KR20120069212A - Light emitting diode and method for fabricating the light emitting device - Google Patents

Abstract

PURPOSE: A light emitting device and a manufacturing method thereof are provided to improve lateral light extraction efficiency by forming a light extraction structure on the side of a transparent support layer. CONSTITUTION: A light emitting structure(120) includes a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer. A reflection layer(140) is formed on the lower side of a light emitting structure. A transparent support layer(200) is formed between the light emitting structure and the reflection layer. The reflection layer has an uneven shape. The transparent support layer corresponds to the uneven shape.

Description

Light emitting device and method for manufacturing the light emitting device {Light emitting diode and method for fabricating the light emitting device}

Embodiments are directed to a light emitting device that improves light extraction efficiency while improving stability and reliability of the light emitting device.

Light emitting devices such as light emitting diodes or laser diodes using semiconductors of Group 3-5 or 2-6 compound semiconductor materials of semiconductors have various colors such as red, green, blue and ultraviolet rays due to the development of thin film growth technology and device materials. It is possible to realize efficient white light by using fluorescent materials or combining colors, and it has low power consumption, semi-permanent life, fast response speed, safety and environmental friendliness compared to conventional light sources such as fluorescent and incandescent lamps. Has an advantage.

Therefore, a white light emitting device that can replace a fluorescent light bulb or an incandescent bulb that replaces a Cold Cathode Fluorescence Lamp (CCFL) constituting a backlight of a transmission module of an optical communication means and a liquid crystal display (LCD) display device. Applications are expanding to diode lighting devices, automotive headlights and traffic lights.

On the other hand, the light efficiency of the light emitting device is a very important factor that determines the performance of the light emitting device, there is a need to develop a light emitting device and a method of manufacturing the light emitting device that can increase the light efficiency.

Embodiment is to improve the light extraction efficiency of the light emitting device to improve the light efficiency, while improving the stability and reliability of the light emitting device.

Embodiments include a light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; A reflective layer formed under the light emitting structure; And a transparent support layer formed between the light emitting structure and the reflective layer, wherein the reflective layer is formed to include an uneven shape and has a transparent support layer having a shape corresponding to the uneven shape.

In this case, the concave-convex shape may include at least one protrusion formed in the direction of the light emitting structure.

In addition, the concave-convex shape may be formed including a plurality of step structures.

In addition, the transparent support layer may be formed of a plurality of layers, and the thickness of each layer may be set to a value within the range of 1 μm to 100 μm.

In addition, the transparent support layer may be formed of three layers.

In addition, the light emitting device may further include a conductive layer formed under the reflective layer.

In addition, both ends of the conductive layer may protrude to surround the reflective layer.

In addition, the transparent support layer may be formed of an insulating material having a light transmittance of 70% or more.

In addition, the transparent support layer may be formed of a non-conductive material selected from silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ), and aluminum oxide (Al ₂ O ₃₎ or a non-conductive material in which these are selectively included.

In addition, a light extraction structure may be formed on the side of the transparent support layer.

In addition, a portion of the transparent support layer may include a plurality of through parts penetrating the ohmic layer and in contact with the light emitting structure.

In addition, the light emitting structure may further include an ohmic layer and a current blocking layer, wherein the transparent support layer is formed under the ohmic layer, it may not be formed under the current blocking layer.

The light emitting device according to the embodiment has the effect of improving the light efficiency by improving the side light extraction efficiency, and improve the stability and reliability of the light emitting device.

1 is a view showing an embodiment of a light emitting device,
2A to 2K are views showing a manufacturing method of an embodiment of a light emitting device;
3 is a view showing another embodiment of a light emitting device;
4 is a view showing another embodiment of a light emitting device;
5 is a view showing an effect of improving the directivity angle of the light emitting device according to the embodiment,
6 is a view showing an embodiment of a light emitting device package.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

In the description of the above embodiments, each layer (region), region, pattern or structures may be "on" or "under" the substrate, each layer (layer), region, pad or pattern. In the case of what is described as being formed, "on" and "under" include both being formed "directly" or "indirectly" through another layer. In addition, the criteria for the top or bottom of each layer will be described with reference to the drawings.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size of each component does not necessarily reflect the actual size.

1 is a view showing an embodiment of a light emitting device.

As shown in FIG. 1. The light emitting device of the first embodiment includes a bonding layer 150 formed on the support substrate 160, a conductive layer 170 formed on the bonding layer 150, a reflective layer 140 formed on the conductive layer 170, and a reflective layer ( 140, the ohmic layer 130 formed on the transparent support layer 200, the reflective layer 140, or the transparent support layer 200, the current blocking layer 135 formed on the ohmic layer 130, and the transparent support layer 200. The light emitting structure 120 and the first conductive semiconductor layer 122 including the channel layer 180, the first conductive semiconductor layer 122, the active layer 124, and the second conductive semiconductor layer 126 formed thereon. It may include a first electrode 190 formed on at least a portion of).

As shown, the light emitting device may be provided with a bonding layer 150 and a conductive layer 170 on the support substrate 160.

The conductive layer 170 is a material selected from the group consisting of nickel (Ni), platinum (Pt), titanium (Ti), tungsten (W) vanadium (V), iron (Fe), and molybdenum (Mo) or they are optional. It may be made of an alloy included as.

The conductive layer 170 supports the light emitting structure 120 as a whole, and may minimize mechanical damage (breaking or peeling, etc.) that may occur in the manufacturing process of the light emitting device, and may support the substrate 160 or the bonding layer 150. It is effective to prevent the metal material constituting the diffusion into the light emitting structure (120). In addition, the conductive layer 170 is formed to surround the reflective layer 140 or the transparent support layer 200 to minimize the mechanical damage of the reflective layer 140 and the transparent support layer 200 that may occur in the manufacturing process of the light emitting device. Can be. For example, both ends of the conductive layer 170 may protrude to form a shape surrounding the reflective layer 140.

The reflective layer 140 may be made of a metal layer including aluminum (Al), silver (Ag), nickel (Ni), platinum (Pt), rhodium (Rh), or an alloy containing Al, Ag, Pt, or Rh. . Aluminum or silver may effectively reflect light generated from the active layer 124 to greatly improve the light extraction efficiency of the light emitting device.

The transparent support layer 200 forms a path so that the light emitted from the active layer 124 is emitted to the side of the light emitting device to widen the directivity angle of the light emitting device, and improve side light extraction efficiency of the light emitting device.

That is, in the light emitting device of the prior art, even though the light generated in the direction of the substrate in the active layer 124 is absorbed or using the reflective layer, most of the light is reflected from the reflective layer and extracted to the top of the light emitting device. Various reflection angles are possible, and light through the transparent support layer 200 increases extraction efficiency in the lateral direction of the light emitting device.

The transparent support layer 200 may be made of an insulating material having a light transmittance of a predetermined reference value or more, and the insulating material may be made of an oxide or nitride that is nonconductive. For example, the transparent support layer 200 is a non-conductive material selected from silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ), and aluminum oxide (Al ₂ O ₃₎ having a light transmittance of 70% or more, or optionally It may be formed of a nonconductive material included.

The transparent support layer 200 may be formed by a sputtering deposition method or a chemical deposition method.

When using a sputtering deposition method, when ionized atoms are accelerated by an electric field and collide with the source material of the transparent support layer 200, atoms of the source material are ejected and deposited. In addition, when using a chemical vapor deposition (Chemical Vapor Deposition) method, it can be produced by depositing an oxide having a light transmittance.

The thickness at which the transparent support layer 200 is formed may have various values according to embodiments, and the light emitted from the active layer 124 may be emitted to the side of the light emitting device, that is, the side of the transparent support layer 200. It can be determined by the thickness. For example, the thickness at which the transparent support layer 200 is formed may be set to a value within the range of 1 μm to 100 μm.

In addition, according to the exemplary embodiment, an uneven structure may be formed under the transparent support layer 200.

In some exemplary embodiments, when the uneven structure is formed under the transparent support layer 200, the reflective layer 140 and the conductive layer 170 may also have a uneven structure corresponding thereto.

The concave-convex structure below the reflective layer 140 changes the reflection angle of the light reflected from the reflective layer 140 and incident on the transparent support layer 200 to be emitted to the side of the transparent support layer 200, and emitted from the active layer 124. The light emission efficiency can be improved by reducing the absorption of light inside the light emitting structure. The uneven structure may be formed periodically or aperiodically, and the uneven shape is not limited.

For example, the concave-convex shape includes all shapes of a single or complex shape such as square, hemisphere, triangle, trapezoid, multi-layer, multi-step shape.

In addition, the concave-convex shape formed in the reflective layer 140 or the transparent support layer 200 may include at least one or more protrusions formed in the direction of the light emitting structure, or may include a plurality of step structures.

For example, the reflective layer 140 or the transparent support layer 200 may be formed of multiple layers, for example, three layers.

The uneven structure may be formed using a wet etching process or a dry etching process, or using a wet etching process and a dry etching process. At this time, after forming a mask, the uneven shape may be adjusted by etching.

The dry etching method may be used, such as plasma etching, sputter etching, ion etching, etc., the wet etching process may be used a PEC (Photo Chemical Wet-etching) process. At this time, in the case of the PEC process, by adjusting the amount of the etching liquid (eg, KOH) and the etching rate difference by the GaN crystallinity, it is possible to control the shape of the irregularities of the fine size.

According to an embodiment, the transparent support layer 200 may be formed of a plurality of layers, and the thickness of each layer may be set to a value within the range of 1 μm to 100 μm.

In some embodiments, the uneven structure of the lower portion of the transparent support layer 200 may be formed in a plurality of step structures.

In some embodiments, when the transparent support layer 200 is formed of a plurality of layers, the reflective layer 140 and the conductive layer 170 formed under the transparent support layer 200 may also be formed of a plurality of layers.

In some embodiments, when the lower portion of the transparent support layer 200 is formed in a plurality of step structures, the reflective layer 140 and the conductive layer 170 may also be formed in a plurality of step structures corresponding thereto.

As described above, when the transparent support layer 200 is formed of a plurality of layers or steps, the side area of the transparent support layer 200 is widened, thereby improving the side light extraction efficiency of the light emitting device.

In addition, when the reflective layer 140 and the conductive layer 170 are formed of a plurality of layers, or if the uneven structure is formed, mechanical damage (breaking or peeling, etc.) that may occur in the manufacturing process of the light emitting device by holding the light emitting device stably. ) To minimize the effect.

In addition, according to the embodiment, a light extraction structure for emitting light emitted from the active layer 124 is formed on the side of the transparent support layer 200 can improve the side light extraction efficiency of the light emitting device.

In addition, according to an embodiment, a plurality of through parts may be formed on the transparent support layer 200 to improve the bonding force between the transparent support layer 200 and the ohmic layer 130.

In some embodiments, when the uneven structure is formed on the transparent support layer 200, the transparent support layer 200 and the second conductive semiconductor layer 126 may be in contact with each other.

In some embodiments, the ohmic layer 130 and the reflective layer 140 may be formed under the current blocking layer 130 to electrically connect the ohmic layer 130 and the reflective layer 140. It may not be formed.

In addition, the ohmic layer 130 may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), and 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, Sn, In, Ru, Mg, Zn , Pt, Au, Hf may be formed to include, but are not limited to such materials.

The channel layer 180 may be made of an insulating material, and may include at least one of a metal material and an insulating material. In the case of the metal material, the channel layer 180 may be formed of a material having lower electrical conductivity than the material forming the ohmic layer 130. Power applied to the ohmic layer 130 may not be applied to the channel layer 180.

The channel layer 180 may include at least one of titanium (Ti), nickel (Ni), platinum (Pt), lead (Pb), rhodium (Rh), iridium (Ir), and tungsten (W), or may be oxidized. At least one of aluminum (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ) and titanium oxide (TiO _x ), or indium tin oxide (ITO), aluminum At least one of zinc oxide (AZO) and indium zinc oxide (IZO) may be included, but preferably titanium (Ti), nickel (Ni), platinum (Pt), or tungsten (W). ), Molybdenum (Mo), vanadium (V) and iron (Fe) may include at least one.

When the light emitting structure 120 is etched, the channel layer 180 protects the components disposed below the channel layer 180 from etching, and stably supports the light emitting device to protect against damages that may occur in the manufacturing process. .

The first conductivity type semiconductor layer 122 may be implemented as a group III-V compound semiconductor doped with a first conductivity type dopant, and when the first conductivity type semiconductor layer 112 is an N-type semiconductor layer, The first conductivity type dopant may be an N type dopant and may include Si, Ge, Sn, Se, Te, but is not limited thereto. In some embodiments, irregularities may be formed on the surface of the first conductivity-type semiconductor layer 122. The shape of the irregularities according to the present invention is not limited.

In addition, the active layer 124 may be formed by integrating electrons injected through the first conductivity-type semiconductor layer 122 and holes injected through the second conductivity-type semiconductor layer 126 that are formed thereafter to form an active layer (light emitting layer) material. It is a layer that emits light with energy determined by the energy band.

The second conductivity-type semiconductor layer 126 may be a Group III _- V compound semiconductor doped with a second conductivity type dopant, for example, In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ And 1, 0 ≦ x + y ≦ 1). When the second conductive semiconductor layer 126 is a P-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, Ba, and the like as a P-type dopant.

In addition, a first electrode 190 is formed on at least a portion of the first conductivity-type semiconductor layer 122, and the first electrode 190 includes molybdenum, chromium (Cr), nickel (Ni), and gold (Au). , Aluminum (Al), titanium (Ti), platinum (Pt), vanadium (V), tungsten (W), lead (Pd), copper (Cu), rhodium (Rh) and iridium (Ir) It consists of a metal or an alloy of these metals.

Detailed description of each configuration will be described in detail with reference to FIGS. 2A to 2K.

2A to 2K illustrate a method of manufacturing an embodiment of a light emitting device.

The substrate 100 is prepared as shown in FIG. 2A. The substrate 100 may be formed of a conductive substrate or an insulating substrate. For example, sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga ₂ 0 ₃ At least one of may be used. An uneven structure may be formed on the substrate 100, but is not limited thereto. Impurities on the surface may be removed by wet cleaning the substrate 100.

In addition, the light emitting structure 120 including the first conductive semiconductor layer 122, the active layer 124, and the second conductive semiconductor layer 126 may be formed on the substrate 100.

In this case, a buffer layer (not shown) may be grown between the light emitting structure 120 and the substrate 100 to mitigate the difference in lattice mismatch and thermal expansion coefficient of the material. The material of the buffer layer may be formed of a Group III-V compound semiconductor, and may be formed of at least one of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN. An undoped semiconductor layer may be formed on the buffer layer, but is not limited thereto.

In addition, the light emitting structure 120 may be formed of, for example, metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), or plasma chemical vapor deposition (PECVD). , Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), etc. may be formed using, but is not limited thereto.

The first conductive semiconductor layer 122 may be implemented as a group III-V compound semiconductor doped with a first conductive dopant, and the first conductive semiconductor layer 112 is an N-type semiconductor layer. The first conductive dopant may be an N-type dopant and may include Si, Ge, Sn, Se, or Te, but is not limited thereto.

The first conductive semiconductor layer 122 may be formed of a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). It may include. For example, the first conductive semiconductor layer 112 may be formed of any 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 122 may form an N-type GaN layer using a chemical vapor deposition method (CVD), molecular beam epitaxy (MBE), sputtering, or hydroxide vapor phase epitaxy (HVPE). . In addition, the first conductivity type semiconductor layer 122 includes 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. The gas SiH ₄ may be injected and formed.

The active layer 124 has energy determined by an energy band inherent in the active layer (light emitting layer) material because carriers injected through the first conductive semiconductor layer 122 and the second conductive semiconductor layer 126 meet each other. It is a layer that emits light.

The active layer 124 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, the active layer 114 may be formed by injecting trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) to form a multi-quantum well structure. It is not limited to this.

The well layer / barrier layer of the active layer 124 has a pair structure of at least one of InGaN / GaN, InGaN / InGaN, GaN / AlGaN /, InAlGaN / GaN, GaAs (InGaAs), / AlGaAs, GaP (InGaP) / AlGaP. It may be formed, but is not limited thereto. The well layer may be formed of a material having a lower band gap than the band gap of the barrier layer.

A conductive cladding layer (not shown) may be formed on or under the active layer 124. The conductive clad layer may be formed of an AlGaN-based semiconductor, and may have a higher band gap than the band gap of the active layer 124.

The second conductivity-type semiconductor layer 126 may be a Group III-V compound semiconductor doped with a second conductivity type dopant, for example, In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, Semiconductor material having a composition formula of 0 ≦ x + y ≦ 1). When the second conductivity type semiconductor layer 126 is a P type semiconductor layer, the second conductivity type dopant may include Mg, Zn, Ca, Sr, Ba, or the like as a P type dopant.

The second conductivity type semiconductor layer 126 is a bicetyl cyclone 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 injected to form a p-type GaN layer, but is not limited thereto.

In an embodiment, the first conductive semiconductor layer 122 may be a P-type semiconductor layer, and the second conductive semiconductor layer 126 may be an N-type semiconductor layer. In addition, an N-type semiconductor layer (not shown) may be formed on the second conductive semiconductor layer 126 when the semiconductor having a polarity opposite to that of the second conductive type, for example, the second conductive semiconductor layer is a P-type semiconductor layer. have. Accordingly, the light emitting structure 110 may be implemented as 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.

2B, the channel layer 180 is stacked on the second conductive half layer 126. Here, the channel layer 180 may include at least one of a metal material and an insulating material. In the case of the metal material, the channel layer 180 may be formed of a material having lower electrical conductivity than the material forming the ohmic layer 130. The power applied to the channel layer 180 may not be applied.

The channel layer 180 may include at least one of titanium (Ti), nickel (Ni), platinum (Pt), lead (Pb), rhodium (Rh), iridium (Ir), and tungsten (W), or may be oxidized. At least one of aluminum (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ) and titanium oxide (TiO _x ), or indium tin oxide (ITO), aluminum At least one of zinc oxide (AZO) and indium zinc oxide (IZO) may be included, but preferably titanium (Ti), nickel (Ni), platinum (Pt), or tungsten (W). ), Molybdenum (Mo), vanadium (V) and iron (Fe) may include at least one.

The channel layer 180 protects the components disposed below the channel layer 180 from etching during etching of the light emitting structure 120 to be described later, and stably supports the light emitting device to protect them from damage that may occur in the manufacturing process. There is.

The channel layer 180 is etched to form grooves. The groove may be formed by a dry etching process using a mask.

The ohmic layer 130 and the current blocking layer 135 are stacked on the second conductive semiconductor layer 126 located in the groove formed as shown in FIG. 2C.

In this case, the ohmic layer 130 may be stacked to a thickness of about 200 angstroms. The ohmic layer 130 may selectively use a light transmissive conductive layer and a metal. For example, indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), and indium aluminum zinc (AZO) 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, Sn, In, Ru, Mg, Zn, Pt, Au, can be formed including at least one of Hf, and is not limited to these materials. The ohmic layer 130 may be formed by sputtering or electron beam deposition. In addition, according to the exemplary embodiment, a groove is formed in the ohmic layer 130, and a current blocking layer 135 is formed to distribute the current flow in the horizontal direction, thereby preventing malfunction of the light emitting device due to overcurrent. There is an effect to increase the stability and reliability.

The current blocking layer 135 may be formed between the ohmic layer 130 and the light emitting structure 120. The current blocking layer 135 is a material having a lower electrical conductivity than the reflective layer 140 or the ohmic layer 130, a material forming a Schottky contact with the second conductive semiconductor layer 126, or an electrically insulating material. It can be formed using. For example, the current blocking layer 135 may be formed of ZnO, SiO ₂ , SiON, It may include at least one of Si ₃ N ₄ , Al ₂ O _3, TiO ₂ , Ti, Al, Cr.

The current blocking layer 135 may be formed between the ohmic layer 130 and the second conductive semiconductor layer 126, or may be formed between the reflective layer 140 and the ohmic layer 130, but is not limited thereto. . The current blocking layer 135 is intended to allow a wide spread of current in the light emitting structure 120 and is not required to be formed.

As illustrated in FIG. 2D, the transparent support layer 200 is formed on the ohmic layer 130 or the channel layer 180. The transparent support layer 200 forms a path so that the light emitted from the active layer 124 is emitted to the side of the light emitting device to widen the directivity angle of the light emitting device and to improve the side light extraction efficiency of the light emitting device.

The transparent support layer 200 may be made of an insulating material having a light transmittance of a predetermined reference value or more, and the insulating material may be made of an oxide or nitride that is nonconductive. For example, the transparent support layer 200 may be formed of a silicon oxide (SiO ₂ ) layer, titanium oxide (TiO ₂ ), or aluminum oxide (Al ₂ O ₃₎ layer.

The transparent support layer 200 may be formed by a sputtering deposition method or a chemical deposition method.

When using a sputtering deposition method, when ionized atoms are accelerated by an electric field and collide with the source material of the transparent support layer 200, atoms of the source material are ejected and deposited. In addition, when using a chemical vapor deposition (Chemical Vapor Deposition) method, it can be produced by depositing an oxide having a light transmittance.

The thickness at which the transparent support layer 200 is formed may have various values according to embodiments, and the light emitted from the active layer 124 may be emitted to the side of the light emitting device, that is, the side of the transparent support layer 200. It can be determined by the thickness.

For example, the thickness at which the transparent support layer 200 is formed may be set to a value within the range of 1 μm to 100 μm.

In addition, according to the exemplary embodiment, an uneven structure may be formed on the transparent support layer 200.

The uneven structure under the transparent support layer 200 changes the reflection angle of the light reflected from the reflective layer 140 and incident on the transparent support layer 200 to be emitted to the side of the transparent support layer 200, and the light emitted from the active layer 124. It is possible to increase the luminous efficiency by reducing the absorption in the light emitting structure. The uneven structure may be formed periodically or aperiodically, and the uneven shape is not limited.

For example, the concave-convex shape includes all shapes of a single or complex shape such as square, hemisphere, triangle, trapezoid, multi-layer, multi-step shape.

In addition, the concave-convex shape formed on the transparent support layer 200 may include at least one or more protrusions formed in the direction of the light emitting structure, or may include a plurality of step structures.

In addition, the transparent support layer 200 may be formed of multiple layers, for example, three layers.

The uneven structure may be formed using a wet etching process or a dry etching process, or using a wet etching process and a dry etching process. At this time, after forming a mask, the uneven shape may be adjusted by etching.

The dry etching method may be used, such as plasma etching, sputter etching, ion etching, etc., the wet etching process may be used a PEC (Photo Chemical Wet-etching) process. At this time, in the case of the PEC process, by adjusting the amount of the etching liquid (eg, KOH) and the etching rate difference by the GaN crystallinity, it is possible to control the shape of the irregularities of the fine size.

For example, the upper portion of the transparent support layer 200 may be formed in a plurality of step structures. In some embodiments, the transparent support layer 200 may be formed of a plurality of layers, and the thickness of each layer may be set to a value within the range of 1 μm to 100 μm.

When the uneven structure is formed on the transparent support layer 200, the reflective layer 140 and the conductive layer 170 may also have a uneven structure corresponding thereto.

According to an embodiment, when the transparent support layer 200 is formed of a plurality of layers, the reflective layer 140 and the conductive layer 170 formed on the transparent support layer 200 may also be formed of a plurality of layers.

For example, when the upper portion of the transparent support layer 200 is formed with a plurality of step structures, the reflective layer 140 and the conductive layer 170 formed on the transparent support layer 200 are also formed with a plurality of step structures corresponding thereto. Can be.

As described above, when the transparent support layer 200 is formed of a plurality of layers or steps, the side area of the transparent support layer 200 is widened, thereby improving the side light extraction efficiency of the light emitting device. In addition, the concave-convex structure below the transparent support layer 200 may vary the reflection angle of the light reflected from the reflective layer 140 and incident on the transparent support layer 200 to be emitted to the side of the transparent support layer 200, and the active layer 124. As described above, light emission efficiency can be improved by reducing the light emitted from the light absorbing structure in the light emitting structure.

In addition, when the upper and reflective layers 140 and the conductive layer 170 of the transparent support layer 200 are formed of a plurality of layers, or if the uneven structure is formed, the light emitting device may be stably held and may occur in the manufacturing process of the light emitting device. There is an effect that can minimize the mechanical damage (such as cracking or peeling).

In addition, according to an embodiment, a light extraction structure for emitting light emitted from the active layer 124 may be formed on the side of the transparent support layer 200.

In some embodiments, the ohmic layer 130 may be formed on the current blocking layer 130 to electrically connect the ohmic layer 130 and the reflective layer 140, and the transparent support layer 200 may not be formed.

As shown in FIG. 2E, the reflective layer 140 is formed on the ohmic layer 130 or the transparent support layer 200.

The reflective layer 140 may be formed on the ohmic layer 130 or the transparent support layer 200 to a thickness of about 2,500 ounces. The reflective layer 140 may be formed of, for example, a metal or an alloy including at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, or Hf. Alternatively, the metal or alloy may be formed in a multilayer using light transmitting conductive materials such as ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, and ATO, and specifically, IZO / Ni, AZO / Ag, and IZO. / Ag / Ni, AZO / Ag / Ni, Ag / Cu, Ag / Pd / Cu and the like can be laminated. Aluminum or silver may effectively reflect light generated from the active layer 124 to greatly improve the light extraction efficiency of the light emitting device.

In particular, the reflective layer 140 may improve the light extraction efficiency of the light emitting device by reflecting light generated from the active layer 124 and passing through the transparent support layer 200 to the front and side surfaces of the transparent support layer 200.

According to an exemplary embodiment, when the transparent support layer 200 is formed of a plurality of layers, the reflective layer 140 formed on the transparent support layer 200 may also be formed of a plurality of layers.

In addition, when the uneven structure is formed on the transparent support layer 200, the reflective layer 140 may also be formed with a corresponding uneven structure.

For example, when the upper portion of the transparent support layer 200 is formed with a plurality of step structures, the reflective layer 140 formed on the transparent support layer 200 may also be formed with a plurality of step structures corresponding thereto.

2F, the conductive layer 170 is formed on the reflective layer 140. The conductive layer 170 is a material selected from the group consisting of nickel (Ni-nickel), platinum (Pt), titanium (Ti), tungsten (W) vanadium (V), iron (Fe), molybdenum (Mo). Or they may be made of an alloy optionally included.

In this case, the conductive layer 170 may be formed using a sputtering deposition method. When using a sputtering deposition method, when ionized atoms are accelerated by an electric field and impinge on the source material of layer 3 170, the atoms of the source material are ejected and deposited. Further, according to the embodiment, it may be formed using an electrochemical metal deposition method, a bonding method using a eutectic metal, an electroplating method, an e-beam deposition method, or the like. In some embodiments, the conductive layer 170 may be formed of a plurality of layers.

In some embodiments, when the transparent support layer 200 is formed of a plurality of layers, the conductive layer 170 formed on the transparent support layer 200 may also be formed of a plurality of layers.

In addition, when the uneven structure is formed on the transparent support layer 200, the conductive layer 170 may also be formed with a corresponding uneven structure.

For example, when the upper portion of the transparent support layer 200 has a plurality of step structures, the conductive layer 170 formed on the transparent support layer 200 may also have a plurality of step structures corresponding thereto.

The conductive layer 170 supports the light emitting structure 120 as a whole, thereby minimizing mechanical damage (breaking or peeling, etc.) that may occur in the manufacturing process of the light emitting device.

In particular, the conductive layer 170 is formed to surround the reflective layer 140 and the transparent support layer 200 to minimize the mechanical damage of the reflective layer 140 and the transparent support layer 200 that may occur in the manufacturing process of the light emitting device. Can be. For example, both ends of the conductive layer 170 may protrude to form a shape surrounding the reflective layer.

In addition, when the upper and reflective layers 140 and the conductive layer 170 of the transparent support layer 200 are formed of a plurality of layers, or if the uneven structure is formed, the light emitting device may be stably held and may occur in the manufacturing process of the light emitting device. There is an effect that can minimize the mechanical damage (such as cracking or peeling).

As shown in FIG. 2G, a coupling layer 150 may be formed on the conductive layer 170 to couple the conductive layer 170 and the support substrate 160 to each other. The bonding layer 150 is a material selected from the group consisting of gold (Au), tin (Sn), indium (In), silver (Ag), nickel (Ni), niobium (Nb), and copper (Cu) or It may be formed of an alloy thereof.

And as shown in FIG. 2H. The support substrate 160 may be formed on the bonding layer 150.

The support substrate 160 may be made of a material selected from the group consisting of molybdenum (Mo), silicon (Si), tungsten (W), copper (Cu), and aluminum (Al) or alloys thereof. Gold (Au), Copper Alloy (Cu Alloy), Nickel (Ni-nickel), Copper-Tungsten (Cu-W), Carrier Wafers (e.g. GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, SiGe, Ga) ₂ O _3, etc.) may be optionally included. The conductive support substrate 160 may be formed using an electrochemical metal deposition method or a bonding method using a eutectic metal.

In some embodiments, when holes are injected into the second conductive semiconductor layer 126 through the conductive layer 170, the support substrate 160 may be made of an insulating material. It may be made of nitride. For example, the support substrate 160 may include a silicon oxide (SiO ₂ ) layer, an oxynitride layer, and an aluminum oxide layer.

As shown in FIG. 2I, the substrate 100 is separated.

The substrate 100 may be removed by a laser lift off (LLO) method using an excimer laser or the like, or may be a dry or wet etching method.

For example, when the laser lift-off method focuses and irradiates excimer laser light having a predetermined wavelength toward the substrate 100, thermal energy is applied to the interface between the substrate 110 and the light emitting structure 120. As the interface is concentrated and separated into gallium and nitrogen molecules, separation of the substrate 100 occurs at a portion where the laser light passes.

As shown in FIG. 2J, the side surface of the light emitting structure 120 is etched. In this case, when a material forming the channel layer 180 is detected by an endpoint detecting method, a portion of the side surface of the light emitting structure 120 may be etched by stopping the etching.

At this time, the etching position may be adjusted so that the channel layer 180 is positioned under the light emitting structure 120 to be etched.

When the light emitting structure 120 is etched, the channel layer 180 protects the components disposed under the channel layer 180 from etching, and stably supports the light emitting device to protect against damages that may occur in the manufacturing process. .

In addition, an uneven structure is formed on the first conductive semiconductor layer 122 to improve light extraction efficiency. At this time, the uneven structure can be formed by etching after forming a PEC method or a mask.

In the PEC method, by adjusting the amount of the etchant (for example, KOH or NaOH) and the difference in etching rate due to GaN crystallinity, it is possible to control the shape of the irregularities of the fine size. The uneven structure may be formed periodically or aperiodically.

In addition, according to an embodiment, a two-dimensional photonic crystal may be formed on the surface of the first conductivity-type semiconductor layer 122, and the structure may periodically form at least two dielectrics having different refractive indices at a period of about half the wavelength of light. Can be obtained by arranging. At this time, each dielectric may be provided in the same pattern with each other.

The photonic crystal may control the flow of light by forming a photonic band gap on the surface of the first conductivity type semiconductor layer 122.

The groove and pattern structure of the light emitting structure can increase the light extraction effect by increasing the surface area of the light emitting structure, and the fine concavo-convex structure on the surface can reduce the absorption of light in the light emitting structure, thereby increasing the luminous efficiency.

As illustrated in FIG. 2K, the first electrode 190 may be formed on at least a portion of the first conductivity-type semiconductor layer 122 and on the side surface of the light emitting structure 120.

The first electrode 190 may include, for example, molybdenum, chromium (Cr), nickel (Ni), gold (Au), aluminum (Al), titanium (Ti), platinum (Pt), vanadium (V), and tungsten. (W), lead (Pd), copper (Cu), rhodium (Rh) and iridium (Ir) of any one selected from a metal or an alloy of the metals.

3 is a view showing a light emitting device according to another embodiment.

Referring to FIG. 3, a concave-convex structure, that is, a light extraction structure, for emitting light emitted from the active layer 124 may be formed on a side surface of the transparent support layer 200 of the light emitting device of the embodiment. The light extraction structure on the side of the transparent support layer 200 changes the incident angle of light incident on the side of the transparent support layer 200 to reduce the total reflection at the surface of the transparent support layer 200 to increase the side light extraction effect of the light emitting device. It is possible to increase the light extraction efficiency.

The light extraction structure formed on the side of the transparent support layer 200 may be formed periodically or aperiodic, and the shape of the light extraction structure is not limited.

For example, the shape of the light extraction structure includes all shapes of a single or complex shape such as square, hemisphere, triangle, trapezoid, multi-layer, and multi-step shape.

The light extracting structure may be formed using a wet etching process or a dry etching process, or using a wet etching process and a dry etching process. At this time, the shape of the light extraction structure may be adjusted by etching after forming the mask.

The dry etching method may be used, such as plasma etching, sputter etching, ion etching, etc., the wet etching process may be used a PEC (Photo Chemical Wet-etching) process. At this time, in the case of the PEC process, by controlling the amount of the etching solution (eg, KOH) and the etching rate difference by the GaN crystallinity, it is possible to control the shape of the light extraction structure of the fine size.

Therefore, the light emitting device forms a path such that light emitted from the active layer 124 is emitted to the side of the light emitting device, and forms a light extraction structure on the side of the transparent support layer 200, thereby improving side light extraction efficiency. It works. In particular, the reflective layer 140 may improve the light extraction efficiency of the light emitting device by reflecting light generated from the active layer 124 and passing through the transparent support layer 200 to the front and side surfaces of the transparent support layer 200.

4 is a view showing a light emitting device according to another embodiment.

Referring to FIG. 4, according to an embodiment, a plurality of through parts may be formed on the transparent support layer 200 to improve the bonding force between the transparent support layer 200 and the ohmic layer 130. In other words, a portion of the transparent support layer 200 may include a plurality of through portions penetrating the ohmic layer 130 to contact the light emitting structure.

In some embodiments, when a plurality of through portions are formed on the transparent support layer 200, the transparent support layer 200 and the second conductive semiconductor layer 126 may be in contact with each other.

The plurality of through parts formed on the side or the top of the transparent support layer 200 may be formed periodically or aperiodically, and the shape of the through parts is not limited.

For example, the shape of the penetrating portion includes all shapes of single or complex shapes such as square, hemisphere, triangle, trapezoid, multi-layer, multi-step shape, and the like.

The through structure may be formed using a wet etching process or a dry etching process, or using a wet etching process and a dry etching process. At this time, after forming a mask, the uneven shape may be adjusted by etching.

The dry etching method may be used, such as plasma etching, sputter etching, ion etching, etc., the wet etching process may be used a PEC (Photo Chemical Wet-etching) process. At this time, in the case of the PEC process, the shape of the penetrating portion of the fine size can be adjusted by adjusting the amount of the etchant and the difference in etching speed due to crystallinity.

5 is a view showing an effect of improving the directivity angle of the light emitting device according to the embodiment.

Referring to FIG. 5, it can be seen that the range of the directivity angle 402 of the light emitting device of the embodiment is wider than that of the light emitting device of the prior art. This is because, as described above, the light emitting device of the embodiment includes a transparent support layer, thereby improving side light extraction efficiency.

6 is a cross-sectional view of an embodiment of a light emitting device package.

As shown, the light emitting device package according to the above-described embodiments, the package body 520, the first electrode layer 511 and the second electrode layer 512 installed on the package body 520, and the package body ( The light emitting device 500 according to the exemplary embodiment installed in the 520 and electrically connected to the first electrode layer 511 and the second electrode layer 512, and a filler 540 surrounding the light emitting device 500 are included. do.

The package body 520 may include a silicon material, a synthetic resin material, or a metal material. An inclined surface may be formed around the light emitting device 500 to increase light extraction efficiency.

The first electrode layer 511 and the second electrode layer 512 are electrically separated from each other, and provide power to the light emitting device 500. In addition, the first electrode layer 511 and the second electrode layer 512 may increase the light efficiency by reflecting the light generated from the light emitting device 500, the outside of the heat generated from the light emitting device 500 May also act as a drain.

The light emitting device 500 may be installed on the package body 520 or on the first electrode layer 511 or the second electrode layer 512.

The light emitting device 500 may be electrically connected to the first electrode layer 511 and the second electrode layer 512 by any one of a wire method, a flip chip method, and a die bonding method.

The filler 540 may surround and protect the light emitting device 500. In addition, the filler 540 may include a phosphor to change the wavelength of light emitted from the light emitting device 500.

The light emitting device package may mount at least one of the light emitting devices of the above-described embodiments as one or more, but is not limited thereto.

A plurality of light emitting device packages according to the embodiment may be arranged on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, or the like, which is an optical member, may be disposed on an optical path of the light emitting device package. The light emitting device package, the substrate, and the optical member may function as a light unit. Another embodiment may be implemented as a display device, an indicator device, or a lighting system including the semiconductor light emitting device or the light emitting device package described in the above embodiments, for example, the lighting system may include a lamp and a street lamp. .

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

100: substrate 110: protective layer
120: light emitting structure 122: first conductive semiconductor layer
124: active layer 126: second conductive semiconductor layer
130: ohmic layer 135: current limiting layer
140: reflective layer 150: bonding layer
160: support substrate 170: conductive layer
180: channel layer 190: first
200: transparent support layer 500: light emitting element
511: first electrode layer 512: second electrode layer
520: package body 540: filler

Claims (12)

A light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer;
A reflective layer formed under the light emitting structure; And
A transparent support layer formed between the light emitting structure and the reflective layer;
The reflective layer is formed to include an uneven shape,
Light emitting device comprising a transparent support layer having a shape corresponding to the concave-convex shape. The method of claim 1,
The concave-convex shape includes at least one protrusion formed in the direction of the light emitting structure. The method of claim 1,
The concave-convex shape includes a plurality of step structures. The method of claim 1,
The transparent support layer may be formed of a plurality of layers (Multilayer), the thickness of each layer is set to a value within the range of 1 ㎛ ~ 100 ㎛. The method of claim 4, wherein
The transparent support layer is a light emitting device formed of three layers. The method of claim 1,
The light emitting device further comprises a conductive layer formed under the reflective layer. The method of claim 6,
Both ends of the conductive layer protrudes, the light emitting device surrounding the reflective layer. The method of claim 1,
The transparent support layer is a light emitting device formed of an insulating material having a light transmittance of 70% or more. The method of claim 8,
The transparent support layer is _formed of a non-conductive material selected from silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ), and aluminum oxide (Al ₂ O ₃₎ or a non-conductive material in which these are selectively included. The method of claim 1,
The light emitting device is formed on the side of the transparent support layer light extraction structure. The method of claim 1,
A portion of the transparent support layer includes a plurality of through parts penetrating the ohmic layer and in contact with the light emitting structure. The method of claim 1,
An ohmic layer and a current blocking layer formed under the light emitting structure
More,
The transparent support layer is formed under the ohmic layer, the light emitting device is not formed below the current blocking layer.

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