Light-emitting diode and horizontal type light-emitting device

Abstract

To provide a light-emitting diode with high luminance.SOLUTION: A light-emitting diode 10 includes a light-emitting layer 120, an upper electrode 190 and a lower electrode 170, a first semiconductor layer 110, a second semiconductor layer 130, a third semiconductor layer 150, and a low refractive index dielectric layer 160. The upper electrode 190 and the lower electrode 170 are disposed on both opposite sides of the light-emitting layer 120. The first semiconductor layer 110 is disposed between the light-emitting layer 120 and the upper electrode 190. The second semiconductor layer 130 is disposed between the light-emitting layer 120 and the lower electrode 170. The third semiconductor layer 150 is disposed between the second semiconductor layer 130 and the lower electrode 170. The low refractive index dielectric layer 160 is disposed surrounding the lower electrode 170. The upper electrode 190 and the lower electrode 170 are disposed overlapping with each other when viewed from a vertical direction. The electric characteristics of the first semiconductor layer 110 and the third semiconductor layer 150 are opposite to those of the second semiconductor layer 130.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a light emitting diode, and more particularly to a high brightness light emitting diode. [Background technology]

[0002] Light emitting diodes (LEDs) have the advantages of high brightness, small size, low power consumption, and long life, and are widely used in lighting and display products. Wafer bonding is often used to achieve high brightness in LEDs. The bottom structure of the epitaxial layer of a wafer-bonded LED has the following characteristics: (1) The bottom structure of the epitaxial layer of an LED has a low refractive index dielectric layer and a reflective metal. The lower the refractive index of the dielectric layer, the higher the total reflectance. This dielectric layer and reflective metal reflect the light emitted from the active light emitting layer of the LED upward, enhancing the brightness. (2) When observing the contact metal and transparent conductive layer for conduction at the bottom of the LED from top to bottom, the current conduction points are generally distributed in dots or stripes outside the upper electrode, which can diffuse the current to the outside of the electrode and prevent the light emitted from the active light emitting layer from being blocked by the upper electrode, thereby achieving high brightness.

[0003] However, the above structure has a drawback. When light is emitted by diffusing current through the active light-emitting layer, the portion through which the current flows is usually not provided with a corresponding dielectric layer having a low refractive index, so that the condition that the main light-emitting position corresponds to the position of the optimum reflectance cannot be achieved, and the overall light-emitting efficiency is reduced. In addition, since the conventional technology improves the light-emitting efficiency by improving the current diffusion of the light-emitting diode, the distance between the active light-emitting layer and the ohmic contact electrode is not very large. In general, the distance between the light-emitting layer and the ohmic contact electrode is 2 microns or less. However, if the distance between the light-emitting layer and the ohmic contact electrode is too short, electrical defects such as poor antistatic properties and excessive forward voltage of the light-emitting diode will occur.

[0004] US Patent Publication No. 20130221367A1 discloses a light-emitting diode with a structure similar to the above-mentioned prior art. The metal contact electrode is disposed on the outside of the upper electrode to spread the current. However, the metal contact electrode has the above-mentioned problem of absorbing light and affecting the light extraction of the LED. In order to overcome the above-mentioned problems, it is an urgent task in the industry to develop an innovative light-emitting diode structure and manufacturing process that can increase the brightness while improving problems such as low antistatic properties and high forward voltage. Summary of the Invention

[0005] The main objective of the present invention is to provide a high brightness light emitting diode, which can distribute the current away from the electrodes, avoid the light shielding of the electrodes, improve the light extraction efficiency, and improve the problems such as poor antistatic properties and high forward voltage by adjusting the epitaxial structure.

[0006] In order to achieve the above object, the present invention provides a light-emitting diode including a light-emitting layer, an upper electrode, a lower electrode, a first semiconductor layer, a second semiconductor layer, a third semiconductor layer, and a low refractive index dielectric layer. The upper electrode and the lower electrode are disposed on opposite sides of the light-emitting layer, respectively. The first semiconductor layer is disposed between the light-emitting layer and the upper electrode. The second semiconductor layer is disposed between the light-emitting layer and the lower electrode. The third semiconductor layer is disposed between the second semiconductor layer and the lower electrode. The low refractive index dielectric layer is disposed surrounding the lower electrode. The upper electrode and the lower electrode are disposed overlapping each other when viewed in the vertical direction. The electrical characteristics of the first semiconductor layer and the third semiconductor layer are opposite to those of the second semiconductor layer.

[0007] In an embodiment of the present invention, the light-emitting diode further includes a plurality of epitaxial conduction points disposed in the third semiconductor layer corresponding to positions of the low refractive index dielectric layer, and allows current to flow from the upper electrode through the first semiconductor layer, the light-emitting layer, the second semiconductor layer, each epitaxial conduction point, and the third semiconductor layer to the lower electrode.

[0008] In an embodiment of the present invention, the epitaxial conductive point of the light emitting diode is a composite layer of a heavily doped tunnel effect. In the physical tunnel effect of semiconductors, when an N-type semiconductor and a P-type semiconductor are heavily doped, a tunnel effect from the N-type semiconductor to the P-type semiconductor is obtained, which has the effect of dispersing the current from the electrodes.

[0009] In an embodiment of the present invention, the light emitting diode further includes a current blocking layer disposed in the second semiconductor layer corresponding to the positions of the upper electrode and the lower electrode, so as to provide a non-conductive connection between the upper electrode and the lower electrode and to provide an effect of dispersing current from the electrodes.

[0010] In an embodiment of the present invention, the current blocking layer of the light emitting diode is formed by etching and destroying a portion of the second semiconductor layer between the top electrode and the bottom electrode.

[0011] In an embodiment of the present invention, the light emitting diode further includes a reflective metal layer electrically connected to the bottom electrode.

[0012] In an embodiment of the present invention, the reflective metal layer of the light emitting diode is one selected from the group consisting of gold (Au), silver (Ag), aluminum (Al), beryllium gold (BeAu), zinc gold (ZnAu), or a combination thereof.

[0013] In an embodiment of the present invention, the low refractive index dielectric layer of the light emitting diode is one selected from the group consisting of silicon dioxide (SiO2), silicon nitride (Si3N4), indium tin oxide (ITO), magnesium fluoride (MgF2), or a combination thereof.

[0014] In order to achieve the above object, the present invention further provides a horizontal light emitting device comprising the light emitting diode, a bonding metal layer, and an external electrode, the bonding metal layer extending horizontally outward beyond the first semiconductor layer, the light emitting layer, the second semiconductor layer, and the third semiconductor layer, one end of which is electrically connected to the lower electrode, and the other end of which is electrically connected to the external electrode.

[0015] In an embodiment of the present invention, the horizontal light emitting device further comprises an insulating substrate bonded to the metal layer.

[0016] Those skilled in the art can understand other objects of the present invention, as well as the technical means and embodiments of the present invention, by referring to the drawings and the embodiments described below. [Brief description of the drawings]

[0017] [Figure 1] 1 is a diagram showing a manufacturing process of a light-emitting diode according to an embodiment of the present invention. [Diagram 2] 1 is a diagram showing a manufacturing process of a light-emitting diode according to an embodiment of the present invention. [Diagram 3] 1 is a diagram showing a manufacturing process of a light-emitting diode according to an embodiment of the present invention. [Figure 4] 1 is a diagram showing a manufacturing process of a light-emitting diode according to an embodiment of the present invention. [Diagram 5] 1 is a diagram showing a manufacturing process of a light-emitting diode according to an embodiment of the present invention. [Figure 6] 1 is a diagram showing a manufacturing process of a light-emitting diode according to an embodiment of the present invention. [Figure 7] 1 is a diagram showing a manufacturing process of a light-emitting diode according to an embodiment of the present invention. [Figure 8] 1 is a diagram showing a manufacturing process of a light-emitting diode according to an embodiment of the present invention. [Figure 9] 1 is a diagram showing a manufacturing process of a light-emitting diode according to an embodiment of the present invention. [Figure 10] 1 is a diagram showing a manufacturing process of a light-emitting diode according to an embodiment of the present invention. [Figure 11] FIG. 1 is a top view showing a structure of a light-emitting diode according to an embodiment of the present invention. [Figure 12] 1 is a diagram showing a manufacturing process of a light emitting diode according to another embodiment of the present invention; [Figure 13] 1 is a diagram showing a manufacturing process of a light emitting diode according to another embodiment of the present invention; [Figure 14]1 is a diagram showing a manufacturing process of a light emitting diode according to another embodiment of the present invention; [Figure 15] 1 is a diagram showing a manufacturing process of a light emitting diode according to another embodiment of the present invention; [Figure 16] 1 is a diagram showing a manufacturing process of a light emitting diode according to another embodiment of the present invention; [Figure 17] FIG. 1 is a schematic diagram showing a horizontal light emitting device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The contents of the present invention will be described below through examples. The examples of the present invention are examples of embodiments, and are not intended to limit the present invention to the environments, applications, or specific aspects described in the examples. Therefore, the explanation of the examples is for explaining the present invention, but does not limit the present invention. In the embodiments and drawings, components that are not directly related to the present invention are omitted and not shown. The dimensional relationship between the components in the drawings is for ease of understanding, and does not limit the actual dimensions.

[0019] FIG. 1 is a diagram showing an embodiment of a manufacturing process of a light-emitting diode according to the present invention. The present invention uses gallium arsenide (GaAs) as a substrate 100 for growth, but is not limited thereto. Next, a double heterostructure of aluminum gallium indium arsenide (AlGaInAs) is formed on the gallium arsenide substrate. Specifically, in this embodiment, the double heterostructure includes an N-type first semiconductor layer 110, a light-emitting layer 120 formed on the N-type first semiconductor layer 110, and a P-type second semiconductor layer 130 formed on the light-emitting layer 120. The light-emitting layer 120 is formed in a multiple quantum well (MQW) structure, and includes aluminum gallium arsenide (AlGaAs) as a barrier layer of the multiple quantum well and includes gallium indium arsenide (InGaAs) as a well layer of the quantum well. In addition, the N-type first semiconductor layer 110 is a cladding layer of aluminum gallium arsenide (AlGaAs) doped with silicon (Si). The P-type second semiconductor layer 130 is a cladding layer of aluminum gallium arsenide (AlGaAs) doped with carbon (C). The materials described in the above embodiment are merely examples, and the present invention is not limited thereto. In practice, the material and its composition can be adjusted according to the emission wavelength. For example, the epitaxial layer may be aluminum gallium indium phosphide (AlGaInP), indium gallium phosphide (InGaP), aluminum gallium arsenide (AlGaAs), indium gallium arsenide (InGaAs), indium phosphide (InP), or the like.

[0020] As shown in FIG. 1, a heavily doped tunneling composite layer 140 is formed on the P-type second semiconductor layer 130. The heavily doped tunneling composite layer 140 includes a P-type epitaxial layer 142 and an N-type epitaxial layer 144. The P-type epitaxial layer 142 may be a gallium arsenide (GaAs) epitaxial layer doped with a very high concentration of carbon (C). The N-type epitaxial layer 144 may be a gallium arsenide (GaAs) epitaxial layer doped with a very high concentration of tellurium (Te). After forming the heavily doped tunneling composite layer 140 on the P-type second semiconductor layer 130, a yellow light etching process is performed to pattern the heavily doped composite layer 140. As shown in FIG. 2, the patterned heavily doped composite layer 140 has a current spreading effect due to the tunnel effect between the N-type and P-type semiconductors during operation of the light-emitting diode.

[0021] 3, the epitaxial growth and doping process is performed again to form an N-type third semiconductor layer 150. This N-type third semiconductor layer 150 fills the patterned heavily doped composite layer 140 and covers the entire second semiconductor layer 130 to a certain thickness. In a specific embodiment, the third semiconductor layer 150 may be an epitaxial layer of gallium arsenide (GaAs) doped with silicon (Si).

[0022] As shown in FIG. 4, a dielectric layer 160 is formed on the third semiconductor layer 150. Specifically, the dielectric layer 160 is a low refractive index dielectric layer, and is one selected from the group consisting of silicon dioxide (SiO2), silicon nitride (Si3N4), indium tin oxide (ITO), magnesium fluoride (MgF2), or a combination thereof. Next, as shown in FIG. 5, a pattern etching process is performed on the low refractive index dielectric layer 160 to determine the position of the lower electrode. In detail, the dielectric layer 160 patterned in this process vertically covers the patterned heavily doped composite layer 140, i.e., covers a plurality of epitaxial conductive points 140a.

[0023] Next, as shown in FIG. 6, a metallization process is performed to form a bottom electrode 170. This bottom electrode 170 fills the recessed area of ​​the dielectric layer 160 removed by the etching process shown in FIG. 5. The bottom electrode 170 is surrounded by the patterned low refractive index dielectric layer 160. The bottom electrode 170 is a P-type electrode used as an ohmic contact metal. As described above, the position and pattern structure of the bottom electrode 170 are defined by the dielectric layer 160, so that the bottom electrode 170 does not overlap with the epitaxial conductive points 140a when viewed from the vertical direction.

[0024] As shown in FIG. 7, after forming the lower electrode 170, a metallization process is performed to form a reflective metal layer 180 covering the low refractive index dielectric layer 160 and the lower electrode 170. The reflective metal layer 180 is electrically connected to the lower electrode 170. In practice, the lower electrode 170 and the reflective metal layer 180 can use the same conductive material. Generally, it is one selected from the group consisting of gold (Au), silver (Ag), aluminum (Al), beryllium gold (BeAu), zinc gold (ZnAu), or a combination thereof. The combination of the reflective metal layer 180 and the low refractive index dielectric layer 160 improves the reflection efficiency of the light emitted downward from the light emitting layer 120.

[0025] As shown in Fig. 8, a bonding metal layer 182 for bonding to a permanent bonding substrate is formed on the lower electrode 170 and the reflective metal layer 180 by vapor deposition. Similarly, a bonding metal layer 182 is formed on a permanent bonding substrate 184 by vapor deposition. The bonding metal material may be gold (Au) or an indium gold (InAu) alloy, and the permanent bonding substrate 184 may be, but is not limited to, a silicon substrate or a sapphire substrate. Note that the light-emitting diode structure on the epitaxial substrate 100 is metal-bonded to the permanent bonding substrate 184 by the bonding metal layer 182.

[0026] As shown in FIG. 9, the gallium arsenide epitaxial substrate 100 is removed to expose the first semiconductor layer 110. The whole is turned over so that the permanent bonding substrate 184 is the bottom of the light-emitting diode structure. Then, as shown in FIG. 10, the MESA process is performed. A part of the epitaxial composite layer is etched to form a street on the permanent bonding substrate 184. A patterned top electrode 190 is formed on the first semiconductor layer 110. The top electrode 190 is an N-type electrode, and its electrical properties are opposite to those of the bottom electrode 170. The material of the top electrode 190 is one selected from the group consisting of germanium (Ge), titanium (Ti), platinum (Pt), and gold (Au), or a combination thereof. In particular, the top electrode 190 and the bottom electrode 170 are arranged to overlap each other when viewed vertically. The pattern structures of the top electrode 190 and the bottom electrode 170 are substantially the same. Next, a back electrode 172 electrically connected to the lower electrode 170 is formed on the other surface of the permanently bonded substrate 184, completing the structure of the light-emitting diode 10 according to the present invention.

[0027] In the above structure, FIG. 10 and FIG. 11, which is a top view of FIG. 10, show the positional relationship and pattern structure of the plurality of epitaxial conduction points 140a, the low refractive index dielectric layer 160, the upper electrode 190, and the lower electrode 170 (shown by dotted lines in FIG. 11). Since the plurality of epitaxial conduction points 140a having a tunnel effect are arranged in the third semiconductor layer 150 of the light-emitting diode 10 according to the present invention, the tunnel effect between the N-type epitaxial layer 144 and the P-type epitaxial layer 142 is utilized, and the injected current is guided and dispersed from the upper electrode 190 through the first semiconductor layer 110, the light-emitting layer 120, and the second semiconductor layer 130 to each epitaxial conduction point 140a, and then flows to the third semiconductor layer 150 and the lower electrode 170. As a result, the effect of current diffusion can be obtained by using the plurality of epitaxial conduction points 140a in the structure of the light-emitting diode according to the present invention. In particular, each epitaxial conduction point 140a overlaps with the low refractive index dielectric layer 160 when viewed from the vertical direction. Therefore, when the injected current passes through the light emitting layer and is diffused at the epitaxial conduction point 140a to emit light, the low refractive index dielectric layer overlapping each epitaxial conduction point 140a when viewed from the vertical direction can reflect the light emitted downward from the light emitting layer with optimal reflection efficiency without being blocked by the upper electrode 190, thereby improving the light extraction efficiency. In detail, the first semiconductor layer 110 and the third semiconductor layer 150 are N-type, which is opposite to the electrical characteristics of the P-type second semiconductor layer 130. The P-type second semiconductor layer 130 and the N-type first semiconductor layer 110 and third semiconductor layer 150 can exert an effect as a backflow prevention diode, and it is possible to prevent the upper electrode 190 and the lower electrode 170 from being conductive and adversely affecting the light extraction efficiency.

[0028] In a preferred embodiment, the thickness of the third semiconductor layer 150 is at least 2 microns, and can be as thick as 8 microns. In the structure of the light emitting diode, the thickened third semiconductor layer 150 can increase the distance between the light emitting layer 120 and the lower electrode 170, and improve the antistatic ability of the light emitting diode. This overcomes the drawback of the conventional light emitting diode structure that the distance between the light emitting layer and the lower electrode is short, which causes current concentration and reduces the antistatic ability of the light emitting diode.

[0029] In addition to the above embodiment, other embodiments of the light-emitting diode according to the present invention will be described below. As shown in FIG. 12, as in the previous embodiment, gallium arsenide is used as a growth substrate 200, and an aluminum gallium indium arsenide double heterostructure is formed on the gallium arsenide substrate 200. The structure includes an N-type first semiconductor layer 210, a light-emitting layer 220, and a P-type second semiconductor layer 230. The light-emitting layer 220 is formed on the first semiconductor layer 210. The P-type second semiconductor layer 230 is formed on the light-emitting layer 220. The material compositions of the light-emitting layer 220, the first semiconductor layer 210, and the second semiconductor layer 230 are the same as those of the previous embodiment, and therefore will not be described.

[0030] As shown in FIG. 13, the P-type second semiconductor layer 230 is patterned, and a portion of the P-type second semiconductor layer 230 is removed, for example, by a yellow light wet etching process, until the surface of the light emitting layer 220 is partially exposed, forming a recessed region 240. Then, the epitaxial growth and doping process is performed again to form an N-type third semiconductor layer 250. This N-type third semiconductor layer 250 fills the recessed region 240 of the pattern after the patterning process and covers the entire second semiconductor layer 230 to a certain thickness. In a specific embodiment, the third semiconductor layer 250 may be an epitaxial layer of gallium arsenide doped with silicon. In a preferred embodiment, the thickness of the third semiconductor layer 250 is at least 2 microns, and can be as thick as 8 microns.

[0031] As shown in FIG. 14, a dielectric layer 260 is formed on the third semiconductor layer 250. Specifically, the dielectric layer 260 is a low refractive index dielectric layer, which is one selected from the group consisting of silicon dioxide, silicon nitride, indium tin oxide, and magnesium fluoride, or a combination thereof. Next, a pattern etching process is performed on the low refractive index dielectric layer 260 to determine the position of the lower electrode 270. Next, a metallization process is performed to form the lower electrode 270 surrounded by the low refractive index dielectric layer 260. The lower electrode 270 is a P-type electrode used as an ohmic contact metal. In detail, the position and pattern structure of the lower electrode 270 are due to the pattern processing on the dielectric layer 260. It is necessary to perform a pattern processing on the dielectric layer 260 so that the pattern structure of the lower electrode 270 formed thereafter overlaps with the recessed region 240 in the third semiconductor layer 250 when viewed from the vertical direction, and the pattern structures of both the lower electrode 270 and the recessed region 240 are approximately the same.

[0032] As shown in Fig. 15, after the lower electrode 270 is formed, a metallization process is performed to form a reflective metal layer 280. The reflective metal layer 280 covers the low refractive index dielectric layer 260 and the lower electrode 270, and is electrically connected to the lower electrode 270. In practice, the lower electrode 270 and the reflective metal layer 280 can use the same conductive material, which is generally one selected from the group consisting of gold, silver, aluminum, beryllium gold, and zinc gold, or a combination thereof.

[0033] The subsequent steps are the same as those of the previous embodiment. As shown in FIG. 16, a bonding metal layer 282 and a permanent bonding substrate 284 are sequentially formed on the lower electrode 270 and the reflective metal layer 280, and the epitaxial substrate 200 is removed. Then, a MESA process is performed to form a patterned upper electrode 290 on the first semiconductor layer 210, completing the structure of the light-emitting diode 20 of the second embodiment. The material of the upper electrode 290 is one selected from the group consisting of germanium, titanium, platinum, and gold, or a combination thereof. Similarly, in this embodiment, the upper electrode 290 is disposed vertically above the patterned recessed region 240 in the third semiconductor layer 250, and has substantially the same patterned structure as the recessed region 240 and the lower electrode 270.

[0034] In the above structure, the recessed region 240 is designed to overlap the upper electrode 290 and the lower electrode 270 when viewed vertically. Therefore, in the normal operation of the light-emitting diode 20, the recessed region 240 has a good current blocking effect because the epitaxial structure is destroyed by the etching process. Therefore, the recessed region 240 functions as a current blocking layer to prevent current from being conducted between the upper electrode and the lower electrode. As a result, the injected current is dispersed outside the recessed region 240 and dispersed throughout the structure of the light-emitting diode. The combination of the recessed region 240 and the low refractive index dielectric layer 260 outside the lower electrode 270 allows the light emitted downward from the light-emitting layer to be reflected by the low refractive index dielectric layer with optimal reflection efficiency without being blocked by the upper electrode 290, thereby improving the light extraction efficiency and increasing the brightness of the light-emitting diode 20.

[0035] In the above embodiment, the technical features of the present invention are described using the structure of a vertical light-emitting diode, but the light-emitting diode according to the present invention is not limited to a vertical light-emitting diode. FIG. 17 is a diagram showing an embodiment in which the above-mentioned light-emitting diode structure is applied to a horizontal light-emitting diode. The epitaxial structure of the horizontal light-emitting device 30 shown in FIG. 17 is almost the same as that of the above embodiment. The only difference is that the bonding metal layer 182 extends horizontally outward beyond the first semiconductor layer 110, the light-emitting layer 120, the second semiconductor layer 130, and the third semiconductor layer 150 relative to the other epitaxial layers, one end of which is electrically connected to the lower electrode 170, the other end of which is electrically connected to the external electrode 174, and the permanent bonding substrate 184 bonded to the bonding metal layer 182 is an insulating substrate. The rest of the epitaxial structure can be described in the above, so the description thereof will be omitted.

[0036] The above examples are for explaining the embodiments of the present invention and for explaining the characteristic configuration of the present invention. The present invention is not limited to the above examples. Modifications or equivalent arrangements that can be easily made by those skilled in the art are also within the scope of the present invention. The scope of protection of the rights of the present invention is based on the claims. [Explanation of symbols]

[0037] 10, 20 Light emitting diode 30 Horizontal light emitting device 100, 200 boards 110, 210 First semiconductor layer 120, 220 Light-emitting layer 130, 230 Second semiconductor layer 140 composite layer 140a Epitaxial Conduction Point 142 P-type epitaxial layer 144 N-type epitaxial layer 150, 250 Third semiconductor layer 160, 260 Dielectric layer 170, 270 Lower electrode 172 Back electrode 174 External electrode 180, 280 reflective metal layer 182, 282 bonding metal layer 184, 284 Permanently bonded substrates 190, 290 Lower electrode 240 Concave Area

Claims

1. A light emitting diode, A light-emitting layer; an upper electrode and a lower electrode disposed on opposite sides of the light emitting layer, a first semiconductor layer disposed between the light emitting layer and the upper electrode; a second semiconductor layer disposed between the light emitting layer and the lower electrode; a third semiconductor layer disposed between the second semiconductor layer and the lower electrode; a low refractive index dielectric layer disposed surrounding the lower electrode; The upper electrode and the lower electrode are arranged to overlap each other when viewed in a vertical direction, and electrical characteristics of the first semiconductor layer and the third semiconductor layer are opposite to electrical characteristics of the second semiconductor layer.

2. 2. The light-emitting diode of claim 1, further comprising a plurality of epitaxial conduction points disposed in the third semiconductor layer corresponding to the positions of the low refractive index dielectric layer, and configured to pass a current from the upper electrode through the first semiconductor layer, the light-emitting layer, the second semiconductor layer, each of the epitaxial conduction points, and the third semiconductor layer to the lower electrode.

3. 3. The light emitting diode of claim 2, wherein each of said epitaxial conductive points is a heavily doped tunneling composite layer.

4. 2. The light emitting diode of claim 1, further comprising a current blocking layer disposed in the second semiconductor layer corresponding to positions of the upper electrode and the lower electrode so as to provide a non-conductive connection between the upper electrode and the lower electrode.

5. The light emitting diode according to claim 4 , wherein the current blocking layer is formed by etching and destroying a portion of the second semiconductor layer between the upper electrode and the lower electrode.

6. The light emitting diode of claim 1 , further comprising a reflective metal layer electrically connected to the lower electrode.

7. 7. The light emitting diode of claim 6, wherein the reflective metal layer is one selected from the group consisting of gold (Au), silver (Ag), aluminum (Al), beryllium gold (BeAu), zinc gold (ZnAu), or a combination thereof.

8. The low refractive index dielectric layer is made of silicon dioxide (SiO ２ ), silicon nitride (Si ３ N ４ ), indium tin oxide (ITO), magnesium fluoride (MgF ２ 2. The light emitting diode according to claim 1, wherein the light emitting diode is one selected from the group consisting of:

9. A horizontal light emitting device, A light emitting diode according to any one of claims 1 to 8; A bonding metal layer; An external electrode, A horizontal light-emitting device, wherein the bonding metal layer extends horizontally outward beyond the first semiconductor layer, the light-emitting layer, the second semiconductor layer, and the third semiconductor layer, one end of the bonding metal layer is electrically connected to the lower electrode, and the other end is electrically connected to the external electrode.

10. 10. The horizontal light emitting device according to claim 9, further comprising an insulating substrate bonded to the bonding metal layer.

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