Conductive layer structure and light-emitting device

Abstract

According to the present invention, a conductive layer structure comprises a first conductive layer and a second conductive layer that is electrically connected to the first conductive layer with an adhesive layer therebetween. The adhesive layer is conductive and adheres more strongly to each of the first conductive layer and the second conductive layer than the first conductive layer and the second conductive layer adhere to each other. The second conductive layer is less easily altered than the adhesive layer, covers an end surface and an upper surface of the adhesive layer, and covers a portion of the first conductive layer.

Description

Technical Field

[0001] The present disclosure relates to a conductive layer structure and a light-emitting device.

Background Art

[0002] Patent Document 1 discloses a semiconductor device having a capacitive element. The capacitive element includes a lower electrode, a dielectric film on the lower electrode, and an upper electrode on the dielectric film. An insulating film is formed on the upper electrode with an adhesion layer interposed therebetween, and a contact hole penetrating in the thickness direction is formed in the adhesion layer and the insulating film. For example, a silicon oxide film is used as the insulating film, and for example, Ti is contained in the adhesion layer. A metal wiring is connected to the upper electrode through the contact hole.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] By the way, Ti contained in the adhesion layer deteriorates when exposed to a high-temperature and high-humidity environment, for example, it is oxidized. The oxide of Ti is a high-resistance substance and increases the resistance value in the current path. For example, in an electrode structure or a wiring structure that supplies current to a light-emitting device, if the resistance value increases, there is a risk of inducing an increase in the driving voltage and a light-emitting failure. Therefore, in a conductive layer structure including an electrode structure and a wiring structure, it is desired to effectively suppress or prevent an increase in the resistance value of the current path caused by the adoption of the adhesion layer.

[0005] The conductive layer structure according to the first embodiment of this disclosure comprises a first conductive layer and a second conductive layer electrically connected to the first conductive layer by an adhesive layer interposed therebetween, wherein the adhesive layer is conductive and has an adhesive force to the first conductive layer and the second conductive layer that is stronger than the adhesive force between the first conductive layer and the second conductive layer, the second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top face of the adhesive layer and covers a part of the first conductive layer.

[0006] The conductive layer structure according to the second embodiment of the present disclosure comprises a first conductive layer, a third conductive layer electrically connected to the first conductive layer via an adhesive layer, and a second conductive layer electrically connected to the third conductive layer, wherein the adhesive layer is conductive and has a stronger adhesive force to the first conductive layer and the third conductive layer than the adhesive force between the first conductive layer and the third conductive layer, the second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top face of the adhesive layer, and covers a portion of the first conductive layer.

[0007] The conductive layer structure according to the third embodiment of this disclosure comprises a first conductive layer, a fourth conductive layer formed by interposing an insulator on the first conductive layer, and a second conductive layer to which one end is connected by an adhesive layer interposed on the first conductive layer, the middle portion of which is laminated on an insulator, and the other end is connected by an adhesive layer interposed on the fourth conductive layer. The adhesive layer is conductive and has an adhesive force to each of the first, second, and fourth conductive layers that is stronger than the adhesive force between the first and second conductive layers, or between the fourth and second conductive layers. The second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top surface of the adhesive layer, and covers a part of the first conductive layer and a part of the fourth conductive layer. At the same time, it is electrically connected to a part of the first conductive layer and a part of the fourth conductive layer. .

[0008] A light-emitting device according to a fourth embodiment of the present disclosure comprises a light-emitting element and a conductive layer structure formed on the light-emitting element and supplying current to the light-emitting element, wherein the conductive layer structure comprises a first conductive layer and a second conductive layer electrically connected to the first conductive layer by an adhesive layer interposed therebetween, the adhesive layer being conductive and having a stronger adhesive force to the first conductive layer and the second conductive layer than the adhesive force between the first conductive layer and the second conductive layer, the second conductive layer being less susceptible to deterioration than the adhesive layer, covering the end face and top face of the adhesive layer, and covering a part of the first conductive layer. [Brief explanation of the drawing]

[0009] [Figure 1] This is a longitudinal cross-sectional view of a conductive layer structure and a light-emitting device equipped with a conductive layer structure according to the first embodiment of the present disclosure. [Figure 2A] This is a plan view of the first step illustrating the manufacturing method of the conductive layer structure according to the first embodiment. [Figure 2B] This is a cross-sectional view of the first process, cut along the AA cutting line shown in Figure 2A. [Figure 2C] This is a cross-sectional view of the first process, cut along the BB cutting line shown in Figure 2A. [Figure 3A] This is a plan view of the second step illustrating the manufacturing method of the conductive layer structure according to the first embodiment. [Figure 3B] This is a cross-sectional view of the second process, cut along the AA cutting line shown in Figure 3A. [Figure 3C] This is a cross-sectional view of the second process, cut along the BB cutting line shown in Figure 3A. [Figure 4A] This is a plan view of the third step illustrating the manufacturing method of the conductive layer structure according to the first embodiment. [Figure 4B] This is a cross-sectional view of the third process, cut along the AA cutting line shown in Figure 4A. [Figure 4C] This is a cross-sectional view of the third process, cut along the BB cutting line shown in Figure 4A. [Figure 5] This is a longitudinal cross-sectional view of a conductive layer structure and a light-emitting device equipped with a conductive layer structure according to a second embodiment of the present disclosure. [Figure 6] This is a longitudinal cross-sectional view of a conductive layer structure and a light-emitting device equipped with a conductive layer structure according to a third embodiment of the present disclosure. [Figure 7A] This is a plan view of the first step illustrating the manufacturing method of a conductive layer structure according to the third embodiment. [Figure 7B] This is a cross-sectional view of the first process, cut along the CC cutting line shown in Figure 7A. [Figure 7C] This is a cross-sectional view of the first process, cut along the DD cutting line shown in Figure 7A. [Figure 8A] It is a plan view of a second step for explaining a method of manufacturing a conductive layer structure according to the third embodiment. [Figure 8B] It is a cross-sectional view of the second step cut along the C-C cutting line shown in FIG. 8A. [Figure 8C] It is a cross-sectional view of the second step cut along the D-D cutting line shown in FIG. 8A. [Figure 9A] It is a plan view of a third step for explaining a method of manufacturing a conductive layer structure according to the third embodiment. [Figure 9B] It is a cross-sectional view of the third step cut along the C-C cutting line shown in FIG. 9A. [Figure 9C] It is a cross-sectional view of the third step cut along the D-D cutting line shown in FIG. 9A. [Figure 10] It is a longitudinal cross-sectional configuration diagram of a light-emitting device including a conductive layer structure according to a fourth embodiment of the present disclosure and the conductive layer structure.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. 1. First Embodiment The first embodiment is a first example in which the present technology is applied to a conductive layer structure and a light-emitting device including the conductive layer structure. Here, the light-emitting device is a vertical cavity surface emitting laser (VCSEL) as an example. In the first embodiment, a method of manufacturing the conductive layer structure will also be described. 2. Second Embodiment The second embodiment describes a second example in which the configuration of the conductive layer structure is changed in the conductive layer structure and the light-emitting device according to the first embodiment. 3. Third Embodiment The third embodiment describes a third example in which the configuration of the conductive layer structure is changed in the conductive layer structure and the light-emitting device according to the first embodiment. 4. Fourth Embodiment The fourth embodiment is a fourth example of applying the present technology to a conductive layer structure and a light-emitting device equipped with a conductive layer structure. Here, the light-emitting device is, as an example, a light-emitting diode (LED). 5. Other Embodiments

[0011] <1. First Embodiment> The conductive layer structure 3 and light-emitting device 1 according to the first embodiment of this disclosure will be explained using Figures 1, 2A to 2C, 3A to 3C, and 4A to 4C. Here, the arrow X direction, as shown in the figure, conveniently indicates one planar direction of the conductive layer structure 3 and light-emitting device 1 placed on a plane. The arrow Y direction indicates another planar direction perpendicular to the arrow X direction. The arrow Z direction indicates the upward direction, perpendicular to both the arrow X and arrow Y directions. In other words, the arrow X, arrow Y, and arrow Z directions coincide precisely with the X, Y, and Z axes of the three-dimensional coordinate system, respectively. These directions are provided to aid in understanding the explanation and do not limit the directions of this technology.

[0012] [Configuration of conductive layer structure 3 and light-emitting device 1] (1) General outline of the conductive layer structure 3 and the light-emitting device 1 Figure 1 shows a longitudinal cross-sectional structure of an example of a conductive layer structure 3 and a light-emitting device 1 according to the first embodiment of this disclosure.

[0013] The light-emitting device 1 according to the first embodiment includes a light-emitting element 2. Furthermore, the light-emitting device 1 includes a conductive layer structure 3. The light-emitting element 2 is stacked on a base substrate 10 within a region surrounded on its sides by an insulator 11. In the first embodiment, the light-emitting element 2 is a VCSEL as a surface-emitting laser. The light-emitting element 2 mainly comprises a first reflective layer 21, an emitting layer 22, a current-constricting layer 23, and a second reflective layer 24. Multiple light-emitting elements 2 are arranged in both the X-direction and the Y-direction, with an insulator 11 in between. On the other hand, the conductive layer structure 3 comprises a first conductive layer 31 and a second conductive layer 32 electrically connected to the first conductive layer 31 by an adhesive layer 35 interposed therebetween. The conductive layer structure 3 further comprises a fourth conductive layer 34 formed by interposing an insulator 11 on the first conductive layer 31. The second conductive layer 32 has one end connected to the first conductive layer 31 and the other end connected to the fourth conductive layer 34 by an adhesive layer 35 interposed therebetween. The middle portion of the second conductive layer 32 is laminated on the insulator 11 with an adhesive layer 35 interposed therebetween. The components of the conductive layer structure 3 and the light-emitting device 1 are described in detail below.

[0014] (2) Configuration of the substrate 10 The substrate 10 is used as an epitaxial growth substrate. For example, n-type GaAs is used for the substrate 10. In the first embodiment, the "first conductivity type" is described as "n-type". S is used as the n-type impurity. Furthermore, a buffer layer may be laminated on the substrate 10. When a buffer layer is laminated, a terrace and step structure with high smoothness can be constructed. A contact layer 4 is formed on the side of the substrate 10 opposite to the side on which the light-emitting elements 2 are stacked (the back side). The contact layer 4 supplies current to the light-emitting elements 2.

[0015] (3) Configuration of the light-emitting element 2 (3-1) Configuration of the first reflective layer 21 The first reflective layer 21 is laminated either directly on the substrate 10 or with a buffer layer (not shown) interposed on the substrate 10. The first reflective layer 21 is a semiconductor DBR (Distributed Bragg Reflector) in this case. In other words, the first reflective layer 21 is composed of multiple semiconductor layers having two or more different refractive indices, stacked alternately. For example, the first reflective layer 21 is formed by stacking multiple n-type AlGaAs and n-type GaAs semiconductor layers alternately. The first reflective layer 21 may be made of, for example, a dielectric DBR.

[0016] (3-2) Configuration of the light-emitting layer 22 The light-emitting layer 22 is stacked on the first reflective layer 21. The light-emitting layer 22 is composed of a structure in which multiple barrier layers and quantum well layers are stacked alternately. For example, undoped AlGaInAs is used for the barrier layer. The quantum well layer is composed of at least one element selected from the group III elements Al, Ga, and In, and at least one element selected from the group V elements As, P, and N. Here, the quantum well layer is composed primarily of, for example, undoped AlGaInAs. Furthermore, quantum wires or quantum dots may be used instead of the quantum well layer. In addition, in the first embodiment, the light-emitting layer 22 may be configured as a strain-compensated quantum well.

[0017] (3-3) Configuration of the current constriction layer 23 The current-constricting layer 23 is laminated on the light-emitting layer 22. The current-constricting layer 23 comprises a current-passing region 23A formed in the center and a current-constricting region 23B formed around the current-passing region 23A. The current-passing region 23A is formed, for example, in a circular shape when viewed from the direction of arrow Z (hereinafter simply referred to as "in a plan view"). The current-constricting region 23B is formed, for example, by an oxide or an ion-implanted region.

[0018] (3-4) Configuration of the second reflective layer 24 The second reflective layer 24 is stacked on the current-constricting layer 23. The second reflective layer 24 is a semiconductor DBR in this case. That is, the second reflective layer 24 is constructed by alternately stacking multiple semiconductor layers having two or more different refractive indices, similar to the first reflective layer 21. For example, the second reflective layer 24 is formed by alternately stacking multiple semiconductor layers of p-type AlGaAs and p-type GaAs as the second conductivity type. The second reflective layer 24 may be made of, for example, a dielectric DBR.

[0019] (4) Configuration of the conductive layer structure 3 (4-1) Composition of the first conductive layer 31 The first conductive layer 31 is laminated on the second reflective layer 24 of the light-emitting element 2 and is formed along the periphery of the second reflective layer 24. In a plan view, it is formed in the shape of a ring with a portion missing. The first conductive layer 31 is formed as an electrode or contact layer of the light-emitting element 2. The first conductive layer 31 is formed by a multilayer film in which, for example, Au, Pt, and Ti are sequentially stacked. The Au layer is formed to a thickness of, for example, 50 nm to 500 nm. The Pt layer is formed to a thickness of, for example, 10 nm to 100 nm. The Ti layer is formed to a thickness of, for example, 10 nm to 100 nm.

[0020] The first conductive layer 31 can be formed from one or more materials selected from Au, Al, Cu, Ag, Rh, W, Mo, Ni, Pd, ITO, ITiO, ZnO, and AuGe. Au, Al, Cu, Ag, Rh, W, Mo, Ni, and Pd are metallic materials. ITO, ITiO, and ZnO are transparent metallic materials. AuGe is an alloying material. These materials can be used as single-layer films or multilayer films.

[0021] (4-2) Configuration of the fourth conductive layer 34 The fourth conductive layer 34 is formed on the substrate 10 around the outer periphery of the light-emitting element 2, with the insulator 11 interposed between them. The fourth conductive layer 34 is configured as wiring that supplies current to the light-emitting element 2. The fourth conductive layer 34 is formed of, for example, Au. The Au is formed to a thickness of, for example, 0.5 μm to 5 μm. Furthermore, the fourth conductive layer 34 may be formed from the same material as the material exemplified in the first conductive layer 31.

[0022] (4-3) Composition of the adhesive layer 35 The adhesive layer 35 is formed extending from the first conductive layer 31 to the fourth conductive layer 34. That is, one end of the adhesive layer 35 is laminated on the first conductive layer 31, and the other end of the adhesive layer 35 is laminated on the fourth conductive layer 34. The middle portion of the adhesive layer 35 is formed on the insulator 11. In this configuration, in a plan view, the position of the end face of the adhesive layer 35, excluding the connection point between the first conductive layer 31 and the fourth conductive layer 34, is set to be inward from the position of the end face of the first conductive layer 31. Similarly, the position of the end face of the adhesive layer 35 is set to be inward from the position of the end face of the fourth conductive layer 34.

[0023] The adhesive layer 35 has stronger adhesive force (or bonding force) to each of the first conductive layer 31, the second conductive layer 32, and the fourth conductive layer 34 than the adhesive force between the first conductive layer 31 and the second conductive layer 32, and between the fourth conductive layer 34 and the second conductive layer 32. For example, Ti is used for the adhesive layer 35. The Ti is formed to a thickness of, for example, 10 nm to 100 nm. In addition, the adhesive layer 35 can be formed from one or more materials selected from Ni, Al, Pd, Mg, Si, Cu, Ag, and TiW, in addition to the above-mentioned Ti.

[0024] (4-4) Configuration of the second conductive layer 32 The second conductive layer 32 is configured as an electrode on both the first conductive layer 31 and the fourth conductive layer 34. Furthermore, the second conductive layer 32 is configured as a bridge wiring that electrically connects the first conductive layer 31 to the fourth conductive layer 34. The second conductive layer 32 is formed in a state that covers the end face and top surface of the adhesive layer 35. The second conductive layer 32 is made of a material that is less susceptible to deterioration when exposed to high temperature and high humidity environments compared to the adhesive layer 35. For example, the second conductive layer 32 is made of a material that is less susceptible to oxidation or nitriding compared to the adhesive layer 35. Furthermore, a portion of the second conductive layer 32 also covers the first conductive layer 31 and is electrically connected to the first conductive layer 31. Similarly, another portion of the second conductive layer 32 covers the fourth conductive layer 34 and is electrically connected to the fourth conductive layer 34. The second conductive layer 32 covers the adhesive layer 35 and also covers the first conductive layer 31 and the fourth conductive layer 34 from the adhesive layer 35. As a result, the penetration paths to the interface between the adhesive layer 35 and the first conductive layer 31, and to the interface between the adhesive layer 35 and the fourth conductive layer 34, are both blocked by the second conductive layer 32.

[0025] The second conductive layer 32 is formed of, for example, Au. The Au is formed using electroplating or electroless plating. The second conductive layer 32 is formed to be thicker than the adhesive layer 35, for example, to a thickness of 0.5 μm or more and 3.0 μm or less. The second conductive layer 32 can be formed from one or more materials selected from Cu, Ni, Co, Sn, Pt, Ag, Pb, Zn, and Pd, in addition to Au. All of these materials can be formed by plating.

[0026] [Manufacturing method for conductive layer structure 3] Here, the explanation of the manufacturing method for the light-emitting element 2 is omitted, and only the manufacturing method for the conductive layer structure 3 is briefly explained. Figures 2A, 3A, and 4A show plan views for each step in the manufacturing process of the conductive layer structure 3. Figure 2B shows a cross-sectional view of the conductive layer structure 3 cut along the AA cutting line shown in Figure 2A, and Figure 2C shows a cross-sectional view of the conductive layer structure 3 cut along the BB cutting line shown in Figure 2A. Figure 3B shows a cross-sectional view of the conductive layer structure 3 cut along the AA cutting line shown in Figure 3A, and Figure 3C shows a cross-sectional view of the conductive layer structure 3 cut along the BB cutting line shown in Figure 3A. Figure 4B shows a cross-sectional view of the conductive layer structure 3 cut along the AA cutting line shown in Figure 4A, and Figure 4C shows a cross-sectional view of the conductive layer structure 3 cut along the BB cutting line shown in Figure 4A.

[0027] After the light-emitting element 2 is formed on the substrate 10 (see Figure 1), the first conductive layer 31 and the fourth conductive layer 34 are formed, as shown in Figures 2A to 2C. The first conductive layer 31 is formed on the second reflective layer 24 of the light-emitting element 2. The first conductive layer 31 is formed using, for example, a vapor deposition method, a sputtering method, or a plating method. The fourth conductive layer 34 is formed at a position spaced apart from the light-emitting element 2 with an insulator 11 interposed between it and the first conductive layer 31. The fourth conductive layer 34 is formed using, for example, a vapor deposition method, a sputtering method, or a plating method.

[0028] Next, as shown in Figures 3A to 3C, an adhesive layer 35 is formed extending from the first conductive layer 31 to the fourth conductive layer 34. The adhesive layer 35 is formed using, for example, a sputtering method.

[0029] Next, as shown in Figures 1 and 4A to 4C above, the second conductive layer 32 is formed covering the adhesive layer 35, including its end face and top face. A portion of the second conductive layer 32 is also formed on the first conductive layer 31, and the second conductive layer 32 is electrically connected to the first conductive layer 31. Similarly, another portion of the second conductive layer 32 is also formed on the fourth conductive layer 34, and the second conductive layer 32 is electrically connected to the fourth conductive layer 34. In other words, the second conductive layer 32 is formed as a bridge wiring connecting the first conductive layer 31 and the fourth conductive layer 34. The second conductive layer 32 is formed using electrolytic plating or electroless plating. Therefore, the second conductive layer 32 is selectively deposited on the exposed surfaces of the first conductive layer 31, the fourth conductive layer 34, and the adhesive layer 35. Consequently, photolithography and etching techniques are not required for the formation of the second conductive layer 32.

[0030] [Effects and Effects] The conductive layer structure 3 according to the first embodiment comprises a first conductive layer 31 and a second conductive layer 32, as shown in Figure 1. The second conductive layer 32 is electrically connected to the first conductive layer 31 via an adhesive layer 35. The adhesive layer 35 is conductive and has a stronger adhesive force to the first conductive layer 31 and the second conductive layer 32 than the adhesive force between the first conductive layer 31 and the second conductive layer 32. The second conductive layer 32 is less susceptible to deterioration than the adhesive layer 35 and, including its end faces, covers the adhesive layer 35, with a portion of it connected to the first conductive layer 31. Here, with the adhesive force between the first conductive layer 31 and the second conductive layer 32 strengthened by the adhesive layer 35, the adhesive layer 35 is covered by the second conductive layer 32. In other words, even when exposed to a high-temperature, high-humidity environment, the entry routes for oxygen and other elements into the adhesive layer 35 are blocked. Therefore, it is possible to effectively suppress or prevent an increase in the resistance value of the current path caused by deterioration of the adhesive layer 35. In addition, since a portion of the second conductive layer 32 is directly electrically connected to the first conductive layer 31, the resistance of the current path from the first conductive layer 31 to the second conductive layer 32 can be further reduced.

[0031] Furthermore, in the conductive layer structure 3, as shown in Figure 1, the second conductive layer 32 is thicker than the adhesive layer 35. This allows for an increase in the overall thickness of the conductive layer structure 3, further reducing the resistance of the current path.

[0032] Furthermore, in the conductive layer structure 3 and the method for manufacturing the conductive layer structure 3, as shown in Figures 1, 2A to 2C, and 3A to 3C, the second conductive layer 32 is a plated layer formed by electrolytic plating or electroless plating. The second conductive layer 32 covers the adhesive layer 35, including the end face and the top face, and is also formed on the surface of the first conductive layer 31 that is exposed from the adhesive layer 35, and is formed extending from the adhesive layer 35 to the first conductive layer 31. Therefore, not only the exposed surface of the adhesive layer 35, but also the entry routes for oxygen and other elements into the interface between the first conductive layer 31 and the adhesive layer 35 are eliminated. Consequently, deterioration of the adhesive layer 35 can be effectively suppressed or prevented, and the increase in the resistance value of the current path caused by deterioration of the adhesive layer 35 can be suppressed or prevented even more effectively. In addition, since a portion of the second conductive layer 32 is directly electrically connected to the first conductive layer 31, the resistance of the current path from the first conductive layer 31 to the second conductive layer 32 can be further reduced.

[0033] The conductive layer structure 3 according to the first embodiment, as shown in Figure 1, comprises a first conductive layer 31, a fourth conductive layer 34, and a second conductive layer 32. The fourth conductive layer 34 is formed by interposing an insulator 11 on the first conductive layer 31. The second conductive layer 32 connects one end to the first conductive layer 31 by interposing an adhesive layer 35, forms an intermediate portion on the insulator 11, and connects the other end to the fourth conductive layer 34 by interposing an adhesive layer 35. The adhesive layer 35 is conductive and has a stronger adhesive force to each of the first conductive layer 31, second conductive layer 32, and fourth conductive layer 34 than the adhesive force between the first conductive layer 31 and the second conductive layer 32, or between the fourth conductive layer 34 and the second conductive layer 32. Furthermore, the second conductive layer 32 is less susceptible to deterioration than the adhesive layer 35, and in a state where it covers the adhesive layer 35, including the end face and top face, a portion of it is connected to the first conductive layer 31 and another portion is connected to the fourth conductive layer 34. Here, in a state where the adhesive force between the first conductive layer 31 and the second conductive layer 32, and the adhesive force between the fourth conductive layer 34 and the second conductive layer 32 are strengthened by the adhesive layer 35, the adhesive layer 35 is covered by the second conductive layer 32. In other words, even when exposed to a high temperature and high humidity environment, the entry route of oxygen and other elements into the adhesive layer 35 is blocked. Therefore, it is possible to effectively suppress or prevent an increase in the resistance value of the current path caused by deterioration of the adhesive layer 35. In addition, since a portion of the second conductive layer 32 is directly electrically connected to the first conductive layer 31 and the fourth conductive layer 34, the resistance of the current path from the first conductive layer 31 through the second conductive layer 32 to the fourth conductive layer 34 can be further reduced.

[0034] The light-emitting device 1 according to the first embodiment comprises a light-emitting element 2 and a conductive layer structure 3, as shown in Figure 1. The conductive layer structure 3 is connected to the light-emitting element 2 and supplies current to the light-emitting element 2. The conductive layer structure 3 comprises a first conductive layer 31 and a second conductive layer 32. The second conductive layer 32 is electrically connected to the first conductive layer 31 via an adhesive layer 35. The adhesive layer 35 is conductive and has a stronger adhesive force to the first conductive layer 31 and the second conductive layer 32 than the adhesive force between the first conductive layer 31 and the second conductive layer 32. The second conductive layer 32 is less susceptible to deterioration than the adhesive layer 35 and, including its end face and top face, covers the adhesive layer 35, with a portion of it connected to the first conductive layer 31. Here, with the adhesive force between the first conductive layer 31 and the second conductive layer 32 strengthened by the adhesive layer 35, the adhesive layer 35 is covered by the second conductive layer 32. In other words, even when exposed to a high-temperature, high-humidity environment, the entry routes for oxygen and other elements into the adhesive layer 35 are blocked. Therefore, it is possible to effectively suppress or prevent an increase in the resistance value of the current path caused by deterioration of the adhesive layer 35. In addition, since a portion of the second conductive layer 32 is directly electrically connected to the first conductive layer 31, the resistance of the current path from the first conductive layer 31 to the second conductive layer 32 can be further reduced. In the light-emitting device 1 configured in this way, the resistance value of the current path in the conductive layer structure 3 is small, so it is possible to effectively suppress or prevent increases in the driving voltage and malfunctions in light emission.

[0035] <2. Second Embodiment> The conductive layer structure 3 and light-emitting device 1 according to the second embodiment of this disclosure will be explained with reference to Figure 5. In the second embodiment and subsequent embodiments, the same or substantially the same components as those of the conductive layer structure 3 and light-emitting device 1 according to the first embodiment will be denoted by the same reference numerals, and redundant explanations will be omitted.

[0036] [Configuration of conductive layer structure 3 and light-emitting device 1] Figure 5 shows a longitudinal cross-sectional structure of an example of a conductive layer structure 3 and light-emitting device 1 according to the second embodiment. The light-emitting device 1 according to the second embodiment, like the light-emitting device 1 according to the first embodiment, includes a conductive layer structure 3. The conductive layer structure 3 includes a first conductive layer 31 formed on the second reflective layer 24 of the light-emitting element 2, and a second conductive layer 32 electrically connected to the first conductive layer 31 by an adhesive layer 35 interposed therebetween. In the conductive layer structure 3, a fourth conductive layer 34 is formed around the outer periphery of the light-emitting element 2.

[0037] The conductive layer structure 3 electrically connects the second conductive layer 32 and the fourth conductive layer 34 with a wire 5. The wire 5 is formed using, for example, an ultrasonic bonding method that also uses ultrasonic vibration. For example, an Au wire is used for the wire 5. Note that wire 5 is not limited to Au wire. For example, Al wire, Cu wire, etc. can be used for wire 5.

[0038] Other components are the same as those of the conductive layer structure 3 and the light-emitting device 1 according to the first embodiment.

[0039] [Effects and Effects] In the conductive layer structure 3 and light-emitting device 1 according to the second embodiment, the same effects and benefits as those obtained with the conductive layer structure 3 and light-emitting device 1 according to the first embodiment can be obtained.

[0040] <3. Third Embodiment> The conductive layer structure 3 and light-emitting device 1 according to the third embodiment of this disclosure will be explained using Figures 6, 7A-7C, 8A-8C, and 9A-9C.

[0041] [Configuration of conductive layer structure 3 and light-emitting device 1] Figure 6 shows a longitudinal cross-sectional structure of an example of a conductive layer structure 3 and a light-emitting device 1 according to the third embodiment.

[0042] The light-emitting device 1 according to the third embodiment is equipped with a conductive layer structure 3, similar to the light-emitting device 1 according to the first embodiment. The conductive layer structure 3 comprises a first conductive layer 31 formed on the second reflective layer 24 of the light-emitting element 2, a third conductive layer 33 electrically connected to the first conductive layer 31 via an adhesive layer 35, and a second conductive layer 32 electrically connected to the third conductive layer 33. In the conductive layer structure 3, a fourth conductive layer 34 is formed around the outer periphery of the light-emitting element 2. The fourth conductive layer 34 comprises a third conductive layer 33 electrically connected via an adhesive layer 35, and a second conductive layer 32 electrically connected to the third conductive layer 33. In other words, the adhesive layer 35, the third conductive layer 33, and the second conductive layer 32 are formed extending from the first conductive layer 31 to the fourth conductive layer 34, forming a bridge wiring.

[0043] The third conductive layer 33 is formed to have the same planar shape as the adhesive layer 35 in a planar view. In the manufacturing method, the adhesive layer 35 is patterned using the same mask that is used to pattern the third conductive layer 33 by photolithography. The third conductive layer 33 is formed of, for example, Au. The third conductive layer 33 is formed to a thickness of, for example, 10 nm to 100 nm. In addition to Au, the third conductive layer 33 can be made of the materials exemplified in the first conductive layer 31 described above.

[0044] The second conductive layer 32 is formed on the surface of the third conductive layer 33, and is also formed on the surfaces of the adhesive layer 35, the first conductive layer 31, and the fourth conductive layer 34 that are exposed from the third conductive layer 33.

[0045] Other components are the same as those of the conductive layer structure 3 and the light-emitting device 1 according to the first embodiment.

[0046] [Manufacturing method for conductive layer structure 3] Next, a brief explanation will be given of the method for manufacturing the conductive layer structure 3 according to the third embodiment. Figures 7A to 9A show plan views for each step in the manufacturing process of the conductive layer structure 3. Figure 7B shows a cross-sectional view of the conductive layer structure 3 cut along the CC cutting line shown in Figure 7A, and Figure 7C shows a cross-sectional view of the conductive layer structure 3 cut along the DD cutting line shown in Figure 7A. Figure 8B shows a cross-sectional view of the conductive layer structure 3 cut along the CC cutting line shown in Figure 8A, and Figure 8C shows a cross-sectional view of the conductive layer structure 3 cut along the DD cutting line shown in Figure 8A. Figure 9B shows a cross-sectional view of the conductive layer structure 3 cut along the CC cutting line shown in Figure 9A, and Figure 9C shows a cross-sectional view of the conductive layer structure 3 cut along the DD cutting line shown in Figure 9A.

[0047] After the light-emitting element 2 is formed on the substrate 10 (see Figure 6), the first conductive layer 31 and the fourth conductive layer 34 are formed, as shown in Figures 7A to 7C. The first conductive layer 31 is formed on the second reflective layer 24 of the light-emitting element 2. The fourth conductive layer 34 is formed at a position spaced apart from the light-emitting element 2, with an insulator 11 interposed between it and the first conductive layer 31.

[0048] Next, as shown in Figures 8A to 8C, an adhesive layer 35 and a third conductive layer 33 are formed extending from the first conductive layer 31 to the fourth conductive layer 34. The third conductive layer 33 is formed by laminating it onto the adhesive layer 35. The third conductive layer 33 is formed using, for example, a vapor deposition method or a sputtering method. The third conductive layer 33 and the adhesive layer 35 are patterned by etching using the same mask formed by photolithography.

[0049] Next, as shown in Figures 1 and 9A to 9C above, the second conductive layer 32 is formed, including the end face of the adhesive layer 35, and covering the adhesive layer 35 and the third conductive layer 33. A portion of the second conductive layer 32 is also formed on the first conductive layer 31, and the second conductive layer 32 is electrically connected to the first conductive layer 31. Similarly, another portion of the second conductive layer 32 is also formed on the fourth conductive layer 34, and the second conductive layer 32 is electrically connected to the fourth conductive layer 34. In other words, the second conductive layer 32 is formed as a bridge wiring connecting the first conductive layer 31 and the fourth conductive layer 34. The second conductive layer 32 is formed using electrolytic plating or electroless plating. Therefore, the second conductive layer 32 is selectively deposited on the exposed surfaces of the first conductive layer 31, the fourth conductive layer 34, the adhesive layer 35, and the third conductive layer 33. Consequently, photolithography and etching techniques are not required for the formation of the second conductive layer 32.

[0050] [Effects and Effects] In the conductive layer structure 3 and light-emitting device 1 according to the third embodiment, the same effects and benefits as those obtained with the conductive layer structure 3 and light-emitting device 1 according to the first embodiment can be obtained.

[0051] <4. Fourth Embodiment> The conductive layer structure 3 and light-emitting device 1 according to the fourth embodiment of this disclosure will be explained with reference to Figure 10.

[0052] [Configuration of conductive layer structure 3 and light-emitting device 1] (1) General outline of the conductive layer structure 3 and the light-emitting device 1 Figure 10 shows a longitudinal cross-sectional structure of an example of a conductive layer structure 3 and a light-emitting device 1 according to the fourth embodiment of this disclosure.

[0053] The light-emitting device 1 according to the fourth embodiment includes a light-emitting element 6. Furthermore, the light-emitting device 1 includes a conductive layer structure 3. The light-emitting element 6 is stacked on a base substrate 12 within a region surrounded on its sides by an insulator 14. In the fourth embodiment, the light-emitting element 6 is a light-emitting diode (LED). The light-emitting element 6 is formed by sequentially stacking a first semiconductor layer 61 of a first conductivity type, a light-emitting layer 62, and a second semiconductor layer 63 of a second conductivity type. Multiple light-emitting elements 6 are arranged in both the X-direction and the Y-direction, with an insulator 14 in between.

[0054] On the other hand, the conductive layer structure 3 comprises a first conductive layer 31, a fourth conductive layer 34 formed by interposing an insulator 14 on the first conductive layer 31, and a second conductive layer 32 electrically connected to the first conductive layer 31 and the fourth conductive layer 34 by interposing an adhesive layer 35 on each. The first conductive layer 31, the adhesive layer 35, and the second conductive layer 32 are used as electrodes formed on the second semiconductor layer 63 of the light-emitting element 6 on the right side of the figure. The fourth conductive layer 34, the adhesive layer 35, and the second conductive layer 32 are used as electrodes formed on the second semiconductor layer 63 of the light-emitting element 6 on the left side of the figure. The fourth conductive layer 34 is formed here from the same material as the first conductive layer 31 and is also formed as the same electrode layer. Furthermore, the second conductive layer 32 is also configured as a bridge wiring connecting the first conductive layer 31 and the fourth conductive layer 34.

[0055] Other components are the same as those of the conductive layer structure 3 and the light-emitting device 1 according to the first embodiment.

[0056] [Effects and Effects] In the conductive layer structure 3 and light-emitting device 1 according to the fourth embodiment, the same effects and benefits as those obtained with the conductive layer structure 3 and light-emitting device 1 according to the first embodiment can be obtained.

[0057] In addition, the conductive layer structure 3 and light-emitting device 1 according to the fourth embodiment may employ the conductive layer structure 3 according to the second or third embodiment.

[0058] <5. Other Embodiments> This technology is not limited to the embodiments described above, and can be modified in various ways without departing from its essence. For example, in the above embodiment, an example of the application of this technology to the conductive layer structure of a light-emitting device was described. However, this technology is not limited to light-emitting devices and can be broadly applied to semiconductor devices such as imaging devices and memory devices, liquid crystal display devices, wiring boards, and the conductive layer structures used therein.

[0059] The conductive layer structure according to the first embodiment of this disclosure comprises a first conductive layer and a second conductive layer. The second conductive layer is electrically connected to the first conductive layer via an adhesive layer. The adhesive layer is conductive and has an adhesive force to the first conductive layer and the second conductive layer that is stronger than the adhesive force between the first conductive layer and the second conductive layer. The second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top face of the adhesive layer, and covers a portion of the first conductive layer. In this configuration, the adhesive layer strengthens the bonding force between the first conductive layer and the second conductive layer, and the adhesive layer is then covered by the second conductive layer. This means that even when exposed to high temperature and high humidity environments, the entry routes for oxygen and other elements into the adhesive layer are blocked. Therefore, it is possible to effectively suppress or prevent an increase in the resistance value of the current path caused by deterioration of the adhesive layer.

[0060] A conductive layer structure according to a second embodiment of the present disclosure comprises a first conductive layer, a second conductive layer, and a third conductive layer. The third conductive layer is electrically connected to the first conductive layer via an adhesive layer. The second conductive layer is electrically connected to the third conductive layer. The adhesive layer is conductive and has an adhesive force to the first conductive layer and the third conductive layer that is stronger than the adhesive force between the first conductive layer and the third conductive layer. The second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top face of the adhesive layer, and covers a portion of the first conductive layer. In this configuration, the adhesive layer strengthens the bonding force between the first conductive layer and the third conductive layer, and the adhesive layer is then covered by the second conductive layer. This means that even when exposed to high temperature and high humidity environments, the entry of oxygen and other elements into the adhesive layer is blocked. Therefore, the increase in resistance of the current path caused by deterioration of the adhesive layer can be effectively suppressed or prevented.

[0061] The conductive layer structure according to the third embodiment of this disclosure comprises a first conductive layer, a fourth conductive layer, and a second conductive layer. The fourth conductive layer is formed by interposing an insulator on the first conductive layer. The second conductive layer connects one end to the first conductive layer by interposing an adhesive layer, forms an intermediate portion in the insulator, and connects the other end to the fourth conductive layer by interposing an adhesive layer. The adhesive layer is conductive and has an adhesive force to each of the first, second, and fourth conductive layers that is stronger than the adhesive force between the first and second conductive layers, or between the fourth and second conductive layers. The second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top surface of the adhesive layer, and covers a part of the first conductive layer and a part of the fourth conductive layer. Here, the adhesive layer is covered by the second conductive layer when the adhesive force between the first conductive layer and the second conductive layer, and the adhesive force between the fourth conductive layer and the second conductive layer, are strengthened by the adhesive layer. In other words, even when exposed to a high-temperature, high-humidity environment, the entry route for oxygen and other elements into the adhesive layer is blocked. Therefore, it is possible to effectively suppress or prevent an increase in the resistance value of the current path caused by deterioration of the adhesive layer.

[0062] A light-emitting device according to a fourth embodiment of the present disclosure comprises a light-emitting element and a conductive layer structure formed on the light-emitting element and supplying current to the light-emitting element. The conductive layer structure comprises a first conductive layer and a second conductive layer. The second conductive layer is electrically connected to the first conductive layer by an adhesive layer interposed therebetween. The adhesive layer is conductive and has an adhesive force to the first conductive layer and the second conductive layer that is stronger than the adhesive force between the first conductive layer and the second conductive layer. The second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top face of the adhesive layer, and covers a portion of the first conductive layer. Here, with the adhesive force between the first conductive layer and the second conductive layer strengthened by the adhesive layer, the adhesive layer is covered by the second conductive layer. In other words, even when exposed to a high-temperature, high-humidity environment, the entry route for oxygen and other elements into the adhesive layer is blocked. Therefore, it is possible to effectively suppress or prevent an increase in the resistance value of the current path caused by deterioration of the adhesive layer. Consequently, in the light-emitting device, since the resistance value of the current path in the conductive layer structure is small, it is possible to effectively suppress or prevent an increase in the driving voltage and light emission failure.

[0063] <Structure of this technology> This technology has the following configuration. According to this technology with the following configuration, it is possible to provide a conductive layer structure and a light-emitting device that can effectively suppress or prevent the increase in resistance of the current path caused by the use of an adhesive layer. (1) First conductive layer and The first conductive layer is electrically connected to the second conductive layer via an adhesive layer, The adhesive layer is conductive and has a stronger adhesive force to the first conductive layer and the second conductive layer than the adhesive force between the first conductive layer and the second conductive layer. The conductive layer structure is such that the second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top surface of the adhesive layer, and covers a portion of the first conductive layer. (2) The second conductive layer is thicker than the adhesive layer The conductive layer structure described in (1) above. (3) The adhesive layer is formed of one or more materials selected from Ti, Ni, Al, Pd, Mg, Si, Cu, Ag and TiW. The conductive layer structure described in (1) or (2) above. (4) The first conductive layer is formed of one or more materials selected from Au, Al, Cu, Ag, Rh, W, Mo, Ni, Pd, ITO, ITiO, ZnO, and AuGe. The conductive layer structure described in any one of (1) to (3) above. (5) The second conductive layer is formed by electroplating or electroless plating. The conductive layer structure described in any one of (1) to (4) above. (6) The second conductive layer is formed of one or more materials selected from Au, Cu, Ni, Co, Sn, Pt, Ag, Pb, Zn, and Pd. The conductive layer structure described in any one of (1) to (5) above. (7) The first conductive layer, the adhesive layer, and the second conductive layer constitute the electrodes of the light-emitting element. The conductive layer structure described in any one of (1) to (6) above. (8) First conductive layer and A third conductive layer electrically connected to the first conductive layer via an adhesive layer, The third conductive layer comprises a second conductive layer electrically connected to the third conductive layer, The adhesive layer is conductive and has a stronger adhesive force to the first conductive layer and the third conductive layer than the adhesive force between the first conductive layer and the third conductive layer. The conductive layer structure is such that the second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top surface of the adhesive layer, and covers a portion of the first conductive layer. (9) The adhesive layer and the third conductive layer are formed to be the same shape when viewed from the direction of stacking. The conductive layer structure described in (8) above. (10) The second conductive layer is formed by electroplating or electroless plating. The conductive layer structure described in (8) or (9) above. (11) First conductive layer and A fourth conductive layer formed by interposing an insulator in the first conductive layer, The material comprises a second conductive layer, one end of which is connected to the first conductive layer with an adhesive layer interposed therebetween, forming an intermediate portion on the insulator, and the other end of which is formed on the fourth conductive layer with the adhesive layer interposed therebetween, The adhesive layer is conductive and has an adhesive force to each of the first conductive layer, the second conductive layer, and the fourth conductive layer that is stronger than the adhesive force between the first conductive layer and the second conductive layer, or between the fourth conductive layer and the second conductive layer. The conductive layer structure is such that the second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top surface of the adhesive layer, and covers a part of the first conductive layer and a part of the fourth conductive layer. (12) The second conductive layer is formed by electroplating or electroless plating. The conductive layer structure described in (11) above. (13) Light-emitting element, It comprises a conductive layer structure connected to the light-emitting element and supplying current to the light-emitting element, The aforementioned conductive layer structure is First conductive layer and The first conductive layer is electrically connected to the second conductive layer via an adhesive layer, The adhesive layer is conductive and has a stronger adhesive force to the first conductive layer and the second conductive layer than the adhesive force between the first conductive layer and the second conductive layer. A light-emitting device wherein the second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top surface of the adhesive layer, and covers a portion of the first conductive layer. (14) The light-emitting element is a surface-emitting laser or a light-emitting diode. The light-emitting device described in (13) above. (15) Form a first conductive layer, An adhesive layer is formed on the first conductive layer. The process comprises steps of forming a second conductive layer electrically connected to the first conductive layer by interposing the adhesive layer, The adhesive layer is conductive and has a stronger adhesive force to the first conductive layer and the second conductive layer than the adhesive force between the first conductive layer and the second conductive layer. A method for forming a conductive layer structure, wherein the second conductive layer is formed from a material that is less susceptible to deterioration than the adhesive layer, and is formed on the exposed surfaces of the first conductive layer and the adhesive layer by plating. (16) Form a first conductive layer, An adhesive layer is formed on the first conductive layer. A second conductive layer is formed electrically connected to the first conductive layer by interposing the adhesive layer. The process comprises steps for forming a third conductive layer electrically connected to the second conductive layer, The adhesive layer is conductive and has a stronger adhesive force to the first conductive layer and the third conductive layer than the adhesive force between the first conductive layer and the third conductive layer. A method for forming a conductive layer structure, wherein the second conductive layer is formed from a material that is less susceptible to deterioration than the adhesive layer, and is formed by plating on the exposed surfaces of the first conductive layer, the third conductive layer, and the adhesive layer. (17) Form a first conductive layer, A fourth conductive layer is formed by interposing an insulator in the first conductive layer. An adhesive layer is formed on the first conductive layer and the fourth conductive layer, respectively. The process comprises the steps of forming a second conductive layer, in which one end is electrically connected to the first conductive layer by interposing the adhesive layer, and the other end is electrically connected to the fourth conductive layer by interposing the adhesive layer, The adhesive layer is conductive and has an adhesive force to each of the first conductive layer, the second conductive layer, and the fourth conductive layer that is stronger than the adhesive force between the first conductive layer and the second conductive layer, or between the fourth conductive layer and the second conductive layer. A method for forming a conductive layer structure, wherein the second conductive layer is formed from a material that is less susceptible to deterioration than the adhesive layer, and is formed by plating on the exposed surfaces of the first conductive layer, the fourth conductive layer, and the adhesive layer.

[0064] In the method for manufacturing the conductive layer structure described in (15) to (17) above, the second conductive layer is formed by plating, so the second conductive layer is selectively formed on the surface of the first conductive layer, adhesive layer, etc. Therefore, the steps of forming a mask by photolithography and patterning by etching can be eliminated, thus reducing the number of manufacturing steps in the method for manufacturing the conductive layer structure. Furthermore, since the number of manufacturing steps can be reduced, the manufacturing yield can be improved.

[0065] This application claims priority based on Japanese Patent Application No. 2021-130944, filed with the Japan Patent Office on 10 August 2021, and all contents of that application are incorporated herein by reference.

[0066] Those skilled in the art will understand that various modifications, combinations, subcombinations, and changes can be conceived depending on design requirements and other factors, and that these fall within the scope of the attached claims and their equivalents.

Claims

1. First conductive layer and A fourth conductive layer formed by interposing an insulator in the first conductive layer, The material comprises a second conductive layer, one end of which is connected to the first conductive layer with an adhesive layer interposed therebetween, forming an intermediate portion on the insulator, and the other end of which is formed on the fourth conductive layer with the adhesive layer interposed therebetween, The adhesive layer is conductive and has an adhesive force to each of the first conductive layer, the second conductive layer, and the fourth conductive layer that is stronger than the adhesive force between the first conductive layer and the second conductive layer, or between the fourth conductive layer and the second conductive layer. The second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top surface of the adhesive layer, covers a portion of the first conductive layer and a portion of the fourth conductive layer, and is electrically connected to a portion of the first conductive layer and a portion of the fourth conductive layer. Conductive layer structure.

2. The second conductive layer is thicker than the adhesive layer. The conductive layer structure according to claim 1.

3. The adhesive layer is formed from one or more materials selected from Ti, Ni, Al, Pd, Mg, Si, Cu, Ag, and TiW. The conductive layer structure according to claim 1.

4. The first conductive layer is formed from one or more materials selected from Au, Al, Cu, Ag, Rh, W, Mo, Ni, Pd, ITO, ITiO, ZnO, and AuGe. The conductive layer structure according to claim 1.

5. The second conductive layer is formed by electroplating or electroless plating. The conductive layer structure according to claim 1.

6. The second conductive layer is formed of one or more materials selected from Au, Cu, Ni, Co, Sn, Pt, Ag, Pb, Zn, and Pd. The conductive layer structure according to claim 5.

7. The first conductive layer, the adhesive layer, and the second conductive layer constitute the electrodes of the light-emitting element. The conductive layer structure according to claim 1.

8. The fourth conductive layer is formed of Au The conductive layer structure according to claim 1.

9. Light-emitting element and It comprises a conductive layer structure connected to the light-emitting element and supplying current to the light-emitting element, The aforementioned conductive layer structure is First conductive layer and A fourth conductive layer formed by interposing an insulator in the first conductive layer, The material comprises a second conductive layer, one end of which is connected to the first conductive layer with an adhesive layer interposed therebetween, forming an intermediate portion on the insulator, and the other end of which is formed on the fourth conductive layer with the adhesive layer interposed therebetween, The adhesive layer is conductive and has an adhesive force to each of the first conductive layer, the second conductive layer, and the fourth conductive layer that is stronger than the adhesive force between the first conductive layer and the second conductive layer, or between the fourth conductive layer and the second conductive layer. The second conductive layer is less susceptible to deterioration than the adhesive layer, covers the end face and top surface of the adhesive layer, covers a portion of the first conductive layer and a portion of the fourth conductive layer, and is electrically connected to a portion of the first conductive layer and a portion of the fourth conductive layer. Light-emitting device.

10. The light-emitting element is a surface-emitting laser or a light-emitting diode. The light-emitting device according to claim 9.

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