TWI789293B - Light-emitting device - Google Patents

Abstract

A light-emitting device includes a substrate including a sidewall; a light-emitting stack formed on the substrate, including a first semiconductor layer, an active layer and a second semiconductor layer; a semiconductor structure formed on the substrate, being separated from the light-emitting stack by the first semiconductor layer and surrounding the light-emitting stack; and a distributed bragg reflector covering the light-emitting stack and the semiconductor structure, wherein the semiconductor structure includes a side surface directly connected to the sidewall of the substrate, and a top surface directly connected to the side surface of the semiconductor structure, the top surface includes a top surface of the second semiconductor layer, the distributed bragg reflector comprises a first side surface directly connected to the side surface of the semiconductor structure and a second side surface separated from the side surface of the semiconductor structure by a distance to expose the top surface of the semiconductor structure.

Description

Light emitting element

The present invention relates to a light-emitting element, and in particular to a light-emitting element, which includes a light-emitting stack, a semiconductor structure surrounding the light-emitting stack, and a reflective structure located on the light-emitting stack and the semiconductor structure.

Light-Emitting Diode (Light-Emitting Diode, LED) is a solid-state semiconductor light-emitting element, which has the advantages of low power consumption, low heat generation, long working life, shockproof, small size, fast response and good photoelectric properties, such as Stable emission wavelength. Therefore, light-emitting diodes are widely used in household appliances, equipment indicator lights, and optoelectronic products.

A light emitting element includes a substrate including a side wall; a light emitting stack includes a plurality of outer side walls on the substrate, a light emitting stack includes a first semiconductor layer, an active layer and a second semiconductor layer; a semiconductor structure is located on the substrate, The first semiconductor layer is separated from the light-emitting stack by a distance and surrounds a plurality of outer walls of the light-emitting stack; and a Bragg reflector covers the light-emitting stack and the semiconductor structure, wherein the semiconductor structure includes one side surface directly connected to the side wall of the substrate connected, and an upper surface directly connected to the side surface of the semiconductor structure, the upper surface includes a surface of the second semiconductor layer, the Bragg reflector includes a first side directly connected to the side surface of the semiconductor structure and a second side connected to the side surface of the semiconductor structure. The side surfaces of the semiconductor structure are separated by a distance to expose the upper surface of the semiconductor structure.

A light emitting element includes a substrate including a side wall; a light emitting stack includes a plurality of outer side walls on the substrate, a light emitting stack includes a first semiconductor layer, an active layer and a second semiconductor layer; a semiconductor structure is located on the substrate, The first semiconductor layer is separated from the light-emitting stack by a distance and surrounds a plurality of outer sidewalls of the light-emitting stack; a first groove is located on the substrate, exposing the first semiconductor layer, and is located between the light-emitting stack and the semiconductor structure, The first semiconductor layer exposed by the first groove separates the semiconductor structure and the light-emitting stack at a distance, and the semiconductor structure surrounds the light-emitting stack; a second groove is located on the first semiconductor layer, and the semiconductor structure and the light-emitting stack are separated by a distance. The first trench is separated by a distance and surrounds a plurality of sides of the semiconductor structure; and a Bragg reflector covers the light-emitting stack and the semiconductor structure, wherein the semiconductor structure includes a side surface separated by a distance from the side wall of the substrate, and a semiconductor structure. The side surface of the Bragg mirror directly connects with the upper surface, and the upper surface includes a surface of the second semiconductor layer. The Bragg reflector includes a first side that is directly connected with the side surface of the semiconductor structure or separated by a distance.

In order to make the description of the present invention more detailed and complete, please refer to the description of the following embodiments together with the relevant figures. However, the examples shown below are for illustrating the light-emitting device of the present invention, and the present invention is not limited to the following examples. In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments in this specification are not limited, and the scope of the present invention is not limited thereto, but is merely illustrative. In addition, the size and positional relationship of components shown in the drawings may be exaggerated for clarity. In addition, in the following description, in order to omit detailed description appropriately, the same name and symbol are used for the same or similar member.

FIG. 1 is a top view of a light emitting element 1 disclosed in an embodiment of the present invention. Figure 2 is an enlarged view of the lower left part of Figure 1. Fig. 3 is a scanning electron microscope (SEM) perspective view of Fig. 2 . Figure 4 is a sectional view along the tangent line A-A' of Figure 1. Fig. 5 is a sectional view along the tangent line B-B' of Fig. 1. The light emitting element 1 disclosed in the embodiment is a light emitting diode with flip chip structure.

As shown in the top view of FIG. 1 and the cross-sectional view of FIG. 4, the light-emitting element 1 includes a substrate 10 including sidewalls 10s; a light-emitting stack 11 includes a plurality of outer sidewalls S1 on the substrate 10, and the light-emitting stack 11 includes A first semiconductor layer 111, a second semiconductor layer 112, and an active layer 113 are located between the first semiconductor layer 111 and the second semiconductor layer 112; a semiconductor structure 12 is located on the substrate 10, by the first semiconductor layer 111 There is a distance from the light-emitting stack 11 and surrounds a plurality of outer sidewalls S1 of the light-emitting stack 11; and a Bragg reflector 20 covers the light-emitting stack 11 and the semiconductor structure 12, wherein the semiconductor structure 12 includes a side surface 12s and a substrate The side wall 10s of 10 is directly connected, an inner surface 12ns opposite to the side surface 12s, and an upper surface 12t directly connected to the side surface 12s and the inner surface 12ns, and the Bragg reflector 20 includes a first side surface 201s and a semiconductor structure 12 The side surface 12s of the semiconductor structure 12 is directly connected, and a second side surface 202s is separated from the side surface 12s of the semiconductor structure 12 by a distance to expose the upper surface 12t of the semiconductor structure.

As shown in the top view of FIG. 1, the light-emitting element 1 may have a rectangular or square shape, and as shown in the side views of FIGS. 1 to form a rectangular or square shape. Viewed from the top view, the size of the light emitting element 1 may be, for example, a rectangular shape of 300 μm to 1000 μm or a square shape of 700 μm to 700 μm, but it is not particularly limited thereto.

The substrate 10 may be a growth substrate, including gallium arsenide (GaAs) wafers for epitaxial growth of aluminum gallium indium phosphide (AlGaInP), or sapphire (Al ₂ O ₃ ) wafer, gallium nitride (GaN) wafer or silicon carbide (SiC) wafer.

In one embodiment of the present invention, by metalorganic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor deposition (HVPE), physical vapor deposition (PVD) or ion The electroplating method is used to form a light-emitting stack 11 with optoelectronic properties on the substrate 10, wherein the physical vapor deposition method includes sputtering or evaporation (Evoaporation) method.

As shown in FIGS. 4-5 , the light emitting stack 11 includes a first semiconductor layer 111 , a second semiconductor layer 112 , and an active layer 113 located between the first semiconductor layer 111 and the second semiconductor layer 112 . By changing the physical and chemical composition of one or more layers in the light-emitting stack 11, the wavelength of the light emitted by the light-emitting element 1 can be adjusted. The material of the light emitting stack 11 includes III-V group semiconductor materials, such as Al _x In _y Ga _(1-xy) N or Al _x In _y Ga _(1-xy) P, where 0≦x, y≦1; (x +y)≦1. When the material of the light emitting stack 11 is AlInGaP series material, it can emit red light with a wavelength between 610 nm and 650 nm. When the material of the light-emitting stack 11 is AlInGaP series or InGaN series materials, it can emit green light with a wavelength between 500 nm and 570 nm. When the material of the light emitting stack 11 is an InGaN series material, it can emit blue light with a wavelength between 400 nm and 490 nm. When the material of the light-emitting stack 11 is AlGaN series or AlInGaN series materials, it can emit ultraviolet light with a wavelength between 400 nm and 250 nm.

The first semiconductor layer 111 and the second semiconductor layer 112 can be a cladding layer (cladding layer), both of which have different conductivity types, electric properties, polarities, or provide electrons or holes according to doped elements, such as the first The first semiconductor layer 111 is an n-type semiconductor, and the second semiconductor layer 112 is a p-type semiconductor. The active layer 113 is formed between the first semiconductor layer 111 and the second semiconductor layer 112 . Electrons and holes are driven by a current to recombine in the active layer 113 to convert electrical energy into light energy to emit a light. The active layer 113 can be single heterostructure (single heterostructure, SH), double heterostructure (double heterostructure, DH), double-side double heterostructure (double-side double heterostructure, DDH), or multi-layer quantum well structure (multi-quantum well, MQW). The material of the active layer 113 can be neutral, p-type or n-type semiconductor. The first semiconductor layer 111 , the second semiconductor layer 112 , or the active layer 113 may be a single layer or a structure including multiple sublayers.

The light-emitting stack 11 includes an upper surface and a lower surface, and the active layer 113 includes a first upper surface and a second lower surface, wherein a first upper surface of the light-emitting stack 11 and the first upper surface of the active layer 113 include a A distance includes a second distance between the lower surface of the light emitting stack 11 and the second lower surface of the active layer 113 , and the second distance is greater than the first distance.

In one embodiment of the present invention, the light emitting stack 11 may further include a buffer layer (not shown) located between the first semiconductor layer 111 and the substrate 10 to release the material between the substrate 10 and the light emitting stack 11 The stress generated by lattice mismatch can reduce misalignment and lattice defects, thereby improving epitaxy quality. The buffer layer can be a single layer or a structure comprising multiple sublayers. In one embodiment, PVD aluminum nitride (AlN) may be used as a buffer layer formed between the light emitting stack 11 and the substrate 10 to improve the epitaxial quality of the light emitting stack 11 . In one embodiment, a target for forming PVD aluminum nitride (AlN) is composed of aluminum nitride. In another embodiment, a target composed of aluminum is used to form aluminum nitride reactively with the aluminum target in the presence of a nitrogen source.

As shown in the top view of FIG. 1 , the light-emitting element 1 includes a plurality of outer sidewalls S1 of the light-emitting stack 11 surrounded by a semiconductor structure 12 located on one periphery of the light-emitting element 1 . As shown in the cross-sectional views of FIGS. 4 to 5 , the semiconductor structure 12 is located on the substrate 10 , and the semiconductor structure 12 is isolated from the light emitting stack 11 by the first trench 110 . The first trench 110 includes a minimum width D between 1 μm˜30 μm, preferably between 2 μm˜14 μm, more preferably between 5 μm˜10 μm. The first trench 110 is formed by removing part of the second semiconductor layer 112 and the active layer 113 , and the first trench 110 exposes part of the surface 111t of the first semiconductor layer 111 . The top view shape of the first trench 110 includes a rectangular ring, a polygonal ring, a circular ring, an elliptical ring or an irregular ring, wherein each corner of the rectangle or polygon can be rounded.

In one embodiment of the invention, the semiconductor structure 12 includes the same structure as the light emitting stack 11 . For example, the semiconductor structure 12 includes a first semiconductor layer 111 , a second semiconductor layer 112 and an active layer 113 . The upper surface 12t of the semiconductor structure 12 includes a surface of the second semiconductor layer 112 .

The light emitting device 1 includes one or more grooves 120 surrounded by the second semiconductor layer 112 and/or the active layer 113 . One or more grooves 120 are made by removing part of the second semiconductor layer 112 and the active layer 113 to expose the surface 111t of the first semiconductor layer 111 . One or a plurality of grooves 120 are located in the light emitting stack 11 and each is surrounded by the second semiconductor layer 112 and the active layer 113 . The top-view shapes of one or more grooves 120 each include circle, ellipse, rectangle, polygon, or any shape. The plurality of grooves 120 may have the same or different top-view shapes. The plurality of grooves 120 can be arranged in a plurality of rows, and the grooves 120 on any two adjacent rows or every two adjacent rows can be aligned with each other or staggered. The number of the plurality of grooves 120 is not particularly limited. As shown in the top view of FIG. 1 , the plurality of grooves 120 can be arranged in a fixed pattern at fixed intervals, so that the current can be uniformly distributed along the horizontal direction.

The light emitting stack 11 includes a plurality of outer sidewalls S1 and a plurality of inner sidewalls S2 , wherein the outer sidewalls S1 and inner sidewalls S2 respectively include sidewalls of the first semiconductor layer 111 , the second semiconductor layer 112 and the active layer 113 . One end of the outer sidewall S1 is connected to a surface 112t of the second semiconductor layer 12 , and the other end of the outer sidewall S1 is connected to a surface 111t of the first semiconductor layer 111 . One end of the inner sidewall S2 is connected to the surface 112t of the second semiconductor layer 112 , and the other end of the inner sidewall S2 is connected to the surface 111t of the first semiconductor layer 11 . A plurality of inner sidewalls S2 form around one of the grooves 120 . A plurality of outer sidewalls S1 constitute a periphery of one of the light emitting stacks 11 . As shown in FIG. 4 and FIG. 5, there is a first angle between the outer sidewall S1 and the surface 111t of the first semiconductor layer 111, and there is a second angle between the inner sidewall S2 and the surface 111t of the first semiconductor layer 111. , wherein the angle difference between the first angle and the second angle is less than 20 degrees, preferably less than 14 degrees, more preferably less than 10 degrees. In one embodiment, the first angle includes an obtuse angle, an acute angle or a right angle, and the second angle includes an obtuse angle, an acute angle or a right angle.

The light emitting device 1 includes one or more current blocking layers 14 located on the second semiconductor layer 112 . The current blocking layer 14 is formed of non-conductive materials, including aluminum oxide (Al ₂ O ₃ ), silicon nitride (SiN _x ), silicon oxide (SiO _x ), titanium oxide (TiO _x ), or magnesium fluoride (MgF _x ). The current blocking layer 14 may include a distributed Bragg reflector (DBR) in which insulating materials having different refractive indices are stacked on each other. The current blocking layer 14 has a light transmittance of more than 80% or a light reflectance of more than 80% for the light emitted by the active layer 113 . As shown in FIG. 4 and FIG. 5 , the current blocking layer 14 has an inclined side surface to reduce the risk of delamination from the second semiconductor layer 112 and increase the coverage of subsequent stacked layers.

The light emitting device 1 includes a transparent conductive layer 16 located on the second semiconductor layer 112 and the current blocking layer 14 , and the transparent conductive layer 16 covers a sidewall of the current blocking layer 14 . The surface profile of the transparent conductive layer 16 covering the current blocking layer 14 corresponds to the profile of the current blocking layer 14 . The transparent conductive layer 16 has a stepped outline rather than a flat outline when viewed from a cross section. The material of the transparent conductive layer 16 includes a material transparent to the light emitted by the active layer 113 , such as indium tin oxide (ITO) or indium zinc oxide (IZO). Since the transparent conductive layer 16 is formed on substantially the entire surface of the second semiconductor layer 112 and forms a low-resistance contact with the second semiconductor layer 112, such as an ohmic contact, current can be uniformly diffused through the second semiconductor layer 16 through the transparent conductive layer 112. Layer 112. In one embodiment, the transparent conductive layer 16 includes an outermost side, which is separated from the outer sidewall S1 or the inner sidewall S2 of the light emitting stack 11 by a distance of less than 20 μm, preferably less than 10 μm, more preferably less than 5 μm.

The thickness of the transparent conductive layer 16 may range from 0.1 nm to 100 nm. If the thickness of the transparent conductive layer 16 is less than 0.1 nm, the ohmic contact with the second semiconductor layer 112 cannot be effectively formed because the thickness is too thin. Moreover, if the thickness of the transparent conductive layer 16 is greater than 100 nm, the light emitted by the active layer 113 will be partially absorbed due to the thickness being too thick, thereby causing the problem that the brightness of the light emitting element 1 is reduced.

The light emitting element 1 includes one or a plurality of first contact electrodes 18 located on the first semiconductor layer 111 to be electrically connected to the first semiconductor layer 111, and one or a plurality of second contact electrodes 19 located on the second semiconductor layer 112 to be electrically connected to the second semiconductor layer 112. As shown in FIG. 1 , viewed from a top view of the light emitting device 1 , the first contact electrode 18 includes a first contact electrode pad 18 a and/or a first contact electrode extension 18 b. In this embodiment, the top view shape of the first contact electrode pad 18a includes circle or ellipse, and the top view shape of the first contact electrode extension portion 18b includes strip shape, rectangle shape or polygon shape. The first contact electrode pad 18 a and the first contact electrode extension 18 b include the same stacked structure and thickness.

As shown in FIG. 1 , viewed from a top view of the light emitting element 1 , the second contact electrode 19 includes a second contact electrode pad 19 a and/or a second contact electrode extension 19 b. In this embodiment, the top view shape of the second contact electrode pad 19a includes circle or ellipse, and the top view shape of the second contact electrode extensions 19b 19b includes strip shape, rectangle shape or polygon shape. The second contact electrode pad 19 a and the second contact electrode extension 19 b include the same stacked structure and thickness.

As shown in FIG. 1 , viewed from a top view of the light-emitting element 1 , one or a plurality of first contact electrodes 18 are respectively located in one or a plurality of grooves 120 and are in contact with the first semiconductor layer 111 . The plurality of first contact electrodes 18 are separated from each other, and the first contact electrodes 18 and the groove 120 have the same shape. In order to allow the current to diffuse uniformly through the second semiconductor layer 112 , the position of the second contact electrode 19 is overlapped with the position of the current blocking layer 14 . In an embodiment of the invention, the second contact electrode 19 is located on the current blocking layer 14 and the transparent conductive layer 16 and is in contact with the transparent conductive layer 16 . In one embodiment of the invention, the transparent conductive layer 16 has an opening (not shown) corresponding to the second contact electrode pad 19a, and the second contact electrode pad 19a communicates with the current blocking layer 14 and the second semiconductor layer through the opening. 112 contacts. In one embodiment of the invention, the second contact electrode 19 and the current blocking layer 14 have similar shapes; in another embodiment of the invention, the second contact electrode 19 and the current blocking layer 14 have dissimilar shapes. In one embodiment of the invention, as shown in FIG. 1 , viewed from the top of one of the light emitting elements 1 , the current blocking layer 14 has an area larger than that of the second contact electrode 19 . In another embodiment, the second contact electrode pad 19a and the corresponding current blocking layer 14 below have dissimilar shapes, for example, the second contact electrode pad 19a is circular, and the current blocking layer 14 below it is rectangular. In another embodiment, the second contact electrode pad 19a and the corresponding current blocking layer 14 below it have a similar shape, for example, the second contact electrode pad 19a and the current blocking layer 14 below it are circular, but the second contact electrode pad 19a The center of the circle of the pad 19a and the center of the circle of the current blocking layer 14 below it do not overlap each other. Alternatively, the second contact electrode pad 19a is circular, the current blocking layer 14 below it is rectangular, and the distance between the second contact electrode pad 19a and the current blocking layer 14 below is not equidistant. In another embodiment, the current blocking layer 14 located below the second contact electrode pad 19a includes a plurality of current blocking regions separated from each other, and the transparent conductive layer 16 has an opening at the position below the second contact electrode pad 19a, so that part The second contact electrode pad 19a directly contacts the second semiconductor layer 112 through the opening and the gap between the separated current blocking regions; of course, in one embodiment, the position of the transparent conductive layer 16 below the second contact electrode pad 19a can be Having no opening, the second contact electrode pad 19 a directly contacts the transparent conductive layer 16 .

In another embodiment of the invention, as shown in FIG. 1 , the light emitting device 1 includes one or more first current blocking layers 13 located between the first semiconductor layer 111 and the first contact electrode 18 . The plurality of first current blocking layers 13 are separated from each other by a distance, wherein the distance can be a fixed value. The distance between the two adjacent plural first current blocking layers 13 closer to the first contact electrode pad 18a is farther away from the distance between the two adjacent plural first current blocking layers 13 of the first contact electrode pad 18a long or short distance. The number of the plurality of first current blocking layers 13 may increase as the length of the first contact electrode 18 increases. When the first current blocking layer 13 is formed of a non-conductive material, including aluminum oxide (Al ₂ O ₃ ), silicon nitride (SiN _x ), silicon oxide (SiO _x ), titanium oxide (TiO _x ), or fluoride Magnesium ( _MgFx ). The first current blocking layer 13 may include a distributed Bragg reflector (DBR) in which insulating materials having different refractive indices are stacked on each other. The first current blocking layer 13 has a light transmittance of more than 80% or a light reflectance of more than 80% for the light emitted by the active layer 113 . The first current blocking layer 13 has an inclined side surface to reduce the risk of delamination from the first semiconductor layer 111 and increase the coverage of subsequent stacked layers. In one embodiment of the invention, the width of the plurality of first current blocking layers 13 is greater than the width of the first contact electrode 18 . In one embodiment of the invention, the area of the first current blocking layer 13 located under the first contact electrode pad 18a is larger or smaller than the area of the first contact electrode pad 18a. In one embodiment of the invention, there is no first current blocking layer 13 between the first contact electrode 18 and the first semiconductor layer 111 . In an embodiment of the invention, a transparent conductive layer (not shown) may be included between the first contact electrode 18 and the first semiconductor layer 111 or the first current blocking layer 13 .

As shown in FIG. 4 and FIG. 5 , the transparent conductive layer 16 includes a part located between the current blocking layer 14 and the second contact electrode 19 ; and another part directly contacting the second semiconductor layer 12 . When the current passes through the second contact electrode 19, because the current blocking layer 14 is located below the second contact electrode 19, the current cannot pass through the current blocking layer 14, and is directly conducted downward from the second contact electrode to the second semiconductor layer 12, so the current will After being forced to flow to the transparent conductive layer 16 , the current spreads in the horizontal direction through the transparent conductive layer 16 and conducts the current to the second semiconductor layer 112 .

The first contact electrode 18 and the second contact electrode 19 respectively have an inclined side surface to reduce the risk of delamination from the transparent conductive layer 16 or the first semiconductor layer 111 and increase the coverage of subsequent stacked layers. In one embodiment, the inclined side surface of the first contact electrode 18 and the surface of the first semiconductor layer 111 have an inner angle between 30 degrees and 75 degrees. There is an inner angle between the inclined side surface of the second contact electrode 19 and the surface of the transparent conductive layer 16 between 30 degrees and 75 degrees.

As shown in FIG. 1 , viewed from a top view of the light emitting element 1 , the second contact electrodes 19 are located on the left and right sides of the first contact electrodes 18 .

As shown in FIG. 1, in one embodiment, viewed from a top view of the light-emitting element 1, the first contact electrode pad 18a and the second contact electrode pad 19a include different diameters for identification of different electrical properties .

The first contact electrode 18 and the second contact electrode 19 include metal materials such as chromium (Cr), titanium (Ti), tungsten (W), gold (Au), aluminum (Al), indium (In), tin (Sn) , nickel (Ni) or platinum (Pt) and other metals or alloys of the above materials. The first contact electrode 18 and the second contact electrode 19 can be composed of a single layer or multiple layers. For example, the first contact electrode 18 or the second contact electrode 19 may include Ti/Au layer, Ti/Pt/Au layer, Cr/Au layer, Cr/Pt/Au layer, Ni/Au layer, Ni/Pt/Au layer Or Cr/Al/Cr/Ni/Au layer.

The thickness of the first contact electrode 18 or the second contact electrode 19 is preferably 0.5 μm to 2.5 μm. In one embodiment, an upper surface of the first contact electrode 18 is lower than the surface 112t of the second semiconductor layer 112 , in other words, the thickness of the first contact electrode 18 is smaller than the depth of the groove 120 . In another embodiment, an upper surface of the first contact electrode 18 protrudes from the surface 112t of the second semiconductor layer 112 , in other words, the thickness of the first contact electrode 18 is greater than the depth of the groove 120 . If the thickness of the first contact electrode 18 or the second contact electrode 19 is less than 0.5 μm, current cannot be efficiently conducted. In addition, if the thickness of the first contact electrode 18 or the second contact electrode 19 is greater than 2.5 μm, excessive production time will result in loss in production.

The light emitting device 1 includes a Bragg reflector (DBR) 20 covering the light emitting stack 11 , the transparent conductive layer 16 , the first contact electrode 18 and the second contact electrode 19 . The Bragg reflector (DBR) 20 includes one or a plurality of first openings 201 located on the first contact electrode pad 18a, and exposes a surface of the first contact electrode pad 18a, wherein the first contact electrode extension 18b is a Bragg reflector ( DBR) 20 full coverage. The Bragg reflector (DBR) 20 further includes one or a plurality of second openings 202 located on the second contact electrode pad 19a of the second contact electrode 19, and exposing a surface of the second contact electrode pad 19a, wherein the second contact electrode extends Portion 19b is completely covered by Bragg reflector (DBR) 20 .

In one embodiment of the invention, as shown in the top view of FIG. 1 , the first opening 201 of the Bragg reflector (DBR) 20 includes a first opening diameter smaller than that of the first contact electrode pad 18a. The second opening 202 of the Bragg reflector (DBR) 20 includes a second opening diameter smaller than that of the second contact electrode pad 19a.

In one embodiment of the invention, as shown in the top view of FIG. 1 , one of the plurality of first openings 201 of the Bragg reflector (DBR) 20 is smaller than the plurality of second openings 202 of the Bragg reflector (DBR) 20 one number.

As shown in the side views of FIGS. 4 to 5, a Bragg reflector (DBR) 20 covers the light-emitting stack 11 and the semiconductor structure 12, and reflects light from the active layer 113 of the light-emitting stack 11 to one direction of the substrate 10. . The Bragg reflector 20 includes two or more dielectric materials with different refractive indices stacked alternately. The dielectric material includes aluminum oxide (Al ₂ O ₃ ), silicon nitride (SiN _x ), silicon oxide (SiO _x ), titanium oxide (TiO _x ), or magnesium fluoride (MgF _x ). For example, an insulating reflective layer with high reflectivity can be formed by laminating layers such as SiO ₂ /TiO ₂ or SiO ₂ /Nb ₂ O ₅ . When the wavelength of light emitted by the light emitting element 1 is λ, the optical thickness of the Bragg reflector 20 can be set to be an integer multiple of λ/4. The optical thickness of the Bragg mirror 20 may have a deviation of ±30% on the basis of integer multiples of λ/4. In one embodiment, the Bragg reflector 20 includes one or more die stacks, each die stack includes a plurality of dielectric layer pairs, and each dielectric layer pair includes a first dielectric layer and a second dielectric layer . Wherein, the ratio of the first optical thickness of the first dielectric layer and the second optical thickness of the second dielectric layer to the central wavelength λ ^' of the visible light band (400nm ~ 700nm), such as 550nm, can be greater than 1/4, less than 1/4 or one layer is larger than 1/4 and the other layer is smaller than 1/4.

The Bragg reflector 20 includes a non-conductive material, which can be deposited by physical evaporation (PVD; Physical Vapor Deposition), electron beam evaporation (E-Beam Evaporation), sputtering (Sputtering) or thermal evaporation (Thermal Evaporation) ) to form. Before forming the Bragg reflector 20 , it is preferable to form a dielectric layer (not shown) with a certain thickness, so that the Bragg reflector 20 can be stably formed, and it is also beneficial to light reflection. The material of the dielectric layer (not shown in the figure) is preferably SiO ₂ , and its thickness may be, for example, 0.2 μm˜1 μm. The overall thickness of the Bragg mirror 20 may be 1˜8 μm. In an embodiment of the invention, after forming the Bragg reflector 20, another dielectric layer (not shown) with a certain thickness can be formed to facilitate light extraction.

In one embodiment of the invention, as shown in the scanning electron microscope (SEM) figure of FIG. 3 and the cross-sectional view of FIG. and a second thickness T2 located below the surface 112t of the second semiconductor layer 12, wherein the first thickness T1 is greater than the second thickness T2. For example, the first thickness T1 is greater than 2 μm, preferably greater than 3 μm, more preferably greater than 4 μm, and the second thickness T2 is less than 2 μm.

As shown in the top view of FIG. 1, the cross-sectional views of FIG. 4 and FIG. 5, because the bottom of the Bragg reflector (DBR) 20 is a stacked structure, for example, a light emitting stack 11, a current blocking layer 14, a transparent conductive layer 16. The structure of the first contact electrode 18 or the second contact electrode 19. Therefore, when the light-emitting element 1 undergoes cutting and splitting processes, the Bragg reflector (DBR) 20 is likely to be in the light-emitting element 1 due to these structures with height differences. A fracture surface S is formed around the . When the rupture surface S extends to the light-emitting stack 11 to expose the light-emitting stack 11 , the Bragg reflector (DBR) 20 loses the effect of protecting the light-emitting element 1 , and water vapor easily enters the interior of the light-emitting stack 11 through the rupture surface S. In one embodiment of the present invention, in order to prevent the fracture surface S from extending to the light-emitting stack 11, the light-emitting element 1 includes a semiconductor structure 12 located on the substrate 10, and a first semiconductor layer 111 is provided between the semiconductor structure 12 and the light-emitting stack 11 , the semiconductor structure 12 and the light emitting stack 11 are separated by a distance by the first semiconductor layer 111 , and the semiconductor structure 12 surrounds the light emitting stack 11 . As shown in FIG. 5, due to the film-forming properties of the Bragg reflector (DBR) 20, even if there is a cracked surface S around the light-emitting element 1, the cracked surface S will be as shown on the second side 202s of the Bragg reflector (DBR) 20. , stop at the corner of the semiconductor structure 12 or the first trench 110 .

In one embodiment of the invention, as shown in the scanning electron microscope (SEM) figure of FIG. 3 and the cross-sectional view of FIG. There is an obtuse angle between 95 degrees and 140 degrees, preferably between 100 degrees and 130 degrees, more preferably between 100 degrees and 120 degrees.

In one embodiment of the invention, as shown in the scanning electron microscope (SEM) diagram of FIG. 3 and the cross-sectional diagrams of FIG. 4 and FIG. There is a first angle between 111t, there is a third angle between the inner surface 12ns of the semiconductor structure 12 and the surface 111t of the first semiconductor layer 111, and the first angle is greater than the third angle to avoid the Bragg reflector (DBR) 20 film Breakage of the layer, wherein the angle difference between the first angle and the third angle is less than 30 degrees, preferably less than 20 degrees, more preferably less than 10 degrees.

The light emitting device 1 includes a first electrode pad 21 covering one or a plurality of first openings 201 of a Bragg reflector (DBR) 20 , and contacts the first contact electrode pad 18a through the one or a plurality of first openings 201 . The light-emitting element 1 includes a second electrode pad 22 to cover one or a plurality of second openings 202 of one or a plurality of Bragg reflectors (DBR) 20, and to contact a second contact electrode through one or a plurality of second openings 202 Pad 19a. The first contact electrode pad 18 a and the second contact electrode pad 19 a are respectively electrically connected to the first semiconductor layer 111 and the second semiconductor layer 112 through the first contact electrode extension 18 b and the second contact electrode extension 19 b .

The upper surface of the first electrode pad 21 or the second electrode pad 22 may be non-planar. Specifically, the upper surface of the first electrode pad 21 or the second electrode pad 22 has a surface profile corresponding to the surface profile of the upper surface of the first contact electrode 18 and the upper surface of the second contact electrode 19 . In other words, the first electrode pad 21 or the second electrode pad 22 is disposed on the first contact electrode 18 and the second contact electrode 19, wherein the first contact electrode 18 and the second contact electrode 19 have a non-flat surface profile and thus have a long strip Shaped, rounded or stepped surfaces. As shown in Figures 4 and 5, the upper surface of the first electrode pad 21 or the second electrode pad 22 may include at least one concave portion and at least one protruding portion, which are respectively arranged on the first contact electrode 18 and the second contact electrode 18. In the area where the contact electrode 19 is placed. Accordingly, the upper surface of the first electrode pad 21 or the second electrode pad 22 may have a stepped surface.

From a top view of the light-emitting element 1, as shown in FIG. 1, one or a plurality of first contact electrode pads 18a are only covered by the first electrode pad 21, and one or a plurality of second contact electrode pads 19a are only covered by the first electrode pad 21. Covered by the second electrode pad 22 . One or more first contact electrode extensions 18b are covered by the second electrode pads 22 , and one or more second contact electrode extensions 19b are covered by the first electrode pads 21 and/or the second electrode pads 22 . In one embodiment, one or more first contact electrode extensions 18 b are covered by the first electrode pad 21 and the second electrode pad 22 . In one embodiment, one or more first contact electrode pads 18 a are not covered by the first electrode pads 21 , that is, the first electrode pads 21 are disposed away from the first contact electrode pads 18 a. In one embodiment, one or a plurality of first contact electrode extensions 18b are not covered by the first electrode pad 21 and/or the second electrode pad 22, that is, the first electrode pad 21 and/or the second electrode pad 22 It is provided avoiding the first contact electrode extension 18b. In one embodiment, one or more second contact electrode pads 19 a are not covered by the second electrode pads 22 , that is, the second electrode pads 22 are arranged to avoid the second contact electrode pads 19 a. In one embodiment, one or a plurality of second contact electrode extensions 19b are not covered by the first electrode pad 21 and/or the second electrode pad 22, that is, the first electrode pad 21 and/or the second electrode pad 22 The second contact electrode extension 19b is avoided.

The first electrode pad 21 and the second electrode pad 22 include metal materials such as chromium (Cr), titanium (Ti), tungsten (W), gold (Au), aluminum (Al), indium (In), tin (Sn) , nickel (Ni), platinum (Pt) and other metals or alloys of the above materials. The first electrode pad 21 and the second electrode pad 22 can be composed of a single layer or multiple layers. For example, the first electrode pad 21 or the second electrode pad 22 may include Ti/Au layer, Ti/Pt/Au layer, Cr/Au layer, Cr/Pt/Au layer, Ni/Au layer, Ni/Pt/Au layer Or Cr/Al/Cr/Ni/Au layer. The first electrode pad 21 and the second electrode pad 22 can be used as a current path for supplying power from an external power source to the first semiconductor layer 111 and the second semiconductor layer 112 .

In an embodiment of the present invention, the first electrode pad 21 includes a dimension that is the same as or different from that of the second electrode pad 22 , and the dimension may be a width or an area. For example, the top view area of the first electrode pad 21 or the second electrode pad 22 may be 0.8 times or more and less than 1 time the value obtained by adding the top view areas of the first electrode pad 21 and the second electrode pad 22 .

The first electrode pad 21 or the second electrode pad 22 respectively includes an inclined side surface, so the cross-sectional area of the first electrode pad 21 or the second electrode pad 22 can change along the thickness direction. For example, the side view cross-sectional area of the first electrode pad 21 or the second electrode pad 22 may gradually become smaller along the direction away from the upper surface of the light emitting stack 11 .

There is a gap between the first electrode pad 21 and the second electrode pad 22, and the gap includes a shortest distance of about 10 μm or more and a longest distance of about 250 μm or less. Within the above range, by reducing the distance between the first electrode pad 21 and the second electrode pad 22, the top view area of the first electrode pad 21 and the second electrode pad 22 can be increased, thereby improving the heat dissipation of the light emitting element 1. efficiency and avoid short circuit between the first electrode pad 21 and the second electrode pad 22 .

The first electrode pad 21 and the second electrode pad 22 have a thickness between 1-100 μm, preferably between 1.5-6 μm.

FIG. 6 is a top view of a light emitting element 2 disclosed in another embodiment of the present invention. Fig. 7 is a sectional view along the tangent line C-C' of Fig. 6. The light emitting element 2 disclosed in the embodiment is a light emitting diode with flip chip structure. The light-emitting element 2 and the light-emitting element 1 include the same or similar components, wherein the same or similar components will be described below with the same reference numerals in FIGS. 6-7 .

As shown in the top view of FIG. 6 and the cross-sectional view of FIG. 7, the light-emitting element 2 includes a substrate 10 including sidewalls 10s; a light-emitting stack 11 includes a plurality of outer sidewalls S1 on the substrate 10, and the light-emitting stack 11 includes A first semiconductor layer 111, a second semiconductor layer 112, and an active layer 113 are located between the first semiconductor layer 111 and the second semiconductor layer 112; a semiconductor structure 12 is located on the substrate 10, by the first semiconductor layer 111 A distance from the light-emitting stack 11 and surrounding multiple sides of the light-emitting stack 11; a first groove 110 is located on the substrate 10, exposing the first semiconductor layer 111, and is located between the light-emitting stack 11 and the semiconductor structure 12; A second trench 1101 is located on the substrate 10, exposing the first semiconductor layer 111, separated by a distance from the first trench 110 by the semiconductor structure 12 and surrounding a plurality of sides of the semiconductor structure 12; and a Bragg reflector 20 covering the light emitting A stack 11 and a semiconductor structure 12, wherein the semiconductor structure 12 includes a distance between one side surface 12s and the side wall 10s of the substrate 10, an inner side surface 12ns opposite to the side surface 12s, and a side surface 12s and the inner side surface 12ns directly Contacting the upper surface 12t, the Bragg reflector 20 includes a first side 201s directly connected to the side 111s of the first semiconductor layer 111 and a second side 202s directly connected to the side surface 12s of the semiconductor structure 12 .

In one embodiment of the invention, the second side 202s of the Bragg mirror 20 is directly connected to the inner surface 12ns of the semiconductor structure 12 .

As shown in the top view of FIG. 6, the light-emitting element 2 includes a first trench 110 and a second trench 1101 on the first semiconductor layer 111, and surrounds a plurality of sides of the light-emitting stack 11, wherein the semiconductor structure 12 is located on the first semiconductor layer 111. Between the first groove 110 and the second groove 1101 , and surround multiple sides of the light emitting stack 11 . As shown in the cross-sectional view of FIG. 7 , the semiconductor structure 12 is located on the substrate, and the semiconductor structure 12 is isolated from the light emitting stack 11 by the first trench 110 . The first trench 110 includes a minimum width D between 1 μm˜30 μm, preferably between 2 μm˜14 μm, more preferably between 5 μm˜10 μm. The first trench 110 is formed by removing part of the second semiconductor layer 112 and the active layer 113 , and the first trench 110 exposes part of the first semiconductor layer 111 . The top view shape of the first trench 110 includes a rectangular ring, a polygonal ring, a circular ring, an elliptical ring or an irregular ring, wherein each corner of the rectangle or polygon can be rounded.

As shown in the cross-sectional view of FIG. 7, the second trench 1101 includes a minimum width D1 between 1 μm~80 μm, preferably between 2 μm~50 μm, more preferably between 5 μm~20 μm between. The second trench 1101 is formed by removing part of the second semiconductor layer 112 and the active layer 113 , and the second trench 1101 exposes part of the first semiconductor layer 111 . The top-view shape of the second groove 1101 includes a rectangle or a polygon ring, wherein each corner of the rectangle or polygon can be rounded.

In one embodiment of the invention, the semiconductor structure 12 includes the same structure as the light emitting stack 11 . For example, the semiconductor structure 12 includes a first semiconductor layer 111 , a second semiconductor layer 112 and an active layer 113 . The upper surface 12t of the semiconductor structure 12 includes a surface of the second semiconductor layer 112 .

As shown in the top view of FIG. 6 and the cross-sectional view of FIG. 7, because the Bragg reflector (DBR) 20 is a stacked structure, for example, a light emitting stack 11, a current blocking layer 14, a transparent conductive layer 16, a first contact Electrode 18 or second contact electrode 19 and other structures, so when the light emitting element 2 undergoes cutting and splitting processes, the Bragg reflector (DBR) 20 is likely to form a fracture surface S around the light emitting element 2 due to these structures with height differences . When the rupture surface S extends to the light-emitting stack 11 to expose the light-emitting stack 11 , the Bragg reflector (DBR) 20 loses the effect of protecting the light-emitting element 2 , and water vapor easily enters the interior of the light-emitting stack 11 through the rupture surface S. In one embodiment of the present invention, in order to prevent the rupture surface S from extending to the light emitting stack 11, the light emitting element 2 includes a semiconductor structure 12 located on the substrate 10, and a first trench 110 is provided between the semiconductor structure 12 and the light emitting stack 11 The exposed first semiconductor layer 111 , the first semiconductor layer 111 exposed by the first trench 110 separates the semiconductor structure 12 from the light emitting stack 11 by a distance, and the semiconductor structure 12 surrounds the light emitting stack 11 . As shown in FIG. 6, because of the film-forming properties of the Bragg reflector (DBR) 20, even if there is a cracked surface S around the light-emitting element 2, the cracked surface S will be as shown on the second side 202s of the Bragg reflector (DBR) 20. , stop at the corner of the semiconductor structure 12 , the first trench 110 or the second trench 1101 .

In one embodiment of the invention, the second side 202s of the Bragg reflector (DBR) 20 is directly connected to the side surface 12s of the semiconductor structure 12 as shown in the cross-sectional view of FIG. In other words, a first acute angle is included between the second side surface 202s and the upper surface 12t of the semiconductor structure 12, and a first obtuse angle is included between the side surface 12s and the upper surface 12t of the semiconductor structure 12, wherein the first acute angle and the first obtuse angle are complementary. For example, the first acute angle is between 20 degrees and 85 degrees, and the first obtuse angle is between 95 degrees and 160 degrees.

In one embodiment of the invention, when the second side 202s of the Bragg reflector 20 is directly connected with the inner surface 12ns of the semiconductor structure 12, the second side 202s of the Bragg reflector (DBR) 20 and the inner surface of the semiconductor structure 12 The interval between 12 ns includes an obtuse angle between 95 degrees to 140 degrees, preferably between 100 degrees to 130 degrees, more preferably between 100 degrees to 120 degrees.

In one embodiment of the present invention, the light emitting device 2 includes a plurality of semiconductor structures 12 located around one of the light emitting device 1 to surround the light emitting stack 11 (not shown). The plurality of semiconductor structures 12 are separated from the light emitting stack 11 by the first trench 110 , and two adjacent semiconductor structures 12 are separated from each other by the third trench (not shown). A plurality of semiconductor structures 12 and a plurality of third grooves (not shown) are alternately arranged to increase the adhesion between the Bragg reflector (DBR) 20 and the light-emitting stack 11 and/or the semiconductor structure 12, avoiding the Bragg reflector The (DBR) 20 is peeled off from the surface of the light emitting stack 11 and/or the semiconductor structure 12 .

Each of the first groove 110 and the third groove includes a minimum width D between 1 μm˜30 μm, preferably between 2 μm˜14 μm, more preferably between 5 μm˜10 μm. The first trench 110 and the third trench are formed by removing part of the second semiconductor layer 112 and the active layer 113 , and the first trench 110 and the third trench expose part of the first semiconductor layer 111 . The top view shapes of the first trench 110 and the third trench include a rectangle or a polygon ring, wherein each corner of the rectangle or polygon can be rounded.

In one embodiment of the present invention, the light-emitting element 2 further includes a second trench 1101 located at the outermost edge of the light-emitting element 2 to surround the light-emitting stack 11, the plurality of semiconductor structures 12, and the first trench 1101 between the plurality of semiconductor structures 12. Three grooves (not shown).

The plurality of third trenches (not shown) for separating the plurality of semiconductor structures 12 include the same or different minimum width D. As shown in FIG. In an embodiment of the invention, the minimum width D of the third trench gradually increases from the light emitting stack 11 to the semiconductor structure 12 . In another embodiment of the invention, the minimum width D of the third trench gradually decreases from the light emitting stack 11 to the semiconductor structure 12 .

In one embodiment of the invention, the light-emitting element 1 or the light-emitting element 2 further includes a cutting line (not shown) located on the outermost side of the light-emitting element 1 or the light-emitting element 2 . Viewed from one of the light emitting element 1 or the light emitting element 2 , the dicing line surrounds the light emitting stack 11 , the semiconductor structure 12 and the first trench 110 . The dicing line is to expose an upper surface of the substrate 10 by removing the first semiconductor layer 11 , the second semiconductor layer 12 and the active layer 13 . The top-view shape of the cutting line includes a rectangle or a polygon ring. In one embodiment, the top surface of the substrate 10 exposed by the cutting line is a rough surface. The rough surface may be a surface with an irregular shape or a surface with a regular shape, such as a surface with multiple hemispherical shapes, a surface with multiple conical shapes, or a surface with multiple polygonal cone shapes.

Fig. 8 is a schematic diagram of a light emitting device 3 according to an embodiment of the present invention. The light-emitting element 1 or light-emitting element 2 in the foregoing embodiments is mounted on the first pad 511 and the second pad 512 of the package substrate 51 in the form of flip chip. The first spacer 511 and the second spacer 512 are electrically insulated by an insulating portion 53 including insulating material. In flip-chip mounting, the side of the growth substrate opposite to the surface where the electrode pads are formed is set upward as the main light extraction surface. In order to increase the light extraction efficiency of the light emitting device 3 , a reflective structure 54 can be provided around the light emitting element 1 or the light emitting element 2 .

FIG. 9 is a schematic diagram of a light emitting device 4 according to an embodiment of the present invention. The light emitting device 4 is a bulb lamp including a lampshade 602 , a reflector 604 , a light emitting module 610 , a lamp holder 612 , a heat sink 614 , a connecting portion 616 and an electrical connecting element 618 . The light emitting module 610 includes a carrying portion 606 and a plurality of light emitting units 608 located on the carrying portion 606 , wherein the plurality of light emitting units 608 can be the light emitting element 1 , the light emitting element 2 or the light emitting device 3 in the foregoing embodiments.

The various embodiments listed in the present invention are only used to illustrate the present invention, and are not intended to limit the scope of the present invention. Any obvious modifications or changes made by anyone to the present invention will not depart from the spirit and scope of the present invention.

1, 2: Light emitting element 3, 4: Lighting device 10: Substrate 10s: side wall 11: Luminous Lamination 110: the first groove 1101: the second groove 111: the first semiconductor layer 111s: the side of the first semiconductor layer 111t: the surface of the first semiconductor layer 112: the second semiconductor layer 112t: the surface of the second semiconductor layer 113: active layer 12:Semiconductor structure 12t: upper surface 12s: side surface 12ns: inner surface 120: Groove 13: The first current blocking layer 14: Current blocking layer 16: Transparent conductive layer 18: First contact electrode 18a: first contact electrode pad 18b: first contact electrode extension 19: The second contact electrode 19a: Second contact electrode pad 19b: second contact electrode extension 20: Bragg reflector (DBR) 201: first opening 201s: First Side 202: second opening 202s: second side 21: The first electrode pad 22: Second electrode pad D: minimum width D1: minimum width S: rupture surface S1: Outer wall S2: Medial wall T1: first thickness T2: second thickness 51: Package substrate 511: The first gasket 512: second gasket 53: Insulation part 54: Reflection structure 602: lampshade 604: Mirror 606: bearing part 608: Lighting unit 610: Lighting module 612: lamp holder 614: heat sink 616: connection part 618: Electrical connection components

FIG. 1 is a top view of a light emitting element 1 disclosed in an embodiment of the present invention.

Figure 2 is an enlarged view of the lower left part of Figure 1.

Fig. 3 is a scanning electron microscope (SEM) perspective view of Fig. 2 .

Figure 4 is a sectional view along the tangent line A-A' of Figure 1.

Fig. 5 is a sectional view along the tangent line B-B' of Fig. 1.

FIG. 6 is a top view of a light emitting element 2 disclosed in an embodiment of the present invention.

Fig. 7 is a sectional view along the tangent line C-C' of Fig. 6.

Fig. 8 is a schematic diagram of a light emitting device 3 according to an embodiment of the present invention.

FIG. 9 is a schematic diagram of a light emitting device 4 according to an embodiment of the present invention. .

none

1: Light emitting element

10: Substrate

10s: side wall

11: Luminous Lamination

110: the first groove

111: the first semiconductor layer

111t: the surface of the first semiconductor layer

112: the second semiconductor layer

112t: the surface of the second semiconductor layer

113: active layer

12:Semiconductor structure

12t: upper surface

12s: side surface

12ns: inner surface

120: Groove

13: The first current blocking layer

14: Current blocking layer

16: Transparent conductive layer

18: First contact electrode

19: The second contact electrode

20: Bragg reflector (DBR)

201: first opening

201s: First Side

202: second opening

202s: second side

21: The first electrode pad

22: Second electrode pad

S1: Outer wall

S2: Medial wall

Claims (10)

A light-emitting element, comprising: a substrate; a light-emitting stacked layer located on the substrate, the light-emitting stacked layer comprising a first semiconductor layer, a second semiconductor layer, and an active layer located on the first semiconductor layer and the second semiconductor layer between the layers, and the second semiconductor layer includes an upper surface; a first trench surrounds the light emitting stack and exposes a surface of the first semiconductor layer, wherein the top view shape of the first trench includes a rectangular ring shape, polygonal ring, circular ring, elliptical ring or irregular ring, and the first groove includes a minimum width D between 1 μ m ~ 5 μ m; and a Bragg mirror covering The light-emitting stack and the first trench, wherein the Bragg reflector includes a thickness on the light-emitting stack, and the Bragg reflector on the first trench includes a first thickness on the second semiconductor layer. above the upper surface and under the upper surface of the second semiconductor layer, wherein the thickness is greater than the first thickness, the thickness is greater than the second thickness, and the second thickness is less than 2 μm. The light-emitting element described in claim 1, wherein the first thickness is greater than 2 μm. The light-emitting element as described in item 1 of the patent scope of the application, comprising a first contact electrode pad contacting the first semiconductor layer and electrically connected to the first semiconductor layer; and a second contact electrode pad located on the second semiconductor layer To be electrically connected to the second semiconductor layer, wherein an upper surface of the first contact electrode pad is lower than the upper surface of the second semiconductor layer. The light-emitting element as described in item 1 of the patent scope of the application, comprising a first contact electrode pad contacting the first semiconductor layer and electrically connected to the first semiconductor layer; and a second contact electrode pad located at The second semiconductor layer is electrically connected to the second semiconductor layer, wherein an upper surface of the first contact electrode pad protrudes from the upper surface of the second semiconductor layer. The light-emitting element as described in item 3 or item 4 of the scope of the patent application, wherein the Bragg reflector includes a first opening exposing the first contact electrode pad and a second opening exposing the second contact electrode pad, the first The opening includes a first opening diameter smaller than a diameter of the first contact electrode pad, and the second opening includes a second opening diameter smaller than a diameter of the second contact electrode pad. The light-emitting element as described in item 1 of the scope of the patent application, wherein the overall thickness of the Bragg reflector can be 1-8 μm. The light-emitting element described in item 1 of the scope of the patent application includes a dielectric layer comprising SiO ₂ located under the Bragg reflector, and has a thickness between 0.2 μm and 1 μm. The light-emitting element as described in item 3 or item 4 of the scope of the patent application, comprising a current blocking layer located under the second contact electrode pad, wherein the current blocking layer includes a circle center and a circle center of the second contact electrode pad do not overlap each other. The light-emitting element as described in item 5 of the scope of the patent application includes a first electrode pad and a second electrode pad covering the first opening and the second opening respectively, wherein the first electrode pad and the second electrode pad are respectively It includes a concave part and a protruding part. The light-emitting device as described in claim 9 of the patent claims, wherein there is an interval between the first electrode pad and the second electrode pad that is more than 10 μm.

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