JP2006245230A - Semiconductor light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light emitting device which is provided with a transparent conductive oxide film on its semiconductor layer, which can keep transparency and reduce a Schottky barrier between the semiconductor layer and the conductive oxide film while improving light extraction efficiency, and which is provided with en electrode that is low in contact resistance and can realize appropriate ohmic connection. <P>SOLUTION: The semiconductor device is provided with a nitride semiconductor layer and an electrode connected to the nitride semiconductor layer. In this case, the electrode includes a metallic film made of silver or silver alloy being in contact with the nitride semiconductor layer, and the nitride semiconductor layer is provided with (1) an area of which layer is thicker than that in an electrode connection area at least in a part of an area apart from the electrode connection area on its surface, or (2) an area of which layer is different in thickness from the nitride semiconductor layer in the electrode connection area toward a direction being away from the electrode connection area on its surface, and an area of which layer has a nearly similar thickness, in this order. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor light emitting device made of a nitride semiconductor, and more particularly to improvement of an electrode in the semiconductor light emitting device.

2. Description of the Related Art Conventionally, in a flip chip type nitride semiconductor light emitting device, a configuration in which an electrode made of silver or a silver alloy is formed as a p electrode has been used. Since silver reflects light generated in the light emitting layer of the light emitting element with high efficiency, a light emitting element with high luminance can be realized.
However, when silver is used as the p-side electrode material, it is necessary to expose a part of the surface of the silver electrode for connection to the outside, etc., which causes migration and promotes. As a result, there is a problem that the emission intensity and the lifetime are reduced.

Therefore, in order to prevent the surface of the silver electrode from being exposed, a measure is taken in which the silver electrode is completely covered with an electrode material not containing silver and a protective film is formed thereon. However, there is a problem that silver cannot be sufficiently prevented from diffusing into an electrode material not containing silver by heat treatment after electrode formation or due to the heat treatment conditions, and silver migration cannot be prevented. .
In contrast, an SiO ₂ film having a plurality of through holes is arranged between the silver electrode and the electrode material not containing silver, and the silver electrode and the electrode material not containing silver are electrically connected through the through hole. And a method for preventing silver migration has been proposed (for example, Patent Document 1).

JP 2003-168823 A

However, since the SiO ₂ film is disposed between the silver electrode and the electrode material not containing silver, although the electrical connection is ensured by the through hole, the contact resistance between the two increases. .
In addition, even if silver migration to the electrode material not containing silver is suppressed by physical blocking by the SiO ₂ film, it has not yet been effective in effectively preventing silver migration to the nitride semiconductor layer, At present, it is still impossible to suppress a decrease in emission intensity and a decrease in lifetime of the light emitting element due to silver migration.
The present invention has been made in view of the above problems, and in the case where a silver having a high reflection efficiency or an electrode mainly composed of silver is formed on a nitride semiconductor layer in contact with the nitride semiconductor layer, An object of the present invention is to obtain a highly reliable and high-quality semiconductor light-emitting device by effectively preventing migration and preventing physical damage due to peeling of electrodes and the like.

  The inventors of the present invention, as a result of earnest research on silver migration of an electrode made of silver or a silver alloy, as a result of the migration of silver in an electrode made of silver or a silver alloy, in a semiconductor light emitting device made of a nitride semiconductor layer, Find out what is caused by the horizontal electric field when energized, and dramatically avoid silver migration by placing a recessed groove in the depth direction to cut off the horizontal electric field I found out that I can. Further, the inventors have found that sufficient light confinement can be realized by improving the adhesion of the electrode material film to be coated to prevent silver migration, and the present invention has been completed.

  That is, the semiconductor light emitting device of the present invention is a semiconductor device including a nitride semiconductor layer and an electrode connected to the nitride semiconductor layer, and the electrode is in contact with the nitride semiconductor layer. (1) The nitride semiconductor layer has, on the surface thereof, at least part of a region away from the region to which the electrode is connected, and the electrode connection region. (2) The nitride semiconductor layer is nitrided in the electrode connection region in a direction away from the region to which the electrode is connected on the surface thereof. It has a feature that a physical semiconductor layer and a region having different layer thicknesses and a region having substantially the same thickness are provided in this order.

In such a semiconductor element, it is preferable that the region having a different layer thickness is thinner than the nitride semiconductor layer in the electrode connection region.
Further, in the nitride semiconductor layer, it is preferable that a region having a different thickness and a side surface continuous to the same region form an acute angle with the surface of the same region.
Furthermore, the electrode preferably has a first metal film made of silver or a silver alloy, and a second metal film made of a material different from the first metal film and covering the first metal film.
Further, the second metal film is a film continuous to a region where the layer is thicker than the nitride semiconductor layer or a region where the layer thickness is different from that of the nitride semiconductor layer and / or is Schottky connected to the nitride semiconductor layer. It is preferable that

Furthermore, the connection between the first metal film and the nitride semiconductor layer is preferably in ohmic contact with the connection between the second metal film and the nitride semiconductor layer.
In addition, an insulating film covering a part of the electrode is provided, and in particular, the insulating film is a continuous film over a region where the layer is thicker than the nitride semiconductor layer or a region where the nitride semiconductor layer and the layer are different in thickness. The insulating film is preferably at least one selected from the group consisting of silicon nitride or silicon nitride oxide.
Furthermore, the first metal film is preferably formed of a laminated film of at least a film made of silver or a silver alloy and a metal film that does not substantially react with silver disposed on the film.
The nitride semiconductor layer is a second conductivity type nitride semiconductor layer on the first conductivity type nitride semiconductor layer, and in particular, a region thicker than the nitride semiconductor layer or the nitride semiconductor layer It is preferable that the p-type nitride semiconductor layer has regions having different layer thicknesses.

  According to the semiconductor light emitting device of the present invention, the electrode is formed of a metal film made of silver or a silver alloy, and the nitride semiconductor layer is formed on at least a part of the region away from the region where the electrode is connected on the surface. A thickness of a layer thicker than the nitride semiconductor layer in the electrode connection region, or a thickness of the nitride semiconductor layer and the layer in the electrode connection region in a direction away from the region to which the electrode is connected Since the regions having different thicknesses and the regions having the same thickness in this order are provided in this order, the horizontal electric field can be effectively cut off, and as a result, silver migration can be effectively prevented. it can. As a result, it is possible to improve the emission intensity and increase the lifetime, and to obtain a highly reliable and high quality semiconductor light emitting element.

In particular, silver migration can be more reliably prevented when the regions having different thicknesses and the side surfaces continuing to the same region and the surface of the same region form an acute angle.
When a second metal film that covers the first metal film is further formed on the first metal film made of silver or a silver alloy, the first metal film is not exposed. It is possible to prevent contact between water and moisture, and to further prevent silver migration.
Further, when the second metal film is formed of a metal that does not substantially react with silver at least in a region in contact with the metal film, for example, nickel, the abundance ratio of silver in the vicinity of the interface with the nitride semiconductor Will not decrease. That is, silver in the metal film can be prevented from diffusing, moving, and the like to the second metal film side due to the reaction with the second metal film, and the light irradiated from the light emitting layer can be transmitted to the nitride semiconductor. In the vicinity of the surface, the light can be reflected with high efficiency, and the light emission efficiency can be further increased.

  In the case where an insulating film made of a nitride covering at least a part of the electrode is formed, in the electrode of the semiconductor light emitting device, moisture or moisture that can act on the electrode is disposed in the vicinity of the insulating film. It is thought that the nitrogen atom is surely captured. Thereby, even if the electrode including the metal film made of silver or silver alloy is heat-treated and energized, silver migration can be effectively prevented, and the emission intensity is improved and the lifetime is increased, and the reliability is high. A high quality semiconductor light emitting device can be obtained.

In particular, by using a specific nitride as the insulating film, it is possible to easily form the insulating film only by performing a normal manufacturing process, and in addition, moisture or moisture that acts on Ag migration of the silver electrode. By avoiding this, the above effect can be realized more remarkably.
Further, when the electrode is connected to the p-type nitride semiconductor layer, in addition to the above-described effect, in the p-type nitride semiconductor layer in which the diffusion of electrons hardly occurs, a good ohmic contact is ensured, and the current diffusion The reflection efficiency of light from the light emitting layer can be maximized while further improving the above. Therefore, the light extraction efficiency can be improved, and a high-quality and high-performance light-emitting element can be obtained.

  In particular, since the first electrode is ohmically connected to the semiconductor layer and / or the second metal film is Schottky connected to the semiconductor layer, light can be sufficiently confined immediately below the first metal film. Excellent luminous efficiency can be ensured, and the reflection efficiency can be improved by the silver constituting the first metal film. In addition, the adhesion of the first metal film can be improved. Therefore, the emission intensity can be improved and the lifetime can be increased, and a highly reliable and high quality semiconductor light emitting device can be obtained.

As described above, the semiconductor light emitting device of the present invention includes a nitride semiconductor layer and an electrode formed on the nitride semiconductor.
The electrode formed on the nitride semiconductor layer is connected to the nitride semiconductor layer and is formed to include at least a metal film made of silver or a silver alloy (hereinafter referred to as “first metal film”). Moreover, it is preferable to have the 2nd metal film which consists of a material different from a 1st metal film so that a 1st metal film may be coat | covered. This electrode, particularly the first metal film, is preferably ohmic-connected. The ohmic property of the first metal film with respect to the semiconductor layer is more preferably better than the ohmic property of the second metal film with respect to the semiconductor layer. Here, the ohmic connection has a meaning normally used in the field, and refers to, for example, a junction whose current-voltage characteristic is a straight line or a substantially straight line. It also means that the voltage drop and power loss at the junction during device operation are negligibly small. Therefore, contacting ohmic means that the current-voltage characteristic is closer to a straight line. Since the first metal film is ohmic-connected to the semiconductor layer and aims to efficiently input current, and is intended to efficiently reflect the light from the light emitting layer, substantially the entire surface of the semiconductor layer is It is preferable to form with a wide area.

The first metal film may be a silver single layer film, a silver alloy single layer film, or a laminated film containing silver or a silver alloy in the lowermost layer.
The silver alloy is selected from the group consisting of silver and Pt, Co, Au, Pd, Ti, Mn, V, Cr, Zr, Rh, Cu, Al, Mg, Bi, Sn, Ir, Ga, Nd and Re. And an alloy with one or more electrode materials. Ni is difficult to be alloyed with silver, but the silver film may contain Ni element.

The composition of the first metal film may be inclined from the semiconductor layer side to the second metal film side. For example, it may be a silver film or an alloy containing silver and an element other than silver up to about 1% on the semiconductor side, and silver and an element other than silver up to about 5% on the second metal film side. An alloy containing
The film other than the lowermost layer may be silver or a silver alloy, or may be formed of an electrode material that does not contain silver or a silver alloy. Further, the films other than the lowermost layer substantially do not react with silver, a single layer film of two or more kinds of metal or alloy selected from the group including these electrode materials and Ni, or a laminated film of two or more layers. A metal film or the like is preferable.

  A preferred example of the first metal film is a single layer film of silver, and further has a two-layer structure of metal (upper) / silver or silver alloy (lower) that does not substantially react with silver, noble metal (upper) / silver Or a two-layer structure of silver alloy (lower), a three-layer structure of a metal (medium) / silver or silver alloy (lower) that does not substantially react with noble metal (upper) / silver, a noble metal two-layer (upper) / substantially silver and A 4-layer structure of metal (medium) / silver or silver alloy (bottom) that does not react automatically is more preferable. Examples of the noble metal include platinum group metals and gold. Among them, Pt and gold are preferable.

  As a metal that does not substantially react with silver, a metal that does not substantially react with silver at a temperature of 1000 ° C. or less, specifically, nickel (Ni), ruthenium (Ru), osmium (Os), iridium (Ir) , Titanium (Ti), vanadium (V), niobium (Nb), tantalum (Ta), cobalt (Co), iron (Fe), chromium (Cr), tungsten (W), and the like. Of these, Ni is preferable.

  The film thickness of the first metal film is not particularly limited. For example, in the case of a silver or silver alloy single layer, the film thickness that can effectively reflect light from the light emitting layer, specifically, about 200 to 1 μm, About 500 to 3000 mm, preferably about 1000 mm. In the case of a laminated structure, the total film thickness is about 500 to 5 μm and about 500 to 1 μm, and the silver or silver alloy film contained therein can be appropriately adjusted within this range. In the case of a laminated structure, the silver or silver alloy film and the film laminated thereon may have the same shape by patterning in the same process, but the lowermost silver or silver alloy film It is preferable to coat with a film laminated thereon (preferably a metal film that does not react with silver). As a result, no matter what electrode material is formed as a part of the first metal film on the metal film that does not react with silver, it does not come into direct contact with the silver or silver alloy film. Can be blocked.

  Depending on the stacked state of the first metal film, the first metal film may be crystallized at least at the interface with the semiconductor layer, for example, when a nickel film is disposed immediately above the silver single layer film. By crystallization of the first metal film, better ohmic properties with the semiconductor layer can be ensured. Here, crystallization is, for example, a method of observing a cross section by transmission electron microscopy (TEM), a method of observing by scanning electron microscopy (SEM), a method of measuring an electron diffraction pattern, or an ultra-thin film evaluation apparatus. It means that the interface of crystal grains can be visually recognized by an observation method or the like. It is preferable that the crystal grains in this case can be visually recognized as having a diameter (length, height, or width) of about 10 to 100 nm, for example.

  The first metal film is crystallized at the interface with the semiconductor layer by a known method such as vapor deposition, sputtering, ion beam assisted vapor deposition, etc. The method of heat-processing in the temperature range of about 300-600 degreeC for about 10 to 30 minutes under a nitrogen atmosphere is mentioned.

  The second metal film may completely or substantially completely cover the first metal film, or covers a part of the surface and / or side surface of the first metal film like a normal pad electrode or the like. It may be formed as follows. Here, “completely or substantially completely covered” means that the entire upper surface and the entire side surface of the first metal film are substantially covered. Alternatively, the second metal film that completely or substantially completely covers the first metal film may be formed as a so-called cover electrode, and a pad electrode or the like may be further formed thereon.

  Further, the second metal film may be continuously disposed not only on the first metal film but also on the surface of the semiconductor layer as described later. In this case, as will be described later, for example, it is a continuous film extending to a region where the layer is thicker than the semiconductor layer in the region where the first metal film is formed or a region where the thickness of the semiconductor layer and the layer is different. It is preferable.

  When the second metal film is in contact with the semiconductor layer, Schottky connection is preferable. Here, the Schottky connection has a meaning normally used in this field, and refers to a junction whose current-voltage characteristics are not a straight line or a substantially straight line, for example. Moreover, the potential barrier at the junction during device operation is about 0.1 V or more, preferably about 1 to 2 V.

  The method for Schottky connection of the second metal film to the semiconductor layer is not particularly limited, and a known method can be used. For example, after a first metal film having a desired shape is formed on a semiconductor layer by a known method such as a lift-off method, a resist pattern having a window larger than the first metal film is formed on the semiconductor layer. Examples include a method of etching by dry etching or wet etching using the pattern and the first metal film as a mask, a method of surface treatment such as sputtering or ashing (for example, plasma ashing), and the like. As will be described later, the surface of the semiconductor layer to which the second metal film is connected is subjected to normal surface treatment or the like, or is etched to increase or decrease the thickness of the semiconductor layer. In addition, partial irregularities or recesses may be formed to such an extent that the characteristics of the semiconductor layer are not affected. Thereby, the adhesiveness of the second metal film to the semiconductor layer can be improved.

  Further, as a modification, by increasing the potential barrier at the junction between the second metal film and the nitride semiconductor layer at least at the junction between the first metal film and the nitride semiconductor layer, silver or The problem of migration due to the first metal film made of a silver alloy can be reduced. By using an electrode having such a potential barrier relationship, the effect of preventing migration due to the structure in which regions having different film thicknesses are provided on the surface of the nitride semiconductor layer is further improved.

The material of the second metal film is, for example, zinc (Zn), nickel (Ni), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (Os), iridium (Ir), Titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), cobalt (Co), iron (Fe), manganese (Mn), molybdenum (Mo), Metals such as chromium (Cr), tungsten (W), lanthanum (La), copper (Cu), silver (Ag), yttrium (Y), gold (Au), aluminum (Al), alloys, ITO, ZnO ₂ , Examples thereof include a single layer film or a laminated film of a conductive oxide film such as SnO. Among these, a Pt monolayer film, a two-layer structure film of Au (upper) / Pt (lower), a three-layer structure film of Pt (upper) / Au (middle) / Pt (lower), and the like are preferable.

  In particular, when the first metal film is a single layer film of silver or a silver alloy, as described above, the metal that does not substantially react with silver is placed in at least the region of the second metal film in contact with the first metal film. It is preferable to arrange. Moreover, it is preferable to arrange a conductive material usually used for connection with other terminals such as wire bonding, such as gold or platinum, on the upper surface (connection region) of the second metal film on these electrodes. . Furthermore, it is preferable to dispose a material having good adhesion to the insulating film described later on the upper surface of the second metal film.

  The film thickness of the second metal film is not particularly limited. For example, when an Au bump is formed on the second metal film, the second metal film is made relatively thick and an eutectic (Au—Sn, etc.) bump is formed. Specifically, it is preferable to adjust the thickness of the second metal film so that the total film thickness is about 100 to 1000 nm.

In the semiconductor light emitting device of the present invention, the nitride semiconductor layer is configured, for example, by laminating a first conductivity type nitride semiconductor layer, a light emitting layer, and a second conductivity type nitride semiconductor layer in this order on a substrate. Can be mentioned. The first conductivity type indicates p-type or n-type, and the second conductivity type indicates a conductivity type different from the first conductivity type, that is, n-type or p-type. Preferably, the first conductive semiconductor layer is an n-type semiconductor layer, and the second conductive semiconductor layer is a p-type semiconductor layer.
As the substrate, for example, a known insulating substrate and conductive substrate such as sapphire, spinel, SiC, GaN, GaAs or the like can be used. Of these, a sapphire substrate is preferable.
The insulating substrate may be finally removed or may not be removed. When removing the insulating substrate, the p electrode and the n electrode may be formed on the same surface side or may be formed on different surfaces. When the insulating substrate is not removed, both the p electrode and the n electrode are normally formed on the same surface side on the nitride semiconductor layer.

Although the nitride semiconductor layer is not particularly limited, for example, a gallium nitride-based compound semiconductor such as In _X Al _Y Ga _1-XY N (0 ≦ X, 0 ≦ Y, X + Y ≦ 1) is preferably used. It is done. The nitride semiconductor layer may have a single layer structure, but may have a laminated structure such as a homo structure, a hetero structure, or a double hetero structure having a MIS junction, a PIN junction, or a PN junction. It may be a single quantum well structure or a multiple quantum well structure in which thin films that produce effects are stacked. Further, either n-type or p-type impurities may be doped. This nitride semiconductor layer can be formed by a known technique such as metal organic chemical vapor deposition (MOCVD), hydride vapor deposition (HVPE), molecular beam epitaxy (MBE), or the like. The film thickness of the nitride semiconductor layer is not particularly limited, and various film thicknesses can be applied.

Examples of the laminated structure of the nitride semiconductor layer include those shown in the following (1) to (5).
(1) A buffer layer (thickness: 200 mm) made of GaN, an n-side contact layer (4 μm) made of Si-doped n-type GaN, a light emitting layer (30 mm) having a single quantum well structure made of undoped In _0.2 Ga _0.8 N, A p-type cladding layer (0.2 μm) made of Mg-doped p-type Al _0.1 Ga _0.9 N, and a p-side contact layer (0.5 μm) made of Mg-doped p-type GaN.

(2) A buffer layer (thickness: about 100 mm) made of AlGaN, an undoped GaN layer (1 μm), an n-side contact layer (5 μm) made of GaN containing Si of 4.5 × 10 ¹⁸ / cm ³ , and made of undoped GaN An n-side first multilayer film layer composed of three layers: a lower layer (3000 Å), an intermediate layer (300 Å) made of GaN containing Si of 4.5 × 10 ¹⁸ / cm ³ , and an upper layer (50 Å) made of undoped GaN ( Total thickness: 3350 mm), undoped GaN (40 mm) and undoped In _0.1 Ga _0.9 N (20 mm) are repeatedly stacked alternately in 10 layers, and further, undoped GaN (40 mm) is stacked on the n-side first layer 2 multilayer layers (total film thickness: 640 mm), barrier layers (250 mm) made of undoped GaN and well layers (30 mm) made of In _0.3 Ga _0.7 N are alternately repeated 6 Light emitting layer (total film thickness: 1930Å) having a multilayered structure in which barrier layers (250Å) made of undoped GaN are further laminated, Al _0.15 Ga _0.85 N containing 5 × 10 ¹⁹ / cm ³ Mg ( 40 Å) and a Mg containing ^{5 × 10 19 / cm 3 in} 0.03 Ga 0.97 N (25Å) Al 0.15 includes a repeating five layers each 5 × 10 ¹⁹ / cm ³ further Mg are laminated alternately Ga _0.85 N (40 Å P-side multilayer film layer (total film thickness: 365 mm) having a superlattice structure, and p-side contact layer (1200 mm) made of GaN containing 1 × 10 ²⁰ / cm ^{3 of} Mg.

(3) AlGaN buffer layer (film thickness: about 100 mm) undoped GaN layer (1 μm), n-side contact layer (5 μm) made of GaN containing 4.5 × 10 ¹⁸ / cm ³ Si, lower layer made of undoped GaN (3000 Å), an n-side first multilayer film layer (total of 3 layers of an intermediate layer (300 Å) made of GaN containing Si of 4.5 × 10 ¹⁸ / cm ³ and an upper layer (50 Å) made of undoped GaN (total) Film thickness: 3350Å), undoped GaN (40Å) and undoped In _0.1 Ga _0.9 N (20Å) are alternately and repeatedly stacked 10 layers each, and the n-side second of the superlattice structure in which undoped GaN (40Å) is further stacked Multilayer (total thickness: 640 mm), barrier layer (250 mm) made of undoped GaN, well layer (30 mm) made of In _0.3 Ga _0.7 N, and In _0.02 Ga _0.98 N A light emitting layer having a multiple quantum well structure (total film thickness: 1930 Å) formed by repeatedly stacking six layers of first barrier layers (100 Å) and second barrier layers (150 Å) made of undoped GaN repeatedly and alternately. (a layer to be laminated to the repeated alternately is preferably from 3 layers to 6 layers), an in _0.03 comprising Al _0.15 Ga _0.85 N (40Å) and a Mg 5 × 10 ¹⁹ / cm ³ containing Mg 5 × 10 ¹⁹ / cm ³ A p-side multilayer layer having a superlattice structure in which five layers of Ga _0.97 N (25 繰 り 返 し) are alternately laminated and Al _0.15 Ga _0.85 N (40Å) containing 5 × 10 ¹⁹ / cm ^{3 of} Mg is further laminated ( Total film thickness: 365 mm), p-side contact layer (1200 mm) made of GaN containing 1 × 10 ²⁰ / cm ^{3 of} Mg.

Of these, the lower layer (3000 Å) made of undoped GaN provided on the n side is the first layer (1500 Å) made of undoped GaN from the bottom, and the second layer made of GaN containing 5 × 10 ¹⁷ / cm ^{3 of} Si. By making the lower layer of a three-layer structure consisting of (100Å) and a third layer (1500Å) made of undoped GaN, it becomes possible to suppress the variation in _{Vf with} the lapse of the driving time of the light emitting element.
Further, GaN or AlGaN (2000 mm) may be formed between the p-side multilayer film layer and the p-side contact layer. This layer is undoped and exhibits p-type due to diffusion of Mg from adjacent layers. By providing this layer, the electrostatic withstand voltage of the light emitting element is improved. This layer may be omitted when used in a light emitting device provided with an electrostatic protection function separately, but when an electrostatic protection means such as an electrostatic protection element is not provided outside the light emitting element, an electrostatic withstand voltage is not required. Since it can improve, providing is preferable.

(4) Buffer layer, undoped GaN layer, n-side contact layer made of GaN containing 6.0 × 10 ¹⁸ / cm ^{3 of} Si, undoped GaN layer (the above is an n-type nitride semiconductor layer with a total film thickness of 6 nm), Si 5 × 10 ¹⁸ / cm ^{3 of} GaN barrier layers and InGaN well layers are repeatedly stacked in a multiple quantum well light emitting layer (total film thickness: 1000 Å), Mg is 5.0 × 10 5 ^A p-type nitride semiconductor layer (film thickness: 1300 mm) made of GaN containing ¹⁸ / cm ³ .
Furthermore, an InGaN layer (30 to 100 mm, preferably 50 mm) may be provided on the p-type nitride semiconductor layer. Thereby, this InGaN layer becomes a p-side contact layer in contact with the electrode. Thus, even a layer not doped with Mg functions as a p-type nitride semiconductor layer for forming a p-electrode if the film thickness is relatively smaller than that of an adjacent p-type semiconductor layer.

(5) Buffer layer, undoped GaN layer, n-side contact layer made of GaN containing 1.3 × 10 ¹⁹ / cm ^{3 of} Si, undoped GaN layer (the above is an n-type nitride semiconductor layer having a total film thickness of 6 nm), Si Is a multiple quantum well light emitting layer (total film thickness: 800 mm) in which 7 layers of GaN barrier layers and InGaN well layers containing 3.0 × 10 ¹⁸ / cm ³ are alternately stacked, and Mg is 2.5 × 10 ^A p-type nitride semiconductor layer made of GaN containing ²⁰ / cm ³ . On this p-type nitride semiconductor layer, an InGaN layer (30 to 100 mm, preferably 50 mm) may be formed as a p-side contact layer.

  It is preferable that the surface of the nitride semiconductor layer has a region where the layer is thicker than the nitride semiconductor layer in the electrode connection region in at least a part of the region away from the region where the electrode is connected. For example, as shown in FIG. 4, on the surface of the p-type semiconductor layer 5, the p-type semiconductor layer 5 is separated from the region where the first metal film is formed by a distance A away from the first metal film formation region. It has a thick region t. In other words, the groove 410 is formed on the surface of the p-type semiconductor layer 5 and at a part of the outer periphery of the electrode formation region.

  In addition, on the surface of the nitride semiconductor layer, a region (preferably, a thin region) in which the thickness of the nitride semiconductor layer and the layer in the electrode connection region are different from each other in a direction away from the region to which the electrode is connected, May have substantially the same area in this order. For example, as shown in FIG. 1, on the surface of the p-type semiconductor layer 5, first, in the direction away from the region where the first metal film is formed (direction B), first, p in the first metal film formation region. It has a region (for example, a thin region) s different from the thickness of the p-type semiconductor layer 5, and then has a region y substantially the same as the thickness of the p-type semiconductor layer 5 in the first metal film formation region. In other words, the groove 110 is formed on the surface of the p-type semiconductor layer 5 toward the outer periphery of the electrode formation region.

  Alternatively, as shown in FIG. 5, in a direction away from the region where the first metal film is formed, first, a region (for example, a thick region) different from the thickness of the p-type semiconductor layer 5 in the first metal film formation region. X), and then a region z substantially the same as the thickness of the p-type semiconductor layer 5 in the first metal film formation region. In other words, a groove 510 is formed on the surface of the p-type semiconductor layer 5 and on the outer periphery of the electrode formation region.

  As described above, in the region away from the electrode or the region in which the thickness of the nitride semiconductor layer increases or decreases in the direction away from the electrode, a groove recessed from the surface of the nitride semiconductor layer is formed in at least a partial region of the outer periphery of the electrode. It is preferable to arrange so that. The region corresponding to the groove is preferably formed over the entire outer periphery of the electrode. For example, the region between the electrode and another electrode is disposed at least in a region that intersects the flow of electrons. If you do. The region corresponding to the groove has a width of, for example, about 1 to 10 μm, a depth of about 5 mm or more, less than the thickness of the semiconductor layer, and preferably a contact layer when a contact layer is formed on the surface of the semiconductor layer. The thickness is preferably less than the thickness of the layer, for example, about 200 mm or less. However, the width and depth of the region corresponding to the groove are not necessarily constant. A plurality of regions corresponding to the grooves may be formed in parallel so as to intersect the flow of electrons (see FIG. 2).

  Further, the region corresponding to the groove is not necessarily provided so that the end portion of the electrode and the end portion thereof coincide with each other. For example, the end portion of the region corresponding to the groove and the end portion of the electrode There may be a gap (gap) about the margin in the mask alignment in the photolithography process. Further, the region corresponding to the groove may have a shape having a vertical side surface, or a forward mesa shape whose width on the bottom surface side is wide and decreases as it approaches the top surface (that is, regions having different thicknesses and the same The side surface that continues to the region of the same and the surface of the same region form an acute angle or a shape that becomes wider in the depth direction), conversely, the reverse mesa shape that decreases in width as it approaches the bottom surface, and these are combined The shape may be different. Furthermore, due to the formation method, a so-called overhang shape dug below the metal film may be used. A shape in which these shapes are combined may be used.

  Thus, the method of adding or decreasing the thickness of the semiconductor layer is not particularly limited, and a known method can be used. For example, after a metal film having a desired shape is formed on a nitride semiconductor layer by a known method such as a lift-off method, a resist pattern having a window larger than the metal film is formed on the nitride semiconductor layer. A method of etching by dry etching or wet etching using a pattern and a metal film as a mask can be mentioned. Further, before forming the metal film, a resist pattern having a window corresponding to the shape of the groove may be formed, and etching may be performed using this resist pattern as a mask.

  The region corresponding to the groove may be in a state in which a part or the whole of the bottom surface and the side surface is exposed. For example, a part or the whole of the region corresponding to the groove is filled with a second metal film and / or an insulating film described later. Is preferred. In particular, it is preferable that the second metal film is completely embedded, because light generated from the light emitting layer is reflected by the second metal film and the light extraction efficiency can be improved.

In the semiconductor light emitting device of the present invention, an insulating film that covers at least a part of the electrode is preferably formed. As the insulating film, an oxide film (Al ₂ O ₃ or the like), a nitride film, or the like is preferably used, and a nitride film is more preferable. A typical example of the nitride film is a single-layer film or a laminated film such as SiN, TiN, or SiO _x N _y . Among these, a single layer film of SiN or the like is preferable. In this way, by using a film containing N instead of a film with relatively high water content such as SiO ₂ as the insulating film covering the electrode, nitrogen atoms capture water or moisture, and silver and silver alloys It is considered that moisture or moisture to the electrode made of is effectively prevented, and migration of silver can be prevented.
The insulating film does not need to completely cover the electrode, and the electrode is preferably covered except for a region necessary for connection with another terminal. The film thickness of the insulating film is suitably about 400 to 1000 nm, for example.

The semiconductor light emitting device of the present invention is generally quadrangular or substantially similar in shape in plan view, and the first semiconductor layer includes a second semiconductor layer and a light emitting layer in a partial region of one semiconductor light emitting device, A part of the first semiconductor layer in the depth direction is optionally removed to have an exposed region where the surface is exposed. A first electrode is formed on the exposed surface of the first semiconductor layer.
In the semiconductor light emitting device of the present invention, it is preferable that a plurality of irregularities be formed at least in the above-described exposed region where the first electrode is not formed (including the outer edge portion of the semiconductor light emitting device). In other words, as will be described later, even if a light emitting layer is present, holes and electrons are not supplied, so that it does not function as a light emitting layer and a plurality of irregularities are formed in a region that does not emit light itself. Is preferred.

  Thus, by forming the unevenness, (1) the light guided in the first semiconductor layer is taken into the convex portion, and is extracted from the top of the convex portion or the middle portion thereof. (2) The light guided in the first semiconductor layer is irregularly reflected and extracted at the root of the convex portion, and (3) the light emitted laterally from the end surface of the light emitting layer is reflected and scattered by the plurality of convex portions and extracted. In other words, the light emitted in the lateral direction (side surface direction of the semiconductor light emitting element) can be selectively emitted to the second semiconductor layer side by the unevenness, whereby the light extraction efficiency is, for example, 10 to 10%. It can be improved by about 20%, and the light directivity can be controlled. In particular, in a semiconductor light emitting device having a structure in which a light emitting layer is sandwiched between layers having a lower refractive index (so-called double heterostructure), light is confined between the layers having a lower refractive index, so that the lateral direction is increased. This is particularly effective for a light emitting device having such a structure. Furthermore, by providing a plurality of projections and depressions, uniform light extraction can be performed over the entire region on the second semiconductor layer side.

  Concavities and convexities may be formed on the exposed first semiconductor layer by, for example, growing a semiconductor layer to perform a special process for forming a convex portion. However, when the first semiconductor layer is exposed or on each chip It is preferable that the predetermined regions are formed at the same time, for example, when a predetermined region is thinned for division. Thereby, the increase in a manufacturing process can be suppressed. As described above, the unevenness is composed of the same stacked structure as the semiconductor stacked structure of the semiconductor light-emitting element, that is, a plurality of layers made of different materials. Therefore, the light taken into the convex portion is caused by the difference in the refractive index of each layer. It is considered that the light is easily reflected at the interface between the layers, and as a result, the light extraction toward the second semiconductor layer is improved.

  The convex portion in the unevenness may be higher than at least the interface between the light emitting layer and the first semiconductor layer adjacent thereto in the cross section of the semiconductor light emitting device, but the top portion is preferably located on the second semiconductor layer side of the light emitting layer. Furthermore, it is more preferable that the height is substantially the same as that of the second semiconductor layer. That is, it is preferable that the top of the convex portion is formed so as to be higher than the light emitting layer. By configuring the protrusions so as to include the second semiconductor layer, the tops thereof are substantially the same height, so that the second semiconductor layer side from the top of the protrusions is not obstructed by the second electrode or the like described later. Can effectively extract light. By configuring the convex portion to be higher than the second semiconductor layer, preferably the second electrode, light can be extracted more effectively. In addition, the concave portion between the convex portions may be at least lower than the interface between the light emitting layer and the second semiconductor layer adjacent thereto, and is preferably formed to be lower than the light emitting layer.

The density of the unevenness is not particularly limited, and in one semiconductor light emitting device, it can be at least 100, preferably 200, more preferably 300, more preferably 500. Thereby, the said effect can be improved more. Note that the ratio of the area occupied by the region where unevenness is formed as viewed from the electrode forming surface side can be 20% or more, preferably 30% or more, and more preferably 40% or more. The upper limit is not particularly limited, but is preferably 80% or less. The area of one of the projections, at the root of the protrusion, 3～300Myuemu ^2, preferably 6～80Myuemu ^2, more preferably be a 12~50μm ^2.

  The convex portion may have any shape such as a quadrangular shape, a trapezoidal shape, or a semicircular shape, but is preferably a trapezoidal shape, that is, a frustoconical shape in which the convex portion itself gradually narrows. In this case, the inclination angle of the convex portion is, for example, 30 ° to 80 °, and preferably 40 ° to 70 °. That is, by inclining the convex portion so that it gradually becomes thinner toward the tip, the light from the light emitting layer is totally reflected on the surface of the convex portion, or the light guided through the first semiconductor layer is scattered. As a result, light extraction toward the second semiconductor layer can be effectively performed. In addition, the directivity control of light becomes easier and more uniform light extraction is possible as a whole.

In addition, when a convex part is truncated cone shape, the recessed part may be further formed in the upper side (2nd semiconductor layer side) of trapezoid. Thereby, when the light guided in the first semiconductor layer enters the inside of the convex portion, the concave portion formed at the top of the convex portion facilitates light to be emitted toward the second semiconductor layer side.
Furthermore, it is preferable that the convex portions are arranged to be at least partially overlapped by 2 or more, preferably 3 or more, in a direction substantially perpendicular to the emission end face of the semiconductor multilayer structure. Thereby, the light from the light emitting layer is allowed to act on the convex portion with a high probability, so that the above effect can be obtained more easily.

The semiconductor light-emitting device of the present invention is usually mounted on a support substrate by flip chip mounting (face-down mounting) to constitute a semiconductor light-emitting device.
The support substrate may be provided with wiring on at least a surface facing the electrode of the light emitting element, and a protective element or the like may be arbitrarily formed, and fixes and supports the light emitting element mounted in flip chip. The support substrate is preferably made of a material having substantially the same thermal expansion coefficient as that of the light emitting element, for example, aluminum nitride for the nitride semiconductor light emitting element. Thereby, the influence of the thermal stress which generate | occur | produces between a support substrate and a light emitting element can be relieve | moderated. Further, silicon that can be added with a function such as an electrostatic protection element and is inexpensive may be used. The wiring pattern is not particularly limited. For example, it is preferable that a pair of positive and negative wiring patterns be insulated and separated so as to surround one another.
When the support substrate is connected to the lead electrode, wiring may be provided by a conductive member from the surface facing the light emitting element to the surface facing the lead electrode.

  As the support substrate having the function of the protection element, for example, an n-type silicon substrate of an Si diode element can be used. By selectively implanting impurity ions into the n-type silicon substrate, one or more p-type semiconductor regions are formed, and the reverse breakdown voltage is set to a predetermined voltage. Then, a p electrode and an n electrode are formed on the p type semiconductor region and the n type semiconductor region (n type silicon substrate itself) of the silicon substrate. Some of these p-electrode and n-electrode can be used as bonding pads. Alternatively, an n electrode made of Au or the like may be formed on the lower surface of the n-type silicon substrate to form a bonding pad. In the semiconductor region, an electrode having a function of a reflective film made of a silver-white metal material (for example, Al or Ag) may be formed as a p electrode and / or an n electrode.

  When mounting a semiconductor light emitting element on a support substrate, for example, a bump made of Au or the like is placed on the support substrate, or the p electrode and / or the n electrode in the protection element described above is used as a bump, thereby providing the semiconductor light emitting element. The p-electrode and n-electrode are opposed to the bumps or electrodes formed on the support substrate, and are electrically and mechanically connected. The connection can be performed by ultrasonic bonding and / or heat treatment with a bonding member such as Au, eutectic material (Au—Sn, Ag—Sn), solder (Pb—Sn), lead-free solder, or the like. When the wiring and the lead electrode are configured to be directly connected, for example, a bonding member such as Au paste or Ag paste can be used. In the case of using Au as a bump, since connection is obtained by applying ultrasonic waves and heat, there is a risk of damaging the semiconductor layer in the light emitting element. Therefore, as the second metal film of the semiconductor light emitting element, An Au (upper) / Pt (lower) film is preferably formed. Further, when the eutectic material is used as a bump, since only heat is applied, an Au film may be formed as the second metal film, or the first metal film may be a single layer film of Ag. When bumps are used, it is preferable that the area of the bumps is large and the number is large. Accordingly, heat dissipation from the light emitting element can be improved, and the bonding strength of the light emitting element to the support substrate can be increased.

  In the case where a protective element (for example, a diode) is formed on the support substrate, the semiconductor light emitting element and the protective element include a bidirectional diode formed by connecting two diodes in series and a parallel connection of the semiconductor light emitting element. It is preferable to do. As a result, the semiconductor light emitting element can be protected from overvoltage in the forward direction and the reverse direction, and can be a highly reliable semiconductor device.

  The light-emitting element of the present invention preferably has a light conversion member that converts part of light from the light-emitting element into light having a different wavelength. The light conversion member is configured to include at least a fluorescent material that is excited by a light emission wavelength from the light emitting element and emits fluorescent light, or includes a fluorescent material and a binder, and optionally an inorganic member (glass, filler, etc.). The Thereby, the light of the light emitting element is converted, the light from the light emitting element is mixed with the converted light and the fluorescent light, for example, white light whose chromaticity is located on the locus of black body radiation in the chromaticity diagram, It is possible to obtain a light emitting device that emits desired light such as a white color or a light bulb color such as light having a special color rendering index R9 of around 40 at a color temperature of Tcp = 4600K.

  In general, the light conversion member is preferably disposed on the light extraction surface side. For example, the light conversion member includes a fluorescent material, a sealing member that covers a light emitting element to be described later, a die bond material that fixes the submount on which the light emitting element is flip-chip mounted to another support, and the periphery of the light emitting element and the supporting substrate. It can be formed by arranging in and / or around each constituent member such as a support layer such as a resin layer, a submount and a package provided on the substrate. When a plurality of light emitting elements are mounted on one support substrate, they may be arranged in a gap between the elements. In particular, when a fluorescent material is combined with a sealing member, it may be in the form of a sheet that covers the light emission observation surface side surface of the sealing member, and includes a phosphor at a position spaced from the surface and the light emitting element. A layer, a sheet, a cap, or a filter may be provided inside the sealing member. Further, when the light emitting element mounted on the flip chip is covered, it may be formed by a metal mask, screen printing, stencil printing or the like. Thereby, it can form easily with a uniform film thickness.

The light conversion member is a single layer of one kind of fluorescent substance, a single layer in which two or more kinds of fluorescent substances are uniformly mixed, and two or more layers of a single layer containing one kind or two or more kinds of fluorescent substances It can be formed as a laminated structure. In addition, when laminating two or more single layers, the fluorescent substance or the like contained in each layer may be one that converts the wavelength of light having the same wavelength into emitted light having the same wavelength, The incident light having the same wavelength may be converted into the outgoing light having a different wavelength.
In order to reduce color unevenness, it is preferable that the average particle diameter and the shape of each phosphor are comparable. The particle size of the phosphor can be measured by, for example, a volume reference particle size distribution curve described in JP-A No. 2004-207688.

  The light emission color of the light emitting device is selected by appropriately selecting the ratio of the phosphor, the binder, and optionally the inorganic member, the specific gravity of the phosphor, the amount and shape of the phosphor, the emission wavelength of the light emitting element, and the like. The temperature can be changed to obtain an arbitrary white color tone such as light in a light bulb color region. It is preferable that the light from the light emitting element and the light from the phosphor efficiently pass through the mold member outside the light emitting device.

Examples of fluorescent materials include:
(i) rare earth aluminate,
(ii) nitrides or oxynitrides,
(iii) alkaline earth silicate, alkaline earth silicon nitride,
(iv) alkaline earth metal halogen apatite,
(v) alkaline earth metal halogen borate,
(vi) alkaline earth metal aluminate,
(vii) sulfides,
(viii) alkaline earth thiogallate,
(ix) germanate,
(x) rare earth silicates,
(xi) Various fluorescent materials such as organic and organic complexes mainly activated with a lanthanoid element such as Eu. Any of these fluorescent substances can be used.

  In particular, (i) as the rare earth aluminate, those mainly activated by rare earth elements such as Ce, particularly lanthanoid elements, are preferable, and typically aluminum garnet series (particularly activated by cerium). Examples thereof include yttrium / aluminum / garnet phosphors (YAG) and lutetium / aluminum / garnet phosphors (LAG).

As the YAG fluorescent material, for example, those described in JP-A No. 2004-207688 are preferable. Specifically, considering the high brightness and the long-term _{use, (Re 1-x Sm x} ) 3 (Al 1-y Ga y) 5 O 12: Ce (0 ≦ x <1,0 ≦ y ≦ 1 However, Re is preferably at least one element selected from the group consisting of Y, Gd, and La). That is, this fluorescent substance can have an excitation spectrum peak near 470 nm or the like, and can have a broad emission spectrum near 530 nm and extending to 720 nm. In particular, this fluorescent material can increase RGB wavelength components by using a combination of materials having different contents of Al, Ga, Y, La and Gd, Sm. When a YAG phosphor is used, a light emitting device having sufficient light resistance with high efficiency even when used with a light emitting element having an irradiance of (Ee) = 0.1 W · cm ⁻² or more and 1000 W · cm ⁻² or less Can be obtained.

LAG phosphor is represented by the general formula _{(Lu 1-ab R a M} b) 3 (Al 1-c Ga c) 5 O 12 ( where, R represents an essential Ce, Ce, La, Pr, Nd, Sm, Eu , Gd, Tb, Dy, Ho, Er, Tm, Yb, Lr, and M is at least one element selected from Sc, Y, La, Gd, 0.0001 ≦ a ≦ 0.5, 0 ≦ b ≦ 0.5, 0.0001 ≦ a + b <1, 0 ≦ c ≦ 0.8.), For example, (Lu _0.99 Ce _{0.01) 3 Al 5 O 12,} (Lu 0.90 Ce 0.10) 3 Al 5 O 12, include _{(Lu 0.99 Ce 0.01) 3 (} Al 0.5 Ga 0.5) 5 O 12 and the like.

  Since the lutetium / aluminum / garnet phosphor is efficiently excited and emitted by ultraviolet rays or visible light in the wavelength region of 300 nm to 550 nm, it can be effectively used as a phosphor contained in the light conversion member. In addition, since the temperature characteristics are excellent, a light-emitting device with little deterioration and color shift can be obtained.

(Ii) The nitride or oxynitride contains N and at least one element selected from Be, Mg, Ca, Sr, Ba, and Zn, and C, Si, Ge, Sn, Ti, A fluorescent material containing at least one element selected from Zr and Hf is preferable. Moreover, what was activated with the at least 1 element selected from the rare earth elements is preferable. For example,
L _x J _y N _{((2/3) x + (4/3) y)} : R
L _x J _y O _z N _{((2/3) x + (4/3) y- (2/3) z)} : R
_{L x J y Q t O z} N ((2/3) x + (4/3) y + t- (2/3) z): R
(L is at least one group II element selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Zn. J consists of C, Si, Ge, Sn, Ti, Zr, and Hf. At least one Group IV element selected from the group, Q is at least one Group III element selected from the group consisting of B, Al, Ga, and In, and R is Y, La, Ce Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Lu, Sc, Yb, Tm is at least one rare earth element, and L, J, and R are (X, y, and z are 0.5 ≦ x ≦ 3, 1.1.5 <y ≦ 8, 0 <t <0.5, and 0 <z ≦ 3.)
Is mentioned.

Furthermore, (iii) the alkaline earth silicate and the alkaline earth silicon nitride are preferably activated with europium, for example. For example,
(2-x-y) SrO · x (Ba, Ca) O · (1-a-b-c-d) SiO 2 · aP 2 O 5 bAl 2 O 3 cB 2 O 3 dGeO 2: yEu 2+
(Where 0 <x <1.6, 0.005 <y <0.5, 0 <a, b, c, d <0.5).
(2-x-y) BaO · x (Sr, Ca) O · (1-a-b-c-d) SiO 2 · aP 2 O 5 bAl 2 O 3 cB 2 O 3 dGeO 2: yEu 2+
(In the formula, 0.01 <x <1.6, 0.005 <y <0.5, 0 <a, b, c, d <0.5.)
Etc.

The alkaline earth metal halogen apatite fluorescent material is preferably mainly activated by a lanthanoid-based element such as Eu and / or a transition metal-based element such as Mn. For example, M ₅ (PO ₄ ) ₃ X : R _E (M is at least one selected from Sr, Ca, Ba, Mg, Zn; X is at least one selected from F, Cl, Br, I; R _E is Eu and / or Mn.) And the like. For example, calcium chlorapatite (CCA), barium chloroapatite (BCA), Ca ₁₀ (PO ₄ ) ₆ FCl: Sb, Mn, etc. are exemplified.

Examples of the alkaline earth metal borate fluorescent substance include M ₂ B ₅ O ₉ X: R _E (M, X and R _E are as defined above). For example, calcium chlorborate (CCB) is exemplified.
The alkaline earth metal aluminate fluorescent material is preferably activated with europium and / or manganese. For example, europium activated strontium aluminate (SAE), barium magnesium aluminate (BAM), or SrAl ₂ O ₄ : _{R E, Sr 4 Al 14 O} 25: R E, CaAl 2 O 4: R E, BaMg 2 Al 16 O 27: R E, BaMgAl 10 O 17: R E, CaAl 2 O 4: Eu, BaMgAl 10 O 17 : Eu, Mn (R _E is Eu and / or Mn) and the like.

As alkaline earth silicate and alkaline earth silicon nitride,
Me (3-xy) MgSi ₂ O ₃ : xEu, yMn
(In the formula, 0.005 <x <0.5, 0.005 <y <0.5, Me represents Ba and / or Sr and / or Ca.)
Specifically, M ₂ Si ₅ N ₈ : Eu, MSi ₇ N ₁₀ : Eu, M _1.8 Si ₅ O _0.2 N ₈ : Eu, M _0.9 Si ₇ O _0.1 N ₁₀ : Eu
(M is at least one selected from Sr, Ca, Ba, Mg, Zn).

Examples of sulfides include alkaline earth sulfides such as CaS: Eu and SrS: Eu, La ₂ O ₂ S: Eu, Y ₂ O ₂ S: Eu, Gd ₂ O ₂ S: Eu, ZnS: Eu, ZnS: Mn, ZnCdS: Cu, ZnCdS: Ag, Al, ZnCdS: Cu, Al, (Mg, Ca, Sr, Ba) Ga ₂ S ₄ : Eu and the like.
(vii) Examples of the alkaline earth thiogallate include MGa ₂ S ₄ : Eu (M is as defined above).
Examples of the germanate include 3.5MgO · 0.5MgF ₂ · GeO ₂ : Mn, Zn ₂ GeO ₄ : Mn, and the like.

Examples of the rare earth silicate include Y ₂ SiO ₅ : Ce, Y ₂ SiO ₅ : Tb, and the like.
It does not specifically limit as an organic and an organic complex, You may use any well-known thing. For _{example, Mg 6 As 2 O 11:} Mn , etc. are exemplified. Preferably, it is mainly activated with a lanthanoid element such as Eu, but optionally, instead of or in addition to Eu, the above-mentioned rare earth elements and Cu, Ag, Au, Cr, Co, Ni, Ti and Mn You may use at least 1 sort (s) selected from the group which consists of.

  For example, as shown in the following table, the phosphors can be used alone or in combination to obtain an emission color having a desired color temperature and high color reproducibility.

  Examples of the binder include inorganic substances such as inorganic glass, yttria sol, alumina sol, and silica sol; polyolefin resin, polycarbonate resin, polystyrene resin, epoxy resin, acrylic resin, acrylate resin, methacrylic resin (PMMA, etc.), polyimide resin , Fluororesin, silicone resin (eg dimethylsiloxane, methylpolysiloxane, etc.), modified silicone resin, one or more resins such as modified epoxy resin; metal alkoxide, metal diketonate, metal diketonate complex, carboxylic acid Examples thereof include a translucent material formed by a sol-gel method using an organometallic compound such as a metal salt as a starting material; and an organic substance such as a liquid crystal polymer. When the light conversion member is composed of a fluorescent substance or the like and a binder, the fluorescent substance or the like and the binder are preferably used in a weight ratio range of about 0.1 to 10: 1.

  Examples of inorganic members include silica, quartz, titanium oxide, tin oxide, zinc oxide, tin monoxide, calcium oxide, magnesium oxide, beryllium oxide, aluminum oxide, silicon nitride, aluminum nitride, SiC, calcium carbonate, potassium carbonate, Examples thereof include barium carbonate, aluminum hydroxide, magnesium hydroxide, aluminum borate, barium titanate, calcium phosphate, calcium silicate, clay, barium sulfate, clay, inorganic balloon, talc, zeolite, halloysite, and metal pieces (silver powder, etc.). The inorganic member can be contained, for example, at 0.1 to 80% by weight of the total amount of the light conversion member.

  The light conversion member may be, for example, the above-described fluorescent material or the like, optionally mixed with an inorganic member in a binder, and if necessary, using a suitable solvent, potting method, spray method, screen printing method, injection It can be formed into a desired shape by a mold method, a compression method, a transfer method, an injection method, an extrusion method, a lamination method, a calendar method, a vacuum coating method, a powder spray coating method, an electrostatic deposition method, or the like. Moreover, you may utilize the method, electrodeposition, etc. which mix with a fluorescent substance etc. with an inorganic member and a suitable solvent arbitrarily, and shape | mold by pressurizing, heating arbitrarily.

  The semiconductor light emitting device of the present invention is preferably sealed with a sealing member. Thereby, a semiconductor element etc. can be protected from the external force, dust, moisture, etc. from an external environment. Further, by appropriately adjusting the shape, it is possible to impart and control the directivity characteristics of light emitted from the light emitting element, for example, the lens effect. The shape of the sealing member may be various shapes such as an elliptical shape, a cube, and a triangular prism as seen from the light emission observation surface side, such as a convex lens shape, a dome shape, or a concave lens shape. As the sealing member, the same material as the above-described binder and inorganic member can be used. In addition, various colorants, fluorescent substances, and the like may be added in order to obtain a filter effect that cuts unnecessary wavelengths from extraneous light and light emitting elements.

  In addition, the electrode ohmic-connected to the nitride semiconductor layer refers to the second electrode connected to the second conductivity type semiconductor layer and / or the first electrode connected to the first conductivity type semiconductor layer. Especially, it is preferable that it is a p electrode formed in the whole surface of a semiconductor light-emitting device or an area close | similar to the whole surface. Thereby, the light generated in the light emitting layer can be more efficiently reflected by the above-described electrode containing silver, and the reflected light can be used effectively.

  However, the electrode that is ohmic-connected to the nitride semiconductor layer is not necessarily formed by any one of the electrodes, but may be formed by selecting the above-described materials as appropriate for both the p-electrode and the n-electrode, or by using the same stacked structure. May be. Thus, by forming silver or a silver alloy as the first metal film in both electrodes, light is reflected even under the region where the n-electrode is formed, that is, substantially over the entire surface of the semiconductor light emitting device. And the light extraction efficiency can be further improved. In addition, by forming the second metal film over the first metal film in the n-electrode, it is possible to prevent a Schottky connection even after heat treatment and obtain a highly reliable n-electrode. It becomes possible.

Hereinafter, a semiconductor light emitting device of the present invention will be described in detail with reference to the drawings.
Example 1
The semiconductor light emitting device of this example is shown in FIG.
In this semiconductor light emitting device 1, a buffer layer (not shown) made of Al _0.1 Ga _0.9 N and a non-doped GaN layer (not shown) are stacked on a sapphire substrate 2, and an n-type semiconductor layer 3 is formed thereon. A n-side contact layer made of Si-doped GaN, a superlattice n-type cladding layer in which a GaN layer (40Å) and an InGaN layer (20 積 層) are alternately stacked 10 times, and further, a GaN layer As the light-emitting layer 4 and the p-type semiconductor layer 5 having a multiple quantum well structure in which (250Å) and InGaN layers (30Å) are alternately stacked three to six times, an Mg-doped Al _0.1 Ga _0.9 N layer (40Å) and an Mg-doped layer A superlattice p-type cladding layer in which InGaN layers (20Å) are alternately stacked 10 times and a p-side contact layer made of Mg-doped GaN are stacked in this order.

In a partial region of the n-type semiconductor layer 3, the light emitting layer 4 and the p-type semiconductor layer 5 stacked thereon are removed, and further, a part of the n-type semiconductor layer 3 itself in the thickness direction is removed. An n-side ohmic electrode (Al) and a pad electrode (Pt / Au) are formed as the n-side electrode 9 on the exposed n-type semiconductor layer 3.
A metal film 6 made of an Ag film having a thickness of 1000 mm is formed on the p-type semiconductor layer 5, and a groove 110 is formed on the entire outer periphery of the metal film 6. The end of the groove 110 substantially coincides with the end of the metal film 6, has a width of about 5 μm, and a depth of about 10 mm.
A pad electrode 7 made of a Pt film having a thickness of 1000 mm is formed on the metal film 6 so as to completely cover the metal film 6 and to completely fill the groove 110. Further, an insulating film 10 made of a SiN film having a thickness of 6000 mm is formed from the upper surface and side surface of the semiconductor layer on which the electrode is not formed to a part of the pad electrode 7 and the n-side electrode 9.

Such a semiconductor light emitting device can be formed by the following manufacturing method.
<Formation of semiconductor layer>
On a sapphire substrate 2 having a diameter of 2 inches, using a MOVPE reactor, a buffer layer made of Al _0.1 Ga _0.9 N is made 100 μm, a non-doped GaN layer is 1.5 μm, and an n-type semiconductor layer 3 is made of n doped Si-doped GaN. A side contact layer of 2.165 μm, a superlattice n-type cladding layer in which a GaN layer (40 cm) and an InGaN layer (20 cm) are alternately stacked 10 times, a 640 mm, a GaN layer (250 mm) and an InGaN layer (30 mm) As the light emitting layer 4 and the p-type semiconductor layer 5 having a multiple quantum well structure in which 3 to 6 layers are alternately stacked, an Mg-doped Al _0.1 Ga _0.9 N layer (40Å) and an Mg-doped InGaN layer (20Å) are alternately 10 A superlattice p-type cladding layer of 0.2 μm and a p-side contact layer made of Mg-doped GaN are grown in this order to a thickness of 0.5 μm to produce a wafer. It was.

<Etching>
The obtained wafer was annealed in a reaction vessel at 600 ° C. in a nitrogen atmosphere to further reduce the resistance of the p-type cladding layer and the p-side contact layer.
After annealing, the wafer was taken out from the reaction vessel, a mask having a predetermined shape was formed on the surface of the uppermost p-side contact layer, and etching was performed from above the mask with an etching apparatus to expose a part of the n-side contact layer. .

<Formation of electrode>
After removing the mask, the wafer was placed in the sputtering apparatus, and the Ag target was placed in the sputtering apparatus. Using a sputtering apparatus, an argon gas was used as a sputtering gas, and an Ag film having a thickness of 1000 mm was formed on almost the entire surface of the p-side contact layer of the wafer.
The obtained Ag film was patterned into a predetermined shape using a resist pattern. Subsequently, a resist pattern having a predetermined shape having a window larger than the Ag film is formed, and etching is performed using the Ag film and the resist pattern as a mask to form a groove having a width of about 5 μm and a depth of about 10 mm.
Thereafter, with the resist pattern left, a Pt film having a thickness of 1000 mm was formed on the entire surface of the p-side contact layer, and the Pt film was used as a pad electrode 7 covering the entire surface of the Ag film by a lift-off method.
Next, heat treatment was performed at a temperature not higher than the temperature at which Ag and Pt were not mixed without affecting the element characteristics of the semiconductor layer such as the p-side contact layer by an annealing apparatus. On the exposed n-side contact layer, an n-side electrode 9 made of Al / Pt / Au was formed to a thickness of 7000 mm.

<Formation of insulating film>
A mask having a predetermined pattern is formed on the p-side contact layer and the n-side contact layer including the n-side electrode 9 and the pad electrode 7 with a resist, and a SiN film is formed thereon with a thickness of 6000 mm. An insulating film 10 covering a part of the electrode 9 and the pad electrode 7 was formed.
A semiconductor light emitting device 1 was obtained by dividing the obtained wafer at predetermined locations.

The semiconductor light-emitting device formed as described above was energized in an atmosphere of temperature 85 ° C. and humidity 85% under the condition of If = 20 mA. After continuous energization for 10,000 hours, SEM observation on the cross section showed that Ag No microphone was observed and no leakage current was observed.
Further, the upper metal film was firmly adhered to the semiconductor layer, and no peeling was observed. Along with this, when current is supplied to the electrode, it is confirmed that light emission is stronger under the Ag film, which is the lower metal film, than under the area in contact with the upper metal film, and sufficient light confinement is performed. It was done.

For comparison, a light-emitting element similar to the semiconductor light-emitting element described above was formed except that the groove 110 was not formed.
In this semiconductor light emitting device, when current was passed in an atmosphere of temperature 85 ° C. and humidity 85% under the condition of If = 20 mA, a leak current was intermittently generated, and the lifetime of the device was 1000 hours or less.
Further, SEM observation in the cross section confirmed that Ag was precipitated on the n-side contact layer side.

Example 2
In the semiconductor light emitting device of this example, instead of the silver electrode in Example 1, a laminated film of Pt (top) / Ni (medium) / Ag (bottom) was formed at 1000 Å / 1000 Å / 1000 、, and the p electrode and n A semiconductor light emitting device having the same configuration as the semiconductor light emitting device of Example 1 was obtained except that the annealing temperature after electrode formation was increased to about 600 ° C.
Also in the obtained semiconductor light emitting device, when energized in the same manner as in Example 1, the semiconductor light emitting device had good ohmic properties, no generation of microphone, high quality and high reliability even after energization for 10,000 hours. Could get.

Furthermore, before and after energization, the Ag electrode was good in that crystal grains of about 10 to 100 nm were observed near the interface with the p-side contact layer, and the ohmic characteristics did not change.
In addition, since the upper surface of the Ag electrode is covered with Ni that does not react with Ag, alloying of Ag and Ni can be avoided, and Ag is disposed at a high density directly on the nitride semiconductor layer. Therefore, the reflection efficiency is good, and the light extraction efficiency is further improved.

Example 3
As shown in FIG. 2, the semiconductor light emitting device of this example is substantially the same as Example 1 except that the groove 110 in Example 1 has a plurality of, for example, three grooves 21 having a width of 3 μm and a depth of 10 mm. A semiconductor light emitting device having the same structure was obtained.
Each of the obtained semiconductor light emitting devices has good ohmic properties, no migration, high reflection efficiency, high quality and high reliability, as in Example 1. It was.

Example 4
In the semiconductor light emitting device of this example, the groove in Example 1 is located between the p-side Ag film 6 and the n-side electrode 9 in the region where the electron flows intersect as shown in FIG. A semiconductor light emitting device having a configuration substantially similar to that of Example 1 was obtained, except that only the groove 31 was formed. However, the insulating film is omitted in FIG.
Each of the obtained semiconductor light emitting devices has good ohmic properties, no migration, high reflection efficiency, high quality and high reliability, as in Example 1. It was.

Example 5
In the semiconductor light emitting device of this example, a second metal film made of a Pt film was formed on a metal film, and the second metal film was formed as an electrode that also served as a pad electrode without forming a pad electrode. A semiconductor light emitting device similar to that of Example 1 was obtained.
When the obtained semiconductor light emitting device was energized under the same conditions as in Example 1, almost the same results as in the semiconductor light emitting device of Example 1 were obtained.

Example 6
In the semiconductor light emitting device of this embodiment, as shown in FIG. 4, the thickness of the p-type semiconductor layer 5 in the electrode formation region is the same as that in a region corresponding to a so-called groove, and the width is adjacent to the electrode formation region. (A) A semiconductor light emitting device having a configuration substantially similar to that of Example 1 was obtained except that a groove 410 having a depth of 5 μm and a depth of 10 mm was formed.
Each of the obtained semiconductor light emitting devices has good ohmic properties, no migration, high reflection efficiency, high quality and high reliability, as in Example 1. It was.

Example 7
As shown in FIG. 5, the semiconductor light emitting device of this example is the same as that of Example 1 except that the outermost periphery of the p-type semiconductor layer 5 is the same as the film thickness of the p-type semiconductor layer 5 in the electrode formation region. A semiconductor light emitting device having substantially the same configuration was obtained.
Each of the obtained semiconductor light emitting devices has good ohmic properties, no migration, high reflection efficiency, high quality and high reliability, as in Example 1. It was.

Example 8
A semiconductor light emitting device having a configuration substantially similar to that of Example 1 was obtained except that Ar sputtering was performed at 100 W for 3 minutes using the Ag film and the resist pattern as a mask.
In Ar sputtering, a voltage is applied so that the side holding the wafer is negative, whereby Ar ⁺ sputters the surface of the wafer. By this sputtering, a groove (110 in FIG. 1) having a width of about 5 μm and a depth of about 10 nm was formed.
As in Example 1, the obtained semiconductor light emitting device had good ohmic properties, no migration occurred, high reflection efficiency, high quality and high reliability semiconductor light emitting device.

Example 9
As shown in FIGS. 6A and 6B, the semiconductor light emitting device 22 of this example has a buffer layer 12, a non-doped GaN layer 13, and an n side on the sapphire substrate 11 as in Example 1. A contact layer 14, an n-type cladding layer 15, an active layer 16 having a multiple quantum well structure, a p-type cladding layer 17, and a p-side contact layer 18 are stacked in this order. An Ag film 22 is formed on almost the entire surface of the p-side contact layer 18, and a Pt (upper) / Ni (lower) film is stacked thereon as the second metal film 21 to form a p-electrode. An n electrode 19 is formed on the exposed region. A groove 24 is formed in the outer periphery of the Ag film 22 and on the surface of the p-side contact layer 18.

Further, in this semiconductor light emitting device 22, the p-type semiconductor layer and the active layer 16 are removed, and the n-side contact layer 18 is exposed, in the outer edge region of the semiconductor light emitting device 22 where the n electrode 19 is not formed. A plurality of frustoconical convex portions 20 having substantially the same height as the active layer 16 and the p-type semiconductor layer are formed.
The size of the convex portion 20 is about 20 μm ² near the base thereof, the total number of the convex portions is about 800, and the area occupied by the convex portion 20 in one light emitting element is about 16%.
In such a semiconductor light emitting device, in addition to the effect of Example 1, it was found that Φv was improved by about 10% by forming the convex portion as compared with the device having no convex portion. .

Example 10
In this example, as shown in FIG. 7, the light-emitting device was formed by flip-chip mounting the semiconductor light-emitting element 1 shown in Example 1 on the mounting substrate 201.
This light emitting device is configured by mounting the LED chip 1 mounted on the submount substrate 205 via the adhesive layer 204 in the recess 202 of the package 212 including the mounting base 201 to which the leads 203 are fixed. The side surface of the concave portion 202 functions as the reflecting portion 206, and the mounting substrate 201 functions as a heat radiating portion and is connected to an external heat radiator (not shown). In addition, a terrace portion 207 is formed on the mounting base 201 outside the recess 202, and a protective element (not shown) is mounted thereon. An opening is formed as a light extraction portion 208 above the recess 202 of the mounting substrate 201, and a light-transmitting sealing member 209 is embedded and sealed in this opening.
With such a configuration, light can be reflected with high efficiency by the Ag film of the p electrode, and the light extraction efficiency from the substrate side of the semiconductor light emitting element can be further improved.

Example 11
In this embodiment, as shown in FIG. 8, the light-emitting device is formed by flip-chip mounting the semiconductor light-emitting element 1 shown in Embodiment 1 into the recess 120a of the stem 120 via the submount member 160. did.

  In the stem 120, the first lead 121 and the second lead 122 are integrally formed of resin, and part of the end portions of the first lead 121 and the second lead 122 are within the recess 120 a of the stem. Exposed. A submount member 160 is placed on the exposed second lead 122. The LED chip 200 is placed on the submount member 160 and in the approximate center of the recess 120a. The electrode 161 provided on the submount member 160 is electrically connected to the first lead 121 via a wire, and the electrode 162 is electrically connected to the second lead 122 via a wire. Yes.

A sealing member 131 including a phosphor 150 is embedded in the recess 120a of the stem, and further, the sealing member 141 covers a part of the sealing member 131 and the stem 120 thereon.
In this light-emitting device, the semiconductor light-emitting element 1 is directly mounted on a lead without using a submount member, and is bonded and electrically connected through a lead-free solder bump using an ultrasonic vibration device. Also good.
With such a configuration, light can be reflected with high efficiency by the Ag film of the p electrode, and the light extraction efficiency from the substrate side of the semiconductor light emitting element can be further improved.

Example 12
In the semiconductor light emitting device 30 of this embodiment, as shown in FIG. 9A, the n-type semiconductor layer is thinned from the end portion 31 where the n pad electrode is formed toward the center of the light emitting device by etching. The constricted portion 32 is exposed, and is exposed in a shape having an extending portion 33 so as to connect a pair of constricted portions 32 facing each other. A p-type semiconductor layer is formed in a region sandwiching the extending portion 33.
Except for these configurations, the laminated structure is substantially the same as that of the first embodiment.

  As shown in FIG. 9B, a Pt (upper) / Ni (middle) / Ag (lower) laminated film is formed on the p-type semiconductor layer formed in the region sandwiching the extending portion 33. A Pt (upper) / Au (lower) film is formed as the second metal film 34, and is an outer periphery of the laminated film of Pt (upper) / Ni (middle) / Ag (lower), and is a p-type semiconductor layer Grooves (not shown) are formed on the surface. Further, an n-electrode 35 is formed on the n-type semiconductor layer and on the constricted portion 32 and the extending portion 33 from the end portion 31. Also, pad electrodes 36 and 37 are formed on the second metal film 34 and the n-electrode 35, respectively. The pad electrodes 36 and 37 can be formed of the same material at the same time, thereby reducing the number of manufacturing steps for forming the electrodes.

  As shown in FIGS. 10A and 10B, the semiconductor light emitting device 30 configured as described above has conductor wirings 40 and 41 made of, for example, Au formed by plating on an aluminum nitride plate. Two light-emitting devices 43 are configured by flip-chip bonding to the support substrate 42 through p and n pad electrodes and bump electrodes in parallel connection (FIG. 10C).

The conductor wirings 40 and 41 are formed in a comb shape so as to be insulated and separated from each other as a pair of positive and negative electrodes.
From the area connected to the positive electrode side of the positive (+) pole side conductor wiring 40 and the external electrode (not shown) arranged on the support substrate 42, the position is opposed to the p pad electrode of one light emitting element. Extending to a position facing the p-pad electrode of the other light emitting element. Similarly, the negative (−) pole side conductor wiring 41 disposed on the support substrate 42 is connected to an external electrode (not shown) from a region facing one n-pad electrode of one light-emitting element and the other light-emitting element. Extending to a region facing the other n pad electrode of one light emitting element via a region connected to the negative electrode side of the light emitting element and a region facing the other n pad electrode of the other light emitting element. In addition, when viewed from the direction perpendicular to the support substrate 42, the outer edge of the negative-side conductor wiring 41 has a number of arcuate shapes protruding in the direction of the positive-side conductor wiring 40, while the positive-side conductor The outer edge portion of the wiring 40 has a concave shape corresponding to the convex outer edge on the negative electrode side. In addition, the area of the region facing the p pad electrode 36 of the semiconductor light emitting element 30 is larger than the area of the region facing the n pad electrode 37, and the number of p pad electrodes 36 is set larger than the number of n pad electrodes 37. .

  By mounting two semiconductor light emitting elements 30 on such a support substrate 42 in parallel connection, the conductor wiring is simplified as compared with the case of serial connection. In addition, combined with the formation of the conductor wirings 40 and 41 in a comb shape, it is possible to further improve the heat dissipation from the semiconductor light emitting element 30 that is flip-chip mounted.

  Further, in a region other than the region where the semiconductor light emitting element 30 and the support substrate 42 are bonded by the bump electrode 44, a resin layer 39 is disposed between the semiconductor light emitting element 30 and the support substrate 42 with silicone resin. Yes. The silicone resin can be formed by screen printing on the surface of the support substrate 42. And the through-hole is provided in the bump electrode 44 formation area | region of the resin layer 39 by a silicone resin, and the surface of the conductor wiring 40 and 41 is exposed. The inner wall of the through hole in the resin layer 39 has a tapered shape. With such a shape, the connection with the bump electrode 44 can be easily performed.

The bump electrode 44 is made of Au, and includes 24 bumps for bonding the p-pad electrode 36 and 12 bumps for bonding the n-pad electrode 37. The maximum diameter is about 1 × 2 mm for the light-emitting element. Bonding is set to a size of 105 μm and a maximum height of about 40 μm.
Bonding by bumps is performed by applying ultrasonic waves while applying pressure from the substrate side of the light emitting element so that the positive and negative electrodes of the light emitting element face each other directly above the bump. By applying, both the positive and negative electrodes of the light emitting element and the conductor wiring are joined via the bump. At this time, since the silicone resin is soft and rich in elasticity, it shrinks due to pressure, and often enters the gaps on the electrode surface of the LED chip. In addition, the number of bumps in the through hole is adjusted in advance before die bonding so that the bonding force between the electrode of the light emitting element and the conductor wiring is sufficiently larger than the elastic force of the silicone resin compressed by die bonding. deep. In this way, the light emitting element is not pushed back in the direction opposite to the support substrate due to the elastic force of the silicone resin, the strength of bonding between the electrode of the light emitting element and the conductor wiring is kept constant, and Since conduction between the electrode and the conductor wiring is not interrupted, a highly reliable light-emitting device can be obtained.

  The support substrate is cut so as to include a desired number, in FIG. 10, two light emitting elements, mounted on a package, connected to an external electrode through a conductive wire, and becomes a light emitting device. The shape of the support substrate after cutting may be any shape other than a rectangle.

By adopting such a configuration, in the light-emitting element in which heat is likely to be trapped, the inner heat can be dissipated by a relatively large number of bumps mounted and wide conductor wiring, A light emitting device with improved heat dissipation, high luminance light emission, and high reliability can be obtained.
In addition, the presence of the resin layer can substantially eliminate the gap between the semiconductor light emitting element and the support substrate, and prevents the complicated light refraction caused by the air present in the gap, thereby improving the light extraction efficiency. In addition, the heat conduction can be promoted by the resin layer, and the heat dissipation effect can be improved.

  Moreover, with such a configuration, light from the light emitting element can be reflected with high efficiency by the lowermost Ag film constituting the p-electrode, and light extraction from the sapphire substrate side in the flip chip mounted light emitting element is possible. Efficiency can be further improved.

Example 13
The light-emitting device in this example is substantially the same as Example 8 except that a silicone resin containing aluminum oxide is used as a filler, squeezing to the height of the bump or more, screen printing, and forming a resin layer. It is.
Thereby, the light-emitting device with higher light extraction efficiency and higher heat dissipation effect can be obtained.

Example 14
In the light emitting device 45 of this embodiment, as shown in FIG. 11, a translucent resin layer 39a is embedded in a gap formed between the semiconductor light emitting element 30 and the semiconductor light emitting element 30 that are flip-chip mounted. Furthermore, phosphors that emit light having different wavelengths by absorbing at least part of the light from the light emitting element 30 are flush with the light emitting surface side of the light emitting element 30 and the upper surface of the resin layer 39a. This is substantially the same as the light emitting device of Example 11 except that the wavelength conversion member 47 to be contained is formed.
The phosphor may be contained not only in the wavelength conversion member 47 but also in both the resin layers 39 and 39a, or may be contained only in one or both of the resin layers 39 and 39a. .
As described above, the resin layer 39a covers at least the side surface of the light emitting element, whereby the wavelength conversion member 47 can be prevented from entering the side surface side of the semiconductor light emitting element 30 in the formation process.

Example 15
In this embodiment, as shown in FIG. 12, the LED chip 200 is mounted face-up on the mounting base 201 to form a light emitting device.
In this light emitting device, an LED chip 200 is fixed to a recess 202 of a package 212 including a mounting base 201 insulated from a lead 203 via an adhesive layer 204. The concave portion 202 has a shape (tapered shape) whose side surface functions as the reflective portion 206 and becomes wider in the opening direction. With such a shape, light emitted from the LED chip 200 is reflected on the side surface of the recess 202 and travels toward the front of the package, so that light extraction efficiency can be improved. The mounting substrate 201 is made of, for example, glass epoxy resin or ceramic. The adhesive layer 204 is a thermosetting resin such as an epoxy resin, for example. The mounting substrate 201 functions as a heat radiating portion and is connected to an external heat radiator (not shown). In this manner, a light emitting device with excellent thermal design can be obtained with a configuration that separates the mounting base 201 and the leads 203 and can ensure heat dissipation.

Further, a light-transmitting sealing member 209 is embedded in and above the concave portion 202 of the mounting substrate 201, and further formed into an optical lens shape. By providing the optical system (lens), light emission with desired directivity can be obtained.
Further, the electrodes of the LED chip 200 are electrically connected to the leads 203 by wires 210 and extend outside the package.

The package 212 may be formed integrally with the external electrode, and further divided into a plurality of parts and used in combination by fitting or the like. Such a package 212 can be formed relatively easily by insert molding or the like. When the package material is a metal, even if a light emitting device using an LED chip that emits light including ultraviolet rays is used at a high output, it deteriorates due to ultraviolet rays, yellows, etc. The lifetime of the light emitting device can be improved without causing a decrease.
In addition, although the wire 210 is not specifically limited, For example, metals, such as gold | metal | money, copper, platinum, aluminum, and those alloys are used, and it is a diameter of about 10-70 micrometers.

Further, the sealing member 209 protects the LED chip 200, the wire 210, and optionally the coating layer containing the phosphor from the outside, or improves the light extraction efficiency, depending on the use application of the light emitting device. Is provided. The sealing member 209 can relax the directivity from the LED chip 200 by adding a diffusing agent to the mold member, and can also increase the viewing angle.
In this embodiment and any of the above-described embodiments, a concave portion is provided in a metal base, a light emitting element is mounted, and the lead is insulated and separated from the base and hermetically sealed. The LED chip may be directly mounted on the concave portion on the metal substrate like COB. In addition, a single mounting substrate or a single recess in which a plurality of elements are integrated and mounted, or a plurality of light-emitting elements mounted on a substrate may be provided.

  The semiconductor light emitting device of the present invention can be suitably used for a semiconductor light emitting device constituting various light sources such as a backlight light source, a display, illumination, and a vehicle lamp.

It is sectional drawing which shows embodiment of the semiconductor light-emitting device in this invention. It is sectional drawing which shows another embodiment of the semiconductor light-emitting device of this invention. It is sectional drawing (a) and top view (b) which show another embodiment of the semiconductor light-emitting device of this invention. It is sectional drawing which shows another embodiment of the semiconductor light-emitting device of this invention. It is sectional drawing which shows another embodiment of the semiconductor light-emitting device of this invention. It is the top view (a) and partial sectional view (b) which show another embodiment of the semiconductor light-emitting device in this invention. It is sectional drawing which shows the light-emitting device which mounted the semiconductor light-emitting device in this invention. It is sectional drawing which shows another light-emitting device which mounted the semiconductor light-emitting device in this invention. It is the top view (a) which shows arrangement | positioning of the electrode in the semiconductor light-emitting device in this invention, and the top view (b) which shows arrangement | positioning of a pad electrode. It is the top view (a) of the support substrate for mounting the semiconductor light emitting element in this invention, the circuit diagram (b) of the mounted light-emitting device, and sectional drawing (c) which shows a light-emitting device. It is sectional drawing which shows the light-emitting device which mounted the semiconductor light-emitting device in this invention. It is sectional drawing which shows another light-emitting device which mounted the semiconductor light-emitting device in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 30, 70 Semiconductor light-emitting device 2, 11 Sapphire substrate 3 N-type semiconductor layer 4 Light-emitting layer 5 P-type semiconductor layer 6 Metal film 7 Pad electrode 9, 19, 35 n-electrode 10 Insulating film 12 Buffer layer 13 Non-doped GaN layer 14 n-side contact layer 15 n-type cladding layer 16 active layer 17 p-type cladding layer 18 p-side contact layer 20 convex portion 21 second metal film 22 Ag film 24 groove 31 end portion 32 constricted portion 33 extending portion 36, 37 pad electrode 38 P pad electrode 39, 39a Resin layer 40, 41 Conductor wiring 42 Support substrate 43 Light emitting device 47 Wavelength conversion member 110, 210, 310, 410 Groove 120 Stem 120a Recess 121 First lead 122 Second lead 131, 141 Sealing Member 150 Phosphor 160 Submount member 161, 162 Electrode 200 LED chip 01 the mounting substrate 202 recess 203 lead 204 adhesive layer 205 surface 212 package submount substrate 206 in the reflective portion 207 terrace portion 208 light extraction portion 209 sealing member 210 wire 211

Claims (14)

A semiconductor element comprising a nitride semiconductor layer and an electrode connected to the nitride semiconductor layer,
The electrode comprises a metal film containing silver or a silver alloy in contact with the nitride semiconductor layer,
The nitride semiconductor layer has a region having a layer thicker than the nitride semiconductor layer in the electrode connection region in at least a part of a region away from the region to which the electrode is connected on the surface thereof. Semiconductor light emitting device. A semiconductor element comprising a nitride semiconductor layer and an electrode connected to the nitride semiconductor layer,
The electrode comprises a metal film containing silver or a silver alloy in contact with the nitride semiconductor layer,
The nitride semiconductor layer has a thickness substantially the same as a region of the electrode connection region having a layer thickness different from that of the nitride semiconductor layer in a direction away from the region to which the electrode is connected. A semiconductor light emitting element characterized by having the regions in this order.   The element according to claim 2, wherein the regions having different layer thicknesses are thinner than the nitride semiconductor layer in the electrode connection region.   4. The device according to claim 2, wherein the nitride semiconductor layer has an acute angle between a region having a different thickness and a side surface continuous to the same region, and a surface of the same region.   The said electrode has a 1st metal film which consists of silver or a silver alloy, and a 2nd metal film which consists of a material different from this 1st metal film, and coat | covers this 1st metal film. The device according to any one of the above.   The said 2nd metal film is a film | membrane continuous even to the area | region where a layer is thicker than a nitride semiconductor layer, or the area | region where the thickness of a nitride semiconductor layer and a layer differs. element.   The element according to claim 6, wherein the second metal film is Schottky connected to the nitride semiconductor layer.   The element according to claim 7, wherein the connection between the first metal film and the nitride semiconductor layer is in ohmic contact with the connection between the second metal film and the nitride semiconductor layer.   The device according to claim 1, further comprising an insulating film that covers a part of the electrode.   The element according to claim 1, wherein the insulating film is a film continuous up to a region where the layer is thicker than the nitride semiconductor layer or a region where the nitride semiconductor layer and the layer have different thicknesses. .   The element according to claim 1, wherein the insulating film is at least one selected from the group consisting of silicon nitride or silicon nitride oxide.   The said 1st metal film is formed by the laminated film of the film | membrane which consists of silver or a silver alloy at least, and the metal film which does not react substantially with the silver arrange | positioned on this film | membrane. The element of crab.   The element according to claim 1, wherein the nitride semiconductor layer is a second conductivity type nitride semiconductor layer provided on the first conductivity type nitride semiconductor layer. The device according to claim 13, wherein the p-type nitride semiconductor layer has a region thicker than the nitride semiconductor layer or a region having a layer thickness different from that of the nitride semiconductor layer.

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