JP2013102192A - Semiconductor light-emitting element and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting element which can efficiently extract light generated at a luminescent layer, and provide a manufacturing method of the same.SOLUTION: A semiconductor light-emitting element having a first semiconductor layer 1, a second semiconductor layer 2 and a luminescent layer 3 provided between the first and second semiconductor layers, comprises: a laminated structure 1s on which a part of the first semiconductor 1 is exposed on a first principal surface 1a on the second semiconductor layer 2 side by selective removal of the second semiconductor layer 2 and the luminescent layer 3; first and second electrodes including a first region containing a first metal film 7 provided on the first principal surface 1a on the first semiconductor layer 1 and a second region provided on the first semiconductor region and containing a second metal film 4 having a reflection rate against light emitted from the luminescent layer 3 higher than that of the first metal film 7 and contact resistance against the first semiconductor layer 1 higher than that of the first metal film 7; and a dielectric lamination film 11 provided on regions of the first semiconductor layer 1 and the second semiconductor layer 2, which are not covered with the first and second electrodes, and in which a plurality of dielectric films having refraction indexes different from each other are laminated.

Description

  The present invention relates to a semiconductor light emitting device and a method for manufacturing the same.

  Light generated in a semiconductor light emitting device such as an LED (Light Emitting Diode) may be extracted directly outside the device, or may be a semiconductor such as a reflective film, a semiconductor layer / substrate interface, or a substrate / air interface. Some of them are taken out from the element surface, the substrate surface, or the side surface of the element by being repeatedly reflected inside the light emitting element. Part of the light inside the element is absorbed by the n-side electrode or the like having a low reflection efficiency, and part of the light extracted outside the element is absorbed by the mount material or the like, which causes a reduction in light extraction efficiency.

  In order to increase the light extraction efficiency, it is effective to extract light emitted inside the element in a direction in which there is no absorber such as a mount material, by devising the element shape or reflecting film. On the other hand, due to electrode design restrictions such as wire bonding by ball bonding, formation of bumps for flip chip, reduction of voltage drop due to contact resistance of n-side electrode, n-side electrode which is an absorber inside the device The area needs to be increased to some extent. In the case of an element in which the reflective film is compatible with the p-side electrode, the area of the reflective film cannot be freely increased due to restrictions on electrode design such as the design of the light emitting region and the balance with the n-side electrode.

  On the other hand, a technique for providing a semiconductor element made of a nitride semiconductor with few crystal defects by forming a high-quality nitride semiconductor on a substrate is disclosed (Patent Document 1). If there is a layer with many crystal defects, the light emitted from the light emitting layer is absorbed and a loss occurs. Can be suppressed.

JP 2000-31588 A

  The present invention provides a semiconductor light emitting device capable of efficiently extracting light generated in a light emitting layer to the outside and a method for manufacturing the same.

  According to one embodiment of the present invention, the semiconductor device includes a first semiconductor layer, a second semiconductor layer, and a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, and the second semiconductor layer. A stacked structure in which the semiconductor layer and the light emitting layer are selectively removed and a part of the first semiconductor layer is exposed on the first main surface on the second semiconductor layer side; and the first of the stacked structure A first region including a first metal film provided on the main surface and provided on the part of the first semiconductor layer; and the light emitting provided on the part of the first semiconductor layer. A second region including a second metal film having a higher reflectance to light emitted from the layer than the first metal film and a contact resistance with respect to the first semiconductor layer higher than that of the first metal film; A first electrode connected to the first semiconductor layer; and the second semiconductor layer provided on the first main surface of the stacked structure. A second electrode including a connected reflective metal film; and the first semiconductor layer and the second semiconductor on the first main surface and not covered with either the first electrode or the second electrode And a dielectric laminated film formed by laminating a plurality of dielectric films having different refractive indexes, wherein the first region faces the second electrode of the first electrodes. The semiconductor light emitting element is provided, wherein the light emitted from the light emitting layer is emitted to the outside from the first semiconductor layer side.

  According to another aspect of the present invention, the semiconductor device includes a first semiconductor layer, a second semiconductor layer, and a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, A stacked structure in which the second semiconductor layer and the light emitting layer are selectively removed and a part of the first semiconductor layer is exposed on the first main surface on the second semiconductor layer side; A first region including a first metal film provided on the first main surface and provided on the part of the first semiconductor layer; and provided on the part of the first semiconductor layer. A second region portion including a second metal film having a reflectance higher than that of the first metal film and a contact resistance with respect to the first semiconductor layer higher than that of the first metal film; A first electrode connected to the first semiconductor layer, and provided on the first main surface of the stacked structure, A second electrode connected to two semiconductor layers; and on the first main surface, on the first semiconductor layer and the second semiconductor layer that are not covered by any of the first electrode and the second electrode. A dielectric laminated film formed by laminating a plurality of dielectric films having different refractive indexes, and the first region portion is a portion of the first electrode facing the second electrode. And the second electrode is provided between the third metal film, the third metal film, and the second semiconductor layer, and has a higher reflectance to the light than the third metal film. And the fourth metal film is made of the same material as the second metal film, and the light emitted from the light emitting layer is emitted to the outside from the first semiconductor layer side. A method for manufacturing a light emitting device, comprising: a first semiconductor layer; a light emitting layer; A step of stacking and forming two semiconductor layers, a step of removing a part of the second semiconductor layer and the light emitting layer to expose the first semiconductor layer, and a first of the exposed first semiconductor layer. Forming the first metal film in a region, the exposed second region of the first semiconductor layer adjacent to the first region, and the second semiconductor layer, and simultaneously emitting the light emission. Forming a metal film having a reflectance higher than that of the first metal film and higher in contact resistance to the first semiconductor layer than that of the first metal film; and Forming the dielectric multilayer film by alternately laminating dielectric films having different refractive indexes on the first semiconductor layer and the second semiconductor layer exposed from the metal film higher than the first metal film; And a method of manufacturing a semiconductor light emitting device Is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor light-emitting device which can take out the light produced in the light emitting layer to the exterior efficiently, and its manufacturing method are provided.

1 is a schematic view illustrating the configuration of a semiconductor light emitting element according to a first embodiment of the invention. It is a typical sectional view which illustrates the structure of the semiconductor light emitting element of a comparative example. FIG. 6 is a schematic plan view showing a modification of the semiconductor light emitting element according to the first embodiment of the present invention. FIG. 6 is a schematic plan view showing a modification of the semiconductor light emitting element according to the first embodiment of the present invention. It is a graph which illustrates the characteristic of the semiconductor light-emitting device concerning the 1st embodiment of the present invention. FIG. 5 is a schematic cross-sectional view illustrating the configuration of a semiconductor light emitting element according to a second embodiment of the invention. FIG. 6 is a schematic cross-sectional view in order of the processes, illustrating a manufacturing process for a semiconductor light emitting element according to the second embodiment of the invention. FIG. 8 is a schematic cross-sectional view in order of the steps, following FIG. 7. FIG. 5 is a schematic cross-sectional view illustrating the configuration of a semiconductor light emitting element according to a third embodiment of the invention. FIG. 6 is a schematic cross-sectional view illustrating the configuration of another semiconductor light emitting element according to the third embodiment of the invention. FIG. 6 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to a fourth embodiment of the invention. It is a graph which illustrates the characteristic of the semiconductor light-emitting device concerning the 4th Embodiment of this invention. FIG. 10 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to a fifth embodiment of the invention. FIG. 11 is a schematic cross-sectional view in order of the processes, illustrating a method for manufacturing a semiconductor light emitting element according to the fifth embodiment of the invention. FIG. 15 is a schematic cross-sectional view in order of the steps, following FIG. 14. FIG. 16 is a schematic cross-sectional view in order of the steps, following FIG. 15. FIG. 10 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to a sixth embodiment of the invention. FIG. 11 is a schematic cross-sectional view in order of the processes, illustrating a method for manufacturing a semiconductor light emitting element according to the sixth embodiment of the invention. FIG. 19 is a schematic cross-sectional view in order of the steps, following FIG. 18. FIG. 9 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to a seventh embodiment of the invention. FIG. 11 is a schematic cross-sectional view in order of the processes, illustrating a method for manufacturing a semiconductor light emitting element according to a seventh embodiment of the invention. FIG. 22 is a schematic cross-sectional view in order of the steps, following FIG. 21. FIG. 10 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to an eighth embodiment of the invention. FIG. 16 is a schematic cross-sectional view in order of the process, illustrating a method for manufacturing a semiconductor light emitting element according to an eighth embodiment of the invention. FIG. 25 is a schematic cross-sectional view in order of the steps, following FIG. 24. FIG. 20 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to a ninth embodiment of the invention. FIG. 10 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to a tenth embodiment of the invention. It is a typical sectional view which illustrates the structure of the semiconductor light emitting element concerning the 11th embodiment of the present invention. It is a typical sectional view which illustrates the structure of the semiconductor light emitting element concerning a 12th embodiment of the present invention. It is process order typical sectional drawing which illustrates the manufacturing method of the semiconductor light-emitting device concerning the 12th Embodiment of this invention. FIG. 31 is a schematic cross-sectional view in order of the steps, following FIG. 30. FIG. 34 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to a thirteenth embodiment of the invention. It is process order typical sectional drawing which illustrates the manufacturing method of the semiconductor light-emitting device concerning 13th Embodiment of this invention. FIG. 34 is a schematic cross-sectional view in order of the steps, following FIG. 33. It is a flowchart figure which illustrates the manufacturing method of the semiconductor light-emitting device concerning 14th Embodiment of this invention. It is a flowchart figure which illustrates the manufacturing method of the semiconductor light-emitting device based on 15th Embodiment of this invention. It is a flowchart figure which shows the modification of the manufacturing method of the semiconductor light-emitting device concerning the 15th Embodiment of this invention. FIG. 26 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting device according to a sixteenth embodiment of the invention.

Embodiments of the present invention will be described below with reference to the drawings.
Note that the drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio coefficient of the size between the parts, and the like are not necessarily the same as actual ones. Further, even when the same part is represented, the dimensions and ratio coefficient may be represented differently depending on the drawing.
Further, in the present specification and each drawing, the same reference numerals are given to the same elements as those described above with reference to the previous drawings, and detailed description thereof will be omitted as appropriate.

(First embodiment)
FIG. 1 is a schematic view illustrating the configuration of a semiconductor light emitting element according to the first embodiment of the invention.
That is, FIG. 4B is a plan view, and FIG. 4A is a cross-sectional view taken along the line AA ′ in FIG.
As shown in FIG. 1A, in the semiconductor light emitting device 101 according to the first embodiment of the present invention, an n-type semiconductor layer (first semiconductor layer) 1 is formed on a substrate 10 made of sapphire, for example. A stacked structure 1s is formed in which the layer 3 and the p-type semiconductor layer (second semiconductor layer) 2 are stacked in this order.

  A p-side electrode (second electrode) 4, an n-side electrode (first electrode) 7, and a dielectric laminated film 11 are provided on the main surface 1 a side of the laminated structure 1 s.

  A p-side electrode 4 is provided on the main surface 1 a side of the p-type semiconductor layer 2. As will be described later, the p-side electrode 4 includes a second p-side electrode film 4b serving as a high-efficiency reflective film and a first p-side electrode film 4a made of a metal that does not necessarily require high-efficiency reflective characteristics. Can do.

  A part of the p-type semiconductor layer 2 is removed by etching, and an n-side electrode 7 is provided on the exposed main surface 1 a side of the n-type semiconductor layer 1. The n-side electrode 7 includes a second n-side electrode film (second metal film) 7b that serves as a high-efficiency reflective film, and a first n-side electrode film (first metal film) 7a that serves as an ohmic contact region. ing.

  A dielectric multilayer film 11 is provided on the p-type semiconductor layer 2 and the n-type semiconductor layer 1 exposed from the p-side electrode 4 and the n-side electrode 7. The dielectric laminated film 11 is formed by laminating two or more types of dielectrics having different refractive indexes. However, the dielectric multilayer film 11 may be removed in the peripheral portion of the element, and the dielectric multilayer film 11 may be damaged in the peripheral portion of the element by an element isolation process or the like.

The dielectric multilayer film 11 is a combination of a multilayer film of a first dielectric layer (for example, SiO ₂ ) and a second dielectric layer (for example, TiO ₂ ) as two or more types of dielectrics having different refractive indexes. Can be used, that is, a laminated film composed of a total of 10 dielectric layers. At this time, the thickness of each of the first dielectric layer and the second dielectric layer is λ / (4n) where n is the refractive index and λ is the emission wavelength from the light emitting layer 3. Set to
That is, the dielectric multilayer film 11 includes a first dielectric layer having a first refractive index n _1, and a second dielectric layer having a different second refractive index n ₂ from the first refractive index n ₁ When the emission wavelength of the light emitting layer 3 is λ, the thickness of each of the first dielectric layers is substantially λ / (4n ₁ ), and the second dielectric The thickness of each of the layers is substantially λ / (4n ₂ ).

  Thereby, the emitted light from the light emitting layer 3 can be reflected efficiently and reflected to the semiconductor layer side.

  That is, in the semiconductor light emitting device 101 according to this embodiment, the first semiconductor layer (n-type semiconductor layer 1), the second semiconductor layer (p-type semiconductor layer 2), the first semiconductor layer, and the second semiconductor. A laminated structure 1s having a light emitting layer 3 provided between the first and second layers, a first main surface 1a of the laminated structure 1s, and a first semiconductor layer provided on the first semiconductor layer. A first region 8a including a metal film (first p-side electrode film 7a) and a reflectivity with respect to light emitted from the light emitting layer 3 provided on the first semiconductor layer is higher than that of the first metal film. A second region 8b including a second metal film (second n-side electrode film 7b) having a contact resistance with respect to the first semiconductor layer higher than that of the first metal film, and connected to the first semiconductor layer. The first electrode (n-side electrode 7) and the first main surface 1a of the multilayer structure 1s A second electrode (p-side electrode 4) connected to the second semiconductor layer, and the first semiconductor layer exposed from the first electrode and the second electrode on the first main surface 1a, and And a dielectric laminated film 11 provided on the second semiconductor layer and formed by laminating a plurality of types of dielectric films having different refractive indexes.

  In the semiconductor light emitting device 101 according to this embodiment, by providing the n-side electrode 7 with the second n-side electrode film 7b serving as a high-efficiency reflective film, the light emitted from the light-emitting layer 3 is reflected with high efficiency, and the device Can be taken out outside. That is, the light extraction efficiency of the semiconductor light emitting device can be improved.

The second n-side electrode film 7b may be a single layer of silver or aluminum, or an alloy layer containing silver or aluminum and a metal other than these. The reflection efficiency of a normal metal single layer film in the visible light band tends to decrease as the wavelength becomes shorter, but silver and aluminum have high reflection efficiency characteristics for light in the ultraviolet band of 370 nm to 400 nm.
Therefore, when the second n-side electrode film 7b is a silver or aluminum alloy and the semiconductor light-emitting element emits ultraviolet light, it is desirable that the second n-side electrode film 7b on the semiconductor interface side has a higher component ratio of silver or aluminum.
The film thickness of the second n-side electrode film 7b is preferably 100 nm or more in order to ensure the light reflection efficiency.

  On the other hand, the first n-side electrode film 7a serving as an ohmic contact region has a role of reducing contact resistance with the n-type semiconductor layer 1, lowering element resistance, and energizing current.

  The material of the first n-side electrode film 7a formed in the region having ohmic characteristics is not particularly limited, and is composed of a conductive single layer film or multilayer film used as the ohmic electrode of the n-type semiconductor layer 1. The The film thickness of the first n-side electrode film 7a is not particularly limited, and can be selected between 5 nm and 1000 nm.

  By designing the layer structure of the dielectric laminated film 11 to have high-efficiency reflection characteristics with respect to emitted light, special measures are taken in the process while maintaining the insulation between the p-side electrode 4 and the n-side electrode 7. The reflection area on the electrode forming surface can be greatly increased without any problem. That is, the light extraction efficiency of the semiconductor light emitting device can be improved.

  According to the semiconductor light emitting device 101 having such a configuration, an ohmic contact is ensured with the n-type semiconductor layer 1, and an n-side electrode 7 having an area necessary for forming wire bonding or bumps is obtained. A semiconductor light emitting device is obtained in which most of the region other than the first n-side electrode film 7a on the electrode formation surface is a reflective region.

In the specific example shown in FIG. 1B, the n-side electrode 7 occupies one corner of the rectangular semiconductor light emitting element, but the shape of the n-side electrode 7 is not limited to this.
In FIG. 1B, the dielectric laminated film 11 is omitted.

Next, a specific example of a stacked structure of semiconductor layers formed on the substrate 10 will be described.
The semiconductor light emitting device 101 according to the present embodiment is made of, for example, a nitride semiconductor formed on the substrate 10 made of sapphire.

That is, for example, using a metal organic chemical vapor deposition method, a first AlN buffer layer having a high carbon concentration (carbon concentration: 3 × 10 ¹⁸ cm ^{−3 to} 5 × 10 ²⁰⁾ is formed on the substrate 10 whose surface is a sapphire c plane. cm ⁻³ ) of ³ nm to 20 nm, high-purity second AlN buffer layer (carbon concentration 1 × 10 ¹⁶ cm ^{−3 to} 3 × 10 ¹⁸ cm ⁻³ ) of 2 μm, non-doped GaN buffer layer of 3 μm, Si-doped n-type GaN contact 4 μm of the layer (Si concentration 1 × 10 ¹⁸ cm ^{−3 to} 5 × 10 ¹⁸ cm ⁻³ ) and the Si-doped n-type Al _0.10 Ga _0.90 N cladding layer (Si concentration 1 × 10 ¹⁸ cm ⁻³ ) 0.02 [mu] m, Si-doped n-type _Al 0.11 _{Ga 0.89} n barrier layer (Si concentration 1.1~1.5 × ¹⁰ 19 ^{cm -3)} and GaInN light-emitting layer (wavelength 380 nm) and is alternately 0.075μm emitting layer having the multiple quantum well structure formed by periodically laminating a final _Al 0.11 _{Ga 0.89} N barrier layer having a multiple quantum well (Si concentration 1.1~1.5 × ¹⁰ 19 ^{cm -3)} 0.01 μm, Si-doped n-type Al _0.11 Ga _0.89 N layer (Si concentration 0.8 to 1.0 × 10 ¹⁹ cm ⁻³ ) 0.01 μm, non-doped Al _0.11 Ga _0.89 The N spacer layer is 0.02 μm, the Mg doped p-type Al _0.28 Ga _0.72 N clad layer (Mg concentration 1 × 10 ¹⁹ cm ⁻³ ) is 0.02 μm, and the Mg doped p-type GaN contact layer (Mg concentration 1). It is possible to employ a structure in which × 10 ¹⁹ cm ⁻³ ) is 0.1 μm and a high-concentration Mg-doped p-type GaN contact layer (Mg concentration 2 × 10 ²⁰ cm ⁻³ ) is sequentially stacked with a thickness of 0.02 μm. it can.

Here, the n-type semiconductor layer 1 illustrated in FIG. 1A includes a high-carbon concentration first AlN buffer layer, a high-purity second AlN buffer layer, a non-doped GaN buffer layer, a Si-doped n-type GaN contact layer, and A Si-doped n-type Al _0.10 Ga _0.90 N cladding layer may be included.

In addition, the light-emitting layer 3 illustrated in FIG. 1A is formed by alternately stacking three periods of the Si-doped n-type Al _0.11 Ga _0.89 N barrier layer) and the GaInN light-emitting layer (wavelength 380 nm). And a final Al _0.11 Ga _0.89 N barrier layer of the multiple quantum well.

The p-type semiconductor layer 2 illustrated in FIG. 1A includes the Mg-doped p-type Al _0.28 Ga _0.7a N cladding layer, the Mg-doped p-type GaN contact layer, and the high-concentration Mg-doped p. A type GaN contact layer may be included.

By setting the Mg concentration of the Mg-doped p-type GaN contact layer as high as 1 × 10 ²⁰ cm ⁻³ , ohmic contact characteristics with the p-side electrode can be improved. However, in the case of a semiconductor light emitting diode, unlike the semiconductor laser diode, since the distance between the contact layer and the light emitting layer 4 is short, there is a concern about deterioration of characteristics due to Mg diffusion. Therefore, by utilizing the fact that the contact area between the p-side electrode 4 and the contact layer is wide and the current density during operation is low, the Mg concentration is suppressed to 1 × 10 ¹⁹ cm ⁻³ without significantly impairing electrical characteristics. As a result, Mg diffusion can be prevented and the light emission characteristics can be improved.

The first AlN buffer layer having a high carbon concentration serves to alleviate the difference in crystal type from the substrate, and particularly reduces screw dislocations.
Further, the surface of the high purity second AlN buffer layer is flattened at the atomic level. Therefore, defects in the non-doped GaN buffer layer grown thereon are reduced. For this purpose, the thickness of the high purity second AlN buffer layer is preferably thicker than 1 μm. In order to prevent warping due to distortion, the thickness of the high purity second AlN buffer layer is desirably 4 μm or less. The high-purity second AlN buffer layer is not limited to AlN, and may be Al _x Ga _1-x N (0.8 ≦ x ≦ 1), and can compensate for warpage of the wafer.

  The non-doped GaN buffer layer plays a role of reducing defects by performing three-dimensional island growth on the high purity second AlN buffer layer. In order to flatten the growth surface, the average film thickness of the non-doped GaN buffer layer needs to be 2 μm or more. From the viewpoint of reproducibility and warpage reduction, the total film thickness of the non-doped GaN buffer layer is suitably 4 to 10 μm.

  By employing these buffer layers, defects can be reduced to about 1/10 compared to conventional low-temperature grown AlN buffer layers. With this technique, it is possible to produce a highly efficient semiconductor light-emitting device that emits high-concentration Si into the n-type GaN contact layer and emits light in the ultraviolet band. In addition, light absorption in the buffer layer can be suppressed by reducing crystal defects in the buffer layer.

  Then, according to the semiconductor light emitting device 101 of the present embodiment, the second n-side electrode film 7b having high reflectivity is provided on the n-side electrode 7, and further, the dielectric laminated film 11 is provided to emit from the light-emitting layer 3. The reflected light can be reflected with high efficiency and extracted outside the device.

(Comparative example)
FIG. 2 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element of a comparative example.
As shown in FIG. 2, in the semiconductor light emitting device 90 of the comparative example, the n-side electrode 7 is composed of a single metal layer. And the dielectric laminated film 11 is not formed. That is, instead of the dielectric laminated film 11, for example, a SiO ₂ film having a thickness of 400 nm is formed as a single-layer dielectric film (not shown).

Hereinafter, a method for manufacturing the semiconductor light emitting device 90 of the comparative example will be described.
First, in order to form the p-side electrode 4, a patterned lift-off resist is formed on the semiconductor layer, and Ag that becomes a part of the p-side electrode 4 is formed on the p-type contact layer by using a vacuum deposition apparatus to 200 nm. After the lift-off, a sintering process is performed in a nitrogen atmosphere at 350 ° C.

  Similarly, a patterned lift-off resist is formed on the semiconductor layer, and Ti / Pt / Au serving as the n-side electrode 7 is formed with a thickness of 500 nm on the n-type contact layer. Similarly, a patterned lift-off resist is formed on the semiconductor layer, and Pt / Au that becomes another part of the p-side electrode 4 so as to cover a region where Ag that becomes a part of the p-side electrode 4 is formed. Is formed with a film thickness of 500 nm.

Thus, the electrode of the semiconductor light emitting device 90 of the comparative example is configured.
In the semiconductor light emitting device 90 of the comparative example, the entire surface of the n-side electrode 7 is formed of a metal that obtains an ohmic contact. When such a metal is used, the reflectance of the n-side electrode 7 is not necessarily high enough. Further, in the ohmic contact region, a reaction (alloying) is likely to occur between the n-side electrode 7 and the n-type semiconductor layer 1, and this also causes a decrease in light reflectance. Further, when the main surface side on which the electrode is formed is mounted on a submount or the like, the emitted light incident on the region in the main surface where the p-side electrode 4 is not formed is absorbed by the mount material. For this reason, there is room for improvement in terms of the extraction efficiency of light emitted from the light emitting layer 3.

  On the other hand, as already described, according to the semiconductor light emitting device 101 according to the present embodiment, a part of the n-side electrode 7 is formed by the second n-side electrode film 7b having a high reflectivity, and the high reflection characteristics are obtained. By adopting the dielectric laminated film 11 having, the light extraction efficiency can be improved by making almost the entire main surface 1a of the semiconductor layer on which the electrode is formed a reflective structure.

In the semiconductor light emitting device 101 according to the present embodiment, the current flowing between the p-side electrode 4 and the n-side electrode 7 tends to flow in the closest part of both.
Therefore, as in the specific example shown in FIGS. 1A and 1B, the first n-side electrode film 7a is brought closer to the p-side electrode 4 than the second n-side electrode film 7b, thereby forming an ohmic contact region. Even if the area of the 1n-side electrode film 7a is small, it is possible to flow a current between the p-side electrode 4 more reliably.

  As described above, the first n-side electrode film 7 a can be provided in a portion of the n-side electrode 7 facing the p-side electrode 2.

  That is, the contact resistance is not necessarily low by forming a part of the n-side electrode 7 facing the p-side electrode 4 which is a region where current is relatively concentrated when energized with the first n-side electrode film 7a having low contact resistance. The influence on the electrical characteristics due to the formation of the high-efficiency reflective film (second n-side electrode film 7b) on the n-side electrode 7 can be minimized.

  When considering a current path from the second electrode 4 to the first n-side electrode film 7a of the n-side electrode, current tends to concentrate in a region where the distance between the second electrode 4 and the first n-side electrode film 7a is the shortest. In order to alleviate the electric field concentration, it is preferable to design the region having the shortest distance as long as possible among the regions where the second electrode 4 and the first n-side electrode film 7a face each other.

  Further, when viewed in plan, the longer the length of the region where the second electrode 4 and the first n-side electrode film 7a are opposed, the more current paths to the second electrode 4 and the first n-side electrode film 7a increase. Electric field concentration is alleviated and deterioration of the second electrode 4 is suppressed. In consideration of these effects, the area and shape of the second n-side electrode film 7b and the first n-side electrode film 7a and the area and shape of the entire n-side electrode 7 can be appropriately determined.

  According to the semiconductor light emitting device 101 of the present embodiment, a part of the n-side electrode 7 is constituted by a highly efficient reflective film, and a laminated structure in which electrodes are formed by employing the dielectric laminated film 11 having high reflective characteristics. The entire surface of the main surface 1a of the body 1s can have a reflective structure, and most of the emitted light that is repeatedly reflected in the semiconductor layer can be reflected to the substrate side, so that it is absorbed by the mounting material. The light extraction efficiency is expected to improve. By forming a part of the n-side electrode 7 facing the p-side electrode 4, which is a region where current is relatively concentrated when energized, with an electrode structure having a low contact resistance, a high-efficiency reflective film is formed on the n-side electrode 7. This can minimize the influence on the electrical characteristics.

  In the semiconductor light emitting device 101 according to the present embodiment, if a crystal on a single crystal AlN buffer is used, the n-type GaN contact layer can be doped with high concentration Si, and the first n serving as an ohmic contact region of the n-side electrode 7. The contact resistance with the side electrode film 7a can be greatly reduced, the current spread in the first n-side electrode film 7a is suppressed, and the current is more concentrated in a region close to the p-side electrode, so that the ohmic contact of the n-side electrode 7 A design with a reduced area and an increased high-efficiency reflective film area is possible, and high luminous efficiency can be realized even in a wavelength region shorter than 400 nm, where the efficiency usually decreases due to crystal defect reduction.

  In addition, when an amorphous or polycrystalline AlN layer is provided to alleviate the difference in crystal type on the sapphire substrate, the buffer layer itself becomes a light absorber, so that light as a light emitting element can be obtained. In contrast, the p-type first semiconductor layer 1 is formed on the sapphire substrate 10 via the high carbon concentration single crystal AlN buffer layer and the high purity single crystal AlN buffer layer. By forming the light emitting layer 3 and the n-type second semiconductor layer, the buffer layer is unlikely to be an absorber of light and crystal defects can be greatly reduced, so that the absorber in the crystal is greatly reduced. Can do. In this case, the emitted light can be repeatedly reflected within the crystal, increasing the light extraction efficiency in the lateral direction and efficiently reflecting the light to the highly efficient reflection region of the n-side electrode 7. Is possible. Due to these effects, it is possible to realize improvement in emission intensity, high throughput, and low cost.

FIG. 3 is a schematic plan view showing a modification of the semiconductor light emitting device according to the first embodiment of the present invention.
As shown in FIG. 3, in the semiconductor light emitting device 101 a of the modified example according to the first embodiment of the present invention, the n-side electrode 7 is surrounded by the p-side electrode 4 and has a portion extending in four directions. Have.

  Of such an n-side electrode 7, a portion extending in four directions and a portion facing the p-side electrode 4 are formed by a first n-side electrode film 7 a serving as an ohmic contact region. Further, the central portion of the n-side electrode 7 is formed by the second n-side electrode film 7b having a high reflectance.

  According to the semiconductor light emitting device 101a having such a configuration, an ohmic contact is ensured in a portion facing the p-side electrode 4 and current is efficiently and uniformly passed over the entire device, and the center of the n-side electrode 7 is secured. In this part, an area for wire bonding and bumps can be secured, and light can be reflected with high reflectivity in this part.

FIG. 4 is a schematic plan view showing a modification of the semiconductor light emitting device according to the first embodiment of the present invention.
As shown in FIG. 4, in the semiconductor light emitting device 101 b of another modification according to the first embodiment of the present invention, the region for wire bonding or bump in the n-side electrode 7 is a corner portion of the device. Is provided. The n-side electrode 7 has a portion extending in four directions so as to interrupt the p-side electrode 4.

  Of the n-side electrode 7 having such a configuration, a portion extending in the p-side electrode 4 is formed by the first n-side electrode film 7a, and a corner portion for wire bonding or bump is formed by the second n-th electrode. The side electrode film 7b is formed.

  According to the semiconductor light emitting device 101b having such a configuration, current can be efficiently and uniformly flowed over the entire device, and light emitted from the light emitting layer can be highly reflected in the second n-side electrode film 7b. It can be reflected and taken out.

  As illustrated in FIG. 1, FIG. 3 and FIG. 4, the current injected from the outside of the semiconductor light emitting element to the p-side electrode 4 and flowing through the semiconductor layer to the n-side electrode 7 is transferred to the outside of the semiconductor light emitting element. The n-side electrode region to be taken out must be designed widely because wire bonding and bumps are formed for contact between the semiconductor light emitting element and the external terminal. However, the entire region does not need to have ohmic characteristics, and most of the region may be the n-side electrode 7 having high-efficiency reflection characteristics.

At this time, if it is possible to secure an n-side electrode region having ohmic characteristics other than this region, such as the semiconductor light emitting device 101b, the entire region to be taken out of the semiconductor light emitting device is changed to a highly efficient reflective film. You can also.
In addition, the size of the pad required for bonding in the n-side electrode 7 is, for example, about 50 μm to 150 μm.

  On the other hand, the dielectric laminated film 11 has a higher reflectivity as the refractive index ratio of the combined dielectrics is larger, and as the number of combinations (number of pairs) of layers having different refractive indexes is larger. The margin is also widened.

FIG. 5 is a graph illustrating characteristics of the semiconductor light emitting device according to the first embodiment of the invention.
That is, this figure exemplifies the simulation result regarding the reflectance of the emitted light perpendicularly incident on the dielectric multilayer film 11 from GaN, and FIG. 10 (a) exemplifies the dependence of the reflectance on the refractive index ratio. FIG. 4B illustrates the dependence of the reflectance on the number of pairs. The horizontal axis in FIG. 6A represents the refractive index ratio of two types of combinations of dielectrics in the dielectric multilayer film 11, and the horizontal axis in FIG. Represents the number of dielectric pairs, and the vertical axis in FIGS. 4A and 4B represents the reflectance.
In this simulation, each parameter is changed using the physical property values of the material of the dielectric multilayer film 11 of the semiconductor light emitting device 101 described above.

As shown in FIGS. 5 (a) and 5 (b), a reflectance close to 100% can be obtained by appropriately selecting the conditions for both the refractive index ratio and the number of pairs.
For example, as shown in FIG. 5A, in order for the reflectance to be 95% or more, the refractive index ratio is desirably 1.4 or more.
Further, as shown in FIG. 5B, in order to achieve a reflectance of 95% or more, the number of pairs is desirably 3 or more.

  Note that, as the incident angle from GaN to the dielectric laminated film 11 is tilted from the vertical, the reflectivity increases and total reflection occurs at a certain threshold angle.

  From these properties, if the design conditions are selected, it is expected that the light extraction efficiency will be improved by adopting the dielectric laminated film 11 that functions as a reflective film having higher performance than the metallic reflective film. In the semiconductor light emitting device 101 according to this embodiment, the design reflectance of the dielectric multilayer film 11 is 99.7%.

  The dielectric laminated film 11 includes silicon (Si), aluminum (Al), zirconium (Zr), titanium (Ti), niobium (Nb), tantalum (Ta), magnesium (Mg), hafnium (Hf), cerium ( An oxide such as Ce) and zinc (Zn), a nitride, an oxynitride, or the like can be used. The total thickness of the dielectric films to be laminated is preferably 50 nm or more for ensuring insulation and 1000 nm or less for suppressing cracks in the dielectric film. In particular, the first layer on the semiconductor layer side of the dielectric multilayer film 11 is preferably made of a material having a linear expansion coefficient close to that of the semiconductor layer in order to suppress stress between different materials due to heat generation during element operation. For example, when the semiconductor layer is GaN, it is preferable to use, for example, SiN for the first layer on the semiconductor layer side of the dielectric multilayer film 11.

  Since the dielectric laminated film 11 can relieve the stress applied to the inside by laminating different types of dielectrics, even if the total film thickness increases, cracks, cracks, etc. Is less likely to occur, and stress on the semiconductor layer can be relaxed, so that reliability is improved. In particular, the stress relaxation effect is promoted by laminating dielectrics having tensile stress and compressive stress.

  As described above, in the semiconductor light emitting device 101 according to the present embodiment, a part of the n-side electrode 7 is formed by the second n-side electrode film 7b having a high reflectance, and further, a dielectric laminated film having a high reflection characteristic By adopting 11, it is possible to make almost the entire main surface 1a of the semiconductor layer on which the electrode is formed a reflective structure. As a result, when flip chip mounting is performed, most of the emitted light that is repeatedly reflected in the semiconductor layer can be reflected to the substrate side, so that it is not absorbed by the mounting material, and the light extraction efficiency Improvement is expected.

The semiconductor light emitting device 101 according to this embodiment includes at least an n-type semiconductor layer, a p-type semiconductor layer, and a semiconductor layer including a light emitting layer sandwiched between them, and the material of the semiconductor layer is particularly limited. For example, a gallium nitride-based compound semiconductor such as Al _x Ga _1-xy In _y N (x ≧ 0, y ≧ 0, x + y ≦ 1) is used. The method for forming these semiconductor layers is not particularly limited. For example, techniques such as metal organic chemical vapor deposition and molecular beam epitaxial growth can be used.

  In the semiconductor light emitting device according to this embodiment, the substrate material is not particularly limited, but a general substrate such as sapphire, SiC, GaN, GaAs, or Si can be used. The substrate may be finally removed.

(Second Embodiment)
FIG. 6 is a schematic cross-sectional view illustrating the configuration of a semiconductor light emitting element according to the second embodiment of the invention.
As shown in FIG. 6, in the semiconductor light emitting device 102 according to the second embodiment of the present invention, an n-side pad (first pad) 75 is provided on the n-side electrode 7, and the p-side electrode 4. Is provided on the p-side semiconductor 2 and provided on the second p-side electrode film (fourth metal film) 4b and the second p-side electrode film 4b, which is a high-efficiency reflective film, and does not necessarily have high-efficiency reflective characteristics. And a first p-side electrode film (third metal film) 4a made of unnecessary metal. Since other configurations can be the same as those of the semiconductor light emitting device 101 illustrated in FIG.

  That is, the p-side electrode 4 is provided between the first p-side electrode film 4a, the first p-side electrode film 4a, and the second semiconductor layer 2, and has a reflectance with respect to light emitted from the light emitting layer 3. A second p-side electrode film 4b that is higher than the first p-side electrode film 4a.

  As described above, in the semiconductor light emitting device 102 according to this embodiment, the n-side pad 75 is provided on the n-side electrode 7, so that an electrode area necessary for bonding and bump formation can be obtained. The characteristic characteristics are stabilized, and further, the natural oxidation of the second n-side electrode film 7b is prevented, and the device life is improved.

  Further, since the second p-side electrode film 4b, which is a highly efficient reflective film, is provided on the p-side electrode 4 on the p-type semiconductor layer 2 side, the reflectance is further improved. On the second p-side electrode film 4b, high-efficiency reflection characteristics are not required, and the second p-side electrode film 4b can be prevented from being oxidized or sulfided by blocking the second p-side electrode film 4b from the outside air. By providing the first p-side electrode film 4a, high reliability can be obtained.

  The second p-side electrode film 4b can include at least one of silver, aluminum, and an alloy containing any of them. That is, the second p-side electrode film 4b may be a single layer of silver or aluminum, or may be an alloy layer containing silver or aluminum and other metals.

  The second p-side electrode film 4b can be made of the same material as the second n-side electrode film 7b.

  The first p-side electrode film 4a is made of a metal not containing silver and aluminum, and is in electrical contact with the second p-side electrode film 4b. The material of the first p-side electrode film 4a is not particularly limited, and may be a metal single layer film or multilayer film, a metal alloy layer, a conductive oxide film single layer film or multilayer film, or a combination thereof. May be. The film thickness of the 1st p side electrode film 4a is not specifically limited, For example, it can select between 100 nm and 1000 nm.

  The reflection efficiency of a normal metal single layer film with respect to the visible light band tends to decrease as the wavelength becomes shorter in the ultraviolet region of 400 nm or less. However, silver and aluminum can also be used for light in the ultraviolet region of 370 nm to 400 nm. High reflection efficiency characteristics. Therefore, when the second p-side electrode film 4b is made of silver or an aluminum alloy in the ultraviolet light-emitting semiconductor light emitting element, it is desirable that the second p-side electrode film 4b on the semiconductor interface side has a larger component ratio of at least one of silver and aluminum. . The film thickness of the second p-side electrode film 4b is preferably 100 nm or more in order to ensure light reflection efficiency.

  When at least one of silver, aluminum, and an alloy containing any of them is used for the second p-side electrode film 4b, as the distance between the second p-side electrode film 4b and the n-side electrode 7 increases, silver or aluminum, Or the risk of insulation failure and breakdown voltage failure due to migration from any of these alloys is reduced. The p-side electrode 4 facing the n-side electrode 7 in the vicinity of the center of the element has a higher light extraction efficiency if it is formed to the end of the p-type contact layer as long as process conditions such as exposure accuracy allow. When considering a current path from the second p-side electrode film 4b to the first n-side electrode film 7a of the n-side electrode 7, the current is concentrated in a region where the distance between the second p-side electrode film 4b and the first n-side electrode film 7a is the shortest. Therefore, in order to alleviate the electric field concentration, it is preferable to design the region having the shortest distance as long as possible among the regions where the second p-side electrode film 4b and the first n-side electrode film 7a face each other.

  In addition, in plan view, the longer the length of the region where the second p-side electrode film 4b and the first n-side electrode film 7a are opposed, the longer the current flows to the second p-side electrode film 4b and the first n-side electrode film 7a. Since the number of paths increases, the electric field concentration is alleviated and the deterioration of the second p-side electrode film 4b is suppressed. In consideration of these effects, the area and shape of the second p-side electrode film 4b and the distance between the second p-side electrode film 4b and the first n-side electrode film 7a can be determined appropriately.

  On the other hand, the pad of the n-side electrode 7 preferably covers the entire second n-side electrode film 7b in order to block the second n-side electrode film 7b from the outside air. In addition, at least a portion is in electrical contact with the first n-side electrode film 7a. The film thickness of the pad is not particularly limited, and can be selected, for example, from 100 nm to 5000 nm. By forming the n-side pad 75, an electrode area necessary for bonding and bump formation can be obtained, and natural oxidation of the second n-side electrode film 7b can be prevented and the element life can be improved.

Next, an example of a method for forming the n-side electrode 7, the p-side electrode 4 and the dielectric stacked film 11 on the semiconductor layer in the semiconductor light emitting device 102 according to this embodiment will be described.
FIG. 7 is a schematic cross-sectional view in order of the processes, illustrating the manufacturing process of the semiconductor light emitting element according to the second embodiment of the invention.
FIG. 8 is a schematic cross-sectional view in order of the processes following FIG.

  First, as shown in FIG. 7A, in a partial region of the p-type semiconductor layer 2, the p-type semiconductor layer 2 is subjected to dry etching using a mask until the n-type contact layer is exposed on the surface. And the light emitting layer 3 is removed.

  Next, as shown in FIG. 7B, an n-side electrode region having ohmic characteristics, that is, a first n-side electrode film 7a is formed. That is, a patterned lift-off resist (not shown) is formed on the exposed n-type contact layer and becomes an ohmic contact region using, for example, a vacuum deposition apparatus, for example, the first n side made of Ti / Al / Ni / Au, for example. The electrode film 7a is formed to a thickness of 500 nm, and a sintering process is performed in a nitrogen atmosphere at 550 ° C.

  Next, as shown in FIG. 7C, in order to form the p-side electrode 4, a patterned lift-off resist is formed on the p-type contact layer, and the second p-side electrode is formed using, for example, a vacuum evaporation apparatus. As the film to be the film 4b, for example, Ag is formed to a thickness of 200 nm, and after lift-off, sintering is performed in a nitrogen atmosphere at 350 ° C.

  Subsequently, as shown in FIG. 8A, an n-side electrode region having high efficiency reflection characteristics is formed. That is, a lift-off resist in which a region on the n contact layer on the side opposite to the p-side electrode 4 of the first n-side electrode film 7a which is an n-side electrode region having ohmic characteristics is formed (not shown).

Here, in consideration of pattern alignment accuracy, a part of the first n-side electrode film 7a, which is an n-side electrode having ohmic characteristics on the side facing the p-side electrode 4, may be opened.
On the contrary, both electrodes are patterned so that the n-side electrode having high efficiency reflection characteristics, that is, the second n-side electrode film 7b does not run on the n-side electrode having ohmic characteristics, that is, the first n-side electrode film 7a. You may design so that it may leave | separate slightly in consideration of the alignment precision.
Further, the n-side electrode having ohmic characteristics, that is, the n-side electrode having high-efficiency reflection characteristics, that is, the second n-side electrode film 7b so as to cover a part or the whole of the first n-side electrode film 7a. It may be designed so that is formed.

  Then, using a vacuum deposition apparatus, for example, a laminated film of Al (thickness of about 0.2 to 0.5 μm) / Ni (thickness of about 10 to 50 nm) / Au (thickness of about 0.05 to 1 μm) is formed, Thereafter, lift-off is performed to form a second n-side electrode film 7b that becomes a highly efficient reflective film. In this laminated film, Al functions as a highly efficient reflective film. In addition, Au plays a role of protecting the high-efficiency reflective film from being deteriorated by natural oxidation or chemical treatment during the element manufacturing process. In order to improve the adhesion between Al and Au and prevent alloying, Ni is sandwiched between them.

  Next, as shown in FIG. 8B, a patterned lift-off resist (not shown) is formed on the semiconductor layer, and the first p-side electrode film 4a is formed in the region where Ag is formed, for example, Pt / A laminated film of Au is formed with a thickness of 500 nm, and the p-side electrode 4 is formed.

  Further, as shown in FIG. 8C, a patterned lift-off resist (not shown) is formed on the semiconductor layer, and the second n-side electrode film 7b of the n-side electrode 7 having high-efficiency reflection characteristics and ohmic characteristics For example, a laminated film of Ti / Pt / Au is formed with a thickness of 500 nm so as to cover the first n-side electrode film 7 a of the n-side electrode 7 having n-side electrode 75, and the n-side pad 75 is formed.

Then, for example, using a vacuum deposition apparatus, for example, five combinations of laminated films of SiO ₂ and TiO ₂ , that is, a total of 10 dielectric laminated films are formed on the semiconductor. The thickness of each of the SiO ₂ film and the TiO ₂ film is set to a thickness of λ / (4n), where n is the refractive index and λ is the emission wavelength from the light emitting layer 3.
Further, a patterned resist (not shown) is formed thereon, and the dielectric laminated film is removed by an ammonium fluoride treatment so that the p-side electrode 4 and the n-side electrode 7 are exposed. A dielectric laminated film 11 is formed.

  Next, the semiconductor light emitting device 102 according to this embodiment according to this embodiment is manufactured by cleaving or cutting with a diamond blade or the like to form individual LED elements.

  In the semiconductor light emitting devices 101 and 102 according to the first and second embodiments, since the ohmic contact region increases as the region of the first n-side electrode film 7a having the ohmic characteristics constituting the n-side electrode 7 is larger, the operation is performed. The voltage tends to decrease. However, since the current path during operation tends to concentrate on the n-side electrode in the region facing the p-side electrode 4, that is, the first n-side electrode film 7a, the current path decreases when the region of the first n-side electrode film 7a becomes large to some extent. The rate is saturated.

  On the other hand, the narrower the region of the first n-side electrode film 7a having ohmic characteristics that constitutes the n-side electrode 7, the wider the n-side electrode having high efficiency reflection characteristics, that is, the region of the second n-side electrode film 7b can be designed. Improvement in light extraction efficiency is expected.

  In addition, the narrower the region of the first n-side electrode film 7a having ohmic characteristics, the lower the probability that the light reflected in the semiconductor light emitting element is absorbed, so that the light extraction efficiency can be improved.

  Taking these into consideration, the area ratio and shape of the first n-side electrode film 7a of the n-side electrode having ohmic characteristics and the second n-side electrode film 7b of the n-side electrode having high-efficiency reflection characteristics can be appropriately determined. it can.

  That is, in the semiconductor light emitting device 102 according to the present embodiment, a part of the n-side electrode 7 facing the second p-side electrode film 4b of the p-side electrode 4, which is a region where current is relatively concentrated when energized, is contact resistance. By forming with a low second p-side electrode film, it is possible to minimize the influence on the electrical characteristics due to the formation of a high-efficiency reflective film on the n-side electrode 7 that does not necessarily have a low contact resistance.

  When considering a current path from the second p-side electrode film 4b to the first n-side electrode film 7a of the n-side electrode, the current concentrates in a region where the distance between the second p-side electrode film 4b and the first n-side electrode film 7a is the shortest. In order to alleviate the electric field concentration, it is preferable to design the region having the shortest distance as long as possible among the regions where the second p-side electrode film 4b and the first n-side electrode film 7a face each other.

  Further, when viewed in plan, the longer the length of the region where the second p-side electrode film 4b and the first n-side electrode film 7a are opposed, the longer the current path to the second p-side electrode film 4b and the first n-side electrode film 7a. Therefore, the electric field concentration is alleviated and the deterioration of the second p-side electrode film 4b is suppressed. In consideration of these effects, the area and shape of the second n-side electrode film 7b and the first n-side electrode film 7a and the area and shape of the entire n-side electrode 7 can be freely determined.

(Third embodiment)
FIG. 9 is a schematic cross-sectional view illustrating the configuration of a semiconductor light emitting element according to the third embodiment of the invention.
As shown in FIG. 9, in the semiconductor light emitting device 103a according to the third embodiment of the present invention, an n-side transparent electrode (transparent) is interposed between the n-type semiconductor layer 1 and the second n-side electrode film 7b. Electrode) 7t is provided. Except for this, the semiconductor light emitting device according to the first and second embodiments can be the same as the semiconductor light emitting device, and a description thereof will be omitted. In the figure, the substrate 10, the laminated structure 1s, and the p-side electrode 4 illustrated in FIG. 1 are omitted.

  The n-side transparent electrode 7t includes at least one of nickel, indium tin oxide, and zinc oxide, and is in electrical contact with the n-type contact layer and the second n-side electrode film 7b. The transparent electrode refers to a substance having a band gap larger than the emission wavelength to be transmitted or a metal film having a film thickness sufficiently thinner than the reciprocal of the absorption coefficient at the emission wavelength to be transmitted.

  The n-side transparent electrode 7t transmits light from the light-emitting layer 3 reflected in the semiconductor light-emitting element and reflects it by the second n-side electrode film 7b, and is in contact with the n-type semiconductor layer 1 with good electrical characteristics. And the role of preventing the silver or aluminum used in the first n-side electrode film 7a from reacting with the n-type semiconductor layer 1 or diffusing into the n-type semiconductor layer 1, so that the second n-side electrode It is preferable that the shape is substantially the same as that of the film 7b. The film thickness of the n-side transparent electrode 7t is not particularly limited, and can be selected from 1 nm to 500 nm, for example.

  The semiconductor light emitting element 103a according to the present embodiment having such a configuration can provide both high reflection characteristics and high electrical characteristics by providing a transparent electrode in the n-side electrode 7.

FIG. 10 is a schematic cross-sectional view illustrating the configuration of another semiconductor light emitting element according to the third embodiment of the invention.
As shown in FIG. 10, in another semiconductor light emitting device 103 b according to the third embodiment of the present invention, a p-side transparent electrode (transparent electrode) is interposed between the p-type semiconductor layer 2 and the p-side electrode 4. 4t is provided. Except for this, the semiconductor light emitting device according to the first and second embodiments can be the same as the semiconductor light emitting device, and a description thereof will be omitted. In the figure, the substrate 10 and the n-side electrode 7 illustrated in FIG. 1 are omitted.

In the specific example illustrated in FIG. 10, the p-side electrode 4 includes the second p-side electrode film 4b. In this case, the p-side transparent electrode is interposed between the p-type semiconductor layer 2 and the second p-side electrode film 4b. 4t is provided.
In the specific example illustrated in FIG. 10, the p-side transparent electrode 4 t is provided over the entire surface of the p-side electrode 4 (second p-side electrode film 4 b), but the present invention is not limited to this. A p-side transparent electrode 7 t can be provided between at least a part of the side electrode 4 (second p-side electrode film 4 b) and the p-type semiconductor layer 2.

  The p-side transparent electrode 4t contains at least one of nickel, indium tin oxide, and zinc oxide, and is in electrical contact with the p-type contact layer and the p-side electrode 4 (second p-side electrode film 4b).

  The p-side transparent electrode 4t transmits light from the light emitting layer 3 and reflects it by the p-side electrode 4 (second p-side electrode film 4b), and contacts the p-type semiconductor layer 2 with good electrical characteristics. And the role of preventing silver or aluminum used in the second p-side electrode film 4b from reacting with the p-type semiconductor layer 2 or diffusing into the p-type semiconductor layer 2, so that the p-side electrode 4 (first It is preferable that the shape is substantially the same as that of the 2p-side electrode film 4b). The film thickness of the p-side transparent electrode 4t is not particularly limited, and can be selected from 1 nm to 500 nm, for example.

  The semiconductor light emitting element 103b according to the present embodiment having such a configuration can provide both the reflection characteristics and the electric characteristics and can obtain high reliability by providing a transparent electrode in the p-side electrode 4.

  In the semiconductor light emitting device according to this embodiment, a transparent electrode may be provided on both the n-side electrode 7 and the p-side electrode 4. As a result, a highly reliable semiconductor light emitting device with higher light output and stable electrical characteristics can be realized.

  In other words, the semiconductor light emitting device according to this embodiment is at least a part of at least one of between the n-type semiconductor layer 1 and the n-side electrode 7 and between the p-type semiconductor layer 2 and the p-side electrode 4. The transparent electrode provided in can be further provided.

  In any of the semiconductor light emitting devices 101, 101a, 101b, and 102 already described, this transparent electrode (at least one of the n-side transparent electrode 7t and the p-side transparent electrode 4t) can be provided.

(Fourth embodiment)
FIG. 11 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to the fourth embodiment of the invention.
As shown in FIG. 11, in the semiconductor light emitting device 104 according to the fourth embodiment of the present invention, the semiconductor layer sandwiching the light emitting layer 3, that is, the stacked structure 1s has a tapered portion 1t having an inclined surface. Accordingly, the dielectric laminated film 11 covers the tapered portion 1t obliquely. That is, the laminated structure 1 s has a tapered portion 1 t that is inclined with respect to the layer surfaces of the first and second semiconductor layers 1 and 2.
Other than this, since it can be the same as that of the semiconductor light emitting device 101 according to the first embodiment, description thereof is omitted.

  In the laminated structure 1s of the n-type semiconductor layer 1, the light emitting layer 3, and the p-type semiconductor layer 2, in order to provide the n-side electrode 7 and the p-side electrode 4 on the same main surface 1a side, A step is provided between the light emitting layer 3 and the n-type semiconductor layer 1. At this time, the dielectric laminated film 11 is also provided at the step portion. However, the thickness of the dielectric laminated film 11 is reduced at the step portion, and the reflection characteristics of the dielectric laminated film 11 are affected thereby.

  At this time, in the semiconductor light emitting device 104 according to the present embodiment, the step portion is formed into a tapered shape, thereby suppressing this influence as much as possible and maintaining a high reflectance.

  That is, the emitted light incident on the cross section of the semiconductor layer sandwiching the light emitting layer 3 is affected by the film thickness of the dielectric laminated film 11 formed in the direction perpendicular to the cross section of the semiconductor layer. Is also affected by the dielectric laminated film 11 shifted in the thin direction.

  At this time, this step can be suppressed and the high reflectance can be maintained by forming the stepped portion into a tapered shape. The smaller the taper angle, that is, the gentler the inclined surface of the tapered portion 1t, the more the dielectric laminated film in the semiconductor layer cross section functions as designed.

FIG. 12 is a graph illustrating characteristics of the semiconductor light emitting element according to the fourth embodiment of the invention.
That is, this figure illustrates the calculation result of the relationship between the taper angle and the reflectance of the dielectric multilayer film 11, the horizontal axis represents the taper angle, and the vertical axis represents the reflectance of the dielectric multilayer film 11. Represent. Here, the taper angle is an angle formed between the main surface 1a of the laminated structure 1s and the surface of the taper-shaped portion 1t. The smaller the taper angle, the gentler the inclination of the taper-shaped portion 1t, and the taper. When the angle is 90 degrees, the step portions of the n-type semiconductor layer 1 and the p-type semiconductor layer 2 have stepped side surfaces. And the figure has illustrated the calculation result using the design conditions demonstrated with the semiconductor light-emitting device 101 which concerns on 1st Embodiment.

As shown in FIG. 12, when the taper angle is about 40 degrees or less, high reflection characteristics are shown. However, when the taper angle is larger than 40 degrees, the film thickness of the dielectric multilayer film 11 is thin. Therefore, the high reflection characteristics as designed are not exhibited.
Note that the margin of high reflection characteristics with respect to the taper angle becomes wider as the refractive index ratio of the two types of dielectrics to be stacked increases.

  Further, by providing the tapered portion 1t, it is possible to prevent disconnection of the dielectric laminated film 11 in the cross section of the semiconductor layer sandwiching the light emitting layer 3.

  The taper angle of the tapered portion 1t can be appropriately determined based on the element area, light emission characteristics, processing accuracy, and the like of the semiconductor light emitting element.

(Fifth embodiment)
FIG. 13 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to the fifth embodiment of the invention.
FIG. 14 is a schematic cross-sectional view in order of the processes, illustrating a method for manufacturing a semiconductor light emitting element according to the fifth embodiment of the invention.
15 is a schematic cross-sectional view in order of the steps, following FIG.
16 is a schematic cross-sectional view in order of the steps, following FIG.

  As shown in FIG. 13, in the semiconductor light emitting device 105 according to the fifth embodiment of the present invention, the p-type semiconductor layer 2 (p-type contact layer) exposed from the second p-side electrode film 4b is The 1p-side electrode film 4a is in contact, and a dielectric film 11a is provided in a region on the p-type contact layer other than in contact with these electrodes. The first p-side electrode film 4a is provided so as to cover the second p-side electrode film 4b and to be in contact with a part of the dielectric film 11a. Then, the already described dielectric laminated film 11 is provided so as to cover the dielectric film 11a and expose a part of the first p-side electrode film 4a, the first n-side electrode film 7a, and the second n-side electrode film 7b. Yes.

  That is, the semiconductor light emitting element 105 is provided between the dielectric multilayer film 11 and at least a part of the n-type semiconductor layer 1 and the p-type semiconductor layer 2 exposed from the n-side electrode 7 and the p-side electrode 4. A dielectric film 11a is further provided.

The dielectric film 11a has a protruding portion that is not covered with the dielectric multilayer film 11, and at least a part of at least one of the n-side electrode 7 and the p-side electrode 4 is provided on the protruding portion. It has been. In this specific example, a first p-side electrode film 4a which is a part of the p-side electrode 4 is provided on the protruding portion, and the protruding portion is covered with the first p-side electrode film 4a.
Other than this, since it can be the same as that of the semiconductor light emitting device 102 according to the second embodiment, the description thereof is omitted.

  In the semiconductor light emitting device 105 according to the present embodiment, the first p-side electrode film 4a includes a second p-side electrode film 4b, a p-type contact layer exposed between the second p-side electrode film 4b and the dielectric film 11a, Part of the dielectric film 11a.

  Thus, since the second p-side electrode film 4b is covered with the first p-side electrode film 4a, it is isolated from the outside air and the dielectric film 11a, so that it is difficult to be exposed to moisture and ionic impurities, and the second p-side electrode film 4b. Migration, oxidation, and sulfurization reactions can be suppressed.

  In addition, since the first p-side electrode film 4a is formed right next to the end of the second p-side electrode film 4b on the side facing the n-side electrode 7, and a current path is formed right next to the second p-side electrode film 4b, Current concentration on the 2p-side electrode film 4b is alleviated.

  At the same time, a region sandwiched between the p-type semiconductor layer 2 and the first p-side electrode film 4a is formed near the end of the dielectric film 11a facing the end of the second p-side electrode film 4b. A weak electric field is applied between the p-type semiconductor layer 2 and the first p-side electrode film 4a. As a result, a structure in which the electric field gradually decreases from the second p-side electrode film 4b to the dielectric film 11a can be created, so that the electric field concentration in this region can be reduced.

  Further, no special device is required in the manufacturing process, and the manufacturing process can be performed with the same number of processes and the same number of processes. Due to these effects, it is possible to reduce the leakage current, improve the insulation characteristics, improve the withstand voltage characteristics, improve the light emission intensity, increase the life, high throughput, and low cost of the semiconductor light emitting device.

  The electrical characteristics between the first p-side electrode film 4a and the p-type contact layer which is the uppermost layer of the p-type semiconductor layer 2 are less ohmic than those between the second p-side electrode film 4b and the p-type contact layer, and contact resistance Is larger. As a result, current can be efficiently injected into the light emitting layer 3 located immediately below the second p-side electrode film 4b, and light emitted from directly below the second p-side electrode film 4b can be reflected to the substrate side with high efficiency. Therefore, the light extraction efficiency can be improved.

As already described, the first p-side electrode film 4a includes the second p-side electrode film 4b, the p-type contact layer exposed between the second p-side electrode film 4b and the dielectric film 11a, and one of the dielectric films 11a. In particular, the dielectric film 11a on the side facing the n-side electrode 7 is preferably covered over the entire area.
The length of the first p-side electrode film 4a covering the dielectric film 11a is set to 0. 0 in consideration of pattern alignment accuracy in the manufacturing process and securing the area of the second p-side electrode film 4b functioning as a reflective film. It is preferably between 5 μm and 10 μm.

  Hereinafter, a specific example of the method for manufacturing the semiconductor light emitting device 105 according to this embodiment will be described. First, as illustrated in FIG. 14A, light emission from the p-type semiconductor layer 2 is performed by dry etching using a mask until the n-type contact layer is exposed on the surface in a partial region of the p-type semiconductor layer 2. Layer 3 is removed.

Next, as shown in FIG. 14B, SiO ₂ to be the dielectric film 11a is formed on the semiconductor with a film thickness of 100 nm using a thermal CVD apparatus.

Next, as shown in FIG. 14C, an n-side electrode region having ohmic characteristics, that is, a first n-side electrode film 7a is formed. That is, a patterned lift-off resist (not shown) is formed on the semiconductor layer, and a part of the exposed SiO ₂ film on the n-type contact layer is removed by an ammonium fluoride treatment. A first n-side electrode film 7a made of, for example, Ti / Al / Ni / Au, having a thickness of 500 nm, is formed in the region from which the SiO ₂ film has been removed by using a vacuum vapor deposition apparatus, and is formed at a thickness of 550 ° C. Sintering is performed in a nitrogen atmosphere.

Subsequently, in order to form the p-side electrode 4, a patterned lift-off resist (not shown) is formed on the semiconductor layer, and a part of the SiO ₂ film on the p-type contact layer is removed by ammonium fluoride treatment.

At that time, the processing time of ammonium fluoride is adjusted so that the p-type contact layer is exposed between Ag of the second p-side electrode film 4b described later and the SiO ₂ film of the dielectric film 11a. As a specific example, when the etching rate is 400 nm / min, the time for removing the SiO ₂ film in the Ag forming region and the over-exposure for exposing the p-type contact layer located immediately beside the region with a width of 1 μm. The total etching time is about 3 minutes.
For example, Ag is formed to a thickness of 200 nm as the second p-side electrode film 4b in the region from which the SiO ₂ film has been removed by using a vacuum deposition apparatus, and a sintering process is performed in a nitrogen atmosphere at 350 ° C. after lift-off.

Next, as shown in FIG. 15A, an n-side electrode region having high efficiency reflection characteristics is formed. That is, a lift-off resist is formed in which a region on the n-type contact layer on the side opposite to the p-side electrode 4 of the first n-side electrode film 7a which is an n-side electrode region having ohmic characteristics is opened. A part of the SiO ₂ film on the n-type contact layer is removed by an ammonium fluoride treatment, and, for example, Al / Ni / Au is formed using a vacuum deposition apparatus, and then lifted off to form a high-efficiency reflective film. A 2n-side electrode film 7b is formed.

Next, as shown in FIG. 15B, a patterned lift-off resist (not shown) was formed on the semiconductor layer, and was exposed on the entire region where Ag was formed and on the surface immediately next to Ag. For example, Pt / Au is formed to a thickness of 500 nm as the first p-side electrode film 4a so as to cover the entire region of the p-type contact layer and a part of the SiO ₂ film of the dielectric film 11a. The electrode 4 is formed.

  Further, as shown in FIG. 15C, a lift-off resist (not shown) that is similarly patterned is formed on the semiconductor layer, and the second n-side electrode film 7b of the n-side electrode 7 having high-efficiency reflection characteristics is formed. For example, Ti / Pt / Au is formed with a thickness of 500 nm so as to cover the first n-side electrode film 7a of the n-side electrode 7 having characteristics, and an n-side pad 75 is formed.

Then, as shown in FIG. 16, five pairs of SiO ₂ and TiO ₂ to be the dielectric laminated film 11 and a total of 10 layers are formed on the semiconductor by using a vacuum deposition apparatus. Each film thickness is expressed as λ / (4n) where n is the refractive index and λ is the wavelength of light emitted from the light emitting layer 3. A patterned resist is formed thereon, and the dielectric is removed by the ammonium fluoride treatment so that the p-side electrode 4 and the n-side electrode 7 are exposed, and a dielectric laminated film 11 is formed. The dielectric laminated film 11 may be formed by a lift-off method so that the p-side electrode 4 and the n-side electrode 7 are exposed.

  Thus, the semiconductor light emitting device 105 according to this embodiment can be manufactured.

  In the semiconductor light emitting device 105 according to the present embodiment, the dielectric film 11a can be formed on the semiconductor layer before the first n-side electrode film 7a and the second p-side electrode film 4b are formed. Since contamination that adheres to the interface of the semiconductor layer can be greatly reduced, reliability, yield, electrical characteristics, and optical characteristics can be improved.

  In the semiconductor light emitting device 105, the side of the first p-side electrode film 4a that contacts the p-type contact layer functions as a protective film for the second p-side electrode film 4b and a reflection film for the emitted light. It is preferable to use platinum (Pt) or rhodium (Rh) which is high and has a relatively high reflectance.

  When the length of the first p-side electrode film 4a covering the dielectric film 11a is large, it is advantageous in obtaining an electric field relaxation structure via the dielectric film 11a, but there is a risk of short-circuiting with the n-side electrode 7. Get higher. On the other hand, when it is short, the risk of shorting with the n-side electrode 7 is reduced.

  The dielectric film 11a has almost no influence on the reflectivity of the dielectric multilayer film 11, and if a plurality of pairs of dielectrics having different refractive indexes are laminated in the dielectric multilayer film 11, the design reflectivity can be sufficiently increased. In the semiconductor light emitting device 105 according to the present embodiment, the design reflectance of the region where the dielectric film 11a and the dielectric multilayer film 11 are overlapped is, for example, 99.5%.

The second n-side electrode film 7b may be formed on the dielectric film 11a without removing the SiO ₂ film.

(Sixth embodiment)
FIG. 17 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to the sixth embodiment of the invention.
FIG. 18 is a schematic cross-sectional view in order of the processes, illustrating a method for manufacturing a semiconductor light emitting element according to the sixth embodiment of the invention.
FIG. 19 is a schematic cross-sectional view in order of the processes following FIG.

  As shown in FIG. 17, the structure of the semiconductor light emitting device 106 according to the sixth embodiment of the present invention is the same as the configuration of the semiconductor light emitting device 102 according to the second embodiment. However, in the semiconductor light emitting device 106 according to the present embodiment, the second p-side electrode film 4b is made of the same material as the second n-side electrode film 7b.

  In this case, the second p-side electrode film 4b having high efficiency reflection characteristics of the p-side electrode 4 and the second n-side electrode film 7b having high efficiency reflection characteristics can be formed simultaneously.

Hereinafter, a method for manufacturing the semiconductor light emitting device 106 according to this embodiment will be described.
First, as illustrated in FIG. 18A, light emission from the p-type semiconductor layer 2 is performed by dry etching using a mask until the n-type contact layer is exposed on the surface in a partial region of the p-type semiconductor layer 2. Layer 3 is removed.

  Next, as shown in FIG. 18B, in order to form the first n-side electrode film 7a in the n-side electrode region having ohmic characteristics, a patterned lift-off resist (not shown) is formed on the semiconductor layer. On the n-type contact layer, for example, a first n-side electrode film 7a made of Ti / Al / Ni / Au is formed to a thickness of 500 nm, and a sintering process is performed in a nitrogen atmosphere at 550 ° C.

Subsequently, the p-side electrode 4 and the n-side electrode region having high efficiency reflection characteristics are formed simultaneously.
That is, with respect to the first n-side electrode film 7a, which is an n-side electrode region having ohmic characteristics, a lift-off resist in which a region on the n-contact layer opposite to the p-contact layer and a part of the p-type contact layer are opened. Form.

Here, in consideration of pattern alignment accuracy, a part of the n-side electrode (first n-side electrode film 7a) having ohmic characteristics on the side facing the p-contact layer may be opened.
On the contrary, both electrodes are positioned so that the n-side electrode (second n-side electrode film 7b) having high-efficiency reflection characteristics does not run on the n-side electrode (first n-side electrode film 7a) having ohmic characteristics. You may design so that it may leave | separate slightly in consideration of the alignment precision.

  In addition, an n-side electrode (second n-side electrode film 7b) having high-efficiency reflection characteristics is formed so as to cover a part or the whole of the n-side electrode (first n-side electrode film 7a) having ohmic characteristics. It may be designed to be

  Then, as illustrated in FIG. 18C, for example, the second p-side electrode film 4 b and the second n-side electrode film 7 b made of Ag are simultaneously formed with a film thickness of 200 nm using a vacuum deposition apparatus, and the temperature is 350 ° C. Sintering is performed in a nitrogen atmosphere.

  Further, as shown in FIG. 19A, similarly patterned lift-off resist is formed on the semiconductor layer, and, for example, Pt / Au of 500 nm is formed in the region of the second p-side electrode film 4b where Ag is formed. The p-side electrode 4 is formed.

  Next, as shown in FIG. 19B, the same patterned lift-off resist is formed on the semiconductor layer, and the second n-side electrode film 7b having high-efficiency reflection characteristics and the first n-side electrode having ohmic characteristics are formed. For example, Ti / Pt / Au is formed at 500 nm so as to cover a part of the film 7a, and the n-side pad 75 is formed.

Then, as shown in FIG. 19C, using a vacuum deposition apparatus, five pairs of SiO ₂ and TiO ₂ are combined and a total of 10 layers are formed on the semiconductor. Each film thickness is expressed as λ / (4n) where n is the refractive index and λ is the wavelength of light emitted from the light emitting layer 3. A patterned resist (not shown) is formed thereon, and the dielectric is removed so that the p-side electrode 4 and the n-side electrode 7 are exposed by an ammonium fluoride treatment, thereby forming a dielectric laminated film 11. The dielectric laminated film 11 may be formed by a lift-off method so that the p-side electrode 4 and the n-side electrode 7 are exposed.
In this way, the semiconductor light emitting device 106 according to this embodiment can be manufactured.

In the semiconductor light emitting device 106 according to the present embodiment, the second p-side electrode film 4b with high efficiency reflection characteristics of the p-side electrode 4 and the second n-side electrode film 7b with high efficiency reflection characteristics are made of the same material, And it enables it to be formed simultaneously.
Accordingly, the number of steps can be reduced, light generated in the light emitting layer can be efficiently extracted to the outside, and a high-throughput, low-cost semiconductor light-emitting device and a method for manufacturing the same can be provided.

(Seventh embodiment)
FIG. 20 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to the seventh embodiment of the invention.
FIG. 21 is a schematic cross-sectional view in order of the processes, illustrating a method for manufacturing a semiconductor light emitting element according to the seventh embodiment of the invention.
22 is a schematic cross-sectional view in order of the steps, following FIG.

  As shown in FIG. 20, the semiconductor light emitting element 107 according to the seventh embodiment of the present invention is a specific example of the semiconductor device 103b according to the third embodiment. That is, the semiconductor light emitting device 106 is obtained by providing the p-side transparent electrode 4t between the p-side electrode 4 and the p-type semiconductor layer 2 in the semiconductor light-emitting device 102 according to the second embodiment. Other than this, it is the same as the semiconductor light emitting device 102, and thus the description thereof is omitted. Further, the configuration of the p-side transparent electrode 4t and the effect thereof have been described with respect to the third embodiment, and thus the description thereof is omitted.

  Further, in the semiconductor light emitting device 107, the second p-side electrode film 4b and the second n-side electrode film 7b having high efficiency reflection characteristics are formed at the same time.

Hereinafter, a method for manufacturing the semiconductor light emitting device 107 according to this embodiment will be described.
First, as shown in FIG. 21A, light emission from the p-type semiconductor layer 2 is performed by dry etching using a mask until the n-type contact layer is exposed on the surface in a partial region of the p-type semiconductor layer 2. Layer 3 is removed.

  Next, as shown in FIG. 21B, in order to form the first n-side electrode film 7a in the n-side electrode region having ohmic characteristics, a patterned lift-off resist (not shown) is formed on the semiconductor layer. On the n-type contact layer, for example, a first n-side electrode film 7a made of Ti / Al / Ni / Au is formed to a thickness of 500 nm, and a sintering process is performed in a nitrogen atmosphere at 550 ° C.

  As shown in FIG. 21C, in order to form the p-side transparent electrode 4t of the p-side electrode 4, a patterned lift-off resist (not shown) is formed on the semiconductor layer, and a vacuum is formed on the p-type contact layer. Using a vapor deposition device, for example, indium tin oxide (ITO) to be the p-side transparent electrode 4t is formed with a film thickness of 100 nm.

  The first n-side electrode which is an n-side electrode region having ohmic characteristics in order to simultaneously form the high-efficiency reflective regions (second p-side electrode film 4b and second n-side electrode film 7b) of the p-side electrode 4 and the n-side electrode 7. A lift-off resist having an opening on the transparent electrode 4t and a region on the n-contact layer opposite to the transparent electrode 4t on the p-contact layer is formed on the film 7a.

Here, in consideration of pattern alignment accuracy, a part of the n-side electrode (first n-side electrode film 7a) having ohmic characteristics on the side facing the p-contact layer may be opened.
On the contrary, both electrodes align the pattern so that the n-side electrode (second n-side electrode film 7b) having high-efficiency reflection characteristics does not run on the n-side electrode (first n-side electrode film 7a) having ohmic characteristics. You may design so that it may leave | separate slightly in consideration of the precision.
Further, an n-side electrode (second n-side electrode film 7b) having high-efficiency reflection characteristics is formed so as to cover a part or the whole of the n-side electrode (first n-side electrode film 7a) having ohmic characteristics. You may design as follows.

  Then, as shown in FIG. 22A, for example, Al / Ni / Au is formed to a thickness of 300 nm as the second p-side electrode film 4b and the second n-side electrode film 7b by using a vacuum evaporation apparatus.

  Next, as shown in FIG. 22B, the same patterned lift-off resist is formed on the semiconductor layer, and the entire high-efficiency reflective region and the ohmic characteristics of the second p-side electrode film 4b and the n-side electrode 7 are obtained. For example, Ti / Pt / Au is formed to a thickness of 500 nm so as to cover a part of the n-side electrode 7 having the first p-side electrode film 4 a and the n-side pad 75 of the n-side electrode 7.

Then, as shown in FIG. 22C, using a vacuum deposition apparatus, five pairs of SiO ₂ and TiO ₂ are combined, and a total of 10 layers are formed on the semiconductor. Each film thickness is expressed as λ / (4n) where n is the refractive index and λ is the wavelength of light emitted from the light emitting layer 3. A patterned resist is formed thereon, and the dielectric is removed by the ammonium fluoride treatment so that the p-side electrode 4 and the n-side electrode 7 are exposed, and a dielectric laminated film 11 is formed. The dielectric laminated film 11 may be formed by a lift-off method so that the p-side electrode 4 and the n-side electrode 7 are exposed.
In this way, the semiconductor light emitting device 107 according to this embodiment can be manufactured.

In the semiconductor light emitting device 107 according to the present embodiment, the high-efficiency reflective films (second p-side electrode film 4b and second n-side electrode film 7b) of the p-side electrode 4 and the n-side electrode 7 can be formed simultaneously. Further, the first p-side electrode film 4a of the p-side electrode 4 and the n-side pad 75 of the n-side electrode 7 can be formed simultaneously.
Accordingly, the number of steps can be reduced, light generated in the light emitting layer can be efficiently extracted to the outside, and a high-throughput, low-cost semiconductor light-emitting device and a method for manufacturing the same can be provided.

(Eighth embodiment)
FIG. 23 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to the eighth embodiment of the invention.
FIG. 24 is a schematic cross-sectional view in order of the processes, illustrating a method for manufacturing a semiconductor light emitting element according to the eighth embodiment of the invention.
FIG. 25 is a schematic cross-sectional view in order of the steps, following FIG.

  As shown in FIG. 23, in the semiconductor light emitting device 108 according to the eighth embodiment of the present invention, in the semiconductor light emitting device 102 according to the second embodiment, the first n-side electrode film 7a, the n-side pad 75, Is also used. Other than this, since it can be the same as that of the semiconductor light emitting element 102, the description is omitted.

  In the semiconductor light emitting device 108 according to the present embodiment, the second p-side electrode film 4b and the second n-side electrode film 7b having high efficiency reflection characteristics are formed at the same time, and the first p-side electrode film 4a and the first n-side electrode film 7a and the n-side pad 75 can be formed simultaneously.

Hereinafter, a method for manufacturing the semiconductor light emitting device 108 according to the present embodiment will be described.
First, as shown in FIG. 24A, light emission from the p-type semiconductor layer 2 is performed by dry etching using a mask until the n-type contact layer is exposed on the surface in a partial region of the p-type semiconductor layer 2. Layer 3 is removed.

  Next, as shown in FIG. 24B, a part of the n-type contact layer and the p-type contact layer was opened to simultaneously form the high-efficiency reflective regions of the p-side electrode 4 and the n-side electrode 7. A lift-off resist is formed, and, for example, Ag is simultaneously formed with a film thickness of 200 nm as the second p-side electrode film 4b and the second n-side electrode film 7b using a vacuum deposition apparatus, and a sintering process is performed in a nitrogen atmosphere at 350 ° C. Do.

  Further, as shown in FIG. 24C, the first p-side electrode film 4a of the p-side electrode 4 and the first n-side electrode film 7a of the n-side electrode 7 having ohmic characteristics and the n-side pad 75 of the n-side electrode 7 are used. Are formed simultaneously with the second n-side electrode film 7b, which is an n-side electrode region having high-efficiency reflection characteristics, on the n-contact layer on the side facing the p-contact layer, the entire second n-side electrode film 7b, and A lift-off resist having an opening on the second p-side electrode film 4b is formed. For example, Ti / Pt / Au is formed to a thickness of 500 nm as the first p-side electrode film 4a and the first n-side electrode film 7a and the n-side pad 75 using a vacuum deposition apparatus.

Then, as shown in FIG. 25, using a vacuum deposition apparatus, five pairs of SiO ₂ and TiO ₂ are combined, and a total of 10 layers are formed on the semiconductor. Each film thickness is expressed as λ / (4n) where n is the refractive index and λ is the wavelength of light emitted from the light emitting layer 3. A patterned resist is formed thereon, and the dielectric is removed by the ammonium fluoride treatment so that the p-side electrode 4 and the n-side electrode 7 are exposed, and a dielectric laminated film 11 is formed. The dielectric laminated film 11 may be formed by a lift-off method so that the p-side electrode 4 and the n-side electrode 7 are exposed.
In this way, the semiconductor light emitting device 108 according to this embodiment can be manufactured.

  In the semiconductor light emitting device 108 according to this embodiment, the p-side electrode 4 and the high-efficiency reflective film (second n-side electrode film 7b) of the n-side electrode 7 can be formed simultaneously. Further, the first p-side electrode film 4a of the p-side electrode 4 and the first n-side electrode film 7a / n-side pad 75 of the n-side electrode 7 can be formed simultaneously.

  Accordingly, the number of steps can be reduced, light generated in the light emitting layer can be efficiently extracted to the outside, and a high-throughput, low-cost semiconductor light-emitting device and a method for manufacturing the same can be provided.

(Ninth embodiment)
FIG. 26 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to the ninth embodiment of the invention.
As shown in FIG. 26, in the semiconductor light emitting device 109 according to the ninth embodiment of the present invention, the p-side pad 45 is provided on the p-side electrode 4 in the semiconductor light emitting device 101 according to the first embodiment. Is provided. An n-side pad 75 is provided on the n-side electrode 7. Except for these, the semiconductor light emitting device 101 according to the first embodiment can be the same as the semiconductor light emitting device 101, and the description thereof will be omitted.

That is, in the semiconductor light emitting device 109, the p-side pad 45 is provided so as to cover a part or all of the p-side electrode 4. For the p-side pad 45, for example, an Au film having a thickness of 2000 nm can be used.
Thereby, bondability improves. Furthermore, the heat dissipation of the semiconductor light emitting device can be improved.

  The p-side pad 45 can be used as a gold bump, or an AuSn bump can be formed instead of Au.

  The p-side pad 45 may be provided so as to cover at least a part of the dielectric multilayer film 11 in addition to a part or all of the p-side electrode 4. Further, the p-side pad 45 can be formed simultaneously with the n-side pad 745 provided on the n-side electrode 7.

  In addition, when a p-side pad 45 is separately provided on the p-side electrode 4 for improving the bondability of wire bonding, improving the die shear strength when forming gold bumps by a ball bonder, flip chip mounting, etc., the film thickness of the p-side pad 45 Is not particularly limited, and can be selected, for example, between 100 nm and 10,000 nm.

  Thus, in the semiconductor light emitting device 109 according to the present embodiment, the p-side pad 45 (and the n-side pad 75) is provided to improve the bondability in the manufacturing process and improve the heat dissipation. It is possible to provide a semiconductor light emitting element that efficiently extracts generated light to the outside.

(Tenth embodiment)
FIG. 27 is a schematic cross-sectional view illustrating the structure of the semiconductor light emitting element according to the tenth embodiment of the invention.
As shown in FIG. 27, in the semiconductor light emitting device 110 according to the tenth embodiment of the present invention, in the semiconductor light emitting device 101 according to the first embodiment, the p-side electrode 4 is the first p-side already described. It has an electrode film 4a and a second p-side electrode film 4b, and is provided between the first p-side electrode film 4a and the second p-side electrode film 4b, and the material constituting the first p-side electrode film 4a is the second p-side. It has the 3rd p side electrode film (5th metal film) 4c which suppresses spreading | diffusion to the electrode film 4b. Other than this, since it can be the same as that of the semiconductor light emitting device 101 according to the first embodiment, description thereof is omitted.

  The third p-side electrode film 4c is provided between the second p-side electrode film 4b and the first p-side electrode film 4a, and has a function of preventing the first p-side electrode film 4a from diffusing or reacting with the second p-side electrode film 4b. Have. A material that does not react with silver or does not actively diffuse into silver can be used for the third p-side electrode film 4c.

  The third p-side electrode film 4c has a refractory metal that can be used as a diffusion prevention layer, for example, vanadium (V), chromium (Cr), iron (Fe), cobalt (Co), nickel (Ni), niobium (Nb ), Molybdenum (Mo), ruthenium (Ru), rhodium (Rh), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), etc. A film or a laminated film can be used.

  The third p-side electrode film 4c is made of iron (Fe) as a metal that has a high work function and can easily obtain ohmic properties with the p-GaN contact layer so that there is no problem even if it diffuses slightly in the second p-side electrode film 4b. ), Cobalt (Co), nickel (Ni), rhodium (Rh), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), and platinum (Pt) are more preferable.

  The film thickness of the third p-side electrode film 4c is preferably in the range of 5 nm to 200 nm so that the film state can be maintained in the case of a single layer film. In the case of a laminated film, it is not particularly limited, and can be selected, for example, from 10 nm to 10000 nm.

  Thus, according to the semiconductor light emitting device 110 according to the present embodiment, the third p-side electrode film 4c can suppress diffusion and reaction between the first p-side electrode film 4a and the second p-side electrode film 4b. In addition, it is possible to provide a semiconductor light-emitting element that has higher electrical characteristics and reliability and efficiently extracts light generated in the light-emitting layer to the outside.

(Eleventh embodiment)
FIG. 28 is a schematic cross-sectional view illustrating the structure of the semiconductor light emitting element according to the eleventh embodiment of the invention.
As shown in FIG. 28, in the semiconductor light emitting device 111 according to the eleventh embodiment of the present invention, in the semiconductor light emitting device 104 according to the fourth embodiment, the n-type semiconductor layer 1 also has a tapered portion 1r. doing. Accordingly, the dielectric multilayer film 11 obliquely covers the tapered portion 1t of the laminated structure 1s and the tapered portion 1r of the n-type semiconductor layer 1. Other than this, since it can be the same as that of the semiconductor light emitting element 104, the description is omitted.

  In the semiconductor light emitting device 111 according to the present embodiment, light emitted from the light emitting layer 3 is repeatedly reflected at the semiconductor layer-substrate interface having a large refractive index difference and the main surface 1a on which the electrodes are formed. It is easy to be trapped in. Although some light is extracted from the element end face, the square or rectangular semiconductor light emitting element fabricated on the sapphire substrate is not a cleaved face, so the element end face shape is formed by breaking into elements. Reproducibility is poor, and the light extraction efficiency for each element, and hence the light output, varies.

  At this time, according to the semiconductor light emitting device 111 according to the present embodiment, the reproducibility of the light path on the device end surface side is improved by forming the device end surface side of the semiconductor layer by wet etching or dry etching. Further, by covering the element end face side of the semiconductor layer with the dielectric laminated film 11 and reflecting the emitted light toward the substrate side, the light can be extracted efficiently.

  As described above, according to the semiconductor light emitting device 111 according to the present embodiment, it is possible to provide a semiconductor light emitting device that more stably and efficiently extracts light generated in the light emitting layer to the outside.

(Twelfth embodiment)
FIG. 29 is a schematic cross-sectional view illustrating the structure of a semiconductor light emitting element according to the twelfth embodiment of the invention.
FIG. 30 is a schematic cross-sectional view in order of the processes, illustrating a method for manufacturing a semiconductor light emitting element according to the twelfth embodiment of the invention.
FIG. 31 is a schematic cross-sectional view in order of the steps, following FIG.

  As shown in FIG. 29, in the semiconductor light emitting device 112 according to the twelfth embodiment of the present invention, in the semiconductor light emitting device 101 according to the first embodiment, the dielectric film 11a described in the fifth embodiment. Further, the n-side pad 75 described in the second embodiment and the p-side pad 45 described in the ninth embodiment are further provided. However, the shapes of the dielectric film 11a, the dielectric laminated film 11, the n-side pad 75, and the p-side pad 45 are devised, and as will be described later, the manufacturing becomes easier and the process consistency is high.

  That is, the semiconductor light emitting device 112 is provided between the dielectric multilayer film 11 and at least a part of the n-type semiconductor layer 1 and the p-type semiconductor layer 2 exposed from the n-side electrode 7 and the p-side electrode 4. A dielectric film 11a is further provided.

A part of the dielectric film 11a has a protrusion that is not covered with the dielectric multilayer film 11, and a conductive material connected to at least one of the first and second electrodes on the protrusion. At least a portion of the membrane is provided. In this specific example, an n-side pad 75 connected to the n-side electrode 7 and a p-side pad 45 connected to the p-side electrode 4 are provided on the protruding portion. The n-side pad 75 connected to the n-side electrode 7 and the p-side pad 45 connected to the p-side electrode 4 are covered.
Other than this, since it can be the same as that of the semiconductor light emitting element 101, the description is omitted.

  The n-side pad 75 and the p-side pad 45 can include at least one selected from the group consisting of Ru, Pt, and Pd that has a high reflectance with respect to blue light or near-ultraviolet light. Thereby, it is possible to realize a semiconductor light emitting device having an improved reflectance especially for blue light and light in the near ultraviolet region. However, the present invention is not limited to this, and any conductive material can be used for the n-side pad 75 and the p-side pad 45. Alternatively, a stacked film of conductive films can be used.

The semiconductor light emitting device 112 according to this embodiment is manufactured, for example, as follows.
First, as illustrated in FIG. 30A, light emission from the p-type semiconductor layer 2 is performed by dry etching using a mask until the n-type contact layer is exposed on the surface in a partial region of the p-type semiconductor layer 2. Layer 3 is removed.

Next, as shown in FIG. 30B, SiO ₂ to be the dielectric film 11a is formed on the semiconductor with a film thickness of 100 nm using a thermal CVD apparatus. Thus, by using the thermal CVD method, it becomes easy to provide the dielectric film 11a that follows the shape of the step of the multilayer structure 1s.

Next, as shown in FIG. 30C, the dielectric laminated film 11 having a predetermined shape is formed on the SiO ₂ to be the dielectric film 11a. At this time, the method described above can be used as the material of the dielectric laminated film 11 and the formation method thereof.

Next, as shown in FIG. 31 (a), SiO ₂ to be the dielectric film 11a is partially removed by ammonium fluoride treatment, and similarly on the p-type semiconductor layer 2 in the region from which SiO ₂ has been removed. The second p-side electrode film 4b is formed in a predetermined shape, and the first n-side electrode film 7a is formed in a predetermined shape on a part of the n-type semiconductor layer 1 in the region from which SiO ₂ is removed. As the material of the second p-side electrode film 4b and the first n-side electrode film 7a and the method for forming the same, the method described above can be used.

Then, as shown in FIG. 31B, the second n-side electrode film 7b is formed in a predetermined shape on a part of the n-type semiconductor layer 1 in the region where the SiO ₂ is removed. As the material of the second n-side electrode film 7b and the formation method thereof, the method described above can be used.

Then, as illustrated in FIG. 31C, the p-side pad 45 is formed on the p-type semiconductor layer 2, the dielectric film 11 a, and the dielectric stacked film 11 exposed from the p-side electrode 4. The Ru film becomes an n-side pad 75 on the n-type semiconductor layer 1, the dielectric film 11 a, and the dielectric stacked film 11 exposed from the first n-side electrode film 7 a and the second n-side electrode film 7 b. A Ru film is formed. At this time, the formed Ru film can be processed into the shapes of the p-side pad 45 and the n-side pad 75 by the lift-off method. For the film to be the p-side pad 45 and the n-side pad 75, metals such as Pt and Pd can be used in addition to Ru, and other conductive films can also be used.
In this manner, the semiconductor light emitting device 112 according to this embodiment can be formed.

  Since the semiconductor light emitting device 112 according to the present embodiment is further provided with the n-side pad 75 and the p-side pad 45, the bondability in the manufacturing process is improved and the heat generated in the light emitting layer is improved. It is possible to provide a semiconductor light emitting element that is efficiently extracted to the outside. Further, the p-side pad 45 and the n-side pad 75 made of, for example, a Ru film can be formed at a time, and the process can be omitted.

  Furthermore, since the dielectric laminated film 11 is processed before the n-side electrode 7 (the first n-side electrode film 7a and the second n-side electrode film 7b) and the p-side electrode 4, the process consistency is high and the manufacturing is easy. It is.

  That is, the dielectric laminated film 11 is formed by, for example, a lift-off method, and then the dielectric film 11a is processed by, for example, a wet etching method or a dry etching method. Then, the n-side electrode 7 and the p-side electrode 4 are formed on the exposed first and second semiconductor layers, for example, by a lift-off method. Thereby, process consistency is improved and a processing margin is expanded.

(13th Embodiment)
FIG. 32 is a schematic cross-sectional view illustrating the structure of the semiconductor light emitting element according to the thirteenth embodiment of the invention.
FIG. 33 is a schematic cross-sectional view in order of the processes, illustrating a method for manufacturing a semiconductor light emitting element according to the thirteenth embodiment of the invention.
FIG. 34 is a schematic cross-sectional view in order of the steps, following FIG.

  As shown in FIG. 32, in the semiconductor light emitting device 113 according to the thirteenth embodiment of the present invention, in the semiconductor light emitting device 101 according to the first embodiment, the dielectric film 11a described in the fifth embodiment. Further, a tapered portion 1t of the laminated structure 1s described in the fourth embodiment is provided. However, the shapes of the dielectric film 11a, the dielectric laminated film 11, the first and second n-side electrode films 7a and 7b, and the first and second p-side electrode films 4a and 4b are devised, and as described later, Manufacturing is easier.

  That is, the semiconductor light emitting device 113 is provided between the dielectric multilayer film 11 and at least a part of the n-type semiconductor layer 1 and the p-type semiconductor layer 2 exposed from the n-side electrode 7 and the p-side electrode 4. A dielectric film 11a is further provided.

The dielectric film 11a has a protrusion that is not covered with the dielectric multilayer film 11, and at least a part of at least one of the n-side electrode 7 and the p-side electrode 4 is formed on the protrusion. Is provided. In this specific example, a first p-side electrode film 4 a that is a part of the p-side electrode 4 is provided on the protrusion, and the protrusion is a first p-side electrode film 4 a that is a part of the p-side electrode 4. It is covered with.
Other than this, since it can be the same as that of the semiconductor light emitting element 101, the description is omitted.

The semiconductor light emitting device 113 according to the present embodiment is manufactured as follows, for example.
First, as shown in FIG. 33A, light emission from the p-type semiconductor layer 2 is performed by dry etching using a mask until the n-type contact layer is exposed on the surface in a partial region of the p-type semiconductor layer 2. Layer 3 is removed.

Next, as shown in FIG. 33B, SiO ₂ to be the dielectric film 11a is formed on the semiconductor with a film thickness of 100 nm using a thermal CVD apparatus. Thus, by using the thermal CVD method, it becomes easy to provide the dielectric film 11a following the shape of the tapered portion 1t of the laminated structure 1s.

Next, as shown in FIG. 33C, the dielectric laminated film 11 having a predetermined shape is formed on the SiO ₂ to be the dielectric film 11a. At this time, as the dielectric laminated film 11, a laminated film of TiO / (SiO / TiO) ₄ can be used. As described above, the vacuum deposition method can be used for forming the laminated film, and the lift-off method can be used for processing the shape.

In the laminated film of TiO / (SiO / TiO) _{4 used} as the dielectric laminated film 11, each film thickness is λ / (4n, where n is the refractive index and λ is the emission wavelength from the light emitting layer 3. ).

Next, as shown in FIG. 34A, SiO ₂ to be the dielectric film 11a is partially removed by the ammonium fluoride treatment, and the _second p is formed on the p-type semiconductor layer 2 in the region from which SiO ₂ has been removed. The side electrode film 4b is formed in a predetermined shape, and the first n-side electrode film 7a is formed in a predetermined shape on a part of the n-type semiconductor layer 1 in the region from which SiO ₂ is removed. The materials already described can be used for the material of the second p-side electrode film 4b and the first n-side electrode film 7a, and the lift-off method already described can be used for the formation method.

Then, as shown in FIG. 34B, the second n-side electrode film 7b is formed in a predetermined shape on a part of the n-type semiconductor layer 1 in the region where the SiO ₂ is removed. The material already described can be used for the material of the second n-side electrode film 7b, and the lift-off method already described can be used for the formation method.

Then, as shown in FIG. 34C, the first p-side electrode film covers the entire surface of the second p-side electrode film 4b and covers the p-type semiconductor layer 2 exposed from the second p-side electrode film 4b. 4a is formed. The materials described above can be used as the material of the first p-side electrode film 4a, and the lift-off method described above can be used as the formation method.
In this manner, the semiconductor light emitting device 113 according to this embodiment can be formed.

  The semiconductor light emitting device 113 according to the present embodiment has higher reflection characteristics because the laminated structure 1s has the tapered portion 1t.

  Furthermore, since the dielectric laminated film 11 is processed before the n-side electrode 7 (the first n-side electrode film 7a and the second n-side electrode film 7b) and the p-side electrode 4, the process consistency is high and the manufacturing is easy. It is.

  That is, the dielectric laminated film 11 is formed by, for example, a lift-off method, and then the dielectric film 11a is processed by, for example, a wet etching method or a dry etching method. Then, the n-side electrode 7 and the p-side electrode 4 are formed on the exposed first and second semiconductor layers, for example, by a lift-off method. Thereby, process consistency is improved and a processing margin is expanded.

  As described above, the semiconductor light emitting device 113 according to the present embodiment can provide a semiconductor light emitting device that can be easily manufactured by extracting light generated in the light emitting layer to the outside more efficiently and a method for manufacturing the same.

  In the semiconductor light emitting device 113 according to this embodiment, the p-side pad 45 and the n-side pad 75 described in the twelfth embodiment may be provided after the step illustrated in FIG. In this case, the dielectric film 11a has a protrusion that is not covered by the dielectric multilayer film 11, and a conductive material connected to at least one of the first and second electrodes on the protrusion. At least a part of the film is provided.

(Fourteenth embodiment)
FIG. 35 is a flowchart illustrating the method for manufacturing the semiconductor light emitting element according to the fourteenth embodiment of the invention.
As shown in FIG. 35, in the method for manufacturing a semiconductor light emitting device according to the fourteenth embodiment of the present invention, first, a first semiconductor layer (n-type semiconductor layer 1) and a light emitting layer 3 are formed on a substrate 10. Then, the second semiconductor layer (p-type semiconductor layer 2) is stacked and formed (step S110). For this, for example, the method described in regard to the first embodiment can be used.

  Then, the second semiconductor layer and a part of the light emitting layer are removed to expose the first semiconductor layer (step S120). For this, for example, the method described in regard to the second embodiment can be used.

  Then, a first metal film (first n-side electrode film 7a) is formed in the exposed first region of the first semiconductor layer (step S130). For this, for example, the method described in regard to the second embodiment can be used.

  The reflectance of the light emitted from the light emitting layer 3 in the exposed second region of the first semiconductor layer adjacent to the first region and on the second semiconductor layer is the first metal. Metal films (second n-side electrode film 7b and second p-side electrode film 4b) that are higher than the film and have higher contact resistance with respect to the first semiconductor layer than the first metal film are formed (step S140). For this, for example, the method described in regard to the sixth embodiment can be used.

  Then, a dielectric laminated film 11 in which a plurality of types of dielectric films having different refractive indexes are alternately laminated on the first semiconductor layer and the second semiconductor layer exposed from the first electrode and the second electrode. Form. (Step S150). For this, for example, the method described in regard to the second embodiment can be used.

According to the method for manufacturing a semiconductor light emitting device according to the present embodiment, the second p-side electrode film 4b having high efficiency reflection characteristics of the p-side electrode 4 and the second n-side electrode film 7b having high efficiency reflection characteristics are made of the same material. It can be configured and formed simultaneously.
Accordingly, the number of steps can be reduced, light generated in the light emitting layer can be efficiently extracted to the outside, and a method for manufacturing a semiconductor light emitting element with high throughput and low cost can be provided.

  In addition, said step S110-S150 can be interchanged as much as technically possible, and can be implemented simultaneously.

(Fifteenth embodiment)
FIG. 36 is a flowchart illustrating the method for manufacturing the semiconductor light emitting element according to the fifteenth embodiment of the invention.
As shown in FIG. 36, in the method for manufacturing a semiconductor light emitting device according to the fifteenth embodiment of the present invention, first, a first semiconductor layer (n-type semiconductor layer 1) and a light emitting layer 3 are formed on a substrate 10. The second semiconductor layer (p-type semiconductor layer 2) is stacked and formed (step S210). For this, for example, the method described in regard to the first embodiment can be used.

  Then, the second semiconductor layer and a part of the light emitting layer are removed to expose the first semiconductor layer (step S220). For this, for example, the method described in regard to the second embodiment can be used.

  A dielectric multilayer film 11 in which a plurality of types of dielectric films having different refractive indexes are alternately laminated is formed on the first semiconductor layer and the second semiconductor layer (step S230). For this, for example, the method described in regard to the second embodiment can be used.

  A first metal film (first n-side electrode film 7a) is formed in the first region of the first semiconductor layer exposed from the dielectric multilayer film, and the first semiconductor layer exposed from the dielectric multilayer film 11 is formed. In a second region adjacent to the first region, a reflectance for light emitted from the light emitting layer is higher than that of the first metal film, and contact resistance to the first semiconductor layer is higher than that of the first metal film. A two-metal film (second n-side electrode film 7b) is formed (step S240). For this, for example, the method described in regard to the second embodiment can be used.

  As described above, in the method for manufacturing the semiconductor light emitting device according to the present embodiment, the dielectric stack is formed before the first metal film (first n-side electrode film 7a) and the second metal film (second n-side electrode film 7b). A film 11 is provided. That is, the order of steps in the method for manufacturing a semiconductor light emitting device according to the twelfth and thirteenth embodiments.

  According to the inventor's experiment, when the dielectric laminated film 11 is formed at room temperature with a vacuum evaporation apparatus, the etching rate by wet etching is very fast and the workability of the film is low. In addition, when high-temperature heat treatment is performed during film formation or after film formation, zirconium oxide, titanium oxide, and the like have an extremely low etching rate by wet etching, which makes it difficult to process the film. For this reason, the dielectric laminated film 11 can be processed by, for example, a lift-off method.

  At this time, by providing the dielectric laminated film 11 in front of the first metal film (first n-side electrode film 7a) and the second metal film (second n-side electrode film 7b), process consistency is improved, The margin is widened.

  As described above, the semiconductor light emitting device manufacturing method according to the present embodiment provides a method for manufacturing a semiconductor light emitting device that can easily produce light generated in the light emitting layer with high process consistency and that can be efficiently produced. Can do.

FIG. 37 is a flowchart showing a modification of the method for manufacturing the semiconductor light emitting device according to the fifteenth embodiment of the present invention.
As shown in FIG. 37, in the modification of the method for manufacturing the semiconductor light emitting device according to the fifteenth embodiment of the present invention, from the step of exposing the first semiconductor layer (step S <b> 220) During the formation step (step S230), the step difference between the first semiconductor layer and the second semiconductor layer is higher than that on the dielectric stacked film 11 on the first semiconductor layer and the second semiconductor layer. A dielectric film 11a having a high coverage is formed (step S225).

As the dielectric film 11a, as described in the thirteenth embodiment, for example, a SiO ₂ film formed by a thermal CVD method can be used.

  That is, the dielectric film 11a can be formed by chemical vapor deposition.

  Thereby, it is possible to form the dielectric film 11a having high coverage with respect to the step between the first semiconductor layer and the second semiconductor layer.

  As described in the thirteenth embodiment, after the formation of the dielectric film 11a, the dielectric multilayer film 11 is formed by, for example, a lift-off method, and then the dielectric film 11a is formed by, for example, a wet etching method Alternatively, it is processed by a dry etching method. Then, the n-side electrode 7 and the p-side electrode 4 are formed on the exposed first and second semiconductor layers, respectively.

  In the method for manufacturing a semiconductor light emitting device according to this embodiment, as described in the fifth embodiment, the dielectric film 11a is formed on the semiconductor layer before the first n-side electrode film 7a and the second p-side electrode film 4b are formed. Since the structure is formed above, contamination that adheres to the interface between the electrode and the semiconductor layer in the electrode formation step can be significantly reduced, so that reliability, yield, electrical characteristics, and optical characteristics can be improved.

  According to the method for manufacturing a semiconductor light emitting device of the modified example according to the present embodiment, it is possible to provide a method for manufacturing a semiconductor light emitting device with higher process consistency and higher reliability, yield, electrical characteristics, and optical characteristics.

(Sixteenth embodiment)
FIG. 38 is a schematic cross-sectional view illustrating the structure of the semiconductor light emitting device according to the sixteenth embodiment of the invention.
A semiconductor light emitting device 201 according to the sixteenth embodiment of the present invention is a white LED that combines any one of the semiconductor light emitting elements according to the above embodiments and a phosphor. In the following description, the semiconductor light emitting device 101 according to the first embodiment and a phosphor are combined.

  That is, the semiconductor light emitting device 201 according to this embodiment includes any one of the above semiconductor light emitting elements and a phosphor layer irradiated with light emitted from the semiconductor elements.

  As shown in FIG. 38, in the semiconductor light emitting device 201 according to this embodiment, the reflective film 23 is provided on the inner surface of the container 22 made of ceramic or the like, and the reflective film 23 is provided on the inner side surface and the bottom surface of the container 22. Separately provided. The reflective film 23 is made of, for example, aluminum. Among these, the semiconductor light emitting element 101 illustrated in FIG. 1 is installed via the submount 24 on the reflective film 23 provided on the bottom of the container 22.

  Gold bumps 25 are formed on the semiconductor light emitting element 101 by a ball bonder and fixed to the submount 24. You may fix to the submount 24 directly, without using the gold bump 25. FIG.

  For fixing the semiconductor light emitting element 101, the submount 24, and the reflective film 23, it is possible to use bonding with an adhesive, solder, or the like.

  Electrodes patterned so as to insulate the p-side electrode 4 and the n-side electrode 7 of the semiconductor light-emitting element 101 are formed on the surface of the submount 24 on the semiconductor light-emitting element side. A bonding wire 26 is connected to the electrode (not shown). This connection is made at a portion between the reflection film 23 on the inner side surface and the reflection film 23 on the bottom surface.

  A first phosphor layer 211 containing a red phosphor is provided so as to cover the semiconductor light emitting element 101 and the bonding wire 26, and blue, green or yellow phosphors are provided on the first phosphor layer 211. The 2nd fluorescent substance layer 212 containing is formed. A lid portion 27 made of silicon resin is provided on the phosphor layer.

The first phosphor layer 211 includes a resin and a red phosphor dispersed in the resin.
As the red phosphor, for example, Y ₂ O ₃ , YVO ₄ , Y ₂ (P, V) O ₄ can be used as a base material, and trivalent Eu (Eu ³⁺ ) is used as an activator. Include. That is, Y ₂ O ₃ : Eu ³⁺ , YVO ₄ : Eu ^3+, etc. can be used as the red phosphor. The concentration of Eu ³⁺ can be 1% to 10% in terms of molar concentration. As a base material of the red phosphor, LaOS, Y ₂ (P, V) O ₄ or the like can be used in addition to Y ₂ O ₃ and YVO ₄ . In addition to Eu ³⁺ , Mn ⁴⁺ or the like can be used. In particular, by adding a small amount of Bi together with trivalent Eu to the YVO ₄ matrix, absorption at 380 nm increases, so that the luminous efficiency can be further increased. Further, as the resin, for example, silicon resin or the like can be used.

  The second phosphor layer 212 includes a resin and at least one of blue, green, and yellow phosphors dispersed in the resin. For example, a phosphor combining a blue phosphor and a green phosphor may be used, or a phosphor combining a blue phosphor and a yellow phosphor may be used, and a blue phosphor, a green phosphor and a yellow phosphor may be used. You may use the fluorescent substance which combined the fluorescent substance.

As the blue phosphor, for example, (Sr, Ca) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , BaMg ₂ Al ₁₆ O ₂₇ : Eu ^2+, or the like can be used.
As the green phosphor, for example, Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ having trivalent Tb as the emission center can be used. In this case, energy is transferred from Ce ions to Tb ions, so that the excitation efficiency is improved. For example, Sr ₄ Al ₁₄ O ₂₅ : Eu ²⁺ can be used as the green phosphor.
For example, Y ₃ Al ₅ : Ce ³⁺ can be used as the yellow phosphor.
Further, as the resin, for example, a silicon resin or the like can be used.
In particular, trivalent Tb exhibits sharp light emission near 550 nm where the visibility is maximized. Therefore, when combined with sharp red light emission of trivalent Eu, the light emission efficiency is significantly improved.

  According to the semiconductor light emitting device 201 according to the present embodiment, the ultraviolet light of 380 nm generated from the semiconductor light emitting element 101 is emitted to the substrate 10 side of the semiconductor light emitting element 101, and also uses the reflection in the reflective film 23, The phosphors included in each phosphor layer can be excited efficiently.

For example, the phosphor having the emission center of trivalent Eu contained in the first phosphor layer 211 is converted into light having a narrow wavelength distribution around 620 nm, and red visible light can be obtained efficiently. .
In addition, the blue, green, and yellow phosphors included in the second phosphor layer 212 are efficiently excited, and blue, green, and yellow visible light can be efficiently obtained.
As these mixed colors, white light and various other colors can be obtained with high efficiency and good color rendering.

Next, a method for manufacturing the semiconductor light emitting device 201 according to this embodiment will be described.
In addition, since the method demonstrated previously can be used for the process of manufacturing the semiconductor light-emitting device 101, below, the process after the semiconductor light-emitting device 101 is completed is demonstrated.

  First, a metal film to be the reflection film 23 is formed on the inner surface of the container 22 by, for example, sputtering, and this metal film is patterned to leave the reflection film 23 on the inner surface and the bottom surface of the container 22 respectively.

  Next, a gold bump 25 is formed on the semiconductor light emitting device 101 by a ball bonder, and is fixed on a submount 24 having electrodes patterned for the p-side electrode 4 and the n-side electrode 7. It is installed and fixed on the reflective film 23 on the bottom surface of 22. For these fixings, it is possible to use adhesive bonding or soldering. In addition, the semiconductor light emitting element 100 can be directly fixed on the submount 24 without using the gold bumps 25 by the ball bonder.

  Next, an n-side electrode and a p-side electrode (not shown) on the submount 24 are connected to electrodes (not shown) provided on the container 22 side by bonding wires 26.

  Furthermore, a first phosphor layer 211 containing a red phosphor is formed so as to cover the semiconductor light emitting element 101 and the bonding wire 26, and a second phosphor containing a blue, green or yellow phosphor on the first phosphor layer 211. The phosphor layer 212 is formed.

  Each of the methods for forming the phosphor layer is a method in which each phosphor is dispersed in a resin raw material mixed solution, and the resin is cured by heat treatment to cure the resin. In addition, the resin raw material mixed solution containing each phosphor is dropped and allowed to stand for a while and then cured, so that the fine particles of each phosphor are settled, and each fluorescent material is deposited under the first and second phosphor layers 211 and 212. The fine particles of the body can be unevenly distributed, and the luminous efficiency of each phosphor can be appropriately controlled. Thereafter, the lid 27 is provided on the phosphor layer, and the semiconductor light emitting device 201 according to this embodiment, that is, a white LED is manufactured.

In this specification, “nitride semiconductor” means B _x In _y Al _z Ga _1-xyz N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, x + y + z ≦ 1) Semiconductors having all compositions in which the composition ratios x, y, and z are changed within the respective ranges are included. Furthermore, in the above chemical formula, those further including a group V element other than N (nitrogen) and those further including any of various dopants added for controlling the conductivity type are also referred to as “nitride semiconductors”. Shall be included.

The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, those skilled in the art appropriately select the shape, size, material, arrangement relationship, etc. of each element such as a semiconductor multilayer film, metal film, dielectric film, etc. constituting the semiconductor light emitting element from a well-known range. As long as the present invention can be carried out in the same manner and the same effect can be obtained, it is included in the scope of the present invention.
Moreover, what combined any two or more elements of each specific example in the technically possible range is also included in the scope of the present invention as long as the gist of the present invention is included.

  In addition, all semiconductor light-emitting devices and methods for manufacturing the same that can be implemented by those skilled in the art based on the semiconductor light-emitting devices and methods for manufacturing the same described above as embodiments of the present invention are also included in the gist of the present invention. As long as it is included, it belongs to the scope of the present invention.

  In addition, in the category of the idea of the present invention, those skilled in the art can conceive of various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention. .

1 n-type semiconductor layer (first semiconductor layer)
DESCRIPTION OF SYMBOLS 1a 1st main surface 1b 2nd main surface 1s Laminated structure 1t, 1r Tapered shape part 2 p-type semiconductor layer (2nd semiconductor layer)
3 Light emitting layer 4 P-side electrode (second electrode)
4a First p-side electrode film (third metal film)
4b Second p-side electrode film (fourth metal film)
4c Third p-side electrode film (fifth metal film)
4t p side transparent electrode (transparent electrode)
7 n-side electrode (first electrode)
7a First n-side electrode film (first metal film)
7b Second n-side electrode film (second metal film)
7t n-side transparent electrode (transparent electrode)
8a 1st area 8b 2nd area 10 Substrate 11 Dielectric laminated film 11a Dielectric film 22 Container 23 Reflective film 24 Submount 25 Gold bump 26 Bonding wire 27 Cover part 45 P side pad 75 N side pad 90, 101, 101a, 101b, 102, 103a, 103b, 104 to 113 Semiconductor light emitting element 201 Semiconductor light emitting device 211, 212 Phosphor layer

Claims (14)

A first semiconductor layer; a second semiconductor layer; and a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, wherein the second semiconductor layer and the light emitting layer are selective. And a stacked structure in which a part of the first semiconductor layer is exposed on the first main surface on the second semiconductor layer side,
Provided on the first main surface of the laminated structure;
A first region including a first metal film provided on the part of the first semiconductor layer;
Provided on the part of the first semiconductor layer, the reflectance with respect to the light emitted from the light emitting layer is higher than that of the first metal film, and the contact resistance with respect to the first semiconductor layer is the first metal film. A second region comprising a higher second metal film;
A first electrode connected to the first semiconductor layer;
A second electrode including a reflective metal film provided on the first main surface of the multilayer structure and connected to the second semiconductor layer;
A plurality of dielectrics having different refractive indexes provided on the first main surface and on the first semiconductor layer and the second semiconductor layer that are not covered by any of the first electrode and the second electrode A dielectric laminated film in which films are laminated;
With
The first region is a portion of the first electrode facing the second electrode,
The semiconductor light emitting device, wherein the light emitted from the light emitting layer is emitted to the outside from the first semiconductor layer side.   2. The semiconductor light emitting device according to claim 1, wherein the second metal film reflects light emitted from the light emitting layer toward the laminated structure. 3.   3. The semiconductor light emitting element according to claim 1, wherein the dielectric laminated film reflects light emitted from the light emitting layer toward the laminated structure. 4.   The semiconductor light emitting element according to claim 1, further comprising a dielectric film provided between the dielectric multilayer film and the multilayer structure. The second electrode is
A third metal film;
A fourth metal film provided between the third metal film and the second semiconductor layer and having a higher reflectance to the light than the third metal film;
The semiconductor light-emitting device according to claim 1, wherein   6. The semiconductor light emitting element according to claim 5, wherein the fourth metal film is made of the same material as the second metal film.   The second electrode is provided between the third metal film and the fourth metal film, and a fifth metal film that suppresses diffusion of a material contained in the third metal film into the fourth metal film. The semiconductor light-emitting device according to claim 5, further comprising:   And further comprising a transparent electrode provided at least in part between at least one of the first semiconductor layer and the first electrode and between the second semiconductor layer and the second electrode. The semiconductor light-emitting device according to claim 1, wherein the semiconductor light-emitting device is a light-emitting device.   The side surface of the portion where the second semiconductor layer and the light emitting layer are selectively removed is inclined with respect to the layer surfaces of the first and second semiconductor layers. The semiconductor light emitting element as described in one. The dielectric multilayer film includes a first dielectric layer having a first refractive index n _1, alternately, a second dielectric layer having a different second refractive index n ₂ from the first refractive index n ₁ Layered,
When the emission wavelength of the light emitting layer is λ, the thickness of each of the first dielectric layers is substantially λ / (4n ₁ ), and the thickness of each of the second dielectric layers is substantially The semiconductor light emitting device according to claim 1, wherein λ / (4n ₂ ).   11. The semiconductor according to claim 1, wherein the stacked structure further includes a substrate made of sapphire provided on a second main surface facing the first main surface. Light emitting element.   12. The semiconductor light emitting device according to claim 11, wherein the stacked structure further includes a single crystal aluminum nitride layer provided between the substrate and the first semiconductor layer.   13. The semiconductor light emitting device according to claim 12, wherein a portion having a relatively high carbon concentration is provided on the substrate side of the aluminum nitride layer. A first semiconductor layer; a second semiconductor layer; and a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, wherein the second semiconductor layer and the light emitting layer are selective. And a stacked structure in which a part of the first semiconductor layer is exposed on the first main surface on the second semiconductor layer side,
Provided on the first main surface of the laminated structure;
A first region portion including a first metal film provided on the part of the first semiconductor layer;
Provided on the part of the first semiconductor layer, the reflectance with respect to the light emitted from the light emitting layer is higher than that of the first metal film, and the contact resistance with respect to the first semiconductor layer is the first metal film. A second region portion comprising a higher second metal film;
A first electrode connected to the first semiconductor layer;
A second electrode provided on the first main surface of the multilayer structure and connected to the second semiconductor layer;
A plurality of dielectrics having different refractive indexes provided on the first main surface and on the first semiconductor layer and the second semiconductor layer that are not covered by any of the first electrode and the second electrode A dielectric laminated film in which films are laminated;
Including
The first region portion is a portion of the first electrode facing the second electrode,
The second electrode is
A third metal film;
A fourth metal film provided between the third metal film and the second semiconductor layer and having a higher reflectance to the light than the third metal film;
Have
The fourth metal film is made of the same material as the second metal film,
The light emitted from the light emitting layer is a method for manufacturing a semiconductor light emitting device that is emitted to the outside from the first semiconductor layer side,
Laminating the first semiconductor layer, the light emitting layer, and the second semiconductor layer on a substrate;
Removing a part of the second semiconductor layer and the light emitting layer to expose the first semiconductor layer;
Forming the first metal film on the exposed first region of the first semiconductor layer;
At the same time, the reflectance of the light emitted from the light emitting layer on the exposed second region of the first semiconductor layer adjacent to the first region and on the second semiconductor layer is the first metal. Forming a metal film having a higher contact resistance with respect to the first semiconductor layer than the first metal film than the first metal film;
Dielectric films having different refractive indexes are alternately stacked on the first semiconductor layer and the second semiconductor layer exposed from the first metal film and the metal film higher than the first metal film. Forming a laminated body film;
A method of manufacturing a semiconductor light emitting device, comprising:

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