JP2555477B2 - Superconducting thin film and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a high-performance superconducting thin film and a method for producing the superconducting thin film.

[Prior Art] One of the most urgently applied materials is an oxide high temperature superconductor. This perovskite compound is
Higher transition temperatures than metal compound superconductors are expected, and Ba-La-Cu-O high-temperature superconductors have been proposed [J.
G. Bednorz and KAMuller, Zeitshrift Fur Physik B-Condens
ed Matter Vol, 64, 189-193 (1986)]. Furthermore, Bi-S
It was also discovered that the r-Ca-Cu-O-based material exhibits a transition temperature of 100 K or higher [H, Maeda, Y, Tanaka, M, Fukutomi and T.
Asano, Japanese Journal of Applied
Physics (Japanese Journal of Applied Physic
s) Vol, 27, L209-L210 (1988)]. Although the details of the superconducting mechanism of this kind of material are not clear, the transition temperature may be higher than room temperature, and it is not possible to use the conventional high-temperature superconductor as a high-temperature superconductor.
The application in the electronic device field is expected from the original compound.

Higher superconducting transition temperatures have been conventionally expected by alternately stacking superconductors and insulators [MH
Cohen and DHDouglass, Jr., Physical Review ·
Letters (Physical Review Letters) Vol.19, 118-121
(1967)].

Further, as a publicly known example related to the present invention, JP-A-2-2279
The publication No. 11 proposes stacking superconductors (Bi ₂ Sr ₂ Ca ₂ Cu ₃ O _y ) and normal conductors (Bi ₂ Sr ₂ CuO _y (oxide containing Sr) alternately. As a prior example, Japanese Patent Laid-Open No. 2-2931
In Japanese Patent Laid-Open No. 36-36, it is proposed to alternately superpose a superconductor (Bi ₂ Sr ₂ Ca ₂ Cu ₃ O _y ) thin film and an insulator (Ca ₂ PbO _u (oxide containing Ca) thin film). In JP 3-235088 A, a superconducting (Bi-Sr-Ca-Cu-O) thin film and a composition similar to a Bi-based superconductor (Sr-Ca-Cu-O) thin film are alternately laminated ". Proposed, Japanese Patent Laid-Open No. 4-65320 discloses superconducting (Bi-S
r-Ca-Cu-O) thin film and Bi- (Ca, Ba, Sr) -Cu-Re-O
(Where Re is a rare earth) It has been proposed to stack thin films alternately.

[Problems to be Solved by the Invention] However, in order to obtain good superconducting properties, the material of the oxide superconductor needs to be heat-treated at 600 ° C. or higher or heated at the time of formation. The crystallinity collapses, interdiffusion of each element occurs between the insulator and the insulating thin film, and the superconductor, resulting in deterioration of the characteristics of the superconductor and deterioration of the characteristics of the insulator. It is extremely difficult to obtain a periodic laminated structure of a high-temperature oxide superconductor and an insulating film, especially because of the deterioration of the characteristics of the insulator and the superconductor due to the mismatch caused by the difference in the lattice constants of the crystals. Son devices have made the configuration of an integrated device using this structure, which is a typical application example, almost impossible. For example, the above-mentioned JP-A-2-227911, JP-A-2-293136, and JP-A-3
The proposals of Japanese Patent Laid-Open No. 235088 and Japanese Patent Laid-Open No. 4-65320 also have a problem that mutual diffusion of elements between layers cannot be prevented because the lattice constants between layers are different.

In order to solve the problems of the prior art, the present invention obtains a high-performance oxide superconducting thin film laminate by alternately laminating layered oxide superconducting thin films and oxide thin films on a substrate. The purpose is to

[Means for Solving the Problems] In order to achieve the above object, the superconducting thin film of the present invention is a laminate having at least an oxide superconducting thin film on a substrate, and the main component is at least bismuth (Bi), Copper (Cu),
A layered oxide superconducting thin film made of alkaline earth metal (IIa group) and an electrical insulator or semiconductor containing at least one element of calcium (Ca), strontium (Sr), and barium (Ba) as a main component. It is characterized in that it has a structure in which oxide thin films are alternately laminated and substantially prevents mutual diffusion of elements between the superconducting thin film and the oxide thin film.

The method of the present invention is a method for producing a laminate having at least an oxide superconducting thin film on a substrate, which comprises a compound containing at least bismuth (Bi), at least copper (Cu) and an alkaline earth metal (group IIa). A compound containing a layered oxide superconducting thin film formed by periodically laminating, and an oxide thin film which is an electric insulator or semiconductor containing at least one element of at least Ca, Sr, and Ba as a main component. The layers are alternately stacked to substantially prevent mutual diffusion of elements between the superconducting thin film and the oxide thin film.

In the method of the present invention, it is preferable that the respective components of the laminated body are laminated by the molecular deposition method, and the laminated substances forming the respective laminated components are evaporated by at least two kinds of evaporation sources.

In addition, in the method of the present invention, it is preferable that evaporation of the laminated material is performed by sputtering.

Further, in the method of the present invention, it is preferable that the layered oxide superconducting thin film and the oxide thin film are alternately laminated and then heat-treated in an oxidizing atmosphere.

Here, the alkaline earth metal refers to at least one element or two or more elements of the IIa group elements.

[Operation] According to the above-described configuration of the present invention, the main components are at least bismuth (Bi), copper (Cu), and alkaline earth metal (IIa
Group) and a layered oxide superconducting thin film composed of at least one element of at least one element of calcium (Ca), strontium (Sr), and barium (Ba) as a main component are alternately laminated. , It becomes possible to stack the elements between the superconducting thin film and the oxide thin film without mutual diffusion of elements, and as a result, the superconducting transition temperature in the Bi-based superconducting thin film can be stably realized with good reproducibility.

Further, according to the present invention, it is possible to efficiently manufacture a laminated body including at least a superconducting thin film and an oxide thin film on a substrate.

In addition, according to a preferred configuration of the method of the present invention, each of the components of the laminate is laminated by a molecular deposition method, and evaporation of the laminated material forming each of the laminated components is performed by at least two or more evaporation sources, Precise control at the molecular level is possible.

Further, according to the preferred configuration of the method of the present invention in which the evaporation of the laminated material is performed by sputtering, the film thickness and the like can be precisely controlled.

Further, according to the preferable constitution of the method of the present invention in which the layered oxide superconducting thin film and the oxide thin film are alternately laminated and then heat-treated in an oxidizing atmosphere, the crystallinity can be further improved.

[Examples] The present invention will be described in more detail with reference to the following examples.

First, the superconducting thin film according to the first aspect of the present invention has a crystal structure covered by a Bi ₂ O ₂ oxide layer or a layer mainly composed of the Bi ₂ O ₂ oxide layer. Ca whose film formation temperature and a-axis and b-axis length are almost the same as those of the thin film
By taking _1-xy Sr _x Ba _y O insulator thin film and the laminated structure, it allows stacking without interdiffusion of elements between the superconducting thin insulating film, resulting Bi system than The superconducting transition temperature of the conductive thin film was stably realized with good reproducibility.

Furthermore, in the second invention method, in order to achieve a structure extremely stable and on a fine scale, at least
Bi-based layered structure oxide superconducting thin film obtained by periodically stacking an oxide containing Bi and an oxide containing at least copper and an alkaline earth metal element, and a Ca _1-xy Sr _x Bay _y O insulator By stacking the thin film and the thin film alternately, the thin film is manufactured by controlling the molecular level, and thus the stack of the Bi-based superconducting thin film and the insulating film is realized with good reproducibility.

 Next, the oxide superconducting thin film will be described.

Bi-Sr-Ca-Cu-O-based oxide superconducting thin films are usually
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 after that 700 ~ 9
Heat treatment at 50 ℃ is applied to improve superconducting properties.

However, when the insulating film is laminated after the oxide superconducting thin film when the substrate temperature is high, or when heat treatment is performed after the insulating film is formed, mutual diffusion of elements occurs between the superconducting film and the insulating film. It was found that the superconducting properties were significantly degraded. 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 700 to 950 ° C. It is considered essential that it is stable to the heat treatment. The insulating film may be a semiconductor film.

First, the Bi-based superconductor having a structure sandwiched between Bi ₂ O ₂ oxide layers is extremely stable against high-temperature heat treatment,
The materials CaO, SrO, and BaO have high melting points and are stable,
a, Sr, Ba) -O for the Bi-Sr-Ca-Cu-O superconducting thin film, paying attention to the fact that the crystal lattice constant can be freely changed by changing the ratio of Ca, Sr, and Ba. Was investigated as an insulating film.

Figure 1 shows the schematic structure of the (Ca, Sr, Ba) 0 crystal. The crystal is a simple cubic lattice and has a NaCl structure. In the case of SrO, a = 5.1
It has a melting point of 2460 ° C and a thermal expansion coefficient of 11 × 10 ^-6 / ° C. Mainly, the lattice constant can be changed by partially replacing Sr ²⁺ with Ca ²⁺ or Ba ²⁺ .

Next, CaO, SrO, and BaO were used alone, or a solid solution was heated by electron beam heating, evaporated and deposited on a MgO substrate, and its crystallinity was analyzed and examined by X-ray diffraction method and electron beam diffraction method. As a result, it was found that this kind of material crystallizes at a forming temperature of 600-800 ℃. In addition, since the a-axis and b-axis lengths of oxide high-temperature superconductor crystals such as Bi series are approximately 5.4Å, considering this kind of material as an insulating film,
the a-axis length, respectively 5.140A, SrO of 5.542A, Combine BaO solid-phase reaction, the thought that the formation of the optimum insulating film to the oxide superconductor thin film can be realized, Sr _1-X Ba _x O As a result of examining the change of the crystal structure with respect to x, Sr _1-X Ba _x O is x = 0.
It was found that the a-axis length continuously changed between 5.14 and 5.54 for ~ 1.

Further, in order to understand the invention more clearly by using the insulating material of this kind, the invention will be concretely shown in Examples 1 and 2 below. In the previous step, the (Ca, Sr, Ba) O thin film was formed by the electron beam evaporation method, but in Examples 1 and 2, in order to continuously form the Bi-based superconducting thin film in the laboratory. An experiment was conducted by the multi-source sputtering method.

Example 1 FIG. 2 schematically shows a cross-sectional view of the thin film produced in this example. In FIG. 2, Bi-Sr-Ca-Cu was formed on the substrate.
The -O film and the Sr-Ba-O film were alternately laminated. As a stacking method, a binary magnetron sputtering method was used.

FIG. 3 shows a schematic diagram of the binary magnetron sputtering apparatus used in this embodiment. In FIG. 3, 31 is Bi-Sr-Ca.
A —Cu—O fired powder target, 32 is a SrF ₂ + BaF ₂ powder target, 33 is a shutter, 34 is a substrate, and 35 is a heater for heating the substrate. A total of two targets 31, 32 were arranged as shown in FIG. That is, each target is installed so as to be tilted by about 30 ° so as to focus on the MgO (100) substrate 34. Bi-Sr-Ca-Cu- O sintered powder target 31 composition ratio Bi: Sr: Ca: Cu = 2: 1: 1: 1.5 to so as _{Bi 2 O 3, SrCO 3,} Ca
CO ₃ and CuO powder are weighed and baked in air at 900 ° C for 5 hours.
The crushed powder is placed on a copper dish with a diameter of 60 mm. The composition ratio of the SrF ₂ + BaF ₂ powder target 32 is Sr: Ba = 3: 7.
The SrF ₂ powder and the BaF ₂ powder were weighed and mixed so that the resulting mixture was placed in a copper dish having a diameter of 60 mm. There is a rotating shutter 33 in front of the target, and a slit 36 provided in it by being driven by a pulse motor.
Rotation is controlled and the cycle and sputter time for each target can be set. The substrate 34 is heated to about 650 ° C. by the heater 35, and an argon / oxygen (5: 1) mixed atmosphere 3P
Each target was sputtered in the gas of a. Experiments were carried out with the target high frequency sputter power of 31:30 W and 32:10 W.

Bi-Sr-per layer in the schematic diagram of the laminated film in FIG.
The thickness of Ca-Cu-O thin film is about 500Å, and Bi-Sr-Ca-C
The u-O thin film layers were laminated four times so that the total film thickness was 2000Å.

The thickness of the Sr-Ba-O film was changed, and the change in the resistivity of the thin film was examined. The results are shown in FIG. Although the thin film undergoes a superconducting transition even after completion of sputtering deposition, it was heat-treated at 800 ° C. for 5 hours in an oxygen gas atmosphere in order to further improve the crystallinity.

In FIG. 4, reference numerals 41, 42, and 43 respectively show the temperature characteristics of the resistivity of the thin film sample when the thickness of the Sr-Ba-O thin film layer is 100Å, 50Å, 20Å. The superconducting transition temperatures of the temperature characteristics 41, 42 and 43 of resistivity were 118K, 123K and 110K, respectively. Sr
-Bai-Sr-Ca-Cu- with a film thickness of 2000Å that is not laminated with a Ba-O film
The superconducting transition temperature of the O film itself is 120K, and the film thickness is 50Å
It was found that the superconducting transition temperature was higher when the Sr-Ba-O films of No. 2 were alternately laminated. Further, although the detailed reason for this effect is still unknown, as shown in FIG. 4, by periodically stacking the Bi—Sr—Ca—Cu—O film and the Sr—Ba—O film, Bi-Sr-Ca-Cu-O film and Sr-
Since the Ba-O film has substantially the same a-axis (or b-axis) length of the crystal and is epitaxially grown at the interface with each other, there is no influence of mutual diffusion of elements at the stacking interface, and a thin Sr- Bi-Sr-Ca through the Ba-O film
It is considered that some changes in the superconducting mechanism were caused in the Bi-Sr-Ca-Cu-O film by stacking the -Cu-O film, but the mechanism is not yet clear.
However, the superconducting transition temperature of the bulk fired body of Bi-Sr-Ca-Cu-O is 120 to 125 K, and it was confirmed that the superconducting temperature of the Bi-Sr-Ca-Cu-O material was essentially higher than that of the Bi-Sr-Ca-Cu-O material. Although it cannot be determined at present whether or not the conduction transition temperature has risen, it is considered that a crystalline phase having a high superconducting transition temperature can be stably formed by at least using the layered structure shown in this example. .

Note that the effect of increasing the superconducting transition temperature is Bi-Sr-Ca.
It was confirmed by alternately stacking a -Cu-O film and a Sr-Ba-O film, but it was confirmed that the Y-Ba-Cu-O-based oxide superconductor, Pb-Sr
Since the-(Ca, Y) -Cu-O system and the Tl-Ba-Ca-Cu-O system also have a-axis and b-axis lengths almost equal to those of the Bi system, the Bi- The mixing ratio of Ca, Sr, and Ba was changed in the same manner as the Sr-Ca-Cu-O film and the Sr-Ba-O film were alternately laminated.
_{C a1-xy Sr x Ba y} O thin film and the same effect even by laminating the oxide high temperature superconductor thin film of another kind alternately it was confirmed that the obtained.

Embodiment 2 FIG. 5 is a schematic view of the inside of the quaternary magnetron sputtering apparatus used in this embodiment, 51 is a Bi metal target, and 52 is
Is an Sr-Cu alloy target, and 53 is a Ca-Cu alloy target. 54 is a mixed powder target of SrF ₂ + BaF ₂ , 55 is a shutter, 56 is a slit, 57 is a substrate, and 58 is a heater for heating the substrate. The targets 52 and 53 are the element ratio Sr (or
Ca): Cu = 1: 1 alloy target, and Sr: Ba = 3: 7 in the target 54. The targets 51, 52, 53, 54 were arranged as shown in FIG. That is, MgO (100)
Each target is installed so as to be focused on the base 57 with an inclination of about 30 °. DC power was applied to the alloy targets 51, 52 and 53, and high frequency power was applied to 54, and the targets were sputtered. There is a rotating shutter 55 in front of the target, and by controlling the rotation of the slit 56 provided therein with a pulse motor, (Bi → Sr-Cu →
Since sputter deposition can be performed in a cycle of (Ca-Cu->Sr-Cu-> Bi) and further sputtering is performed in an atmosphere containing oxygen, it is possible to alternately stack (Sr, Ba) O films.

The state of stacking is conceptually shown in FIG.
By controlling the input power to 51, 52, 53, 54 and the sputtering time of each target, the film thickness of the Sr-Ba-O film and the Bi-Sr-Ca-Cu-O film deposited on the substrate 57. Can be changed. The substrate 57 was heated to about 700 ° C. by the heater 58, and each target was sputtered in a gas containing 0.5 Pa of an argon / oxygen (1: 1) mixed atmosphere. After forming the thin film, a heat treatment was performed at 850 ° C. for 5 hours in an oxygen atmosphere.

In this example, the sputtering time sputtering current was adjusted so that the composition ratio of the elements of the Bi-Sr-Ca-Cu-O film was Bi: Sr: Ca: Cu = 2: 2: 2: 3.

Furthermore, it seems that the limit of the film thickness that can be reduced while maintaining the crystallinity is several tens of liters. Since it is preferable that the insulating film be as thin as possible, the film thickness of the Sr-Ba-O thin film layer is kept constant at 40Å, and k ・ (Bi → SrCu-CaCu → SrCu → Bi) → 50ÅSr-Ba-
20 cycles of writing O were performed. Then, the temperature change of the resistivity of the thin film formed by changing k was examined. The result at that time is shown in FIG.

In FIG. 7, the changes in resistivity with temperature 71, 72, 73 show the results when k = 2, 6, 10, respectively. As can be seen from this figure, the superconducting transition temperature and the zero resistance temperature were highest when k = 6. In the results of FIG. 7, the superconducting transition temperatures of the temperature changes 71, 72, 73 of the resistivity are respectively
It was 112K, 125K and 118K. It was found that the superconducting transition temperature without stacking with Sr-Ba-O was 120K, and that it increased when k = 6. Although the physical cause of this is not exactly known so far, according to the second embodiment, Bi-Sr
It is considered that this is because both the -Ca-Cu-O thin film and the Sr-Ba-O thin film could be laminated with extremely good controllability.

Further, although the sputtering method was used in the first and second examples, the oxide of Bi and Sr, Ca, Cu, Ba were used.
The oxides of
When the same structure is periodically laminated, it is possible to obtain a thin film having stable film quality with good controllability as in the laminated structure manufacturing method using the sputtering described in the second embodiment. There are several conceivable methods for periodically stacking Bi-O, Sr-Cu-O, Ca-Cu-O, and Sr-Ba-O. MBE in general
Periodic stacking can be achieved by controlling the opening and closing shutters in front of the evaporation source in the apparatus or a multi-source FB deposition apparatus, and by switching the type of gas when the vapor phase growth method is used. 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, it was found that, when different thin layers were laminated on the Bi-based oxide superconductor and the insulating thin film by sputtering, surprisingly good laminated film could be prepared. Due to the high oxygen gas pressure during sputtering and sputter discharge, the introduction of oxygen into the film is further promoted,
It is considered that the superconducting property is reproducible and stabilized, and it is convenient for the formation of a Bi-based phase having a critical temperature of 100 K or higher and the formation of an insulating thin film.

As a method of stacking different substances by sputter deposition, there is a method of periodically controlling the discharge position of one (one) sputtering target having a composition distribution, but sputtering of a plurality of targets having different compositions This can be achieved relatively easily using this 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, a periodic laminated film is realized by periodically moving a plurality of targets to periodically change the targets irradiated by the beams. As described above, the periodic stacking of Bi-based oxides can be relatively easily prepared by sputtering using a plurality of targets.

As shown in Examples 1 and 2, Bi-O, Sr-Cu-O, Ca-Cu-O, S
When r-Ba-O was evaporated from different evaporation sources and Bi-Sr-Ca-Cu-O superconducting thin film and Sr-Ba-O insulating film were periodically laminated, the controllability of m (Bi- It was found that a thin film having a periodic structure of (Sr-Ca-Cu-O) and Sr-Ba-O) can be formed. Where m
Indicates a positive integer. In addition, Bi-Sr-Ca-Cu-
A thin film can be formed by a simple method even if a complex oxide (or fluoride) of O and Sr-Ba-O is used. If different evaporation sources are used, the production method is superior in crystallinity and composition controllability. It was also found that they excel in characteristics such as superconducting transition temperature and critical current density.

Furthermore, it was found that the surface of the Bi-Sr-Ca-Cu-O superconducting thin film and the Sr-Ba-O insulating film produced by the above method are both extremely flat. This is because the different elements forming the layered structure are sequentially laminated separately, so that the deposited elements move only in the plane parallel to the substrate surface, and the vapor deposition element in the direction perpendicular to the substrate surface moves. It is considered that there is no movement of the element. Furthermore, the insulating thin film of this composition is a crystal of a layered perovskite structure,
The length of the a-axis is almost the same as that of Bi-Sr-Ca-Cu-O, and it is considered that continuous epitaxial growth is possible.

Furthermore, it was surprisingly found that the temperature of the substrate and the heat treatment temperature required to obtain good superconducting properties are lower than those in the past.

As described above, the superconducting thin film of the first invention realizes and provides high performance of the oxide superconducting thin film.
The method for producing a superconducting thin film of the invention of 1) achieves the first invention more effectively and has established a process at low temperature which is essential for application of devices and the like, and the industrial value of the invention is great.

As described above, according to the present invention, the main components are at least bismuth (Bi), copper (Cu), alkaline earth metal (II
It has a structure in which a layered oxide superconducting thin film composed of group a) and an oxide thin film containing at least one element of calcium (Ca), strontium (Sr), and barium (Ba) as main components are alternately laminated. Therefore, it is possible to stack the elements between the superconducting thin film and the oxide thin film without mutual diffusion of elements, and as a result, the superconducting transition temperature in the Bi-based superconducting thin film can be stably realized with good reproducibility.

Further, according to the method of the present invention, it is possible to efficiently manufacture a laminated body including at least a superconducting thin film and an oxide thin film on a substrate.

In addition, according to a preferred configuration of the method of the present invention, each of the components of the laminate is laminated by a molecular deposition method, and evaporation of the laminated material forming each of the laminated components is performed by at least two or more evaporation sources, Precise control at the molecular level is possible.

Further, according to the preferable configuration of the method of the present invention in which the evaporation of the laminated material is performed by sputtering, the film thickness and the like can be precisely controlled.

Further, according to the preferable constitution of the method of the present invention in which the layered oxide superconducting thin film and the oxide thin film are alternately laminated and then heat-treated in an oxidizing atmosphere, the crystallinity can be further improved.

[Brief description of drawings]

FIG. 1 is a schematic view of the structure of a (Ca, Sr, Ba) O crystal, FIG. 2 is a schematic view of the structure of a superconducting thin film in the embodiment of the first invention, and FIG. 3 is a view of the embodiment of the first invention. Schematic structure of the experimental apparatus used for producing the superconducting thin film, FIG. 4 is a temperature change of resistivity of the superconducting thin film produced in the embodiment of the first invention,
FIG. 5 is a schematic view of an experimental apparatus used for producing a superconducting thin film in the embodiment of the second invention, FIG. 6 is a conceptual diagram of a superconducting thin film producing structure of the second invention, and FIG. 7 is a second invention. 3 is a temperature characteristic of resistivity of the thin film obtained in the example of FIG. 31,32,51,52,53,54 ... Sputtering target, 33,55
… Shutter, 36,56… Slit, 34,57… MgO substrate, 35,
58… Heater, 41,42,43,71,72,73… Temperature characteristics of thin film resistance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kentaro Se Tsune 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A-2-227911 (JP, A) JP-A-2 -293136 (JP, A) JP-A-3-235088 (JP, A) JP-A-4-65320 (JP, A)

Claims (5)

(57) [Claims] 1. A laminate having at least an oxide superconducting thin film on a substrate, the main component of which is at least bismuth (B
i), a layered oxide superconducting thin film composed of copper (Cu) and an alkaline earth metal (group II) and at least one element of at least calcium (Ca), strontium (Sr) and barium (Ba) as a main component. It has a structure in which oxide thin films which are electrical insulators or semiconductors are alternately laminated, and substantially prevent mutual diffusion of elements between the superconducting thin film and the oxide thin film. And a superconducting thin film. 2. A method for producing a laminate having at least an oxide superconducting thin film on a substrate, comprising a compound containing at least bismuth (Bi), at least copper (Cu) and an alkaline earth metal (group II). A compound containing a layered oxide superconducting thin film formed by periodically laminating, and an oxide thin film which is an electrical insulator or a semiconductor containing at least one element of at least Ca, Sr, and Ba as a main component, A method for producing a superconducting thin film, characterized in that the elements are alternately laminated to substantially prevent mutual diffusion of elements between the superconducting thin film and the oxide thin film. 3. The superconducting thin film according to claim 2, wherein the respective components of the laminated body are laminated by a molecular deposition method, and the laminated substances forming the respective laminated components are evaporated by at least two kinds of evaporation sources. Manufacturing method. 4. The method for producing a superconducting thin film according to claim 3, wherein the evaporation of the laminated material is performed by sputtering. 5. The method for producing a superconducting thin film according to claim 2, wherein the layered oxide superconducting thin film and the oxide thin film are alternately laminated and then heat-treated in an oxidizing atmosphere.