KR101972046B1 - Light emitting device - Google Patents

Abstract

A light emitting device of an embodiment includes a substrate and a first light emitting structure having at least one of etch byproducts remaining on the upper surface surface-treated in the etchant, the first light emitting structure including at least one of AlGaN and InAlGaN, And a second light emitting structure disposed on an upper portion of the first light emitting structure where etch byproducts remain.

Description

[0001]

An embodiment relates to a light emitting element.

Light emitting devices such as a light emitting diode (LD) or a laser diode using semiconductor III-V or II-VI compound semiconductors can be used for various colors such as red, green, blue, and ultraviolet Can be implemented. In addition, the light emitting device can realize a white light beam having high efficiency by combining colors using a fluorescent material, and has advantages such as low power consumption, semi-permanent lifetime, fast response speed, safety, and environment friendliness compared to conventional light sources such as fluorescent lamps and incandescent lamps .

Therefore, it is possible to replace a transmission module of an optical communication means, a light-emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of a liquid crystal display (LCD) Applications of light emitting devices to white light emitting diode lighting devices, automotive headlights, and traffic lights are being expanded.

1 is a schematic cross-sectional view of a conventional light emitting device, including a substrate 10, a buffer layer 20, and a light emitting structure 30.

The substrate 10 shown in FIG. 1 may be made of sapphire, ZnO, SiC, or the like, and the buffer layer 20 may be made of GaN or AlN. Further, the light emitting structure 20 is composed of an n-type semiconductor layer, an active layer and a p-type semiconductor layer.

2A and 2B are photographs of the light emitting device shown in FIG. 1 taken along the line 2-2 'and taken by an electron microscope. 2A is a photograph of a top surface of 20 mu m in width and 20 mu m in width, and Fig. 2B is a photograph of a top surface of 5 mu m in width and length, respectively.

If the light emitting device shown in FIG. 1 is an ultraviolet (UV) light emitting device or a deep ultraviolet (DUV) light emitting device, UV or DUV is absorbed by GaN, resulting in a decrease in luminous efficiency. In order to improve this, an n-type semiconductor layer of a UV or DUV light emitting device can be generally implemented with AlGaN instead of GaN. However, if the content of aluminum in AlGaN is increased to 20% or more, there is a problem that the size of the grain 40 becomes large as shown in FIG. 2A. In addition, as shown in FIG. 2B, there is a problem that a large number of pits 42 exist on the surface of the light emitting structure 20. FIG. Due to such grains and pits, the luminous intensity of the light emitting element is lowered, and reliability and yield are lowered.

The embodiment provides a high-quality light emitting device that emits light of ultraviolet or deep ultraviolet wavelength.

The light emitting device of the embodiment includes a substrate; And a first light emitting structure disposed on the substrate, the first light emitting structure including at least one of AlGaN and InAlGaN, the first light emitting structure having at least one etching by-product on an upper surface thereof; And a second light emitting structure disposed on top of the first light emitting structure having the at least one etching byproduct.

The light emitting device may further include a buffer layer disposed between the substrate and the first light emitting structure. The at least one etch byproduct may comprise at least one of K, Cl, P, Na, S,

According to an embodiment, the first light emitting structure includes a first conductive type first semiconductor layer disposed on the substrate, the first conductive type semiconductor layer having the at least one etching by-product on the upper surface thereof, A first conductive type second semiconductor layer disposed on the conductive type first semiconductor layer; An active layer disposed on the first conductive type second semiconductor layer and emitting ultraviolet light or deep ultraviolet light; And a second conductive semiconductor layer disposed on the active layer.

According to another embodiment, the first light emitting structure includes a first conductive semiconductor layer disposed on the substrate; An active layer disposed on the first conductive semiconductor layer and emitting ultraviolet light or deep ultraviolet light; And a second conductive type first semiconductor layer disposed on the active layer and having the at least one etching by-product on the upper surface, wherein the second light emitting structure includes a first conductive type semiconductor layer disposed on the second conductive type first semiconductor layer, 2 conductivity type second semiconductor layer.

According to another embodiment, the first light emitting structure may include: a first conductive semiconductor layer disposed on the substrate; A lower active layer disposed on the first conductive semiconductor layer and having the at least one etching by-product remaining on the upper surface, the second light emitting structure comprising: an upper active layer disposed on the lower active layer; And a second conductive type semiconductor layer disposed on the first active layer, and the lower and upper active layers emit ultraviolet light or deep ultraviolet light.

The first conductivity type may be n-type, the second conductivity type may be p-type, the first conductivity type may be p-type, and the second conductivity type may be n-type. The buffer layer may include at least one of AlN, AlGaN, and GaN.

In the light emitting device according to the embodiment, when the light emitting structure, that is, the first conductivity type semiconductor layer, the active layer, or the second conductivity type semiconductor layer is grown, the upper surface of the first light emitting structure is subjected to wet etching using an etchant It does not have grains and pits, has high luminous intensity, improves reliability and yield, and can have high quality.

1 is a schematic cross-sectional view of a conventional light emitting device.
2A and 2B are photographs of the light emitting device shown in FIG. 1 taken along the line 2-2 'and taken by an electron microscope.
Fig. 3 shows a cross-sectional view of the light emitting device of the embodiment.
4A to 4C show an embodiment of the light emitting device illustrated in FIG.
5A to 5C are cross-sectional views illustrating a method of manufacturing the light emitting device illustrated in FIG.
FIGS. 6A to 6D are photographs of the light emitting device illustrated in FIG. 3 taken along an 6-6 'line and photographed by an electron microscope.
7 is a cross-sectional view of a light emitting device package according to an embodiment.
8 is a perspective view of a lighting unit according to an embodiment.
9 is an exploded perspective view of the backlight unit according to the embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to facilitate understanding of the present invention. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. Embodiments of the invention are provided to more fully describe the present invention to those skilled in the art.

In the description of the embodiment according to the present invention, in the case of being described as being formed on the "upper" or "on or under" of each element, on or under includes both elements being directly contacted with each other or one or more other elements being indirectly formed between the two elements. Also, when expressed as "on" or "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size of each component does not entirely reflect the actual size.

3 is a cross-sectional view of the light emitting device 100 of the embodiment.

The light emitting device 100 illustrated in FIG. 3 includes a substrate 110, a buffer layer 120, a first light emitting structure 130, and a second light emitting structure 140.

The substrate 110 may comprise a conductive material or a non-conductive material. Alternatively, the substrate 110 may include a light-transmitting material or a non-light-transmitting material. For example, the substrate 110 includes at least one of sapphire (Al ₂ O ₃ ), GaN, SiC, ZnO, GaP, InP, Ga ₂ O ₃ , GaAs, and Si. For example, when the substrate 110 is a silicon substrate, it may have a (111) crystal plane as a principal plane.

The buffer layer 120 is disposed between the substrate 110 and the first light emitting structure 130 to improve the lattice mismatch between the substrate 110 and the first light emitting structure 130. For example, when the substrate 110 is a silicon substrate, it is easy to make the large diameter and the thermal conductivity is excellent. However, due to the difference in thermal expansion coefficient between the silicon and the nitride first light emitting structure 130 and the lattice mismatch, Cracks may be generated on the surface of the substrate. In order to prevent this, a buffer layer 120 is disposed between the substrate 110 and the first light emitting structure 130. The buffer layer 120 may include, but is not limited to, at least one material selected from the group consisting of Al, In, N, and Ga, for example. For example, if the light emitting device 100 illustrated in FIG. 3 emits light having an ultraviolet wavelength, the buffer layer 120 may include GaN, and if the light emitting device 100 emits light having a deep ultraviolet wavelength The buffer layer 120 may include AlN. For example, the buffer layer 120 may include at least one of AlN, AlGaN, and GaN.

Further, the buffer layer 120 may have a single-layer structure or a multi-layer structure. The buffer layer 120 may be omitted or an intermediate layer (not shown) may be additionally disposed between the buffer layer 120 and the first light emitting structure 130 according to an embodiment of the present invention. The intermediate layer serves to further reinforce the role of the buffer layer 120 described above.

The first light emitting structure 130 has at least one etch byproduct 134 disposed on the buffer layer 120 and remaining on the top surface that has been surface treated with at least one etchant. Here, when the light emitting device 100 emits light having a wavelength of ultraviolet (UV) or deep UV, the first light emitting structure 130 may include at least one of AlGaN and InAlGaN. According to an embodiment, at least one etch byproduct 134 remaining on the surface of the first light emitting structure 130 may include at least one of K, Cl, P, Na, S,

Also, the second light emitting structure 140 is disposed on top of the first light emitting structure 130 where at least one etching by-product 134 remains.

Each of the first and second light emitting structures 130 and 140 may be an undoped semiconductor layer, a p-type semiconductor layer, or an n-type semiconductor layer.

In addition, the etching by-product 134 in the light emitting device 100 is a result of the wet etching process using the etching liquid 190 as illustrated in FIG. In the case of FIG. 3, when the wet etching process is performed once, only one etching by-product 134 is shown to be disposed, but the embodiment is not limited thereto. That is, when the wet etching process is performed a plurality of times, a plurality of etch byproducts 134 may remain in the first light emitting structure 130 in the vertical direction.

Figs. 4A-4C illustrate embodiments 100A, 100B, and 100C of the light emitting device 100 illustrated in Fig.

According to one embodiment, the first light emitting structure 130 illustrated in FIG. 3 corresponds to the first light emitting structure 156 illustrated in FIG. 4A. The first light emitting structure 156 may include a first conductive type first semiconductor layer 156 disposed on the buffer layer 120 and having at least one etch byproduct 154 remaining on the upper surface.

The second light emitting structure 140 illustrated in FIG. 3 corresponds to the second light emitting structure 158, 160, and 170 illustrated in FIG. 4A. The second light emitting structures 158, 160 and 170 include a first conductive type second semiconductor layer 158, an active layer 160, and a second conductive type semiconductor layer 170. The first conductive type second semiconductor layer 158 is disposed on the first conductive type first semiconductor layer 156 on which the etching byproduct 154 is formed. The first conductive semiconductor layer 150 includes a first conductive type first semiconductor layer 156 and a first conductive type second semiconductor layer 158. The active layer 160 is disposed on the first conductive type second semiconductor layer 158 and emits ultraviolet light or deep ultraviolet light. The second conductive semiconductor layer 170 is disposed on the active layer 160.

In the above-described light emitting device 100A illustrated in FIG. 4A, the etching by-product 154 is disposed on the upper surface of the first conductive type semiconductor layer 150. FIG.

According to another embodiment, the first light emitting structure 130 illustrated in FIG. 3 corresponds to the first light emitting structure 150, 160, and 176 illustrated in FIG. 4B. The first light emitting structure 150, 160, and 176 includes a first conductive semiconductor layer 150, an active layer 160, and a first conductive semiconductor layer 176. The first conductive semiconductor layer 150 is disposed on the buffer layer 120. The active layer 160 is disposed on the first conductive semiconductor layer 150 and emits ultraviolet light or deep ultraviolet light. The second conductive type first semiconductor layer 176 is disposed over the active layer 160 and includes at least one etch byproduct 174 remaining on the upper surface.

The second light emitting structure 140 illustrated in FIG. 3 corresponds to the second light emitting structure 178 illustrated in FIG. 4B. The second light emitting structure 178 is disposed on the second conductive type first semiconductor layer 176 as the second conductive type second semiconductor layer 178. The second conductive semiconductor layer 170 includes a second conductive type first semiconductor layer 176 and a second conductive type second semiconductor layer 178.

In the light emitting device 100B illustrated in FIG. 4B, the etching by-product 174 is disposed in the second conductive type semiconductor layer 170. FIG.

According to another embodiment, the first light emitting structure 130 illustrated in FIG. 3 corresponds to the first light emitting structures 150 and 166 illustrated in FIG. 4C. The first light emitting structures 150 and 166 include a first conductive semiconductor layer 150 and a lower active layer 166. The first conductive semiconductor layer 150 is disposed on the buffer layer 120. The lower active layer 166 is disposed over the first conductivity type semiconductor layer 150 and has at least one etch byproduct 164 remaining on the upper surface.

The second light emitting structure 140 illustrated in FIG. 3 includes the second light emitting structure 168, 170 illustrated in FIG. 4C. The second light emitting structure 168, 170 includes an upper active layer 168 and a second conductive semiconductor layer 170. The upper active layer 168 is disposed on the lower active layer 166 and the second conductive semiconductor layer 170 is disposed on the upper active layer 168. The active layer 160 includes lower and upper active layers 166 and 168, and emits ultraviolet light or deep ultraviolet light.

In the light emitting device 100C illustrated in Fig. 4C, the etching by-product 164 is disposed in the active layer 160. [

The light emitting structure 180 illustrated in FIGS. 4A to 4C includes a first conductive semiconductor layer 150, an active layer 160, and a second conductive semiconductor layer 170.

The first conductive semiconductor layer 150 may be formed of a compound semiconductor such as a group III-V or a group II-VI doped with a first conductive dopant, and may be doped with a first conductive dopant. When the first conductive semiconductor layer 150 is an n-type semiconductor layer, the first conductive dopant may include Si, Ge, Sn, Se, and Te as an n-type dopant, but the present invention is not limited thereto.

For example, the first conductive semiconductor layer 150 may have a composition formula of Al _x In _y Ga _(1-xy) N (0? X? 1, 0? _Y? 1, 0? _X + Semiconductor material. The first conductive semiconductor layer 150 may include one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP and InP. If the light emitting devices 100A, 100B and 100C illustrated in FIGS. 4A to 4C are ultraviolet (UV) or deep UV light emitting devices, the first conductivity type semiconductor layer 150 may be formed of InAlGaN and AlGaN At least one or a stacked structure thereof.

The active layer 160 is formed in such a manner that electrons (or holes) injected through the first conductivity type semiconductor layer 150 and holes (or electrons) injected through the second conductivity type semiconductor layer 170 meet with each other, 160) that emits light having energy determined by the energy band inherent to the material.

The active layer 160 may be a single well structure, a multi-well structure, a single quantum well structure, a multi quantum well (MQW), a quantum-wire structure, or a quantum dot ) Structure. ≪ / RTI >

The well layer / barrier layer of the active layer 160 may be formed of any one or more pairs of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs (InGaAs) / AlGaAs, GaP (InGaP) But are not limited thereto. The well layer may comprise a material having a band gap energy lower than the band gap energy of the barrier layer.

A conductive clad layer (not shown) may be disposed above and / or below the active layer 160. The conductive cladding layer may include a semiconductor material having a band gap energy higher than the band gap energy of the barrier layer of the active layer 160. [ For example, the conductive clad layer may include GaN, AlGaN, InAlGaN, superlattice structure, or the like. Further, the conductive clad layer may be doped with n-type or p-type.

The second conductive semiconductor layer 170 may include a semiconductor compound and may be formed of a compound semiconductor such as a Group III-V or a Group II-VI. For example, the second conductivity type semiconductor layer 170 may include a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0? X? 1, 0? _Y? 1, 0? _X + y? can do. The second conductivity type semiconductor layer 170 may be doped with a second conductivity type dopant. When the second conductivity type semiconductor layer 170 is a p-type semiconductor layer, the second conductivity type dopant may include Mg, Zn, Ca, Sr, and Ba as a p-type dopant. If the light emitting devices 100A, 100B, and 100C illustrated in FIGS. 4A to 4C are UV or DUV light emitting devices, the second conductivity type semiconductor layer 170 may include at least one of InAlGaN and AlGaN, .

The first conductive semiconductor layer 150 may be a p-type semiconductor layer and the second conductive semiconductor layer 170 may be an n-type semiconductor layer. Alternatively, the first conductivity type semiconductor layer 150 may be an n-type semiconductor layer, and the second conductivity type semiconductor layer 170 may be a p-type semiconductor layer.

The light emitting structure 180 may have 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.

In addition, the thickness of the n-type semiconductor layer in the light emitting structure 180 may be thicker than the thickness of the p-type semiconductor layer.

Hereinafter, a method of manufacturing the light emitting device 100 illustrated in FIG. 3 will be described with reference to the accompanying drawings. However, it is needless to say that the light emitting device 100 illustrated in FIG. 3 may be manufactured by other methods without being limited thereto.

5A to 5C are process cross-sectional views illustrating a method of manufacturing the light emitting device 100 illustrated in FIG.

Referring to FIG. 3A, a buffer layer 120 is formed on a substrate 110. Here, the substrate 110 may comprise a conductive or non-conductive material. Alternatively, / the substrate 110 may comprise a light-transmitting or non-light-transmitting material.

The buffer layer 120 may be formed on the substrate 110 before the first light emitting structure 130 is formed on the substrate 110. [ The buffer layer 120 may be formed of at least one material selected from the group consisting of, for example, Al, In, N, and Ga, but is not limited thereto. In addition, the buffer layer 120 may be formed as a single layer or a multilayer structure.

Next, referring to FIG. 5B, a first light emitting structure 130 is formed on the buffer layer 120. As described above, according to the embodiment, the first light emitting structure 130 may be formed in various structures as illustrated in FIGS. 4A, 4B, or 4C.

4C, the upper surface of the first light emitting structure 130 may be wet-etched by the etchant 190, and the upper surface of the first light emitting structure 130 may be wet- Etch. Here, at least one of KOH, HCl, H ₃ PO ₄ , NaOH, H ₂ SO ₄ and nitric acid may be used as the etchant 190 used in the wet etching process.

In the wet etching process, the temperature, the time, and the concentration of the etchant 190 that etch the upper surface of the first light emitting structure 130 by the etchant 190 may have the relationship shown in Table 1 below.

Temperature time The concentration of the etchant 190 fixing ↓ ↑ ↓ fixing ↑ ↑ ↓ fixing ↓ ↑ fixing

Referring to Table 1, the wet etching time can be reduced (↓) by increasing (↑) the concentration of the etching liquid 190 when the temperature is fixed. Alternatively, the temperature can be decreased (↓) by increasing (↑) the concentration of the etchant 190 when the time is fixed. Alternatively, when the concentration of the etchant 190 is fixed, the time can be reduced (↓) by increasing (↑) the temperature. Alternatively, when the concentration of the etchant 190 is fixed, the time can be increased (↑) by decreasing the temperature (↓).

According to the embodiment, KOH having a concentration of 35% to 55%, for example, 45% is used as the etching solution 190, and the first light emitting structure 190 is heated at a temperature of 90 ° C to 190 ° C, for example, 140 ° C for 5 minutes to 20 minutes Wet etching may be performed on the upper surface of the semiconductor substrate 130.

When the result of the wet etching performed by the etching solution 190 is washed, the etching byproduct 134 remains on the upper surface of the first light emitting structure 130. If KOH is used as the etching liquid 190, K as the etching by-product 134 remains on the upper surface of the first light emitting structure 130. When Cl, P, Na, S, and N are used as etchant byproducts 134 in the first light emitting structure 130 using HCl, H ₃ PO ₄ , NaOH, H ₂ SO ₄ and HNO ₃ as the etchant 190, Respectively.

Next, as illustrated in FIG. 3, a second light emitting structure 140 is formed on the first light emitting structure 130 where the etching byproduct 134 remains on the upper surface. The second light emitting structure 140 has a structure as illustrated in FIG. 4A, FIG. 4B, or FIG. 4C described above.

The first conductive semiconductor layer 150, the active layer 160, and the second conductive semiconductor layer 170 may be formed as follows, regardless of the structure of the first and second light emitting structures 130 and 140, But is not limited thereto.

The first conductive semiconductor layer 150 may be formed of a compound semiconductor such as a group III-V or a group II-VI doped with a first conductive dopant, and the first conductive dopant may be doped. When the first conductive semiconductor layer 150 is an n-type semiconductor layer, the first conductive dopant may include Si, Ge, Sn, Se, and Te as an n-type dopant, but the present invention is not limited thereto.

For example, the first conductive semiconductor layer 150 may have a composition formula of Al _x In _y Ga _(1-xy) N (0? X? 1, 0? _Y? 1, 0? _X + May be formed using a semiconductor material. The first conductive semiconductor layer 150 may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP and InP. If the light emitting device 100 illustrated in FIG. 3 is an ultraviolet (UV) or deep ultraviolet light emitting device, the first conductivity type semiconductor layer 150 may be formed of at least one of InAlGaN and AlGaN, And may be formed in a laminated structure of these.

The active layer 160 may be a single well structure, a multi-well structure, a single quantum well structure, a multi quantum well (MQW), a quantum-wire structure, or a quantum dot ) Structure.

The well layer / barrier layer of the active layer 160 may be formed of any one or more pairs of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs (InGaAs) / AlGaAs, GaP (InGaP) But are not limited thereto. The well layer may be formed of a material having a band gap energy lower than the band gap energy of the barrier layer.

A conductive clad layer (not shown) may be formed on and / or below the active layer 160. The conductive cladding layer may be formed of a semiconductor having a band gap energy higher than the band gap energy of the barrier layer of the active layer 160. [ For example, the conductive clad layer may include GaN, AlGaN, InAlGaN, superlattice structure, or the like. Further, the conductive clad layer may be doped with n-type or p-type.

The second conductive semiconductor layer 170 may be formed of a semiconductor compound, and may be formed of a compound semiconductor such as a group III-V or II-VI group. For example, the second conductivity type semiconductor layer 170 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 + . The second conductivity type semiconductor layer 170 may be doped with a second conductivity type dopant. When the second conductivity type semiconductor layer 170 is a p-type semiconductor layer, the second conductivity type dopant may include Mg, Zn, Ca, Sr, and Ba as a p-type dopant. If the light emitting device 100 illustrated in FIG. 3 is a UV or DUV light emitting device, the second conductivity type semiconductor layer 170 may be formed of at least one of InAlGaN and AlGaN, or may be formed of a stacked structure thereof. have.

6A to 6D illustrate photographs of the light emitting device 100 illustrated in FIG. 3 taken by 6-6 'line and taken by an electron microscope. Figs. 6A and 6B are photographs of upper surfaces of 20 mu m in width and 20 mu m in height, respectively, and Figs. 6C and 6D are photographs of upper surfaces of 5 mu m in width and 5 mu m in size, respectively. Here, FIGS. 6A and 6C are photographs for a wet etching process for 10 minutes, and FIGS. 6B and 6D are photographs for a wet etching process for 20 minutes.

5c, when the upper surface of the first light emitting structure 130 is wet-etched by the etching solution 190, defects such as grains and pits existing in the first light emitting structure 130 Merged and removed. Accordingly, the second light emitting structure 140 formed on the first light emitting structure 130 from which the defect is removed has no defect or is at least reduced. Comparing the photographs shown in FIGS. 2A and 2B with the photographs shown in FIGS. 6A to 6D, it can be seen that the light emitting device 100 according to the present embodiment has no grain and no pits.

The light emitting device 100 according to the above-described embodiment has various embodiments 100A, 100B, and 100C, and each of the embodiments 100A, 100B, and 100C may have a horizontal, vertical, or flip-bonding structure. Vertical, vertical or flip-bonding light-emitting devices using the structure illustrated in FIGS. 4A to 4C are obvious from the level of those skilled in the art, and therefore, detailed description thereof will be omitted here.

Hereinafter, the structure and operation of the light emitting device package including the light emitting element will be described.

7 is a cross-sectional view of a light emitting device package 200 according to an embodiment.

The light emitting device package 200 according to the embodiment includes the package body 205, the first and second lead frames 213 and 214 provided on the package body 205, and the package body 205 A light emitting device 220 electrically connected to the first and second lead frames 213 and 214 and a molding member 240 surrounding the light emitting device 220.

The package body portion 205 may be formed of silicon, synthetic resin, or metal, and may be formed with an inclined surface around the light emitting device 220.

The first and second lead frames 213 and 214 are electrically separated from each other and serve to supply power to the light emitting device 220. The first and second lead frames 213 and 214 may function to increase light efficiency by reflecting the light generated from the light emitting device 220. The heat generated from the light emitting device 220 may be transmitted to the outside It may also serve as a discharge.

The light emitting device 220 may be the light emitting device 100 (100A to 100C) illustrated in FIGS. 3 to 4C, but is not limited thereto.

The light emitting device 220 may be disposed on the first or second lead frame 213 or 214 or may be disposed on the package body 205 as illustrated in FIG.

The light emitting device 220 may be electrically connected to the first and / or second lead frames 213 and 214 by a wire, a flip chip, or a die bonding method. The light emitting device 220 illustrated in FIG. 7 may be electrically connected to the first lead frame 213 through the wire 230 and directly electrically connected to the second lead frame 214, but is not limited thereto.

The molding member 240 can surround and protect the light emitting device 220. In addition, the molding member 240 may include a phosphor to change the wavelength of light emitted from the light emitting device 220.

A plurality of light emitting device packages according to embodiments may be arranged on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, a fluorescent sheet, and the like may be disposed on the light path of light emitted from the light emitting device package. The light emitting device package, the substrate, and the optical member may function as a backlight unit or function as a lighting unit. For example, the lighting system may include a backlight unit, a lighting unit, a pointing device, a lamp, and a streetlight.

8 is a perspective view of the illumination unit 300 according to the embodiment. However, the illumination unit 300 of Fig. 8 is an example of the illumination system, but is not limited thereto.

The illumination unit 300 includes a case body 310, a connection terminal 320 installed in the case body 310 and supplied with power from an external power source, a light emitting module unit 330 installed in the case body 310, ).

The case body 310 is formed of a material having a good heat dissipation property, and may be formed of metal or resin.

The light emitting module unit 330 may include a substrate 332 and at least one light emitting device package 200 mounted on the substrate 332.

The substrate 332 may be a printed circuit pattern on an insulator and may be a printed circuit board (PCB), a metal core PCB, a flexible PCB, a ceramic PCB, or the like .

In addition, the substrate 332 may be formed of a material that efficiently reflects light, or may be formed of a color whose surface is efficiently reflected, for example, white, silver, or the like.

At least one light emitting device package 200 may be mounted on the substrate 332. Each of the light emitting device packages 200 may include at least one light emitting device 220, for example, a light emitting diode (LED). The light emitting diode may include a colored light emitting diode that emits red, green, blue, or white colored light, and a UV light emitting diode that emits ultraviolet (UV) light.

The light emitting module unit 330 may be arranged to have a combination of various light emitting device packages 200 to obtain colors and brightness. For example, a white light emitting diode, a red light emitting diode, and a green light emitting diode may be arranged in combination in order to secure a high color rendering index (CRI).

The connection terminal 320 may be electrically connected to the light emitting module unit 330 to supply power. In the embodiment, the connection terminal 320 is connected to the external power source by being inserted in a socket manner, but the present invention is not limited thereto. For example, the connection terminal 320 may be formed in a pin shape and inserted into an external power source, or may be connected to an external power source through wiring.

9 is an exploded perspective view of the backlight unit 400 according to the embodiment. However, the backlight unit 400 of FIG. 9 is an example of the illumination system, and the present invention is not limited thereto.

The backlight unit 400 includes a light guide plate 410, a reflective member 420 under the light guide plate 410, a bottom cover 430, a light emitting module unit 440 for providing light to the light guide plate 410 ). The bottom cover 430 houses the light guide plate 410, the reflection member 420, and the light emitting module unit 440.

The light guide plate 410 serves to diffuse light to make a surface light source. The light guide plate 410 is made of a transparent material, and may be made of, for example, acrylic resin such as PMMA (polymethyl methacrylate), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin copolymer (COC), and polyethylene naphthalate As shown in FIG.

The light emitting module unit 440 provides light to at least one side of the light guide plate 410, and ultimately acts as a light source of the display device in which the backlight unit is installed.

The light emitting module 440 may be in contact with the light guide plate 410, but is not limited thereto. Specifically, the light emitting module unit 440 includes a substrate 442 and a plurality of light emitting device packages 400 mounted on the substrate 442. The substrate 442 may be in contact with the light guide plate 410, but is not limited thereto.

The substrate 442 may be a PCB including a circuit pattern (not shown). However, the substrate 442 may include not only general PCB but also metal core PCB (MCPCB), flexible PCB, and the like, but the present invention is not limited thereto.

The plurality of light emitting device packages 200 may be mounted on the substrate 442 such that the light emitting surface on which the light is emitted is spaced apart from the light guiding plate 410 by a predetermined distance.

A reflective member 420 may be formed under the light guide plate 410. The reflective member 420 reflects the light incident on the lower surface of the light guide plate 410 so as to face upward, thereby improving the brightness of the backlight unit. The reflective member 420 may be formed of, for example, PET, PC, PVC resin or the like, but is not limited thereto.

The bottom cover 430 may house the light guide plate 410, the light emitting module 440, the reflective member 420, and the like. To this end, the bottom cover 430 may be formed in a box shape having an opened top surface, but the present invention is not limited thereto.

The bottom cover 430 may be formed of a metal or a resin, and may be manufactured using a process such as press molding or extrusion molding.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

10, 110: substrate 20, 120: buffer layer
100, 100A, 100B, 100C, 220: light emitting device 130: first light emitting structure
134, 154, 164, 174: etching by-product 140: second light emitting structure
150: first conductivity type semiconductor layer 160: active layer
170: second conductivity type semiconductor layer 180: light emitting structure
205: package body portion 213, 214: lead frame
240: molding member 300: illuminating unit
310: Case body 320: Connection terminal
330, 440: light emitting module part 400: back light unit
410: light guide plate 420: reflective member
430: bottom cover

Claims (12)

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A first light emitting structure disposed on the substrate, the first light emitting structure including at least one of AlGaN and InAlGaN, having at least one etching by-product on an upper surface thereof; And
And a second light emitting structure disposed on top of the first light emitting structure having the at least one etching by-
The first light emitting structure
And a first conductive type first semiconductor layer disposed on the substrate and having the at least one etched byproduct on the upper surface,
The second light emitting structure
A first conductive type second semiconductor layer disposed on the first conductive type first semiconductor layer;
An active layer disposed on the first conductive type second semiconductor layer and emitting ultraviolet light or deep ultraviolet light; And
And a second conductive semiconductor layer disposed on the active layer. Board;
A first light emitting structure disposed on the substrate, the first light emitting structure including at least one of AlGaN and InAlGaN, having at least one etching by-product on an upper surface thereof; And
And a second light emitting structure disposed on top of the first light emitting structure having the at least one etching by-
The first light emitting structure
A first conductive semiconductor layer disposed on the substrate;
An active layer disposed on the first conductive semiconductor layer and emitting ultraviolet light or deep ultraviolet light; And
And a second conductive type first semiconductor layer disposed on the active layer and having the at least one etch byproduct on the upper surface,
The second light emitting structure
And a second conductive type second semiconductor layer disposed on the second conductive type first semiconductor layer. Board;
A first light emitting structure disposed on the substrate, the first light emitting structure including at least one of AlGaN and InAlGaN, having at least one etching by-product on an upper surface thereof; And
And a second light emitting structure disposed on top of the first light emitting structure having the at least one etching by-
The first light emitting structure
A first conductive semiconductor layer disposed on the substrate;
And a lower active layer disposed on the first conductive semiconductor layer and having the at least one etch byproduct remaining on the upper surface,
The second light emitting structure
An upper active layer disposed on the lower active layer; And
And a second conductive semiconductor layer disposed on the upper active layer,
Wherein the lower and upper active layers emit ultraviolet light or deep ultraviolet light. delete delete delete 7. The method according to any one of claims 4 to 6,
Wherein the at least one etch byproduct comprises at least one of K, Cl, P, Na, S, 11. The method of claim 10,
And a buffer layer disposed between the substrate and the first light emitting structure. 12. The light emitting device of claim 11, wherein the buffer layer comprises at least one of AlN, AlGaN, and GaN.

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