JP2006332610A - Light emitting element and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting element which has a structure wherein a light emitting layer part and a Si substrate are laminated with a metal layer between them, and is hard to decrease lamination strength and reflection factor. <P>SOLUTION: A main metal layer 10c forming a reflecting surface is formed on a second principal surface of a compound semiconductor layer 50, and further a first brazing material layer 10s1 comprising an AuSn brazing material whose melting point is 364°C or below is so arranged as to coat the main metal layer 10c. A second brazing material layer 10s2 comprising AuSn brazing material whose melting point is 364°C or below is arranged on a first principal surface of a Si substrate 7. Then, the first brazing material layer 10s1 and the second brazing material layer 10s2 are piled and pressurized, and at the same time, heat treatment for lamination is performed for them at the temperature which is equal to or higher than the melting point of the AuSn brazing material and lower than 364°C, to bind and laminate the first brazing material layer 10s1 and the second brazing material layer 10s2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method for manufacturing a light emitting element and a light emitting element.

JP-A-7-66455 JP 2001-339100 A

  As a result of many years of progress in materials and element structures used in light-emitting elements such as light-emitting diodes and semiconductor lasers, the photoelectric conversion efficiency inside the elements is gradually approaching the theoretical limit. Therefore, when an element with higher luminance is to be obtained, the light extraction efficiency from the element is extremely important. For example, in a light emitting device having a light emitting layer portion formed of AlGaInP mixed crystal, a thin AlGaInP (or GaInP) active layer is sandwiched between an n-type AlGaInP cladding layer and a p-type AlGaInP cladding layer having a larger band gap. By adopting a sandwiched double hetero structure, a high-luminance element can be realized. Such an AlGaInP double heterostructure can be formed by epitaxially growing each layer of an AlGaInP mixed crystal on a GaAs single crystal substrate by utilizing the lattice matching of the AlGaInP mixed crystal with GaAs. And when using this as a light emitting element, usually a GaAs single crystal substrate is often used as it is as a substrate. However, since the AlGaInP mixed crystal constituting the light emitting layer has a larger band gap than GaAs, the emitted light is absorbed by the GaAs substrate, and it is difficult to obtain sufficient light extraction efficiency. In order to solve this problem, a method (for example, Patent Document 1) in which a reflective layer made of a semiconductor multilayer film is inserted between a substrate and a light emitting element has also been proposed. Therefore, only light incident at a limited angle is reflected, and a significant improvement in light extraction efficiency cannot be expected in principle.

  Therefore, in various publications including Patent Document 2, a GaAs substrate for growth is peeled off, while a reinforcing element substrate (having conductivity: for example, a Si substrate) is passed through a reflective Au layer. A technique for bonding to a release surface is disclosed. This Au layer has an advantage that the reflectivity is high and the dependency of the reflectivity on the incident angle is small.

  However, the above method has a problem in that when the Au layer constituting the reflective layer is bonded to the light emitting layer portion, problems such as peeling and a decrease in reflectance are likely to occur. An object of the present invention is to provide a method for manufacturing a light-emitting element having a structure in which a light-emitting layer part and an element substrate are bonded via a metal layer, and a structure in which a reduction in bonding strength and reflectance is unlikely to occur. It is to provide a light emitting element obtained thereby.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, a method for manufacturing a light-emitting device of the present invention includes:
The first main surface of the compound semiconductor layer having the light emitting layer portion is a light extraction surface, and an element substrate is bonded to the second main surface side of the compound semiconductor layer via a metal layer, and the compound semiconductor layer of the metal layer and Is a manufacturing method of a light emitting element in which the bonding surface forms a reflecting surface,
Forming a main metal layer forming a reflective surface on the second main surface of the compound semiconductor layer, and further disposing a first brazing material layer made of AuSn-based brazing so as to cover the main metal layer;
On the other hand, a second brazing filler metal layer made of AuSn brazing material is disposed on the first main surface of the element substrate,
By superposing the first brazing filler metal layer and the second brazing filler metal layer and applying pressure in that state, they are bonded and heat-treated at a temperature higher than the melting point of the AuSn brazing filler metal and lower than the melting point of the main metal layer. The first brazing filler metal layer and the second brazing filler metal layer are bonded and bonded together.

In the light emitting device of the present invention, the first main surface of the compound semiconductor layer having the light emitting layer portion is used as a light extraction surface, and the element substrate is bonded to the second main surface side of the compound semiconductor layer through the metal layer. A light-emitting element in which a bonding surface of the metal layer and the compound semiconductor layer forms a reflection surface,
A main metal layer that forms a reflective surface is formed on the second main surface of the compound semiconductor layer, and a first brazing material layer made of AuSn brazing material is disposed so as to cover the main metal layer,
On the other hand, a second brazing filler metal layer made of AuSn brazing material is disposed on the first main surface of the element substrate,
The first brazing filler metal layer and the second brazing filler metal layer are bonded and bonded in a molten form.

  In the present invention, the AuSn brazing material refers to a brazing material in which one of Au and Sn is a main component (50% by mass or more) and the other is a subcomponent having the highest mass content.

  When bonding the Si substrate and the compound semiconductor layer through the metal layer, in order to obtain a uniform bonded state, the stacked body in which the element substrate and the compound semiconductor layer are stacked is pressed through the metal layer. It is effective to perform the heat treatment while bonding. However, when the applied pressure is excessively high, a thin compound semiconductor layer is likely to be cracked or cracked, and the product yield is liable to decrease. However, as described above, the first brazing filler metal layer and the second brazing filler metal layer made of AuSn brazing filler metal are overlapped, and in that state, the bonding heat treatment temperature is set to a temperature higher than the melting point of the AuSn brazing filler metal. If the bonding is performed, a uniform bonding state can be obtained at a relatively low temperature without applying a very high pressure, which contributes to an improvement in product yield.

  The type of element substrate that can be employed in the present invention is not particularly limited, but a Si substrate can be suitably employed in the present invention as a conductive substrate that is easy to ensure the flatness of the bonded surface and is relatively inexpensive. . Instead of the Si substrate, other semiconductor substrates such as a GaAs substrate, a GaP substrate, or a SiC substrate can be employed. Furthermore, when it is not necessary to use the element substrate as a light-emitting element energization path, an insulating substrate such as a glass substrate or a quartz substrate can be used.

  When an Si substrate is employed as the element substrate, it is desirable that the melting point of the AuSn brazing material constituting the first brazing material layer and the second brazing material layer be less than 364 ° C. In this case, by setting the bonding heat treatment temperature lower than 364 ° C., the eutectic reaction between the Au component of the AuSn brazing material and the Si component of the Si substrate is suppressed, and the main treatment from the Si substrate side is performed during the bonding heat treatment. It is also possible to prevent a problem that Si rises in the metal layer and lowers the reflectance.

  One of the first brazing filler metal layer and the second brazing filler metal layer is a low-temperature AuSn-based brazing material having a melting point of less than 364 ° C., and the other is a high-temperature AuSn-based brazing material having a melting point of 364 ° C. or more. It is also possible to perform bonding by setting the melting point of the AuSn brazing material to be higher than the melting point of the high temperature AuSn brazing material. In this way, melting on the high temperature AuSn brazing material side is suppressed, but bonding can be performed without any problem due to melting of the low temperature AuSn brazing material. In particular, when the main metal layer is an Au-based layer, the first brazing filler metal layer is a high-temperature AuSn-based brazing material having a melting point of 364 ° C. or higher so that the first brazing material on the side in contact with the main metal layer at the time of bonding is used. Melting of the layer is suppressed, and the brazing material erosion of the main metal layer can be suppressed.

  When it is desired to set the melting point to less than 364 ° C., for example, an AuSn brazing material containing Au as a main component (50% by mass or more) and containing Sn in an amount of more than 16% by mass and less than 27% by mass can be used. . When the Sn content is 16% by mass or less or 27% by mass or more, the melting point of the AuSn brazing material becomes 364 ° C. or more, which is the Au—Si eutectic temperature, and it is premised on the melting of the AuSn brazing material. In some cases, it is impossible to set the bonding heat treatment temperature below 364 ° C. The AuSn brazing material may contain Sn as a main component (50 mass% or more). In addition to Au and Sn, the AuSn brazing material may be made of Pb, Ga for further lowering the melting point of the AuSn brazing material. It is also possible to contain subcomponents such as Bi. As described above, when one of the first brazing filler metal layer and the second brazing filler metal layer is a high-temperature AuSn brazing filler having a melting point of 364 ° C. or higher, for example, Sn is 10% by mass to 16% by mass, or 27 It is good to adjust to the composition range of mass% or more and 35 mass% or less (remainder Au).

  When adopting the above composition as an Au-Sn binary alloy for an AuSn brazing material, the bonding heat treatment is desirably performed at a temperature of 280 ° C. or higher and 360 ° C. or lower (above the melting point of the AuSn brazing material). Good. If the bonding heat treatment temperature is less than 280 ° C., it becomes impossible to melt the AuSn brazing material having the above composition. Moreover, Si diffusion from the Si substrate to the AuSn brazing material can be more effectively suppressed by setting the bonding heat treatment temperature to 360 ° C. or less.

  The main metal layer contains at least 95% by mass of any of Au, Ag and Al, and in combination with the Si diffusion blocking effect by the AuSn-based brazing material, the reflecting surface has a very good reflectivity. And contributes to the improvement of the light extraction efficiency of the resulting light-emitting element.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a conceptual diagram showing a light emitting device 100 according to an embodiment of the present invention. The light emitting element 100 has a structure in which a light emitting layer portion 24 is bonded to a first main surface of a Si substrate 7 made of n-type Si single crystal as an element substrate via a metal layer 10. The light emitting layer portion 24 includes the active layer 5 made of a non-doped (Al _x Ga _1-x ) _y In _1-y P (where 0 ≦ x ≦ 0.55, 0.45 ≦ y ≦ 0.55) mixed crystal. , the first-conductivity-type cladding layer, in this embodiment the p-type cladding layer 6 made of p-type _{(Al z Ga 1-z)} y in 1-y P ( except x <z ≦ 1), wherein the first conductivity type the second-conductivity-type cladding layer different from the clad layer, in this embodiment interposed by an n-type _{(Al z Ga 1-z)} y in 1-y P ( except x <z ≦ 1) n-type cladding layer 4 made of According to the composition of the active layer 5, the emission wavelength can be adjusted in the green to red region (the emission wavelength (peak emission wavelength) is 550 nm or more and 670 nm or less). In the light emitting device 100, the p-type AlGaInP cladding layer 6 is disposed on the metal electrode 9 side, and the n-type AlGaInP cladding layer 4 is disposed on the metal layer 10 side. The term “non-doped” as used herein means “does not actively add dopant”, and contains a dopant component inevitably mixed in a normal manufacturing process (for example, 10 ¹³ to 10 ¹⁶ / cm 3). It is not excluded that the upper limit is about ³ ).

  In addition, a current diffusion layer 20 made of AlGaAs is formed on the main surface of the light emitting layer portion 24 opposite to the side facing the Si substrate 7, and the light emitting layer portion 24 is formed at the approximate center of the main surface. A metal electrode (for example, Au electrode) 9 for applying a light emission driving voltage is formed so as to cover a part of the main surface. A region around the metal electrode 9 on the main surface of the current diffusion layer 20 forms a light extraction region from the light emitting layer portion 24. The light emitting layer portion 24 and the current diffusion layer 20 form the compound semiconductor layer 50.

  Further, a metal electrode (back electrode: for example, an Au electrode) 15 is formed on the back surface of the Si single crystal substrate 7 so as to cover the entire surface. When the metal electrode 15 is an Au electrode, an AuSb bonding alloyed layer 16 obtained by alloying AuSb alloy and Si is interposed between the metal electrode 15 and the Si single crystal substrate 7 as a substrate-side bonding alloyed layer. It is. The bonding alloying layer is not particularly limited as long as the contact resistance can be reduced by alloying with the Si substrate. For example, a p-type Si substrate can be used as the Si substrate, and in this case, a bonded alloyed layer made of Al or an Al alloy is preferably used. Even when an n-type Si substrate is used, the material of the bonding alloying layer is not limited to the AuSb alloy.

  The Si single crystal substrate 7 is manufactured by slicing and polishing a Si single crystal ingot, and the thickness thereof is, for example, 100 μm or more and 500 μm or less. Then, the light emitting layer portion 24 is bonded with the metal layer 10 interposed therebetween. In this embodiment, the metal layer 10 includes an AuSn brazing filler metal layer 10s and a main metal layer 10c, which will be described later.

  Between the light emitting layer portion 24 and the metal layer 10, an AuGeNi bonding alloyed layer 32 (for example, Ge: 15% by mass, Ni: 10% by mass, and the remainder Au is used as the light emitting layer side bonding alloyed layer). The layer is alloyed with the compound semiconductor on the light emitting layer portion 24 side), which contributes to reducing the series resistance of the device. The AuGeNi bonding alloyed layer 32 is formed in a dispersed manner on the main surface of the metal layer 10 and has a formation area ratio of 1% to 25%. Further, between the Si single crystal substrate 7 and the metal layer 10, an AuSb bonding alloyed layer 31 (for example, Sb: as a substrate side bonding alloyed layer) is in contact with the first main surface of the Si single crystal substrate 7. An AuSb alloy made of 5% by mass and the balance Au is alloyed with Si forming the substrate 7). Again, the material of the bonding alloying layer is not limited to the AuSb alloy.

  The entire surface of the AuSb bonding alloyed layer 31 is covered with an AuSn brazing material layer 10 s that forms a part of the metal layer 10. The AuSn brazing filler metal layer 10s contains Au as a main component and Sn in a range of more than 16% by mass and less than 27% by mass, and has a thickness of 50 nm or more and 5 μm or less (in this embodiment, Au— Sn binary alloy (Sn content: for example, 20 mass%, thickness is 600 nm). A main metal layer 10c (which forms a part of the metal layer 10) is disposed so as to cover the entire surface of the AuSn brazing filler metal layer 10s. The AuSn brazing filler metal layer 10s is disposed in contact with the main metal layer 10c and the bonding alloying layer 31 on the Si substrate 7 side. As will be described later, the AuSn brazing filler metal layer 10s is obtained by integrating the first brazing filler metal layer 10s1 and the second brazing filler metal layer 10s2 in a molten form.

  The main metal layer 10c is made of a metal containing Au, Ag, or Al as a main component, specifically, a metal having a content of Au, Ag, or Al of 95% by mass or more. The main metal layer 10c forms a reflection surface, and light from the light emitting layer portion 24 is extracted in a form in which light reflected directly from the light extraction surface is superimposed on light reflected by the main metal layer 10c. In the present embodiment, the main metal layer 10c is an Au-based main metal layer made of pure Au or an Au alloy having an Au content of 95% by mass or more. The thickness of the main metal layer 10c is preferably 80 nm or more in order to ensure a sufficient reflection effect. Moreover, although there is no restriction | limiting in particular in the upper limit of the thickness of the main metal layer 10c, since a reflective effect is saturated, it determines suitably by balance with cost (for example, about 10 micrometers).

  The bonded alloying layers 31 and 16 provided between the Si single crystal substrate 7 and the metal layer 10 and between the Si single crystal substrate 7 and the back-side electrode 15 are not limited to the AuSb alloy as described above. For example, an AuSn alloy can be used. In particular, when the bonding alloyed layer 31 between the metal layer 10 is made of an AuSn alloy, the bonding alloyed layer 31 itself exhibits a function of suppressing Si diffusion from the Si single crystal substrate 7 side to the metal layer 10 side. There is a case. In this case, by providing the AuSn brazing material layer 10s as described above separately from the bonding alloying layer 31 made of the AuSn alloy, the effect of suppressing the Si diffusion toward the metal layer 10 side is further improved.

Hereinafter, a method for manufacturing the light emitting device 100 of FIG. 1 will be described.
First, as shown in Step 1 of FIG. 2, a p-type GaAs buffer layer 2 is made of, for example, 0.5 μm and AlAs on the main surface of a GaAs single crystal substrate 1 which is a semiconductor single crystal substrate forming a light emitting layer growth substrate. The peeling layer 3 is epitaxially grown in this order, for example, in the order of 0.5 μm, and the current diffusion layer 20 made of p-type AlGaAs is, for example, 5 μm. Thereafter, a 1 μm p-type AlGaInP cladding layer 6, a 0.6 μm AlGaInP active layer (non-doped) 5, and a 1 μm n-type AlGaInP cladding layer 4 are epitaxially grown in this order as the light emitting layer portion 24.

  Next, as shown in step 2, the main metal layer 10c is formed so as to cover the light emitting layer portion 24 on which the bonding alloying layer 32 has been formed, and further from the AuSn brazing material so as to cover the main metal layer 10c. A first brazing filler metal layer 10s1 is formed by vapor deposition or sputtering. On the other hand, as shown in step 3, for example, an AuSb bonding metal layer is formed on both main surfaces of a separately prepared Si single crystal substrate 7 (n-type), and alloying heat treatment is performed in a temperature range of 100 ° C. to 500 ° C. To obtain AuSb bonding alloyed layers 31 and 16. Then, a second brazing filler metal layer 10s2 made of an AuSn-based brazing material is formed on the AuSb bonding alloyed layer 31 by vapor deposition or sputtering (the first brazing filler metal layer 10s1 and the second brazing filler metal layer 10s2 are either Is also made of an AuSn binary alloy (Sn content: for example, 20% by mass) having the same composition with a melting point of 364 ° C. or less. Each thickness is 600 nm. Further, the back electrode layer 15 (for example, made of Au-based metal) is formed on the AuSb bonding alloying layer 16. In the above steps, each metal layer can be formed by sputtering or vacuum deposition.

  Then, as shown in Step 4, the first brazing filler metal layer 10s1 and the second brazing filler metal layer 10s2 are overlapped and pressed to have a temperature equal to or higher than the melting point of the brazing filler metal and lower than 364 ° C., preferably 280 ° C. to 360 °. Bonding heat treatment is performed at a temperature not higher than ° C., for example, 300 ° C. The Si single crystal substrate 7 is bonded to the light emitting layer portion 24 via the first brazing material layer 10s1 and the second brazing material layer 10s2. The first brazing filler metal layer 10s1 and the second brazing filler metal layer 10s2 are integrated by the bonding heat treatment to form an AuSn brazing filler metal layer 10s.

  In the case of the Au—Sn binary brazing material, the Sn content is in the range of more than 16% by mass and less than 27% by mass, and the melting point is less than 364 ° C., which is the Au—Si binary eutectic temperature. The first brazing filler metal layer 10s1 and the second brazing filler metal layer 10s2 can be melted and bonded while suppressing the diffusion of Si into the inside, and a uniform bonding state can be easily realized at low temperature and low pressure. can do. Further, the diffusion of the Si component from the Si single crystal substrate 7 toward the main metal layer 10c is blocked by the AuSn brazing filler metal layer 10s, and the seepage of the Si component toward the main metal layer 10c is effectively prevented. . As a result, a problem that the reflection surface of the main metal layer 10c finally obtained is contaminated by Si component diffusion is prevented.

  On the other hand, when the brazing material is not the AuSn-based brazing material, the AuSb bonding alloyed metal layer 31 penetrates from the Si single crystal substrate 7 due to the thermal history when the second brazing material layer 10s2 is formed by vapor deposition or the like. Si may diffuse and the Si may spring up on the outermost surface of the second brazing material layer 10s2. When the heated Si is oxidized, the bonding of the first brazing filler metal layer 10s1 and the second brazing filler metal layer 10s2 may be significantly inhibited. However, by forming the brazing filler metal layer as described above as an AuSn brazing filler metal layer, even when the second brazing filler metal layer 10s2 is formed, the Si upwelling due to its thermal history and the oxidation is effectively prevented, The bonding strength between the Si single crystal substrate 7 and the light emitting layer part (compound semiconductor layer) 24 by the first brazing material layer 10s1 and the second brazing material layer 10s2 can be further increased.

  Moreover, in the said process, since 1st brazing filler metal layer 10s1 and 2nd brazing filler metal layer 10s2 are fuse | melted and bonded together, the applied pressure of bonding is 5 kPa or more and 1000 kPa or less is enough. By being able to reduce the pressure of the bonding in this way, cracks and occurrence of cracks in the light emitting layer portion 24 during the bonding process, in particular, scattered points arranged between the main metal layer 10c and the light emitting layer portion 24. It is possible to effectively suppress the occurrence of cracks around the metal bonding metal layer 32 and to maintain good light emission characteristics over a long period of time.

  Next, the process proceeds to step 5, and the substrate bonded body is immersed in an etching solution made of, for example, a 10% hydrofluoric acid aqueous solution, and the AlAs release layer 3 formed between the buffer layer 2 and the light emitting layer portion 24 is selectively etched. As a result, the GaAs single crystal substrate 1 (which is opaque to the light from the light emitting layer portion 24) is peeled and removed from the laminate of the light emitting layer portion 24 and the Si single crystal substrate 7 bonded thereto. . It should be noted that an etch stop layer made of AlInP is formed in place of the AlAs release layer 3, and a GaAs single crystal is used by using a first etching solution (for example, ammonia / hydrogen peroxide mixed solution) having selective etching properties with respect to GaAs. Etch and remove the substrate 1 together with the GaAs buffer layer 2 and then etch stop using a second etchant that has selective etching properties with respect to AlInP (for example, hydrochloric acid: hydrofluoric acid may be added to remove the Al oxide layer) A step of etching away the layer can also be employed.

  Then, as shown in step 6, an electrode 9 for wire bonding (bonding pad: FIG. 1) is provided so as to cover a part of the first main surface of the current diffusion layer 20 exposed by peeling of the GaAs single crystal substrate 1. Form. Thereafter, the semiconductor chip is diced by a usual method, and this is fixed to a support and wire bonding of a lead wire is performed, followed by resin sealing to obtain a final light emitting element.

  Note that one of the first brazing filler metal layer 10s1 and the second brazing filler metal layer 10s2 is a low-temperature AuSn brazing material having a melting point of less than 364 ° C., and the other is a high-temperature AuSn brazing material having a melting point of 364 ° C. or more. It is also possible to perform the bonding by setting the melting point of the low temperature AuSn brazing material to be higher than the melting point of the high temperature AuSn brazing material. The AuSn-based brazing filler metal layer 10s of the obtained light emitting element is identified as a brazing filler metal layer having a different composition between the first brazing filler metal layer 10s1 and the second brazing filler metal layer 10s2, but one of them is melted and bonded. There is no change in form.

  In particular, the first brazing filler metal layer 10s1 is made of a high-temperature AuSn brazing material having a melting point of 364 ° C. or higher, so that the first brazing filler metal layer 10s1 made of the high-temperature AuSn brazing material on the side in contact with the main metal layer 10c at the time of bonding is melted. Is suppressed, and the brazing material erosion of the main metal layer 10c can be suppressed. The high-temperature AuSn brazing material can be composed of an Au—Sn binary brazing material containing Sn in a range of 10 mass% to 16 mass%, or 27 mass% to 35 mass%. In particular, if a material containing Sn in an amount of 27% by mass to 35% by mass (for example, 30% by mass) is used, the Au content in the brazing material can be reduced, and the cost can be reduced.

  Further, the element substrate may be replaced with another semiconductor substrate such as a GaAs substrate, a GaP substrate, or a SiC substrate instead of the Si substrate 7. Furthermore, when it is not necessary to use the element substrate as a light-emitting element energization path, an insulating substrate such as a glass substrate or a quartz substrate can be used.

The schematic diagram which shows 1st embodiment of the light emitting element of this invention by laminated structure. Explanatory drawing which shows an example of the manufacturing process of the light emitting element of FIG.

Explanation of symbols

1 GaAs single crystal substrate (light emitting layer growth substrate)
4 n-type cladding layer 5 active layer 6 p-type cladding layer 7 Si single crystal substrate (element substrate)
DESCRIPTION OF SYMBOLS 9 Metal electrode 10 Metal layer 10c Main metal layer 10s AuSn type | system | group brazing filler metal layer 10s1 1st brazing filler metal layer 10s2 2nd brazing filler metal layer 24 Light emitting layer part 100 Light emitting element

Claims (8)

The first main surface of the compound semiconductor layer having the light emitting layer portion is a light extraction surface, and an element substrate is bonded to the second main surface side of the compound semiconductor layer via a metal layer, and the compound semiconductor layer of the metal layer And a manufacturing method of a light emitting element in which a joint surface forms a reflective surface,
Forming a main metal layer that forms the reflective surface on the second main surface of the compound semiconductor layer, and further disposing a first brazing material layer made of AuSn-based brazing so as to cover the main metal layer;
On the other hand, a second brazing material layer made of AuSn-based brazing material is disposed on the first main surface of the element substrate,
The first brazing filler metal layer and the second brazing filler metal layer are overlaid and bonded and heat-treated at a temperature higher than the melting point of the AuSn brazing filler metal and lower than the melting point of the main metal layer while pressing in that state. Thus, the first brazing filler metal layer and the second brazing filler metal layer are bonded and bonded together.   2. The method of manufacturing a light emitting element according to claim 1, wherein the element substrate is a Si substrate, and the melting point of the AuSn brazing material constituting the first brazing filler metal layer and the second brazing filler metal layer is less than 364 ° C. 3. .   The method for manufacturing a light-emitting element according to claim 1, wherein the AuSn brazing material contains Au as a main component and contains Sn in an amount of more than 16 mass% and less than 27 mass%.   The method for manufacturing a light-emitting element according to claim 3, wherein the AuSn brazing material is made of an Au—Sn binary alloy, and the bonding heat treatment is performed at 280 ° C. or higher and 360 ° C. or lower.   5. The method for manufacturing a light-emitting element according to claim 1, wherein the main metal layer contains 95 mass% or more of any one of Au, Ag, and Al. The first main surface of the compound semiconductor layer having the light emitting layer portion is a light extraction surface, and an element substrate is bonded to the second main surface side of the compound semiconductor layer via a metal layer, and the compound semiconductor layer of the metal layer A light-emitting element in which the joint surface forms a reflective surface,
A main metal layer that forms the reflective surface is formed on the second main surface of the compound semiconductor layer, and a first brazing material layer made of AuSn-based brazing material is disposed so as to cover the main metal layer,
On the other hand, a second brazing filler metal layer made of AuSn brazing material is disposed on the first main surface of the element substrate,
The light emitting device, wherein the first brazing filler metal layer and the second brazing filler metal layer are bonded and bonded in a molten form.   The light emitting device according to claim 6, wherein the device substrate is a Si substrate. The light emitting device according to claim 6 or 7, wherein the AuSn brazing material contains Au as a main component and Sn in an amount of more than 16% by mass and less than 27% by mass.

Images