JPH11186665A - Semiconductor light emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light emitting element which suppresses a p-type impurity doped in a p-type AlGaInP clad layer from diffusing into an active layer to avoid deteriorating the characteristics. SOLUTION: An AlGaInP semiconductor light emitting element has a p-type Alz Ga1-z As layer 13 doped at a high concn. with a p-type impurity harder to diffuse than Zn or Mg, for example, C between an active layer 4 and p-type (Alx Ga1-y ,y In1-y P layer doped with a p-type impurity Zn or Mg. The p-type Alz Ga1-z As layer 13 has a thickness of 0.05-0.3 μm and doping concn. of the p-type impurity is 2×10<17> -2×10<19> cm<-3> . The active layer 4 has an MQW structure having an undoped GaInP quantum well layer and undoped AlGaInP barrier layer or having an undoped GaInP quantum well layer and p-type AlGaAs barrier layer doped with a p-type impurity such as C which is hard to diffuse.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor light emitting device, and more particularly, to an AlGaInP semiconductor light emitting device.

[0002]

2. Description of the Related Art Al using an active layer of GaInP
GaInP-based semiconductor lasers have wavelengths of 620 to 700 nm.
In the short wavelength region of 620 to 660 nm, the difference in energy gap between the active layer and the cladding layer (corresponding to the height of the hetero barrier between the active layer and the cladding layer) is small. There is a problem that carriers injected into the active layer during operation overflow from the active layer, thereby lowering quantum efficiency.

Therefore, in order to suppress the decrease in quantum efficiency, the p-side AlGaI
When growing the nP cladding layer, the AlGaInP
A portion of the cladding layer near the active layer is highly doped with Zn or Mg as a p-type impurity.

[0004]

However, the Zn or Mg doped in the p-type AlGaInP cladding layer as described above is easily diffused during the crystal growth or by a thermal process performed in a subsequent process, and the active layer is not doped with Zn or Mg. It is likely to get into it. When Zn or Mg enters the active layer in this manner, the characteristics of the AlGaInP-based semiconductor laser rapidly deteriorate in several hours.

Accordingly, an object of the present invention is to provide a p-type Al
It is an object of the present invention to provide a semiconductor light emitting device capable of preventing a p-type impurity doped in a GaInP clad layer from entering an active layer by diffusion and preventing deterioration of characteristics.

Another object of the present invention is to provide a semiconductor light emitting device capable of improving modulation characteristics and temperature characteristics.

[0007]

According to a first aspect of the present invention, an active layer is formed of an n-type AlGaI.
In a semiconductor light emitting device having a structure sandwiched between an nP cladding layer and a p-type AlGaInP cladding layer, a p-type Al
AlGaIn doped with a p-type impurity that is less diffused than the p-type impurity doped in the GaInP cladding layer.
P-type II composed of a III-V compound semiconductor different from P
A cladding layer of an IV group compound semiconductor is provided.

In the first invention, the thickness of the p-type III-V compound semiconductor cladding layer is preferably 0.05 μm.
m or more and 0.3 μm or less, more preferably 0.1
It is selected to be not less than μm and not more than 0.3 μm. Where p-type II
The lower limit of the thickness of the IV compound semiconductor clad layer is set to 0.0
The reason why the thickness is set to 5 μm is that if the thickness of the p-type group III-V compound semiconductor cladding layer is smaller than 0.05 μm, the p-type III-V compound semiconductor may be formed by crystal growth at the time of manufacturing the semiconductor light emitting device or thermal processing in the subsequent process. This is to prevent p-type impurities doped in the p-type AlGaInP cladding layer from diffusing through the p-type III-V compound semiconductor cladding layer and entering the active layer. The reason why the upper limit of the thickness of the type III-V compound semiconductor cladding layer is set to 0.3 μm is that the p-type III-V compound semiconductor
When the thickness of the group V compound semiconductor cladding layer is larger than 0.3 μm, the characteristics of the semiconductor light emitting device may be adversely affected,
This is for preventing the time required for crystal growth from being unnecessarily long.

In the first invention, the doping concentration of the p-type impurity in the p-type III-V compound semiconductor cladding layer is preferably 2 × in order to sufficiently increase the quantum efficiency.
It is selected from 10 ¹⁷ cm ⁻³ or more and 2 × 10 ¹⁹ cm ⁻³ or less.

In the first invention, a specific example of the p-type III-V compound semiconductor clad layer is p-type AlG
In addition to the aAs cladding layer, a p-type GaInAsP cladding layer is used.

In the first invention, the p-type AlGaInP
The p-type impurity doped into the cladding layer is typically
Zn or Mg. On the other hand, the p-type impurity doped into the p-type III-V compound semiconductor clad layer is:
When doped into the III-V compound semiconductor constituting the p-type III-V compound semiconductor cladding layer, it acts as a p-type impurity and diffuses more than the p-type impurity doped into the p-type AlGaInP cladding layer. Basically, anything that is difficult can be used,
Specifically, in addition to C, it is Si, Ge, or the like.

In the first invention, typically, the p-type III-V compound semiconductor cladding layer is formed of n-type AlGa.
Almost lattice-matched with the semiconductor substrate together with the InP cladding layer and the p-type AlGaInP cladding layer.

According to a second aspect of the present invention, the active layer is formed of an n-type A
In a semiconductor light emitting device having a structure sandwiched between an lGaInP cladding layer and a p-type AlGaInP cladding layer, the active layer has an undoped GaInP layer as a quantum well layer and diffuses more than a p-type impurity doped in the p-type AlGaInP cladding layer. Difficult p-type impurity doped,
It has a multiple quantum well structure using a p-type III-V compound semiconductor layer made of a III-V compound semiconductor different from AlGaInP as a barrier layer.

In the second invention, typically, the thickness of the undoped GaInP layer as the quantum well layer is selected to be 2 nm or more and 20 nm or less, and the p-type III-
The thickness of the group V compound semiconductor layer is selected from 2 nm to 10 nm.

In the second aspect of the present invention, the doping concentration of the p-type impurity in the p-type III-V compound semiconductor layer as the barrier layer is such that the effect of improving the modulation characteristics and the temperature characteristics can be sufficiently obtained while the barrier layer is sufficiently improved. In order to avoid problems due to excessively doping, it is preferable to use 1 × 10 ¹⁷ cm ^−3.
It is selected to be not less than 2 × 10 ¹⁹ cm ⁻³ .

In the second invention, specific examples of the p-type III-V compound semiconductor layer include a p-type GaInAsP layer in addition to a p-type AlGaAs layer.

In the second invention, the p-type AlGaInP
The p-type impurity doped into the cladding layer is typically
Zn or Mg. On the other hand, the p-type impurity doped into the p-type III-V compound semiconductor layer as the barrier layer of the active layer is doped into the III-V compound semiconductor constituting the p-type III-V compound semiconductor layer. When doped, it acts as a p-type impurity and is less likely to diffuse than a p-type impurity doped in a p-type AlGaInP cladding layer, and is undoped as a quantum well layer of an active layer.
Basically, any material can be used as long as it hardly diffuses into the layer.
And Si, Ge, and the like.

According to the first aspect of the present invention having the above-described structure, the p-type impurity doped in the p-type AlGaInP cladding layer is more diffused between the active layer and the p-type AlGaInP cladding layer. By providing a p-type III-V compound semiconductor clad layer made of a III-V compound semiconductor different from AlGaInP doped with a difficult p-type impurity, the p-type AlGaInP clad layer is Is separated from the active layer by the thickness of the group III compound semiconductor cladding layer, and thus the p-type AlG
It becomes difficult for the p-type impurity doped in the aInP cladding layer to enter the active layer by diffusion. In addition, p-type III-
Since the p-type impurity doped in the V-type compound semiconductor clad layer is more difficult to diffuse than the p-type impurity doped in the p-type AlGaInP clad layer, the p-type impurity doped in the p-type III-V compound semiconductor clad layer is not diffused. There is little possibility that the type impurities may enter the active layer by diffusion. Furthermore, p
By sufficiently increasing the doping concentration of the p-type impurity in the type III-V compound semiconductor cladding layer, high quantum efficiency can be obtained.

According to the second aspect of the present invention configured as described above, the barrier layer forming the active layer is formed of a p-type III-
Since the semiconductor layer is a group V compound semiconductor layer, modulation characteristics and temperature characteristics are improved by the effect of using an impurity-doped layer instead of an undoped layer as a barrier layer. Moreover, the p-type impurity doped in the p-type III-V compound semiconductor layer as the barrier layer hardly diffuses into the undoped GaInP layer as the quantum well layer, so that the impurity enters the quantum well layer. Therefore, it is possible to prevent the active layer from being deteriorated.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. In all the drawings of the embodiments, the same or corresponding portions are denoted by the same reference numerals.

FIG. 1 shows an AlGaInP-based semiconductor laser according to a first embodiment of the present invention.

As shown in FIG. 1, in the AlGaInP-based semiconductor laser according to the first embodiment, an n-type G
An n-type GaAs buffer layer 2 and an n-type (A
l _x Ga _1-x ) _y In _1-y P cladding layer 3, active layer 4,
p-type (Al _x Ga _{1 -x} ) _y In _{1 -y} P cladding layer 5, p
GaInP etching stop layer 6, p-type (Al _x G
a _1-x ) _y In _1-y P clad layer 7, p-type GaInP intermediate layer 8 and p-type GaAs cap layer 9 are sequentially laminated.

Here, an n-type GaAs substrate 1 and an n-type GaAs
s buffer layer 2 and n-type (Al _x Ga _{1 -x} ) _y In
_{The 1-y} P cladding layer 3 is doped with, for example, Si as an n-type impurity, and has a p-type (Al _x Ga _{1 -x} ) _y In _{1 -y} P cladding layer 5, a p-type GaInP etching stop layer 6,
The type (Al _x Ga _{1 -x} ) _y In _{1 -y} P cladding layer 7, the p-type GaInP intermediate layer 8 and the p-type GaAs cap layer 9 are doped with, for example, Zn as a p-type impurity.

As the n-type GaAs substrate 1, for example,
A material having a (100) plane orientation or a material whose main surface is a surface off by, for example, 5 to 15 ° from the (100) surface is used.

P-type (Al _x Ga _{1 -x} ) _y In _{1 -y} P cladding layer 7, p-type GaInP intermediate layer 8 and p-type GaAs
The cap layer 9 has a stripe shape extending in one direction. An n-type GaAs current confinement layer 10 is buried in both sides of the stripe portion, thereby forming a current confinement structure. The width of the stripe portion is, for example, 1.5 to 6 μm. Here, the n-type GaAs current confinement layer 10 is doped with, for example, Si as an n-type impurity.

The p-type GaAs cap layer 9 and the n-type Ga
On the As current confinement layer 10, a p-side electrode 11 made of, for example, a Ti / Pt / Au electrode is provided in ohmic contact with the p-type GaAs cap layer 9. On the back surface of the n-type GaAs substrate 1, an n-side electrode 12 made of, for example, an AuGe / Ni electrode is provided in ohmic contact with the n-type GaAs substrate 1.

The active layer 4 includes, for example, an undoped GaInP layer as a quantum well layer and an undoped A
GaInP / Al in which 1GaInP layers are alternately stacked
It has a GaInP multiple quantum well (MQW) structure.

Further, n-type (Al _x Ga _{1 -x} ) _y In _{1 -y}
P cladding layer 3 and p-type (Al _x Ga _{1 -x} ) _y In
The composition ratios x and y in the _1-y P cladding layers 5 and 7 are selected so that these layers lattice-match with the n-type GaAs substrate 1. Specifically, for example, x = 0.7 and y = 0.5 has been chosen.

The AlGaInP according to the first embodiment
In addition to the above-described configuration similar to the conventional AlGaInP-based semiconductor laser, the active layer 4
A p-type Al _z Ga _{1 -z} As clad layer 13 is provided between the mold (Al _x Ga _{1 -x} ) _y In _{1 -y} P clad layer 5. The p-type Al _z Ga _{1 -z} As cladding layer 13 is doped with p as a p-type impurity, which has a much smaller diffusion coefficient than Zn and is hard to diffuse. The doping concentration of C in the p-type Al _z Ga _{1 -z} As cladding layer 13 is selected to be sufficiently high, and specifically, 2 × 10 ^17
２2 × 10 ¹⁹ cm ⁻³ . Note that C is Al
When doped into GaInP, it does not act as a p-type impurity, but when doped into AlGaAs, it acts as a p-type impurity. Also, p-type (Al _x Ga _{1 -x} ) _y In
The doping concentration of the _1-y P cladding layer 5 is usually p-type Al
_z Ga _1-z As less than the doping concentration of the cladding layer 13, for example, about 1 × 10 ¹⁷ cm ^-3. This p-type A
The thickness of the l _z Ga _{1 -z} As clad layer 13 is, for example, 0.1 mm.
It is selected from 1 to 0.3 μm. Also, the p-type Al _z Ga
The Al composition ratio z in the _1-z As clad layer 13 is such that the p-type Al _z Ga _1-z As clad layer 13 is n-type GaAs.
It is selected as a value that lattice-matches with the substrate 1, and specifically,
A value in the range of 0.3 ≦ z ≦ 1, for example, z = 0.3 is selected.

As an example of the thickness of each semiconductor layer in the AlGaInP-based semiconductor laser, the n-type GaAs buffer layer 2 has a thickness of 0.3 μm and the n-type (Al _x Ga _{1 -x} ) _y I
The n _{1 -y} P cladding layer 3 is 1.2 μm, p-type (Al _x Ga
_1-x ) _y In _1-y P cladding layer 5 is μm, p-type Ga
The InP etching stop layer 6 has a thickness of 10 to 500 nm, p
The type (Al _x Ga _{1 -x} ) _y In _{1 -y} P cladding layer 7 has a thickness of 1 μm.
m, p-type GaInP intermediate layer 8 is 0.1 μm, p-type GaAs
The s cap layer 9 is 0.3 μm.

Next, a method of manufacturing the AlGaInP-based semiconductor laser according to the first embodiment configured as described above will be described.

The AlGaInP according to the first embodiment
In order to manufacture a system-based semiconductor laser, first, an n-type GaAs buffer layer 2 and an n-type (Al _x Ga _{1 -x} ) _y In _{1 -y} P cladding layer 3 are formed on an n-type GaAs substrate 1 by, for example, MOCVD. , Active layer 4, p-type Al _z Ga _{1 -z} As clad layer 13, p-type (Al _x Ga _{1 -x} ) _y In _{1 -y} P clad layer 5, p-type GaInP etching stop layer 6, p-type (Al _{x Ga 1-x) y In} 1-y P cladding layer 7, p-type G
An aInP intermediate layer 8 and a p-type GaAs cap layer 9 are sequentially grown. Here, when the n-type GaAs buffer layer 2 and the n-type (Al _x Ga _{1 -x} ) _y In _{1 -y} P clad layer 3 are grown, Si is doped as an n-type impurity. As for the p-type layer, C is doped as a p-type impurity when the p-type Al _z Ga _{1 -z} As clad layer 13 is grown, and the p-type (Al _x Ga _{1 -x} ) _y In _{1 -y} P clad layer is grown. 5, p-type GaInP etching stop layer 6, p-type (A
l _x Ga _1-x ) _y In _1-y P cladding layer 7, p-type GaI
During the growth of the nP intermediate layer 8 and the p-type GaAs cap layer 9, Zn is doped as a p-type impurity.

Next, a stripe-shaped resist pattern (not shown) extending in one direction is formed on the p-type GaAs cap layer 9 by lithography, and this resist pattern is used as a mask to form a p-type GaInP etching stop layer. 6, a p-type GaAs cap layer 9,
p-type GaInP intermediate layer 8 and p-type (Al _x Ga _1-x )
_{The y} In _1-y P clad layer 7 is sequentially etched by a wet etching method, and these p-type (Al _x Ga _1-x )
_{The y} In _1-y P clad layer 7, the p-type GaInP intermediate layer 8, and the p-type GaAs cap layer 9 are patterned in a stripe shape. Thus, a stripe portion having a desired height and shape is formed.

Next, after removing the resist pattern used as a mask in the above-mentioned wet etching, for example, M
The n-type GaAs current confinement layer 10 is selectively grown by the OCVD method to bury the portions on both sides of the stripe portion. During this selective growth, usually, a p-type Ga
An SiO ₂ film or the like is formed on the As cap layer 9 and this S
Growth is performed using the iO ₂ film as a mask.

Next, p-type GaAs is formed by, for example, a vacuum evaporation method.
A p-side electrode 11 is formed on the entire surface of the s cap layer 9 and the n-type GaAs current confinement layer 10, and an n-side electrode 12 is formed on the back surface of the n-type GaAs substrate 1 in the same manner. Thereby, the target AlGaInP-based semiconductor laser is manufactured.

As described above, according to the first embodiment, the p-type Al _z Ga is placed between the active layer 4 and the p-type (Al _x Ga _{1 -x} ) _y In _{1 -y} P cladding layer 5. _{Since the 1-z} As cladding layer 13 is provided, the p-type (Al _x Ga
_1-x ) _y In _1-y P cladding layer 5 is formed of this p-type Al _z Ga
It is separated from the active layer 4 by the thickness of the _1-z As cladding layer 13 and is therefore p-type (Al _x Ga _{1 -x} ) _y In
_The possibility that Zn doped in the _1-y P cladding layer 5 enters the active layer 4 by diffusion is very low. Moreover, C doped as a p-type impurity in the p _- type Al _z Ga _{1 -z} As cladding layer 13 is extremely difficult to diffuse, so that the p-type Al
The possibility that C doped in the l _z Ga _{1 -z} As cladding layer 13 enters the active layer 4 by diffusion is very low. As a result, the p-type (Al _x G
a _1-x ) _y In _1-y Zn doped in the P cladding layer 5
In addition, C doped in the p-type Al _z Ga _{1 -z} As clad layer 13 hardly enters the active layer 4 by diffusion, so that deterioration of the active layer 4 can be prevented. Moreover,
P-type Al _z Ga provided in the immediate vicinity of the active layer 4
_Since the doping concentration of C in the _1-z As cladding layer 13 is sufficiently high, leakage current due to overflow of carriers from the active layer 4 is small, high quantum efficiency can be obtained, and operation current can be reduced. As well as
The life of the element at the time of high-temperature operation can be improved. As described above, AlGaInP having good characteristics and long life
Based semiconductor laser can be realized.

Next, A according to the second embodiment of the present invention will be described.
An lGaInP-based semiconductor laser will be described. FIG. 2 shows an AlGaInP-based semiconductor laser according to the second embodiment.

The AlGaInP according to the second embodiment
A semiconductor laser having a structure as shown in FIG. As shown in FIG. 3, in this case, the active layer 4 is made of, for example, undoped GaI as a quantum well layer.
It has a GaInP / p-type AlGaAs MQW structure in which nP layers and p-type AlGaAs layers as barrier layers are alternately stacked. Here, the p-type AlGaAs layer serving as a barrier layer is doped with C as a p-type impurity. The doping concentration of C in the p-type AlGaAs layer is, for example, 1 × 1
0 ^{17 to} 2 × 10 ¹⁹ cm ⁻³ . The thickness of the undoped GaInP layer as the quantum well layer is, for example, 2 to 20 n.
m, the thickness of the p-type AlGaAs layer as a barrier layer is, for example, 2 to 10 nm. Further, in this case, the active layer 4 and p
A p-type (Al _x Ga _{1 -x} ) _y In _{1 -y} P cladding layer 14 is provided between the Al _z Ga _{1 -z} As cladding layer 13. Other than that, A according to the first embodiment
The description is omitted because it is the same as that of the 1GaInP-based semiconductor laser.

According to the second embodiment, the following advantages can be obtained in addition to the same advantages as the first embodiment. That is, the active layer 4 is made of GaInP / p-type Al
It has a GaAs MQW structure and the GaInP / p
Doped in the p-type AlGaAs layer as the barrier layer in the p-type AlGaAs MQW structure is very difficult to diffuse, so that C is added to the undoped GaInP layer as the quantum well layer.
Is prevented from entering by diffusion to prevent the active layer 4 from deteriorating, and the barrier layer is doped with p-type AlG.
With the aAs layer, modulation characteristics and temperature characteristics can be improved.

Next, an optical disk reproducing apparatus using the AlGaInP-based semiconductor laser according to the first or second embodiment as a light emitting element will be described. FIG. 4 shows the configuration of the optical disk reproducing apparatus.

As shown in FIG. 4, this optical disk reproducing apparatus has a semiconductor laser 101 as a light emitting element. As the semiconductor laser 101, the AlGaInP-based semiconductor laser according to the above-described first or second embodiment is used. This optical disk reproducing device also guides the emitted light of the semiconductor laser 101 to the optical disk D,
A known optical system for reproducing the reflected light (signal light) from the optical disk D, that is, the collimator lens 10
2, a beam splitter 103, a quarter-wave plate 104, an objective lens 105, a detection lens 106, a light receiving element 107 for signal light detection, and a signal light reproducing circuit 108.

In this optical disk reproducing apparatus, the outgoing light L of the semiconductor laser 101 is collimated by a collimator lens 102, further passed through a beam splitter 103, and the degree of polarization is adjusted by a 波長 wavelength plate 104. The light is condensed by the lens 105 and is incident on the optical disk D. Then, the signal light L ′ reflected by the optical disc D is applied to the objective lens 105 and the 波長 wavelength plate 104.
After the light is reflected by the beam splitter 103 through the detection lens 106, the light is incident on the light receiving element 107 for signal light detection, where it is converted into an electric signal.
At 08, the information written on the optical disc D is reproduced.

According to this optical disk reproducing apparatus, since the AlGaInP-based semiconductor laser according to the first or second embodiment having a long life is used as the semiconductor laser 101, the life of the optical disk reproducing apparatus can be extended. .

Here, the case where the AlGaInP-based semiconductor laser according to the first or second embodiment is applied to the light emitting element of the optical disk reproducing device has been described.
It can be applied to the light emitting element of the optical disc recording / reproducing device and the optical disc recording device, as well as the light emitting element of the optical device such as the optical communication device and the light emitting device of the in-vehicle equipment which needs to be operated at a high temperature. It is also possible to apply.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above embodiments, and various modifications based on the technical concept of the present invention are possible.

For example, the numerical values, structures, processes, and the like described in the first and second embodiments are merely examples, and different numerical values, structures, processes, and the like may be used as needed.

Specifically, in the first and second embodiments, the p-type GaInP etching stop layer 6 is used, but the p-type GaInP etching stop layer 6 may be omitted as necessary.

In the first and second embodiments, the case where the present invention is applied to an AlGaInP-based semiconductor laser has been described.
It may be applied to a P-based light emitting diode.

[0049]

As described above, according to the first aspect of the present invention, the diffusion between the active layer and the p-type AlGaInP cladding layer is smaller than that of the p-type impurity doped in the p-type AlGaInP cladding layer. By providing a p-type III-V compound semiconductor cladding layer made of a III-V compound semiconductor different from AlGaInP doped with a p-type impurity which is difficult to be doped, the p-type AlGaInP cladding layer is doped with p-type Impurities can be prevented from entering the active layer by diffusion, and deterioration of characteristics of the semiconductor light emitting element can be prevented.

According to the second aspect of the present invention, the active layer is formed of an undoped GaInP layer as a quantum well layer, and a p-type A
AlGaI doped with a p-type impurity that is less diffused than the p-type impurity doped in the lGaInP cladding layer.
p-type I made of III-V compound semiconductor different from nP
By having a multiple quantum well structure using the II-V compound semiconductor layer as a barrier layer, the modulation characteristics and the temperature characteristics of the semiconductor light emitting device can be improved.

[Brief description of the drawings]

FIG. 1 shows an AlGaIn according to a first embodiment of the present invention.
It is sectional drawing which shows a P-type semiconductor laser.

FIG. 2 shows an AlGaIn according to a second embodiment of the present invention.
It is sectional drawing which shows a P-type semiconductor laser.

FIG. 3 shows an AlGaIn according to a second embodiment of the present invention.
FIG. 3 is an energy band diagram for explaining a P-based semiconductor laser.

FIG. 4 shows A according to the first or second embodiment of the present invention;
FIG. 2 is a schematic diagram illustrating an optical disc reproducing apparatus using an lGaInP-based semiconductor laser as a light emitting element.

[Explanation of symbols]

1 ... n-type GaAs substrate, 3 ... n-type (Al _x Ga
_1-x ) _y In _1-y P clad layer, 4... Active layer, 5,
7, 14 ... p-type (Al _x Ga _1-x ) _y In _1-y P clad layer, 6 ... p-type GaInP etching stop layer, 8 ... p-type GaInP intermediate layer, 9 ... p-type Ga
As cap layer, 10... N-type GaAs current confinement layer,
11 ... p-side electrode, 12 ... n-side electrode, 13 ...
p-type Al _z Ga _1-z As cladding layer

Claims (17)

[Claims] 1. A semiconductor light emitting device having a structure in which an active layer is sandwiched between an n-type AlGaInP cladding layer and a p-type AlGaInP cladding layer, wherein the p-type AlGaInP cladding layer is provided between the active layer and the p-type AlGaInP cladding layer. A p-type III-V compound semiconductor clad layer made of a III-V compound semiconductor different from AlGaInP and doped with a p-type impurity that is more difficult to diffuse than a p-type impurity doped in the clad layer is provided. Characteristic semiconductor light emitting device. 2. The semiconductor light emitting device according to claim 1, wherein said p-type III-V compound semiconductor cladding layer has a thickness of 0.05 μm or more and 0.3 μm or less. 3. The semiconductor light emitting device according to claim 1, wherein the thickness of the p-type III-V compound semiconductor cladding layer is 0.1 μm or more and 0.3 μm or less. 4. The doping concentration of the p-type impurity in the p-type III-V compound semiconductor cladding layer is 2 × 10 ^17.
2. The semiconductor light emitting device according to claim 1, wherein said semiconductor light emitting device has a size of not less than cm ^{-3 and not} more than 2 × 10 ¹⁹ cm ^-3 . 5. The semiconductor light emitting device according to claim 1, wherein said p-type III-V compound semiconductor cladding layer is a p-type AlGaAs cladding layer. 6. The semiconductor light emitting device according to claim 1, wherein said p-type III-V compound semiconductor clad layer is a p-type GaInAsP clad layer. 7. The semiconductor light emitting device according to claim 1, wherein the p-type impurity doped in the p-type AlGaInP cladding layer is Zn or Mg. 8. The p-type impurity doped in the p-type III-V compound semiconductor cladding layer is C, Si or Ge.
The semiconductor light emitting device according to claim 1, wherein 9. The semiconductor light emitting device according to claim 1, wherein said p-type III-V compound semiconductor cladding layer is substantially lattice-matched with a semiconductor substrate. 10. A semiconductor light emitting device having a structure in which an active layer is sandwiched between an n-type AlGaInP cladding layer and a p-type AlGaInP cladding layer, wherein the active layer has an undoped GaInP layer as a quantum well layer and a p-type AlGaInP cladding layer. Doped with a p-type impurity that is more difficult to diffuse than a doped p-type impurity,
A semiconductor light emitting device having a multiple quantum well structure using a p-type group III-V compound semiconductor layer made of a group III-V compound semiconductor different from AlGaInP as a barrier layer. 11. The semiconductor light emitting device according to claim 10, wherein said undoped GaInP layer has a thickness of 2 nm or more and 20 nm or less. 12. The semiconductor light emitting device according to claim 10, wherein said p-type III-V compound semiconductor layer has a thickness of 2 nm or more and 10 nm or less. 13. The doping concentration of the p-type impurity in the p-type III-V compound semiconductor layer is 1 × 10 ¹⁷ cm ^−3.
11. The semiconductor light emitting device according to claim 10, wherein the size is not more than 2 × 10 ¹⁹ cm ⁻³ . 14. The semiconductor device according to claim 1, wherein said p-type III-V compound semiconductor layer is a p-type AlGaAs layer.
0. A semiconductor light emitting device according to item 0. 15. The semiconductor light emitting device according to claim 10, wherein said p-type III-V compound semiconductor layer is a p-type GaInAsP layer. 16. The semiconductor light emitting device according to claim 10, wherein the p-type impurity doped in the p-type AlGaInP cladding layer is Zn or Mg. 17. The p-type impurity doped in the p-type III-V compound semiconductor cladding layer is C, Si or G
11. The semiconductor light emitting device according to claim 10, wherein e is e.