JP2017112194A - Semiconductor light-emitting element and method of manufacturing semiconductor light-emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting element of realistic structure combining high ESD susceptibility and good light emission characteristics.SOLUTION: A semiconductor light-emitting element includes a substrate, a laminate where the same type of semiconductor materials are laminated in multiple layers for the substrate, a light-emitting part formed by laminating a first n-type semiconductor layer, a light-emitting active layer, and a first p-type semiconductor layer each other as a part of the laminate, and emitting light by application of a voltage, and a protection part formed by laminating a second n-type semiconductor layer and a second p-type semiconductor layer each other as a part of the laminate between the substrate and the light emitting part, and protecting the light emitting part electrically by being connected in parallel with the light emitting part.SELECTED DRAWING: Figure 1

Description

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

Conventionally, a nitride semiconductor material typified by GaN has been used as a semiconductor material constituting a semiconductor laser (LD: Laser Diode) or a semiconductor light emitting diode (LED: Light Emitting Diode) covering an emission wavelength from ultraviolet to green. ing.
A light emitting element made of this nitride semiconductor material emits light when a forward voltage is applied, but if a rapid high voltage is applied in the reverse direction due to static electricity or the like, it causes a failure due to dielectric breakdown. As a method for dealing with such a failure, in a light emitting device equipped with a light emitting element, a protective diode is reversely connected in parallel to improve an ESD (Electro-Static Discharge) withstand voltage, thereby causing dielectric breakdown of the light emitting element. The method of suppressing is taken (for example, refer patent document 1).
Patent Document 1 describes a group III nitride semiconductor light-emitting device in which a compensation diode for reverse withstand voltage compensation is provided as a protective element in order to prevent destruction of the light-emitting device due to rapid reverse voltage application (this specification). (The above configuration is referred to as Conventional Example 1 for convenience.) The compensation diode is provided separately from the light emitting element in the light emitting device, and is configured to be wired in the light emitting device by a metal wire.

In Patent Document 1, as another configuration example (in this specification, this configuration example is referred to as Conventional Example 2 for convenience), a light emitting portion and a compensation diode are formed adjacent to each other on the same sapphire substrate. A device structure is also described. In Conventional Example 2, the light emitting section and the compensation diode have a structure separated by a groove reaching the sapphire substrate. The light emitting unit and the compensation diode are electrically connected via a wire.
In Patent Document 1, as another configuration example (in this specification, this configuration example is referred to as Conventional Example 3 for convenience), an n-type GaN layer is further formed on the p-type nitride semiconductor of the light emitting portion. There is also described an element structure in which a p-type GaN layer is stacked and a compensation diode having a structure in which an n electrode and a p electrode are formed on both semiconductor layers, respectively.

Patent Document 2 discloses a light-emitting element part, a protective element part, and an LED manufactured using a GaN-based semiconductor epitaxially grown on a Si substrate (hereinafter sometimes abbreviated as “epi-growth”). Have been disclosed which are formed of a nitride semiconductor and a Si semiconductor, respectively.
According to the technology disclosed in Patent Document 2, by providing a tunnel junction portion with a heterojunction of Si / GaN in one of the light emitting element portion and the protective element portion, the protective element portion to the light emitting element portion, or the light emitting element portion. It is also described that the flow of electric current and the movement of electric charge can be made smooth from the protective element portion to the protective element portion.
Patent Document 2 discloses that the junction between a light emitting element portion made of a nitride semiconductor and a protection element portion made of a Si semiconductor is a laminated interface of different material layers, and when the protection element portion and the light emitting element portion are connected in reverse parallel. In addition, it is also described that since one connection is made at the laminated interface (tunnel junction), no wiring or wiring structure is required.

JP-A-9-148625 JP 2006-339629 A

In the case of the conventional example 1 described in Patent Document 1, since a compensation diode is required in addition to the light emitting element, there is a problem that the component cost increases accordingly. Furthermore, in the case of this conventional example 1, it is necessary to attach a compensation diode in the light emitting device separately from the light emitting element. For this reason, when mounting by wire wiring including a light emitting element is performed in the light emitting device, there is a problem in that the manufacturing cost increases due to an increase in the number of wires and the complicated handling of the wires.
In addition, in the case of the conventional example 2 described in Patent Document 1, the cost of components that are increased by using components other than the light emitting elements can be suppressed, but the chip area increases by the amount of compensation diodes other than the light emitting elements. There is a problem that the manufacturing cost of the entire device increases.
Furthermore, in the case of Conventional Example 3 described in Patent Document 1, since the compensation diode is provided on a part of the light emitting element, the increase in the manufacturing cost due to the above-described component cost and the increase in the chip area is suppressed. it can.

However, when the light emitting element is, for example, an LED, the area of the light emitting portion is reduced by the amount of the compensation diode, so that there is a problem that the light emission characteristic per chip is lowered.
In order to cope with this problem, a method of reducing the compensation diode region, in other words, a method of reducing the pn junction area of the compensation diode can be considered, but the limit value of the current that can flow safely through the compensation diode is also considered. descend. For this reason, when a very large reverse voltage is applied to a light emitting device having such a small compensation diode, the current limit value may be exceeded due to a sudden increase in forward current flowing in the compensation diode. As a case, there is a risk that the compensation diode will fail.

Further, in the structure described in Patent Document 2, when a nitride semiconductor, which is a lattice mismatch material, is epitaxially grown on the Si semiconductor protection element portion, the lattice strain between the nitride semiconductor and Si is relaxed in the initial growth stage. Therefore, a buffer layer made of a nitride semiconductor material having low crystallinity is generally provided. However, due to the low crystallinity, it is difficult to stably produce the buffer layer by stably controlling the electrical characteristics.
This is because, for example, when a buffer layer is formed on the protection element portion, a region where the resistance of the buffer layer is extremely high occurs on the upper surface of the protection element portion, or a region showing a substantially insulating property occurs. It shows the possibility.
When the structure described in Patent Document 2 is used, for example, an Si / GaN junction including the buffer layer may be provided as part of the n-type layer on the protective element side. However, due to the unstable electrical characteristics of the buffer layer with low crystallinity, protection with stable electrical characteristics, such as the resistance of the n-type layer on the protective element side being extremely high or almost no current flowing It becomes difficult to manufacture the element with a high yield, and lacks reality.

In addition, even when the Si / GaN junction is provided as a part of the n-type layer on the light emitting element side, it is difficult to manufacture a light emitting element having stable light emission characteristics with high yield for the same reason as described above. Become.
As described above, any of the conventionally proposed configurations is difficult to actually manufacture a semiconductor light emitting device having both a high ESD withstand voltage and good light emission characteristics.
Therefore, an object of the present invention is to provide a semiconductor light emitting device having a realistic structure that has both a high ESD withstand voltage and good light emission characteristics.

  In order to solve the above problems, one embodiment of a semiconductor light emitting device according to the present invention includes a substrate, a stacked body in which semiconductor materials similar to each other are stacked on the substrate, and a first n-type semiconductor. A light emitting portion that emits light upon application of a voltage, a second n-type semiconductor layer, and a second p-type semiconductor layer. A protection unit that electrically protects the light emitting unit by being connected in parallel to the light emitting unit, wherein a p-type semiconductor layer is stacked between the substrate and the light emitting unit as a part of the stacked body. And comprising.

By using a similar semiconductor material as in the present invention, the problem of unstable bonding characteristics caused by bonding between different semiconductor materials, which is a concern in the structure of Patent Document 2, is resolved. Both of the protective elements can be stably and uniformly manufactured.
The configuration of the semiconductor light-emitting element will be described in an easy-to-understand manner. Two devices are overlapped on the upper and lower sides, with the substrate side as the bottom, the protective portion at the bottom, and the light-emitting portion made of a semiconductor material similar to the protective portion at the top. It becomes the composition.
At least a part of this protective part constitutes a pn diode, and this pn diode is connected in parallel (more specifically, reversely connected in parallel) to the light emitting part constituted by the pin diode. It functions as a protective diode for the light emitting part.
According to the semiconductor light emitting element of the present invention in which the protective part is provided under the light emitting part, the area of the protective part can be equal to or larger than that of the light emitting part. As a result, the current limit value that can be passed to the protection unit is remarkably increased, so that the protection element is prevented from being destroyed.
In the semiconductor light emitting device, the semiconductor material of the second p-type semiconductor layer may be GaN or AlGaN.

In the semiconductor light emitting device, the second p-type semiconductor layer may be a layer of In _X Ga _1-X N (0.01 ≦ X ≦ 0.1) in contact with the second n-type semiconductor layer. Multiple layers may be included. In that it contains a layer of such _{In X Ga 1-X N (} 0.01 ≦ X ≦ 0.1), pn junction is realized on the entire surface in contact with the second n-type semiconductor layer.
In the semiconductor light emitting device, the semiconductor material of the second p-type semiconductor layer contains a p-type impurity at a concentration of 1.0 × 10 ¹⁸ cm ^{−3 to} 5.0 × 10 ¹⁹ cm ⁻³ . It is preferable. Within this concentration range, the p-type region after the activation annealing has a high carrier concentration, and the resistance is lowered to such an extent that it sufficiently functions as the p-type layer of the protective part.

In the semiconductor light emitting device, it is preferable that the first p-type semiconductor layer is located at a position farthest from the substrate in the stacked body.
When the semiconductor light emitting device having this configuration is formed in the same manner as the manufacturing process estimated in the above-described Conventional Example 3, the first p electrode of the first p-type semiconductor layer as the uppermost layer that affects the characteristics of the light emitting portion is formed. Since the region to be formed is always protected by the etching mask, it is not affected by damage during dry etching. Therefore, since a good ohmic connection is established for the connection between the protected first p-type semiconductor and the first p-electrode, the electrical characteristics and the light-emitting characteristics of the light-emitting portion do not deteriorate.

Further, in the semiconductor light emitting device, the substrate is a substrate made of a nitride semiconductor, and an electrode for electrically connecting to the protective portion through the substrate on the opposite side of the substrate from the stacked body. Is preferably provided. According to the semiconductor light emitting device having this preferred configuration, since the n electrode of the protective portion is formed on the back surface of the substrate, the number of wire wirings provided on the top surface of the light emitting device during mounting can be reduced to two.
When the semiconductor material of the stacked body is a nitride semiconductor and a GaN substrate is used as the substrate, the crystallinity is remarkably improved, so that the characteristics of the light emitting part are further improved and the nitride semiconductor is formed on the heterogeneous semiconductor substrate. Since it is not necessary to provide a so-called special buffer layer for each semiconductor substrate material for epitaxial growth of the material, an easily stable epitaxial growth layer (hereinafter sometimes referred to as “epi layer”) may be used. Can grow.

In the semiconductor light emitting device, the semiconductor material of the stacked body is a nitride semiconductor, and the substrate is made of one or more materials selected from the group of sapphire, Si, SiC, ZnO, and AlN. May be.
The semiconductor light emitting element may be a laser or a light emitting diode. When the semiconductor light emitting device is a laser, the first n-type semiconductor layer is a plurality of layers including a cladding layer adjacent to the active layer, and the first p-type semiconductor layer is formed on the active layer. A plurality of layers including adjacent clad layers may be provided, and at least one of the first n-type semiconductor layer and the first p-type semiconductor layer may include a constriction portion for constricting current.

  Furthermore, in order to solve the above-described problem, one embodiment of a method for manufacturing a semiconductor light emitting device according to the present invention is a stacking step in which a stack is formed by stacking a plurality of semiconductor materials similar to each other on a substrate. Then, as a part of the stacked body, a first n-type semiconductor layer, a light-emitting active layer, and a first p-type semiconductor layer, which serve as a light-emitting portion that emits light when a voltage is applied, are stacked. As another part, the second n-type semiconductor layer and the second p-type semiconductor layer that are connected in parallel to the light-emitting part to be a protective part that electrically protects the light-emitting part are formed on the substrate. A stacking process for stacking between the light emitting unit and the light emitting unit, and an etching process for scraping the stacked body in a stepped manner, out of the second n-type semiconductor layer or the second p-type semiconductor layer in the protective unit A first etching step exposing one or more, and the first n And a second etching step of exposing either the semiconductor layer or the first p-type semiconductor layer, having an electrode forming step of forming an electrode on each layer exposed by the etching process.

According to the above manufacturing method, the semiconductor light emitting device according to the present invention can be easily manufactured.
In the manufacturing method, the first etching step is a step of cutting the first region of the stacked body, and the second etching step is a step of cutting the second region of the stacked body. Also good. In this case, the etching step may include the active of the first n-type semiconductor layer and the first p-type semiconductor layer for another third region excluding the first region and the second region. It may be a step of forming a ridge portion by scraping a layer located on a side farther from the substrate than the layer by a predetermined height.

  According to the semiconductor light emitting device and the method for manufacturing the semiconductor light emitting device of the present invention, it is possible to provide a semiconductor light emitting device having a realistic structure having both a high ESD withstand voltage and good light emission characteristics.

1 is a cross-sectional configuration diagram illustrating a semiconductor laser that is a first embodiment of a semiconductor light emitting device. It is a figure which shows the mounting state of the semiconductor laser shown in FIG. It is a figure which shows the lamination process of the manufacturing process of a semiconductor laser. It is a figure which shows the etching process of the manufacturing process of a semiconductor laser. It is a figure which shows another etching process of the manufacturing process of a semiconductor laser. It is a figure which shows the formation processes, such as an upper surface electrode, of the manufacturing process of a semiconductor laser. It is a figure which shows the lower surface electrode formation process of the manufacturing process of a semiconductor laser. It is a circuit block diagram which shows the equivalent circuit of the laser apparatus of 1st Embodiment. It is a cross-sectional block diagram which shows the semiconductor laser which is 2nd Embodiment of a semiconductor light-emitting device. It is a circuit block diagram which shows the equivalent circuit of the laser apparatus of 2nd Embodiment. It is a cross-sectional block diagram which shows the light emitting diode (LED) which is 3rd Embodiment of the semiconductor light-emitting device of this invention. It is a figure which shows 4th Embodiment which employ | adopted dissimilar board | substrate material.

Specific embodiments of the semiconductor light emitting device of the present invention described above will be described below with reference to the drawings.
<First Embodiment>
FIG. 1 is a cross-sectional configuration diagram illustrating a semiconductor laser which is a first embodiment of a semiconductor light emitting device.
The semiconductor laser 100 of the first embodiment includes a low Si concentration n-type GaN layer 2, a Mg-doped GaN layer 3 doped with Mg, and an n-type GaN layer 4 as an n-type contact layer on a GaN substrate 1. Then, an n-type AlGaN layer 5 as an n-type cladding layer is laminated in this order.
On the n-type AlGaN layer 5, an active layer 6 that emits light, a p-type AlGaN layer 7 doped with Mg as a p-type cladding layer, and a p-type GaN doped with Mg as a p-type contact layer. Layer 8 is laminated in this order. As a result, a semiconductor multilayer structure from the n-type GaN layer 2 to the p-type GaN layer 8 is formed on the GaN substrate 1. . This semiconductor laminated structure corresponds to an example of a laminated body referred to in the present invention.

In this semiconductor laminated structure, the n-type GaN layer 2 and the Mg-doped GaN layer 3 form a protective part, and the n-type contact layer is an n-type GaN layer 4 to a p-type contact layer p-type GaN layer 8. A light emitting unit is configured. Such a protective part and a light emitting part correspond to an example of each of the protective part and the light emitting part referred to in the present invention. The combination of the n-type GaN layer 4 and the n-type AlGaN layer 5 corresponds to an example of the first n-type semiconductor layer according to the present invention, and the active layer 6 is an example of the active layer according to the present invention. Equivalent to. A combination of the p-type AlGaN layer 7 and the p-type GaN layer 8 corresponds to an example of the first p-type semiconductor layer according to the present invention. Furthermore, the n-type GaN layer 2 of the protective part corresponds to an example of the second n-type semiconductor layer according to the present invention, and the Mg-doped GaN layer 3 of the protective part is an example of the second p-type semiconductor layer according to the present invention. It corresponds to.
In FIG. 1, the active layer 6 is shown as a single layer for the sake of simplicity, but in practice, for example, a well-known multiple quantum well (MQW: Multi) using InGaN, AlGaN, GaN or the like is used. -Quantum-Well) structure or single quantum well (SQW) structure. In these structures, the semiconductor material used, the composition ratio, and the like differ depending on the emission wavelength.

A part of the p-type GaN layer 8 and the p-type AlGaN layer 7 constituting the p-type region of the light-emitting portion has a striped ridge portion having a desired shape for current confinement by well-known nitride semiconductor dry etching. Is formed. A protective film 9 made of SiO ₂ is formed on the side and surface of the p-type AlGaN layer 7 except for the p-type GaN layer 8 exposed at the top of the ridge. This ridge portion corresponds to an example of the narrow portion according to the present invention.
The p-electrode 13 that is in ohmic contact with the p-type GaN layer 8 of the light emitting portion is in contact with the p-type GaN layer 8 existing at the top of the ridge portion, and in addition to the desired region on the protective film 9. It extends in the direction and is formed so as to cover a part of the protective film 9.
The n-electrode 12 in the light-emitting portion is in contact with the n-type GaN layer 4 exposed by etching the p-type AlGaN layer 7, the active layer 6, and the n-type AlGaN layer 5 in a desired region away from the stripe-shaped ridge portion. And is in ohmic contact with the n-type GaN layer 4.

By etching a desired region from the surface of the n-type GaN layer 4 of the light emitting part, the surface of the Mg-doped GaN layer 3 constituting the p-type layer of the protective part is exposed, and the Mg-doped GaN exposed as such On the surface of the layer 3, a p-electrode 11 constituting a protective part is formed.
At this time, it becomes difficult for the exposed surface of the second p-type semiconductor layer constituting the protection portion to obtain a good ohmic contact with the p-electrode due to the influence of etching damage, resulting in a Schottky junction. However, the junction between the second p-type semiconductor layer damaged by dry etching and the p-electrode is only a Schottky junction. The forward rising voltage of the pn diode serving as the protection unit has a voltage value added with the height of the Schottky barrier in the Schottky junction. The Schottky barrier height is estimated to be at most 2 eV at the highest from 1.5 eV. From this, it is considered that the forward rising voltage of the protection unit is about 4.5V to 5V. Since this value is sufficiently smaller than the reverse breakdown voltage of a standard pin diode, the function of the protection unit is not impaired. Conversely, due to this influence, when a forward voltage is applied to the light emitting part (pin diode) side to cause a light emitting operation, the reverse leakage current on the protective part (pn diode) side is further reduced. That is, there is an effect that an unnecessary current component due to the reverse leakage current of the protection unit during the light emitting operation can be reduced.

The p electrode 11 of the protection part and the n electrode 12 of the light emitting part are electrically connected by a metal wiring pattern 14. As the metal material used for the p-electrode 11 and the n-electrode 12, in the case of the p-electrode 11, the contact portion with the semiconductor layer is made of a material selected from platinum group elements such as Ni, Pd, Pt, and the like. It is formed of a laminated film in which low resistance metals such as gold are laminated. In the case of the n-electrode 12, a well-known structure in which TiAl or the like is laminated is used. The metal wiring pattern 14 is formed of a single layer film mainly composed of a low-resistance metal material such as gold, Al, or copper, or a laminated film with other metals.
The p-electrode 11 for connecting to the protective part may be formed in a small part of the entire light-emitting element, and the p-electrode 11 of the protective part is connected to the n-electrode 12 of the light-emitting part and the upper surface of the light-emitting element. Electrical connection can be made using metal or the like. Therefore, the chip area of the entire light emitting element is not significantly increased, and the number of wire wirings provided on the upper surface of the element at the time of mounting can be reduced to three instead of four, which is the same as the number of electrodes. From this, it is possible to suppress a complicated wire wiring layout as in the conventional example 1 and the conventional example 2 and an increase in manufacturing cost due to an increase in chip area.

The n electrode 10 of the protection part is formed on the back side of the GaN substrate 1 and is in ohmic contact with the back side of the GaN substrate.
FIG. 2 is a diagram showing a mounting state of the semiconductor laser 100 shown in FIG.
In the mounting process of the semiconductor laser 100, the n-electrode 10 of the protection unit is fixed to the submount 19 by the solder 15, and the p-electrode 13 of the light emitting unit is also connected to the submount 19 by the wire wiring 16. And electrically connected. Thus, the n electrode 10 of the protection part and the p electrode 13 of the light emitting part, which are electrically connected to each other, are connected to the positive terminal of the laser device 150 which is a light emitting device by the wire wiring 17 extending from the submount 19.
In the mounting process, the p-electrode 11 serving as the protection part and the n-electrode 12 serving as the light-emitting part are connected to the ground (common) terminal of the laser device 150 serving as the light-emitting device by the wire wiring 18 extending from the metal wiring pattern 14. .

The structure of the semiconductor laser 100 that is the first embodiment of the semiconductor light emitting device of the present invention and the mounting state of the semiconductor laser 100 that is the light emitting device have been described above. This will be briefly described with reference to the drawings.
3 to 7 are diagrams showing a manufacturing process of the semiconductor laser 100. Hereinafter, the steps will be described in order with reference to the drawings.
In the manufacturing process of the semiconductor laser 100, a stacking process is first executed. FIG. 3 shows the lamination process. In this stacking step, all nitride semiconductor layers from the n-type GaN layer 2 to the p-type GaN layer 8 constituting the protective part and the light emitting part are epitaxially grown on the GaN substrate 1. This lamination process corresponds to an example of the lamination process referred to in the present invention.

Next, an etching process of a manufacturing process is performed. FIG. 4 shows an etching process. In this etching step, each epi layer (specifically, from the n-type GaN layer 4 of the light emitting portion to the p-type GaN is formed by using a well-known insulating film forming technique, a photolithography technique, and a dry etching technique using a chlorine-based gas. The cross-sectional shape is processed stepwise so that each layer reaching the layer 8 has a desired planar shape.
The step-like processing will be described in more detail. (1) First, as shown in FIG. 4A, the thickness of the n-type GaN layer 4 in the first region R1 etched up to the n-type GaN layer 4 Etching is performed to a depth corresponding to.
(2) Next, as shown in FIG. 4B, the n-type AlGaN layer 5 to the p-type AlGaN layer for both the second region R2 and the first region R1 etched to the n-type AlGaN layer 5 are used. Etching is further performed by a depth corresponding to the thickness shown in FIG. At this time, the first region R1 etched first is etched twice and becomes deeper.
(3) Further, as shown in FIG. 4C, the third region R3 excluding the ridge portion and the first and second regions R1 and R2 are further etched by the height of the ridge portion. As a result, the first region R1 is etched three times, the second region R2 is etched twice, and the third region R3 is etched once, and each region is stepped up to a desired depth. To be processed.
This etching process corresponds to an example of the etching process referred to in the present invention.

In addition, an etching process is not limited above, The following another etching processes may be employ | adopted.
FIG. 5 is a diagram showing another etching process.
(1) First, as shown in FIG. 5A, the upper surface of the Mg-doped GaN layer 3 in a state where a resist film is formed in a region excluding the first region R1 that is etched to the upper surface of the Mg-doped GaN layer 3 The step of etching the first region R1 is performed until the surface is exposed.
(2) Next, as shown in FIG. 5B, a resist film was formed in each of the region except for the second region R2 etched to the upper surface of the n-type GaN layer 4 and the first region R1. In this state, a process of etching the second region R2 is performed until the upper surface of the n-type GaN layer 4 is exposed.
(3) Further, as shown in FIG. 5C, the resist film is formed in the region to be the ridge portion and the first region R1 and the second region R2, respectively, by the height of the ridge portion. A step of etching the third region R3 is performed.

  Following such an etching step, an annealing step (not shown) of the manufacturing process is performed. In this annealing step, an activation annealing process is performed in order to activate carriers in each of the Mg-doped GaN layer 3 constituting the protective part and the p-type AlGaN layer 7 and the p-type GaN layer 8 constituting the light emitting part. As the activation annealing treatment, for example, the heating and holding is performed for about 10 to 30 minutes while heating at 600 ° C. in air. Thereby, the carrier density of each of the Mg-doped GaN layer 3, the p-type AlGaN layer 7, and the p-type GaN layer 8 is improved.

Next, an upper surface electrode forming step of the manufacturing process is performed. FIG. 6 shows a process for forming the upper surface electrode and the like. In the upper surface electrode formation process, a protective film, an electrode, and the like are formed on the upper surface side of the GaN substrate 1. Specifically, the protective film 9 made of SiO ₂ is formed on the side surface and the surface of the p-type AlGaN layer 7 except for the p-type GaN layer 8 exposed at the top of the ridge portion. Further, the p-electrode 11, the n-electrode 12, and the p-electrode 13 are formed using a well-known photolithography technique, an electron beam vapor deposition method, and a lift-off method, respectively. Thereafter, a metal wiring pattern 14 that electrically connects the p-electrode 11 and the n-electrode 12 is formed using these photolithography techniques. This upper surface electrode formation process corresponds to an example of an electrode formation process according to the present invention.

Next, the lower surface electrode forming step of the manufacturing process is performed. FIG. 7 shows a lower surface electrode forming step. In this lower surface electrode forming step, the n electrode 10 is formed on the lower surface side of the GaN substrate 1.
The semiconductor laser 100 is completed by such a manufacturing process.
Here, comparing the above-described conventional example 3 with the present embodiment, the conventional example 3 also has a method in which all the semiconductor layers from the light emitting portion to the compensation diode portion are epitaxially grown and then processed into a desired shape for each layer by dry etching. Presumed to be used. However, in Conventional Example 3, the compensation diode portion is etched away by dry etching to expose the p-type nitride semiconductor surface of the light emitting portion, and the p-type nitride semiconductor of the light emitting portion is affected by the damage during dry etching. The surface deteriorates, making it difficult to establish a good ohmic connection with the p-electrode. For this reason, in Conventional Example 3, the electrical characteristics (for example, diode characteristics) of the light emitting portion are lowered, and it is difficult to provide a semiconductor light emitting device having excellent light emitting characteristics.

  On the other hand, in the case of the present embodiment, the p-type GaN layer 8 that influences the characteristics of the light emitting portion is in the uppermost layer (that is, the position farthest from the GaN substrate 1). Even in the case where the etching process shown is used, the region where the p-electrode 13 is formed is always protected by the etching mask and thus is not affected by damage during dry etching. Therefore, since a good ohmic connection is established between the protected p-type GaN layer 8 and the p-electrode 13, the electrical characteristics and the light-emitting characteristics of the light-emitting portion are not deteriorated.

By the way, the region where the carrier of the Mg-doped GaN layer 3 is activated by the activation annealing process in the annealing step described above is limited to the region where the surface of the Mg-doped GaN layer 3 is exposed by dry etching and the vicinity thereof. This is due to the cause described below.
The purpose of the activation annealing treatment is to moderately desorb H (hydrogen) contained in the so-called p-type layer to which Mg is added. This desorption of H activates the p-type carrier and improves the carrier density. To do. Such H desorption works in the situation where there is no Si-added nitride semiconductor layer on the nitride semiconductor layer to which Mg is added, such as the p-type AlGaN layer 7 and the p-type GaN layer 8 in the light emitting portion. Thus, the carrier can be sufficiently activated.

However, since the p-type GaN layer 3 of the protective part has an n-type GaN layer 4 and an n-type AlGaN layer 5 added with Si in an upper layer in a region other than the surface exposed by dry etching, the H in the region is Not fully desorbed.
For this reason, the conductivity type of the p-type GaN layer 3 in the region where the Si-added layer is present in the upper layer is not a clear p-type but exhibits extremely high resistance characteristics.
Therefore, the equivalent circuit of the laser device 150 shown in FIG. 2 has the circuit configuration shown in FIG.
As shown in FIG. 8, the laser device 150 has a circuit configuration in which the light emitting unit 151 and the protective diode 152 are reversely connected in parallel, and the high resistor 153 is also connected in parallel.
The protection diode 152 protects the light emitting unit 151 by causing a current to flow to the protection diode 152 side when a rapid reverse high voltage is applied to the light emitting unit 151 due to static electricity or the like. Thereby, the ESD withstand voltage of the laser device 150 (and the semiconductor laser 100) is improved.

On the other hand, the high-resistance element 153 shows the junction between the n-electrode 10 and the n-electrode 12 through the Mg-doped GaN layer 3 that has not been activated as described above. Since the high-resistance element 153 has extremely high resistance characteristics as described above, the circuit configuration shown in FIG. 8 does not hinder the operation of the light-emitting unit 151.
In addition, since the high resistance body 153 releases the current by assisting the protection diode 152 when a high reverse voltage is applied to the light emitting section 151, the current limit value of the entire protection section is improved, and the protection diode 152 This prevents malfunctions.
As described above, even if there is a region where carriers are not activated in the Mg-doped GaN layer 3, the protective portion of the semiconductor laser 100 effectively functions as an example of the protective portion according to the present invention.
The Si concentration of the low Si concentration n-type GaN layer 2 constituting the n-type layer of the protective part is preferably 5.0 × 10 ¹⁷ cm ⁻³ or less, more preferably 1.0. × 10 ¹⁷ cm ⁻³ or less Lowering the Si concentration of the n-type GaN layer 2 can reduce the reverse leakage current in the pn diode of the protection part, and thus can reduce unnecessary leakage current during forward operation of the light emitting part.

In the first embodiment described above, general Mg is selected as the p-type impurity. However, the p-type impurity added to the first p-type semiconductor layer and the second p-type semiconductor layer according to the present invention. Is not particularly limited to this, and any impurity that exhibits p-type conductivity may be used.
The Mg concentration of the Mg-doped GaN layer 3 is desirably 1.0 × 10 ¹⁸ cm ⁻³ or more and 5.0 × 10 ¹⁹ cm ⁻³ or less. By setting this concentration range, the p-type region after the activation annealing has a high carrier concentration, and the resistance is lowered to such an extent that it sufficiently functions as the p-type layer of the protective portion.

Moreover, although the case where GaN was applied as a Mg dope layer of a protective part was described, you may use AlGaN besides this. Even in the case of AlGaN, if the Al composition is up to about 4%, it is possible to sufficiently exhibit p-type characteristics in the Mg concentration range.
In addition, the Mg concentration of the p-type GaN layer 8 is desirably 1.0 × 10 ¹⁹ cm ⁻³ or more and 3.0 × 10 ²⁰ cm ⁻³ or less, and may have a two-layer structure having different Mg concentrations. In particular, increasing the Mg concentration on the outermost surface side has an effect of improving the ohmic connection with the p-electrode.
Further, the Al composition of the n-type AlGaN layer 5 and the p-type AlGaN layer 7 is not particularly limited, and it goes without saying that an Al composition that functions as a cladding layer may be selected according to the emission wavelength in the light-emitting portion. .

In the first embodiment, SiO ₂ is applied as the protective film. However, the present invention is not limited to this, and it is not limited to this, and has an insulating property such as SiN, SiON, Al ₂ O ₃ , and a normal semiconductor element. Any insulating film material can be selected as long as it is an insulating film material that can be formed and processed in the manufacturing process.
The conditions for the activation annealing treatment are not limited to the above-described atmosphere, temperature, and time, and the annealing conditions can be appropriately selected depending on the conditions of the annealing apparatus used.
In the semiconductor laser 100 of the first embodiment manufactured with the configuration shown in FIG. 1, as a result of evaluating the forward characteristics of the protection unit, the forward rising voltage is in the range of 4.6 V to 5.1 V, and after the rising, The current also tended to increase proportionally as in a normal diode. As a result, the value is sufficiently low with respect to the reverse withstand voltage (˜80 V) of the light emitting part, and the forward current smoothly increases on the protection part side, thereby increasing the reverse direction with respect to the light emitting part side. No voltage is applied.

Therefore, the semiconductor laser 100 according to the first embodiment is sufficiently protected by the above-described operation of the protection unit in parallel with the light emitting unit even when a high voltage is applied in the reverse direction to the light emitting unit. A failure on the light emitting unit side can be prevented in advance.
Moreover, as a result of evaluating the reverse direction characteristic of the said protection part, it turned out that the leak current to -20V is a low value as 10 nA or less. This indicates that the ratio of the leakage current of the protective part in the forward current during forward operation of the light emitting part is remarkably reduced, so that the electrical characteristics and light emitting characteristics are good on the light emitting part side. Can be obtained.

Second Embodiment
Next, a second embodiment of the semiconductor light emitting device of the present invention will be described.
FIG. 9 is a cross-sectional configuration diagram showing a semiconductor laser which is a second embodiment of the semiconductor light emitting device.
The semiconductor laser 200 of the second embodiment shown in FIG. 9 has the same structure as the semiconductor laser 100 of the first embodiment shown in FIG. 1 except that the configuration of the p-type layer in the protection unit is different. Hereinafter, description will be made focusing on differences from the first embodiment, and redundant description will be omitted.
In the semiconductor laser 200 of the second embodiment, a p-type InGaN layer doped with Mg between the low Si concentration n-type GaN layer 2 constituting the protective part and the Mg-doped GaN layer 3 doped with Mg. (Mg-doped InGaN layer) 20 is provided. That is, the Mg-doped layer of the protective part is constituted by a two-layer structure of the Mg-doped GaN layer 3 and the Mg-doped InGaN layer 20, and the Mg-doped layer constituted by such a two-layer structure is the second aspect of the present invention. Corresponds to an example of the p-type semiconductor layer.

Unlike the GaN layer to which Mg is added, the InGaN layer to which Mg is added exhibits p-type conductivity from the beginning even without activation annealing treatment. Furthermore, the carrier activation rate is higher than that of the GaN layer to which Mg is added. For this reason, the semiconductor laser 200 of the second embodiment includes the Mg-doped InGaN layer 20, so that even if an unactivated region is generated in the upper Mg-doped GaN layer 3, the effect of the Mg-doped InGaN layer 20 A clear pn junction is established in the entire protection part.
Therefore, an equivalent circuit of a laser device in which the semiconductor laser 200 of the second embodiment is mounted in the same manner as in FIG. 2 has a circuit configuration shown in FIG.
The laser device 250 is mounted with the semiconductor laser 200 according to the second embodiment, and has a circuit structure in which a protective diode 252 is reversely connected in parallel to the light emitting unit 251.
Due to the effect of the Mg-doped InGaN layer 20 described above, the entire protection unit functions as the protection diode 252. And since the pn junction area in the protection part side becomes larger than the pn junction area in 1st Embodiment, the forward current which flows through a pn junction interface in a protection part increases.

Further, in the case of the second embodiment, since the region of the high resistance 153 as shown in FIG. 8 is eliminated, the reverse direction characteristics of the protection part are almost dominated by the pn junction. For this reason, there is an effect that the reverse leakage current in the protection unit is further reduced.
As a result of evaluating the reverse direction characteristics of the protective portion of the semiconductor laser 200 of the second embodiment manufactured with the configuration shown in FIG. 9, no clear leakage current appeared up to about −30V. From this, it can be considered that there is almost no extra current component due to the protective part during forward operation of the light emitting part.

In addition, as a result of evaluating the forward characteristics of the protection unit, the rising voltage was about 4.7 V, and although there was no obvious difference with respect to the semiconductor laser 100 of the first embodiment, The slope of the current became steep (the differential resistance was reduced to about one third). From this, the semiconductor laser 200 of the second embodiment can further reduce the influence of the rapid and remarkably high reverse voltage applied to the light emitting part due to static electricity or the like, as compared with the semiconductor laser 100 of the first embodiment.
In the second embodiment described above, the In composition of the Mg-doped InGaN layer 20 was not specified, but the above effect can be sufficiently obtained if the In composition is 1% or more and at most 10% or less. be able to. More preferably, it is 2% or more and 8% or less.

The film thickness of the Mg-doped InGaN layer 20 is preferably 10 nm or more and 100 nm or less. Although it depends on the In composition, if it is thinner than 10 nm, a tunnel current or the like may occur, and a good pn junction may not be obtained in the protective part. On the other hand, when the thickness is larger than 100 nm, the crystallinity of the Mg-doped InGaN layer 20 itself may be deteriorated, or the crystallinity of the light emitting portion grown on the upper layer may be lowered.
Furthermore, the Mg concentration of the Mg-doped InGaN layer 20 is desirably 1.0 × 10 ¹⁸ cm ⁻³ or more and 5.0 × 10 ¹⁹ cm ⁻³ or less. By setting the Mg concentration within this range, the Mg-doped InGaN layer 20 can sufficiently function as a p-type semiconductor layer even when activation annealing is not performed.
In the semiconductor laser 200 of the second embodiment, if a more specific example of the Mg-doped p-type InGaN layer 20 is given, p-type In ₀ having an Mg concentration of 1.0 × 10 ¹⁹ cm ⁻³ and a film thickness of 50 nm. _.07 GaN _0.93 layer.

  As described above, when the semiconductor laser 200 according to the second embodiment provided with the Mg-doped p-type InGaN layer 20 is used, both the protective portion and the light emitting portion are provided as in the semiconductor laser 100 according to the first embodiment. Is composed only of a nitride semiconductor material. For this reason, there exists an effect which the electrical property in both a light emission part and a protection part, and the light emission characteristic of a light emission part are stabilized. As a result, a low-cost semiconductor laser having both a high ESD withstand voltage and good light emission characteristics can be realized.

<Third Embodiment>
Next, a third embodiment of the semiconductor light emitting device of the present invention will be described.
FIG. 11 is a cross-sectional configuration diagram showing a light emitting diode (LED) which is a third embodiment of the semiconductor light emitting device of the present invention.
11 includes a low Si concentration n-type GaN buffer layer 31, a p-type InGaN layer 32 doped with Mg, and an Mg-doped AlGaN layer 33 doped with Mg on a sapphire substrate 30. They are stacked in this order. Furthermore, on the Mg-doped AlGaN layer 33, an n-type GaN layer 34 as an n-type contact layer, an active layer (light-emitting layer) 35 composed of an undoped InGaN-based multiple quantum well layer, and a contact layer to which Mg is added P-type GaN layers 36 are stacked in this order. As a result, a semiconductor multilayer structure is formed on the sapphire substrate 30 from the low Si concentration n-type GaN buffer layer 31 to the p-type GaN layer 36. This semiconductor laminated structure also corresponds to an example of a laminated body referred to in the present invention.

  In this semiconductor laminated structure, the n-type GaN buffer layer 31, the p-type InGaN layer 32, and the Mg-doped AlGaN layer 33 constitute a protective part, and the n-type contact layer is changed from the n-type GaN layer 34 to the p-type contact layer. The light emitting part is constituted by up to a certain p-type GaN layer 36. Such a protective part and a light emitting part also correspond to an example of each of the protective part and the light emitting part referred to in the present invention. The n-type GaN layer 34 corresponds to an example of the first n-type semiconductor layer according to the present invention, the active layer 35 corresponds to an example of the active layer according to the present invention, and the p-type GaN layer 36 refers to the present invention. This corresponds to an example of a first p-type semiconductor layer. Further, the n-type GaN buffer layer 31 corresponds to an example of the second n-type semiconductor layer according to the present invention, and the combination of the p-type InGaN layer 32 and the Mg-doped AlGaN layer 33 is the second according to the present invention. This corresponds to an example of a p-type semiconductor layer.

The n-type GaN layer 34 is exposed by etching from the p-type GaN layer 36 to the active layer (light-emitting layer) 35 in the region excluding the light-emitting surface, and a desired region on the exposed n-type GaN layer 34 is included in the desired region. N electrodes 37 are provided and are in ohmic contact with the n-type GaN layer 34.
A transparent electrode 38 is provided in a desired region on the p-type GaN layer 36, and a p-electrode 39 is provided on a part of the transparent electrode 38. As the transparent electrode 38, a well-known ITO (indium tin oxide) film can be applied.
A desired region is further etched from the surface of the n-type GaN layer 34 exposed by the etching, and the surface of the Mg-doped AlGaN layer 33 constituting the p-type layer of the protective part is exposed. A p-electrode 40 constituting a protective part is formed in a desired region on the surface of the Mg-doped AlGaN layer 33 thus exposed. As described above, the junction between the Mg-doped AlGaN layer 33 and the p electrode 40 is not ohmic but Schottky due to the influence of etching damage.

Further, the p electrode 40 of the protection part and the n electrode 37 of the light emitting part are electrically connected by a metal wiring pattern 42.
The n-electrode 41 constituting the protection part is formed in a desired region on the surface of the n-type GaN buffer layer 31 exposed by etching further in the depth direction from the surface of the Mg-doped AlGaN layer 33, and the n-type GaN buffer An ohmic connection is made to the layer 31.
The connection method of each electrode at the time of mounting of the light emitting diode 300 having such a structure conforms to the connection method in the first embodiment shown in FIG. 2, and the manufacturing process of the light emitting diode 300 is also shown in FIGS. The detailed description is omitted because it conforms to the manufacturing process in the first embodiment.

Since the light emitting diode 300 shown in FIG. 11 has a structure in which light emitted from the active layer 35 is mainly emitted to the surface side, the p electrode of the protective portion is used to reflect the light emitted from the active layer as much as possible. The layer in contact is not an Mg-doped GaN layer but an Mg-doped AlGaN layer.
By providing such an Mg-doped AlGaN layer 33, the difference in refractive index from the active layer is increased to a small extent, so that downward light emitted from the active layer is reflected upward by the Mg-doped AlGaN layer 33. Thus, there is an effect of improving the light emission characteristics in the light emitting portion.
The Mg-doped AlGaN layer 33 is a single AlGaN layer, but instead of this single-layer Mg-doped AlGaN layer 33, a superlattice structure of a higher Al composition Mg-doped AlGaN layer and Mg-doped GaN layer is formed. Even if it is used, the same effect of improving the light emission characteristics can be obtained.

In general, a light emitting diode has a chip area that is significantly larger than that of a semiconductor laser. Therefore, in the third embodiment, a pn junction is established on the entire surface as a configuration of a p-type layer of a protective portion, thereby causing reverse leakage. A configuration including an Mg-doped InGaN layer that can reduce the current is adopted.
With this configuration, an unnecessary current component at the time of forward operation of the light emitting unit can be significantly cut, so that favorable light emission characteristics can be obtained in the light emitting unit.
Furthermore, since the chip area is increased, there is an effect that the limit value of the current that can be safely passed through the protection unit is also greatly increased.
In the third embodiment described above, the example in which the sapphire substrate is used as the substrate has been described, but in addition to this, a different substrate material capable of epitaxially growing a nitride semiconductor can be adopted.

FIG. 12 is a diagram showing a fourth embodiment in which a different substrate material is used.
In the light emitting diode 400 of the fourth embodiment, a Si substrate 51 is employed instead of the sapphire substrate 30 in the third embodiment. A buffer layer 50 made of a material appropriately selected to reduce lattice distortion is provided between the Si substrate 51 and the n-type GaN buffer layer 31. The other structure is the same as that of the third embodiment.
By providing such a buffer layer 50 on the Si substrate 51 and then epitaxially growing a nitride semiconductor material, a nitride semiconductor multilayer film with good crystallinity can be formed.

Furthermore, by forming both the light emitting part and the protective part using such a nitride semiconductor multilayer film with good crystallinity, the electrical characteristics of both the light emitting part and the protective part and the light emitting characteristics of the light emitting part are stabilized. effective.
In addition to the Si substrate 51 exemplified here, a SiC substrate, an AlN substrate, a ZnO substrate, and the like can also be employed as different kinds of substrate materials capable of epitaxially growing a nitride semiconductor. When these different substrate materials are employed, an appropriate material for relaxing the lattice distortion is selected as the material of the buffer layer 50.
Moreover, such a dissimilar substrate material can be employed not only as a light emitting diode but also as a substrate of a semiconductor laser.

  In each of the embodiments described above, an example in which the present invention is applied to a semiconductor light emitting device using a nitride semiconductor material has been described. However, the present invention is similarly applied to other semiconductor light emitting devices based on GaAs. Thus, the above-described effect can be obtained in the same manner. As a result, even a GaAs-based semiconductor light emitting device can provide a semiconductor light emitting device having a realistic structure that has both high ESD withstand voltage and good light emitting characteristics.

DESCRIPTION OF SYMBOLS 100 ... Semiconductor laser, 150 ... Laser apparatus, 1 ... GaN substrate, 2 ... n-type GaN buffer layer, 3 ... Mg-doped GaN layer, 4 ... n-type GaN layer, 5 ... n-type AlGaN layer, 6 ... Active layer, 7 ... p-type AlGaN layer, 8 ... p-type GaN layer, 9 ... protective film, 10 ... n-electrode of protective part, 11 ... p-electrode of protective part, 12 ... n-electrode of light-emitting part, 13 ... p-electrode of light-emitting part, DESCRIPTION OF SYMBOLS 14 ... Metal wiring pattern, 15 ... Solder, 16, 17, 18 ... Wire wiring, 19 ... Submount, 151 ... Light emission part, 152 ... Protection diode, 153 ... High resistance, 200 ... Semiconductor laser, 250 ... Laser apparatus, DESCRIPTION OF SYMBOLS 20 ... p-type InGaN layer, 251 ... Light-emitting part, 252 ... Protection diode, 300 ... Light-emitting diode, 30 ... Sapphire substrate, 31 ... Low Si concentration n-type GaN layer, 32 ... p-type InGaN layer, 33 ... Mg dough AlGaN layer, 34 ... n-type GaN layer, 35 ... active layer (light-emitting layer), 36 ... p-type GaN layer, 37 ... n-electrode in light-emitting part, 38 ... transparent electrode, 39 ... p-electrode in light-emitting part, 40 ... protection P electrode, 41 ... n electrode of protective part, 42 ... metal wiring pattern, 50 ... buffer layer, 51 ... Si substrate

Claims (15)

A substrate,
A stacked body in which semiconductor materials similar to each other are stacked in a plurality of layers with respect to the substrate;
A light emitting portion that emits light by application of voltage, wherein the first n-type semiconductor layer, the active layer that emits light, and the first p-type semiconductor layer are stacked on each other as part of the stacked body;
A second n-type semiconductor layer and a second p-type semiconductor layer are stacked on each other between the substrate and the light emitting unit as part of the stacked body, and are connected in parallel to the light emitting unit. A protective portion for electrically protecting the light emitting portion;
A semiconductor light emitting device comprising:   The semiconductor light emitting element according to claim 1, wherein the semiconductor material of the second p-type semiconductor layer is GaN.   2. The semiconductor light emitting element according to claim 1, wherein the semiconductor material of the second p-type semiconductor layer is AlGaN. The second p-type semiconductor layer is a plurality of layers including a layer of In _X Ga _1-X N (0.01 ≦ X ≦ 0.1) in contact with the second n-type semiconductor layer. The semiconductor light emitting device according to claim 1, wherein The second p-type semiconductor layer contains a p-type impurity at a concentration of 1.0 × 10 ¹⁸ cm ⁻³ or more and 5.0 × 10 ¹⁹ cm ⁻³ or less. 5. The semiconductor light emitting device according to any one of items 1 to 4.   6. The semiconductor light-emitting element according to claim 1, wherein the first p-type semiconductor layer is located at a position farthest from the substrate in the stacked body. The substrate is a substrate made of a nitride semiconductor;
The electrode for electrically connecting with the said protection part through this board | substrate is provided in the opposite side to the said laminated body of the said board | substrate, The any one of Claim 1 to 6 characterized by the above-mentioned. The semiconductor light-emitting device described in 1. The semiconductor material of the laminate is a nitride semiconductor,
The semiconductor light-emitting element according to claim 1, wherein the substrate is a GaN substrate. The semiconductor material of the laminate is a nitride semiconductor,
7. The semiconductor light emitting element according to claim 1, wherein the substrate is made of one or more materials selected from the group consisting of sapphire, Si, SiC, ZnO, and AlN.   The semiconductor light-emitting element according to claim 1, wherein the semiconductor light-emitting element is a laser. The first n-type semiconductor layer is a plurality of layers including a clad layer adjacent to the active layer;
The first p-type semiconductor layer is a plurality of layers including a cladding layer adjacent to the active layer;
11. The semiconductor light emitting element according to claim 10, wherein a constriction portion for confining current is provided in at least one of the first n-type semiconductor layer and the first p-type semiconductor layer.   The semiconductor light-emitting element according to claim 1, wherein the semiconductor light-emitting element is a light-emitting diode. A stacking step of stacking a plurality of semiconductor materials similar to each other on a substrate to form a stacked body, and a first n serving as a light emitting portion that emits light by application of voltage as a part of the stacked body The light emitting unit is electrically protected by laminating a type semiconductor layer, an active layer that emits light, and a first p type semiconductor layer, and being connected in parallel to the light emitting unit as another part of the stacked body A laminating step of laminating a second n-type semiconductor layer and a second p-type semiconductor layer, which serve as a protective portion, between the substrate and the light emitting portion;
An etching step of cutting the stacked body in a stepped manner, wherein the first etching step exposes one or more of the second n-type semiconductor layer or the second p-type semiconductor layer in the protection portion; A second etching step of exposing either one of the n-type semiconductor layer or the first p-type semiconductor layer,
Forming an electrode on each layer exposed by the etching step; and
A method for manufacturing a semiconductor light emitting device, comprising: The first etching step is a step of cutting the first region of the laminate;
The method of manufacturing a semiconductor light emitting element according to claim 13, wherein the second etching step is a step of cutting the second region of the stacked body.   In the third region other than the first region and the second region, the etching step is more effective than the active layer of the first n-type semiconductor layer and the first p-type semiconductor layer. 15. The method of manufacturing a semiconductor light-emitting element according to claim 14, wherein the ridge portion is formed by cutting a layer located on a side away from the substrate by a predetermined height.

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