JP2883504B2 - Stacked semiconductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated semiconductor having a group III-V semiconductor thin film and constituting a semiconductor light emitting device such as a light emitting diode or a laser diode.

[0002]

2. Description of the Related Art A group III-V semiconductor in which nitrogen N is a group V element has a wide energy gap Eg (for example, Al
N is Eg = 6.28 eV, GaN is Eg = 3.39 eV
Vg and InN are Eg = 1.95 eV. )
Early commercialization as a light emitting material in the visible and ultraviolet regions is desired.

[0003] At present, research is being vigorously pursued with a focus on GaN for practical use. Since GaN has a very high dissociation pressure of nitrogen and makes it difficult to produce a large single crystal serving as a substrate, a GaN thin film is formed by epitaxial growth on a heterogeneous substrate. Since GaN usually has a wurtzite crystal structure, sapphire having a hexagonal system is often used as a substrate. However, wurtzite crystals have a V
Since a group element is unlikely to enter a normal lattice position, even a crystal to which an impurity is not added usually shows n-type conductivity due to a high free electron concentration due to a group V vacancy. Therefore, it is very difficult to obtain a p-type semiconductor from a wurtzite crystal, and the added p-type impurity is not easily activated and has a high resistance. For this reason, it is very difficult for the wurtzite crystal to form a pn junction essential for a semiconductor light emitting device.

On the other hand, G having a zinc blende type crystal structure
In III-V semiconductors such as aAs and InP, n-type and p-type semiconductors are easily obtained by adding impurities. Therefore, a p-type semiconductor can be easily obtained also from GaN by using a zinc blende type crystal. The wurtzite type is the most stable crystal structure of GaN, but the zinc blende type also exists as a metastable phase. The following Table 1 shows that when nitrogen N is a V element,
2 shows lattice constants a and c and an energy gap Eg of a II-V group semiconductor. FIG. 7 shows the values of the lattice constant a and the energy gap Eg when the zinc blende type nitride is mixed.

[0005]

[Table 1]

At present, a GaN semiconductor thin film having a zinc blende type crystal structure is formed on a cubic Si crystal substrate or GaAs.
2. Description of the Related Art A stacked semiconductor has been developed in which a semiconductor is stacked on a crystal substrate or a β-SiC crystal substrate by molecular beam epitaxial growth.

[0007]

However, in the above laminated semiconductor, Si or GaAs used as a crystal substrate is used.
Since s has a very large lattice mismatch with GaN, which is a semiconductor thin film, and a lattice mismatch ratio of 20% or more, G
There is a problem that many lattice defects exist in the aN crystal.

In the above-mentioned laminated semiconductor, β-SiC used as a crystal substrate has a small lattice mismatch as compared with Si or GaAs, but it is difficult to produce a crystal substrate. However, there is a problem that the versatility is poor because the processing is difficult because of its hardness. Further, as a cubic buffer layer for relaxing lattice mismatch between a cubic Si, GaAs crystal substrate and a cubic GaN semiconductor thin film, a β-SiC crystal substrate, which is difficult to manufacture as described above, There is no other than.

Due to the above-mentioned problems, at present, the development of semiconductor light-emitting devices such as light-emitting diodes and laser diodes has not been advanced to the point where the doping characteristics of GaN having a zinc blende type crystal structure are described. .

Accordingly, an object of the present invention is to provide a high quality semiconductor thin film having few lattice defects, easy n-type and p-type impurity doping, and suitable for manufacturing a semiconductor light emitting device such as a light emitting diode or a laser diode. It is to provide a laminated semiconductor.

[0011]

According to a first aspect of the present invention, there is provided a multi- layer semiconductor comprising a substrate, a nitride αN (α
Is any one of Al, Ga, In, or
A mixture of at least two of Al, Ga, and In)
Group III-V semiconductor thin film having a zinc blende type crystal structure
Buffer the crystal thin film with rutile crystal structure between
It is characterized by being formed as a layer.

Further , as a crystal thin film , metal oxide MO ₂
(M is any one of Ti, V, Mn, Ru, Sn, Os, Pb, or Ti, V, Mn, Ru, S
It is desirable to use a mixture of at least two of n, Os, and Pb).

Further, as the crystal thin film , a metal fluoride M
F ₂ (M is Mg, V, Mn, Fe, Co, Ni, Zn
One of Mg , V, Mn, Fe,
It is desirable to use a mixture of at least two of Co, Ni, and Zn).

[0014]

According to the present invention, Si or GaAs is used as the substrate.
Even when s is used, the zinc blende composed of the nitride αN is formed by a crystal thin film having a rutile type crystal structure as a buffer layer having a lattice mismatch ratio with the nitride αN smaller than that of the Si or GaAs crystal substrate. III-V of type crystal structure
The lattice defect of the group III semiconductor thin film is reduced as compared with the conventional example.

Therefore, according to the first aspect of the present invention, the quality of the above-mentioned semiconductor thin film having a zinc blende type crystal structure in which n-type and p-type impurity doping is easy is improved, and a high-quality light emitting diode or laser diode is obtained. Thus, a laminated semiconductor suitable for manufacturing a semiconductor light-emitting element such as described above is realized.

The zinc blende type crystal has a cubic system, whereas the rutile type crystal has a tetragonal system. A cubic crystal has the same length of the crystal axis a, b, and c as defined by the crystal itself, whereas a tetragonal crystal has the length of the crystal axis a. And the length of the crystal axis b are equal, but the length of the crystal axis c is not equal to the length of the crystal axis a and the crystal axis b. However, in the crystal plane (001) perpendicular to the crystal axis c, both the cubic crystal and the tetragonal crystal form a square lattice with the crystal axis a = the crystal axis b. Therefore,
Crystal growth of a group III-V semiconductor thin film having the zincblende crystal structure on a crystal plane (001) of a crystal thin film having a tetragonal rutile-type crystal structure in a direction perpendicular to the plane (001). Thus, the difference in crystal structure between the rutile-type crystal thin film and the zinc-blende-type III-V semiconductor thin film can have no adverse effect on the laminated structure between them.

According to the first aspect of the present invention, as the crystal thin film having a rutile type crystal structure, metal oxide MO ₂ (M is Ti, V, Mn, Ru, Sn, O
any one of s, Pb, or Ti, V, M
a mixture of at least two of n, Ru, Sn, Os, and Pb) and a metal fluoride MF ₂ (M is Mg, V, Mn,
In the case of using any one of Fe, Co, Ni, and Zn, or a mixture of at least two of Mg, V, Mn, Fe, Co, Ni, and Zn), The lattice mismatch rate with the nitride αN becomes particularly small, and the zinc-blende-type crystal structure of the nitride αN II
Lattice defects of the IV group semiconductor thin film are particularly reduced as compared with the conventional example. Therefore, the quality of the semiconductor thin film having a zinc blende crystal structure in which n-type and p-type impurity doping is easy is particularly improved, and a laminated semiconductor particularly suitable for manufacturing a high-quality semiconductor light-emitting device such as a light-emitting diode or a laser diode. Is realized.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 shows a rutile-type crystal structure as a reference example .
An example in which a crystal substrate is used is shown. In this embodiment, a group III-V semiconductor thin film 2 of zinc blende type crystal structure made of nitride CaN is laminated on a crystal plane (001) of a TiO ₂ crystal substrate 1 having a rutile type crystal structure. is there. As a method for stacking the GaN, a metal organic vapor phase epitaxy (MOVPE) using trimethylgallium (CH ₃ ) ₃ Ga as a gallium source and ammonia NH ₃ as a nitrogen source was used. As shown in the following Table 2, TiO ₂ and G on the crystal plane (001)
The lattice mismatch rate Δa with aN was about 2%, and a good laminated semiconductor with very few lattice defects was obtained as compared with the conventional example.

[0019]

[Table 2]

In other words, according to this embodiment, the zinc-blende-type crystal structure having an easy n-type and p-type impurity doping is provided.
The quality of the II-V semiconductor thin film 2 can be greatly improved as compared with the conventional example, and a stacked semiconductor suitable for manufacturing a high performance semiconductor light emitting device such as a light emitting diode or a laser diode can be realized.

X-ray diffraction analysis of the above laminated semiconductor revealed that a sharp diffraction peak of the GaN crystal plane (002) was observed, confirming the growth of zinc blende-type GaN single crystal. The lattice constant of GaN calculated from the diffraction angle of the X-ray diffraction was 4.49 °, which was consistent with the conventionally reported value.

The electrical properties of the GaN semiconductor thin film 2 of the above embodiment are high resistance when non-doped,
The carrier concentration is 10 ¹⁶ to 10 respectively by Se doping.
P-type semiconductors and N-type semiconductors with low resistance can be realized in the range of ¹⁹ cm ^-3 . Then, the TiO ₂ crystal substrate 1, since an n-type conductivity by dissociation of oxygen by laminating an n-type GaN semiconductor thin film, a p-type GaN semiconductor thin film in this order on TiO ₂ crystal substrate 1, high-performance It is possible to manufacture an ultra-violet LED.

FIG. 4 shows this specific embodiment. In the present embodiment, a group III-V semiconductor thin film having a zinc blende type crystal structure made of nitride GaN is provided on a crystal plane (001) of a TiO ₂ crystal substrate 1 having a rutile type crystal structure, and an n-type GaN semiconductor thin film. 31 and a p-type GaN semiconductor thin film 32 are laminated in this order to form a light emitting layer. As the doping material, selenium Se is used for the n-type and zinc Zn is used for the p-type. Further, the carrier concentration of each of the n-type GaN semiconductor thin film 31 and the p-type GaN semiconductor thin film 32 is 1 × 10 ¹⁸ cm ^{− Three}
It was adjusted to become.

Since the TiO ₂ crystal substrate 1 exhibits n-type conductivity due to dissociation of oxygen, the n-type ohmic electrode 33 and the p-type GaN semiconductor thin film 32 are provided on the TiO ₂ substrate 1 side.
By forming the p-type ohmic electrode 34 on the side, current injection becomes possible. The injected electrons and holes recombine at the pn junction existing at the interface between the n-type GaN semiconductor thin film 31 and the p-type GaN semiconductor thin film 32 to emit light. As shown in Table 1, the bandgap of GaN having a zinc blende type crystal structure is 3.45 eV.
It was confirmed to function as a light emitting diode that emits 0 nm ultraviolet light. The above is a reference example.

FIG. 2 shows a first embodiment of the present invention. In this embodiment, the crystal plane (00
1) A ZnF ₂ crystal thin film 12 having a rutile crystal structure is laminated thereon as a buffer layer, and a nitride Ga _{1-x of} a mixture of Ga and In is formed on the crystal plane (001) of the ZnF ₂ crystal thin film 12. It is obtained by laminating group III-V semiconductor thin films 13 having a zinc blende type crystal structure made of In _x N (x = 0.4). As a method of laminating the ZnF ₂ crystal thin film 12,
Using a molecular beam epitaxy method (MBE) using a ZnF ₂ solid source, the Ga _1-x In _x N thin film 13 is laminated using a solid source of Ga and In and a nitrogen gas source which is plasma-decomposed. Molecular beam epitaxy (MBE) was used.

In the ZnF ₂ crystal thin film 12 having the rutile type crystal structure, the lattice constant a = 4.49 ° of GaN and the lattice constant a of InN = 5.01 ° of the zinc blende type crystal structure shown in Table 1.
Has an intermediate lattice constant a = 4.7034 ° (see Table 2). Therefore, the In _{1 of the} Ga _1-x In _x N thin film 13
By setting the mixed crystal ratio x to 0.4, the above Ga _1-x I
The n _x N thin film 13 can be lattice matched to the ZnF ₂ crystal thin film 12, it is possible to lattice mismatch ratio to about 0%. Therefore, lattice defects of the Ga _1-x In _x N thin film 13 can be substantially eliminated.

Therefore, according to this embodiment, despite the use of the same Si semiconductor substrate 11 as the conventional example,
The quality of the Ga _1-x In _x N thin film 13 having a zinc-blende-type crystal structure in which n-type and p-type impurity doping is easy can be greatly improved as compared with the conventional example, and high-performance light-emitting diodes and laser diodes can be used. A stacked semiconductor suitable for manufacturing a semiconductor light emitting element can be realized.

Since the Ga _1-x In _x N thin film 13 is a mixed crystal of GaN and InN, the energy gap is smaller than that of GaN for ultraviolet light emission. Therefore, by using the above embodiment, a visible light emitting element can be manufactured. The above Si
In place of the ZnF ₂ crystal thin film 12 on the semiconductor substrate 11, if stacking a large buffer layer lattice constant than the ZnF ₂ crystal thin film 12, without increasing the lattice mismatch ratio, the Ga _1-x Since the In mixed crystal ratio of the In _x N thin film 13 can be made larger than 0.4, the light emission of the light emitting element can be made longer wavelength.

A specific example of the semiconductor light emitting device using the group III-V semiconductor thin film of the above embodiment as a light emitting layer will be described with reference to FIG. In the present embodiment, the crystal plane (00
1) A ZnF ₂ crystal thin film 12 having a rutile-type crystal structure is stacked thereon as a buffer layer, and a nitride Ga _{1-x of} a mixture of Ga and In is formed on a crystal plane (001) of the ZnF ₂ crystal thin film 12. A group III-V semiconductor thin film having a zinc blende type crystal structure made of In _x N (x = 0.4) was converted into n-type Ga _1-x In _x
N semiconductor thin film 41, p-type Ga _1-x In _x N semiconductor thin film 42
And the n-type Ga _1-x In _x N semiconductor thin film 41
An n-type ohmic electrode 43 is formed, and a p-type ohmic electrode 44 is formed on the p-type Ga _1-x In _x N semiconductor thin film. As a doping material, n-type S
Be was used for the i and p types.

The two Ga _1-x In _x N semiconductor thin films 41, 4
2, both GaN semiconductor thin films 3 of the embodiment shown in FIG.
Since the same electrical properties as those of the first and second ohmic electrodes 43 and 44 were obtained, current injection from both the ohmic electrodes 43 and 44 was possible. Since the Ga _1-x In _x N semiconductor thin films 41 and 42 are a mixed crystal of GaN and InN, the energy gap is lower than that of GaN for ultraviolet light emission, and a visible light emitting device can be manufactured. The pn junction existing at the interface between the two Ga _1-x In _x N (x = 0.4) semiconductor thin films 41 and 42 is 4
Blue light emission of 40 nm was observed, and it was confirmed to function as a light emitting diode.

Further, instead of the ZnF ₂ crystal thin film 12 on the Si semiconductor substrate 11, the ZnF ₂ crystal thin film 12
If a buffer layer having a larger lattice constant is stacked, the emission wavelength of the light emitting element can be made longer, and light can be emitted in the entire visible region from blue to red, as in the above embodiment . For example, green light emission of 550 nm is obtained at x = 0.8, and red light emission of 650 nm is obtained at x = 1.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the crystal plane (00
1) A Sn _1-z Mn _z O ₂ (z = 0.1) crystal thin film 22 as a buffer layer having a rutile type crystal structure is laminated thereon, and the Sn _1-z Mn _z O ₂ (z = 0) .1) Crystal thin film 22
On the crystal plane (001) of Al _1-y In _y N (y = 0.
5), Ga _1-x In _x N (x = 0.4), Al _1-y In _y N
(Y = 0.5) Zinc-blende-type crystal structure II
It is obtained by sequentially stacking IV group semiconductor thin films 23, 24, and 25. Each of the thin films 22, 23, 24, and 25 is laminated by a molecular beam epitaxy method, and a Sn and Mn solid source is used for crystal growth of the Sn _1-z Mn _1-z O ₂ crystal thin film 22 in this lamination. And a gas source of oxygen. In addition, as growth materials for the above Al _1-y In _y N (y = 0.5), trimethyl aluminum (CH ₃ ) ₃ Al, triethyl indium (CH ₃ CH ₂ ) ₃ In, and NN dimethyl hydrazine (CH ₃ ) with _{2 N 2 H 2, Ga 1} -x In x N (x
= 0.4) as the growth raw materials are trimethylgallium (CH ₃ ) ₃ Ga and trimethylindium (CH ₃ CH ₂ ).
₃ In and NN dimethylhydrazine (CH ₃ ) ₂ N ₂ H ₂ were used.

In the above embodiment, the above Al _1-y In _y N
(Y = 0.5), the lattice mismatch with the thin film 23 is S
Sn _1-z Mn _z O having a rutile-type crystal structure as a buffer layer much smaller than i or GaAs crystal substrates
₂ (z = 0.1) The crystalline thin film 22 is
1, the same Ga substrate as the conventional semiconductor substrate is used.
Despite the use of the As semiconductor substrate 21, the above Al
Lattice defects in the group III-V semiconductor thin film 23 having a zinc blende type crystal structure made of _1-y In _y N (y = 0.5) can be almost eliminated.

The thin films 23, 24 and 25 are group III-V semiconductor thin films having the same zinc blende type crystal structure, and have no lattice mismatch.
5 naturally has almost no lattice defects.

In other words, according to this embodiment, even if the same GaAs semiconductor substrate as the conventional one is used as the semiconductor substrate, the zinc-blende group III-V semiconductor thin film 23 with which n-type and p-type impurity doping is easy. , 24, and 25 can be realized, and a high-performance stacked semiconductor suitable for manufacturing a semiconductor light emitting device such as a light emitting diode or a laser diode can be realized.

In this embodiment, AlInN / GaI
Since it has an nN / AlInN double hetero structure,
By performing appropriate doping, a laser diode capable of emitting visible light laser by current injection can be realized.

A specific example of the semiconductor light emitting device using the group III-V semiconductor thin film of the above embodiment as a light emitting layer will be described with reference to FIG. In this embodiment, a Sn ₁ -z _Mnz O ₂ (z = 0.1) crystal thin film 2 as a buffer layer having a rutile crystal structure is formed on a crystal plane (001) of an n-type GaAs semiconductor substrate 51.
The n-type Al _1-y In _y (y =
0.5) 52, non _- doped Ga _1-x In _x N (x = 0.
4) A group III-V semiconductor thin film 52, 53, 54 having a zinc-blende-type crystal structure composed of 53 and p-type Al _1-y In _y N (y = 0.5) 54 is sequentially laminated. further,
An n-type ohmic electrode 55 is provided on the n-type GaAs semiconductor substrate 51 side, and Si is provided on the p-type Al _1-y In _y N semiconductor thin film 54 side.
A p-type ohmic electrode 57 via an insulating film 56 made of N or the like
Are formed. The insulating film 56 has a stripe 58 for current injection. As doping materials, Si was used for the N-type and Be was used for the P-type. In this embodiment, Al _1-y In _y N / Ga _1-x In _x N / A
It has an l _1-y In _y N double hetero structure, and laser oscillation becomes possible if current is injected from the n-type ohmic electrode 55 and the p-type ohmic electrode 57. In this case, blue laser light of 440 nm is obtained as in the embodiment shown in FIG.
It can be used as a structure of a light emitting diode with higher efficiency.

Further, non _- doped Ga _1-x I
The use of a buffer layer having n _x N suitable rutile crystal structure can be increased In composition ratio x of the semiconductor thin film 53,
The oscillation wavelength can be made longer.

In the first and second embodiments of the present invention, a Si semiconductor substrate and a GaAs semiconductor substrate are used as semiconductor substrates, but a rutile type crystal substrate (for example, SnO 2) is used as the semiconductor substrate. _A rutile-type crystal thin film (for example, a RuO ₂ thin film) as a buffer layer on the rutile-type crystal substrate, and a zinc-blende type using nitrogen N as a group V element on the rutile-type crystal thin film. A group III-V semiconductor thin film having a crystal structure (for example, a GaN thin film) may be laminated. If a pn junction is formed in this GaN thin film and light emission is performed by current injection, it can be used as an ultraviolet light emitting diode as in the embodiment shown in FIG.

It is needless to say that employing a multilayer structure of a rutile crystal and a compositionally graded structure of a rutile crystal as the buffer layer is effective for manufacturing a high-performance semiconductor light emitting device.

An AlN / MnO ₂ / PbO ₂ / Si substrate is an example of the structure of the laminated semiconductor according to the second aspect of the present invention in which a multilayer structure of a rutile crystal is employed as the buffer layer. In this case, since the light emitting layer is made of AlN, 200 nm
UV light is obtained.

Further, as a structural example of the laminated semiconductor according to the second aspect of the present invention, wherein the composition gradient type structure of the rutile crystal is adopted as the buffer layer, Ga _{1 -x} In _x N (x = 0.25) / Mn _{1 -w} M
g _w F ₂ (w = 0 → 1) / GaP substrate. In this case, 400 nm ultraviolet light is obtained.

[0043]

As is clear from the above description, the laminated semiconductor according to the first aspect of the present invention comprises a substrate, a nitride αN
(Α is any one of Al, Ga, In, if
Or a mixture of at least two of Al, Ga, and In
Group III-V semiconductor having a zinc blende type crystal structure
A crystal thin film having a rutile crystal structure is
It is formed as a buffer layer. Therefore, the claim
According to the invention described in Item 1, the substrate is the same as the conventional substrate.
Even when Si or GaAs is used, the nitride αN
Lattice mismatch is smaller than that of Si and GaAs crystal substrates.
Crystal with rutile-type crystal structure as a thin buffer layer
Depending on the film, the zinc-blende type crystal structure composed of the nitride αN
Lattice defects of III-V semiconductor thin films
Can be reduced. Therefore, the invention of claim 1
According to the description, even if the same substrate as the conventional example is used, n-type and p-type
The above half of zinc blende type crystal structure which is easy to dope impurities
The quality of the conductor thin film can be improved compared to the
A laminated semiconductor suitable for manufacturing a conductor light emitting element can be realized.

[0044] Further, in the invention described in the claim 1, as a crystalline thin film having a rutile crystal structure, the metal oxide MO ₂ (M is, Ti, V, Mn, Ru , Sn, O
any one of s, Pb, or Ti, V, M
n, Ru, Sn, Os, Pb) or metal fluoride MF ₂ (M is Mg, V, Mn, F
e, one of Co, Ni, Zn, or M
g, V, Mn, a mixture of at least two of Fe, Co, Ni, and Zn), the crystal thin film having the rutile-type crystal structure has a lattice mismatch with the nitride αN. Particularly, the lattice defects of the group III-V semiconductor thin film having a zinc blende type crystal structure composed of the nitride αN can be particularly reduced as compared with the conventional example. Therefore, the quality of the semiconductor thin film having a zinc blende type crystal structure that can be easily doped with n-type and p-type impurities can be particularly improved, and a laminated semiconductor particularly suitable for manufacturing a high-quality semiconductor light emitting device such as a light emitting diode or a laser diode. Can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a laminated structure according to an embodiment of the present invention. (Reference diagram)

FIG. 2 is a schematic view showing a laminated structure according to a first embodiment of the present invention.

FIG. 3 is a schematic view showing a laminated structure according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram showing an example in which the semiconductor thin film shown in FIG. 1 is used as a light emitting layer.

FIG. 5 is a schematic view showing an example in which the semiconductor thin film shown in FIG. 2 is used as a light emitting layer.

FIG. 6 is a schematic diagram showing an example in which the semiconductor thin film shown in FIG. 3 is used as a light emitting layer.

FIG. 7 is a diagram showing a lattice constant and a forbidden band width of a zinc blende type nitride mixed crystal.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor ▲ Yoshi ▼ Tomohiko Tadashi 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside (72) Inventor Naohiro Suyama 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Toshio Hata 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Prefecture Inside Sharp Corporation (72) Inventor Ken Takeshi 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Sharp Corporation (56 References JP-A-5-283744 (JP, A) JP-A-3-211888 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 33/00 JICST file (JOIS)

Claims (3)

(57) [Claims] A substrate and a nitride αN (α is Al, G
a, In, one of Al, Ga,
Zinc blend comprising at least two of In)
Between the III-V semiconductor thin film having an ore-type crystal structure;
Of a crystal thin film with a crystal structure as a buffer layer
A laminated semiconductor characterized by the following. 2. The method according to claim 1, wherein the crystalline thin film is a metal oxide MO _2.
(M is Ti, V, Mn, Ru, Sn, Os, Pb
Any one of Ti, V, Mn, Ru, S
a mixture of at least two of n, Os and Pb)
The stacked semiconductor according to claim 1, wherein 3. The method according to claim 1, wherein the crystal thin film is a metal fluoride MF _2.
(M is Mg, V, Mn, Fe, Co, Ni, Zn
Any one of the following, or Mg, V, Mn, Fe, C
o, Ni, and Zn).
The stacked semiconductor according to claim 1, wherein