JP2012054447A - Semiconductor light-emitting element, light-emitting device, lighting unit, and display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting element having high reliability, a light-emitting device having the semiconductor light-emitting element, and a lighting unit and a display unit having the light-emitting device.SOLUTION: A semiconductor light-emitting element 100 has a first semiconductor layer for light emission in which an n-type semiconductor sublayer 112, an active sublayer (not shown), and a p-type semiconductor sublayer 113 are stacked on a substrate 1; and a second semiconductor layer for light emission in which an n-type semiconductor sublayer 122 for light emission, an active sublayer (not shown), and a p-type semiconductor sublayer 123 are stacked on the substrate 1. Additionally, the semiconductor light-emitting element 100 has a first semiconductor layer for protection in which an n-type semiconductor sublayer 212 for protection, an active sublayer (not shown), and a p-type semiconductor sublayer 213 are stacked; and a second semiconductor layer for protection in which an n-type semiconductor sublayer 222 for protection, an active layer (not shown), and a p-type semiconductor sublayer 223 are stacked.

Description

  The present invention relates to a semiconductor light emitting device in which a semiconductor layer in which an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are stacked on a substrate, a light emitting device including the semiconductor light emitting device, an illumination device including the light emitting device, and a display. Relates to the device.

  Light emitting diodes have been attracting attention as a light source because of their low power consumption and long life compared to fluorescent lamps and incandescent lamps that have been used as light sources in the past. It has come to be used in a wide range of fields, such as backlight light sources, illumination light sources, and amusement equipment decorations.

  Such light-emitting diodes can emit required single colors such as blue, blue-green, green and red according to the application, or can emit red, green and blue multicolors in one package. is there. In addition, light-emitting diodes that can emit white light in combination with phosphors have been commercialized.

  For example, a white light-emitting diode (light-emitting device) having a surrounding portion that surrounds an LED chip (semiconductor light-emitting element), including a phosphor that emits light when excited by light of a predetermined wavelength, and has good light emission efficiency and light emission intensity It is disclosed (see Patent Document 1).

JP 2004-161789 A

  However, the light-emitting diode (light-emitting device) disclosed in Patent Document 1 includes one LED chip (semiconductor light-emitting element) in the package, so that the LED chip is in a leaked state (for example, contributes to light emission) for some reason. When the current is increased, the light emission of the light emitting diode becomes unstable. In the worst case, the light emitting diode is turned off. Applications of light emitting diodes are expanding to various fields, and particularly in fields where high reliability is required to maintain safety, such as in-vehicle light emitting diodes, highly reliable light emitting diodes are required. It has been.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a highly reliable semiconductor light-emitting element, a light-emitting device including the semiconductor light-emitting element, a lighting device including the light-emitting device, and a display device. To do.

  According to a first aspect of the present invention, there is provided a semiconductor light emitting device in which a semiconductor layer in which an n type semiconductor layer, an active layer, and a p type semiconductor layer are stacked is formed on a substrate, wherein the n type semiconductor layer and the active layer are formed on the substrate. First and second light emitting semiconductor layers, each of which is laminated with an n type semiconductor layer, an active layer, and a p type semiconductor layer, and the first and second light emitting semiconductor layers are laminated. A first wiring layer for connecting the first and second protective semiconductor layers for protecting the layer, the n-type semiconductor layer of the first light-emitting semiconductor layer, and the p-type semiconductor layer of the second light-emitting semiconductor layer. A second wiring layer connecting the p-type semiconductor layer of the first protective semiconductor layer and the n-type semiconductor layer of the second protective semiconductor layer, and a p-type semiconductor layer of the first light emitting semiconductor layer, A third wiring layer connecting the n-type semiconductor layer of the first protective semiconductor layer; A fourth wiring layer connecting the n-type semiconductor layer of the second light-emitting semiconductor layer and the p-type semiconductor layer of the second protective semiconductor layer; and the n-type semiconductor layer of the second light-emitting semiconductor layer. A first bonding electrode and a second bonding electrode connected to the p-type semiconductor layer of the first light emitting semiconductor layer.

  According to a second aspect of the present invention, in the first aspect, the area of the n-type semiconductor layer of the first and second light emitting semiconductor layers is the same as that of the n-type semiconductor layer of the first and second protective semiconductor layers. It is characterized by being larger than the area.

  A semiconductor light emitting device according to a third invention is the semiconductor light emitting device according to the first invention or the second invention, wherein the n-type semiconductor layers of the first and second light emitting semiconductor layers are annularly laminated along the outer periphery of the substrate, The n-type semiconductor layers of the first and second protective semiconductor layers are stacked on the inner peripheral side of the n-type semiconductor layers of the first and second light emitting semiconductor layers.

  According to a fourth aspect of the present invention, there is provided the semiconductor light emitting device according to the first or second aspect, wherein the substrate has a rectangular shape, and the first and second light emitting semiconductor layers and the first and second protective semiconductor layers are respectively provided. The dimensions of the n-type semiconductor layers of the first and second light emitting semiconductor layers that are stacked at the four corners of the substrate along the outer periphery of the substrate are the n-type semiconductors of the first and second protective semiconductor layers. The layer is longer than the dimension along the outer periphery of the substrate.

  A light-emitting device according to a fifth aspect of the present invention includes the semiconductor light-emitting element according to any one of the first to fourth aspects of the present invention and a housing portion that houses the semiconductor light-emitting element.

  A lighting device according to a sixth aspect of the invention includes the light emitting device according to the fifth aspect of the invention.

  A display device according to a seventh aspect includes the light emitting device according to the fifth aspect.

  In the first invention, the first and second light emitting semiconductor layers in which the n-type semiconductor layer, the active layer, and the p-type semiconductor layer are stacked on the substrate, respectively, and the n-type semiconductor layer, the active layer, and the p on the substrate. And a first protective semiconductor layer for protecting the first and second light emitting semiconductor layers, respectively. Then, the n-type semiconductor layer of the first light-emitting semiconductor layer and the p-type semiconductor layer of the second light-emitting semiconductor layer are connected by the first wiring layer, and the p-type semiconductor layer of the first protective semiconductor layer and the second protection layer are connected. The n-type semiconductor layer of the first semiconductor layer is connected by the second wiring layer, and the p-type semiconductor layer of the first light emitting semiconductor layer and the n-type semiconductor layer of the first protective semiconductor layer are connected by the third wiring layer. The n-type semiconductor layer of the second light emitting semiconductor layer and the p-type semiconductor layer of the second protective semiconductor layer are connected by the fourth wiring layer. Then, the first bonding electrode is connected to the n-type semiconductor layer of the second light emitting semiconductor layer, and the second bonding electrode is connected to the p-type semiconductor layer of the first light emitting semiconductor layer. That is, the light emitting semiconductor layers are connected in series, the protective semiconductor layers are connected in series, and the series circuit of the protective semiconductor layers is connected in antiparallel to the series circuit of the light emitting semiconductor layers. As a result, even when one of the light emitting semiconductor layers is in a leaked state, the light emitting function can be ensured by the other light emitting semiconductor layer, so that, for example, a situation where the light emitting semiconductor layer falls into an unstable lighting state or a light-off state is avoided. Thus, high reliability can be ensured. In addition, since the series circuit of the protective semiconductor layer is connected to the series circuit of the light emitting semiconductor layer, the light emitting semiconductor layer can be protected from overvoltage or static electricity, and one of the protective semiconductor layers is Even in a leak state, the protective function is maintained by the other protective semiconductor layer, so that high reliability can be ensured.

  In the second invention, the areas of the n-type semiconductor layers of the first and second light emitting semiconductor layers are larger than the areas of the n-type semiconductor layers of the first and second protective semiconductor layers. Thereby, a protective element can be incorporated while suppressing a decrease in light emission efficiency of the semiconductor light emitting element.

  In the third invention, the n-type semiconductor layers of the first and second light emitting semiconductor layers are annularly stacked along the outer periphery of the substrate, and the n-type semiconductor layers of the first and second protective semiconductor layers are: The first and second light emitting semiconductor layers are stacked on the inner peripheral side of the n-type semiconductor layer. In general, light emitted from the light emitting semiconductor layer in the central portion of the substrate is less likely to be taken out of the semiconductor light emitting element than light emitted from the light emitting semiconductor layer in the peripheral portion of the substrate. Therefore, by disposing a protective semiconductor layer in the center of the substrate where the light extraction efficiency is poor and arranging a light emitting semiconductor layer in the periphery of the substrate where the light extraction efficiency is good, it is possible to suppress a decrease in light emission efficiency and to protect the element. Can be built in.

  In the fourth invention, the substrate has a rectangular shape, and the first and second light emitting semiconductor layers and the first and second protective semiconductor layers are stacked at the four corners of the substrate. The dimension of the first and second light emitting semiconductor layers along the outer periphery of the n-type semiconductor layer is longer than the dimension of the first and second protective semiconductor layers along the outer periphery of the substrate. To do. In general, light emitted from the light emitting semiconductor layer at the periphery of the substrate is more easily extracted outside the semiconductor light emitting element than light emitted from the light emitting semiconductor layer at the center of the substrate. Therefore, by making the length of the light emitting semiconductor layer along the periphery of the substrate with good light extraction efficiency longer than the length of the protective semiconductor layer, it is possible to suppress a decrease in light emission efficiency and incorporate a protective element. .

  In the fifth invention, a light emitting device accommodates the above-described semiconductor light emitting element. As a result, it is possible to avoid a situation where the light is turned off and ensure high reliability.

  In the sixth invention and the seventh invention, by providing the above-described light emitting device, it is possible to provide a lighting device and a display device capable of avoiding a situation of being turned off and ensuring high reliability. .

  According to the present invention, even when one of the light emitting semiconductor layers is in a leaked state, the light emitting function can be secured by the other light emitting semiconductor layer, so that the situation where the light emitting semiconductor layer falls into an unstable lighting state or extinguishing state is prevented. By avoiding this, high reliability can be ensured. In addition, since the series circuit of the protective semiconductor layer is connected to the series circuit of the light emitting semiconductor layer, the light emitting semiconductor layer can be protected from overvoltage or static electricity, and one of the protective semiconductor layers is Even in a leak state, the protective function is maintained by the other protective semiconductor layer, so that high reliability can be ensured.

FIG. 3 is a schematic diagram illustrating an example of a planar structure of the semiconductor light emitting element of the first embodiment. It is sectional drawing which shows an example of the cross-sectional structure of the semiconductor light-emitting device in the II-II line | wire of FIG. It is sectional drawing which shows an example of the cross-sectional structure of the semiconductor light-emitting device in the III-III line of FIG. FIG. 3 is a circuit diagram of the semiconductor light emitting element of the first embodiment. FIG. 6 is an explanatory diagram showing a manufacturing process of the semiconductor light-emitting element of the first embodiment. FIG. 6 is an explanatory diagram showing a manufacturing process of the semiconductor light-emitting element of the first embodiment. FIG. 6 is a schematic diagram illustrating an example of a planar structure of a semiconductor light emitting element according to a second embodiment. It is sectional drawing which shows an example of the cross-sectional structure of the semiconductor light-emitting device in the VIII-VIII line of FIG. It is sectional drawing which shows an example of the cross-sectional structure of the semiconductor light-emitting device in the IX-IX line of FIG. It is a schematic diagram which shows an example of a structure of the light-emitting device of this Embodiment.

(Embodiment 1)
Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a schematic view showing an example of a planar structure of the semiconductor light emitting device 100 of the first embodiment, and FIG. 2 is a cross sectional view showing an example of a cross sectional structure of the semiconductor light emitting device 100 taken along the line II-II in FIG. 3 is a cross-sectional view showing an example of a cross-sectional structure of the semiconductor light emitting device 100 taken along the line III-III in FIG. 1, and FIG. 4 is a circuit diagram of the semiconductor light emitting device 100 of the first embodiment.

  The semiconductor light emitting device 100 of the present embodiment (hereinafter also referred to as “light emitting device”) is obtained by separating a light emitting device by cutting a wafer on which a plurality of light emitting devices are formed into a rectangular parallelepiped shape with a predetermined dimension. For example, an LED chip. 1 to 3, reference numeral 1 denotes a sapphire substrate. The sapphire substrate 1 (hereinafter referred to as “substrate”) has a rectangular shape in plan view, and the vertical and horizontal dimensions are, for example, about 0.35 mm, but the dimensions are not limited thereto.

  As shown in FIGS. 1 to 3, the semiconductor light emitting device 100 includes a first light emitting semiconductor layer in which an n type semiconductor layer 112 for light emission, an active layer (not shown), and a p type semiconductor layer 113 are stacked on a substrate 1. (LED 11), a light emitting n-type semiconductor layer 122, an active layer (not shown), and a second light emitting semiconductor layer (LED 12) in which a p-type semiconductor layer 123 is laminated are formed. In addition, the semiconductor light emitting device 100 includes a protective n-type semiconductor layer 212, an active layer (not shown), a first protective semiconductor layer (LED 21) in which a p-type semiconductor layer 213 is stacked, and a protective n-type semiconductor layer 222. A second protective semiconductor layer (LED 22) in which an active layer (not shown) and a p-type semiconductor layer 223 are stacked is formed.

  More specifically, each of the first and second light emitting semiconductor layers and the first and second protective semiconductor layers is formed on an AlN buffer layer (not shown) and an undoped GaN layer (not shown) having a thickness of about 2 μm. (Not shown), an n-type semiconductor layer (112, 122, 212, 222), an active layer (not shown), and a p-type semiconductor layer (113, 123, 213, 223) are laminated in this order. The n-type semiconductor layer includes, for example, an n-GaN (gallium nitride) layer having a thickness of about 2 μm, an n-AlGaInN cladding layer, and the like. The active layer is composed of a GaN / InGaN-MQW (Multi-quantum Well) type active layer or the like. The p-type semiconductor layer includes a p-AlGaInN layer, a p-GaN layer of about 0.3 μm, a p-InGaN layer as a contact layer, and the like. Thus, a compound semiconductor layer is formed to form an LED structure as a light emitting semiconductor layer and a protective semiconductor layer. In addition, the structure which does not form an undoped GaN layer may be sufficient.

  As shown in FIGS. 2 and 3, current diffusion layers (114, 114) are formed on the surfaces of the p-type semiconductor layers (113, 123) of the first light emitting semiconductor layer (LED 11) and the second light emitting semiconductor layer (LED 12). 124). The current diffusion layer is, for example, an ITO film (indium tin oxide film) that is a conductive transparent film.

  As shown in FIG. 2, the n-type semiconductor layer 122 of the second light emitting semiconductor layer (LED 12), the n-type semiconductor layer 212 of the first protective semiconductor layer (LED 21), and the n of the second protective semiconductor layer (LED 22). An n-ohmic electrode 5 is formed on the surface of the type semiconductor layer 222. As shown in FIG. 3, an n-ohmic electrode 5 is formed on the surface of the n-type semiconductor layer 112 of the first light emitting semiconductor layer (LED 11).

  The n-ohmic electrode 5 is formed by, for example, forming a film of V / Au / Al / Ni / Au by vacuum deposition, patterning by a lift-off method, and heating to about 500 ° C. in a mixed atmosphere of nitrogen and oxygen. Can do. The n ohmic electrode 5 is a portion that performs electrical junction with the n-type semiconductor layer 2.

  The n-type semiconductor layer 122 of the second light emitting semiconductor layer has the first bonding electrode 61 formed through the n ohmic electrode 5.

  A second bonding electrode 62 is formed on the surface of the current diffusion layer 114 of the first light emitting semiconductor layer. That is, the second bonding electrode 62 is connected to the p-type semiconductor layer 113 of the first light emitting semiconductor layer.

  The second bonding electrode 62 is connected to the n-type semiconductor layer 212 of the first protective semiconductor layer via the wiring layer 63.

  The p-type semiconductor layer 213 of the first protective semiconductor layer is connected to the n-type semiconductor layer 222 of the second protective semiconductor layer by the wiring layer 64 through the current diffusion layer 214.

  The p-type semiconductor layer 223 of the second protective semiconductor layer is connected to the first bonding electrode 61 by the wiring layer 65 through the current diffusion layer 224.

  As shown in FIGS. 1 and 3, the n-type semiconductor layer 112 of the first light emitting semiconductor layer is connected to the current diffusion layer 124 of the second light emitting semiconductor layer by wiring layers 66 and 67. That is, the n-type semiconductor layer 112 of the first light emitting semiconductor layer is connected to the p-type semiconductor layer 123 of the second light emitting semiconductor layer by the wiring layers 66 and 67.

  The first bonding electrode 61, the second bonding electrode 62, and the wiring layers 63, 64, 65, 66 can be formed, for example, by depositing Ti / Au by vacuum deposition. Since Ti / Au is used as the material of the bonding electrodes 61 and 62, it is excellent in mechanical strength and is easy to bond, and is difficult to peel off. In addition, as a material of the bonding electrodes 61 and 62, a metal such as Ni / Au can be used.

The first light emitting semiconductor layer (LED11), the second light emitting semiconductor layer (LED12), the first protective semiconductor layer (LED21), and the second protective semiconductor layer (LED22) are interconnect layers 63, 64, 65. , 66 are electrically insulated by a SiO ₂ film 7 as a protective film except for the portions connected by.

  With the configuration as described above, the semiconductor light emitting device 100 has the circuit configuration shown in FIG. That is, the first light emitting semiconductor layer LED11 and the second light emitting semiconductor layer LED12 are connected in series by the wiring layers 66 and 67, and the first protective semiconductor layer LED21 and the second protective semiconductor layer LED22 are connected to the wiring layer 64. Are connected in series, and the series circuit of the protective semiconductor layers LED21 and LED22 is connected in reverse parallel to the series circuit of the light emitting semiconductor layers LED11 and LED12 by the wiring layers 63 and 65.

  As a result, even when one of the light emitting semiconductor layers is in a leaked state, the light emitting function can be ensured by the other light emitting semiconductor layer, so that, for example, a situation where the light emitting semiconductor layer falls into an unstable lighting state or a light-off state is avoided. Thus, high reliability can be ensured. In addition, since the series circuit of the protective semiconductor layer is connected to the series circuit of the light emitting semiconductor layer, the light emitting semiconductor layer can be protected from overvoltage or static electricity, and one of the protective semiconductor layers is Even in a leak state, the protective function is maintained by the other protective semiconductor layer, so that high reliability can be ensured.

  Moreover, as shown in FIGS. 1-3, the area (area in planar view) of the n-type semiconductor layer 2 of the first and second light emitting semiconductor layers LED11 and LED12 is the first and second protective semiconductor layers LED21. , Larger than the area of the n-type semiconductor layer 2 of the LED 22. Thereby, a protection element can be incorporated while suppressing a decrease in the light emission efficiency of the semiconductor light emitting element 100.

  1 to 3, the first and second light emitting semiconductor layers LED11 and the n-type semiconductor layer 2 of the LED12 are laminated in an annular shape along the outer periphery of the substrate 1 to provide first and second protective layers. The n-type semiconductor layer 2 of the semiconductor layers LED21 and LED22 is laminated on the inner peripheral side of the first and second light emitting semiconductor layers LED11 and LED12. In general, light emitted from the light emitting semiconductor layer in the central portion of the substrate is less likely to be taken out of the semiconductor light emitting element than light emitted from the light emitting semiconductor layer in the peripheral portion of the substrate. Therefore, by arranging the protective semiconductor layers LED21 and LED22 in the central part of the substrate 1 having poor light extraction efficiency and arranging the light emitting semiconductor layers LED11 and LED12 in the peripheral part of the substrate 1 having good light extraction efficiency, light emission efficiency is achieved. And a protective element can be incorporated.

  Next, a method for manufacturing the semiconductor light emitting device 100 of the first embodiment will be described. 5 and 6 are explanatory views showing the manufacturing process of the semiconductor light emitting device 100 of the first embodiment. 5 and FIG. 6 are explanatory diagrams in the cross section shown in FIG.

  As shown in FIG. 5A, an AlN buffer layer (not shown) is first grown on a substrate (sapphire substrate) 1 at about 400 ° C. by metal organic chemical vapor deposition (MO-CVD). Thereafter, an n-type semiconductor layer 2 including an undoped GaN layer of about 2 μm, an n-GaN layer of about 2 μm and an n-AlGaInN cladding layer, a GaN / InGaN-MQW type active layer (not shown), and p-AlGaInN An LED structure is generated in which a p-type semiconductor layer 3 composed of a layer, a p-GaN layer of about 0.3 μm, and a p-InGaN layer as a contact layer is formed in this order. While irradiating the substrate 1 taken out from the MO-CVD apparatus with ultraviolet rays, the substrate 1 is heated to about 400 ° C. to activate the p-type semiconductor layer 3.

  As shown in FIG. 5B, the n-type semiconductor layer 2 where the n-ohmic electrode 5 is to be formed is exposed by photolithography and dry etching using the photoresist as a mask. The etching depth is, for example, 500 nm.

  As shown in FIG. 5C, a transparent current diffusion layer (114, 124, 214, 224) of an ITO film (indium tin oxide film) by a film formation method such as vacuum deposition or sputtering is shown in FIG. 5C. (Not shown) is formed to a thickness of about 400 nm and patterned by a lift-off method. Thus, current diffusion layers (114, 124, 214, 224) are formed on the light emitting surfaces of the first and second light emitting semiconductor layers and the current diffusion surfaces of the first and second protective semiconductor layers.

  As shown in FIG. 5D, a V / Au / Al / Ni / Au film is formed by vacuum deposition, and patterning is performed by a lift-off method to form an n ohmic electrode 5. The portion where the film is left, that is, the portion where the n-ohmic electrode 5 is formed is the first and second light emitting semiconductor layers and the n-type semiconductor layers (112, 122, 212, 222) of the first and second protective semiconductor layers. It is an ohmic junction provided in the exposed part. After the patterning, the n ohmic electrode 5 and the current diffusion layers (114, 124, 214, 224) are annealed simultaneously by heating to about 500 ° C. in a mixed atmosphere of nitrogen and oxygen by a tube furnace.

  As shown in FIG. 6E, the first and second light emitting semiconductor layers and the first and second protective semiconductor layers are electrically separated from each other by photolithography and dry etching. The semiconductor layer between the first and second protective semiconductor layers and the semiconductor layer around the first and second light emitting semiconductor layers are etched until the substrate 1 is exposed.

As shown in FIG. 6F, the SiO ₂ film 7 is formed on the entire surface by plasma CVD, the first and second bonding semiconductor electrodes 61 and 62 are provided by diluted hydrofluoric acid, the first and second light emitting semiconductor layers, The n-ohmic electrode 5 in each of the first and second protective semiconductor layers, the upper portion of the current diffusion layer (114, 124, 214, 224) and the SiO ₂ film 7 in the element isolation portion are removed.

  As shown in FIG. 6G, a Ti / Au film is formed by vacuum deposition, and patterning is performed by lift-off to form bonding electrodes 61 and 62 and wiring layers 63, 64, 65, and 66. As a result, a series circuit of two light emitting LED structures (LED11, LED12) and a series circuit of two protective LED structures (LED21, LED22) are connected in reverse parallel in one package (LED chip). An LED wafer on which a plurality of LED chips are formed is completed.

  Thereafter, the element (LED chip) is separated by laser scribing to complete the light emitting element 100 (LED chip), which is assembled into a package.

  As described above, in the semiconductor light emitting device 100 of the first embodiment, two semiconductor layers (LED structures) as light emitting elements are connected in series in a single chip, and the semiconductor layers (LED structures) as protective elements are connected. Are connected in series, and each series circuit is connected in antiparallel. Thereby, while having high reliability with respect to static electricity, even when one semiconductor layer (LED structure) enters a leak state both in the forward direction and in the reverse direction of the semiconductor light emitting device 100, the other semiconductor layer (LED structure) ) Can maintain the functions (light emitting function, protective function). In particular, the semiconductor light emitting device of the present embodiment is very effective in a field or application where high reliability is required for safety, such as a light emitting diode for vehicle use.

  Moreover, since the voltage (battery voltage) of the in-vehicle power supply is usually 12V, in the case of a conventional light emitting diode having only one LED chip, the light emitting diode is driven with a forward voltage of about 3V, and the rest 9V (12V-3V) is consumed by resistance or the like. On the other hand, in the semiconductor light emitting device 100 according to the present embodiment, since the two LED structures are connected in series, the semiconductor light emitting device 100 is driven with a forward voltage of about 6 V, thereby reducing wasteful power consumption. Can do.

  In the first embodiment described above, a GaN-based semiconductor layer is used. However, the present invention is not limited to this. For example, a semiconductor layer such as AlGaInP can also be used.

(Embodiment 2)
In the first embodiment, the protective semiconductor layer is disposed in the central portion of the substrate 1, but the arrangement of the light emitting semiconductor layer and the protective semiconductor layer is not limited thereto. A protective semiconductor layer may be disposed on one side of the rectangular substrate 1 and a light emitting semiconductor layer may be disposed on the remaining three sides. The difference from the first embodiment is the semiconductor layer arrangement method.

  7 is a schematic view showing an example of a planar structure of the semiconductor light emitting device 120 of the second embodiment, and FIG. 8 is a cross sectional view showing an example of a cross sectional structure of the semiconductor light emitting device 120 taken along the line VIII-VIII of FIG. 9 is a cross-sectional view showing an example of the cross-sectional structure of the semiconductor light emitting device 120 taken along the line IX-IX in FIG.

  As shown in FIGS. 7 to 9, the semiconductor light emitting device 120 includes the first and second light emitting semiconductor layers (LED 11 and LED 12) and the first and second protective semiconductor layers (LED 21 and LED 22) on the substrate 1. Laminate at the four corners. That is, each semiconductor layer is arranged so that the surface of the substrate 1 is divided into four parts by the first and second light emitting semiconductor layers (LED11, LED12) and the first and second protective semiconductor layers (LED21, LED22).

  As shown in FIGS. 8 and 9, current diffusion layers 114 and 124 are formed on the surfaces of the p-type semiconductor layers 112 and 122 of the first light emitting semiconductor layer (LED 11) and the second light emitting semiconductor layer (LED 12). It is. The current diffusion layer is, for example, an ITO film (indium tin oxide film) that is a conductive transparent film.

  As shown in FIGS. 8 and 9, the n-type semiconductor layers 112 and 122 of the first and second light emitting semiconductor layers (LED11 and LED12), the n-type semiconductor layer 212 of the first protective semiconductor layer (LED21), and the An n-ohmic electrode 5 is formed on the surface of the n-type semiconductor layer 222 of the illustrated second protective semiconductor layer (LED 22).

  The n-type semiconductor layer 122 of the second light emitting semiconductor layer has the first bonding electrode 61 formed through the n ohmic electrode 5.

  A second bonding electrode 62 is formed on the surface of the current diffusion layer 114 of the first light emitting semiconductor layer. That is, the second bonding electrode 62 is connected to the p-type semiconductor layer 113 of the first light emitting semiconductor layer.

  The second bonding electrode 62 is connected to the n-type semiconductor layer 212 of the first protective semiconductor layer via the wiring layer 63.

  The p-type semiconductor layer 213 of the first protective semiconductor layer is connected to the n-type semiconductor layer 222 of the second protective semiconductor layer by the wiring layer 64 through the current diffusion layer 214.

  The p-type semiconductor layer 223 of the second protective semiconductor layer is connected to the first bonding electrode 61 by the wiring layer 65 through the current diffusion layer 224.

  7 and 8, the n-type semiconductor layer 112 of the first light emitting semiconductor layer is connected to the current diffusion layer 124 of the second light emitting semiconductor layer by the wiring layer 66. That is, the n-type semiconductor layer 112 of the first light emitting semiconductor layer is connected to the p-type semiconductor layer 123 of the second light emitting semiconductor layer by the wiring layer 66.

The first light emitting semiconductor layer (LED11), the second light emitting semiconductor layer (LED12), the first protective semiconductor layer (LED21), and the second protective semiconductor layer (LED22) are interconnect layers 63, 64, 65. , 66 are electrically insulated by a SiO ₂ film 7 as a protective film except for the portions connected by.

  With the configuration as described above, the semiconductor light emitting device 120 has a circuit configuration similar to the circuit configuration shown in FIG.

  As shown in FIG. 7, the dimension (L1 + L2 + L3 in FIG. 7) of the n-type semiconductor layer 2 of the first and second light emitting semiconductor layers along the outer periphery of the substrate 1 is set to be the same as that of the first and second protective semiconductor layers. The length of the n-type semiconductor layer 2 is longer than the dimension along the outer periphery of the substrate 1 (M1 + M2 + M3 in FIG. 7). In general, light emitted from the light emitting semiconductor layer at the periphery of the substrate is more easily extracted outside the semiconductor light emitting element than light emitted from the light emitting semiconductor layer at the center of the substrate. Therefore, by making the length of the light emitting semiconductor layer along the peripheral portion of the substrate 1 with good light extraction efficiency longer than the length of the protective semiconductor layer, it is possible to suppress a decrease in light emission efficiency and incorporate a protective element. it can.

  The manufacturing method of the semiconductor light emitting device 120 is the same as the manufacturing method of the semiconductor light emitting device 100 of the first embodiment, and thus description thereof is omitted. As described above, in the semiconductor light emitting device 120 of the second embodiment, two semiconductor layers (LED structures) as light emitting elements are connected in series in a single chip, and a semiconductor layer (LED structure) as a protective element is connected. Are connected in series, and each series circuit is connected in antiparallel. Thereby, while having high reliability with respect to static electricity, even when one semiconductor layer (LED structure) is leaked in both the forward direction and the reverse direction of the semiconductor light emitting device 120, the other semiconductor layer (LED structure) ) Can maintain the functions (light emitting function, protective function). In particular, the semiconductor light emitting device of the present embodiment is very effective in a field or application where high reliability is required for safety, such as a light emitting diode for vehicle use.

  FIG. 10 is a schematic diagram illustrating an example of the configuration of the light emitting device 200 of the present embodiment. The light-emitting device 200 is a light-emitting diode, and includes any one of the semiconductor light-emitting elements 100 and 120 described above and a housing portion that houses any one of the semiconductor light-emitting elements 100 and 120. Hereinafter, the case where the semiconductor light emitting element 100 is used will be described.

  As shown in FIG. 10, the light emitting device (light emitting diode) 200 includes lead frames 201 and 202, and one end portion of the lead frame 201 is provided with a recess 201 a as a housing portion. A semiconductor light emitting element (LED chip) 100 is bonded and fixed to the bottom of the recess 201a by die bonding.

  One bonding electrode of the LED chip 100 is wire-bonded to the lead frame 201 by a wire 204, and the other bonding electrode is wire-bonded to the lead frame 202 by a wire 204. The recess 201a is filled with a translucent resin to form a cover 203 that covers the LED chip 100. In addition, the fluorescent substance 205 according to the emission color of the LED chip 100 can also be contained in the coating | coated part 203. FIG.

  The end portions of the lead frames 201 and 202 on which the covering portion 203 is formed are housed in a lens 206 having a convex end portion. The lens 206 is formed of a translucent resin such as an epoxy resin.

  The light emitting device (light emitting diode) 200 accommodates the semiconductor light emitting element 100 described above. As a result, it is possible to avoid a situation where the light is turned off due to a leak state or the like and to ensure high reliability.

  In addition, a circuit board on which a large number of the above-described light emitting diodes 200 are mounted, and a power supply unit that drives a predetermined voltage to the light emitting diodes 200 in order to obtain a required brightness include a lighting device, a display device, a signal lamp, or a road information device. It can also be incorporated into such devices. For example, a lighting device, a display device, a signal lamp, or a road information device includes the light emitting device (light emitting diode) 200 of the present embodiment as a light source. Accordingly, it is possible to provide an illumination device, a display device, a signal lamp, or a road information device that can avoid a situation where the light is turned off due to a leak state or the like and can ensure high reliability.

1 Substrate 2, 112, 122, 212, 222 n-type semiconductor layer 3, 113, 123, 213, 223 p-type semiconductor layer 61 first bonding electrode 62 second bonding electrode 63, 64, 65, 66 wiring layer

Claims (7)

In a semiconductor light emitting device in which a semiconductor layer in which an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are stacked on a substrate is formed.
First and second light-emitting semiconductor layers each including an n-type semiconductor layer, an active layer, and a p-type semiconductor layer stacked on the substrate;
An n-type semiconductor layer, an active layer and a p-type semiconductor layer are stacked on the substrate, respectively, and first and second protective semiconductor layers for protecting the first and second light emitting semiconductor layers;
A first wiring layer connecting the n-type semiconductor layer of the first light-emitting semiconductor layer and the p-type semiconductor layer of the second light-emitting semiconductor layer;
A second wiring layer connecting the p-type semiconductor layer of the first protective semiconductor layer and the n-type semiconductor layer of the second protective semiconductor layer;
A third wiring layer connecting the p-type semiconductor layer of the first light emitting semiconductor layer and the n-type semiconductor layer of the first protective semiconductor layer;
A fourth wiring layer connecting the n-type semiconductor layer of the second light emitting semiconductor layer and the p-type semiconductor layer of the second protective semiconductor layer;
A first bonding electrode connected to the n-type semiconductor layer of the second light emitting semiconductor layer;
And a second bonding electrode connected to the p-type semiconductor layer of the first light emitting semiconductor layer.   2. The semiconductor according to claim 1, wherein areas of the n-type semiconductor layers of the first and second light emitting semiconductor layers are larger than areas of the n-type semiconductor layers of the first and second protective semiconductor layers. Light emitting element. N-type semiconductor layers of the first and second light emitting semiconductor layers are annularly stacked along an outer periphery of the substrate;
The n-type semiconductor layers of the first and second protective semiconductor layers are:
3. The semiconductor light emitting element according to claim 1, wherein the first and second light emitting semiconductor layers are stacked on an inner peripheral side of an n-type semiconductor layer. 4. The substrate has a rectangular shape,
Each of the first and second light emitting semiconductor layers and the first and second protective semiconductor layers are stacked at four corners of the substrate;
The dimensions of the n-type semiconductor layers of the first and second light emitting semiconductor layers along the outer periphery of the substrate are the dimensions of the n-type semiconductor layers of the first and second protective semiconductor layers along the outer periphery of the substrate. 3. The semiconductor light emitting device according to claim 1, wherein the semiconductor light emitting device is longer.   5. A light emitting device comprising: the semiconductor light emitting element according to claim 1; and a housing portion that houses the semiconductor light emitting element.   An illumination device comprising the light-emitting device according to claim 5.   A display device comprising the light-emitting device according to claim 5.

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