KR102561565B1 - Light emitting device and light emitting device package - Google Patents

Abstract

The embodiment relates to a light emitting device, a method for manufacturing a light emitting device, a light emitting device package, and a lighting device.
The light emitting device of the embodiment includes a lower electrode; a light emitting structure located on the lower electrode and including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer; an upper electrode pad located on the light emitting structure; and at least one branch electrode connected to the upper electrode pad, wherein the upper electrode pad includes at least one connection electrode connected to the at least one branch electrode, and the at least one connection electrode is integrally formed with the upper electrode pad, , may protrude from the side surface of the upper electrode pad at regular intervals.

Description

Light emitting device and light emitting device package {LIGHT EMITTING DEVICE AND LIGHT EMITTING DEVICE PACKAGE}

The embodiment relates to a light emitting device, a method for manufacturing a light emitting device, a light emitting device package, and a lighting device.

A light emitting device (Light Emitting Device) is a p-n junction diode that converts electrical energy into light energy. It can be created with compound semiconductors such as group III and group V on the periodic table, and various colors can be realized by adjusting the composition ratio of compound semiconductors. possible.

When a forward voltage is applied to a light emitting device, electrons in the n layer and holes in the p layer combine to emit energy corresponding to the energy gap between the conduction band and the valence band. It is mainly emitted in the form of heat or light, and when emitted in the form of light, it becomes a light emitting device.

The light emitting device can implement various colors by adjusting the composition ratio of the semiconductor compound. For example, the light emitting device may be a blue light emitting device, a green light emitting device, an ultraviolet (UV) light emitting device, or a red (RED) light emitting device.

A general light emitting device includes a light emitting structure including an active layer and first and second conductivity type semiconductor layers including different dopants with the active layer interposed therebetween, and electrodes connected to the first and second conductivity type semiconductor layers are provided. include

A general light emitting device has a problem in that an operating voltage is increased and an output voltage is decreased due to a current crowding phenomenon that occurs when current is concentrated around the electrodes. In addition, the electrodes absorb or block light, resulting in a decrease in light extraction efficiency.

Embodiments provide a light emitting device, a method for manufacturing a light emitting device, a light emitting device package, and a lighting device capable of improving luminous flux by reducing light loss while improving current density.

The light emitting device of the embodiment includes a lower electrode 140; a light emitting structure 110 positioned on the lower electrode 140 and including a first conductivity type semiconductor layer 112, an active layer 114, and a second conductivity type semiconductor layer 116; an upper electrode pad 174 positioned on the light emitting structure 110; at least one branch electrode 172 connected to the upper electrode pad 174; and an upper ohmic layer 171 positioned below the at least one branch electrode 172, wherein the upper electrode pad 174 is connected to at least one connection electrode 174a connected to the at least one branch electrode 172. ), and the at least one connection electrode 174a is formed integrally with the upper electrode pad 174 and may protrude from a side surface of the upper electrode pad 174 at regular intervals.

The light emitting device package 200 of the embodiment may include the light emitting device 100 .

In the embodiment, the connection electrode protruding from the upper electrode pad and the branch electrode are connected to improve current spreading.

In the embodiment, light loss due to light absorption can be improved by reducing the area of the upper ohmic layer because the connection electrode protruding from the upper electrode pad and the branch electrode are connected.

The embodiment can improve the luminous flux by improving current spreading and light loss.

1 is a plan view illustrating a light emitting device according to an embodiment.
FIG. 2 is a view showing A of FIG. 1 .
FIG. 3 is a cross-sectional view of a light emitting device taken along the line II' of FIG. 1 .
4 is a view comparing the luminous intensity of Comparative Examples 1 and 2 and Examples.
5 to 10 are diagrams illustrating a method of manufacturing a light emitting device according to an embodiment.
11 is a plan view illustrating a light emitting device according to another embodiment.
12 is a plan view illustrating a light emitting device according to another embodiment.
13 is a cross-sectional view illustrating a light emitting device package according to an embodiment.

In the description of the embodiment, each layer (film), region, pattern or structure is "on/over" or "under" the substrate, each layer (film), region, pad or pattern. In the case where it is described as being formed in, "on/over" and "under" include both "directly" or "indirectly" formed through another layer. do. In addition, the criteria for the top/top or bottom of each layer will be described based on the drawings.

1 is a plan view of a light emitting device according to an embodiment, FIG. 2 is a view of A in FIG. 1 , and FIG. 3 is a cross-sectional view of the light emitting device taken along line Ⅰ′ in FIG. 1 . .

1 to 3, the light emitting device 100 according to the embodiment includes a light emitting structure 110, an upper electrode pad 174, a branch electrode 172, a first reflective layer 132, and a lower electrode ( 140) may be included.

The light emitting structure 110 may be positioned on the lower electrode 140 , and the upper electrode pad 174 and the branch electrodes 172 may be positioned on the light emitting structure 110 .

The light emitting structure 110 includes a first conductivity type semiconductor layer 112, an active layer 114 located under the first conductivity type semiconductor layer 112, and a second conductivity type semiconductor layer located under the active layer 114 ( 116) may be included.

The lower electrode 140 may include a lower ohmic pattern 141 , a second reflective layer 142 , a bonding layer 144 , and a support substrate 146 .

The lower ohmic pattern 141 may contact the lower surface of the light emitting structure 110 . The lower ohmic pattern 141 may directly contact the light emitting structure 110 . That is, the second conductivity type semiconductor layer 116 may contact the lower ohmic pattern 141 and may be positioned on an upper surface of the lower ohmic pattern 141 .

The second reflective layer 142 may be formed of a single layer or a plurality of layers of a material having excellent electrical contact and high reflectivity.

The bonding layer 144 and the support member 146 may be formed of a single layer or a plurality of layers.

The first reflective layer 132 may be positioned on the same plane as the lower ohmic pattern 141 . The first reflective layer 132 may be positioned parallel to the lower ohmic pattern 141 . For example, the lower ohmic pattern 141 may be spaced apart at regular intervals in a dot shape. The diameter or horizontal width of the first reflective layer 132 may be larger than that of the lower ohmic pattern 141 positioned between the first reflective layers 132 , but is not limited thereto. The first reflective layer 132 may have the same thickness as the lower ohmic pattern 141, but is not limited thereto. The first reflective layer 132 may directly contact the lower surface of the light emitting structure 110 . The first reflective layer 132 may directly contact the second conductivity type semiconductor layer 116 . The first reflective layer 132 may be formed of a single layer or a plurality of layers.

The light emitting device 100 of the embodiment may include an upper electrode pad 174 and branch electrodes 172 . Although one upper electrode pad 174 and a plurality of branch electrodes 172 are limited and described in the embodiment, the present invention is not limited thereto, and at least two or more upper electrode pads 174 and branch electrodes 172 are used. can be placed. Here, in the embodiment, an upper ohmic layer 171 may be positioned between the first conductivity-type semiconductor layer 112 and the branch electrode 172 . The upper ohmic layer 171 may be disposed under the branch electrode 172 . The upper ohmic layer 171 may be formed of a single layer or a plurality of layers of a material having excellent electrical contact with a semiconductor.

The upper electrode pad 174 may be disposed along an edge of the light emitting structure 110 . The upper electrode pad 174 may include four side parts along an edge of the light emitting structure 110 . Specifically, the upper electrode pad 174 includes a first side portion 174a connectable with a wire, second and third side portions 174b and 174c connected to both edges of the first side portion 174a, and It may include a fourth side part 174d connected to the ends of the second and third side parts 174b and 174c and facing the first side part 174a. The first side portion 174a may have a larger area than the second to fourth side portions 174b, 174c, and 174d. A width of the first side portion 174a may be wider than that of the second to fourth side portions 174b, 174c, and 174d. For example, the width of the first side portion 174a may be 100 μm or more for wire bonding, but is not limited thereto. The second to fourth side portions 174b, 174c, and 174d may have the same width as each other, but are not limited thereto.

The upper electrode pad 174 may be disposed on an upper surface of the first conductivity type semiconductor layer 112 . The upper electrode pad 174 may directly contact the first conductivity type semiconductor layer 112 . A region of the upper electrode pad 174 in contact with the first conductive semiconductor layer 112 may make a Schottky contact. For example, current may be limited through a potential barrier of a junction between the upper electrode pad 174 and the first conductive type semiconductor layer 112 by reverse bias. Therefore, the upper electrode pad 174 may not make ohmic contact with the first conductivity type semiconductor layer 112 . Accordingly, since the embodiment induces current to flow through the branch electrodes 172 that are in ohmic contact with the first conductivity-type semiconductor layer 112, the overall current spreading effect is improved, so that light output can be improved.

The upper electrode pad 174 may include at least one connection electrode 174p. The number of connection electrodes 174p may be plural. The connection electrode 174p may protrude from a side surface of the upper electrode pad 174 . The connection electrode 174p may be formed integrally with the upper electrode pad 174 or may be formed separately. The connection electrode 174p may protrude from a side surface of the upper electrode pad 174 and be electrically connected to the branch electrode 172 . The connection electrode 174p may protrude toward the inside of the upper electrode pad 174 . For example, the connection electrode 174p may protrude from the first side portion 174a of the upper electrode pad 174 toward the fourth side portion 174d. Also, the connection electrode 174p may protrude from the fourth side portion 174d toward the first side portion 174a.

The connection electrode 174p may have a function of transferring current from the upper electrode pad 174 to the branch electrode 172 . That is, the current provided from the upper electrode pad 174 may be provided to the branch electrode 172 by the connection electrode 174a. Therefore, the light emitting device 100 of the embodiment transfers the current that can be concentrated on the upper electrode pad 174 by the connection electrode 174p to the connection electrode 174p to improve the current spread and improve the luminous intensity. can In addition, in the embodiment, since the area of the branch electrode 172 is narrowed by the length of the connection electrode 174p, the area of the upper ohmic layer 171 disposed below the branch electrode 172 may also be narrowed. That is, since the area of the upper ohmic layer 171 having a higher bandgap energy than that of the active layer 114 is narrowed, light absorption by the upper ohmic layer 171 can be reduced and optical loss can be improved.

The thickness of the connection electrode 174p may correspond to the thickness of the upper electrode pad 174, but is not limited thereto. The connection electrode 174p may protrude from the side surface of the upper electrode pad 174 at regular intervals. The distance between the connection electrodes 174p may be 50 μm to 150 μm, but is not limited thereto. Adjacent connection electrodes 174p may be regularly arranged at intervals of 50 μm to 150 μm to reduce light absorption, improve luminous flux, and improve a current spreading effect. When the distance between the connection electrodes 174p is less than 50 μm, as the area of the connection electrode 174p and the area of the branch electrode 172 increase, the luminous flux may decrease due to light absorption. When the distance between the connection electrodes 174p is greater than 150 μm, as the distance between the connection electrodes 174p and the branch electrodes 172 increases, the overall current spreading effect may decrease, and the operating voltage VF3 ) can increase.

The connection electrode 174p may overlap a portion of the branch electrode 172 . A portion of an upper surface of the connection electrode 174p may vertically overlap a portion of the branch electrode 172 and the upper ohmic layer 171 . A portion of the lower surface of the connection electrode 174p may directly contact a portion of the upper surface of the branch electrode 172 and a portion of the side surface of the upper ohmic layer 171 . For example, the overlapping area of the branch electrode 172 and the connection electrode 174p may be 1% to 90% of the total area of the connection electrode 174p, for example, the branch electrode 172 and the connection electrode 174p. ) may be 20% to 50% of the total area of the connection electrode 174p, but is not limited thereto. The branch electrode 172 and the connection electrode 174p overlap by 1% to 90% of the total area of the connection electrode 174p to maintain connection reliability between the branch electrode 172 and the connection electrode 174p. The current spreading effect can be improved.

When the overlapping area of the connection electrode 174p overlapping the branch electrode 172 is less than 1% of the total area of the connection electrode 174p, the connection between the branch electrode 172 and the connection electrode 174p Reliability may deteriorate. When the overlapping area of the connection electrode 174p overlapping the branch electrode 172 exceeds 90% of the total area of the connection electrode 174p, the current spreading effect may decrease. The connection electrode 174p may be disposed on an upper surface of the first conductive semiconductor layer 112 and an upper surface of the branch electrode 172 . A width of the connection electrode 174p may be constant from an area adjacent to the upper electrode pad 174 to an end area, but is not limited thereto. For example, the width of the connection electrode 174p may decrease as the distance from the upper electrode pad 174 increases. That is, the width of the end of the connection electrode 174p may be smaller than the width of the connection electrode 174p adjacent to the upper electrode pad 174 . An end of the connection electrode 174p may have a curvature such as a hemispherical shape.

The length L of the connection electrode 174p may be 20 μm or more. For example, the length (L) of the connection electrode 174p may be 20 μm to 60 μm. When the length (L) of the connection electrode 174p is less than 20 μm, current spread may be reduced. When the length L of the connection electrode 174p is greater than 60 μm, the light extraction efficiency may decrease due to the connection electrode 174p having low light transmittance, and the operating voltage VF3 may increase.

A width W of the connection electrode 174p may be greater than or equal to 5 μm. For example, the width W of the connection electrode 174p may be 5 μm to 20 μm. When the width W of the connection electrode 174p is less than 5 μm, current is concentrated around the connection electrode 174p due to the thin width, and thus the operating voltage VF3 may increase. When the width W of the connection electrode 174p is greater than 20 μm, light extraction efficiency may decrease due to the connection electrode 174p having low light transmittance.

The width W of the connection electrode 174p may be greater than or equal to the width of the branch electrode 172, but is not limited thereto.

The upper electrode pad 174 and the connection electrode 174p may be formed of a single layer or a plurality of layers, and may be formed of at least one of Ti, Cr, Ni, Al, Pt, Au, W, Cu, Mo, and Cu-W. It may be formed, but is not limited thereto.

In the embodiment, the upper electrode pad 174 is disposed without breaking along the edge of the light emitting structure 110, and the connection electrode 174p is the first side portion 174a of the upper electrode pad 174 facing each other. and a structure in which the plurality of branch electrodes 172 are disposed to face each other from the fourth side portion 174d and are disposed inside the upper electrode pad 174, but is not limited thereto.

In the light emitting device 100 according to the embodiment, the connection electrode 174p protruding from the upper electrode pad 174 and the branch electrode 172 are connected to improve current spreading, and the band gap energy is reduced by the active layer 114. Since the area of the upper ohmic layer 171 that is greater than ) is narrowed, light absorption by the upper ohmic layer 171 can be reduced and light loss can be improved.

Accordingly, the light emitting device 100 according to the exemplary embodiment may improve luminous intensity by improving current spreading and reducing light loss.

4 is a diagram comparing the luminous intensity of Comparative Examples 1 and 2 and Example.

Comparative Example 1 includes an upper electrode pad and a branch electrode integrally made of a material having the same resistance as each other. That is, in Comparative Example 1, the upper electrode pad and the branch electrodes have the same thickness, the same material, and the same resistance, and the upper electrode pad and the branch electrodes may directly contact the light emitting structure. That is, in Comparative Example 1, the upper ohmic layer is removed under the upper electrode pad and the branch electrode.

Comparative Example 2 includes an upper electrode pad and a branch electrode, and includes an upper ohmic layer under the branch electrode. A part of the branch electrode is disposed under the upper electrode pad and is directly connected to the upper electrode pad. That is, the branch electrode of Comparative Example 2 may directly contact the upper electrode pad.

The embodiment may employ the technical features of FIGS. 1 to 3 . That is, the embodiment includes a connection electrode protruding from the upper electrode pad, and the connection electrode may be connected to the branch electrode.

Comparing Comparative Examples 1 and 2 with the embodiment, the luminous flux of Example can be improved by 40% or more than Comparative Example 1 and 4% or more than Comparative Example 2 by the connection electrode protruding from the upper electrode pad. can

Hereinafter, a method of manufacturing a light emitting device according to an embodiment will be described with reference to FIGS. 5 to 10 .

Referring to FIG. 5 , first, a substrate 102 is prepared. The substrate 102 may be a material with excellent thermal conductivity. The substrate 102 may be formed of a single layer or multiple layers. The substrate 102 may be a conductive substrate or an insulating substrate. For example, the substrate 102 may be at least one of GaAs, sapphire (Al ₂ O ₃ ), SiC, Si, GaN, ZnO, GaP, InP, Ge, and Ga ₂ O ₃ . The substrate 102 may be subjected to a cleaning process before forming the light emitting structure 110 to remove surface impurities.

The light emitting structure 110 may be formed on the substrate 102 . The light emitting structure 110 may emit light of a red wavelength, but is not limited thereto. The light emitting structure 110 includes a first conductivity type semiconductor layer 112, an active layer 114 formed on the first conductivity type semiconductor layer 112, and a second conductivity type semiconductor formed on the active layer 114. Layer 116 may be included. The light emitting structure 110 may have the same width in a cross section or may become smaller as the second conductivity type semiconductor layer 116, the active layer 114, and the first conductivity type semiconductor layer 112 go forward, but is not limited thereto.

The first conductivity-type semiconductor layer 112 may be implemented with a semiconductor compound, for example, a compound semiconductor such as group II-IV and group III-V. The first conductivity type semiconductor layer 112 may be formed in a single layer or multiple layers. The first conductivity type semiconductor layer 112 may be doped with a first conductivity type dopant. For example, when the first conductivity-type semiconductor layer 112 is an n-type semiconductor layer, it may include an n-type dopant. For example, the n-type dopant may include Si, Ge, Sn, Se, or Te, but is not limited thereto. The first conductive semiconductor layer 112 may include a semiconductor material having a composition formula of In _x Al _y Ga _1-xy P (0=x=1, 0=y=1, 0=x+y=1). It may, but is not limited thereto. For example, the first conductive semiconductor layer 112 may be formed of one or more of AlGaP, InGaP, AlInGaP, InP, GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, and GaP. .

The first conductive semiconductor layer 112 may be formed using a method such as chemical vapor deposition (CVD), molecular beam epitaxy (MBE), sputtering, or hydroxide vapor phase epitaxy (HVPE), but is not limited thereto. .

The active layer 114 may be formed on the first conductivity type semiconductor layer 112 .

The active layer 114 may selectively include a single quantum well, multiple quantum well (MQW), quantum wire structure, or quantum dot structure. The active layer 114 may be made of a compound semiconductor. For example, the active layer 114 may be implemented with at least one of group II-IV and group III-V compound semiconductors.

The active layer 114 may include a quantum well and a quantum wall. When the active layer 114 is implemented as a multi-quantum well structure, quantum wells and quantum walls may be alternately disposed. The quantum well and the quantum wall may be made of a semiconductor material having a composition formula of In _x Al _y Ga _1-xy P (0≤x≤1, 0≤y≤1, 0≤x+y≤1), respectively; GaInP/AlGaInP, GaP/AlGaP, InGaP/AlGaP, InGaN/GaN, InGaN/InGaN, GaN/AlGaN, InAlGaN/GaN, GaAs/AlGaAs, and InGaAs/AlGaAs may be formed as one or more pair structures, but is not limited thereto. .

The second conductivity type semiconductor layer 116 may be formed on the active layer 114 . The second conductivity-type semiconductor layer 116 may be implemented with a semiconductor compound, for example, a group II-IV and a group III-V compound semiconductor. The second conductivity-type semiconductor layer 116 may be formed in a single layer or multiple layers. The second conductivity type semiconductor layer 116 may be doped with a second conductivity type dopant. For example, the second conductive AlGaN-based semiconductor layer 116 is a semiconductor material having a composition formula of In _x Al _y Ga _1-xy P (0=x=1, 0=y=1, 0=x+y=1) It may include, but is not limited to. When the second conductive AlGaN-based semiconductor layer 116 is a p-type semiconductor layer, the second conductive dopant is a p-type dopant and may include Mg, Zn, Ca, Sr, Ba, or the like.

Although the first conductivity type AlGaN-based semiconductor layer 112 is described as an n-type semiconductor layer and the second conductivity-type AlGaN-based semiconductor layer 116 is described as a p-type semiconductor layer, the first conductivity-type AlGaN-based semiconductor layer ( 112) may be formed as a p-type semiconductor layer, and the second conductivity-type AlGaN-based semiconductor layer 116 may be formed as an n-type semiconductor layer, but is not limited thereto. A semiconductor having a polarity opposite to that of the second conductivity type, for example, an n-type semiconductor layer (not shown) may be formed on the second conductivity type AlGaN-based semiconductor layer 116 . Accordingly, the light emitting structure 110 may be implemented with any one of an n-p junction structure, a p-n junction structure, an n-p-n junction structure, and a p-n-p junction structure.

Referring to FIG. 6 , the first reflective layer 132 and the lower ohmic pattern 141 may be formed on the light emitting structure 110 .

For example, the first reflective layer 132 may be deposited on the light emitting structure 110 and may include a plurality of holes (not shown) through which the light emitting structure 110 is exposed through an etching process using a photoresist. The lower ohmic pattern 141 may be deposited in the plurality of holes, but is not limited thereto.

The lower ohmic pattern 141 may be formed of a material having excellent electrical contact with a semiconductor. The lower ohmic pattern 141 may be formed in a single layer or multiple layers. The lower ohmic pattern 141 includes Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, indium tin oxide (ITO), indium zinc oxide (IZO), IZTO(indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO(indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc) oxide), IZON (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx/ITO, Ni/IrOx/Au, and Ni/IrOx/Au/ It may be formed including at least one of ITO, but is not limited to these materials.

The lower ohmic pattern 141 may directly contact the second conductivity type semiconductor layer 116 . Although not shown in the drawing, a separate reflective layer (not shown) may be formed between the lower ohmic pattern 141 and the second conductivity type semiconductor layer 116 .

The first reflective layer 132 may include at least one metal layer (not shown) and at least one insulating layer (not shown), but is not limited thereto. In addition, the first reflective layer 132 may be a Distributed Bragg Reflector (DBR), but is not limited thereto.

Referring to FIG. 7 , the lower electrode 140 may be formed on the light emitting structure 110 . Here, the lower electrode 140 includes the configuration of the lower ohmic pattern 141, but is not limited thereto.

The lower electrode 140 may include a second reflective layer 142 , a bonding layer 144 and a support substrate 146 .

The second reflective layer 142 may be formed of a single layer or multiple layers. The second reflective layer 142 may be formed of a material having excellent electrical contact and high reflectivity. For example, the second reflective layer 142 may be formed of a single layer or multiple layers of a metal or alloy including at least one of Pd, Ir, Ru, Mg, Zn, Pt, Ag, Ni, Al, Rh, Au, and Hf. .

The bonding layer 144 may be formed as a single layer or multiple layers. The bonding layer 144 may be formed of a material having excellent electrical contact. For example, the bonding layer 144 may be Ni, Ti, Au or an alloy thereof, but is not limited thereto.

The support substrate 146 may be formed in a single layer or multiple layers. The support substrate 146 may be formed of a material having excellent electrical contact. For example, the support substrate 146 may optionally include a carrier wafer (eg, GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, etc.), Cu, Au, Cu Alloy, Ni, Cu-W, or the like. .

Referring to FIG. 8 , the substrate ( 102 in FIG. 7 ) may be removed. As a method of removing the substrate (102 in FIG. 7), a laser, chemical etching, or physical etching may be used. For example, the removal method of the substrate (102 in FIG. 7) may use a laser lift-off method. The laser lift-off method provides energy to the interface between the substrate ( 102 in FIG. 7 ) and the light emitting structure 110, so that the bonding surface of the light emitting structure 110 is thermally decomposed and the substrate 102 and the light emitting structure 110 are thermally decomposed. ) can be separated.

The first conductivity type semiconductor layer 112 may be exposed from the substrate ( 102 in FIG. 7 ).

Although not shown in the drawing, a light extraction pattern (not shown) having a plurality of concave portions and a plurality of convex portions in a rough shape may be formed on the exposed surface of the first conductivity type semiconductor layer 112 .

Referring to FIG. 9 , the upper ohmic layer 171 and the branch electrode 172 may be formed on the exposed first conductivity type semiconductor layer 112 . The upper ohmic layer 171 may be deposited on the first conductivity type semiconductor layer 112 , and the branch electrode 172 may be deposited on the upper ohmic layer 171 . That is, the upper ohmic layer 171 may be disposed between the first conductivity type semiconductor layer 112 and the branch electrode 172 .

The upper ohmic layer 171 may be formed as a single layer or multiple layers. The upper ohmic layer 171 may be formed of a material having excellent electrical contact with a semiconductor. For example, the upper ohmic layer 171 may include Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, indium tin oxide (ITO), or indium zinc oxide (IZO). , IZTO(indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO(indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IZON (IZO Nitride), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx/ITO, Ni/IrOx/Au, and Ni/IrOx/Au /ITO, but is not limited to these materials.

The branch electrode 172 may be formed of a single layer or multiple layers, and may be formed of at least one of Ti, Cr, Ni, Al, Pt, Au, W, Cu, Mo, and Cu-W, but is not limited thereto. .

The branch electrode 172 may adopt the technical features of FIGS. 1 to 3 .

Referring to FIG. 10 , the upper electrode pad 174 may cover the exposed portion of the first conductive semiconductor layer 112 and the branch electrode 172 .

The upper electrode pad 174 may include at least one connection electrode 174p protruding to the side. The upper electrode pad 174 and the connection electrode 174p may adopt the technical features of FIGS. 1 to 3 .

The upper electrode pad 174 may be formed of a single layer or multiple layers, and may be formed of at least one of Ti, Cr, Ni, Al, Pt, Au, W, Cu, Mo, and Cu-W, but is not limited thereto. no.

The manufacturing method of the light emitting device shown in FIGS. 5 to 10 has been described based on the exemplary embodiment, but is not limited thereto, and the order of each manufacturing step may be changed.

In the light emitting device of the embodiment, since the connection electrode 174a protruding from the side of the upper electrode pad 174 is directly connected to the branch electrode 172, the current supplied from the upper electrode pad 174 is transmitted through the connection electrode 174a. It may be constantly separated and provided to the branch electrodes 172 .

Therefore, the light emitting device 100 according to the embodiment can improve luminous intensity by improving current spread by the connection electrode 174a. In addition, in the embodiment, the area of the branch electrode 172 is narrowed by the length of the connection electrode 174a, and the area of the upper ohmic layer 171 disposed under the branch electrode 172 may also be narrowed. . That is, since the area of the upper ohmic layer 171 having a higher bandgap energy than the active layer 114 is narrowed, light absorption by the upper ohmic layer 171 can be reduced and light loss can be improved.

11 is a plan view illustrating a light emitting device according to another embodiment.

As shown in FIG. 11, the light emitting device 101 of another embodiment includes an upper electrode pad 274 disposed on a light emitting structure and disposed along an edge of the light emitting structure,

The upper electrode pad 274 may include four first to fourth side portions 274a, 274b, 274c, and 274d and first and second connection electrodes 274p1 and 274p2.

The first connection electrode 274p1 may extend from the first side portion 274a, and the second connection electrode 274p2 may extend from the fourth side portion 274d. The first connection electrode 274p1 protrudes from the first side portion 274a toward the fourth side portion 274d, and the second connection electrode 274p2 extends from the fourth side portion 274d to the first side portion ( 274a) may protrude in the direction.

That is, the upper electrode pad 274 may adopt the technical characteristics of the upper electrode pad (174 in FIGS. 1 to 10) of the embodiment.

The light emitting device 101 of another embodiment may include first and second branch electrodes 272a and 272b.

The first and second branch electrodes 272a and 272b may be spaced apart from each other by a predetermined distance. That is, the first branch electrode 272a may be connected to the first connection electrode 274p1 protruding from the first side portion 274a. The second branch electrode 272p2 may be connected to the second connection electrode 274p2 protruding from the fourth side portion 274d. An end of the first branch electrode 272a may be spaced apart from an end of the second branch electrode 272b by a predetermined distance.

The light emitting device 101 of another embodiment may adopt the technical characteristics of the light emitting device of the embodiments of FIGS. 1 to 10 except for the structure of the first and second branch electrodes 272a and 272b.

The light emitting device 101 according to another embodiment is provided by the first and second branch electrodes 272a and 272b connected to the first and second connection electrodes 274p1 and 274p2 protruding from the upper electrode pad 274, respectively. Current spreading may be improved, and since an area of the upper ohmic layer having a higher bandgap energy than that of the active layer is narrowed, light absorption by the upper ohmic layer may be reduced and optical loss may be improved.

Accordingly, the light emitting device 101 according to another embodiment can improve the current spread and reduce the light loss to increase the luminous intensity. FIG. 12 is a plan view illustrating a light emitting device according to another embodiment.

As shown in FIG. 12, the light emitting device 102 of another embodiment adopts the technical features of the light emitting device of the embodiment of FIGS. 1 to 10 except for the upper electrode pad 374 and the branch electrode 372. can do.

The upper electrode pad 374 may be disposed in the central region of the light emitting device, but is not limited thereto. The shape of the upper electrode pad 374 may be variously changed. At least one connection electrode 374p may be included on an outer surface of the upper electrode pad 374 . The branch electrode 372 may be connected to the connection electrode 374p.

The light emitting device 102 of another embodiment may adopt the technical features of the light emitting device of the embodiments of FIGS. 1 to 10 except for the structure of the upper electrode pad 374, the connection electrode 374p, and the branch electrode 372. can

In the light emitting device 102 according to another embodiment, current spreading can be improved by the branch electrode 372 connected to the connection electrode 374p protruding outward from the upper electrode pad 374, and the band gap energy is reduced. Since the area of the upper ohmic layer, which is larger than the active layer, is narrowed, light absorption by the upper ohmic layer may be reduced and light loss may be improved.

Accordingly, the light emitting device 102 according to another embodiment may improve luminous intensity by improving current spreading and reducing light loss.

13 is a cross-sectional view illustrating a light emitting device package according to an embodiment.

As shown in FIG. 13, the light emitting device package 200 according to the embodiment includes a package body 205, a first lead frame 213 and a second lead frame 214 installed on the package body 205. ), and a light emitting device 100 disposed on the second lead frame 214 and electrically connected to the first lead frame 213 and the second lead frame 214, and the light emitting device 100 A surrounding molding member 240 may be included. The molding member 240 may include a phosphor and may include a concave or convex upper surface.

The light emitting device 100 may adopt technical features of the embodiments of FIGS. 1 to 10 .

The first lead frame 213 and the second lead frame 214 are electrically separated from each other, and the first lead frame 213 is electrically connected to the light emitting device 100 by a wire 230 to It may serve to provide power to the light emitting device 100 . In addition, the first lead frame 213 and the second lead frame 214 may serve to increase light efficiency by reflecting light generated from the light emitting device 100, and in the light emitting device 100 It can also play a role in discharging the generated heat to the outside.

The light emitting device 100 may be electrically connected to the first lead frame 213 or the second lead frame 214 by any one of a wire method, a flip chip method, and a die bonding method.

The light emitting device 100 according to the embodiment may be applied to a backlight unit, a lighting unit, a display device, an indicator device, a lamp, a street light, a vehicle lighting device, a vehicle display device, a smart watch, etc., but is not limited thereto.

Features, structures, effects, etc. described in the embodiments above are included in at least one embodiment, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, and effects illustrated in each embodiment can be combined or modified with respect to other embodiments by those skilled in the art in the field to which the embodiments belong. Therefore, contents related to these combinations and modifications should be construed as being included in the scope of the embodiments.

Although the above has been described centering on the embodiment, this is only an example and does not limit the embodiment, and those skilled in the art in the field to which the embodiment belongs may find various things not exemplified above to the extent that they do not deviate from the essential characteristics of the embodiment. It will be appreciated that variations and applications of branches are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the embodiments set forth in the appended claims.

171: upper ohmic layer
172, 372: branch electrode
174, 274, 374: upper electrode pad
174p, 374p: connection electrode

Claims (10)

lower electrode;
a light emitting structure positioned on the lower electrode and including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer;
an upper electrode pad disposed along an edge of the light emitting structure; and
At least one branch electrode connected to the upper electrode pad,
The upper electrode pad includes at least one connection electrode connected to the at least one branch electrode,
The upper electrode pad includes a first side portion, second and third side portions connected to both ends of the first side portion, and a fourth side portion connected to the second and third side portions and facing the first side portion; At least one connection electrode is a light emitting element protruding from the first side portion or the fourth side portion.
According to claim 1,
The at least one connection electrode has a one-to-one correspondence with the at least one branch electrode. According to claim 1,
The at least one connection electrode has a region overlapping with the at least one branch electrode. According to claim 1,
The length of the at least one connection electrode is 20㎛ to 60㎛ light emitting device. According to claim 1,
A width of the at least one connection electrode is a light emitting device of 5 μm to 20 μm. According to claim 1,
A width of the at least one connection electrode is greater than or equal to a width of the at least one branch electrode. According to claim 1,
The at least one connection electrode includes a first connection electrode protruding from the first side and a second connection electrode protruding from the fourth side, and ends of the first and second connection electrodes are spaced apart from each other by a predetermined distance. light emitting device. delete A light emitting device package comprising the light emitting device of any one of claims 1 to 7. According to claim 1,
The light emitting device further comprising an upper ohmic layer positioned under the at least one branched electrode.

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