JP6892909B2 - Light emitting element and light emitting element package - Google Patents

Description

The present invention relates to a light emitting element and a light emitting element package in which the light emitting element is covered with a package.

The semiconductor device described in Patent Document 1 below has a structure in which a semiconductor element is die-bonded to a mounting substrate with a die-bonding material. This semiconductor element is an LED and has a laminated structure in which an n-type GaN contact layer, a light emitting layer, a p-type AlGaN clad layer, and a p-type GaN contact layer are epitaxially grown on a crystal substrate which is a sapphire substrate. .. The back surface of the crystal substrate is metallized by a metal laminate including a reflective layer and a protective layer. Examples of the material of the reflective layer include Al and the like. When the light of the light emitting layer is directed to the back surface side of the crystal substrate, this light is reflected to the front surface side of the crystal substrate by the reflection layer.

Japanese Unexamined Patent Publication No. 2005-72148

In the light emitting element, improvement of brightness (high brightness), improvement of adhesion between adjacent layers, and improvement of heat dissipation for heat generated by light emission (high heat dissipation) are desired.
An object of the present invention is to provide a light emitting element and a light emitting element package capable of increasing brightness and improving adhesion.
Another object of the present invention is to provide a light emitting element and a light emitting element package capable of achieving high heat dissipation.

In the present invention, a sapphire substrate having a surface on the light extraction surface side and a back surface on the opposite side of the surface, a first conductive semiconductor layer laminated on the surface of the sapphire substrate, and the first conductive semiconductor layer. The light emitting layer laminated on the light emitting layer, the second conductive semiconductor layer laminated on the light emitting layer, and Ag are included and arranged on the back surface side of the sapphire substrate, and the light from the sapphire substrate is emitted from the sapphire substrate. A reflective layer that reflects toward the surface, an adhesive layer that is arranged between the sapphire substrate and the reflective layer, is made of ITO, and adheres to the reflective layer, and is arranged between the sapphire substrate and the adhesive layer. A conductive multilayer reflecting mirror in which the reflective layer is adhered by the adhesive layer, and is composed of two layers having a difference in refractive index alternately laminated to each other and have different thicknesses. It is a light emitting element including a conductive multilayer reflector having a first multilayer reflector, a second multilayer reflector, and a third multilayer reflector.

Further, in the present invention, the first periodic thickness, which is the layer thickness of the two layers layered one by one in the first multilayer reflecting mirror section, and the two layers in the second multilayer reflecting mirror section. The second period thickness, which is the layer thickness of one layer at a time, and the third period thickness, which is the layer thickness of one layer of the two types of layers in the third multilayer reflector, are different. It is characterized by. The present invention is also characterized in that the first multilayer reflector is 10% thicker than the second multilayer reflector and the second multilayer reflector is 10% thicker than the third multilayer reflector. And. Further, the present invention, the two layers, and having a SiO ₂ layer made of SiO _2, and TiO ₂ layers of TiO _2. Further, in the present invention, the SiO ₂ layer of the first multilayer reflector is thicker than _{the SiO 2 layer of the second multilayer reflector, and the TiO 2} layer of the first multilayer reflector is the second multilayer reflection. thicker than the TiO ₂ layer of the mirror portion, the second SiO ₂ layer of the multilayer reflection mirror portion is thicker than the SiO ₂ layer of the third multilayer reflection mirror portion, the TiO ₂ layer of the second multilayer reflection mirror portion is the It is characterized in that it is thicker than _{the TiO 2} layer of the third multilayer reflector. Further, the present invention is characterized in that the first multilayer reflector, the second multilayer reflector, and the third multilayer reflector are laminated in this order so as to be closer to the sapphire substrate. To do. Further, the present invention is characterized in that the side surface of the adhesive layer and the side surface of the sapphire substrate are flush with each other. Further, the present invention is characterized in that the side surfaces of the conductive multilayer reflector and the side surfaces of the adhesive layer and the sapphire substrate are flush with each other. Further, the present invention is characterized in that the reflective layer is smaller than the adhesive layer and the peripheral edge portion of the adhesive layer is exposed from the reflective layer side in a plan view seen from the thickness direction of the sapphire substrate. To do. Further, the present invention is characterized in that the back surface of the sapphire substrate is a rough surface. Further, the present invention is characterized in that the interface between the conductive multilayer reflecting mirror and the adhesive layer is a mirror surface. A light emitting element package including a light emitting element and a package containing the light emitting element.

FIG. 1 is a schematic plan view of a light emitting device according to an embodiment of the present invention. FIG. 2 is a schematic bottom view of the light emitting element of FIG. FIG. 3 is a schematic cross-sectional view of the light emitting element of FIG. 1, showing a cross section taken along the cutting line AA of FIG. FIG. 4 is a schematic cross-sectional view of a conductive multilayer reflector in a light emitting element. FIG. 5 is a graph showing the relationship between the brightness change rate in the light emitting element and the thickness (film thickness) of the adhesive layer. FIG. 6 is a graph showing the relationship between the incident angle and the reflectance in each of the light emitting element and the conductive multilayer reflector. FIG. 7 is a graph showing the relationship between wavelength and reflectance in a conductive multilayer reflector. FIG. 8 is a schematic cross-sectional view of the light emitting element package. FIG. 9 is a schematic cross-sectional view of the light emitting element according to the modified example. FIG. 10 is a schematic cross-sectional view of a light emitting element package to which the light emitting element according to the first comparative example is applied. FIG. 11 is a schematic cross-sectional view of the light emitting element according to the second comparative example. FIG. 12 is a graph showing the relationship between the current and the light output in the light emitting element. FIG. 13 is a graph showing the relationship between the energization time of the light emitting element and the junction temperature. FIG. 14 is a graph showing the relationship between the injection current and the junction temperature in the light emitting element.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic plan view of a light emitting element 1 according to an embodiment of the present invention. FIG. 2 is a schematic bottom view of the light emitting element 1 of FIG. FIG. 3 is a schematic cross-sectional view of the light emitting element 1 of FIG. 1, and shows a cross section taken along the cutting line AA of FIG.
As shown in FIGS. 1 and 2, for example, the light emitting element 1 has a rectangular chip shape in a plan view having a long side and a short side. The long side of the chip-shaped light emitting element 1 is 0.2 mm to 3.0 mm, and the short side is 0.1 mm to 2.0 mm.

With reference to FIG. 3, the light emitting element 1 is a light emitting element having a so-called two-wire structure. The light emitting element 1 includes a sapphire substrate 2 having a front surface 3 and a back surface 4, a first conductive semiconductor layer 6, a light emitting layer 7, and a second conductive semiconductor layer 8 laminated in this order on the surface 3 of the sapphire substrate 2. .. The laminate of the first conductive semiconductor layer 6, the light emitting layer 7, and the second conductive semiconductor layer 8 constitutes a rectangular parallelepiped semiconductor laminated structure portion 90. The longitudinal direction of the semiconductor laminated structure portion 90 and the longitudinal direction of the light emitting element 1 coincide with each other (see also FIG. 1). Further, in this embodiment, the front surface 3 (upper surface in FIG. 3) of the sapphire substrate 2 is on the light extraction surface side, and the back surface 4 (lower surface in FIG. 3) is on the opposite side of the surface 3. When the light emitting layer 7 emits light, most of the light passes through the second conductive semiconductor layer 8 and is taken out from the opposite side (upper side of FIG. 3) of the sapphire substrate 2 with respect to the light emitting layer 7.

The sapphire substrate 2 is made of sapphire, which is a material transparent to the emission wavelength (for example, 450 nm) of the light emitting layer 7. Specifically, "transparent with respect to the emission wavelength" means, for example, a case where the transmittance of the emission wavelength is 60% or more. The thickness of the sapphire substrate 2 is, for example, 200 μm to 300 μm. The above-mentioned "planar view" refers to a case where the sapphire substrate 2 is viewed from the thickness direction.

On the back surface 4 of the sapphire substrate 2, a conductive multilayer reflector 9, an adhesive layer 10, a reflective layer 11, a barrier metal 12, and a bonding metal 13 are laminated in this order as a configuration included in the light emitting element 1.
The conductive multilayer reflector 9 is formed on the entire back surface 4 of the sapphire substrate 2 so that the side surface (outer shell) 14 thereof is flush with the side surface 5 of the sapphire substrate 2. In the conductive multilayer reflector 9, the upper surface in FIG. 2 is the front surface 15 which is the bonding surface with the back surface 4 of the sapphire substrate 2, and the lower surface in FIG. 2 is the back surface 16 which is the bonding surface with the adhesive layer 10. .. That is, the conductive multilayer reflector 9 is arranged between the sapphire substrate 2 and the adhesive layer 10.

FIG. 4 is a schematic cross-sectional view of the conductive multilayer reflector 9 in the light emitting element 1.
In FIG. 4, the upper side of the conductive multilayer reflector 9 is the front surface 15 side (sapphire substrate 2 side), and the lower side of the conductive multilayer reflector 9 is the back surface 16 side (adhesive layer 10 side).
In the conductive multilayer reflector 9, the thickness of each of the two layers having a difference in refractive index is set to one quarter of the wavelength of the reflected light, and the two layers are alternately laminated. It is configured and has a high reflectance of 95% or more. As the two types of layers, two types having a large difference in refractive index are selected from the layers of _{SiO 2} , SiN, Al ₂ O ₃ , TIO ₂ , and Ta ₂ O _5. In this embodiment, a layer of the two, and the SiO ₂ layer 17 made of SiO _2, include the TiO ₂ layer 18 made of TiO _2. The refractive index of SiO ₂ is about 1.46, and the refractive index of _{TiO 2 is about 2.66. Here, the SiO 2} layer 17 is located on both the front surface 15 and the back surface 16 of the conductive multilayer reflector 9.

The conductive multilayer reflector 9 has a first multilayer reflector 91, a second multilayer reflector 92, and a third multilayer reflector 93 having different periodic structures (reflection band characteristics). Each of the first multilayer reflector section 91, the second multilayer reflector section 92, and the third multilayer reflector section 93 is a so-called DBR (Distributed Bragg Reflector). Instead of DBR, it may also be called a multilayer dielectric mirror structure.

Each of the first multilayer reflector section 91, the second multilayer reflector section 92, and the third multilayer reflector section 93 is configured by alternately stacking _{SiO 2} layer 17 and TiO _{2 layer 18.} In the DBR, each optical path length (= _{refractive index of SiO 2} or TiO _{2 x layer thickness T) of the SiO 2} layer 17 and the TiO ₂ layer 18 is 1/4 of the wavelength of the light to be reflected by each multilayer reflector. Is consistent with. Therefore, in each multi-layer reflecting mirror unit, each _{layer thickness T of the SiO 2} layer 17 and the TIO ₂ layer 18 has a refractive index of _{SiO 2} or TiO ₂ that is one-fourth of the wavelength of the light to be reflected by each multi-layer reflecting mirror unit. Obtained by dividing by.

The first multilayer reflective mirror 91, TiO ₂ layers 18 (first 1TiO ₂ layer having the SiO ₂ layer 17 (the first 1SiO ₂ layer 17A) the thickness of the second layer thickness T2 having a thickness of the first thickness T1 It is a laminated conductive film in which 18A) is alternately laminated for a plurality of cycles. The _{layer thickness of the first SiO 2} layer 17A and the 1st TiO ₂ layer 18A stacked one by one is referred to as the first period thickness S1 (= T1 + T2).

The second multilayer reflection mirror portion 92, TiO ₂ layers 18 (first 2TiO ₂ layer having the SiO ₂ layer 17 (the first 2SiO ₂ layer 17B) the thickness of the fourth layer thickness T4 having a thickness of the third layer thickness T3 It is a laminated conductive film in which 18B) and 18B) are alternately laminated for a plurality of cycles. The _{layer thickness of the second SiO 2} layer 17B and the _2nd TiO 2 layer 18B stacked one by one is referred to as the second period thickness S2 (= T3 + T4).

The third multilayer reflective mirror 93, TiO ₂ layers 18 (first 3TiO ₂ layer having the SiO ₂ layer 17 (the first 3SiO ₂ layer 17C) the thickness of the sixth layer thickness T6 having a thickness of 5 thickness T5 It is a laminated conductive film in which 18C) is alternately laminated for a plurality of cycles. The _{layer thickness of the third SiO 2} layer 17C and the 3rd TiO ₂ layer 18C stacked one by one is referred to as the third period thickness S3 (= T5 + T6).

In the conductive multilayer reflector 9, the first layer thickness T1, the second layer thickness T2, the third layer thickness T3, the fourth layer thickness T4, the fifth layer thickness T5, the sixth layer thickness T6, and the first layer thickness T6 are described above. The cycle thickness S1, the second cycle thickness S2, and the third cycle thickness S3 have regularity according to any one of the following patterns, for example.
First pattern: The first layer thickness T1, the third layer thickness T3, and the fifth layer thickness T5 are equal, and the second layer thickness T2, the fourth layer thickness T4, and the sixth layer thickness T6 are equal (that is, the first layer thickness T6). The cycle thickness S1, the second cycle thickness S2, and the third cycle thickness S3 are equal). In this case, the first multilayer reflecting mirror unit 91, the second multilayer reflecting unit 42, and the third multilayer reflecting unit 43 all have the same configuration.

Second pattern: The first layer thickness T1, the third layer thickness T3, and the fifth layer thickness T5 are different, the second layer thickness T2, the fourth layer thickness T4, and the sixth layer thickness T6 are different, and the first cycle thickness is different. S1 and the second cycle thickness S2 and the third cycle thickness S3 are different. In this embodiment, this second pattern is adopted, the first layer thickness T1> the third layer thickness T3> the fifth layer thickness T5, the second layer thickness T2> the fourth layer thickness T4> the sixth layer. The thickness is T6, and the first cycle thickness S1> the second cycle thickness S2> the third cycle thickness S3. Specifically, there is a difference of about 10% between the first layer thickness T1 and the third layer thickness T3, and a difference of about 10% between the third layer thickness T3 and the fifth layer thickness T5. Further, there is a difference of about 10% between the second layer thickness T2 and the fourth layer thickness T4, and a difference of about 10% between the fourth layer thickness T4 and the sixth layer thickness T6. Therefore, there is a difference of about 10% between the first cycle thickness S1 and the second cycle thickness S2, and a difference of about 10% between the second cycle thickness S2 and the third cycle thickness S3.

Third pattern: The first layer thickness T1, the third layer thickness T3, and the fifth layer thickness T5 are different, the second layer thickness T2, the fourth layer thickness T4, and the sixth layer thickness T6 are different, and the first cycle thickness S1 And the second cycle thickness S2 and the third cycle thickness S3 are equal. For example, the first layer thickness T1> the third layer thickness T3> the fifth layer thickness T5, the second layer thickness T2 <the fourth layer thickness T4 <the sixth layer thickness T6, and the first cycle thickness S1 = the second. This is the case where the periodic thickness S2 = the third periodic thickness S3.

In FIG. 4, the first multilayer reflector section 91, the second multilayer reflector section 92, and the third multilayer reflector section 93 are laminated in this order so as to be closer to the sapphire substrate 2, but the first multilayer reflection The order of stacking the mirror unit 91, the second multilayer reflector unit 92, and the third multilayer reflector unit 93 can be changed as appropriate. Further, the conductive multilayer reflector 9 in FIG. 4 had three multilayer reflecting mirror portions, that is, a first multilayer reflecting mirror portion 91, a second multilayer reflecting mirror portion 92, and a third multilayer reflecting mirror portion 93. The number of the multilayer reflecting mirror portions constituting the conductive multilayer reflecting mirror 9 can be arbitrarily set as long as it is a plurality (two or more).

In FIG. 3, the conductive multilayer reflector 9 _{schematically shows a state in which SiO 2} layer 17 and TiO ₂ layer 18 are alternately laminated by a striped pattern.
The adhesive layer 10 is formed on the entire back surface 16 of the conductive multilayer reflector 9. Therefore, in a plan view, the conductive multilayer reflector 9 and the adhesive layer 10 are formed in the same pattern that matches the back surface 16 of the conductive multilayer reflector 9, and the region of the conductive multilayer reflector 9 and the adhesive layer are formed. The 10 regions are in agreement.

As described above, the conductive multilayer reflector 9, the adhesive layer 10, the reflective layer 11, the barrier metal 12, and the bonded metal 13 are laminated in this order on the back surface 4 of the sapphire substrate 2. Therefore, the reflective layer 11 is laminated on the side opposite to the conductive multilayer reflector 9 (lower side in FIG. 3) with respect to the adhesive layer 10. The barrier metal 12 is laminated on the side opposite to the adhesive layer 10 (lower side in FIG. 3) with respect to the reflective layer 11. The bonding metal 13 is laminated on the side opposite to the reflective layer 11 (lower side in FIG. 3) with respect to the barrier metal 12. That is, the adhesive layer 10 is arranged between the sapphire substrate 2 and the reflective layer 11. Further, the reflective layer 11 is arranged on the back surface 4 side of the sapphire substrate 2. Further, the barrier metal 12 and the bonding metal 13 are arranged on the side opposite to the adhesive layer 10 with respect to the reflective layer 11. Further, the barrier metal 12 is arranged between the reflective layer 11 and the bonding metal 13.

The adhesive layer 10 is made of ITO (indium tin oxide), which is a material transparent to the emission wavelength of the light emitting layer 7. The adhesive layer 10 is adhered to the reflective layer 11 and the reflective layer 11 is adhered to the conductive multilayer reflecting mirror 9. Further, there is a correlation between the thickness of the adhesive layer 10 and the brightness of the light emitting element 1. When the luminance change rate is used instead of the luminance in the light emitting element 1 with reference to FIG. 5, the higher the luminance is, the closer the luminance change rate is to 100%. Then, as the thickness (film thickness) of the adhesive layer 10 is increased, the rate of change in brightness decreases. The thickness of the adhesive layer 10 is preferably 20 nm or less, and more preferably 10 nm or less so that the brightness change rate is close to 100%. Returning to FIG. 3, as described in the method of manufacturing the light emitting element 1 described later, the configuration on the front surface 3 side of the sapphire substrate 2 (semiconductor laminated structure portion 90, etc.) is formed, and then the configuration on the back surface 4 side of the sapphire substrate 2 is formed. For the convenience of making, the adhesive layer 10 cannot be formed at a temperature higher than a predetermined value in order to prevent heat damage to the structure on the surface 3 side. Therefore, the adhesive layer 10 is not sufficiently transparent, but since the thickness is as thin as 20 nm or less, it is difficult to absorb light, and the adhesive layer 10 has almost no effect on the brightness. Further, in order not to affect the reflectance of the conductive multilayer reflector 9, the interface between the conductive multilayer reflector 9 and the adhesive layer 10 is preferably a mirror surface rather than a rough surface.

The reflective layer 11 is made of a material containing Ag. The reflective layer 11 of this embodiment is made of an alloy containing Ag, Pd, and Cu (AdPdCu alloy), but may be an AdPtCu alloy using Pt instead of Pd. In the case of the AdPdCu alloy, the compounding ratio of each metal is preferably about 99% for Ag, 0.6% for Pd, and 0.2% for Cu. By containing Pd and Cu in this ratio, sulfurization that is likely to occur in Ag alone can be suppressed. In a plan view, the reflective layer 11 is smaller than the adhesive layer 10 and is located inside the region of the adhesive layer 10. Therefore, the peripheral edge portion 10A of the adhesive layer 10 is exposed from the reflective layer 11 side (see also FIG. 2). The thickness of the reflective layer 11 is about 100 nm.

The barrier metal 12 is formed by laminating a layer of TiW alloy (titanium / tungsten alloy) and a layer of Pt in this order from the reflection layer 11 side.
The bonding metal 13 is made of a material containing Au. The bonded metal 13 of this embodiment is made of an AuSn alloy. As described above, the barrier metal 12 composed of the TiW alloy layer and the Pt layer has a higher melting point than the bonded metal 13. That is, since the barrier metal 12 having a melting point higher than that of the bonding metal 13 is interposed between the reflective layer 11 (AgPdCu alloy) and the bonding metal 13 (AuSn alloy), the component (Sn) of the bonding metal 13 is present. Diffusion to the reflective layer 11 can be satisfactorily suppressed. The thickness of the bonded metal 13 is about 2 μm.

Each of the barrier metal 12 and the bonding metal 13 is formed in the same pattern as the reflective layer 11 in a plan view.
On the other hand, on the surface 3 of the sapphire substrate 2, a plurality of convex portions 35 projecting toward the first conductive semiconductor layer 6 are formed. These convex portions 35 are discretely arranged on the surface 3 of the sapphire substrate 2 so that adjacent objects are spaced apart from each other. The arrangement form of the entire plurality of convex portions 35 may be, for example, a matrix shape or a staggered shape. Each convex portion 35 is made of SiN (silicon nitride). Since the convex portion 35 made of SiN is formed on the surface 3 of the sapphire substrate 2, it is reflected by the reflection layer 11 and is incident on the interface between the sapphire substrate 2 and the first conductive semiconductor layer 6 at various angles. It is possible to suppress the total reflection of the light to be reflected on the reflection layer 11 side at the interface. As a result, the light extraction efficiency can be improved.

The first conductive semiconductor layer 6 is laminated on the surface 3 of the sapphire substrate 2. The first conductive semiconductor layer 6 covers the entire surface 3 of the sapphire substrate 2. The first conductive semiconductor layer 6 is made of an n-type nitride semiconductor (for example, GaN) and is transparent to the emission wavelength of the light emitting layer 7.
Regarding the first conductive semiconductor layer 6, in FIG. 3, the lower surface covering the front surface 3 of the sapphire substrate 2 is referred to as the back surface 61, and the upper surface opposite to the back surface 61 is referred to as the front surface 62. The front surface 62 has a first region 19 that is one step lower toward the back surface 61 side and a second region 20 that is higher than the first region 19.

Assuming that the first conductive semiconductor layer 6 in the first region 19 is referred to as a drawer portion 21 drawn from the semiconductor laminated structure portion 90, the side surface 22 of the drawer portion 21 is flush with the side surface 5 of the sapphire substrate 2. It is pulled out to the position where it is aligned with. With reference to FIG. 1, the lead-out portion 21 (see the hatched portion in FIG. 1) crosses the annular outer peripheral portion 23 surrounding the semiconductor laminated structure portion 90 and the semiconductor laminated structure portion 90 from the outer peripheral portion 23. It includes a straight portion 24 extending linearly in the direction.

The straight portion 24 of the lead-out portion 21 includes a pad space 25 (for example, a circular space) arranged on the peripheral edge of the semiconductor laminated structure portion 90 and a wiring space 26 extending linearly along the longitudinal direction of the light emitting element 1. including. In this embodiment, the pad space 25 is arranged at one end in the longitudinal direction of the light emitting element 1 (the right end in FIG. 1), and the wiring space 26 is located on the opposite side of the pad space 25 in the longitudinal direction from the pad space 25 (FIG. 1). It extends to the left side in 1).

The first electrode 27 is formed in contact with the surface of the drawer portion 21. The first electrode 27 includes a first metal wiring 28 laid on the lead-out portion 21, and a first pad 29 formed on the first metal wiring 28 in the pad space 25.
The first metal wiring 28 is made of, for example, Al or Cr. In this embodiment, the first metal wiring 28 is formed by forming Al so as to be in contact with the drawing portion 21 (first conductive semiconductor layer 6) and forming Cr on the Al. The thickness of the first metal wiring 28 is, for example, about 1000 nm.

In this embodiment, the first metal wiring 28 has an outer peripheral portion 23 along the short side (the short side on the right side in FIG. 1) of the straight portion 24 of the lead-out portion 21 and the semiconductor laminated structure portion 90 on the side close to the pad space 25. The first metal wiring 28 forms a contact of the first electrode 27 with respect to the first conductive semiconductor layer 6. Further, the first metal wiring 28 is formed in the pad space 25 in a disk shape having a width slightly smaller than the width of the pad space 25, and the straight portion 24 (that is, the wiring space 26) other than the pad space 25 and The outer peripheral portion 23 is formed in a fine line shape.

With reference to FIG. 3, the first pad 29 is formed in a columnar shape (in this embodiment, a columnar shape, see FIG. 1) protruding above the second conductive semiconductor layer 8 from the pad space 25. The thickness is, for example, about 1000 nm. The first pad 29 is made of, for example, Ag, solder or AuSn alloy.
With respect to the first electrode 27, the first metal wiring 28 crosses the reflective layer 11 in the longitudinal direction (of the light emitting element 1) in a plan view and faces the reflective layer 11 in the thickness direction of the sapphire substrate 2. .. However, since the first metal wiring 28 is formed in a thin line shape (see FIG. 1), the influence on the extraction efficiency of the light reflected by the reflection layer 11 can be small. On the other hand, the first pad 29, which is wider than the first metal wiring 28, also faces the reflective layer 11, but since the first pad 29 faces only the peripheral edge of the reflective layer 11, the first pad 29 faces the reflective layer 11. Similar to the metal wiring 28, the effect on the extraction efficiency of the light reflected by the reflective layer 11 is small.

The light emitting layer 7 is laminated on the first conductive semiconductor layer 6. The light emitting layer 7 covers the entire second region 20 on the surface 3 of the first conductive semiconductor layer 6. In this embodiment, the light emitting layer 7 is made of a nitride semiconductor containing In (for example, InGaN).
The second conductive semiconductor layer 8 is laminated on the light emitting layer 7 in the same pattern as the light emitting layer 7. Therefore, in a plan view, the region of the second conductive semiconductor layer 8 coincides with the region of the light emitting layer 7. The second conductive semiconductor layer 8 is made of a p-type nitride semiconductor (for example, GaN) and is transparent to the emission wavelength of the light emitting layer 7. As described above, the light emitting diode structure (semiconductor laminated structure portion 90) in which the light emitting layer 7 is sandwiched between the first conductive semiconductor layer 6 which is an n-type semiconductor layer and the second conductive semiconductor layer 8 which is a p-type semiconductor layer is formed. It is formed.

A transparent electrode layer 30 is formed on the surface of the second conductive semiconductor layer 8, and the transparent electrode layer 30 forms a contact of the second electrode 31 (described later) with respect to the second conductive semiconductor layer 8. There is. The transparent electrode layer 30 is made of, for example, a material (for example, ITO, ZnO) that is transparent to the emission wavelength of the light emitting layer 7. The thickness of the transparent electrode layer 30 is, for example, about 100 nm.

A second electrode 31 is formed on the surface 34 of the transparent electrode layer 30. The second electrode 31 is made of, for example, Ag, solder or AuSn alloy. With reference to FIG. 1, the second electrode 31 has a second pad 32 arranged on the peripheral edge of the semiconductor laminated structure portion 90 and a second metal extending from the second pad 32 along the side surface of the semiconductor laminated structure portion 90. The wiring 33 is integrally included.
In this embodiment, the second pad 32 is arranged on the opposite side (left side in FIG. 1) of the first pad 29 in the longitudinal direction of the semiconductor laminated structure portion 90, and is a part of the second metal wiring 33 (semiconductor laminated structure portion). The portion along the side surface of the 90) extends parallel to the first metal wiring 28 on the straight line portion 24 in a plan view. In particular, the second metal wiring 33 is provided on one side and the other side of the first metal wiring 28 so as to sandwich the first metal wiring 28 on the straight line portion 24, and each of the second metal wires 33 is provided. The wiring 33 is integrally connected to the end portion (left end portion in FIG. 1) of the second pad 32 on the side far from the first pad 29.

Regarding the second electrode 31, since the second metal wiring 33 is laid in the vicinity of the outside of the reflection layer 11 so as to avoid the reflection layer 11 in a plan view, the influence on the extraction efficiency of the light reflected by the reflection layer 11 There is almost no. On the other hand, the second pad 32 faces the reflective layer 11, and the second pad 32 is arranged on the opposite side of the first pad 29 in the longitudinal direction of the semiconductor laminated structure portion 90, and is the peripheral edge of the reflective layer 11. It faces only the part. Therefore, as with the first pad 29, the effect on the extraction efficiency of the light reflected by the reflective layer 11 is small.

In this light emitting element 1, when a forward voltage is applied between the second electrode 31 (second pad 32) and the first electrode 27 (first pad 29) with reference to FIG. 3, the second electrode 31 is used. A current flows toward the first electrode 27. The current flows from the second electrode 31 toward the first electrode 27 through the transparent electrode layer 30, the second conductive semiconductor layer 8, the light emitting layer 7, and the first conductive semiconductor layer 6 in this order. As a result of the current flowing in this way, electrons are injected from the first conductive semiconductor layer 6 into the light emitting layer 7, and holes are injected from the second conductive semiconductor layer 8 into the light emitting layer 7, and these holes and electrons are injected. Is recombined in the light emitting layer 7 to generate blue light having a wavelength of 440 nm to 460 nm from the light emitting layer 7. This light passes through the second conductive semiconductor layer 8 and the transparent electrode layer 30, and is taken out from the surface 34 (light extraction surface) of the transparent electrode layer 30.

The light directed from the light emitting layer 7 toward the first conductive semiconductor layer 6 passes through the first conductive semiconductor layer 6 and the sapphire substrate 2 in this order. Then, this light is emitted from the interface between the sapphire substrate 2 and the conductive multilayer reflecting mirror 9 and the interface between the SiO ₂ layer 17 and the TiO ₂ layer 18 in the conductive multilayer reflecting mirror 9 (with the first multilayer reflecting mirror unit 91). Reflection occurs at the interface between the second multilayer reflector section 92 and the interface between the second multilayer reflector section 92 and the third multilayer reflector section 93 (see FIG. 4). The reflected light passes through the sapphire substrate 2, the first conductive semiconductor layer 6, the light emitting layer 7, the second conductive semiconductor layer 8 and the transparent electrode layer 30 in this order, and is taken out from the surface 34. Further, the light transmitted through the conductive multilayer reflector 9 is transmitted through the adhesive layer 10 and reflected at the interface between the adhesive layer 10 and the reflective layer 11. The reflected light is transmitted in this order through the adhesive layer 10, the conductive multilayer reflector 9, the sapphire substrate 2, the first conductive semiconductor layer 6, the light emitting layer 7, the second conductive semiconductor layer 8, and the transparent electrode layer 30. And is taken out from the surface 34. In this way, each of the conductive multilayer reflector 9 and the reflective layer 11 reflects the light from the sapphire substrate 2 toward the surface 3 on the light extraction surface (surface 34 of the transparent electrode layer 30) side of the sapphire substrate 2. ..

Here, the current flows from the second electrode 31 toward the first electrode 27 through the transparent electrode layer 30, the second conductive semiconductor layer 8, the light emitting layer 7, and the first conductive semiconductor layer 6, but the sapphire substrate 2 It is not necessary to flow through the reflective layer 11 on the back surface 4 side of the above. Therefore, when forming the reflective layer 11, the heat treatment for alloying the reflective layer 11 is not required, and the reflectance of the reflective layer 11 is high. Further, in the reflective layer 11, since Pd and Cu are added to Ag instead of Ag alone, the decrease in reflectance in the reflective layer 11 due to the contact between the reflective layer 11 and the adhesive layer 10 is suppressed. ing.

The light emitting element 1 has a conductive multilayer reflecting mirror 9 composed of a DBR as described above. As a feature of the DBR, the reflectance of light L close to vertical incidence is high, but when the incident angle θ (see FIG. 3) becomes large and reaches a predetermined critical angle, the reflectance sharply decreases. In FIG. 6, the relationship between the incident angle θ and the reflectance is shown, and the DBR of the conventional structure is shown by a broken line. In the DBR having the conventional structure, the critical angle is about 35 degrees.

In order to increase the reflectance, it is necessary to increase the maximum reflectance (reflectance in the incident angle range below the critical angle) and to widen the wavelength band of light that can be reflected (corresponding wavelength band). Is.
In the conductive multilayer reflector 9, in order to increase the maximum reflectance, the number of times light is reflected in the conductive multilayer reflector 9 is increased, and therefore, the SiO ₂ layer 17 and the TiO ₂ layer 18 ( The number (number of layers) (see FIG. 4) is increasing. Specifically, the total number of layers of the conductive multilayer reflector 9 is 29 layers (= _{14 pairs of SiO 2} layer 17 and TiO ₂ layer 18 + 14 pairs of the front surface 15 or the back surface 16 of the conductive multilayer reflector 9). SiO ₂ layer 17 is 1 layer).

In the conductive multilayer reflector 9, as described above, in order to widen the wavelength band, a plurality of multilayer reflectors (this embodiment) in which the individual thicknesses _{of the SiO 2} layer 17 and the TiO _{2 layer 18 and the overall thickness are different.} , The first multilayer reflector section 91, the second multilayer reflector section 92, and the third multilayer reflector section 93) are adopted. Ideally, the total number of layers of each of the first multilayer reflector section 91, the second multilayer reflector section 92, and the third multilayer reflector section 93 is preferably the above-mentioned 29 layers, but in this embodiment, it is preferable. , 29 layers are divided into three by a first multilayer reflector section 91, a second multilayer reflector section 92, and a third multilayer reflector section 93. In this way, for example, the first multilayer reflector unit 91 can reflect light in the long wavelength region, the second multilayer reflector unit 92 can reflect light in the middle wavelength region, and the third multilayer reflector unit 93 can reflect light in the middle wavelength region. It can reflect light in the short wavelength range.

FIG. 7 shows the relationship between the wavelength of light and the reflectance of the conductive multilayer reflector 9. _{The thickness of each of the SiO 2} layer 17 and the TiO ₂ layer 18 is constant in the conductive multilayer reflector 9 (the first multilayer reflector 91, the second multilayer reflector 92, and the third multilayer reflector 93). Is the same configuration), it is shown by a dotted line, and the wavelength band is in the range of about 410 nm to 520 nm. As in this embodiment, in the first multilayer reflector section 91, the second multilayer reflector section 92, and the third multilayer reflector section 93, _{the thickness of each of the SiO 2} layer 17 and the TiO ₂ layer 18 is about 10%. When it is changed in increments (when the thickness of the other multi-layer reflector is changed by ± about 10% with reference to the second multi-layer reflector 92), it is indicated by a single point chain line, and the wavelength band is It extends to the range of about 400 nm to 550 nm. _{On the other hand, when the thicknesses of the SiO 2} layer 17 and the TiO ₂ layer 18 are varied by about 20% in the 1st multilayer reflector section 91, the 2nd multilayer reflector section 92, and the 3rd multilayer reflector section 93. (When the thickness of the other multilayer reflector is changed by ± about 20% with reference to the second multilayer reflector 92), as shown by the solid line, the wavelength band is widened, but the reflectance is 500 nm. It is not stable because it is locally reduced in the range of ~ 520 nm. Therefore, in this embodiment, the total number of layers of the conductive multilayer reflector 9 is 29, and the first multilayer reflector 91, the second multilayer reflector 92, and the third multilayer reflector 93 have SiO ₂ The thickness of each of the layer 17 and the TiO ₂ layer 18 is varied by about 10%.

By adopting such a conductive multilayer reflector 9, the critical angle becomes larger from about 35 degrees to about 50 degrees as compared with the DBR having the conventional structure, as shown by the alternate long and short dash line with reference to FIG. (See the white arrow in FIG. 6). That is, the conductive multilayer reflector 9 can further increase the reflectance and can also reflect light in a wider band.
In FIG. 6, the alternate long and short dash line indicates the reflectance of the reflective layer 11, and the reflectance of the reflective layer 11 is constant at about 90% over the entire incident angle θ. Then, in FIG. 6, the solid line shows the reflectance of the entire light emitting element 1, and this reflectance is the higher of the conductive multilayer reflector 9 and the reflecting layer 11 for each region of the incident angle θ. It is a combination of reflectance lines (either the one-point chain line or the two-point chain line described above). That is, at an incident angle θ up to a critical angle of 50 degrees, the conductive multilayer reflector 9 exhibits higher reflectance than the reflective layer 11, and at an incident angle θ exceeding a critical angle of 50 degrees, the reflective layer 11 exhibits a higher reflectance than the reflective layer 11. It exhibits a higher reflectance than the conductive multilayer reflector 9.

Strictly speaking, the solid line showing the reflectance of the entire light emitting element 1 should overlap with the corresponding portion of the alternate long and short dash line, but for convenience of explanation, the alternate long and short dash line is shown in FIG. And is shown away from the alternate long and short dash line.
Next, an example of a method for manufacturing the light emitting element 1 will be described.
In order to manufacture the light emitting element 1 shown in FIG. 3, for example, a layer made of SiN (SiN layer) is formed on the surface of a substrate wafer (for example, a wafer having a thickness of 600 μm to 1000 μm), and a resist pattern (not shown) is formed. ) Is used as a mask to separate the SiN layer into a plurality of convex portions 35. Next, the semiconductor laminated structure portion 90 is formed by epitaxially growing the first conductive semiconductor layer 6, the light emitting layer 7, and the second conductive semiconductor layer 8 on the surface of the substrate wafer so as to cover these convex portions 35. To form. Next, for example, the transparent electrode layer 30 is formed by depositing the material (ITO or the like) of the transparent electrode layer 30 on the semiconductor laminated structure 90 by a sputtering method.

Next, the transparent electrode layer 30 and the semiconductor laminated structure 90 are etched through a mask having a predetermined shape. As a result, the semiconductor laminated structure portion 90 is formed into a predetermined shape (rectangular in plan view), and at the same time, a drawer portion 21 formed of an extension portion of the first conductive type semiconductor layer 6 is formed.
Next, the first electrode 27 is formed on the lead-out portion 21 (first conductive semiconductor layer 6), and the second electrode 31 is formed on the transparent electrode layer 30.

Then, with the front surface side of the substrate wafer protected, the substrate wafer is ground from the back surface to a thickness of 200 μm to 300 μm.
_{Next, the SiO 2} layer 17 and the TiO ₂ layer 18 are alternately laminated on the back surface of the substrate wafer according to the second pattern described above to form the conductive multilayer reflector 9.
Next, the adhesive layer 10 is formed over the entire back surface 16 of the conductive multilayer reflector 9. Then, for example, the material of the reflective layer 11 (AgPdCu alloy or the like) is deposited on the entire back surface 16 of the adhesive layer 10 by a sputtering method to form the reflective layer 11.

Next, a resist pattern (not shown) covering only a region having a predetermined width on the planned cutting line of the substrate wafer in the reflective layer 11 is formed on the back surface of the reflective layer 11, and the barrier metal 12 is formed through the resist pattern. The material (TiW alloy or the like) and the material of the bonding metal 13 (AuSn alloy or the like) are deposited in this order. Then, the unnecessary portion of the material of the barrier metal 12 and the bonding metal 13 (the portion deposited on the resist pattern) is lifted off together with the resist pattern. Then, the barrier metal 12 and the bonding metal 13 are formed so as to selectively expose a part of the reflective layer 11 along the planned cutting line. Next, for example, the reflective layer 11 exposed from the barrier metal 12 and the bonded metal 13 is removed (etched off) by dry etching. As a result, the peripheral edge portion 10A of the adhesive layer 10 is selectively exposed along the planned cutting line.

Next, the laser beam is scanned from the back surface side of the substrate wafer using a laser processing machine. As a result, a split guide groove that penetrates the adhesive layer 10 and reaches the middle of the substrate wafer is formed. After that, by applying an external force to the substrate wafer, the substrate wafer is divided into individual pieces (chips) of each light emitting element 1 with the division guide groove as a boundary. As a result, the individual piece of the light emitting element 1 of FIG. 3 is obtained.

Alternatively, the substrate wafer is cut (diced) along the planned cutting line using a laser scriber or the like without exposing the peripheral edge portion 10A of the adhesive layer 10, and the substrate wafer is cut into individual pieces of each light emitting element 1. It may be divided. In that case, unlike the configuration in which the peripheral edge portion 10A of the adhesive layer 10 in FIG. 3 is exposed, the adhesive layer 10, the reflective layer 11, the barrier metal 12, and the bonded metal 13 have the same pattern in a plan view.

FIG. 8 is a schematic cross-sectional view of the light emitting element package 51.
The light emitting element package 51 includes a light emitting element 1, a support substrate 52, and a package 53. The support substrate 52 may be regarded as a part of the package 53.
The light emitting element 1 is arranged on the support substrate 52 by joining the bonding metal 13 to the support substrate 52. At this time, the light emitting element 1 is in a face-up posture so that the surface 3 of the sapphire substrate 2 faces upward.

The support substrate 52 is provided so as to be exposed from both ends of the insulating substrate 54 that supports the light emitting element 1 and both ends of the insulating substrate 54, and a pair of metal electrodes (the first) that electrically connect the light emitting element 1 and the outside. It has one external electrode 55 and a second external electrode 56).
Then, the first electrode 27 (first pad 29) of the light emitting element 1 and the first external electrode 55 are connected by the first wire 57. Further, the second electrode 31 (second pad 32) of the light emitting element 1 and the second external electrode 56 are connected by a second wire 58.

The package 53 is a case filled with resin, and is fixed to the support substrate 52 in a state in which the light emitting element 1 is housed (covered) and protected. In the light emitting element 1 in this state, the surface 3 side of the sapphire substrate 2 is exposed. The package 53 has a reflecting portion 59 made of, for example, Ag plating on the side surface (a portion facing the light emitting element 1), and the light emitted from the light emitting element 1 is reflected by the reflecting portion 59 and taken out to the outside.

Some of the resins constituting the package 53 contain a phosphor or a reflective agent. For example, when the light emitting element 1 emits blue light, the light emitting element package 51 can emit white light by containing a yellow phosphor in the resin. The light emitting element package 51 can be used for lighting equipment such as a light bulb by gathering a large number of them, and can also be used for a backlight of a liquid crystal television or a headlamp of an automobile or the like.

Further, as shown in FIG. 9, a light emitting element 70 having a configuration in which the conductive multilayer reflector 9 is omitted in the above-mentioned light emitting element 1 can also be adopted. In the light emitting element 70, the same reference numerals are given to the parts corresponding to the parts described in the above-mentioned light emitting element 1, and detailed description of the parts will be omitted.
In the light emitting element 70, only the adhesive layer 10 exists between the reflective layer 11 and the sapphire substrate 2, and the adhesive layer 10 adheres the reflective layer 11 to the back surface 4 of the sapphire substrate 2. Further, in order to improve the adhesiveness between the sapphire substrate 2 and the adhesive layer 10, the interface between the sapphire substrate 2 and the adhesive layer 10 is preferably a rough surface. The manufacturing method of the light emitting element 70 omits the manufacturing step of the conductive multilayer reflector 9 from the manufacturing method of the light emitting element 1 described above. Further, the above-mentioned light emitting element package 51 (see FIG. 8) may include the light emitting element 70, the support substrate 52, and the package 53.

In the above light emitting elements 1 and 70, the light from the light emitting layer 7 is immediately emitted from the front surface 3 of the sapphire substrate 2, or once passes through the adhesive layer 10 toward the back surface 4 side of the sapphire substrate 2 and is transmitted to the reflective layer 11. After being reflected by, it is emitted from the surface 3 of the sapphire substrate 2.
Since the reflective layer 11 contains Ag having a higher reflectance than Al, the reflectance of the reflective layer 11 can be improved, and the brightness of the light emitting element 1 can be increased accordingly. On the other hand, by interposing an adhesive layer 10 made of ITO between the reflective layer 11 containing Ag and the sapphire substrate 2, the adhesion between the reflective layer 11 and the sapphire substrate 2 can be improved.

Since the thickness of the adhesive layer 10 is as thin as 20 nm or less, the light transmission in the adhesive layer 10 can be improved, so that a large amount of light can be reflected in the reflective layer 11. Therefore, the brightness of the light emitting element 1 can be increased.
Further, even if the light emitting element 1 generates heat due to the light emission of the light emitting layer 7, the bonded metal 13 containing Au having a high thermal conductivity can effectively dissipate heat (to the package 53 side). That is, it is possible to increase the heat dissipation of the light emitting element 1.

Further, in the case of the light emitting element 1 shown in FIG. 3, since the conductive multilayer reflecting mirror 9 is also present in addition to the reflecting layer 11 as a configuration for reflecting light, as compared with the case where only the reflecting layer 11 is present, compared with the case where only the reflecting layer 11 is present. The reflectance of light can be improved, and the brightness of the light emitting element 1 can be further increased accordingly. Further, the adhesive layer 10 improves the adhesion between the conductive multilayer reflector 9 and the reflective layer 11.

Further, in the case of the light emitting element 70 shown in FIG. 9, since the adhesive layer 10 adheres the reflective layer 11 to the back surface 4 of the sapphire substrate 2, the adhesion between the reflective layer 11 and the sapphire substrate 2 is improved. Can be done.
In order to demonstrate the effects on the brightness, heat dissipation, etc. of the light emitting elements 1,70, the light emitting elements 1,70 and the light emitting elements 80, 81 according to the comparative example were manufactured. In the light emitting elements 80 and 81, the parts corresponding to the parts described in the light emitting elements 1 and 70 are designated by the same reference numerals, and detailed description of the parts will be omitted.

With reference to FIG. 10, the light emitting element 80 according to the first comparative example omits all of the conductive multilayer reflector 9, the adhesive layer 10, the reflective layer 11, the barrier metal 12 and the bonding metal 13 from the light emitting elements 1 and 70. (See FIGS. 3 and 9). Therefore, in the light emitting element 80 alone, nothing is formed on the back surface 4 of the sapphire substrate 2. The light emitting element 80 is bonded to the support substrate 52 of the package 53 by a paste agent 82 such as an epoxy resin applied to the back surface 4 of the sapphire substrate 2. In the case of the light emitting element 80, when the light emitting layer 7 emits light, the light is not reflected in the light emitting element 80 even if it passes through the sapphire substrate 2, but is reflected by the reflecting portion 59 of the package 53.

With reference to FIG. 11, the light emitting element 81 according to the second comparative example omits all of the conductive multilayer reflecting mirror 9, the adhesive layer 10 and the reflecting layer 11 from the light emitting elements 1, 70, and instead reflects a reflection made of Al. It is a configuration in which the layer 83 is adopted (see FIGS. 3 and 9). Therefore, in the light emitting element 81, the reflective layer 83, the barrier metal 12, and the bonding metal 13 are laminated in this order on the back surface 4 of the sapphire substrate 2. The thickness of the reflective layer 83 is, for example, about 100 nm. The reflectance of the reflective layer 83 made of Al is inferior to that of the reflective layer 11 (including Ag) of the light emitting elements 1,70. In the case of the light emitting element 81, when the light emitting layer 7 emits light, the light directed to the sapphire substrate 2 side is transmitted through the sapphire substrate 2 and then reflected at the interface between the sapphire substrate 2 and the reflective layer 83.

The specific value of the reflectance for light having a wavelength of 450 nm is 93% in the light emitting element 80 thanks to the reflecting portion 59 (Ag plating) of the package 53 (see FIG. 10). On the other hand, in the light emitting element 81 having the reflecting layer 83 made of Al, the reflectance in the case of the element alone is 86%. Further, in the light emitting element 70 (see FIG. 9) having the reflective layer 11 made of AgPdCu, the reflectance of the element alone is 91%. Further, in the light emitting element 1 (see FIG. 3) having the conductive multilayer reflecting mirror 9 in addition to the reflecting layer 11, the reflectance of the element alone is the highest at 95%.

FIG. 12 shows the relationship between the current and the light output (indicating the brightness as an index) in each light emitting element when a current is passed through each of the light emitting elements 1, 70, 80, and 81. It can be seen that the light output of the light emitting element 1 (solid line portion) and the light emitting element 70 (one-dot chain line portion) is improved as compared with the light emitting element 80 (broken line portion) having no configuration for reflecting light. .. In particular, the light emitting element 1 having a configuration in which the conductive multilayer reflector 9 is added to the light emitting element 70 has the highest light output, which is about 4% higher than that of the light emitting element 80 (see the white arrow). The light output of the light emitting element 81 (two-point chain line portion) having the reflecting layer 83 having a reflectance lower than that of the light emitting layer 7 of the light emitting elements 1 and 70 is lower than that of the light emitting element 80 (broken line portion).

Regarding the actual luminance characteristics, assuming that the light output of the light emitting element 80 is 1.00, the light output of the light emitting element 81 is inferior to 0.91, the light emitting element 70 is 1.00, and the light emitting element 1 is 1.04. Is the highest.
FIG. 13 shows the relationship between the energization time and the junction temperature (temperature in the light emitting element) when a predetermined current (for example, 100 mA) is continuously injected. The lower the junction temperature, the better the heat dissipation. The light emitting elements 1, 70, 81 (round dots) having the bonded metal 13 have a lower junction temperature (up to about 20 degrees, and are outlined) than the light emitting elements 80 (triangular dots) not provided with the bonded metal 13. (See arrow), good heat dissipation. In the light emitting element 80, heat tends to be trapped, so that the above-mentioned paste agent 82 (see FIG. 10) is deteriorated by heat and tends to become cloudy, which may further reduce the reflectance.

Further, FIG. 14 shows the relationship between the injection current and the junction temperature when the injection current is increased. Since the light emitting elements 1, 70, 81 (round dots) having the bonded metal 13 have good heat dissipation, the light emitting elements 80 (triangular dots) not provided with the bonded metal 13 by the time they reach a predetermined junction temperature. ) Can inject about twice as high current. Specifically, the heat dissipation of the light emitting element 80 not provided with the bonded metal 13 is 51 ° C./W, whereas the heat dissipation of the light emitting elements 1, 70, 81 having the bonded metal 13 is as good as 14 ° C./W. Is.

Further, when the bonded metal 13 is used, the adhesion between the light emitting elements 1, 70, 81 and the package 53 (support substrate 52) is sufficiently secured to withstand a force of 500 gf or more.
Although the embodiments of the present invention have been described above, the present invention can also be implemented in other embodiments.

For example, in the light emitting element package 51 shown in FIG. 8, the light emitting element 1 has the bonding metal 13, but the support substrate 52 of the package 53 may have the bonding metal 13. In this case, in the light emitting element 1, the reflective layer 11 is bonded to the bonding metal 13 on the package 53 side. Also in this case, the barrier metal 12 described above is arranged between the reflective layer 11 and the bonded metal 13 in order to prevent the component (Sn) of the bonded metal 13 from diffusing into the reflective layer 11. Is preferable. Further, the package 53 has not only the bonding metal 13 but also the barrier metal 12, and the reflective layer 11 of the light emitting element 1 is bonded to the barrier metal 12 laminated on the bonding metal 13 on the package 53 side. You may.

Further, in the light emitting element 1 described above, the conductive multilayer reflector 9, the adhesive layer 10, the reflective layer 11, the barrier metal 12, and the bonding metal 13 are laminated in this order on the back surface 4 of the sapphire substrate 2. .. That is, although the reflective layer 11 is adhered to the conductive multilayer reflecting mirror 9 on the sapphire substrate 2 side by the adhesive layer 10, the adhesive layer 10 may be omitted. In that case, the conductive multilayer reflector 9 also functions as an adhesive layer and adheres the reflective layer 11 to the sapphire substrate 2.

Further, in the above-described embodiment, the example in which the first conductive type is the n type and the second conductive type is the p type has been described, but the first conductive type is the p type and the second conductive type is the n type. May be configured. That is, in the above-described embodiment, the structure in which the conductive type is inverted between the p-type and the n-type is also one embodiment of the present invention. Further, in the above-described embodiment, GaN has been exemplified as the nitride semiconductor constituting the first conductive semiconductor layer and the second conductive semiconductor layer, but other nitrides such as aluminum nitride (AlN) and indium nitride (InN) have been exemplified. A physical semiconductor may be used. Nitride semiconductors can generally be represented as Al _x In _y Ga _1-xy N (0 ≦ x ≦ 1,0 ≦ y ≦ 1,0 ≦ x + y ≦ 1). Further, the present invention may be applied not only to nitride semiconductors but also to other compound semiconductors such as GaAs and light emitting devices using semiconductor materials (for example, diamond) other than compound semiconductors.

In addition, various design changes can be made within the scope of the matters described in the claims.

1 Light emitting element 2 Sapphire substrate 3 Front surface 4 Back surface 6 First conductive semiconductor layer 7 Light emitting layer 8 Second conductive semiconductor layer 9 Conductive multilayer reflector 10 Adhesive layer 11 Reflective layer 12 Barrier metal 13 Bonded metal 34 Surface 51 Light emitting element Package 53 Package 70 Light emitting element

Claims (11)

A sapphire substrate having a surface on the light extraction surface side and a back surface on the opposite side of the surface,
A first conductive semiconductor layer laminated on the surface of the sapphire substrate,
A light emitting layer laminated on the first conductive semiconductor layer and
The second conductive semiconductor layer laminated on the light emitting layer and
A reflective layer containing Ag, which is arranged on the back surface side of the sapphire substrate and reflects light from the sapphire substrate toward the front surface of the sapphire substrate.
An adhesive layer arranged between the sapphire substrate and the reflective layer, made of ITO, and adhered to the reflective layer,
Wherein a multi-layer reflector wherein the reflective layer is that is adhered by said adhesive layer is disposed between the sapphire substrate and the adhesive layer, that the two layers having a refractive index difference are stacked alternately the first multilayer reflector part which respective thicknesses are configured respectively different, and a multi-layer reflector that having a second multilayer reflection mirror portion and the third multilayer reflection mirror portion, the light emitting element. The first period thickness, which is the layer thickness of the two types of layers stacked one by one in the first multilayer reflector section, and the layer thickness of the two types of layers stacked one by one in the second multilayer reflector section. The third period thickness, which is the layer thickness, is different from the third period thickness, which is the layer thickness of the two types of layers stacked one by one in the third multilayer reflecting mirror unit, according to claim 1. Light emitting element. The first or second layer of the present invention, wherein the first multilayer reflector is 10% thicker than the second multilayer reflector, and the second multilayer reflector is 10% thicker than the third multilayer reflector. Light emitting element. The two layers has a SiO ₂ layer made of SiO _2, and TiO ₂ layers of TiO _2, the light emitting device according to claim 3. Wherein the first multilayer reflector part SiO ₂ layer thicker than the SiO ₂ layer of the second multilayer reflection mirror portion, wherein the first multilayer reflector part TiO ₂ layer of the TiO ₂ layer is the second multilayer reflection mirror portion of the Thicker than
The SiO ₂ layer of the second multilayer reflector is thicker than _{the SiO 2} layer of the third multilayer reflector, and the TiO ₂ layer of the _{second multilayer reflector is the TiO 2 layer of the third multilayer reflector.} The light emitting element according to claim 4, which is thicker than the above. Any one of claims 1 to 5, wherein the first multilayer reflector, the second multilayer reflector, and the third multilayer reflector are laminated in this order so as to be closer to the sapphire substrate. The light emitting element according to the item. The light emitting element according to any one of claims 1 to 6, wherein the side surface of the adhesive layer and the side surface of the sapphire substrate are flush with each other. Before the side surface of Kio layer reflector, and each side of the adhesive layer and the sapphire substrate is flush light emitting device of claim 7. The light emitting element according to claim 8, wherein the reflective layer is smaller than the adhesive layer and the peripheral edge portion of the adhesive layer is exposed from the reflective layer side in a plan view seen from the thickness direction of the sapphire substrate. Is the interfacial specular to the previous Kio layer reflector and the adhesive layer, light-emitting device according to any one of claims 1-9. The light emitting element according to any one of claims 1 to 10 and
A light emitting element package including a package containing the light emitting element.

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