JP2014154693A - Group iii nitride semiconductor light-emitting element and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a group III nitride semiconductor light-emitting element and a manufacturing method of the same, which achieve simplification of a manufacturing process while preventing the occurrence of cracks and voids.SOLUTION: A light-emitting element 100 is a substrate lift-off semiconductor light-emitting element from which a growth substrate is removed. The light-emitting element 100 comprises a support medium 110, a passivation film 120, a cover metal layer 130, a reflective p-contact electrode 140, an insulation film 150, an n-contact electrode 160, a semiconductor layer 170, a p-electrode P1 and an n-electrode N1. The support medium 110 is a ceramic sprayed layer formed by ceramic spraying.

Description

  The present invention relates to a group III nitride semiconductor light emitting device and a method for manufacturing the same. More specifically, the present invention relates to a group III nitride semiconductor light-emitting device and a method for manufacturing the same, in which the manufacturing process is simplified.

  Some Group III nitride semiconductor light emitting devices are manufactured by a substrate lift-off method in which after a semiconductor layer is grown on a growth substrate, the growth substrate is removed from the semiconductor layer. The substrate lift-off method includes a laser lift-off method using a laser and a chemical lift-off method using a chemical solution. In the laser lift-off method, the growth substrate is removed from the semiconductor layer by irradiating the interface between the semiconductor layer and the growth substrate with a laser. In the chemical lift-off method, a layer that can be dissolved in a predetermined chemical solution is formed in advance between the semiconductor layer and the growth substrate, and the growth substrate is removed from the semiconductor layer by dissolving the soluble layer using the chemical solution. .

  In such a semiconductor light emitting device in which the growth substrate is removed as described above, in order to increase the mechanical strength, the semiconductor layer is generally bonded to some supporting substrate. For example, Patent Document 1 discloses that by heating a first metal layer of a stacked body having a semiconductor layer and a second metal layer of a stacked body having a support substrate at a temperature of 100 to 200 ° C. Has been disclosed (see paragraphs [0015]-[0019] and FIG. 2 of Patent Document 1). In addition, a technique using AuSn eutectic solder for joining a laminate having a semiconductor layer and a laminate having a support substrate is disclosed (see paragraphs [0034]-[0039] and FIG. 4 of Patent Document 1). .

JP 2010-186829 A

  However, when the metal layers are bonded together or soldered as described above, the following process is required. That is, it is necessary to perform 1) a process of providing a metal layer on both the semiconductor layer side and the support substrate side, and 2) a process of bonding them together while heating them or bonding them by heating and melting them. In the method for manufacturing a semiconductor light emitting device having these steps, the number of steps is large. That is, the cycle time is long.

  Also, the adhesion is weak at the interface between the two metal layers bonded together. For this reason, there is a risk of causing cracks at the interface. In addition, voids may occur in the soldered solder layer. Moreover, since the material of the solder layer is used, the cost is high.

  The present invention has been made to solve the above-described problems of the prior art. That is, the problem is to provide a group III nitride semiconductor light-emitting device and a method for manufacturing the same that prevent the generation of cracks and voids and simplify the manufacturing process.

  The group III nitride semiconductor light emitting device according to the first aspect is electrically connected to a semiconductor layer having a light emitting layer, a p-type semiconductor layer, and an n-type semiconductor layer, a support that supports the semiconductor layer, and the p-type semiconductor layer. a p-electrode, and an n-electrode conducting to the n-type semiconductor layer. The support is a ceramic sprayed layer obtained by spraying ceramic.

  This group III nitride semiconductor light emitting device has a support formed by ceramic spraying. In ceramic spraying, when the molten particles collide with the substrate to be sprayed, the temperature of the molten particles is not so high and the heat capacity of the molten particles is also small. Therefore, the molten particles hardly apply heat to the base material bonded to the ceramic sprayed layer. Therefore, the stress resulting from the difference between the thermal expansion coefficient of the substrate and the thermal expansion coefficient of the ceramic hardly occurs. In addition, it can be discriminate | determined by analyzing a cross-sectional photograph whether the support body was formed by thermal spraying.

  The group III nitride semiconductor light emitting device according to the second aspect has at least one bonded layer bonded to a support.

  In the group III nitride semiconductor light emitting device according to the third aspect, the bonded layer has a concavo-convex shape portion on a surface facing the support, and the support has a concavo-convex shape portion on the surface facing the bonded layer. Corresponding uneven shape. Since the support is a ceramic sprayed layer, the ceramic sprayed layer is formed so as to absorb the unevenness of the uneven shape portion of the bonded layer.

  The group III nitride semiconductor light emitting device according to the fourth aspect has an n contact electrode in contact with the n type semiconductor layer. And the uneven | corrugated shaped part of a to-be-joined layer is formed along the shape of an n contact electrode. At this time, the uneven shape of the support is a shape corresponding to the uneven portion of the bonded layer.

  In the group III nitride semiconductor light-emitting device according to the fifth aspect, at least a part of the bonded layers is a passivation film. This passivation film plays a role of improving adhesion to the support. It also plays a role of protecting electrodes made of metal.

  In the group III nitride semiconductor light emitting device according to the sixth aspect, the bonding surface of the passivation film with the support is roughened. Since the surface of the passivation film is roughened, the contact area between the support and the passivation film is increased, and the adhesion becomes stronger.

  In the group III nitride semiconductor light-emitting device according to the seventh aspect, neither the bonding layer or the solder layer obtained by heating and bonding the two metal layers exists between the support and the semiconductor layer. Therefore, there is no possibility that voids are generated in the sticking layer or the solder layer or cracks are generated.

  In the group III nitride semiconductor light emitting device according to the eighth aspect, a metal layer is formed on the surface of the support opposite to the semiconductor layer.

  In the group III nitride semiconductor light-emitting device according to the ninth aspect, the p electrode and the n electrode are exposed at positions opposite to the support. The light extraction surface is on the side where the n-electrode is exposed.

  A method for manufacturing a group III nitride semiconductor light emitting device according to a tenth aspect includes a semiconductor layer forming step of growing a semiconductor layer made of a group III nitride semiconductor on a growth substrate, and a substrate including the semiconductor layer opposite to the growth substrate. A ceramic spraying step of spraying ceramic from the side position to form a support; and a growth substrate removing step of removing the growth substrate from the semiconductor layer.

  In this method for manufacturing a semiconductor light emitting device, the support is formed by ceramic spraying. Therefore, the process of joining the laminated body containing a semiconductor layer and the laminated body containing a support body like the past is unnecessary. Therefore, the number of steps of the method for manufacturing the semiconductor light emitting device is smaller than that of the conventional method. Also, the cycle time is short.

  In the group III nitride semiconductor light-emitting device manufacturing method according to the eleventh aspect, the semiconductor layer has a p-type semiconductor layer. This method for manufacturing a group III nitride semiconductor light-emitting device includes a p-contact electrode forming step for forming a p-contact electrode on the p-type semiconductor layer, and a passivation film forming step for forming a passivation film on the p-contact electrode. In the ceramic spraying step, ceramic is sprayed on the passivation film.

  In the group III nitride semiconductor light-emitting device manufacturing method according to the twelfth aspect, the semiconductor layer has an n-type semiconductor layer. In this method of manufacturing a group III nitride semiconductor light emitting device, a non-through hole extending from a p-type semiconductor layer to an n-type semiconductor layer is formed to expose a part of the n-type semiconductor layer, and an n-contact electrode is formed at the exposed portion. An n contact electrode forming step to be formed; and an insulating film forming step of covering the n contact electrode with an insulating film.

  The manufacturing method of the group III nitride semiconductor light-emitting device according to the thirteenth aspect includes a flattening step of flattening the opposite surface of the semiconductor layer in the support.

  According to the present invention, there are provided a group III nitride semiconductor light-emitting device and a method for manufacturing the same, in which the manufacturing process is simplified while preventing the generation of cracks and voids.

It is the perspective view seen from the upper direction of the light emitting element concerning an embodiment. It is sectional drawing which shows the AA cross section of FIG. It is a figure which shows the shape of the n contact electrode of the light emitting element which concerns on embodiment. It is a figure for demonstrating the laminated structure of the n electrode of the light emitting element which concerns on embodiment. It is FIG. (1) for demonstrating the manufacturing method of the light emitting element which concerns on embodiment. It is FIG. (2) for demonstrating the manufacturing method of the light emitting element which concerns on embodiment. It is FIG. (3) for demonstrating the manufacturing method of the light emitting element which concerns on embodiment. It is FIG. (4) for demonstrating the manufacturing method of the light emitting element which concerns on embodiment. It is FIG. (5) for demonstrating the manufacturing method of the light emitting element which concerns on embodiment. It is FIG. (6) for demonstrating the manufacturing method of the light emitting element which concerns on embodiment. It is FIG. (The 7) for demonstrating the manufacturing method of the light emitting element which concerns on embodiment. It is FIG. (8) for demonstrating the manufacturing method of the light emitting element which concerns on embodiment. It is FIG. (9) for demonstrating the manufacturing method of the light emitting element which concerns on embodiment. It is a figure which shows the modification of the light emitting element which concerns on embodiment. It is a figure for demonstrating the modification of the manufacturing method of the light emitting element which concerns on embodiment.

  Hereinafter, specific embodiments will be described with reference to the drawings, taking a semiconductor light emitting element as an example. However, the present invention is not limited to the embodiment. Moreover, the laminated structure of the semiconductor layer of the semiconductor light emitting element mentioned later is an illustration. Of course, a laminated structure different from that of the embodiment may be used. And the thickness of each layer in each figure is shown conceptually and does not indicate the actual thickness.

1. Semiconductor Light-Emitting Element FIG. 1 is a view of a light-emitting element 100 of this embodiment as viewed from above. FIG. 2 is a cross-sectional view showing the AA cross section of FIG. The light emitting device 100 is a substrate lift-off type semiconductor light emitting device from which a growth substrate is removed. The light emitting device 100 includes a support 110, a passivation film 120, a cover metal layer 130, a reflective p-contact electrode 140, an insulating film 150, an n-contact electrode 160, a semiconductor layer 170, a p-electrode P1, and an n-electrode N1.

The semiconductor layer 170 has a plurality of layers made of a group III nitride semiconductor. Here, the group III nitride semiconductor is a semiconductor represented by _{Al x In y Ga z N (} x + y + z = 1,0 ≦ x ≦ 1,0 ≦ y ≦ 1,0 ≦ z ≦ 1). The semiconductor layer 170 includes a p-type semiconductor layer 171, a light emitting layer 172, and an n-type semiconductor layer 173. The light emitting layer 172 has a well layer and a barrier layer. The structure of the light emitting layer 172 may be a single quantum well structure (SQW) or a multiple quantum well structure (MQW). The p-type semiconductor layer 171 has a p-type cladding layer and a p-type contact layer. The n-type semiconductor layer 173 has an n-type cladding layer and an n-type contact layer. Further, the surface of the n-type semiconductor layer 173 opposite to the light emitting layer 172 is a roughened light extraction surface 174. Thus, the light extraction surface 174 is on the side where the n-electrode N1 is exposed. The laminated structure of these semiconductor layers 170 is an example, and other laminated structures may be used.

The support 110 supports the semiconductor layer 170 and prevents the light emitting element 100 from being deformed. The support 110 is a ceramic sprayed layer formed by ceramic spraying, as will be described later. The passivation film 120 covers the surface of the cover metal layer 130 on the support 110 side. The passivation film 120 is a bonded layer bonded to the support 110. The material of the passivation film 120 is, for example, SiO ₂ or Si ₃ N ₄ .

  The cover metal layer 130 is a layer for preventing electromigration. For example, the metal of the reflective p contact electrode 140 is prevented from diffusing. The material of the cover metal layer 130 may be, for example, any one of Pt, Au, Rh, Ag, Pd, Ti, Ni, W, or an alloy thereof, or a layered structure thereof. Good.

The reflective p-contact electrode 140 is for conducting with the p-type semiconductor layer 171. The reflective p-contact electrode 140 is in contact with the p-type contact layer. The reflective p contact electrode 140 is also a reflective layer for reflecting light emitted from the semiconductor layer 170. The material of the reflective p-contact electrode 140 is, for example, Ag, Rh, Pt, Ru, or an alloy containing these metals as a main component. Alternatively, a light-transmitting conductive film such as ITO or IZO and a highly reflective metal layer such as Ag, Al, or Rh may be laminated. The insulating film 150 is a layer for preventing conduction between the n contact electrode 160 and the reflective p contact electrode 140. The material of the insulating layer 150 is, for example, SiO ₂ or Si ₃ N ₄ .

  The p electrode P <b> 1 is a pad electrode that conducts with the p-type semiconductor layer 171. As the material of the p-electrode P1, a material (Ti / Al) formed in the order of Ti and Al from the cover metal layer 130 side can be used. Moreover, you may use what was formed in order of Ti / Au and Ti / Ni / Au. The material of the outermost surface is preferably Au.

  The n contact electrode 160 is for electrical connection with the n-type semiconductor layer 173. The n contact electrode 160 is in contact with the n-type contact layer. FIG. 3 shows the shape of the n contact electrode 160. As shown in FIG. 3, the n-contact electrode 160 has a shape close to a lattice shape. That is, the beam is stretched in a planar manner to form an integrated shape. As shown in FIG. 4, the n-contact electrode 160 is formed, for example, in the order of V and Al from the n-type semiconductor layer 173 side (upper side in FIG. 4).

  The n electrode N <b> 1 is a pad electrode that is electrically connected to the n-type semiconductor layer 173. The stacked structure of the n-electrode N1 is formed, for example, in the order of Ti and Au from the n-contact electrode 160 side (downward in FIG. 4). At this time, the stacked structure of the n contact electrode 160 and the n electrode N1 is a structure formed in the order of Al, V, Ti, and Au from the lower side in FIG. Yes.

  The stacked structure of the n-contact electrode 160 may be Ti / Al, V / Au, Ti / Au, or Ni / Au in order from the n-type semiconductor layer 173 side (upper side in FIG. 4) in addition to the above-described structure. . The same structure as that of the n contact electrode 160 may be used for the stacked structure of the n electrode N1. Further, the same structure as that of the p electrode P1 can be used for the stacked structure of the n electrode N1. Furthermore, the laminated structure of the n-electrode N1 and the laminated structure of the p-electrode P1 can be made the same and formed simultaneously. As shown in FIG. 2, the p electrode P <b> 1 and the n electrode N <b> 1 are exposed at positions opposite to the support 110.

2. Support (ceramic sprayed layer)
As described above, the support 110 is a ceramic sprayed layer formed by ceramic spraying. The ceramic sprayed layer is formed by stacking molten particles. For this reason, the ceramic sprayed layer contains a certain amount of oxide, and grain boundaries also appear remarkably. The ceramic sprayed layer contains fine pores and unmelted particles. Since the ceramic sprayed layer has the above-described characteristic points, it can be determined whether or not the ceramic sprayed layer is manufactured by ceramic spraying by observing a cross section with a microscope such as SEM.

The material of the support 110 is, for example, alumina (Al ₂ O ₃ ). The thickness of the support 110a to be sprayed is about 1 mm. Moreover, it may be within the range of 0.3 mm or more and 3.0 mm or less. Further, the thickness of the support 110 may be changed according to the material used and the diameter of the wafer. In order to facilitate separation when separating the individual elements from the wafer, the support 110 can be thinned. The thickness of the support 110 after thinning is about 0.5 mm. Moreover, the thickness may be in the range of 0.3 mm or more and 1.5 mm or less.

  As shown in FIG. 2, the exposed surface 111 of the support 110 is flat. On the other hand, unevenness 113 is formed on the surface 112 of the support 110 on the semiconductor layer 170 side. The concave portion of the unevenness 113 is formed along the shape of the n contact electrode 160. In other words, the unevenness 113 has a groove formed along the shape of the n-contact electrode 160. The unevenness 113 has a shape that meshes with the uneven shape of the passivation film 120. Thus, the passivation film 120 has a concavo-convex shape portion on the surface facing the support 110. On the other hand, the support 110 has a concavo-convex 113 corresponding to the concavo-convex shape portion of the passivation film 120 on the surface facing the passivation film 120.

3. Manufacturing method of semiconductor light emitting device 3-1. Semiconductor layer forming step Crystals of each semiconductor layer made of a group III nitride semiconductor are epitaxially grown by metal organic chemical vapor deposition (MOCVD). As shown in FIG. 5, the semiconductor layer 170 is formed on the main surface of the sapphire substrate S10 that is the growth substrate. The formation order is the order of the n-type semiconductor layer 173, the light emitting layer 172, and the p-type semiconductor layer 171 from the sapphire substrate S10 side. In addition, a low temperature buffer layer is preferably formed before the semiconductor layer 170 is formed.

3-2. Next, a recess 175 is formed in the semiconductor layer 170 by dry etching. At that time, SiO ₂ may be used as a mask. As shown in FIG. 6, the recess 175 is a non-through hole that reaches the n-type semiconductor layer 173 from the p-type semiconductor layer 171 side. The n-type contact layer 176 of the n-type semiconductor layer 173 is exposed at the bottom of the recess 175. The shape of the recess 175 is close to the shape of the n-contact electrode 160 shown in FIG. Then, as shown in FIG. 7, n contact electrode 160 is formed on n type contact layer 176.

3-3. Then, as shown in FIG. 8, the n contact electrode 160, a part of the surface 171a, and the exposed portions of the p-type semiconductor layer 171, the light emitting layer 172, and the n-type semiconductor layer 173 exposed by dry etching are formed. An insulating film 150 is formed so as to cover it. As a result, the n-contact electrode 160 is covered with the n-type contact layer 176 of the semiconductor layer 170 and the insulating film 150. At this time, the portion of the insulating film 150 is a convex portion protruding from the surface 171 a of the semiconductor layer 170.

3-4. Next, a reflective p-contact electrode 140 is formed on the p-type contact layer 171a of the p-type semiconductor layer 171 by using a sputtering method. A part of the reflective p-contact electrode 140 covers the insulating film 150. And the location which covers the insulating film 150 among the reflective p-contact electrodes 140 has a convex shape.

3-5. Cover Metal Layer Formation Step Next, the cover metal layer 130 is formed on the reflective p contact electrode 140. Here, the cover metal layer 130 is formed over the entire surface of the wafer. A portion of the cover metal layer 130 along the n contact electrode 160 has a convex shape.

3-6. Next, as shown in FIG. 9, a passivation film 120 is formed on the cover metal layer 130. Here, the passivation film 120 is formed over the entire surface of the wafer. At this time, the passivation film 120 has an uneven shape. This uneven shape is formed with a protrusion along the shape of the n-contact electrode 160.

3-7. Next, ceramic is sprayed onto the base material including the semiconductor layer 170 from the position opposite to the sapphire substrate S10, that is, the position on the passivation film 120 side. Here, a low pressure plasma spraying method is used. At that time, thermal spraying is performed inside a decompression chamber supplied with an inert gas such as Ar or N ₂ as an atmospheric gas. The temperature of the growth substrate during ceramic spraying is in the range of 10 ° C. or higher and 150 ° C. or lower. This temperature range is merely an example, and is not limited to this range. Thereby, as shown in FIG. 10, the support body 110a which consists of a ceramic sprayed layer is formed. The support 110a is bonded to the passivation film 120. In addition, since element isolation is not performed at this stage, the support body 110a is disk shape.

3-8. Growth Substrate Removal Step After forming the support 110a, the sapphire substrate S10 that is the growth substrate is removed from the semiconductor layer 170. For example, the sapphire substrate S10 can be removed by laser lift-off. FIG. 11 shows a state after removing the sapphire substrate S10.

3-9. Next, recesses 177 and 178 are formed from the side of the n-type semiconductor layer 173 exposed by removing the sapphire substrate S10. This may be performed by dry etching. The cover metal layer 130 is exposed at the bottom of the recess 177. The n contact electrode 160 is exposed at the bottom of the recess 178. That is, the formation of the recess by dry etching reaches the cover metal layer 130 and the n-contact electrode 160, and stops at these metal layers.

  Then, as shown in FIG. 12, a p-electrode P1 is formed on the cover metal layer 130 of the recess 177. An n-electrode N 1 is formed on the n-contact electrode 160 in the recess 178. After that, a surface roughening process or an insulating film may be performed as a light extraction surface.

3-10. Element Isolation Step Here, as shown in FIG. 13, the element is isolated using a YAG laser. Of course, the elements may be separated by other methods. Thereby, the light emitting element 100 shown in FIG. 2 etc. is manufactured. Note that heat treatment may be appropriately performed in the above manufacturing process. In addition, before the element separation, the sprayed support 110a can be thinned by polishing. Of course, the surface of the support 110a in that case is flat.

4). Comparison with a semiconductor light emitting device using a conventional support substrate 4-1. Effect of Support Body The light emitting device 100 of the present embodiment includes a support body 110 made of a ceramic sprayed layer. The support 110 plays a role of (A) increasing the mechanical strength of the light emitting element 100, as well as (B) a bonding material with the stacked body including the semiconductor layer 170, and (C) a semiconductor layer. It has a function of absorbing irregularities of a laminate including The support substrate of the conventional semiconductor light emitting device does not have the effects (B) and (C).

4-2. Internal Structure of Support As described above, the light emitting device 100 of the present embodiment includes the support 110 made of a ceramic sprayed layer. The ceramic sprayed layer has a structure in which molten particles collide to form a film and deposit. And it contains an oxide. The support 110 contains fine pores and unmelted particles. Therefore, the cross-sectional structure of the support 110 is different from the cross-sectional structure of the ceramic substrate manufactured by firing. This difference can be observed by a cross-sectional photograph using a microscope such as SEM.

4-3. Conventionally, a laminate including a semiconductor layer and a laminate including a support substrate are joined by solder bonding. Therefore, in the case where unevenness is present in the stacked body including the semiconductor layer, the solder bonding layer (or other layer) absorbed the unevenness when bonded to the support substrate. That is, unevenness corresponding to the unevenness of the laminate including the semiconductor layer is formed in the solder bonding layer or the like. On the other hand, in this embodiment, the support body 110 which is a ceramic sprayed layer absorbs the unevenness. That is, the unevenness 113 is formed on the surface 112 of the support 110 on the semiconductor layer 170 side. The unevenness 113 has a shape corresponding to the unevenness of a member (passivation film 120 or the like) bonded to the support 110. On the other hand, the exposed surface 111 is substantially flat. That is, in the support 110, the surface 112 on the semiconductor layer 170 side has unevenness 113, and the exposed surface 111 on the opposite side is flat. In a normal ceramic substrate, it is very difficult to provide an uneven shape corresponding to the joint surface.

4-4. Presence / absence of a solder bonding layer In general, a light emitting element using a conventional ceramic substrate has a solder bonding layer. This is for bonding the semiconductor layer grown on the growth substrate and the support substrate. In the light emitting device 100 of this embodiment, this bonding is not necessary. Therefore, the light emitting element 100 does not have a solder bonding layer. Moreover, it does not have the layer which prevents the metal of a solder layer from diffusing. Since there is no solder joint layer itself, no void is generated inside the solder joint layer. Therefore, in the manufacturing method of the semiconductor light emitting device of this embodiment, there are few initial defective products and the yield is good. Conventionally, as the solder of the solder bonding layer, for example, other lead-free solders are used in addition to Au-Sn solder. There is also no adhesive layer in which two metal layers are heated and bonded together. In addition, there is no bonding layer using metal paste or metal nanoparticles.

4-5. As described above, in the method of manufacturing the semiconductor light emitting device of this embodiment, neither the solder bonding process nor the bonding process of heating and bonding the two metal layers is performed. Therefore, the number of steps is smaller than that of the conventional manufacturing method. That is, the cycle time is short. In addition, the conventional bonding process in which the metal layers are bonded together is performed at a high temperature of at least about 200 ° C., generally close to 300 ° C. For this reason, the substrate is warped due to the difference in thermal expansion coefficient between the substrate and the semiconductor layer. As a result, peeling at the internal lamination interface, wrapping defects or the like may occur during element separation. When these occur, the yield decreases. On the other hand, in this embodiment, the temperature of the molten particles is sufficiently low, and such warpage hardly occurs. Therefore, the yield is sufficiently high as compared with the conventional case.

5. Modified example 5-1. Type of ceramic In this embodiment, the support 110 is made of alumina (Al ₂ O ₃ ). However, oxide ceramics such as titania (TiO ₂ ), chromia (Cr ₂ O ₃ ), yttria (Y ₂ O ₃ ), and zirconia (ZrO ₂ ) can also be used. A plurality of these materials may be used. The ceramic is not limited to the above-mentioned oxide-based ceramics, but includes hydroxide-based, carbide-based, nitride-based, halide-based, carbonate-based, and phosphate-based ceramics. However, it is limited to materials that can be sprayed.

  For example, high thermal conductivity ceramic such as AlN or SiC can be sprayed. The thermal conductivity of AlN and SiC is high. Therefore, the light emitting element 100 having the support 110 on which these are thermally sprayed has high heat dissipation.

5-2. Kind of thermal spraying method In this embodiment, the low pressure plasma spraying method was used. However, other methods may be used. For example, any of an atmospheric plasma spraying method, a high-speed flame spraying method, and a welding rod type flame spraying method may be used. Of course, other thermal spraying methods than the above can be applied as long as the ceramic thermal spraying can be performed.

5-3. Formation of Metal Layer Further, the metal layer 210 may be formed on the surface of the support 110 opposite to the semiconductor layer 170, that is, the exposed surface 111. The light emitting element 200 is shown in FIG. In this case, the total thickness of the support 110 and the metal layer 210 may be in the range of 0.3 mm to 1.5 mm. However, this is merely an example, and is not limited to this range. A sputtering method or the like may be used for forming the metal layer 210. Moreover, you may form by thermal spraying. In that case, the light emitting element 200 has a support 110 made of a ceramic sprayed layer and a metal layer 210 made of a metal sprayed layer. The heat dissipation of the entire device can be improved by forming a thin alumina, which is a general ceramic having a low thermal conductivity, and forming a thick metal having a high thermal conductivity such as Cu. Alternatively, alumina (Al ₂ O ₃ ) and copper (Cu) may be alternately sprayed and laminated.

5-4. Electrode Shape of Light-Emitting Element In the light-emitting element 100 of this embodiment, the reflective p-contact electrode 140 has a plate shape, and the n-contact electrode 160 has a shape close to a lattice shape. However, other shapes are possible. For example, the reflective p-contact electrode and the n-contact electrode may be comb-shaped and mesh with each other. Other shapes may also be used.

5-5. Passivation Film In this embodiment, the support 110 is formed by spraying ceramic on the passivation film 120. However, the passivation film 120 is not necessarily provided. However, the passivation film 120 plays a role of enhancing adhesion to the support 110 and also plays a role of protecting the electrode made of metal. Since the thermally sprayed ceramic layer is not a dense layer and has a low ability to protect electrodes made of metal, it is better to provide the passivation film 120. Then, by applying a roughening process such as a blast process to the passivation film 120, the adhesion between the passivation film 120 and the support 110 becomes higher.

5-6. Growth substrate In this embodiment, a sapphire substrate was used as the growth substrate. However, other substrates such as a Si substrate may be used. Further, when removing the growth substrate, other methods such as a chemical lift-off method may be used instead of the laser lift-off method.

5-8. Cutting allowance for element isolation In the present embodiment, the cover metal layer 130 is formed over the entire surface of the wafer. However, as shown in FIG. 15, the reflective p-contact electrode 140 is covered and a portion serving as an end portion of the light-emitting element, that is, a portion for cutting off the element separated in the element separation step is not covered. Thereby, a metal layer can be made not to exist in the cutting margin of an element. Therefore, the element can be easily separated. At this time, the layers to be bonded to the support 110 are the passivation film 120 and the insulating film 150.

5-9. Concave and convex shape In the present embodiment, the support 110 has a concave and convex 113. However, the n contact electrode 160 can be flattened by, for example, reducing the vertical width in FIG. Thus, it does not need to have an uneven shape.

6). Summary of the present embodiment The light emitting device 100 of the present embodiment has a support 110 made of a ceramic sprayed layer. Since the support 110 is formed by ceramic spraying, it does not have a solder joint layer. Therefore, no void is generated when solder is joined. In addition, an uneven shape that meshes with the uneven shape of the stacked body including the semiconductor layer 170 is formed on the surface of the support 110 on the semiconductor layer 170 side.

  Further, the method for manufacturing a semiconductor light emitting device of this embodiment does not have a solder bonding step. Since the manufacturing process is simplified as described above, the cycle time is shorter than the conventional one. In addition, since no Au—Sn solder is used, the material cost can be reduced. Further, the support 110 of the light emitting device 100 manufactured by this manufacturing method hardly warps. This is because the temperature at which the molten particles collide is not so high, and the generated thermal stress is small. Therefore, the yield is high. That is, the manufacturing cost is lower.

  The embodiment described above is merely an example. Therefore, naturally, various improvements and modifications can be made without departing from the scope of the invention. For example, it is not limited to the metal organic chemical vapor deposition method (MOCVD method). Any other method may be used as long as the crystal is grown using a carrier gas. Further, the semiconductor layer may be formed by other epitaxial growth methods such as a liquid phase epitaxy method and a molecular beam epitaxy method.

DESCRIPTION OF SYMBOLS 100 ... Light emitting element 110 ... Support body 120 ... Passivation film 130 ... Cover metal layer 140 ... Reflective p contact electrode 150 ... Insulating film 160 ... n contact electrode 170 ... Semiconductor layer 171 ... P-type semiconductor layer 172 ... Light emitting layer 173 ... n Type semiconductor layer N1... N electrode P1... P electrode

Claims (13)

A semiconductor layer having a light emitting layer, a p-type semiconductor layer, and an n-type semiconductor layer;
A support for supporting the semiconductor layer;
A p-electrode conducting with the p-type semiconductor layer;
An n-electrode conducting to the n-type semiconductor layer;
Have
The support is
A group III nitride semiconductor light-emitting device characterized by being a ceramic sprayed layer obtained by spraying ceramic. The group III nitride semiconductor light-emitting device according to claim 1,
A group III nitride semiconductor light-emitting device comprising at least one bonded layer bonded to the support. The group III nitride semiconductor light-emitting device according to claim 2,
The bonded layer is
It has a concavo-convex shape portion on the surface facing the support,
The support is
A group III nitride semiconductor light-emitting device having a concavo-convex shape corresponding to the concavo-convex portion on a surface facing the bonded layer. The group III nitride semiconductor light-emitting device according to claim 3,
An n-contact electrode in contact with the n-type semiconductor layer;
The uneven portion of the bonded layer is
A group III nitride semiconductor light-emitting device, which is formed along the shape of the n-contact electrode. The group III nitride semiconductor light-emitting device according to any one of claims 2 to 4,
At least some of the bonded layers are
A group III nitride semiconductor light-emitting device, which is a passivation film. The group III nitride semiconductor light-emitting device according to claim 5,
A group III nitride semiconductor light-emitting device, wherein a surface of the passivation film bonded to the support is roughened. The group III nitride semiconductor light-emitting device according to any one of claims 1 to 6,
A group III nitride semiconductor light-emitting device characterized in that none of a bonding layer and a solder layer obtained by heating and bonding two metal layers exists between the support and the semiconductor layer. The group III nitride semiconductor light-emitting device according to any one of claims 1 to 7,
A group III nitride semiconductor light-emitting device, wherein a metal layer is formed on a surface of the support opposite to the semiconductor layer. The group III nitride semiconductor light-emitting device according to any one of claims 1 to 8,
The p electrode and the n electrode are
Exposed at the opposite side of the support,
The light extraction surface is
A group III nitride semiconductor light emitting device, wherein the n electrode is on the exposed side. In the method of manufacturing a group III nitride semiconductor light emitting device,
A semiconductor layer forming step of growing a semiconductor layer made of a group III nitride semiconductor on a growth substrate;
A ceramic spraying step of spraying ceramic on a base material including the semiconductor layer from a position opposite to the growth substrate to form a support;
A growth substrate removing step of removing the growth substrate from the semiconductor layer;
A method for producing a Group III nitride semiconductor light-emitting device, comprising: In the manufacturing method of the group III nitride semiconductor light-emitting device according to claim 10,
The semiconductor layer has a p-type semiconductor layer,
A p-contact electrode forming step of forming a p-contact electrode on the p-type semiconductor layer;
A cover metal layer forming step of forming a cover metal layer on the p-contact electrode;
A passivation film forming step of forming a passivation film on the cover metal layer;
Have
In the ceramic spraying process,
A method of manufacturing a group III nitride semiconductor light-emitting device, characterized in that ceramic is sprayed onto the passivation film. In the manufacturing method of the group III nitride semiconductor light-emitting device according to claim 11,
The semiconductor layer has an n-type semiconductor layer,
An n-contact electrode forming step of forming a non-through hole extending from the p-type semiconductor layer to the n-type semiconductor layer, exposing a part of the n-type semiconductor layer, and forming an n-contact electrode at the exposed portion;
An insulating film forming step of covering the n-contact electrode with an insulating film;
A method for producing a Group III nitride semiconductor light-emitting device, comprising: In the manufacturing method of the group III nitride semiconductor light-emitting device according to any one of claims 10 to 12,
A method for producing a group III nitride semiconductor light emitting device, comprising: a planarization step of planarizing a surface of the support opposite to the semiconductor layer.

Images