Light-emitting element

Abstract

To provide a light-emitting element that can achieve higher output and is highly reliable. [Solution] A light-emitting element comprising: a semiconductor structure having a first semiconductor layer of a first conductivity type, an active layer disposed below the first semiconductor layer, and a second semiconductor layer of a second conductivity type disposed below the active layer; a first electrode including a covering portion made of an insulating material disposed on the upper surface of the first semiconductor layer, a metal layer disposed inside the covering portion, a translucent electrode disposed on the upper surface of the covering portion and the upper surface of the first semiconductor layer, an external connection portion disposed on the upper surface of the translucent electrode, and an extended portion extending from the external connection portion; and a second electrode disposed on the second semiconductor layer, wherein in a plan view, at least a part of the extended portion overlaps with the covering portion and the metal layer, and in a plan view, the external connection portion includes a first region that overlaps with the covering portion but does not overlap with the metal layer.

Description

[Technical Field]

[0001] This disclosure relates to a light-emitting element. [Background technology]

[0002] Patent Document 1 proposes a light-emitting element comprising a first electrode electrically connected to a first conductivity type semiconductor layer, and a second electrode located on a transparent electrode layer arranged on a second conductivity type semiconductor layer and electrically connected to the transparent electrode layer. The second electrode includes a second electrode pad and a second electrode extension extending from the second electrode pad, and a structure is disclosed in which the light extraction efficiency is improved by providing a second reflective layer between the second electrode and the transparent electrode layer. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2018-113442 [Overview of the project] [Problems that the invention aims to solve]

[0004] Such light-emitting elements are desirable to exhibit higher output while also being more reliable. Therefore, the object of this disclosure is to provide a light-emitting element that can achieve higher output and is more reliable. [Means for solving the problem]

[0005] One embodiment of the light-emitting element relating to is A semiconductor structure comprising a first semiconductor layer of a first conductivity type, an active layer disposed below the first semiconductor layer, and a second semiconductor layer of a second conductivity type disposed below the active layer, A covering portion made of an insulating material disposed on the upper surface of the first semiconductor layer, A metal layer disposed inside the coating portion, A light-transmitting electrode is disposed on the upper surface of the coating portion and the upper surface of the first semiconductor layer, A first electrode including an external connection portion disposed on the upper surface of the light-transmitting electrode and an extended portion extending from the external connection portion, The invention comprises a second electrode disposed on the second semiconductor layer, In a plan view, the extended portion overlaps with the coating portion and the metal layer. In a plan view, the external connection portion includes a first region that overlaps with the covering portion but does not overlap with the metal layer.

[0006] Another embodiment of the present invention is a light-emitting element, A semiconductor structure comprising a first semiconductor layer of a first conductivity type, an active layer disposed below the first semiconductor layer, and a second semiconductor layer of a second conductivity type disposed below the active layer, A coating portion disposed on the upper surface of the first semiconductor layer, comprising one or more elements selected from Zr, Si, V, Nb, Hf, Ta, Al, Ce, In, Sb, and Zn, and one or more elements selected from oxygen and nitrogen, A metal layer disposed inside the coating portion, A light-transmitting electrode is disposed on the upper surface of the coating portion and the upper surface of the first semiconductor layer, A first electrode including an external connection portion disposed on the upper surface of the light-transmitting electrode and an extended portion extending from the external connection portion, The invention comprises a second electrode disposed on the second semiconductor layer, In a plan view, the extended portion overlaps with the coating portion and the metal layer. In a plan view, the external connection portion includes a first region that overlaps with the covering portion but does not overlap with the metal layer. [Effects of the Invention]

[0007] The light-emitting element according to the embodiment of this disclosure can achieve higher output and higher reliability. [Brief explanation of the drawing]

[0008] [Figure 1A]It is a schematic plan view showing an example of a light-emitting element according to Embodiment 1. [Figure 1B] It is a schematic cross-sectional view taken along line 1b-1b of FIG. 1A. [Figure 1C] It is a schematic partial cross-sectional view taken along line 1c-1c of FIG. 1A. [Figure 1D] It is a schematic partial cross-sectional view taken along line 1d-1d of FIG. 1A. [Figure 1E] It is a schematic plan view showing another example of a light-emitting element according to Embodiment 1. [Figure 1F] It is a schematic partial enlarged cross-sectional view showing the structure directly under the extension part of the light-emitting element according to Embodiment 1. [Figure 1G] It is a schematic partial cross-sectional view showing the structure near the extension part of the light-emitting element according to Embodiment 1-1. [Figure 1H] It is a schematic partial cross-sectional view showing the structure near the external connection part of the light-emitting element according to Embodiment 1-2. [Figure 1I] It is a schematic partial cross-sectional view showing the structure near the extension part of the light-emitting element according to Embodiment 1-2. [Figure 1J] It is a schematic partial cross-sectional view showing the structure near the external connection part of the light-emitting element according to Embodiment 1-3. [Figure 1K] It is a schematic partial cross-sectional view showing the structure near the external connection part of the light-emitting element according to Embodiment 1-4. [Figure 2A] It is a schematic plan view of a light-emitting element according to Embodiment 2. [Figure 2B] It is a schematic cross-sectional view taken along line 2b-2b of FIG. 2A. [Figure 2C] It is a schematic partial cross-sectional view taken along line 2c-2c of FIG. 2A. [Figure 2D] It is a schematic partial enlarged cross-sectional view showing another example of the structure directly under the external connection part of the light-emitting element according to Embodiment 2. [Figure 2E] It is a schematic partial cross-sectional view showing yet another example of the structure near the external connection part of the light-emitting element according to Embodiment 2. [Figure 3A] It is a schematic plan view of a light-emitting element according to Embodiment 3. [Figure 3B] It is a schematic cross-sectional view taken along line 3b-3b of FIG. 3A. [Figure 3C] This is a schematic partial cross-sectional view along the line 3c-3c in Figure 3A. [Figure 4] This is a schematic plan view illustrating a method for determining the boundary between the external connection portion and the extended portion of the first electrode of a light-emitting element. [Modes for carrying out the invention]

[0009] The following describes embodiments of the light-emitting element according to the present invention. Note that the drawings referenced in the following description are schematic representations of the present invention, and therefore the scale, spacing, and positional relationships of the components may be exaggerated, or some components may be omitted from the illustration. Furthermore, the scale and spacing of components may not match between the plan view and the cross-sectional view. In the following description, the same names and reference numerals generally indicate the same or identical components, and detailed explanations will be omitted as appropriate.

[0010] In this specification, terms such as "top," "bottom," etc., indicate the relative positions of components in the drawings referenced for explanatory purposes, and are not intended to indicate absolute positions unless otherwise specified.

[0011] The inventors conducted research to provide a light-emitting element with higher output and reliability. They conceived the idea of ​​reducing light absorption by the electrodes and improving the output of the light-emitting element by placing a metal layer between the electrodes and the semiconductor structure. Further research by the inventors revealed for the first time that in light-emitting elements with a metal layer, wire bonding to the external connection of the electrodes makes the electrodes more prone to delamination from the semiconductor layer. Based on these findings, the inventors completed a light-emitting element that improves output by placing a metal layer while reducing electrode delamination during wire bonding. The following describes the light-emitting elements according to Embodiments 1 to 3 of the present invention.

[0012] [Embodiment 1] Figure 1A is a schematic plan view of the light-emitting element 10A according to Embodiment 1. Figure 1B is a schematic cross-sectional view taken along the line 1b-1b in Figure 1A. Figure 1C is a schematic partial cross-sectional view taken along the line 1c-1c in Figure 1A, mainly showing the structure near the external connection portion 16a of the first electrode 16. Figure 1D is a schematic partial cross-sectional view taken along the line 1d-1d in Figure 1A, mainly showing the structure near the extended portion 16b of the first electrode 16.

[0013] The light-emitting element 10A in this embodiment comprises a semiconductor structure 12, a covering portion 21, a metal layer 13, a light-transmitting electrode 15, a first electrode 16, and a second electrode 17. Preferably, the light-emitting element 10A 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. Note that the light-emitting element 10A shown in Figure 1A is illustrated without the protective layer 20. The light-emitting element 10A may also include a substrate 11 below the semiconductor structure 12 to support the semiconductor structure 12.

[0014] The semiconductor structure 12 includes a first semiconductor layer 12a of a first conductivity type, an active layer 12c disposed below the first semiconductor layer 12a, and a second semiconductor layer 12b of a second conductivity type disposed below the active layer 12c. The covering portion 21 is made of an insulating material and is disposed on the upper surface of the first semiconductor layer 12a. The metal layer 13 is disposed inside the covering portion 21. Translucent electrodes 15 are disposed on the upper surface of the covering portion 21 and the upper surface of the first semiconductor layer 12a. The first electrode 16 includes an external connection portion 16a disposed on the upper surface of the translucent electrode 15 and an extended portion 16b extending from the external connection portion 16a. The second electrode 17 is disposed on the second semiconductor layer 12b.

[0015] In a plan view of the light-emitting element 10A, at least a portion of the extended portion 16b overlaps with the coating portion 21 and the metal layer 13. In this specification, a plan view refers to viewing the light-emitting element 10A from the first electrode 16 side. In the example of the light-emitting element 10A shown in Figure 1A, the metal layer 13 is located in the hatched area and partially overlaps with each of the three extended portions 16b. As can be seen from Figures 1B and 1D, at least a portion of the light traveling from the active layer 12c to the extended portion 16b is reflected by the metal layer 13 before reaching the extended portion 16b and can be extracted from the light-emitting element 10A. This reduces light absorption by the extended portion 16b and improves the output of the light-emitting element 10A.

[0016] Furthermore, the metal layer 13 may be positioned such that a portion of the extended portion 16b does not overlap with the metal layer 13. In the example shown in Figure 1A, the extended portion 16b does not overlap with the metal layer 13 near the external connection portion 16a, which has a roughly circular shape in plan view. This is advantageous in that it further enhances the effect of reducing peeling of the external connection portion 16a, as will be described later. On the other hand, from the viewpoint of further enhancing the effect of improving the output of the light-emitting element 10A, it is preferable that, in a plan view, almost the entire extended portion 16b overlaps with the metal layer 13, as shown in Figure 1E of the light-emitting element 10A1.

[0017] As shown in Figures 1B and 1C, in a plan view of the light-emitting element 10A, the external connection portion 16a includes a first region 161 that overlaps with the coating portion 21 but does not overlap with the metal layer 13. This configuration reduces the likelihood of the external connection portion 16a peeling off during wire bonding, as will be explained below.

[0018] If a metal layer 13 is located directly beneath the external connection portion 16a, wire bonding to the external connection portion 16a may cause the metal layer 13 to delaminate from the covering portion 21 at the interface between the metal layer 13 and the covering portion 21 directly beneath the external connection portion 16a due to the impact during wire bonding. This is thought to be because the adhesion between the metal layer 13 and the covering portion 21 is low due to the properties of the materials used for the metal layer 13 and the covering portion 21. Starting from this delamination, there is a risk that the external connection portion 16a will delaminate from the semiconductor structure 12. If the external connection portion 16a delaminates, the reliability of the light-emitting element will decrease. For example, the adhesion between the metal layer 13 and the covering portion 21 is smaller than the adhesion between the semiconductor structure 12 and the covering portion 21.

[0019] In this embodiment, the light-emitting element 10A has the metal layer 13 arranged such that the external connection portion 16a includes a first region 161 where the metal layer 13 is not present directly beneath it. In other words, by reducing the interface area between the metal layer 13, which is a region with low adhesion, and the coating portion 21 between the external connection portion 16a and the semiconductor structure 12, it is possible to reduce the peeling of the external connection portion 16a from the semiconductor structure 12 during wire bonding. As a result, the reliability of the light-emitting element 10A can be increased.

[0020] In the light-emitting element 10A shown in Figure 1A, the external connection portion 16a does not overlap with the metal layer 13 at all in a plan view. In other words, the entire external connection portion 16a constitutes the first region 161. Furthermore, in a plan view, the portion of the extended portion 16b adjacent to the external connection portion 16a does not overlap with the metal layer 13. Therefore, the external connection portion 16a becomes even less likely to peel off from the semiconductor structure 12. However, it should be noted that the effect of improving the output of the light-emitting element 10A decreases because the amount of light reaching the extended portion 16b from the active layer 12c increases.

[0021] The following details each component.

[0022] (Semiconductor structure 12) The semiconductor structure 12 includes 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 includes a first semiconductor layer 12a, a second semiconductor layer 12b, and an active layer 12c located between the first semiconductor layer 12a and the second semiconductor layer 12b. The semiconductor structure 12 may be placed on the upper surface of the substrate 11. The shape of the semiconductor structure 12 in plan view is, for example, rectangular. If the semiconductor structure 12 is rectangular in plan view, the length of one side is 100 μm or more and 2000 μm or less.

[0023] The first conductivity type is either p-type or n-type. The second conductivity type is a different conductivity type from the first conductivity type and 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. By applying a voltage between the first electrode 16, which is placed on the first semiconductor layer 12a and electrically connected to the first semiconductor layer 12a, and the second electrode 17, which is placed on the second semiconductor layer 12b and electrically connected to the second semiconductor layer 12b, the active layer 12c emits light.

[0024] The semiconductor structure 12 may have regions where the first semiconductor layer 12a and the active layer 12c are partially absent, i.e., first exposed portion 12d1 and second exposed portion 12d2 which are recessed from the surface of the first semiconductor layer 12a and where the second semiconductor layer 12b is exposed from the bottom of the recess.

[0025] In the example shown in Figure 1A, the first exposed portion 12d1 and the second exposed portion 12d2 are arranged along the outer circumference of the light-emitting element 10A in a plan view. More specifically, in a plan view, the strip-shaped first exposed portion 12d1 is arranged along the four sides of the light-emitting element 10A, and furthermore, the semi-elliptical second exposed portion 12d2 is arranged approximately in the center of one side of the light-emitting element 10A, connected to the first exposed portion 12d1. The second electrode 17 is arranged in the semi-elliptical second exposed portion 12d2. The position and shape of the second exposed portion 12d2 can be changed as appropriate based on the other structure of the light-emitting element. In this specification, the first exposed portion 12d1 and the second exposed portion 12d2 may be collectively referred to as the exposed portion 12d.

[0026] The first semiconductor layer 12a, the second semiconductor layer 12b, and the active layer 12c are, for example, In X Al Y Ga 1-X-Y Nitride semiconductors such as N(0≦X, 0≦Y, X+Y<1) are used.

[0027] (Covered part 21) The covering portion 21 is positioned on the upper surface of the first semiconductor layer 12a and partially covers the upper surface of the first semiconductor layer 12a. As shown in Figure 1A, in a plan view, it is preferable that the outer edge of the covering portion 21 is located outside the outer edge of the first electrode 16. The distance between the outer edge of the covering portion 21 and the outer edge of the first electrode 16, that is, the width of the covering portion 21 located outside the first electrode 16, is, for example, 2 μm or more and 7 μm or less. The coating portion 21 is made of an insulating material, preferably a light-transmitting insulating material. Alternatively, the coating portion 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, and one or more elements selected from oxygen and nitrogen.

[0028] By making the coating portion 21 from these materials, the electrical connection between the metal layer 13, which is located inside the coating portion 21, and the light-transmitting electrode 15 can be reduced, thereby further improving the reliability of the light-emitting element 10A. Suitable materials for the coating portion 21 include, for example, oxides, nitrides, or oxynitride oxides of Zr, Si, V, Nb, Hf, Ta, Al, Ce, In, Sb, Zn, etc., with SiO2, SiN, and SiON being particularly preferred. The material for the coating portion 21 is preferably selected considering the properties that are particularly important depending on the purpose, such as improved moisture resistance and improved output.

[0029] For example, from the viewpoint of improving moisture resistance, since a metal layer 13 is arranged inside the coating portion 21, it is preferable that the coating portion 21 be made of a material with excellent moisture resistance, such as silicon, so that moisture does not reach the metal layer 13.

[0030] On the other hand, from the viewpoint of improving output, it is preferable that the coating portion 21 be made of a material with a refractive index less than or equal to that of the first semiconductor layer 12a in order to effectively extract light from the semiconductor structure 12. In this specification, unless otherwise specified, the refractive index refers to the refractive index at the peak wavelength of the light emitted from the semiconductor structure 12. Furthermore, it is even more preferable that the coating portion 21 be made of a material with a refractive index greater than or equal to that of the translucent electrode 15, in order to facilitate the effective transmission of light emitted from the semiconductor structure 12 through the translucent electrode 15, which will be described later. As an example, consider the case where the semiconductor structure 12 is made of a nitride semiconductor and the peak wavelength of light emitted from the active layer 12c is 455 nm. The refractive index of the first semiconductor layer 12a is approximately 2.4, and if indium tin oxide (ITO) is used as the translucent electrode 15, its refractive index is approximately 1.97. Therefore, it is preferable that the coating portion 21 be made of SiN, which has a refractive index of approximately 2.01. This reduces the reflection of light at the interface between the coating portion 21 and the translucent electrode 15, and allows light from the semiconductor structure 12 to the coating portion 21 to be extracted to the outside more efficiently.

[0031] The thickness of the coating portion 21 can be, for example, approximately 100 nm to 300 nm.

[0032] As shown in Figure 1F, the covering portion 21 may be formed from multiple layers. Figure 1F is a schematic partially enlarged cross-sectional view mainly showing the metal layer 13 located directly below the stretched portion 16b and the covering portion 21 that surrounds it. An example of the covering portion 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 the same material as the covering portion 21 described above. By constructing the coating portion 21 from a first layer 21a, a second layer 21b, and a third layer 21c, the metal layer 13 contained within the coating portion 21 can be insulated from both the first semiconductor layer 12a located below the metal layer 13 and the translucent electrodes 15 located above and on the sides of the metal layer 13.

[0033] The first layer 21a, the second layer 21b, and the third layer 21c may each be made of different materials, or two layers may be made of the same material and one layer may be made of a different material, or all three layers may be made of the same material. If two or more of the first layer 21a, the second layer 21b, and the third layer 21c are made of the same material, it may be difficult to distinguish them. In that case, these layers may be treated as a single unit and considered as a "covering portion 21" as shown in Figure 1D.

[0034] The thickness of the first layer 21a can be, for example, 80 nm or more and 300 nm or less. By setting the thickness of the first layer 21a to 80 nm or more, the metal layer 13 and the first semiconductor layer 12a can be more reliably insulated, and reflection at the interface between the first layer 21a and the first semiconductor layer 12a can be effectively generated. By setting the thickness of the first layer 21a to 300 nm or less, the thickness of the covering portion 21 including the first layer 21a does not become too thick, and the occurrence of disconnection of the translucent electrode 15 formed on the covering portion 21 can be reduced. Here, in this specification, the thickness of each member refers to the maximum thickness in a cross-sectional view of that member.

[0035] The thickness of the second layer 21b can be, for example, 80 nm or more and 120 nm or less. By setting the thickness of the second layer 21b to 80 nm or more, the metal layer 13 and the translucent electrode 15 can be more reliably insulated. By setting the thickness of the second layer 21b to 120 nm or less, the thickness of the coating portion 21 including the second layer 21b does not become too thick, and the occurrence of wire breakage of the translucent electrode 15 formed on the coating portion 21 can be reduced.

[0036] The thickness of the third layer 21c can be, for example, 100 nm to 500 nm. The third layer 21c reflects light emitted from the active layer 12c directly beneath the external connection portion 16a, thereby reducing absorption by the external connection portion 16a. By setting the thickness of the third layer 21c in the external connection portion 16a to this range, the amount of light absorbed by the external connection portion 16a can be reduced.

[0037] (metal layer 13) As shown in Figures 1B and 1D, the metal layer 13 is located inside the coating portion 21, which is situated between the first semiconductor layer 12a and the stretched portion 16b of the first electrode 16. As shown in Figure 1F, when the coating portion 21 is composed of three layers, a first layer 21a, a second layer 21b, and a third layer 21c, the metal layer 13 is located between the first layer 21a and the second layer 21b, and is further covered by the third layer 21c, thus being positioned inside the coating portion 21. 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 side surface of the metal layer 13.

[0038] By arranging the metal layer 13, light that penetrates into the coating portion 21 (first layer 21a in the case of a three-layer structure) without being reflected at the interface between the coating portion 21 (first layer 21a) and the first semiconductor layer 12a can be reflected back to the first semiconductor layer 12a by the metal layer 13. As a result, the output of the light-emitting element 10A can be improved compared to the case where the coating portion 21 does not include the metal layer 13.

[0039] In this embodiment, as shown in Figures 1B and 1C, the metal layer 13 is not placed inside the coating portion 21 sandwiched between the first semiconductor layer 12a and the external connection portion 16a of the first electrode 16. This reduces the occurrence of delamination of the external connection portion 16a caused by the metal layer 13 when wire bonding is performed to the external connection portion 16a.

[0040] The reflectivity of the metal layer 13 with respect to the peak wavelength of light from the active layer 12c is greater than the reflectivity of the first electrode 16 with respect to the peak wavelength of light from the active layer 12c. The metal layer 13 is made of a metallic material having a high reflectivity with respect to the peak wavelength of light from the active layer 12c. For example, the metal layer 13 is made of a metallic material having a reflectivity of 70% or more, preferably 80% or more, with respect to the peak wavelength of light from the active layer 12c. As the metal layer 13, for example, Al, Ag, or alloys containing these metallic materials can be used. Furthermore, from the viewpoint of reducing the dissolution of the metal layer 13 by the solution used in patterning and other processes performed after the formation of the metal layer 13, it is preferable to use AlCu, which has better corrosion resistance than Al, as the metal layer 13. The thickness of the metal layer 13 can be, for example, 80 nm or more and 120 nm or less.

[0041] (Transparent electrode 15) The translucent electrode 15 is positioned on the upper surface of the coating portion 21 and on the upper surface of the first semiconductor layer 12a that is not covered by the coating portion 21. The translucent electrode 15 is electrically connected to the first semiconductor layer 12a. A portion of the translucent electrode 15 is positioned between the first electrode 16 and the coating portion 21. The translucent electrode 15 is positioned to cover substantially the entire upper surface of the first semiconductor layer 12a, allowing the current supplied to the first electrode 16 to be diffused over a wider area of ​​the first semiconductor layer 12a.

[0042] It is preferable to use a conductive metal oxide as the material for the translucent electrode 15. Examples of translucent electrodes 15 include oxides containing at least one element selected from the group consisting of Zn, In, Sn, Ga, and Ti. For example, ITO, zinc oxide (ZnO), indium oxide (In2O3), tin oxide (SnO2), and indium zinc oxide (IZO) can be used for the translucent electrode 15. In particular, ITO is a suitable material for the translucent electrode 15 that covers substantially the entire upper surface of the first semiconductor layer 12a because it has high translucency to visible light and high conductivity.

[0043] From the viewpoint of reducing light absorption by the translucent electrode 15, it is preferable to make the translucent electrode 15 thinner. The thickness of the translucent electrode 15 can be, for example, 30 nm to 100 nm, preferably 35 nm to 80 nm.

[0044] (1st electrode 16) The first electrode 16 includes an external connection portion 16a positioned on the upper surface of the translucent electrode 15 and an extended portion 16b extending from the external connection portion 16a. The external connection portion 16a may be positioned on the upper surface of the translucent electrode 15. The external connection portion 16a is an area for connecting to the outside by wire bonding or the like. The shape of the external connection portion 16a in plan view can be, for example, approximately circular, approximately rectangular, or semi-elliptical. In the example in Figure 1A, the shape of the external connection portion 16a in plan view is approximately circular. The extended portion 16b is an auxiliary electrode for efficiently diffusing the current supplied via the external connection portion 16a to the light-transmitting electrode 15. In a plan view, the width of the extended portion 16b is narrower than the width of the external connection portion 16a.

[0045] In some cases, the external connection portion 16a and the extension portion 16b can be easily distinguished, while in other cases, it may be difficult to distinguish them. When the boundary 16c between the external connection portion 16a and the extension portion 16b can be uniquely determined as in the light-emitting element 10A shown in FIG. 1A, the external connection portion 16a and the extension portion 16b can be separated based on the boundary 16c. In the example shown in FIG. 1A, since the extension portion 16b having a substantially constant width extends from the external connection portion 16a in a plan view, the boundary 16c between the external connection portion 16a and the extension portion 16b can be uniquely determined. In the light-emitting element 10D shown in FIG. 4, it is difficult to uniquely determine the boundary 16c between the external connection portion 16a and the extension portion 16b. In the example shown in FIG. 4, since the extension portion 16b having a non-constant width extends from the external connection portion 16a in a plan view, it is difficult to uniquely determine the boundary 16c between the external connection portion 16a and the extension portion 16b. In such a case, the boundary 16c between the external connection portion 16a and the extension portion 16b is determined by the following procedure.

[0046] In the light-emitting element 10D shown in FIG. 4, the extension portion 16b includes a curved extension portion 16b1 and a linear extension portion 16b2, and the tips of each are rounded in a plan view. In the curved extension portion 16b1, first, in the vicinity of the tip of the extension portion 16b1, the width of the extension portion 16b1 is measured at a position where the edges on both sides of the extension portion 16b1 are substantially parallel, and this is taken as the reference width W 16b1 of the extension portion 16b1. Here, the "width" of the extension portion 16b1 is the dimension in the direction orthogonal to the extension direction of the extension portion 16b1 in a plan view. Next, from the tip side of the extension portion 16b1 toward the external connection portion 16a, the width of the extension portion 16b1 is measured at a plurality of locations. The position where the measured width becomes 1.5 times the reference width W 16b1 is taken as the boundary 16c between the external connection portion 16a and the extension portion 16b1. Instead of measuring the width of the extension portion 16b1, a determination instrument that can determine whether it is 1.5 times the dimension of the reference width W 16b1 may be used. For example, two parallel lines are drawn on a transparent sheet such that the gap between them is 1.5 times the reference width W 16b1 (1.5×W 16b1 ) to make a determination instrument, and using that determination instrument, the position where the width becomes 1.5 times the reference width W 16b1 may be specified.

[0047] Similarly, for the straight extension portion 16b2, the width of the extension portion 16b2 is measured near the tip of the extension portion 16b2 at a position where the edges on both sides of the extension portion 16b2 are almost parallel, and this is used for the extension portion 16b 12 Standard width W 16b2 Let's assume that. Next, the width of the extended portion 16b2 is measured at multiple points, starting from the tip of the extended portion 16b2 toward the external connection portion 16a. The measured width is the reference width W. 16b2 The point where the distance is 1.5 times the standard width is defined as the boundary 16c between the external connection part 16a and the extension part 16b2. 16b2 The boundary 16c may be determined using a determination tool that can determine whether or not it is 1.5 times the dimension.

[0048] In the light-emitting element 10A according to this embodiment, a covering portion 21 made of insulating material is arranged between the first electrode 16 (external connection portion 16a and extended portion 16b) and the first semiconductor layer 12a of the semiconductor structure 12. In other words, the first electrode 16 and the first semiconductor layer 12a are not in direct contact. The first electrode 16 is electrically connected to the first semiconductor layer 12a via a light-transmitting electrode 15. By arranging the covering portion 21 in this manner, it becomes difficult for current to flow from the first electrode 16 to the semiconductor structure 12 in the region directly beneath it. Therefore, the light emission of the semiconductor structure 12 in the region directly beneath the first electrode 16 is reduced, and the absorption of light by the first electrode 16 can be reduced. Furthermore, since the current flowing to the semiconductor structure 12 can be increased in regions other than the region directly beneath the first electrode 16, the light-emitting element 10A can be made to emit light efficiently.

[0049] The external connection portion 16a of the first electrode 16 can be made of, for example, Cu, Au, or an alloy mainly composed of these metals, so as to be suitable for connection to the outside by wire bonding or the like. The external connection portion 16a and the extended portion 16b of the first electrode 16 may also be made of the same material.

[0050] In a plan view of the light-emitting element 10A, at least a portion of the extended portion 16b overlaps with the coating portion 21 and the metal layer 13. In other words, the metal layer 13 is located directly beneath at least a portion of the extended portion 16b. Since some of the light from the active layer 12c toward the first electrode 16 is reflected by the metal layer 13, light absorption by the first electrode 16 is reduced, and the output of the light-emitting element 10A can be increased.

[0051] On the other hand, in a plan view of the light-emitting element 10A, the external connection portion 16a includes a first region 161 that overlaps with the coating portion 21 but does not overlap with the metal layer 13. Directly below the first region 161, there is no interface between the coating portion 21 and the metal layer 13. Because the interface between the coating portion 21 and the metal layer 13 has low adhesion, if it is subjected to an impact when wire bonding is performed on the external connection portion 16a, there is a risk of interfacial delamination occurring at the interface directly beneath the external connection portion 16a. This interfacial delamination may lead to delamination between the semiconductor structure 12 and the external connection portion 16a. Therefore, in order to reduce delamination at the interface between the coating portion 21 and the metal layer 13, the metal layer 13 is positioned such that the external connection portion 16a includes a first region 161 where there is no interface between the coating portion 21 and the metal layer 13. This reduces the delamination of the external connection portion 16a from the semiconductor structure 12 when wire bonding is performed to the external connection portion 16a.

[0052] From the viewpoint of reducing peeling of the external connection portion 16a, it is preferable that the entire external connection portion 16a is the first region 161, as shown in Figure 1C.

[0053] The dimensions of the first electrode 16 can be set appropriately, taking into consideration the dimensions of the light-emitting element 10A, etc. For example, the external connection portion 16a of the first electrode 16 has a maximum dimension of 50 μm to 100 μm in plan view and an area of ​​1950 μm. 2 More than 7850μm 2The following applies, where the stretched portion 16b has a width of 2 μm or more and 10 μm or less in a plan view. The thickness of the first electrode 16 is, for example, 0.5 μm or more and 4 μm or less. The thickness of the external connection portion 16a and the thickness of the stretched portion 16b may be the same or different.

[0054] (2nd electrode 17) The second electrode 17 is located on the second semiconductor layer 12b. The second electrode 17 is located on the upper surface of the second semiconductor layer 12b, which is exposed from the bottom surface of the second exposed portion 12d2, which has a shape that is approximately semi-elliptical in plan view. The second electrode 17 can be made of, for example, Cu, Au, or an alloy mainly composed of these metals, so that it is suitable for connection to the outside by wire bonding or the like.

[0055] (Protective layer 20) The protective layer 20 is optionally included in the light-emitting element 10A to cover and protect substantially the entire upper surface of the light-emitting element 10A. If the light-emitting element 10A has a protective layer 20, as shown in Figures 1B and 1C, the protective layer 20 has an opening that exposes a portion of the upper surface of the external connection portion 16a of the first electrode 16. Wire bonding to the external connection portion 16a is performed on the upper surface of the external connection portion 16a exposed through the opening in the protective layer 20. Note that the protective layer 20 does not have to cover the sides and a portion of the upper surface (near the outer edge) of the external connection portion 16a. In other words, the sides and upper surface of the external connection portion 16a may be exposed from the protective layer 20. It is preferable to use a material that is transparent and insulating for the protective layer 20. For example, SiO2 or SiON can be used for the protective layer 20.

[0056] (Circuit board 11) The substrate 11 is optionally included in the light-emitting element 10A to support the semiconductor structure 12. The substrate 11 may also be a growth substrate for epitaxial growth of the semiconductor structure 12. For example, if a nitride semiconductor is used for the semiconductor structure 12, a sapphire (Al2O3) substrate can be used as the substrate 11.

[0057] (Manufacturing method) An example of a manufacturing method for the light-emitting element 10A will be described. A semiconductor structure 12 is prepared on the upper surface of a substrate 11, which includes a second semiconductor layer 12b, an active layer 12c, and a first semiconductor layer 12a, and has an exposed portion 12d where the second semiconductor layer 12b is exposed. The semiconductor structure 12 can be formed, for example, by the MOCVD (Metal Organic Vapor Deposition) method.

[0058] A metal layer 13 is formed inside the coating portion 21 at a predetermined position on the upper surface of the first semiconductor layer 12a (corresponding to the extended portion 16b of the first electrode 16 shown in Figure 1). There are two methods for forming the metal layer 13 embedded in the coating portion 21, for example.

[0059] The first method involves forming a metal layer 13 inside a covering portion 21, which includes a first layer 21a, a second layer 21b, and a third layer 21c, as shown in Figure 1F. First, a laminated structure is formed by sequentially forming a first layer 21a made of insulating material, a metal layer 13, and a second layer 21b made of insulating material at a predetermined position on the upper surface of the first semiconductor layer 12a (a position corresponding to the stretched portion 16b). Next, a third layer 21c made of insulating material is formed so as to cover the upper and side surfaces of the laminated structure. This forms the metal layer 13 located inside the covering portion 21.

[0060] The second method involves sandwiching a metal layer 13 between two layers of insulating material in a covering portion 21. First, a first insulating layer is formed at a predetermined position on the upper surface of the first semiconductor layer 12a (a position corresponding to the stretched portion 16b). Next, a metal layer 13 is formed on the upper surface of the first insulating layer, and in a plan view, inside the outer edge of the first insulating layer. Subsequently, a second insulating layer, having approximately the same dimensions as the first insulating layer, is formed to cover the upper and side surfaces of the metal layer 13.

[0061] The metal layer 13 can be deposited using known film deposition methods such as sputtering or chemical vapor deposition (CVD).

[0062] The coating portion 21 can be formed, for example, by sputtering, chemical vapor deposition, or the like.

[0063] A translucent electrode 15 is formed on the upper and side surfaces of the covering portion 21 and on the upper surface of the first semiconductor layer 12a that is not covered by the covering portion 21. The translucent electrode 15 can be formed, for example, by sputtering. Then, a first electrode 16 is formed at a predetermined position on the upper surface of the translucent electrode 15, and a second electrode 17 is formed at a predetermined position on the upper surface of the second semiconductor layer 12b that is exposed from the second exposed portion 12d2. The first electrode 16 and the second electrode can be formed, for example, by sputtering.

[0064] Finally, a protective layer 20 is formed, consisting of an insulating material, that covers the semiconductor structure 12, the translucent electrode 15, the extended portion 16b of the first electrode 16, the first exposed portion 12d1, and the second exposed portion 12d2. The protective layer 20 can be formed, for example, by sputtering or chemical vapor deposition. The protective layer 20 may cover part of the sides and top surfaces of the external connection portion 16a of the first electrode 16 and the second electrode 17, as long as it does not hinder wire bonding between them.

[0065] The following describes in detail the possible configurations of the light-emitting element 10A according to this embodiment. For the light-emitting elements 10A2 to 10A5 according to embodiments 1-1 to 1-4, the differences from the light-emitting element 10A according to embodiment 1 will be explained, and similar configurations will not be described.

[0066] [Embodiment 1-1] Figure 1G shows a schematic cross-sectional view of the light-emitting element 10A2 according to Embodiment 1-1, mainly illustrating the structure around the extended portion 16b of the first electrode 16. In the light-emitting element 10A according to Embodiment 1 shown in Figure 1F, the thicknesses of the first layer 21a, the second layer 21b, and the metal layer 13 are substantially constant at both ends and the center in the lateral direction, whereas in Modification 1, the thicknesses of these layers vary in the lateral direction. Figure 1G corresponds to a schematic cross-sectional view along the line 1d-1d in Figure 1A.

[0067] In the light-emitting element 10A2 of Embodiment 1-1, in a cross-sectional view, the thickness of the first layer 21a, the second layer 21b, and the metal layer 13 is thinner at both ends in the lateral direction and thicker in the center. By making the thickness of the metal layer 13 thinner at both ends than at the center, the edges of the metal layer 13 can be easily covered by the first layer 21a and the second layer 21b. As a result, the metal layer 13 is less susceptible to the influence of the external environment by the first layer 21a and the second layer 21b, reducing alteration and deterioration of the metal layer 13, and resulting in a light-emitting element 10A2 with improved reliability.

[0068] [Embodiment 1-2] Figures 1H and 1I show schematic cross-sectional views of the light-emitting element 10A3 according to Embodiment 1-2. Figure 1H illustrates the structure around the external connection portion 16a of the first electrode 16, and Figure 1I illustrates the structure around the extended portion 16b of the first electrode 16.

[0069] As shown in Figure 1H, the light-emitting element 10A3 according to Embodiment 1-2 includes a reflective electrode 22a in the first electrode 16, which is located between the light-transmitting electrode 15 and the external connection portion 16a. The reflectivity of the reflective electrode 22a with respect to the peak wavelength of light emitted by the active layer 12c is higher than that of the external connection portion 16a.

[0070] In a plan view of the light-emitting element 10A, the first region 161 of the external connection portion 16a, which overlaps with the coating portion 21 but does not overlap with the metal layer 13, overlaps with the reflective electrode 22a. Since the first region 161 does not overlap with the metal layer 13, the metal layer 13 cannot reflect light from the active layer 12c toward the first region 161 of the external connection portion 16a. The light-emitting element 10A3 according to the modified example 2 is equipped with a reflective electrode 22a at a position overlapping with the first region 161, so that light from the active layer 12c toward the first region 161 can be reflected by the reflective electrode 22a. This reduces the light absorbed by the external connection portion 16a and further improves the output of the light-emitting element 10A3. Note that the reflectance of the reflective electrode 22a with respect to the peak wavelength of light emitted by the active layer 12c may be lower than the reflectance of the metal layer 13 with respect to the peak wavelength of light emitted by the active layer 12c. On the other hand, the adhesion between the reflective electrode 22a and the coating portion 21 can be made higher than the adhesion between the metal layer 13 and the coating portion 21.

[0071] In a plan view of the light-emitting element 10A, it is preferable that the outer edge of the reflective electrode 22a is located outside the outer edge of the external connection portion 16a. In other words, in a plan view, it is preferable that the reflective electrode 22a is larger than the external connection portion 16a and completely overlaps with the external connection portion 16a. When this is shown in a cross-sectional view as in Figure 1H, the width W22a of the reflective electrode 22a is larger than the width W16a of the external connection portion 16a. Note that the relationship between the width W22a of the reflective electrode 22a and the width W16a of the external connection portion 16a only needs to be established in the same cross-section, and the relationship between the width W22a of the reflective electrode 22a in one cross-section and the width W16a of the external connection portion 16a in another cross-section is not relevant.

[0072] The "width" of the reflective electrode 22a in a cross-sectional view refers to the dimension in the direction perpendicular to the thickness direction of the reflective electrode 22a, and the "width" of the external connection portion 16a in a cross-sectional view refers to the dimension in the direction perpendicular to the thickness direction of the external connection portion 16a. By configuring it in this way, the reflective electrode 22a can be placed along the entire optical path of light from the active layer 12c to the first region 161 of the external connection part 16a, thereby further improving the output of the light-emitting element 10A3.

[0073] The reflective electrode 22a is made of a conductive material and has a multilayer structure having a single layer or multiple layers, for example, made of a metal or alloy. An example of a multilayer structure is one in which an Rh-Cr alloy layer and a Pt layer are stacked from the side of the translucent electrode 15. The reflective electrode 22a may have the function of reflecting light as well as the function of improving contact with the translucent electrode 15.

[0074] As shown in Figure 1I, it is preferable to also place a reflective electrode 22b between the translucent electrode 15 and the stretched portion 16b. As shown in Figure 1I, when the metal layer 13 and the reflective electrode 22b are present directly below the stretched portion 16b, it is preferable that the width W13 of the metal layer 13 is greater than the width W22b of the reflective electrode 22b. Here, the "width" of the metal layer 13 and the "width" of the reflective electrode 22b refer to the dimensions in the direction perpendicular to the stretching direction of the stretched portion 16b when viewed from above. Figure 1I is a cross-sectional view of the stretched portion 16b in a plane perpendicular to the stretching direction, and the width W13 of the metal layer 13 and the width W22b of the reflective electrode 22b correspond to the dimensions in the direction perpendicular to the stretching direction of the stretched portion 16b.

[0075] When the extension portion 16b extends in a straight line, the extension direction is a straight line, and the direction perpendicular to the extension direction is also uniquely determined. On the other hand, when the extension portion 16b extends in a partially bent or curved manner, the extension direction is also bent or curved. The direction "perpendicular" to the bent or curved extension direction is defined as the direction perpendicular to the extension direction when a tangent line is drawn to the bent or curved extension direction at the position where the width is to be measured.

[0076] Furthermore, as shown in Figure 1I, it is preferable that the width W22b of the reflective electrode 22b is greater than the width W16b of the extended portion 16b. The "width" of the extended portion 16b is the maximum dimension in the direction perpendicular to the extension direction of the extended portion 16b when viewed from above. By configuring it in this way, the reflective electrode 22b can be placed along the entire optical path of light from the active layer 12c to the extended portion 16b, thereby further improving the output of the light-emitting element 10A3.

[0077] [Embodiments 1-3, 1-4] Figure 1J shows a schematic cross-sectional view of the light-emitting element 10A4 according to Embodiment 1-3, and Figure 1K shows a schematic cross-sectional view of the light-emitting element 10A5 according to Embodiment 1-4. Figures 1J and 1K illustrate the structure around the external connection portion 16a of the first electrode 16, respectively. As shown in Figures 1J and 1K, the external connection portion 16a of the light-emitting element 10A4 according to Modification 3 and the light-emitting element 10A5 according to Modification 4 may include a third region 163 that does not overlap with the coating portion 21 and the metal layer 13 in a plan view. In the third region 163, since the coating portion 21 does not exist between the translucent electrode 15 and the semiconductor structure 12, the contact area between the translucent electrode 15 and the semiconductor structure 12 increases, and the forward voltage (Vf) of the light-emitting elements 10A4 and 10A5 can be reduced.

[0078] However, in order to fully obtain the effects obtained by providing the covering portion 21, it is preferable to control the area of ​​the third region 163 to an appropriate range. When the area in which the external connection portion 16a overlaps with the covering portion 21 in a plan view of the light-emitting elements 10A4 and 10A5 is taken as 100%, it is preferable that the area of ​​the third region 163 be 30% or more and 70% or less.

[0079] As shown in Figure 1J, in an example of a light-emitting element 10A4 having a third region 163, in a plan view, the third region 163 is located inside the outer edge of the covering portion 21. When the light-emitting element 10A4 is viewed in cross-section, as shown in Figure 1J, the third region 163 of the external connection portion 16a is surrounded by the first region 161 which overlaps with the covering portion 21.

[0080] As shown in Figure 1K, in another example of the light-emitting element 10A5 having a third region 163, in a plan view, the third region 163 is outside the outer edge of the covering portion 21. When the light-emitting element 10A5 is viewed in cross-section, as shown in Figure 1K, the third region 163 of the external connection portion 16a surrounds the first region 161.

[0081] [Embodiment 2] The following description of the light-emitting element 10B according to Embodiment 2 will be given with reference to Figures 2A to 2E. The explanation will focus on the differences from the light-emitting element 10A according to Embodiment 1. Details regarding the same configuration and materials as the light-emitting element 10A according to Embodiment 1 will be omitted.

[0082] Figure 2A is a schematic plan view of the light-emitting element 10B according to Embodiment 2. Figure 2B is a schematic cross-sectional view taken along the line 2b-2b in Figure 2A. Figure 2C is a schematic partial cross-sectional view taken along the line 2c-2c in Figure 2A, mainly showing the structure near the external connection portion 16a of the first electrode 16.

[0083] The light-emitting element 10B according to Embodiment 2 differs from Embodiment 1 in that, in a plan view, the external connection portion 16a of the first electrode 16 partially overlaps with the metal layer 13. In other words, in the light-emitting element 10B according to Embodiment 2, the external connection portion 16a includes a first region 161 that does not overlap with the metal layer 13 and a second region 162 that overlaps with the metal layer 13. In the example shown in Figure 2A, the second region 162 is annular.

[0084] As shown in Figure 2A, in a plan view of the light-emitting element 10B, at least a portion of the first region 161 is surrounded by a metal layer 13. The metal layer 13 may overlap with the external connection portion 16a. In other words, as shown in Figure 2C, the external connection portion 16a may include a second region 162 that overlaps with the covering portion 21 and the metal layer 13. As shown in Figures 2A and 2C, the first region 161 may further be included outside the second region 162. Since the metal layer 13 is positioned directly beneath the second region 162 of the external connection portion 16a, some of the light traveling from the active layer 12c to the external connection portion 16a is reflected by the metal layer 13 before reaching the external connection portion 16a and can be extracted from the light-emitting element 10B. This reduces light absorption by the external connection portion 16a and improves the output of the light-emitting element 10B.

[0085] When arranging the second region 162, it is preferable to control the area of ​​the second region 162 to an appropriate range. In a plan view of the light-emitting element 10B, when the area of ​​the external connection part 16a is set to 100%, it is preferable that the area of ​​the second region 162 be between 10% and 40%.

[0086] Furthermore, since the interface between the metal layer 13 and the coating portion 21 exists directly beneath the second region 162 of the external connection portion 16a, there is a risk of interfacial delamination occurring when wire bonding is performed on the external connection portion 16a, which may induce delamination of the external connection portion 16a from the semiconductor structure 12. As shown in Figure 2C, in order to reduce interfacial delamination as much as possible, it is preferable not to place the metal layer 13 directly beneath the center of the external connection portion 16a where the impact during wire bonding is greatest. In other words, as shown in Figure 2A, in a plan view, it is preferable that the first region 161 is located in a region that includes the center of the external connection portion 16a.

[0087] The metal layer 13 positioned directly beneath the second region 162 of the external connection portion 16a can have the same configuration as the metal layer 13 positioned directly beneath the stretched portion 16b in Embodiment 1. For example, as shown in Figure 2E, the covering portion 21 surrounding the metal layer 13 can be composed of a first layer 21a, a second layer 21b, and a third layer 21c, similar to Figure 1F of Embodiment 1. Furthermore, as shown in Figure 2E, similar to Figure 1H of Embodiment 1, in a plan view of the light-emitting element 10B, the first region 161 of the external connection portion 16a, which overlaps with the coating portion 21 but does not overlap with the metal layer 13, preferably overlaps with the reflective electrode 22a. The reflective electrode 22a does not necessarily overlap with the second region 162, but it is more preferable that it overlaps with the second region 162.

[0088] [Embodiment 3] The following description of the light-emitting element 10C according to Embodiment 3 will be given with reference to Figures 3A to 3C. The explanation will focus on the differences from the light-emitting elements 10A and 10B according to Embodiments 1 and 2. Details regarding the same configuration and materials as the light-emitting elements 10A and 10B according to Embodiments 1 and 2 will be omitted.

[0089] Figure 3A is a schematic plan view of the light-emitting element 10C according to Embodiment 3. Figure 3B is a schematic cross-sectional view taken along the line 3b-3b in Figure 3A. Figure 3C is a schematic partial cross-sectional view taken along the line 3c-3c in Figure 3A, mainly showing the structure near the external connection portion 16a of the first electrode 16.

[0090] The light-emitting element 10C according to Embodiment 3 differs from Embodiment 2 in that, in a plan view, the metal layer 13 overlapping the external connection portion 16a of the first electrode 16 is divided into multiple sections. In other words, in the light-emitting element 10C according to Embodiment 3, the external connection portion 16a includes multiple second regions 162. In the example shown in Figure 3A, it includes four second regions 162.

[0091] As shown in Figure 3A, the light-emitting element 10C includes a plurality of second regions 162 in a plan view. A first region 161 is arranged between adjacent second regions 162 in a plan view. Since the metal layer 13 is positioned directly beneath the second region 162 of the external connection portion 16a, some of the light traveling from the active layer 12c towards the external connection portion 16a is reflected by the metal layer 13 before reaching the external connection portion 16a and can be extracted from the light-emitting element 10C. This reduces light absorption by the external connection portion 16a and improves the output of the light-emitting element 10C.

[0092] Furthermore, as shown in Figure 3B, similar to Embodiment 2, in order to minimize interfacial delamination at the interface between the coating portion 21 and the metal layer 13, it is preferable not to provide the metal layer 13 directly below the center of the external connection portion 16a, where the impact during wire bonding is greatest. In other words, as shown in Figure 3A, in a plan view, it is preferable that the first region 161 is located in a region that includes the center of the external connection portion 16a.

[0093] Similar to Embodiment 2, the covering portion 21 surrounding the metal layer 13 positioned directly beneath the multiple second regions 162 of the external connection portion 16a can be composed of a first layer, a second layer, and a third layer (not shown).

[0094] Although the light-emitting element according to the present invention has been specifically described above in terms of embodiments for carrying out the invention, the spirit of the present invention is not limited to these descriptions and must be interpreted broadly based on the claims. Furthermore, it goes without saying that various modifications and alterations based on these descriptions are also included in the spirit of the present invention.

[0095] The disclosures herein include the following embodiments. [Section 1] A semiconductor structure comprising a first semiconductor layer of a first conductivity type, an active layer disposed below the first semiconductor layer, and a second semiconductor layer of a second conductivity type disposed below the active layer, A covering portion made of an insulating material disposed on the upper surface of the first semiconductor layer, A metal layer disposed inside the coating portion, A light-transmitting electrode is disposed on the upper surface of the coating portion and the upper surface of the first semiconductor layer, A first electrode including an external connection portion disposed on the upper surface of the light-transmitting electrode and an extended portion extending from the external connection portion, The invention comprises a second electrode disposed on the second semiconductor layer, In a plan view, at least a portion of the extended portion overlaps with the coating portion and the metal layer. In a plan view, the external connection portion includes a first region that overlaps with the covering portion but does not overlap with the metal layer, thereby providing a light-emitting element. [Section 2] A semiconductor structure comprising a first semiconductor layer of a first conductivity type, an active layer disposed below the first semiconductor layer, and a second semiconductor layer of a second conductivity type disposed below the active layer, A coating portion disposed on the upper surface of the first semiconductor layer, comprising one or more elements selected from Zr, Si, V, Nb, Hf, Ta, Al, Ce, In, Sb, and Zn, and one or more elements selected from oxygen and nitrogen, A metal layer disposed inside the coating portion, A light-transmitting electrode is disposed on the upper surface of the coating portion and the upper surface of the first semiconductor layer, A first electrode including an external connection portion disposed on the upper surface of the light-transmitting electrode and an extended portion extending from the external connection portion, The invention comprises a second electrode disposed on the second semiconductor layer, In a plan view, at least a portion of the extended portion overlaps with the coating portion and the metal layer. In a plan view, the external connection portion includes a first region that overlaps with the covering portion but does not overlap with the metal layer, thereby providing a light-emitting element. [Section 3] The light-emitting element according to claim 1 or 2, wherein the covering portion includes a first layer disposed below the metal layer, a second layer disposed above 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. [Section 4] The light-emitting element according to any one of items 1 to 3, wherein the entire external connection portion is the first region. [Section 5] A light-emitting element according to any one of claims 1 to 3, wherein, in a plan view, at least a portion of the first region is surrounded by the metal layer. [Section 6] In a plan view, the first region is located in a region including the center of the external connection portion, according to any one of claims 1 to 5. [Section 7] In a plan view, the external connection portion further includes a second region that overlaps with the covering portion and the metal layer, according to any one of claims 1 to 3. [Section 8] The external connection portion includes a plurality of the second regions, as described in item 7. [Section 9] The first electrode further includes a reflective electrode between the light-transmitting electrode and the external connection portion, which has a higher reflectivity to the peak wavelength of light emitted by the active layer than the external connection portion. A light-emitting element according to any one of items 1 to 8, wherein, in a plan view, the first region overlaps with the reflective electrode. [Section 10] In a plan view, the outer edge of the reflective electrode is located outside the outer edge of the external connection portion, as described in item 9. [Section 11] The light-emitting element according to item 9 or 10, wherein the reflective electrode is further disposed between the translucent electrode and the stretched portion. [Section 12] The light-emitting element according to item 11, wherein the width of the metal layer in a direction perpendicular to the stretching direction of the stretched portion is greater than the width of the reflective electrode. [Section 13] In a plan view, the external connection portion further includes a third region that does not overlap with the covering portion and the metal layer, according to any one of claims 1 to 3. [Section 14] The light-emitting element according to item 13, wherein, in a plan view, the area of ​​the third region is 30% or more and 70% or less of the area in which the external connection portion overlaps with the covering portion. [Section 15] The light-emitting element according to item 13 or 14, wherein, in a plan view, the third region is located inside the outer edge of the covering portion. [Section 16] The light-emitting element according to item 13 or 14, wherein, in a plan view, the third region is located outside the outer edge of the covering portion. [Industrial applicability]

[0096] The light-emitting element of the present invention can be used as a backlight source for liquid crystal displays, various lighting fixtures, large displays, and other light sources. [Explanation of Symbols]

[0097] 10A, 10A2, 10A3, 10A4, 10A5, 10B, 10C light-emitting element 11 circuit boards 12 Semiconductor Structures 12a First semiconductor layer 12b Second semiconductor layer 12c active layer 13 Metal layer 15 Translucent electrode 16 1st electrode 16a External connection section 16b Extension part 17 Second electrode 20 protective layer 21 Covering part 21a 1st layer 21b 2nd layer 21c 3rd layer 22a, 22b reflective electrodes 161 1st area 162 Second area 163 Third area

Claims

1. A semiconductor structure comprising a first semiconductor layer of a first conductivity type, an active layer disposed below the first semiconductor layer, and a second semiconductor layer of a second conductivity type disposed below the active layer, A covering portion made of an insulating material disposed on the upper surface of the first semiconductor layer, A metal layer disposed inside the coating portion, A light-transmitting electrode is disposed on the upper surface of the coating portion and the upper surface of the first semiconductor layer, A first electrode including an external connection portion disposed on the upper surface of the light-transmitting electrode and an extended portion extending from the external connection portion, The invention comprises a second electrode disposed on the second semiconductor layer, In a plan view, at least a portion of the extended portion overlaps with the coating portion and the metal layer. In a plan view, the external connection portion includes a first region that overlaps with the covering portion but does not overlap with the metal layer, thereby providing a light-emitting element.

2. A semiconductor structure comprising a first semiconductor layer of a first conductivity type, an active layer disposed below the first semiconductor layer, and a second semiconductor layer of a second conductivity type disposed below the active layer, A coating portion disposed on the upper surface of the first semiconductor layer, comprising one or more elements selected from Zr, Si, V, Nb, Hf, Ta, Al, Ce, In, Sb, and Zn, and one or more elements selected from oxygen and nitrogen, A metal layer disposed inside the coating portion, A light-transmitting electrode is disposed on the upper surface of the coating portion and the upper surface of the first semiconductor layer, A first electrode including an external connection portion disposed on the upper surface of the light-transmitting electrode and an extended portion extending from the external connection portion, The invention comprises a second electrode disposed on the second semiconductor layer, In a plan view, at least a portion of the extended portion overlaps with the coating portion and the metal layer. In a plan view, the external connection portion includes a first region that overlaps with the covering portion but does not overlap with the metal layer, thereby providing a light-emitting element.

3. The light-emitting element according to claim 1, wherein the covering portion includes a first layer disposed below the metal layer, a second layer disposed above 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. The light-emitting element according to claim 1, wherein the entire external connection portion is the first region.

5. The light-emitting element according to claim 1, wherein, in a plan view, at least a portion of the first region is surrounded by the metal layer.

6. The light-emitting element according to claim 1, wherein, in a plan view, the first region is located in a region including the center of the external connection portion.

7. The light-emitting element according to claim 1, wherein, in a plan view, the external connection portion further includes a second region that overlaps with the covering portion and the metal layer.

8. The light-emitting element according to claim 7, wherein the external connection portion includes a plurality of the second regions.

9. The first electrode further includes a reflective electrode between the light-transmitting electrode and the external connection portion, which has a higher reflectivity to the peak wavelength of light emitted by the active layer than the external connection portion. The light-emitting element according to claim 1, wherein in a plan view, the first region overlaps with the reflective electrode.

10. The light-emitting element according to claim 9, wherein, in a plan view, the outer edge of the reflective electrode is located outside the outer edge of the external connection portion.

11. The light-emitting element according to claim 9, wherein the reflective electrode is further disposed between the light-transmitting electrode and the stretched portion.

12. The light-emitting element according to claim 11, wherein the width of the metal layer in a direction perpendicular to the stretching direction of the stretched portion is greater than the width of the reflective electrode.

13. The light-emitting element according to claim 1, wherein, in a plan view, the external connection portion further includes a third region that does not overlap with the covering portion and the metal layer.

14. The light-emitting element according to claim 13, wherein, in a plan view, the area of ​​the third region is 30% or more and 70% or less of the area where the external connection portion overlaps with the covering portion.

15. The light-emitting element according to claim 13, wherein, in a plan view, the third region is located inward from the outer edge of the covering portion.

16. The light-emitting element according to claim 13, wherein, in a plan view, the third region is located outside the outer edge of the covering portion.

Images