Light-emitting components

Abstract

The present invention discloses a light-emitting element, which comprises a substrate including a side wall; a light-emitting stack located on the substrate, the light-emitting stack comprising a first semiconductor layer, an active layer and a second semiconductor layer; a semiconductor structure located on the substrate, separated from the light-emitting stack by a distance through the first semiconductor layer and surrounding the light-emitting stack; and a Bragg reflector covering the light-emitting stack and the semiconductor structure, wherein the semiconductor structure comprises a side surface directly connected to the side wall of the substrate, and an upper surface directly connected to the side surface, the upper surface comprising an upper surface of the second semiconductor layer, and the 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 upper surface of the semiconductor structure.

Description

Technical Field

[0001] The present invention relates to a light emitting element, and more particularly to a light emitting element comprising 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. Background Art

[0002] Light-Emitting Diode (LED) is a solid-state semiconductor light-emitting element with the advantages of low power consumption, low heat generation, long service life, shock resistance, small size, fast response speed and good photoelectric properties, such as stable light emission wavelength. Therefore, LEDs are widely used in household appliances, equipment indicator lights, and optoelectronic products. Summary of the invention

[0003] The present invention discloses a light-emitting element, which comprises a substrate comprising a side wall; a light-emitting stack comprising a plurality of outer side walls located on the substrate, the light-emitting stack comprising a first semiconductor layer, an active layer and a second semiconductor layer; a semiconductor structure located on the substrate, the plurality of outer side walls being separated from the light-emitting stack by the first semiconductor layer and surrounding the light-emitting stack; and a Bragg reflector covering the light-emitting stack and the semiconductor structure, wherein the semiconductor structure comprises a side surface directly connected to the side wall of the substrate, and an upper surface directly connected to the side surface of the semiconductor structure, the upper surface comprising a surface of the second semiconductor layer, and the 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 upper surface of the semiconductor structure.

[0004] The present invention discloses a light-emitting element, which comprises a substrate comprising a side wall; a light-emitting stack comprising a plurality of outer side walls located on the substrate, the light-emitting stack comprising a first semiconductor layer, an active layer and a second semiconductor layer; a semiconductor structure located on the substrate, separated from the light-emitting stack by a distance through the first semiconductor layer and surrounding the plurality of outer side walls of the light-emitting stack; a first groove located on the substrate, exposing the first semiconductor layer, and located between the light-emitting stack and the semiconductor structure, the first semiconductor layer exposed by the first groove separates the semiconductor structure from the light-emitting stack by a distance, and the semiconductor structure surrounds the light-emitting stack; a second groove located on the first semiconductor layer, separated from the first groove by a distance through the semiconductor structure and surrounding the plurality of side surfaces of the semiconductor structure; and a Bragg reflector covering the light-emitting stack and the semiconductor structure, wherein the semiconductor structure comprises a side surface separated from the side wall of the substrate by a distance, and an upper surface directly connected to the side surface of the semiconductor structure, the upper surface comprises a surface of the second semiconductor layer, and the Bragg reflector comprises a first side surface directly connected to or separated from the side surface of the semiconductor structure by a distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 It is a top view of a light emitting element 1 disclosed in one embodiment of the present invention;

[0006] Figure 2 for Figure 1 A magnified image of the lower left part;

[0007] Figure 3 for Figure 2 Scanning electron microscope (SEM) stereogram;

[0008] Figure 4 For along Figure 1 A cross-sectional view of the tangent line A-A';

[0009] Figure 5 For along Figure 1 A cross-sectional view of the tangent line B-B';

[0010] Figure 6 It is a top view of a light emitting element 2 disclosed in an embodiment of the present invention;

[0011] Figure 7 For along Figure 6 A cross-sectional view of the tangent line C-C';

[0012] Figure 8 is a schematic diagram of a light emitting device 3 according to an embodiment of the present invention;

[0013] Fig. 9 FIG. 4 is a schematic diagram of a light emitting device 4 according to an embodiment of the present invention.

[0014] Explanation of symbols

[0015] 1 Light-emitting element

[0016] 2 Light-emitting element

[0017] 3 Lighting device

[0018] 4 Lighting device

[0019] 10 substrate

[0020] 10s side wall

[0021] 11 Luminous Overlays

[0022] 110 First Groove

[0023] 1101 Second Groove

[0024] 111 First semiconductor layer

[0025] 111s Side view of the first semiconductor layer

[0026] 111t Surface of the first semiconductor layer

[0027] 112 Second semiconductor layer

[0028] 112t Surface of the second semiconductor layer

[0029] 113 Active layer

[0030] 12 Semiconductor Structure

[0031] 12t Upper surface

[0032] 12s side surface

[0033] 12ns inner surface

[0034] 120 grooves

[0035] 13. First current blocking layer

[0036] 14 Current blocking layer

[0037] 16 Transparent conductive layer

[0038] 18. First contact electrode

[0039] 18a First contact electrode pad

[0040] 18b First contact electrode extension

[0041] 19 Second contact electrode

[0042] 19a Second contact electrode pad

[0043] 19b Second contact electrode extension

[0044] 20. Deflector Bragg Reflector (DBR)

[0045] 201 First Opening

[0046] 201s First side

[0047] 202 Second Opening

[0048] 202s Second side

[0049] 21. First electrode pad

[0050] 22. Second electrode pad

[0051] D Minimum width

[0052] D1 minimum width

[0053] S fracture surface

[0054] S1 lateral wall

[0055] S2 inner wall

[0056] T1 First thickness

[0057] T2 Second thickness

[0058] 51 Package substrate

[0059] 511 First Gasket

[0060] 512 Second gasket

[0061] 53 Insulation

[0062] 54 Reflection Structure

[0063] 602 Lampshade

[0064] 604 Reflector

[0065] 606 bearing part

[0066] 608 Lighting Unit

[0067] 610 Light emitting module

[0068] 612 Lamp Holder

[0069] 614 Heat sink

[0070] 616 Connection

[0071] 618 Electrical connection components DETAILED DESCRIPTION

[0072] In order to make the description of the present invention more detailed and complete, please refer to the description of the following embodiments and the relevant illustrations. The embodiments shown below are used to illustrate the light-emitting elements of the present invention, and the present invention is not limited to the following embodiments. In addition, the dimensions, materials, shapes, relative configurations, etc. of the constituent parts recorded in the embodiments of this specification are not limited to this, but are simply illustrated. The size or positional relationship of the components shown in each figure may be exaggerated for the purpose of clear description. Moreover, in the following description, in order to appropriately omit detailed description, the same or similar components are displayed with the same name or symbol.

[0073] Figure 1 It is a top view of a light emitting element 1 disclosed in an embodiment of the present invention. Figure 2 for Figure 1 Enlarged view of the lower left portion. Figure 3 for Figure 2 Scanning electron microscope (SEM) stereogram. Figure 4 For along Figure 1 Cross-sectional view of the tangent line A-A'. Figure 5 For along Figure 1 The light emitting element 1 disclosed in the embodiment is a light emitting diode with a flip-chip structure.

[0074] like Figure 1 The top view and Figure 4 As shown in the cross-sectional view, the light-emitting element 1 includes a substrate 10 including a side wall 10s; a light-emitting stack 11 including a plurality of outer side walls S1 located on the substrate 10, the light-emitting stack 11 including 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; a semiconductor structure 12 located on the substrate 10, separated from the light-emitting stack 11 by a distance through the first semiconductor layer 111, and surrounding the plurality of outer side walls S1 of the light-emitting stack 11; and a Bragg reflector 20 covering The light emitting stack 11 and the semiconductor structure 12, wherein the semiconductor structure 12 includes a side surface 12s directly connected to the side wall 10s of the substrate 10, 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 directly connected to the side surface 12s of the semiconductor structure 12, and a second side surface 202s separated by a distance from the side surface 12s of the semiconductor structure 12 to expose the upper surface 12t of the semiconductor structure.

[0075] like Figure 1 As shown in the top view of FIG. 1 , the light emitting element 1 may have a rectangular or square shape, and may be Figure 4-5 As shown in the side view of FIG. 1 , the substrate 10 of the light emitting element 1 includes a plurality of side walls 10s located around the light emitting element 1 to form a rectangular or square shape. From the top view, the size of the light emitting element 1 can be, for example, a rectangular shape of 300 μm×1000 μm or a square shape of 700 μm×700 μm, but is not particularly limited thereto.

[0076] The substrate 10 may be a growth substrate, including a gallium arsenide (GaAs) wafer for epitaxially growing aluminum gallium indium phosphide (AlGaInP), or a sapphire (Al2O3) wafer for growing indium gallium nitride (InGaN). 2 O 3 ) wafer, gallium nitride (GaN) wafer or silicon carbide (SiC) wafer.

[0077] In one embodiment of the present invention, a light-emitting stack 11 having photoelectric properties is formed on a substrate 10 by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor phase deposition (HVPE), physical vapor deposition (PVD) or ion plating, wherein the physical vapor deposition method includes sputtering or evaporation.

[0078] like Figure 4-5 As shown, 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. The wavelength of the light emitted by the light emitting element 1 can be adjusted by changing the physical and chemical composition of one or more layers in the light emitting stack 11. The material of the light emitting stack 11 includes III-V semiconductor materials, such as Al x In y Ga (1-x-y) N or Al x In y Ga (1-x-y) P, where 0≤x, y≤1; (x+y)≤1. When the material of the light-emitting stack 11 is an AlInGaP series material, it can emit red light with a wavelength between 610nm and 650nm. When the material of the light-emitting stack 11 is an AlInGaP series material or an InGaN series material, it can emit green light with a wavelength between 500nm and 570nm. When the material of the light-emitting stack 11 is an InGaN series material, it can emit blue light with a wavelength between 400nm and 490nm. When the material of the light-emitting stack 11 is an AlGaN series material or an AlInGaN series material, it can emit ultraviolet light with a wavelength between 400nm and 250nm.

[0079] The first semiconductor layer 111 and the second semiconductor layer 112 may be cladding layers, and the two have different conductivity types, electrical properties, polarities, or provide electrons or holes according to doped elements. For example, the first semiconductor layer 111 is an n-type electrical semiconductor, and the second semiconductor layer 112 is a p-type electrical semiconductor. The active layer 113 is formed between the first semiconductor layer 111 and the second semiconductor layer 112. Electrons and holes recombine in the active layer 113 under a current drive, converting electrical energy into light energy to emit a light. The active layer 113 may be a single heterostructure (SH), a double heterostructure (DH), a double-side double heterostructure (DDH), or a multi-quantum well (MQW). The material of the active layer 113 may be a neutral, p-type, or n-type electrical 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 a plurality of sub-layers.

[0080] 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 distance is included between the upper surface of the light-emitting stack 11 and the first upper surface of the active layer 113, and a second distance is included 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.

[0081] 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, for releasing the stress generated by the material lattice mismatch between the substrate 10 and the light-emitting stack 11, so as to reduce dislocation and lattice defects, thereby improving the epitaxial quality. The buffer layer may be a single layer or a structure including multiple sublayers. In one embodiment, PVD aluminum nitride (AlN) may be selected 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, the target material for forming PVD aluminum nitride (AlN) is composed of aluminum nitride. In another embodiment, a target material composed of aluminum is used to reactively form aluminum nitride with an aluminum target material in a nitrogen source environment.

[0082] like Figure 1 As shown in the top view of FIG. 1 , the light emitting element 1 includes a semiconductor structure 12 located at a periphery of the light emitting element 1 to surround a plurality of outer sidewalls S1 of the light emitting stack 11. Figure 4-5 As shown in the cross-sectional view, 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 groove 110. The first groove 110 includes a minimum width D between 1 μm and 30 μm, preferably between 2 μm and 14 μm, and more preferably between 5 μm and 10 μm. The first groove 110 is formed by removing part of the second semiconductor layer 112 and the active layer 113, and the first groove 110 exposes a part of the surface 111t of the first semiconductor layer 111. The top view shape of the first groove 110 includes a rectangular ring, a polygonal ring, a circular ring, an elliptical ring or an irregular ring, wherein the corners of the rectangle or polygon can be rounded.

[0083] In one embodiment of the invention, the semiconductor structure 12 comprises the same structure as the light emitting stack 11. For example, the semiconductor structure 12 comprises a first semiconductor layer 111, a second semiconductor layer 112 and an active layer 113. The upper surface 12t of the semiconductor structure 12 comprises a surface of the second semiconductor layer 112.

[0084] The light-emitting element 1 includes one or more grooves 120 surrounded by the second semiconductor layer 112 and / or the active layer 113. The one or more grooves 120 are formed 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. The one or more 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 the one or more grooves 120 include a circle, an ellipse, a rectangle, a polygon, or any shape. The multiple grooves 120 may include the same or different top-view shapes. The multiple grooves 120 may be arranged in multiple rows, and the grooves 120 on any two adjacent rows or each two adjacent rows may be aligned with each other or staggered. The number of the multiple grooves 120 is not particularly limited. For example Figure 1 As shown in the top view of FIG. 1 , the plurality of grooves 120 may be arranged in a fixed pattern at fixed intervals so that the current may be evenly dispersed in the horizontal direction.

[0085] The light emitting stack 11 includes a plurality of outer side walls S1 and a plurality of inner side walls S2, wherein the outer side walls S1 and the inner side walls S2 respectively include a side wall of the first semiconductor layer 111, the second semiconductor layer 112 and the active layer 113. One end of the outer side wall S1 is connected to a surface 112t of the second semiconductor layer 12, and the other end of the outer side wall S1 is connected to a surface 111t of the first semiconductor layer 111. One end of the inner side wall S2 is connected to the surface 112t of the second semiconductor layer 112, and the other end of the inner side wall S2 is connected to the surface 111t of the first semiconductor layer 11. The plurality of inner side walls S2 form a periphery of the groove 120. The plurality of outer side walls S1 form a periphery of the light emitting stack 11. As shown in FIG. Figure 4 and Figure 5 As shown, 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, and 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.

[0086] The light emitting element 1 includes one or more current blocking layers 14 located on the second semiconductor layer 112. The current blocking layer 14 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 magnesium fluoride (MgF xThe current blocking layer 14 may include a distributed Bragg reflector (DBR) in which insulating materials with different refractive indices are stacked one on top of the other. The current blocking layer 14 has a light transmittance of more than 80% or a light reflectivity of more than 80% for the light emitted by the active layer 113. Figure 4 and Figure 5 As shown, the current blocking layer 14 has an inclined side surface to reduce the risk of peeling off from the second semiconductor layer 112 and increase the coverage of subsequent stacking layers.

[0087] The light emitting element 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 side wall 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 profile from a cross-sectional view, rather than a flat profile. The material of the transparent conductive layer 16 includes a material that is 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, such as an ohmic contact, with the second semiconductor layer 112, the current can be uniformly diffused through the second semiconductor layer 112 through the transparent conductive layer 16. In one embodiment, the transparent conductive layer 16 includes an outermost side, which is separated from the outer side wall S1 or the inner side wall S2 of the light emitting stack 11 by a distance less than 20 μm, preferably less than 10 μm, and more preferably less than 5 μm.

[0088] The thickness of the transparent conductive layer 16 may be in the range of 0.1 nm to 100 nm. If the thickness of the transparent conductive layer 16 is less than 0.1 nm, it is too thin to effectively form an ohmic contact with the second semiconductor layer 112. Moreover, if the thickness of the transparent conductive layer 16 is greater than 100 nm, it is too thick to partially absorb the light emitted by the active layer 113, thereby causing the problem of reduced brightness of the light emitting element 1.

[0089] The light emitting element 1 includes one or more first contact electrodes 18 located on the first semiconductor layer 111 to be electrically connected to the first semiconductor layer 111, and one or more second contact electrodes 19 located on the second semiconductor layer 112 to be electrically connected to the second semiconductor layer 112. Figure 1 As shown, from a top view of the light-emitting element 1, the first contact electrode 18 includes a first contact electrode pad 18a and / or a first contact electrode extension 18b. In this embodiment, the top view shape of the first contact electrode pad 18a includes a circle or an ellipse, and the top view shape of the first contact electrode extension 18b includes a strip, a rectangle or a polygon. The first contact electrode pad 18a and the first contact electrode extension 18b include the same stacked structure and thickness.

[0090] like Figure 1 As shown, from a top view of the light-emitting element 1, the second contact electrode 19 includes a second contact electrode pad 19a and / or a second contact electrode extension 19b. In this embodiment, the top view shape of the second contact electrode pad 19a includes a circle or an ellipse, and the top view shape of the second contact electrode extension 19b includes a strip, a rectangle or a polygon. The second contact electrode pad 19a and the second contact electrode extension 19b include the same stacked structure and thickness.

[0091] like Figure 1 As shown, from a top view of the self-luminous element 1, one or more first contact electrodes 18 are respectively located in one or more grooves 120 and contact the first semiconductor layer 111. The multiple first contact electrodes 18 are separated from each other, and the first contact electrodes 18 and the grooves 120 have the same shape. In order to allow the current to diffuse evenly through the second semiconductor layer 112, the position of the second contact electrode 19 overlaps the position of the current blocking layer 14. In one embodiment of the invention, the second contact electrode 19 is located above the current blocking layer 14 and the transparent conductive layer 16, and contacts 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 contacts the current blocking layer 14 and the second semiconductor layer 112 through the opening. In one embodiment of the invention, the second contact electrode 19 has a similar shape to the current blocking layer 14; in another embodiment of the invention, the second contact electrode 19 has a dissimilar shape to the current blocking layer 14. In one embodiment of the invention, as Figure 1As shown, from a top view of the self-luminous element 1, the current blocking layer 14 includes an area larger than an area of ​​the second contact electrode 19. In another embodiment, the second contact electrode pad 19a and the corresponding current blocking layer 14 thereunder have dissimilar shapes, for example, the second contact electrode pad 19a is circular, and the current blocking layer 14 thereunder is rectangular. In another embodiment, the second contact electrode pad 19a and the corresponding current blocking layer 14 thereunder have similar shapes, for example, the second contact electrode pad 19a and the current blocking layer 14 thereunder are circular, but the center of the second contact electrode pad 19a and the center of the current blocking layer 14 thereunder do not overlap. Alternatively, the second contact electrode pad 19a is circular, and the current blocking layer 14 thereunder is rectangular, and the distances around the second contact electrode pad 19a and the current blocking layer 14 thereunder are non-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 below the second contact electrode pad 19a, so that a portion of the second contact electrode pad 19a directly contacts the second semiconductor layer 112 through the opening and the gap between the current blocking regions separated from each other; of course, in one embodiment, the transparent conductive layer 16 may not have an opening below the second contact electrode pad 19a, and the second contact electrode pad 19a directly contacts the transparent conductive layer 16.

[0092] In another embodiment of the invention, Figure 1 As shown, the light emitting element 1 includes one or more first current blocking layers 13 located between the first semiconductor layer 111 and the first contact electrode 18. The multiple first current blocking layers 13 are separated from each other by a distance, wherein the distance can be a fixed value. The distance between two adjacent multiple first current blocking layers 13 closer to the first contact electrode pad 18a is longer or shorter than the distance between two adjacent multiple first current blocking layers 13 farther from the first contact electrode pad 18a. The number of the multiple first current blocking layers 13 can 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 magnesium fluoride (MgF x). The first current blocking layer 13 may include a distributed Bragg reflector (DBR), in which the distributed Bragg reflector has insulating materials with different refractive indices stacked on each other. The first current blocking layer 13 has a transmittance of more than 80% or a light reflectivity 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 peeling from the first semiconductor layer 111 and increase the coverage of subsequent stacking. In one embodiment of the invention, the width of multiple 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 below the first contact electrode pad 18a is greater than or less 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 one 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.

[0093] like Figure 4 and Figure 5 As shown, the transparent conductive layer 16 includes a portion located between the current blocking layer 14 and the second contact electrode 19, and another portion directly contacts the second semiconductor layer 12. When 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. Therefore, the current is forced to flow to the transparent conductive layer 16, and then diffuses in the horizontal direction through the transparent conductive layer 16, and conducts the current to the second semiconductor layer 112.

[0094] The first contact electrode 18 and the second contact electrode 19 each have an inclined side surface to reduce the risk of peeling from the transparent conductive layer 16 or the first semiconductor layer 111 and increase the coverage of subsequent stacking. In one embodiment, the inclined side surface of the first contact electrode 18 has an inner angle between 30 degrees and 75 degrees with the surface of the first semiconductor layer 111. The inclined side surface of the second contact electrode 19 has an inner angle between 30 degrees and 75 degrees with the surface of the transparent conductive layer 16.

[0095] like Figure 1 As shown, from a top view of the self-luminous element 1 , the second contact electrode 19 is located on the left and right sides of the first contact electrode 18 .

[0096] like Figure 1 As shown, in one embodiment, from a top view of the light-emitting element 1 , the first contact electrode pad 18 a and the second contact electrode pad 19 a include different diameters for identification of different electrical properties.

[0097] 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) or alloys thereof. The first contact electrode 18 and the second contact electrode 19 may be composed of a single layer or a plurality of layers. For example, the first contact electrode 18 or the second contact electrode 19 may include a Ti / Au layer, a Ti / Pt / Au layer, a Cr / Au layer, a Cr / Pt / Au layer, a Ni / Au layer, a Ni / Pt / Au layer or a Cr / Al / Cr / Ni / Au layer.

[0098] 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 less 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, it cannot effectively conduct current. In addition, if the thickness of the first contact electrode 18 or the second contact electrode 19 is greater than 2.5 μm, manufacturing losses are caused due to excessive production time.

[0099] The light emitting element 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 more first openings 201 located on the first contact electrode pad 18a and exposing a surface of the first contact electrode pad 18a, wherein the first contact electrode extension 18b is completely covered by the Bragg reflector (DBR) 20. The Bragg reflector (DBR) 20 also includes one or more 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 extension 19b is completely covered by the Bragg reflector (DBR) 20.

[0100] In one embodiment of the invention, Figure 1 As shown in the top view, the first opening 201 of the DBR 20 includes a first opening diameter smaller than a diameter of the first contact electrode pad 18a. The second opening 202 of the DBR 20 includes a second opening diameter smaller than a diameter of the second contact electrode pad 19a.

[0101] In one embodiment of the invention, Figure 1As shown in the top view of FIG. 1 , a number of the plurality of first openings 201 of the DBR 20 is smaller than a number of the plurality of second openings 202 of the DBR 20 .

[0102] like Figure 4-5 As shown in the side view of FIG. 1 , the Bragg reflector (DBR) 20 covers the light emitting stack 11 and the semiconductor structure 12, and reflects the 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, by stacking SiO 2 / TiO 2 or SiO 2 / Nb 2 O 5 The insulating reflective layer with high reflectivity is formed by layers of the same material. When the wavelength of the light emitted by the light emitting element 1 is λ, the optical thickness of the Bragg reflector 20 can be set to an integer multiple of λ / 4. The optical thickness of the Bragg reflector 20 can have a deviation of ±30% based on the integer multiple of λ / 4. In one embodiment, the Bragg reflector 20 includes one or more die stacks, each die stack includes multiple dielectric layer pairs, and each dielectric layer pair includes a first dielectric layer and a second dielectric layer. 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), for example, 550nm, can be greater than 1 / 4, less than 1 / 4, or one layer is greater than 1 / 4 and the other layer is less than 1 / 4.

[0103] The Bragg reflector 20 includes a non-conductive material and can be formed by physical vapor deposition (PVD), electron beam evaporation (E-Beam Evaporation), sputtering or thermal evaporation. Before forming the Bragg reflector 20, a dielectric layer (not shown) having a certain thickness is preferably formed so that the Bragg reflector 20 can be stably formed and light reflection is also facilitated. The material of the dielectric layer (not shown) is preferably SiO2, and its thickness can be, for example, The overall thickness of the Bragg reflector 20 may be In one embodiment of the invention, after forming the Bragg reflector 20, another dielectric layer (not shown) with a certain thickness may be formed to facilitate light extraction.

[0104] In one embodiment of the invention, Figure 3 Scanning electron microscope (SEM) images and Figure 5 As shown in the cross-sectional view of , the Bragg reflector 20 includes a first thickness T1 located on the surface 112t of the second semiconductor layer 12 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, and more preferably greater than 4 μm, and the second thickness T2 is less than 2 μm.

[0105] like Figure 1 The top view of Figure 4 and Figure 5 As shown in the cross-sectional view, because there is a stacked structure below the Bragg reflector (DBR) 20, for example, the light-emitting stack 11, the current blocking layer 14, the transparent conductive layer 16, the first contact electrode 18 or the second contact electrode 19 and other structures, when the light-emitting element 1 undergoes the cutting and splitting manufacturing process, the Bragg reflector (DBR) 20 is prone to form a fracture surface S around the light-emitting element 1 due to these structures with height differences. When the fracture surface S extends to the light-emitting stack 11 and exposes 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 fracture 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, and the semiconductor structure 12 is separated from the light-emitting stack 11 by a distance through the first semiconductor layer 111, and the semiconductor structure 12 surrounds the light-emitting stack 11. As shown Figure 5 As shown, due to the film forming characteristics of the DBR 20 , even if there is a crack surface S around the light emitting element 1 , the crack surface S will stop at the corner of the semiconductor structure 12 or the first trench 110 as shown in the second side surface 202s of the DBR 20 .

[0106] In one embodiment of the invention, Figure 3 Scanning electron microscope (SEM) images and Figure 5 As shown in the cross-sectional view, the second side surface 202s of the DBR 20 and the inner surface 12ns of the semiconductor structure 12 include an obtuse angle between 95 degrees and 140 degrees, preferably between 100 degrees and 130 degrees, and more preferably between 100 degrees and 120 degrees.

[0107] In one embodiment of the invention, Figure 3 Scanning electron microscope (SEM) images of Figure 4 and Figure 5 As shown in the cross-sectional view, there is a first angle between the outer wall S1 of the light-emitting stack 11 and the surface 111t of the first semiconductor layer 111, and 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 breakage of the Bragg reflector (DBR) 20 film layer, wherein the angle difference between the first angle and the third angle is less than 30 degrees, preferably less than 20 degrees, and more preferably less than 10 degrees.

[0108] The light emitting element 1 includes a first electrode pad 21 to cover one or more first openings 201 of the DBR 20, and to contact the first contact electrode pad 18a through the one or more first openings 201. The light emitting element 1 includes a second electrode pad 22 to cover one or more second openings 202 of the DBR 20, and to contact the second contact electrode pad 19a through the one or more second openings 202. The first contact electrode pad 18a and the second contact electrode pad 19a are electrically connected to the first semiconductor layer 111 and the second semiconductor layer 112 through the first contact electrode extension 18b and the second contact electrode extension 19b, respectively.

[0109] 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 profiles of the upper surfaces of the first contact electrode 18 and the upper surfaces 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-planar surface profile and thus have a strip-shaped, circular or stepped surface. Figure 4 and Figure 5 As shown, the upper surface of the first electrode pad 21 or the second electrode pad 22 may include at least one recessed portion and at least one protruding portion, which are respectively disposed in the regions where the first contact electrode 18 and the second contact electrode 19 are disposed. Therefore, the upper surface of the first electrode pad 21 or the second electrode pad 22 may have a stepped surface.

[0110] From a top view of the self-luminous element 1, Figure 1As shown, one or more first contact electrode pads 18a are only covered by the first electrode pad 21, and one or more second contact electrode pads 19a are only covered by the second electrode pad 22. One or more first contact electrode extensions 18b are covered by the second electrode pad 22, and one or more second contact electrode extensions 19b are covered by the first electrode pad 21 and / or the second electrode pad 22. In one embodiment, one or more first contact electrode extensions 18b are covered by the first electrode pad 21 and the second electrode pad 22. In one embodiment, one or more first contact electrode pads 18a are not covered by the first electrode pad 21, that is, the first electrode pad 21 is arranged to avoid the first contact electrode pad 18a. In one embodiment, one or more 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 are arranged to avoid the first contact electrode extension 18b. In one embodiment, one or more second contact electrode pads 19a 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 19a. In one embodiment, one or more second contact electrode extensions 19b are not covered by the first electrode pads 21 and / or the second electrode pads 22, that is, the first electrode pads 21 and / or the second electrode pads 22 are arranged to avoid the second contact electrode extensions 19b.

[0111] 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 may be composed of a single layer or multiple layers. For example, the first electrode pad 21 or the second electrode pad 22 may include a Ti / Au layer, a Ti / Pt / Au layer, a Cr / Au layer, a Cr / Pt / Au layer, a Ni / Au layer, a Ni / Pt / Au layer or a Cr / Al / Cr / Ni / Au layer. The first electrode pad 21 and the second electrode pad 22 can serve as a current path for an external power source to supply power to the first semiconductor layer 111 and the second semiconductor layer 112.

[0112] In one embodiment of the present invention, the first electrode pad 21 includes a size that is the same as or different from a size of the second electrode pad 22, and the size 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 greater than 0.8 times and less than 1 times the value obtained by adding the top view areas of the first electrode pad 21 and the second electrode pad 22.

[0113] The first electrode pad 21 or the second electrode pad 22 includes an inclined side surface, so the side-view 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 can gradually decrease as it moves away from the upper surface of the light-emitting stack 11.

[0114] 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 gap between the first electrode pad 21 and the second electrode pad 22, the upper viewing area of ​​the first electrode pad 21 and the second electrode pad 22 can be increased, thereby improving the heat dissipation efficiency of the light-emitting element 1 and avoiding a short circuit between the first electrode pad 21 and the second electrode pad 22.

[0115] The first electrode pad 21 and the second electrode pad 22 have a thickness between 1 and 100 μm, preferably between 1.5 and 6 μm.

[0116] Figure 6 It is a top view of a light emitting element 2 disclosed in another embodiment of the present invention. Figure 7 For along Figure 6 The light emitting element 2 disclosed in the embodiment is a light emitting diode with a 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 are Figure 6-7 The same reference numerals are used in the following description.

[0117] like Figure 6 The top view and Figure 7As shown in the cross-sectional view, the light-emitting element 2 includes a substrate 10 including a side wall 10s; a light-emitting stack 11 including multiple outer side walls S1 located on the substrate 10, 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; a semiconductor structure 12 located on the substrate 10, separated from the light-emitting stack 11 by a distance through the first semiconductor layer 111 and surrounding multiple side surfaces of the light-emitting stack 11; a first groove 110 located on the substrate 10, exposing the first semiconductor layer 111, and located between the light-emitting stack 11 and the semiconductor structure 12; a second groove 1101 located on the substrate 10 , exposing the first semiconductor layer 111, and being separated from the first trench 110 by a distance through the semiconductor structure 12 and surrounding multiple side surfaces of the semiconductor structure 12; and a Bragg reflector 20 covering the light-emitting stack 11 and the semiconductor structure 12, wherein the semiconductor structure 12 includes a side surface 12s separated from the side wall 10s of the substrate 10 by a distance, an inner side surface 12ns opposite to the side surface 12s, and an upper surface 12t directly connected to the side surface 12s and the inner side surface 12ns, and the Bragg reflector 20 includes a first side surface 201s and the side surface 111s of the first semiconductor layer 111 and a second side surface 202s and the side surface 12s of the semiconductor structure 12 directly connected.

[0118] In one embodiment of the invention, the second side surface 202 s of the Bragg reflector 20 is directly connected to the inner surface 12 ns of the semiconductor structure 12 .

[0119] like Figure 6 As shown in the top view of FIG. 1 , the light emitting element 2 includes a first trench 110 and a second trench 1101 located on the first semiconductor layer 111 and surrounding multiple side surfaces of the light emitting stack 11, wherein the semiconductor structure 12 is located between the first trench 110 and the second trench 1101 and surrounding multiple side surfaces of the light emitting stack 11. Figure 7 As shown in the cross-sectional view, 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 groove 110. The first groove 110 includes a minimum width D between 1 μm and 30 μm, preferably between 2 μm and 14 μm, and more preferably between 5 μm and 10 μm. The first groove 110 is formed by removing part of the second semiconductor layer 112 and the active layer 113, and the first groove 110 exposes part of the first semiconductor layer 111. The top view shape of the first groove 110 includes a rectangular ring or a polygonal ring, a circular ring, an elliptical ring or an irregular ring, wherein the corners of the rectangle or polygon can be rounded.

[0120] like Figure 7As shown in the cross-sectional view of , the second trench 1101 includes a minimum width D1 between 1 μm and 80 μm, preferably between 2 μm and 50 μm, and more preferably between 5 μm and 20 μm. The second trench 1101 is formed by removing a portion of the second semiconductor layer 112 and the active layer 113, and the second trench 1101 exposes a portion of the first semiconductor layer 111. The top view of the second trench 1101 includes a rectangular or polygonal ring, wherein each corner of the rectangle or polygon can be rounded.

[0121] In one embodiment of the invention, the semiconductor structure 12 comprises the same structure as the light emitting stack 11. For example, the semiconductor structure 12 comprises a first semiconductor layer 111, a second semiconductor layer 112 and an active layer 113. The upper surface 12t of the semiconductor structure 12 comprises a surface of the second semiconductor layer 112.

[0122] like Figure 6 The top view and Figure 7 As shown in the cross-sectional view, because the Bragg reflector (DBR) 20 is a stacked structure, for example, the light-emitting stack 11, the current blocking layer 14, the transparent conductive layer 16, the first contact electrode 18 or the second contact electrode 19 and other structures, when the light-emitting element 2 undergoes the cutting and splitting manufacturing process, the Bragg reflector (DBR) 20 is prone to form a fracture surface S around the light-emitting element 2 due to these structures with height differences. When the fracture surface S extends to the light-emitting stack 11 and exposes 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 fracture 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 2 includes a semiconductor structure 12 located on the substrate 10, and a first semiconductor layer 111 exposed by a first groove 110 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 through the first semiconductor layer 111 exposed by the first groove 110, and the semiconductor structure 12 surrounds the light emitting stack 11. Figure 6 As shown, due to the film forming characteristics of the Bragg reflector (DBR) 20, even if there is a crack surface S around the light emitting element 2, the crack surface S will stop at the corner of the semiconductor structure 12, the first trench 110 or the second trench 1101 as shown in the second side surface 202s of the Bragg reflector (DBR) 20.

[0123] In one embodiment of the invention, Figure 7As shown in the cross-sectional view of FIG. 1 , the second side surface 202s of the DBR 20 is directly connected to the side surface 12s of the semiconductor structure 12. 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.

[0124] In one embodiment of the invention, when the second side surface 202s of the Bragg reflector 20 is directly connected to the inner surface 12ns of the semiconductor structure 12, an obtuse angle between the second side surface 202s of the Bragg reflector (DBR) 20 and the inner surface 12ns of the semiconductor structure 12 is between 95 degrees and 140 degrees, preferably between 100 degrees and 130 degrees, and more preferably between 100 degrees and 120 degrees.

[0125] In one embodiment of the present invention, the light emitting element 2 includes a plurality of semiconductor structures 12 located around the light emitting element 1 to surround the light emitting stack 11 (not shown). The plurality of semiconductor structures 12 are isolated from the light emitting stack 11 by the first groove 110, and two adjacent plurality of semiconductor structures 12 are spaced apart from each other by the third groove (not shown). The plurality of semiconductor structures 12 and the 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, so as to prevent the Bragg reflector (DBR) 20 from peeling off from the surface of the light emitting stack 11 and / or the semiconductor structure 12.

[0126] The first trench 110 and the third trench each have a minimum width D between 1 μm and 30 μm, preferably between 2 μm and 14 μm, and more preferably between 5 μm and 10 μm. The first trench 110 and the third trench are formed by removing a portion of the second semiconductor layer 112 and the active layer 113, and the first trench 110 and the third trench expose a portion of the first semiconductor layer 111. The top view of the first trench 110 and the third trench includes a rectangular or polygonal ring, wherein each corner of the rectangle or polygon can be rounded.

[0127] In one embodiment of the present invention, the light emitting element 2 further includes a second trench 1101 located at an outermost periphery of the light emitting element 2 to surround the light emitting stack 11 , the plurality of semiconductor structures 12 , and a third trench (not shown) located between the plurality of semiconductor structures 12 .

[0128] A plurality of third trenches (not shown) for separating a plurality of semiconductor structures 12 include the same or different minimum widths D. In one embodiment of the invention, the minimum width D of the third trenches 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 trenches gradually decreases from the light-emitting stack 11 to the semiconductor structure 12.

[0129] In one embodiment of the invention, the light-emitting element 1 or the light-emitting element 2 further includes a cutting path (not shown) located at the outermost side of the light-emitting element 1 or the light-emitting element 2. From a top view of the light-emitting element 1 or the light-emitting element 2, the cutting path surrounds the light-emitting stack 11, the semiconductor structure 12 and the first groove 110. The cutting path is formed by removing the first semiconductor layer 11, the second semiconductor layer 12 and the active layer 13 to expose an upper surface of the substrate 10. The top view shape of the cutting path includes a rectangular or polygonal ring. In one embodiment, the upper surface of the substrate 10 exposed by the cutting path is a rough surface. The rough surface can 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.

[0130] Figure 8 Schematic diagram of a light emitting device 3 according to an embodiment of the present invention. The light emitting element 1 or the light emitting element 2 in the above-mentioned embodiment is mounted on the first pad 511 and the second pad 512 of the packaging substrate 51 in the form of a flip chip. The first pad 511 and the second pad 512 are electrically insulated by an insulating portion 53 containing an insulating material. Flip chip mounting is to set the side of the growth substrate opposite to the electrode pad forming surface 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 set around the light emitting element 1 or the light emitting element 2.

[0131] Fig. 9 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 carrier 606 and a plurality of light emitting units 608 located on the carrier 606, wherein the plurality of light emitting units 608 may be the light emitting element 1, the light emitting element 2 or the light emitting device 3 in the aforementioned embodiment.

[0132] The embodiments listed in the present invention are only used to illustrate the present invention, and are not used to limit the scope of the present invention. Any obvious modification or change made by anyone to the present invention does not deviate from the spirit and scope of the present invention.

Claims

1. A light emitting element, characterized in that: Include: a substrate including sidewalls; A light-emitting stack, comprising a plurality of outer sidewalls located on the substrate, the light-emitting stack comprising a first semiconductor layer, a second semiconductor layer, and an active layer located between the first semiconductor layer and the second semiconductor layer; A first groove surrounds the light emitting stack and exposes the first semiconductor layer, wherein the top view shape of the first groove includes a rectangular ring, a polygonal ring, a circular ring, an elliptical ring or an irregular ring; and A Bragg reflector covers the light emitting stack and the first groove, The Bragg reflector includes a thickness located on the light emitting stack, and the Bragg reflector located on the first groove includes: a first thickness located above the upper surface of the second semiconductor layer; and a second thickness located below the upper surface of the second semiconductor layer, and 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.

2. The light-emitting element as described in claim 1 comprises a semiconductor structure located on the substrate and separated from the light-emitting stack by the first groove, wherein the semiconductor structure comprises the first semiconductor layer, the second semiconductor layer, and the active layer is located between the first semiconductor layer and the second semiconductor layer. 3 . The light emitting device as claimed in claim 2 , wherein the first trench is located between the semiconductor structure and the light emitting stack, and the first trench comprises a minimum width D between 1 μm and 30 μm. 4 . The light emitting device as claimed in claim 3 , comprising a second trench located on the substrate and separated from the first trench by a distance through the semiconductor structure. The light emitting device as claimed in claim 1 , comprising a cutting line to expose an upper surface of the substrate, wherein the upper surface is a rough surface. The light emitting device as claimed in claim 1 , wherein the first thickness is greater than the second thickness.

7. The light-emitting element as described in claim 2, wherein the semiconductor structure includes a side surface, an inner surface opposite to the side surface, and an upper surface directly connected to the side surface and the inner surface, and the Bragg reflector includes 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 so as to expose the upper surface of the semiconductor structure. 8 . The light emitting device as claimed in claim 7 , wherein an obtuse angle is formed between the second side surface of the Bragg reflector and the inner surface of the semiconductor structure, and the obtuse angle is between 95 degrees and 140 degrees.

9. The light-emitting element as described in claim 1 comprises a first contact electrode and a second contact electrode located on the first semiconductor layer and the second semiconductor layer of the light-emitting stack, wherein the first contact electrode comprises a first contact electrode pad and a first contact electrode extension, and the second contact electrode comprises a second contact electrode pad and a second contact electrode extension. 10 . The light emitting device as claimed in claim 1 , wherein the Bragg reflector comprises a first opening exposing a first contact electrode pad and a second opening exposing a second contact electrode pad, and the first contact electrode extension and the second contact electrode extension are covered by the Bragg reflector.

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