JP2004288729A - Light emitting element and method of manufacture the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting element in which a light retrieving efficiency can be improved without changing the structure of a semiconductor laminate structure including a light emitting layer. <P>SOLUTION: The light emitting element 1 includes the compound semiconductor layer having the light emitting layer 24. A metal electrode 9 for applying a light emission drive voltage to the light emitting layer 24 is disposed in the shape for covering the partial area of the light retrieving main surface of the compound semiconductor layer. At least the part of the compound semiconductor layer is formed as an Al-containing compound semiconductor layer 221 containing Al. An Al insulating layer 11 brought into contact with the Al-containing compound semiconductor layer 221 is disposed in a shape covering the area including the geometrical center of gravity position of the direct under-region. A metal electrode 9 is energized with the Al-containing compound semiconductor layer 221 at the non-forming region 13 of the Al insulating layer 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light emitting device and a method for manufacturing the same.
[0002]
[Prior art]
[Patent Document 1]
JP-A-5-102605 [Patent Document 2]
Japanese Patent Application Laid-Open No. 05-013813 [Patent Document 3]
Japanese Patent Application Laid-Open No. 05-0667849 [Patent Document 4]
JP-A-09-07221 [Patent Document 5]
JP-A-10-154831 [Patent Document 6]
JP-A-11-017218 [Patent Document 7]
JP-A-11-186595
The light emitting element has a structure in which a compound semiconductor layer is laminated to form a light emitting layer portion including a pn junction. Specifically, one of the main surfaces on the p-layer side or the n-layer side of the element chip having the light emitting layer portion is fixed on the stage using a silver paste or the like, and the other main surface side is made of Au or the like. Generally, a structure is used in which a metal electrode is arranged, an Au wire for energization is bonded to the metal electrode, and the whole is resin-molded.
[0004]
Since this metal electrode functions as a light-shielding body, it is formed, for example, so as to cover only the central portion of the main surface of the light-emitting layer portion, and light is extracted from the surrounding electrode-free region. However, when a voltage for driving the device is applied to this electrode, the current density in the device is high immediately below the electrode, and is low in the region around the electrode which is the light extraction region, so that the light extraction efficiency is likely to be reduced. . Heretofore, attempts have been made to solve this problem mainly from the viewpoint of improving the semiconductor laminated structure itself including the light emitting layer portion. As a typical example, there is a method in which an inversion layer having a conductivity type opposite to that of the semiconductor layer is buried at a position directly below the electrode inside the compound semiconductor layer in contact with the electrode (for example, Patent Documents 1 to 7).
[0005]
[Problems to be solved by the invention]
However, in the method of burying the inversion layer, it is necessary to insert a photolithography step for forming the inversion layer corresponding to the electrode region in the middle of the epitaxial growth step of the compound semiconductor layer, which increases the number of steps and consequently decreases the manufacturing efficiency. There is a problem that easily leads to
[0006]
It is an object of the present invention to provide a light emitting device capable of improving light extraction efficiency without changing the structure of a semiconductor laminated structure itself including a light emitting layer portion, and a method of manufacturing the same.
[0007]
[Means for Solving the Problems and Functions / Effects]
In order to solve the above problems, the light emitting device of the present invention is
Having a compound semiconductor layer having a light emitting layer portion, a metal electrode for applying a light emission drive voltage to the light emitting layer portion is disposed so as to cover a partial region of the light extraction main surface of the compound semiconductor layer,
At least a part of the compound semiconductor layer is an Al-containing compound semiconductor layer containing Al,
In a part of the region directly below the metal electrode, between the Al-containing compound semiconductor layer and the metal electrode, the Al-based insulating layer in contact with the Al-containing compound semiconductor layer defines a region including the geometric center of gravity of the region directly below. Placed in a covering form,
The metal electrode is electrically connected to the Al-containing compound semiconductor layer directly or indirectly through another compound semiconductor layer outside the region where the Al-based insulating layer is formed.
[0008]
According to the structure of the light emitting device of the present invention, at least a part of the compound semiconductor layer is an Al-containing compound semiconductor layer, and the Al-containing compound semiconductor is formed in a part of a region directly below the metal electrode disposed on the light extraction main surface side. An Al-based insulating layer in contact with the Al-containing compound semiconductor layer is disposed between the layer and the metal electrode as a current blocking layer. Specifically, an Al-based insulating layer is disposed in a partial area including the geometric center of gravity of the area immediately below the area where light extraction is most hindered by the metal electrode. According to this structure, the region where light extraction is easily hindered can be blocked by the Al-based insulating layer, and the current is diffused in the in-plane direction of the Al-based insulating layer, so that the current flows through the metal electrode. After approaching the outer peripheral edge, a current can be caused to flow toward the Al-containing compound semiconductor layer outside the Al-based insulating layer. Thus, a current can be supplied to the light emitting layer in a form avoiding the region immediately below the metal electrode, and the light extraction efficiency can be improved. Further, unlike the conventional light emitting device, it is not necessary to bury the inversion layer, and as a result, a light emitting device with improved light extraction efficiency is realized without changing the structure of the semiconductor laminated structure itself including the light emitting layer portion. I do. Further, since the Al-based insulating layer can be easily formed by using the Al component contained in the surface layer portion of the Al-containing compound semiconductor layer, a photolithography step for forming an inversion layer is performed by using a compound semiconductor as in a conventional light emitting element. There is no need to insert the layer in the middle of the epitaxial growth process, and the manufacturing process can be simplified.
[0009]
Although another insulating layer can be interposed between the Al-based insulating layer and the metal electrode, if the current-blocking ability of the Al-based insulating layer is sufficiently high, the metal electrode may be in contact with the Al-based insulating layer. They can be arranged, and the element structure can be further simplified.
[0010]
In order to reduce light emission in a region directly below the metal electrode, an Al-based insulating layer is disposed so as to face the center of the main surface of the metal electrode on the bonding side with the compound semiconductor layer. On the outside, it is preferable to adopt a structure in which the junction-side main surface of the metal electrode is electrically connected to the Al-containing compound semiconductor layer. Thereby, light emission at the center of the electrode, which is easily blocked by the metal electrode, is effectively suppressed, and the light extraction efficiency can be further improved.
[0011]
In the Al-containing compound semiconductor layer, a region of the main light extraction surface that is not covered by the metal electrode can be covered by an Al-based passivation layer in contact with the Al-containing compound semiconductor layer. As a result, deterioration of the Al-containing compound semiconductor layer due to oxidation of the Al component is suppressed, and the life of the element can be extended. Further, the Al-based passivation layer can be easily formed by using an Al component contained in a surface portion of the Al-containing compound semiconductor layer. In this case, if the Al-based passivation layer is formed so as to enter the outer peripheral portion of the main surface of the metal electrode on the side of the junction with the Al-containing compound semiconductor layer, the Al-based passivation layer may be formed from the outer peripheral edge of the metal electrode with respect to the Al-containing compound semiconductor layer. Crevice corrosion does not easily progress, and the life of the element can be further extended.
[0012]
As another mode effective for suppressing the crevice corrosion, a region of the Al-containing compound semiconductor layer, which is not covered by the metal electrode on the main light extraction surface, is formed on the side surface of the metal electrode and the Al-containing compound semiconductor layer of the metal electrode. A structure covered with a passivation layer together with the outer peripheral portion of the main surface on the non-joining side with the substrate can also be exemplified. In this case, the passivation film is not limited to the Al-based insulating layer as long as it can prevent oxidation of the Al component of the Al-containing compound semiconductor layer, and can be formed as, for example, a SiO ₂ film.
[0013]
Next, the light emitting layer portion can be formed of AlGaInP as having a double hetero structure in which a first conductivity type clad layer, an active layer, and a second conductivity type clad layer are laminated in this order. Thereby, a light emitting element with high luminance can be realized. In this configuration, when a current-carrying electrode wire is bonded to the metal electrode, a cushion layer made of an Al-containing compound semiconductor having a band gap larger than that of the active layer may be formed on the second conductive type clad layer. it can. The Al-based insulating layer is formed in contact with the cushion layer. For example, when wires are joined by ultrasonic welding or thermosonic bonding that adds more heat, impact stress due to ultrasonic waves or heating (and pressurization) concentrates on the compound semiconductor layer immediately below the metal electrodes. Then, crystal defects such as dislocations are introduced as damage. When the damaged region reaches the active layer portion, the following problems are specifically caused.
(1) Direct decrease in light emission luminance. The cause is considered to be an increase in the non-light-emitting transition process due to crystal defects.
(2) Reduction in element life. When energization is continued to the light emitting layer in which dislocations are formed, current concentrates on the dislocations, so that the dislocations are likely to multiply, and the emission luminance deteriorates with time.
[0014]
However, by interposing the cushion layer containing Al as described above between the second conductivity type cladding layer and the metal electrode, even if a damaged region occurs when the electrode wire is joined to the metal electrode, The influence of the damaged region remains in the cushion layer and hardly affects the active layer. In addition, the cushion layer has an advantage that the Al-based insulating layer (or Al-based passivation layer) can be formed more easily because the Al component is added more than the active layer for suppressing light absorption.
[0015]
Further, since the cushion layer is made of a compound semiconductor having a larger band gap than the active layer in the light emitting layer portion, it is difficult to absorb light from the light emitting layer portion, which contributes to an improvement in light extraction efficiency. Specific examples of the material of the cushion layer include AlGaAs, GaAsP, and AlGaAsP. Further, when the cushion layer is formed thin, it works advantageously from the viewpoint of suppressing light absorption. Specifically, the thickness of the cushion layer is desirably adjusted to 0.1 μm or more and 30 μm or less. If the thickness of the cushion layer is less than 0.1 μm, the total thickness of the bonding-side semiconductor layer tends to be insufficient, and the effect of bonding the electrode wires tends to reach the light emitting layer portion. On the other hand, when the thickness of the cushion layer exceeds 30 μm, the resistivity in the layer thickness direction increases when the dopant concentration is kept low, leading to a decrease in luminous efficiency due to an increase in the series resistance of the device. In addition, it takes a long time to grow a thick cushion layer, and a large amount of raw materials are required, which tends to cause a decrease in manufacturing efficiency and an increase in cost. More preferably, the thickness of the cushion layer is 0.5 μm or more and 10 μm or less. The cushion layer can be, for example, a current diffusion layer having a higher dopant concentration than the second conductivity type cladding layer.
[0016]
Next, the method for manufacturing a light-emitting element of the present invention is the method for manufacturing a light-emitting element of the present invention, based on the Al component contained in the outermost layer portion of the Al-containing compound semiconductor layer contained in the compound semiconductor layer. It is characterized in that an Al-based insulating layer is formed. Since the Al-based insulating layer used in the light emitting device of the present invention can be easily formed by using the Al component contained in the surface layer portion of the Al-containing compound semiconductor layer, photolithography for forming an inversion layer is performed as in a conventional light emitting device. It is not necessary to insert the process in the middle of the epitaxial growth process of the compound semiconductor layer, and the manufacturing process can be simplified.
[0017]
The Al-based insulating layer can be formed as, for example, an Al-based nitride layer. However, since the Al component is easily oxidized, the method of forming the Al-based insulating layer as an Al-based oxide layer is a simple process. It is more advantageous from the viewpoint of conversion. In this case, by oxidizing the outermost layer of the Al-containing compound semiconductor layer, an Al-based insulating layer composed of an Al-based oxide layer can be easily formed. The Al-based oxide layer can be formed by, for example, thermal oxidation of an Al-containing compound semiconductor layer. However, since it is necessary to form the Al-based oxide layer only in a part of the region directly below the metal electrode, a heat-resistant mask material is used. Accordingly, the surface of the Al-containing compound semiconductor layer must be patterned, and it is difficult to avoid complicated processes. Therefore, a method of forming an Al-based oxide layer serving as an Al-based insulating layer by contacting an oxidizing solution with a part of a region where a metal electrode is to be arranged on the main surface of the Al-containing compound semiconductor layer is to be adopted. Is desirable. According to this method, a region that should be brought into contact with the oxidizing solution can be patterned using a normal photoresist, and the process can be simplified.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a conceptual diagram showing a light emitting device 1 according to one embodiment of the present invention. The light-emitting element 1 has a light-emitting layer portion 24 made of AlGaInP formed on one main surface of an n-type GaAs single crystal substrate (hereinafter, also simply referred to as “substrate”) 7 with an n-type GaAs buffer layer 2 interposed therebetween. A p-type cushion layer 221 is formed so as to cover the light emitting layer portion 24. Further, a metal electrode 9 made of Au or the like is arranged on the cushion layer 221 so as to cover a part of the main surface thereof, and an electrode wire 47 made of Au or the like is joined thereto. . On the other hand, on the other main surface side of the substrate 7, a back electrode layer 15 made of a metal such as an Au-Ge-Ni alloy is formed on the entire surface.
[0019]
The light-emitting layer portion 24 is made of (Al _x Ga _1-x ) _y In _1-y P mixed crystal, and has a first conductivity type clad layer 4, a second conductivity type clad layer 6, and a first conductivity type clad. The active layer 5 is located between the layer 4 and the cladding layer 6 of the second conductivity type and has a double hetero structure. Specifically, the active layer 5 made of a non-doped (Al _x Ga _1-x ) _y In _{1 -y} P (where 0 ≦ x ≦ 0.55, 0.45 ≦ y ≦ 0.55) mixed crystal is formed. has a p-type _{(Al x Ga 1-x)} y in 1-y P cladding layer 6 and the n-type _{(Al x Ga 1-x)} y in 1-y P cladding layer 4 and the sandwiched. In the light emitting device 1 of FIG. 1, the p-type AlGaInP cladding layer 6 (the p-type dopant is Zn: C from an organic metal molecule can also contribute as a p-type dopant) is disposed on the cushion layer 221 side. The n-type AlGaInP cladding layer 4 (the n-type dopant is Si) is disposed on the 15th side. It is obvious to those skilled in the art that the term "non-doped" as used herein means "do not actively add a dopant", and a dopant component unavoidably mixed in a normal manufacturing process. (For example, the upper limit is about 10 ¹³ to 10 ¹⁶ / cm ³ ) is not excluded. The p-type AlGaInP cladding layer 6 has a p-type carrier concentration (majority carrier concentration) of 5 × 10 ¹⁶ / cm ³ or more and less than 1 × 10 ¹⁸ / cm ³ , preferably 1 × 10 ¹⁷ / cm ³ or more and 7 × 10 7 / cm ^{3. 17} / cm ³ or less.
[0020]
In the present embodiment, the cushion layer 221 is made of an AlGaAs layer containing Zn as a p-type dopant (an Al-containing intermediate layer: for example, Al _x Ga _1-x As, x = about 0.7), an Al-containing compound. It is a semiconductor layer. The p-type AlGaInP cladding layer has a p-type dopant concentration of 1 × 10 ¹⁷ / cm ³ or more and 2 × 10 ¹⁹ / cm ³ or less, preferably 5 × 10 ¹⁷ / cm ³ or more and 1 × 10 ¹⁹ / cm ³ or less. It is set to be larger than 6 and functions as a current spreading layer. The thickness of the cushion layer 221 is 0.1 μm or more and 30 μm or less, preferably 0.5 μm or more and 10 μm or less.
[0021]
On the surface of the cushion layer 221 forming the Al-containing compound semiconductor layer, a part of the region immediately below the metal electrode 9 that includes the geometric center of gravity, The Al-based insulating layer 11 is formed in contact with the cushion layer 221 so as to face the center of the surface. Outside the Al-based insulating layer 11, the bonding-side main surface of the metal electrode 9 is directly connected to the cushion layer 221. In the present embodiment, the metal electrode 9 and the cushion layer 221 are electrically connected in the annular conductive region 13 along the periphery of the metal electrode 9.
[0022]
The light extraction main surface of the cushion layer 221 is covered with an Al-based passivation layer 12 in a region not covered with the metal electrode 9 in contact with the cushion layer 221. In the present embodiment, the light emitting layer portion 24 as well as the cushion layer 221 is configured as an Al-containing compound semiconductor layer, and the peripheral side surface is also covered with the Al-based passivation layer 12.
[0023]
Hereinafter, a method for manufacturing the light emitting device 1 of FIG. 1 will be described.
First, as shown in step A of FIG. 2, the n-type GaAs buffer layer 2 is formed on the first main surface of the GaAs single crystal substrate 7, and then the n-type AlGaInP cladding layer 4 and the AlGaInP active layer 5 are formed as the light emitting layer 24. , And a p-type AlGaInP cladding layer 6 (see FIG. 1) are epitaxially grown in this order. Next, as shown in Step B, a cushion layer 221 made of AlGaAs is epitaxially grown.
[0024]
The epitaxial growth of each of these layers can be performed by a known metal organic vapor phase epitaxy (MOVPE) method. The following can be used as a source gas serving as a component source of Al, Ga, In, P, and As;
-Al source gas; trimethyl aluminum (TMAl), triethyl aluminum (TEAl), etc .;
Ga source gas; trimethylgallium (TMGa), triethylgallium (TEGa), etc.
In source gas: trimethyl indium (TMIn), triethyl indium (TEIn), or the like.
P source gas: tert-butyl phosphine (TBP), phosphine (PH ₃ ), etc.
· As source gas; tertiary butyl arsine (TBA), such as arsine (AsH _3).
[0025]
The following can be used as the dopant gas;
(P-type dopant)
· Mg source: such as biscyclopentadienyl magnesium _(Cp 2 Mg).
-Zn source: dimethyl zinc (DMZn), diethyl zinc (DEZn) and the like.
(N-type dopant)
-Si source: silicon hydride such as monosilane.
[0026]
The growth of each layer can be performed continuously in the same vapor phase growth apparatus by switching the source gas. Further, the dopant concentration of each layer can be adjusted to a desired value by the supply ratio of the dopant gas to the source gas. Next, the process proceeds to step C in FIG. 2, where the back electrode layer 15 is formed on the second main surface of the substrate 7 by a vacuum deposition method. Further, as in the step D, the metal electrode 9 is arranged in each region of the cushion layer 221 corresponding to each light emitting element chip, and baking for fixing the electrode is performed at an appropriate temperature, whereby the light emitting element wafer 50 is obtained. .
[0027]
FIG. 3 shows the details of the step D. First, as in Step 1, the photoresist layer 30 is patterned on the main surface of the cushion layer 221 by using a well-known photolithography step so that only the portion intended as the conductive region 13 is covered with the photoresist layer 30. While forming. Then, in this state, as shown in Step 2, an oxidizing solution composed of an ammonia / hydrogen peroxide mixed solution is brought into contact with the main surface of the cushion layer 221 not covered with the photoresist layer 30. As a result, Al-based oxide layers 11 'and 12' are formed in the outermost layer by selective oxidation of Al in AlGaAs using a mixed solution of ammonia and hydrogen peroxide. The thickness of the Al-based oxide layers 11 'and 12' is, for example, 100 nm or more and 200 nm or less. If the thickness of the Al-based oxide layers 11 ′ and 12 ′ is less than 100 nm, the insulating effect tends to be insufficient. If the thickness exceeds 200 nm, the formation takes a long time, leading to a reduction in manufacturing efficiency.
[0028]
Next, as shown in Step 3, the photoresist layer 30 is removed. Oxidation of Al in the region is prevented by the photoresist layer 30, and the surface of the cushion layer 221 made of AlGaAs is exposed to form the conduction region 13. Then, as shown in Step 4, a metal electrode 9 is formed by vapor deposition or sputtering so as to cover the conductive region 13 and the Al-based oxide layer 11 'inside thereof. As a result, the Al-based oxide layer 11 'immediately below the metal electrode 9 becomes the Al-based insulating layer 11 functioning as a current blocking layer, and the Al-based oxide layer 12' forming the outer region of the metal electrode 9 becomes the Al-based passivation layer. It becomes 12.
[0029]
Next, the light emitting element wafer 50 is half-diced as shown in step E of FIG. 4, and the processing strain on the dicing surface is removed by mesa etching as shown in step F, and then the light emitting element chip is scribed in step G. 51. Then, after the separation or after the above-mentioned half dicing, the peripheral side surfaces of the cushion layer 221 and the light emitting layer portion 24 are selectively oxidized to Al in the compound semiconductor layer forming the peripheral side surfaces. Covered with layers. Then, as shown in step H, the back electrode layer 15 (see FIG. 1) is fixed to the terminal electrode 9a also serving as a support using a conductive paste such as an Ag paste, while the electrode wire 47 is connected to the metal electrode 9. Are bonded, and the resin mold 52 is formed as shown in Step I, whereby the light emitting element 1 is obtained.
[0030]
According to the light emitting element 1 obtained as described above, the following effects are achieved. That is, when the electrode wires 47 are joined to the metal electrodes 9 made of Au, for example, ultrasonic welding (or thermosonic bonding) is used. When the impact stress of this ultrasonic welding strongly affects the active layer 5 shown in FIG. 1, damage such as crystal defects occurs in the active layer 5, which leads to a decrease in light emission intensity and the like. However, in the light emitting device of the present embodiment, since the cushion layer 221 is interposed, the damaged area remains in the cushion layer 221 and the influence is hard to extend deep into the light emitting layer portion 24, so that the light emission luminance is correspondingly increased. There is no worry that it will be damaged.
[0031]
Since the cushion layer 221 has a higher dopant concentration than the second conductivity type cladding layer 6, the current can be sufficiently spread, and the light-emitting layer portion 24 can be uniformly energized. Further, an Al-based insulating layer 11 serving as a current blocking layer is formed on the surface of the cushion layer 221 so as to cover a central region of the region immediately below the metal electrode 9 where light extraction is easily hindered. This makes it possible to block a current in a region where light extraction is difficult with the Al-based insulating layer 11, and to diffuse the current in the in-plane direction of the Al-based insulating layer 11, so that the current flows through the metal electrode 9. It can be close to the outer peripheral edge. As a result, current can be supplied to the light emitting layer portion 24 in a manner avoiding the region immediately below the metal electrode 9, and the light extraction efficiency can be increased. Further, the Al-based insulating layer 11 is formed by oxidizing the Al component of the cushion layer 221 together with the Al-based passivation layer 12, and is easy to manufacture.
[0032]
As shown in Step 4 of FIG. 3, when the Al-based passivation layer 12 is formed so as to enter the outer peripheral edge of the main surface of the metal electrode 9 on the side of the joint with the cushion layer 221, the Al-containing passivation layer 12 contains Al. Crevice corrosion from the outer peripheral edge of the metal electrode 9 to the cushion layer 221 does not easily progress, and the life of the element can be further extended.
[0033]
Hereinafter, various modifications of the light emitting device of the present invention will be described (common portions are denoted by the same reference numerals as those of the light emitting device 1 in FIG. 1 and detailed description is omitted). In the light emitting element 100 shown in FIG. 5, the region where the Al-based insulating layer 11 is formed is excluded from the main surface of the Al-containing compound semiconductor having a larger band gap energy than the active layer 5, that is, the cushion layer 221 made of AlGaAs in this embodiment. The entire surface of the portion is covered with an Al-free compound semiconductor layer, in this embodiment, a GaP layer 222. In the present embodiment, the dopant concentration of the GaP layer 222 is set higher than that of the cushion layer 221 in order to reduce the contact resistance with the metal electrode 9. The metal electrode 9 is formed in contact with the Al-based insulating layer 11 and the Al-free compound semiconductor layer 222 surrounding the outer periphery thereof. The metal electrode 9 is electrically connected to the cushion layer 221 via the GaP layer 222 at the outer peripheral edge of the joint-side main surface.
[0034]
The manufacturing process of the above structure is as follows. First, as shown in Step 1 of FIG. 6, a GaP layer 222 is epitaxially grown so as to cover the entire main surface of the cushion layer 221. Further, a region of the GaP layer 222 except for a region where the Al-based insulating layer 11 is to be formed is removed. The entire surface is covered with a photoresist layer 30. Then, as shown in Step 2, the GaP layer 222 exposed in the window 30w of the photoresist layer 30 is removed using an etching solution composed of a sulfuric acid / hydrogen peroxide mixed solution, and further, the AlGaAs exposed by the removal is removed. The cushion layer 221 is oxidized using an oxidizing solution comprising an ammonia / hydrogen peroxide mixed solution. Thereby, the outermost layer portion of the exposed cushion layer 221 becomes the Al-based insulating layer 11. Then, as shown in step 3, the photoresist layer 30 is removed, and as shown in step 4, the metal electrode 9 is formed so as to cover the Al-based insulating layer 11 and the surrounding GaP layer 222.
[0035]
In the light emitting device 200 of FIG. 7, the region of the cushion layer 221 made of the Al-containing compound semiconductor that is not covered by the metal electrode 9 on the main light extraction surface is formed by the side surface 9 d of the metal electrode 9 and the metal electrode 9. It is covered by the passivation layer 14 together with the outer peripheral edge 9e of the main surface on the non-joining side with the cushion layer 221. In the present embodiment, the passivation film 14 is a SiO ₂ film. The manufacturing process of the above structure is as follows. First, as shown in Step 1 of FIG. 8, the entire surface of the cushion layer 221 except for the region where the Al-based insulating layer 11 is to be formed is covered with the photoresist layer 30. Next, as shown in Step 2, the outermost layer portion of the cushion layer 221 exposed in the window 30w of the photoresist layer 30 is oxidized using an oxidizing solution composed of an ammonia / hydrogen peroxide mixed solution to form an Al-based material. An insulating layer 11 is formed. In step 3, the photoresist layer 30 is removed, and as shown in step 4, the metal electrode 9 is formed so as to cover the Al-based insulating layer 11 and the surrounding cushion layer main surface area. Then, as shown in Step 5, the main surface of the cushion layer 221 is covered together with the side surface 9d of the metal electrode 9 and the outer peripheral edge 9e of the main surface of the metal electrode 9 on the non-joining side with the cushion layer 221. The passivation layer 14 is formed by sputtering or the like.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a first embodiment of a light emitting device of the present invention in a laminated structure.
FIG. 2 is an explanatory view showing an example of a manufacturing process of the light emitting device of FIG.
FIG. 3 is a detailed explanatory view of a step D in FIG. 2;
FIG. 4 is an explanatory view following FIG. 2;
FIG. 5 is a schematic view showing a second embodiment of the light emitting device of the present invention in a laminated structure.
FIG. 6 is an explanatory view showing an example of a manufacturing process of the light emitting device of FIG.
FIG. 7 is a schematic diagram showing a third embodiment of the light emitting device of the present invention in a laminated structure.
FIG. 8 is an explanatory view showing an example of a manufacturing process of the light-emitting element of FIG.
[Explanation of symbols]
1,100,200 Light-emitting element 4 n-type cladding layer (first conductivity type cladding layer)
5 Active layer 6 p-type cladding layer (second conductivity type cladding layer)
9 Metal electrode 11 Al-based insulating layer 12 Al-based passivation layer 14 Passivation layer 221 Cushion layer (Al-containing semiconductor layer)

Claims (10)

Having a compound semiconductor layer having a light emitting layer portion, a metal electrode for applying a light emission drive voltage to the light emitting layer portion is disposed so as to cover a partial region of the light extraction main surface of the compound semiconductor layer,
At least a part of the compound semiconductor layer is an Al-containing compound semiconductor layer containing Al.
In a part of the region directly below the metal electrode, between the Al-containing compound semiconductor layer and the metal electrode, an Al-based insulating layer that is in contact with the Al-containing compound semiconductor layer sets the geometric center of gravity of the region immediately below. It is arranged so as to cover the containing area,
A light-emitting element, wherein the metal electrode is electrically connected to the Al-containing compound semiconductor layer directly or indirectly via another compound semiconductor layer outside a region where the Al-based insulating layer is formed. The light emitting device according to claim 1, wherein the Al-based insulating layer is disposed in contact with the metal electrode. The Al-based insulating layer is formed so as to face a central portion of the main surface of the metal electrode on the bonding side with the compound semiconductor layer, and the bonding-side main surface of the metal electrode is provided outside the Al-based insulating layer. 3. The light emitting device according to claim 1, wherein the light emitting device is electrically connected to the Al-containing compound semiconductor layer. 4. 4. The Al-containing compound semiconductor layer, wherein a region of the light extraction main surface that is not covered by the metal electrode is covered by an Al-based passivation layer in contact with the Al-containing compound semiconductor layer. Item 2. The light-emitting element according to item 1. The light emitting device according to claim 4, wherein the Al-based passivation layer is formed so as to penetrate an outer peripheral portion of a main surface of the metal electrode on a bonding side with the Al-containing compound semiconductor layer. In the Al-containing compound semiconductor layer, a region of the light extraction main surface that is not covered by the metal electrode is located outside a side surface of the metal electrode and a main surface of the metal electrode on a non-joining side with the Al-containing compound semiconductor layer. The light emitting device according to claim 1, wherein the light emitting device is covered with a passivation layer together with a peripheral portion. The light emitting layer portion is made of AlGaInP and has a double hetero structure in which a first conductivity type clad layer, an active layer, and a second conductivity type clad layer are laminated in this order, and the second conductivity type is formed. 2. A cushion layer made of an Al-containing compound semiconductor having a larger band gap than the active layer is formed on the clad layer, and the Al-based insulating layer is formed in contact with the cushion layer. 7. The light-emitting device according to any one of items 6 to 6. The method for manufacturing a light emitting device according to any one of claims 1 to 7, wherein the Al component is contained based on an Al component contained in an outermost layer portion of the Al-containing compound semiconductor layer contained in the compound semiconductor layer. A method for manufacturing a light emitting element, comprising forming a system insulating layer. The method according to claim 8, wherein the Al-based insulating layer is formed as an Al-based oxide layer by oxidizing an outermost layer of the Al-containing compound semiconductor layer. The Al-based oxide layer forming the Al-based insulating layer is formed by contacting an oxidation treatment liquid with a part of the main surface of the Al-containing compound semiconductor layer where the metal electrode is to be arranged. The method for manufacturing a light emitting device according to claim 10, wherein

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