JPH10308533A - Galium-nitride-based compound semiconductor light emitting element, its manufacture and light emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to improve optical transmittance by transmitting the light generated in the inside of a laminated structure through a light transmitting electrode comprising the metal containing oxygen, and taking out the light. SOLUTION: A light emitting element 10 has a laminated body, wherein a buffer layer 14, an n-type layer 16, and a p-type layer 18 are laminated on a sapphire substrate 12 in this sequence. Then, a part of the P-type layer 18 is removed by etching. An n-type electrode 20 and an overcoat layer 22 are deposited on the surface of the exposed n-type layer 16. At this time, on the surface of the p-type layer 19, an impurity layer 24 and a light transmitting electrode 26 are formed. The transmitting electrode 26 is composed of, e.g. nickel containing oxygen and hydrogen. In addition, magnesium is also contained. On the remaining surface of the p-type layer 18 and the n-type layer 16, insulating layers 28 are deposited, respectively. Furthermore, a bonding pad 30, which is connected to the light transmitting electrode 26, is formed on the insulating film 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gallium nitride-based compound semiconductor light emitting device, a method of manufacturing the same, and a light emitting device. More specifically, the present invention provides a method for forming Ga on a substrate.
In a light emitting device in which gallium nitride-based compound semiconductor layers such as N, InGaN, and GaAlN are stacked, a gallium nitride-based compound semiconductor light-emitting device having a light-transmitting electrode so as to extract light from the surface of the stacked semiconductor layers, and The present invention relates to a manufacturing method and a light emitting device.

[0002]

2. Description of the Related Art In recent years, GaN, InGaN, GaAlN
Gallium nitride-based compound semiconductors have attracted attention as light emitting diodes (LEDs) that emit light in the blue or green wavelength region. The use of such a gallium nitride-based compound semiconductor has enabled high-intensity light emission in the blue or green region, which has been considered difficult. These gallium nitride-based compound semiconductors are generally crystal-grown on a sapphire substrate.

However, sapphire has an electrical insulating property. Therefore, in a gallium nitride based semiconductor light emitting device, unlike a light emitting device using a conductive substrate such as gallium arsenide, an electrode is provided on the back surface of the substrate. Can not. For this reason, it is necessary to form both an anode and a cathode on the side of the semiconductor layer on which the crystal has grown. Further, in gallium nitride-based compound semiconductor light-emitting devices, since the sapphire substrate has translucency with respect to the emission wavelength, the device is often mounted with the electrode surface facing down, and light is often extracted from the sapphire substrate side. . In this specification, “gallium nitride-based compound semiconductor” refers to Gax A
ly In1-xy N (0 <x, y ≦ 1, x + y ≦
In the chemical formula 1), semiconductors of all compositions in which the composition ratios x and y are changed within the respective ranges are included. For example, GaN (x = 1, y = 0) is also referred to as “Gax A
ly In1-xy N ".

FIG. 8 is a sectional view showing a schematic structure of a light emitting device using a conventional gallium nitride-based compound semiconductor light emitting device. First, the light emitting element 110 will be described. The light emitting element 110 has a GaN buffer layer 114 and an n-type G
An aN layer 116 and a p-type GaN layer 118 are stacked in this order. On the p-type GaN layer 118, a p-side electrode 120 is deposited. Also, p-type Ga
A portion of the N layer 118 is removed by etching to form n-type GaN
The layer 116 is exposed, and an n-side electrode 122 is deposited on the surface. On the n-side electrode 122, an overcoat electrode 124 is further laminated.

[0005] Such a light emitting element 110 is mounted on a mounting surface of a lead frame 130 with a conductive adhesive material 140 such as a silver paste with the electrodes 120 and 124 facing downward. In the conventional light emitting device as shown in FIG. 8, a driving current is injected from the p-type GaN layer 118 to the n-type GaN layer 116 to emit light. Of this emission,
The upward component in the figure is the sapphire substrate 11 as it is.
2 and is taken out. In addition, the light emitting component going downward in the figure is reflected by the p-side electrode 120 and goes upward, and is transmitted through the sapphire substrate 112 and extracted.

[0006]

However, in the conventional semiconductor light emitting device as shown in FIG.
The protrusion easily spread to the electrode gap 132 of the lead frame 130 and the pn junction gap 128 of the light emitting element 110. As a result, a short circuit occurs between the electrodes and the junction, the yield in the mounting process is remarkably reduced, and a problem may occur in long-term reliability.

To avoid these problems, the element size may be increased and the pn junction gap 128 and the lead frame electrode gap 132 may be increased. However, when the element size is increased, the number of elements obtained from the wafer is reduced, which causes a new problem that the manufacturing cost is increased.

[0008] The present invention has been made in view of such a point. That is, the present invention makes it possible to extract light from the semiconductor layer side by forming an electrode having good translucency and ohmic properties on the surface of the semiconductor layer, and it is sufficient to mount the sapphire substrate as the lower surface. An object of the present invention is to provide a gallium nitride-based compound semiconductor light-emitting device, a method of manufacturing the same, and a light-emitting device, which have not only high emission intensity but also improved production yield and reliability.

[0009]

That is, a semiconductor light emitting device according to the present invention comprises a substrate, at least one layer of a gallium nitride-based compound semiconductor of the first conductivity type deposited on the substrate, A stacked structure comprising at least one layer of a second conductive type gallium nitride-based compound semiconductor deposited on the conductive type gallium nitride-based compound semiconductor layer; and the second conductive type gallium nitride-based compound semiconductor. A light-transmitting electrode formed of a metal containing oxygen, formed on the surface of the compound semiconductor layer, and transmitting light emitted inside the laminated structure through the light-transmitting electrode. It is configured as a feature of being taken out.

Further, by further containing hydrogen in the translucent electrode, light transmittance can be improved and light can be extracted more efficiently.

[0011] Further, by making the translucent electrode further contain the above-mentioned second conductivity type dopant, the contact resistance can be reduced.

The metal constituting the light-transmitting electrode is nickel, titanium, platinum, tungsten, palladium, molybdenum, vanadium, iridium, rhodium,
By using a metal selected from the group consisting of cobalt, gold, magnesium, and aluminum, a good electrode having high light transmittance can be formed. Further, the substrate is sapphire, the first conductivity type is n-type, the second conductivity type is p-type, and the dopant is
By using magnesium as the metal and constituting the translucent electrode with nickel, a high-performance light-emitting element can be obtained by using a conventional material and a manufacturing process.

Further, in the manufacturing method according to the present invention, at least one layer of the first conductivity type gallium nitride-based compound semiconductor is grown on the substrate, and the first conductivity type gallium nitride-based compound semiconductor layer is formed. A crystal growth step of growing at least one layer of the second conductivity type gallium nitride based compound semiconductor on the surface of the second conductivity type gallium nitride based compound semiconductor; An impurity deposition step of depositing an impurity layer containing a dopant of the formula, an electrode formation step of forming a light-transmitting electrode made of a metal containing oxygen on the surface of the impurity layer, and a heat treatment. A heat treatment step of diffusing the dopant from the impurity layer into the layer of the second conductivity type gallium nitride-based compound semiconductor and the light-transmitting electrode to reduce contact resistance;
It is characterized by having comprising.

Here, in the heat treatment step, hydrogen contained in the gallium nitride-based compound semiconductor layer of the second conductivity type is released, and at least a part of the released hydrogen is converted into the light-transmitting electrode. , The light transmittance of the light-transmitting electrode can be further improved.

Further, the metal constituting the light-transmitting electrode is:
Nickel, titanium, platinum, tungsten, palladium,
By using a metal selected from the group consisting of molybdenum, vanadium, iridium, rhodium, cobalt, gold, magnesium, and aluminum, a good electrode with high light transmittance can be formed.

Further, the substrate is sapphire, the first conductivity type is n-type, the second conductivity type is p-type, and the dopant is magnesium, forming the light-transmitting electrode. By configuring the metal as being characterized in that it is nickel, a high-performance light-emitting element can be manufactured without largely changing materials and manufacturing equipment.

Further, the light emitting device according to the present invention comprises a lead
A light-emitting element including a frame and any one of the light-emitting elements described above, mounted on a mounting portion of a lead frame with the substrate serving as an adhesive surface, and transmitting light generated inside the laminated structure of the light-emitting element to the light-transmitting electrode. And a light emitting device with high performance can be obtained by a simple manufacturing process.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view illustrating a configuration of a gallium nitride-based compound semiconductor light emitting device of the present invention. That is, the light-emitting device 10 according to the present invention includes a buffer layer 14, an n-type layer 16,
The p-type layer 18 has a stacked body that is stacked in this order. Then, a part of the p-type layer 18 is removed by etching, and the n-side electrode 20 and the overcoat layer 22 are deposited on the exposed surface of the n-type layer 16.

Here, in the present invention, the impurity layer 24 and the translucent electrode 26 are formed on the surface of the p-type layer 18. The impurity layer 24 shown in FIG. 1 is obtained through a process of diffusing impurities such as magnesium into the p-type layer 18 and the electrode layer 26 by performing a heat treatment after depositing an impurity thin film layer such as magnesium. Things. Therefore, the thickness and composition of the impurity layer 24 after the completion of the manufacturing process vary depending on the thickness of the impurity deposited during the manufacturing process and the conditions of the subsequent heat treatment. For example, when all of the initially deposited impurities completely diffuse and mix into the p-type layer 18 and the electrode layer 26 by the subsequent heat treatment, the impurity layer 24 does not substantially exist after the end of the manufacturing process.
On the other hand, if a part of the initially deposited impurities diffuses into the p-type layer 18 and the electrode layer 26 by the subsequent heat treatment, but the remaining part remains undiffused, the impurity may remain even after the manufacturing process. Layer 24 is present. FIG. 1 illustrates a case where the impurity layer remains as described above.

The translucent electrode 26 is made of, for example, nickel containing oxygen and hydrogen, and further contains the above-mentioned magnesium. On the remaining surface portions of the p-type layer 18 and the n-type layer 16, insulating films 28
Has been deposited. Further, a bonding pad 30 connected to the translucent electrode 26 is formed on the insulating film 28.

First, the light transmitting electrode 26 of such a light emitting element will be described. FIG. 2 is a characteristic diagram showing light transmittance when nickel contains oxygen and hydrogen. That is, the horizontal axis in the figure represents the wavelength of light, and the vertical axis represents the light transmittance. Further, FIG. 3 shows the light transmittance of each of the nickel thin film, the nickel thin film containing oxygen, and the nickel thin film containing oxygen and hydrogen. Here, the thickness of each thin film is 10 nm for the nickel thin film, and 50 nm for the nickel thin film containing oxygen and the nickel thin film containing oxygen and hydrogen.

As can be seen from FIG. 2, the light transmittance is 40% or less in the case of only nickel, but the transmittance is remarkably improved and rises to about 85% when oxygen is introduced. That is, the light transmittance of the nickel film into which oxygen is introduced is more than twice as large as that of the nickel thin film although the film thickness is about five times as thick. In addition, the transmittance is improved to about 90% when hydrogen is introduced. As described above, by including oxygen and hydrogen in nickel, light transmittance can be increased to nearly 90% in the emission wavelength region of the gallium nitride-based semiconductor. As a result, light of sufficient intensity can be extracted through the translucent electrode 26.

Here, the optimum oxygen content of the translucent electrode 26 depends on the type of metal element and the method of forming the electrode. According to the experiments of the present inventors, as a general tendency, when the oxygen content is too low, the light transmission is not sufficient,
If the oxygen content was too high, the conductivity tended to be insufficient. According to an experiment using nickel as a metal element, when a light-transmitting electrode is deposited by sputtering in an oxygen-containing atmosphere, the oxygen content in the formed nickel oxide is about It was found that when the content was 70% or less, good translucency and conductivity were obtained.

Next, the impurity layer 2 of the light emitting device 10 of the present invention
The operation of No. 4 will be described. In the present invention, as described above, an impurity such as magnesium is deposited on the surface of the p-type layer 18 and the impurity is removed by heat treatment.
The light is diffused into the mold layer 18 and the translucent electrode 26. In this case, the same dopant as the conductivity type of the p-type layer 18 is used as the impurity. As described above, by diffusing the dopant, the ohmic property of the translucent electrode 26 is greatly improved. According to the experiment of the present inventor, as described above, the deposited dopant is all diffused by the heat treatment,
Even when the impurity layer 24 does not remain after the manufacturing process, the effect of improving the ohmic property similarly occurs.

FIG. 3 is a diagram showing a comparison between the case where the magnesium impurity layer 24 is provided and the case where the magnesium impurity layer 24 is not provided.
It is a characteristic diagram. Here, a prototype element for evaluation was produced, and I
-V characteristics were evaluated. As can be seen from the figure, in the element in which magnesium is not introduced, almost no current flows up to a voltage of 2 volts or more, indicating a strong rectification characteristic. However, in the element in which magnesium is introduced, a linear voltage-current characteristic is obtained, the ohmic property is greatly improved, and the contact resistance of the electrode is significantly reduced. According to the present invention, a layer of magnesium as a p-type dopant is provided between the p-type layer 18 and the translucent electrode 26, and then heat treatment is performed to diffuse magnesium. Therefore, magnesium is introduced at a high concentration near the interface between the p-type layer 18 and the translucent electrode 26, and the contact resistance can be reduced extremely effectively.

On the other hand, when the p-type layer is crystal-grown, hydrogen is often taken into the crystal. This hydrogen is released from the p-type layer during the above-described heat treatment, diffuses into the translucent electrode 26 made of nickel containing oxygen, and has an effect of further increasing the transmittance of the electrode.

As described above, according to the present invention,
First, the light transmittance of the translucent electrode 26 is significantly improved.
Further, the ohmic properties of the electrodes are also improved. As a result, unlike the conventional device as shown in FIG. 8, light can be efficiently extracted from the light emitting layer side, that is, the gallium nitride semiconductor side.

Next, a modified example of the present invention will be described.
FIG. 4 is an enlarged view of a main part around a p-side electrode, showing a second example of the light emitting device according to the present invention. In the light-emitting device shown in FIG. 1, a first thin-film metal layer 25 is formed on a p-type layer 18, and a light-transmitting electrode 26 is further formed thereon. The first thin-film metal layer 25 is desirably a thin film that transmits light emitted from the light-emitting element. For example, gold having a thickness of about 5 nanometers can be used. Also,
The light-transmitting electrode 26 can be, for example, a layer of nickel containing oxygen having a thickness of about 100 nanometers. As described above, by providing the thin-film metal layer 25 between the translucent electrode 26 and the p-type layer 18, the sheet resistance of the electrode can be reduced and the conductivity can be improved. Furthermore, if a material having good ohmic properties with the p-type layer 18 is selected as the material of the thin film metal layer 25, it is not necessary to provide the impurity layer 24 as described above with reference to FIG.

Next, FIG. 5 is an enlarged view of a main part around a p-side electrode, showing a third example of the light emitting device according to the present invention. In the light-emitting device shown in FIG. 1, an impurity layer 24 is first formed on a p-type layer 18, and a first thin-film metal layer 25 and a light-transmitting electrode 26 are formed in this order on the impurity layer 24. Have been. Here, as described above with reference to FIG. 1, the impurity layer 24 is formed by depositing an impurity serving as a dopant of the p-type layer 18.
This layer is left after heat treatment is performed to diffuse the impurities into upper and lower layers. The first thin-film metal layer 25 is desirably a thin film that transmits light emitted from the light-emitting element, as in the case of FIG. 4 described above.
Gold on the order of nanometers can be used. The translucent electrode 26 can be, for example, a layer of nickel containing oxygen having a thickness of about 100 nanometers.

In the light emitting device shown in FIG. 5, an impurity layer 24 serving as a dopant is provided between the p-type layer 18 and the first thin-film metal layer 25, and the impurity is removed by heat treatment. The first thin film metal layer 25 is diffused. Accordingly, in addition to the above-described effect of reducing the sheet resistance of the electrode, the effect of improving the ohmic contact of the electrode contact and reducing the contact resistance can be obtained.

Next, the manufacturing process of the light emitting layer according to the present invention will be described with reference to FIG. First, a buffer layer 14, an n-type layer 16, and a p-type layer 18 are formed on a sapphire substrate 12.
Are grown in this order. As a material of the buffer layer 14, for example, GaN can be used. n-type layer 16
For example, n-type GaN can be used. Further, as a material of the p-type layer 18, for example, p-type GaN can be used. Further, an n-type cladding layer, an active layer, and a p-type cladding layer may be laminated in this order between the n-type layer 16 and the p-type layer 18. As a crystal growth method for each of these semiconductor layers, for example, a metal organic chemical vapor deposition method (M
OCVD) can be used. When MOCVD is used, hydrogen of the carrier gas may be taken into the crystal, and as described above, this hydrogen diffuses into the nickel electrode 26 during the heat treatment of the element to improve the light transmittance. Can also be obtained.

However, as another growth method, for example,
Vapor-phase growth methods that do not use organic metals as raw materials,
An epitaxial method (CBE) can also be used.

Following the crystal growth, a part of the p-type layer 18 is
The n-type layer 16 is exposed by patterning by an EP method and further etching by a reactive ion etching (RIE) method or the like.

Next, patterning is performed by the PEP method, titanium and gold are deposited on the surface of the n-type layer 16 in this order, and the n-side electrode 20 is formed by the lift-off method.

Next, patterning is performed by the PEP method, a magnesium layer having a thickness of about 1 nm is deposited on the p-type layer 18, and a nickel layer containing oxygen having a thickness of about 100 nm is further deposited. -These are patterned by the off method. As a method for depositing these layers, for example, a high frequency sputtering method can be used. That is, by performing sputtering in an atmosphere containing oxygen with nickel as a target, a nickel layer containing oxygen can be deposited.

Next, heat treatment is performed. The condition depends on the thickness of the magnesium layer and the like. According to experiments performed by the present inventors, it has been found that it is desirable to perform a heat treatment at a temperature of 400 ° C. or higher in order to cause diffusion of impurities and improve ohmic properties. Also, if the heat treatment temperature is too high,
It has been found that adverse effects such as release of oxygen from the nickel layer may occur, and that the upper limit of the temperature is desirably set to 800 ° C.

Here, the condition of the heat treatment was set at 700 ° C. for 2 hours.
0 minutes. Due to this heat treatment, hydrogen is released from the p-type layer 18 and diffuses into the nickel electrode layer 26 to improve the light transmittance. Further, magnesium is diffused and activated in the p-type layer 18 and the electrode 26, respectively, so that the ohmic properties are improved and the contact resistance is reduced. Further, the adhesion between the p-side electrode 26 and the p-type layer 18 is also improved.

Next, an insulating film 28 is deposited. Insulating film 28
For example, silicon oxide or silicon nitride can be used. Furthermore, the bonding pad 30 and the overcoat 22 are formed by patterning by PEP method and further etching. These may have, for example, a structure in which titanium and gold are stacked in this order.

FIG. 6 is a characteristic diagram showing current / voltage characteristics and light output characteristics of the light emitting device obtained by the above-described steps. That is, the horizontal axis in the figure represents current, the left vertical axis represents light output, and the right vertical axis represents forward voltage. Further, the solid line in the figure represents the light output characteristics, and the broken line represents the current / voltage characteristics. As shown in the figure, the light emitting device according to the present invention has a very low contact resistance and shows good current-voltage characteristics. Also, the rise of the light output characteristics is good. The forward voltage with respect to a current of 20 mA was about 3.3 volts, and the light output was about 90 microwatts. Further, variations in current-voltage characteristics and light output characteristics within the wafer surface are extremely small, and the element yield is 92%.
% Was very good.

In the above description relating to the light emitting device 10 according to the present invention, the configuration in which the n-type layer 16 and the p-type layer 18 are laminated on the sapphire substrate 12 in this order is exemplified. However, the present invention is not limited to this. That is, the present invention can be similarly applied to a configuration in which the p-type layer and the n-type layer are stacked in the reverse order. In this case, on the sapphire substrate 12 via a buffer layer,
First, a p-type layer is grown, and then a p-type layer is grown. And
A thin film of an impurity serving as an n-type dopant may be deposited on the n-type layer, and a metal electrode layer containing oxygen and having a high light transmittance may be formed thereon. Also in this case, the heat treatment can improve the ohmic properties and light transmittance of the electrodes.

In the above-described example, nickel is used as the metal element of the translucent electrode 26, and GaN is used as the semiconductor layers 14 to 18. However, the present invention is not limited to this. According to the experiments of the present inventors, in addition to nickel, as metal elements contained in the translucent electrode, titanium, platinum, tungsten, palladium, molybdenum, vanadium, iridium, rhodium, cobalt, gold, magnesium, and aluminum It has been found that similarly good results can be obtained even when any one or a plurality of metal elements are selected and used.

As the semiconductors 14 to 18, Gax
Aly In1-xy N (0 <x, y ≦ 1, x +
In the chemical formula of y ≦ 1), a semiconductor appropriately selected from all compositions in which the composition ratios x and y are changed within the respective ranges can be used.

In the manufacturing method, the heat treatment is performed according to the respective purposes such as improvement of the ohmic property of the p-side electrode 26, improvement of the light transmittance of the p-side electrode 26, and improvement of the ohmic property of the n-side electrode 20. And may be applied separately. Further, in order to introduce oxygen and hydrogen into the p-side electrode 26, heat treatment may be performed in each gas atmosphere.

FIG. 7 is a schematic structural view showing a light emitting device using the light emitting element according to the present invention. Unlike the conventional light emitting device shown in FIG. 6, in the light emitting device according to the present invention, the light emitting element 10 is mounted on the lead frame 70 with the sapphire substrate 12 facing downward. Then, the p-side bonding pad 30 and the n-side overcoat 22
And wires 76 and 76 are respectively bonded.

According to the present invention, since light can be extracted from the front surface side of the light emitting element 10, a cup type lead frame 70 used in a gallium arsenide type LED is used as shown in FIG. be able to. Since such a cup-type lead frame 70 has the light reflecting wall 74 around the mounting portion of the light emitting element, the light collecting property is improved. Further, unlike the conventional light emitting device as shown in FIG. 8, a short circuit between the electrodes or the junction due to the "protrusion" of the conductive adhesive does not occur. Therefore, manufacturing yield and long-term reliability are improved.

Further, in the apparatus shown in FIG. 7, it is not necessary to precisely adjust the mounting position of the light emitting element according to the electrode pattern. Therefore, the mounting operation is facilitated, and the productivity of the assembling process is improved.

[0047]

The present invention is embodied in the form described above, and has the following effects.

First, according to the present invention, by using a metal electrode layer containing oxygen and hydrogen as an electrode, the light transmittance of the electrode layer is improved, and the light from the light emitting layer is transmitted through the electrode efficiently. You can take it out.

According to the present invention, since light can be efficiently extracted from the surface side of the element, the assembling process can be simplified, and short-circuiting between the electrodes, which has been a problem in the past, can be eliminated. Can be. In addition, manufacturing costs are reduced and long-term reliability is improved.

Further, according to the present invention, the ohmic property is improved by adding a dopant which gives the conductivity type of the semiconductor layer to the vicinity of the interface between the electrode and the semiconductor layer in contact with the electrode at a high concentration, thereby improving the contact resistance of the electrode. Can be reduced.

According to the present invention, the heat treatment
The light transmittance of the electrode can be further improved by a simple method of releasing hydrogen contained in the semiconductor layer and diffusing it into the electrode layer. That is, the manufacturing cost can be reduced, and the yield can be improved.

As described above, according to the present invention, a semiconductor light emitting device having high performance and high reliability can be produced at a high yield by a simple process, and the industrial advantage is great.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view illustrating a configuration of a gallium nitride-based compound semiconductor light emitting device of the present invention.

FIG. 2 is a characteristic diagram showing light transmittance when nickel and oxygen are contained in nickel.

FIG. 3 is an IV characteristic diagram of a light emitting element showing a comparison between a case where a magnesium impurity layer 24 is provided and a case where a magnesium impurity layer 24 is not provided.

FIG. 4 is an enlarged view of a main part around a p-side electrode, showing a second example of the light emitting device according to the present invention.

FIG. 5 is an enlarged view of a main part around a p-side electrode, showing a third example of the light emitting device according to the present invention.

FIG. 6 is a characteristic diagram showing current / voltage characteristics and light output characteristics of a light emitting device obtained according to the present invention.

FIG. 7 is a schematic configuration diagram illustrating a light emitting device using a light emitting element according to the present invention.

FIG. 8 is a cross-sectional view illustrating a schematic configuration of a light emitting device using a conventional gallium nitride-based compound semiconductor light emitting element.

[Explanation of symbols]

 10, 110 semiconductor light emitting device 12, 112 sapphire substrate 14, 114 buffer layer 16, 116 n-type layer 18, 118 p-type layer 20, 122 n-side electrode 22, 124 overcoat 24 impurity layer 25 first thin film metal layer 26 Translucent electrode 28 Insulating film 30 Bonding pad 70, 130 Lead frame 74 Reflective wall 76 Wire 140 Conductive adhesive

Claims (12)

[Claims] 1. A substrate, at least one layer of a first conductivity type gallium nitride based compound semiconductor deposited on the substrate, and deposited on the first conductivity type gallium nitride based compound semiconductor layer A stacked structure comprising at least one layer of the second conductive type gallium nitride-based compound semiconductor, and oxygen formed on the surface of the second conductive type gallium nitride-based compound semiconductor and containing oxygen And a light-transmissive electrode made of a metal selected from the group consisting of nickel, titanium, platinum, tungsten, palladium, molybdenum, vanadium, iridium, rhodium, cobalt, gold, magnesium, and aluminum. A gallium nitride-based compound semiconductor light-emitting device, wherein light generated inside a body is extracted through the light-transmitting electrode. 2. A light-transmitting thin-film metal layer provided between the second-conductivity-type gallium nitride-based compound semiconductor layer and the light-transmitting electrode. The light emitting device according to claim 1. 3. The light emitting device according to claim 1, wherein the thin film metal layer further contains a dopant that makes the gallium nitride-based compound semiconductor the second conductivity type. 4. The light emitting device according to claim 1, wherein the translucent electrode further contains a dopant that makes the gallium nitride-based compound semiconductor the second conductivity type. 5. The light emitting device according to claim 1, wherein said translucent electrode further contains hydrogen. 6. The method according to claim 6, wherein the substrate is sapphire, the first conductivity type is n-type, the second conductivity type is p-type, and the metal forming the light-transmitting electrode is nickel. The light emitting device according to claim 1, wherein 7. A method for growing at least one layer of a gallium nitride-based compound semiconductor of the first conductivity type on a substrate, wherein at least one layer of a gallium nitride-based compound semiconductor of the first conductivity type is formed on the first conductivity-type gallium nitride-based compound semiconductor. A crystal growth step of growing a layer of a two-conductivity-type gallium nitride-based compound semiconductor; and forming nickel, titanium, platinum, tungsten, palladium, molybdenum on the surface of the second-conductivity-type gallium nitride-based compound semiconductor layer. Forming a translucent electrode comprising a metal selected from the group consisting of vanadium, iridium, rhodium, cobalt, gold, magnesium, and aluminum, and further containing oxygen; and an electrode forming step. Of manufacturing a gallium nitride based compound semiconductor light emitting device. 8. A method for growing at least one layer of a gallium nitride-based compound semiconductor of the first conductivity type on a substrate, wherein at least one layer of a gallium nitride-based compound semiconductor of the first conductivity type is formed on the substrate. A crystal growth step of growing a two-conductivity-type gallium nitride-based compound semiconductor layer; and forming an impurity layer containing the second-conductivity-type dopant on a surface of the second-conductivity-type gallium nitride-based compound semiconductor layer. Depositing, on the surface of the impurity layer, a metal selected from the group consisting of nickel, titanium, platinum, tungsten, palladium, molybdenum, vanadium, iridium, rhodium, cobalt, gold, magnesium, and aluminum An electrode forming step of forming a translucent electrode further containing oxygen, and performing a heat treatment at a temperature of 400 ° C. or more, A heat treatment step of reducing the contact resistance by diffusing the dopant from the pure layer into the layer of the second conductivity type gallium nitride based compound semiconductor and the translucent electrode. A method for manufacturing a gallium compound semiconductor light emitting device. 9. The method according to claim 7, wherein said electrode forming step includes a step of depositing said translucent electrode by sputtering said metal in an atmosphere containing oxygen.
Or the method of 8. 10. In the heat treatment step, hydrogen contained in the gallium nitride-based compound semiconductor layer of the second conductivity type is released, and at least a part of the released hydrogen is used as the light-transmitting electrode. The method according to claim 8, wherein the method is contained. 11. The substrate is sapphire; the crystal growth method in the crystal growth step is a vapor growth method including hydrogen gas; the first conductivity type is n-type; and the second conductivity type is p. The method according to claim 10, wherein the dopant is magnesium, the metal forming the translucent electrode is nickel, and the heat treatment is performed at a temperature of 800 ° C. or less. 12. A light-emitting device comprising: a lead frame; and the light-emitting element according to claim 1; wherein the light-emitting element is provided on a mounting portion of the lead frame on a back surface of the substrate. A light-emitting device mounted as a bonding surface so that light emitted inside the laminated structure of the light-emitting element is extracted through the light-transmitting electrode.