JP2012129249A - Light-emitting diode, light-emitting diode lamp, and method for manufacturing light-emitting diode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting diode and a light-emitting diode lamp which are excellent in heat dissipation, have high luminous efficiency, and are capable of emitting light with high luminance, and to provide a method for manufacturing the light-emitting diode.SOLUTION: The light-emitting diode of the present invention, in which a functional substrate is joined to a light-emitting part including a light-emitting layer, is characterized in that it comprises a reflection part which is disposed on the outer peripheral side of the light-emitting part at a distance from the light-emitting part and reflects light emitted from a side surface of the light-emitting part in a direction away from the functional substrate.

Description

  The present invention relates to a light emitting diode, a light emitting diode lamp, and a method for manufacturing a light emitting diode.

Light emitting diodes (English abbreviation: LED) that emit visible light such as blue, green, red, yellow, or white, and ultraviolet and infrared light are known. For example, in visible light, light emission having a light emitting layer made of aluminum phosphide, gallium, indium (composition (Al _X Ga _1-X ) _Y In _1-YP ; 0 ≦ X ≦ 1, 0 <Y ≦ 1) 2. Description of the Related Art A compound semiconductor LED that includes a portion and a substrate on which the light emitting portion is formed is known.

As the substrate, gallium arsenide (GaAs) or the like that is optically opaque with respect to the light emitted from the light emitting layer and that is not mechanically strong is generally used.
However, recently, in order to obtain a brighter visible light-emitting diode and to further improve the mechanical strength of the light-emitting element, the substrate is removed, and then the transmitted light is transmitted or transmitted. A support layer (functional substrate) made of a material that reflects and is excellent in mechanical strength is bonded.
For example, Patent Documents 1 to 7 disclose a technique (junction LED formation technique) in which the support layer (functional substrate) is bonded to the light emitting layer again. Furthermore, Patent Document 8 discloses a technique related to the bonding technique, and discloses a light emitting device in which an ohmic metal is embedded in an organic adhesive layer in which a metal layer and a reflective layer are bonded.

With the development of the junction-type LED forming technology, the degree of freedom of the substrate to be bonded to the light emitting portion has increased, for example, a composite material combining a metal material having high functions such as reflection, heat dissipation, and mechanical strength, and a suitable material. The functional board | substrate which consists of etc. can be used. By using a functional substrate as the substrate, it is possible to ensure optical performance and heat dissipation from the light emitting portion, suppress deterioration of the light emitting layer, and extend the life.
In particular, a high-power light-emitting diode that needs to emit light with a high current has a larger amount of heat generation than a conventional one, and ensuring heat dissipation is a more important issue. Therefore, bonding a functional substrate to the light emitting part is useful for increasing the output and extending the life of the light emitting diode.

  However, the device for extracting light emitted from the side surface of the light emitting portion bonded to the functional substrate with respect to the main light extraction surface has been insufficient. Depending on the shape of the package, the light from the side surface of the light emitting part has no reflecting structure and the like, resulting in a loss of light that cannot be extracted from the package.

Japanese Patent No. 3230638 JP-A-6-302857 JP 2002-246640 A Japanese Patent No. 2588849 JP 2001-57441 A JP 2007-81010 A JP 2006-32952 A JP-A-2005-236303

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a light emitting diode, a light emitting diode lamp, and a method for manufacturing the light emitting diode that are excellent in heat dissipation, have high luminous efficiency, and can emit light with high luminance.

In order to achieve the above object, the present invention employs the following configuration. That is,
(1) A step of forming a light emitting part layer including a light emitting layer on a semiconductor substrate, a step of bonding a functional substrate to the light emitting part layer, a step of removing the semiconductor substrate, and the light emitting part layer, Etching from the surface side from which the semiconductor substrate is removed until the functional substrate is exposed, forming a groove portion along the chip division planned line in a range including the chip division planned line in plan view, and the light emitting unit A step of separating a layer into light emitting portions of each chip, and a step of forming a side reflecting portion on the functional substrate in the groove portion at a position away from the outer peripheral edge of the light emitting portion. A method for manufacturing a light emitting diode.
Here, the “light emitting part layer” is used to indicate a group of layers formed of light emitting parts before being formed into chips, but is also simply referred to as “light emitting part” below.
The “chip division planned line” is a line scheduled to be cut to divide into chips, and is also called “street” or “spacing”.
(2) forming a light emitting layer including a light emitting layer on a semiconductor substrate, forming a reflective structure on the light emitting layer, and bonding the functional substrate on the reflective structure; The step of removing the semiconductor substrate and the light emitting part layer are etched from the surface side from which the semiconductor substrate is removed until the functional substrate is exposed, and in a range including a chip division planned line in plan view Forming a groove portion along the chip splitting line, separating the light emitting portion layer into light emitting portions of each chip, and a position on the functional substrate in the groove portion away from the outer peripheral edge of the light emitting portion And a step of forming a side reflection portion on the light emitting diode.
(3) Either the step (1) or (2), wherein the step of forming the side reflecting portion uses a laser to form the side reflecting portion by a melt of the functional substrate using a laser. The manufacturing method of the light emitting diode as described in any one of.
(4) The method for manufacturing a light-emitting diode according to any one of (1) and (2), wherein the step of forming the side reflecting portion is performed by a plating method.
(5) A light-emitting diode in which a functional substrate is bonded to a light-emitting unit including a light-emitting layer, the light-emitting diode is disposed on the outer peripheral side of the light-emitting unit and spaced apart from the light-emitting unit, and is emitted from a side surface of the light-emitting unit A light emitting diode comprising a side reflecting portion that reflects light in a direction away from the functional substrate.
(6) The light-emitting diode according to (1), wherein the side reflection portion has an inclined surface that reflects light emitted from a side surface of the light-emitting portion.
(7) The light-emitting diode according to any one of (5) and (6), wherein the side reflecting portion is provided in a peripheral region on the functional substrate.
(8) The light-emitting diode according to any one of (6) and (7), wherein a metal film is provided on the inclined surface.
(9) The light-emitting diode according to any one of (5) to (8), wherein a reflective structure is provided between the light-emitting portion and the functional substrate.
(10) The light-emitting diode according to any one of (5) to (9), wherein the side reflecting portion includes a material of the functional substrate.
(11) The light-emitting diode according to any one of (5) to (10), wherein the side reflecting portion includes any one of copper, aluminum, nickel, silver, or gold. .
(12) The functional substrate according to any one of (5) to (11), wherein the functional substrate includes any one of copper, aluminum, silver, molybdenum, tungsten, or gold. Light emitting diode.
(13) The light-emitting diode according to any one of (5) to (12), wherein the functional substrate is a laminated substrate of copper and molybdenum.
(14) The light emitting diode according to any one of (5) to (13), wherein the light emitting layer includes any one of an AlGaInP layer, an AlGaAs layer, and a GaInN layer.
(15) A light-emitting diode lamp comprising the light-emitting diode according to any one of (5) to (13) above and a package substrate on which the light-emitting diode is mounted.

  Since the light-emitting diode of the present invention includes a side reflection portion that is arranged apart from the light-emitting portion on the outer peripheral side of the light-emitting portion, a high current is applied to effectively use light emission from the side surface of the light-emitting portion. Can emit light with high brightness.

  The light-emitting diode according to the present invention is a substrate in which a functional substrate bonded to a light-emitting portion including a light-emitting layer is a metal substrate or a surface where a reflective layer is formed on the surface (bonding surface side) of silicon, AlN, SiC, GaP, Ge, or the like. In some cases, light can be emitted with higher brightness by applying a high current.

  The light-emitting diode lamp of the present invention is a light-emitting diode lamp having the above-described light-emitting diode and a package substrate on which the light-emitting diode is mounted. When the thermal resistance of the package substrate is 100 ° C./W or less, heat dissipation is achieved. And emits light with high brightness.

(A) It is a top view which shows an example of the light emitting diode which is embodiment of this invention. (B) It is sectional drawing along A-A 'of (a). It is process sectional drawing which shows an example of the manufacturing process of the functional board | substrate used for the light emitting diode which is embodiment of this invention. It is process sectional drawing which shows an example of the manufacturing process of the light emitting diode which is embodiment of this invention. It is process sectional drawing which shows an example of the manufacturing process of the light emitting diode which is embodiment of this invention. It is process sectional drawing which shows an example of the manufacturing process of the light emitting diode which is embodiment of this invention. It is process sectional drawing which shows an example of the manufacturing process of the light emitting diode which is embodiment of this invention. It is process sectional drawing which shows an example of the manufacturing process of the light emitting diode which is embodiment of this invention. It is process sectional drawing which shows an example of the manufacturing process of the light emitting diode which is embodiment of this invention. It is sectional drawing which shows an example of the light emitting diode which is embodiment of this invention. It is sectional drawing which shows another example of the light emitting diode lamp which is embodiment of this invention. It is sectional drawing which shows another example of the light emitting diode which is embodiment of this invention.

Hereinafter, modes for carrying out the present invention will be described.
<Light emitting diode>
1A and 1B are diagrams showing an example of a light emitting diode according to an embodiment of the present invention. FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along line AA ′ in FIG. FIG.
As shown in FIG. 1, a light emitting diode (LED) 1 according to an embodiment of the present invention is a light emitting diode in which a functional substrate 5 is bonded to a light emitting unit 3 including a light emitting layer 2. A side reflection part 6 is provided that is spaced apart from the light emitting part 3 and is disposed in the peripheral region 5 a on the functional substrate 5 and reflects light emitted from the side surface of the light emitting part 3 in a direction away from the functional substrate 5. .
The side reflecting portion 6 has an inclined surface 6 </ b> A that reflects light emitted from the side surface of the light emitting portion 3.
Further, the reflective structure 4 is provided between the light emitting unit 3 and the functional substrate 5.
The side reflector reflects the light emitted from the side surface of the light emitting part in a direction away from the functional substrate including the front direction, whereas the reflecting structure reflects the light emitted from the light emitting part in the front direction. To do.

<Light emitting part>
The light emitting unit 3 is a compound semiconductor stacked structure including the light emitting layer 2 and is an epitaxial stacked structure formed by stacking a plurality of epitaxially grown layers.
As the light emitting unit 3, for example, a known light emitting layer such as an InGaN layer can be used. However, a bonding technique for a functional substrate has been established, and an AlGaInP layer or an AlGaAs layer using an opaque substrate is more effective and more desirable. AlGaInP layer is a layer consisting of the general formula _{(Al X Ga 1-X)} Y In 1-Y P (0 ≦ X ≦ 1,0 <Y ≦ 1) material represented by. This composition is determined according to the emission wavelength of the light emitting diode.
Similarly, in the case of an Al _X Ga _1-X As (0 ≦ X ≦ 1) layer used for manufacturing red and infrared light emitting diodes, the composition of the constituent materials depends on the emission wavelength of the light emitting diodes. Determined.
The light-emitting portion 3 is a compound semiconductor of either n-type or p-type conductivity, and a pn junction is formed inside. Note that the polarity of the surface of the light-emitting portion 3 may be either p-type or n-type, but it is desirable that the n-type that is easy to diffuse current is on the surface side.

As shown in FIG. 1B, the light emitting unit 3 includes, for example, a contact layer 12b, a cladding layer 10a, a light emitting layer 2, a cladding layer 10b, and a contact layer 13.
The contact layer 12b is a layer for lowering the contact resistance of the ohmic electrode, and is made of, for example, Si-doped n-type (Al _0.5 Ga _0.5 ) _0.5 In _0.5 P, and includes a carrier. The concentration is 2 × 10 ¹⁸ cm ⁻³ and the layer thickness is 1.5 μm.
The clad layer 10a is made of, for example, n-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P doped with Si, and has a carrier concentration of 8 × 10 ¹⁷ cm ^−3. The thickness is 1 μm.

The light emitting layer 2 is, for example, 10 pairs of undoped (Al _0.2 Ga _0.8 ) _0.5 In _0.5 P / (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P. The layer thickness is 0.8 μm.
The light emitting layer 2 has a structure such as a double hetero structure (Double Hetero: DH), a single quantum well structure (Single Quantum Well: SQW), or a multiple quantum well structure (Multi Quantum Well: MQW). Here, the double heterostructure is a structure in which carriers responsible for radiative recombination can be confined. The quantum well structure has a well layer and two barrier layers sandwiching the well layer. The SQW has one well layer and the MQW has two or more well layers. As a method for forming the light emitting portion 3, MOCVD method or the like can be used.
In order to obtain light emission excellent in monochromaticity from the light emitting layer 2, it is particularly preferable to use an MQW structure as the light emitting layer 2.

The clad layer 10b is made of, for example, p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P doped with Mg, the carrier concentration is 2 × 10 ¹⁷ cm ⁻³ , and the layer thickness is 1 μm.
The contact layer 13 may be made of a transparent material such as GaP, AlGaInP, or AlGaAs for the purpose of reducing the current diffusion and the contact resistance between the electrodes. For example, it is a p-type (Al _0.5 Ga _0.5 ) _0.5 In _0.5 P layer doped with Mg, the carrier concentration is 3 × 10 ¹⁸ cm ⁻³ , and the layer thickness is 2 μm.

  The configuration of the light emitting unit 3 is not limited to the above-described structure. For example, a current diffusion layer that diffuses the element driving current in a planar manner in the entire light emitting unit 3 or a region through which the element driving current flows is used. A current blocking layer or a current confinement layer for limiting may be provided.

<First electrode, second electrode>
The first electrodes 7, 7 a and the second electrode 8 are ohmic electrodes, and their shape and arrangement are not particularly limited as long as the current is uniformly diffused in the light emitting unit 3. For example, a known electrode such as a circular shape or a rectangular shape can be used in plan view, and the electrodes can be arranged as a single electrode or a combination of a plurality of electrodes.

As the material of the first electrodes 7 and 7a, when an n-type compound semiconductor is used as the contact layer 12b, for example, AuGe, AuSi, or the like can be used for an AlGaAs-based or AlGaInP-based semiconductor. When a p-type compound semiconductor is used for the contact layer 12b, for example, AuBe, AuZn, or the like can be used. For other semiconductor materials such as InGaN, a known technique can be used as a combination of electrode materials.
Further, Au or the like can be further laminated thereon to prevent oxidation and improve wire bonding characteristics.

  As the material of the second electrode 8, when an n-type compound semiconductor is used, for example, a material containing AuGe, AuSi or the like can be used. When a p-type compound semiconductor is used, for example, A material containing AuBe, AuZn, or the like can be used. For other semiconductor materials such as InGaN, a known technique can be used as a combination of electrode materials.

<Reflection structure>
The reflective structure is provided between the light emitting portion and the functional substrate, and has a function of reflecting light emitted downward from the light emitting layer (functional substrate side) to a single layer or a laminated structure. It does not matter if it consists of For example, a single layer metal film or a laminated structure of a transparent conductive film and a metal film can be used.
In the embodiment shown in FIG. 1, the reflective structure 4 is formed on the surface 3 b of the light emitting unit 3 on the reflective structure 4 side so as to cover the second electrode 8. The reflective structure 4 is formed by laminating a metal film 15 and a transparent conductive film 14.
In addition, in embodiment which joins a light emission part and a functional board | substrate directly, it does not have a reflection structure.

  The metal film having a high reflectance is made of a metal whose main material is copper, silver, gold, aluminum, or an alloy thereof. When these materials are combined with an appropriate emission wavelength, the reflectance can be 90% or more. By forming a highly reflective metal film, the light from the light emitting layer 2 is reflected in the front direction by the metal film, and the light extraction efficiency in the front direction can be improved. However, low incident angle light is emitted from the side, not from the front. Effective use of the light emitted from this side surface can increase the brightness of the light-emitting diode lamp.

<Functional substrate>
The functional substrate 5 may be a single layer or a laminated structure.
The functional substrate 5 can be made of a plurality of metal layers (plates). In particular, it is preferable that two types of metal layers are alternately laminated, and it is more preferable that the number of layers of the two types of metal layers be an odd number in total.
For example, when the two first metal layers have a laminated structure with the second metal layer sandwiched therebetween, the thermal conductivity is 130 W / m · K or more, and the thermal expansion coefficient is substantially equal to that of the light emitting portion. It is preferable that the first metal layer and the second metal layer having a thermal conductivity of 230 W / m · K or more are preferable. The metal substrate having high thermal conductivity as the functional substrate ensures ohmic contact with the light emitting part, Most preferred because it can be directly joined. When an opaque substrate is used, the structure has both ohmic contact and reflection function. For example, in the case of a Si substrate, a composite substrate produced by forming a highly reflective metal film such as silver or gold on the surface is preferably used as the functional substrate.
What consists of a laminated board | substrate of copper and molybdenum is also preferable.
FIG. 2B shows a functional substrate in which one substantially flat plate-like second metal plate 22 is sandwiched between two substantially flat plate-like first metal plates 21. In this case, the first metal plate 21 is preferably made of a metal having a high reflectance.

When using a metal substrate as the functional substrate 5, from the viewpoint of warping or cracking of the metal substrate, when using a material having a smaller thermal expansion coefficient than the light emitting unit 3 as the second metal plate 22, the first metal plate 21, 21 is preferably made of a material having a thermal expansion coefficient larger than that of the light emitting portion 3. Since the thermal expansion coefficient of the metal substrate as a whole is close to the thermal expansion coefficient of the compound semiconductor layer, it is possible to suppress warping and cracking of the metal substrate when the compound semiconductor layer and the metal substrate are joined, and the light emitting diode This is because the production yield can be improved. Similarly, when a material having a larger thermal expansion coefficient than that of the compound semiconductor layer 2 is used as the second metal plate 22, the first metal plates 21 and 21 are made of a material having a smaller thermal expansion coefficient than that of the compound semiconductor layer 2. It is preferable to use it. Since the thermal expansion coefficient of the metal substrate as a whole is close to the thermal expansion coefficient of the compound semiconductor layer, it is possible to suppress warping and cracking of the metal substrate when joining the compound semiconductor layer and the metal substrate, and the production yield of light emitting diodes It is because it can improve.
From the above viewpoint, any of the two types of metal layers may be the first metal layer or the second metal layer.
Examples of the two metal layers include silver (thermal expansion coefficient = 18.9 ppm / K), copper (thermal expansion coefficient = 16.5 ppm / K), gold (thermal expansion coefficient = 14.2 ppm / K), and aluminum. (Thermal expansion coefficient = 23.1 ppm / K), nickel (thermal expansion coefficient = 13.4 ppm / K) and a metal layer made of any of these alloys, molybdenum (thermal expansion coefficient = 5.1 ppm / K), Combinations of tungsten (thermal expansion coefficient = 4.3 ppm / K), chromium (thermal expansion coefficient = 4.9 ppm / K), and a metal layer made of any of these alloys can be used.
A preferred example is a metal substrate composed of three layers of Cu / Mo / Cu. From the above viewpoint, the same effect can be obtained with a metal substrate composed of three layers of Mo / Cu / Mo, but the metal substrate composed of three layers of Cu / Mo / Cu is a Cu layer that has high mechanical strength and is easy to process Mo. Therefore, there is an advantage that processing such as cutting is easier than a metal substrate composed of three layers of Mo / Cu / Mo.

  The thermal expansion coefficient of the entire metal substrate is, for example, 6.1 ppm / K for a three-layer metal substrate of Cu (30 μm) / Mo (25 μm) / Cu (30 μm), and Mo (25 μm) / Cu (70 μm). In the case of a metal substrate composed of three layers of / Mo (25 μm), it is 5.7 ppm / K.

From the viewpoint of heat dissipation, the metal layer constituting the metal substrate is preferably made of a material having high thermal conductivity. This is because the heat dissipation of the metal substrate can be increased, the light emitting diode can emit light with high brightness, and the life of the light emitting diode can be extended.
For example, silver (thermal conductivity = 420 W / m · K), copper (thermal conductivity = 398 W / m · K), gold (thermal conductivity = 320 W / m · K), aluminum (thermal conductivity = 236 W / m) · K), molybdenum (thermal conductivity = 138 W / m · K), tungsten (thermal conductivity = 174 W / m · K), and alloys thereof are preferably used.
More preferably, the metal layers are made of a material having a thermal expansion coefficient substantially equal to that of the compound semiconductor layer. In particular, the material of the metal layer is preferably a material having a thermal expansion coefficient that is within ± 1.5 ppm / K of the thermal expansion coefficient of the compound semiconductor layer. As a result, it is possible to reduce stress due to heat applied to the light emitting portion when the metal substrate and the compound semiconductor layer are joined, and to suppress cracking of the metal substrate due to heat when the metal substrate is connected to the compound semiconductor layer. The manufacturing yield of the light emitting diode can be improved.
The thermal conductivity of the entire metal substrate is, for example, 250 W / m · K for a three-layer metal substrate of Cu (30 μm) / Mo (25 μm) / Cu (30 μm), and Mo (25 μm) / Cu (70 μm) / In the case of a metal substrate composed of three layers of Mo (25 μm), it is 220 W / m · K.

The thickness of the functional substrate 5 is preferably 50 μm or more and 250 μm or less, but more preferably 150 μm or less.
When the thickness of the functional substrate 5 is larger than 250 μm, it is not preferable because the manufacturing cost of the light emitting diode is increased and it is difficult to cut the chip. In addition, when the thickness of the functional substrate 5 is less than 50 μm, cracking, bending, warping, etc. are likely to occur during handling, which may reduce the manufacturing yield. The optimal thickness varies depending on the substrate material.

<Side reflection part>
The side reflecting portion 6 is disposed on the outer peripheral side of the light emitting portion 3 so as to be separated from the light emitting portion 3 and has a function of reflecting light emitted from the side surface of the light emitting portion 3 in a direction away from the functional substrate 5. It is preferable to reflect light emitted substantially perpendicularly from the side surface of the light emitting layer in a direction away from the functional substrate, and more preferably to reflect in the front direction.
The side reflection part 6 preferably has an inclined surface 6 </ b> A that reflects light emitted from the side surface of the light emitting part 3. A metal film may be provided on the inclined surface 6A.
An inclined surface having an inclination angle of 45 ° ± 30 °, desirably 45 ° ± 20 ° is preferable. Even if the height of the reflecting portion is low, it is effective. Considering the formation technology and cost of the reflecting portion, it is desirable that the surface is equal to or lower than the chip surface.
Further, the side reflecting portion 6 is provided in the peripheral region 5 a on the functional substrate 5.
Moreover, the side reflection part 6 may contain the material of the functional substrate 5, and may contain any one of copper, aluminum, nickel, silver, or gold | metal | money.

  When the same material as the metal film constituting the functional substrate as described above is used for the side reflecting portion, it is desirable that the side reflecting portion is made of a material having a high reflectance of 90% or more.

  Although it is most desirable to arrange the side reflecting portions so as to surround the outer periphery of the light emitting portion, it is sufficiently effective to remove the four corners which are singular points of the rectangular chip. Further, for example, only two sides facing each other may be partially formed.

<Method for Manufacturing Light-Emitting Diode (First Embodiment)>
Next, the manufacturing method of the light emitting diode which is embodiment of this invention is demonstrated.
The method for manufacturing a light emitting diode according to the first embodiment includes a step of forming a light emitting portion layer including a light emitting layer on a semiconductor substrate, a step of bonding a functional substrate to the light emitting portion layer, and removing the semiconductor substrate. Etching the process and the light emitting part layer from the surface side from which the semiconductor substrate has been removed until the functional substrate is exposed, and forming a groove along the chip splitting line in a range including the chip splitting line in plan view Forming and separating the light emitting part layer into light emitting parts of each chip, and forming a side reflecting part on the functional substrate in the groove part at a position away from the outer peripheral edge of the light emitting part.

Here, the “step of forming the side reflection portion” can be performed by forming the side reflection portion using a laser and a functional substrate melt. At this time, a functional substrate may be cut along a chip division planned line by using a laser to form a chip, and at the same time, the side reflection portion may be formed by a melted material by laser.
The laser wavelength can be used without limitation as long as it has a high output that is absorbed by a commercially available metal. For example, 355 nm, 532 nm, 1064 nm, etc. are common. The laser output is preferably about 1 W to 10 W. If the output is low, it takes a long time to cut and the productivity is extremely reduced. On the other hand, if the output is too high, the light emitting layer may be damaged.
It is desirable to form a protective film for preventing reattachment on the surface of the wafer. When there is no protective film, it is difficult to adjust the cutting conditions so that re-adhesion does not occur. A method of forming a protective film and cutting a plurality of irradiations is easy to form the side reflection portion. A part of the protective film and the substrate is cut by the first irradiation, and a functional substrate (for example, metal) is reattached only to a part where the protective film near the cut part is removed by the second irradiation. It is desirable to form.
For example, a photoresist (photosensitive resin) or a water-soluble resin such as polyvinyl alcohol can be used as the protective film. A water-soluble resin is preferable because it can be easily removed by washing with water. Since the protective film is sublimated by the first laser irradiation, a material that absorbs the laser to some extent or evaporates due to heat generation under the protective film is desirable.

In addition, the “step of forming the side reflection portion” can be performed by a plating method.
After forming a protective film other than the planned cutting part (street), a plating method is used to form a side reflection part made of a plating layer having a trapezoidal cross section at the cutting part. For electroplating, which is easy to form a thick film, for example, a two-layer structure of Ni plating and gold plating is desirable. A thickness of 5 to 10 μm is desirable. After the plating step, it is also desirable to form a silver film having a high reflectance, for example, by sputtering or vapor deposition.
Thereafter, cutting or separation is performed using a mechanical or laser. The width of the street can be adjusted according to the cutting method, the height of the reflecting portion, and the like. 10-40 micrometers is suitable.

Hereinafter, the present embodiment will be described in detail with reference to the drawings.
<Manufacturing process of functional substrate>
The functional substrate may be a single layer or a laminated structure.
A manufacturing process of a metal laminated substrate will be described with reference to FIG. 2 as an example of the functional substrate 5 having a laminated structure.

First, two substantially flat plate-like first metal plates 21 and one substantially flat plate-like second metal plate 22 are prepared.
Next, as shown in FIG. 2A, the second metal plate 22 is inserted between the two first metal plates 21, and these are stacked. The first metal plate 21 is preferably made of a highly reflective metal.

  Next, three metal plates stacked on a predetermined pressure device are arranged, and a load is applied to the first metal plate 21 and the second metal plate 22 in the direction of the arrow at a high temperature. As a result, a functional substrate 5 composed of three layers is formed as shown in FIG.

In addition, after this, after cutting according to the magnitude | size of the joint surface of the light emission part (wafer) 3, you may mirror-finish the surface.
Further, a bonding auxiliary film may be formed on the bonding surface 5b of the functional substrate 5 in order to stabilize electrical contact. As the bonding auxiliary film, gold, platinum, nickel, or the like can be used. For example, first, nickel is deposited to a thickness of 0.1 μm, and then gold is deposited to a thickness of 0.5 μm on the nickel.
Furthermore, a eutectic metal such as AuSn having a low melting point may be formed instead of the auxiliary bonding film. Thereby, a joining process can be simplified.

<Light emitting portion and second electrode forming step>
First, as shown in FIG. 3, a plurality of epitaxial layers are grown on the one surface 11 a of the semiconductor substrate 11 to form an epitaxial multilayer 17. The semiconductor substrate 11 is a substrate for forming an epitaxial layered body 17 and is, for example, a Si-doped n-type GaAs single crystal substrate in which one surface 11a is inclined by 15 ° from the (100) plane. As described above, when an AlGaInP layer or an AlGaAs layer is used as the epitaxial multilayer 17, a gallium arsenide (GaAs) single crystal substrate is used as the substrate on which the epitaxial multilayer 17 is formed.

  As a method for forming the light emitting portion 3, a metal organic chemical vapor deposition (MOCVD) method, a molecular beam epitaxy (MBE) method, a liquid phase epitaxy (Liquid Phase Epitaxy) method, or the like. Can be used.

In the present embodiment, the low pressure MOCVD method using trimethylaluminum ((CH ₃ ) ₃ Al), trimethylgallium ((CH ₃ ) ₃ Ga), and trimethylindium ((CH ₃ ) ₃ In) as group III constituent elements. Each layer is epitaxially grown using
Note that biscyclopentadienylmagnesium (bis- (C ₅ H ₅ ) ₂ Mg) is used as a Mg doping material. Further, disilane (Si ₂ H ₆ ) is used as a Si doping raw material. Further, phosphine (PH ₃ ) or arsine (AsH ₃ ) is used as a raw material for the group V constituent element.
The p-type GaP layer 13 is grown at 750 ° C., for example, and the other epitaxial growth layers are grown at 730 ° C., for example.

Specifically, first, a buffer layer 12 a made of n-type GaAs doped with Si is formed on one surface 11 a of the semiconductor substrate 11. As the buffer layer 12a, for example, n-type GaAs doped with Si is used, the carrier concentration is 2 × 10 ¹⁸ cm ⁻³ , and the layer thickness is 0.2 μm.
Next, a contact layer 12b made of Si-doped n-type (Al _0.5 Ga _0.5 ) _0.5 In _0.5 P is formed on the buffer layer 12a.
Next, a clad layer 10a made of n-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P doped with Si is formed on the contact layer 12b.
Next, undoped (Al _0.2 Ga _0.8 ) _0.5 In _0.5 P / (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P 10 is formed on the cladding layer 10a. A light emitting layer 2 having a pair of laminated structures is formed.
Next, a clad layer 10 b made of p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P doped with Mg is formed on the light emitting layer 2.
Next, a Mg-doped p-type GaP layer 13 is formed on the cladding layer 10b.

Next, the surface 13a of the p-type GaP layer 13 opposite to the semiconductor substrate 11 is mirror-polished to a depth of 1 μm from the surface, so that the surface roughness is, for example, 0.20 nm or less.
Next, as shown in FIG. 4, a second electrode (ohmic electrode) 8 is formed on the surface 13 a opposite to the semiconductor substrate 11 of the p-type GaP layer 13. For example, the second electrode 8 is formed by laminating Au having a thickness of 0.2 μm on AuBe having a thickness of 0.4 μm. For example, the second electrode 8 has a circular shape of 12 μmφ when viewed in plan, and is formed at intervals of 80 μm.

<Reflection structure forming process>
Next, as shown in FIG. 5, a transparent conductive film 14 made of an ITO film is formed so as to cover the surface 13 a opposite to the semiconductor substrate 11 of the p-type GaP layer 13 and the second electrode 8. Next, a heat treatment at 450 ° C. is performed to form an ohmic contact between the second electrode 8 and the transparent conductive film 14.
In the embodiment in which the light emitting unit and the functional substrate are directly joined, there is no reflection structure forming step.

Next, as shown in FIG. 6, a film made of a silver (Ag) alloy is formed on the surface 14 a of the transparent conductive film 14 on the side opposite to the epitaxial laminated body 17 by using a vapor deposition method. Tungsten (W) and platinum (Pt) are each 0.1 μm, gold (Au) is 0.5 μm, and AuGe eutectic metal (melting point 386 ° C.) is 1 μm.
Thereby, the reflective structure 4 including the metal film 15 and the transparent conductive film 14 is formed.

<Functional substrate bonding process>
In FIG. 7, the process of joining the reflective structure 4 and the functional substrate 5 is shown.
The semiconductor substrate 11 on which the reflective structure 4 and the epitaxial laminated body 17 are formed and the functional substrate 5 formed in the functional substrate manufacturing process are carried into a decompression device, and the joint surface 4a of the reflective structure 4 is obtained. And the bonding surface 5b of the functional substrate 5 are disposed so as to be opposed to each other.
Next, after evacuating the inside of the decompression device to 3 × 10 ⁻⁵ Pa, a weight of 200 g / cm ² is applied while the semiconductor substrate 11 and the functional substrate 5 are heated to 390 ° C. 4 and the bonding surface 5b of the functional substrate 5 are bonded to form a bonded structure 18.
As a bonding method, for example, a known technique such as diffusion bonding, metal eutectic bonding, an adhesive, or a room temperature bonding method can be applied.

<Semiconductor substrate and buffer layer removal step>
Next, as shown in FIG. 8, the semiconductor substrate 11 and the buffer layer 12a are selectively removed from the bonding structure 18 with an ammonia-based etchant. Thereby, the light emission part (light emission part layer) 3 which has the light emitting layer 2 is formed.

<First electrode forming step>
Next, a conductive film for an electrode is formed on the surface 3a of the light emitting unit 3 on the side opposite to the reflective structure 4 by using, for example, a vacuum deposition method.
For example, a metal layer structure made of AuGe / Ni / Au can be used as the electrode conductive film. For example, AuGe (Ge mass ratio 12%) is formed to a thickness of 0.15 μm, Ni is then formed to a thickness of 0.05 μm, and Au is further formed to a thickness of 0.2 μm. Thereafter, for example, it is preferable to alloy each metal of the n-type ohmic electrode (first electrode) 6 by performing a heat treatment at 420 ° C. for 3 minutes. Thereby, the resistance of the n-type ohmic electrode (first electrode) 6 can be reduced.

  Next, by using a general photolithography means, for example, as shown in FIG. 1, the electrode conductive film is patterned into a circular shape in plan view, Au is deposited by 1 μm, and the light emitting diode 1 having the bonding electrode is formed. Is made.

<Functional substrate cutting and side reflection portion forming step>
As shown in FIG. 9, until the functional substrate 5 is exposed, the light emitting part layer 3 and the reflective structure 4 in the range 32 including the cut portion (chip division planned line) 31 that partitions the light emitting diode into a desired size are exposed. The grooves 33 are formed by etching along the planned chip division lines 31. Thereby, the light emitting part layer is separated into light emitting parts for each chip.
Next, for example, using a laser at a pitch of 0.8 mm, the functional substrate at the cut portion is cut into, for example, square light-emitting diode chips (LED chips) along the chip division planned line 31.
If cutting is easy, the reflective structure need not be removed. Moreover, as an etchant used for removal, a known etchant suitable for the material or a combination thereof can be used.
As described above, the functional substrate 5 is cut into chips by using the laser along the planned chip division line 31 and at the same time the functional substrate 5 in the groove 33 is separated from the outer peripheral end of the light emitting unit 3. The side reflection part 6 can be formed in the peripheral area 5a.

As for the size of the light emitting diode, for example, the length of the diagonal line of the substantially rectangular light emitting portion 3 when viewed in plan is 1.1 mm. At this time, when Cu / Mo / Cu is used as the functional substrate 5, at the same time as cutting, the peripheral region 5a on the functional substrate 5 is, for example, a convex made mainly of copper having a height of 3 to 20 μm and a width of 5 to 20 μm. A part (side reflection part) 6 is formed. In this embodiment, the convex part (side reflecting part) 6 is made of copper which is a material of the functional substrate. The inclination angle of the convex part (side reflection part) is, for example, about 30 to 60 °.
At this time, the wavelength of the laser can be used without limitation as long as it has a high output that is absorbed by a commercially available metal. For example, 355 nm, 532 nm, 1064 nm, etc. are common. The laser output is preferably about 1 W to 10 W. If the output is low, it takes a long time to cut and the productivity is extremely reduced. On the other hand, if the output is too high, the light emitting layer may be damaged.
It is desirable to form a protective film for preventing reattachment on the surface of the wafer. When there is no protective film, it is difficult to adjust the cutting conditions so that re-adhesion does not occur. It is easy to form a side reflection part by forming a protective film and cutting a plurality of times of irradiation. The first irradiation cuts a part of the protective film and the functional substrate, and the second irradiation forms the reflective part by reattaching the metal of the functional substrate only to the part where the protective film near the cut portion is removed. It is desirable to do.
The higher the output and the smaller the number of times of cutting, the higher the height of the convex portion, the wider the width when there is no protective film, and the narrower width when there is a protective film.
For example, when the substrate is cut once with high output, the height of the convex portion is high and the angle is likely to be large.
Thereafter, the chip is washed.

In this light-emitting diode, light emitted from the side surface of the light-emitting portion 3 is reflected in the front direction by the inclined surface 6A of the convex portion (side reflection portion) 6.
Thus, according to the light emitting diode of the present invention, since the functional substrate is bonded to the light emitting diode and the side reflection portion is formed, high light emission efficiency is obtained even in a high current region.

In the method for manufacturing a light emitting diode according to the embodiment of the present invention, there is a cost merit when the formation of the convex portion (side reflection portion) is performed simultaneously with the cutting of the functional substrate.
In addition, the functional substrate 5 includes a first metal layer 21 having a thermal conductivity of 130 W / m · K or more and a thermal expansion coefficient substantially equal to that of the light emitting part, and a thermal conductivity of 230 W / m · K or more. When the second metal layer 22 is formed by pressure bonding at a high temperature, the substrate is prevented from cracking at the time of bonding, has excellent heat dissipation, and a high voltage is applied to emit light with high brightness. A light emitting diode that can be manufactured can be manufactured.

<Light emitting diode lamp>
The light emitting diode lamp which is embodiment of this invention using the light emitting diode manufactured by the manufacturing method of the light emitting diode of 1st Embodiment is demonstrated.
FIG. 10 is a schematic cross-sectional view showing an example of a light-emitting diode lamp according to an embodiment of the present invention.
As shown in FIG. 10, a light emitting diode lamp 40 according to an embodiment of the present invention is mounted on a package substrate 45, two electrode terminals 43 and 44 formed on the package substrate 45, and the electrode terminal 44. The light-emitting diode 1 includes a transparent resin (sealing resin) 41 made of silicon or the like formed so as to cover the light-emitting diode 1.
The light emitting diode 1 includes the light emitting unit 3, the reflective structure 4, the functional substrate 5, the first electrode 6, and the second electrode 8, so that the functional substrate 5 is connected to the electrode terminal 43. Has been placed. The first electrode 6 and the electrode terminal 44 are wire bonded. The voltage applied to the electrode terminals 43 and 44 is applied to the light emitting unit 3 through the first electrode 6 and the second electrode 8, and the light emitting layer included in the light emitting unit 3 emits light. The emitted light is extracted in the front direction f.

The package substrate 45 preferably has a thermal resistance of 100 ° C./W or less. Thereby, even when electric power of 1 W or more is applied to the light emitting layer 2 to emit light, the light emitting layer 2 can function, and the heat dissipation of the light emitting diode 1 can be further enhanced.
The shape of the package substrate is not limited to this, and a package substrate having another shape may be used. Also in LED lamp products using package substrates of other shapes, sufficient heat dissipation can be ensured, so that a light-emitting diode lamp with high output and high brightness can be obtained.

  A light emitting diode package 40 according to an embodiment of the present invention is a light emitting diode lamp 40 having a light emitting diode 1 and a package substrate 45 on which the light emitting diode 1 is mounted. The thermal resistance of the package substrate 45 is 100 ° C./W or less. In some cases, heat dissipation is excellent, and high voltage can be applied to emit light with high brightness.

  When the light emitting diode package 40 according to the embodiment of the present invention emits light by applying a power of 1 W or more to the light emitting layer 2 of the light emitting diode 1, the light emitting diode package 40 is excellent in heat dissipation, applies high current, and has high brightness. Can emit light.

<Method for Manufacturing Light Emitting Diode (Second Embodiment)>
FIG. 11 is a diagram illustrating an example of a light-emitting diode manufactured by the method for manufacturing a light-emitting diode according to the second embodiment of the present invention.
As shown in FIG. 11, a light emitting diode (LED) 51 according to an embodiment of the present invention uses a functional substrate 55 instead of the functional substrate 5 and is joined with AuIn, and the side reflecting portion 15 is formed by a plating method. This is different from the first embodiment. In addition, the same code | symbol is attached | subjected and shown about the member same as the member shown in 1st Embodiment.
Plating can be performed by a known method using a commercially available plating solution.

A light-emitting diode (LED) 51 according to an embodiment of the present invention includes a light-emitting unit 3 including a light-emitting layer (not shown) and a functional substrate 55 bonded to the light-emitting unit 3 through a reflective structure 4. is doing.
The functional substrate 55 includes Ti ohmic electrodes on the front surface (light emitting portion side) and the back surface of the Si substrate. An Au film is further formed on the back surface to form an antioxidant film. An AuIn film is formed on the front surface instead of AuGe, and is bonded to the light emitting portion. Specifically, for example, a Ti ohmic electrode can be formed with a thickness of 0.2 μm, an Au film can be formed with a thickness of 0.5 μm, AuIn can be formed with a thickness of 1 μm, and bonding can be performed at 240 ° C.
Instead of the Si substrate, a Ge substrate, a GaP substrate, a SiC substrate, or the like can be used.

  After removing the light emitting part layer 3 of the chip division planned line, the ITO film and the Ag layer constituting the reflective structure 4, a Pt layer is formed, and Ni / Au plating treatment is performed on the Pt layer, For example, a convex part (side reflection part) having a thickness of 5 μm and a width of 10 μm is formed. In this case, the inclined surface can be about 60 degrees, for example.

Hereinafter, the present invention will be specifically described based on examples. However, the present invention is not limited only to these examples.
Example 1
First, the functional substrate of Example 1 having a three-layer structure of Cu (50 μm) / Mo (25 μm) / Cu (50 μm) was formed using the method shown in the first embodiment. A Pt (0.1 μm) / Au (0.5 μm) film was formed on the bonding surface of the functional substrate. The functional substrate of Example 1 had a thermal expansion coefficient of 6 ppm / K and a thermal conductivity of 230 W / m · K.

Next, using the method shown in the first embodiment, a light emitting part and a reflective structure were formed, and the functional substrate was bonded to the light emitting diode, thereby producing a light emitting diode of Example 1.
The contact layer 12b is made of Si-doped n-type (Al _0.5 Ga _0.5 ) _0.5 In _0.5 P, has a carrier concentration of 2 × 10 ¹⁸ cm ⁻³ , and a layer thickness of 1.5 μm. It was. The clad layer 10a is made of Si-doped n-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P, has a carrier concentration of 8 × 10 ¹⁷ cm ⁻³ , and a layer thickness of 1 μm. did. The light emitting layer 2 has a laminated structure of 10 pairs of undoped (Al _0.2 Ga _0.8 ) _0.5 In _0.5 P / (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P. The layer thickness was 0.8 μm. The clad layer 10b is made of Mg-doped p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P, has a carrier concentration of 2 × 10 ¹⁷ cm ⁻³ , and a layer thickness of 1 μm. did. Further, the GaP layer 13 is a p-type GaP layer doped with Mg, the carrier concentration is 3 × 10 ¹⁸ cm ⁻³ , and the layer thickness is 2 μm.
Furthermore, the first electrode was formed as a stacked structure of AuGe / Ni / Au, and the second electrode was formed as a stacked structure of AuBe / Au. In addition, as the reflective structure, a transparent conductive film made of ITO and a laminated structure made of Ag alloy / W / Pt / Au / AuGe were used.
The copper / molybdenum / copper substrate was cut with a laser.
At this time, in order to prevent reattachment of metal generated at the time of cutting to the electrode or the light emitting surface, a protective film that transmits laser light is applied to the surface. The thickness of the protective film is about 1 μm.
Cutting was performed by irradiating the same cutting line twice with a laser having a wavelength of 355 nm and a power of 4 W. In the first irradiation, the protective film of the cut portion and the metal substrate having a thickness of about half were cut. In the second irradiation, the metal substrate is completely cut, and in the first cutting, the metal (copper) is reattached and solidified on the surface of the metal substrate where the protective film in the vicinity of the cut portion disappears, Protrusions were formed on the outer periphery of the chip.
The convex portion had a height of about 10 μm and a width of about 12 μm. A reflective portion having an angle of about 40 ° was formed with respect to the light emitting layer. Thereafter, the cleaning and the protective film were removed.
The light emitting diode of Example 1 was assembled in a lamp, 2.4 V was applied, and a current of 500 mA was applied to emit red light with a main wavelength of 620 nm. A high luminous efficiency of about 70 lm / W was obtained. At this time, the luminous efficiency of the light-emitting diode lamp was improved by the effect of the functional substrate and the convex portion.

(Example 2)
The difference from Example 1 is that a plating step is added after laser cutting.
Cutting was performed by irradiating the same cutting line with a laser having a wavelength of 355 nm and a power of 2 W three times. In the first irradiation, the protective film of the cut portion and the metal substrate having a thickness of about half were cut. In the second irradiation, the metal substrate is completely cut, and in the first cutting, the metal (copper) is reattached and solidified on the surface of the metal substrate where the protective film in the vicinity of the cut portion disappears, Small protrusions were formed on the outer periphery of the chip.
The convex portion had a height of about 3 μm and a width of about 4 μm. A reflective portion having an angle of about 40 ° was formed with respect to the light emitting layer. Next, 1 μm of Ni and 2 μm of gold plating were applied to form a convex part having a height of 6 μm and a width of 10 μm.
The light emitting diode of Example 2 was assembled in a lamp, 2.4 V was applied, and a current of 500 mA was applied to emit red light with a main wavelength of 620 nm. A high luminous efficiency of about 69 lm / W was obtained. At this time, the luminous efficiency of the light-emitting diode lamp was improved by the effect of the functional substrate and the convex portion.

(Comparative example)
A light emitting diode lamp was manufactured under the same conditions as in Example 1 except that the cutting process of Example 1 was cut by a mechanical dicing method. Therefore, since the cutting process was performed by a mechanical dicing method, the peripheral region of the functional substrate was flat, and no convex portion was formed.

  A 2.4 V voltage was applied to the light emitting diode lamp and a current of 500 mA was applied to emit red light having a main wavelength of 620 nm. It was about 64 lm / W. At this time, the extraction efficiency from the convex part of the light emitting diode was lowered, and the light emission output was reduced by about 10% from the example.

  The light-emitting diode and the light-emitting diode lamp of the present invention are excellent in heat dissipation, have high luminous efficiency, and can emit light with high brightness. Therefore, the light-emitting diode and the light-emitting diode lamp can be used for various display lamps, lighting fixtures, etc. May be available in In addition, the light emitting diode manufacturing method can produce light emitting diodes that are excellent in heat dissipation, have high luminous efficiency, and can emit light with high brightness, and can be used for various display lamps, lighting fixtures, etc. It can be used in the industries that use it.

1 Light-emitting diode (light-emitting diode chip)
2 Light emitting layer 3 Light emitting part (light emitting part layer)
3A Light-Emitting Section 4 Reflective Structure 5, 55 Functional Substrate 5a Peripheral Regions 6, 15, Side Reflector 6A Inclined Surface 7 First Electrode 8 Second Electrode 11 Semiconductor Substrate (Epitaxial Growth Substrate)
10a, 10b Cladding layer 12a Buffer layer 12b Contact layer 13 GaP layer 17 Epitaxial laminated body 21 First metal layer 22 Second metal layer 25 Metal laminated film 31 Chip division planned line 32 Range including chip division planned line 33 Groove 40 Light emitting diode lamp 41 Transparent resin 43, 44 Electrode terminal 45 Package substrate 46 Wire 51 Light emitting diode (light emitting diode chip)

Claims (15)

Forming a light emitting layer including a light emitting layer on a semiconductor substrate;
Bonding a functional substrate to the light emitting layer;
Removing the semiconductor substrate;
Etching the light emitting portion layer from the surface side from which the semiconductor substrate is removed until the functional substrate is exposed, and forming a groove portion along the chip division planned line in a range including the chip division planned line in plan view Forming and separating the light emitting part layer into light emitting parts of each chip;
And a step of forming a side reflection portion on the functional substrate in the groove portion at a position away from the outer peripheral end of the light emitting portion. Forming a light emitting layer including a light emitting layer on a semiconductor substrate;
Forming a reflective structure in the light emitting layer;
Bonding the functional substrate on the reflective structure;
Removing the semiconductor substrate;
Etching the light emitting portion layer from the surface side from which the semiconductor substrate is removed until the functional substrate is exposed, and forming a groove portion along the chip division planned line in a range including the chip division planned line in plan view Forming and separating the light emitting part layer into light emitting parts of each chip;
And a step of forming a side reflection portion on the functional substrate in the groove portion at a position away from the outer peripheral end of the light emitting portion.   3. The light-emitting diode according to claim 1, wherein in the step of forming the side reflecting portion, the side reflecting portion is formed by a melt of the functional substrate using a laser. Production method.   The method of manufacturing a light emitting diode according to claim 1, wherein the step of forming the side reflecting portion is performed by a plating method. A light emitting diode in which a functional substrate is bonded to a light emitting portion including a light emitting layer,
A side reflection part is provided on the outer peripheral side of the light emitting part so as to be separated from the light emitting part and reflects light emitted from the side surface of the light emitting part in a direction away from the functional substrate. Light emitting diode.   The light emitting diode according to claim 5, wherein the side reflecting portion has an inclined surface that reflects light emitted from a side surface of the light emitting portion.   The light emitting diode according to claim 5, wherein the side reflecting portion is provided in a peripheral region on the functional substrate.   The light emitting diode according to claim 6, wherein a metal film is provided on the inclined surface.   The light emitting diode according to any one of claims 5 to 8, further comprising a reflective structure between the light emitting unit and the functional substrate.   The light emitting diode according to any one of claims 5 to 9, wherein the side reflection portion includes a material of the functional substrate.   11. The light emitting diode according to claim 5, wherein the side reflecting portion includes any one of copper, aluminum, nickel, silver, and gold.   The light emitting diode according to claim 5, wherein the functional substrate includes any one of copper, aluminum, silver, molybdenum, tungsten, and gold.   The light emitting diode according to claim 5, wherein the functional substrate is a laminated substrate of copper and molybdenum.   The light emitting diode according to claim 5, wherein the light emitting layer includes any one of an AlGaInP layer, an AlGaAs layer, and a GaInN layer.   A light-emitting diode lamp comprising the light-emitting diode according to claim 5 and a package substrate on which the light-emitting diode is mounted.

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