JP3169177B2 - Substrate for epitaxial growth and semiconductor light emitting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for epitaxial growth and a method of manufacturing the same, and a semiconductor light emitting device formed by epitaxial growth on the substrate for epitaxial growth.

[0002]

2. Description of the Related Art In an advanced information processing society, a technology for transmitting large-capacity information such as video information at a high speed and recording the information on a recording medium is essential. In recent years, the development of optical information processing technologies for optical communication networks and optical disks has been remarkable.
Further development is expected for the multimedia society of the 21st century. Semiconductor light emitting devices such as semiconductor light emitting diodes (LEDs) and semiconductor laser diodes (LDs) have excellent characteristics as light sources in these optical technologies. It has been.

A semiconductor light emitting device mainly comprises an active layer for generating laser light, and a cladding layer for injecting carriers into the light emitting layer and confining carriers and laser light in the light emitting layer. A semiconductor material having a larger forbidden band width than the active layer is used for the cladding layer. By setting the composition, thickness, and doping concentration of the active layer and the cladding layer to optimal values, a semiconductor light emitting device having highly efficient light emitting characteristics can be obtained.

[0004] These semiconductor light emitting devices are made of GaAs or I
AlGaAs on a binary compound semiconductor substrate such as nP
It is formed by epitaxially growing a ternary or quaternary semiconductor mixed crystal layer of s or InGaAsP. In order to obtain a high-quality semiconductor crystal, a crystal having few non-radiative recombination centers such as defects and dislocations is desirable. In a semiconductor light emitting device, in order to prevent defects and dislocations, the lattice constant of a cladding layer constituting the device is basically made to match the lattice constant of a binary compound semiconductor substrate. In order to satisfy such a lattice matching condition, types of semiconductor mixed crystals and compositions of constituent elements used in the cladding layer are limited.

In order to spread the LD for communication, it is desirable that the LD be low in price and that it can be used even at a high ambient temperature. At a high environmental temperature, the electron carriers injected into the active layer easily overflow from the active layer to the cladding layer, and the luminous efficiency is significantly reduced. In order to suppress such carrier overflow, it is effective to use a semiconductor mixed crystal having a large forbidden band width as the cladding layer. However, since the kind and composition of the semiconductor mixed crystal used for the cladding layer are limited to a range that satisfies the lattice matching condition between the cladding layer and the substrate, it is not easy to obtain an LD that can be used even at a high ambient temperature.

[0006] An LD for optical communication usually has an IP on an InP substrate.
It is formed using an nP cladding layer. Since a material having a larger bandgap than InP, such as AlGaAs or AlGaInP, can be lattice-matched on the GaAs substrate, an optical communication LD having excellent temperature characteristics can be obtained by using such a material for the LD cladding layer. Could be However, when forming an LD emitting light in the 1.3 μm band required for optical communication on a GaAs substrate by using InGaAs having a small forbidden band width for the active layer, strong strain occurs in the InGaAs active layer, and the crystal is formed. Degraded quality, high performance L
There is a problem that D cannot be formed.

In Journal of Crystal Grouse, 1997, Vol. 173, p. 42, p. 50 to p. 50, "In _x with composition gradually changed using In _0.25 Ga _0.75 As crystal as seed. Ga _1-x As (X = 0.05-0.3
0) There is a paper on an InGaAs ternary substrate produced by liquid phase crystal growth entitled "Bridgeman growth of single crystal". This aims at newly producing an InGaAs substrate having a lattice constant between GaAs and InP and forming a high-performance LD on the InGaAs substrate. I
On the nGa As substrate, In having a larger forbidden band width than InP is used.
AlAs can be formed with lattice matching and is free from defects and dislocations.
Since an nGaAs active layer can be formed, a high-performance LD that emits light in the 1.3 μm band can be obtained.

However, as can be seen from the fact that many compound semiconductor substrates are binary, it is thermodynamically difficult to make a ternary substrate such as InGaAs. The reason for this is that in the liquid phase growth method close to thermal equilibrium, InGaAs is converted to InA.
This is because phase separation easily occurs between s and GaAs. 1.3 μm
In order to obtain an LD that emits light in the band, an In _0.25 Ga _0.75 As substrate having an In composition of at least 0.25 is required. However, increasing the In composition to at least 0.1 significantly deteriorates the ternary bulk crystal quality. There is a problem of deterioration.

On the other hand, since the development of a ternary substrate requires a large cost, it is impossible to supply LD at a low price.
There is also a problem that D will not spread. In recent years, optical disks have been in the limelight as recording and storage media for video information and data. A semiconductor laser is used for reading information from the optical disk and writing information to the optical disk. Since the storage capacity of an optical disk increases in inverse proportion to the square of the wavelength of laser light, shortening the wavelength of a semiconductor laser is extremely significant in improving the storage capacity of an optical disk. From this point of view, there is a strong demand for lasers in the green region and the blue region more than the conventional red region. If semiconductor lasers of three primary colors of red, green, and blue are provided, development and performance improvement of various optical devices such as a display device and a full-color printer can be brought about. Nitride III under such background
Research and development of a next-generation blue-green light-emitting element using a group V compound semiconductor are being actively conducted.

In these blue-green light emitting devices, a GaN buffer layer is grown on a sapphire substrate,
It is manufactured by epitaxially growing an N clad layer and an InGaN light emitting layer. For a blue-green LD element, AlGaN
Is optimal as a cladding layer, but because of lattice mismatch with the GaN buffer layer, it must be grown to have a sufficient thickness to maintain crystal quality and to confine light. is there. In addition, since the sapphire substrate has a high refractive index, light confinement in the active layer tends to be further weakened.

Therefore, if a ternary mixed crystal substrate of AlGaN is used, it is expected that a blue-green LD device will have higher performance. However, the ternary mixed crystal substrate of AlGaN is similar to the GaN substrate,
It is very difficult to obtain bulk crystals by liquid phase growth. In addition, AlGaN, unlike GaN, is not suitable for a buffer layer. The reason for this is that AlGaN easily causes a change in composition due to strain, and it is difficult to grow a uniform and flat thick film. As described above, a ternary substrate is expected to be realized in a display and a light emitting element for information processing.

[0012] In recent years, there has been reported epitaxial growth beyond the constraint of lattice matching with a substrate. 1997 Applied Physics Letters, Volume 71, 776 pages
There is a paper entitled "Defect-Free InSb Growth on GaAs-Compliant Universal Substrate". GaAs
The s-compliant universal substrate (hereinafter referred to as “CU substrate”) is a GaAs substrate obtained by bonding and transferring a GaAs thin film to a GaAs substrate by rotating the in-plane crystal orientation. This report reports that InSb bulk (layer thickness: 650 nm) having a lattice mismatch of as much as 14% was grown epitaxially on a GaAs CU substrate without defects and without dislocations.

A conventionally known substrate bonding is a bonding between different kinds of materials. Even if the bonding is made of the same kind of material, the bonding is performed by matching the crystal orientations in the plane, and it has not been considered to etch and further grow a bulk having a different crystal orientation thereon. This paper does not describe the mechanism of defect-free growth in detail,
The transferred GaAs thin film plays a role of a buffer layer between a GaAs substrate and an InSb epitaxial layer having a different lattice constant, and plays a role of preventing dislocations from being formed in a direction perpendicular to the substrate. Seem.

Since the junction-transferred GaAs thin film has a different plane orientation, the bonding with the GaAs substrate is weakened. The junction-transferred GaAs thin film is strongly bonded to the InSb epitaxial layer having the same plane orientation, and even if the in-plane lattice constant is increased, the bonding with the substrate is weakened. It is presumed that no dislocation is formed in the direction perpendicular to the substrate.

FIG. 23 is a conceptual diagram of a conventional method of manufacturing a GaAs CU substrate. First, n-G having a layer thickness of 350 μm
a 1 μm layer of Al on an As (100) substrate 2301
As etching stop layer 2302 and 3 nm thick GaAs
A thin film layer 2303 is sequentially grown, cooled to room temperature, and taken out. Next, n-GaAs is placed in an alloy furnace in a hydrogen atmosphere.
The GaAs thin film layer 2303, which is the growth surface of the (100) substrate 2301, and the surface of the n-GaAs (100) substrate 2304 are set to <01 of the n-GaAs (100) substrate 2301.
1> direction 2306 and n-GaAs (100) substrate 23
An angle 23 of about 40 ° with the <011> direction 2305 of 04
07 so as to make contact. In this state, the two substrates 2301 and 2304 are heated to 550 ° C. while being held at a pressure of 10 MPa.
04 is torsionally joined on the torsion joint surface 2308.

Next, GaAs (10
0) The substrate 2301 and the AlAs etching stop layer 2301 having a thickness of 1 μm are removed by etching to remove GaAs having a thickness of 3 nm.
The s thin film layer 2303 is exposed to obtain a GaAs CU substrate. FIG. 24 is a sectional view of a conventional CU substrate. The conventional CU substrate 2204 is a GaAs (100) substrate 22
01 and GaAs (1) through the torsion joint interface 2202.
00) GaAs layer 2203 laminated on substrate 2201
Consists of

[0017]

As the thickness of the transferred GaAs thin film layer, which is the outermost layer of the CU substrate, is smaller, an epitaxial layer having a large lattice mismatch with the substrate can be grown without defects. Tend. For this reason, it is important to control the thickness of the GaAs thin film layer to be transferred on the atomic layer order.

For example, in a conventional method of manufacturing a CU substrate, C
The U substrate has a structure of GaAs / AlAs / GaAs. In a GaAs / AlAs / GaAs structure, when GaAs is etched, the etching may be stopped with AlAs by using an ammonia-based etchant or the like. However, only hydrochloric acid (HCl) and hydrofluoric acid (HF) are known as selective etchants for etching GaAs and stopping etching with AlAs. When selective etching is performed with HCl or HF, which is a strong acid, the surface of the GaAs thin film layer loses its specularity, and it is difficult to control the thickness of the GaAs thin film layer to be transferred by atomic layer order. If selective etching is performed with HCl or HF, the GaAs thin film layer to be transferred is removed by etching, or the thickness of the layer becomes uneven in the plane.

Further, the CU substrate is heated before the growth, and the CU substrate is heated.
In the process of evaporating the surface oxide film of the GaAs thin film layer of the substrate, the thickness of the GaAs thin film layer changes. As described above, in the conventional CU substrate manufacturing method and the conventional CU substrate, the transferred GaAs thin film layer cannot be controlled with sufficient accuracy, and therefore, there is a problem that a constant CU substrate effect cannot be obtained with good reproducibility. there were.

As described above, since the transferred GaAs thin film layer may be removed by etching, reducing the thickness of the GaAs thin film layer to about several atomic layers has a large risk. However, conversely, the transferred GaAs
When the thickness of the thin film layer is increased to 5 nm or more, there is a problem that a bulk epitaxial layer having a large lattice mismatch with the substrate cannot be grown without any defect.

Generally, even on a conventional CU substrate, it is difficult to grow a ternary mixed crystal having a lattice constant different from that of the substrate. This is because, when there is a lattice mismatch with the substrate, the ternary mixed crystal is different from the binary crystal in that the composition tends to fluctuate due to strain, and it is difficult to grow uniformly and flatly. It has been reported that the critical film thickness of a ternary mixed crystal having a lattice constant mismatch of 0.5% is increased by growth on a CU substrate. However, there is no report that a ternary mixed crystal having a layer thickness of 1 μm or more was formed defect-free and flat.

Japanese Patent Application Laid-Open No. 8-162715 discloses a semiconductor light emitting device using a bonded substrate. Specifically, by using a growth substrate having a region having a different plane orientation by bonding, a desired film thickness distribution is realized in a self-aligned manner in the different plane orientation region by utilizing the plane orientation dependence of the crystal growth region. , To reduce light confinement. However, fundamentally, the above-mentioned problem has not been solved even in this semiconductor light emitting device.

The present invention has been made in view of the above-mentioned problems of the conventional example, and can control the thickness of the transferred GaAs thin film layer with sufficient accuracy, and can reduce the thickness of the substrate. An object of the present invention is to provide a substrate for epitaxial growth capable of growing a bulk epitaxial layer having a large lattice mismatch without defects and flat, and a method for manufacturing the same.

[0024]

In order to achieve the above object, according to the present invention, an epitaxial growth is performed on a substrate for epitaxial growth having a structure in which one or more semiconductor layers are stacked on a base crystal substrate. The outermost semiconductor layer is made of three or more types of constituent elements, and at least one pair of adjacent two semiconductor layers different from the outermost semiconductor layer or the mother crystal substrate and the different from the outermost semiconductor layer are different from each other. Two semiconductor layers have the same crystal structure,
The two semiconductor layers or the host crystal substrate and one semiconductor layer have the same plane orientation of a bonding surface where they are bonded to each other.
One semiconductor layer or the mother crystal substrate and one semiconductor layer are joined while being rotated by a fixed angle relatively about an axis perpendicular to the joining surface as an axis, and the two semiconductor layers or the mother crystal substrate and one semiconductor layer are joined together. There is provided a substrate for epitaxial growth, characterized in that directions of crystal orientations in the junction plane of two semiconductor layers are different.

Preferably, the crystal constituting the host crystal substrate is a semiconductor crystal comprising two or less types of constituent elements. The whole board is
As described in claim 3, it is preferable that the semiconductor device is of a single conductivity type. According to a fourth aspect of the present invention, in the epitaxial growth substrate according to the first, second or third aspect, the lattice constant a1 (nm) of the outermost semiconductor layer and the lattice constant of the mother crystal substrate or a semiconductor layer adjacent to the mother crystal substrate are determined. Lattice constant a
Provided is a substrate for epitaxial growth, wherein the degree of lattice mismatch X (%) determined from 2 (nm) satisfies the following expression.

0.2 ≦ | X | ≦ 30 X = (a1−a2) × 100 / a2. In the substrate for epitaxial growth according to claim 1, 2, 3 or 4, the crystal within the bonding plane is provided. Two adjacent semiconductor layers having different azimuthal directions or the ternary semiconductor layer on the outermost surface of the mother crystal substrate and one semiconductor layer or the three semiconductor layers.
Provided is a substrate for epitaxial growth, wherein the thickness of the semiconductor layer closer to the source semiconductor layer is 5 nm or less.

[0027] Claim 6 is Claim 1, 2, 3, 4
6. The substrate for epitaxial growth according to claim 5, wherein the two semiconductor layers or the mother crystal substrate and one semiconductor layer have the same constituent elements and the same composition. It is preferable that the layer thickness H (nm) of the outermost semiconductor layer satisfies the following expression.

1 ≦ H ≦ (15 / | X |) In the substrate for epitaxial growth according to claim 1, the two semiconductor layers or the host crystal A substrate for epitaxial growth is provided, wherein one of the substrate and one of the semiconductor layers is an outermost semiconductor layer.

As described in claim 9, it is preferable that the semiconductor layers on both sides of the bonding surface are of the same kind. Further, as described in claim 10, the same type of semiconductor layer is preferably a ternary semiconductor layer. Claim 11 is Claim 1, 2, 3, 4,
11. The substrate for epitaxial growth according to 5, 6, 7, 8, 9 or 10, wherein the bonding surface has a (100) plane orientation, and the <011> crystal of the two semiconductor layers or the base crystal substrate and one semiconductor layer Provided is a substrate for epitaxial growth, characterized in that the angle θ formed by the azimuth is either θ1 or θ2 satisfying the following condition.

Θ1−0.5 ° ≦ θ ≦ θ1 + 0.5 ° θ2−0.5 ° ≦ θ ≦ θ2 + 0.5 ° θ1 and θ2 are expressed as | (1 + X) with respect to the lattice mismatch X (%). / 100) 2- (k2 + m2) / n2 | For a set of natural numbers (k, m, n) that satisfies 1 ≦ k ≦ m ≦ n ≦ 100, tan (θ1) = k / m tan (θ2) = M / k.

According to a twelfth aspect of the present invention, the outermost semiconductor layer is
As noted, In_X1Ga_{1- X1}As layer (0 <X1
<1) or In_X2Ga_1-X1P layer (0 <X2 <1)
Is preferred. Also, it is described in claim 13.
As described above, the outermost semiconductor layer In _X1Ga_1-X1As
The In composition X1 of the layer is 0.28 ≦ X1 ≦ 0.36,
Or In_X2Ga_1-X2When the In composition X2 of the P layer is 0.76 ≦
It is preferable that X2 ≦ 0.84.

According to a fourteenth aspect of the present invention, the outermost semiconductor layer is an Al _Y Ga _{1 -Y} N layer (0 <Y <1).
Or In _Z Ga _1-Z N layer is preferably (0 <Z <1). According to a fifteenth aspect, there is provided a semiconductor light emitting device comprising: the epitaxial growth substrate according to any one of the first to fourteenth aspects; and a cladding layer made of a semiconductor lattice-matched to a semiconductor layer on the outermost surface of the epitaxial growth substrate. provide. In this semiconductor light emitting device, the cladding layer may be made of In _W Al.
_1-W As, In composition W is 0.28 ≦ W ≦ 0.36
It is preferred that

According to a seventeenth aspect, the semiconductor light emitting device oscillates at a wavelength of 2.7 μm. An eighteenth aspect of the present invention is the method for manufacturing a substrate for epitaxial growth according to any one of the first to fourteenth aspects, wherein the epitaxial substrate on which the outermost ternary semiconductor layer is grown and the mother substrate are joined in a vacuum. And controlling the angle between the in-plane crystal orientations of the mother substrate and the epitaxial substrate so that they are in contact with each other, and after contacting the two substrate surfaces at room temperature, 200 ° from room temperature.
Bonding the two substrates by increasing the temperature to a temperature equal to or higher than C and providing a method for manufacturing a substrate for epitaxial growth.

In carrying out this method, claim 19
As described, molecular beam epitaxial growth equipment
It is preferable to use Claim 20 is Claim 1 or Claim 2
14. Fabrication of the substrate for epitaxial growth according to any one of 14.
A ternary semiconductor layer on a GaAs substrate on the outermost surface
And Al_0.5Ga_{0. Five}Epi grown with adjacent As layer
The process of joining the GaAs substrate with the taxi substrate
About, NH_FourOH and H_TwoO_TwoMixed at a constant volume ratio
The GaAs substrate is selectively formed with the prepared etching solution.
Removal process, HCl and H_ThreePO _FourAt a constant volume ratio
The above-mentioned Al is selectively formed using an etching solution prepared by mixing.
_0.5Ga_0.5Removing the As layer.
Provides a method for manufacturing a substrate for epitaxial growth, which is a feature
I do.

[0035] Claim 21, claims 1 to an epitaxial growth substrate manufacturing method according to 12 any one of ternary semiconductor layer of the outermost surface on a GaAs substrate and the In _0.5
Ga _0. epitaxial substrate where the ₅ P layer is grown by adjacent, the steps for bonding the GaAs base board, H ₃ P
Selectively removing the GaAs substrate with an etching solution prepared by mixing O ₄ , H ₂ O _2, and H ₂ O at a constant volume ratio, and selectively removing the In _0.5 Ga with an HCl solution.
_{And a step} of removing the _0.5 P layer.

[0036]

For example, in a GaAs-based epitaxial growth substrate of the present invention, a ternary semiconductor layer such as InGaAs is formed on a GaAs thin film layer of a GaAs-based CU substrate. Since these epitaxial layers are grown and formed by a crystal growth method such as the MBE method, the thickness of the epitaxial layers can be controlled by the atomic layer order.

In manufacturing the substrate for epitaxial growth according to the present invention, the epitaxial substrate is rotated in a plane with respect to the base substrate so that the base substrate and the epitaxial substrate form a certain angle from a state in which the crystal orientations match. After the bonding, the epitaxial substrate is removed by chemical etching, leaving the epitaxial layer. Since the chemical etching is performed up to the surface of the ternary semiconductor layer and does not reach the GaAs thin film layer, the thickness of the GaAs thin film layer of the epitaxial growth substrate according to the present invention is kept uniform.

In the substrate for epitaxial growth according to the present invention, since the transferred GaAs thin film layer is not likely to be removed by etching, the thickness of the GaAs thin film layer can be made very small. In addition, the substrate for epitaxial growth according to the present invention is heated before the growth, so that the surface of the substrate 3
Even if the surface oxide film of the original semiconductor layer is evaporated, the thickness of the GaAs thin film layer is not affected. Therefore, according to the substrate for epitaxial growth and the method of manufacturing the same according to the present invention, the thickness of the GaAs thin film can be controlled on the atomic layer order by the action of protecting the GaAs thin film layer by the ternary semiconductor layer.
Therefore, a bulk epitaxial layer having a large lattice mismatch with the base substrate can be grown uniformly and defect-free with good reproducibility.

Further, in the epitaxial growth substrate according to the present invention, since the ternary semiconductor layer is formed on the surface,
It is easy to grow a ternary semiconductor bulk layer lattice-matched to it uniformly without defects. Specifically, a first conventional example of a substrate in which a surface layer is made of a ternary mixed crystal, a second conventional example of a CU substrate, and an epitaxial growth substrate according to the present invention,
The operation of the present invention will be described by comparing the difference in the growth mode on those substrates.

FIG. 25 shows a substrate of the first conventional example and a substrate thereon.
It is sectional drawing which shows a growth state. This substrate 1908 has n
A layer thickness of 100 n on a GaAs (100) substrate 1901
m-n-GaAs buffer layer 1902 and a layer thickness of 8 nm.
n-In_0.32Ga_0.68Epitaxial As layer 1903
It is a substrate that has been grown and manufactured. On this substrate, n-In
_0.32Ga_0.68When the As layer 1904 is grown by MBE,
N-In at the beginning of growth _0.32Ga_0.68As layer 1904
It grows flat in the growth direction 1906. However, n-In
_0.32Ga_0.68As layer 1904 and n-GaAs (100)
There was a lattice mismatch of as much as 1.5% with the substrate 1901.
N-In_0.32Ga_0.68The As layer 1904 will soon be
If the thickness exceeds the boundary thickness (10 nm), the crystal relaxes and becomes non-flat.
Changes into a growth surface 1905,
Threading dislocations 1907 occur.

FIG. 26 is a sectional view showing a second conventional example substrate and a growth state thereon. The GaAs CU substrate 2009 includes an n-GaAs (100) substrate 2001,
N-GaAs (100) through torsional junction interface 2002
N-GaAs having a thickness of several nm bonded to the substrate 2001
And a layer 2003. When the n-In _0.32 Ga _0.68 As growth layer 2004 is grown by MBE on the GaAs CU substrate 2009, no threading dislocation occurs from the substrate to the epitaxial layer due to the function of the CU substrate. That is, the dislocation-free epitaxial layer 2006 grows initially, but in the early growth stage, the composition changes due to lattice mismatch strain, so that three-dimensional growth 2007 is likely to occur, and flat growth is hindered.

FIG. 1 is a sectional view showing an epitaxial growth substrate according to the present invention and a growth state thereon. The substrate 2108 of the present invention is an n-GaAs (100) substrate 210
1. n-GaAs (10
0) n-Ga having a thickness of 2 nm bonded to the substrate 2101
As layer 2103, n-In _0.32 Ga _0.68 A having a thickness of 8 nm
The s layer 2104 is formed. N-In _0.32 on the substrate 2108
When the Ga _0.68 As growth layer 2105 is grown by MBE,
No threading dislocation occurs from the substrate to the epitaxial layer due to the function of the CU substrate. In this substrate 2108, n-
In _0.32 Ga _0.68 As layer 2104 and n-In _0.32 Ga
_{Since the 0.68} As growth layer 2105 is lattice-matched, the composition does not fluctuate in the initial stage of growth, and the dislocation-free epitaxial layer 2106 having the flat growth surface 2107 grows in the growth direction 2109.

The action of the epitaxial growth substrate according to the present invention will be described in detail. The junction-transferred n-GaAs layer 2
103 serves as a buffer layer between an n-GaAs (100) substrate 2101 and an n-In _0.32 Ga _0.68 As growth layer 2105 having a different lattice constant, and serves to prevent dislocations from being formed in a direction perpendicular to the substrate. Plays a role in preventing. Since the junction-transferred n-GaAs layer 2103 has a different crystal orientation in the bonding plane from that of the n-GaAs (100) substrate 2101, the bond with the n-GaAs (100) substrate 2101 is weakened. Junction-transferred n-In _0.32 G
The hetero thin film composed of a _0.68 As layer 2104 / n-GaAs layer 2103 has n-In _0.32 G having the same crystal orientation.
a _0.68 As is strongly coupled to the As growth layer 2105, so that even if the in-plane lattice constant increases, n-GaAs
Since the bond with the (100) substrate 2101 is weakened, it is not transmitted directly to the n-GaAs (100) substrate 2101, and dislocations may be formed in a direction perpendicular to the n-GaAs (100) substrate 2101. Absent.

[0044]

FIG. 2 shows a first embodiment of the present invention.
It is a sectional view of such an epitaxial growth substrate. First
The substrate for epitaxial growth according to the embodiment has a layer thickness of 35.
0 μm n-GaAs (100) substrate 101, twisted junction
N-GaAs (100) substrate 101 through interface 102
N-GaAs layer 103 having a layer thickness of 2 nm,
8 nm thick n-In_0.32Ga_0.68From the As layer 104
You. n-type impurity of n-GaAs (100) substrate 101
, N-GaAs layer 103, n-In_0.32Ga_0.68
Si is used as the n-type impurity of the As layer 104.
Doping concentration is 1 × 10 ¹⁸cm^-3It is. n-GaAs
s layer 103 and n-In_0.32Ga_0.68As layer 104 has n
-GaAs (100) Same (100) face as substrate 101
Have a rank. n-GaAs layer 103 and n-In_0.32Ga
_0.68The direction of the <011> crystal orientation in the plane of the As layer 104 is
The <011> direction and n-GaAs (1
00) Angle between <011> crystal direction in plane of substrate 101
The degree is 39.3 ゜. n-GaAs layer 103 and n-I
n_0.32Ga_0.68The As layer 104 is made of n-GaAs (10
0) At the torsion bonding interface 102 with respect to the substrate 101
And the angle <39.3 ° around the <100> direction perpendicular to the substrate surface.
It is formed by rotating and joining by an angle.

N-In _0.32 Ga _0.68 As which is the outermost semiconductor layer of the substrate for epitaxial growth according to this embodiment.
The layer 104 is composed of three types of constituent elements, In, Ga, and As. The n-GaAs (100) substrate 101 and the adjacent n-GaAs layer 103 have the same (100) plane orientation at the bonding surface and have an in-plane crystal direction, for example, a direction perpendicular to the orientation flat of the substrate. <011> Direction is different.

The n-GaAs (100) substrate 101, which is the base crystal substrate of the epitaxial growth substrate of the present embodiment, is composed of two types of constituent elements, Ga and As, and is entirely a single n-type conductive element. Type. In the substrate for epitaxial growth of the present embodiment, the lattice constant a1 (nm) of the n-In _0.32 Ga _0.68 As layer 104 which is the outermost semiconductor layer and the base substrate n-GaAs (100) substrate 1
Lattice mismatch X determined from lattice constant a2 (nm) of 01
X = (a1−a2) × 100 / a2 = 1.5, and the condition of 0.2 ≦ | X | ≦ 30 is satisfied.

In the substrate for epitaxial growth according to the present embodiment, the crystal orientation in the junction plane is different, and two adjacent semiconductor layers of n-GaAs (10
0) n- which is a semiconductor layer closer to the outermost ternary semiconductor layer 104 between the substrate 101 and the n-GaAs layer 103;
The thickness of the GaAs layer 103 is set to 5 nm or less.

Further, in the substrate for epitaxial growth according to the present embodiment, the crystal orientation in the junction plane is different, and n-GaAs (10
0) The substrate 101 and the n-GaAs layer 103 are made of the same constituent elements and the same composition. The substrate for epitaxial growth according to the present embodiment has a semiconductor layer n-In on the outermost surface.
_{0. 32} Ga _0.68 As layer 104 having a thickness of H (nm) is 1 ≦ H ≦
10 = (15 / 1.5).

The substrate for epitaxial growth according to the present embodiment comprises an n-GaAs layer 103 and n-In _0.32 Ga _0.68 A
The <110> direction of the s layer 104 and n-GaAs (10
0) The angle θ between the <110> direction of the substrate 101 is 39.
3 ゜. The twist angle of θ = 39.3 ° at the time of joining is n-
In _0.32 Ga _0.68 As layer 104 and n-GaAs (10
0) A natural number satisfying 1 ≦ k ≦ m ≦ n ≦ 100 where | (1 + 1.5 / 100) 2- (k2 + m2) / n2 | For the set (k, m, n) = (9, 11, 14), tan
(Θ1) = 9/11, tan (θ2) = 11/9 Two angles θ1 = 39.3 and θ2 = 50.7 satisfying 11/9
One. At this time, the n-GaAs (100) substrate 10
1 and n-GaAs layer 103 and n-In _0.32 Ga _0.68 A
The s layer 104 is relatively stably twisted and joined.

Hereinafter, a method for manufacturing the substrate for epitaxial growth according to the first embodiment will be described. As a crystal growth method at the time of fabrication, a molecular beam epitaxy (MBE) method, a gas source molecular beam epitaxy (GSMBE) method, a metal organic chemical vapor deposition (MOVPE) method, or the like is used.

The growth temperature of GaAs is 600 ° C. to 650 ° C.
The gas pressures of ° C and As are different for each growth method. In the GSMBE method, AsH3 (arsine) having a flow rate of 3 sccm is supplied for 100 times.
It is thermally decomposed at 0 ° C. and supplied to the substrate with an As ₂ molecular beam.
The pressure in the growth chamber is about 1 × 10 ⁻⁵ Torr. As a group III raw material, a metal raw material of In, Ga, or Al is used. The thickness of the growth layer is determined by the group III molecular beam intensity and the growth time. In the GSMBE method, a change in the thickness of the epitaxial layer at the atomic level of the growing epitaxial layer can be observed by a reflection high energy electron diffraction (RHEED) apparatus, so that the thickness of the monolayer epitaxial layer can be controlled.

FIG. 3 is a conceptual diagram showing a method of manufacturing a substrate for epitaxial growth according to the first embodiment. First, an n-Al _0.5 Ga _0.5 As etching stop layer 2401 having a thickness of 100 nm and n-In _0.32 Ga having a thickness of 8 nm are formed on an n-GaAs (100) substrate 2400 having a thickness of 350 μm.
_{A 0.68} As layer 2402 and an n-GaAs thin film layer 2403 having a thickness of 2 nm are sequentially grown and cooled at room temperature to obtain an epitaxial substrate 2506.

FIG. 4 is a conceptual diagram of the substrate bonding apparatus. Hereinafter, a method of bonding substrates will be described with reference to FIG. In a vacuum device 2503 connected to a vacuum pump 2501 via a gate valve 2502, a substrate holder 2505 to which the epitaxial substrate 2506 shown in FIG.
Is attached to a heating stage 2504. n-GaAs
The s (100) substrate 2404 (see FIG. 3), that is, the substrate holder 2507 to which the mother substrate 2508 is attached is gripped by the transfer rod 2509, and the magnet 2510 attached around the transfer rod 2509 is rotated in the direction 2511. , Twist angle 2407 (see FIG. 3)
To determine.

That is, the n-GaAs (100) substrate 2
The surface of 404 and the surface of n-GaAs thin film layer 2403 are
<110> direction 2405 of n-GaAs (100) substrate 2404 and <110> direction of n-GaAs (100) substrate 2400
The magnet 2510 attached around the transfer rod 2509 is rotated so that the angle formed by the 110> direction 2406 becomes a twist angle 2407 of 39.3 °.

Further, the magnet 2510 is translated in the direction 2512 and brought into contact at room temperature such that the surfaces of the two substrates 2404 and 2506 face each other, and the magnet 2510 is moved.
And hold the pressure applied. The substrate is gradually heated to a temperature at which the oxide film of the n-GaAs (100) substrate 2404 evaporates to 650 ° C.
After holding for 1 minute, stop heating and cool to room temperature. By this operation, the two substrates 2404 and 2506 are torsionally joined.

The two substrates 24 bonded in this manner are
04,2506 was taken out into the atmosphere, embedding the n-GaAs (100) substrate 2404 with wax on a glass plate facing _{down, NH 4 OH: H 2 O} 2 = 1: 20 selective etching solution (volume ratio) (Etching rate at 25 ° C. is 144 μm / hour) for 2.5 hours, and n-Ga
The As (100) substrate 2400 is removed and washed with water. After the glass plate is placed on the heated heater to dissolve the wax, the substrates 2404 and 2506 are removed from the glass plate, and the wax is removed with a stripping solution.
6 is washed with water and organic, and nitrogen is blown to remove water droplets.

Immediately before epitaxial growth, HCl: H
₃ PO ₄ = 1: 1 (volume ratio) selective etching solution (5
Etching at 0 ° C. at an etching rate of 300 nm / min) for 25 to 30 seconds, and n-Al having a layer thickness of 100 nm
_{The 0.5} Ga _0.5 As etching stop layer 2401 is removed. It is confirmed that the color of the interference light on the surface changes and becomes stable during etching. The substrate is washed with water for 2 minutes, sprayed with nitrogen to remove water droplets, and immediately put into a vacuum growth apparatus. Thus, the epitaxial growth substrate according to the first embodiment is obtained.

When etching is performed using a selective etching solution of HCl: H ₃ PO ₄ = 1: 1 (volume ratio), there is a feature that the etched surface is always a mirror surface. As described above, the manufacturing method of the base plate for epitaxial growth according to the present embodiment uses a molecular beam epitaxial growth apparatus, and the epitaxial substrate having the ternary semiconductor layer grown on the outermost surface and the base substrate are placed inside the vacuum apparatus. Bonding, making precise rotation control of the angle between the mother substrate and the in-plane crystal orientation of the epitaxial substrate to make contact, and from room temperature to a temperature of 200 ° C or more with the two substrate surfaces in contact at room temperature It is characterized in that it is increased and joined.

Further, in the method of manufacturing a substrate for epitaxial growth according to the present embodiment, in order to remove the substrate and the etching stop layer, the ternary semiconductor layer and the Al _0.5 Ga _0.5 As layer are adjacent to the outermost surface on the GaAs substrate. After joining the epitaxial substrate grown and grown and the GaAs base substrate, selectively removing the GaAs substrate with an etching solution prepared by mixing NH ₄ OH and H ₂ O ₂ at a constant volume ratio; And an etching solution prepared by mixing HCl and H ₃ PO ₄ at a constant volume ratio to selectively form Al _0.5 G
a _0.5 As layer is removed.

The etching stop layer 2401 has a thickness of 100
nm n-In_0.5Ga_0.5P can also be used
You. In that case, the GaAs substrate 2400 is selectively removed.
H as an etchant_ThreePO_Four: H_TwoO_Two: H_TwoO =
1: 1:10 (volume ratio) (etching rate at 25 ° C)
Is 600 nm / min). Also, n-In_0.5Ga
_0.5P The etching of the etching stop layer 2401
Use hydrochloric acid or the like.

The size of the twist angle for joining the substrates relatively stably will be described below. Two substrates 2506, 2
The twist angle 2407 of 39.3 ° at the time of 404 bonding is n−I
n _{0. 32} Ga _0.68 As layer 2402 and the n-GaAs (10
0) A natural number satisfying 1 ≦ k ≦ m ≦ n ≦ 100 where | (1 + 1.5 / 100) 2- (k2 + m2) / n2 | For the set (k, m, n) = (9, 11, 14), tan
(Θ1) = 9/11, tan (θ2) = 11/9 Two angles θ1 = 39.3 and θ2 = 50.7 satisfying 11/9
One. At this time, the two substrates 2506 and 2404 are relatively stably joined.

FIG. 5 is an explanatory diagram of the twist joint angle. FIG. 5 is a conceptual view showing a partial relationship of the atomic arrangement when the surface of the epitaxial substrate on which the layer including the ternary semiconductor layer is bonded and transferred onto the base substrate is viewed from above. The base substrate is 3 with respect to the ternary semiconductor layer.
They are joined at a twist angle of 9.3 °. Since the lattice constant of the ternary semiconductor layer is 1.5% larger than the lattice constant of the mother substrate, the atomic spacing is also increased by 1.5%. Therefore, 11 surface atoms 2600 of the base substrate, 9 surface atoms 2601 of the base substrate, and 14 ternary semiconductor atoms 2603 have an apex angle of 3
Form a right triangle with a twist angle 2604 of 9.3 °. The atoms of the GaAs thin film layer that are in contact with the surface atoms 2600 of the base substrate are stretched until they have the same lattice constant as the ternary semiconductor, and fall into the position having the lowest energy at a ratio of one in fourteen. When the lattice constant of the ternary semiconductor layer is 1.5% larger than the lattice constant of the base substrate, the twist angle of 39.3 ° is an angle at which the two substrates are relatively stably joined.

FIG. 6 shows a light beam according to a second embodiment of the present invention.
FIG. 2 is a sectional layer structure diagram of a semiconductor laser for communication. Second fruit
The embodiment is for the epitaxial growth according to the first embodiment.
Semiconductor laser diode formed on substrate 215
(LD). Semiconductor laser diode according to the present embodiment
The ion is n-type substrate 201, n-G with a layer thickness of 350 μm.
aAs (100) substrate 202, torsional bonding interface 203, layer
2 nm thick n-GaAs layer 204, 8 nm thick n-GaAs layer
In_0.32Ga_0.68As layer 205, 100 nm thick n-
In_0.32Ga_0.34Al_0.34As layer 206, 1 μm thick
n-In_0.32Ga _0.68As clad layer 207, layer thickness 20
0 nm n-In_0.43Ga_0.23Al_0.34As light confinement
Layer 208, multiple quantum well active layer 209, layer thickness 200 nm
P-In _0.43Ga_0.23Al_0.34As light confinement layer 21
0, p-In with a layer thickness of 1 μm_0.32Ga _0.68As cladding layer
211, p-In with a layer thickness of 100 nm_0.32Ga_0.34Al
_0.34As layer 212, p-In_0.32Ga_0.68As layer 21
3. Consisting of a p-type electrode 214.

FIG. 7 is a sectional structural view of the multiple quantum well active layer 209. The multiple quantum well active layer 209 has a layer thickness of 10 n.
m of In _0.43 Ga _0.23 Al _0.34 As barrier layer 301 and the layer thickness 7nm In _0.54 Ga _0.46 As well layer 302 a layer 303, 304 combines two pairs alternately and an In _0.43 Ga
_It consists of a _0.23 Al _0.34 As barrier layer 305. In the semiconductor diode shown in FIG. 6, n-GaAs (100)
S is used as an n-type impurity of the substrate 202, and Si is used as an impurity of the other n-type epitaxial layers. The doping concentration is 1 × 10 ¹⁸ cm ⁻³ . Be is used as an impurity of the p-type epitaxial layer. The doping concentration is 5 × 10 ¹⁷ cm ⁻³ . The epitaxial layers above the n-GaAs layer 204 all have the same crystallographic orientation, and are 39.3 ° with respect to the n-GaAs (100) substrate 202 with the <100> direction perpendicular to the substrate plane as the axis. Has a crystal orientation rotated by an angle of. The resonator of the semiconductor LD is formed by cleavage and dry etching.

The semiconductor laser for optical communication according to the present embodiment corresponds to the semiconductor light emitting device according to the present invention. That is, the p-In _0.32 Ga _0.68 As cladding layer 211
Is a semiconductor lattice-matched to the n-In _0.32 Ga _0.68 As layer 205 which is the outermost semiconductor layer of the substrate for epitaxial growth. Claim 14
Corresponding to the p-In _0.32 Ga _0.68 As cladding layer 21
1 is In _w A having an In composition w such that 0.28 ≦ W ≦ 0.36
l _1-W As.

The p-In _0.32 Ga _0.68 As cladding layer 211 having a thickness of 1 μm is a material having the largest energy level at the lower end of the conduction band at the gamma point among III-V compound semiconductors, and is formed of In _0.54 Ga _0.46 As. The energy level difference ΔEc at the bottom of the conduction band from the well layer 302 shows a large value of 1.05 eV at room temperature. Even when the ambient temperature rises to 100 ° C., electrons having a small effective mass overflow from the active layer.
Therefore, the change of the threshold current value of the present semiconductor laser diode is small. On the other hand, since the energy level difference ΔEv at the bottom of the valence band of both is as small as 0.12 eV, holes having a large effective mass are uniformly distributed in the multiple quantum well, and the threshold value of the present semiconductor laser diode can be kept low. it can. As a result, the semiconductor laser diode according to the present embodiment may have excellent temperature characteristics.

N-In _0.32 Ga _0.34 A having a thickness of 100 nm
l _0.34 As layer _{206, n-In 0. 32 Ga 0.68} As layer 2
05 and n-In _0.32 Al _0.68 As cladding layer 207 has an intermediate bandgap, has the effect of relaxing the band barrier, facilitating injection of electrons into the cladding layer, and keeping the operating voltage low. The n-In _0.32 Ga _0.68 As layer 20 which is a surface layer of the epitaxial growth substrate 215 according to the first embodiment
5 does not contain Al. Therefore, there is an advantage that the oxide film on the surface easily evaporates at the start of the growth, and a high-quality epitaxial layer can be grown.

FIG. 8 is a sectional view of an epitaxial growth substrate according to a third embodiment of the present invention. The substrate for epitaxial growth according to the present embodiment has an n-
InP (100) substrate 401, n-InP layer 403 having a thickness of 2 nm bonded to n-InP (100) substrate 401 through torsion bonding interface 402, and n-In _0.32 Ga having a thickness of 8 nm and having tensile strain. _{It is} composed of a _0.68 As layer 404.

The n-type impurities of the n-InP (100) substrate 401 include S, n-InP layer 403, n-In _0.32 Ga
Si is used as the n-type impurity of the _0.68 As layer 404. The doping concentration is 1 × 10 ¹⁸ cm ⁻³ . n-
InP layer 403 and the n-In _{0. 32} Ga _0.68 As layer 404
Is the same as the n-InP (100) substrate 401 (100)
It has a plane orientation. n-InP layer 403 and n-In _0.32 G
The direction of the <110> crystal orientation in the plane of the a _0.68 As layer 404 coincides, and the <110> direction and n-InP (1
00) The <110> crystal direction in the plane of the substrate 401 is 3
The angle is 9.3 °. n-InP layer 403 and n
The -In _0.32 Ga _0.68 As layer 404 is formed of n-InP (10
0) It is formed by being rotated at an angle of 39.3 ° around a <100> direction perpendicular to the substrate surface at a twist bonding interface 402 with respect to the substrate 401.

The n-In _0.32 Ga _0.68 As layer 404 and the n-
Lattice mismatch of InP (100) substrate 401 is -1.5%
The n-In _0.32 Ga _0.68 As layer 404 having a thickness of about 8 nm has a layer thickness equal to or less than the critical thickness. The substrate for epitaxial growth according to the third embodiment is obtained by bonding InP substrates to each other, and has a feature that bonding is easier than that of a GaAs substrate because the evaporation temperature of an oxide film is lower than that of a GaAs substrate. Further, by growing the epitaxial layer portion of the semiconductor laser for optical communication according to the second embodiment on the substrate for epitaxial growth according to the third embodiment, a laser diode having high temperature characteristics on an InP substrate can be obtained. can get.

FIG. 9 is a sectional view of an epitaxial growth substrate according to a fourth embodiment of the present invention. The substrate for epitaxial growth according to the fourth embodiment includes an n-InP (100) substrate 501 having a layer thickness of 350 μm, a torsional junction interface 502.
, An n-InP layer 503 having a thickness of 2 nm and an n-In _0.75 Ga _0.25 As layer 504 having a compressive strain of 8 nm in thickness, which are joined to an n-InP (100) substrate 501 through the substrate. The impurities and the impurity concentrations are the same as in the third embodiment. The torsional joint interface 502 can be formed in the same manner as the torsional joint interface 402. n-In _0.75 Ga _0.25 A
The lattice mismatch between the s layer 504 and the n-InP (100) substrate 501 is about + 1.5%, and the n-In
_{The 0.75} Ga _0.25 As layer 504 has a thickness less than the critical thickness.

FIG. 10 is a sectional view showing a layer structure of a medical semiconductor laser according to a fifth embodiment of the present invention. The medical semiconductor laser according to the fifth embodiment is a laser diode formed on the substrate for epitaxial growth according to the fourth embodiment shown in FIG. The medical semiconductor laser according to the present embodiment has a substrate 613 having the same structure as the epitaxial growth substrate shown in FIG.
-In _0.75 Ga _0.25 As buffer layer 605, layer thickness 1 μm
N-In _0.75 Al _0.25 As clad layer 606, layer thickness 2
00 nm n-In _0.75 Ga _0.25 As optical confinement layer 60
7, multiple quantum well active layer 608, 200 nm p-type
In _0.75 Ga _0.25 As optical confinement layer 609, thickness 1 μm
P-In _0.75 Al _0.25 As clad layer 610, layer thickness 2
It comprises a p-In _0.75 Ga _0.25 As layer 611 of 00 nm and a p-type electrode 612.

FIG. 11 is a sectional view showing the structure of the multiple quantum well active layer 608. The multiple quantum well active layer 608 has a thickness of 10
nm In _0.75 Ga _0.25 As barrier layer 701 and layer thickness 7 n
layers 703 and 704 in which two InAs well layers 702 are alternately combined, and In _0.75 Ga _0.25 A having a thickness of 10 nm.
The s barrier layer 705 is formed. The lattice mismatch between the In _0.75 Ga _0.25 As barrier layer 701 and the InAs well layer 702 is about 1.5%, and the InAs well layer 7 has a thickness of 7 nm.
02 has a layer thickness equal to or less than the critical thickness.

The semiconductor laser according to the fifth embodiment shown in FIG. 10 has a characteristic of oscillating at a wavelength of 2.7 μm. The 2.7 μm wavelength band has a maximum water absorption wavelength band, and a living body contains a large amount of water. Therefore, the 2.7 μm wavelength laser is a laser.
It can be applied to medical instruments such as Zames. Usually In
When a laser diode is formed on a P substrate, the wavelength is limited to 2.1 μm because of the limitation due to the critical thickness of the well layer. However, by forming the laser diode on the epitaxial growth substrate according to the present invention, A semiconductor laser having a wavelength band of 2.7 μm can be realized on an InP substrate by using the same material as that of the related art. The laser diode on the InP substrate has characteristics that light confinement is large and carrier concentration can be easily controlled.

The sixth embodiment of the present invention is the sixth embodiment of the present invention.
Active Layer Portion of Medical Semiconductor Laser According to Fifth Embodiment
The present invention relates to a semiconductor laser for medical use in which only the semiconductor laser is changed. FIG.
Is a multiple quantum well of a semiconductor laser according to a sixth embodiment.
It is sectional drawing of an active layer part. In the sixth embodiment,
The quantum well active layer 810 has a 10 nm thick In layer._{0. 75}G
a_0.25As barrier layer 801 and 5 nm thick InAs_0.99
N_0.01Layer 8 in which four sets of well layers 802 are alternately combined
03, 804, 805, 806, 807, 808, and layers
10 nm thick In_0.75Ga_0.25From the As barrier layer 809
Become. In_{0. 75}Ga_0.25As barrier layer 801 and InAs
_0.99N_0.01The lattice mismatch of the well layer 802 is about 1.4%.
The strain amount and the layer thickness of the multiple quantum well active layer 810 are critical.
It is less than the film thickness. Forbidden instead of InAs well layer
InAs with small band width_0.99N _0.01Using well layer 802
The quantum wavelength while keeping the oscillation wavelength fixed at 2.7 μm.
Reduce the well layer thickness of the well to 5 nm and reduce the number of well layers to 4
Can be increased. By increasing the number of well layers
As a result, the characteristic temperature of the laser diode is improved.

The number of well layers is set to two, and the well layer thickness and N
By increasing the composition, a laser diode that oscillates at a wavelength of 3 μm or more can be produced. FIG. 13 is a sectional view of a substrate for epitaxial growth according to the seventh embodiment of the present invention. The substrate for epitaxial growth according to the seventh embodiment includes an n-GaAs (100) substrate 901 having a layer thickness of 350 μm, and an n-GaAs (1)
00) n-Ga having a thickness of 2 nm bonded to the substrate 901
An As layer 903, an n-GaN layer 904 having a thickness of 1 nm, and an n-Al _0.30 Ga _0.70 N layer 905 having a thickness of 2 nm. The impurity and the impurity concentration are 1 × as in the third embodiment.
It is 10 ¹⁸ cm ^-3 . The torsional bonding interface 902 is formed by rotating the crystal orientation at the bonding interface, similarly to the torsional bonding interface 502.

Hereinafter, a method of manufacturing the substrate for epitaxial growth according to the seventh embodiment will be described. GSMBE
After growing an n-type GaN low-temperature buffer layer on a sapphire C-plane at a low temperature of 400 ° C. by 100 nm by using the growth method, the n-type GaN buffer layer is grown to 3 μm at a growth temperature of 700 ° C. Due to the effect of the GaN low-temperature buffer layer, the surface becomes a mirror surface. As the N source, radical nitrogen obtained by decomposing nitrogen by high-frequency plasma is used. In GSMBE growth, GaN can be grown at a low temperature, and its crystal structure is GaAs.
It becomes the same sphalerite type as.

Further, a 2 nm thick n-Al _0.30 Ga
_{A 0.70} N layer 905 and a 1 nm thick n-GaN layer 904 are grown, the substrate temperature is reduced to 650 ° C., and a 1 nm thick n-GaN layer 904 is grown.
A GaAs layer 903 is grown. S for n-punt
Be is used for i and p dopants. This epitaxial substrate is torsionally bonded to an n-GaAs (100) substrate 901 in a vacuum. By removing the sapphire substrate and the n-type GaN buffer layer by etching, n-Al _0.30 G
The substrate for epitaxial growth according to the present embodiment having the a _0.70 N layer 905 as the surface layer can be obtained.

The substrate for epitaxial growth according to the seventh embodiment corresponds to the substrate for epitaxial growth according to claim 12, wherein the semiconductor layer on the outermost surface is Al _Y Ga ₁ -YN.
(0 <Y <1). FIG. 14 is a sectional layer structure diagram of a blue semiconductor laser for optical information processing according to an eighth embodiment of the present invention. A blue semiconductor laser for optical information processing is used as a light source for reading or writing on an optical disk. The blue semiconductor laser for optical information processing according to the present embodiment is a laser diode formed on the substrate for epitaxial growth according to the seventh embodiment shown in FIG.

The blue semiconductor laser for optical information processing according to the present embodiment has a substrate 1014 having the same structure as the substrate for epitaxial growth shown in FIG.
_0.30 Ga _0.70 N cladding layer 1006, 100 nm-thick n-GaN optical confinement layer 1007, multiple quantum well active layer 1008, 100 nm-thick p-GaN optical confinement layer 1
009, p-Al _0.30 Ga _0.70 N cladding layer 1010 having a thickness of 0.8 μm, p-Al _0.10 Ga having a thickness of 200 nm
_0.90 N layer 1011, 400 nm-thick p-GaN layer 10
12, a p-type electrode 1013.

FIG. 15 is a sectional view of a multiple quantum well active layer 1008 of the semiconductor laser according to the eighth embodiment. The multiple quantum well active layer 1008 is made of In _0.05 G having a thickness of 5 nm.
an In _0.20 of a _{0. 95} N barrier layer 1101 and the layer thickness 2.5nm
Layers 1103, 1104, 1105, 1106, 110 in which four sets of Ga _0.80 N well layers 1102 are alternately combined
7 and 1108 and an In _0.05 Ga _0.95 N barrier 1109 having a layer thickness of 5 nm.

Since the blue semiconductor laser according to this embodiment is formed on the ternary substrate 1014 according to the present invention, a high-quality LD crystal can be grown. The crystal structure of the laser diode becomes a zinc-blende type similar to that of GaAs, and the mass of the hole in the active layer tends to be small, which is effective in reducing the threshold current value of the laser diode.

The substrate 101 used in this embodiment
4 has an n-type conductivity type, as shown in FIG.
An n-type electrode 1000 can be formed on the back surface of the substrate 1014.
Blue semiconductor laser p-type electrode 1013 according to this embodiment
By fusing the side to a diamond heat sink, a blue laser diode having excellent heat dissipation can be provided. Further, there is an advantage that inexpensive GaAs can be used as the substrate.

FIG. 16 is a sectional view of a substrate for epitaxial growth according to a ninth embodiment of the present invention. The substrate for epitaxial growth according to the present embodiment includes a sapphire substrate 1201 having a thickness of 350 μm, a GaN buffer layer 1202, and a GaN buffer layer 1202 through a twisted junction interface 1203.
And a 1 nm thick n-GaN layer 1204 and a 2 nm thick n-Al _0.30 Ga _0.70 N layer 1205.

The impurities and the impurity concentrations are the same as in the third embodiment. The torsional bonding interface 1203 is the torsional bonding interface 1
Similarly to 002, it is formed by rotating the crystal orientation at the bonding interface. The substrate for epitaxial growth according to the present embodiment is a substrate for providing a blue LED on a normal sapphire substrate. FIG. 17 is a sectional view of the substrate for epitaxial growth according to the tenth embodiment of the present invention. The substrate for epitaxial growth according to the tenth embodiment has a layer thickness of 350
μm sapphire substrate 1301, GaN buffer layer 13
02, n-GaN layer 13 having a thickness of 1 nm which is bonded to GaN buffer layer 1302 via torsional bonding interface 1303
04, 2 nm thick n-In _0.70 Ga _0.30 N layer 1305
Consists of

The impurities and the impurity concentrations are the same as in the third embodiment. The torsional bonding interface 1203 is the torsional bonding interface 1
Similar to 002, it is formed by rotating the crystal orientation at the bonding interface. The substrate for epitaxial growth according to the present embodiment is a substrate for providing a red LED on a sapphire substrate. On the substrate for epitaxial growth according to the present embodiment, n
By using an n-type or p-type In _0.70 Al _0.30 N cladding layer and an n-InN layer which are lattice-matched with the -In _0.70 Ga _0.30 N layer 1305 as a light emitting layer, a high-luminance red light emitting diode (LED) can be formed. it can. Regarding the wavelength, doping of Si into the light emitting layer causes light emission at the impurity level, so that red light emission is obtained. This makes it red,
Three primary colors of blue and green can be formed by the GaN-based LED. Red,
The availability of the three primary colors of blue and green opens applications that have great demand for color printers and displays.

FIG. 18 is a sectional view of an epitaxial growth substrate according to an eleventh embodiment of the present invention. The epitaxial growth substrate according to this embodiment has a layer thickness of 350 μm.
N-Si substrate 1401, n having a layer thickness of 1 nm bonded to n-Si substrate 1401 via torsional bonding interface 1402
-Si layer 1403, n-GaN layer 140 having a thickness of 2 nm
4. An n-Al _0.30 Ga _0.70 N layer 1405 having a thickness of 2 nm.

The substrate for epitaxial growth according to the present embodiment is a substrate for epitaxial growth for providing a laser diode on an n-Si substrate. Since the n-Si substrate is inexpensive, a fusion device of the LSI technology of Si and the optical element can be realized. For example, the present invention can be applied to optical interconnection between LSI boards and the like. FIG. 19 is a sectional view of the substrate for epitaxial growth according to the twelfth embodiment of the present invention. The substrate for epitaxial growth according to the present embodiment is made of n-GaAs (100) having a layer thickness of 350 μm.
N-Ga via the substrate 1501 and the torsional joint interface 1502
Layer thickness 2 nm bonded to As (100) substrate 1501
Of the n-In _0.32 Ga _0.68 As layer 1503.

The substrate for epitaxial growth according to the present embodiment corresponds to claim 8, wherein two adjacent semiconductor layers or substrates having different crystal orientations in the junction plane and one of the one semiconductor layer are included. One is the outermost ternary semiconductor layer n−
It is characterized by being an In _0.32 Ga _0.68 As layer 1503. FIG. 20 is a sectional view of the substrate for epitaxial growth according to the thirteenth embodiment of the present invention. The substrate for epitaxial growth according to this embodiment has a layer thickness of 350 μm.
m-n-GaAs (100) substrate 1601, n-GaAs (100) substrate 160 via torsional junction interface 1602
N-In _0.80 Ga _0.20 P with a layer thickness of 2 nm joined to
The layer 1603 is formed. This embodiment corresponds to claims 8 and 11.

That is, one of two adjacent semiconductor layers 1601 and 1603 having different crystal orientations in the junction plane is the outermost ternary semiconductor layer n-In _0.80 Ga _0.20 P layer 1603 and In which is a semiconductor layer on the surface
_X2 an In composition X2 of the Ga _1-X2 P layer 1603 0.76 ≦ X
It is characterized in that 2 ≦ 0.84. N-In _0.80 Ga _0.20 P layer 1603 having a thickness of 2nm in this embodiment n-In _{0. 32} Ga _0.68 As layer and n-an In _0.32
Since the lattice matching is performed with the Al _0.68 As layer, a laser diode having excellent temperature characteristics can be grown using the n-In _0.32 Ga _0.68 As layer 211 of the second embodiment as a cladding layer.

FIG. 21 is a sectional view of an epitaxial growth substrate according to a fourteenth embodiment of the present invention. The epitaxial growth substrate according to this embodiment has a layer thickness of 350 μm.
N-InP (100) substrate 1701, n-In _0.32 G
An a _0.68 As layer 1702 and a 2 nm thick n-In _0.32 Ga _0.68 As layer 1704 joined to the n-In _0.32 Ga _0.68 As layer 1702 via the torsional junction interface 1703. This embodiment corresponds to claim 8. The substrate for epitaxial growth according to the present embodiment is characterized in that the semiconductor layers on both sides of the torsional junction interface 1703 are the same ternary semiconductor layer. For this reason, there is a feature that the bonding of the semiconductor layers on both sides of the torsional bonding interface is facilitated.

FIG. 22 is a sectional view of an epitaxial growth substrate according to a fifteenth embodiment of the present invention. The epitaxial growth substrate according to this embodiment has a layer thickness of 350 μm.
N-Si substrate 1801, n-layer having a thickness of 1 nm bonded to n-Si substrate 1801 via torsional bonding interface 1802
-Si layer 1803, n-SiGe layer 180 having a thickness of 2 nm
4. An n-CSiGe layer 1805 having a thickness of 2 nm.
The substrate for epitaxial growth according to the present embodiment has n-S
This is a substrate for epitaxial growth for providing a SiGe-based semiconductor light emitting device formed on an i-substrate. In the substrate for epitaxial growth according to the present embodiment, the outermost surface is a ternary semiconductor n-CSiGe layer 1805, and the semiconductor n-Si substrates 180 on both sides sandwiching the torsional junction interface 1802.
1. The feature is that the n-Si layer 1803 is a semiconductor layer of the same kind. For this reason, there is an advantage that the bonding of the semiconductor layers on both sides of the torsional bonding interface is easy. n-Si
The substrate is inexpensive, and a fusion device of Si LSI technology and an optical element can be realized.

[0093]

The semiconductor laser for optical communication formed on the substrate for epitaxial growth according to the present invention has the lowest energy level at the lower end of the conduction electron band among the III-V compound semiconductors excluding GaN-based nitride. High quality In _0.32 Al
_{It has a 0.68} As layer as a cladding layer and has an In _0.54 G
a It has a _0.46 As layer as a well layer of the quantum well active layer. The difference ΔEc between the energy levels at the bottom of the conduction band of the two.
Is as large as 1.05 eV, and the difference ΔEv between the energy levels at the upper end of the valence band is as small as 0.12 eV.

In _0.32 Al _0.68 As / In _0.32 Ga _0.68 lattice-matched to the epitaxial growth substrate according to the present invention.
ΔEc at the As hetero interface is 0.77 eV. on the other hand,
ΔEc of the In _0.52 Al _0.48 As / InP hetero interface lattice-matched to the InP substrate on which the conventional laser diode is formed is 0.27 eV. ΔEc of the present invention is about three times larger.

The semiconductor light emitting device for optical communication according to the present invention comprises:
Since ΔEc is the largest among the semiconductor light emitting devices for optical communication, the electron trapping efficiency is high, and carrier overflow hardly occurs. Therefore, the change in the threshold current value of the light emitting element with respect to the ambient temperature is small,
A characteristic temperature exceeding 0K can be expected. Since ΔEv is small, no localization of holes occurs in some of the well layers.
A semiconductor light emitting device having a stable wavelength and a low threshold current value and having excellent modulation characteristics can be obtained.

In the semiconductor light emitting device according to the present invention,
Since only As is used as the group V element constituting the growth layer, the interface can be grown only by switching the group III element. Therefore, a laser diode structure having a steep interface can be easily manufactured. By using the substrate for epitaxial growth of the present invention, a medical application semiconductor laser oscillating at a wavelength of 2.7 μm can be realized on an InP substrate. The laser diode on the InP substrate has an advantage that light confinement is large and carrier concentration can be easily controlled.

Since the blue semiconductor laser formed by using the semiconductor light emitting device according to the present invention is formed on the ternary substrate according to the present invention, a high-quality laser diode crystal can be grown. The crystal structure of the laser diode becomes a zinc-blende type similar to that of GaAs, and the mass of the hole in the active layer tends to be small, which is effective in reducing the threshold current value of the laser diode.

Further, since the epitaxial growth substrate according to the present invention has an n-type conductivity type, an n-type electrode can be formed on the back surface of the substrate, and heat dissipation can be achieved by fusing the p-type electrode side to a diamond heat sink. It is possible to produce a blue laser diode excellent in quality. Further, there is a point that inexpensive GaAs or Si can be used as the substrate.

When the substrate for epitaxial growth according to the present invention is formed as a ternary substrate, a GaN-based high-brightness red light emitting diode can be formed on the substrate.
Thereby, the three primary colors of red, blue and green can be formed by the GaN-based light emitting diodes, which opens applications that have great demand for color printers and displays. According to the present invention, a ternary substrate having any composition can be provided relatively easily, so that the degree of freedom in material selection is widened, and a high-performance laser diode or light-emitting diode that emits light in a wavelength band that has been impossible in the past can be realized. Can be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a substrate according to the present invention and growth thereon.

FIG. 2 is a cross-sectional view of the substrate for epitaxial growth according to the first embodiment.

FIG. 3 is a conceptual diagram illustrating a method for manufacturing an epitaxial growth substrate according to the first embodiment of the present invention.

FIG. 4 is a conceptual diagram of a substrate bonding apparatus used for manufacturing an epitaxial growth substrate according to the first embodiment.

FIG. 5 is an explanatory diagram of a twist joint angle.

FIG. 6 is a semiconductor laser for optical communication according to a second embodiment.
It is a sectional layer structure figure of the.

FIG. 7 is a sectional structural view of a multiple quantum well active layer in a second embodiment.

FIG. 8 is a cross-sectional view of an epitaxial growth substrate according to a third embodiment.

FIG. 9 is a sectional view of a substrate for epitaxial growth according to a fourth embodiment.

FIG. 10 shows a medical semiconductor laser as a fifth embodiment.
It is a sectional layer structure figure of the.

FIG. 11 is a sectional structural view of a multiple quantum well active layer according to a fifth embodiment.

FIG. 12 is a sectional view of a multiple quantum well active layer of a semiconductor laser according to a sixth embodiment.

FIG. 13 is a sectional view of a substrate for epitaxial growth according to a seventh embodiment.

FIG. 14 is a sectional layer structure diagram of a blue semiconductor laser for optical information processing according to an eighth embodiment.

FIG. 15 is a sectional view of a multiple quantum well active layer in an eighth embodiment.

FIG. 16 is a cross-sectional view of an epitaxial growth substrate according to a ninth embodiment.

FIG. 17 is a sectional view of a substrate for epitaxial growth according to a tenth embodiment.

FIG. 18 is a sectional view of an epitaxial growth substrate according to an eleventh embodiment.

FIG. 19 is a sectional view of an epitaxial growth substrate according to a twelfth embodiment.

FIG. 20 is a sectional view of an epitaxial growth substrate according to a thirteenth embodiment.

FIG. 21 is a sectional view of an epitaxial growth substrate according to a fourteenth embodiment.

FIG. 22 is a sectional view of an epitaxial growth substrate according to a fifteenth embodiment.

FIG. 23 is a conceptual diagram illustrating a method for manufacturing a conventional CU substrate.

FIG. 24 is a cross-sectional view of a conventional CU substrate.

FIG. 25 is a cross-sectional view showing a cross section of another conventional substrate and a growth thereon.

FIG. 26 is a cross-sectional view showing a cross section of a substrate of another conventional example and growth thereon.

[Explanation of symbols]

101 n-GaAs (100) substrate 102 torsional junction interface 103 n-GaAs layer 104 n-In _0.32 Ga _0.68 As layer 201 n-type substrate 202 n-GaAs (100) substrate 203 torsional junction interface 204 n-GaAs layer 205 n- In _0.32 Ga _0.68 As layer 206 n-In _0.32 Ga _0.34 Al _0.34 As layer 207 n-In _0.32 Ga _0.68 As cladding layer 208 n-In _0.43 Ga _0.23 Al _0.34 As Optical confinement layer 209 Multiple quantum well active layer 210 p-In _0.43 Ga _0.23 Al _0.34 As Optical confinement layer 211 p-In _0.32 Ga _0.68 As cladding layer 212 p-In _0.32 Ga _0.34 Al _0.34 As layer 213 p-In _0.32 Ga _0.68 As layer 214 p-type electrode 301, 303, 305 In _0.43 Ga _0.23 Al _0.34 A
s barrier layer 302, 304 In _0.54 Ga _0.46 As well layer 401 n-InP (100) substrate 402 torsional junction interface 403 n-InP layer 404, 504 n-In _0.32 Ga _0.68 As layer 501 n-InP (100) substrate 502 Twist junction interface 503 n-InP layer 600 n electrode 601 n-InP (100) substrate 602 twist junction interface 603 n-InP layer 604 n-In _0.75 Ga _0.25 As layer 605 n-In _0.75 Ga _0.25 As buffer layer 606 n- In _0.75 Ga _0.25 As cladding layer 607 n-In _0.75 Ga _0.25 As optical confinement layer 608 Multiple quantum well active layer 609 p-In _0.75 Ga _0.25 As optical confinement layer 610 p-In _0.75 Ga _0.25 As cladding layer 611 p-In _0.75 Ga _0.25 As layer 612 p-type electrode 701, 703, 705 In _0.75 Ga _0.25 As barrier layer 702, 704 InAs well layer 801, 803, 805, 807, 809 In _0.75 G
a _0.25 As barrier layer 802, 804, 806, 808 In _0.99 N _0.01 well layer 810 Multiple quantum well active layer 1201 Sapphire substrate 1202 GaN buffer layer 1203 Twisted junction interface 1204 n-GaN layer 1205 n-Al _0.30 Ga _0.70 N layer 1301 Sapphire substrate 1302 GaN buffer layer 1303 twisted junction interface 1304 n-GaN layer 1305 n-In _0.70 Ga _0.30 N layer 1901 n-GaAs (100) substrate 1902 n-GaAs buffer layer 1903, 1904 n-In _0.32 Ga _0.68 As layer 1905 dislocation 2001 n-GaAs non-flat growth surface 1907 epitaxial layer (100) substrate 2002 twisting junction interface 2003 n-GaAs layer 2004 n-in _0.32 Ga _0.68 as grown layer 2006 epitaxial layer of dislocation-free 007 Three-dimensional growth by strain 2301 GaAs (100) substrate 2302 AlAs etching stop layer 2303 GaAs thin film layer 2304 GaAs (100) substrate 2305 <011> direction 2306 <011> direction 2307 Twist angle of θ = 40 ° 2501 Vacuum pump 2502 Ge -Valve 2503 Vacuum device 2504 Heating stage 2505 Substrate holder 2506 Epitaxial substrate 2507 Substrate holder 2508 Base substrate 2509 Transfer rod 2510 Magnet 2601 11 surface atoms of base substrate 2602 9 surface atoms of base substrate 2603 3 ternary semiconductor atoms 14 2604 39.3 ° twist angle

──────────────────────────────────────────────────続 き Continued on the front page (56) References Applied Physics Letters 70 [13] (1997) pp. 1754-1756 Applied Physics Letters 71 [10] (1997) pp. 1344-1346 1996 IEEE LEOS ANNUAL MEETING Vol. 2 (1996) p. 352-353 (58) Field surveyed (Int. Cl. ⁷ , DB name) H01S 5/00-5/50 H01L 21/203 H01L 21/205 H01L 33/00 JICST file (JOIS)

Claims (21)

(57) [Claims] 1. An epitaxial growth substrate having a structure in which one or more semiconductor layers are stacked on a mother crystal substrate, wherein the outermost semiconductor layer to be epitaxially grown is made of three or more types of constituent elements, At least one set of two adjacent semiconductor layers different from each other or the mother crystal substrate and one semiconductor layer different from the outermost semiconductor layer have the same crystal structure, and the two semiconductor layers or the mother crystal The plane orientation of the bonding surface where the substrate and the one semiconductor layer are bonded to each other is equal, and the two semiconductor layers or the mother crystal substrate and the one semiconductor layer are relatively constant with respect to an axis perpendicular to the bonding surface. The two semiconductor layers or the mother crystal substrate and one semiconductor layer are bonded in a state rotated by an angle, and directions of crystal orientations in the bonding plane are different from each other. Epitaxial growth substrate to be. (2) Two kinds of crystals constituting the host crystal substrate
It is a semiconductor crystal composed of the following elements
2. The substrate for epitaxial growth according to claim 1, wherein (3) Specially, the entire substrate is of a single conductivity type.
The substrate for epitaxial growth according to claim 1 or 2,
Board. (4) The lattice constant a1 of the outermost semiconductor layer
(Nm) and the host crystal substrate or the host crystal substrate
Determined from the lattice constant a2 (nm) of the adjacent semiconductor layer
The lattice mismatch X (%) satisfies the following expression.
4. A substrate for epitaxial growth according to claim 1, 2 or 3.
Board. 0.2 ≦ │X│ ≦ 30 X = (a1−a2) × 100 / a2 (5) The direction of the crystal orientation in the bonding plane is different
Two adjacent semiconductor layers or the host crystal substrate and one semiconductor
The outermost ternary semiconductor layer in the body layer or the ternary semiconductor layer
The thickness of the semiconductor layer closer to the layer is 5 nm or less.
The epitaxial layer according to claim 1, 2, 3, or 4,
Growth substrate. 6. The two semiconductor layers or the base crystal group
Whether the plate and one semiconductor layer have the same constituent elements and the same composition
6. The method of claim 1, 2, 3, 4, or 5, wherein
Substrate for epitaxial growth. 7. Layer thickness H (nm) of the outermost semiconductor layer
Satisfies the following expression:
7. The substrate for epitaxial growth according to 4, 5, or 6. 1 ≦ H ≦ (15 / │X│) Claim 8. The two semiconductor layers or the base crystal group
One of the plate and one semiconductor layer is the outermost semiconductor layer.
Claim 1, 2, 3, 4, 5, 6 or
8. The substrate for epitaxial growth according to 7. 9. The semiconductor layers on both sides sandwiching the bonding surface are the same
3. The semiconductor device according to claim 1, wherein
For epitaxial growth according to 3, 4, 5, 6, 7 or 8
substrate. 10. The semiconductor layer of the same type is a ternary semiconductor
Epitaxy according to claim 9, characterized in that it is a layer.
Substrate for cell growth. 11. The bonding surface has a (100) plane orientation.
And The two semiconductor layers or the host crystal substrate and one semiconductor
The angle θ formed by the <011> crystal orientation of the body layer satisfies the following condition.
The characteristic is either θ1 or θ2 to be added.
Claim 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10
Substrate for epitaxial growth. θ1-0.5 ° ≦ θ ≦ θ1 + 0.5 ° θ2-0.5 ° ≦ θ ≦ θ2 + 0.5 ° θ1 and θ2 are calculated based on the lattice mismatch X (%). | (1 + X / 100) 2- (k2 + m2) / n2 | Of natural numbers such that 1 ≦ k ≦ m ≦ n ≦ 100 that minimizes
For (k, m, n), tan (θ1) = k / m tan (θ2) = m / k Meet. 12. The topmost semiconductor layer is In. _X1 Ga _1-X1 As
Layer (0 <X1 <1) or In _X2 Ga _1-X2 The P layer (0 <X2 <1)
Claims 1, 2, 3, 4, 5, 6, 7, 8, 9,
12. The substrate for epitaxial growth according to 10 or 11. Claim 13 In which is the semiconductor layer on the outermost surface _X1 Ga
_1-X1 In composition X1 of the As layer is 0.28 ≦ X1 ≦ 0.36,
Or In _X2 Ga _1-X2 When the In composition X2 of the P layer is 0.76 ≦ X2 ≦ 0.
The epitaxy according to claim 12, wherein the number is 84.
Substrate for char growth. 14. The outermost semiconductor layer is Al _Y Ga _1-Y N layer
(0 <Y <1) or In _Z Ga _1-Z Features N layers (0 <Z <1)
Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 1
12. The substrate for epitaxial growth according to 0 or 11. 15. 15. The method according to claim 1, wherein
A substrate for epitaxial growth; The same as the semiconductor layer on the outermost surface of the substrate for epitaxial growth.
A cladding layer made of semiconductors that are A semiconductor light emitting device comprising: 16. The cladding layer is In _W Al _1-W As
And the In composition W is 0.28 ≦ W ≦ 0.36
The semiconductor light emitting device according to claim 14, wherein 17. It oscillates at a wavelength of 2.7 μm.
17. The semiconductor light emitting device according to claim 15, wherein: 18. 15. The method according to claim 1, wherein
A method for producing a substrate for epitaxial growth, comprising: Epitaxial substrate on which the outermost ternary semiconductor layer is grown
And the mother substrate in a vacuum, The mother substrate and the epitaxial substrate,
The angle between the in-plane crystal orientations is controlled by rotation so that
Let After bringing the two substrate surfaces into contact at room temperature,
Join these two substrates by increasing the temperature to over ℃
Do Method for producing substrate for epitaxial growth characterized by the following:
Law. (19) Using molecular beam epitaxial growth equipment
19. The epitaxial layer according to claim 18, wherein
Manufacturing method of growth substrate. 20. 15. The method according to claim 1, wherein
A method for producing a substrate for epitaxial growth, comprising: The outermost ternary semiconductor layer and Al on a GaAs substrate _0.5 Ga _0.5 As
An epitaxial substrate grown with adjacent layers;
Bonding with the As mother substrate, NH _Four OH and H _Two O _Two Made by mixing at a constant volume ratio
Selectively removing the GaAs substrate with a polishing solution, HCl and H _Three PO _Four Made by mixing with a fixed volume ratio
Solution with the Al solution _0.5 Ga _0.5 Remove the As layer, Method for producing substrate for epitaxial growth characterized by the following:
Law. 21. 15. The method according to claim 1, wherein
A method for producing a substrate for epitaxial growth, comprising: On the GaAs substrate, the outermost ternary semiconductor layer and In _0.5 Ga _0.5 P
An epitaxial substrate grown with adjacent layers;
Bonding with the As mother substrate, H _Three PO _Four And H _Two O _Two And H _Two O prepared by mixing O at a certain volume ratio
Selectively removing the GaAs substrate with a etching solution; Selective In with HCl solution _0.5 Ga _0.5 Remove the P layer, Method for producing substrate for epitaxial growth characterized by the following:
Law.