JPH06104498A - Superconducting element and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a superconducting element whose performance is stable and reproducible by adopting a superconductor-made A electrode and B electrode whose main component comprises at least copper or alkaline earth-made oxide superconductor and making the components of a junction part identical to that of the above insulator. CONSTITUTION:This invention covers a superconductor element which comprises a superconductor-made A electrode 2 installed on a buffer layer 1 in a substrate 7 and a superconductor-made B electrode 3 which faces the A electrode 2 by way of a junction part 4 in a partial area and a contact electrode 6 formed in partial contact with the B electrode 3 and an electrode separation layer 5 which separates the contact electrode 6 from the A electrode 2. The main component of the buffer layer 1 and the junction part 4 is an oxide insulator thin film which includes at least one element, such as calcium(Ca), strontium(Sr), barium(Ba) and the main components of the A electrode 2 and the B electrode 3 consist of at least copper (Cu) and alkaline earth (11a group).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting element of superconducting application technology and a manufacturing method thereof.

[0002]

2. Description of the Related Art Bi-Sr-Ca-Cu-O-based materials discovered in recent years have superconducting transition temperatures of 100 K or more [H.Maeda, Y. Tanaka, M. Fukutomi and T. Asano, Japanese Journal of Applied Physics Vol.27, L209
-210 (1988)], the field of application of superconductors was greatly expanded.

Regarding the superconducting device which is one of the practical applications, the oxide superconductor is divided into two parts, and they are slightly contacted again to make the Josephson device and the oxide superconductor into a thin film.
Bridge-type Josephson devices with small constrictions have been prototyped.

[0004]

Among the elements that have been experimentally manufactured in the past, reproducibility was not obtained and characteristics were unstable in the type called point contact type in which oxide superconductors were in contact with each other. . Further, the bridge-type element having a constriction in the oxide superconductor has a problem of being damaged by a slight electrostatic shock.

Therefore, a superconducting element having a laminated junction type structure using an oxide superconductor is desired. However, it is difficult to manufacture a junction in which a very thin non-superconducting layer is uniformly present on one surface, and it is difficult to realize it. It is considered to be rare and difficult to manufacture with good reproducibility. Furthermore, since the oxide superconductor is formed at a relatively high temperature, the non-superconducting layer at the joint and the superconducting electrode layer lose their joint due to mutual thermal diffusion, and pinholes are formed in the non-superconducting layer. There was a problem.

Also, due to the lattice mismatch due to the difference in crystal structure between the material used for the superconducting electrode layer and the material for the non-superconducting layer, the crystallinity of the superconducting electrode located above deteriorates and It has been pointed out that there are problems such as deterioration of conductivity. Furthermore, it has been found that the surface / interface states of the superconducting electrode layer and the non-superconducting layer have a great influence on the state of the substrate surface, in addition to the difference in the crystal structure of the above materials. That is, the surface of the thin film deposited on the base body is also formed to have the surface roughness reflecting the surface roughness of the base body. Film thickness 1000nm
It was difficult to grow a non-superconducting layer having a film thickness of several tens of nm or less flatly and two-dimensionally because the thin film of (1) was affected by the surface of the substrate.

In order to solve the above-mentioned problems of the prior art, it is an object of the present invention to provide a superconducting device in which a stable and uniform non-superconducting layer can be obtained with good reproducibility, and a method for manufacturing the same. To do.

[0008]

In order to achieve the above object, the superconducting element of the present invention comprises, on a substrate, at least one of calcium (Ca), strontium (Sr) and barium (Ba) as main components. An oxide insulator thin film containing an element is deposited, an A electrode made of a superconductor on the insulator thin film, and a B electrode made of a superconductor in contact with the A electrode in a partial region via a junction, A superconducting device comprising a contact electrode formed in contact with a part of the B electrode, and an electrode separation layer separating the contact electrode and the A electrode, wherein the A electrode made of a superconductor and the B
The main component of the electrode is at least copper (Cu), alkaline earth (II
It is an oxide superconductor made of a group a), wherein the main component of the junction is substantially the same as the main component of the insulator. (However, alkaline earth refers to at least one element of the IIa group elements.) Next, in the method for producing a superconducting device of the present invention, at least calcium (Ca), strontium as a main component is formed on the substrate.
(Sr), an oxide insulator thin film containing one or more elements of barium (Ba) is deposited, and an A electrode made of a superconductor is formed on the insulator thin film, and a part is formed through a junction with the A electrode. A superconducting device including a B electrode made of a superconductor in contact with a region, a contact electrode formed in contact with a part of the B electrode, and an electrode separation layer separating the contact electrode and the A electrode. In the manufacturing method of
The electrode is characterized in that it is formed by periodically stacking an oxide containing Bi and an oxide containing copper and an alkaline earth (group IIa). (However, alkaline earth refers to at least one element of the IIa group elements.) In the above-mentioned manufacturing method, the temperature of the substrate is from 300 ° C to 7 ° C.
It is preferably set to 00 ° C.

In the above manufacturing method, it is preferable that the evaporation is performed by sputtering. Further, in the above-mentioned manufacturing method, it is preferable that the layer material is evaporated by at least two kinds of evaporation sources.

[0010]

According to the structure of the present invention, the main components of the A and B electrodes made of a superconductor are at least copper (
Cu), an alkaline earth (group IIa) oxide superconductor, and by making the main component of the junction substantially the same as the main component of the insulator, a stable and uniform non-superconductor Layers are obtained with good reproducibility. That is, Ca _1-xy Sr _x B
a _y O is an insulator having a lattice constant close to that of the a- and b-axes of an oxide superconductor and having a crystal structure of NaCl type simple cubic lattice structure, and has a high melting point of about 2000 ° C. and its crystal The lattice constant can be changed continuously by changing x and y. Further, this kind of material is liable to undergo a solid phase reaction, and when deposited on the substrate, it grows so as to fill the irregularities of the substrate and provides an extremely flat surface, so that Ca _1-xy Sr _x Ba _y formed on the substrate is formed. An oxide superconducting thin film with excellent surface flatness and few crystal grain boundaries on the O insulator thin film can easily obtain an epitaxial interface, and as a result, it is thermally stable and does not have a mutual diffusion of constituent elements. An interface between the conductive layer and the non-superconducting layer can be formed, and a superconducting element exhibiting excellent current-voltage characteristics can be formed.

Further, according to the structure of the manufacturing method of the present invention,
A Ca _1-xy Sr _x Bay _y O insulator thin film is formed on a substrate, and an oxide containing at least Bi, an oxide containing at least copper and alkaline earth (group IIa), and Ca are formed on the insulator.
_By periodically laminating a _1-xy Sr _x Bay _y O thin film and producing a thin film by controlling the molecular level,
The Bi-based superconducting thin film layer and the Ca1-x-ySrxBayO insulating thin film layer can be laminated with good reproducibility, and a high-quality superconducting device can be obtained.

[0012]

EXAMPLES The present invention will be described in more detail with reference to the following examples. Usually, the oxide superconducting thin film is obtained by vapor deposition on a substrate heated to 400 to 700 ° C. After vapor deposition, the thin film shows superconducting properties as it is, but it is then heat-treated at 700-950 ℃ to improve the superconducting properties.

However, normally, an oxide superconducting thin film having a film thickness of 100 nm or less has a superconducting transition temperature almost equal to that of the bulk fired body, but the zero resistance temperature is lower than that of the bulk fired body. For example, the Bi-Sr-Ca-Cu-O-based superconductor has a zero resistance temperature of about 105 K in the bulk fired body, whereas it has a maximum resistance of 80 K in a thin film having a thickness of several 10 nm. It was found that when an oxide superconducting thin film was formed on a substrate, the element of the substrate diffused into the thin film at the interface between the substrate and the thin film, destroying the crystal structure of the thin film. Bi-Sr-Ca-C
La Ga O ₃ (a = 0.5482 nm, which is considered to be relatively close to the a-axis (or b-axis) length of u-O superconductor crystal,
b = 0.5526 nm, a = 0.54 n in Bi-Sr-Ca-Cu-O system
When m) is selected as the substrate, Ga is Bi-Sr-C at the interface.
It diffused into the a-Cu-O thin film and the distance was about 50 nm. According to the experiment, the film thickness of Bi-Sr-Ca-Cu-O thin film is about 100 nm.
In the following thin films, the superconducting transition temperature was uniformly lower than that of the bulk fired body. Such a phenomenon occurs even if any substrate is selected. Generally, the method for forming an oxide superconducting thin film is as follows.
It is roughly divided into two. That is, (1) heating the thin film to 400 ℃
Deposit on the following substrates (in amorphous state), then heat-treat in an atmosphere above the crystallization temperature, (2) deposit a thin film on the substrate at the crystallization temperature, (3) heat above the crystallization temperature A thin film is deposited on the formed substrate, and heat treatment is performed later.

However, in the above methods (1) and (3),
The thin film was heated to the crystallization temperature (500 ° C) or higher
Therefore, a thin film with many crystal grain boundaries reflecting the irregularities of the substrate is formed.
Or (2) and (3), the substrate temperature during thin film deposition
Mutual diffusion of elements occurs between the substrate and thin film due to its high
However, it became clear in the examination experiment. Such problems are oxidation
It can be avoided by lowering the crystallization temperature of the superconducting thin film
Can, N₂O, NO ₂Base on ozone, oxygen radicals
Crystallization temperature by forming a thin film while spraying on
Even if the temperature is lowered, the unevenness of the substrate and the high energy of vapor deposition particles
Oxide superconducting thin film with a film thickness of 10 nm and excellent crystallinity
No membrane could be obtained. So oxide on the substrate
If the superconducting thin film is used as a base and the oxide superconducting thin film
In order to achieve epitaxial growth without mutual diffusion,
Epitaxial growth on the body
Insulating film of buffer where conductive thin film grows epitaxially
The present invention has been accomplished by conducting a search and examination.

First, CaO, SrO, and BaO materials have a high melting point and are stable. For (Ca, Sr, Ba) -O, the crystal lattice constant is changed by changing the ratio of Ca, Sr, and Ba. Focusing on the ability to change
The superconducting transition temperature was higher than the liquid nitrogen temperature, and it was studied as an insulating film on a substrate for a Bi-Sr-Ca-Cu-O superconducting thin film, which is promising for practical use as a superconducting device.

FIG. 1 shows a schematic diagram of the structure of a (Ca, Sr, Ba) 0 crystal. The crystal has a simple cubic lattice and a NaCl structure, a = 0.514 nm in the case of SrO, a melting point of 2460 ° C, and a thermal expansion coefficient of 11 x 10 ^-6 / ° C. Mainly, the lattice constant is Sr ²⁺
Can be changed by partially substituting Ca ²⁺ or Ba ²⁺ . CaO, SrO, and BaO are used alone, or the solid solution is heated by electron beam to evaporate Mg.
It was deposited on an O substrate, and its crystallinity was analyzed and examined by an X-ray diffraction method and an electron diffraction method. As a result, this kind of material
It was found to crystallize at a forming temperature of 600-800 ° C.
In addition, a of a high temperature oxide superconductor crystal such as Bi system
Since the axial length and the b-axis length are approximately 0.54 nm, when considering this kind of material as an insulating film, the a-axis length is 0.514 nm.
nm, Sr O of 0.5542Nm, Combine Ba O solid-phase reaction, the thought that the formation of the optimum insulating film to the oxide superconductor thin film can be achieved, crystals by x of Sr _1-x Ba _x O As a result of an experimental examination of the change in structure, it was found that Sr _1-x Ba _x O continuously changes in the a-axis length of 0.514 to 0.554 nm for x = 0 to 1. In addition, when this insulating material is formed as a buffer layer on a substrate and a superconducting thin film is further formed on it, the surface flatness of the superconducting thin film is extremely superior to the case where no buffer layer is formed. It turns out that there are few.

A more specific embodiment will be described below. In the previous experiment, the (Ca, Sr, Ba) O thin film was formed by the electron beam evaporation method, but the ion beam sputtering method was used to form the Bi-based superconducting thin film.

First, in order to realize a laminated structure of the Bi type superconducting thin film used as the A electrode and the B electrode and the junction, the interaction between the Bi type superconducting thin film and various insulating films was examined.

Usually, the Bi type superconducting thin film is obtained by vapor deposition on a substrate heated to 600 to 700 ° C. After vapor deposition, the thin film shows superconducting properties as it is, but it is then heat-treated at 850-950 ℃ to improve the superconducting properties.

However, when an insulator film is successively laminated on the Bi-based superconducting thin film when the substrate temperature is high, or when heat treatment is performed after the insulator film is formed, a heat treatment is performed between the superconducting film and the insulator film. It was found that mutual diffusion of elements occurred and the superconducting properties were significantly deteriorated. In order to prevent mutual diffusion, the crystallinity of the superconducting film and the insulating film is excellent, the lattice matching between the superconducting film and the insulating film is excellent, and the insulating film is 850 It is considered essential to be stable to heat treatment at ~ 950 ° C.

As a result of conducting various studies,
Tomo Calcium (Ca), Strontium (Sr), Baliu
The oxide insulator thin film containing one or more elements of Ba
It has been found that it is suitable as a limbal membrane. With this reason
And Ca_1-xySr_xBa _yO has a lattice constant higher than that of oxide
Near the a-axis and b-axis of the conductor, the Bi-based superconducting thin film
Has good lattice matching of crystals, NaCl type simple cubic
An insulator with a lattice-structured crystal structure and a melting point of 2000
It is thought to be as high as ℃ and extremely stable thermally.
Be done.

Example 1 FIG. 2 is a sectional view of a superconducting device which is an example of the present invention.
You Further, FIG. 3 is a process showing a method of manufacturing the superconducting device.
It is a diagram. In FIG. 3a, first, a MgO substrate is used as a substrate.
Used for No. 7, by rf magnetron sputtering method
10 nm thick Sr_0.3Ba_0.7O thin film buffer layer
1 is deposited, and then Bi having a thickness of 300 nm is deposited. ₂Sr₂Ca
Cu₂O₈Rf magnetron sputtering with A electrode 2
It was produced by the method. This film is a c-axis oriented thin film and has a superconducting transition temperature.
The degree was 80K. After the A electrode 2 is formed, contact is continued.
Sr as joint part 4_0.3Ba_0.7O thin film by rf magnetro
50 nm is deposited by the sputtering method, and the B electrode 3
As in the case of the A electrode 2, Bi ₂Sr₂CaCu₂O₈film
To 300 nm by rf magnetron sputtering
It was deposited (Fig. 3b). Production of A electrode 2 and B electrode 3
The production atmosphere is a 1: 1 mixed gas atmosphere of oxygen and argon.
And Bi_2.5Sr₂CaCu_2.5O_{8 + x}Target
Then, sputtering was performed and the substrate was manufactured at a temperature of 650 ° C. Ba
The substrate temperature during the deposition of the buffer 1 and the bonding portion 4 is 650.
Sr: Ba = 3: 7 Sr-Ba-O as a target at ℃
A fired body was used. The junction 4 and the B electrode 3 are c-axis oriented
As a thin film, the B electrode 3 had a superconducting transition temperature of 80K.
After that, photolithography using a negative resist
And shape of superconducting element by ion milling
(FIG. 3c), the negative resist is removed, and the interelectrode separation layer 5 is formed.
As 1 micron CaF₂By vacuum evaporation
After loading, spin-on glass 9 is spin-coated to make the surface flat
(Fig. 3d). Further until the A electrode surface appears,
The surface was scraped by milling (Fig. 3e). Finally,
O₂B electrode surface exposed by exposure to gas plasma
After recovering the damage caused by the
A 500 nm Pt film 6 as a contact electrode
rf magnetron sputtering method for superconducting
The conducting element was completed (Fig. 3f). Figure 4 shows this superconducting device.
Shows the current-voltage characteristics at 50K. 150 micron
A pair of superconducting tunnel currents flow, and hysteresis
It operated as a superconducting tunnel element. This thing
, A high resistance non-superconducting material at the junction of the two superconducting electrodes.
A conducting layer is formed, and the tunnel current in that layer was observed.
It was confirmed. That is, according to the present invention, it is stable and uniform.
Easy stacking type
It was. This can be considered as follows. sand
That is, the buffer layer 1 of the Sr-Ba-O thin film is formed on the surface of the substrate 7.
Epitaxial growth to fill irregularities, surface flatness
Since the excellent A electrode 2 was produced,
Pole 3 also has crystallinity and stable surface and interface.
It is considered to be one.

Further, the Bi-Sr-Ca-Cu-O superconductor is B
Focusing on the fact that the i ₂ O ₂ oxide layer has a layered structure in which a structure made of Sr—Ca—Cu—O is sandwiched, the invention of the method for manufacturing a superconducting element has been achieved.

That is, for the A electrode and the B electrode, the oxide of Bi and the oxides of Sr, Ca, and Cu are separately evaporated in vacuum from different evaporation sources, and then the Sr-Ba-O buffer layer or Sr-Ba is evaporated. Bi-O → Sr-Cu-O → Ca- on the -O junction
When the layers are periodically laminated in the order of Cu-O->Sr-Cu-O-> Bi-O, the controllability is far better than that of the manufacturing method shown in (Example 1), the film quality is stable, and the film surface is Extremely flat B
It was found that the i-Sr-Ca-Cu-O thin film and the Sr-Ba-O junction can be effectively laminated.

By sequentially laminating the different elements constituting the layered structure separately, the vapor deposition elements that are laminated only within the plane parallel to the substrate surface, the buffer layer, or the bonding layer move. It is considered that this is because there is no movement of elements in the direction perpendicular to the substrate surface. Furthermore, the length of the a-axis of Sr-Ba-O crystals is Bi-Sr-Ca-
Almost the same as that of Cu-O, and the unevenness of the substrate surface is Sr-Ba-
It is relaxed and flattened in the O buffer layer, followed by Bi-
Sr-Ca-Cu-O layer, Sr-Ba-O junction layer, Bi-Sr-Ca-
It is considered that all of the Cu-O layers can be epitaxially grown two-dimensionally continuously.

In addition to the above, it was found that the temperature of the substrate and the heat treatment temperature required for obtaining good superconducting properties are lower than those of the conventional ones. Bi-O, Sr-Cu-O, Ca-Cu-O, Sr-
There are several possible methods for stacking Ba-O periodically. In general, periodic stacking can be achieved by controlling the opening and closing shutters in front of the evaporation source in an MBE apparatus or a multi-source EB vapor deposition apparatus, or by switching the type of gas during the vapor phase growth method. it can. However, sputtering deposition has hitherto been unsuitable for stacking very thin layers of this type. The reason for this is considered to be contamination of impurities due to high gas pressure during film formation and damage by particles having high energy. However,
When different thin layers were laminated on this Bi-based oxide superconductor by sputtering, it was discovered that a favorable laminated film can be produced. High oxygen gas pressure and sputtering discharge during sputtering are 100K of Bi system.
It is considered that it is convenient for the formation of the phase having the above critical temperature and the formation of the Sr-Ba-O insulator film.

As a method of stacking different substances by sputter deposition, there is a method of periodically controlling the discharge position of one sputtering target provided with a composition distribution, which is called sputtering of a plurality of targets having different compositions. This can be achieved relatively easily using the method. In this case, the sputtering amount of each of the plurality of targets can be periodically controlled, or a shutter can be provided in front of the target to periodically open and close the target to form a periodic laminated film. It can also be manufactured by a method in which the substrate is moved cyclically and moved over each target. When laser sputtering or ion beam sputtering is used, if multiple targets are moved periodically and the beam irradiation target is changed periodically,
A periodically laminated film is realized. As described above, the periodic stacking of Bi-based oxides can be relatively easily manufactured by sputtering using a plurality of targets.

Embodiment 2 FIG. 5 shows a schematic view of the ternary magnetron sputtering apparatus used in this embodiment. In FIG. 5, 10 is a Bi-O firing target, 11 is a Sr-Ca-Cu-O firing target, 12 is a Sr-Ba-O firing target, 13, 14 and 15 are shutters, 16 is a MgO substrate, and 17 is A heater for heating a substrate is shown. A total of three targets 10, 11 and 12 were arranged as shown in FIG. That is, MgO (100) substrate 16
Each target is installed so as to be tilted by about 30 ° so as to focus on. The sputtering time can be set freely by opening and closing the shutters 13, 14, and 15.
The substrate 16 was heated to about 600 ° C. by the heater 17 and each target was sputtered in a gas of argon / oxygen (5: 1) mixed atmosphere 3 Pa. Oxygen gas was introduced as the oxygen gas, and the ratio was changed. High frequency power injected to each target is Bi-O: 30W, Sr-C
The experiment was conducted with a-Cu-O: 50W and Sr-Ba-O: 50W. Bi-O → Sr-Ca-Cu-O → Bi-O is sputtered in a cycle and the composition ratio of elements of the Bi-Sr-Ca-Cu-O film is B.
The composition of the target was adjusted so that i: Sr: Ca: Cu = 2: 2: 2: 3, and the above cycle was repeated 20 times.
A phase with a critical temperature above K could be produced. The composition ratio in the Sr-Ba-O thin film was adjusted by changing the composition of the target so that Sr: Ba = 3: 7. Further, the buffer layer → A electrode → junction → B electrode is formed by Sr-Ba-O → Bi-Sr-Ca-Cu-O → Sr-Ba-O → Bi-S by the above method.
It was possible to continuously stack r-Ca-Cu-O. Further, after stacking the buffer layer, the A electrode, the bonding portion, and the B electrode, a superconducting device was prepared according to (Example 1). As a result, current-voltage characteristics similar to those in FIG. 4 were obtained at 80K. It is considered that this is because the manufacturing method effectively contributes. That is, a buffer layer is formed on the substrate, and Bi-Sr-Ca-Cu-
By forming the O thin film in a two-dimensional layered form, the interface between the A electrode and the junction or the interface between the junction and the B electrode formed on the buffer layer may be extremely stable and may have excellent flatness. , Sr-Ba-O (junction) on Bi-Sr-Ca-Cu-O thin film (A electrode), or Bi-Sr-Ca-Cu-O thin film on Sr-Ba-O thin film (junction) This is because (B electrode) is continuously epitaxially grown, there is no mutual diffusion of elements between the electrode and the junction, and the superconductivity of the Bi-Sr-Ca-Cu-O superconductor is not impaired. it is conceivable that.

In addition, Sr-Ba-O of the buffer layer and the joint portion
It was also found that the substrate temperature at the time of forming a thin film is 300 ° C. to 700 ° C., which is optimum for obtaining good crystallinity.

[0030]

As described above, the superconducting device of the present invention has the same constant as the A and B electrodes made of a Bi type superconductor, is thermally stable, and is epitaxially grown so as to fill the irregularities of the base. After depositing (Ca, Sr, Ba) O on the substrate, the A electrode and the subsequent layers are deposited and formed, and it is also used as a bonding portion, which is excellent in flatness of the interface and crystallinity of the A and B electrodes. There is an effect that a superconducting device can be manufactured.

Further, the manufacturing method of the present invention is a manufacturing method capable of efficiently and stably providing the superconducting device,
This means that a superconducting quantum interferometer having a Josephson element as a constituent element is currently put into practical use as one of superconducting applications, but the superconducting element of the present invention operates as a Josephson element. When used, there is an effect that a superconducting quantum interferometer can be constructed.

Further, the superconducting element of the present invention can be used as a switching element having low power consumption, a high-sensitivity high-frequency mixer using nonlinearity, or a quantum effect peculiar to a superconductor.

[Brief description of drawings]

FIG. 1 is a structural schematic diagram of a (Ca, Sr, Ba) O crystal according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a superconducting device according to an embodiment of the present invention.

FIG. 3 is a process diagram of a manufacturing method according to an embodiment of the present invention.

FIG. 4 is a current-voltage characteristic diagram of the same.

FIG. 5 is a schematic view of an experimental apparatus used in an example of the present invention.

[Explanation of symbols]

 1 A electrode 2 Buffer layer 3 B electrode 4 Bonding part 5 Electrode separation layer 6 Contact electrode 7 Base material 8 Negative resist 9 Spin-on-glass 10, 11, 12 Sputtering target 13, 14, 15 Shutter 16 Mg O base material 17 Base material heating heater

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideaki Adachi, Inventor Hideaki Adachi 1006, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Kentaro Se Tsune, Kentaro, Kadoma, Osaka Prefecture

Claims (5)

[Claims] 1. A substrate containing at least calcium (Ca), strontium (Sr), and barium (Ba) as main components.
Depositing an oxide insulator thin film containing one or more elements of
An A electrode made of a superconductor on the insulator thin film;
A B electrode made of a superconductor that is in contact with the electrode in a partial area via a junction, a contact electrode formed by contacting a part of the B electrode, and an electrode separating the contact electrode and the A electrode. In a superconducting device consisting of an inter-layer separation layer,
The main component of the A electrode and the B electrode made of a superconductor is an oxide superconductor made of at least copper (Cu) and alkaline earth (Group IIa), and the main component of the junction is the insulator. A superconducting device, which is substantially the same as the main component. (However, alkaline earth refers to at least one element of the IIa group elements.) 2. A main component of at least calcium (Ca), strontium (Sr), barium (Ba) on the substrate.
Depositing an oxide insulator thin film containing one or more elements of
An A electrode made of a superconductor on the insulator thin film;
A B electrode made of a superconductor that is in contact with the electrode in a partial area via a junction, a contact electrode formed by contacting a part of the B electrode, and an electrode separating the contact electrode and the A electrode. In the method for manufacturing a superconducting device including an interlayer separation layer, the A electrode and the B electrode are formed by periodically stacking an oxide containing Bi and an oxide containing copper and alkaline earth (group IIa). A method for manufacturing a superconducting device, comprising: (However, alkaline earth refers to at least one element of the IIa group elements.) 3. The method for producing a superconducting device according to claim 2, wherein the temperature of the base is set to 300 ° C. to 700 ° C. 4. The evaporation is performed by sputtering.
A method for manufacturing the superconducting device according to. 5. The method for manufacturing a superconducting device according to claim 2, wherein the evaporation of the laminated material is performed by at least two kinds of evaporation sources.