KR102221112B1 - Light emitting device and lighting system - Google Patents

Abstract

The embodiment relates to a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system.
The light emitting device according to the embodiment includes a first conductivity-type semiconductor layer 112, an active layer 114 on the first conductivity-type semiconductor layer 112, and a second conductivity-type semiconductor layer on the active layer 114 ( 116, a first recess region R1 exposing an upper surface of the first conductivity type semiconductor layer 112 by removing portions of the second conductivity type semiconductor layer 116 and the active layer 114, A first electrode 131 on the exposed first conductivity type semiconductor layer 112 and a first reflective electrode disposed on the first electrode 131 and having a horizontal width wider than that of the first electrode 131 130, a first pad electrode 137 on the first reflective electrode 130 and a second pad electrode 147 on the second conductivity type semiconductor layer 116.

Description

Light emitting device and lighting system {LIGHT EMITTING DEVICE AND LIGHTING SYSTEM}

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

Light Emitting Device (LED) is a pn junction diode that converts electric energy into light energy, and can be generated using a group 3-5 or group 2-6 semiconductor compound on the periodic table, and is a semiconductor compound. Various colors can be realized by adjusting the composition ratio of.

For example, nitride semiconductors are attracting great interest in the development of optical devices and high-power electronic devices due to their high thermal stability and wide band gap energy. Such nitride semiconductors have been commercialized and widely used in a blue light emitting device, a green light emitting device, an ultraviolet (UV) light emitting device, and a red light emitting device.

On the other hand, the light emitting device is utilized in the form of a package and a predetermined pad electrode is formed for electrical connection. However, there is a problem in that the light output is deteriorated by the pad electrode absorbing or blocking the emitted light.

The embodiment is to provide a light emitting device capable of improving light output, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system.

The light emitting device according to the embodiment includes a first conductivity-type semiconductor layer 112, an active layer 114 on the first conductivity-type semiconductor layer 112, and a second conductivity-type semiconductor layer on the active layer 114 ( 116, a first recess region R1 exposing an upper surface of the first conductivity type semiconductor layer 112 by removing portions of the second conductivity type semiconductor layer 116 and the active layer 114, A first electrode 131 on the exposed first conductivity type semiconductor layer 112 and a first reflective electrode disposed on the first electrode 131 and having a horizontal width wider than that of the first electrode 131 130, a first pad electrode 137 on the first reflective electrode 130 and a second pad electrode 147 on the second conductivity type semiconductor layer 116.

In addition, the light emitting device 103 according to the embodiment includes a first conductivity type semiconductor layer 112, an active layer 114 on the first conductivity type semiconductor layer 112, and a second conductivity on the active layer 114. Type semiconductor layer 116 and a first recess region exposing the upper surface of the first conductivity type semiconductor layer 112 by removing portions of the second conductivity type semiconductor layer 116 and the active layer 114 ( R1), the first electrode 131 on the exposed first conductivity type semiconductor layer 112, and a horizontal width wider than that of the first electrode 131 and disposed on the first electrode 131 A first reflective electrode 130, a first pad electrode 137 on the first reflective electrode 130, a second pad electrode 147 on the second conductivity type semiconductor layer 116, and the A support member 150 disposed on the first recess region R1 and the second conductive semiconductor layer 116, and a third reflection disposed between the support member 150 and the first pad electrode 137 It may include an electrode 136.

The lighting system according to the embodiment may include a light-emitting unit including the light-emitting device.

The embodiment may provide a light emitting device capable of improving light output, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system.

1 is a cross-sectional view of a light emitting device according to a first embodiment.
2 is a conceptual diagram of a reflection path of a light emitting device according to the first embodiment.
3 is a cross-sectional view of a light emitting device according to a second embodiment.
4 is a cross-sectional view of a light emitting device according to a third embodiment.
5 to 14 are cross-sectional views illustrating a method of manufacturing a light emitting device according to an embodiment.
15 is a cross-sectional view of a light emitting device package according to an embodiment.
16 is a perspective view of a lighting device according to the embodiment.

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

(Example)

As described above, the light emitting device is used in the form of a package, and there is a problem in that the light output is deteriorated because the pad electrode formed for electrical connection absorbs or blocks the emitted light. In the prior art, a Distributed Bragg-Reflectors (DBR) structure is used to prevent light absorption or blocking, but such a technology has a high possibility of lowering reliability and a low process efficiency.

Accordingly, the embodiment is to provide a light emitting device capable of improving light output.

1 is a cross-sectional view of a light emitting device 100 according to a first embodiment.

The light emitting device 100 according to the first embodiment includes a first conductivity type semiconductor layer 112, an active layer 114 on the first conductivity type semiconductor layer 112, and a second conductivity type semiconductor layer 114 on the active layer 114. A first recess region exposing the top surface of the first conductivity type semiconductor layer 112 by removing a conductive type semiconductor layer 116 and a portion of the second conductivity type semiconductor layer 116 and the active layer 114 (R1), a first electrode 131 on the exposed first conductivity type semiconductor layer 112 and a horizontal width wider than that of the first electrode 131 and disposed on the first electrode 131 A first reflective electrode 130 to be formed, a first pad electrode 137 on the first reflective electrode 130 and a second pad electrode 147 on the second conductivity type semiconductor layer 116 I can.

The first conductivity type semiconductor layer 112, the active layer 114, and the second conductivity type semiconductor layer 116 may be referred to as a light emitting structure 110.

The light emitting device according to the embodiment may be packaged in the form of a flip chip, but is not limited thereto.

2 is a conceptual diagram of a reflection path of the light emitting device 100 according to the first embodiment.

In an embodiment, the first reflective electrode 130 may be disposed to extend upward on the first electrode 131, and the total horizontal width of the first reflective electrode 130 is It may be provided wider than the horizontal width. Through this, light L emitted from the active layer 114 is mostly reflected downward from the first reflective electrode 130 and light reaching the first pad electrode 137 is minimized, thereby increasing light output. .

The first reflective electrode 130 may be formed of a material having excellent reflectivity and excellent electrical contact. For example, the first reflective electrode 130 may be formed of a metal or an alloy containing at least one of Ag, Al, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf. I can.

In addition, the first reflective electrode 130 may be formed in a multilayer using the metal or alloy and a light-transmitting conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, and ATO. For example, IZO/Ni , AZO/Ag, IZO/Ag/Ni, AZO/Ag/Ni, etc. can be stacked.

In addition, the first reflective electrode 130 may include a material having excellent bonding strength. For example, the first reflective electrode 130 may include at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, and Ta.

In an embodiment, the first reflective electrode 130 is electrically connected to the first electrode 131 and extends upwardly, and at least one side from the first connection reflective electrode 133 It may include a first wing reflective electrode 135 extending horizontally.

The first connection reflective electrode 133 and the first wing reflective electrode 135 may be formed of the same material or different materials.

The first wing reflective electrode 135 may extend from the first connection reflective electrode 133 to both sides, and the horizontal width of the first connection reflective electrode 133 is a horizontal width of the first electrode 131 It can be wider.

From a plan view, light output by increasing the ratio of light reflected from the first wing reflective electrode 135 by forming as wide an area where the first wing reflective electrode 135 overlaps the light emitting structure 110 as possible. Can increase

Accordingly, the first wing reflective electrode 135 may have a wider horizontal width than that of the first recess region R1 and may be disposed to overlap the second conductivity type semiconductor layer 116 between the top and bottom.

In the embodiment, the horizontal width of the first wing reflective electrode 135 is designed to be wider than the horizontal width of the first pad electrode 137 disposed on the upper side thereof to minimize the absorption of light from the first pad electrode 137. To increase the light output.

In an embodiment, the first reflective electrode 130 may include a plurality of layers. For example, the first reflective electrode 130 may include a reflective layer having relatively high reflectivity (not shown) and a coupling layer having relatively high coupling property (not shown) on the bottom side.

As the reflective layer, a metal containing at least one of Ag, Al, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, or an alloy thereof may be employed. In the case of a light emitting device in the visible light region, it is possible to increase reflectivity when an Ag-based reflective layer is disposed on the bottom surface, and in the case of a light-emitting device in the UV region, an Al-based reflective layer is disposed on the bottom surface to increase reflectivity.

As the bonding layer, at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, or Ta may be employed, but is not limited thereto.

The embodiment may include a support member 150 disposed on the first recess region R1 and the second conductivity type semiconductor layer 116.

The support member 150 may be formed of a dielectric layer such as oxide or nitride, or a resin material such as silicon or epoxy to form an insulating support layer, but is not limited thereto.

A heat diffusion agent (not shown) may be added to the support member 150 to improve heat generation characteristics.

The heat spreading agent may be included in the support member 150 at about 1 to 99 Wt/%, and thus may be added at 50% or more for heat diffusion efficiency.

The heat diffusion agent may include at least one of oxides, nitrides, fluorides, and sulfides including materials such as Al, Cr, Si, Ti, Zn, and Zr. The heat spreading agent may be powder particles, grains, fillers, additives, and the like of a predetermined size.

For example, a ceramic material may be included as a heat spreader, and the ceramic material may include low temperature co-fired ceramic (LTCC) or high temperature co-fired ceramic (HTCC). have.

The ceramic material may be formed of nitride or metal nitride having a higher thermal conductivity than oxide among insulating materials such as nitride or oxide. The metal nitride may include, for example, a material having a thermal conductivity of 140 W/mK or more.

For example, ceramic materials are SiO ₂ , Si _x O _y , Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , BN, Si ₃ N ₄ , SiC(SiC-BeO), BeO , CeO, AlN may be a ceramic (Ceramic) series.

In an embodiment, the active layer 114 may include a quantum well and a quantum wall.

At this time, in the embodiment, the distance D between the outermost quantum well closest to the first wing reflective electrode 135 among the quantum wells of the active layer 114 and the bottom surface of the first wing reflective electrode 135 is n× By setting λ _n /4 (where n is an integer and λ _n is the length of the wavelength in the supporting member), the maximum reflectance can be increased by constructive interference.

According to the embodiment, the reflectance of light emitted by the first reflective electrode 130 having high reflectivity and reliability is increased, and the distance between the active layer and the first wing reflective electrode 135 of the first reflective electrode 130 is increased. By controlling under constructive interference conditions, it is possible to maximize light output by obtaining an optimal reflectance.

In an embodiment, the support member 150 may be disposed inside the first pad electrode 137 and the second pad electrode 147.

Accordingly, the second pad electrode 147 may be disposed on a side surface and an upper surface of the support member 150.

The embodiment includes a second reflective electrode 141 disposed between the second conductivity-type semiconductor layer 116 and the second pad electrode 147 to absorb light from the bottom of the second pad electrode 147. It can be minimized to improve the light output.

3 is a cross-sectional view of a light emitting device 102 according to a second embodiment.

The second embodiment can adopt the technical features of the first embodiment. For example, in the second embodiment, the first electrode 131 on the exposed first conductivity type semiconductor layer 112, and the first electrode 131 has a horizontal width wider than that of the first electrode 131 It may include a first reflective electrode 130 disposed thereon.

The first reflective electrode 130 is electrically connected to the first electrode 131 and extends horizontally on at least one side from the first connecting reflective electrode 133 extending upward and the first connecting reflective electrode 133 The first wing reflective electrode 135 may be included.

In the second embodiment, a substrate 105 may be further provided under the first conductivity type semiconductor layer 112, and a light extraction pattern P may be provided on a bottom surface of the substrate 105.

The substrate 105 may be a conductive substrate or an insulating substrate. For example, the substrate 105 may be at least one _{of sapphire (Al 2} O ₃ ), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ 0 _3. A light extraction pattern P is formed on the bottom surface of the substrate 105 to maximize light extraction efficiency, thereby increasing light output.

4 is a cross-sectional view of a light emitting device 103 according to a third embodiment.

The light emitting device 103 according to the third embodiment includes a first conductivity type semiconductor layer 112, an active layer 114 on the first conductivity type semiconductor layer 112, and a second conductivity type semiconductor layer 114 on the active layer 114. A first recess region exposing the top surface of the first conductivity type semiconductor layer 112 by removing a conductive type semiconductor layer 116 and a portion of the second conductivity type semiconductor layer 116 and the active layer 114 (R1), a first electrode 131 on the exposed first conductivity type semiconductor layer 112 and a horizontal width wider than that of the first electrode 131 and disposed on the first electrode 131 A first reflective electrode 130 that is formed, a first pad electrode 137 on the first reflective electrode 130, a second pad electrode 147 on the second conductivity type semiconductor layer 116, A support member 150 disposed on the first recess region R1 and the second conductivity-type semiconductor layer 116, and a third disposed between the support member 150 and the first pad electrode 137 A reflective electrode 136 may be included.

The third embodiment can adopt the technical features of the first embodiment or the second embodiment, and will be described below mainly with the main features of the third embodiment.

The third embodiment may include a third reflective electrode 136 disposed between the support member 150 and the first pad electrode 137. The horizontal width of the third reflective electrode 136 may be greater than the horizontal width of the first electrode 131. Through this, light absorption in the first pad electrode 137 may be minimized, thereby increasing light output.

The third embodiment may further include a fourth reflective electrode 146 disposed on a bottom surface of the second pad electrode 147 to minimize light absorption from the second pad electrode 147 to increase the outline output. .

The third reflective electrode 136 or the fourth reflective electrode 146 may be formed of a material having excellent reflectivity and excellent electrical contact. For example, the third reflective electrode 136 or the fourth reflective electrode 146 may contain at least one of Ag, Al, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, and Hf. It may be formed of a containing metal or alloy.

In addition, the third reflective electrode 136 or the fourth reflective electrode 146 may be formed in a multilayer using the metal or alloy and a transparent conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, , For example, IZO/Ni, AZO/Ag, IZO/Ag/Ni, AZO/Ag/Ni, etc. can be stacked.

In addition, the third reflective electrode 136 or the fourth reflective electrode 146 may include a material having excellent bonding strength. For example, the third reflective electrode 136 or the fourth reflective electrode 146 may include at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, or Ta. .

In an embodiment, the third reflective electrode 136 or the fourth reflective electrode 146 may include a plurality of layers. For example, the third reflective electrode 136 or the fourth reflective electrode 146 may include a reflective layer with relatively high reflectivity (not shown) and a coupling layer with relatively high coupling property on the bottom side. I can.

As the reflective layer, a metal containing at least one of Ag, Al, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, or an alloy thereof may be employed. In the case of a light emitting device in the visible light region, it is possible to increase reflectivity when an Ag-based reflective layer is disposed on the bottom surface, and in the case of a light-emitting device in the UV region, an Al-based reflective layer is disposed on the bottom surface to increase reflectivity.

As the bonding layer, at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, or Ta may be employed, but is not limited thereto.

The embodiment may provide a light emitting device capable of improving light output.

Hereinafter, a method of manufacturing a light emitting device according to an embodiment will be described with reference to FIGS. 5 to 14. Hereinafter, description will be made based on the second embodiment, but the embodiment is not limited thereto.

First, a substrate 105 is prepared as shown in FIG. 5, and the substrate 105 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate. For example, the substrate 105 may be at least one _{of sapphire (Al 2} O ₃ ), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ 0 _3. The upper surface of the substrate 105 may have an uneven structure (not shown), but the embodiment is not limited thereto. The substrate 105 may be wet cleaned to remove impurities from the surface.

Thereafter, a light emitting structure 110 including a first conductivity type semiconductor layer 112, an active layer 114, and a second conductivity type semiconductor layer 116 may be formed on the substrate 105.

A buffer layer (not shown) may be formed on the substrate 105. The buffer layer can alleviate lattice mismatch between the material of the light emitting structure 110 and the substrate 105, and the material of the buffer layer is a group 3-5 compound semiconductor such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN , AlInN may be formed of at least one of.

An undoped semiconductor layer may be formed on the buffer layer, but the embodiment is not limited thereto.

Next, the first conductivity-type semiconductor layer 112 formed on the substrate 105 or the buffer layer may be implemented with a semiconductor compound, for example, a compound semiconductor such as Group 3-5, Group 2-6, etc. , A first conductivity type dopant may be doped. When the first conductivity-type semiconductor layer 112 is an n-type semiconductor layer, the first conductivity-type dopant is an n-type dopant and may include Si, Ge, Sn, Se, and Te, but is not limited thereto.

The first conductivity type semiconductor layer 112 may include _{a semiconductor material having a composition formula of In x} Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). I can. For example, the first conductivity type semiconductor layer 112 is formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, InP Can be.

The first conductivity-type semiconductor layer 112 may form an N-type GaN layer using a method such as chemical vapor deposition (CVD), molecular beam epitaxy (MBE), sputtering, or hydroxide vapor phase epitaxy (HVPE). . In addition, the first conductivity-type semiconductor layer 112 is a silane containing n-type impurities such as _{trimethyl gallium gas (TMGa), ammonia gas (NH 3} ), nitrogen gas (N _{2 ), and silicon (Si) in the chamber.} It may be formed by injecting gas (SiH _{4 ).}

Next, in the formed active layer 114, electrons injected through the first conductivity-type semiconductor layer 112 and holes injected through the second conductivity-type semiconductor layer 116 formed later meet each other to form an active layer (light emitting layer). It is a layer that emits light with energy determined by the energy band inherent in the material.

The active layer 114 may be formed of at least one of a single quantum well structure, a multi quantum well structure (MQW), a quantum-wire structure, or a quantum dot structure. For example, in the active layer 114, trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) may be injected to form a multiple quantum well structure. It is not limited thereto.

The active layer 114 may include a well layer/barrier layer structure. For example, the active layer 114 may be formed in one or more pair structures of InGaN/GaN, InGaN/InGaN, GaN/AlGaN, InAlGaN/GaN, GaAs (InGaAs)/AlGaAs, GaP (InGaP)/AlGaP, but It is not limited to this. The well layer may be formed of a material having a band gap lower than that of the barrier layer.

Next, the electron blocking layer 118 is formed on the active layer 114 to serve as electron blocking and MQW cladding of the active layer, thereby improving luminous efficiency. For example, the electron blocking layer 118 may be formed of an Al _x In _y Ga _(1-xy) N (0≦x≦1,0≦y≦1) based semiconductor. In addition, the electron blocking layer 118 may be formed of an Al _z Ga _(1-z) N/GaN (0≦z≦1) superlattice, but is not limited thereto.

Next, the second conductivity type semiconductor layer 116 may be implemented with a semiconductor compound, for example, a compound semiconductor such as group 3-5, group 2-6, etc., and may be doped with a second conductivity type dopant. have

For example, the second conductivity type semiconductor layer 116 is _{a semiconductor having a composition formula of In x} Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) It may contain substances. When the second conductivity-type semiconductor layer 116 is a p-type semiconductor layer, the second conductivity-type dopant is a p-type dopant, and may include Mg, Zn, Ca, Sr, Ba, and the like.

The second conductivity type semiconductor layer 116 is a vicetyl cyclo containing p-type impurities such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N _{2 ), and magnesium (Mg) in the chamber.} Pentadienyl magnesium (EtCp ₂ Mg) {Mg(C ₂ H ₅ C ₅ H ₄ ) ₂ } may be implanted to form a p-type GaN layer, but is not limited thereto.

In an embodiment, the first conductivity-type semiconductor layer 112 may be implemented as an n-type semiconductor layer, and the second conductivity-type semiconductor layer 116 may be implemented as a p-type semiconductor layer, but is not limited thereto. In addition, a semiconductor, for example, an n-type semiconductor layer (not shown) having a polarity opposite to that of the second conductivity type may be formed on the second conductivity type semiconductor layer 116. Accordingly, the light emitting structure 110 may be implemented in 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.

Thereafter, an ohmic layer 120 may be formed on the second conductivity type semiconductor layer 116.

The ohmic layer 120 may be formed by stacking a single metal, a metal alloy, or a metal oxide in multiple layers so as to efficiently inject holes. For example, the ohmic layer may be formed of an excellent material that is in electrical contact with a semiconductor. For example, the ohmic layer 120 is ITO (indium tin oxide), IZO (indium zinc oxide), 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, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt , Au, and may be formed to include at least one of Hf, but is not limited to these materials.

Next, as shown in FIG. 6, a portion of the ohmic layer 120, the second conductivity type semiconductor layer 116, the electron blocking layer 118, and the active layer 114 using a predetermined first mask (not shown) as an etching mask. Is removed to form a first recess region R1 exposing the top surface of the first conductivity type semiconductor layer 112. The first recess region R1 may be formed by wet etching or dry etching, and a side surface of the first recess region R1 may have a vertical or predetermined inclination.

Next, as shown in FIG. 7, a first electrode 131 may be formed on the first conductivity type semiconductor layer 112 of the exposed first recess region R1. The first electrode 131 is at least one of titanium (Ti), chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), tungsten (W), and molybdenum (Mo). It can also be formed into one.

Next, as shown in FIG. 8, a first support member 151 may be formed on the first recess region R1, the second conductivity type semiconductor layer 116, and the ohmic layer 120. The first support member 151 may be formed on a partial region of the ohmic layer 120 to expose a region where the second pad electrode 147 will be formed thereafter.

The first support member 151 may be formed of a dielectric layer such as oxide or nitride or a resin material such as silicon or epoxy to form an insulating support layer, but is not limited thereto.

A heat spreader (not shown) may be added to the first support member 151 to improve heat generation characteristics.

The heat spreading agent may be included in the first support member 151 in an amount of about 1 to 99 Wt/%, so that it may be added in an amount of 50% or more for heat diffusion efficiency.

The heat diffusion agent may include at least one of oxides, nitrides, fluorides, and sulfides including materials such as Al, Cr, Si, Ti, Zn, and Zr. The heat spreading agent may be powder particles, grains, fillers, additives, and the like of a predetermined size.

For example, a ceramic material may be included as a heat spreader, and the ceramic material may include low temperature co-fired ceramic (LTCC) or high temperature co-fired ceramic (HTCC). have.

The ceramic material may be formed of nitride or metal nitride having a higher thermal conductivity than oxide among insulating materials such as nitride or oxide. The metal nitride may include, for example, a material having a thermal conductivity of 140 W/mK or more.

For example, ceramic materials are SiO ₂ , Si _x O _y , Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , BN, Si ₃ N ₄ , SiC(SiC-BeO), BeO , CeO, AlN may be a ceramic (Ceramic) series.

Meanwhile, as described above, the active layer 114 may include a quantum well and a quantum wall. At this time, in the embodiment, the distance D between the outermost quantum well closest to the first wing reflective electrode 135 formed later among the quantum wells of the active layer 114 and the bottom surface of the first wing reflective electrode 135 is _n × λ n / 4 set as (where, n is an integer, λ _n is the length of the wavelength within the dielectric), whereby it is possible to increase the maximum of the reflectivity by the constructive interference.

Since the distance condition can be controlled by the height of the first support member 151, the outermost quantum well closest to the upper surface of the first support member 151 among the quantum wells of the active layer 114 and the first support The distance D from the upper surface of the member 151 is set to n×λ _n /4 (where n is an integer, and λ _n is the length of the wavelength in the support member), so that the maximum reflectivity can be increased by constructive interference. .

Next, as shown in FIG. 9, a second recess region R2 may be formed in the first support member 151 so that the upper surface of the first electrode 131 is exposed. For example, the second recess region R2 may be formed by wet etching or dry etching using a predetermined visual mask, but is not limited thereto.

Next, as shown in FIG. 10, a first reflective electrode 130 electrically connected to the first electrode 131 may be formed. In this case, the second reflective electrode 141 may be formed on the exposed ohmic layer 120. The second reflective electrode 141 may increase light output by preventing absorption of light by the bottom surface of the second pad electrode 147 formed later.

The first reflective electrode 130 includes a first connection reflective electrode 133 formed in the second recess region R2 and a first wing reflective electrode 135 formed on the first support member 151 can do.

For example, in an embodiment, the first reflective electrode 130 may be disposed to extend upwardly on the first electrode 131, and the total horizontal width of the first reflective electrode 130 is the first electrode It may be provided wider than the horizontal width of (131). Through this, light emitted from the active layer 114 is mostly reflected downward from the first reflective electrode 130, and light reaching the first pad electrode 137 formed thereafter is minimized, thereby increasing light output. .

The first reflective electrode 130 may be formed of a material having excellent reflectivity and excellent electrical contact. For example, the first reflective electrode 130 may be formed of a metal or an alloy containing at least one of Ag, Al, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf. I can. The second reflective electrode 141 may also be formed of the same material as the first reflective electrode 130, but is not limited thereto.

In addition, the first reflective electrode 130 may be formed in a multilayer using the metal or alloy and a light-transmitting conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, and ATO. For example, IZO/Ni , AZO/Ag, IZO/Ag/Ni, AZO/Ag/Ni, etc. can be stacked.

In addition, the first reflective electrode 130 may include a material having excellent bonding strength. For example, the first reflective electrode 130 may include at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, and Ta.

In an embodiment, the first reflective electrode 130 is electrically connected to the first electrode 131 and extends upwardly, and at least one side from the first connection reflective electrode 133 It may include a first wing reflective electrode 135 extending horizontally.

The first connection reflective electrode 133 and the first wing reflective electrode 135 may be formed of the same material or different materials.

The first wing reflective electrode 135 may extend from the first connection reflective electrode 133 to both sides, and the horizontal width of the first connection reflective electrode 133 is a horizontal width of the first electrode 131 It can be wider.

From a plan view, light output by increasing the ratio of light reflected from the first wing reflective electrode 135 by forming as wide an area where the first wing reflective electrode 135 overlaps the light emitting structure 110 as possible. Can increase

Accordingly, the first wing reflective electrode 135 may have a wider horizontal width than that of the first recess region R1 and may be disposed to overlap the second conductivity type semiconductor layer 116 between the top and bottom.

In the embodiment, the horizontal width of the first wing reflective electrode 135 is designed to be wider than the horizontal width of the first pad electrode 137 disposed on the upper side thereof to minimize the absorption of light from the first pad electrode 137. To increase the light output.

In an embodiment, the first reflective electrode 130 may include a plurality of layers. For example, the first reflective electrode 130 may include a reflective layer having relatively high reflectivity (not shown) and a coupling layer having relatively high coupling property (not shown) on the bottom side.

As the reflective layer, a metal containing at least one of Ag, Al, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, or an alloy thereof may be employed. In the case of a light emitting device in the visible light region, it is possible to increase reflectivity when an Ag-based reflective layer is disposed on the bottom surface, and in the case of a light-emitting device in the UV region, an Al-based reflective layer is disposed on the bottom surface to increase reflectivity.

As the bonding layer, at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, or Ta may be employed, but is not limited thereto.

Next, as shown in FIG. 11, the support member 150 may be formed by forming a second support member 152 on the first reflective electrode 130 and the first support member 151. The second support member 152 may be formed of the same material as the first support member 151.

For example, the second support member 152 may be formed of a dielectric layer such as oxide or nitride or a resin material such as silicon or epoxy to form an insulating support layer, but is not limited thereto. A heat spreader may be added to the second support member 152 to improve heat generation characteristics.

Next, as shown in FIG. 12, a third recess region R3 may be formed in the second support member 152 so that the upper surface of the first electrode 131 is exposed. For example, the third recess region R3 may be formed by wet etching or dry etching using a predetermined visual mask, but is not limited thereto.

Next, as shown in FIG. 13, a first pad electrode 137 may be formed on the third recess region R3 and the support member 150, and the second reflective electrode 141 and the support member 150 ) On the second pad electrode 147 may be formed. The first pad electrode 137 or the second pad electrode 147 may include at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, or Ta, but is limited thereto. It is not.

In the embodiment, as shown in FIG. 4, a fourth reflective electrode 146 disposed between the support member 150 and the second pad electrode 147 is further formed to absorb light from the second pad electrode 147. By minimizing, it is possible to increase the gwak output.

The fourth reflective electrode 146 may be formed of a material having excellent reflectivity and excellent electrical contact. For example, the fourth reflective electrode 146 is formed of a metal or alloy containing at least one of Ag, Al, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf. I can.

In an embodiment, the fourth reflective electrode 146 may include a plurality of layers. For example, the fourth reflective electrode 146 may include a reflective layer having relatively high reflectivity (not shown) and a coupling layer having relatively high coupling property (not shown) on the bottom side.

As the reflective layer, a metal containing at least one of Ag, Al, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, or an alloy thereof may be employed. In the case of a light emitting device in the visible light region, it is possible to increase reflectivity when an Ag-based reflective layer is disposed on the bottom surface, and in the case of a light-emitting device in the UV region, an Al-based reflective layer is disposed on the bottom surface to increase reflectivity. As the bonding layer, at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, or Ta may be employed, but is not limited thereto.

Next, as shown in FIG. 14, by forming a light extraction pattern P on the bottom surface of the substrate 105, the light extraction efficiency can be maximized to increase light output.

The embodiment can provide a light emitting device capable of improving light output and a method of manufacturing the light emitting device.

A plurality of light emitting devices according to the embodiment may be arrayed on a substrate in the form of a package, and an optical member such as a light guide plate, a prism sheet, a diffusion sheet, and a fluorescent sheet may be disposed on a path of light emitted from the light emitting device package.

15 is a diagram illustrating a light emitting device package 200 in which a light emitting device is installed according to embodiments.

The light emitting device package 200 according to the embodiment includes a package body part 202, a third electrode layer 212 and a fourth electrode layer 211 installed on the package body part 202, and the package body part 202 A molding member 230 that is installed on and surrounds the light emitting device 102 and includes a phosphor 23 and includes a light emitting device 102 electrically connected to the third electrode layer 212 and the fourth electrode layer 211 It may include. The light-emitting device 102 is an example of the light-emitting device according to the second embodiment described above, but is not limited thereto, and the light-emitting device according to the first embodiment 100 and the third embodiment 3 may also be employed. have.

The package body portion 202 may be formed of a silicon material, a synthetic resin material, or a metal material, and a reflective layer 204 having an inclined surface may be formed around the light emitting device 102.

The third electrode layer 212 and the fourth electrode layer 211 are electrically separated from each other, and serve to provide power to the light emitting device 102. In addition, the third electrode layer 212 and the fourth electrode layer 211 may serve to increase light efficiency by reflecting light generated from the light emitting device 102, and It can also play a role in discharging heat to the outside.

The light-emitting device 102 may be installed on the package body part 202 or on the third electrode layer 212 or the fourth electrode layer 211.

The light emitting device 102 may be electrically connected to the third electrode layer 212 and/or the fourth electrode layer 211 by any one of a wire method, a flip chip method, or a die bonding method. In the embodiment, the first pad electrode 137 and the second pad electrode 147 of the light emitting device 102 are connected to the fourth electrode layer 211 and the third electrode layer 212 in a flip-chip manner. , The embodiment is not limited thereto.

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

16 is an exploded perspective view of a lighting system according to an embodiment.

The lighting device according to the embodiment may include a cover 2100, a light source module 2200, a radiator 2400, a power supply unit 2600, an inner case 2700, and a socket 2800. In addition, the lighting device according to the embodiment may further include one or more of a member 2300 and a holder 2500. The light source module 2200 may include a light emitting device or a light emitting device package according to the embodiment.

The light source module 2200 may include a light source unit 2210, a connection plate 2230, and a connector 2250. The member 2300 is disposed on an upper surface of the radiator 2400 and has guide grooves 2310 into which a plurality of light source units 2210 and a connector 2250 are inserted.

The holder 2500 blocks the receiving groove 2719 of the insulating part 2710 of the inner case 2700. Accordingly, the power supply unit 2600 accommodated in the insulating unit 2710 of the inner case 2700 is sealed. The holder 2500 has a guide protrusion 2510.

The power supply unit 2600 may include a protrusion 2610, a guide portion 2630, a base 2650, and an extension 2670. The inner case 2700 may include a molding unit together with the power supply unit 2600 therein. The molding part is a part where the molding liquid is solidified, and allows the power supply part 2600 to be fixed inside the inner case 2700.

Features, structures, effects, and the like described in the embodiments above are included in at least one embodiment, and are not necessarily limited to only one embodiment. Further, the features, structures, effects, etc. illustrated in each embodiment may be implemented by combining or modifying other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be interpreted as being included in the scope of the embodiments.

Although the embodiments have been described above, these are only examples and are not intended to limit the embodiments, and those of ordinary skill in the field to which the embodiments belong are not departing from the essential characteristics of the embodiments. It will be seen that branch transformation and application 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 in the appended claims.

A first conductivity type semiconductor layer 112; An active layer 114;
A second conductivity type semiconductor layer 116; Recess area R1; A first electrode 131;
A first reflective electrode 130; A first connection reflective electrode 133; The first wing reflective electrode 135
A first pad electrode 137; A second pad electrode 147;

Claims (16)

A first conductivity type semiconductor layer;
An active layer on the first conductivity type semiconductor layer;
A second conductivity type semiconductor layer on the active layer;
A recess region from which a portion of the second conductivity type semiconductor layer and the active layer are removed to expose an upper surface of the first conductivity type semiconductor layer;
A first electrode on the exposed first conductivity type semiconductor layer;
A first reflective electrode having a horizontal width wider than that of the first electrode and disposed on the first electrode;
A first pad electrode on the first reflective electrode; And
A light emitting device comprising a second pad electrode on the second conductivity type semiconductor layer. The method of claim 1,
The first reflective electrode is
A first connection reflective electrode electrically connected to the first electrode and extending upward,
A light emitting device comprising a first wing reflective electrode extending horizontally on at least one side of the first connection reflective electrode. The method of claim 2,
The first wing reflective electrode is
It extends to both sides from the first connection reflective electrode,
A light emitting device having a horizontal width of the first connection reflective electrode wider than that of the first electrode. The method of claim 2,
The first wing reflective electrode is
A light emitting device having a horizontal width of the first connection reflective electrode wider than a horizontal width of the first pad electrode. The method of claim 2,
The light emitting device further comprises a support member disposed on the recess region and the second conductivity type semiconductor layer. The method of claim 5,
The support member
A light emitting device disposed inside the first pad electrode and the second pad electrode. The method of claim 5,
The active layer includes a quantum well and a quantum wall,
The distance between the outermost quantum well closest to the first wing reflective electrode among the quantum wells and the bottom of the first wing reflective electrode is n×λ _n /4 (where n is an integer, λ _n is the length of the wavelength in the dielectric) ) Light emitting device. The method of claim 6,
The second pad electrode is
Light-emitting devices disposed on the side and upper surfaces of the support member. The method of claim 1,
A light emitting device further comprising a second reflective electrode disposed between the second conductivity type semiconductor layer and the second pad electrode. A first conductivity type semiconductor layer;
An active layer on the first conductivity type semiconductor layer;
A second conductivity type semiconductor layer on the active layer;
A recess region from which a portion of the second conductivity type semiconductor layer and the active layer are removed to expose an upper surface of the first conductivity type semiconductor layer;
A first electrode on the exposed first conductivity type semiconductor layer;
A first reflective electrode having a horizontal width wider than that of the first electrode and disposed on the first electrode;
A first pad electrode on the first reflective electrode;
A second pad electrode on the second conductivity type semiconductor layer;
A support member disposed on the recess region and the second conductivity type semiconductor layer; And
A light emitting device including a third reflective electrode disposed between the support member and the first pad electrode. The method of claim 10,
A light emitting device further comprising a fourth reflective electrode disposed on a bottom surface of the second pad electrode. The method of claim 10,
The horizontal width of the third reflective electrode is
A light emitting device larger than the horizontal width of the first electrode. The method of claim 10,
The first reflective electrode is
A first connection reflective electrode electrically connected to the first electrode and extending upward,
A light emitting device comprising a first wing reflective electrode extending horizontally on at least one side of the first connection reflective electrode. The method of claim 13,
The third reflective electrode is
A light emitting device extending upward from the first wing reflective electrode and disposed on an upper surface of the support member. The method of claim 10,
Further comprising a substrate under the first conductivity type semiconductor layer,
A light emitting device provided with a light extraction pattern on the bottom surface of the substrate. A lighting system comprising a light-emitting unit including any one of the light-emitting elements of claim 1.

Images