KR102249627B1 - Light emitting device and lighting system - Google Patents

Abstract

The light emitting device according to the embodiment includes a second electrode layer; A second conductivity type semiconductor layer disposed on the second electrode layer; An active layer disposed on the second conductivity type semiconductor layer; A first conductivity type semiconductor layer disposed on the active layer; And a first electrode layer disposed on the first conductivity type semiconductor layer. Including, wherein the first electrode layer is characterized in that it comprises a metal oxide layer having a perovskite structure.
The light emitting device of the embodiment has a perovskite structure, has a sufficient thickness, and emits light using a metal oxide layer having a light extraction pattern, thereby improving light extraction efficiency, and after sufficiently diffusing the current to the first electrode layer. Injecting into the light emitting structure has the advantage of improving luminous efficiency.

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 is a pn junction diode that converts electrical energy into light energy. It can be created as a compound semiconductor such as Group III and Group V on the periodic table. Various colors can be realized by controlling the composition ratio of the compound semiconductor. It is possible.

When the forward voltage is applied, the electrons in the n-layer and the holes in the p-layer are combined to emit energy equivalent to the band gap energy of the conduction band and the balance band. , This energy is mainly emitted in the form of heat or light, and when it is radiated in the form of light, it becomes a light-emitting device.

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 bandgap energy. In particular, a blue light emitting device, a green light emitting device, and an ultraviolet (UV) light emitting device using a nitride semiconductor have been commercialized and widely used.

As the demand for high-efficiency LEDs has recently increased, improvement in light intensity has become an issue.

Particularly, in order to improve the luminous intensity, the role of the electrode layer that diffuses and injects current across the semiconductor layer is becoming important.

The embodiment is to provide a light emitting device capable of improving luminous intensity, 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 second electrode layer; A second conductivity type semiconductor layer disposed on the second electrode layer; An active layer disposed on the second conductivity type semiconductor layer; A first conductivity type semiconductor layer disposed on the active layer; And a first electrode layer disposed on the first conductivity type semiconductor layer. Including, wherein the first electrode layer is characterized in that it comprises a metal oxide layer having a perovskite structure.

In addition, the light emitting device according to the embodiment includes a substrate; A first conductivity type semiconductor layer disposed on the substrate; An active layer disposed on the first conductivity type semiconductor layer; A second conductivity type semiconductor layer disposed on the active layer; And a first electrode layer disposed on the second conductivity-type semiconductor layer. Including, wherein the first electrode layer is characterized in that it comprises a metal oxide layer having a perovskite structure.

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

According to the embodiment, a light emitting device having an optimal structure capable of increasing luminous intensity, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system can be provided.

The light emitting device of the embodiment has a perovskite structure, has a sufficient thickness, and emits light using a metal oxide layer having a light extraction pattern, thereby improving light extraction efficiency.

The light emitting device of the embodiment has an advantage of sufficiently diffusing current to the first electrode layer and then injecting it into the light emitting structure to improve luminous efficiency.

In addition, the first electrode layer of the embodiment has an advantage of being able to implement a sufficient thickness at low cost.

In addition, according to the embodiment, a light emitting device capable of improving quantum confinement effect, improving luminous efficiency, and improving device reliability, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system can be provided.

1 is a cross-sectional view of a light emitting device according to a first embodiment.
2 is a diagram showing a perovskite crystal structure.
3 is a plan view of a first electrode layer according to the first embodiment.
4 is a plan view of a first electrode layer according to a second embodiment.
5 is a plan view of a first electrode layer according to a third embodiment.
6 to 8 show a method of manufacturing a light emitting device according to an embodiment.
9 is a cross-sectional view of a light emitting device according to a fourth 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, the criteria for the top/top or bottom of each layer will be described based on the drawings.

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

Referring to FIG. 1, the light emitting device 100 according to the first embodiment includes a second electrode layer 87, a second conductivity type semiconductor layer 13 on the second electrode layer 87, and the second conductivity. An active layer 12 on the type semiconductor layer 13, a first conductivity type semiconductor layer 11 on the active layer 12, and a first electrode layer 200 on the first conductivity type semiconductor layer 11 The first electrode layer 200 may include a current diffusion layer 220 and an electrode pad 210 on the current diffusion layer 220.

Conventionally, in order to diffuse the current supplied through the electrode pad 210 into the light emitting structure 10, an electrode pattern radiated around the electrode pad 210 is disposed, and a current blocking layer (CBL) is formed under the electrode pattern. Placed.

In addition, a method of diffusing current by disposing a light-transmitting electrode layer such as ITO under the electrode layer has also been proposed.

However, since the electrode pad 210, the electrode pattern, and the current blocking layer are disposed on a surface from which light is emitted from the light emitting device, there is a problem in that light extraction efficiency is reduced by absorbing or reflecting light.

That is, in terms of current diffusion, it is advantageous to increase the area occupied by the electrode pad 210 and the electrode pattern on the surface of the light emitting device, but it is advantageous to reduce the area in terms of the efficiency in which light is extracted. off).

The technique of reducing the electrode pattern and disposing the electrode pad 210 on the ITO has a disadvantage in that the cost of ITO is high and the electrode layer cannot be formed with a sufficient thickness. In addition, due to the thin thickness, the GaN epitaxial may be damaged when texturing the ITO surface based on etching, resulting in lower reliability of the device and lower luminous efficiency.

The embodiment is a light-emitting device capable of improving luminous efficiency while maintaining the reliability of the device at low cost by forming an electrode layer using a material that is low in cost and can be formed in a sufficient thickness, has high electrical conductivity, and is advantageous for forming a light extraction pattern. I want to provide.

In addition, the embodiment is to provide a light emitting device capable of improving phosphor conversion efficiency by extracting light using an electrode layer having a sufficient thickness.

2 is a diagram showing a perovskite crystal structure.

Perovskite crytal structure is a metal oxide with a special structure that shows not only the properties of conductors but also superconductivity.

The basic component of this perovskite is a cubic AMX3 structure, where A is an organic cation, M is a metal cation, and X is an anion including a halogen or oxide.

In the case of such a perovskite metal oxide, the electrical conductivity is very high depending on the type and crystal structure of the elements constituting it, so that a superconducting phenomenon may occur, and may be configured to have a light-transmitting property.

For example, as the perovskite metal oxide, KNbO ₃ , BaSnO ₃ , CaZrO ₃ , SrCeO _3, etc. may be used.In particular, BaSnO ₃ has high light transmission efficiency, low cost, and electrical conductivity. It has a high advantage.

Since the perovskite metal oxide is produced through a method of growing a wafer, it is difficult to apply it to a light emitting device.

In the embodiment, it is proposed to use a perovskite metal oxide having a desired thickness as an electrode layer through a method of growing a perovskite metal oxide into a wafer and then slicing it and depositing it on the surface of a light emitting device.

Hereinafter, the first electrode layer 200 formed using perovskite metal oxide will be described.

3 is a plan view of the first electrode layer 200 according to the first embodiment.

3, the first electrode layer 200 according to the first embodiment is disposed on the electrode pad 210, the metal oxide layer 220 disposed under the electrode pad 210, and the metal oxide layer 220 The auxiliary electrode 230 may be included.

At least one electrode pad 210 may be formed on the metal oxide layer 220, and may be electrically connected to the first conductivity type semiconductor layer 11 to inject current.

The electrode pad 210 may include metal layers having characteristics of an ohmic contact, an adhesive layer, and a bonding layer, and may be non-transmissive, but is not limited thereto. For example, the electrode pad 210 is selected from Ti, Ru, Rh, Ir, Mg, Zn, Al, In, Ta, Pd, Co, Ni, Si, Ge, Ag, and Au, and optional alloys thereof. Can be.

However, when the electrode pad 210 directly contacts the first conductivity-type semiconductor layer 11, current is intensively supplied only around the region where the electrode pad 210 is disposed, and the first conductivity-type semiconductor layer 11 ) It cannot supply current throughout.

Accordingly, a metal oxide layer 220 for current diffusion may be disposed between the electrode pad 210 and the first conductivity type semiconductor layer 11.

The metal oxide layer 220 may serve to diffuse a current so that the current injected from the electrode pad 210 can be injected across the entire surface of the first conductivity type semiconductor layer 11. In addition, light extraction texturing for light extraction may be formed on the surface of the metal oxide layer 220, thereby improving light extraction efficiency.

The metal oxide layer 220 may include the aforementioned perovskite metal oxide, and may include, for example, KNbO ₃ , BaSnO ₃ , CaZrO ₃ or SrCeO _{3 -} .

The perovskite metal oxide has high conductivity and may have light transmittance, and thus, when the perovskite metal oxide is used as the metal oxide layer 220, light extraction efficiency may be improved.

In addition, by cutting the perovskite metal oxide to a sufficient thickness and depositing it on the first conductivity type semiconductor layer 11, current diffusion can be improved, and texturing for light extraction on the surface is formed without damage to the semiconductor layer. can do.

For example, the metal oxide layer 220 of the first electrode layer 200 may be formed to a thickness of 50 to 150 μm.

Table 1 shows the operating voltage and luminous efficiency according to the thickness of the metal oxide layer 220.

Referring to Table 1, it can be seen that when the metal oxide layer 220 is formed in a thickness of 50 μm or less, current spreading is not performed smoothly, resulting in a decrease in luminous efficiency Po. Further, although the metal oxide layer 220 may be formed to have a thickness of 150 μm or more, the luminous efficiency is no longer significantly improved when the metal oxide layer 220 is formed to a thickness of 150 μm or more.

In addition, the metal oxide layer 220 may further include an ohmic contact layer (not shown) for ohmic contact with the first conductivity type semiconductor layer 11.

The ohmic contact layer (not shown) may be formed of, for example, a transparent conductive oxide film. The ohmic contact layer is, for example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), AZO (Aluminum Zinc Oxide), AGZO (Aluminum Gallium Zinc Oxide), IZTO (Indium Zinc Tin Oxide), IAZO (Indium Aluminum Zinc Oxide) ), IGZO (Indium Gallium Zinc Oxide), IGTO (Indium Gallium Tin Oxide), ATO (Antimony Tin Oxide), GZO (Gallium Zinc Oxide), IZON (IZO Nitride), ZnO, IrOx, RuOx, NiO, Pt, Ag, It may be formed of at least one material selected from Ti.

In addition, the metal oxide layer 220 may further include a current blocking portion CBL disposed under the electrode pad 210, but is not limited thereto.

Meanwhile, the electrode pad 210 may be disposed at a corner or corner of the metal oxide layer 220.

In this case, current diffusion may be difficult to a corner opposite to the corner where the electrode pad 210 is disposed, or to a corner opposite to the corner where the electrode pad 210 is disposed.

Accordingly, in the metal oxide layer 220, the auxiliary electrode 230 may be further disposed at a corner or corner corresponding to the corner or corner where the electrode pad 210 is disposed.

For example, referring to FIG. 3, when the electrode pad 210 is disposed at a specific corner of the metal oxide layer 220, the auxiliary electrode 230 may be disposed near a corner facing the specific corner. have. In more detail, the auxiliary electrode 230 may be disposed along both corners connected to a corner facing the corner where the electrode pad 210 is disposed.

The auxiliary electrode 230 may be disposed above, below or within the metal oxide layer 220. When FIG. 1 is viewed in the XY cross-sectional view of FIG. 2, the auxiliary electrode 230 of the embodiment is shown to be interposed between the metal oxide layer 220 and the first conductivity type semiconductor layer 11, but is not limited thereto. Does not.

That is, since the auxiliary electrode 230 may affect the direction in which the current injected from the electrode pad flows, the auxiliary electrode 230 is disposed in an area farthest from the area where the electrode pad 210 is located in the metal oxide layer 220. It is preferable to be, but is not limited thereto.

The auxiliary electrode 230 is electrically connected through the electrode pad 210 and the metal oxide layer 220 to guide the current supplied from the electrode pad 210, thereby improving current diffusion and operating. You can reduce the voltage.

Meanwhile, a current blocking pattern (not shown) may be further formed under the auxiliary electrode 230, but is not limited thereto.

The auxiliary electrode 230 may include metal layers having characteristics of an ohmic contact, an adhesive layer, and a bonding layer, and may be non-transmissive, but is not limited thereto. For example, the auxiliary electrode 230 is selected from Ti, Ru, Rh, Ir, Mg, Zn, Al, In, Ta, Pd, Co, Ni, Si, Ge, Ag, and Au, and optional alloys thereof. Can be.

Hereinafter, various patterns in which the structure of the first electrode layer 200 is changed will be described by dividing embodiments, and the same reference numerals are inserted for configurations of the same concept, and descriptions of overlapping descriptions will be omitted.

4 is a plan view of a first electrode layer according to a second embodiment.

Referring to FIG. 4, the first electrode layer 201 according to the second embodiment may include at least one electrode pad 211 and a metal oxide layer 220 disposed under the electrode pad 211. .

At least one electrode pad 211 may be disposed on the metal oxide layer 220, and may be electrically connected to the first conductivity type semiconductor layer 11 to inject current.

When the auxiliary electrode 230 is disposed as in the first embodiment, light extraction efficiency may be reduced due to the auxiliary electrode 230 and the current blocking pattern CBL formed under the auxiliary electrode 230.

Accordingly, the first electrode layer 200 of the second embodiment does not include the auxiliary electrode 230 and is intended to diffuse current only with the metal oxide layer 220.

However, since the auxiliary electrode 230 is not formed, current may be concentrated around the electrode pad 211, so the electrode pad 211 is preferably disposed in the center of the metal oxide layer 220. It is not limited thereto.

That is, the first electrode layer 201 of the second embodiment may include an electrode pad 211 disposed on the central portion of the metal oxide layer 220 and a metal oxide layer 220 formed to have a sufficient thickness. Current may be diffused and injected over the entire surface of the first conductivity type semiconductor layer 11.

In this case, a current blocking portion (not shown) may be further disposed under the electrode pad 211, but the present invention is not limited thereto.

5 is a plan view of the first electrode layer 200 according to the third embodiment.

5, the first electrode layer 202 according to the third embodiment includes at least one electrode pad 212, a metal oxide layer 220 disposed under the electrode pad 212, and the metal oxide. It may include an auxiliary electrode 230 disposed on the layer 220.

In order to prevent the current from being concentrated around the electrode pad 212, a plurality of electrode pads 212 may be formed.

For example, referring to FIG. 5, a first electrode pad 212a and a second electrode pad 212b may be disposed at both corners of one edge of the metal oxide layer 220, respectively.

In this case, an auxiliary electrode 232 may be disposed at an edge facing the edge where the electrode pad 212 is formed.

The current injected from the first electrode pad 212a and the second electrode pad 212b may flow in the direction of the auxiliary electrode 232 to diffuse the current throughout the metal oxide layer 220.

The auxiliary electrode 232 may be disposed above, below or within the metal oxide layer 220. Referring to FIG. 1, the auxiliary electrode 232 of the embodiment is shown to be interposed between the metal oxide layer 220 and the first conductivity type semiconductor layer 11, but is not limited thereto.

6 to 8 show a method of manufacturing a light emitting device according to an embodiment.

Hereinafter, a method of manufacturing a light emitting device according to an embodiment will be described with reference to FIGS. 6 to 8. On the other hand, although the description will focus on the first embodiment, the embodiment is not limited thereto.

According to the method of manufacturing a light emitting device according to the embodiment, as shown in FIG. 6, a first conductivity type semiconductor layer 11, an active layer 12, and a second conductivity type semiconductor layer 13 may be formed on the substrate 5. . The first conductivity type semiconductor layer 11, the active layer 12, and the second conductivity type semiconductor layer 13 may be defined as a light emitting structure 10.

The substrate 5 may be formed of, for example, _{at least one of a sapphire substrate (Al 2} O ₃ ), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto. A buffer layer (not shown) may be further formed between the first conductivity type semiconductor layer 11 and the substrate 5.

For example, the first conductivity-type semiconductor layer 11 is formed of an n-type semiconductor layer to which an n-type dopant is added as a first conductivity-type dopant, and the second conductivity-type semiconductor layer 13 is a second conductivity-type dopant. As a p-type dopant may be formed as a p-type semiconductor layer is added. In addition, the first conductivity-type semiconductor layer 11 may be formed of a p-type semiconductor layer, and the second conductivity-type semiconductor layer 13 may be formed of an n-type semiconductor layer.

The first conductivity-type semiconductor layer 11 may include, for example, an n-type semiconductor layer. The first conductivity type semiconductor layer 11 _{is formed of 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. The first conductivity-type semiconductor layer 11 may be selected from, for example, InAlGaN, GaN, AlGaN, AlInN, InGaN, AlN, InN, etc., and doped with n-type dopants such as Si, Ge, Sn, Se, Te, etc. Can be.

In the active layer 12, electrons (or holes) injected through the first conductivity type semiconductor layer 11 and holes (or electrons) injected through the second conductivity type semiconductor layer 13a meet each other, It is a layer that emits light due to a difference in a band gap of an energy band according to a material forming the active layers 12 and 12a. The active layer 12 may be formed in any one of a single well structure, a multiple well structure, a quantum dot structure, or a quantum wire structure, but is not limited thereto.

The active layer 12 may be formed of 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).} When the active layer 12 is formed in the multi-well structure, the active layer 12 may be formed by stacking a plurality of well layers and a plurality of barrier layers, for example, in a cycle of an InGaN well layer/GaN barrier layer. Can be formed.

The second conductivity-type semiconductor layer 13 may be implemented as, for example, a p-type semiconductor layer. The second conductivity type semiconductor layer 13 _{is formed of 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. The second conductivity-type semiconductor layer 13 may be selected from, for example, InAlGaN, GaN, AlGaN, InGaN, AlInN, AlN, InN, etc., and doped with p-type dopants such as Mg, Zn, Ca, Sr, Ba, etc. Can be.

Meanwhile, the first conductivity-type semiconductor layer 11 may include a p-type semiconductor layer, and the second conductivity-type semiconductor layer 13 may include an n-type semiconductor layer. In addition, a semiconductor layer including an n-type or p-type semiconductor layer may be further formed on the second conductivity-type semiconductor layer 13, and accordingly, the light emitting structure 10 is np, pn, npn, pnp junction It may have at least any one of the structures. In addition, doping concentrations of impurities in the first conductivity-type semiconductor layer 11 and the second conductivity-type semiconductor layer 13 may be uniformly or non-uniformly formed. That is, the structure of the light-emitting structure 10 may be formed in various ways, but is not limited thereto.

In addition, a first conductivity type InGaN/GaN superlattice structure or an InGaN/InGaN superlattice structure may be formed between the first conductivity type semiconductor layer 11 and the active layer 12. In addition, a second conductivity type AlGaN layer may be formed between the second conductivity type semiconductor layer 13 and the active layer 12.

Next, as shown in FIG. 7, a partial region of the first conductivity type semiconductor layer 11 may be exposed by etching the light emitting structure 10. In this case, the etching may be performed by wet etching or dry etching.

Thereafter, a channel layer 30, an ohmic contact pattern 15, and a reflective layer 17 may be formed on the light emitting structure 10.

For example, the channel layer 30 is at least one from the group consisting _{of Si0 2} , Si _x O _y , Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO _{2, AlN, etc.} Can be selected and formed.

The ohmic contact pattern 15 may be disposed between the reflective layer 17 and the second conductivity type semiconductor layer 13. The ohmic contact pattern 15 may be disposed in contact with the second conductivity type semiconductor layer 13.

The ohmic contact pattern 15 may be formed to come into ohmic contact with the light emitting structure 10. The reflective layer 17 may be electrically connected to the second conductivity type semiconductor layer 13. The ohmic contact pattern 15 may include a region in ohmic contact with the light emitting structure 10.

The ohmic contact pattern 15 may be formed of, for example, a transparent conductive oxide film. The ohmic contact pattern 15 is, for example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), AZO (Aluminum Zinc Oxide), AGZO (Aluminum Gallium Zinc Oxide), IZTO (Indium Zinc Tin Oxide), IAZO (Indium Zinc Oxide). Aluminum Zinc Oxide), IGZO(Indium Gallium Zinc Oxide), IGTO(Indium Gallium Tin Oxide), ATO(Antimony Tin Oxide), GZO(Gallium Zinc Oxide), IZON(IZO Nitride), ZnO, IrOx, RuOx, NiO, Pt , Ag, and Ti may be formed of at least one material selected from.

The reflective layer 17 may be formed of a material having a high reflectivity. For example, the reflective layer 17 may be formed of a metal or alloy including at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Cu, Au, and Hf. In addition, the reflective layer 17 includes the metal or alloy and 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), etc. It can be formed in multiple layers. For example, in an embodiment, the reflective layer 17 may include at least one of Ag, Al, Ag-Pd-Cu alloy, or Ag-Cu alloy.

For example, the reflective layer 17 may include an Ag layer and a Ni layer alternately, and may include a Ni/Ag/Ni, or a Ti layer, or a Pt layer. In addition, the ohmic contact pattern 15 may be formed under the reflective layer 17, and at least a portion may pass through the reflective layer 17 to make ohmic contact with the light emitting structure 10.

Subsequently, a metal layer 50, a bonding layer 60, a support member 70, and a temporary substrate 90 may be formed on the reflective layer 17.*

The metal layer 50 may include at least one of Au, Cu, Ni, Ti, Ti-W, Cr, W, Pt, V, Fe, and Mo materials. The metal layer 50 may function as a diffusion barrier layer.

According to an embodiment, the first electrode layer electrically connected to the second conductivity type semiconductor layer 13 may include at least one of a reflective layer, an ohmic contact layer, and a metal layer. According to an embodiment, the first electrode layer may include all of a reflective layer, an ohmic contact layer, and a metal layer, and may include one layer or two layers among them.

The metal layer 50 may perform a function of preventing a material included in the bonding layer 60 from diffusing toward the reflective layer 17 in a process in which the bonding layer 60 is provided. The second metal layer 50 may prevent a material such as tin (Sn) included in the bonding layer 60 from affecting the reflective layer 17.

The bonding layer 60 includes a barrier metal or a bonding metal, for example, at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, Nb, Pd, or Ta. Can include. The support member 70 supports the light emitting structure 10 according to the embodiment and may perform a heat dissipation function. The bonding layer 60 may be implemented as a seed layer.

The support member 70 is, for example, Ti, Cr, Ni, Al, Pt, Au, W, Cu, Mo, Cu-W or a semiconductor substrate implanted with impurities (for example, Si, Ge, GaN, GaAs, ZnO, SiC, SiGe, etc.) may be formed of at least one of. In addition, the support member 70 may be formed of an insulating material.

The temporary substrate 90 may be formed on the support member 70. The temporary substrate 90 may be formed of at least one of a metal material, a semiconductor material, or an insulating material.

Next, as shown in FIG. 8, the substrate 5 is removed from the gallium nitride semiconductor layer 14. As an example, the substrate 5 may be removed by a laser lift off (LLO) process. The laser lift-off process (LLO) is a process in which the substrate 5 and the gallium nitride semiconductor layer 14 are separated from each other by irradiating a laser to the lower surface of the substrate 5.

In addition, an isolation etching process, a process of forming the second electrode layer 87, a scribing process, a process of forming the reflector 40, and a process of removing the temporary substrate 90 may be performed. This process is an example, and the process sequence may be variously modified as needed.

Thereafter, a metal oxide layer 220 may be formed on the light emitting structure 10.

When the auxiliary electrode 230 is added according to the embodiment, before the metal oxide layer 220 is formed, the auxiliary electrode 230 may be first formed on the light emitting structure 10.

The metal oxide layer 220 may be directly grown on the light-emitting structure 10 to form.

Alternatively, the metal oxide layer 220 may be separately grown on a wafer to a sufficient thickness, then sliced to fit the size of the light emitting structure 10, and then deposited by applying heat on the light emitting structure 10. In order for the metal oxide layer 220 to maintain a perovskite structure, a deposition method may be more effective, but is not limited thereto.

After the metal oxide layer 220 is formed on the light emitting structure 10, roughness may be formed on the upper surface of the metal oxide layer 220. The roughness may be first formed on the metal oxide layer 220 and then deposited on the light emitting structure 10.

A light extraction pattern may be provided on the upper surface of the metal oxide layer 220. An uneven pattern may be provided on the upper surface of the metal oxide layer 220. The light extraction pattern provided on the metal oxide layer 220 may be formed by a PEC (Photo Electro Chemical) etching process as an example. Accordingly, according to the embodiment, it is possible to increase the external light extraction effect.

Next, an electrode pad 210 may be formed on the light emitting structure 10.

The electrode pad 210 may be electrically connected to the first conductivity type semiconductor layer 11. A partial region of the electrode pad 210 may contact the first conductivity type semiconductor layer 11. According to the embodiment, power may be applied to the light emitting structure 10 through the electrode pad 210 and the first electrode layer 87.

The electrode pad 210 may be implemented as an ohmic layer, an intermediate layer, and an upper layer. The ohmic layer may implement ohmic contact by including a material selected from Cr, V, W, Ti, and Zn. The intermediate layer may be implemented with a material selected from Ni, Cu, Al, or the like. The upper layer may include Au, for example. The electrode pad 210 may include at least one of Cr, V, W, Ti, Zn, Ni, Cu, Al, and Au.

In addition, a scribing process is performed so that the side surfaces of the channel layer 30 and the support member 70 may be exposed. Subsequently, the reflective part 40 may be formed on the side surface of the channel layer 30 and the side surface of the support member 70. Thereafter, the temporary substrate 90 is removed so that an individual light emitting device can be formed.

According to an embodiment, the reflective part 40 may be disposed on the channel layer 30. The reflective part 40 may be disposed in contact with the channel layer 30. The reflective part 40 may be disposed on a side surface of the support member 70. The reflective part 40 may be disposed in contact with a side surface of the support member 70. According to an exemplary embodiment, the reflective part 40 may be arranged such that a first region disposed above the channel layer 30 and a second region disposed on a side surface of the support member 70 are connected to each other.

In addition, the reflective part 40 may be disposed on the side of the metal layer 50. The reflective part 40 may be disposed in contact with a side surface of the metal layer 50. The reflective part 40 may be disposed on a side surface of the bonding layer 60. The reflective part 40 may be disposed in contact with a side surface of the bonding layer 60. The reflective part 40 may be disposed to be spaced apart from the light emitting structure 10. The reflective part 40 may be disposed electrically insulated from the light emitting structure 10.

The reflective part 40 may be made of a material having good reflectivity. For example, the reflective part 40 may include at least one of Ag, Al, and Pt. The reflective part 40 may be formed to a thickness of 50 nanometers to 5000 nanometers, for example.

The reflective part 40 prevents the light emitted from the light-emitting structure 10 to be incident and absorbed by the channel layer 30, the metal layer 50, the bonding layer 60, and the support member 70. Can be prevented. That is, the reflection part 40 reflects light incident from the outside so that light is absorbed and lost from the channel layer 30, the metal layer 50, the bonding layer 60, and the support member 70. Can be prevented.

As the reflective part 40 is disposed, roughness is applied to any one of the side surface of the channel layer 30, the side surface of the metal layer 50, the side surface of the bonding layer 60, and the side surface of the support member 70. Even when is formed, all sides of the light emitting device according to the embodiment can be implemented smoothly. That is, since the surface of the reflective part 40 can be formed smoothly, the side surface of the channel layer 30, the side surface of the metal layer 50, the side surface of the bonding layer 60, and the support member in a scribing process, etc. Even when the roughness or burr is formed on any one of the side surfaces of the 70, the side surfaces of the light emitting device according to the embodiment can all be implemented smoothly.

According to the embodiment, it is possible to provide a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system capable of improving light extraction efficiency while maintaining the reliability of the device.

9 is a cross-sectional view of a light emitting device according to a fourth embodiment.

The light emitting device 101 of the fourth embodiment has a structure different from that of the light emitting device 100 of the first embodiment, and the same reference numerals are inserted for configurations of the same concept, and descriptions of overlapping descriptions will be omitted.

6, the light emitting device 101 according to the fourth embodiment includes a substrate 5, a reflective layer 15 on the substrate 5, and a first conductivity type semiconductor layer on the reflective layer 15. (11), an active layer 12 on the first conductivity type semiconductor layer 11, a second conductivity type semiconductor layer 13 on the active layer 12, and the second conductivity type semiconductor layer 13 ) May include a first electrode layer 200 and a second electrode layer 87 on the first conductivity type semiconductor layer 11.

The first electrode layer 200 may include the first electrode layer 200 according to the first embodiment, the second embodiment, or the third embodiment.

That is, the first electrode layer 200 includes an electrode pad 210, a metal oxide layer 220 disposed under the electrode pad 210, and an auxiliary electrode 230 disposed on the metal oxide layer 220. Can include.

The light emitting device has a perovskite structure, has a sufficient thickness, and emits light using the metal oxide layer 220 having a light extraction pattern, thereby improving light extraction efficiency.

In addition, the light-emitting device has an advantage of sufficiently diffusing current through the first electrode layer 200 and then injecting it into the light-emitting structure 10 to improve luminous efficiency.

Although the first embodiment of the light emitting device has described a vertical structure, and the fourth embodiment has described a horizontal structure, the first electrode layer 200 of the embodiment may be applied to a light emitting device having various structures such as a flip chip. It will be natural that there is.

In addition, the light emitting device according to this embodiment may be installed in the light emitting device package.

In addition, in the light emitting device package in which the light emitting device is installed according to the embodiment, a plurality of light emitting device packages are arranged on a substrate, and an optical member such as a light guide plate, a prism sheet, a diffusion sheet, a fluorescent sheet, etc. are disposed on a path of light emitted from the light emitting device package I can. Such a light emitting device package, a substrate, and an optical member may function as a backlight unit or a lighting unit. For example, the lighting system may include a backlight unit, a lighting unit, an indicator device, a lamp, and a street light.

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. Furthermore, the features, structures, effects, and the like illustrated in each embodiment may be combined or modified for 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 construed 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 present embodiment. 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.

First conductivity type semiconductor layer 11, active layer 12,
A second conductivity type semiconductor layer 13, a gallium nitride semiconductor layer 14,
First electrode layer 200, second electrode layer 87

Claims (12)

A second electrode layer;
A second conductivity type semiconductor layer disposed on the second electrode layer;
An active layer disposed on the second conductivity type semiconductor layer;
A first conductivity type semiconductor layer disposed on the active layer; And
A first electrode layer disposed on the first conductivity type semiconductor layer; Including,
The first electrode layer,
A metal oxide layer disposed on the second conductivity type semiconductor layer and including a metal oxide having a perovskite structure;
An electrode pad disposed on the metal oxide layer; And
And an auxiliary electrode disposed between the second conductivity-type semiconductor layer and the metal oxide layer,
The electrode pad is disposed at a corner of the metal oxide layer,
The auxiliary electrodes are disposed along both corners connected to the corner facing the corner where the electrode pad is disposed,
The metal oxide layer and the auxiliary electrode directly contact an upper surface of the first conductivity type semiconductor layer,
The thickness of the metal oxide layer is 50 μm to 150 μm,
A light emitting device in which a horizontal width of a lower surface of the metal oxide layer in contact with an upper surface of the first conductivity type semiconductor layer is the same as a horizontal width of an upper surface of the first conductivity type semiconductor layer. delete delete delete delete delete The method of claim 1,
The metal oxide layer is a light emitting device comprising at least one _{of KNbO 3} , BaSnO ₃ , CaZrO ₃ or SrCeO _3. delete delete delete delete A lighting system comprising a light-emitting unit comprising the light-emitting element according to claim 1 or 7.

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