JP2014150177A - Semiconductor light-emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting element having a highly-reliable lamination structure.SOLUTION: A semiconductor light-emitting element comprises: a supporting body 21; a first bonding layer placed on the supporting body; a second bonding layer placed on the first bonding layer; a semiconductor structure layer 14 placed on the second bonding layer and including an active layer 12; and an encapsulation part 19 placed between the first bonding layer and the second bonding layer. The encapsulation part is provided at an outer peripheral part of a bonding region where the first bonding layer and the second bonding layer are bonded, and is adhered to the first bonding layer and the second bonding layer over the whole periphery.

Description

  The present invention relates to a semiconductor light emitting device.

  A semiconductor light emitting device such as a light emitting diode (LED) is usually formed by growing a semiconductor film having an n-type semiconductor layer, a light emitting layer, a p-type semiconductor layer, and the like on a growth substrate, and forming electrodes on the semiconductor film. Produced.

  As a semiconductor light-emitting element that aims to extract more light emitted from the light-emitting layer to the outside, Patent Document 1 provides a support prepared separately by providing a metal junction layer made of a metal reflective layer or the like on a p-type semiconductor layer. A semiconductor light emitting device having a so-called bonded structure having a structure in which a growth substrate is removed after bonding to a body via a metal bonding layer is disclosed. Patent Document 2 discloses a semiconductor light emitting element having a structure in which a groove reaching the n-type semiconductor layer from the p-type semiconductor layer side is formed in addition to the bonding structure, and an auxiliary electrode is formed in the groove. ing.

Utility model registration No. 3108273 JP 2011-216524 JP

  When a semiconductor light emitting element having a bonded structure is manufactured, the semiconductor structure layer and the support are bonded by thermocompression bonding via the bonding layer. For example, after forming a plurality of bonding layers on the surface of the semiconductor structure layer on the p-type semiconductor layer side, forming a similar bonding layer on the support, and then supporting both bonding layers by heating and pressure bonding. Bond the body to the semiconductor structure layer.

  For example, gold (Au) is used as the bonding metal. When performing bonding using Au, for example, compared to a case where a eutectic metal made of an alloy of gold and tin (Au—Sn) is used for bonding, the bonding temperature at the time of thermocompression bonding can be set low ( When Au—Sn is used, it is necessary to increase the pressure bonding temperature to about 320 to 350 ° C., whereas when Au is used, about 200 ° C. may be used. When an Au layer is used as a bonding metal, an Au layer is formed on the outermost surfaces of the bonding layer on the semiconductor structure layer side and the bonding layer on the support side, and both are bonded by thermocompression bonding or the like.

  However, when joining the Au layer on the semiconductor structure layer side and the Au layer on the support side, depending on the surface state of the Au layer before joining, the Au layer on the joined semiconductor structure layer side and the Au layer on the support side There may be a gap at the interface. For example, when forming an Au layer on the semiconductor structure layer side, Au particles adhere to the surface of the Au layer so that irregularities are formed on the surface of the Au layer. A gap may occur at the interface between the Au layer on the structure layer side and the Au layer on the support side.

  If this gap reaches the side of the interface, the chemical solution used in the post-bonding process (for example, an alkaline solution used for forming the light extraction structure, a remover used for removing the resist layer in the process using photolithography, a defect) The acid solution used for cleaning the metal material leaking out of the metal or the like enters the inside of the element (semiconductor structure layer or electrode region) from the gap at the side of the bonding layer.

  As described above, the penetration of a liquid or gas such as a chemical solution or corrosive gas into the element causes a defect of the element. In particular, metal materials such as Ag, Ti, and Al used for the material of the reflective metal layer and the electrode are dissolved by the chemical solution and do not perform their functions. In addition, the reliability of the light emitting element such as strength and lifetime is reduced.

  The present invention has been made in view of the above points, and provides a semiconductor light-emitting device having a highly reliable bonding structure that prevents intrusion of chemicals and gases into the device and has excellent light extraction efficiency. The purpose is that.

  A semiconductor light emitting device according to the present invention is disposed on a support, a first bonding layer disposed on the support, a second bonding layer disposed on the first bonding layer, and a second bonding layer. A semiconductor structure layer including an active layer, and a sealing portion disposed between the first bonding layer and the second bonding layer, the sealing portion including the first bonding layer and the first bonding layer. It is provided in the outer peripheral part of the joining area | region where 2 joining layers were joined, and is closely_contact | adhered to the 1st joining layer and the 2nd joining layer over the perimeter.

(A) And (b) is sectional drawing explaining the structure of the semiconductor light-emitting device of Example 1. FIG. It is an enlarged view of the part enclosed with the broken line of Fig.1 (a). 3A to 3D are cross-sectional views illustrating the manufacturing process of the semiconductor light emitting device of Example 1. FIG. FIGS. 3E to 3H are cross-sectional views illustrating the manufacturing steps of the semiconductor light emitting device of Example 1. FIGS. 3 (i) to 3 (k) are cross-sectional views illustrating the manufacturing process of the semiconductor light emitting device of Example 1. FIG. (A) is sectional drawing which shows the structure of the semiconductor light-emitting device of Example 2, (b) is a figure which shows typically the positional relationship of the junction area | region, sealing part, and n electrode in the top view. 10 is a cross-sectional view showing a step of forming an n electrode in the semiconductor light emitting device of Example 2. FIG. 6 is a cross-sectional view illustrating a step of forming a sealing portion in the semiconductor light emitting element of Example 2. FIG. 6 is a top view of a semiconductor light emitting device of a comparative example of Example 2 and an enlarged view of an n electrode portion thereof. FIG.

  In the following, embodiments will be described with reference to the accompanying drawings. However, for convenience of explanation, some portions (layer thickness, positional relationship, etc.) may be schematically illustrated.

With reference to FIG. 1, the structure of the semiconductor light emitting device 10 of Example 1 will be described in detail. The semiconductor light emitting device 10 has a structure in which an n-type semiconductor layer (first semiconductor layer) 11, an active layer 12, and a p-type semiconductor layer (second semiconductor layer) 13 are stacked in this order. The n-type semiconductor layer 11, the active layer 12, and the p-type semiconductor layer 13 have a composition of Al _x In _y Ga _z N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, x + y + z = 1). Have. The active layer 12 has a single layer structure, a single quantum well structure, or a multiple quantum well structure. Hereinafter, the entire n-type semiconductor layer 11, active layer 12, and p-type semiconductor layer 13 are referred to as a semiconductor structure layer 14.

  The upper surface of the semiconductor structure layer 14, that is, the surface of the n-type semiconductor layer 11 is configured as a light extraction surface that extracts the light emitted from the active layer 12 to the outside. The surface of the n-type semiconductor layer 11 is removed from the surface of the n-type semiconductor layer 11 exposed by removing the growth substrate (the growth substrate 26 described later) used for the growth of the semiconductor structure layer 14 from the semiconductor structure layer 14. Become. Therefore, since the light emitted from the active layer 12 does not cause total reflection at the interface between the growth substrate and the n-type semiconductor layer 11, a large amount of light can be taken out.

  A light extraction structure 15 is formed on the surface of the n-type semiconductor layer 11. The light extraction structure 15 is, for example, a cone shape or a column shape formed on the surface of the n-type semiconductor layer 11 by performing wet etching with an alkaline solution or by performing dry etching after forming a light extraction pattern with a resist or the like. It consists of unevenness. The light emitted from the active layer 12 passes through the unevenness of the light extraction structure 15, and most of the light is extracted outside.

  A reflective electrode layer 16 is formed on the bottom surface of the semiconductor structure layer 14, that is, on the bottom surface of the p-type semiconductor layer 13. The reflective electrode layer 16 is made of a highly reflective metal, for example, Ag or an alloy containing Ag. In addition to functioning as a p-side electrode, the reflective electrode layer 16 reflects light emitted from the active layer 12 in the direction of the p-type semiconductor layer 13, that is, in the direction opposite to the light extraction surface. The light has a function of directing the light toward the direction, that is, the light extraction surface.

  A diffusion prevention layer 17 is formed on the lower surface of the reflective electrode layer 16. The diffusion prevention layer 17 is formed so as to cover the entire reflective electrode layer 16. The diffusion preventing layer 17 is made of a metal such as Ti, W, or Pt. In the diffusion preventing layer 17, the metal material constituting the semiconductor-side bonding layer 18 and the support-side bonding layer 22 diffuses into the reflective electrode layer 16, and the reflective function of the reflective electrode layer 16 and the reflective electrode layer 16 and the p-type semiconductor layer 13 It has a function to prevent the ohmic contact of the glass from being damaged.

  A semiconductor side bonding layer (second bonding layer) 18 is formed on the lower surface of the diffusion preventing layer 17. The semiconductor-side bonding layer 18 is composed of at least one metal layer having an Au layer as the outermost layer. For example, the semiconductor-side bonding layer 18 is formed sequentially from the diffusion prevention layer 17 side in the order of a Ti layer, a Pt layer, and an Au layer.

  A sealing portion 19 is formed on the outer peripheral portion on the lower surface of the semiconductor side bonding layer 18 without interruption along the outer peripheral portion. The sealing portion 19 is a region 20A inside the sealing portion 19 in the bonding region 20 on the outer peripheral portion of the bonding region 20 between the semiconductor-side bonding layer 18 and a support-side bonding layer (first bonding layer) 22 described later. Is provided so as to surround. That is, the sealing part 19 is provided so as to seal or seal the region 20 </ b> A inside the sealing part 19.

  The positional relationship between the sealing portion 19 and the bonding region 20 is shown in FIG. FIG. 1B shows the sealing portion 19, the bonding region 20, and the inner region 20 </ b> A when projected onto a plane parallel to the semiconductor structure layer 14, that is, when viewed from a direction perpendicular to the semiconductor structure layer 14. The positional relationship of the sealing part 19, the joining area | region 20, and the area | region 20A inside it in the top view is shown.

  As shown in FIG. 1B, the sealing portion 19 is a region facing the reflective electrode layer 16 formation region in the region 20 </ b> A inside the sealing portion 19 in the bonding region 20 when the element is viewed from above. Is formed so as to surround. That is, the sealing portion 19 is formed so as to seal the region immediately below the formation region of the reflective electrode layer 16 in the bonding region 20. The sealing portion 19 is made of a metal such as Au. Details of the sealing portion 19 will be described later with reference to FIG.

  The semiconductor light emitting element 10 is supported by a support 21. Specifically, the support-side bonding layer 22 is formed on the support 21, and the support-side bonding layer 22 is bonded to the semiconductor-side bonding layer 18 and the sealing portion 19. The support 21 is made of a conductive material such as Si, Cu, or CuW. The support-side bonding layer 22 is composed of at least one metal layer whose outermost layer (the layer closest to the semiconductor-side bonding layer 18) is an Au layer. For example, the support side bonding layer 22 is sequentially formed from the support 21 side in the order of a Pt layer, a Ti layer, a Pt layer, and an Au layer.

An n electrode (connection electrode) 24 is formed on the upper surface of the n-type semiconductor layer 11. The n-electrode 24 is formed using a metal generally used as an electrode material such as Ti, Al, or Pt. On the surface of the n-type semiconductor layer 11 excluding the portion where the n-electrode 24 is formed, the side surface of the semiconductor structure layer 14, the side surface of the semiconductor-side bonding layer 18, and the upper surface of the support-side bonding layer 22 outside the bonding region 20 A protective layer 23 for protecting the element surface is formed. The protective layer 23 is made of an insulating material, for example, SiO ₂ .

  FIG. 2 is an enlarged view of a portion surrounded by a broken line in FIG. As described above with reference to FIG. 1, the sealing portion 19 is a region inside the sealing portion 19 on the outer peripheral portion of the bonding region 20 where the semiconductor side bonding layer 18 and the support side bonding layer 22 are bonded. It is formed so as to surround 20A. The sealing portion 19 is in close contact with the semiconductor-side bonding layer 18 and the support-side bonding layer 22 over the entire circumference. That is, no gap is formed at the interface between the sealing portion 19 and the semiconductor-side bonding layer 18 and at the interface between the sealing portion 19 and the support-side bonding layer 22.

  Moreover, the semiconductor side joining layer 18, the sealing part (periphery sealing part) 19, and the support body side joining layer 22 form the composite joining layer by thermocompression bonding. Specifically, for example, the outermost layer of the semiconductor-side bonding layer 18 (that is, the layer closest to the support-side bonding layer) is composed of an Au layer, and the outermost layer of the support-side bonding layer 22 (that is, the most semiconductor-side bonding layer side). The layer) is made of an Au layer, and the sealing portion 19 is made of Au. Therefore, Au, which is a component of the semiconductor side bonding layer 18, the sealing portion 19, and the support side bonding layer 22, is integrated (bonded) by thermocompression bonding, and the semiconductor side bonding layer 18, the sealing portion 19 and the support side. The entire bonding layer 22 is a composite bonding layer.

  The sealing portion 19 is provided so as to be sandwiched between the semiconductor-side bonding layer 18 and the support-side bonding layer 22. The sealing portion 19 is in close contact with the semiconductor-side bonding layer 18 and the support-side bonding layer 22. Accordingly, it is possible to seal the region 20 </ b> A (including the void 25 described later) inside the sealing portion 19 in the bonding region 20. The sealing portion 19 can prevent the chemical liquid or gas used in the subsequent process from entering the element. Furthermore, a composite bonding layer having high bonding strength between the element and the support can be formed.

  The layer thickness of the sealing portion 19 is preferably larger than the irregularities (for example, about several nm) on the surfaces of the semiconductor side bonding layer 18 and the support side bonding layer 22 in view of not impairing the sealing function. On the other hand, since the load received at the time of thermocompression bonding cannot be biased, the layer thickness of the sealing portion 19 is preferably not too large. In the present embodiment, the case where the sealing portion 19 has a layer thickness of 10 nm will be described, but the layer thickness of the sealing portion 19 is preferably in the range of 5 to 20 nm, for example.

  With the provision of the sealing portion 19, there may be a slight gap 25 in the vicinity of the sealing portion 19 where the semiconductor side bonding layer 18 and the support side bonding layer 22 are not in close contact. However, even if the void 25 is formed, the other portion, that is, the bonding region 20 where the void 25 is not formed is not affected by the layer thickness of the sealing portion 19, and the semiconductor-side bonding layer 18 and the support-side bonding layer 22 are not affected. Are in close contact with each other without bending.

  Next, a manufacturing process of the semiconductor light emitting element 10 will be described with reference to FIGS. For ease of explanation and understanding, the two adjacent semiconductor light emitting elements 10 of the semiconductor wafer will be described.

FIG. 3A is a cross-sectional view illustrating a semiconductor structure layer forming step. First, Al _x In _y Ga _z N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, respectively) is formed on the growth substrate 26 by metal organic chemical vapor deposition (MOCVD). An n-type semiconductor layer 11, an active layer 12, and a p-type semiconductor layer 13 having 0 ≦ z ≦ 1, x + y + z = 1) are sequentially grown.

  In this example, a sapphire substrate having a C-plane crystal growth surface was used as the growth substrate 26. In addition, an n-GaN layer was formed as the n-type semiconductor layer 11, and a p-GaN layer was formed as the p-type semiconductor layer 13. The active layer 12 has a multiple quantum well structure having five InGaN well layers (well layers).

  Specifically, first, the sapphire substrate 26 was placed on a susceptor in an MOCVD apparatus, and thermal cleaning was performed. Next, an undoped GaN layer (not shown) as an underlayer was formed on the sapphire substrate 26 by about 1 μm, and the n-GaN layer 11 was grown by about 7 μm. Subsequently, the formation of an InGaN well layer (layer thickness of about 2.2 nm) and the formation of a GaN barrier layer (barrier layer) (layer thickness of about 15 nm) are repeated to activate a multi-quantum well structure having five InGaN well layers. Layer 12 was formed. Thereafter, a p-AlGaN cladding layer (not shown) was grown on the active layer 12 by about 40 nm, and the p-GaN layer 13 was grown by about 150 nm.

  FIG. 3B is a cross-sectional view illustrating the reflective electrode layer forming step. As shown in FIG. 3B, the reflective electrode layer 16 is formed on the p-GaN layer 13. The reflective electrode layer 16 is formed, for example, by depositing a reflective metal using a vacuum vapor deposition method or a sputtering method and patterning it by photolithography. In this embodiment, Ag is used as the material of the reflective electrode layer 16.

  FIG. 3C is a cross-sectional view illustrating a diffusion prevention layer forming step and a semiconductor side bonding layer forming step. In the diffusion preventing layer forming step, the diffusion preventing layer 17 is formed so as to cover the entire reflective electrode layer 16. Further, in the semiconductor side bonding layer forming step, the semiconductor side bonding layer (second bonding layer) 18 is formed on the diffusion preventing layer 17. The diffusion prevention layer 17 and the semiconductor-side bonding layer 18 are formed by depositing a metal using, for example, a vacuum evaporation method or a sputtering method and patterning it by photolithography.

  In this example, a diffusion prevention layer 17 (layer thickness: 500 nm) made of TiW was formed by sputtering using a mask having a pattern that is one size larger than the pattern used to form the reflective electrode layer 16. Thereafter, a Ti layer (layer thickness: 50 nm), a Pt layer (layer thickness: 100 nm), and an Au layer (layer thickness: 200 nm) were formed as the semiconductor-side bonding layer 18 by sputtering, and a pattern of each layer was formed by lift-off.

  FIG. 3D is a cross-sectional view for explaining the element isolation etching step. In the element isolation etching step, the individual semiconductor light emitting elements 10 are divided by etching. Specifically, the semiconductor structure layer 14 is separated by performing dry etching such as reactive ion etching after patterning, for example. In this example, a resist layer (not shown) was formed in a portion to be the semiconductor light emitting element 10, and the semiconductor structure layer 14 was removed by reactive ion etching until the growth substrate 26 was exposed.

  FIG. 3E is a cross-sectional view illustrating the sealing part forming step. As shown in FIG. 3E, the sealing portion 19 is formed along the outer peripheral portion of the surface of the semiconductor side bonding layer 18. The sealing part 19 is formed by, for example, forming a layer made of a sealing material using an electron beam evaporation method or the like and performing patterning. In this example, an Au layer having a layer thickness of 10 nm was formed on the semiconductor-side bonding layer 18, and the sealing portion 19 was formed by performing lift-off.

  FIG. 3F is a cross-sectional view illustrating the support forming process and the bonding process. In the support formation process, a support-side bonding layer (first bonding layer) 22 is formed on the support 21. In the bonding step, the support-side bonding layer 22, the semiconductor-side bonding layer 18, and the sealing portion 19 are bonded by thermocompression bonding. The sealing portion 19 is in close contact with the semiconductor-side bonding layer 18 and the support-side bonding layer 22 by the bonding process.

  In this embodiment, a Pt layer (layer thickness: 200 nm), a Ti layer (layer thickness: 600 nm), a Pt layer (layer thickness: 50 nm), and an Au layer (layer thickness: 1000 nm) are formed on a Si substrate as the support 21. ) Was formed. Thereafter, the support 21 was bonded to the semiconductor structure layer 14 by heating and press-bonding the support-side bonding layer 22, the sealing portion 19, and the semiconductor-side bonding layer 18.

  FIG. 3G is a cross-sectional view illustrating the growth substrate removing step. 3 (g) to FIG. 3 (k) are interchanged. After the bonding step, the growth substrate 26 is removed from the semiconductor structure layer 14. In this example, the sapphire substrate 26 was removed by laser lift-off. A KrF excimer laser was used as the laser source.

  FIG. 3H is a cross-sectional view illustrating the light extraction structure forming step. In the light extraction structure forming step, the light extraction structure 15 composed of a plurality of concavities and concavities in the shape of a cone or column is formed on the surface of the n-type semiconductor layer 11 of the semiconductor structure layer 14 exposed by removing the growth substrate 26. To do. The light extraction structure 15 is formed by, for example, wet etching using an alkaline solution such as KOH (potassium hydroxide) or TMAH (tetramethylammonium hydroxide), or dry etching such as reactive ion etching. In this example, the light extraction structure 15 composed of a plurality of irregularities was formed on the surface of the n-GaN layer 11 by wet etching using KOH.

FIG. 3I is a cross-sectional view illustrating the protective layer forming step. In this step, the protective layer 23 is formed on the surface and side surfaces of the semiconductor structure layer 14 excluding the portion where the n-electrode 24 described later is formed, on the side surfaces of the semiconductor-side bonding layer 18 and on the exposed upper surface of the support-side bonding layer 22. Form. The protective layer 23 is formed, for example, by depositing the protective layer 23 using a sputtering method or an electron beam vapor deposition method and then performing patterning by photolithography or the like. In this example, SiO ₂ having a thickness of about 300 nm was formed by sputtering.

  FIG. 3J is a cross-sectional view illustrating the n-electrode formation step. In this step, the n-electrode 24 is formed on the exposed portion of the semiconductor structure layer 14. The n electrode 24 is formed using, for example, a Ti layer, an Al layer, or a Pt layer. The n-electrode 24 is formed, for example, by forming an electrode metal using an electron beam evaporation method or a sputtering method, and then patterning it using lift-off.

  FIG. 3K is a cross-sectional view illustrating the chip forming process. After the n-electrode forming step, the support 21 and the support-side bonding layer 22 are cut by a technique such as dicing and divided into individual semiconductor light emitting elements. The semiconductor light emitting device 10 was fabricated through the above steps.

  In addition, although the case where the semiconductor light emitting element has the diffusion preventing layer that covers the reflective electrode layer has been described, the diffusion preventing layer may not be provided. For example, a semiconductor-side bonding layer including a metal layer having a diffusion preventing function may be used, and the semiconductor-side bonding layer may be formed at the bottom of the reflective electrode layer. Further, although the case where the protective layer is formed on almost the entire surface of the element has been described, the protective layer may be formed on the surface and side surfaces of the semiconductor structure layer (excluding the portion where the n-electrode is formed).

  Moreover, although the case where the surface of the n-type semiconductor layer, that is, the light extraction surface has a light extraction structure made of irregularities has been described, the light extraction surface may not have the light extraction structure. For example, the light extraction surface may have a flat structure.

  Moreover, although the case where the sealing part is formed outside the reflective electrode layer in the top view has been described, all of the sealing part may not be formed outside the reflective electrode layer. The sealing part should just be formed in the outer part of all the outer parts without a discontinuity rather than the outer edge of a reflective electrode layer. For example, the inner edge part of the sealing part may be formed inside the outer edge of the reflective electrode layer in a top view.

  Moreover, although the case where the sealing part was formed along the outer peripheral part of a joining area | region was demonstrated, the sealing part may be formed along the outer end part (outer edge) of a joining area | region. For example, the sealing portion may be formed along the outer edge of the semiconductor side bonding layer. That is, the joining area | region does not need to be formed in the outer side of the sealing part.

  Further, although the case where the reflective electrode layer is provided between the p-type semiconductor layer and the diffusion prevention layer has been described, the reflective electrode layer may not be formed between the p-type semiconductor layer and the diffusion prevention layer. For example, instead of the reflective electrode layer such as Ag, a p-side electrode using a material (for example, NiAu alloy) having a reflectance lower than Ag may be connected to the p-type semiconductor layer.

  The case where the semiconductor-side bonding layer and the support-side bonding layer are composed of a plurality of metal layers has been described, but the semiconductor-side bonding layer and the support-side bonding layer are the outermost layers thereof, that is, the semiconductor-side bonding layer on the most support-side side. As long as both the layer and the layer closest to the semiconductor structure layer of the support-side bonding layer are made of an Au layer, they may not be made of a plurality of metal layers. For example, the support body side joining layer may be comprised only from Au layer.

  As described above, in the semiconductor light emitting device according to this example, the sealing portion is provided in the outer peripheral portion of the bonding region where the first bonding layer and the second bonding layer are bonded, and extends over the entire circumference. In close contact with the first and second bonding layers. The sealing portion is formed so as to surround a region inside the sealing portion in the bonding region. Therefore, the chemical solution is prevented from entering the element from the junction region, and it is possible to provide a semiconductor light emitting element with high reliability, high quality, and high light emission efficiency.

  FIGS. 4A and 4B are cross-sectional views illustrating the structure of the semiconductor light emitting device 30 of the second embodiment. The semiconductor light emitting element 30 has an n-electrode (connection electrode) 44 formation position, an insulating layer 45 associated therewith, an electrode region sealing portion 49, and a p-bonding pad 46. The semiconductor light emitting device 10 has the same configuration as that of the semiconductor light emitting device 10 of Example 1, except that the semiconductor light emitting device 10 has the same structure as that of the semiconductor light emitting device 10 except for the steps described below. .

  The semiconductor light emitting device 30 includes a semiconductor structure layer 34 including an n-type semiconductor layer (first semiconductor layer) 31, an active layer 32, and a p-type semiconductor layer (second semiconductor layer) 33, a light extraction structure 35, and a reflective electrode layer. 36, diffusion prevention layer 37, semiconductor-side bonding layer (second bonding layer) 38, sealing portion 48, electrode region sealing portion 49, support 41, support-side bonding layer (first bonding layer) 42, protection A layer 43, an n-electrode (connection electrode) 44, an insulating layer 45, and a p-bonding pad 46 are provided.

The n electrode 44 penetrates the p-type semiconductor layer 33 and the active layer 32, reaches the n-type semiconductor layer 31, and is connected to the n-type semiconductor layer 31. That is, the n-electrode 44 is connected to the n-type semiconductor layer 31 not from the surface of the n-type semiconductor layer 31 but from the inside of the element. Therefore, the n-electrode 44 does not hinder light extraction on the light extraction surface, and the light extraction efficiency can be improved. The n-electrode 44 is formed so as to be separated from the reflective electrode layer 36 and the diffusion prevention layer 37 with the insulating layer 45 interposed therebetween. The insulating layer 45 is made of an insulating material, for example, SiO ₂ . The insulating layer 45 insulates the n electrode 44 from the reflective electrode layer 36 and the diffusion prevention layer 37 which are p electrodes.

  Referring to FIG. 5, for example, the n-electrode 44 and the insulating layer 45 are provided with a region where the reflective electrode layer 36 and the diffusion prevention layer 37 are not formed on the p-type semiconductor layer 33 of the semiconductor structure layer 34. After an opening reaching from the surface of the semiconductor layer 33 to a part of the n-type semiconductor layer 31 is formed, an n-electrode 44 is formed in the opening, and an insulating layer 45 is formed except for the portion where the n-electrode 44 is formed. It is formed by doing.

  More specifically, first, the semiconductor structure layer 34 was formed, and then the reflective electrode layer 36 and the diffusion prevention layer 37 were formed (FIG. 5A). Next, in the portion where the p-type semiconductor layer 33 is exposed, an opening reaching the surface of the p-type semiconductor layer 33 from the p-type semiconductor layer 33 to the n-type semiconductor layer 31 is formed by etching (FIG. 5B). ). Subsequently, an n-electrode 44 was formed in the opening (FIG. 5C). The n-electrode 44 was formed to have the same height as the diffusion prevention layer 37 or a smaller height. Thereafter, an insulating layer 45 was formed so as to cover the entire diffusion prevention layer 37 and the n-electrode 44 (FIG. 5D). Subsequently, an opening for exposing the n-electrode 44 was formed on the surface of the insulating layer 45 (FIG. 5E). In this way, an n-electrode 44 was formed.

  The semiconductor light emitting element 30 has a p bonding pad 46 on the surface (upper surface) of the diffusion preventing layer 37 where the reflective electrode layer 36 is not formed. For example, the p bonding pad 46 is provided with a portion where the reflective electrode layer 36 is not formed on the p-type semiconductor layer 33, and an opening reaching the diffusion prevention layer 37 from the surface of the n-type semiconductor layer 31 is formed in the portion. The p bonding pad 46 is formed in the opening. The p bonding pad 46 is made of a known metal such as Ti or Pt. In this embodiment, a p-bonding pad 46 is formed by sequentially forming a Ti layer (layer thickness: 100 nm), a Pt layer (layer thickness: 200 nm), and an Au layer (layer thickness: 500 nm) from the diffusion prevention layer 37 side. Formed.

  The semiconductor light emitting element 30 of Example 2 was formed so as to surround a region 40B facing the formation region of the n electrode 44 in the junction region 40 in addition to the sealing portion (peripheral sealing portion) of Example 1. An electrode region sealing portion 49 is provided. That is, the electrode region sealing portion 49 is formed around the region 40B immediately below the n-electrode 44 so as to seal the region 40C inside the electrode region sealing portion 49 of the bonding region 40. The positional relationship among the bonding regions 40, 40A, 40B, and 40C, the sealing portion 48, and the electrode region sealing portion 49 on the bonding surface between the semiconductor-side bonding layer 38 and the support-side bonding layer 42 is a plane in FIG. This is schematically shown in the figure. 4A is a cross-sectional view taken along the line WW in FIG. 4B.

  Since the sealing portion (outer peripheral sealing portion) 48 is formed in the outer peripheral portion of the bonding region 40 where the semiconductor side bonding layer 38 and the support side bonding layer 42 are bonded, the bonding region is the same as in the first embodiment. It is possible to prevent the chemical liquid from entering the region 40 </ b> A inside the sealing portion 48 in 40. Further, in the present embodiment, an electrode region sealing portion 49 is formed around a region 40B facing the formation region of the n electrode 44 in the junction region 40. Accordingly, it is possible to prevent the chemical solution from entering the n-electrode 44 in a double manner. By configuring the sealing portion 48 and the electrode region sealing portion 49 in this way, it is possible to prevent a liquid or gas from entering the element and to configure a high-quality and highly reliable semiconductor light emitting element. .

  In the present embodiment, the case where the sealing portion 48 and the electrode region sealing portion 49 are formed on the semiconductor side bonding layer 38 has been described. Specifically, as shown in FIG. 6A, after forming the semiconductor-side bonding layer 38 on the insulating layer 45, the sealing portion 48 and the electrode region sealing portion 49 were formed. However, as another method, the sealing portion 48 and the electrode region sealing portion 49 may be formed before the formation of the semiconductor side bonding layer 38. Specifically, for example, as shown in FIG. 6B, after forming the protrusion formation portions 48A and 49A corresponding to the sealing portion 48 and the electrode region sealing portion 49 on the insulating layer 45, the semiconductor side The bonding layer 38 may be formed.

  When the semiconductor side bonding layer 38 is formed after forming the protrusion forming portions 48A and 49A, the protrusions 48 and 49 corresponding to the protrusion forming portions 48A and 49A are formed on the upper surface of the semiconductor side bonding layer 38, respectively. This protrusion has the same function as the sealing portion 48 and the electrode region sealing portion 49 of this embodiment. Thus, the sealing part 48 and the electrode area sealing part 49 may be formed.

  Further, the sealing portion and the electrode region sealing portion may be formed on the upper surface of the support-side bonding layer. For example, before or after forming the support-side bonding layer on the support, a protrusion forming portion or a sealing portion may be formed on the support or on the support-side bonding layer. In this case, the sealing portion does not need to be formed on the upper surface and the lower surface of the semiconductor side bonding layer. In addition, as a material for the protrusion forming portion, for example, any of materials that form a bonding layer (semiconductor-side bonding layer or support-side bonding layer) can be used. In this embodiment, since the lowermost layer (the layer closest to the insulating layer) of the semiconductor side bonding layer is a Ti layer, the protrusion forming portion can be formed using Ti.

  FIG. 7 shows, as a comparative example of this example, when a semiconductor light emitting element having the same configuration as that of the semiconductor light emitting element 30 is observed from above, except that the sealing portion 48 and the electrode region sealing portion 49 are not provided. The image is shown. The lower part of the figure shows an image of the entire upper surface, and the upper part of the figure shows an enlarged image of the periphery of the n-electrode 44 (the part surrounded by the broken line in the lower image).

In the semiconductor light emitting device of this comparative example, it is possible to confirm a portion where Al, which is the material of the n-electrode 44, is dissolved by a chemical solution (portion surrounded by a broken line in the upper image) (this portion is 3 in this figure). Can be confirmed). It is understood that this is because a gap is generated at the bonding interface between the semiconductor-side bonding layer and the support-side bonding layer, and the chemical solution enters the n-electrode portion from this gap and dissolves the electrode material. In this comparative example, it was also confirmed that a gap was generated at the bonding interface. When the electrode has this portion, it cannot function as an electrode, and smooth current supply to the element cannot be performed.
As described above, the semiconductor light emitting device 30 of this example has the sealing portion 48 on the outer peripheral portion of the bonding region 40 between the semiconductor side bonding layer 38 and the support side bonding layer 42, and the n electrode 44 is formed in the region. An electrode region sealing portion 49 is provided so as to surround the opposing bonding region 40B. Therefore, it is possible to prevent the chemical solution used after the bonding process from entering the element, and the trouble that the n-electrode 44 is dissolved by the chemical solution is greatly reduced. Furthermore, the electrode can reliably supply current to the element. Therefore, it is possible not only to improve the lifetime and reliability of the element, but also to provide a semiconductor light emitting element with high light emission efficiency.

DESCRIPTION OF SYMBOLS 10, 30 Semiconductor light emitting element 14, 34 Semiconductor structure layer 16, 36 Reflective electrode layer 18, 38 Semiconductor side joining layer 19, 39 Sealing part 20, 40 Joint area | region 21, 41 Support body 22, 42 Support body side joining layer 24, 44 n-electrode

Claims (4)

A support;
A first bonding layer disposed on the support;
A second bonding layer disposed on the first bonding layer;
A semiconductor structure layer including an active layer disposed on the second bonding layer;
A sealing portion disposed between the first bonding layer and the second bonding layer,
The sealing portion is provided on an outer peripheral portion of a bonding region where the first bonding layer and the second bonding layer are bonded to each other, and the first bonding layer and the second bonding layer are provided over the entire circumference. A semiconductor light-emitting element characterized by being in close contact with the bonding layer.   The first bonding layer is composed of at least one metal layer whose outermost layer is an Au layer, and the second bonding layer is composed of at least one metal layer whose outermost layer is an Au layer, and the sealing portion The semiconductor light-emitting device according to claim 1, wherein is made of Au. The semiconductor structure layer is formed in order of the second semiconductor layer having the second conductivity type, the active layer, and the first semiconductor layer having the first conductivity type from the second bonding layer side. A reflective electrode layer is formed between the second semiconductor layer and the second bonding layer,
The semiconductor light-emitting element according to claim 1, wherein the sealing portion is provided so as to surround a region facing the formation region of the reflective electrode layer in the bonding region.   A connection electrode penetrating through the second semiconductor layer and the active layer and reaching the first semiconductor layer and connected to the first semiconductor layer; the first bonding layer; and the second bonding layer; And an electrode region sealing portion formed so as to surround a region facing the formation region of the connection electrode in the junction region. The semiconductor light emitting element as described.