JP3221073B2 - Light emitting element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device, and more particularly, to a light emitting device using a ZnSe (zinc selenide) -based material.

[0002]

2. Description of the Related Art In recent years, attempts have been actively made to realize a blue light emitting device using a ZnSe-based material, and various reports have been made so far.

[0003]

However, p-type ZnS
At the contact interface between e and the metal, a potential barrier having a height of 1 eV or more exists. On the other hand, the carrier concentration in p-type ZnSe realized so far is at most 1 × 10 ¹⁸ c
m ⁻³ . For this reason, in a light emitting element using a ZnSe-based material, it is essentially difficult to obtain ohmic contact of the p-side electrode with the p-type ZnSe layer. As a result, there are problems that the applied voltage required for the operation of the light emitting element is increased, and that the characteristics of the element are degraded due to generation of heat due to power loss at the contact interface between the p-side electrode and the p-type ZnSe layer. Was.

Recently, a ZnSe-based injection type II-V in which a p-side electrode is formed using contact between p-type ZnSe and Au (gold).
Group I semiconductor laser (Appl. Phys. Lett. 59, 1272 (199
Although 1)) has been proposed, even in this semiconductor laser, good ohmic contact of the p-side electrode with the p-type ZnSe layer has not been obtained, and the applied voltage required for laser oscillation is as high as ２０20 V.

Accordingly, an object of the present invention is to provide a p-type ZnSe
By realizing ohmic contact with the p-side electrode in a light-emitting element using a layer, it is possible to reduce the applied voltage required for operation and to prevent the generation of heat at the contact interface of the p-side electrode. An object of the present invention is to provide a light-emitting element capable of improving element characteristics.

[0006]

As described above, the carrier concentration in the p-type ZnSe realized so far is at most about 1 × 10 ¹⁸ cm ^-3 ,
The carrier concentration in type ZnTe (zinc telluride) is As
By using a dopant of a group V element such as (arsenic), P (phosphorus), N (nitrogen), and Sb (antimony),
A value of about 10 ¹⁹ cm ^-3 can be easily obtained.
The height of the potential barrier at the contact interface between p-type ZnTe and the metal is about 0.5 eV. Therefore, p-type Zn
For Te, an ohmic contact can be easily realized by using a metal such as Au.

The present invention has been made based on the above findings.

That is, in order to achieve the above object, a first invention of the present invention is to provide a p-type ZnSe layer (3) and a p-type ZSe
Between the nTe layer (4) and the p-type ZnSe _x Te _1-x layer (
However, 0 <x <1) (7) is provided, and p-type Zn
Se _x Te _1-x layer (7) and p-type ZnTe layer (4) Gae
It is patterned by etching, p-type ZnTe
An electrode (5) made of metal is provided on the layer (4).
A light-emitting element characterized by the above-mentioned.

A second aspect of the present invention is a p-type ZnSe layer
ZnSe barrier layer between (3) and p-type ZnTe layer (4)
And a multiple quantum well layer (1
1) is provided, and made of metal on the p-type ZnTe layer (4).
Light-emitting element provided with an electrode (5)
I am a child.

[0010] A third invention of the present invention is a method for producing Zn and Se.
Comprising at least ZnTe with a cladding layer (10) containing
a ZnSe barrier layer between the p-type contact layer (4) and
A multiple quantum well layer (11) composed of a ZnTe quantum well layer is
And made of metal on the contact layer (4)
A light emitting device provided with an electrode (5)
It is.

[0011]

SUMMARY OF] According to the light emitting device according to the first aspect of the invention, p-type ZnTe layer (4) Ru metal deposition on the electrodes (5)
Is provided, so that ohmic contact of the electrode (5) can be realized. As a result, it is possible to reduce the applied voltage necessary for the operation of the light emitting element, and to prevent the generation of heat due to power loss at the contact interface of the electrode (5) , and thereby to improve the element characteristics. Can be improved. The p-type ZnSe layer (3) and the p-type ZnTe
A p-type ZnSe _x Te _1-x layer (7) is provided between the layer (4).
The p-type ZnSe layer (3) and the p-type
Discontinuity of valence band at junction with ZnTe layer (4)
Effective reduction of the height of the potential barrier
The applied voltage required for the operation of the light emitting device
Can be further reduced.

According to the light emitting device of the second aspect of the present invention, an electrode made of metal is provided on the p-type ZnTe layer (4).
Since (5) is provided, the ohmic contact of the electrode (5) is provided.
Tactile can be realized. As a result, the light emitting element
The applied voltage required for operation can be reduced.
In addition, heat generation due to power loss at the contact interface of the electrode (5)
To improve device characteristics by preventing
Can be Further, the p-type ZnSe layer (3) and the p-type Z
ZnSe barrier layer and ZnTe amount between nTe layer (4)
A multiple quantum well layer (11) comprising
The number of holes injected from the electrode (5)
The quantum level of each quantum well layer of the quantum well layer (11)
P-type ZnTe layer (4) by tunnel effect
Can flow into the p-type ZnSe layer (3).
Junction between the p-type ZnSe layer (4) and the p-type ZnSe layer (3)
Effective potential barrier due to valence band discontinuity
The light emitting element
The required applied voltage can be greatly reduced.

According to the light emitting device of the third aspect of the present invention, a p-type contact layer made of at least ZnTe
(4) The metal electrode (5) is provided on the
And ohmic contact of the electrode (5) can be realized.
You. As a result, the applied voltage required for the operation of the light emitting element
The contact area of the electrode (5) can be reduced.
Generation of heat due to power loss on the surface can be prevented
As a result, the element characteristics can be improved. Also,
Cladding layer (10) containing Zn and Se and contact layer
(4) ZnSe barrier layer and ZnTe quantum well layer
Multiple quantum well layer (11) consisting of
As a result, holes injected from the electrode (5) are
Via the quantum level of each quantum well layer of the door layer (11)
From the contact layer (4) by tunnel effect
The cladding layer (1) can flow to the layer (10).
The potential barrier due to the discontinuity of the valence band at the junction between the contact layer ( 0) and the contact layer (4) can be effectively eliminated, whereby the applied voltage required for the operation of the light emitting element can be significantly reduced. .

[0014]

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 ZnS according to a first embodiment of the present invention.
1 shows an e-based light emitting diode.

As shown in FIG. 1, in the ZnSe-based light emitting diode according to the first embodiment, for example, a Ga (Si) -doped n-type GaAs substrate 1
A (gallium) -doped n-type ZnSe layer 2 and, for example, an N-doped p-type ZnSe layer 3 are sequentially stacked, and a pn junction is formed by the n-type ZnSe layer 2 and the p-type ZnSe layer 3. On this p-type ZnSe layer 3, a p-type ZnTe layer 4 as a contact layer is laminated.
An Au electrode 5 as a p-side electrode is provided on the Te layer 4. On the back surface of the n-type GaAs substrate 1, an In (indium) electrode 6 is provided as an n-side electrode.

In this case, the thickness of the n-type GaAs substrate 1 is, for example, 350 μm and the carrier concentration is, for example, n = 1 × 10 ¹⁸
cm ⁻³ , the thickness of the n-type ZnSe layer 2 is, for example, 1.5 μm,
The carrier concentration is, for example, n = (1-5) × 10 ¹⁷ cm ⁻³ ,
The thickness of the p-type ZnSe layer 3 is, for example, 1 μm, the carrier concentration is, for example, N _A −N _D = (2-5) × 10 ¹⁷ cm ⁻³ , the thickness of the p-type ZnTe layer 4 is, for example, 20 nm, and the carrier concentration is, for example, 20 nm. N _A −N _D 〜１０10 ¹⁹ cm ⁻³ . Where N _A
The acceptor concentration, N _D is the donor concentration. Also, A
The diameter of the u electrode 5 is, for example, 1 mm.

The fact that the N-doped p-type ZnTe layer 4 can achieve a carrier concentration of N _A -N _D -10〜１０10 ¹⁹ cm ^-3 requires that the N-doped p-type ZnTe layer 4 has a thickness of 1-2 μm grown epitaxially on a GaAs substrate. This was confirmed by measuring the capacitance-voltage characteristics performed on the doped ZnTe layer.

In order to manufacture the ZnSe-based light emitting diode according to the first embodiment configured as described above, an n-type G
For example, molecular beam epitaxy (MBE) on the aAs substrate 1
After an n-type ZnSe layer 2, a p-type ZnSe layer 3, and a p-type ZnTe layer 4 are sequentially epitaxially grown by a method, an Au electrode 5 is formed on the p-type ZnTe layer 4, and an In-type electrode is formed on the back surface of the n-type GaAs substrate 1. The electrode 6 may be formed.
Here, N is added to the p-type ZnSe layer 3 and the p-type ZnTe layer 4.
Is doped, for example, by electron cyclotron resonance (EC
R) Perform using a plasma gun.

The lattice constant of ZnTe (6.10)
1 °) and the lattice constant of ZnSe (5.667 °), there is a difference of about 8%, so that the p-type ZSe on the p-type ZnSe layer 3
In order to grow the nTe layer 4 in an elastically distorted state, the thickness of the p-type ZnTe layer 4 needs to be less than its critical thickness, that is, about 3 nm or less. Considering the contact with the Au electrode 5, this p-type Z
It is desirable that the nTe layer 4 be thicker. Thus p
When the thickness of the p-type ZnTe layer 4 is made larger than the critical thickness, dislocations are introduced into the p-type ZnTe layer 4.
Since the nTe layer 4 is for obtaining good ohmic contact with the Au electrode 5 as the p-side electrode, the introduction of dislocations is not so problematic, and therefore, for example, the thickness may be about 0.5 to 1 μm. Conceivable. In this first embodiment,
As described above, the thickness of the p-type ZnTe layer 4 is selected to be an intermediate thickness of 20 nm.

When the voltage (V) -current (I) characteristics at room temperature of the ZnSe-based light emitting diode according to the first embodiment were measured, the results shown in FIG. 2 were obtained.

On the other hand, for comparison, an n-type ZnSe layer 102 is formed on an n-type GaAs substrate 101 as shown in FIG.
And a p-type ZnSe layer 103 are sequentially stacked.
An Au electrode 104 is provided on the nSe layer 103, and the n-type G
A ZnSe-based light emitting diode having a structure in which an In electrode 105 was provided on the back surface of the aAs substrate 101 was separately manufactured, and its voltage-current characteristics at room temperature were measured. As a result, the result shown in FIG. 11 was obtained.

As can be seen from FIG. 11, in the ZnSe-based light emitting diode shown in FIG. 10 in which the p-type ZnTe layer is not used, the current rises at about 20 V with respect to the forward applied voltage. On the other hand, as can be seen from FIG. 2, in the ZnSe-based light emitting diode according to the first embodiment shown in FIG. 1, the current rises at about 10 V with respect to the forward applied voltage, and the rise voltage is lower than that in FIG. About 10V
Has also been reduced.

As described above, according to the first embodiment,
Since the p-type ZnTe layer 4 is provided on the p-type ZnSe layer 3 and the Au electrode 5 as a p-side electrode is provided on the p-type ZnTe layer 4, ohmic contact of the Au electrode 5 is realized. be able to. As a result, it is possible to significantly reduce the applied voltage necessary for the operation of the light emitting diode and to obtain good voltage-current characteristics.

Further, since the ohmic contact of the Au electrode 5 can be realized, the Au electrode 5 and the p-type Z
Generation of heat due to power loss at the contact interface with the nTe layer 4 can be prevented, thereby improving element characteristics.

The rising voltage of the current in the voltage-current characteristic shown in FIG. 2 is about 10 V.
The rising voltage of 0 V is still considerably higher than the built-in voltage (up to 2.5 V) of the pn junction of ZnSe. This is because the ohmic contact between the p-type ZnTe layer 4 and the Au electrode 5 is insufficient and the valence band at the contact interface between the p-type ZnSe layer 3 and the p-type ZnTe layer 4 is approximately It is conceivable that there is a discontinuity with a magnitude of 0.5 eV. To solve the former problem, p
It is effective to increase the thickness of the type ZnTe layer 4. On the other hand, the latter problem can be solved by a second embodiment of the present invention described below.

FIG. 3 shows ZnS according to a second embodiment of the present invention.
1 shows an e-based light emitting diode.

As shown in FIG. 3, in the ZnSe-based light emitting diode according to the second embodiment, the p-type ZnSe _x Te _1-x is provided between the p-type ZnSe layer 3 and the p-type ZnTe layer 4.
(0 <x <1) layer 7 is provided. This p-type ZnS
e _x Te _1-x Se composition ratio in the layer 7 x, the p-type Z
It may be constant in the thickness direction of the nSe _x Te _1-x layer 7, or from p = 1 at the interface with the p-type ZnSe layer 3, p-type Z
A graded structure in which x continuously changes to x = 0 at the interface with the nTe layer 4 may be used. The other configuration is the same as that of the ZnSe-based light emitting diode according to the first embodiment, and the description is omitted.

According to the second embodiment, the p-type ZnSe layer provided between the p-type ZnSe layer 3 and the p-type ZnTe layer 4
top energy of the valence band of the _x Te _1-x layer 7 is p-type Z
Energy at the top of the valence band of the nSe layer 3 and p-type ZnT
Since the energy is intermediate between the energy at the top of the valence band of the e-layer 4 and the discontinuity of the valence band at the contact interface between the p-type ZnSe layer 3 and the p-type ZnTe layer 4 is effectively reduced. Which results in a forward rise voltage,
Therefore, the applied voltage required for the operation of the light emitting diode can be further reduced as compared with the first embodiment.

FIG. 4 shows a ZnS according to a third embodiment of the present invention.
1 shows an e-based light emitting diode.

As shown in FIG. 4, in the ZnSe-based light emitting diode according to the third embodiment, the p-type ZnSe _x Te _1-x layer 7 and the p-type ZnTe
Has a stripe shape with a width W ′. An Au electrode 5 as a p-side electrode is provided on the entire surface of the p _- type ZnSe _x Te _1-x layer 7, the p-type ZnTe layer 4, and the p-type ZnSe layers 3 on both sides thereof.

In this case, the Au electrode 5 is in ohmic contact with the p-type ZnTe layer 4, but not in ohmic contact with the p-type ZnSe layer 3. Alternatively, the height of the potential barrier at the contact interface between the Au electrode 5 and the p-type ZnTe layer 4 is smaller than the height of the potential barrier at the contact interface between the Au electrode 5 and the p-type ZnSe layer 3. As a result, when a voltage is applied between the Au electrode 5 and the In electrode 6, only the contact portion between the Au electrode 5 and the p-type ZnTe layer 4
It is possible to form a stripe-shaped current injection region. That is, in the third embodiment, the Au electrode 5
The current constriction is performed by selectively injecting current only at the contact portion between the stripe-shaped p-type ZnTe layer 4 and the p-type ZnTe layer 4.

In order to manufacture the ZnSe-based light emitting diode according to the third embodiment, an n-type Z
nSe layer 2, p-type ZnSe layer 3, p-type ZnSe _x Te
_{After the 1-x} layer 7 and the p-type ZnTe layer 4 are sequentially epitaxially grown, the p-type ZnTe layer 4 and the p-type ZnSe _x Te
_{The 1-x} layer 7 may be patterned into a stripe shape by etching, and then the Au electrode 5 and the In electrode 6 may be formed.

According to the third embodiment, in addition to the same advantages as the second embodiment, the following advantages can be obtained. That is, a Si ₃ N ₄ (silicon nitride) film, SiO
₂ There are light-emitting diodes and semiconductor lasers whose current is confined using an insulating film such as a (silicon dioxide) film or a polyimide film. However, when these are mounted on a heat sink with the p-side electrode facing down, Since current constriction is performed using an insulating film having a low rate, there is a problem that thermal resistance is increased and element characteristics are likely to deteriorate. On the other hand, the ZnSe-based light emitting diode according to the third embodiment does not use an insulating film for current confinement. Therefore, when mounting on a heat sink with the p-side electrode facing down, the thermal resistance must be reduced. Accordingly, the element characteristics can be improved.

Next, the ZnS according to the fourth embodiment of the present invention will be described.
The e-type semiconductor laser will be described.

FIG. 5 shows a ZnSe-based semiconductor laser according to the fourth embodiment.

As shown in FIG. 5, in the ZnSe-based semiconductor laser according to the fourth embodiment, an active layer comprising an n-type ZnMgSSe layer 8 as an n-type cladding layer, for example, an undoped ZnSSe layer on an n-type GaAs substrate 1. Layer 9, p-type ZnMgSSe layer 1 as p-type cladding layer
0, p-type ZnSe layer 3 as contact layer and p-type Z
An nTe layer 4 is sequentially stacked, and Au is formed on the p-type ZnTe layer 4.
An electrode 5 is provided, and an n-type GaAs substrate 1 is provided.
Is provided with an In electrode 6 on its back surface.

In this case, the n-type ZnMgSSe layer 8, the active layer 9, and the p-type ZnMgSSe layer 10 form a light emitting region composed of a ZnSe-based pn junction.

According to the fourth embodiment, since the Au electrode 5 as the p-side electrode is provided on the p-type ZnTe layer 4, ohmic contact of the Au electrode 5 can be realized. As a result, the applied voltage required for laser oscillation can be reduced. Further, the Au electrode 5 and the p-type Zn
Since heat generation due to power loss at the contact interface with the Te layer 4 can be prevented, heat generation at portions other than the pn junction is reduced, and continuous oscillation at room temperature becomes possible.

By the way, 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 is 10
It can be ¹⁹ cm ^-3 or more. In addition, p-type Zn
The magnitude of the discontinuity of the valence band at the Se / p-type ZnTe interface is about 0.5 eV. Such p-type ZnSe /
The valence band of p-type ZnTe junction, assuming step junction, the p-type ZnSe side W = bending of (2εφ _T / qN _A) band across the width of the ^1/2 (1) occurs. Here, q is the absolute value of the electron charge, ε is the dielectric constant of ZnSe, and φ _T is p
Represents a discontinuous potential (about 0.5 eV) of the valence band at the interface of ZnSe / p-type ZnTe.

When W is calculated in this case using equation (1), W = 320 °. FIG. 6 shows how the top of the valence band changes along the direction perpendicular to the p-type ZnTe / p-type ZnSe 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. 6, in this case, the valence band of p-type ZnSe is p-type ZnT
It is bent down toward e. The change in the downwardly convex valence band is caused by the change of the p-type ZnSe / p-type ZnT from the p-side electrode.
It acts as a potential barrier for holes injected into the e-junction.

Thus, in the ZnSe-based semiconductor laser shown in FIG. 5, the p-type ZnSe layer 3 and the p-type ZnT
It can be seen that the potential barrier existing at the contact interface with the e layer 4 as shown in FIG. 6 hinders holes injected from the Au electrode 5 into the p-type ZnTe layer 4 from going to the light emitting region. Therefore, a fifth embodiment of the present invention will be described next, which can substantially eliminate such a potential barrier and thereby improve voltage-current characteristics.

[0043] Figure 7 is a the p-type wide quantum well made of p-type ZnTe in a single quantum well sandwiched between the barrier layer on both sides of the quantum well layer made of p-type ZnSe consisting ZnTe L _z The result of how the one quantum level E ₁ changes is obtained by quantum mechanical calculation for a well-type potential of a finite barrier. However, in this calculation, the mass of electrons in the quantum well layer and the barrier layer is p
Assuming the effective mass m _{h of} holes in the type ZnSe and p-type ZnTe, 0.6 m ₀ (m ₀ : rest mass of electrons) was used,
The depth of the well is set to 0.5 eV.

[0044] From FIG. 7, by reducing the width L _z of the quantum well, it can be seen that it is possible to increase the quantum level E ₁ formed in the quantum well. This is used in the fifth embodiment of the present invention.

FIG. 8 shows a ZnS according to a fifth embodiment of the present invention.
1 shows an e-based semiconductor laser.

As shown in FIG. 8, in the ZnSe-based semiconductor laser according to the fifth embodiment, the thickness of the quantum well layer made of p-type ZnTe is provided between the p-type ZnSe layer 3 and the p-type ZnTe layer 4. _Lz is changed from p-type ZnSe layer 3 to p-type ZnSe.
P-type ZnT gradually increasing in thickness toward the Te layer 4
An e / ZnSe multiple quantum well (MQW) layer 11 is provided.

In this case, the bending of the band generated over the width W from the p-type ZnSe / p-type ZnTe interface to the p-type ZnSe side is represented by a distance x from the p-type ZnSe / p-type ZnTe interface.
The quadratic function of FIG. 6 is given by φ (x) = φ _T {1− (x / W) ² } (2). Therefore, the design of the p-type ZnTe / ZnSe multiple quantum well layer 11 is based on the equation (2),
quantum level E ₁ formed in each of the quantum well layer coincides with the peak energy of the valence band of the p-type ZnSe and p-type ZnTe consisting nTe, yet varied stepwise L _z to be equal to each other It can be done by doing.

FIG. 9 shows the width L of the barrier layer made of p-type ZnSe in the p-type ZnTe / ZnSe multiple quantum well layer 11.
_B shows a design example of a quantum well width L _z in the case of a 20Å a. Here, the acceptor concentration N _A of the p-type ZnSe layer 3 is 5 × 10 ¹⁷ cm ^−3, and the acceptor concentration N _A of the p-type ZnTe layer 4 is 1 × 10 ¹⁹ cm ⁻³ . As shown in FIG. 9, in this case, the width L _z of the seven quantum wells in total is
That the quantum level E ₁ is p-type ZnSe and p-type ZnTe
Of to match the Fermi level, L _z = 3 Å toward the p-type ZnSe layer 3 to the p-type ZnTe4, 4Å, 5Å,
6 °, 8 °, 11 ° and 17 °.

[0049] Incidentally, when designing the widths L _z of the quantum well, strictly speaking, level of the respective quantum wells must consider the interaction of them for binding to each other, also, the quantum Although the effect of distortion due to lattice mismatch between the well and the barrier layer must be taken into account, it is in principle sufficiently possible to design the quantum level of the multiple quantum well to be flat as shown in FIG.

In FIG. 9, holes injected into the p-type ZnTe are formed by the tunneling effect via the quantum level E ₁ formed in each quantum well of the p-type ZnTe / ZnSe multiple quantum well layer 11 by the tunnel effect. Since it can flow to the ZnSe side, the potential barrier at the p-type ZnSe / p-type ZnTe interface is effectively eliminated. Therefore, according to the ZnSe-based semiconductor laser according to the fifth embodiment, good voltage-
Current characteristics can be obtained, and the applied voltage required for laser oscillation can be significantly reduced. In this case, since the current crossing the p-type ZnTe / ZnSe multiple quantum well layer 11 is due to the tunnel effect, there is a slight resistance component, but providing the p-type ZnTe / ZnSe multiple quantum well layer 11 is particularly difficult. There is a great effect in reducing the forward rise voltage of the diode.

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, in the above-described fourth and fifth embodiments, the light-emitting region is formed by the n-type ZnMgSSe layer 8, the active layer 9, and the p-type ZnMgSSe layer 10. The present invention can be applied to a ZnSe-based semiconductor laser having a region. Specifically, for example, an n-type ZnSSe layer, an n-type ZnSe layer, a ZnCd
Active layer composed of Se strained quantum well, p-type ZnSe layer and p-type ZnSe layer
The present invention can be applied to a ZnSe-based semiconductor laser in which a light emitting region is formed by a type ZnSSe layer.

Further, in the fifth embodiment described above, p
The first quantum level E ₁ of each quantum well layer in the type ZnTe / ZnSe multiple quantum well layer 11 is equal to each other;
In addition, it is made to coincide with the Fermi level of p-type ZnTe and p-type ZnSe, but more generally, p-type ZnT
at least one quantum level of each quantum well layer in the e / ZnSe multiple quantum well layer 11 is equal to each other;
In addition, it may be made to coincide with the Fermi level of p-type ZnTe and p-type ZnSe.

[0054]

As described above, according to the present invention,
Since the ohmic contact of the p-side electrode can be realized in the light emitting element using the p-type ZnSe layer, the applied voltage necessary for the operation can be reduced, and
Since the generation of heat at the contact interface between the side electrodes can be prevented, the element characteristics can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a ZnSe-based light emitting diode according to a first embodiment of the present invention.

FIG. 2 is a graph showing measurement results of voltage-current characteristics at room temperature of the ZnSe-based light emitting diode shown in FIG.

FIG. 3 is a cross-sectional view illustrating a ZnSe-based light emitting diode according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a ZnSe-based light emitting diode according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing a ZnSe-based semiconductor laser according to a fourth embodiment of the present invention.

FIG. 6 is an energy band diagram illustrating a valence band near a p-type ZnSe / p-type ZnTe interface.

FIG. 7 is a graph showing a change in the first quantum level E ₁ of the quantum well with respect to the width L _z of the quantum well made of p-type ZnTe.

FIG. 8 is a sectional view showing a ZnSe-based semiconductor laser according to a fifth embodiment of the present invention.

9 is an energy band diagram showing a design example of a p-type ZnSe / ZnTe multiple quantum well layer in the ZnSe-based semiconductor laser shown in FIG.

FIG. 10 is a cross-sectional view showing a conventional ZnSe-based light emitting diode.

FIG. 11 is a graph showing measurement results of voltage-current characteristics of the ZnSe-based light emitting diode shown in FIG. 10 at room temperature.

[Explanation of symbols]

Reference Signs List 1 n-type GaAs substrate 2 n-type ZnSe layer 3 p-type ZnSe layer 4 p-type ZnTe layer 5 Au electrode 7 p-type ZnSe _x Te _1-x layer 8 n-type ZnMgSSe layer 9 active layer 10 p-type ZnMgSSe layer 11 p-type ZnTe / ZnSe multiple quantum well layer

Continued on the front page (72) Inventor Takao Miyajima 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Masafumi Ozawa 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Stock In-company (72) Inventor Katsuhiro Akimoto 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-2-122565 (JP, A) JP-A-61-59785 (JP) JP-A-3-270278 (JP, A) JP-A-11-505066 (JP, A) JP-A-6-508003 (JP, A) Appl. Phys. Lett. Vol. 61, No. 26, p. 3160-3162 (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 33/00 H01S 5/00-5/50

Claims (7)

(57) [Claims] 1. Between a p-type ZnSe layer and a p-type ZnTe layer
P-type ZnSe _x Te _1-x Layer (however, 0 <x <1)
Is provided, The above p-type ZnSe _x Te _1-x Layer and the above p-type ZnTe layer
Is patterned by etching, An electrode made of metal is provided on the p-type ZnTe layer.
Is A light-emitting element, comprising: 2. The p-type ZnSe layer and the p-type ZnT.
The above electrode is provided on the e layer A contract characterized by that
The light emitting device according to claim 1. 3. An electrode mounted on a heat sink.
ing The light emitting device according to claim 2, wherein: 4. Between a p-type ZnSe layer and a p-type ZnTe layer
Multiplex consisting of ZnSe barrier layer and ZnTe quantum well layer
A quantum well layer is provided, An electrode made of metal is provided on the p-type ZnTe layer.
Is A light-emitting element, comprising: 5. The method according to claim 1, wherein said ZnTe quantum well layer has a thickness of p
It becomes thicker toward the type ZnTe layer Characterized by
The light emitting device according to claim 4. 6. A cladding layer containing Zn and Se is less.
And a p-type contact layer made of ZnTe
Multiple quantum well composed of Se barrier layer and ZnTe quantum well layer
Door layer is provided, An electrode made of metal is provided on the contact layer.
To A light-emitting element, comprising: 7. The method according to claim 1, wherein the thickness of the ZnTe quantum well layer is
Thicker towards the contact layer Characterized by
The light emitting device according to claim 6.