KR20170120878A - Light emitting module and medical apparatus - Google Patents

Abstract

The present invention relates to a light emitting module and a medical apparatus. According to the present invention, the light emitting module comprises: a circuit board; a light emitting unit including a plurality of light emitting element packages with a half amplitude (FWHM) of 17 nm or less disposed on the circuit board; and a heat radiation unit disposed on the rear surface of the light emitting unit. The plurality of light emitting element packages has a first pitch in a first direction and a second pitch in a second direction that is perpendicular to the first direction. The first and second pitches may be 30 to 50% of the width or diameter of a target area to which light is irradiated from the light emitting unit. Therefore, according to embodiments, a high-efficiency and high-reliability light emitting module for treatment in a UVN wavelength can be implemented. Also, according to embodiments, the size and manufacturing costs of the light emitting module can be reduced by forming a target area uniformity of 70% or more and reducing the number of light emitting element packages.

Description

[0001] LIGHT EMITTING MODULE AND MEDICAL APPARATUS [0002]

Embodiments relate to a light emitting module and a medical instrument.

A light emitting diode (LED) is one of light emitting devices that emits light when current is applied. The light emitting diode is capable of emitting light with high efficiency at a low voltage, thus providing excellent energy saving effect.

Nitride semiconductors have attracted great interest in the development of optical devices and high output electronic devices due to their high thermal stability and wide band gap energy. Particularly, ultraviolet (UV) light emitting elements, blue light emitting elements, green light emitting elements, and red light emitting elements using nitride semiconductors are commercially available and widely used.

The ultraviolet light emitting device (UV LED) is a light emitting device that emits light in a wavelength range of 200 nm to 400 nm. The ultraviolet light-emitting device has a short wavelength and a long wavelength depending on the application. The short wavelength may be used for sterilization or purification, and the long wavelength may be used for an exposure machine, a curing machine, or the like. In particular, UVB of 280 nm to 320 nm can be used in medical equipment and the like.

Recently, ultraviolet light-emitting devices of UVB used in precision medical instruments are required to realize a high-efficiency ultraviolet light-emitting device capable of realizing a target wavelength within 280 nm to 320 nm and capable of driving a high current. Furthermore, a light emitting module for a medical device is required to reduce the number of light emitting devices, realize a light uniformity of 70% or more, and realize a therapeutic wavelength band.

Embodiments can provide a light emitting module and a medical device that can improve the uniformity of light in a target area.

The embodiment can provide a light emitting module and a medical instrument capable of realizing UVB of 300 to 320 nm driven by a high current of 200 mA or more.

The embodiment can provide a light emitting module and a medical instrument capable of improving the reliability of a therapeutic ultraviolet wavelength having a full width at half maximum (FWHM) of 17 nm or less.

The embodiment can provide a light emitting module and a medical instrument that realize a 300 to 320 nm UVB of a high current driving of 200 mA or more, a half width (FWHM) of 17 nm or less, and a light uniformity of 70% or more.

A light emitting module according to an embodiment includes a circuit board, a light emitting portion disposed on the circuit board and including a plurality of light emitting device packages having a full width at half maximum (FWHM) of 17 nm or less; And a heat dissipation unit disposed on a rear surface of the light emitting unit, wherein the plurality of light emitting device packages have a first pitch in a first direction and a second pitch in a second direction orthogonal to the first direction, And the second pitch may be 30% to 50% of the width or diameter of the target region irradiated with light from the light emitting portion. Therefore, the embodiment can realize a highly reliable light emitting module for medical treatment with high efficiency of UVB wavelength. In addition, the embodiment realizes a target area uniformity of 70% or more and reduces the number of light emitting device packages, thereby reducing the size and manufacturing cost of the light emitting module.

The medical instrument according to the embodiment includes the light emitting module and the optical compensator to realize a high efficiency, reliable and effective wavelength (300 nm to 320 nm), realizes a target area uniformity of 70% or more, The size and manufacturing cost of the medical device can be reduced.

Embodiments can improve the reliability of the light therapy light emitting module by realizing the uniformity of the ultraviolet wavelength provided in the target area TA to 70% or more.

The embodiment can improve the reliability of the light therapy light emitting module by implementing an ultraviolet wavelength of an effective wavelength (300 nm to 320 nm) for phototherapy driven by a high current of 200 mA or more.

The embodiment can provide a light emitting module and a medical instrument that can improve the reliability of a therapeutic ultraviolet wavelength having a full width at half maximum (FWHM) of 17 nm or less.

The embodiment has a uniformity of light of 70% or more and reduces the number of the plurality of light emitting device packages having a pitch of 30% to 50% of the target area width or diameter, thereby reducing the size of the light emitting module, .

1 is a perspective view illustrating a light emitting module according to an embodiment.
2 is a plan view showing a light emitting portion of the light emitting module of FIG.
3 is a diagram showing the uniformity of the light emitting module of the embodiment.
4 is a cross-sectional view illustrating a medical instrument including a light emitting module according to another embodiment.
5 is a diagram showing the uniformity of the light emitting module of another embodiment.
6 is a plan view showing a light emitting device package of the embodiment.
7 is a plan view showing an ultraviolet light emitting device included in the light emitting device package of FIG.
8 is a cross-sectional view of an ultraviolet light emitting device cut along the line I-I 'of FIG.
FIG. 9 is a cross-sectional view showing the EBL between the active layer and the second conductive type semiconductor layer of FIG. 8. FIG.
10 is a diagram showing an energy bandgap diagram of the last quantum barrier layer, the EBL and the second conductivity type semiconductor layer of the active layer according to the embodiment.
11 is a cross-sectional view illustrating the AlN template, the first superlattice layer, the first conductive type first semiconductor layer, the second superlattice layer, and the first conductive type second semiconductor layer of FIG.
12 is a graph showing the power of light according to the quantum wall thickness of the active layer according to the embodiment.
13 is a graph showing the reliability according to the thickness of the second conductive type first semiconductor layer of the embodiment.
14 is a view showing the surface of the second conductive type second semiconductor layer of the embodiment.
15 to 19 are cross-sectional views illustrating a method of manufacturing an ultraviolet light-emitting device according to an embodiment.

In the description of the embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under" the substrate, each layer Quot; on "and" under "are intended to include both" directly "or" indirectly " do. Also, the criteria for top, bottom, or bottom of each layer will be described with reference to the drawings.

FIG. 1 is a perspective view illustrating a light emitting module according to an embodiment of the present invention. FIG. 2 is a plan view showing a light emitting portion of the light emitting module of FIG. 1, and FIG. 3 is a diagram illustrating a uniformity of the light emitting module of the embodiment.

1 to 3, the light emitting module 10 of the embodiment may include the light emitting portion 20, the first and second heat dissipating portions 30 and 40, and the like. Although the embodiment limits the construction of the first and second heat dissipation units 30 and 40, it is not limited thereto. The embodiment requires a highly reliable light emitting module 10 for medical treatment with a high efficiency of UVB wavelength. In addition, the light emitting module 10, which realizes the uniformity of the target area TA by 70% or more and reduces the total size and the manufacturing cost by reducing the number of the light emitting device packages 200, Is required. For this, the embodiment has a high current driving of 200 mA or more and a half width (FWHM) of 17 nm or less, and light emitted from the light emitting portion 20 can have a uniformity of 70% or more in the target area TA. Here, the uniformity is defined as a center area where the illuminance is maximized in the target area and an edge area where the illuminance is minimum, and the minimum illuminance (Min) / the maximum illuminance (Max) can be defined.

The first heat-radiating portion 30 may be disposed on the rear surface of the light-emitting portion 20. The first heat dissipating unit 30 may directly contact the light emitting unit 20 and may emit heat generated from the light emitting unit 20. [ The first heat dissipation unit 30 may be, for example, a heat sink, but is not limited thereto. The first heat dissipation unit 30 may include a plurality of heat dissipation fins. Here, the heat dissipation fins may increase the heat dissipation area to improve the heat dissipation efficiency.

The second heat dissipation unit 40 may be disposed on the rear surface of the first heat dissipation unit 30. [ The second heat-dissipating unit 40 may be in direct contact with the first heat-dissipating unit 30. The second heat dissipating unit 40 may include a function of discharging the heat conducted to the first heat dissipating unit 30 to the outside. For example, the second heat dissipation unit 40 may include a cooling fan using air convection, but the present invention is not limited thereto.

The light emitting portion 20 of the embodiment may include a circuit board 21 and a plurality of light emitting device packages 200. The plurality of light emitting device packages 200 may be mounted on the front surface of the circuit board 21. Can be mounted. Here, the circuit board 21 may be in contact with the first heat radiating part 30 on the rear surface thereof.

The circuit board 21 may include a resin-based printed circuit board (PCB), a metal core PCB, a flexible PCB, a ceramic PCB, and an FR-4 substrate.

The plurality of light emitting device packages 200 may emit a wavelength of UVB of 300 to 320 nm which is driven by a high current of 100 mA or more. Specifically, the plurality of light emitting device packages 200 may implement an effective wavelength for optical therapy (300 nm to 320 nm) having a full width at half maximum (FWHM) of 17 nm or less. In general, an ultraviolet light emitting device having a full width at half maximum (FWHM) of 20 nm or less is difficult to apply to medical devices such as atopic treatments by destroying DNA, proteins and the like at 300 nm or less, especially 298 nm or less. The light emitting device package 200 of the embodiment realizes a full width at half maximum (FWHM) of 17 nm or less to improve the reliability of the light therapy light emitting module 200.

The light emitting module 10 of the embodiment can achieve a uniformity of 70% or more in the target area TA in which the light of the emitted ultraviolet wavelength is projected. The uniformity may be defined as a central area where the illuminance is maximized in the target area TA and an edge area where the illuminance is minimum. The minimum illuminance Min and the maximum illuminance Max may be defined. For example, the target area TA may have a width W1, W2 of 20 mm and a width of 30 mm from the light emitting part 20 of the light emitting module 100, but the present invention is not limited thereto. The target area TA may have a width W1, W2 of 10 mm to 30 mm. Specifically, the target area TA may have a uniformity of 70% or more and a minimum illuminance Min of 10 mW / cm 2 or more, which is defined as a minimum light intensity / a maximum light intensity Max as a light therapy target .

If the uniformity is less than 70%, the reliability of phototherapy may be lowered due to the difference in illuminance between the central region and the edge region of the target region TA.

The plurality of light emitting device packages 200 may have a first pitch P1 in a first direction X-X 'and a second direction Y-Y' orthogonal to the first direction X- To the second pitch P2. The first and second pitches P1 and P2 may be 30% to 50% of the widths W1 and W2 of the target area TA. The first and second pitches P1 and P2 may be 10 mm or more. The first and second pitches P1 and P2 may be 10 mm to 15 mm. The first and second pitches P1 and P2 may be equal to each other, but the present invention is not limited thereto. For example, the first and second pitches P1 and P2 may be different from each other. For example, the embodiment may include first and second pitches P1 and P2 of 10 mm to achieve a uniformity of 70% or greater in a target area TA having a width W1, W2 of 30 mm spaced 20 mm apart, The light emitting device package 200 may include a plurality of light emitting device packages 200 having the same structure. Here, each light emitting device package 200 may have a luminous intensity Po of 10 mW or more. The light emitting device package 200 will be described in detail with reference to FIGS. 6 to 19. FIG.

The embodiment can improve the reliability of the light therapy light emitting module 10 by realizing the uniformity of the ultraviolet wavelength provided in the target area TA to 70% or more.

The embodiment can improve the reliability of the light therapy light emitting module 10 by realizing ultraviolet light having an effective wavelength (300 nm to 320 nm) for phototherapy driven by a high current of 200 mA or more.

The embodiment can provide a light emitting module and a medical instrument that can improve the reliability of a therapeutic ultraviolet wavelength having a full width at half maximum (FWHM) of 17 nm or less.

The embodiment is characterized in that a plurality of light emitting device packages 200 having a light uniformity of 70% or more and a pitch of 30% to 50% of the target area TA width W1, 200 can be reduced, thereby reducing the size of the light emitting module 10 and reducing the manufacturing cost.

FIG. 4 is a cross-sectional view showing a medical device including a light emitting module according to another embodiment, and FIG. 5 is a view showing a uniformity of a light emitting module in another embodiment.

2, 4, and 5, the medical device 70 including the light emitting module of another embodiment may be configured such that the light emitted from the light emitting portion 20 in the circular target area TA has a uniformity of 70% ). Here, the minimum illuminance Min of the edge area of the light emitting module of the other embodiments is constant, so that it can have a higher uniformity than the light emitting module of the embodiment of FIGS. 1 to 3. Here, the minimum illuminance of the light emitting module of the embodiment of Fig. 3 appears locally in the corner area of the rectangular target area. Therefore, the light emitting module of another embodiment can improve the uniformity reliability of the target area TA.

The construction of the light emitting portion 20 and the first and second heat dissipating portions 30 and 40 of other embodiments can adopt the technical features of the light emitting module 20 of Figs.

The medical instrument 70 of another embodiment requires a highly reliable light emitting module for medical treatment with a highly efficient UVB wavelength. In another embodiment, the uniformity of the target area is 70% or more, and the number of the light emitting device packages included in the light emitting module is reduced, thereby reducing the size of the medical device 70 and reducing the manufacturing cost. do. For this, the embodiment has a high current driving of 200 mA or more and a half width (FWHM) of 17 nm or less, and light emitted from the light emitting portion 20 may have a uniformity of 70% or more in the circular target region TA . Here, the uniformity can be defined as a minimum area roughness (Max) / a maximum roughness (Max) for a central area where the illuminance is maximized in the target area and an edge area where the illuminance is minimum.

The medical instrument 70 may include an optical compensator 60. The light compensating unit 60 may be disposed on the light emitting unit 20. The light compensating unit 60 may be disposed in the light output area of the medical device 70. The optical compensator 60 may include first to third compensators 61, 63 and 65. The first compensator 61 may be disposed on the second compensator 63. The first compensator 61 may include a function of diffusing light. The first compensator 61 may include, but is not limited to, Teflon.

The second compensating unit 63 may be disposed below the first compensating unit 61 and may be disposed on the light emitting unit 20. The light emitted from the light emitting unit 20 may be directly irradiated onto the second compensation unit 63. The second compensator 63 may include a material excellent in light transmittance. In addition, the second compensator 63 may include a function of diffusing light. For example, the second compensation unit 63 may include a glass-based material. The second compensation unit 63 is, for _{example, LiF, MgF 2, CaF 2} , BaF 2, Al 2 O 3, may be formed of a transparent material of SiO ₂ or the optical glass (N-BK7), the case of SiO ₂ , Quadrate crystal or UV Fused Silica. Also, the second compensator 63 may be a low iron glass.

The third compensation unit 65 may include a function of wrapping and diffusing the outer edges of the first and second compensation units 63. The third compensation unit 65 may include a function of diffusing light into a ring type.

In another embodiment, an optical compensator 60 including first to third compensators 61, 63 and 65 is disposed on the light emitting module, and the light emitted from the light emitter 20 is guided to the target area TA. So that the uniformity can be improved.

The light emitting portion 20 of another embodiment includes a plurality of light emitting device packages 200. The plurality of light emitting device packages 200 may emit UVB wavelengths of 300 to 320 nm. . The plurality of light emitting device packages 200 may have various wavelengths within 300 nm to 320 nm. The plurality of light emitting device packages 200 can selectively use various wavelengths such as phototherapy and experiments. To this end, the plurality of light emitting device packages 200 may have at least two different wavelengths. For example, a part of the light emitting device package 200 may emit a wavelength of 300 to 315 nm, and another part of the light emitting device package may emit a wavelength of 315 to 320 nm. The plurality of light emitting device packages 200 may emit a wavelength of UVB of 300 to 320 nm which is driven by a high current of 100 mA or more. Specifically, the plurality of light emitting device packages 200 may implement an effective wavelength for optical therapy (300 nm to 320 nm) having a full width at half maximum (FWHM) of 17 nm or less. In general, an ultraviolet light emitting device having a full width at half maximum (FWHM) of 20 nm or less is difficult to apply to medical devices such as atopic treatments by destroying DNA, proteins and the like at 300 nm or less, especially 298 nm or less. The light emitting device package 200 of the embodiment realizes a full width at half maximum (FWHM) of 17 nm or less to improve the reliability of the light therapy light emitting module 200.

The light emitting module of another embodiment can achieve a uniformity of 70% or more in the circular target area TA in which light of the emitted ultraviolet wavelength is projected. The uniformity can be defined as a central area where the roughness is maximized in the circular target area TA and a minimum roughness Min and a maximum roughness Max as to the edge areas where the roughness is minimum. For example, the circular target area TA may be 20 mm away from the light emitting part 20 of the light emitting module 100 and have a diameter W3 of 30 mm, but is not limited thereto. The circular target area TA may have a diameter W3 of 10 mm to 40 mm. Specifically, the circular target area TA may have a minimum illuminance Min / a maximum illuminance Max The defined uniformity may be greater than 70% and the minimum illuminance Min may be greater than or equal to 10 mW / cm < 2 >.

If the uniformity is less than 70%, the reliability of phototherapy may be deteriorated due to the difference in illuminance between the center portion and the edge region of the circular target region TA.

(Y-Y ') having a first pitch (P1) in a first direction (X-X') of the plurality of light emitting device packages (200) and orthogonal to the first direction To the second pitch P2. The first and second pitches P1 and P2 may be 30% to 50% of the diameter W3 of the circular target area TA. The first and second pitches P1 and P2 may be 10 mm or more. The first and second pitches P1 and P2 may be 10 mm to 15 mm. The first and second pitches P1 and P2 may be equal to each other, but the present invention is not limited thereto. For example, the first and second pitches P1 and P2 may be different from each other. For example, the embodiment may include a first and a second 10 mm of 10 mm to achieve a uniformity of 70% or more in a circular target area TA spaced 20 mm from the medical device 70 and having a diameter W3 of 30 mm. 25 light emitting device packages 200 having pitches P1 and P2 may be included. Here, each light emitting device package 200 may have a luminous intensity Po of 10 mW or more. The light emitting device package 200 will be described in detail with reference to FIGS. 6 to 19. FIG.

Another embodiment can improve the reliability of the phototherapy device 70 by realizing the uniformity of the ultraviolet wavelength provided in the target area TA to 70% or more.

Another embodiment can improve the reliability of the phototherapy device 70 by implementing an ultraviolet wavelength of an effective wavelength (300 to 320 nm) for phototherapy with a high current driving of 200 mA or more.

Other embodiments can provide a medical device 70 that can improve the reliability of the therapeutic ultraviolet wavelength with a half-width (FWHM) of 17 nm or less.

Another embodiment is a light emitting device package having a plurality of light emitting device packages 200 having a light uniformity of 70% or more and having a pitch of 30% to 50% of the circular target area TA diameter W3 200 can be reduced, thereby reducing the size of the light emitting module and reducing the manufacturing cost. Thus, another embodiment can reduce the size and manufacturing cost of the medical device 70. [

6 is a plan view showing a light emitting device package of the embodiment.

6, the light emitting device package 200 of the embodiment includes the light emitting device 100, the package body 201, the heat dissipating frame 210, the protection device 260, the first and second lead frames 220 , 230).

The package body 201 may include at least one of a light-transmitting material, a reflective material, and an insulating material. The package body 201 may include a material having a reflectance higher than that of the light emitted from the light emitting device 100. The package body 201 may be a resin-based insulating material. For example, the package body 201 is a polyphthalamide (PPA: Polyphthalamide), a resin material, a silicone such as an epoxy or silicone (Si), metallic material, PSG (photo sensitive glass), sapphire (Al ₂ O _3), printing And a circuit board (PCB). The package body 201 may have a square shape, for example, but the shape thereof may not be audible. The top view shape of the package body 201 may be circular or polygonal.

The package body 201 may be coupled to the first and second lead frames 220 and 230. The body 120 may include a cavity 203 for exposing a portion of the upper surface of the first and second lead frames 220 and 230. The cavity 203 may expose a part of the upper surface of the first lead frame 220 and may expose a part of the upper surface of the second lead frame 230.

The first and second lead frames 220 and 230 may be spaced apart from each other and coupled with the package body 201. The second lead frame 230 may include the light emitting device 100 and the protection device 260. The first wire 100W1 of the light emitting device 100 may be connected to the first lead frame 220, And the wire 260W of the protection element 260 may be connected, but the present invention is not limited thereto. The first and second lead frames 220 and 230 may include a conductive material. For example, the first and second lead frames 220 and 230 may include at least one of titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum (Ta) (Al), tin (Sn), silver (Ag), phosphorous (P), iron (Fe), tin . For example, the first and second lead frames 220 and 230 of the embodiment may be composed of a base layer including copper (Cu) and an antioxidant layer including silver (Ag) covering the base layer, no.

The second lead frame 230 includes a first lead portion 231a exposed in a center region of the cavity 203 and a second lead portion 231b symmetrically diagonally intersecting the first lead frame 220, A third lead part 231c disposed in a corner area of the cavity 203 in which the protection element 260 is mounted and a diagonal corner area. The first to third lead portions 231a, 231b and 131c are formed on the upper surface of the second lead frame 230 exposed on the bottom surface of the cavity 203, .

The first lead frame 220 may have a diagonal bent structure symmetrical to the second lead portion 231b, but the present invention is not limited thereto.

The heat radiating frame 210 includes first and second radiating electrodes 211 and 213 and the first radiating electrode 211 includes a first pad portion 211a connected to the first wire 100W1 And the second radiation electrode 213 may include a second pad portion 213a connected to the second wire 100W2.

The light emitting device 100 may be mounted on the heat dissipating frame 210. The light emitting device 100 may include the technical features of FIGS.

The protection element 260 may be disposed on the third lead portion 231c. The protection element 260 may be disposed on the upper surface of the second lead frame 230 exposed from the package body 201. The protection element 260 may be a Zener diode, a thyristor, a TVS (Transient Voltage Suppression), or the like, but is not limited thereto. The protection element 160 of the embodiment will be described as a zener diode that protects the light emitting device 100 from ESD (Electro Static Discharge). The protection element 260 may be connected to the first lead frame 130 through a wire.

7 is a plan view showing an ultraviolet light emitting device included in the light emitting device package of FIG. 6, FIG. 8 is a sectional view of the ultraviolet light emitting device cut along the line I-I 'of FIG. 7, 10 is a diagram showing energy band gap diagrams of the last quantum wall of the active layer, the EBL and the second conductivity type semiconductor layer according to the embodiment, and FIG. 11 is a cross- A first superlattice layer, a first conductive type first semiconductor layer, a second superlattice layer, and a first conductive type second semiconductor layer of FIG. 8; FIG.

As shown in FIGS. 7 to 11, the ultraviolet light emitting device 100 according to the embodiment may include the light emitting structure 110. The light emitting structure 110 of the embodiment can realize a high current driving of 100 mA or more. The light emitting structure 110 of the embodiment can realize 300 to 320 nm UVB of a high current driving of 100 mA or more. The light emitting structure 110 of the embodiment can improve the defect, improve the light emitting efficiency, improve the light power, and improve the reliability. For this, the light emitting structure 110 of the embodiment includes an AlN template (template) 111, a first superlattice layer 120a, a first conductive type first semiconductor layer 112a, a second superlattice layer The first conductive semiconductor layer 120b, the first conductive semiconductor layer 112b, the active layer 114, the electron blocking layer 130, the first conductive semiconductor layer 116a, A second electrode 116b, first and second electrodes 151 and 153, respectively.

The substrate 101 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate. For example, the substrate 101 may use at least one of sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ O ₃ . A concavo-convex structure may be formed on the substrate 101, but the present invention is not limited thereto.

The AlN template 111 may be formed on the substrate 101. The AlN template 111 may include a buffer function. The AlN template 111 may alleviate the lattice mismatch between the material of the light emitting structure 110 formed on the AlN template 111 and the substrate 101. The AlN template 111 may include AlN, Group 5 or Group 6 compound semiconductors such as GaN, InN, InGaN, AlGaN, InAlGaN, and AlInN. The AlN template 111 may be grown on the substrate 101 to improve defects due to the difference in lattice constant of the AlGaN-based semiconductor layers to be grown thereafter. The AlN template 111 may have a fully-strained epitaxial structure, thereby improving the luminous efficiency in the growth of a semiconductor layer having an ultraviolet wavelength. That is, the AlN template 111 can improve the crystallinity of the AlGaN-based semiconductor layers to be grown, thereby improving the luminous efficiency of the ultraviolet light-emitting device 100.

The first superlattice layer 120a may be disposed on the AlN template 111. [ The first conductive type first semiconductor layer 112a may be disposed on the first super lattice layer 120a. The second superlattice layer 120b may be disposed on the first conductive type first semiconductor layer 112a. The first conductive type second semiconductor layer 112b may be disposed on the second superlattice layer 120b. The first superlattice layer 120a, the first conductive semiconductor layer 112a, the second superlattice layer 120b, and the first conductive semiconductor layer 112b gradually decrease in Al composition, The lattice mismatch and defects between the template 111 and the active layer 114 can be improved.

The first superlattice layer 120a may be formed on the AlN template 111. The first superlattice layer 120a may be disposed on the AlN template 111 and may have a lattice mismatch between the AlN template 111 and the material of the light emitting structure 110 formed on the first superlattice layer 120a, And may include a function to improve defects. That is, the first superlattice layer 120a may include an Al composition closer to the first conductive type first semiconductor layer 112a than the AlN template 111 to improve defects on the AlN template 111 .

Specifically, the first superlattice layer 120a may include an AlN 121a and an AlGaN 121b formed in alternating 10 to 20 pairs. The AlGaN 121b may include a semiconductor material having a composition formula of Al _x Ga _1-x N (0.5 _{? X} ? 0.6). The AlGaN 121b may include an Al composition of 50% to 60%, and the thickness of each of the AlN 121a and the AlGaN 121b of the embodiment may be 1 nm to 5 nm.

If the AlGaN 121a and the AlGaN 121b are less than 10 pairs, the first superlattice layer 120a may have a defect improving effect. When the number of AlN 121a and AlGaN 121b is more than 20 pairs, the crystallinity of the first superlattice layer 120a may be degraded due to a difference in lattice constant. The AlGaN 121b may be a first conductive AlGaN. The AlGaN 121b may be an unintentionally doped GaN. For example, the AlGaN 121b may be unintentionally AlGaN having a first conductivity type during the growth process.

The first conductive type first semiconductor layer 112a may be formed on the first super lattice layer 120a. The first conductive type first semiconductor layer 112a may be disposed between the first superlattice layer 120a and the second superlattice layer 120b. The first conductive type first semiconductor layer 112a may have an Al composition that overlaps the first superlattice layer 120a and the second superlattice layer 120b. The first conductive type first semiconductor layer 112a has an Al composition ranging from the first superlattice layer 120a and the second superlattice layer 120b to overlap the first superlattice layer 120a and the second superlattice layer 120b. Defects can be absorbed and removed. That is, the first conductive type first semiconductor layer 112a may include a function of improving lattice mismatch and defects between the first superlattice layer 120a and the second superlattice layer 120b.

The first conductive type first semiconductor layer 112a may be formed of a compound semiconductor such as a group III-V element or a group II-VI element. For example, the first conductive type first semiconductor layer 112a may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, . The first conductive type first semiconductor layer 112a of the embodiment may include a semiconductor material having a composition formula of Al _y Ga _1-y N (0.5 _{? Y} ? 0.6). The first conductive type first semiconductor layer 112a of the embodiment may include an Al composition of 50% to 60%, and the thickness of the first conductive type first semiconductor layer 112a of the embodiment may be 10 nm to 1000 nm . In the embodiment, the first conductive type first semiconductor layer 112a having a thickness of 200 nm will be described as an example. The first conductive type first semiconductor layer 112a may be doped with a first conductive type dopant. When the first conductive type dopant is an n-type semiconductor layer, the n-type dopant may include Si, Ge, Sn, Se, and Te, but is not limited thereto.

The second superlattice layer 120b may be formed on the first conductive type first semiconductor layer 112a. The second superlattice layer 120b may include a layer having the same Al composition as the first conductive type first semiconductor layer 112a. The second superlattice layer 120b is disposed on the first conductive type first semiconductor layer 112a and is formed on the first conductive type semiconductor layer 112a and the second superlattice layer 120a. And improve the lattice mismatch and defects between the materials of the light emitting structure 110 that are exposed. The second superlattice layer 120b may include a first conductive type first AlGaN 123a and a first conductive type second AlGaN 123b formed to alternate 10 to 20 pairs.

The first conductive type first AlGaN 123a may include a semiconductor material having a composition formula of Al _a Ga _1-a N (0.5? A? 0.6). The first conductive type first AlGaN 123a may include an Al composition of 50% to 60%, and the first conductive type first AlGaN 123a may have a thickness of 1 nm to 5 nm .

The first conductive type second AlGaN (123b) may include a semiconductor material having a composition formula of Al _b Ga _{1 -b} N (0.45 _{? B} ? 0.55). The first conductive type second AlGaN (123b) may include an Al composition of 45% to 55%, and the thickness of each of the first conductive type second AlGaN (123b) of the embodiment may be 1 nm to 5 nm . The first conductive type second AlGaN (123b) may have a lower Al composition than the first conductive type first AlGaN (123a). When the first conductive dopant is an n-type semiconductor layer, the n-type dopant may include Si, Ge, Sn, Se, and Te. However, the present invention is not limited thereto. In the embodiment, the Al composition gradually decreases from the AlN template 111 to the active layer 114, thereby improving the crystallinity.

The first conductive type second semiconductor layer 112b may be formed on the second super lattice layer 120b. The first conductive type second semiconductor layer 112b may be formed of a compound semiconductor such as a group III-V element or a group II-VI element. For example, the first conductive type second semiconductor layer 112b may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, . The first conductive type second semiconductor layer 112b of the embodiment may include a semiconductor material having a composition formula of Al _z Ga _1-z N (0.45 _{? Z} ? 0.55). The first conductive type second semiconductor layer 112b of the embodiment may include an Al composition of 45% to 55%, and the thickness of the first conductive type second semiconductor layer 112b of the embodiment may be 500 nm to 1000 nm . In the embodiment, the first conductive type second semiconductor layer 112b having a thickness of 1000 nm will be described as an example. The first conductive type second semiconductor layer 112b may be doped with a first conductive type dopant.

The active layer 114 may be formed of at least one of a single quantum well structure, a multi quantum well (MQW) structure, a quantum-wire structure, or a quantum dot structure. The active layer 114 is formed by injecting electrons (or holes) injected through the first conductive type second semiconductor layer 112b and holes (or electrons) injected through the second conductive type first semiconductor layer 116a And emits light according to a band gap difference of an energy band according to the material of the active layer 114. [

The active layer 114 may be made of a compound semiconductor. The active layer 114 may be formed of at least one of compound semiconductors such as Group 3-Group 5 or Group 2-6. The active layer 114 may include a quantum well and a quantum wall. When the active layer 114 is implemented as a multiple quantum well structure, quantum wells and quantum wells can be alternately arranged. The quantum well and the quantum wall may be formed of any one or more pairs of AlGaN / GaN, AlGaN / AlGaN, InGaN / InGaN, InAlGaN / GaN, GaAs / AlGaAs, InGaAs / AlGaAs, GaP / AlGaP and InGaP AlGaP But is not limited thereto.

The thickness of each of the quantum wells of the active layer 114 may be 10% to 25% of the thickness of each of the quantum wells. That is, the thickness of each of the quantum wells may be four to ten times the thickness of each of the quantum wells. Referring to FIG. 12, the active layer 114 of the embodiment can improve the power of light by a quantum well structure having a thickness of 10% to 25% of the quantum wall. For example, each of the quantum wells may be 1.5 nm to 2.5 nm. 12 is a graph showing the power of light according to the thickness of a quantum well of the active layer 114 having a quantum wall of 10.9 nm, and shows the highest power of light in a quantum well having a thickness of 2.1 nm. If the thickness of each of the quantum wells is less than 10% or more than 25% of the thickness of each of the quantum wells, the crystallinity may deteriorate or the carrier movement may decrease. If the thickness of each of the quantum wells is out of the range of 10% to 25% of the thickness of each of the quantum wells, the recombination of electrons and holes from the active layer 114 may be reduced and the power of light may be lowered.

The EBL 130 may be formed on the active layer 114. The EBL 130 may include a second dopant. The EBL 130 of the embodiment may include a plurality of barriers 131, 133, 135, 137 and a plurality of wells 132, 134, 136. For example, the EBL 130 may be formed of three or more pairs of Group III-V or II-VI compound semiconductors, for example, the EBL 130 may be formed of AlGaN / AlGaN. The EBL 130 may be doped with a second conductivity type dopant. For example, when the EBL 130 is a p-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as a p-type dopant. The EBL 130 of the embodiment may include a function for increasing the carrier provided to the active layer 114 to realize a UVB of 300 to 320 nm at a high current driving of 100 mA or more. In addition, the EBL 130 may include an electron blocking function for blocking electrons, thereby improving the luminous efficiency. For this, the EBL 130 including the second conductivity type dopant of the embodiment may have a plurality of barriers 131, 133, 135, and 137 and a plurality of wells 132, 134, and 136 in three-paired alternation. The plurality of barriers 131, 133, 135, 137 and the plurality of wells 132, 134, 136 of the embodiment can improve the luminous efficiency by the Al composition and the thickness.

The EBL 130 may include a higher Al composition than the last quantum wall of the active layer 114 as a reference REF as the final quantum wall of the active layer 114. For example, the last quantum wall of the active layer 114 may include an Al composition of 45%, and the plurality of barriers 131, 133, 135, and 137 may include an Al composition of 50% or more. The Al composition of the EBL 130 may block electrons and confine holes to improve the efficiency of light emission by increasing carrier injection of the active layer 114.

The plurality of barriers 131, 133, 135, and 137 may include a first barrier 131 in contact with the active layer 114, a last barrier 137 in contact with the second conductive type first semiconductor layer 116a, 1 barrier 131 and the last barrier 137. The first and second intermediate barriers 133, Here, one of the first and second intermediate barriers 133 and 135 may be omitted, or may be a plurality of at least two. The plurality of wells 132,134 and 136 may be located between the first barrier 131 and the first intermediate barrier 133 and between the first and second intermediate barriers 133 and 135, And a third well 136 between the second intermediate barrier 135 and the last barrier 137. The second well 134 may include a second well 136, The EBL 130 of the embodiment includes a plurality of the barriers 131, 133, 135, 137 and the plurality of wells 132, 134, 136 of a three-pair structure, but is not limited thereto.

The first barrier layer 131 may have a higher Al composition than the last quantum barrier layer of the active layer 114. For example, the first barrier 131 may include a semiconductor material having a composition formula of Al _p Ga _1-p N (0.50 _{? P} ? 0.74). The first barrier 131 of the embodiment may include an Al composition of 50% to 74%, and the first barrier 131 of the embodiment may have a thickness W1 that is less than the thickness W2 of the first well 132. [ It may be thicker. The thickness (W1) of the first barrier 131 in the embodiment may be 3 nm to 10 nm.

The last barrier 137 may have a higher Al composition than the second conductive type first semiconductor layer 116a. For example, the last barrier 139 may include a semiconductor material having a composition formula of _{Al q Ga 1-q N (} 0.50≤q≤0.74). The last barrier 139 of the embodiment may include an Al composition of 50% to 74% and the last barrier 139 of the embodiment may have a thickness W7 that is thicker than the thickness W6 of the third well 136 . The thickness W7 of the last barrier 139 of the embodiment may be between 3 nm and 10 nm.

The first and second intermediate barriers 133 and 135 may have an Al composition that is higher than the first barrier 131 and the last barrier 137. The EBL 130 of the embodiment can improve hole injection. For example, the EBL 130 may enhance the efficiency of light emission by increasing carrier injection of the active layer 114 by confining holes in the first and second intermediate barriers 133 and 135. The first and second intermediate barriers 133 and 135 may include a semiconductor material having a composition formula of Al _r Ga _{1 -r} N (0.55 _r 0.74). The first and second intermediate barriers 133 and 135 of the embodiment may include an Al composition of 55% to 74%. The thicknesses W3 and W5 of the first and second intermediate barriers 133 and 135 may be greater than the thickness W4 of the second well 134 in the embodiment. The thicknesses W3 and W5 of the first and second intermediate barriers 133 and 135 of the embodiment may be 3 nm to 10 nm. For example, when the EBL 130 includes the first barrier 131 and the last barrier 137 having an Al composition of 54% and the first and second intermediate barriers 133 and 135 having a composition of 64% The output voltage can be improved by 30% or more than that of the ultraviolet light emitting device.

The plurality of wells 132,134 and 136 may include a first well 132 between the first barrier 131 and the first intermediate barrier 133 and a second barrier 132 between the first and second intermediate barriers 133 and 135. [ Two wells 134 and a third well 136 between the second intermediate barrier 135 and the last barrier 137.

The first well 132 may include a lower Al composition than the last quantum wall of the active layer 114. The first well 132 may include a semiconductor material having a composition formula of Al _e Ga _1-e N (0.24 _{? E} ? 0.45). The thickness W2 of the first well 132 in the embodiment may be thinner than the thickness W2 of the first barrier 131 and the thickness W3 of the first intermediate barrier 133. [ The thickness W2 of the first well 132 in the embodiment may be between 1 nm and 5 nm.

The second well 134 may comprise a lower Al composition than the last quantum wall of the active layer 114. The second well 134 may comprise a semiconductor material having a composition formula of Al _f Ga _{1 -f} N (0.24 _{? F} ? 0.48). The thickness W4 of the second well 132 in the embodiment may be thinner than the thicknesses W3 and W5 of the first and second intermediate barriers 133 and 135. [ The thickness W4 of the second well 134 in the embodiment may be between 1 nm and 5 nm.

The third well 136 may include a lower Al composition than the last quantum wall of the active layer 114. The third well 136 may comprise a semiconductor material having a compositional formula of Al _g Ga _1-g N (0.24 _{? G} ? 0.48). The thickness W6 of the third well 136 in the embodiment may be thinner than the thickness W5 of the second intermediate barrier 135 and the thickness W7 of the last barrier 137. [ The thickness W6 of the third well 136 in the embodiment may be between 1 nm and 5 nm. The second and third wells 134 and 136 may have the same Al composition and thickness, but are not limited thereto.

In the embodiment, the EBL 130 may be disposed on the active layer 114 to improve the efficiency of injecting carriers to improve the efficiency of light emission. The embodiment can realize a UVB of 300 to 320 nm with a high current driving of 100 mA or more.

The second conductive type first semiconductor layer 116a may be formed on the EBL 130. The second conductive type first semiconductor layer 116a may be formed of a compound semiconductor such as a group III-V element or a group II-VI element. For example, the second conductive type first semiconductor layer 116a may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, . The second conductive type first semiconductor layer 116a of the embodiment may include a semiconductor material having a composition formula of Al _s Ga _{1 -s} N (0.20 _{? S} ? 0.45). The second conductive type first semiconductor layer 116a may include an Al composition of 20% to 45%.

The thickness of the second conductive type first semiconductor layer 116a may be 40 nm or more. 13 is a graph showing the reliability according to the thickness of the second conductive type first semiconductor layer of the embodiment. Referring to FIG. 13, when the second conductive type first semiconductor layer 116a of the embodiment has a thickness of 40 nm or more, the change of the output voltage with time is constant, and the reliability can be improved. The thickness of the second conductive type first semiconductor layer 116a in the embodiment may be 40 nm to 300 nm. The second conductive type first semiconductor layer 116a may be doped with a second conductive type dopant. When the second conductive type first semiconductor layer 116a is a p-type semiconductor layer, the second conductive type dopant may include Mg, Zn, Ca, Sr, and Ba as a p-type dopant. When the thickness of the second conductive type first semiconductor layer 116a of the embodiment is less than 40 nm, the reliability may be lowered due to an output voltage which gradually decreases according to the driving time of the ultraviolet light emitting element 100.

Here, the first conductive type second semiconductor layer 112b and the first conductive type second semiconductor layer 112b may include an n-type semiconductor layer, the second conductive type first semiconductor layer 116a, 2 semiconductor layer 116b is a p-type semiconductor layer, the first conductive type second semiconductor layer 112b and the first conductive type second semiconductor layer 112b may be a p-type semiconductor layer, Type first semiconductor layer 116a and the second conductive type second semiconductor layer 116b may be formed of an n-type semiconductor layer, but the present invention is not limited thereto. A semiconductor, for example, an n-type semiconductor layer (not shown) having a polarity opposite to the second conductivity type may be formed on the first and second semiconductor layers 116a and 116b. have. Accordingly, the light emitting structure 110 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.

The second conductive type second semiconductor layer 116b may be formed on the second conductive type first semiconductor layer 116a. The second conductive type second semiconductor layer 116b is formed on the second conductive type first semiconductor layer 116a and the second conductive type first semiconductor layer 116b for ohmic contact of the second conductive type first semiconductor layer 116a and the second electrode 153, Two electrodes 153 may be disposed. The second conductive type second semiconductor layer 116b may be a GaN including a first conductive type dopant for ohmic contact between the second conductive type first semiconductor layer 116a and the second electrode 153, But is not limited thereto. The second conductive type second semiconductor layer 116b may be flat on the surface directly contacting the second electrode 153. For this, the second conductive type second semiconductor layer 116b may be formed by a 2D growth method. 14 is a view showing the surface of the second conductive type second semiconductor layer of the embodiment. The second conductive type second semiconductor layer 116b of the embodiment has a thickness of 50 nm or less for the ohmic contact between the second conductive type first semiconductor layer 116a and the second electrode 153, (RMS) may be 1 nm or less, for example, 0.1 nm to 1.0 nm. The second conductive type second semiconductor layer 116b of the embodiment may include a surface roughness (RMS) of 1 nm or less to improve the reliability of contact with the second electrode 153 formed later.

The first electrode 151 may be disposed on the first conductive type second semiconductor layer 112b. The first electrode 151 may be electrically connected to the first conductive type second semiconductor layer 112b. The first electrode 151 may be electrically insulated from the second electrode 153. The first electrode 151 may be a conductive oxide, a conductive nitride, or a metal. For example, the contact layer 171 may be formed of ITO (Indium Tin Oxide), ITON (ITO), IZO, IZON, Aluminum Zinc Oxide (AZO) (Indium Zinc Tin Oxide), IZO (Indium Aluminum Zinc Oxide), IGZO (Indium Gallium Zinc Oxide), IGTO (Indium Gallium Tin Oxide), ATO (Antimony Tin Oxide) , At least one of ZnO, IrOx, RuOx, NiO, Au, Cu, Ni, Ti, Ti-W, Cr, W, Pt, V, Fe and Mo. .

The second electrode 153 may be disposed on the second conductive type second semiconductor layer 116b. The second electrode 153 may be electrically connected to the second conductive type second semiconductor layer 116b. The second electrode 153 may be a conductive oxide, a conductive nitride, or a metal. For example, the contact layer 171 may be formed of ITO (Indium Tin Oxide), ITON (ITO), IZO, IZON, Aluminum Zinc Oxide (AZO) (Indium Zinc Tin Oxide), IZO (Indium Aluminum Zinc Oxide), IGZO (Indium Gallium Zinc Oxide), IGTO (Indium Gallium Tin Oxide), ATO (Antimony Tin Oxide) , At least one of ZnO, IrOx, RuOx, NiO, Au, Cu, Ni, Ti, Ti-W, Cr, W, Pt, V, Fe and Mo. .

The ultraviolet light emitting device 100 of the embodiment may have a full width at half maximum (FWHM) of 17 nm or less. In general, an ultraviolet light emitting device having an FWHM of 20 nm or more is difficult to apply to medical equipment such as atopic treatment by destroying DNA, protein, etc. at 300 nm or less, particularly 298 nm or less. The embodiment can realize the FWHM of 17 nm or less including the 10% to 25% thickness of each of the quantum walls of each of the quantum wells of the active layer 114, thereby improving the reliability of the ultraviolet light emitting device applied to the medical device.

In the ultraviolet light emitting device 100 of the embodiment, the EBL 130 is disposed on the active layer 114 to improve the carrier injection efficiency, thereby realizing high current driving of 100 mA or more. Specifically, the embodiment is characterized in that the first and second intermediate barriers 133 and 135 are formed by a structure of the EBL 130 having an Al composition higher than that of the first barrier 131 and the last barrier 137, UVB of 320 nm can be realized.

The embodiment is characterized in that a first conductive type first semiconductor layer 112a, a first superlattice layer 120a, a first conductive type second semiconductor layer 112b, a second superlattice layer 120b and a second superlattice layer 120b are formed between the substrate 101 and the active layer 114, It is possible to improve the light emitting efficiency by improving defects including the gap layer 120b.

The embodiment can improve the power of light by the active layer 114 including a quantum well having a thickness of 10% to 25% of the thickness of the quantum wall.

The embodiment can improve reliability by the second conductive type first semiconductor layer 116a having a thickness of 40 nm or more.

The embodiment can be applied to a medical device such as an atopy treatment by implementing an ultraviolet light emitting device 100 having a wavelength of 300 to 320 nm of 100 mA or more.

15 to 19 are cross-sectional views illustrating a method of manufacturing an ultraviolet light-emitting device according to an embodiment.

Referring to FIG. 15, a method of manufacturing an ultraviolet light emitting device according to an embodiment of the present invention includes the steps of: forming an AlN template (template) 111, a first superlattice layer 120a, The first semiconductor layer 112a, the second superlattice layer 120b, and the first conductive type second semiconductor layer 112b may be formed.

The substrate 101 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate. For example, the substrate 101 may use at least one of sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ O ₃ . A concavo-convex structure may be formed on the substrate 101, but the present invention is not limited thereto.

The AlN template 111, the first superlattice layer 120a, the first conductive type first semiconductor layer 112a, the second superlattice layer 120b, and the first conductive type second semiconductor layer 112b may be formed of organic A metal organic chemical vapor deposition (MOCVD), a chemical vapor deposition (CVD), a plasma enhanced chemical vapor deposition (PECVD), a molecular beam epitaxy (MBE), a hydride (HVPE), but the present invention is not limited thereto.

The AlN template 111, the first superlattice layer 120a, the first conductive type first semiconductor layer 112a, the second superlattice layer 120b, and the first conductive type second semiconductor layer 112b have a thickness of 100 mbar Lt; / RTI > or less.

The AlN template 111 may be formed on the substrate 101. The AlN template 111 may include a buffer function. The AlN template 111 may alleviate the lattice mismatch between the material of the light emitting structure 110 formed on the AlN template 111 and the substrate 101. The AlN template 111 may include AlN, Group 5 or Group 6 compound semiconductors such as GaN, InN, InGaN, AlGaN, InAlGaN, and AlInN.

The first superlattice layer 120a may be disposed on the AlN template 111. [ The first conductive type first semiconductor layer 112a may be disposed on the first super lattice layer 120a. The second superlattice layer 120b may be disposed on the first conductive type first semiconductor layer 112a. The first conductive type second semiconductor layer 112b may be disposed on the second superlattice layer 120b. The first superlattice layer 120a, the first conductive semiconductor layer 112a, the second superlattice layer 120b, and the first conductive semiconductor layer 112b gradually decrease in Al composition, The lattice mismatch and defects between the template 111 and the active layer 114 can be improved.

The first superlattice layer 120a may be formed on the AlN template 111. The first superlattice layer 120a may be disposed on the AlN template 111 and may have a lattice mismatch between the AlN template 111 and the material of the light emitting structure 110 formed on the first superlattice layer 120a, And may include a function to improve defects. The first superlattice layer 120a may include AlN 121a and AlGaN 121b formed in alternating 10 to 20 pairs. The AlGaN 121b may include a semiconductor material having a composition formula of Al _x Ga _1-x N (0.5 _{? X} ? 0.6). The AlGaN 121b may include an Al composition of 50% to 60%, and the thickness of each of the AlN 121a and the AlGaN 121b of the embodiment may be 1 nm to 5 nm. If the AlGaN 121a and the AlGaN 121b are less than 10 pairs, the first superlattice layer 120a may have a defect improving effect. When the number of AlN 121a and AlGaN 121b is more than 20 pairs, the crystallinity of the first superlattice layer 120a may be degraded due to a difference in lattice constant. The AlGaN 121b may be a first conductive AlGaN. The AlGaN 121b may be an unintentionally doped GaN. For example, the AlGaN 121b may be unintentionally AlGaN having a first conductivity type during the growth process.

The first conductive type first semiconductor layer 112a may be formed on the first super lattice layer 120a. The first conductive type first semiconductor layer 112a may be formed of a compound semiconductor such as a group III-V element or a group II-VI element. For example, the first conductive type first semiconductor layer 112a may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, . The first conductive type first semiconductor layer 112a of the embodiment may include a semiconductor material having a composition formula of Al _y Ga _1-y N (0.5 _{? Y} ? 0.6). The first conductive type first semiconductor layer 112a of the embodiment may include an Al composition of 50% to 60%, and the thickness of the first conductive type first semiconductor layer 112a of the embodiment may be 10 nm to 1000 nm . In the embodiment, the first conductive type first semiconductor layer 112a having a thickness of 200 nm will be described as an example. The first conductive type first semiconductor layer 112a may be doped with a first conductive type dopant. When the first conductive type dopant is an n-type semiconductor layer, the n-type dopant may include Si, Ge, Sn, Se, and Te, but is not limited thereto.

The second superlattice layer 120b may be formed on the first conductive type first semiconductor layer 112a. The second superlattice layer 120b is disposed on the first conductive type first semiconductor layer 112a and is formed on the first conductive type semiconductor layer 112a and the second superlattice layer 120a. And improve the lattice mismatch and defects between the materials of the light emitting structure 110 that are exposed. The second superlattice layer 120b may include a first conductive type first AlGaN 123a and a first conductive type second AlGaN 123b formed to alternate 10 to 20 pairs.

The first conductive type first AlGaN 123a may include a semiconductor material having a composition formula of Al _a Ga _1-a N (0.5? A? 0.6). The first conductive type first AlGaN 123a may include an Al composition of 50% to 60%, and the first conductive type first AlGaN 123a may have a thickness of 1 nm to 5 nm .

The first conductive type second AlGaN (123b) may include a semiconductor material having a composition formula of Al _b Ga _{1 -b} N (0.45 _{? B} ? 0.55). The first conductive type second AlGaN 123b may include an Al composition of 45% to 55%, and each of the first conductive type second AlGaNs 123b may have a thickness of 1 nm to 5 nm. The first conductive type second AlGaN (123b) may have a lower Al composition than the first conductive type first AlGaN (123a). When the first conductive dopant is an n-type semiconductor layer, the n-type dopant may include Si, Ge, Sn, Se, and Te. However, the present invention is not limited thereto. In the embodiment, the Al composition gradually decreases from the AlN template 111 to the active layer 114, thereby improving the crystallinity.

The first conductive type second semiconductor layer 112b may be formed on the second super lattice layer 120b. The first conductive type second semiconductor layer 112b may be formed of a compound semiconductor such as a group III-V element or a group II-VI element. For example, the first conductive type second semiconductor layer 112b may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, . The first conductive type second semiconductor layer 112b of the embodiment may include a semiconductor material having a composition formula of Al _z Ga _1-z N (0.45 _{? Z} ? 0.55). The first conductive type second semiconductor layer 112b of the embodiment may include an Al composition of 45% to 55%, and the thickness of the first conductive type second semiconductor layer 112b of the embodiment may be 500 nm to 1000 nm . In the embodiment, the first conductive type second semiconductor layer 112b having a thickness of 1000 nm will be described as an example. The first conductive type second semiconductor layer 112b may be doped with a first conductive type dopant.

Referring to FIG. 16, the active layer 114 and the EBL 130 may be formed on the first conductive type second semiconductor layer 112b. The active layer 114 and the EBL 130 may be formed by a method such as MOCVD, CVD, PECVD, molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE) But the present invention is not limited thereto.

The formation conditions of the active layer 114 and the EBL 130 can improve light power and improve light efficiency.

The active layer 114 may be formed of at least one of a single quantum well structure, a multi quantum well (MQW) structure, a quantum-wire structure, or a quantum dot structure. The active layer 114 is formed by injecting electrons (or holes) injected through the first conductive type second semiconductor layer 112b and holes (or electrons) injected through the second conductive type first semiconductor layer 116a And emits light according to a band gap difference of an energy band according to the material of the active layer 114. [

The active layer 114 may be made of a compound semiconductor. The active layer 114 may be formed of at least one of compound semiconductors such as Group 3-Group 5 or Group 2-6. The active layer 114 may include a quantum well and a quantum wall. When the active layer 114 is implemented as a multiple quantum well structure, quantum wells and quantum wells can be alternately arranged. The quantum well and the quantum wall may be formed of any one or more pairs of AlGaN / GaN, AlGaN / AlGaN, InGaN / InGaN, InAlGaN / GaN, GaAs / AlGaAs, InGaAs / AlGaAs, GaP / AlGaP and InGaP AlGaP But is not limited thereto.

In the active layer 114 of the embodiment, the thickness of each of the quantum wells may be 10% to 25% of the thickness of each of the quantum wells. Referring to FIG. 12, the active layer 114 of the embodiment can improve the power of light by a quantum well structure having a thickness of 10% to 25% of the quantum wall. For example, each of the quantum wells may be 1.5 nm to 2.5 nm. 12 is a graph showing the power of light according to the thickness of a quantum well of the active layer 114 having a quantum wall of 10.9 nm, and shows the highest power of light in a quantum well having a thickness of 2.1 nm.

The EBL 130 may be formed on the active layer 114. The EBL 130 may include a second dopant. The EBL 130 of the embodiment may include a plurality of barriers 131, 133, 135, 137 and a plurality of wells 132, 134, 136. For example, the EBL 130 may be formed of three or more pairs of Group III-V or II-VI compound semiconductors, for example, the EBL 130 may be formed of AlGaN / AlGaN. The EBL 130 may be doped with a second conductivity type dopant. For example, when the EBL 130 is a p-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as a p-type dopant. The EBL 130 of the embodiment may include a function for increasing the carrier provided to the active layer 114 to realize a UVB of 300 to 320 nm at a high current driving of 100 mA or more. In addition, the EBL 130 may include an electron blocking function for blocking electrons, thereby improving the luminous efficiency. For this, the EBL 130 including the second conductivity type dopant of the embodiment may have a plurality of barriers 131, 133, 135, and 137 and a plurality of wells 132, 134, and 136 in three-paired alternation. The plurality of barriers 131, 133, 135, 137 and the plurality of wells 132, 134, 136 of the embodiment can improve the luminous efficiency by the Al composition and the thickness.

The EBL 130 may include a high Al composition with respect to the final quantum wall of the active layer 114 as a reference (REF). For example, the last quantum wall of the active layer 114 may include an Al composition of 50%, and the plurality of barriers 131, 133, 135, and 137 may include an Al composition of at least 45%. The plurality of barriers 131, 133, 135, and 137 may include an Al composition higher than the plurality of wells 132, 134, and 136 and higher than the last quantum barrier layer of the active layer 114 . The Al composition of the EBL 130 may block electrons and confine holes to improve the efficiency of light emission by increasing carrier injection of the active layer 114.

The plurality of barriers 131, 133, 135, and 137 may include a first barrier 131 in contact with the active layer 114, a last barrier 137 in contact with the second conductive type first semiconductor layer 116a, 1 barrier 131 and the last barrier 137. The first and second intermediate barriers 133, Here, one of the first and second intermediate barriers 133 and 135 may be omitted, or may be a plurality of three or more. The plurality of wells 132,134 and 136 may be located between the first barrier 131 and the first intermediate barrier 133 and between the first and second intermediate barriers 133 and 135, And a third well 136 between the second intermediate barrier 135 and the last barrier 137. The second well 134 may include a second well 136,

The first barrier layer 131 may have a higher Al composition than the last quantum barrier layer of the active layer 114. For example, the first barrier 131 may include a semiconductor material having a composition formula of Al _p Ga _1-p N (0.50 _{? P} ? 0.74). The first barrier 131 of the embodiment may include an Al composition of 50% to 74%, and the first barrier 131 of the embodiment may have a thickness W1 that is less than the thickness W2 of the first well 132. [ It may be thicker. The thickness (W1) of the first barrier 131 in the embodiment may be 3 nm to 10 nm.

The last barrier 139 may have a higher Al composition than the second conductive type first semiconductor layer 116a. For example, the last barrier 139 may include a semiconductor material having a composition formula of _{Al q Ga 1-q N (} 0.50≤q≤0.74). The last barrier 139 of the embodiment may include an Al composition of 50% to 74% and the last barrier 139 of the embodiment may have a thickness W7 that is thicker than the thickness W6 of the third well 136 . The thickness W7 of the last barrier 139 of the embodiment may be between 3 nm and 10 nm.

The first and second intermediate barriers 133 and 135 may have an Al composition that is higher than the first barrier 131 and the last barrier 137. The EBL 130 of the embodiment can improve hole injection. For example, the EBL 130 may enhance the efficiency of light emission by increasing carrier injection of the active layer 114 by confining holes in the first and second intermediate barriers 133 and 135. The first and second intermediate barriers 133 and 135 may include a semiconductor material having a composition formula of Al _r Ga _{1 -r} N (0.55 _r 0.74). The first and second intermediate barriers 133 and 135 of the embodiment may include an Al composition of 55% to 74%. The thicknesses W3 and W5 of the first and second intermediate barriers 133 and 135 may be greater than the thickness W4 of the second well 134 in the embodiment. The thicknesses W3 and W5 of the first and second intermediate barriers 133 and 135 of the embodiment may be 3 nm to 10 nm. Specifically, the EBL 130 including the first barrier 131 and the last barrier 137 having an Al composition of 54% and the first and second intermediate barriers 133 and 135 having a composition of 64% has a general ultraviolet light emission The output voltage can be improved by 30% or more than that of the device.

The plurality of wells 132,134 and 136 may include a first well 132 between the first barrier 131 and the first intermediate barrier 133 and a second barrier 132 between the first and second intermediate barriers 133 and 135. [ Two wells 134 and a third well 136 between the second intermediate barrier 135 and the last barrier 137.

The first well 132 may include a lower Al composition than the last quantum wall of the active layer 114. The first well 132 may include a semiconductor material having a composition formula of Al _e Ga _1-e N (0.24 _{? E} ? 0.45). The thickness W2 of the first well 132 in the embodiment may be thinner than the thickness W2 of the first barrier 131 and the thickness W3 of the first intermediate barrier 133. [ The thickness W2 of the first well 132 in the embodiment may be between 1 nm and 5 nm.

The second well 134 may comprise a lower Al composition than the last quantum wall of the active layer 114. The second well 134 may comprise a semiconductor material having a composition formula of Al _f Ga _{1 -f} N (0.24 _{? F} ? 0.48). The thickness W4 of the second well 132 in the embodiment may be thinner than the thicknesses W3 and W5 of the first and second intermediate barriers 133 and 135. [ The thickness W4 of the second well 134 in the embodiment may be between 1 nm and 5 nm.

The third well 136 may include a lower Al composition than the last quantum wall of the active layer 114. The third well 136 may comprise a semiconductor material having a compositional formula of Al _g Ga _1-g N (0.24 _{? G} ? 0.48). The thickness W6 of the third well 136 in the embodiment may be thinner than the thickness W5 of the second intermediate barrier 135 and the thickness W7 of the last barrier 137. [ The thickness W6 of the third well 136 in the embodiment may be between 1 nm and 5 nm. The second and third wells 134 and 136 may have the same Al composition and thickness, but are not limited thereto.

In the embodiment, the EBL 130 may be disposed on the active layer 114 to improve the efficiency of injecting carriers to improve the efficiency of light emission. The embodiment can realize a UVB of 300 to 320 nm with a high current driving of 100 mA or more.

Referring to FIG. 17, a second conductive type first semiconductor layer 116a and a second conductive type second semiconductor layer 116b may be formed on the EBL 130. Referring to FIG. The second conductive type first semiconductor layer 116a and the second conductive type second semiconductor layer 116b may be formed using a metal organic chemical vapor deposition (MOCVD) method, a chemical vapor deposition (CVD) method, a plasma chemical vapor deposition (PECVD) MBE, hydride vapor phase epitaxy (HVPE), and the like. However, the present invention is not limited thereto.

The second conductive type first semiconductor layer 116a and the second conductive type second semiconductor layer 116b may be grown at a pressure between the first conductive type second semiconductor layer 112b and the EBL 130 . For example, the second conductive type first semiconductor layer 116a and the second conductive type second semiconductor layer 116b may be grown at a pressure of 450 mbar, but the present invention is not limited thereto.

The second conductive type first semiconductor layer 116a may be formed on the EBL 130. The second conductive type first semiconductor layer 116a may be formed of a compound semiconductor such as a group III-V element or a group II-VI element. For example, the second conductive type first semiconductor layer 116a may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, . The second conductive type first semiconductor layer 116a of the embodiment may include a semiconductor material having a composition formula of Al _s Ga _{1 -s} N (0.20 _{? S} ? 0.45). The second conductive type first semiconductor layer 116a may include an Al composition of 20% to 45%. The thickness of the second conductive type first semiconductor layer 116a may be 40 nm or more. 13 is a graph showing the reliability according to the thickness of the second conductive type first semiconductor layer of the embodiment. Referring to FIG. 13, when the second conductive type first semiconductor layer 116a of the embodiment has a thickness of 40 nm or more, the change of the output voltage with time is constant, and the reliability can be improved. The thickness of the second conductive type first semiconductor layer 116a in the embodiment may be 40 nm to 300 nm. The second conductive type first semiconductor layer 116a may be doped with a second conductive type dopant. When the second conductive type first semiconductor layer 116a is a p-type semiconductor layer, the second conductive type dopant may include Mg, Zn, Ca, Sr, and Ba as a p-type dopant.

The second conductive type second semiconductor layer 116b may be formed on the second conductive type first semiconductor layer 116a. The second conductive type second semiconductor layer 116b is electrically connected to the second conductive type first semiconductor layer 116a for ohmic contact between the second conductive type first semiconductor layer 116a and the second electrode 153 ) And the second electrode (153 in Fig. 2). The second conductive type second semiconductor layer 116b may be a GaN type semiconductor including a first conductive type dopant for ohmic contact between the second conductive type first semiconductor layer 116a and the second electrode 153 However, the present invention is not limited thereto. The second conductive type second semiconductor layer 116b may be flat on the surface directly contacting the second electrode 153 (FIG. 2). For this, the second conductive type second semiconductor layer 116b may be formed by a 2D growth method. 14 is a view showing the surface of the second conductive type second semiconductor layer of the embodiment. The second conductive type second semiconductor layer 116b of the embodiment realizes a flat surface by 2D growth, thereby improving the reliability of contact with the second electrode 153 (FIG. 2).

Referring to FIG. 18, the first and second electrodes 151 and 153 may be formed on the light emitting structure 110. The light emitting structure 110 is formed by mesa etching so that a portion of the first conductive type second semiconductor layer 112b is partially removed from the active layer 114, the EBL 130, the second conductive type first semiconductor layer 116a, And may be exposed from the conductive second semiconductor layer 116b.

The first electrode 151 may be formed on the exposed first conductive type second semiconductor layer 112b. The first electrode 151 may be electrically connected to the first conductive type second semiconductor layer 112b. The first electrode 151 may be electrically insulated from the second electrode 153.

The second electrode 153 may be formed on the second conductive type second semiconductor layer 116b. The second electrode 153 may be electrically connected to the second conductive type second semiconductor layer 116b.

The first and second electrodes 151 and 153 may be a conductive oxide, a conductive nitride, or a metal. For example, the first and second electrodes 151 and 153 may be formed of ITO (indium tin oxide), ITON (indium tin oxide), IZO (indium zinc oxide), IZON (indium zinc oxide), AZO Gallium Zinc Oxide), IZTO (Indium Zinc Tin Oxide), IZO (Indium Aluminum Zinc Oxide), IGZO (Indium Gallium Zinc Oxide), IGTO (Indium Gallium Tin Oxide), ATO (Antimony Tin Oxide) , IZON (IZO Nitride), ZnO, IrOx, RuOx, NiO, Au, Cu, Ni, Ti, Ti-W, Cr, W, Pt, And may be formed in multiple layers.

Referring to FIG. 19, the embodiment may be a flip chip structure in which the first and second electrodes 151 and 153 are disposed below. The first insulating layer 161 may be formed on the light emitting structure 110 by exposing a portion of the lower surface of the first and second electrodes 151 and 153. The first insulating layer 161 may be in contact with the bottom of the light emitting structure 110 in which the first and second electrodes 151 and 153 are disposed.

First and second connection electrodes 171 and 173 may be formed on the lower surfaces of the first and second electrodes 151 and 153 exposed from the first insulation layer 161. The first and second connection electrodes 171 and 173 may be formed by a plating process, but the present invention is not limited thereto. The first insulating layer 161 may be an oxide or a nitride. For example, the first insulating layer 161 may include at least one of SiO ₂ , Si _x O _y , Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , Can be selected.

The first and second connection electrodes 171 and 173 may be a metal or an alloy including at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Cu, have. The first and second connection electrodes 171 and 173 are formed of a metal or an alloy of ITO (Indium Tin Oxide), IZO (Indium-Zinc-Oxide), IZTO (Indium-Zinc-Tin-Oxide) Indium-Aluminum-Zinc-Oxide (IGZO), Indium-Gallium-Tin-Oxide (IGTO), Aluminum-Zinc-Oxide (AZO), and Antimony-Tin-Oxide It may be a single layer or multiple layers of a transparent conductive material.

The second insulating layer 163 may be formed under the first insulating layer 161 and may be in direct contact with the first insulating layer 161. The second insulating layer 163 may be formed on the side of the first and second connection electrodes 171 and 173 while exposing the lower portions of the first and second connection electrodes 171 and 173. The second insulation layer 163 may be formed by adding a thermal diffusion material to the resin material such as silicon or epoxy. The heat spreader may include at least one material selected from the group consisting of oxides, nitrides, fluorides, and sulfides having a material such as Al, Cr, Si, Ti, Zn, and Zr. The heat spreader may be defined as a powder particle, a grain, a filler, or an additive having a predetermined size. The second insulating layer 163 may be omitted.

The first and second pads 181 and 183 may be formed on the first and second connection electrodes 171 and 173 exposed from the second insulating layer 163. The first and second pads 181 and 183 may be a metal or an alloy including at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Cu, . The first and second pads 181 and 183 may be formed of a metal or an alloy of ITO (Indium-Tin-Oxide), IZO (Indium-Zinc-Oxide), IZTO (Indium-Zinc-Tin- Transparent, such as Aluminum-Zinc-Oxide (IGZO), Indium-Gallium-Zinc-Oxide (IGZO), IGTO (Indium-Gallium-Tin- Oxide), AZO It may be a single layer or multiple layers of conductive material.

Although the embodiment includes the substrate 101 disposed on the first conductive type second semiconductor layer 112b, the present invention is not limited thereto. For example, the substrate 101 may be removed by a laser lift off (LLO) process. Here, the laser lift-off process (LLO) is a process of irradiating a laser beam to the lower surface of the substrate 101 to peel the substrate 101 and the light emitting structure 110 from each other.

The ultraviolet light emitting device 100 of the embodiment may have a full width at half maximum (FWHM) of 17 nm or less. In general, an ultraviolet light emitting device having an FWHM of 20 nm or more is difficult to apply to medical equipment such as atopic treatment by destroying DNA, protein, etc. at 300 nm or less, particularly 298 nm or less. The embodiment can realize the FWHM of 17 nm or less including the 10% to 25% thickness of each of the quantum walls of each of the quantum wells of the active layer 114, thereby improving the reliability of the ultraviolet light emitting device applied to the medical device.

The active layer 114 and the EBL 130 of the embodiment can improve the light power and improve the light efficiency.

In the embodiment, the EBL 130 is disposed on the active layer 114 to improve carrier injection efficiency, thereby realizing high current driving of 100 mA or more. Specifically, the embodiment is characterized in that the first and second intermediate barriers 133 and 135 are formed by a structure of the EBL 130 having an Al composition higher than that of the first barrier 131 and the last barrier 137, UVB of 320 nm can be realized.

The embodiment is characterized in that a first conductive type first semiconductor layer 112a, a first superlattice layer 120a, a first conductive type second semiconductor layer 112b, a second superlattice layer 120b and a second superlattice layer 120b are formed between the substrate 101 and the active layer 114, It is possible to improve the light emitting efficiency by improving defects including the gap layer 120b.

The embodiment can improve the power of light by the active layer 114 including a quantum well having a thickness of 10% to 25% of the thickness of the quantum wall.

The embodiment can improve reliability by the second conductive type first semiconductor layer 116a having a thickness of 40 nm or more.

The light emitting device package according to the embodiment can be applied to a medical instrument, a lighting unit, a pointing device, a lamp, a streetlight, a vehicle lighting device, a vehicle display device, a smart watch, but is not limited thereto.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment and are not necessarily limited to one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments can be combined and modified by other persons having ordinary skill in the art to which the embodiments belong. Accordingly, the contents of such combinations and modifications should be construed as being included in the scope of the embodiments.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It can be seen that the modification and application of branches are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

10: Light emitting module
20:
30: a first heat-
40: a second heat-
60:
70: Medical devices
111: AlN template
112a: first conductive type first semiconductor layer
112b: a first conductive type second semiconductor layer
114:
116a: a second conductive type first semiconductor layer
116b: a second conductive type second semiconductor layer
120a: first superlattice layer
120b: second superlattice layer
130: EBL
131: 1st barrier
132: first well
133: first intermediate barrier
134: second well
135: second intermediate barrier
136: Third Well
137: The Last Barrier
200: Light emitting device package

Claims (11)

CLAIMS 1. A light emitting device comprising: a circuit board; a light emitting portion disposed on the circuit board and including a plurality of light emitting device packages having a full width at half maximum (FWHM) of 17 nm or less; And
And a heat dissipation unit disposed on a rear surface of the light emitting unit,
Wherein the plurality of light emitting device packages have a first pitch in a first direction and a second pitch in a second direction orthogonal to the first direction, and the first and second pitches are light emitted from the light emitting portion The light emitting module is 30% to 50% of the width or diameter of the target area.
The method according to claim 1,
Wherein the first and second pitches are the same size as each other.
3. The method of claim 2,
Wherein the first and second pitches have different sizes from each other.
The method according to claim 1,
Wherein the first and second pitches are 10 mm to 15 mm.
The method according to claim 1,
Wherein the target region is spaced 20 mm from the light emitting device package and has a rectangular shape with a width of 10 mm to 30 mm.
The method according to claim 1,
Wherein the target region is 20 mm away from the light emitting device package and has a circular shape with a diameter of 10 mm to 30 mm.
The method according to claim 1,
Wherein the light emitting unit emits a wavelength of 300 nm to 320 nm having a uniformity of 70% or more in the target region.
8. The method of claim 7,
Wherein the uniformity is a minimum roughness / maximum roughness with respect to a central region where the illuminance is maximized in the target region and an edge region where the illuminance is minimum.
9. The method of claim 8,
Wherein the minimum illuminance is 10 mW / cm 2 or more.
A light emitting module according to any one of claims 1 to 9, And
And an optical compensator disposed on the light emitting module.
11. The method of claim 10,
Wherein the optical compensation unit includes first to third compensation units,
Wherein the first compensator is disposed on the second compensator and includes Teflon,
Wherein the second compensation unit includes a glass-based material having a high transmittance disposed on the light-emitting unit,
And the third compensating unit surrounds the outer sides of the first and second compensating units in a ring type.

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