JPH065915A - Semiconductor light emitting element - Google Patents

Abstract

PURPOSE:To provide a semiconductor light emitting element capable of performing high-efficiency light emission within a region from red color to blue color by forming and producing a layer comprising a semiconductor of the same base on a substrate having high quality. CONSTITUTION:A compound semiconductor of chalcopyrite group containing at least one kind of Ag, Se, S as well as Ga, Al and In is used as a material for forming light-emitting portions 11 and 12 by using a high-quality InP substrate 100. In this semiconductor, its lattice constant coincides with the lattice constant of InP forming the substrate 100 within the range of composition ratio where light in the red to blue region is oscillated, so that semiconductor layers 11 and 12 lattice-matching to the substrate 100 can be obtained.

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, such as a light emitting diode device, which can emit red to blue light having a wavelength of about 720 nm to 450 nm, which is used in a color display, and a semiconductor in a high density optical disk system. The present invention relates to a semiconductor light emitting device used as a laser device or the like.

[0002]

2. Description of the Related Art Since a current injection type semiconductor light emitting device has a high luminous efficiency, it is widely used as a small size and high brightness display device, a semiconductor laser device and the like.

In order to realize a full color display or a full color laser printer, it is necessary to emit light of the three primary colors of red, green and blue. Therefore, a light emitting diode element and a semiconductor capable of emitting light with high efficiency in the entire visible light range of red to blue are provided. Laser development is underway.

Conventionally, for example, a gallium arsenide-based material (Ga) has been used as a current injection type semiconductor light emitting device using a pn junction.
As / GaAlAs, GaAs / InGaAlP), etc.
A semiconductor light emitting element formed using a III-V group compound semiconductor material is known. However, since these materials have a narrow band gap, the semiconductor light emitting device using these materials can only emit light in the region from near infrared to red.

In order to obtain a semiconductor light emitting device that emits blue light, it is necessary to use a material having a wider band gap.

As a material having a large forbidden band width, there is a direct transition type gallium nitride-based (GaN / InGaAlN) material. However, although the material of this system has a large forbidden band width, there is no suitable semiconductor substrate capable of lattice matching. Therefore, it is difficult to fabricate electrodes because a sapphire substrate or the like, which is a dielectric, must be used although the lattice constants are similar. Further, since a large strain is generated between the substrate and the semiconductor layer laminated on the substrate, the reliability of the device cannot be sufficiently obtained.

In addition, an indirect transition type material such as silicon carbide (Si
C) and gallium phosphide (GaP) using impurity emission have been used as light emitting diode materials. However, these materials are inferior in light emission efficiency to the direct transition type gallium arsenide-based material and it is difficult to achieve high brightness. Moreover, S
When iC is used, a semiconductor light emitting device that can be used as a semiconductor laser device cannot be manufactured.

A material having a large forbidden band width is represented by zinc selenide (Zn _u Cd _1-u ) (S _v Se _1-v ) (u and v are 0 or more and 1 or less) II. -Group VI compound semiconductor materials are being considered as the most promising. In this zinc selenide-based material, as shown in FIG.
It is possible to obtain a material whose lattice constant is almost the same as that of GaAs, which makes it easy to obtain a large substrate of high quality, that is, G
It has a great feature that it can be lattice matched with aAs.

However, under the condition that the above zinc selenide material can be lattice-matched with GaAs,
The range in which the forbidden band can be changed is narrow, 460 nm to 470
Only blue light of about nm can be obtained. As a method of increasing the emission wavelength, there is a method of increasing the amount of Cd and forming an active layer using a ZnCdSe layer having a lattice constant deviated from the lattice constant of GaAs by several%. However, in this method, a large stress is applied between the light emitting layer and the substrate, so that crystal defects increase. Therefore, since the light emitting layer cannot be formed thick, it is difficult to manufacture a highly efficient semiconductor light emitting element that can be used as a light emitting diode.

Japanese Unexamined Patent Publication No. 1-175788 discloses Ga
There is disclosed a semiconductor laser device formed on a P substrate using a Cu (GaAl) (SSe) ₂ material which is a chalcopyrite group compound semiconductor lattice-matched to the substrate.
As shown in FIG. 7, the chalcopyrite group compound semiconductor is capable of emitting light in the green to ultraviolet region within a composition ratio range capable of lattice matching with GaP. However, in this semiconductor laser device, red light is not obtained within a composition ratio range capable of lattice matching with GaP, and in order to obtain red light, impurity emission must be used, and current injection with good conversion efficiency is required. The mold cannot emit three primary colors.

The chalcopyrite group compound semiconductor means a compound semiconductor having a chalcopyrite type crystal structure.

[0012]

As described above, a semiconductor light emitting device in which a light emitting layer is formed by using semiconductors of various materials has been proposed. In any of the above conventional semiconductor light emitting devices, a red light emitting device is used. There is nothing that can emit all three primary colors of green, blue and blue.
The semiconductor light emitting device formed on one substrate has a drawback that the emission color is considerably limited.

An object of the present invention is to solve the above-mentioned drawbacks, and it is produced by forming a layer made of a semiconductor of the same system on one substrate of high quality, and within the range from red to blue. It is an object of the present invention to provide a semiconductor light emitting device that can emit light with high efficiency and can also be used as a semiconductor laser.

[0014]

In a semiconductor light emitting device of the present invention, a semiconductor layer is laminated on an InP semiconductor substrate, the semiconductor layer having a lattice constant substantially equal to that of the substrate, and Ag. , Se, S and Ga, Al and I
It is composed of a chalcopyrite group compound semiconductor containing at least one of n, and thereby the above object is achieved.

[0015]

In the semiconductor light emitting device of the present invention, a high quality InP substrate is used, and Ag is used as a material for forming the light emitting portion.
A chalcopyrite group compound semiconductor containing Se, S and at least one of Ga, Al and In is used. In this semiconductor, since the lattice constant of InP forming the substrate matches the lattice constant within the composition ratio range in which light in the red to blue region is oscillated,
A semiconductor layer lattice-matched to the substrate can be obtained. Furthermore, a sufficiently large difference in the forbidden band can be obtained between semiconductors having different composition ratios selected within the above composition ratio range, so that a semiconductor light emitting device that can be used as a semiconductor laser can be obtained.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view of an essential part of an embodiment of a semiconductor light emitting device of the present invention. In this semiconductor light emitting device, an n-type InP substrate 100 is provided with an n-type InP substrate.
A buffer layer 101 is formed, and further on that,
An n-type semiconductor layer 11 and a p-type semiconductor layer 12 each made of an AgGa (S _z Se _1-z ) ₂ layer (z is greater than 0 and less than 1) are formed. On the p-type semiconductor layer 12,
A p-type InP contact layer 13 is laminated. In this laminated body, Au and S are provided on the n-type InP substrate 100 side.
The ohmic electrode 15 made of n is formed on the p-type InP contact layer 13 side, and the ohmic electrode 14 made of Au and Zn is formed on the p-type InP contact layer 13 side.
Are vapor-deposited and formed, and the element main body 16 is formed from these. The element body 16 is the ohmic electrode 1 on the n side.
The semiconductor chip 23 is mounted on the stem 25a with 5 being the lower side, and is connected to the stem 25b described later by the wire 26.

A method of manufacturing the above semiconductor light emitting device will be described with reference to FIG.

First, a wafer-shaped n-type InP substrate 100
The above-mentioned semiconductor layers are laminated on each other. The growth process of the semiconductor layer in this semiconductor light emitting device includes, for example,
Ordinary molecular beam epitaxy (MBE) as shown below
The method can be used.

By the way, in many cases, impurities are attached to the surface of the substrate 100, and crystal defects and the like generated when the surface is polished are present. When a semiconductor layer is grown, it may be difficult to obtain a crystal with excellent quality. In order to avoid this, the first method for growing chalcopyrite group compound semiconductors
Growth chamber and a second growth chamber that is used for growing InP and can be connected to and separated from the first growth chamber in a vacuum. InP buffer layer 10 on heated n-type InP substrate 100
1 is grown to form a high quality InP plane. n type I
After forming the nP buffer layer 101, the wafer is moved to a first growth chamber in vacuum.

As a growth material for a chalcopyrite group compound semiconductor, high purity Ag, Ga having a purity of 99.99% or more,
In a first growth chamber in which a vacuum was made using S, Se and Al,
The n-type semiconductor layer 11 and the p-type semiconductor layer 12 are formed by irradiating the substrate 100 heated to about 550 ° C. with a molecular beam of the above material to grow a crystal. The ratio of the amounts of S and Se atoms in the first growth chamber is adjusted so that the semiconductor layer to be grown can be lattice-matched with the InP substrate 100. However, the total amount should be sufficiently larger than other atoms. As the doping material, S as the n-type material
N was used as the i and p type material.

After the p-type semiconductor layer 12 is formed, the wafer is carried to a second growth chamber in a vacuum atmosphere and p-type InP is added.
The contact layer 13 is laminated. This wafer is second
Of Au and Zn on the n-type InP substrate 1 side and Au and Zn on the p-type InP contact layer 13 side to elevate the temperature in vacuum to form ohmic electrodes 15 and 14, respectively. To do. From the above, FIG. 2 (a)
The laminated body shown in is formed.

Next, as shown in FIG. 2B, a photoresist 20 is applied on the p-side electrode 14 in the laminate obtained above. After that, the photoresist 20 is removed by a usual photolithography method, leaving a circular photoresist pattern 21 having a diameter of about 100 μm.
Using the photoresist pattern 21 as a mask, the electrode 14 and the p-type InP contact layer 13 are removed by using an ordinary ion beam etching method or the like, for example, Ar ion beam 22. After the etching is completed, the wafer is cut into the element body 16, and the element body 16 is a heat sink or a stem 25 also serving as a heat sink.
The semiconductor chip 23 is fused on the surface a by In (not shown).

The semiconductor chip 23 obtained above is shown in FIG.
As shown in (c), the stem 26 is connected by the wire 26.
5b is connected. These are molded with a transparent resin 14 such as polycarbonate or polymethylmethacrylate (PMMA) to form a semiconductor light emitting device.

The operating principle of the above semiconductor light emitting device is similar to that of a normal single hetero structure type light emitting diode. n
The electrode 15 on the p-type InP substrate 100 side is set to a negative potential, and the p-type In
By setting the electrode 14 on the P contact layer 13 side to a positive potential, electrons are injected from the n side and holes are injected from the p side. The electrons diffuse quickly, but the holes accumulate in the p-type layer and do not diffuse much to the n-side. Therefore, the electrons efficiently recombine with the holes accumulated on the p-side to emit light.

Substrate 100 and substrate 1 in this embodiment
The details of each semiconductor layer formed on 00 are as follows.

InP substrate 100: thickness 300 μm, In
P buffer layer 101: 1 μm thick, n-type semiconductor layer 11:
AgGa (S _0.49 Se _0.51 ) ₂ , thickness 1 μm, p-type semiconductor layer 12: AgGa (S _0.49 Se _0.51 ) ₂ , thickness 1 μ
m, InP contact layer: thickness 0.5 μm.

The oscillation wavelength of this semiconductor light emitting device is about 5
55 nm, and green light emission was obtained. This semiconductor light emitting device can be used as a light emitting diode device.

The compound semiconductor used in the present invention is not limited to that used in this embodiment, and the lattice constant thereof is substantially the same as that of the InP substrate, and at least one of Ag, S, Se and Ga, Al and In is selected. A chalcopyrite group compound semiconductor containing a seed is used.

FIG. 7 shows ZnCdSSe-based material and AgG.
The relationship between the lattice constant of the aAlInSSe-based material and the forbidden band width and the relationship with the emission wavelength are shown. ZnCdSS
As shown in FIG. 7, the e-based material has substantially the same lattice constant as that of GaAs, which makes it easy to obtain a large substrate of high quality, and has a lattice matching. However, even if the ratio of S and Se is changed within the range of the composition ratio that allows lattice matching with GaAs, only blue light can be obtained, and a mixed crystal having a large difference in forbidden band cannot be obtained.

As shown in FIG. 7, the AgGaAlInSSe-based material has a composition ratio capable of obtaining light in the wavelength range of 720 nm to 450 nm, that is, light in the red to blue region. In the ratio In
It has a lattice constant that substantially matches the lattice constant of P. That is, in the _{Ag (Ga w Al x In y} ) (S z Se 1-z) 2, the composition ratio w, x, the values of y and z, w, x, y in the range of 0 to 1 inclusive, z is in the range of more than 0 and less than 1, and a lattice constant approximately equal to that of InP is obtained.

In the first embodiment, the n-type semiconductor layer 11 and the p-type semiconductor layer 12 are made of Ag (Ga _w Al _x In _y ).
The n-type semiconductor layer 11 and the p-type semiconductor layer 12 are formed by using a material in which the composition ratios x and y of (S _z Se _1-z ) ₂ are 0, that is, a material not containing Al and In. By adjusting the composition ratios w, x, and y related to the group atoms, semiconductor light emitting devices having different emission wavelengths can be manufactured.

For example, in the semiconductor light emitting device of Example 1, when AgIn (S _0.82 Se _0.18 ) ₂ is used as the semiconductor for forming the n-type semiconductor layer 11 and the p-type semiconductor layer 12, the semiconductor light emission emits red light. Element is obtained, Ag
When Al (S _0.35 Se _0.65 ) ₂ is used, a semiconductor light emitting device that emits blue light is obtained.

Within the above composition ratio, that is, w,
When the values of x, y, and z are w, x, and y in the range of 0 or more and 1 or less, and z is in the range of more than 0 and less than 1, a sufficiently large forbidden band difference is obtained. Since semiconductor materials having different composition ratios can be selected, a semiconductor light emitting element that can be sufficiently used as a semiconductor laser element can be obtained by forming a clad layer and an active layer using this semiconductor material.

As described above, AgG used in the present invention
The aAlInSSe-based semiconductor has a lattice constant that substantially matches the lattice constant of InP in the range where the composition ratio thereof oscillates light in the green to blue region. In the semiconductor light emitting device of the present invention, distortion does not occur because the InP substrate and the semiconductor layer are lattice-matched.

In this embodiment, the light emitting portion is the junction between the n-type semiconductor layer 11 and the p-type semiconductor layer 12, and n
Although the composition ratio of the p-type semiconductor layer 11 and the composition ratio of the p-type semiconductor layer 12 are the same, a homojunction is formed. It may have a heterostructure. Furthermore, sandwiched between a layer comprising the two layers 11 and 12 from the _{Ag (Ga w Al x In y} ) (S z Se 1-z) 2 having a larger forbidden band width may be a double heterostructure. However, for example, the above-mentioned AgAl (S
_When a layer containing Al such as _0.35 Se _0.65 ) ₂ is exposed after ion beam etching, Al in the layer is prevented from being oxidized and deteriorating the element body. Requires extreme caution.

In this embodiment, since the InP layer is formed as the contact layer on the semiconductor layer formed on the InP substrate, the ohmic electrode can be easily formed.

Example 2 FIG. 3 is a schematic diagram showing Example 2 of the semiconductor light emitting device of the present invention.

A p-type InP buffer layer 301 is formed on the p-type InP substrate 300, and Ag (Ga _w Al _x In _y ) (Se) is further formed thereon.
First p-type semiconductor layer 31 and second p-type semiconductor layer 3 formed of a chalcopyrite group compound semiconductor composed of _1-z S _z ) ₂
2, the third p-type semiconductor layer 33 is formed. Part of each of the second p-type semiconductor layer 32 and the third p-type semiconductor layer 33 is removed, and a part of the underlying layer is exposed.
The semiconductor layer stacked on the type InP buffer layer 301 has a step shape. The shaded portions in the drawing, that is, the portion 34 of which the upper surface is exposed in the first p-type layer 31, the portion 35 of which the upper surface is exposed in the second p-type semiconductor layer 32, and the upper portion of the third p-type semiconductor layer 33 36
Is an n-type layer in which diffused impurities are diffused.
Thereby, the first p-type semiconductor layer 31 and the second p-type semiconductor 3
2, the third p-type semiconductor layer 33 and the respective n-type diffusion regions 3
A pn junction is formed at each junction with 4, 35 and 36. A p-type electrode 310 is formed on the substrate 300, and n-type electrodes 37, 38, 39 are formed on the semiconductor layer side.

In the above semiconductor light emitting device, each semiconductor layer can be formed by an ordinary gas source molecular beam epitaxy method. As a raw material of the chalcopyrite group compound semiconductor, high-purity Ag, Ga, Al, In, hydrogen selenide (H ₂ Se), hydrogen sulfide (H ₂ S) was used, and p
N was used as the type doping material, and Si was used as the diffusion impurities. When growing the first n-type semiconductor layer 31, the second n-type semiconductor layer 32, and the third n-type semiconductor layer 33, the supply amounts of H ₂ Se and H ₂ S are strictly controlled by a mass flow controller, and the substrate 300 and the substrate 300 is formed on the _{Ag (Ga w Al x in y} ) (Se 1-z S z) 2
It is adjusted so that it can be lattice-matched with the layer made of. As a result, in the semiconductor light emitting device of this embodiment, lattice mismatch can be suppressed within 0.1%.

After forming the third p-type semiconductor layer 33, ordinary photolithography and ion beam etching are repeated twice to form the second p-type semiconductor layer 32 and the third p-type semiconductor layer.
A part of the p-type semiconductor layer 33 is removed to expose a part of the layer below them. After that, the diffusion regions 34, 35 and 36 have S
i is diffused to make these regions n-type.

When a current is injected into this semiconductor light emitting device,
An interface between the first p-type semiconductor layer 31 and its n-type region 34, an interface between the second n-type semiconductor layer 32 and its n-type region 35, a third
Since the pn junction is formed at each interface between the n-type semiconductor layer 33 and the n-type region 36, recombination of electrons and holes occurs at the junction surface, and each of the layers 31, 3 and 3.
Emissions λ ₁ , λ ₂ , and λ ₃ corresponding to the forbidden band widths of 2, 33 are obtained.

Substrate 300 and substrate 3 in this embodiment
Details of the respective semiconductor layers formed on 00 are as follows.

InP substrate 300: thickness 300 μm, In
P buffer layer 301: 1 μm thick, first p-type semiconductor layer 3
1: AgIn (S _0.82 Se _0.18 ) ₂ , thickness 1 μm, second
p-type semiconductor layer 32: AgGa (S _0.49 Se _0.51 ) ₂ , thickness 1 μm, third p-type semiconductor layer 33: AgAl (S _0.35 S
e _0.65 ) ₂ , thickness 1 μm.

The oscillation wavelength is λ ₁ = 720 nm (red),
λ ₂ = 555 nm (green) and λ ₃ = 450 nm (blue). This semiconductor light emitting device can be used as a light emitting diode.

In the semiconductor light emitting device shown in this embodiment, an arbitrary emission wavelength can be obtained by selecting an electrode to be energized, and further, full-color emission or white color can be obtained by adjusting the amount of current injected into each layer. It is possible to emit light.

Example 3 FIG. 3 is a schematic diagram showing Example 3 of the semiconductor light emitting device of the present invention. In this semiconductor light-emitting device, n-type n-type InP buffer layer 401 on an InP substrate 400 is formed, on its further respectively _{Ag (Ga w Al x In y} ) (Se 1-z S z) 2 Non-doped first barrier layer 41, non-doped first light emitting layer 42, non-doped second barrier layer 43, non-doped second light emitting layer 44, non-doped third barrier layer 45, p-type cap layer formed of a chalcopyrite group compound semiconductor 46 is formed. A p-type partial electrode 48 is formed on the p-type cap layer 46, and an n-type electrode 47 is formed on the entire surface of the substrate 400 side.

In this example, a semiconductor layer was formed on the n-type InP substrate 420 by using a metal organic vapor phase epitaxy (MOCVD) method. As a growth material, high-purity cyclopentadienyltriethylphosphine silver (C ₅ H ₅ A
g · P (C ₂ H ₅ ) ₃ ), triethylindium (In
(C ₂ H ₅ ) ₃ ), triethylgallium (Ga (C
₂ H ₅ ) ₃ ), triethylaluminum (Al (C ₂ H ₅ ) ₃ ), H ₂ Se, H ₂ S
Was used. As a growth doping material, Si was used as an n-type material. Substrate temperature is 600 ° C during semiconductor layer growth
And When growing, the supply amounts of H ₂ S and H ₂ Se are kept constant, respectively, while being set sufficiently higher than the amounts of other elements. The ratio of the amount of In supplied to the amount of Ga supplied,
Alternatively, the ratio of the supply amount of Ga and the supply amount of Al is kept constant, and the ratio of Ag to these Group III elements is set so as to satisfy the stoichiometry. Also in this embodiment, the lattice mismatch is small and can be suppressed to within about 0.3%.

After forming the p-type cap layer 46, the n-type electrode 47 on the substrate 400 side and the p-type electrode 48 on the p-type cap layer 46 side are formed by vapor deposition.

The operation principle of this semiconductor light emitting device will be described with reference to FIG. FIG. 4 shows a forbidden band width structure of a main part of this semiconductor light emitting device. In FIG. 4, the forbidden band width of the n-type InP buffer layer 401 is 401a, and the non-doped first
The forbidden band width of the barrier layer 41 is 41a, the forbidden band width of the non-doped first light emitting layer 42 is 42a, and the non-doped second barrier layer 4 is
The band gap of No. 3 is 43a, the band gap of the non-doped second light emitting layer 44 is 44a, the band gap of the non-doped third barrier layer 45 is 45a, and the band gap of the p-type cap layer 46 is 46a.

When a current is injected into this semiconductor light emitting device,
Electrons e and holes h are injected into the non-doped layers from the non-doped first barrier layer 41 to the non-doped third barrier layer 45, and the electrons are included in the non-doped first light emitting layer 42 and the non-doped second light emitting layer 44 surrounded by the energy barriers. By recombination of e and holes h, light emission corresponding to the forbidden band width of each layer can be obtained. The energy barrier is not surrounded by the non-doped third barrier layer 45 and the p-type cap layer 46, but since the layer thickness is large, the probability that electrons and holes are recombined in the non-doped third barrier layer 45. Becomes larger, it becomes possible to emit light. That is, the non-doped third barrier layer 45 also has a function as a light emitting layer. Therefore, even in this semiconductor light emitting device, each layer 4
Light emission λ ₄ , λ ₅ , λ corresponding to the forbidden band width of 2, 44, 45
You get ₆ .

Substrate 400 and substrate 4 in this embodiment
Details of the respective semiconductor layers formed on 00 are as follows.

InP substrate 400: thickness 300 μm, In
P buffer layer 401: 1 μm thick, first barrier layer 41:
Ag (In _0.9 Ga _0.1 ) (S _0.8 Se _0.2 ) ₂ , thickness 0.
5 μm, first light emitting layer 42: AgIn (S _0.82 Se _0.18 ).
₂ , thickness of 0.1 μm, second barrier layer 43: Ag (Ga _0.9
Al _0.1 ) (S _0.5 Se _0.5 ) ₂ , thickness 0.1 μm, second light emitting layer 44: AgGa (S _0.49 Se _0.51 ) ₂ , thickness 0.1
μm, third barrier layer 45: AgAl (S _0.35 Se _0.65 ).
₂ , thickness 0.3 μm, p-type cap layer 46: AgAl
(S _0.35 Se _0.65 ) ₂ , thickness 1 μm, oscillation wavelength is λ ₄ =
720 nm (red), λ ₅ = 555 nm (green), λ ₆ =
It was 450 nm (blue). This semiconductor light emitting device
It can be used as a light emitting diode.

In the semiconductor light emitting device of this embodiment,
Current injection is not performed individually in each light emitting layer, but is performed in each layer simultaneously. Therefore, this element alone cannot obtain monochromatic light. However, white light can be obtained by adjusting the emission intensity of each color. Further, by providing a filter corresponding to each color on the emission end face of the element, it is possible to obtain monochromatic light separated into each color.

(Embodiment 4) FIG. 6 is a perspective view of a principal portion of a semiconductor light emitting device according to Embodiment 4 of the present invention. An n-type InP buffer layer 501 is formed on the n-type InP substrate 500, and Ag (Ga _w Al _x I) is further formed thereon.
n _y ) (S _z Se _{1 -z} ) ₂ made of n-type cladding layer 51, non-doped active layer 52, p-type cladding layer 53, p-type InP
The contact layer 55 is laminated. A polyimide film 56 is formed on the p-type InP contact layer 55, and the polyimide film 56 is partially removed to have a width of 2 mm.
A 0 μm stripe-shaped window portion 60 is formed. N is provided on each of the substrate 500 side and the polyimide film 56 side.
A p-type ohmic electrode 58 and a p-type ohmic electrode 57 are formed.

This semiconductor light emitting device can adopt the same MBE method as in Example 1 as a laminating method, and is manufactured as follows.

First, in the second growth chamber, a wafer-shaped n-type I
An n-type InP buffer layer 501 is grown on the nP substrate 500. Next, in the first growth chamber, the InP buffer layer 50
N-type clad layer 51, undoped active layer 52, p
The mold cladding layer 53 is formed. Then, the wafer is moved to a second growth chamber in vacuum to form a p-type InP contact layer 55.

After the p-type InP contact layer 55 is formed, the wafer is taken out of the second growth chamber, the polyimide film 56 is applied, and ordinary photolithography is performed.
The window 60 is formed. Then, an electrode material is vapor-deposited in the same manner as in Example 1, the electrode material is vapor-deposited on the entire surface of the n-type InP substrate 500 side, and the temperature is raised in nitrogen gas or the like to form the p-type ohmic electrodes 57 and n, respectively. Type ohmic electrode 58
To form.

After forming the electrodes 58 and 57, the wafer is placed on the surfaces 61a and 61b orthogonal to the stripes of the electrodes 57.
Cleavage is performed to obtain the element body. The cleavage planes 61a and 62a each function as a mirror of the laser resonator. The obtained element body is fused to a heat sink or a stem (not shown) also serving as a heat sink by using In (not shown) to form a semiconductor light emitting element.

In this embodiment, the length L of the semiconductor light emitting element (the distance between the cleavage planes 61a and 61b) is set to 10
It was formed to a thickness of about 00 μm.

Substrate 500 and substrate 5 in this embodiment
Details of the respective semiconductor layers formed on 00 are as follows.

InP substrate 500: thickness 300 μm, In
P buffer layer 501: 1 μm thick, n-type cladding layer 5
1: AgAl (S _0.35 Se _0.65 ) ₂ , thickness 1 μm, active layer 52: AgGa (S _0.49 Se _0.51 ) ₂ , thickness 0.08
μm, p-type cladding layer 53: AgAl (S _0.35 S
e _0.65 ) ₂ , thickness 1 μm, InP contact layer 55: thickness 0.5 μm.

The oscillation wavelength of this semiconductor light emitting device is about 5
55 nm and green light was obtained. This semiconductor light emitting device can be used as a semiconductor laser device.

[0064] The semiconductor even in the light emitting device, n-type cladding layer 51, active layer 52, Ag to form a p-type cladding layer _{53 (Ga w Al x In y} ) (S z Se 1-z) each composition ratio of ₂ By adjusting w, x, y, and z, a semiconductor light emitting device that oscillates in another color can be obtained. For example, when the n-type clad layer 51, the active layer 52, and the p-type clad layer 53 are formed using the following semiconductors, red light is obtained.

N-type clad layer 51: AgGa (S _0.49 S
e _0.51 ) ₂ , thickness 1 μm, active layer 52: AgIn (S
_0.82 Se _0.18 ) ₂ , thickness 0.08 μm, p-type cladding layer 53: AgGa (S _0.49 Se _0.51 ) ₂ , thickness 1 μm.

The oscillation wavelength of this semiconductor light emitting device is 620n.
It was m.

To make the emission color blue, for example,
The active layer 52 is AgAlSe₂It may be formed by using.
In this case, the cladding layers 51 and 53 are
To have a large energy gap and a low refractive index
For example, AgAl (S_0.35Se _{0. 65})₂With active layer
The lattice constant of 52 is about 2.
Although it deviates by 5%, in that case, prevent deterioration of crystallinity due to strain.
In order to protect the active layer 52, the thickness of the active layer 52 is sufficiently thin, for example, 70 angstroms.
It may be about strom.

In the case of this structure, the emission wavelength corresponding to the energy gap of the active layer 52 is 490 nm (light blue), but since the thickness of the active layer is sufficiently thin, it is about 470 n due to the quantum effect.
A wavelength of m (blue) is obtained.

Furthermore, AgAl (S
_When the active layer 52 is formed using _0.35 Se _0.65 ) ₂ , for example, a semiconductor material such as MgSe that can be lattice-matched with InP and has a lower refractive index than AgAl (S _0.35 Se _0.65 ) ₂ is used. The clad layers 51 and 53 can be formed as well. Although MgSe is a II-VI group compound semiconductor, as shown in FIG. 7, it can be almost lattice-matched with InP and has a forbidden band width of AgAl (S _0.35 Se _0.65 ) ₂
It is much larger and does not absorb oscillating light. As long as the material has a refractive index lower than that of the active layer and can be lattice-matched with InP, the cladding images 51, 5
It can be used as a material forming 3.

When MgSe is used, the forbidden band width of the cladding layer 53 and the forbidden band of the InP contact layer 55 are provided between the cladding layer 53 and the InP contact layer 55 as shown by the broken line in FIG. It is preferable to provide the buffer layer 54 having a forbidden band width having an intermediate value of the width. Since the difference between the forbidden band width of the clad layer 53 and the forbidden band width of the InP contact layer 55 is large, the resistance at the interface between these two layers is large, but the buffer layer 54 should be interposed between the two layers. The resistance can be prevented from increasing.
As such a buffer layer 54, for example, p-type Ag
A layer formed of In (S _0.82 Se _0.18 ) ₂ with a thickness of 0.3 μm is used. The forbidden band width is a value between the forbidden band width of the cladding layer 53 and the forbidden band width of the InP contact layer 55. Any material having

The active layer 52 is made of AgAl (S _0.35 Se _0.65 ).
₂ and the cladding layers 51 and 53 are formed of MgS.
e as the buffer layer 54, and p
In the semiconductor light-emitting device formed using the type AgIn (S _0.82 Se _0.18 ) ₂ , blue light was obtained by oscillating at 450 nm.

In the semiconductor light emitting device of Example 4, an example of an electrode stripe type double heterostructure device is shown for simplification, but the SCH having a double clad layer is shown.
(Separate Confinement Heterostructure) type, GRI
N-SCH (Graded Index Separate Confinement Hete
The present invention can be applied to other structures used as GaAs-based or InP-based semiconductor laser devices such as rostructure). In addition, the optical characteristics are improved by adopting a normal buried ridge stripe type structure,
It can be a semiconductor light emitting device that can be used in an optical disc system.

In the semiconductor light emitting device to which the present invention is applied, it is possible to provide a semiconductor laser device in which the focused diameter of oscillated laser light is about 0.5 μm at maximum.
Therefore, the upper limit of the condensing diameter can be reduced by about 40% as compared with the converging diameter of the conventional GaAs semiconductor laser device being about 0.8 μm at maximum. for that reason,
The recording density of the optical disk recording system can be improved to about 2.5 times that of the conventional one.

[0074]

According to the present invention, a semiconductor light emitting device capable of emitting light with high brightness in the red to blue region can be formed by using one high quality substrate and the same type of semiconductor material. . Therefore, an element capable of emitting light of each of the three primary colors can be obtained, and a full-color display can be realized.

Further, since a plurality of semiconductor layers are formed using one substrate and a plurality of forbidden band widths are changed to form a plurality of light emitting portions having different emission colors, a device emitting a single color. Not only can a full-color display be formed using one substrate, but also a display that emits white light can be manufactured.

Further, according to the present invention, it is possible to manufacture a semiconductor light emitting device which can oscillate with high efficiency in the red to blue region and can be used as a semiconductor laser. A full color laser printer can be realized by using the semiconductor light emitting device of the present invention. Further, it can be preferably used for an optical disk system, a magneto-optical recording disk system, etc., and by using the semiconductor light emitting device of the present invention, it is possible to increase the density of these systems.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a semiconductor light emitting device according to a first embodiment.

FIG. 2 is an explanatory diagram of a manufacturing process of the semiconductor light emitting device of Example 1.

FIG. 3 is a schematic view showing a semiconductor light emitting element of Example 2.

FIG. 4 is a schematic view showing a semiconductor light emitting device of Example 3.

FIG. 5 is a diagram showing a forbidden band width structure of a main part of the semiconductor light emitting element of Example 3;

FIG. 6 is a perspective view of a main part of a semiconductor light emitting device according to a fourth embodiment.

FIG. 7 shows InP and Ag (Ga _w Al _x In _y ) (S _z Se
FIG. 3 is a diagram showing a relationship between a lattice constant and a forbidden band width and a relationship with an emission wavelength in _1-z ) ₂ .

[Explanation of symbols]

 100 InP substrate 11 n-type semiconductor layer 12 p-type semiconductor layer 13 InP contact layer 300 InP substrate 31, 32, 33 p-type semiconductor layer 34, 35, 36 n-type region 400 InP substrate 41, 43, 45 non-doped barrier layer 42, 44 Non-doped light emitting layer 500 InP substrate 51 n-type clad layer 52 active layer 53 p-type clad layer 55 InP contact layer

Claims (3)

[Claims] 1. A semiconductor layer is laminated on an InP semiconductor substrate, the semiconductor layer having a lattice constant substantially equal to the lattice constant of the substrate, and Ag, Se, S and Ga, Al.
A semiconductor light emitting device comprising a chalcopyrite group compound semiconductor containing at least one of In and In. 2. A plurality of the semiconductor layers are provided on the substrate, each of which is Ag (Ga _w Al _x In _y ) (S _z S
e _1-z ) ₂ (w, x, y are each 0 or more and 1 or less,
And the sum of w, x, and y is 1, and z is larger than 0 and smaller than 1). 3. The semiconductor light emitting device according to claim 1, wherein an InP layer is laminated on the semiconductor layer.