KR101158075B1 - Light emitting diode having distributed bragg reflector - Google Patents

Abstract

A light emitting diode having a distributed Bragg reflector is disclosed. The light emitting diode is positioned above the substrate, the light emitting structure including an active layer interposed between the first conductive semiconductor layer and the second conductive semiconductor layer, an upper insulating layer covering the light emitting structure, and positioned below the substrate. And a distributed Bragg reflector for reflecting light emitted from the light emitting structure, and a metal reflective layer positioned below the Distributed Bragg reflector. Here, the distributed Bragg reflector has a reflectivity of 90% or more for light of the first wavelength in the blue wavelength region, light of the second wavelength in the green wavelength region, and light of the third wavelength in the red wavelength region. Accordingly, a light emitting diode capable of improving light extraction efficiency of a light emitting diode package implementing white light may be provided.

Description

LIGHT EMITTING DIODE HAVING DISTRIBUTED BRAGG REFLECTOR}

The present invention relates to light emitting diodes, and more particularly to light emitting diodes having a distributed Bragg reflector.

BACKGROUND ART A gallium nitride-based light emitting diode emitting blue or ultraviolet rays is applied to various applications, and various kinds of light emitting diode packages emitting mixed color light, for example, white light, required for a backlight unit or general lighting, are commercially available.

Since the light output of the light emitting diode package mainly depends on the light efficiency of the light emitting diode, efforts are being made to improve the light efficiency of the light emitting diode. In particular, efforts have been made to improve light extraction efficiency of light emitting diodes. As one of these efforts, a technique of forming a metal reflector on a lower surface of a transparent substrate such as sapphire is known.

1 shows a reflectance measured by forming an aluminum layer on a lower surface of a conventional sapphire substrate.

Referring to FIG. 1, the sapphire substrate without the aluminum layer shows a reflectance of about 20%, but when the aluminum layer is formed, it shows that the reflectance is about 80% over the entire wavelength of the visible light region. have.

2 shows a reflectance measured by periodically distributing TiO ₂ / SiO ₂ on the lower surface of the sapphire substrate to form a distributed Bragg reflector.

Instead of the aluminum layer, when a distributed Bragg reflector (DBR) is provided for light emitted from a light emitting diode, for example, light having a peak wavelength of 460 nm, as shown in FIG. 2, a blue wavelength region, for example, a wavelength of 400 to 500 nm. It can be seen that the reflectance reaches almost 100% in the region.

However, the DBR can only increase the reflectance of some regions of the visible light region and the reflectance of the other regions is considerably low. That is, as shown in Figure 2, the reflectance is rapidly reduced for a wavelength of about 520nm or more, the reflectance is less than 50% in most 550nm or more.

Therefore, when the LEDR is applied to a light emitting diode package that implements white light, the LEDR shows high reflectance for light in the blue wavelength region emitted from the light emitting diode, but the DBR for light in the green and / or red wavelength region is high. It does not exhibit effective reflective properties and therefore has limitations in improving light efficiency in the package.

On the other hand, gallium nitride-based semiconductor has a refractive index of about 2.4. Therefore, since the refractive index difference with respect to external air or molding resin is relatively large, a large part of the light generated in the active layer by total internal reflection at the interface with them is trapped in the semiconductor layer and cannot be emitted to the outside. Accordingly, there is a need for a technology capable of improving light extraction efficiency by reducing light loss due to total internal reflection.

The problem to be solved by the present invention is to provide a light emitting diode suitable for a package that implements mixed light, in particular white light.

Another object of the present invention is to provide a light emitting diode capable of improving the light efficiency in a package.

Another object of the present invention is to provide a light emitting diode capable of reducing light loss due to total internal reflection.

A light emitting diode according to embodiments of the present invention includes a substrate; A light emitting structure disposed on the substrate and including an active layer interposed between a first conductive semiconductor layer and a second conductive semiconductor layer; An upper insulating layer covering the light emitting structure; A distributed bragg reflector positioned below the substrate and reflecting light emitted from the light emitting structure; And a metal reflecting layer positioned below the distributed Bragg reflector. Here, the distributed Bragg reflector has a reflectivity of 90% or more for light of the first wavelength in the blue wavelength region, light of the second wavelength in the green wavelength region, and light of the third wavelength in the red wavelength region.

The upper insulating layer covers the light emitting structure to protect the light emitting structure. In addition, the metal reflective layer is incident at various incidence angles to reflect the light passing through the distributed Bragg reflector to increase the light reflectance to improve the light extraction efficiency. The metal reflective layer may include, for example, an aluminum layer or a silver (Ag) layer.

The distributed Bragg reflector has a structure in which at least two layers having different refractive indices are alternately stacked. For example, the distributed Bragg reflector may have a structure in which an SiO ₂ layer and at least one layer of a TiO ₂ layer or an Nb ₂ O ₅ layer are alternately and repeatedly stacked.

Appl. No. 10-2009-0109870, filed November 13, 2009 of the applicant, discloses a light emitting diode having a distributed Bragg reflector having a reflectance of 90% or more for light in the wavelengths of blue, green and red regions. This application provides a distributed Bragg reflector having a high reflectance not only for the blue region but also for light in the wavelength of the green or red region by repeatedly stacking layers having different refractive indices, such as TiO ₂ / SiO ₂ . The present inventors have found that when the Ag epoxy paste is applied to the distributed Bragg reflector formed by repeated stacking of TiO ₂ / SiO ₂ (41 layers) and cured, the reflectance of the distributed Bragg reflector is reduced compared to before Ag epoxy paste curing. This is expected because the number of layers constituting the distributed Bragg reflector is relatively small, so that the reflectance decreases due to light scattering at the Interface Bragg reflector and Ag epoxy interface or light absorption by Ag epoxy. In order to prevent this, it is necessary to further increase the number of stacked Bragg reflectors. On the other hand, the increase in the number of stacked Bragg reflectors can reduce the influence due to the state of the distributed Bragg reflector and Ag epoxy interface, but the light loss can be caused by the light absorption of each layer constituting the distributed Bragg reflector, thereby reducing the reflectance. have.

Therefore, by adopting Nb ₂ O ₅ having a lower light absorption than TiO ₂ to form a distributed Bragg reflector of SiO ₂ / Nb ₂ O ₅ , it is possible to prevent light loss due to an increase in the number of stacked layers.

Preferably, the distributed Bragg reflector may comprise at least 25 pairs of layers having different refractive indices, for example, SiO ₂ / Nb ₂ O ₅ .

The distributed Bragg reflector may be in contact with the bottom surface of the substrate, preferably SiO ₂ may be in contact with the bottom surface of the substrate. By forming SiO ₂ first on the lower surface of the substrate, the adhesion of the distributed Bragg reflector can be improved. In addition, the last layer of the distributed Bragg reflector may be SiO ₂ . The last layer functions as a protective layer that protects the distributed Bragg reflector.

In addition, a protective layer may be located under the metal reflective layer. The protective layer covers the metal reflective layer to prevent the metal reflective layer from oxidizing or diffusing.

In some embodiments, the upper insulating layer may be a refractive index grading layer in which the refractive index is gradually or gradually reduced from the light emitting structure side. Accordingly, light extraction efficiency may be improved through the upper insulating layer. The upper insulating layer may be SiO ₂ .

The light emitting diode may further include a transparent conductive layer interposed between the second conductive semiconductor layer and the upper insulating layer. The transparent conductive layer may be a refractive index grading layer in which the refractive index is gradually or gradually reduced from the second conductive semiconductor layer side. Therefore, total internal reflection due to the difference in refractive index at the interface between the second conductive semiconductor layer and the transparent conductive layer can be reduced, and furthermore, the refractive index at the interface between the transparent conductive layer and air or the transparent conductive layer and the upper insulating layer is reduced. The total internal reflection due to the difference can be reduced. The transparent conductive layer may be ITO or ZnO.

On the other hand, the transparent conductive layer may be a layer having a relatively low refractive index compared to the conventional transparent conductive layer formed. For example, the transparent conductive layer may be formed by thermal evaporation, electron beam deposition, ion beam assisted deposition, or sputtering, wherein the transparent conductive layer is deposited on the source or target by tilting the substrate surface relative to the source or target. It may have a relatively low refractive index compared to the case where the substrate surface is disposed in the normal position with respect to the deposition. In addition, when the substrate is rotated during the deposition of the transparent conductive layer, the transparent conductive layer is formed asymmetrically on the substrate by changing the substrate rotational speed over time or stopping the rotation of the substrate to form a transparent conductive layer having a low refractive index as a whole. Can be deposited. The transparent conductive layer helps to emit light to improve the light extraction efficiency of the light emitting diode.

The present invention also provides a light emitting diode package for implementing mixed light such as white light. The light emitting diode package has a mounting surface for mounting a light emitting diode, and the light emitting diode described above is mounted on the mounting surface. The package also includes a phosphor for wavelength converting light emitted from the light emitting diode, and may include an adhesive, such as Ag epoxy, for attaching the light emitting diode to the mounting surface.

According to embodiments of the present invention, by employing a distributed Bragg reflector having a high reflectance over a wide wavelength region of visible light, it is possible to improve the light efficiency of a light emitting diode package that implements mixed light, for example, white light. Furthermore, by adopting a distributed Bragg reflector that repeatedly stacks SiO ₂ / Nb ₂ O ₅ , the absorption of light by the Distributed Bragg reflector can be reduced, further increasing the number of stacked Bragg reflectors, even after being mounted in a light emitting diode package. High reflectance can be maintained. Further, by forming a protective layer together with the metal reflective layer under the distributed Bragg reflector, it is possible to prevent the distributed Bragg reflector and the metal reflective layer from being deformed when mounted in the package. Furthermore, the light extraction efficiency of the light emitting diode can be improved by forming the upper insulating layer and / or the transparent conductive layer as the refractive index grading layer.

1 is a graph showing the reflectance of aluminum on a sapphire substrate.
2 is a graph showing the reflectance of a distributed Bragg reflector on a sapphire substrate.
3 is a cross-sectional view illustrating a light emitting diode having a distributed Bragg reflector according to an embodiment of the present invention.
4 is a graph showing the light absorption of TiO ₂ and Nb ₂ O ₅ .
5 is a schematic cross-sectional view of an electron beam deposition apparatus for explaining a method of forming a transparent conductive layer having a relatively low refractive index according to an embodiment of the present invention.
6 is a cross-sectional view for describing a transparent conductive layer having a gradient refractive index according to an embodiment of the present invention.
7 is a cross-sectional view illustrating a light emitting diode package mounted with a light emitting diode according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided as examples to ensure that the spirit of the present invention to those skilled in the art will fully convey. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. And in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

3 is a cross-sectional view illustrating a light emitting diode 20 having a distributed Bragg reflector 40 according to an embodiment of the present invention.

Referring to FIG. 3, the light emitting diode 20 includes a substrate 21, a light emitting structure 30, a distributed Bragg reflector 40, an upper insulating layer 37, and a metal reflecting layer 41. In addition, the light emitting diode 20 may include a buffer layer 23, a transparent electrode 31, a first electrode pad 33, and a second electrode pad 35.

The substrate 21 is not particularly limited as long as it is a transparent substrate. For example, the substrate 21 may be a sapphire or SiC substrate. The substrate 21 may also have a predetermined pattern, such as a sapphire substrate (PSS) patterned on an upper surface thereof. Meanwhile, the area of the substrate 21 determines the total area of the chip. The area of the substrate 21 may be 90,000 μm ^{2 or} more, and may be 1 mm ^{2 or} more.

The light emitting structure 30 is positioned on the substrate 21. The light emitting structure 30 includes an active layer 27 interposed between the first conductive semiconductor layer 25, the second conductive semiconductor layer 29, and the first and second conductive semiconductor layers 25 and 29. ). Here, the first conductivity type and the second conductivity type may be opposite conductivity types, and the first conductivity type may be n type, the second conductivity type may be p type, or vice versa.

The first conductive semiconductor layer 25, the active layer 27, and the second conductive semiconductor layer 29 may be formed of a gallium nitride-based compound semiconductor material, that is, (Al, In, Ga) N. The active layer 27 has a composition element and composition ratio determined so as to emit light of a required wavelength such as ultraviolet light or blue light. The first conductive semiconductor layer 25 and / or the second conductive semiconductor layer 29 may be formed as a single layer, as shown, but may be formed in a multilayer structure. In addition, the active layer 27 may be formed of a single quantum well or multiple quantum well structures. In addition, a buffer layer 23 may be interposed between the substrate 21 and the first conductivity-type semiconductor layer 25.

The semiconductor layers 25, 27, and 29 may be formed using a MOCVD or MBE technique, and may be patterned to expose a portion of the first conductive semiconductor layer 25 using photolithography and etching processes. have.

On the other hand, the distribution Bragg reflector 40 is located under the substrate 21. The distribution Bragg reflector 40 is formed by alternately stacking layers having different refractive indices, and in addition to light generated in the blue wavelength region, for example, light generated in the active layer 27, light in the yellow wavelength region or green and / or The light in the red wavelength region also has a relatively high reflectivity of 90% or more. Further, the distributed Bragg reflector 40 may have a reflectivity of at least 90% over a wavelength range of, for example, 400-700 nm.

A distributed Bragg reflector 40 having a relatively high reflectance over a wide wavelength range is formed by controlling the respective optical thicknesses of the layers of material that are repeatedly stacked. The distributed Bragg reflector 40 may be formed, for example, by alternately stacking a first layer of SiO ₂ and a second layer of TiO ₂ , but preferably, a first layer of SiO ₂ and a second layer of Nb ₂ O ₅ . Alternately laminated.

As the number of stacked layers of the first layer and the second layer increases, the influence of another material layer in contact with the lower surface of the distributed Bragg reflector 40 may be reduced. When the number of laminated layers is small, after curing the adhesive layer such as Ag epoxy paste, the reflectance of the distributed Bragg reflector 40 can be reduced. Therefore, the number of stacked Bragg reflectors 40 is preferably 50 or more, that is, 25 pairs.

In addition, as the number of stacks increases, the light absorption by the material layers in the distributed Bragg reflector 40 may be increased, thereby reducing the reflectance. 4 shows changes in absorption coefficient K according to wavelengths of TiO ₂ and Nb ₂ O ₅ . In the case of TiO ₂ , the absorption coefficient becomes zero at about 600 nm or more, and an absorption coefficient of about 0.2 is shown for light generated in the active layer 27, for example, light having a blue wavelength. In contrast, Nb ₂ O ₅ has an absorption coefficient of nearly zero over the visible range. Therefore, the distributed Bragg reflector 40 can be formed by repeatedly stacking SiO ₂ / Nb ₂ O ₅ to prevent loss due to light absorption even if the number of stacked layers is increased.

The first or second layers stacked alternately do not have to have the same thickness, and the first layers and the first layers and the first layers and the second layers do not have to have the same thickness, but have relatively high reflectance not only for the wavelength of the light generated in the active layer 27 but also for other wavelengths in the visible region. The thickness of the two layers is chosen. In addition, the distributed Bragg reflector may be formed by stacking a plurality of distributed Bragg reflectors having a high reflectance for a specific wavelength band.

For example, in a package in which the light emitting diode according to the present invention is mounted to implement white light, light having a wavelength other than the light emitted from the light emitting diode may be incident to the light emitting diode, and the light having the different wavelength may be incident on the light emitting diode. It can be reflected back using a distributed Bragg reflector to improve the light extraction efficiency of the package.

Meanwhile, the first and last layers of the distribution Bragg reflector 40 may be SiO ₂ . By placing SiO ₂ on the first layer and the last layer of the distributed Bragg reflector 40, the distributed Bragg reflector 40 can be stably attached to the substrate 21, and the distributed Bragg reflector using the last SiO ₂ layer. 40 can be protected.

Referring again to FIG. 3, the metal reflective layer 41 is positioned below the distributed Bragg reflector 40. The metal reflective layer 41 is a metal reflective layer having a high reflectance, and may be, for example, an aluminum layer or a silver (Ag) layer. The metal reflecting layer 41 reflects light transmitted through the distribution Bragg reflector 40 because the incident angle is large.

In addition, a protective layer 43 may be located under the metal reflective layer 41. The protective layer 43 covers the metal reflective layer 41 to prevent the metal reflective layer 41 from being deformed by oxidation or diffusion. The protective layer 43 may be formed of a metal layer or an insulating layer, but is preferably formed of a metal layer in order to improve heat dissipation characteristics of the light emitting diode.

Meanwhile, the upper insulating layer 37 may be positioned on the light emitting structure 30. The upper insulating layer 37 covers the light emitting structure 30 to protect the light emitting structure 30 from the external environment. As illustrated, the upper insulating layer 37 may cover the transparent electrode layer 31, and may also cover the side surface of the mesa formed by mesa etching and the exposed surface of the first conductivity-type semiconductor layer 25. .

The upper insulating layer 37 may be formed of a transparent insulating layer, for example, SiO ₂ , which transmits light generated by the active layer 27. Furthermore, the upper insulating layer 37 may be a refractive index grading layer in which the refractive index is gradually or gradually reduced from the light emitting structure 30 side. For example, while the upper insulating layer 37 is formed using chemical vapor deposition, process variables such as deposition rate, temperature, pressure, reactant gas flow rate, or plasma power may be varied to first deposit a dense layer and then gradually The refractive index grading layer can be formed by depositing a low density layer. Since the refractive index of the upper insulating layer 37 is lowered outward from the light emitting structure layer 30 side, total internal reflection of light emitted through the upper insulating layer 37 can be reduced.

Meanwhile, the transparent electrode layer 31 may be formed of, for example, ITO or ZnO on the second conductive semiconductor layer 29. The transparent electrode layer 31 may be interposed between the second conductive semiconductor layer 29 and the upper insulating layer 37. The transparent electrode layer 31 has a lower specific resistance than the second conductive semiconductor layer 29 to disperse current. Meanwhile, a first electrode pad 33, for example, an n-electrode pad 33, is formed on the first conductive semiconductor layer 25, and a second electrode pad 35, for example, is formed on the transparent electrode layer 31. The p-electrode pad 35 is formed. As illustrated, the p-electrode pad 35 may be electrically connected to the second conductive semiconductor layer 29 through the transparent electrode layer 31, but is not limited thereto. Directly to (29).

The transparent electrode layer 31 may be formed using thermal deposition, electron beam deposition, ion beam assisted deposition, or sputtering. In this case, the transparent electrode layer 31 may be a low refractive index layer having a relatively low refractive index or a refractive index grading layer in which the refractive index is gradually or gradually reduced from the second conductive semiconductor layer 29.

5 is a schematic cross-sectional view of an electron beam deposition apparatus 50 to explain a method of forming a transparent electrode layer 31 having a relatively low refractive index as an example of the transparent electrode layer 31 according to an embodiment of the present invention. .

Referring to FIG. 5, the electron beam deposition apparatus includes a vacuum chamber 51, a substrate support 55, a rotator 52, a shaft 53, an electron beam evaporator 57, and a source 59, and a gas inlet ( 51a) and an exhaust port 51b.

In the substrate 10, semiconductor layers are typically grown on a substrate 21 such as sapphire to have a second conductive semiconductor layer 29 thereon. The substrate 10 is disposed on the substrate support 55. In general, a plurality of substrates 10 are arranged on the substrate support 55, with each substrate 10 arranged such that its top surface faces the source 59. That is, the source 59 is disposed on a line perpendicular to the surface of the substrate 10 and passing through the center of the substrate 10. The substrate support 55 may have a concave shape so that each of the plurality of substrates 10 is disposed in a normal position (indicated by a dotted line) with respect to the source. In addition, the substrate support 55 may be rotated by the rotator 52. That is, the rotator 52 rotates the shaft 53, and the substrate support 55 may be rotated by the shaft 53. By the rotation, a uniform transparent electrode layer 31 may be deposited on the substrate 10, particularly the plurality of substrates 10.

However, in the present embodiment, the substrate 10 may be disposed to be inclined with respect to the source 59 without being disposed at the normal position (indicated by the dotted lines). That is, the source 59 is perpendicular to the plane of the substrate 10 and deviates from the straight line passing through the center of the substrate 10. When arranging a plurality of substrates 10, each substrate 10 may be disposed to be inclined with respect to the source to the same extent.

When the source is evaporated by the electron beam and the transparent electrode layer is deposited on the substrate 10, the transparent electrode layer 31 is deposited in an inclined direction rather than in a vertical direction with respect to the surface of the substrate 10. As a result, the density of the transparent electrode layer 31 can be lowered relatively, and the refractive index of the transparent electrode layer 31 can be lowered relatively, compared with the case where the substrate 10 is disposed at the normal position and deposited. Therefore, light loss due to total internal reflection at the interface between the transparent electrode layer 31 and the air or at the interface between the transparent electrode layer 31 and the upper insulating layer 37 can be reduced.

Furthermore, in this embodiment, the transparent electrode layer 31 deposited on the substrate 10 can be asymmetrically deposited by intentionally stopping the rotation of the substrate 10 by the rotator 52 or changing the rotation state. have. Accordingly, the transparent electrode layer 31 having a low refractive index as a whole can be deposited.

In the present embodiment, the electron beam evaporation apparatus has been described as an example, but the thermal evaporation method and the ion beam assisted evaporation method may be similarly adopted to arrange the substrate inclinedly or to adjust the rotation of the substrate. Furthermore, in the transparent electrode layer deposition technique using the sputtering method, the transparent electrode layer having a low refractive index can be deposited by inclining the substrate with respect to the target.

6 is a cross-sectional view for describing another example of the transparent electrode layer 31 according to an exemplary embodiment of the present invention.

Referring to FIG. 6, it is generally similar to the light emitting diode described with reference to FIG. 1, except that the transparent electrode layer 31a is a refractive index grading layer. That is, the transparent electrode layer 31a is a refractive index grading layer in which the refractive index is gradually or gradually reduced from the second conductive semiconductor layer 29 side.

The transparent electrode layer 31a may be formed using a thermal evaporation method, an electron beam evaporation method, an ion beam assisted evaporation method, or a sputtering method, and at this time, by changing process parameters such as deposition rate, temperature, pressure, reactive gas flow rate, or plasma power, density The refractive index grading layer can be formed by first depositing a high layer and then gradually depositing a lower density layer. Since the refractive index of the transparent electrode layer 31a is lowered outward from the second conductive semiconductor layer 29 side, total internal reflection of light emitted through the transparent electrode layer 31a can be reduced.

7 is a cross-sectional view showing a light emitting diode package mounted with a light emitting diode 20 according to an embodiment of the present invention.

Referring to FIG. 7, the light emitting diode package includes a package body 60, leads 61a and 61b, a light emitting diode 20, and a molding part 63. The package body 60 may be formed of a plastic resin.

The package body 60 may have a mounting surface M for mounting the light emitting diode 20 and may have a reflective surface R on which light emitted from the light emitting diode 20 is reflected. Meanwhile, the light emitting diode 20 is mounted on the mounting surface M and is electrically connected to the leads 61a and 61b through bonding wires. The light emitting diode 20 may be attached to the mounting surface M by an adhesive 62, and the adhesive may be formed by, for example, curing an Ag epoxy paste.

The light emitting diode 20 has a distributed Bragg reflector 40, as described with reference to FIG. 3, and has a metal reflective layer 41 and an upper insulating layer 37.

The light emitting diode package may emit mixed color light, for example, white light, and may include a phosphor for wavelength converting light emitted from the light emitting diode 20. The phosphor may be contained in the molding part 63, but is not limited thereto.

Since the light emitting diode 20 includes a distribution Bragg reflector 40, when the wavelength-converted light from the phosphor is directed to the mounting surface M through the light-emitting diode 20, the wavelength-converted light is distributed Bragg reflector. It is reflected by the high reflectance by 40 and emitted to the outside. Accordingly, a light emitting diode package having higher light efficiency than a conventional light emitting diode package may be provided.

Furthermore, when the upper insulating layer 37 and / or the transparent electrode layer 31 is a refractive index grading layer, the light extraction efficiency may be further increased in the light emitting diode 20 to further reduce light loss inside the light emitting diode 20. have.

In the present embodiment, a package including a phosphor together with the light emitting diode 20 to implement white light is described, but the present invention is not limited thereto. Various packages are known for emitting white light, and the light emitting diode 20 is applicable to any package.

Claims (13)

Board;
A light emitting structure disposed on the substrate and including an active layer interposed between a first conductive semiconductor layer and a second conductive semiconductor layer;
An upper insulating layer covering the light emitting structure;
A distributed bragg reflector positioned below the substrate and reflecting light emitted from the light emitting structure; And
It includes a metal reflective layer located below the distribution Bragg reflector,
The distributed Bragg reflector has a reflectivity of at least 90% for light at a first wavelength in a blue wavelength region, light at a second wavelength in a green wavelength region, and light at a third wavelength in a red wavelength region. The light emitting diode of claim 1, wherein the distributed Bragg reflector has a structure in which an SiO ₂ layer and at least one layer of a TiO ₂ layer or an Nb ₂ O ₅ layer are alternately stacked. The light emitting diode of claim 1, wherein the distributed Bragg reflector comprises at least 25 pairs of SiO ₂ / Nb ₂ O ₅ . The light emitting diode of claim 1, wherein the distributed Bragg reflector is in contact with the bottom surface of the substrate, wherein SiO ₂ is in contact with the bottom surface of the substrate. The light emitting diode of claim 4, wherein the last layer of the distributed Bragg reflector is SiO ₂ . The light emitting diode of claim 1, further comprising a protective layer under the metal reflective layer. The light emitting diode of claim 1, wherein the upper insulating layer is a refractive index grading layer in which the refractive index is gradually or gradually reduced from the light emitting structure side. The light emitting diode of claim 7, wherein the upper insulating layer is SiO ₂ . The light emitting diode of claim 1, further comprising a transparent conductive layer interposed between the second conductive semiconductor layer and the upper insulating layer. 10. The light emitting diode of claim 9, wherein the transparent conductive layer is a refractive index grading layer whose refractive index is gradually or gradually reduced from the second conductive semiconductor layer side. The light emitting diode of claim 10, wherein the transparent conductive layer is ITO or ZnO. The method of claim 9, wherein the transparent conductive layer is formed by thermal evaporation, electron beam evaporation, ion beam assisted evaporation or sputtering,
The transparent conductive layer is a light emitting diode having a relatively low refractive index compared to the case of depositing by placing the substrate surface in a normal position relative to the source or target by depositing the substrate surface relative to the source or target. A mounting surface for mounting the light emitting diode;
The light emitting diode according to any one of claims 1 to 12 mounted on the mounting surface; And
A light emitting diode package comprising a phosphor for wavelength conversion of light emitted from the light emitting diode.

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