecting electrode 22b are the dimensions in the direction orthogonal to the extension direction of the extension area 16b.

[0102] In the case where an extension area 16b is straight, the direction of extension is a straight line, and the direction orthogonal to the direction of extension is uniquely determined. On the other hand, in the case where an extension area 16b is partially bent or curved, the direction of extension is also bent or curved. A direction "orthogonal" to a bent or curved direction of extension refers to one that is orthogonal to the tangent line drawn such that it is tangent to the bent or curved direction of extension at a point where the width is measured.

[0103] As in Fig. As shown in Figure 1I, the width W22b of the reflecting electrode 22b is also preferably larger than the width W16b of the extension region 16b. The “width” of the extension region 16b refers to the maximum dimension in the direction orthogonal to the extension direction of the extension region 16b in a top view.

[0104] Such a configuration allows the reflecting electrode 22b to be provided along the entire path of the light rays moving from the active layer 12c towards the extension regions 16b, in such a way that the output of the light-emitting element 10A3 can be further increased. Embodiments 1-3 and 1-4

[0105] Fig. Figure 1J is a schematic cross-sectional view of a light-emitting element 10A4 according to embodiment 1-3, and Fig. 1K is a schematic cross-sectional view of a light-emitting element 10A5 according to embodiment 1-4. Fig. 1 year and Fig. 1K each represent the structure around the external connection area 16a of the first electrode 16.

[0106] As in Fig. 1 year and Fig. As shown in Figure 1K, the external connection area 16a in the light-emitting element 10A4 according to the third variation and the light-emitting element 10A5 according to the fourth variation can include a third region 163 which, in a top view, does not overlap the cover part 21 and the metal layer 13. With the third region 163, in which the cover part 21 is not present between the light-transmitting electrode 15 and the semiconductor structure 12, the contact area between the light-transmitting electrode 15 and the semiconductor structure 12 can be increased, thereby reducing the forward voltage (Vf) of the light-emitting elements 10A4 and 10A5.

[0107] To adequately demonstrate the effect of providing the cover part 21, the area of ​​the third region 163 is preferably controlled to be within a suitable range. In a top view of the light-emitting elements 10A4 and 10A5, the area of ​​the third region 163 is preferably set to 30% to 70% of the area in which the external connection area 16a overlaps the cover part 21.

[0108] As in Fig. As shown in Figure 1J, in an example of the light-emitting element 10A4, which includes a third region 163, the third region 163 is located in a top view within the outer edges of the cover part 21. In a cross-sectional view of the light-emitting element 10A4, as shown in Figure 1J, the third region 163 is located within the outer edges of the cover part 21. Fig. As shown in Figure 1J, the third region 163 of the external connection area 16a is surrounded by the first region 161, which overlaps the cover part 21.

[0109] As in Fig. As shown in Figure 1K, in another example of the light-emitting element 10A5, which includes a third region 163, the third region 163 is located in a top view outside the outer edges of the cover part 21. In a cross-sectional view of the light-emitting element 10A5, as shown in Figure 1K, the third region 163 is located outside the outer edges of the cover part 21. Fig. As shown in 1K, the third region 163 of the external connection area 16a surrounds the first region 161. Design 2

[0110] A light-emitting element 10B according to embodiment 2 is described below with reference to Fig. 2A to Fig. 2E is described. The differences to the light-emitting element 10A according to embodiment 1 are primarily explained. A detailed description of similar features and materials as in the light-emitting element 10A according to embodiment 1 is omitted.

[0111] Fig. 2A is a schematic top view of a light-emitting element 10B according to embodiment 2. Fig. 2B is a schematic cross-sectional view, taken along line 2b-2b in Fig. 2A. Fig. 2C is a schematic partial cross-sectional view, taken along line 2c-2c in Fig. 2A, which mainly shows the structure around the external connection area 16a of the first electrode 16.

[0112] The light-emitting element 10B according to embodiment 2 differs from embodiment 1 in that the external connection area 16a of the first electrode 16 partially overlaps the metal layer 13 in a top view. In other words, in the light-emitting element 10B according to embodiment 2, the external connection area 16a includes a first region 161 that does not overlap the metal layer 13 and a second region 162 that does overlap the metal layer 13. In the Fig. In the example shown in 2A, the second region 162 is ring-shaped.

[0113] As in Fig. As shown in Figure 2A, in a top view of the light-emitting element 10B, at least a portion of the first region 161 is surrounded by the metal layer 13. The metal layer 13 can overlap the external connection area 16a. In other words, as shown in Figure 2A, the metal layer 13 can overlap the external connection area 16a. Fig. As shown in Figure 2C, the external connection area 16a can include a second region 162 that overlaps the cover part 21 and the metal layer 13. As shown in Fig. 2A and Fig. As shown in 2C, the first region 161 can also be provided outside the second region 162.

[0114] Since the metal layer 13 is located directly below the second region 162 of the external connection area 16a, a portion of the light traveling from the active layer 12c towards the external connection area 16a is reflected by the metal layer 13 before reaching the external connection area 16a and is thus extracted by the light-emitting element 10B. This can reduce the light absorption by the external connection area 16a, thereby increasing the output of the light-emitting element 10B.

[0115] In the event that a second region 162 is provided, the area of ​​the second region 162 is preferably controlled such that it is within a suitable range. In a top view of the light-emitting element 10B, the area of ​​the second region 162 is preferably set to 10% or more and 40% or less of the area of ​​the external connection area 16a.

[0116] Due to the presence of an interface between the metal layer 13 and the cover part 21 directly below the second region 162 of the external interconnection area 16a, interface separation can occur during wire joining of the external interconnection area 16a, which could induce the separation of the external interconnection area 16a from the semiconductor structure 12. To reduce the interface separation as much as possible, as described in Fig. As shown in Figure 2C, it is preferred that the metal layer 13 is not located directly below the center of the external connection area 16a, which is subject to maximum impact during wire joining. In other words, the first region 161 is preferably located in a region that includes the center of the external connection area 16a in a top view, as shown in Figure 2C. Fig. 2A shown.

[0117] The metal layer 13, which is located directly below the second region 162 of the external connection area 16a, can have a similar configuration to the metal layer 13, which is located directly below the extension areas 16b. For example, as in Fig. 2E shown, similar to in Fig. 1F of embodiment 1, the cover part 21, which covers the metal layer 13, is composed of a first layer 21a, a second layer 21b and a third layer 21c.

[0118] As in Fig. 2E shown, overlapping, similar to in Fig. 1H of embodiment 1, in a top view of the light-emitting element 10B, the first region 161, which overlaps the cover part 21 but does not overlap the metal layer 13, of the external connection area 16a, preferably the reflective electrode 22a. The reflective electrode 22a need not overlap the second region 162, but preferably does. embodiment 3

[0119] A light-emitting element 10C according to embodiment 3 is described below with reference to Fig. 3A to Fig. 3C is described. The differences to the light-emitting elements 10A and 10B according to embodiments 1 and 2 are primarily explained. A detailed description of similar features and materials as in the light-emitting elements 10A and 10B according to embodiments 1 and 2 is omitted.

[0120] Fig. Figure 3A is a schematic top view of a light-emitting element 10C according to embodiment 3. Fig. 3B is a schematic cross-sectional view, taken along line 3b-3b in Fig. 3A. Fig. 3C is a schematic cross-sectional view, taken along line 3c-3c in Fig. 3A, which primarily shows the structure around the external connection area 16a of the first electrode 16.

[0121] The light-emitting element 10C according to embodiment 3 differs from embodiment 2 in that the metal layer 13, which overlaps the external connection area 16a of the first electrode 16, is divided into several sections. In other words, in the light-emitting element 10C according to embodiment 3, the external connection area 16a comprises a plurality of second regions 162. In the Fig. In the example shown in 3A, the external connection area 16a includes four second regions 162.

[0122] As in Fig. As shown in Figure 3A, the majority of second regions 162 are contained within the light-emitting elements 10C in a top view of the light-emitting elements 10C. A first region 161 is provided between two second regions 162 that are adjacent to each other in a top view.

[0123] Since the metal layer 13 is located directly below the second region 162 of the external connection area 16a, a portion of the light traveling from the active layer 12c towards the external connection area 16a is reflected by the metal layer 13 before reaching the external connection area 16a and is thus extracted by the light-emitting element 10C. This can reduce the light absorption by the external connection area 16a, thereby increasing the output of the light-emitting element 10C.

[0124] To reduce the chances of interface separation as much as possible, it is advisable, as in Fig. Figure 3B shows, similarly to embodiment 2, it is preferred that the metal layer 13 is not located directly below the center of the external connection area 16a, which is subjected to the maximum impact during wire joining. In other words, as in Fig. As shown in Figure 3A, the first region 161 is preferably located in a region which, in a top view, includes the center of the external connection area 16a.

[0125] Similar to embodiment 2, the cover part 21, which encloses the metal layer 13, which is arranged directly below the plurality of second regions 162 of the external connection area 16a, can be composed of a first layer, a second layer and a third layer (not shown).

[0126] The above description specifically outlines light-emitting elements according to embodiments of the present invention, based on specific implementation designs. However, the present invention is not limited to those described above but must be interpreted broadly based on the scope of the claims. Various changes and modifications made based on the above description are encompassed by the concept of the invention.

[0127] Light-emitting elements according to the present invention can be used as various light sources, such as backlighting light sources for liquid crystal displays, as various lighting fixtures, large displays and the like.

[0128] The light-emitting elements according to embodiments of the present disclosure have the following aspects.

[0129] [Aspect 1] Light-emitting element, comprising: a semiconductor structure, comprising: a first semiconductor layer of a first conductivity type, an active layer located below the first semiconductor layer, and a second semiconductor layer of a second conductivity type, located below the active layer; a cover part made of an insulating material and arranged on an upper surface of the first semiconductor layer; a metal layer that is arranged within the cover part; a light-transmitting electrode located on an upper surface of the cover part and the upper surface of the first semiconductor layer; a first electrode, including: an external connection area located on an upper surface of the light-transmitting electrode, and an area of ​​extension that extends from the external connection area; and a second electrode located on the second semiconductor layer, wherein: at least one area of ​​the extent overlaps the cover part and the metal layer in a top view; and The external connection area comprises a first region which, in plan view, overlaps the cover part but does not overlap the metal layer.

[0130] [Aspect 2] Light-emitting element, comprising: a semiconductor structure, comprising: a first semiconductor layer of a first conductivity type, an active layer located below the first semiconductor layer, and a second semiconductor layer of a second conductivity type, located below the active layer; a cover part arranged on an upper surface of the first semiconductor layer and containing one or more elements selected from Zr, Si, V, Nb, Hf, Ta, Al, Ce, In, Sb and Zn, and either one or both of oxygen and nitrogen; a metal layer that is arranged within the cover part; a light-transmitting electrode located on an upper surface of the cover part and the upper surface of the first semiconductor layer; a first electrode including: an external connection area located on an upper surface of the light-transmitting electrode, and an area of ​​extension that extends from the external connection area; and a second electrode located on the second semiconductor layer, wherein: at least one area of ​​the extent overlaps the cover part and the metal layer in the top view; and The external connection area comprises a first region which, in plan view, overlaps the cover part but does not overlap the metal layer.

[0131] [Aspect 3] Light-emitting element according to aspect 1 or 2, wherein: The cover part includes: a first layer that is arranged below the metal layer, a second layer that is arranged on top of the metal layer, and a third layer that covers the second layer and is in contact with the upper surface of the first semiconductor layer.

[0132] [Aspect 4] Light-emitting element according to one of aspects 1 to 3, where the entirety of the external connection area is the first region.

[0133] [Aspect 5] Light-emitting element according to one of aspects 1 to 4, wherein in the top view at least one area of ​​the first region is surrounded by the metal layer.

[0134] [Aspect 6] Light-emitting element according to one of aspects 1 to 5, wherein the first region in the top view includes a center of the external connection area.

[0135] [Aspect 7] Light-emitting element according to one of aspects 1 to 6, wherein the external connection area further comprises one or more second regions which overlap the cover part and the metal layer in plan view.

[0136] [Aspect 8] Light-emitting element according to one of aspects 1 to 7, wherein the external connection area includes a plurality of the second regions.

[0137] [Aspect 9] Light-emitting element according to one of aspects 1 to 8, wherein: the first electrode further comprises a reflective electrode between the light-transmitting electrode and the external connection area, which has a higher reflectance for the peak wavelength of the light emitted by the active layer than that of the external connection area, and the first region overlaps the reflecting electrode in the top view.

[0138] [Aspect 10] Light-emitting element according to aspect 9, wherein an outer edge of the reflecting electrode is located outside an outer edge of the external connection area in the top view.

[0139] [Aspect 11] Light-emitting element according to aspect 9 or 10, wherein the reflecting electrode is further provided between the light-transmitting electrode and the extension area.

[0140] [Aspect 12] Light-emitting element according to aspect 11, wherein a width of the metal layer is greater than a width of the reflecting electrode in a direction orthogonal to an extension direction of the extension area.

[0141] [Aspect 13] Light-emitting element according to one of aspects 1 to 3, wherein the external connection area further comprises a third region which, in plan view, does not overlap the cover part and the metal layer.

[0142] [Aspect 14] Light-emitting element according to aspect 13, wherein in the top view an area of ​​the third region is 30% to 70% of an area in which the external connecting area overlaps the cover part.

[0143] [Aspect 15] Light-emitting element according to aspect 14, wherein the third region in the top view is located within an outer edge of the cover part.

[0144] [Aspect 16] Light-emitting element according to aspect 14, wherein the third region in the top view is located outside an outer edge of the cover part. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2024-168693

[0001] JP 2018-113442

[0003]

Claims

[1] Light-emitting element, comprising: a semiconductor structure, comprising: a first semiconductor layer of a first conductivity type, an active layer located below the first semiconductor layer, and a second semiconductor layer of a second conductivity type, located below the active layer; a cover part made of an insulating material and arranged on an upper surface of the first semiconductor layer; a metal layer that is arranged within the cover part; a light-transmitting electrode located on an upper surface of the cover part and the upper surface of the first semiconductor layer; a first electrode, including: an external connection area located on an upper surface of the light-transmitting electrode, and an area of ​​extension that extends from the external connection area; and a second electrode located on the second semiconductor layer, wherein: at least one area of ​​the extent overlaps the cover part and the metal layer in a top view; and The external connection area comprises a first region which, in plan view, overlaps the cover part but does not overlap the metal layer. [2] Light-emitting element, comprising: a semiconductor structure, comprising: a first semiconductor layer of a first conductivity type, an active layer located below the first semiconductor layer, and a second semiconductor layer of a second conductivity type, located below the active layer; a cover part arranged on an upper surface of the first semiconductor layer and containing one or more elements selected from Zr, Si, V, Nb, Hf, Ta, Al, Ce, In, Sb and Zn, and either one or both of oxygen and nitrogen; a metal layer that is arranged within the cover part; a light-transmitting electrode located on an upper surface of the cover part and the upper surface of the first semiconductor layer; a first electrode including: an external connection area located on an upper surface of the light-transmitting electrode, and an area of ​​extension that extends from the external connection area; and a second electrode located on the second semiconductor layer, wherein: at least one area of ​​the extent overlaps the cover part and the metal layer in the top view; and The external connection area comprises a first region which, in plan view, overlaps the cover part but does not overlap the metal layer. [3] Light-emitting element according to claim 1 or 2, wherein: The cover part includes: a first layer that is arranged below the metal layer, a second layer that is arranged on top of the metal layer, and a third layer that covers the second layer and is in contact with the upper surface of the first semiconductor layer. [4] Light-emitting element according to any one of claims 1 to 3, wherein the first region is an entirety of the external connection area. [5] Light-emitting element according to any one of claims 1 to 4, wherein in the top view at least one area of ​​the first region is surrounded by the metal layer. [6] Light-emitting element according to any one of claims 1 to 5, wherein the first region in the top view includes a center of the external connection area. [7] Light-emitting element according to any one of claims 1 to 6, wherein the external connection area further comprises one or more second regions which overlap the cover part and the metal layer in the top view. [8] Light-emitting element according to any one of claims 1 to 7, wherein the external connection area comprises a plurality of the second regions. [9] Light-emitting element according to any one of claims 1 to 8, wherein: the first electrode further comprises a reflective electrode between the light-transmitting electrode and the external connection area, which has a higher reflectance for the peak wavelength of the light emitted by the active layer than that of the external connection area, and the first region overlaps the reflecting electrode in the top view. [10] Light-emitting element according to claim 9, wherein an outer edge of the reflecting electrode is located outside an outer edge of the external connection area in the top view. [11] Light-emitting element according to claim 9 or 10, wherein the reflecting electrode is further provided between the light-transmitting electrode and the extension area. [12] Light-emitting element according to claim 11, wherein a width of the metal layer is greater than a width of the reflecting electrode in a direction orthogonal to an extension direction of the extension area. [13] Light-emitting element according to any one of claims 1 to 3, wherein the external connection area further comprises a third region which, in plan view, does not overlap the cover part and the metal layer. [14] Light-emitting element according to claim 13, wherein in the top view an area of ​​the third region is 30% to 70% of an area in which the external connection area overlaps the cover part. [15] Light-emitting element according to claim 14, wherein the third region is located in the top view within an outer edge of the cover part. [16] Light-emitting element according to claim 14, wherein the third region is located outside an outer edge of the cover part in the top view.

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