JPH07154035A - Semiconductor light emitting element - Google Patents

Abstract

PURPOSE:To realize a blue or green semiconductor light emitting element which can operate without heating while exhibiting excellent light and carrier confinement characteristics and can be fabricated easily using a ZnMqSSe based compound conductor as the material of a clad layer. CONSTITUTION:An n-type Zn1-pMgpSqSe1-q clad layer 3, an n-type ZnSe optical waveguide layer 4, an active layer 5, a p-type ZnSe optical waveguide layer 6, a p-type Zn1-pMgpSqSe1-q clad layer 7, a p-type ZnSvSe1-v layer 8 and a p-type ZnSe contact layer 9 are formed sequentially on an n-type GaAs substrate 1 through an n-type ZnSe buffer layer 2. A p-type electrode 11 is formed on the p-type ZnSe contact layer 9 and an n-side electrode 12 is formed on the rear of the n-type GaAs substrate 1 thus constituting a semiconductor light emitting element, e.g. a semiconductor laser or a LED. The active layer 5 is composed of an i-type Zn1-zCdzSe, for example.

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, and more particularly to a semiconductor light emitting device capable of emitting blue or green light, such as a semiconductor laser or a light emitting diode.

[0002]

2. Description of the Related Art In recent years, in order to improve the recording density of optical discs and the resolution of laser printers, there has been an increasing demand for semiconductor light emitting devices capable of emitting light at a short wavelength, particularly semiconductor lasers. Research is being actively conducted aiming at

A II-VI group compound semiconductor is promising as a material used for manufacturing a semiconductor light emitting device capable of emitting light at such a short wavelength. In particular, the ZnMgSSe-based compound semiconductor, which is a quaternary II-VI group compound semiconductor, is
It is known to be suitable as a material for a clad layer and an optical waveguide layer when a blue or green emitting semiconductor laser having a wavelength of 400 to 550 nm is formed on a GaAs substrate (for example, Electron. Lett. 28 (1992). ) 1798).

[0004]

However, in the above-mentioned ZnMgSSe compound semiconductor, the lattice constant and the bandgap energy are likely to change due to the change in the composition thereof, so that it is difficult to stably manufacture the semiconductor laser. There is.

Further, in particular, the p-type ZnMgSSe-based compound semiconductor used for the p-type clad layer has a low effective dopant concentration of about 10 ¹⁷ cm ^−3, so that the resistance of the p-type clad layer is high. There is also a problem that this causes heat generation during operation of the semiconductor laser.

Therefore, an object of the present invention is to obtain a blue to green color using a ZnMgSSe compound semiconductor as a material for a cladding layer, which has good light confinement characteristics and carrier confinement characteristics, generates little heat during operation, and is easy to manufacture. Another object of the present invention is to provide a semiconductor light emitting device capable of emitting light.

[0007]

In order to achieve the above object, the present invention provides a first conductivity type first cladding layer (3) made of a ZnMgSSe type compound semiconductor laminated on a compound semiconductor substrate (1). ), An active layer (5) laminated on the first cladding layer (3), and a second conductivity type second cladding layer (ZnMgSSe-based compound semiconductor laminated on the active layer (5)). 7) and a ZnSSe-based compound semiconductor layer (8, 17) on the second cladding layer (7) and / or between the compound semiconductor substrate (1) and the first cladding layer (3). ) Is provided, it is a semiconductor light emitting element characterized by the above-mentioned.

In a preferred embodiment of the semiconductor light emitting device according to the present invention, the ZnSSe based compound semiconductor layer (8) is laminated only on the second cladding layer (7).

Here, the ZnSSe-based compound semiconductor layer (8) preferably has a thickness of 0 for the reason of achieving a sufficiently low resistance while ensuring good optical confinement characteristics and carrier confinement characteristics. 1 to 2 μm, and the second
The cladding layer (7) has a thickness of 0.2 to 2 μm. In this case, the total thickness of the second cladding layer (7) and the ZnSSe-based compound semiconductor layer (8) is preferably 0.4 μm.
Selected for m or more.

In another preferred embodiment of the semiconductor light emitting device according to the present invention, the compound semiconductor substrate (1) and the first
The ZnSSe-based compound semiconductor layer (17) is provided only between the ZnSSe-based compound semiconductor layer (17) and the cladding layer (3).

Here, the ZnSSe-based compound semiconductor layer (17) preferably has a thickness of 0 for the reason of sufficiently lowering the resistance while ensuring good light confinement characteristics and carrier confinement characteristics. .1-2 μm, and the thickness of the first cladding layer (7) is 0.2-2 μm.
In this case, the total thickness of the first cladding layer (7) and the ZnSSe-based compound semiconductor layer (17) is preferably 0.
It is selected to be 4 μm or more.

In still another preferred embodiment of the semiconductor light emitting device according to the present invention, the second cladding layer (8)
A ZnSSe-based compound semiconductor layer (8, 1) between the upper and the compound semiconductor substrate (1) and the first cladding layer (3).
7) is provided.

Here, the thickness of the ZnSSe-based compound semiconductor layer (8, 17) is preferably set for the reason of sufficiently reducing the resistance while ensuring good light confinement characteristics and carrier confinement characteristics. Is 0.1 to 2 μm, the thickness of the first cladding layer (3) is 0.2 to 2 μm, and the thickness of the second cladding layer (7) is 0.2 to 2 μm.
Is. In this case, the first cladding layer (7) and Zn
The total thickness of the SSe-based compound semiconductor layer (17) is preferably 0.4 μm or more, and the total thickness of the second cladding layer (7) and the ZnSSe-based compound semiconductor layer (8) is also preferably. It is selected to be 0.4 μm or more.

In the above-described embodiment of the semiconductor light emitting device according to the present invention, the impurity concentrations of the first cladding layer (3) and the second cladding layer (7) are set so as to sufficiently lower the resistance. N _a -N _D | (N _a is the acceptor concentration, N _D is the donor concentration) 5 × is preferably at 10 ¹⁶ to 1 × 1
0 ¹⁸ is selected in the range of cm ^-3, the impurity concentration of the ZnSSe compound semiconductor layer (8, 17) is, | N _A -N _D | preferably of ^{1 × 10 17 ~2 × 10 18} cm -3 in Selected in the range.

In the semiconductor light emitting device according to the present invention,
When the second cladding layer (7) and the ZnSSe-based compound semiconductor layer (8) are p-type, it is preferable that the p-type contact layer (9) made of ZnSe-based compound semiconductor is formed on the ZnSSe-based compound semiconductor layer (8). ) Are stacked.

Here, the thickness of the p-type contact layer (9) is preferably 30 to 150 nm. The impurity concentration of the p-type contact layer (9), in order to achieve the sufficiently low resistance, | N _A -N _D | at preferably 5 × 10 ¹⁷ to 5
It is selected within a range of × 10 ¹⁸ cm ^-3 .

In the semiconductor light emitting device according to the present invention,
The active layer (5) is made of, for example, a ZnCdSe based compound semiconductor. In this case, when the semiconductor light emitting device is configured as a semiconductor laser, the oscillation wavelength is ZnCdS.
Depending on the composition of the e-based compound semiconductor, the wavelength band is green or blue.

A GaAs substrate is preferably used as the compound semiconductor substrate (1).

[0019]

According to the semiconductor light emitting device of the present invention, the second
Since the ZnSSe-based compound semiconductor layer (8, 17) is provided on the clad layer (7) and / or between the compound semiconductor substrate (1) and the first clad layer (3), for example, When the ZnSSe-based compound semiconductor layer (8) is provided on the cladding layer (7), this ZnSS
By using the e-based compound semiconductor layer (8) also as the second conductivity type cladding layer, a second ZnMgSSe-based compound semiconductor which is not as easily epitaxially grown as a binary or ternary II-VI group compound semiconductor is used. The thickness of the cladding layer (7) can be minimized, and accordingly, the manufacturing of the semiconductor light emitting device can be facilitated accordingly. Further, when the entire thickness of the second-conductivity-type clad layer is the same, the second-conductivity-type clad layer is replaced with ZnMgSSe.
Compared with the case where the second clad layer (7) made of a compound semiconductor is used, the second conductivity type clad layer is made of Zn.
The resistance of the second conductivity type clad layer can be made lower when the second clad layer (7) made of the MgSSe-based compound semiconductor and the ZnSSe-based compound semiconductor layer (8) are used. This can suppress heat generation during operation of the semiconductor light emitting device. Moreover, in this case, good optical confinement characteristics and carrier confinement characteristics can be secured.

When the p-type contact layer (9) made of ZnSe type compound semiconductor is laminated on the upper side of the second cladding layer (7) made of ZnMgSSe type compound semiconductor, it is formed on the second clad layer (7). Rather than directly laminating the p-type contact layer (9), a ZnSSe-based compound semiconductor layer (8) having a lattice constant substantially equal to that of the second cladding layer (7) is laminated on the second cladding layer (7). And this Zn
Laminating the p-type contact layer (9) on the SSe-based compound semiconductor layer (8) can improve the crystallinity of these layers.

As described above, the light confinement property and the carrier confinement property are good, the heat generation during operation is small, and the manufacturing is easy, and the light emission of blue or green is possible by using the ZnMgSSe compound semiconductor as the material of the cladding layer. A semiconductor light emitting device can be realized.

[0022]

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 parts are designated by the same reference numerals.

FIG. 1 shows a semiconductor laser according to the first embodiment of the present invention. The semiconductor laser according to the first embodiment has an SCH (Separate Confinement Heterostructure) structure.

As shown in FIG. 1, in the semiconductor laser according to the first embodiment, for example, S is used as an n-type impurity.
On the n-type GaAs substrate 1 having a (100) plane orientation doped with i, for example, n doped with Cl as an n-type impurity
Type ZnSe buffer layer 2, for example, Cl as an n-type impurity
N-type Zn _1-p Mg _p S _q Se _1-q cladding layer 3 doped with, for example, n doped with Cl as an n-type impurity
-Type ZnSe optical waveguide layer 4, active layer 5, for example p-type ZnSe optical waveguide layer 6 doped with N as a p-type impurity, for example p _- type Zn _1-p Mg _p doped with N as a p-type impurity
S _q Se _1-q cladding layer 7, for example N as p-type impurity
A p-type ZnS _v Se _1-v layer 8 doped with and a p-type ZnSe contact layer 9 doped with N as a p-type impurity, for example, are sequentially stacked.

In this case, the upper layers of the p-type ZnSe contact layer 9 and the p-type ZnS _v Se _1-v layer 8 are patterned in a stripe shape. The width of this stripe portion is, for example, 5 μm.

On the p-type ZnS _v Se _1-v layer 8 other than the above-mentioned stripe portion, for example, a thickness of 300 is provided.
An insulating layer 10 made of an alumina (Al ₂ O ₃ ) film having a thickness of 10 nm is formed. Then, stripe-shaped p-type ZnS
A p-side electrode 11 is formed on the e-contact layer 9 and the insulating layer 10. A portion of the p-side electrode 11 in contact with the p-type ZnSe contact layer 9 serves as a current passage.
Here, the p-side electrode 11 has, for example, a thickness of 1
Pd film of 0 nm, Pt film of 100 nm and thickness of 3
Au / Pt / having a structure in which an Au film of 00 nm is sequentially laminated.
A Pd electrode is used. On the other hand, an n-side electrode 12 such as an In electrode is in contact with the back surface of the n-type GaAs substrate 1.

In the semiconductor laser according to the first embodiment, so-called end face coating is applied. That is, FIG. 2 shows a cross section parallel to the cavity length direction of the semiconductor laser according to the first embodiment. As shown in FIG.
Of the pair of resonator end faces perpendicular to the cavity length direction, the front end face from which the laser light is extracted is coated with a multilayer film composed of an Al ₂ O ₃ film 13 having a thickness of 74 nm and a Si film 14 having a thickness of 31 nm. The 74 nm-thick Al ₂ O ₃ film 13 and the thickness of ₃ nm are formed on the end face on the rear side from which laser light is not extracted, of the pair of cavity end faces perpendicular to the cavity length direction.
A multilayer film in which two 1-nm Si films 14 are stacked is coated. Here, the thickness of the multilayer film composed of the Al ₂ O ₃ film 13 and the Si film 14 is selected so that the optical distance obtained by multiplying the refractive index thereof is equal to 1/4 of the oscillation wavelength of the laser light. ing. In this case, the reflectance of the front end face is 70%, and the reflectance of the rear end face is 95%.
%.

In this first embodiment, the active layer 5 is preferably a single quantum well structure consisting of an i-type Zn _1-z Cd _z Se quantum well layer with a thickness of 2 to 20 nm, for example 9 nm. Have. In this case, the n-type ZnSe optical waveguide layer 4 and the p-type ZnSe optical waveguide layer 6 form a barrier layer.

The Mg composition ratio p of the n-type Zn _1-p Mg _p S _q Se _1-q cladding layer 3 and the p-type Zn _1-p Mg _p S _q Se _1-q cladding layer 7 is 0.09, for example. The S composition ratio q is, for example, 0.18, and the band gap E _{g at} that time is
Is about 2.94 eV at 77K. The n-type Zn _1-p Mg _p S _q Se _1-q cladding layer 3 and the p-type Z having the Mg composition ratio p = 0.09 and the S composition ratio q = 0.18.
The n _1-p Mg _p S _q Se _1-q cladding layer 7 is lattice-matched with GaAs. In addition, i-type Zn _1-z C constituting the active layer 5
The Cd composition ratio z of the d _z Se quantum well layer is, for example, 0.19, and the band gap E _{g at} that time is 77 K, which is about 2.
It is 54 eV. In this case, n-type Zn _{1- p} Mg _p S _q S
e _1-q clad layer 3 and p-type Zn _1-p Mg _p S _q Se
_I- type Zn _1-z C constituting the _1-q clad layer 7 and the active layer 5
The difference Δg in the band gap E _g between the d _z Se quantum well layer and Δ
E _g is 0.40 eV. The value of the band gap E _g at room temperature can be obtained by subtracting 0.1 eV from the value of the band gap E _g at 77K.

In this case, n-type Zn _1-p Mg _p S _q Se
_1-q thickness of the cladding layer 3 is 1.5μm example, the impurity concentration is N _D -N _A, for example, 5 × 10 ¹⁷ cm ^-3. The thickness of the n-type ZnSe waveguide layer 4 is 80nm for example, an impurity concentration N _D -N _A, for example, 5 × 10 ¹⁷ cm
^-3 . The thickness of the p-type ZnSe waveguide layer 6 is 80nm for example, for example, an impurity concentration N _A -N _D 5
It is × 10 ¹⁷ cm ^-3 . p-type Zn _1-p Mg _p S _q Se
_1-q thickness of the cladding layer 7 is 0.8μm example, the impurity concentration is N _A -N _D, for example, 2 × 10 ¹⁷ cm ^-3. The p-type ZnS _v Se _1-v layer 8 has a thickness of, for example, 0.8 μm.
m, and the impurity concentration is N _A −N _D , for example, 8 × 10 ¹⁷
cm ^-3 . The thickness of the p-type ZnSe contact layer 9 is, for example, 45 nm, the impurity concentration is N _A -N _D, for example, 8 × 10 ¹⁷ cm ^-3.

The thickness of the n-type ZnSe buffer layer 2 has a slight lattice mismatch between ZnSe and GaAs. Therefore, the n-type ZnSe buffer layer is caused by this lattice mismatch. In order to prevent dislocation from occurring during the epitaxial growth of the layer 2 and the layers thereon, the thickness is selected to be sufficiently smaller than the critical thickness of ZnSe (up to 100 nm), but in this first embodiment, it is 33 nm, for example. .

The resonator length L of the semiconductor laser according to the first embodiment is selected to be, for example, 640 μm, and the width in the direction perpendicular to the resonator length direction is selected to be, for example, 400 μm.

In the first embodiment, p-type Zn_1-pM
g_pS_qSe_1-qP-type Zn laminated on the clad layer 7
S_vSe_1-vLayer 8 may be p-type Zn, as the case may be._1-pMg
_pS_qSe_1-qThe second p-type cladding added to the cladding layer 7.
Function as a cathode layer, p-type Zn _1-pMg_pS_qSe_1-qKu
A function for lattice matching with the lad layer 7, a heat sink described later.
On the chip end face when mounting the laser chip on the
To prevent short circuit due to creeping up of solder
One or more of the functions as a spacer layer
Have a function. p-type Zn_1-pMg_pS_qSe_1-qClutch
The balance between the Mg composition ratio p and the S composition ratio q of the oxide layer 7
There is this p-type ZnS_vSe_1-vThe S composition ratio v of the layer 8 is
0 <v ≦ 0.1, preferably 0.06 ≦ v ≦ 0.08
Selected in the range, especially p-type Zn_1-pMg_pS_qSe
_1-qOptimal S set for lattice matching with the clad layer 7
The composition ratio v is 0.06.

As described above, p-type Zn _1-p Mg _p S _q Se
_By laminating the p-type ZnS _v Se _1-v layer 8 on the _1-q clad layer 7, various advantages as described below can be obtained. That is, when the p-type ZnS _v Se _1-v layer 8 is used as the second p-type cladding layer, the p-type is not as easy to grow epitaxially as the binary or ternary II-VI compound semiconductor. Zn _1-p Mg _p S _q Se
The thickness of the _1-q clad layer 7 can be minimized, and accordingly, the manufacturing of the semiconductor laser is correspondingly facilitated. If the p-type cladding layers have the same total thickness, p
Compared to the case where the p-type cladding layer is composed of only the p-type Zn _1-p Mg _p S _q Se _1-q cladding layer 7, the p-type cladding layer has the p-type Zn _1-p Mg _p S _q Se _1-q cladding. Layer 7 and p-type Z
The resistance of the p-type clad layer can be made lower when it is composed of the nS _v Se _1-v layer 8. Particularly, as described above, for example, the thickness is about 0.8 μm and N _A -N _D is 2 × 10 5.
The p-type Zn _1-p Mg _{p Sq} Se _1-q cladding layer 7 having a thickness of about ¹⁷ cm ^{-3, the} thickness of about 0.8 μm, and the N _A -N _D of 8 ×.
When the p-type ZnS _v Se _1-v layer 8 of about 10 ¹⁷ cm ⁻³ is used, the resistance of the entire p-type cladding layer should be sufficiently low without deteriorating the optical confinement property and the carrier confinement property. You can

When the p-type ZnSe contact layer 9 is directly laminated on the p-type Zn _1-p Mg _{p Sq} Se _1-q cladding layer 7, a lattice mismatch exists between these layers, resulting in crystallinity. Deterioration is likely to occur, but p-type Zn _1-p Mg _p S
A p-type ZnS _v Se _1-v layer 8 having a lattice constant substantially equal to that of the _q Se _1-q clad layer 7 is laminated, and the p-type Zn
Since the p-type ZnSe contact layer 9 is laminated on the S _v Se _1-v layer 8, the crystallinity of these p-type ZnS _v Se _1-v layer 8 and p-type ZnSe contact layer 9 should be improved. You can

Furthermore, by making the thickness of the p-type ZnS _v Se _1-v layer 8 sufficiently large, the solder used for mounting the laser chip on the heat sink crawls the end face of the laser chip. It is possible to effectively prevent the p-side and the n-side from going up and being short-circuited.
That is, as shown in FIG. 3, the laser chip is p-side down with the p-side electrode 11 facing down.
When mounting on 1, the solder 42 exists only between the laser chip and the heat sink 41 as shown by the solid line, but there is no problem if the soldering is not performed well, so that one end of the laser chip end face is used. Even if the solder 42 crawls linearly as shown by the chain line, p
Since the thickness of the type ZnS _v Se _1-v layer 8 is sufficiently large, the solder 42 crawled up on the end face of the laser chip
Exceeds the active layer 5 and the n-type ZnSe optical waveguide layer 4 and the n-type ZnSe
It is possible to prevent the _1-p Mg _p S _q Se _1-q cladding layer 3 from reaching the clad layer 3 and the like, and normally to prevent the solder 42 from creeping up far before the active layer 5.
As a result, when mounting the laser chip, the p
It is possible to prevent the side and the n side from being short-circuited, thus facilitating mounting of the laser chip.

Next, a method of manufacturing the semiconductor laser according to the first embodiment constructed as described above will be described.

FIG. 4 shows a molecular beam epitaxy (MBE) apparatus used for epitaxially growing each layer forming a laser structure in the method for manufacturing a semiconductor laser according to the first embodiment. As shown in FIG.
The BE apparatus includes a plurality of molecular beam sources (K cells) 54 and a substrate to be epitaxially grown in a vacuum container 53 that can be evacuated to an ultra-high vacuum by an ultra-high vacuum exhaust apparatus 52 attached via a gate valve 51. And a substrate holder 55 for holding an electron cyclotron resonance (ECR) plasma cell 56.

In order to manufacture the semiconductor laser according to the first embodiment, first, the vacuum container 5 of the MBE apparatus shown in FIG.
After mounting the n-type GaAs substrate 1 on the substrate holder 55 in the unit 3, heating the n-type GaAs substrate 1 to a temperature sufficiently higher than the growth temperature, for example, 580 ° C. to clean the surface, The n-type GaAs substrate 1 has a predetermined epitaxial growth temperature, preferably in the range of 250 to 300 ° C., more preferably in the range of 280 to 300 ° C.,
Specifically, for example, the temperature is lowered to 295 ° C. to start epitaxial growth. That is, on the n-type GaAs substrate 1, MB
By the E method, the n-type ZnSe buffer layer 2 and the n-type Zn _1-p
Mg _p S _q Se _1-q cladding layer 3, n-type ZnSe optical waveguide layer 4, i-type Zn _1-z Cd _z Se quantum well layer active layer 5, p-type ZnSe optical waveguide layer 6, p-type Zn _{1 -p} Mg _p S
_{The q} Se _1-q clad layer 7, the p-type ZnS _v Se _1-v layer 8 and the p-type ZnSe contact layer 9 are sequentially epitaxially grown. In this case, these layers can be epitaxially grown with good crystallinity, and therefore deterioration such as reduction of the light output of the semiconductor laser can be suppressed and high reliability can be obtained.

In the above epitaxial growth by the MBE method, Zn having a purity of 99.9999% was used as the Zn raw material, Mg having a purity of 99.9% was used as the Mg raw material, and 99.9999% ZnS was used as the S raw material. And Se having a purity of 99.9999% is used as the Se raw material. In addition, the n-type ZnSe buffer layer 2 and the n-type Zn _1-p
The doping of Cl as an n-type impurity in the Mg _p S _q Se _1-q cladding layer 3 and the n-type ZnSe optical waveguide layer 4 is performed by using ZnCl ₂ having a purity of 99.9999% as a dopant. On the other hand, p-type ZnSe optical waveguide layer 6, p-type Z
n _1-p Mg _p S _q Se _1-q cladding layer 7 and p-type Zn
Doping of N as a p-type impurity of the Se contact layer 9 is performed by irradiating N ₂ plasma generated by ECR.

Next, a stripe-shaped resist pattern (not shown) having a predetermined width is formed on the p-type ZnSe contact layer 9.
After the formation of p, the resist pattern is used as a mask for p
The type ZnS _v Se _1-v layer 8 is partially etched in the thickness direction by wet etching. By this, p
-Type ZnSe contact layer 9 and p-type ZnS _v Se _1-v
The upper portion of the layer 8 is patterned into a stripe shape.

Next, an Al ₂ O ₃ film was vacuum-deposited on the entire surface while leaving the resist pattern used for the above-mentioned etching, and this resist pattern was formed on the A film.
It is removed together with the l ₂ O ₃ film (lift-off). As a result, p-type ZnS _v Se _{1-v in the} part other than the stripe part
An insulating layer 10 made of an Al ₂ O ₃ film is formed only on the layer 8.

Next, a Pd film, a Pt film, and an Au film are sequentially vacuum-deposited on the entire surface of the stripe-shaped p-type ZnSe contact layer 9 and the insulating layer 10 to form a p-side electrode 11 composed of an Au / Pt / Pd electrode. Then, the p-side electrode 11 is brought into ohmic contact with the p-type ZnSe contact layer 9 by heat treatment if necessary. On the other hand, n-type Ga
An n-side electrode 12 such as an In electrode is formed on the back surface of the As substrate 1.

After that, the n-type GaAs substrate 1 on which the laser structure is formed as described above is cleaved into, for example, a bar shape having a width of 640 μm to form both resonator end faces, and then the front side of the resonator is formed by vacuum deposition. Al ₂ O ₃ film 13 and Si on the end face
A multi-layered film including the film 14 is formed, and a multi-layered film in which the Al ₂ O ₃ film 13 and the Si film 14 are repeated two cycles is formed on the rear end surface. After the end face coating is applied in this manner, the bar is cleaved into a chip having a width of 400 μm for packaging.

FIG. 5 shows the results of measurement of the optical output-current characteristics of the semiconductor laser according to the first embodiment at room temperature (296K) with and without injection current. The measurement was performed by mounting a laser chip on a heat sink 41 made of, for example, copper with p-side down as shown in FIG. As can be seen from FIG. 5, the threshold current I _th when the injection current is continuously flowed is about 45 mA, which is about 1.5 kA / c.
It corresponds to the threshold current density J _th of m ² . On the other hand, the threshold current I _th is about 42 when the injection current is pulsed.
mA. Here, the measurement of the light output-current characteristics when the injection current was continuously flowed was performed by increasing the injection current from 0 to 100 mA at a speed of 500 mA / sec. on the other hand,
The pulse width of the injection current is 2 μs, and the repetition rate is 1 m.
s. As can be seen from FIG. 5, the slope efficiencies S _d when the injection current is pulsed and when it is continuously flowed are 0.34 W / A and 0.31 W / A, respectively.
Is. P-side electrode 11 at the threshold of laser oscillation
The applied voltage between the n-side electrode 12 and the n-side electrode 12 is about 17V.

FIG. 6 shows the measurement result of the emission spectrum when the semiconductor laser according to the first embodiment is oscillated at room temperature (296K). As can be seen from FIG. 6, stimulated emission is observed at the wavelengths of 521.6 nm and 523.5 nm in the pulsed operation and the continuous operation, respectively.

As can be seen from the above, according to the first embodiment, the SC which emits green light and has a low threshold current density capable of continuous oscillation at a wavelength of 523.5 nm at room temperature.
A semiconductor laser having an H structure can be realized. This semiconductor laser generates little heat during operation and is easy to manufacture.

The i-type Zn _1-z C which constitutes the active layer 5
When the Cd composition ratio z of the d _z Se quantum well layer is, for example, 0.05, the band gap E _g is 77K and 2.72 eV.
And the n-type Zn _1-p Mg _{p Sq} Se _1-q cladding layer 3
And the p-type Zn _1-p Mg _p S _q Se _1-q cladding layer 7 have a Mg composition ratio p and an S composition ratio q of, for example, 0.1 and 0.1, respectively.
The band gap E _g is 7 and 0.24.
3.07 eV at 7K, then n-type Zn _1-p M
g _p S _q Se _1-q cladding layer 3 and p-type Zn _1-p Mg
The difference ΔE _g of the band gap E _g between the _p S _q Se _1-q cladding layer 7 and the i-type Zn _1-z Cd _z Se quantum well layer forming the active layer 5 is 0.35 eV. In this case, the oscillation wavelength is about 473 nm.

Further, i-type Zn _{1 -z} C which constitutes the active layer 5
When the Cd composition ratio z of the d _z Se quantum well layer is, for example, 0.10, the band gap E _g is 77K and 2.65 eV.
And the n-type Zn _1-p Mg _{p Sq} Se _1-q cladding layer 3
And the p-type Zn _1-p Mg _p S _q Se _1-q cladding layer 7 have a Mg composition ratio p and an S composition ratio q of, for example, 0.1 and 0.1, respectively.
The band gap E _g at 3 and 0.21 is 7
3.00 eV at 7K, then n-type Zn _1-p M
g _p S _q Se _1-q cladding layer 3 and p-type Zn _1-p Mg
The difference ΔE _g of the band gap E _g between the _p S _q Se _1-q cladding layer 7 and the i-type Zn _1-z Cd _z Se quantum well layer forming the active layer 5 is 0.35 eV. In this case, the oscillation wavelength is about 486 nm.

Further, i-type Zn ₁ -z forming the active layer 5 is formed.
The Cd composition ratio z of the Cd _z Se quantum well layer is, for example, 0.12.
And the band gap E _g is 77K and 2.62e.
V, and n-type Zn _1-p Mg _p S _q Se _1-q cladding layer 3 and p-type Zn _1-p Mg _p S _q Se _1-q cladding layer 7
For example, the Mg composition ratio p and the S composition ratio q of 0.
The bandgap E _g at 10 and 0.17 is 2.97 eV at 77 K, and the n-type Zn _{1-p at} that time is 2.97 eV.
Mg _p S _q Se _1-q cladding layer 3 and p-type Zn _1-p M
g _p S _q Se _1-q i constituting the clad layer 7 and the active layer 5
The difference ΔE _g of the band gap E _{g from} the Zn ₁ -z Cd _z Se quantum well layer of the type is 0.35 eV. In this case, the oscillation wavelength is about 491 nm.

Further, i-type Zn _{1 -z} C which constitutes the active layer 5
When the Cd composition ratio z of the d _z Se quantum well layer is set to, for example, 0.20, the band gap E _g is 77 K and 2.51 eV.
And the n-type Zn _1-p Mg _{p Sq} Se _1-q cladding layer 3
And the Mg composition ratio p and the S composition ratio q of the p-type Zn _1-p Mg _p S _q Se _1-q cladding layer 7 are 0.0
The band gap E _g at 3 and 0.08 is 7
2.86 eV at 7K, then n-type Zn _1-p M
g _p S _q Se _1-q cladding layer 3 and p-type Zn _1-p Mg
The difference ΔE _g of the band gap E _g between the _p S _q Se _1-q cladding layer 7 and the i-type Zn _1-z Cd _z Se quantum well layer forming the active layer 5 is 0.35 eV. In this case, the oscillation wavelength is about 514 nm.

FIG. 7 shows a semiconductor laser according to the second embodiment of the present invention. The semiconductor laser according to the second embodiment also has the SCH structure.

As shown in FIG. 7, in the semiconductor laser according to the second embodiment, for example, S is used as an n-type impurity.
On the n-type GaAs substrate 1 having a (100) plane orientation doped with i, for example, n doped with Cl as an n-type impurity
Type ZnSe buffer layer 2, for example, Cl as an n-type impurity
N-type Zn _1-p Mg _p S _q Se _1-q cladding layer 3 doped with, for example, n doped with Cl as an n-type impurity
-Type ZnSe optical waveguide layer 4, active layer 5, for example p-type ZnSe optical waveguide layer 6 doped with N as a p-type impurity, for example p _- type Zn _1-p Mg _p doped with N as a p-type impurity
S _q Se _1-q cladding layer 7, for example N as p-type impurity
Doped p-type ZnS _v Se _1-v layer 8, for example, p-type ZnSe contact layer 9 doped with N as a p-type impurity, a quantum well layer made of p-type ZnTe, and p-type ZnSe
P-type ZnTe / Zn in which barrier layers composed of
An Se multiple quantum well (MQW) layer 15 and a p-type ZnTe contact layer 16 doped with N as a p-type impurity, for example, are sequentially stacked. p-type ZnTe / ZnSeM
The QW layer 15 will be described in detail later.

In this case, the p-type ZnTe contact layer 1
6, p-type ZnTe / ZnSe MQW layer 15, p-type ZnS
The upper layers of the e-contact layer 9 and the p-type ZnS _v Se _1-v layer 8 are patterned in a stripe shape. The width of this stripe portion is, for example, 5 μm.

P-type Zn in the portion other than the above-mentioned stripe portion
Insulating layer 10 made of Al ₂ O ₃ film on S _v Se _1-v layer 8
Is formed as in the first embodiment. In this case, the stripe-shaped p-type ZnTe contact layer 1
A p-side electrode 11 is formed on the insulating layer 6 and the insulating layer 10. As the p-side electrode 11, for example, an Au / Pt / Pd electrode similar to that used in the first embodiment is used. n-type GaA
The n-side electrode 12 such as an In electrode is in contact with the back surface of the s substrate 1 as in the first embodiment.

Although not shown, the semiconductor laser according to the second embodiment is also provided with the same end face coating as in the first embodiment.

In the second embodiment, the active layer 5 has an i-type Z having a thickness of 2 to 20 nm, for example, 9 nm.
It has a single quantum well structure composed of n _{1 -z} Cd _z Se quantum well layers. In this case, the n-type ZnSe optical waveguide layer 4 and p
Similar to the first embodiment, the ZnSe optical waveguide layer 6 constitutes a barrier layer.

The Mg composition ratio p and the S composition ratio q and the activity of the n-type Zn _1-p Mg _p S _q Se _1-q clad layer 3 and the p-type Zn _1-p Mg _p S _q Se _1-q clad layer 7 The i-type Zn _1-z Cd _z Se quantum well layer constituting the layer 5 has the same Cd composition ratio z as in the first embodiment. Similarly, n-type Zn _1-p
Mg _p S _q Se _1-q cladding layer 3, n-type ZnSe optical waveguide layer 4, p-type ZnSe optical waveguide layer 6, p-type Zn _1-p Mg _p S
The thickness and impurity concentration of the _q Se _1-q clad layer 7, the p-type ZnS _v Se _1-v layer 8 and the p-type ZnSe contact layer 9 are the same as those described in the first embodiment. In addition, p-type Zn
The thickness of the Te contact layer 16 is, for example, 70 nm,
The impurity concentration is, for example, 1 × 10 ¹⁹ cm ⁻³ .

Similar to the semiconductor laser according to the first embodiment, the resonator length L of the semiconductor laser according to the second embodiment is L.
Is, for example, 640 μm, and the width in the direction perpendicular to the cavity length direction is, for example, 400 μm.

The p-type ZnTe / ZnSe MQW layer 1 described above
5 is provided for the p-type ZnSe contact layer 9
When the p-type ZnTe contact 16 and the p-type ZnTe contact 16 are directly bonded, a large discontinuity occurs in the valence band at the bonding interface, which serves as a barrier against holes injected from the p-side electrode 11 into the p-type ZnTe contact layer 16. This is to effectively eliminate this barrier.

That is, the upper limit of the carrier concentration in p-type ZnSe is usually about 5 × 10 ¹⁷ cm ^-3.
The carrier concentration in the type ZnTe can be 10 ¹⁹ cm ⁻³ or more. In addition, p-type ZnSe / p-type ZnTe
The valence band discontinuity at the interface is about 0.5 eV
Is. The valence band of such a p-type ZnSe / p-type ZnTe junction, the junction is assumed to be a step junction, W = the p-type ZnSe side ^{_{(2εφ T / qN A) 1/2}} (1) Width The band is bent over. Here, q is the absolute value of electron charge, ε is the dielectric constant of ZnSe, and φ _T is p.
Represents the discontinuous potential (about 0.5 eV) in the valence band at the ZnSe / p-type ZnTe interface.

When W is calculated in this case using the equation (1), W = 32 nm. FIG. 8 shows how the top of the valence band changes along the direction perpendicular to the p-type ZnSe / p-type ZnTe interface at this time. However, it is approximated that the Fermi levels of p-type ZnSe and p-type ZnTe coincide with the top of the valence band. As shown in FIG. 8, in this case, the valence band of p-type ZnSe is p-type Zn
Turns down towards Te. This downward convex valence band change acts as a potential barrier for holes injected from the p-side electrode 11 into the p-type ZnSe / p-type ZnTe junction.

This problem is caused by the p-type ZnSe contact layer 9
Between the p-type ZnTe contact layer 16 and the p-type ZnTe contact layer 16
The problem can be solved by providing the / ZnSeMQW layer 15. This p-type ZnTe / ZnSe MQW layer 15
Is specifically designed as follows, for example.

FIG. 9 shows the width L _W of the quantum well made of p-type ZnTe in a single quantum well having a structure in which a quantum well layer made of p-type ZnTe is sandwiched by barrier layers made of p-type ZnSe on both sides. The results obtained by quantum mechanical calculation for the well-type potential of the finite barrier show how the one quantum level E ₁ changes. However, in this calculation, the effective mass m of holes in p-type ZnSe and p-type ZnTe is defined as the mass of electrons in the quantum well layer and the barrier layer.
Assuming _h , 0.6 m ₀ (m ₀ : static mass of electron) is used, and the depth of the well is 0.5 eV.

It can be seen from FIG. 9 that the quantum level E ₁ formed in the quantum well can be increased by reducing the width L _W of the quantum well. p-type ZnTe / Zn
The SeMQW layer 15 is designed by utilizing this fact.

In this case, the band bending generated over the width W from the p-type ZnSe / p-type ZnTe interface to the p-type ZnSe side is the distance x from the p-type ZnSe / p-type ZnTe interface.
The quadratic function of (FIG. 8) φ (x) = φ _T {1- (x / W) ² } (2) is given. Therefore, p-type ZnTe / ZnSeMQW
The layer 15 is designed based on the equation (2) based on the quantum level E ₁ formed in each of the quantum well layers made of p-type ZnTe.
So that L is equal to the energy at the top of the valence band of p-type ZnSe and p-type ZnTe, and is equal to each other.
_This can be done by changing _W stepwise.

FIG. 10 shows p-type ZnTe / ZnSeMQW.
A design example of the quantum well width L _W when the width L _B of the p-type ZnSe barrier layer in the layer 15 is 2 nm is shown. Here, the acceptor concentration N of the p-type ZnSe contact layer 9
_A is 5 × 10 ¹⁷ cm ^−3, and the acceptor concentration N _A of the p-type ZnTe contact layer 16 is 1 × 10 ¹⁹ cm ⁻³ . As shown in FIG. 10, in this case, the total quantum well width L _W is 7 and the quantum level E ₁ is p-type ZnS.
L _W = 0.3 nm, 0.4 n from the p-type ZnSe contact layer 9 toward the p-type ZnTe contact layer 16 so as to match the Fermi levels of e and p-type ZnTe.
m, 0.5 nm, 0.6 nm, 0.8 nm, 1.1n
m, 1.7 nm.

When designing the width L _W of the quantum well, strictly speaking, since the levels of the respective quantum wells are coupled to each other, it is necessary to consider their interaction. Although the effect of strain due to the lattice mismatch between the well and the barrier layer must be taken into consideration, it is theoretically possible to set the quantum level of the multiple quantum well flat as shown in FIG.

In FIG. 10, the holes injected into the p-type ZnTe are resonantly tunneled to the p-type ZnSe side via the quantum level E ₁ formed in each quantum well of the p-type ZnTe / ZnSe MQW layer 15. Since it can flow, the potential barrier at the p-type ZnSe / p-type ZnTe interface effectively disappears. Therefore, according to the semiconductor laser of the second embodiment, good voltage-current characteristics can be obtained and the applied voltage required for laser oscillation can be greatly reduced.

Since the method of manufacturing the semiconductor laser according to the second embodiment is the same as the method of manufacturing the semiconductor laser according to the first embodiment, the description thereof will be omitted.

According to the second embodiment, similarly to the first embodiment, it is possible to realize a semiconductor laser capable of continuous oscillation at room temperature, for example, having a SCH structure which emits green light and has a low threshold current density. . The semiconductor laser generates little heat during operation and is easy to manufacture.
Particularly, in the second embodiment, the p-type ZnTe / ZnSe MQW layer 15 and the p-type ZnTe contact layer 16 are laminated on the p-type ZnSe contact layer 9, and the p-type Zn contact layer 16 is formed.
Since the p-side electrode 11 is in contact with the nTe contact layer 16, heat generation during operation of the semiconductor laser can be extremely reduced, and the applied voltage required for laser oscillation can be significantly reduced as described above. be able to.

FIG. 11 shows a semiconductor laser according to the third embodiment of the present invention. The semiconductor laser according to the third embodiment also has the SCH structure.

As shown in FIG. 11, in the semiconductor laser according to the third embodiment, for example, as an n-type impurity, an n-type GaAs substrate 1 having a (100) plane orientation doped with Si as an n-type impurity is used. Cl-doped n-type ZnSe buffer layer 2, eg C as n-type impurity
n-type ZnS _v Se _1-v layer 17 doped with l, for example, n-type Zn _1-p Mg doped with Cl as an n-type impurity
_p S _q Se _1-q cladding layer 3, for example, n-type ZnSe optical waveguide layer 4 doped with Cl as an n-type impurity, active layer 5, for example, p-type Zn doped with N as a p-type impurity
Se optical waveguide layer 6, for example p _- type Zn _1-p Mg _p S _q Se _1-q cladding layer 7 doped with N as a p-type impurity, for example p-type ZnSe contact layer 9 doped with N as a p-type impurity. , P-type ZnTe / ZnSe MQW layer 15 and p-type Zn doped with N as a p-type impurity, for example
Te contact layers 16 are sequentially stacked.

That is, in the third embodiment, n
The n-type ZnS _v Se _1-v layer 17 is laminated on the n-type ZnSe buffer layer 2 on the n-type ZnS _v Se _1-v layer 17, and the n-type Zn _1-p Mg layer is formed on the n _- type ZnS _v Se _1-v layer 17. _p S _q S
The e _1-q clad layer 3 is laminated. This n-type ZnS
_{The v} Se _1-v layer 17 is a p-type Zn _1-p layer in the first embodiment.
Mg _p S _q Se _1-q p-type Zn stacked on the clad layer 7
It has the same function as the S _v Se _1-v layer 8. For example, the n-type ZnS _v Se _1-v layer 17, n-type Zn _1-p Mg p S
_It is used as an n-type clad layer together with the _q Se _1-q clad layer 3.

Since the other structure is the same as that of the semiconductor laser according to the second embodiment, its explanation is omitted. Since the method of manufacturing the semiconductor laser according to the third embodiment is substantially the same as the method of manufacturing the semiconductor laser according to the second embodiment, the description thereof will be omitted.

According to the third embodiment, it is possible to obtain various advantages substantially similar to those of the second embodiment.

FIG. 12 shows a semiconductor laser according to the fourth embodiment of the present invention. The semiconductor laser according to the fourth embodiment also has the SCH structure.

As shown in FIG. 12, in the semiconductor laser according to the fourth embodiment, for example, as an n-type impurity, an n-type GaAs substrate 1 having a (100) plane orientation doped with Si as an n-type impurity is used. Cl-doped n-type ZnSe buffer layer 2, eg C as n-type impurity
n-type ZnS _v Se _1-v layer 17 doped with l, for example, n-type Zn _1-p Mg doped with Cl as an n-type impurity
_p S _q Se _1-q cladding layer 3, for example, n-type ZnSe optical waveguide layer 4 doped with Cl as an n-type impurity, active layer 5, for example, p-type Zn doped with N as a p-type impurity
Se optical waveguide layer 6, for example p _- type Zn _1-p Mg _p S _q Se _1-q cladding layer 7 doped with N as a p-type impurity, for example p-type ZnS _v S doped with N as a p-type impurity.
e _1-v layer 8, for example, p-type ZnSe contact layer 9 doped with N as a p-type impurity, p-type ZnTe / ZnSe
The MQW layer 15 and a p-type ZnTe contact layer 16 doped with N as a p-type impurity, for example, are sequentially stacked.

That is, in the fourth embodiment, as in the first and second embodiments, p-type Zn _1-p Mg is used.
_{p -} type ZnS _v Se _1-v on the _p S _q Se _1-q clad layer 7
While the layer 8 is laminated, as in the third embodiment,
An n-type ZnS _v Se _1-v layer 17 is laminated on an n-type ZnSe buffer layer 2 on an n-type GaAs substrate 1, and n _- type Zn _1-p Mg is formed on the n _- type ZnS _v Se _1-v layer 17. _p S _q S
The e _1-q clad layer 3 is laminated.

In this case, p-type Zn _1-p Mg _p S _q S
e _1-q clad layer 7 is also n-type Zn _1-p Mg _p S _q Se _1-q
It is possible to obtain the advantage that the clad layer 3 can also have the necessary minimum thickness.

Since the other structure is the same as that of the semiconductor laser according to the second embodiment, its explanation is omitted. Since the method of manufacturing the semiconductor laser according to the fourth embodiment is almost the same as the method of manufacturing the semiconductor laser according to the second embodiment, the description thereof will be omitted.

According to the fourth embodiment, various advantages substantially similar to those of the second embodiment can be obtained.

Next, a fifth embodiment in which the present invention is applied to a light emitting diode will be described. A light emitting diode according to the fifth embodiment is shown in FIG.

As shown in FIG. 13, in the light emitting diode according to the fifth embodiment, for example, as an n-type impurity, an n-type GaAs substrate 1 having a (100) plane orientation doped with Si as an n-type impurity is used. Cl-doped n-type ZnSe buffer layer 2, eg C as n-type impurity
n-type Zn _1-p Mg _p S _q Se _1-q cladding layer 3 doped with l, for example, n-type ZnSe optical waveguide layer 4 doped with Cl as an n-type impurity, for example i-type Zn _1-z Cd _z S
An active layer 5 composed of an e quantum well layer, for example, a p-type ZnSe optical waveguide layer 6 doped with N as a p-type impurity, for example p
P-type Zn _1-p Mg _p S doped with N as a type impurity
_q Se _1-q cladding layer 7, for example p-type ZnS _v Se _1-v layer 8 doped with N as a p-type impurity, and for example p
A p-type ZnSe contact layer 9 doped with N as a type impurity is sequentially stacked.

In this case, on the p-type ZnSe contact layer 9, the p-side electrode 11 having an opening which is a light extraction portion is formed. A portion of the p-side electrode 11 in contact with the p-type ZnSe contact layer 9 serves as a current passage. Here, as the p-side electrode 11, for example, an Au / Pt / Pd electrode is used as in the first to fourth embodiments. Further, the n-side electrode 12 such as an In electrode is in contact with the back surface of the n-type GaAs substrate 1,
This is the same as the first to fourth embodiments.

Since the method of manufacturing the light emitting diode according to the fifth embodiment is the same as the method of manufacturing the semiconductor laser according to the first embodiment, the description thereof will be omitted.

According to the fifth embodiment, for example, a light emitting diode which emits green light and has a low operating current density can be realized. The light emitting diode generates less heat during operation and is easy to manufacture.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made based on the technical idea of the present invention.

For example, the n-type ZnSe optical waveguide layer 4 and p used in the above-described first to fifth embodiments are used.
An i-type ZnSe optical waveguide layer may be used instead of the type ZnSe optical waveguide layer 6. Furthermore, from the viewpoint of lattice matching,
Instead of these n-type ZnSe optical waveguide layer 4 and p-type ZnSe optical waveguide layer 6, in particular n = 0.06 n-type ZnS _u
It is desirable to use the Se _1-u layer and the p-type ZnS _u Se _1-u layer or the i-type ZnS _u Se _1-u layer.

In addition, in the above-mentioned first to fifth embodiments, the p-type ZnSe optical waveguide layer 6 and the p-type Zn _1-p Mg _{p are formed.}
The doping of N as a p-type impurity such as the S _q Se _1-q clad layer 7, the p-type ZnS _v Se _1-v layer 8, the p-type ZnSe contact layer 9, and the p-type ZnTe contact layer 16 was generated by ECR. Although it is performed by irradiating with N ₂ plasma, this N doping may be performed, for example, by irradiating with N ₂ excited by high-frequency plasma.

Further, in the above-described first to fifth embodiments, the GaAs substrate is used as the compound semiconductor substrate, but the compound semiconductor substrate is, for example, Ga.
A P substrate or the like may be used.

In the above-described first to fourth embodiments, the case where the present invention is applied to the semiconductor laser having the SCH structure has been described.
It is also possible to apply to a semiconductor laser having a structure (Double Heterostructure).

Furthermore, p in the fifth embodiment described above is used.
As the side electrode 11, a transparent electrode may be used instead of the Au / Pt / Pd electrode, and this transparent electrode may be formed on the entire surface of the p-type ZnSe contact layer 9.

[0094]

As described above, according to the present invention, Zn having excellent optical confinement characteristics and carrier confinement characteristics, little heat generation during operation, and being easy to manufacture.
A semiconductor light emitting device capable of emitting blue or green light can be realized by using an MgSSe-based compound semiconductor as a material for the cladding layer.

[Brief description of drawings]

FIG. 1 is a sectional view showing a semiconductor laser according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a semiconductor laser according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a state in which the semiconductor laser according to the first embodiment of the present invention is mounted on a heat sink.

FIG. 4 is a schematic diagram showing an example of an MBE apparatus used for manufacturing a semiconductor laser according to the first embodiment of the present invention.

FIG. 5 is a graph showing an example of measurement results of optical output-current characteristics at room temperature of the semiconductor laser according to the first embodiment of the present invention.

FIG. 6 is a graph showing an example of the measurement result of the emission spectrum of the semiconductor laser according to the first embodiment of the present invention at room temperature.

FIG. 7 is a sectional view showing a semiconductor laser according to a second embodiment of the present invention.

FIG. 8 is an energy band diagram showing a valence band near a p-type ZnSe / p-type ZnTe interface.

FIG. 9 is a graph showing changes in the first quantum level E ₁ of the quantum well with respect to the width L _W of the quantum well made of p-type ZnTe.

FIG. 10 is an energy band diagram showing a design example of a p-type ZnTe / ZnSe MQW layer in the semiconductor laser according to the second embodiment of the present invention.

FIG. 11 is a sectional view showing a semiconductor laser according to a third embodiment of the present invention.

FIG. 12 is a sectional view showing a semiconductor laser according to a fourth embodiment of the present invention.

FIG. 13 is a sectional view showing a light emitting diode according to a fifth embodiment of the present invention.

[Explanation of symbols]

1 n-type GaAs substrate 2 n-type ZnSe buffer layer 3 n-type Zn _1-p Mg _p S _q Se _1-q clad layer 4 n-type ZnSe optical waveguide layer 5 active layer 6 p-type ZnSe optical waveguide layer 7 p-type Zn _{1 -p} Mg _p S _q Se _1-q clad layer 8 p-type ZnS _v Se _1-v layer 9 p-type ZnSe contact layer 10 insulating layer 11 p-side electrode 12 n-side electrode 15 p-type ZnTe / ZnSe MQW layer 16 p-type ZnTe Contact layer 17 n-type ZnS _v Se _1-v layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noriichi Nakayama 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (11)

[Claims] 1. A ZnM laminated on a compound semiconductor substrate.
A first conductivity type first cladding layer made of a gSSe-based compound semiconductor, an active layer stacked on the first cladding layer, and a second conductivity type made of a ZnMgSSe-based compound semiconductor stacked on the active layer. In a semiconductor light emitting device having a second type cladding layer, a ZnSSe-based compound semiconductor layer is provided on the second cladding layer and / or between the compound semiconductor substrate and the first cladding layer. A semiconductor light emitting device characterized by the above. 2. The Zn is formed only on the second cladding layer.
The semiconductor light emitting device according to claim 1, wherein SSe-based compound semiconductor layers are laminated. 3. The semiconductor light emitting device according to claim 1, wherein the ZnSSe-based compound semiconductor layer is provided only between the compound semiconductor substrate and the first cladding layer. 4. The Zn layer on the second cladding layer and between the compound semiconductor substrate and the first cladding layer.
The semiconductor light emitting element according to claim 1, further comprising an SSe-based compound semiconductor layer. 5. The ZnSSe-based compound semiconductor layer has a thickness of 0.1 to 2 μm, and the second cladding layer has a thickness of 0.2 to 2 μm. Semiconductor light emitting device. 6. The thickness of the ZnSSe-based compound semiconductor layer is 0.1 to 2 μm, and the thickness of the first cladding layer is 0.2 to 2 μm. Semiconductor light emitting device. 7. The ZnSSe-based compound semiconductor layer has a thickness of 0.1 to 2 μm, the first cladding layer has a thickness of 0.2 to 2 μm, and the second cladding layer has a thickness of 0.2 to 2 μm. Is 0.2 to 2 μm. The semiconductor light emitting device according to claim 4, wherein 8. The second cladding layer and the ZnS
The Se-based compound semiconductor layer is p-type, and a p-type compound semiconductor layer of ZnSe-based compound semiconductor is formed on the ZnSSe-based compound semiconductor layer.
The semiconductor light emitting device according to claim 2, wherein the mold contact layer is laminated. 9. The p-type contact layer has a thickness of 30 to 1
The semiconductor light emitting device according to claim 8, wherein the semiconductor light emitting device has a thickness of 50 nm. 10. The semiconductor light emitting device according to claim 1, wherein the active layer is made of a ZnCdSe compound semiconductor. 11. The semiconductor light emitting device according to claim 1, wherein the compound semiconductor substrate is a GaAs substrate.