JP5196097B2 - Semiconductor light emitting device manufacturing method, semiconductor light emitting device, and light emitting device using the same - Google Patents

Description

  In a method for manufacturing a light-emitting element having a semiconductor light-emitting element structure on a substrate and a laminated structure such as a reflective layer on the back side of the substrate, and the light-emitting element and the light-emitting device, the laminated structure is provided with a desired shape. The present invention relates to a method for manufacturing a light-emitting element with improved light extraction from the light-emitting element, and the light-emitting element and light-emitting device.

  In order to efficiently extract the light emitted from the device outside the device, a conventional semiconductor light emitting device is proposed that has a light extraction surface and a light reflection surface for collecting light on the light extraction surface. Has been.

JP 2005-340365 A Japanese Patent Laying-Open No. 2005-064426 JP 2004-228290 A JP 2004-031526 A JP 2003-338468 A

  Each document proposes various processing methods by laser processing (laser scribing), and (1) [Document 1] discloses that laser processing is used to define a wiring layer of a wiring board, (2) [References 3 to 5] Laser processing of the substrate from the semiconductor layer side, (3) [References 2 and 4] Laser irradiation from the back side, (4) [Reference 3] Semiconductor layer and other layers And the like that process the substrate and the substrate at the same time.

  On the other hand, as shown in FIG. 3, if the substrate and / or semiconductor layer is made of a material that can transmit laser light, it is difficult to control the processing depth. When processing at the same time, the metal layer is ablated within a part of the irradiation time, and the substrate is irradiated with laser light for the remaining time. At this time, the substrate and the semiconductor layer are exposed. In particular, damage to the semiconductor layer causes serious problems. On the other hand, setting the reflecting layer and the adhesive layer in desired shapes and making them different from each other complicates the manufacturing process, increases the number of steps, and causes manufacturing difficulties.

  In addition, in the light-emitting element, the element structure, the reflective layer provided on the substrate side, and the adhesive layer to the mounting substrate are used for optical characteristics such as light-emitting output of the light-emitting element, thermal characteristics such as heat dissipation and durability, and reliability during mounting. Further, it affects the reliability of the element and the light emitting device. A light-emitting element and a light-emitting device having high characteristics are excellent for high output, for example, illumination.

  The present invention has been made in view of the above circumstances, and in the manufacturing method, a laminate on the back side of a substrate such as a reflective layer is easily defined in a desired shape. In the light emitting element and the light emitting element, the light emitting characteristics, heat dissipation characteristics, and reliability Can be obtained.

The method for manufacturing a light-emitting element according to the first aspect of the present invention comprises a step of forming a semiconductor on a first main surface of a substrate and providing a light-emitting element structure on the second main surface of the substrate. A step of providing a laminated structure including a reflective layer; and an upper layer that irradiates the laminated structure with laser light, partially removes an upper layer of the structure, and defines an upper layer of the laminated structure corresponding to the light emitting element The lower layer is exposed by irradiating the exposed portion of the lower layer exposed from the upper layer by the removing step and the upper layer removing step with a laser beam having a light density larger than the light density of the laser beam in the upper layer removing step , leaving a part of the exposed portion. Removing a part of the reflective layer and a part in the depth direction of the substrate located in the lower layer exposed portion to provide a dividing groove in the substrate region exposed from the laminated structure; It comprises.

  In the present invention, the upper layer side of the laminated structure on the back side of the substrate is first laser processed to remove part of it, and the upper layer portion is patterned, and then the substrate is simultaneously removed by laser processing together with the exposed lower layer. Then, it is patterned. Therefore, it is possible to form a laminated structure in which different shapes are formed in the upper layer and the lower layer part, and to provide a dividing groove on the substrate, so that a suitable laminated structure can be used without using a method with many steps such as photolithography. Can be patterned.

  As another form according to the first aspect, (1) a step of dividing the substrate along the dividing groove after forming the dividing groove of the substrate, (2) light density of the irradiation laser light in the upper layer removing step Is lower than the light density in the lower layer removal step, (3) the irradiation area of the laser beam in the upper layer removal step is larger than the irradiation area in the lower layer removal step, and (4) the lower layer is wider than the upper layer in the cross section. (5) The substrate exposed region exposed from the lower layer is substantially the same or wider than the opening width in the second main surface of the substrate dividing groove. (6) The substrate and the semiconductor light emitting element structure are adapted for laser light. And (7) the laminated structure is thicker on the upper layer side and thinner on the lower layer side, and has different materials or compositions.

  By dividing along the dividing groove provided on the substrate, a light emitting element having a laminated structure of a desired shape can be obtained. In the processing of the upper layer and the lower layer, laser light irradiation is performed at different light densities, particularly the lower layer processing Sometimes it is possible to form a substrate groove at the same time by processing at high density, and the laminated structure can be defined with the desired processing (removal) shape and width by making the irradiation area different during upper and lower layer processing can do. Further, by making the upper layer wider than the lower layer, suitable laser processing can be achieved. Furthermore, by these laser processing (upper layer / lower layer removing step), when the semiconductor and the substrate are transparent to the laser beam, the substrate and the semiconductor can be prevented from being damaged by the laser beam. In addition, by removing the lower layer, the width of the groove of the substrate exposed region exposed from the lower layer is made substantially the same as or smaller than the removed width of the lower layer, thereby making it possible to perform preferable substrate division.

  In addition, in the light emitting device, the upper layer side serving as the adhesive layer and the lower layer side serving as the reflective layer and the first heat radiation layer have different shapes, preferably a wider lower layer side, so that a suitable light reflecting structure can be obtained. A structure excellent in heat dissipation, mountability, light emission characteristics, and a suitable combination with a sealing member / light converting member can be obtained.

  Moreover, there exists an advantage shown below by processing and patterning the upper layer side of a laminated structure, its lower layer side, and the dividing groove of a board | substrate by a separate process. In a laser processing apparatus, when a laminated structure composed of a relatively thick metal layer and a substrate material such as a different material or a hard oxide are processed at the same time, as shown in a comparative example in FIG. In some cases, the laser light propagates through the transmissive substrate and reaches the semiconductor layer on the surface side, thereby damaging the semiconductor layer. On the other hand, the upper layer side is removed first, and the lower layer side and part of the depth of the substrate are removed as a desired shape and pattern from the lower layer exposed part exposed from the upper layer pattern, thereby mass production. It is possible to manufacture a light-emitting element having a light reflection and heat dissipation structure that is excellent in accuracy and accurate.

  In addition, since the substrate exposed region from the dividing groove opening and the lower layer is substantially the same, a light emitting device having a reflective layer on almost the entire back surface of the substrate can be obtained, and the light can be suitably reflected on the light emitting device structure side and also radiated heat. It is possible to make an element having excellent properties.

  As an aspect (second aspect) according to the light emitting element of the present invention, semiconductor light emission having a semiconductor light emitting element structure on the first main surface of the substrate and a laminated structure including a reflective layer on the second main surface. An element, wherein the laminated structure has an upper layer side and a lower layer side including an extending portion extending outward from the upper layer side, and the light emitting element structure is provided with a light emitting structure on a substrate surface A laminated structure having a light emitting structure and a semiconductor structure different from the light emitting structure, the second main surface of the substrate having an exposed region exposed from the laminated structure, and facing the light emitting structure; The lower layer side and the upper layer side are provided, and the lower layer side extending portion and the substrate exposed region are provided to face the semiconductor structure portion. As shown in FIG. 1 and the like, a laminated structure (upper layer and lower layer) such as a reflective layer is provided corresponding to the light emitting structure portion, and further has a lower layer extending portion extending outward from the upper layer, thereby reflecting light. A light-emitting element having an excellent structure and excellent heat dissipation can be obtained.

  As another aspect according to the second aspect, (1) the laminated structure has at least a reflective layer on the lower layer side and an adhesive layer on the upper layer side. (2) the laminated structure is on the upper layer side. In comparison, (3) the semiconductor structure portion is arranged at the peripheral portion of the light emitting element, and the substrate exposed region and the lower layer extending portion are arranged facing the peripheral portion. (4) The light emitting element has positive and negative electrodes on the upper surface side of the light emitting element structure.

  The reflective structure of the second main surface of the substrate, for example, by providing a reflective layer on the lower layer side to provide the reflective function of the light-emitting element, and providing an adhesive layer on the upper layer side for bonding to the mounting substrate, suitable reflection It can be a mounting structure. In addition, if the lower layer side is wider than the upper layer side, suitable reflection and heat conduction can be realized on the wider lower layer side, and a good heat dissipation path can be formed on the upper layer side. By being thicker, the heat capacity is excellent and the mountability is excellent. Furthermore, the substrate exposed region exposed from the lower layer is at least the peripheral portion of the light emitting element, that is, the lower layer is provided by exposing the outer peripheral portion, so that light extraction in the substrate exposed region is excellent, and light reflection inside the device It can be an element having excellent efficiency and heat dissipation characteristics.

  As another aspect, in a light emitting device mounted on a mounting substrate via an adhesive layer of the laminated structure, suitable light extraction and heat dissipation characteristics can be obtained. As another form of this light emitting device, (1) the adhesive layer of the laminated structure is disposed in the light emitting element, (2) has a sealing member that covers the light emitting element, and the sealing member is a mounting substrate. And (3) the sealing member has a light conversion member that converts a part of light emitted from the light emitting element. In 1 above, the adhesive layer does not spread to the outside of the element, and suitable light extraction can be realized. In 2 above, the sealing member is inside the element so that suitable light extraction from the element to the sealing member is performed. A light emitting device with a light emission color can be obtained.

  In patterning the semiconductor structure on the back surface of the substrate, the number of steps such as photolithography is large, and the patterning can be performed without using a method with a large manufacturing cost and without damaging the semiconductor layer like laser light. Further, even in a relatively thick laminated structure, after thinning by the first laser processing, the thin film portion and the substrate can be removed by the second laser processing to form a split groove on the substrate.

  In the light-emitting element, a reflective layer is provided on almost the entire back surface of the substrate, and the lower layer and the upper layer of the laminated structure are disposed facing the light-emitting structure portion that is the main heat generating portion on the substrate surface, so that the light reflection characteristics are excellent. A light emitting element with excellent heat dissipation can be obtained. Further, the light emitting device can be excellent in mounting and sealing of the light emitting element, and excellent in light emission characteristics and heat dissipation characteristics.

  Hereinafter, embodiments of the invention will be described with reference to the drawings as appropriate. However, the embodiment described below exemplifies a light emitting element manufacturing method, a light emitting element, and a light emitting device for embodying the technical idea of the present invention. Is not specified as below. Further, the present specification by no means specifies the members shown in the claims to the members of the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified, and are merely explanations. It's just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

(Embodiment 1) Device Manufacturing Method The invention according to Embodiment 1 of the present invention is to process a laminated film 50 such as a metal layer provided in a semiconductor element into a desired shape. In the following example, a method of providing a light emitting element structure of a nitride semiconductor on a substrate 10 and providing a laminated structure 50 such as a light reflecting layer on the back surface side / mounting side of the substrate will be described with reference to FIGS. Will be described. Here, FIG. 1 is a view showing a structure in which a light emitting element is bonded on a mounting substrate, FIG. 1 (a) is a cross-sectional view in the plan view of FIG. 1 (b), and FIGS. These are sectional views and plan views for explaining the respective steps of the production method of the present invention, and FIGS. 3A to 3C are sectional views for explaining the dividing steps of the production method of the present invention. In the following, description will be made in the order of the manufacturing steps of the examples, but the order of some steps is not limited.

[Light emitting element (semiconductor element) and formation process thereof]
As a semiconductor element, a stacked structure of a semiconductor to be a light emitting element structure is provided on a substrate. For example, the first main surface of the substrate includes a semiconductor layer of each conductivity type such as an n-type semiconductor and a p-type semiconductor, and has a light emitting structure 25. In a nitride semiconductor, as shown in FIG. On the sapphire substrate, an n-type nitride semiconductor layer 22, an active layer (light-emitting layer) 23, and a p-type nitride semiconductor layer 24 are stacked via a base layer 21 such as a buffer layer as in the embodiments described later. Thus, the semiconductor structure 20 is formed.

  As a light-emitting element structure, a basic structure includes an n-type semiconductor, a p-type semiconductor, or other conductive type semiconductor layer, and a light-emitting region that emits light at the interface between the n-type semiconductor and the p-type semiconductor. Some have a structure. As in the above example, a structure having a light emitting layer and an active layer between an n-type semiconductor and a p-type semiconductor is preferable. The active layer may have either a multiple quantum well structure or a single quantum well structure, and is preferably a multiple quantum well structure. In the present invention, the semiconductor may have a structure without an active layer. In this case, light is emitted at the interface between the n-type semiconductor and the p-type semiconductor to form a light emitting region. Preferably, the first conductive type semiconductor layer 22, the active layer 23, and the second conductive type semiconductor layer 24 are formed, and the semiconductor layer is partially removed so that the first conductive type semiconductor layer is exposed, and the electrode is formed. Is formed.

  As a specific example of the light emitting element, as shown in FIG. 1, the light emitting element has a semiconductor structure in which a light emitting element structure is laminated on the first main surface of the substrate 10, and each conductive type layer 22, 24 electrodes (n electrode 30 and p electrode 40) are provided. In this example, the light-emitting element structure has the first main surface side as a main light extraction side. Further, the above electrode formation structure has a light emitting element structure having a light emitting structure portion 25 in which a light emitting region is left and a semiconductor structure portion 26 of a non-light emitting portion in a region where an electrode or the like is formed. Prior to the electrode formation, a desired element structure is formed by providing a semiconductor processing step in which the laminated structure 20 is partially processed and removed. Here, FIG. 1 shows an outline of a cross section (FIG. 1A) and an upper surface (FIG. 1B) of the light emitting element 100 placed on the mounting substrate 80.

  The semiconductor layer 20 on the substrate 10 is an n-type element having a thickness of about 1 to 2 μm as an element structure layer through a base layer having a thickness of about 1 to 2 μm including a buffer layer such as a nucleation layer on a different substrate. A type semiconductor layer 22, a light emitting layer 23 having a thickness of about 50 to 150 nm, and a p type semiconductor layer 24 having a thickness of about 100 to 300 nm are formed. Each layer may be composed of two or more layers.

As the nitride semiconductor, for example, a semiconductor having a general formula of In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1) can be used. The method for growing the nitride semiconductor layer is not particularly limited. For example, a method known as a method for growing a semiconductor or nitride semiconductor, such as MOVPE, MOCVD, HVPE, or MBE, can be used. In particular, MOCVD is preferable because it can be grown with good crystallinity. In addition to this, a group III element partially substituted with B may be used, or a group V element partially substituted with P and As may be used. As each conductivity type layer, the n-type semiconductor layer contains at least one of group IV elements such as Si, Ge, Sn, S, O, Ti, Zr, Cd, or group VI elements as n-type impurities. The p-type semiconductor layer can be formed by containing Mg, Zn, Be, Mn, Ca, Sr or the like as a p-type impurity. In each conductive type layer, an undoped layer, insulating / semi-insulating (i-type), reverse conductive type layer / portion, etc. may be provided in part. For example, there are a current blocking layer / region, a reverse conductivity type tunnel layer, and the like. The underlayer 21 can be omitted depending on the type of the substrate 10 and the growth conditions of the semiconductor layer. Further, layers other than the conductive type layer, for example, the base layer and the buffer layer may be omitted depending on crystal growth conditions and the like, and it is preferable to have at least two conductive type layers as an element structure. As the light emitting structure, in addition to the pn junction, a structure such as p-i-n, or another structure such as a MIS structure can be used.

  In addition to gallium nitride compound semiconductors, the present invention can also be applied to GaAs, GaP compound semiconductors, AlGaAs, InAlGaP, and the like.

As the substrate, a substrate made of sapphire (C-plane, A-plane, R-plane), SiC, or the like, which is suitable as a substrate for a semiconductor light emitting element using a nitride semiconductor as a semiconductor, can be used. . Examples of other substrates include spinel (MgAl ₂ O ₄ ), SiC, NGO (NdGaO ₃ ) substrate, LiAlO ₂ substrate, LiGaO ₃ substrate, and GaN. The substrate is transparent to the light of the light emitting element and the laser light used for processing the back laminate 50 described later, and is made of a material having a refractive index different from that of the semiconductor layer, for example, a material different from the semiconductor layer It is preferable. As a result, light is reflected or refracted at the interface between the substrate and the semiconductor layer, and the light can be collected on the semiconductor layer side. Further, a substrate whose refractive index is smaller than that of the semiconductor layer, for example, a nitride semiconductor This is because a sapphire substrate or the like is preferable, and light can be confined on the semiconductor layer side having a small refractive index and light can be extracted more effectively on the first main surface side. When the light of the semiconductor light emitting element propagates in the substrate, as shown in FIGS. 1 and 4, the light is preferably reflected by a reflective layer 51 r provided on the back surface of the substrate, which will be described later, and the laminated body 50 on the back surface is formed. Light extraction is performed in the exposed region 50w.

[N-side electrode (negative electrode), p-side electrode (positive electrode)]
As shown in FIG. 2B, an electrode structure is formed on the stacked structure 20 formed on the substrate 10. By this laminated structure processing and electrode structure formation, an element region 60, an active region 60a of the element, and the like are formed, and an element structure in which a light emitting structure portion 25 and a semiconductor structure portion 26 such as an electrode formation portion are disposed on a substrate, respectively. It is formed. Each electrode (first electrode 30, second electrode 40) is provided in a semiconductor layer of each conductivity type (first conductivity type 22, second conductivity type 24). In an embodiment described later, the n-type layer 22 is exposed in a part of the semiconductor structure, and the exposed n-type layer 22 is formed by laminating W, Pt, and Au in this order as the n-side electrode 30, and p-type. An ITO transparent electrode is formed as a translucent p-side electrode 40 on the surface of the layer 24. Further, in the p-side electrode 40, a p-side pad electrode 42 is formed on a part of the p-side contact electrode 41, and W, Pt, and Au are formed in this order in the same process as the n-side electrode in the same manner as the n-side electrode. . The n-side electrode and the p-side pad electrode are formed to a thickness of about 0.7 to 2.3 μm, and the p-side electrode is formed to a thickness of about 10 to 300 nm. The step of forming the electrode structure can be carried out before or after any step between the formation of the semiconductor structure and the division of the substrate, preferably before the step of providing the laminated structure on the back surface of the substrate, more preferably the semiconductor It is to be carried out after the process of processing the structure to form an element structure.

  A conventionally known electrode or the like can be used as each conductivity type electrode of the nitride semiconductor. As an electrode material having both translucency and conductivity, ITO (indium tin oxide), ZnO, an alloy of Ni and Au, or the like can be used. In particular, ITO is excellent in translucency and conductivity, and can be used not only for the p-side electrode but also for the n-side electrode, which is preferable in terms of improving the efficiency of external light extraction. The material for the p-side electrode can be any material other than those described above as long as it can make ohmic contact with the p-type semiconductor layer, and the same applies to the n-side electrode. As shown in FIGS. 7 and 8, the p-side electrode 40 has a two-layer structure of a contact-side electrode 41 and an external connection-side electrode 42. When the light-emitting structure side is the light-emitting side of the device, the contact electrode 41 is a substantially transparent electrode. The first and second electrodes 30 and 40 can be laminated in the same manner. For example, in the same process as the p-electrode 40, the n-electrode 30 is used as the translucent contact electrode 31 and the external connection electrode 32. Each layer of each electrode can be provided.

[Laminated structure (substrate second main surface) and formation process thereof]
After the element structure is provided, as shown in FIG. 2B, a laminated structure in which a plurality of layers such as a reflective layer are laminated on the second main surface which is the back surface of the substrate. At this time, the laminated structure is provided with at least two layers having different materials and compositions, the lower layer side (substrate side) is a reflective layer that reflects light from the light emitting element, and the upper layer side is a barrier layer and a mounting substrate. And an adhesive layer for adhesion to each other. The laminated structure is formed by laminating each layer on substantially the entire second main surface of the substrate. Here, the formation and order of the semiconductor structure is not particularly limited, but the stacked structure is preferably formed after the semiconductor structure is formed in consideration of the temperature at the time of forming the semiconductor layer. Further, using a metal mask or the like, each layer such as a reflective layer may be formed in a periodic pattern shape, with substantially the entire back surface of the substrate as a formation region.

  After forming the laminated structure, as shown in FIGS. 2C and 2D, a process of partially removing the upper layer side and the lower layer side of the laminated structure, and a process of forming a split groove in the substrate are provided.

  As one example of the laminated structure, an Al layer is formed as a reflective layer on the surface of the substrate (second main surface), subsequently, a W layer is formed as a barrier layer of the reflective layer, and Au—Sn is formed as an adhesive layer. A structure provided with a eutectic material. The material / composition of each layer is appropriately selected in consideration of the adhesion between the substrate and the adjacent layer and the function of each layer, and the same applies to the film thickness of each layer. The details will be described in Embodiment 2. Here, FIG. 2C is a schematic diagram showing a cross section (FIG. 2C (a)) and an upper surface (FIG. 2C (b)) of the upper layer side removal step, and FIG. 2D is a lower layer side removal step. FIG. 3 is a schematic diagram showing a section (FIG. 2D (a)) and an upper surface (FIG. 2D (b)) of the process of forming a dividing groove.

[Processing of laminated structure and method thereof]
As shown in FIGS. 2C and 2D, the laminated structure is processed and partially removed through at least two steps in the thickness direction, and the processed layer is patterned in each step. As shown in FIG. 2C, the basic method for defining the laminated structure according to the present embodiment is as follows. After the removal process is performed, as shown in FIG. 2D, the lower layer portion 51, which is exposed by removing the upper layer, is removed at a depth at which a portion of the substrate is exposed to define the lower layer portion. Here, the laser beam irradiation in the laminated structure, the upper layer / lower layer removal step, or the like may be a method of irradiating the entire processing region, but is preferably a method of scanning and processing the laser beam irradiation. It is preferable in processing accuracy, processing depth selectivity, and processing dust reduction.

  The laser light is not particularly limited, but a gas laser, an excimer laser, or the like can be used in addition to a solid-state laser such as a YAG laser. The wavelength is not particularly limited, and the wavelength, the primary, secondary, and third harmonics of each laser that can be processed such as laminated structure and its processing (melting / evaporation / removal), substrate and its groove formation, etc. , And use as appropriate.

  The method for cracking the substrate is not particularly limited, and a method for pressing and cracking the substrate (wafer) such as a breaker device or a roller device can be used.

  Processing of the laminated structure in each of the above steps is preferably performed by laser processing. As other processing methods, scribing, machining such as a dicer, wet using a photolithography technique, dry etching, and the like can also be used. Laser processing can reduce the number of man-hours such as mask formation as compared with the etching method, is excellent in mass productivity, and this effect becomes remarkable particularly when each layer is processed in a different shape. On the other hand, machining has disadvantages such as difficulty in machining accuracy in the depth direction and the like, and restrictions on the shape of the structure such as machining width and shape as compared with laser machining. Here, for example, in the case of using a YAG laser (third harmonic (wavelength 355 nm)), it can be removed in the range of about 30 to 100 μm width on the upper layer side, and 5 in the simultaneous formation with the lower layer side, that is, the substrate groove. It can be processed within a range of about 15 μm.

  The laser beam irradiation and processing of the laminated structure in the present embodiment has the following excellent actions and effects.

  The laminated structure on the back side of the substrate (second principal surface side) can be suitably processed without adversely affecting the laminated structure on the opposing surface (first principal surface) of the substrate. FIG. 4 shows an example of laser processing of a laminated structure shown as a comparative example. When the entire depth of the laminated structure 50 is laser-processed, laser light irradiation during processing is performed on the substrate and the substrate. May reach the semiconductor layer on the first main surface side and damage the portion as indicated by 10x and 20x in the figure. This is because, when a laminated structure is to be processed, after the laminated structure is removed within the irradiation time by, for example, irradiating the substrate with laser light having an output and density that does not cause multiphoton absorption on the substrate. This is because the substrate and the semiconductor on the first main surface are also irradiated, particularly when the removal is performed with a wide width. In the present invention, since the partial thickness of the laminated structure is removed in a two-stage process in each step, the irradiation area on the substrate exposed surface immediately after the removal is reduced, particularly in the processing on the lower layer side. Compared to processing, the light density is low, multiphoton absorption is suppressed, and the light-transmitting substrate / semiconductor is transmitted. Therefore, processing is possible without damage. In addition, in the laminated structure of different materials, the controllability of the removal depth may be lowered, and as shown in the figure, the removed portions of the two layers 51 and 52 of different materials have the substrate exposure depth. 50 w-A, 50 w-B having a depth that leaves a part of the first layer, etc. may occur as variations between wafers and between wafers.

  In particular, when the substrate, in addition to the semiconductor, is transparent to the irradiated laser light, and further has the laser light absorptivity, it causes such a problem. When the substrate is irradiated with laser light and part of it is damaged, the damaged part is altered, for example, the light absorption of the light emitting element and the resulting deterioration of the characteristics, the generation of cracks or chips in the damaged part due to the load when dividing the substrate, etc. And so on. On the other hand, if the substrate is transparent to laser light, the semiconductor on the side facing the stacked structure is irradiated with laser light, and damage to the semiconductor layer causes deterioration of the element structure.

  In the above embodiment, the laminated structure is processed in at least two stages, that is, the upper layer side and the lower layer side, particularly laser processing, so that such a problem can be solved. In this case, preferably, the laser light density on the upper layer side is reduced and that on the lower layer side is increased, thereby suppressing the occurrence of damage to the deeper layer side, that is, the substrate and the semiconductor layer, during the upper layer side processing. it can. On the other hand, on the lower layer side, if the light density is increased, for example, if the energy is the same, the irradiation area / spot diameter is decreased, and the substrate is processed by suitable reflection layer processing and multiphoton absorption by high density / small area irradiation. Grooves can be formed. Further, it is preferable that the light irradiation area and the cross-sectional width be larger and wider on the upper layer side and smaller and narrower on the lower layer side. By removing the upper layer with a wider width, it is exposed with a wider width than the processing part on the lower layer side to be processed next, and it is possible to reduce the occurrence of problems due to dust during processing, positioning and accuracy during lower layer processing Can be improved. That is, it is more preferable to apply a combination of light density and area / width. At this time, as shown in FIGS. 2C and 2D, the upper layer side processing / removal region and the lower layer side processing / removal region substantially coincide with each other, that is, almost the entire region in the upper layer side removal region 52w, Although it is preferable to use the lower layer side processing region, the lower layer side of the partial region may be processed while leaving a partial region of the upper layer side removal region 52w. For example, in FIGS. 2C and 2D, in the upper layer removal region 52w where the lower layer corresponding to the peripheral portion of the element is exposed, the lower layer removal 51w and the substrate dividing groove 61 are formed at the four corners of the element. In addition to this, there are examples in which the substrate is divided by the dividing groove of the cruciform, in addition to this, there are intermittent, for example, dotted line-like removal of the lower layer, an example of forming the dividing groove, etc. on the four sides of the element. Depending on the type and method of splitting, various lower layer removal regions 51w and split groove forming regions can be formed as appropriate. In the substrate division, it is preferable that a dividing groove is provided in the entire outer periphery of the element, and this is particularly effective in a substrate material such as sapphire that has high hardness and poor cleavage.

  In the processing of the upper layer and the lower layer, in particular, when laser processing is performed on the upper layer side, selective processing in the depth direction can be used by utilizing the characteristics of light, which is preferable. This is because the laser beam irradiated from the upper layer side is reflected by the light reflecting layer provided on the lower layer side 51, and the processing depth positioning, that is, processing with high selectivity is made possible. This is because, within the irradiation time, the laser beam is reflected after removal of the upper layer side, and control can be performed so as to stop processing at a depth greater than that. Therefore, the light reflecting layer in the lower layer 51 or the layer 52 on the upper layer side 52 is preferably adjacent to the lower layer on the upper layer side (the surface side facing the substrate side) at least in the laser light and wavelength. Such processing depth selectivity can be utilized by having a light reflectance higher than that of the layer, and more preferably having a light reflectance higher than that of almost the entire depth of the upper layer. At this time, the light density can be made particularly effective by making the upper layer side lower than the lower layer side.

  As described above, in the two-stage processing of the upper layer and the lower layer, machining, etching, or the like can be used for a part. Preferably, from the viewpoint of the depth selectivity in the upper layer 52 described above, processing of the lower layer side 51 Alternatively, these alternative means can be used in forming the substrate dividing groove. Specifically, after laser processing of the upper layer side, in the exposed lower layer region, using a machining means capable of cutting the lower layer, for example, a scoring cutter, etc., the lower layer is removed, and further to the substrate It is also possible to form a groove. As the machining means, a dicer or the like may be used in addition to a scriber. At this time, the upper layer may be formed wider than the width according to the width of the machining blade or the like. The removal process of the lower layer and the groove formation on the substrate may be performed simultaneously, or may be processed in multiple ways, and different processing means may be used in each process. Preferably, when the lower layer removal and the substrate groove formation are performed at the same time, adverse effects on the lower layer during the formation of the substrate groove can be kept low.

  By processing the layered structure in stages, each layer can be defined in a desired shape according to each layer configuration and each function of the layered structure. A structure suitable for a light reflection structure, light emission characteristics, heat dissipation characteristics, and the like can be provided. This will be described in a second embodiment described later.

[Wafer]
The semiconductor wafer 11-13 will be described below with reference to the specific example shown in FIG.

  The wafer 11 on which the semiconductor structure 20 is provided on the substrate 10 is held by a plate-like support member 70 in the same manner as the wafer shown in FIG. Here, the supporting member 70 is specifically called a wafer sheet / adhesive sheet or the like, and is provided with an adhesive member 71 for adhering / holding the wafer / substrate on the base material 70 in order to further increase the element spacing. It is an elastic member that can be extended, and preferably has flexibility by dividing the element.

  In FIG. 3A, a wafer 11 provided with a semiconductor structure 20 and having a substrate 10 is bonded to a support member 70, and a step of processing / removing the substrate coating 50 and a step of forming a dividing groove 61 of the substrate are performed. As described above, the coating 50 is processed after the semiconductor structure 20 is provided, preferably after the light emitting structure and the electrode structure are provided. Here, FIG. 3 does not show the light emitting structure / electrode structure. In FIG. 3A, a part of the film 50 is removed, an opening 51w is provided, a parting groove 61 is provided in a part thereof, and as shown in FIG. 3B, an exposed part 10e where a part of the substrate is exposed is formed. Provided in a part of the opening 51w.

  Subsequently, as shown in FIG. 3B, the wafer 12 is provided on the supporting member 70 by separating the wafer by the dividing groove 61 and holding the elements separated from each other by the groove 63 in the wafer state by the substrate separating process described above. . Further, as indicated by the white arrow in the figure, the supporting member 70 is extended to widen the distance between the elements 100 to obtain a wafer state (holding state) 13 used for transporting the elements and mounting them on the light emitting device.

(Embodiment 2) Light-Emitting Element As described in Embodiment 1 above, the basic structural example of the element of this embodiment is a light-emitting element structure as a semiconductor element structure on the first main surface of the substrate 10. Is provided, and includes a multilayer structure including a reflective layer that reflects light of the light emitting element on the back surface side (second main surface side) of the substrate.

  The semiconductor structure, the light emitting element structure, and the electrode structure on the first main surface side of the substrate 10 are the same as those in the first embodiment, but the portions related to the element will be described in detail below.

  As a basic structure of the light emitting element structure, the p-type layer 24, the light-emitting layer 23, the n-type layer 22 and the like described above are provided, and the light-emitting structure portion 25 serving as a light-emitting region, the light-emitting layer, and the p-type layer are provided. And the like, and a part of the semiconductor, for example, the n-type layer 22 is provided, and the semiconductor structure portion 26 of the non-light-emitting region to be a non-light-emitting region is formed. Here, in the non-light emitting region, in addition to the region 22a in which the electrode of the remaining conductive type layer such as the n electrode shown in FIGS. In addition to the region of the semiconductor layer that is partially exposed, for example, the exposed portion 22c of the outer peripheral portion of the device shown in FIGS. 7 and 8, the region from which the semiconductor on the substrate has been removed is included. Refers to the area provided. As shown in FIGS. 5B, 7, 8, etc., at least a part of the light emitting region 26 may be separated by the non-light emitting region 26 and formed as a plurality of regions in the element. As in the examples of FIGS. 7 and 8, even in the case where one light emitting region connected in the plane is partially separated by a non-light emitting region, particularly in the case of being separated in a cross section. Thus, the element 100 including the plurality of separated light emitting regions 26 is obtained. As in this example, the non-light emitting region 26 may be separated in the plane, may not be separated in the plane like the light emitting region 25, and may be partially separated, and the same applies to the light emitting region. . As shown in FIGS. 1 and 5, a structure in which a laminated structure and an element structure are provided on almost the entire surface of the substrate may be used, or a structure in which they are provided in a partial region of the substrate may be used. It becomes the standard of the area.

  Here, FIG. 5 is a schematic cross-sectional view showing a structure of a light emitting element according to an embodiment and a partial structure of a light emitting device in which the light emitting element is mounted on a mounting substrate 80 (180), and FIG. 5B is a cross-sectional view taken along line AA in FIG. 5A, FIG. 5C is a schematic view illustrating a cross-section taken along line BB of the upper surface 5A, and FIG. 6 is another example of FIG.

  The light emitting device 100 of the present embodiment can be applied to a device having one light emitting region in one device as shown in FIGS. 1, 5A, etc., but preferably, it is shown in FIGS. Thus, it works suitably in an element having a plurality of light emitting regions. This is because an element having a plurality of light emitting regions 26 has a relatively large area, and its element driving, for example, current diffusion, is more complicated than that of an element in one light emitting region. This is because there are new structural problems such as a heat dissipation structure, and the element stack structure, particularly its layer structure, and the shape and arrangement of each layer influence these problems.

[Reflection layer and substrate coating film (laminated structure)]
The reflective layer is a layer that efficiently reflects the light emitted by the semiconductor element into the substrate and inside the element, and extracts the light reflected thereby from the externally exposed end face of another substrate / element. The reflective layer is preferably formed of a material that does not deteriorate due to the emission wavelength of the semiconductor light emitting device. Specific examples include metal materials and / or alloys thereof, compounds such as metal oxides, mixtures thereof, and the like. For example, when the semiconductor layer is formed of a nitride semiconductor, it is preferable to use Ag, Al, Rh, Pt, Pd, or the like. When silver or a silver alloy is used, an element with high reflectance and good light extraction can be obtained. In addition, a semiconductor device and a light-emitting device with good heat dissipation can be obtained, heat generation when a large current is passed can be reduced, and the output of the element can be increased. When Al or an alloy containing Al is used, it is possible to obtain a semiconductor light-emitting element that satisfies the reflectance and heat dissipation and has good adhesion to the sapphire substrate and does not cause defects due to peeling of the reflective layer. When Rh or Rh alloy is used, intermediate characteristics between Ag and Al can be obtained, and a reflective layer having relatively excellent stability can be obtained. Here, although the reflective layer is described as a single layer, the present invention is not limited to this, and a reflective layer having a multilayer structure can be used as described later. The position where the reflective layer is formed may be on the second main surface of the translucent substrate. Preferably, the light reflection function can be enhanced by being formed in contact with the light-transmitting substrate. Further, an intervening layer such as an adhesion layer for improving the adhesion between the translucent substrate and the reflective layer may be provided.

  As a method for forming the reflective layer, it can be formed by a method known in the art, for example, a vapor deposition method, a sputtering method, an ion beam assisted vapor deposition method, a plating method, or the like. The film thickness of the reflective layer may be any film thickness that can sufficiently reflect the light irradiated here. Specifically, the film thickness is 0.05 μm to 1 μm, preferably 0.1 μm to 0.3 μm. is there. The reflective layer may be a single layer made of a single metal material, may be a single layer made of an alloy, a single metal material or a laminated structure including an alloy layer, a single metal material And a laminated structure composed of an alloy layer. When the processing method described in the first embodiment is used, even if the thickness of the reflective layer is smaller than that of the upper layer, the reflection of a desired shape with respect to the element region 60 is possible due to depth selectivity. Can be with the lower layer 51 of the layer.

  Specific examples of the shape of the reflective layer and the region to be formed in the present invention will be described below. The region is formed so that the effects of the present invention can be obtained. Preferably, an exposed portion 10e where the second main surface of the substrate is exposed is formed at the end portion of the element, which tends to improve light extraction. From another point of view, it is preferable in terms of light extraction and heat dissipation to provide a reflective layer in the central part of the element or the central area of the light emitting part 26 where the heat of the element tends to be trapped. Specific shapes include polygons such as triangles and rectangles, circles, crosses, and lattices. It is preferable to provide a cross shape because good light extraction can be realized in relation to the light emitting layer as described later.

  As an example of the laminated structure of the substrate coating, at least a reflective layer is provided in the lower layer, and a barrier layer, an adhesive layer, and the like are provided on the upper layer side. A part of the reflective layer may be provided in the upper layer 52. However, since a thin reflective layer is usually formed, it is preferable to dispose the reflective layer in the lower layer 51.

  It is also possible to provide a protective layer, a barrier layer, or an adhesive layer on the reflective layer, and a part of these may be provided at least in the upper layer and a part may be provided in the lower layer. Examples of protective layers that can protect the reflective layer include platinum group elements (Ru, Rh, Pd, Os, Ir, Pt) and refractory metals when protecting Al, Al alloys, Ag, and Ag alloys. W, Mo, Ta, and Ni can be used. As the protective layer or a part thereof, an adhesive layer or a barrier layer that prevents the reflection layer from diffusing when the element is bonded to the mounting substrate 80 may be provided. Specific examples of the material include W and Mo. Of these high melting point materials, Pt, Ni, Rh, Au and the like are preferable. The adhesive layer is used as an adhesive to the mounting substrate of the element, for example, a material that can be interposed between the substrate and the semiconductor element and function as a die bond material. For example, a eutectic alloy such as Au—Sn can be used. Besides, In, Pb—Pd, Au—Ga, Au and Ge, Si, In, Zn, Sn, Al, Zn, Ge, Examples include Mg, Si, In, Cu, Ge, In, Ag—Ge, and Cu—In alloys. Apart from the laminated structure, a resin material such as a silicone resin or an epoxy resin, a paste material such as a silver paste, or the like can be used as an adhesive material between the substrate coating 50 of the element and the substrate 80. The protective layer, barrier layer, and adhesive layer may be a single layer or a multilayer structure. Moreover, although the film thickness of each layer is not specifically limited, the whole adhesive layer is formed with a film thickness of about 0.1 μm to 5 μm, for example, and each single layer of the protective layer and the barrier layer is about 0.01 μm to 1 μm.

  Here, the light emitting element structure in each embodiment and each aspect of the present invention will be described. 1 and 5 are schematic diagrams for explaining a part of a light emitting device according to an embodiment, and FIG. 6 is a light emitting device structure according to a comparative example and a light emitting device in which the light emitting device 100 is mounted on a mounting substrate 80, and FIG. FIG. 5B shows an example of a light emitting element 100 having a plurality of light emitting structure portions 26, which is a structure sealed by a sealing member 90 having a light conversion member 91. FIG.

  The basic structure will be described with reference to FIG. 1. Light is emitted from the light emitting region of the light emitting element 100 on the first main surface side of the substrate 10 (the white arrow in the figure), the reflective layer on the second main surface of the substrate, etc. The light that is reflected by the light and reaches the other end as indicated by the arrow in the figure is extracted. On the other hand, since the light emitting region is a main driving region, it becomes a heat generating region, and preferably, when the substrate coating 50 is provided in the region covering the region, as shown by the dotted line arrow in the figure. In addition, a structure in which heat is radiated to the mounting substrate 80 side can be obtained. Here, as shown in the drawing, light is efficiently extracted in the vicinity of the edge of the substrate in the cross section and in the outer peripheral portion within the substrate surface, so that the reflective layer and its coating 50 are exposed at this portion, and the substrate exposed portion 10e. Is preferably provided. Similarly, it is preferable to provide the non-light emitting region 26 in this portion in the element structure from the viewpoint of light extraction and heat dissipation due to the positional relationship with the laminated structure. As shown in FIG. 1, since the heat generated from the light emitting region is thermally diffused, it is preferable that the laminated structure is provided in the entire region of the substrate surface because the heat dissipation property is improved while the optical property is deteriorated. The laminated structure, in particular, at least the upper layer side, the adhesive layer is disposed so as to oppose the light emitting region, and more preferably, the light emitting region is provided so as to cover the other region. Efficient heat dissipation characteristics can be obtained.

  In addition, regarding the relationship between the reflective layer, the lower layer 51, the adhesive layer, and the upper layer 52, as shown in the comparative example of FIG. 6, the upper layer side can be widened during mounting. As in the example of 1, the lower layer side is preferably wider and larger than the upper layer side. This is mainly due to the structure that receives the heat diffused in the lateral direction from the light emitting region 26 and transmits it to the upper layer side from the lower layer protruding portion in the wide lower layer side, particularly the extended portion 50p protruding from the upper layer. This is because the heat of the heat generating part can be efficiently removed. Further, in the example in which the upper layer side is wide (FIG. 6), light emission (arrow in the figure) of the element is blocked, and loss such as light absorption may occur. As shown in FIG. 6A, the upper layer side adhesive layer has the same width and width as the lower layer 51 side or the element region before mounting, so that the upper layer side is wider than the element region and lower layer 51 side after mounting. A portion extending therefrom is formed, blocking the reflective layer 81 of the substrate 80, and lowering the light extraction efficiency and output of the light emitting device, and hence power efficiency (lm / W) by absorbing light on the upper layer side. . On the other hand, the comparative example of FIG. 6B shows an example in which the adhesive layer on the upper layer side 52 extends to the substrate side. In this case, the light emitted from the substrate end is shielded and the above characteristics are obtained by light absorption or the like. Reduce.

  In the example of the present invention, as shown in FIG. 1, even after mounting on the substrate 80, even if the upper layer side 52 expands in the width direction before mounting, the element region, preferably the lower layer side 51 is narrower, By being provided so as to be arranged on the inner side, such a problem of light absorption by the upper layer side 52 can be solved. Further, since the protruding portion 51p from the upper layer side of the reflective layer (lower layer 51) becomes larger than that, return light, particularly light reflected between the mounting substrate 80 and the lower layer from the upper layer side of the reflective layer. It can be reflected by the exposed surface 51e, light loss can be reduced, and the light output of the light emitting device can be increased by shielding the narrow upper layer side. For this reason, the lower layer of the protrusion 51p is preferably formed of a reflective layer. In addition, as a mounting problem, the mounting surface 80m and the adhesive layer (upper layer 52) may be affected by the flatness of the mounting surface 80m, particularly in the case of a ceramic substrate package with unevenness on the mounting surface. There are problems such as insufficient adhesion area, poor heat dissipation, and poor mounting. On the other hand, in the present invention, since the width and area of the adhesive layer on the upper layer 52 side are smaller than those on the substrate surface, preferably the reflective layer on the lower layer side, these problems tend to be improved, which is preferable. Even if the narrow upper adhesive layer is deformed by thermocompression during mounting and spreads in the width direction, there is a protrusion 51p on the lower layer side. In addition, it is possible to suppress the device variation and to increase the height compression amount on the upper layer side during mounting even on an uneven mounting surface, thereby improving the followability to the mounting surface.

  Further, in the structure in which the light emitting element 100 is mounted on the mounting substrate 80 and is sealed with the sealing member 90, as shown in FIG. 5A, it is sealed in the gap between the substrate exposed portion 10e and the substrate 80. There is a case where the structure is filled with a stop member, and in that case, light extraction from the exposed portion 10e tends to be higher than in a gas phase such as air, which is preferable. Further, in the example in which the sealing member 90 includes a light conversion member 91 such as a phosphor, when the distribution of the member 91 is a sedimentation distribution as in the example of FIG. In particular, the sealing member for the filling portion allows the light conversion member to be disposed closer to the element, and this effect can be enhanced.

  In the example of FIG. 5B, a structure portion 26x having a light-emitting structure as a non-light-emitting region without providing the second electrode 40 on the light-emitting structure is shown as the semiconductor structure portion 26. As in the formation region 22a of the first electrode 30, a structure in which the laminated structure 20 is not processed and is formed as a non-light emitting portion may be used. Further, as shown as another inset in the dotted line encircled region in FIG. 5B, a recess structure in which the semiconductor structure portion 26x having such a light emitting structure is processed and a recess portion is provided in the light emitting portion 25 to separate a part thereof. Further, a height similar to that of the light emitting structure, a convex structure having a semiconductor stack, and a concavo-convex structure 26x-1 including them can be used. The recess structure can also be partially provided in the light emitting structure 25. In addition to the concavo-convex structure 10r at the interface between the substrate 10 and the semiconductor layer 20, it is also possible to provide a concavo-convex structure on the external end surface of the substrate / semiconductor, and to provide a reflective surface 10v structure inclined from the side surface at the end of the substrate 10. . Such a concavo-convex structure and inclined structure can increase the light extraction efficiency. For example, in the example shown in FIGS. 7 and 8, the concavo-convex structure, particularly the concave / convex portion 20x, is provided in the element driving region 60a such as the region between the light emitting structure 25 and the region between the first electrode 30 and the light emitting structure 25. Can be provided to enhance the light extraction structure. Further, the above structure can be provided adjacent to the outer periphery of the device, for example, the outer light emitting structure 25b.

  5B, 7 and 8, as described above, the light-emitting element structure has a plurality of light-emitting regions 25. In such a case, the light-emitting regions 25 are covered as described above. A reflective layer (lower layer side 51) and a substrate coating 50 of a laminated structure are preferably provided. However, if the entire light emitting region is covered, there is a light shielding effect by the laminated structure described above, that is, a loss due to absorption of light reaching the reflective layer and the laminated structure, and a decrease in light extraction efficiency. In the partial light emitting regions, particularly the light emitting portions 25-1 and 25b arranged on the outer side and the outer periphery of the element, it is preferable that the covering area is formed smaller than the other inner light emitting regions 25-2 and 25b. This is the same reason as described above, and the element, the edge of the substrate, and the vicinity of the outer edge are exposed from the reflective layer (the lower layer 51) and the laminated structure 50, for example, as shown by the white arrow in FIG. 5B. This is because the light emission of each light emitting region is efficiently extracted therefrom. On the other hand, in terms of heat dissipation, the light emitting regions 25-2, 25a are arranged inside or sandwiched between other light emitting regions as compared with the light emitting regions 25-1, 25b arranged outside the element region. Since heat is propagated as shown by the dotted arrow in FIG. 5B and becomes a high temperature part, preferably, when a reflective layer is provided so as to cover at least this light emitting region, it is suitably reflected as indicated by a black arrow in the figure. In addition, the provision of the laminated structure 50 is preferable because it allows suitable heat dissipation. Therefore, the exposed portion 10e and the protruding portion 51p are arranged in the outer light emitting regions 25-1 and 25b, and the laminated structure of the upper layer 51 and the lower layer 52 is provided in the inner light emitting regions 25-2 and 25a. . As the plane size of these structures (protrusions / concaves / grooves), a width of 0.5 to 5 μm, preferably 1 to 3 μm, can be suitably manufactured.

  More preferably, the non-light-emitting region provided between the light-emitting regions 25, for example, the electrode forming portion 26a is covered and extended to the outer light-emitting regions 25-1 and 25b, thereby dissipating heat from the light-emitting region. It can be efficient. The light emitting region 31b is preferably formed so as to cover 1/3 or more, preferably 1/2 or more of the width or area. Alternatively, the exposed portion from the reflective layer and the laminated structure exposes the substrate edge and the outer edge portion of the element, preferably the non-light emitting region of the outer peripheral portion, and one of the outer light emitting regions 25-1 and 25b. It is preferable to expose a region of / 5 or more. The upper layer side 52, for example, the formation region of the adhesive layer should be formed so as to cover at least a part of the inner light emitting regions 25-2, 25a, preferably the outer light emitting regions 25-1, 25b in addition to the inner light emitting regions 25-2, 25a. Is preferred. Further, as shown in another example of FIG. 5B, the laminated structure 50 and the reflective layer can be partially cross-sectioned or separated in a plane (dotted line 50w in the figure). Corresponding to the portion 25, a lower layer 51 and a coating 50 are formed, and the substrate exposed portion 10e and the coating opening 50w are provided in the outer edge portion of the light emitting portion 25 and the semiconductor structure portion 26. In addition, the laser processing of the above-described embodiment can be used for such a separation structure, and processing can be performed in the same process as the processing of other regions such as the outer peripheral portion of the element.

  In the above light emitting device 100, as shown in FIGS. 1 and 5, the coating 50 and the adhesive layer 52 on the upper layer side 52 are placed on the substrate 80 (170) so as to face the mounting portion 80m (180m). The mounting substrate 80 (180) includes one having a structure in which a reflective layer 81 (181) is provided on a substrate 82 (182). Hereinafter, an example of a light emitting device in which the light emitting element 100 is mounted will be described.

(Embodiment 3) Light-emitting device 200
A light emitting device 200 equipped with the light emitting element 100 described in the above embodiment will be described. 9A and 9B, the light emitting element 100 is mounted on the light emitting element mounting portion 173 of the mounting base / region 201. Examples of the mounting substrate include stems for light emitting elements and light receiving elements (210 in FIG. 9B), ceramic substrates for flat mounting, plastic substrates, and the like. Specifically, it is preferable to use a mounting substrate made of AlN or a metallic mounting substrate because a light emitting device with high heat dissipation can be obtained. Since the mounting surface 180m on which the semiconductor light emitting element is mounted is made of a metal material, the light extracted outside the light emitting element is reflected, and a light emitting device having a suitable light directivity can be obtained. A metal material is used for, for example, the lead electrode 210 on the surface inside the device on which a light emitting element such as a mounting surface is placed and the light reaches, and the reflective surface 203, and the metal material emits light of the emission wavelength of the light emitting device. Metal materials that can reflect with high reflectivity are preferred. Specifically, Ag, Al, Rh, etc. are mentioned in the reflective layer 81 (181) etc., and a plating film etc. are formed. As shown in FIG. 9, the light emitting device includes the above-described substrate such as a reflective layer on the second main surface through an adhesive layer 160 on an element mounting portion 180m provided on the base material / housing 220 of the device. A semiconductor light emitting device 100 provided with a coating 150 (first layer / lower layer side 151, second layer / upper layer side 152) and an adhesive layer 160 such as eutectic solder is mounted by thermocompression bonding or the like, and a wire 250 or the like is mounted on each electrode. Thus, the light-emitting element 200 is connected to the lead electrodes 210 (a, b) of the light-emitting device 200, and the light-emitting element is sealed with the sealing member 230. Reference numerals 122 to 124 and 110 in the figure correspond to the layers 22 to 24 and the substrate 10 of the light emitting element. In FIG. 9A, each electrode lead 210 penetrates into the base body 220 of the light emitting device 200, is exposed to a region where the light emitting element is placed, and is electrically connected to the electrode connecting portion with a wire 250. Furthermore, it has a structure in which the exposed region is sealed with a light-transmitting sealing member 230 that seals the light-emitting element together with the light emitting element, or an airtight sealing. In the example of FIG. 7B, the sealing member 230 has a structure that also serves as a base material of the apparatus. As the sealing member, transparent resin or glass having excellent weather resistance such as epoxy resin, silicone resin, fluorine resin, etc. is used, and the member has a diffusing agent, a colorant, and a light stabilizer as necessary. May be. In addition to these resin materials, solder such as eutectic solder, eutectic material, Ag paste, or the like is used for the adhesive member 180.

Further, as described in the example of FIG. 5A, the light of the light emitting element is placed on the optical path between the light emitting element of the light emitting device 200 and the exit of the device, for example, the lens portion of FIG. It is also possible to obtain various emission colors by having a light conversion member that at least partially converts the light. Examples of the light conversion member include a YAG phosphor suitably used for white light emission of a blue LED, and a nitride phosphor that converts near ultraviolet to visible light into a yellow to red region. In particular, the phosphor of garnet structure, such as a YAG · TAG at the time of high luminance and long-term use, for example, _{(Re 1-x Sm x)} 3 (Al 1-y Ga y) 5 O 12: Ce (0 ≦ x <1, 0 ≦ y ≦ 1, where Re is preferably Y, Gd, La, Tb, etc. The nitride-based phosphor and the oxynitride phosphor are Sr—Ca—Si—N. : Eu, Ca-Si-N: Eu, Sr-Si-N: Eu, Sr-Ca-Si-ON: Eu, Ca-Si-ON: Eu, Sr-Si-O-N: Eu It includes the general formula _{L X Si Y N (2 /} 3X + 4 / 3Y): Eu or _{L X Si Y O Z N (} 2 / 3X + 4 / 3Y-2 / 3Z): Eu (L is, Sr, Ca, Sr Or any of these phosphors and other phosphors as appropriate. More, it is possible to obtain a desired emission color of the light emitting device.

Each of the above embodiments, configurations, and the like can be applied in appropriate combination.
[Example 1]
A buffer layer (underlying layer) is provided on a 2 inchφ C-plane sapphire substrate, and an n-type nitride semiconductor layer, an active layer (light emitting layer), which has a light emitting element structure, as shown in FIG. 2A, A p-type nitride semiconductor layer is laminated to form the following laminated structure.

  On the C-plane sapphire substrate, a 10 nm undoped AlGaN buffer layer and an undoped GaN layer (1500 nm) are stacked as an underlayer (not shown), and then an n layer 21 is formed as Si doped GaN (4100 nm). N-side contact layer, undoped GaN layer (300 nm), Si-doped GaN layer (30 nm), undoped GaN layer (50 nm), undoped GaN layer (4 nm) and InGaN layer (2 nm) on n-side contact layer 11 A multilayer film in which 10 pairs are laminated is formed. Next, an active layer having a quantum well structure in which six pairs of undoped GaN barrier layers and undoped InGaN well layers (3 nm) are alternately stacked, and finally the barrier layers are formed as an active layer on the n layer. Subsequently, on the active layer, as a p layer, a multilayer film layer in which five pairs of Mg-doped AlGaN and InGaN are laminated, an undoped AlGaN layer (280 nm), and a p-side contact layer of Mg-doped GaN (120 nm) are grown.

Next, on the surface of the substrate (on the element structure side), the stacked structure is partially etched by photolithography at a depth at which the n-type layer is exposed, for example, RIE, and an exposed n-layer semiconductor structure portion; And a light emitting structure portion in which the light emitting structure of the p layer and the n layer is left without being etched. As shown in FIG. 2B, the surface of the light emitting structure (p-type layer surface) and the surface of the semiconductor structure (surface of the n-type layer) are respectively (translucent) p-electrode (example: ITO), n-electrode (W / Pt / Au).
Subsequently, as shown in FIG. 2C, a laminated structure in which an Al (100 nm) reflective layer and an Au—Sn (multilayer film in which Au and Sn are alternately laminated) adhesive layers are provided on substantially the entire back surface of the wafer substrate. Form the body.

Subsequently, as shown in FIG. 2D, using the laser irradiation apparatus, the third harmonic (wavelength 355 nm) of the YAG laser is used as the light source, and the laminated structure is irradiated with the laser light from the upper layer side. The adhesive layer on the side is partially removed corresponding to the light emitting structure on the front side. Here, the focal point of the laser beam is defocused above the upper layer, and the beam diameter is about 150 μm, the irradiation energy density is 30 MJ / cm ² , and scanning is performed in the form of separation lines (lattice) as chip sections, as shown in the figure. , Processed to a width of about 75 μm and a depth at which the surface of the reflective layer is exposed.

Next, as shown in FIG. 2E, the lower layer (extending portion) including the reflective layer located in the exposed portion from the upper layer is irradiated with laser light having a smaller irradiation area and higher light density than the laser light. Then, at the same time that the lower layer of the irradiation part is removed, a split groove is provided in the substrate located below the irradiation part. At this time, the laser beam is irradiated with a diameter of about 15 μm and an irradiation energy density of 1 MJ / cm ² around the center of the width of the upper layer opening with the lower layer surface as a focal point to form a cone-shaped groove having a substrate depth of about 20 μm. . In this way, as shown in FIG. 2E, a laminated structure (upper layer and lower layer) having a pattern corresponding to the light emitting structure portion and a lower layer that is wider than the upper layer and covers the substrate facing the semiconductor structure portion on the surface side. It is formed.

Finally, a split groove is provided, and the light emitting element chip is obtained by cutting along the groove.
[Example 2]
As shown in FIG. 2F, after patterning the upper layer in Example 1, the lower layer extension is mechanically removed by scoring using a jig that can cut the lower layer and cut the substrate. Then, at the same time as patterning the lower layer, a split groove is provided in the substrate. The opening widths of the upper layer and the lower layer can be substantially the same as those in the first embodiment.
[Comparative Example 1]
After the laminated structure is formed in the same manner as in the example (FIG. 2C), as shown in FIG. 4, the laminated structure and the substrate are processed at the same time by irradiating with laser light. In some of the wafers, partial removal of the laminated structure and formation of a split groove in the substrate are observed, but in many other cases, defective removal of the laminated structure and damage to the semiconductor layer are observed.

In addition, when the dividing grooves are formed at the same time, the patterning of the laminated structure, particularly the width of the removed portion is reduced, and the desired shape cannot be obtained.
[Comparative Example 2]
As in the above example, the upper layer of the laminated structure is removed, and the exposed lower layer extension is overetched so that the upper layer becomes wider by wet etching using the upper layer as a mask to remove part of the lower layer. A light emitting device as shown in FIG. 4 is obtained.

The resulting light emitting device covers a region that is substantially the same as or narrower than the light emitting structure on the substrate surface side. Therefore, in the peripheral portion of the light emitting structure and the semiconductor structure outside the light emitting device, during high current and high output operation , Heat dissipation becomes insufficient, and a high temperature region is formed.
Example 3
The light-emitting element according to Example 3 is manufactured with an element size of □ 1 mm (1 mm × 1 mm) shown in FIG. Here, FIG. 7A is a schematic top view of the device, and FIG. 7B is a schematic cross-sectional view taken along the line AA of FIG. 7A.

  The stacked semiconductor structure 20 (22-24), the electrode structures 30 and 40, and the substrate coating 50 are formed in the same manner as in the first embodiment. As shown in the figure, the element structure is such that the first and second electrodes 30 and 40 have external connection portions 30b and 42b and wiring portions 30a and 42a extending therefrom, respectively. The longitudinal light emitting structure 25 has a structure including an outer light emitting structure 25b between the first and second electrodes 30, 41 and an inner light emitting structure 25a between the first electrodes. The semiconductor structure portion 26 is a first conductive type layer exposed portion 22a where the first electrode 30 is provided, and includes a region 26a disposed between the light emitting structure portions and a layer 22c in which the first conductive type layer is exposed at the outer periphery of the element. The outer edge region 26b is provided. The second electrode has a structure of a first layer 41 on the lower layer side provided on almost the entire surface of the light emitting structure, and a second layer 42 having a wiring part 42a and an external connection part 42b on the first layer. In this structure, two rectangular regions surrounding the first electrode are formed by the second layer. The light emitting structure portions 25a and 25b provided alternately with the first electrode wiring in the longitudinal shape have a structure having light emitting structure portions 25c under the second electrode second layer 42 wiring portions at both ends. When the light emitting structure portions 25a, b are extended to the element driving region 60a, the light emitting structure portions 25A, B each partially including the structure portion 25c can be obtained.

  Here, as the dimensions of each structure, the thickness of the substrate 10 is about 50 to 200 μm (about 90 μm in the above example). In the laminated structure 20, the thickness of the base layer 21 is about 1 to 2 μm. The n-type semiconductor layer 22 The thickness of the active layer / light emitting layer 23 is about 50 to 150 nm, the thickness of the p-type semiconductor layer 24 is about 100 to 300 nm, and the light emitting structure from the surface of the n-type exposed layers 22a and c. The height of the first electrode and the second electrode (first layer) is about 0.01 to 0.5 μm, and the second layer and pad electrode are about 1 to 3 μm (about 1.5 μm in Example 1). The thickness of the external connection part / pad electrode is about 50 to 150 μm in thickness, the electrode wiring parts 30a and 42a are 10 to 20 μm in width, the electrode and the light emitting structure part The distance is about 5 to 20 μm. Other examples are made with similar dimensions.

  As shown in the figure, the substrate coating 50 is provided with a substrate exposed portion 10e facing the element outer peripheral portion / semiconductor structure portion 22c, and has a wider cross section than that. Further, the exposed portion 10e extends to the outer light emitting structure 25b, and the lower layer side extending portion 51p and the upper layer 52 are provided in part of the lower layer 51 in the light emitting portion 25b. A lower layer 51 wider than the upper layer 52 is provided.

Thus, the light can be extracted more favorably by the substrate exposed portion 10e of the element peripheral portion 22c, and the effect can be enhanced by being provided also in the light emitting portion 25b. On the other hand, the upper and lower layers are provided on the inner light emitting portion 25a to enhance the heat dissipation effect, and further, the heat generation from the adjacent light emitting portion 25b is provided by extending to the structure portion 26a of the adjacent electrode forming portion 22a. In addition, the heat can be suitably exhausted, and further, the heat radiation effect can be further enhanced by extending to at least a part of the light emitting portion 25b. By providing the lower layer extending part 51p in the light emitting part 25b, a suitable light reflecting structure can be obtained.
Example 4
Example 4 is an example of a □ 800 μm (800 × 800 μm) light emitting element shown in FIG. 8A is a schematic top view of the light-emitting element, and FIG. 8B is a schematic cross-sectional view taken along AA in FIG. 8A. The dimensions of each structural part are the same as those described in the third embodiment.

  Explained in comparison with Example 3, as in Example 3, each electrode 30, 40 (41, 42) is provided with a pad electrode part of the external connection part and a wiring part extending in one direction based on the pad electrode part, The wiring portions of the first and second electrodes are arranged so as to face each other and translate, and the external connection portions 30b and 42b of each electrode are provided at each end of the wiring portion so as to face each other in the extending direction. The wiring portion is provided between the portions 30b and 42b. As in the third embodiment, the light emitting structure 25 is provided with structure portions 25a and 25b whose longitudinal direction is the extending direction, disposed between the first and second electrodes and the wiring portion, and disposed outside the element. The light emitting unit 25b is disposed between the first electrode 30 and the light emitting unit 25a including the wiring unit 42a-2 on the upper part thereof. Unlike the third embodiment, the wiring part 42a-2 of the inner light emitting part 25a extends from the outer connection part 42b to the wiring part 42a-3 that crosses between the connection parts 42b.

  The substrate coating 50 is different from the third embodiment in that the upper layer 52 side is a narrow region of the light emitting portion 25b provided with the connecting portion 30b, does not reach the outer light emitting portion 25b, and reaches the structure portion 26 of the inner electrode forming portion 22a. It has a structure in which a part is provided in the wide region of the light emitting part 25b provided with the wiring part 30a. In this structure, as compared with the structure in which the upper layer and the lower layer are provided in the light emitting part 25b in each part of the first electrode as in Example 3, the heat dissipation tends to be lowered, but in a partial region of the connection part 30b. The effect is small because it is limited.

  Although not shown in Examples 3 and 4, the width of the substrate exposed portion 10e (distance from the side surface of the substrate), the width of the lower layer extending portion (distance from the upper layer end to the lower layer end), and the sum ( The distance from the upper layer end portion to the substrate side surface) is formed to be substantially the same at the outer edge portion of the substrate.

  The light emitting device of the present invention can be applied not only to a nitride semiconductor but also to other material-based light emitting devices such as GaAs (AlGaAs, etc.), InP (AlInGaP), and not only in the visible light region but also in nitride. Semiconductors can be used for light emission in the near ultraviolet and ultraviolet regions, and can also be used for electromagnetic waves of other wavelengths. Further, the present invention is not limited to a light emitting element, and can be applied to various semiconductors, for example, an optical semiconductor such as a light receiving element, and other electronic devices having a laminated structure. In the above description, the substrate coating 50 has been described as a laminated structure having two or more layers. However, the present invention can also be applied to a structure in which the upper layer is omitted, for example, the lower layer side and its processing (and processing of the substrate).

1 is a schematic plan view (FIG. 1B) of a part of a light-emitting element and a light-emitting device according to an embodiment of the present invention (a cross-sectional view taken along line AA in FIG. 1B) (FIG. 1A). FIG. 9 is a schematic cross-sectional view illustrating a manufacturing method according to an embodiment of the present invention. FIG. 9 is a schematic cross-sectional view illustrating a manufacturing method according to an embodiment of the present invention. The schematic sectional drawing explaining the comparative example of this invention. 1 is a schematic cross-sectional view illustrating a part of a light-emitting element and a light-emitting device according to an embodiment of the present invention. 1 is a schematic cross-sectional view illustrating a part of a light-emitting element and a light-emitting device according to an embodiment of the present invention. FIG. 6 is a schematic cross-sectional view illustrating a light-emitting element according to a comparative example of the present invention. 1 is a schematic plan view illustrating a structure of a semiconductor light emitting element according to an embodiment of the present invention. FIG. 7B is a schematic cross-sectional view taken along the line AA in FIG. 7A. 1 is a schematic cross-sectional view of a semiconductor light emitting element according to an embodiment of the present invention. 1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. 1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention.

Explanation of symbols

10 ... Substrate (10e: Exposed part of substrate, 10x: Damaged part), 11 ... Wafer, 12 ... Wafer (after element separation / sheet pasting), 13 ... Wafer (after stretching),
20 ... Semiconductor structure (20x: damaged part), 21 ... Underlayer, 22 ... First conductivity type layer, 23 ... Active layer (light emitting layer), 24 ... Second conductivity type layer, 25 ... Light emitting structure, 26 ... Semiconductor Structure part,
30 ... first electrode, 31 ... ohmic layer side, translucent electrode, 32 ... external connection, pad electrode, 40 ... second electrode,
50 ... Laminated structure, coating film (50w ... opening), 51 ... first layer, lower layer side (51e: lower layer exposed portion, 51p ... lower layer extending portion, 51r: reflective layer, 51w ... opening), 52 ... Second layer, upper layer side (52w: opening),
60: Element region (60a: active region), 61: Split groove, 62: Pre-groove position, 63: Substrate division,
70 ... supporting member, stretchable adhesive sheet (70e: supporting member after stretching), 71 ... adhesive layer / member, 72 ... base material,
80 ... Mounting base (80m: Mounting part), 81,181 ... Reflective film, 82,182 ... Base material

Claims (7)

A method for manufacturing a semiconductor light emitting device, comprising:
Forming a semiconductor on the first main surface of the substrate to provide a light emitting element structure;
Providing a laminated structure including a reflective layer on the second main surface of the substrate,
An upper layer removing step of irradiating the laminated structure with a laser beam to partially remove an upper layer of the structure , and defining an upper layer of the laminated structure corresponding to the light emitting element structure ;
The lower layer exposed to the lower layer exposed from the upper layer by the upper layer removing step is irradiated with a laser beam having a light density higher than the light density of the laser beam in the upper layer removing step to leave a part of the exposed portion. Removing a part of the reflective layer and a part in the depth direction of the substrate located in the lower layer exposed portion to provide a dividing groove in the substrate region exposed from the laminated structure;
A method for manufacturing a semiconductor light emitting device comprising: A method of manufacturing a semiconductor light emitting device according to claim 1,
A method for manufacturing a semiconductor light emitting device, comprising the step of dividing the substrate along the dividing groove after forming the dividing groove on the substrate.   A method of manufacturing a semiconductor light emitting device according to claim 1,
  A method for manufacturing a semiconductor light emitting device, wherein an irradiation area of laser light in the upper layer removal step is larger than an irradiation area in the lower layer removal step.   4. The method for manufacturing a semiconductor light emitting element according to claim 1, wherein the lower layer is wider than the upper layer in a cross section. 5.   It is a manufacturing method of the semiconductor light-emitting device as described in any one of Claims 1-4, Comprising: The board | substrate exposure area | region exposed from the said lower layer is compared with the opening width in the 2nd main surface of the said board | substrate dividing groove. A method of manufacturing a semiconductor light emitting device that is substantially the same or wide.   6. The method for manufacturing a semiconductor light emitting element according to claim 1, wherein the substrate and the semiconductor light emitting element structure are translucent to laser light.   The method for manufacturing a semiconductor light emitting device according to claim 1, wherein the laminated structure is thicker on the upper layer side, thinner on the lower layer side, and made of different materials or compositions. .

Images