JPH07254755A - Semiconductor light emitting element - Google Patents

Abstract

PURPOSE:To facilitate the ohmic contact of the p-side electrode, to reduce the serial resistance and to stabilize the characteristics by arranging an intermediate layer containing Te between a p-type InP substrate and an active layer. CONSTITUTION:A p-InP buffer layer 2, a superlattice layer 3 that is comprised of eight p-ZnTe/p-ZnMgSeTe sublayers and a p-ZnMgSeTe layer 4 are formed in sequence by a molecular beam epitaxial method on a p-type InP substrate 1. The thickness of each sublayer of the superlattice layer is determined so that forbidden bands change gradually from the sublayer in contact with the buffer layer 2 to the sublayer in contact with the p-ZnMgSeTe layer 4. Then a ZnSeTe active layer 5, an n-ZnMgSeTe layer 6 and a CdSSeTe layer 7 are formed in sequence. An insulating film of SiO2 is formed by a CVD method, stripes are formed by a general etching method and the element is completed by cleavage after an n side electrode 9 and a p side electrode 10 are formed by evaporation. With this the ohmic contact at p side electrode 10 is provided and the serial resistance is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device,
In particular, the present invention relates to a semiconductor light emitting device which has stable characteristics and is capable of emitting green or blue light.

[0002]

2. Description of the Related Art Demands for semiconductor lasers that emit light in green, blue, and even in the ultraviolet region are increasing due to demands for higher density of optical discs. In addition, the realization of semiconductor lasers in the green to ultraviolet range makes it possible to increase the sensitivity of optical printers, and there is a growing demand for their industrial realization.

Up to now, a semiconductor laser using a II-VI group compound semiconductor as a laser diode in the visible short wavelength region, for example, Electronics Letters 29 No. 16 pp. 1488-1.
The structure described in 489 (1993) has been proposed and room temperature continuous oscillation up to 523.5 nm has been realized. Further, Japanese Patent Laid-Open No. 5-21892 proposes a II-VI group semiconductor laser capable of emitting short wavelength light, which is constructed on an InP substrate.

[0004]

However, in these II-VI group semiconductor lasers, it is difficult to make ohmic contact with the p-side electrode and the series resistance is large, so that stable characteristics cannot be obtained. It was The object of the present invention is to solve the problems that the above-mentioned conventional technology has, and to have stable characteristics,
Another object of the present invention is to provide a II-VI group semiconductor light emitting device capable of emitting short wavelength light.

[0005]

The above-mentioned objects are at least as follows.
A semiconductor light emitting device comprising a II-VI group compound semiconductor and epitaxially growing a p-type InP substrate, a clad layer having a p-type conductivity type, an active layer, and a clad layer having a n-type conductivity type. This can be achieved by providing a semiconductor light emitting device characterized in that at least one intermediate layer containing Te is provided between the p-type InP substrate and the active layer.

Further, the above object is to provide the above-mentioned Te-containing intermediate layer with Zn _1-xy Be _x Mg _y Se _z Te _1-z (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦
It can be effectively achieved by configuring with z <1).

Further, the above-mentioned object is to provide the above-mentioned Te-containing intermediate layer with Zn _1-xy Cd _x Mg _y Se _z Te _1-z (0≤x≤10, ≤y≤1, 0≤
It can be effectively achieved by configuring with z <1).

The above object is effectively achieved by providing a superlattice layer between the p-type InP substrate and the Te-containing intermediate layer so that the effective band gap gradually changes. can do.

Further, the above-mentioned object is to make the above-mentioned superlattice layer II-VI.
It can be effectively achieved by using a group compound semiconductor.

Further, the above-mentioned object is
And Zn _1-xy Be _x Mg _y Se _z Te _1-z (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z
It can be effectively achieved by configuring with ≦ 1).

Further, the above-mentioned object is
And Zn _1-xy Cd _x Mg _y Se _z Te _1-z (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z
It can be effectively achieved by configuring with ≦ 1).

Further, as another structure for achieving the above object, a forbidden band width E _g3 (that is, a forbidden band width E _g3 between the forbidden band width E _g1 of the p-type InP substrate and the forbidden band width E _g2 of the intermediate layer containing Te) ( , E _{g 1} <E _g3 <E _g2 ).
The present invention invented a semiconductor laser characterized in that at least one layer was provided between the InP substrate and the above-mentioned intermediate layer containing Te.

In addition, the above-mentioned object is to make the above-mentioned semiconductor intermediate layer into Z
n _1-xy Be _x Mg _y Se _z Te _1-z (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1)
It can be effectively achieved by configuring

Further, the above-mentioned object is to make the semiconductor intermediate layer Z
n _1-xy Cd _x Mg _y Se _z Te _1-z (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1)
It can be effectively achieved by configuring

Further, the above-mentioned object is to use Zn _{1-xy as the} active layer.
This can be effectively achieved by using Mg _x Cd _y Se _z Te _1-z (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1).

The above object can be effectively achieved by forming the active layer from a material whose lattice constant in the absence of biaxial stress is smaller than that of the p-type InP substrate. .

[0017]

FIG. 3 shows a schematic sectional view of a conventional II-VI group semiconductor laser. In this structure, the p-side electrode is 1 for p-ZnSe 20.
0 is set. However, since ZnSe has a large forbidden band width of about 2.67 eV, ohmic contact is not obtained, and the contact resistance is extremely high. Therefore, the amount of heat generated by current injection is large, and stable operation has not been obtained.

On the other hand, in the structure of the present invention, since the p-type InP substrate 1 is used as shown in FIG.
An ohmic contact of 0 is easily obtained. Furthermore, the p-type clad layer 4 does not contain sulfur (S) and therefore has a relatively small work function. Zn _1-x Mg _x Se _y Te _1-y (0 ≦ x ≦ 1, 0 ≦ y ≦ 1) compound semiconductor If a superlattice is formed between the p-type InP substrate 1 and the p-type clad layer 4 so that the effective band gap gradually changes between them, the p-InP buffer layer 2 Since holes can be smoothly injected into the p-ZnMgSeTe clad layer 4 from, the series resistance is small and stable operation can be obtained. In addition, FIG. 6 shows that in the II-VI group semiconductor laser formed on the p-InP substrate 1, the p-InP buffer layer 2 and the p-ZnMgSeTe cladding layer 25 have a p-
This is an example in which two intermediate layers of a ZnSeTe layer 31 and a p-ZnMgSeTe layer 32 are provided. In this case also, the p-type InP substrate 1
Therefore, the ohmic contact of the p-type electrode 10 can be easily obtained, and the p-InP buffer layer 2 to the p-ZnMgSeTe cladding layer can be obtained.
Since holes can be smoothly injected into 25, series resistance is small and stable operation can be obtained.

[0019]

EXAMPLES The constitution of the present invention will be specifically described below with reference to examples.

[0020]

[Embodiment 1] A first embodiment of the present invention will be described with reference to FIG. First, the production of the semiconductor light emitting device of the present invention will be described. The p-InP buffer layer 2 (acceptor concentration N) is formed on the p-InP substrate 1 by the molecular beam epitaxy method.
_A = 1 × 10 ¹⁸ (/ cm ³ ), thickness 2.0 μm) and p-ZnTe / p-Zn
_{0.5 Mg 0. 5 Se 0.75 Te 0.25} 8 cycles consisting superlattice layer 3, p-
Zn _0.5 Mg _0.5 Se _0.75 Te _0.25 layer _{4 (N A = 5 × 10} 17 (/ cm 3), a thickness of 2.0 .mu.m) were sequentially formed a. Here, the structure of the superlattice is as shown in Fig. 2, and the acceptor concentration N _A of p-ZnTe 11
Is 5 × 10 ¹⁷ (/ cm ³ ), N of p-Zn _0.5 Mg _0.5 Se _0.75 Te _0.25 12
_A was set to 5 × 10 ¹⁷ (/ cm ³ ). The film thickness of each layer is p-I
From the side in contact with the nP buffer layer 2 (left side in the figure), p-Zn _0.5
Mg _0.5 Se _0.75 Te _0.25 It is determined that the forbidden band width gradually changes to the side in contact with Layer 4 (right side of the figure). In this example,
The thickness of one cycle was fixed at 45Å, and the thickness was changed at 5Å pitch between 5 and 40Å. That is, in FIG. 2, Zn _0.5 Mg _0.5
The thickness of Se _0.75 Te _0.25 / ZnTe is (5Å / 40Å), (1
(0Å / 35Å), (15Å / 30Å), (20Å / 25Å), (25Å / 20Å),
(30Å / 15Å), (35Å / 10Å), (40Å / 5Å).

Subsequently, ZnSe _0.53 Te _0.47 active layer 5 (undoped, thickness 100 Å), n-Zn _0.5 Mg _0.5 Se _0.75 Te _0.25 layer 6
(Donor concentration N _D = 1 × 10 ¹⁸ (/ cm ³ ), thickness 2.0 μm), CdS
_0.9 Se _0.05 Te _0.05 Layer 7 (N _D = 1 × 10 ¹⁸ (/ cm ³ ), Thickness 0.01μ
m) were formed in sequence. As the dopant, nitrogen was used for the p-type layer and chlorine was used for the n-type layer. Next, the SiO ₂ insulating film 8 is formed by the CVD method, and the width is 15 μm by the usual etching method.
m stripes were formed. Finally, using the evaporation method,
After forming the side electrode 9 and the p-side electrode 10, the semiconductor laser shown in FIG. 1 was produced by cleaving to a length of about 1 mm.

The semiconductor laser obtained as described above continuously oscillated at room temperature with a threshold current of about 50 mA.
The oscillation wavelength was about 540 nm.

[0023]

Second Embodiment A second embodiment of the present invention will be described with reference to FIG. First, the production of the semiconductor light emitting device of the present invention will be described. p-InP buffer layer 2 (acceptor concentration N _A = 1 × 10 5) on p-InP substrate 1 by molecular beam epitaxy
¹⁸ (/ cm ³ ), thickness 2.0 μm) and p-InP / p-Zn _0.5 Mg _0.5 Se
_0.75 Te _0.25 8 superlattice layer 22, p-Zn _0.5 Mg _0.5
Se _0.75 Te _0.25 layer _{4 (N A = 5 × 10} 17 (/ cm 3), a thickness of 2.0 .mu.m) were sequentially formed a. Here, the superlattice layer 22, p-InP (N _A =
^{1 × 10 18 (/ cm 3} )) and _{p-Zn 0.5 Mg 0.5 Se 0.75} Te 0.25 (N A = 5
It is composed of × 10 ¹⁷ (/ cm ³ ). The film thickness of each layer is p
From the side in contact with the -InP buffer layer _{2 p-Zn 0. 5 Mg 0.5} Se
_0.75 Te _0.25 It is decided that the forbidden band width gradually changes to the side in contact with layer 4. In this example, the thickness of one cycle is 45Å
It was fixed at 5 Å and changed at 5 Å pitch. That is, the thickness of Zn _0.5 Mg _0.5 Se _0.75 Te _0.25 / InP is (5Å / 40Å), (10Å / 35Å), (15Å / 30Å), (20Å / 2
(5Å), (25Å / 20Å), (30Å / 15Å), (35Å / 10Å), (40
Å / 5Å).

Subsequently, ZnSe _0.53 Te _0.43 active layer 5 (undoped, thickness 100 Å), n-Zn _0.5 Mg _0.5 Se _0.75 Te _0.25 layer 6
(Donor concentration N _D = 1 × 10 ¹⁸ (/ cm ³ ), thickness 2.0 μm), CdS
_0.9 Se _{0.0 5} Te _0.05 Layer 7 (N _D = 1 × 10 ¹⁸ (/ cm ³ ), Thickness 0.01μ
m) were formed in sequence. As the dopant, nitrogen was used for the p-type layer and chlorine was used for the n-type layer. Next, the SiO ₂ insulating film 8 is formed by the CVD method, and the width is 15 μm by the usual etching method.
m stripes were formed. Finally, using the evaporation method,
After forming the side electrode 9 and the p-side electrode, the semiconductor laser shown in FIG. 4 was produced by cleaving to a length of about 1 mm.

The semiconductor laser obtained as described above continuously oscillated at room temperature with a threshold current of about 60 mA. The oscillation wavelength was 540 nm.

[0026]

Third Embodiment A third embodiment of the present invention will be described with reference to FIG. First, the production of the semiconductor light emitting device of the present invention will be described. p-InP buffer layer 2 (acceptor concentration N _A = 1 × 10 5) on p-InP substrate 1 by molecular beam epitaxy
¹⁸ (/ cm ³ ), thickness 2.0 μm) and p-ZnTe / p-ZnSe 8 superlattice layer 23, p-Zn _0.25 Mg _0.75 Se _0.9 Te _0.1 layer 24 (N
_A = 5 × 10 ¹⁷ (/ cm ³ ) and a thickness of 2.0 μm) were sequentially formed. Here, the superlattice layer _{23, p-ZnTe (N A =} 5 × 10 17 (/ cm 3)), p
- composed of _{ZnSe (N A = 5 × 10} 17 (/ cm 3)). Also,
The film thickness of each layer is determined so that the band gap gradually changes from the side in contact with the p-InP buffer layer 2 to the side in contact with the p-Zn _0.25 Mg _0.75 Se _0.9 Te _0.1 layer 24. In this example, 1
The thickness of the cycle was fixed at 45Å, and varied from 5Å to 40Å at 5Å pitch. That is, the thickness of ZnSe / ZnTe is p-I
From the side in contact with the nP buffer layer 2 (5Å / 40Å), (10Å /
(35Å), (15Å / 30Å), (20Å / 25Å), (25Å / 20Å), (30
Å / 15Å), (35Å / 10Å), and (40Å / 5Å).

Subsequently, a ZnMgSeTe-based multiple quantum well active layer 25
(Undoped, thickness 0.04 μm), n-Zn _0.25 Mg _0.75 Se _0.9 Te
_0.1 layer 26 (donor concentration N _D = 1 × 10 ¹⁸ (/ cm ³ ), thickness 2.0μ
m), CdS _0.9 Se _0.05 Te _0.05 layer 7 (N _D = 1 × 10 ¹⁸ (/ cm ³ ), thickness 0.01 μm) were sequentially formed. The ZnMgSeTe-based multiple quantum well active layer 25 is composed of a Zn _0.5 Mg _0.5 Se _0.75 Te _0.25 barrier layer 27 having a thickness of 5 nm and a well layer 28 (tensile strain of about 1%) of ZnSe _0.65 Te _0.35 having a thickness of 3 nm. There is. As the dopant, nitrogen was used for the p-type layer and chlorine was used for the n-type layer. Next, a SiO ₂ insulating film was provided by the CVD method, and a stripe having a width of 15 μm was formed by the usual etching method. Finally, an n-type electrode and a p-type electrode were formed by using the vapor deposition method, and then cleaved to a length of about 1 mm to manufacture the semiconductor laser of FIG.

The semiconductor laser obtained as described above continuously oscillated at room temperature with a threshold current of about 50 mA. Also,
The oscillation wavelength was about 510 nm.

[0029]

Fourth Embodiment A fourth embodiment of the present invention will be described with reference to FIG. First, the production of the semiconductor light emitting device of the present invention will be described. By the molecular beam epitaxy method, the p-InP buffer layer 2 (acceptor concentration N _A = 1 × is formed on the p-InP substrate 1).
10 ¹⁸ (/ cm ³ ), thickness 2.0 μm) and p-ZnSe _0.53 Te _0.47 layer 29
(N _A = 5 × 10 ¹⁷ (/ cm ³ ), thickness 0.1 μm), p-Zn _0.5 Mg _0.5 Se
_0.75 Te _0.25 layer _{30 (N A = 5 × 10} 17 (/ cm 3), a thickness of 0.1 [mu] m) were sequentially formed.

Subsequently, p-Zn _0.25 Mg _0.75 Se _0.9 Te _0.1 layer 24
^{_{(N A = 5 × 10 17}} (/ cm 3), a thickness of 2.0μm), ZnMgSeTe based multi-quantum well active layer 25 (undoped, thickness 0.04 .mu.m), n-Zn
_0.25 Mg _{0.7 5} Se _0.9 Te _0.1 Layer 26 (donor concentration N _D = 1 × 10 ¹⁸ (/
cm ³ ), thickness 2.0 μm), CdS _0.9 Se _0.05 Te _0.05 layer 7 (N _D = 1 ×)
10 ¹⁸ (/ cm ³ ) and a thickness of 0.01 μm) were sequentially formed. Where Zn
The MgSeTe-based multiple quantum well active layer 25 is made of Zn _0.5 Mg with a thickness of 5 nm.
_0.5 Se _0.75 Te _0.25 Barrier layer 27 and 3 nm thick Zn _0.8 Mg _0.2 Se
It is composed of a well layer 31 of _0.6 Te _0.4 . As the dopant, nitrogen was used for the p-type and chlorine was used for the n-type. Next, a SiO ₂ insulating film was provided by the CVD method, and a stripe having a width of 15 μm was formed by the usual etching method. Finally, the n-side electrode and the p-side electrode were formed by using the vapor deposition method, and then cleaved to a length of about 1 mm to manufacture the semiconductor laser of FIG.

The semiconductor laser obtained as described above continuously oscillated at room temperature with a threshold current of about 60 mA. Also,
The oscillation wavelength was about 490 nm.

The structure of the semiconductor light emitting device of the present invention is also effective for structures other than those shown in the above embodiments. That is, for example, the active layer Zn _1-x Mg _x S shown in Examples 1 to 4 above.
In addition to e _y Te _{1- y} (0 ≦ x ≦ 1, 0 ≦ y ≦ 1), Zn _1-x Cd _x Se _y Te
A quaternary compound of _1-y (0 ≦ x ≦ 1, 0 ≦ y ≦ 1) can also be applied. Further, it is not always necessary to lattice match with the InP substrate, and a strain system may be used.

Further, the present invention is not limited to the laser structure shown in the above embodiment, but various semiconductor lasers such as distributed feedback laser, Bragg reflection laser, wavelength tunable laser,
It can also be applied to a laser with an external resonator and a surface emitting laser.

Furthermore, the present invention is not limited to semiconductor lasers,
It can also be applied to semiconductor devices that require current injection, such as light emitting diodes and optical switches.

[0035]

EFFECTS OF THE INVENTION By using the semiconductor light emitting device having the structure of the present invention, the problems of the prior art can be solved, the characteristics are stable, and a II-VI group semiconductor laser capable of emitting short wavelength light can be obtained. Could be provided. That is, according to the present invention, the ohmic contact of the p-type electrode is possible and the series resistance can be significantly reduced. Therefore, the green or blue light emitting semiconductor laser using the II-VI group compound semiconductor can be continuously connected at room temperature. Oscillation is possible. As a result, it is possible to provide a semiconductor laser that can be applied to a light source for high density optical discs, a green or blue LED substitute light source, a light source for high-sensitivity laser printers, a light source for displays, and the like.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of an embodiment of a semiconductor light emitting device of the present invention.

FIG. 2 is an energy band diagram of the superlattice in FIG.

FIG. 3 is a sectional view showing a configuration of a conventional semiconductor light emitting device.

FIG. 4 is a cross-sectional view showing the configuration of another embodiment of the semiconductor light emitting device of the present invention.

FIG. 5 is a cross-sectional view showing the configuration of still another embodiment of the semiconductor light emitting device of the present invention.

FIG. 6 is a cross-sectional view showing the configuration of still another embodiment of the semiconductor light emitting device of the present invention.

[Explanation of symbols]

1 ... p-InP substrate, 2 ... p-InP buffer layer, 3 ... pZ
nTe / p-Zn _0.5 Mg _0.5 Se _0.75 Te _0.25 4, 4 ... p-Zn _0.5 Mg
_0.5 Se _0.75 Te _0.25 layer, 5 ... ZnSe _0.53 Te _0.47 active layer, 6 ...
n-Zn _0.5 Mg _0.5 Se _0.75 Te _0.25 layer, 7 ... CdS _0.9 Se _0.05 Te
_0.05 layer, 8 ... SiO ₂ insulating film, 9 ... n-side electrode, 10 ... p-side electrode, 11 ... p-ZnTe layer, 12 ... p-Zn _0.5 Mg _0.5 Se _0.75 Te _0.25
Layer, 13 ... n-GaAs substrate, 14 ... n-ZnMgSSe cladding layer, 1
5 ... n-ZnSe optical guide layer, 16 ... ZnCdSe quantum well active layer, 1
7 ... p-ZnSe optical guide layer, 18 ... p-ZnMgSSe cladding layer,
19 ... p-ZnSSe layer, 20 ... p-ZnSe layer, 21 ... Polyimide resin, 22 ... p-InP / p-Zn _0.5 Mg _0.5 Se _0.75 Te _0.25 superlattice layer, 23 ... p-ZnTe / p-ZnSe superlattice Layer, 24 ... p-Zn _0.25 M
g _0.75 Se _0.9 Te _0.1 layer, 25 ... ZnMgSeTe system multiple quantum well active layer, 26 ... n-Zn _0.25 Mg _0.75 Se _0.9 Te _0.1 layer, 27 ... Zn _0.5 Mg
_0.5 Se _0.75 Te _0.25 barrier layer, 28 ... ZnSe _0.65 Te _0.35 well layer, 29 ... p-ZnSe _0.53 Te _0.47 layer, 30 ... p-Zn _0.5 Mg _0.5 Se
_0.75 Te _0.25 layer, 31 ... Zn _0.8 Mg _0.2 Se _0.6 Te _0.4 well layer.

Claims (12)

[Claims] 1. A p-type InP substrate, which is composed of at least a II-VI group compound semiconductor, is epitaxially grown on a p-type clad layer having a p-type conductivity, an active layer, and a clad layer having an n-type conductivity. A semiconductor light emitting device, wherein at least one intermediate layer containing Te is provided between the p-type InP substrate and the active layer. 2. The above-mentioned intermediate layer containing Te is Zn _1-xy Be _x Mg _y
2. The semiconductor light emitting device according to claim 1, wherein the semiconductor light emitting device is composed of Se _z Te _1-z (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z <1). 3. The intermediate layer containing Te is Zn _1-xy Cd _x Mg _y
2. The semiconductor light emitting device according to claim 1, wherein the semiconductor light emitting device is composed of Se _z Te _1-z (0 ≦ x ≦ 10, ≦ y ≦ 1, 0 ≦ z <1). 4. A superlattice layer having an effective forbidden band width gradually changing is provided between the p-type InP substrate and the intermediate layer containing Te. 3. The semiconductor light emitting device according to any one of 3 above. 5. The semiconductor light emitting device according to claim 4, wherein the superlattice layer is composed of a II-VI group compound semiconductor. 6. The superlattice layer comprises InP and Zn _1-xy Be _x Mg _y Se _z
The semiconductor light emitting device according to claim 4, wherein the semiconductor light emitting device is composed of Te _1-z (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1). 7. The superlattice layer comprises InP and Zn _1-xy Cd _x Mg _y Se _z
The semiconductor light emitting device according to claim 4, wherein the semiconductor light emitting device is composed of Te _1-z (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1). 8. The forbidden band width E _g1 of the p-type InP substrate and the
Forbidden band width E between the middle layer containing Te and E _g2
At least one semiconductor intermediate layer having _g3 (that is, E _g1 <E _g3 <E _g2 ) is provided between the p-type InP substrate and the intermediate layer containing Te. Three
The semiconductor light emitting device according to any one of 1. 9. The semiconductor intermediate layer is Zn _1-xy Be _x Mg _y Se _z Te
9. The semiconductor light emitting device according to claim 8, wherein the semiconductor light emitting device comprises _1-z (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1). 10. The semiconductor intermediate layer is Zn _1-xy Cd _x Mg _y Se _z T
9. The semiconductor light emitting device according to claim 8, wherein the semiconductor light emitting device is formed of e _{1 -z} (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1). 11. The active layer comprises Zn _1-xy Mg _x Cd _y Se _z Te _1-z (0
≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1), The semiconductor light emitting device according to claim 1. 12. The active layer is made of a material whose lattice constant in the absence of biaxial stress is smaller than that of the p-type InP substrate. A semiconductor light-emitting device according to item 1.