Semiconductor light emitting device and method for manufacturing the same

Abstract

To provide a semiconductor light emitting device capable of bonding a phosphor plate and a light emitting element by surface activated bonding in air.SOLUTION: A semiconductor light emitting device has a light emitting element containing a semiconductor light emitting layer and a phosphor plate bonded to the light emitting element. A buffer layer made of dielectric material that transmits the light emitted by the light emitting element is placed between the light emitting element and the phosphor plate. The light emitting element and phosphor plate are bonded through the buffer layer. The buffer layer is amorphous.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a semiconductor light emitting device having a structure in which a semiconductor light emitting element and a phosphor plate are directly bonded to each other without an intermediary of a resin adhesive layer or the like. [Background technology]

[0002] Patent Documents 1 and 2 disclose methods for manufacturing light-emitting devices in which a phosphor plate is directly bonded to a light-emitting element by surface activated bonding (SAB) without using an adhesive when mounting the phosphor plate on the light-emitting element. Light-emitting devices manufactured by these methods do not include an adhesive layer with a refractive index different from that of the light-emitting element or phosphor plate (particularly an adhesive layer with a refractive index lower than that of the light-emitting element or phosphor plate), and therefore the light extraction efficiency from the light-emitting device is improved.

[0003] Specifically, the manufacturing method of Patent Document 1 involves arranging pre-divided light-emitting elements on an intermediate substrate, polishing the bonding surfaces of the light-emitting elements and phosphor ceramic, and then placing the elements in a vacuum device. In the vacuum device, each bonding surface is irradiated with an ion beam of a rare gas element (at least one of He, Ne, Ar, and Kr), and the bonding surfaces are then brought into contact with each other and pressed together to bond them. After the bonded light-emitting elements and phosphor ceramic are removed from the vacuum device, the phosphor ceramic is cut into individual light-emitting devices by dicing to separate them.

[0004] On the other hand, Patent Document 2 discloses a method of manufacturing individual light-emitting devices by directly bonding a substrate of a light-emitting element and a phosphor plate by surface-activated bonding and then cutting both the light-emitting element and the phosphor plate for each light-emitting device. In this manufacturing method, an element substrate on which a plurality of light-emitting elements are formed and a phosphor plate are bonded by surface-activated bonding. Before bonding, the element substrate is thinned by a grinding and polishing technique, and a laser beam is irradiated at a position that becomes the inter-element boundary of the thinned element substrate to form cracks. The phosphor plate is brought into contact with the element substrate having the cracks and pressed to be bonded by surface-activated bonding. Then, the phosphor plate is cut by a blade up to the middle of the thickness of the phosphor plate. Pressing the position that becomes the inter-element boundary from the light-emitting element side cuts the element substrate by the cracks, and at the same time, the semiconductor structure, wiring structure of the light-emitting elements where cracks were not provided, and the uncut portion of the phosphor plate are also cut and fragmented.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the manufacturing method of Patent Document 1, since the bonding surface of the light-emitting element and the phosphor ceramic is surface-treated by irradiating an ion beam of a rare gas element, it is necessary to arrange the light-emitting element and the phosphor ceramic in a vacuum device. After irradiating the ion beam, without opening the vacuum device to the atmosphere, the bonding surface of the light-emitting element and the phosphor ceramic is brought into contact and bonded in a vacuum. Therefore, all operations such as surface activation treatment, alignment, substrate heating, and substrate weighting need to be performed in a vacuum, which complicates the device configuration and makes the device expensive, resulting in an increase in the cost of the product.

[0007] Furthermore, the manufacturing method of Patent Document 1 involves first individualizing and arranging the light-emitting elements, then surface-activating and bonding the phosphor ceramic onto the light-emitting elements, and then cutting the phosphor ceramic into individual light-emitting devices. This creates the problem that the size of the phosphor ceramic in each individual light-emitting device is necessarily larger than that of the light-emitting elements.

[0008] On the other hand, in the manufacturing method of Patent Document 2, the light emitting elements are not singulated in advance, but cracks are introduced in advance in the element substrate by laser light so that the element substrate can be broken later, which reduces the strength of the element substrate. Therefore, when the phosphor plate is brought into contact with the element substrate and pressure is applied for surface activation bonding, it is necessary to limit the load applied in order to prevent the element substrate from cracking.

[0009] Furthermore, in a process after bonding the element substrate and the phosphor plate, the element substrate may crack due to internal stress, external stress, etc. If the element substrate is warped or an external force is applied, the element substrate and the phosphor plate may peel off from each other at the bonding surface.

[0010] An object of the present invention is to provide a semiconductor light emitting device having a highly reliable bond between a phosphor plate and a light emitting element by surface activated bonding. [Means for solving the problem]

[0011] In order to achieve the above object, the semiconductor light emitting device of the present invention has a light emitting element including a semiconductor light emitting layer, and a phosphor plate bonded to the light emitting element. A buffer layer made of a dielectric material that transmits light emitted by the light emitting element is disposed between the light emitting element and the phosphor plate. The light emitting element and the phosphor plate are bonded via the buffer layer. The buffer layer is amorphous. Effect of the Invention

[0012] According to the semiconductor light emitting device of the present invention, the bonding reliability between the phosphor plate and the light emitting element can be improved by surface activated bonding. [Brief description of the drawings]

[0013] [Figure 1] 1A and 1B are a cross-sectional view and a top view of a semiconductor light-emitting device according to a first embodiment. [Diagram 2] 3(a) to 3(g) are explanatory views showing a manufacturing process of the semiconductor light emitting device according to the first embodiment. [Diagram 3] 3(a) to 3(e) are explanatory views showing a manufacturing process of the semiconductor light emitting device according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing the shape of the laminate after the manufacturing process of FIG. [Diagram 5] 5(a) to 5(f) are diagrams showing examples of the cross-sectional shape of a notch 110 formed in the step of FIG. 3(b) in the first embodiment. [Figure 6] 5(a) and 5(b) are a cross-sectional view and a top view of a semiconductor light-emitting device according to a modified example of the first embodiment. [Figure 7] FIG. 4 is a cross-sectional view of a semiconductor light emitting device according to a second embodiment. [Figure 8] 5(a) to 5(g) are explanatory views showing a manufacturing process of the semiconductor light emitting device according to the second embodiment. [Figure 9] 5(a) to 5(e) are explanatory views showing a manufacturing process of the semiconductor light emitting device according to the second embodiment. [Figure 10] 6(a) to 6(j) are explanatory views showing a manufacturing process of the semiconductor light emitting device according to the third embodiment. [Figure 11] FIG. 13 is a cross-sectional view of a semiconductor light emitting device according to a fourth embodiment. [Figure 12] 10(a) to 10(i) are explanatory views showing a manufacturing process of the semiconductor light emitting device according to the fourth embodiment. [Figure 13] 13(h-1), (h-2) and (i) are explanatory views showing another example of the manufacturing process of the semiconductor light emitting device according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below.

[0015] <<First embodiment>> A semiconductor light emitting device according to a first embodiment will be described with reference to Figures 1 to 4. Figures 1(a) and (b) are a cross-sectional view and a top view of a semiconductor light emitting device 1 according to the first embodiment.

[0016] As shown in Fig. 1(a), the semiconductor light-emitting device 1 of this embodiment has a structure in which a phosphor plate 20 is bonded to the upper surface of a light-emitting element 10 by surface activated bonding (SAB). In the semiconductor light-emitting device 1 of Fig. 1(a), the light-emitting element 10 is a flip-chip type light-emitting element, and is configured to include a semiconductor light-emitting layer 12, an element substrate 11 arranged on the upper surface of the light-emitting layer 12, and a pair of electrodes 13 arranged on the lower surface of the semiconductor light-emitting layer 12. The phosphor plate 20 is bonded to the upper surface of the element substrate 11.

[0017] A buffer layer 21 is disposed on the bonding surface between the element substrate 11 and the phosphor plate 20. The side surfaces of the light emitting element 10, the buffer layer 21, and the phosphor plate 20 are partially formed by dicing and partially formed by cleavage, but have a smooth shape without any sharp angles, and are covered with a light-reflective multilayer film 40. The light-reflective multilayer film 40 does not necessarily have to be provided. Instead of forming the light-reflective multilayer film 40, the side surfaces may be covered with a light-reflective resin.

[0018] In the example of Figures 1(a) and (b), the semiconductor light-emitting device 1 is mounted on a wiring board 30 having a pair of wirings 32 and a substrate 31, and the pair of electrodes 13 of the light-emitting element 10 are electrically connected to the pair of wirings 32.

[0019] The light emitting element 10 may be, for example, a blue LED in which the element substrate 11 is any one of a sapphire substrate, a spinel substrate, and a GaN substrate, and the semiconductor light emitting layer 12 includes a GaN layer.

[0020] Phosphor plate 20 absorbs a portion of the light emitted from semiconductor light emitting layer 12 and emits fluorescent light of a predetermined wavelength, thereby converting the wavelength of the light emitted from semiconductor light emitting layer 12 and emitting it from the upper surface.

[0021] The phosphor plate 20 is, for example, a Ce-doped YAG (Y 3 Al 5 O 12 ) Composite ceramic phosphor plate with dispersed phosphor particles (Al 2 O 3 The phosphor plate 20 is made of a composite ceramic phosphor plate (Al 2 O 3 The phosphor plate is not limited to Ce:YAG (YAG / Ce:YAG), but may be a phosphor plate made of a single crystal of Ce:YAG, a phosphor ceramic plate with a YAG base (YAG / Ce:YAG), or glass. In the composite ceramic phosphor plate, the particle size and density of the YAG particles may be appropriately selected according to the application.

[0022] Surface activated bonding utilizes intermolecular forces between materials on both sides of the bonding surface, and the distance between the molecules of the materials on both sides of the bonding surface must be set to a distance at which intermolecular forces act (up to 0.5 nm or less). Therefore, in order to bond the phosphor plate 20 and the element substrate 11 by surface activated bonding, it is necessary to flatten the surfaces of the phosphor plate 20 and the element substrate 11 to a roughness equal to or less than the distance at which intermolecular forces act (up to 0.5 nm or less).

[0023] The composite ceramic phosphor plate constituting phosphor plate 20 is composed of microcrystalline grains, and the hardness of the microcrystalline grains of the ceramic matrix and the microcrystalline grains of the phosphor differs. The hardness of the microcrystalline grains also differs depending on the direction in which the crystal axis of the microcrystals faces in phosphor plate 20. Therefore, even when phosphor plate 20 is polished, surface steps (roughness) of about 1 / 20 the particle size of the abrasive grains in the slurry used for polishing remain.

[0024] Specifically, for example, a composite ceramic phosphor plate (Al 2 O 3 In the case of a phosphor plate 20 of Al / Ce:YAG, when it is mirror-polished with a slurry containing 1 μm diamond particles as abrasive grains,2 O 3 Due to the difference in hardness between Ce and YAG, a step of about 50 nm remains at the boundary between the crystal grains. In addition, in the case of a Ce:YAG phosphor plate with a YAG matrix (a plate in which Ce-doped YAG phosphor particles are dispersed in a YAG ceramic matrix), the matrix and phosphor particles are ceramics of the same chemical formula, but due to the presence of fine crystal grains, a surface step of about ±2 nm (roughness Ra ~ 1.5 nm) remains even when polished by a CMP (chemical mechanical polishing) method with a slurry containing diamond particles with a particle size of 50 nm as an abrasive. Therefore, it is difficult to flatten the surface of the phosphor plate 20 to a roughness below the distance at which intermolecular forces act (~ 0.5 nm or less).

[0025] Therefore, in this embodiment, a buffer layer 21 is disposed on the phosphor plate 20 and on the bonding surface between the light emitting element 10 and the phosphor plate 20. The buffer layer 21 is an amorphous layer of a dielectric material. The amorphous layer can be flattened by polishing or the like to a roughness equal to or less than the distance at which intermolecular forces act (up to 0.5 nm or less). Therefore, by disposing the amorphous buffer layer 21 at least on the lower surface of the phosphor plate 20, it can be easily bonded to the light emitting element 10 by surface activated bonding.

[0026] The amorphous buffer layer 21 may be provided not only on the lower surface of the phosphor plate 20 but also on both the upper surface of the element substrate 11. Also, the buffer layer 21 may be provided only on the element substrate 11.

[0027] The amorphous buffer layer 21 referred to here is one that does not show any diffraction peaks in the X-ray diffraction chart when X-ray diffraction is measured. However, although the amorphous buffer layer 21 does not show any diffraction peaks derived from crystals in X-ray diffraction in principle, it is acceptable for peaks to appear due to microcrystalline grains generated at the interface with the underlayer when the buffer layer 21 is formed. Even in this case, the volume ratio of the amorphous phase in the amorphous buffer layer 21 to the entire layer is preferably 90% or more. The buffer layer 21 is preferably transparent to the light emitted by the light emitting element 10, and in particular, is preferably free from light absorption over the entire white spectrum.

[0028] The buffer layer 21 may be made of any inorganic material that has a thermal expansion coefficient and refractive index close to those of the joined members, the phosphor plate 20 and the light emitting element 10, has excellent thermal conductivity when made into a thin film, has good acid-alkali resistance, and is less susceptible to stress corrosion, and can be polished to a roughness equal to or less than the distance at which intermolecular forces act (up to 0.5 nm or less). The buffer layer 21 preferably has a relatively high Young's modulus (hardness).

[0029] For example, the buffer layer 21 may be made of an oxide containing Al (aluminum oxide, Al 2 O 3 etc.), silicon oxide (SiO 2 etc.), niobium oxide (Nb 2 O 5 etc.), tantalum oxide (Ta 2 O 5 etc.), titanium dioxide (TiO 2 etc.), yttrium oxide (Y 2 O 3 etc.), magnesium oxide (MgO etc.) and zirconium oxide (ZrO 2 In particular, inorganic transparent dielectric materials such as oxides containing Al (Al 2 O 3 ) is suitable for the buffer layer 21 because it has a thermal expansion coefficient and a refractive index close to those of the phosphor plate 20 and the light emitting element 10, has high thermal conductivity when made into a thin film, and is resistant to corrosion.

[0030] The reason why the thermal expansion coefficient of the buffer layer 21 is preferably close to that of the bonded members is that if the difference in thermal expansion coefficient between the bonded members and the buffer layer is large, the distortion will be large when the temperature is returned to room temperature after bonding. 2 O 3 etc.) are silicon oxide (SiO 2Since the difference in thermal expansion coefficient between the joined parts is small compared to other materials, there is little joint distortion in the usage environment and the joint has high resistance to environmental temperature changes (thermal shock).

[0031] The higher the thermal conductivity of the buffer layer 21, the more the heat generated from the phosphor plate 20 can be dissipated to the outside via the light emitting element 10 and the mounting substrate. 2 O 3 etc.) are silicon oxide (SiO 2 etc.), it has a high thermal conductivity and can be expected to have a high heat dissipation effect.

[0032] Moreover, it is desirable that the refractive index of the buffer layer 21 is close to or larger than that of the element substrate 11. The blue light emitted from the light emitting element 10 passes through the element substrate 11 (e.g., a sapphire substrate, refractive index 1.76) and enters the phosphor plate 20. At this time, if the buffer layer 21 sandwiched between the element substrate 11 and the phosphor plate 20 has a low refractive index, light rays that enter the interface between the element substrate 11 and the buffer layer 21 at a large angle of incidence are totally reflected and confined in the element substrate 11. Therefore, it is advantageous for light extraction that the refractive index of the buffer layer 21 is as close to or larger than that of the element substrate 11 as possible. Al 2 O 3 (Refractive index 1.64) is SiO 2 The refractive index is closer to that of the element substrate 11 (refractive index 1.46), and when used as the buffer layer 21, the light extraction efficiency can be improved.

[0033] The buffer layer 21 preferably has a relatively high Young's modulus (hardness). If the Young's modulus is too low, there is a concern that the buffer layer 21 itself may be destroyed. For example, the Young's modulus is preferably about 50 GPa or more, but the higher the Young's modulus, the better, provided that the required surface flatness is met. 2 O 3 SiO 2 Higher Young's modulus (Al 2 O 3 is 112 GPa, SiO 2When used as the buffer layer 21, high bonding reliability can be obtained.

[0034] The material of the buffer layer 21 is aluminum oxide (Al 2 O 3 As the phosphor plate 20, for example, a composite ceramic phosphor plate (Al 2 O 3 In the case of using Ce:YAG, the buffer layer 21 is made of Al, which is the base material of the phosphor plate 20. 2 O 3 Since the materials are the same, the bonding strength at the interface is high. That is, in the region where the base material of the phosphor plate 20 and the buffer layer 21 contact each other, the bonding is homogeneous and has the same thermal expansion coefficient, so there is no residual stress after bonding, and a stable bond can be achieved.

[0035] The material of the buffer layer 21 is aluminum oxide (Al 2 O 3 The element substrate 11 is made of sapphire (Al 2 O 3 When using , the thermal expansion coefficient is the same because it is a homogeneous bond, so there is no residual stress after bonding and a stable bond can be achieved.

[0036] Therefore, the element substrate 11, the buffer layer 21 and the phosphor plate 20 can be stably bonded together by homogeneous bonding.

[0037] The thickness of the amorphous buffer layer 21 may be any thickness that can cover the irregularities of the phosphor plate 20 or the light emitting element 10 and can flatten the surface of the buffer layer 21 by polishing or the like to a roughness equal to or less than the distance at which intermolecular forces act (up to 0.5 nm or less). Specifically, the thickness of the buffer layer 21 is preferably, for example, 50 nm to 2 μm, and particularly preferably about 200 nm to 600 nm.

[0038] The amorphous buffer layer 21 can be formed by physical vapor deposition such as EB (electron beam) deposition, which heats a material with an electron beam, or sputtering, or by vapor phase deposition such as CVD (chemical vapor deposition), or ALD (atomic layer deposition). In particular, it is preferable to form the buffer layer 21 by physical vapor deposition, with minimal use of substrate heating. In particular, the EB deposition is suitable because it allows the amorphous buffer layer 21 to be easily formed without adjusting the substrate temperature during deposition.

[0039] CMP polishing can be used to polish the surfaces of the amorphous buffer layer 21, the phosphor plate 20, and the light emitting element 10. The CMP polishing uses a nanoslurry (diamond, silica, or alumina) having a particle size of several nm to several tens of nm.

[0040] Specifically, for example, the phosphor plate 20 is polished by CMP polishing (chemical mechanical polishing) using a slurry containing diamond particles with a particle size of 50 nm as an abrasive, and if necessary, the polished surface is further finely scraped, organic contaminants on the surface are removed, and ultraviolet light (e.g., excimer light) treatment and plasma treatment are performed to activate the bonding surface (breaking the bonds of surface molecules and forming dangling bonds), and then a buffer layer 21 is formed by physical vapor deposition (EB, sputtering) or vapor phase growth (ALD or CVD).

[0041] Immediately after deposition, the surface of the buffer layer 21 has an uneven shape that follows the unevenness of the polished surface of the phosphor plate 20. However, by polishing the buffer layer 21 by CMP, it is possible to flatten it to a roughness that is less than the distance at which intermolecular forces act (up to about 0.5 nm or less). The CMP polishing of the buffer layer 21 is performed, for example, using a surface plate equipped with a buff having a relatively low hardness and a silica-based slurry.

[0042] Furthermore, by using an amorphous buffer layer 21, the hardness is lower than that of a buffer layer 21 made of a single crystal, and the buffer layer 21 has flexibility when the phosphor plate 20 provided with the buffer layer 21 is brought into contact with the element substrate 11. Therefore, by applying pressure, the buffer layer 21 undergoes plastic deformation and can be closely fitted to the surface shape of the element substrate 11, making it easy to perform surface activated bonding.

[0043] It is preferable that the buffer layer 21 does not include any voids. If any voids are included, the surface flatness of the buffer layer 21 deteriorates, which can cause a decrease in the bonding strength of the surface activated bonding.

[0044] In this embodiment, when manufacturing the semiconductor light emitting device 1, a large phosphor plate 20 having a series of phosphor plates 20 of a plurality of semiconductor light emitting devices 1 is bonded onto a large element substrate 11 having a configuration in which a plurality of light emitting elements 10 are connected to form a laminate. Then, in order to divide the laminate at the boundary positions of the plurality of semiconductor light emitting devices 1 into individual semiconductor light emitting devices 1, incisions are made from the phosphor plate 20 side of the laminate by dicing or the like, and notches are formed from the light emitting layer 12 side of the element substrate 11.

[0045] At this time, the cuts are formed so as to penetrate the buffer layer 21. Specifically, the cuts are formed so as to penetrate the buffer layer 21 and reach the element substrate 11. That is, the cuts are formed so as to penetrate the bonding surface between the phosphor plate 20 and the light-emitting element plate 100 (in this embodiment, the interface between the buffer layer 21 and the element substrate 11) and reach the light-emitting element plate 100 (in this case, the element substrate 11).

[0046] This releases the internal stress on the bonding surface between the phosphor plate 20 and the element substrate 11, and prevents stress from concentrating on the bonding surface when an external force is applied, thereby preventing the element substrate 11 and the phosphor plate from peeling off at the bonding surface, thereby improving the manufacturing yield.

[0047] When the buffer layer 21 is provided on both the phosphor plate 20 and the element substrate 11, the interface between the first buffer layer on the phosphor plate 20 side and the second buffer layer on the element substrate 11 side becomes the bonding interface, so the notch is formed to penetrate at least the first buffer layer and the bonding surface.

[0048] In addition, when the buffer layer 21 is provided only on the element substrate 11 side, the interface between the buffer layer 21 and the phosphor plate 20 becomes the bonding surface, so the cut is formed to penetrate at least the phosphor plate 20 and the bonding surface.

[0049] <Manufacturing method> Figures 2 and 3 are diagrams illustrating a method for manufacturing a semiconductor light emitting device according to this embodiment.Figure 4 is a cross-sectional view showing the shape of the laminate after the manufacturing process of Figure 3(c).

[0050] Each manufacturing process will be described with reference to FIGS.

[0051] (Polishing process of light emitting element 10) 2(a), a light-emitting element plate 100 is prepared in which a plurality of semiconductor light-emitting layers 12 and electrodes 13 are arranged with gaps in the main plane direction on the lower surface of a continuous element substrate 11. The spacing between the plurality of semiconductor light-emitting layers 12 of the light-emitting element plate 100 is designed so that individual light-emitting elements 10 can be obtained by dividing the element substrate 11 at the boundaries between adjacent light-emitting elements 10.

[0052] As shown in FIG. 2( a ), a support substrate 50 is bonded to the arrayed semiconductor light emitting layers 12 of the light emitting element plate 100 by a heat resistant adhesive layer 60 .

[0053] As shown in FIG. 2(b), the back surface side of the support substrate 50 (the surface opposite to the side to which the semiconductor light emitting layer 12 is adhered) is fixed to a polishing stage 80-1 by an adhesive layer 90-1.

[0054] A polishing platen 70-1 is prepared, and a slurry containing diamond abrasive grains is used to cut and polish the back surface of the element substrate 11 of the light-emitting element plate 100 to make it thinner and to flatten the surface of the element substrate 11 to a roughness (Ra) equal to or less than the distance at which intermolecular forces act (up to 0.5 nm or less).

[0055] Specifically, for example, a grinding process, a mechanical polishing process, and a CMP polishing process are carried out in this order using the polishing platen 70-1.

[0056] For example, in the grinding process, a grinding device uses a grindstone with a grain size of #230 to reduce the thickness of the element substrate 11 (for example, 830 μm) to 150 μm. The roughness (Ra) of the element substrate 11 after grinding is about 200 nm.

[0057] Next, in the mechanical polishing process, the surface of the element substrate 11 having a thickness of 150 μm after the grinding process is mechanically polished for the first time using a slurry containing diamond abrasive grains with a particle size of 6 μm, thereby reducing the roughness (Ra) of the element substrate 11 to less than 50 nm. This first mechanical polishing process can remove scratches and cracks on the surface that occurred in the grinding process. The thickness of the element substrate after this first mechanical polishing process is about 120 μm. Thereafter, a second mechanical polishing is performed using a slurry containing diamond abrasive grains with a particle size of 1 μm, thereby reducing the roughness (Ra) of the element substrate 11 to less than 10 nm.

[0058] Next, in the CMP polishing step, CMP polishing is performed using a slurry containing diamond abrasive grains with a grain size of 50 nm, and the roughness (Ra) of the element substrate 11 is reduced to less than 0.5 nm.

[0059] Through these steps, the surface of the element substrate 11 can be made flat to a roughness (Ra) of less than 0.5 nm, which is equal to or smaller than the distance at which intermolecular forces act (up to 0.5 nm or less).

[0060] Next, as shown in FIG. 2(c), the surface of the element substrate 11 after polishing is subjected to ultraviolet light (excimer light) treatment and plasma treatment.

[0061] Specifically, the polished surface of the element substrate 11 is irradiated with ultraviolet light (excimer light: wavelength (175±15) nm) and cleaned.

[0062] Next, the light-emitting element plate 100 is placed in a vacuum device, and Ar, O 2 ,N 2 Plasma of any one of these gases or a mixed gas of two or more of these gases is generated using high-frequency power (100 W to 450 W, preferably 250 W to 350 W), and the polished surface of the element substrate 11 is plasma-treated for a predetermined treatment time (1 min to 10 min, preferably 3 min to 6 min) to activate the surface.

[0063] This removes impurities from the surface of the element substrate 11 and generates dangling bonds. Thereafter, the element substrate 11 is exposed to the atmosphere to form hydroxyl groups (-OH) in the dangling bonds on the plasma irradiated surface.

[0064] (Polishing process of phosphor plate 20) Meanwhile, as shown in FIG. 2(d), a phosphor plate 20 large enough to connect the phosphor plates 20 of a plurality of semiconductor light emitting devices 1 is prepared and fixed to a polishing stage 80-2 by an adhesive layer 90-2.

[0065] A polishing platen 70-2 is prepared, and the surface of the phosphor plate 20 is polished by the polishing platen 70-2 using a slurry containing diamond abrasive grains.

[0066] Specifically, for example, a mechanical polishing step and a CMP polishing step are performed in sequence using the polishing platen 70-2.

[0067] In the mechanical polishing process, the surface of the phosphor plate 20 is mechanically polished using a slurry containing diamond abrasive grains with a particle size of 6 μm, and then further mechanically polished using a slurry containing diamond abrasive grains with a particle size of 1 μm, thereby reducing the roughness (Ra) of the element substrate 11 to less than 10 nm.

[0068] Next, in the CMP polishing step, CMP polishing is performed using a slurry containing diamond abrasive grains with a grain size of 50 nm, and the roughness (Ra) of the phosphor plate is reduced to less than 1 nm. Note that this CMP polishing step is performed as necessary.

[0069] Thereafter, the polishing stage 80-2 is removed from the phosphor plate 20.

[0070] (Deposition and polishing of buffer layer 21) Next, as shown in FIG. 2( e ), an amorphous buffer layer 21 is formed on the polished surface of the phosphor plate 20 .

[0071] Here, amorphous aluminum oxide (Al 2 O 3 A film having a thickness of 600 nm is formed on the polished surface of the phosphor plate 20. Specifically, for example, Al for deposition is used as a deposition source. 2 O 3 Using powder, oxygen partial pressure is ~1×10 -2 The phosphor plate 20 is heated or cooled at 1000 K, and the aluminum oxide (Al 2 O 3 etc.) to form a film.

[0072] Next, as shown in FIG. 2(f), the surface of the phosphor plate 20 opposite to the surface on which the buffer layer 21 is formed is fixed to a polishing stage 80-3 by an adhesive layer 90-3.

[0073] A polishing platen 70-3 is prepared, and a slurry containing silica particles of several nm to several tens of nm is used to polish the surface of the buffer layer 21 of the phosphor plate 20 by CMP using the polishing platen 70-3, so that the roughness (Ra) is less than 0.5 nm. This roughness (Ra) is equal to or less than the distance at which intermolecular forces act (up to 0.5 nm or less).

[0074] Next, as shown in Fig. 2(g), the polished surface of the phosphor plate 20 is treated with ultraviolet light (excimer light) and plasma to form dangling bonds, and then exposed to the atmosphere to form hydroxyl groups (-OH) on the dangling bonds DB. The conditions for these treatments are the same as those in Fig. 2(c), so the explanation is omitted.

[0075] It is preferable that the ultraviolet light (excimer light) treatment and plasma treatment of the element substrate 11 in FIG. 2(c) and the ultraviolet light (excimer light) treatment and plasma treatment of the phosphor plate 20 in FIG. 2(g) are completed simultaneously.

[0076] After the plasma treatment, the light emitting element 10 and the phosphor plate 20 are taken out from the vacuum device.

[0077] (Joining process) 3(a), the light-emitting element plate 100 supported by the support substrate 50 is mounted on the heating and pressing table 200, and the phosphor plate 20 is mounted thereon. At this time, the light-emitting element plate 100 is mounted so that the surface of the element substrate 11 of the light-emitting element plate 100 that has been polished, treated with ultraviolet light (excimer light), and treated with plasma comes into contact with the surface of the buffer layer 21 of the phosphor plate 20 that has been polished, treated with ultraviolet light (excimer light), and treated with plasma. As a result, the surface of the element substrate 11 and the surface of the buffer layer 21 of the phosphor plate 20 are temporarily bonded by hydrogen bonding between hydroxyl groups to form hydrogen bonded parts.

[0078] 3(a), the light-emitting element plate 100 and the phosphor plate 20 are heated under normal pressure to 100°C to 300°C, preferably 150°C to 250°C, by the heating and pressing table 200. Furthermore, a load (e.g., 2 MPa or more, preferably 10 MPa or more) is applied to the light-emitting element plate 100 and the phosphor plate 20 by the heating and pressing table 200. The heated and pressed state is maintained for 30 minutes or more, preferably 2 hours or more, and the light-emitting element plate 100 and the phosphor plate 20 are bonded by surface activated bonding.

[0079] By surface activated bonding, the element substrate 11 and the phosphor plate 20 are bonded via the buffer layer 21 to form a laminate. At this time, the hydroxyl groups are thermally decomposed by pressure and heat, and the hydrogen atoms in the hydroxyl groups are expelled to form oxygen bonds, while the excess hydroxyl groups are converted into water and hydrogen gas (H 2 O, H 2 ) and then detach from the bonded interface.

[0080] Alternatively, the light-emitting element plate 100 and the phosphor plate 20 may be placed in a vacuum device and bonded by heating and pressurizing under reduced pressure.

[0081] (Notch formation process) As shown in FIG. 3(b), groove-shaped cuts 110 of a predetermined depth are made from the phosphor plate 20 side of the laminate at positions corresponding to the gaps between the plurality of semiconductor light emitting layers.

[0082] The cut 110 reaches the buffer layer 21 and penetrates the buffer layer 21. The cut 110 penetrates the bonding surface between the phosphor plate 20 and the light-emitting element plate 100 and reaches the element substrate 11.

[0083] Specifically, for example, the cuts 110 are formed by blade dicing using a blade with a blade width of 20 μm to 500 μm. The depth of the cuts 110 is formed so as to penetrate through the phosphor plate 20 and the buffer layer 21 and into the element substrate 11 to a depth of 1 μm to 50 μm, preferably 1 μm to 20 μm.

[0084] The cross-sectional shape of the notch 110 may be any of a rectangle (FIG. 5(a)), a trapezoid (FIG. 5(b)), a rectangle with rounded corners (FIG. 5(c)), a trapezoid with rounded corners (FIG. 5(e)), or a parabola (FIG. 5(f)), as shown in FIGS. 5(a) to 5(f). However, a shape with rounded corners (FIGS. 5(c) to 5(f)) is preferable, and a parabola (FIG. 5(f)) is particularly preferable.

[0085] The cut 110, which has a parabolic cross section (FIG. 5(f)), has a shape in which a tip 110a of the cut cross section is closest to the lower surface (the surface on which the semiconductor light emitting layer 12 is mounted) of the element substrate 11. Therefore, in a singulation process described later, by applying force to the laminate, stress is concentrated at the tip 110a, and the element substrate 11 can be divided by cleavage or the like starting from this position.

[0086] Although the notches 110 are formed by blade dicing here, they can also be formed by laser dicing.

[0087] (Notch forming process) Next, as shown in FIG. 3(c), the support substrate 50 is removed from the semiconductor light emitting layer 12, and an adhesive sheet 120 is attached to the phosphor plate 20 side of the laminate.

[0088] A groove-shaped cutout 130 is formed in the element substrate 11 in the gap between the plurality of semiconductor light emitting layers 12 from the light emitting element plate 100 side of the laminate.

[0089] Specifically, for example, a laser scriber is used to focus laser light 170 through a lens 171 and irradiate the element substrate 11 in the gaps between the plurality of semiconductor light emitting layers 12, thereby forming groove-shaped notches .

[0090] The sum of the depth of the notch 130 and the depth of the cut 110 is set to be shallower than the thickness of the laminate. The laminate is designed to be divided by cracking such as cleavage.

[0091] Note that a protective film may be formed by a coating method on the surface of the semiconductor light emitting layer before forming the notch 130 using a laser scribing device. The protective film prevents dirt generated by laser scribing from adhering to the surface of the semiconductor light emitting layer. The protective film can be removed by washing with water in a later process.

[0092] It is preferable to use a nano-pulse or pico-pulse laser as the laser light 170. The wavelength of the laser light 170 may be 355 nm.

[0093] The shape of the notch 130 is preferably wedge-shaped, the width of the notch 130 is preferably 10 μm or less, and more preferably 2 μm or less, and the depth of the notch 130 is preferably 2 μm or more, and more preferably 5 μm or more.

[0094] This results in the laminate having the shape shown in FIG.

[0095] After the notch 130 is formed, the laminate is washed with water and organic cleaning to remove dirt caused by the laser scribing.

[0096] In addition, in Fig. 3(c), the laser 170 is irradiated from the semiconductor light emitting layer 12 side, but it is also possible to irradiate the laser 170 from the phosphor plate 20 side to form the notch 130 at the position of the notch 130 in the element substrate 11 in Fig. 3(c). For example, a stealth dicing device can be used to form a fractured surface in the element substrate 11.

[0097] Also, here, because the intervals between the semiconductor light emitting layers 12 are narrow, the notches 130 are formed by laser scribing, but it is also possible to provide the notches 130 by blade dicing using a thin blade.

[0098] (Singulation process) As shown in FIG. 3( d ), the laminate is attached to an adhesive sheet 150 with the surface of the light emitting element 10 facing downward.

[0099] When the roller 140 is pressed evenly over the entire surface of the phosphor plate 20 of the laminate, the element substrate 11 between the tip 110a of the cut 110 and the tip 130a of the cutout 130 (see FIG. 5(e)) is broken and cracked (see FIG. 5(e)). As a result, the semiconductor light emitting devices 1 are separated.

[0100] In addition, since the element substrate 11 warps due to a temperature rise caused by the irradiation of the laser light, by appropriately setting the conditions when irradiating the laser 170 to form the notches 130 in the step of Fig. 3(c), it is possible to cleave the element substrate 11 between the notches 130 and the cuts 110 and separate them simply by irradiating the laser 170 to form the notches 130. In this case, the step of applying force by the roller 140 can be omitted.

[0101] (Step of spacing the semiconductor light emitting devices 1) 3(e), the adhesive sheet 150 is stretched (expanded) in the direction of the main surface to increase the spacing between the semiconductor light emitting devices 1 on the adhesive sheet 150. This makes the semiconductor light emitting devices 1 ready for handling. In this manner, the semiconductor light emitting device 1 can be manufactured (see FIG. 1).

[0102] As described above, in this embodiment, by providing a buffer layer 21 and polishing the buffer layer 21, the phosphor plate 20 can be bonded to the light emitting device by a surface activated bonding method without being affected by the crystal grains of the phosphor plate 20.

[0103] In this embodiment, the cut 110 is provided in the laminate in which the element substrate 11 and the phosphor plate of the light-emitting element plate 100 are surface-activatedly bonded to each other, to a depth that reaches the buffer layer 21, thereby preventing peeling at the bonding surface due to internal stress at the bonding surface or external force. Furthermore, in the dicing for providing the cut 110, since the substrate is hardly diced after penetrating the bonding surface (approximately 5 μm to 20 μm), a narrow dicing blade can be used. Therefore, the width of the cut 110 provided between the light-emitting elements can be made small.

[0104] Furthermore, by providing the notch 130 between adjacent semiconductor light emitting layers, the element substrate therebetween can be accurately and easily divided by cleavage or the like at the position connecting the notch 130 and the cut 110. Thus, the phosphor plate and the element substrate can be accurately divided and separated into individual semiconductor light emitting devices 1, improving the manufacturing yield.

[0105] In this embodiment, a semiconductor light-emitting device having a pair of electrodes 13 was manufactured as shown in FIG. 1, but a structure having two pairs of electrodes 13 in one semiconductor light-emitting device as shown in FIGS. 6(a) and (b) can also be manufactured by the manufacturing process described above.

[0106] <Evaluation> When a cross section of buffer layer 21 of the manufactured semiconductor light emitting device was observed with a TEM (transmission electron microscope), neither a crystal lattice nor crystal grains were observed, and it was confirmed that buffer layer 21 was amorphous. Therefore, it is presumed that when X-ray diffraction is measured for buffer layer 21, no diffraction peak is shown in the X-ray diffraction chart. <Effects> In the semiconductor light-emitting device of the first embodiment, an amorphous buffer layer 21 is disposed between the phosphor plate 20 and the light-emitting element 10, so that the bonding process between the phosphor plate 20 and the light-emitting element 10 by surface activated bonding as shown in FIG. 3(a) can be performed in the atmosphere.

[0107] Furthermore, by using the amorphous buffer layer 21, even if a material such as a composite ceramic phosphor plate, whose surface irregularities are difficult to flatten to a roughness (0.5 nm or less) that allows surface activation bonding, is used as the phosphor plate 20, the amorphous buffer layer 21 can be relatively easily made to have a roughness of 0.5 nm or less, making bonding by surface activation bonding possible. Therefore, a semiconductor light emitting device with a highly reliable bonding surface by surface activation bonding can be provided.

[0108] The material of the amorphous buffer layer 21 is Al. 2 O 3When this material is used, the refractive index and thermal expansion coefficient are close to those of the element substrate 11 and the phosphor plate, the thermal conductivity is large when made into a thin film, and the Young's modulus is high, making it difficult to break down, so that a semiconductor light emitting device can be provided that has high light extraction efficiency, good heat dissipation, and is difficult to break down.

[0109] In particular, the material of the amorphous buffer layer 21 is aluminum oxide (Al 2 O 3 The element substrate 11 is a sapphire substrate, and the phosphor plate 20 is a composite ceramic phosphor plate (Al 2 O 3 When using a ferroelectric material such as Ce:YAG, the bonding can be performed stably by surface activated bonding using homogeneous bonding.

[0110] <<Second embodiment>> A semiconductor light emitting device according to the second embodiment will be described. As shown in Fig. 7, the semiconductor light emitting device according to the second embodiment does not include an element substrate 11, and a semiconductor light emitting layer 12 and a phosphor plate 20 are bonded together with a buffer layer 21 interposed therebetween.

[0111] A method for manufacturing the semiconductor light emitting device of the second embodiment will be described with reference to Figures 8 and 9. Note that, in the manufacturing steps shown in Figures 8 and 9, manufacturing steps similar to those shown in Figures 2 and 3 will be briefly described.

[0112] As shown in FIG. 8(a), a light emitting element plate 100 in which a semiconductor light emitting layer 12 is formed on the front surface of an element substrate 11 is prepared.

[0113] 8(b), the semiconductor light emitting layer 12 is processed into the shape of the semiconductor light emitting layer 12 for each semiconductor light emitting device by etching, etc. Then, a pair of electrodes 13 is formed on each semiconductor light emitting layer 12.

[0114] 8(c), the electrode 13 of the semiconductor light emitting layer 12 is fixed onto a light-transmitting supporting substrate 301 by an adhesive layer 302 made of a resin adhesive.

[0115] As shown in Fig. 8(d), the element substrate (sapphire substrate) 11 is irradiated with laser light such as an excimer laser, and the element substrate 11 is removed by laser lift-off, thereby exposing the semiconductor light emitting layer 12 as shown in Fig. 8(e).

[0116] 8(e), the exposed semiconductor light emitting layer 12 is polished to flatten the surface, and then subjected to ultraviolet light (excimer light) treatment and plasma treatment. The polishing, ultraviolet light (excimer light) treatment and plasma treatment are performed in the same manner as in the steps of FIGS. 2(a) to 2(c) of the first embodiment.

[0117] In the step of Fig. 8(f), the phosphor plate 20 is polished, and an amorphous buffer layer 21 is formed on the polished surface. The surface of the buffer layer 21 is polished, and then subjected to ultraviolet light (excimer light) treatment and plasma treatment. These treatments are performed in the same manner as the steps of Fig. 2(d) to (g) in the first embodiment.

[0118] 8(g), phosphor plate 20 is placed on semiconductor light emitting layer 12 so that buffer layer 21 is in contact with it, and heat and pressure are applied to surface activate and bond semiconductor light emitting layer 12 and phosphor plate 20. This step is performed in the same manner as the step of FIG. 3(a) in the first embodiment.

[0119] Next, in the step of FIG. 9( a ), ultraviolet light is irradiated to generate bubbles, thereby removing the support substrate 301 and adhesive layer 302 from the semiconductor light emitting layer 12 .

[0120] In addition, when a substrate such as Si is used as the support substrate 301 and the semiconductor light emitting layer 12 is attached by an adhesive layer 302 made of a metal material, a sacrificial layer made of silver is formed as an intermediate layer of the adhesive layer 302, and the support substrate 301 and the adhesive layer 302 can be removed by dissolving the sacrificial layer with nitric acid or the like.

[0121] 9(b), an adhesive sheet 350 is attached to the semiconductor light emitting layer 12 side for support, and a cut 341 is formed in the phosphor plate 20. This step is performed in the same manner as the step of FIG. 3(b) in the first embodiment, but differs from the first embodiment in that the depth of the cut 341 is formed so as not to reach the buffer layer 21.

[0122] In the step of Fig. 9(c), the adhesive sheet 350 is removed, and an adhesive sheet 360 is attached to the phosphor plate 20 side for support. From the light-emitting element plate 100 side of the laminate, a laser scriber is used to focus laser light 170 with a lens 171 in the buffer layer 21 in the gaps between the semiconductor light-emitting layers 12, to form groove-shaped notches 342. This step is performed in the same manner as the step of Fig. 3(c) in the first embodiment, but differs from the first embodiment in that the notches 342 are formed directly in the buffer layer 21.

[0123] In this embodiment, the notch 342 is formed, but since the buffer layer 21 is a thin film, it may be formed arbitrarily as necessary. That is, the notch 342 does not have to be provided.

[0124] Also, a notch 342 may be provided at the tip of the cut 341 .

[0125] Thereafter, adhesive sheet 360 is removed, and adhesive sheet 370 is again attached to the semiconductor light emitting layer 12 side for support, and the steps of Figures 9(d) to 9(e) are carried out in the same manner as the steps of Figures 3(d) and (e) of the first embodiment to separate individual semiconductor light emitting devices.

[0126] As described above, in the second embodiment, even in the light emitting element 10 from which the element substrate 11 has been removed, the phosphor plate 20 can be bonded by surface activated bonding.

[0127] In this embodiment, since the notch 342 is provided in the buffer layer 21, it is possible to prevent the light emitting element 10 from being subjected to stress.

[0128] Other effects are similar to those of the first embodiment.

[0129] <<Third embodiment>> A semiconductor light emitting device according to the third embodiment will be described with reference to Fig. 10. The semiconductor light emitting device according to the third embodiment has a similar configuration to the semiconductor light emitting device according to the second embodiment shown in Fig. 7, but the manufacturing process differs from that of the second embodiment. In the second embodiment, in the steps of Fig. 9(b) to (d), incisions 341 and notches 342 are formed to break phosphor plate 20 and separate the semiconductor light emitting devices, but in the third embodiment, phosphor plate 20 is cut by dicing.

[0130] A method for manufacturing the semiconductor light emitting device of the third embodiment will be described with reference to Fig. 10. Note that, in the manufacturing process shown in Fig. 10, manufacturing steps similar to those shown in Figs. 8 and 9 will be briefly described.

[0131] The steps of Figures 10(a) to 10(h) are performed in the same manner as the steps of Figures 8(a) to 8(g) and 9(a), thereby forming a laminate in which a common phosphor plate 20 is bonded via a buffer layer 21 to the upper surface of the semiconductor light emitting layers 12 arranged at intervals.

[0132] 10(i), an adhesive sheet 330 is attached to the semiconductor light emitting layer 12 side to support the laminate. From the phosphor plate 20 side, cuts 340 are formed by dicing to cut the phosphor plate 20 and the buffer layer 21. This separates the semiconductor light emitting devices.

[0133] 10(j), the adhesive sheet 330 is stretched (expanded) in the direction of the main surface to increase the spacing between the semiconductor light emitting devices on the adhesive sheet 330. This makes the semiconductor light emitting devices ready for handling.

[0134] In this manner, the semiconductor light emitting device shown in FIG. 7 can be manufactured.

[0135] In the manufacturing method of the third embodiment 3, the phosphor plate 20 is cut by dicing, so compared to the cutting method as in the second embodiment, it is desirable to arrange the semiconductor light-emitting layers 12 with a wider spacing by the width of the notch 340 caused by the thickness of the dicing blade.

[0136] <<Fourth embodiment>> The semiconductor light emitting device of the fourth embodiment will be described with reference to Figures 11, 12, and 13. As shown in Figure 11, the semiconductor light emitting device of the fourth embodiment does not include an element substrate 11, similar to the semiconductor light emitting device of the second embodiment shown in Figure 7, but unlike the second embodiment, includes a Si substrate 201 instead of the wiring substrate 30 that supplies power to the semiconductor light emitting element 12.

[0137] The Si substrate 201 has a pair of upper electrodes 211, 212 on its upper surface, and a pair of lower electrodes 221, 222 on its lower surface. One of the upper electrodes 211 and one of the lower electrodes 221 are connected by a through electrode 231 that passes through a via provided in the Si substrate 201.

[0138] The pair of upper electrodes 211 and 212 are connected to the pair of electrodes 13 of the semiconductor light emitting element 10, respectively.

[0139] Insulating layers 232 are disposed between the through electrode 231 and the inner wall of the via, between the lower surface of the upper electrode 211 and the Si substrate 201, and between the upper surface of the lower electrode 221 and the Si substrate 201. This allows a current to flow to the upper electrode 211 via the lower electrode 221 and the through electrode 231.

[0140] A current flows from the other lower electrode 222 to the other upper electrode 212 via the Si substrate 201 .

[0141] A method for manufacturing the semiconductor light emitting device of the fourth embodiment will be described with reference to Fig. 12. Note that, in the manufacturing process shown in Fig. 12, manufacturing steps similar to those shown in Figs. 8 and 9 will be briefly described.

[0142] The steps of Figures 12(a) and 12(b) are performed in the same manner as those of Figures 8(a) and 8(b). As a result, a plurality of semiconductor light emitting layers 12 are formed at predetermined intervals on the element substrate 11, and a pair of electrodes 13 are formed on the semiconductor light emitting layers 12.

[0143] 12(c), upper electrodes 211, 212 of a Si substrate 201 having the configuration shown in FIG. 11, which has been prepared in advance, are fixed to the electrode 13 of the semiconductor light emitting layer 12 by metal-to-metal bonding using heat and pressure. The Si substrate 201 is mounted on a support 210.

[0144] In the step of FIG. 12(d), the element substrate 11 is removed by laser lift-off in the same manner as in FIG. 8(d).

[0145] In the step of FIG. 12(e), similarly to FIG. 8(e), the semiconductor light emitting layer 12 is polished to flatten the surface, and then subjected to ultraviolet light (excimer light) treatment and plasma treatment.

[0146] 8(f), the phosphor plate 20 is polished, and an amorphous buffer layer 21 is formed on the polished surface. The surface of the buffer layer 21 is polished, and then subjected to ultraviolet light (excimer light) treatment and plasma treatment.

[0147] 8(g), phosphor plate 20 is placed on semiconductor light emitting layer 12 so that buffer layer 21 is in contact with it, and heat and pressure are applied to surface activate bond semiconductor light emitting layer 12 and phosphor plate 20. An adhesive sheet 220 is attached to the lower surface of Si substrate 220.

[0148] 12(h), the phosphor plate 20 is cut by dicing or laser dicing at positions between the semiconductor light emitting devices 12, and the cutting is continued to cut the Si substrate 201 as well. This separates the semiconductor light emitting devices.

[0149] 12(i), adhesive sheet 150 is stretched (expanded) in the direction of the main surface to increase the spacing between semiconductor light emitting devices 1 on adhesive sheet 220. This makes the semiconductor light emitting devices ready for handling.

[0150] In this manner, the semiconductor light emitting device shown in FIG. 11 can be manufactured.

[0151] In the manufacturing method of Fig. 12, in the step of Fig. 12(h), the phosphor plate 20 and the Si substrate 201 are cut in one go by dicing or laser dicing, but the phosphor plate 20 and the Si substrate 201 may be cut separately. That is, instead of the step of Fig. 12(h), the steps of Fig. 13(h-1) and (h-2) are performed.

[0152] 13(h-1), dicing is used to form incisions 241 that cut only the phosphor plate 20. An adhesive sheet 240 is attached to the upper surface of the phosphor plate 20 to support it.

[0153] 13(h-2), the phosphor plate 20 is placed face down, and the adhesive sheet 220 on the Si substrate 201 is peeled off. In this state, the Si substrate 201 is cut by laser dicing to form notches 242. This separates the semiconductor light emitting devices. The adhesive sheet 220 is attached to the top surface of the Si substrate 201 to support it.

[0154] 13(i), adhesive sheet 240 is peeled off, and adhesive sheet 220 is stretched (expanded) in the direction of the main surface, thereby increasing the spacing between semiconductor light emitting devices 1 on adhesive sheet 220. This makes the semiconductor light emitting devices ready for handling.

[0155] In the steps of FIG. 13(h-1) and (h-2), since the phosphor plate 20 and the Si substrate 201 are cut separately, appropriate dicing blades, laser irradiation conditions for laser dicing, and the like can be set appropriately for each.

[0156] In addition, an example in which dicing is used in the step of FIG. 13(h-1) and laser dicing is used in the step of FIG. 13(h-2) has been described, but dicing and laser dicing may be reversed, or both may be cut under different conditions by dicing or laser dicing.

[0157] The semiconductor light emitting device of the fourth embodiment shown in Fig. 11 is the main element form of blue LEDs for which mass production processes have been established similarly to flip chips, and can mount phosphor plates at the wafer level, including element forms without substrate via structures. Also, compared to phosphor mounting structures that use adhesives with poor thermal conductivity and low refractive index, the semiconductor light emitting device of Fig. 11 can improve light extraction efficiency and improve heat dissipation of phosphors.

[0158] The technology of the semiconductor light emitting device of this embodiment described above can be used in a lamp light source unit or a white light source module. [Explanation of symbols]

[0159] 1. Semiconductor light-emitting device 10 Light emitting element 11 Element substrate 12 Semiconductor light-emitting layer 13 electrodes 18 Buffer layer 20 Phosphor Plate 21 Buffer layer 30 Wiring board 31 Substrate 32 Wiring 40 Light reflective multilayer film 50 Support substrate 60 Heat-resistant adhesive layer 70 Polishing Plate 80 Polishing Stage 90 Adhesive layer 100 Light emitting element plate 110 Cut 110a tip 120 Adhesive Sheet 130 Cutout 130a tip 140 Roller 150 Adhesive Sheet 170 Laser 171 Lens 200 Pressure Table 201 Si substrate 210 Adhesive Sheet 211 Top electrode 212 Top electrode 220 Adhesive Sheet 221 Bottom electrode 222 Bottom electrode 231 Through electrode 232 Insulating layer 240 Adhesive Sheet 241 Cut 242 Cut 301 Support substrate 302 Adhesive layer 310 Support stand 330 Adhesive Sheet 340 Cut 341 Cut 342 Notch 350 Adhesive Sheet 360 Adhesive Sheet 370 Adhesive Sheet

Claims

1. A light emitting element including a semiconductor light emitting layer and a phosphor plate bonded to the light emitting element, a buffer layer made of a dielectric material that transmits light emitted by the light emitting element is disposed between the light emitting element and the phosphor plate; the light emitting element and the phosphor plate are bonded via the buffer layer; The semiconductor light emitting device is characterized in that the buffer layer is an amorphous layer.

2. 2. The semiconductor light emitting device according to claim 1, The semiconductor light emitting device is characterized in that, when an X-ray diffraction is measured, the buffer layer does not show a diffraction peak in an X-ray diffraction chart.

3. 2. The semiconductor light emitting device according to claim 1, 2. A semiconductor light-emitting device, wherein the buffer layer is any one of an aluminum oxide layer, a niobium oxide layer, a zirconium oxide layer, a magnesium oxide layer, a silicon oxide layer, a titanium oxide layer, a tantalum oxide layer, and a yttrium oxide layer.

4. 2. The semiconductor light emitting device according to claim 1, The phosphor plate is bonded to the semiconductor light emitting layer with the buffer layer sandwiched therebetween.

5. 2. The semiconductor light emitting device according to claim 1, the semiconductor light emitting layer is bonded to the phosphor plate with the buffer layer therebetween; the semiconductor light emitting layer includes a GaN layer; 4. The semiconductor light emitting device, wherein the buffer layer is an aluminum oxide layer.

6. 2. The semiconductor light emitting device according to claim 1, the light emitting device includes a device substrate supporting the semiconductor light emitting layer; the element substrate is bonded to the phosphor plate with the buffer layer interposed therebetween; The device substrate is sapphire and the buffer layer is an aluminum oxide layer. A semiconductor light emitting device comprising:

7. 7. The semiconductor light emitting device according to claim 5, The semiconductor light emitting device is characterized in that the phosphor plate is a composite ceramic phosphor plate in which phosphor particles are dispersed in an alumina ceramic matrix.

8. A method for manufacturing a semiconductor light emitting device in which a phosphor plate that absorbs light emitted from a semiconductor light emitting layer and emits fluorescence is bonded to a light emitting element including the semiconductor light emitting layer, the method comprising the steps of: a light emitting element polishing step of polishing an upper surface of the light emitting element; a phosphor polishing step of polishing a lower surface of the phosphor plate; a deposition step of depositing an amorphous buffer layer made of a dielectric material on at least one of an upper surface of the light emitting element and a lower surface of the phosphor plate; a bonding step of mounting the phosphor plate on the light-emitting element so that an upper surface of the light-emitting element faces a lower surface of the phosphor plate, and heating and pressurizing the phosphor plate to bond the phosphor plate onto the light-emitting element plate.

9. 9. A method for manufacturing a semiconductor light emitting device according to claim 8, comprising the steps of: The method for producing a semiconductor light emitting device, wherein the film forming step forms the amorphous buffer layer by a deposition method in which a deposition source is heated by an electron beam.

10. 9. A method for manufacturing a semiconductor light emitting device according to claim 8, comprising the steps of: In the light emitting element polishing step, the light emitting element is arranged on a support with a gap therebetween in a main plane direction, and upper surfaces of the arranged light emitting elements are polished; The bonding step includes mounting the common phosphor plate on the arranged plurality of light-emitting elements, and bonding upper surfaces of the light-emitting elements and a lower surface of the phosphor plate with the buffer layer interposed therebetween.

4. A method for manufacturing a semiconductor light emitting device comprising the steps of:

11. 9. A method for manufacturing a semiconductor light emitting device according to claim 8, comprising the steps of: In the light emitting element polishing step, the light emitting element has a plurality of semiconductor light emitting layers arranged on a lower surface of a common element substrate, and the upper surface of the common element substrate is polished; The bonding step bonds the upper surface of the element substrate and the lower surface of the phosphor plate with the buffer layer interposed therebetween.

4. A method for manufacturing a semiconductor light emitting device comprising the steps of:

12. A method for manufacturing a semiconductor light emitting device according to claim 10, comprising the steps of: A method for manufacturing a semiconductor light emitting device, further comprising, after the bonding step, a singulation step of cutting or breaking the phosphor plate at positions between the arranged plurality of light emitting elements.

13. A method for manufacturing a semiconductor light emitting device according to claim 11, comprising the steps of: A method for manufacturing a semiconductor light-emitting device, further comprising, after the bonding step, a singulation step of cutting or breaking the phosphor plate and the element substrate at positions between the arranged plurality of light-emitting elements.

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