JP4483513B2 - Semiconductor light emitting device and epitaxial wafer for semiconductor light emitting device - Google Patents

Description

  The present invention relates to a structure of a semiconductor light emitting device (light emitting diode LED, semiconductor laser LD) having a high brightness and a long life and an epitaxial wafer for a semiconductor light emitting device, and in particular, zinc (Zn) and magnesium (Mg) are used as p-type impurities. The present invention relates to a structure suitable for the AlGaInP light emitting element.

  Light emitting diodes (LEDs) are widely used as industrial and consumer display elements. As a high-brightness LED, there was an AlGaAs red LED. However, although LEDs with shorter wavelengths than red were GaAsP and GaP, only low luminance was obtained. However, since it has recently become possible to grow AlGaInP-based crystal layers by the MOVPE method, it has become possible to produce orange, yellow, and green high-intensity LEDs.

  Conventionally, it is known that when a LED or LD operates at a high output or at a high temperature, a leakage current due to an overflow of electrons from the active layer to the p-type cladding layer increases, and a threshold current and an operating current increase. In order to achieve stable high temperature and high output operation, it is desirable to increase the carrier concentration of the p-type cladding layer as much as possible. Therefore, zinc (Zn) is generally used as the p-type impurity of the p-type cladding layer.

However, when Zn is used as the p-type impurity, there is a problem that Zn is diffused to the active layer as the carrier concentration of the p-type cladding layer is increased, leading to deterioration of device characteristics and reliability. For this reason, Zn had to be doped at a low concentration. The carrier concentration of the p-type cladding layer when Zn is used as the p-type impurity is normally set to a relatively low concentration of about 4 × 10 ¹⁷ cm ⁻³ .

As a countermeasure for this problem, an active layer to form a light-emitting portion sandwiched by n-type and p-type cladding layer on the n-type substrate, the Zn-doped p-type current expansion goldenrod its Zn-doped p-type cladding layer In the structure of the formed semiconductor light emitting device, it has been proposed to insert a Zn diffusion suppression layer (undoped AlGaInP spacer layer) of 500 nm or more between the undoped active layer and the p-type cladding layer (see, for example, Patent Document 1). . In Patent Document 1, on the active layer, Zn-doped p-type cladding layer, a layer structure of sequentially stacked semiconductor light emitting element Zn-doped p-type current diffusion layer, and the assumption that the Zn is directed to the active layer side It has become.

  It is also known to increase the carrier concentration of the p-type cladding layer and the p-type contact layer thereon using magnesium (Mg) having a smaller diffusion constant than Zn as the p-type impurity (for example, patents) Reference 2). In Patent Document 2, a layered structure of a semiconductor light emitting device is formed in which an Mg-doped p-type cladding layer and an Mg-doped p-type contact are sequentially laminated on an active layer.

In addition, a Zn-doped p-type cladding layer and a Zn-doped p-type current diffusion layer are sequentially stacked on the active layer, and a thin high-resistance layer doped with Mg is provided in the Zn-doped p-type current diffusion layer. The structure is known (see, for example, Patent Document 3). This Mg-doped p-type high resistance layer is inserted for the purpose of diffusing the current injected from the p-side electrode in the cross-sectional lateral direction. In Patent Document 3, a layered structure of a semiconductor light emitting device is obtained in which a Zn-doped p-type cladding layer, a Mg-doped p-type high resistance layer, and a Zn-doped p-type cladding layer are sequentially laminated on an active layer.
JP 2003-179254 A Japanese Patent No. 2778405 JP-A-8-3211

  As described above, in a semiconductor light emitting device having a structure in which an active layer is sandwiched between an n-type and a p-type cladding layer on an n-type substrate, Zn has conventionally been used as a p-type dopant for the p-type cladding layer. Although it has been used, since Zn has a feature of being easily diffused, when Zn is doped into the p-type cladding layer, this Zn diffuses to the active layer, resulting in a decrease in emission luminance and reliability. There has been a problem that it causes a decrease and a reverse breakdown with time.

  On the other hand, as a p-type dopant instead of Zn, Mg can be added to the p-type cladding layer because it is less diffusible than Zn. For example, a GaP layer is used for the current diffusion layer. In the case of an AlGaInP-based LED epitaxial structure, there is an energy barrier due to band discontinuity between the p-type AlGaInP cladding layer and the p-type GaP current diffusion layer, and there is a property that current does not easily flow. Therefore, a p-type AlGaInP semiconductor layer (band discontinuity eliminating layer) with a high carrier concentration is inserted to reduce this energy barrier. However, since the desired carrier concentration cannot be obtained with Mg dopant, there is a problem that this energy barrier cannot be relaxed and the Vf becomes high.

  In short, conventionally, when Zn is used as the p-type dopant of the p-type cladding layer, there is a problem that Zn diffuses to the active layer, and when Mg is used, a desired carrier concentration is difficult to obtain.

  Therefore, the object of the present invention is to solve the above problems, and even if Zn is used as a dopant in the p-type semiconductor layer in the vicinity of the active layer, Zn diffusion into the active layer is reduced, resulting in high brightness, high reliability, Another object of the present invention is to provide a light-emitting element capable of obtaining an LED and an LD having a reverse breakdown voltage structure with little deterioration with time.

  In order to achieve the above object, the present invention is configured as follows.

The semiconductor light-emitting device according to the invention of claim 1 is a semiconductor light-emitting device having a structure in which an active layer made of undoped AlGaInP is sandwiched between an n- type and p- type AlGaInP cladding layer on an n- type GaAs substrate. By placing a p-type AlGaInP cladding layer doped with at least zinc (Zn) between the p-type AlGaInP cladding layer doped with at least magnesium (Mg) and the active layer made of undoped AlGaInP , magnesium and zinc interdiffusion of using the previous SL zinc of at least the p-type zinc-doped AlGaInP cladding layer, the p-type AlGaInP cladding least magnesium previous SL opposite side is doped with an active layer side of undoped AlGaInP It spreads to the layer side It is characterized by the above structure.

The semiconductor light emitting device according to the invention of claim 2, the active layer of undoped AlGaInP form a light-emitting portion sandwiched by n-type and p-type AlGaInP cladding layer on the n-type GaAs substrate, a p-type thereon in the semiconductor light-emitting device having a structure forming a current diffusion layer made of GaP, or AlGaAs, between the active layer made of the undoped AlGaInP current diffusion layer made of p-type GaP or AlGaAs at least magnesium-doped, by at least zinc installing p-type AlGaInP cladding layer doped, by utilizing interdiffusion of magnesium and zinc, zinc before Symbol p-type AlGaInP cladding layer at least zinc is doped, composed of the undoped AlGaInP the opposite side of the front Symbol Sukunakutomoma the active layer side Magnesium is characterized in that the structure to diffuse the current diffusion layer side composed of doped p-type GaP or AlGaAs. This structure having a current diffusion layer made of p-type GaP or AlGaAs on the light-emitting portion (FIG. 1, FIG. 2) is obtained by identifying.

The semiconductor light emitting device according to the invention of claim 3, the active layer of undoped AlGaInP form a light-emitting portion sandwiched by n-type and p-type AlGaInP cladding layer on the n-type GaAs substrate, a p-type thereon in the semiconductor light-emitting device having a structure forming a current diffusion layer made of GaP, or AlGaAs, before Symbol p-type current diffusion layer made of GaP or AlGaAs of a layer at least magnesium is doped, the adjacent thereto between the undoped become at least zinc provided on the active layer side composed of AlGaInP is a two-layer structure of the doped layer, the active layer and the current diffusion layer before SL two-layer structure consisting of the undoped AlGaInP, at least By installing a p-type AlGaInP semiconductor layer doped with zinc, the mutual interaction between magnesium and zinc Using the diffusion, before Symbol zinc least zinc p-type doped AlGaInP semiconductor layer, wherein the p-type at least magnesium previous SL opposite side is doped with an active layer side of undoped AlGaInP GaP or AlGaAs characterized in that the structure to diffuse the current diffusion layer side composed of.

An epitaxial wafer for a semiconductor light emitting device according to a fourth aspect of the present invention is a semiconductor light emitting device having a structure in which an active layer made of undoped AlGaInP is sandwiched between an n- type and p- type AlGaInP cladding layer on an n- type GaAs substrate. in the epitaxial wafer element, between the active layer made of the undoped AlGaInP and at least p-type magnesium-doped AlGaInP cladding layer, by placing a p-type AlGaInP cladding layer at least zinc is doped, magnesium and zinc interdiffusion using a prior SL zinc p-type AlGaInP cladding layer at least zinc is doped, the p-type AlGaI at least magnesium previous SL opposite side is doped with an active layer side of undoped AlGaInP The structure is characterized by diffusing to the nP cladding layer side.

An epitaxial wafer for a semiconductor light emitting device according to a fifth aspect of the present invention includes: a light emitting portion in which an active layer made of undoped AlGaInP is sandwiched between n type and p type AlGaInP cladding layers on an n type GaAs substrate; in p-type GaP or semiconductor light-emitting device epitaxial wafer having a structure forming a current diffusion layer made of AlGaAs, activity comprising the undoped AlGaInP current diffusion layer made of p-type GaP or AlGaAs at least magnesium-doped between the layers, by placing a p-type AlGaInP cladding layer at least zinc is doped, by utilizing interdiffusion of magnesium and zinc, the zinc before Symbol p-type AlGaInP cladding layer at least zinc-doped Undoped AlGaInP The active layer side consisting, characterized in that the structure to at least magnesium previous SL opposite diffuses into the current diffusion layer side composed of GaP or AlGaAs p-type doped. This structure having a current diffusion layer made of p-type GaP or AlGaAs on the light-emitting portion (FIG. 1, FIG. 2) is obtained by identifying.

An epitaxial wafer for a semiconductor light-emitting device according to a sixth aspect of the present invention includes: a light-emitting portion in which an active layer made of undoped AlGaInP is sandwiched between an n- type and a p- type AlGaInP cladding layer on an n- type GaAs substrate; in p-type GaP or semiconductor light-emitting device epitaxial wafer having a structure forming a current diffusion layer made of AlGaAs, before Symbol p-type current diffusion layer made of GaP or AlGaAs of a layer at least magnesium-doped, at least zinc is made from a two-layer structure of the doped layer, the active layer and the current diffusion layer composed of the undoped AlGaInP before SL two-layer structure which the adjacent disposed on the active layer side composed of the undoped AlGaInP And a p-type AlGaInP semiconductor layer doped with at least zinc. By installing, by utilizing interdiffusion of magnesium and zinc, before Symbol zinc p-type AlGaInP semiconductor layer which at least zinc is doped, prior Symbol least magnesium opposite to the active layer side composed of the undoped AlGaInP There is characterized in that the structure to diffuse the current diffusion layer side composed of doped p-type GaP or AlGaAs.

<Key points of the invention>
In order to achieve the above object, according to the present invention, a p-type semiconductor layer (for example, a p-type cladding layer) near the active layer is doped with zinc and magnesium is doped adjacent to the semiconductor layer ( For example, a p-type current diffusion layer, a p-type contact layer, a p-type cladding layer, etc.) are provided. By doing so, zinc diffuses in the p-type semiconductor layer doped with magnesium, and as a result, zinc diffusion occurs in the direction opposite to the active layer side . As a result, a light emitting device capable of obtaining an LED and an LD having a structure in which zinc is less diffused into the active layer can be manufactured. Thus, a semiconductor light emitting device with high luminance, high reliability, and low withstand voltage deterioration over time can be obtained. .

  The present invention differs from Patent Documents 1 to 3 in the following points.

Patent Document 1, undoped spacer layer on the active layer, Zn-doped p-type cladding layer, the configuration only Zn-doped p-type current expansion goldenrod exists, i.e., the configuration does not exist Mg-doped layer on the active layer However, the idea of utilizing the interdiffusion of the present invention does not exist.

  Patent Document 2 has a configuration in which only an Mg-doped p-type cladding layer and an Mg-doped p-type contact layer exist on the active layer, that is, a configuration in which no Zn-doped layer exists on the active layer. The idea of utilizing the interdiffusion of the present invention does not exist.

Patent Document 3, on the active layer, Zn-doped p-type cladding layer, a Zn-doped p-type current expansion goldenrod, Mg-doped p-type high-resistance layer, discloses an arrangement in which Zn-doped p-type current diffusion layer is present ing. However, this Mg-doped p-type high resistance layer is inserted for the purpose of diffusing the current injected from the p-side electrode in the lateral direction of the cross section. That is, Patent Document 3 belongs to a completely different technology that does not have the technical idea of the present invention that diffuses Zn to the side opposite to the active layer side by mutual diffusion.

  According to the present invention, the following excellent effects can be obtained.

According to the semiconductor light emitting device or the epitaxial wafer for a semiconductor light emitting device of the present invention, a p-type semiconductor layer doped with at least Zn is disposed between the p-type semiconductor layer doped with at least Mg and the active layer, and magnesium zinc utilizing interdiffusion of zinc was the structure to diffuse the p-type semiconductor layer side to said at least Mg opposite side is doped with the active layer side, the light-emitting diode doped with conventional zinc Alternatively, zinc does not diffuse into the active layer compared to laser diodes. Therefore, according to the present invention, it is possible to manufacture an LED or LD that does not have a decrease in light emission luminance, a decrease in reliability, and a reverse breakdown voltage with time.

  In addition, according to the semiconductor light emitting device or the epitaxial wafer for semiconductor light emitting device of the present invention, zinc is not diffused from the p-type semiconductor layer doped with Zn into the active layer due to its structure. Since the semiconductor layer (for example, the undoped spacer layer of Patent Document 1) for preventing Zn diffusion inserted between the layer and the p-type cladding layer can be eliminated, the manufacturing cost can be reduced.

  Hereinafter, the present invention will be described based on the illustrated embodiments.

  1 is an n-type (first conductivity type) substrate 2 made of GaAs, an n-type cladding layer 3, an active layer 4, and a Zn-doped p-type (second conductivity type). The cladding layer 5, the Zn-doped p-type band discontinuity eliminating layer 6, the Zn-doped p-type current diffusion layer 7, the Mg-doped p-type current diffusion layer 8, and the Mg-doped p-type contact layer 9 are sequentially laminated. In this epitaxial wafer for semiconductor light emitting device, the back electrode 1 is formed on the entire back surface of the n-type substrate 2 side, and the surface electrode 10 is formed on a part of the Mg-doped p-type contact layer 9. The semiconductor light emitting device shown in FIG. 1 is manufactured by being divided into chips.

  An epitaxial wafer for producing the semiconductor light emitting device shown in FIG. 2 is formed on an n-type (first conductivity type) substrate 2 made of GaAs, an n-type cladding layer 3, an active layer 4, and a Zn-doped p-type (second conductivity type). The cladding layer 5, the Mg-doped p-type current diffusion layer 8, and the Mg-doped p-type contact layer 9 are sequentially laminated. In this epitaxial wafer for semiconductor light emitting device, the back electrode 1 is formed on the entire back surface of the n-type substrate 2 side, and the surface electrode 10 is formed on a part of the Mg-doped p-type contact layer 9. The semiconductor light emitting device shown in FIG. 2 is manufactured by being divided into chips.

  An epitaxial wafer for producing the semiconductor light emitting device shown in FIG. 3 is formed on an n-type (first conductivity type) substrate 2 made of GaAs, an n-type cladding layer 3, an active layer 4, and a Zn-doped p-type (second conductivity type). The cladding layer 5, the Mg-doped p-type cladding layer 11, and the Mg-doped p-type contact layer 9 are sequentially stacked. In this epitaxial wafer for semiconductor light emitting device, the back electrode 1 is formed on the entire back surface of the n-type substrate 2 side, and the surface electrode 10 is formed on a part of the Mg-doped p-type contact layer 9. The semiconductor light emitting device shown in FIG. 2 is manufactured by being divided into chips.

  In the semiconductor light emitting device of FIGS. 1 to 2, a light emitting part in which an active layer 4 is sandwiched between an n type cladding layer 3 and a p type cladding layer 5 is formed on an n type substrate 2, and an Mg doped p type current is formed thereon. In the structure in which the diffusion layer 8 and the Mg-doped p-type contact layer 9 are formed, a Zn-doped p-type cladding layer 5 is provided between the Mg-doped p-type current diffusion layer 8 and the active layer 4.

  In the semiconductor light emitting device of FIG. 3, a light emitting part is formed on an n type substrate 2 with an active layer 4 sandwiched between an n type clad layer 3 and a p type clad layer 5, and an Mg doped p type clad layer 11 is formed thereon. In the structure in which the Mg-doped p-type contact layer 9 is formed, a Zn-doped p-type cladding layer 5 is provided between the Mg-doped p-type cladding layer 11 and the active layer 4.

  In any of the semiconductor light emitting devices of FIGS. 1 to 3, a Zn-doped layer (Zn-doped p-type cladding layer 5, Zn-doped p-type band discontinuity eliminating layer 6, Zn-doped p-type) is formed above the active layer 4. A current diffusion layer 7) and an Mg doped layer (Mg doped p-type current diffusion layer 8, Mg doped p-type contact layer 9, Mg-doped p-type cladding layer 11) are sequentially provided. However, in the form of FIG. 1, the Zn-doped p-type cladding layer 5 and the p-type semiconductor layer (Mg-doped p-type current diffusion layer 8) are sandwiched between the Zn-doped p-type band discontinuity eliminating layer 6 and the Zn-doped p-type. 2 and 3, the Zn-doped p-type cladding layer 5 and the p-type semiconductor layer (Mg-doped p-type current diffusion layer 8, Mg-doped p-type cladding layer) are provided. 11) are provided adjacent to each other.

Because of this structure, between the Zn-doped p-type cladding layer 5 and the like and the Mg-doped p-type semiconductor layer (Mg-doped p-type current diffusion layer 8, Mg-doped p-type contact layer 9 or Mg-doped p-type cladding layer 11), Interdiffusion between Zn and Mg occurs, and Zn such as the Zn-doped p-type cladding layer 5 is diffused to the Mg-doped p-type semiconductor layer side opposite to the active layer 4 side . Therefore, diffusion of Zn into the active layer 4 is suppressed.

  The structure of a light emitting diode (LED) according to an embodiment of the present invention is shown in FIG. In the following description, each layer is described as having a specific conductivity type, but the present invention is not limited to this, and the n-type and p-type semiconductor layers may be reversed.

On the n-type substrate 2 made of GaAs by the MOVPE method, the n-type cladding layer 3 made of Si-doped AlGaInP having a thickness of 0.5 μm and a carrier concentration of 1 × 10 ¹⁸ cm ⁻³ has a thickness of 0.5 μm. An active layer 4 made of undoped AlGaInP, a Zn-doped p-type cladding layer 5 made of Zn-doped AlGaInP with a thickness of 0.5 μm and a carrier concentration of 5 × 10 ¹⁷ cm ⁻³ , a thickness of 0.1 μm and a carrier concentration of 2 Zn doped p-type band discontinuity eliminating layer 6 made of Zn doped AlGaInP with × 10 ¹⁸ cm ⁻³ , Zn doped p type made of Zn doped GaP with a thickness of 0.5 μm and a carrier concentration of 1 × 10 ¹⁸ cm ⁻³ Current diffusion layer 7, Mg-doped p-type current diffusion layer 8 made of Mg-doped GaP with a thickness of 8 μm and a carrier concentration of 3 × 10 ¹⁸ cm ⁻³ , a thickness of 0.2 μm and a carrier concentration of 1 × 10 ¹⁹ cm ^- Mg-doped p-type contact layers 9 made of ³ Mg-doped GaP were sequentially formed.

  SIMS analysis (secondary ion analysis) confirmed that the p-type semiconductor layer contained both Zn and Mg, but the active layer did not diffuse and was an undoped layer.

  Then, after forming the back electrode 1 on the entire surface of the epitaxial wafer for semiconductor light emitting elements on the n-type substrate 2 side and the surface electrode 10 on a part of the Mg-doped p-type contact layer 9, the epitaxial wafer for semiconductor light emitting elements is used. An LED chip was manufactured and its characteristics were evaluated. As a result, compared with a normal Zn-doped LED, the output and operating voltage Vf of the LED remain unchanged at about 2.2 mW and 1.98 V, and the initial output after the continuous energization test is improved and increased by 20%. The reliability was as high as 100.3%.

  In the LED structure using GaP for the Mg-doped p-type current diffusion layer 8 as described above, since there is Zn diffusion of the Zn-doped p-type band discontinuity eliminating layer 6, this Zn-doped p-type band discontinuity eliminating layer 6 It is desirable that the semiconductor layer adjacent to Zn is doped with Zn (Zn-doped p-type current diffusion layer 7).

  The structure of a light emitting diode (LED) according to the second embodiment of the present invention is shown in FIG. In the following description, each layer is described as having a specific conductivity type, but the present invention is not limited to this, and the n-type and p-type semiconductor layers may be reversed.

On the n-type substrate 2 made of GaAs by the MOVPE method, the n-type cladding layer 3 made of Si-doped AlGaInP having a thickness of 0.5 μm and a carrier concentration of 1 × 10 ¹⁸ cm ⁻³ , and undoped having a thickness of 0.5 μm An active layer 4 made of AlGaInP, a Zn-doped p-type cladding layer 5 made of Zn-doped AlGaInP with a thickness of 0.5 μm and a carrier concentration of 5 × 10 ¹⁷ cm ⁻³ , a thickness of 8 μm and a carrier concentration of 3 × 10 ¹⁸ Mg-doped p-type current diffusion layer 8 composed of Mg-doped AlGaAs of cm ^-3, a Mg-doped p-type contact layer 9 in which the carrier concentration in the thickness 0.2μm is made of Mg-doped GaAs of 1 × 10 ¹⁹ cm ^-3 sequentially Formed.

  SIMS analysis confirmed that the p-type semiconductor layer contained both Zn and Mg, but neither diffused into the active layer and was an undoped layer.

  An LED chip was manufactured from this epitaxial wafer for a semiconductor light emitting device, and its characteristics were evaluated. As a result, compared with a normal Zn-doped LED, the output of the LED chip and the operating voltage Vf remain unchanged at about 2.1 mW and 1.92 V, and the initial output after the continuous energization test is improved by 20%. High reliability with 100.3% of increase.

[Other Examples, Modifications]
In the above embodiment, the light emitting diode has been described as an example. However, even in the epitaxial structure for a laser diode, if the p-type cladding layer is doped with Zn and an Mg-doped layer is provided thereon, Zn is activated by mutual diffusion. Since it diffuses to the Mg doped layer side opposite to the side, high reliability is achieved.

1 is a cross-sectional view showing a semiconductor light emitting element according to a first embodiment of the present invention. It is sectional drawing which shows the semiconductor light-emitting device concerning 2nd embodiment of this invention. It is sectional drawing which shows the semiconductor light-emitting device concerning 3rd embodiment of this invention.

Explanation of symbols

1 Back electrode 2 n-type substrate 3 n-type cladding layer 4 active layer 5 Zn-doped p-type cladding layer 6 Zn-doped p-type band discontinuity eliminating layer 7 Zn-doped p-type current diffusion layer 8 Mg-doped p-type current diffusion layer 9 Mg Doped p-type contact layer 10 Surface electrode 11 Mg-doped p-type cladding layer

Claims (6)

In a semiconductor light-emitting device having a structure in which an active layer made of undoped AlGaInP is sandwiched between an n- type and p- type AlGaInP cladding layer on an n- type GaAs substrate,
By placing a p-type AlGaInP cladding layer doped with at least zinc between the p-type AlGaInP cladding layer doped with at least magnesium and the active layer made of undoped AlGaInP ,
P by utilizing interdiffusion of magnesium and zinc, zinc before Symbol p-type AlGaInP cladding layer at least zinc is doped, wherein the at least magnesium previous SL opposite to the active layer side of undoped AlGaInP is doped A semiconductor light emitting device characterized by having a structure in which it diffuses to the side of the type AlGaInP cladding layer. an active layer made on an n-type GaAs substrate of undoped AlGaInP form a light-emitting portion sandwiched by n-type and p-type AlGaInP cladding layer, to form a current diffusion layer made of p-type GaP or AlGaAs thereon In a semiconductor light emitting device having a structure,
Between the active layer and the current diffusion layer made of p-type at least magnesium-doped GaP or AlGaAs comprising said undoped AlGaInP, by placing a p-type AlGaInP cladding layer at least zinc-doped,
P by utilizing interdiffusion of magnesium and zinc, zinc before Symbol p-type AlGaInP cladding layer at least zinc is doped, wherein the at least magnesium previous SL opposite to the active layer side of undoped AlGaInP is doped the semiconductor light emitting element characterized in that it has a structure to diffuse the current diffusion layer side composed of a type of GaP or AlGaAs. an active layer made on an n-type GaAs substrate of undoped AlGaInP form a light-emitting portion sandwiched by n-type and p-type AlGaInP cladding layer, to form a current diffusion layer made of p-type GaP or AlGaAs thereon In a semiconductor light emitting device having a structure,
Before Symbol p-type current diffusion layer made of GaP or AlGaAs of a layer at least magnesium-doped, a layer at least zinc-doped provided in the active layer side composed of the undoped AlGaInP adjacent thereto of consists two-layer structure, between the front Symbol bilayer active layer and the current diffusion layer composed of the undoped AlGaInP structure, by providing the p-type AlGaInP semiconductor layer which at least zinc-doped,
P by utilizing interdiffusion of magnesium and zinc, zinc before Symbol p-type AlGaInP semiconductor layer which at least zinc is doped, wherein the at least magnesium previous SL opposite to the active layer side of undoped AlGaInP is doped the semiconductor light emitting element characterized in that it has a structure to diffuse the current diffusion layer side composed of a type of GaP or AlGaAs. In an epitaxial wafer for a semiconductor light emitting device having a structure in which an active layer made of undoped AlGaInP is sandwiched between an n- type and p- type AlGaInP cladding layer on an n- type GaAs substrate,
By placing a p-type AlGaInP cladding layer doped with at least zinc between the p-type AlGaInP cladding layer doped with at least magnesium and the active layer made of undoped AlGaInP ,
P by utilizing interdiffusion of magnesium and zinc, zinc before Symbol p-type AlGaInP cladding layer at least zinc is doped, wherein the at least magnesium previous SL opposite to the active layer side of undoped AlGaInP is doped An epitaxial wafer for a semiconductor light-emitting element, characterized in that the structure diffuses toward the side of the AlGaInP cladding layer. an active layer made on an n-type GaAs substrate of undoped AlGaInP form a light-emitting portion sandwiched by n-type and p-type AlGaInP cladding layer, to form a current diffusion layer made of p-type GaP or AlGaAs thereon In an epitaxial wafer for a semiconductor light emitting device having a structure,
Between the active layer and the current diffusion layer made of p-type at least magnesium-doped GaP or AlGaAs comprising said undoped AlGaInP, by placing a p-type AlGaInP cladding layer at least zinc-doped,
P by utilizing interdiffusion of magnesium and zinc, zinc before Symbol p-type AlGaInP cladding layer at least zinc is doped, wherein the at least magnesium previous SL opposite to the active layer side of undoped AlGaInP is doped type GaP or epitaxial wafer for a semiconductor light emitting element characterized in that the structure to diffuse the current diffusion layer side made of AlGaAs. an active layer made on an n-type GaAs substrate of undoped AlGaInP form a light-emitting portion sandwiched by n-type and p-type AlGaInP cladding layer, to form a current diffusion layer made of p-type GaP or AlGaAs thereon In an epitaxial wafer for a semiconductor light emitting device having a structure,
Before Symbol p-type current diffusion layer made of GaP or AlGaAs of a layer at least magnesium-doped, a layer at least zinc-doped provided in the active layer side composed of the undoped AlGaInP adjacent thereto of consists two-layer structure, between the front Symbol bilayer active layer and the current diffusion layer composed of the undoped AlGaInP structure, by providing the p-type AlGaInP semiconductor layer which at least zinc-doped,
P by utilizing interdiffusion of magnesium and zinc, zinc before Symbol p-type AlGaInP semiconductor layer which at least zinc is doped, wherein the at least magnesium previous SL opposite to the active layer side of undoped AlGaInP is doped type GaP or epitaxial wafer for a semiconductor light emitting element characterized in that the structure to diffuse the current diffusion layer side made of AlGaAs.

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