JPH04170394A - Superconducting thin film and its production - Google Patents
Superconducting thin film and its productionInfo
- Publication number
- JPH04170394A JPH04170394A JP2300395A JP30039590A JPH04170394A JP H04170394 A JPH04170394 A JP H04170394A JP 2300395 A JP2300395 A JP 2300395A JP 30039590 A JP30039590 A JP 30039590A JP H04170394 A JPH04170394 A JP H04170394A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- substrate
- oxide
- superconducting thin
- oxide superconducting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000010409 thin film Substances 0.000 title claims abstract description 104
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- 239000000758 substrate Substances 0.000 claims abstract description 64
- 229910052712 strontium Inorganic materials 0.000 claims abstract description 17
- 229910052788 barium Inorganic materials 0.000 claims abstract description 15
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 15
- 239000011575 calcium Substances 0.000 claims description 20
- 239000010408 film Substances 0.000 claims description 17
- 239000010949 copper Substances 0.000 claims description 15
- 238000000151 deposition Methods 0.000 claims description 11
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 8
- 229910052802 copper Inorganic materials 0.000 claims description 8
- 230000008021 deposition Effects 0.000 claims description 5
- 229910052594 sapphire Inorganic materials 0.000 claims description 5
- 239000010980 sapphire Substances 0.000 claims description 5
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 4
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims description 4
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 claims description 4
- 229910001218 Gallium arsenide Inorganic materials 0.000 claims description 3
- 238000010894 electron beam technology Methods 0.000 abstract description 7
- 238000009792 diffusion process Methods 0.000 abstract description 5
- 230000004888 barrier function Effects 0.000 abstract description 2
- 229910015901 Bi-Sr-Ca-Cu-O Inorganic materials 0.000 abstract 2
- 239000013078 crystal Substances 0.000 description 15
- 239000002887 superconductor Substances 0.000 description 13
- 238000010438 heat treatment Methods 0.000 description 12
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 12
- 239000000395 magnesium oxide Substances 0.000 description 11
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 11
- 239000000463 material Substances 0.000 description 10
- 238000000034 method Methods 0.000 description 9
- 239000002245 particle Substances 0.000 description 8
- 238000001704 evaporation Methods 0.000 description 7
- 230000008018 melting Effects 0.000 description 7
- 238000002844 melting Methods 0.000 description 7
- 230000007704 transition Effects 0.000 description 7
- -1 SrTiO3 Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 238000002425 crystallisation Methods 0.000 description 5
- 230000008025 crystallization Effects 0.000 description 5
- 230000008020 evaporation Effects 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 229910026161 MgAl2O4 Inorganic materials 0.000 description 4
- 229910052596 spinel Inorganic materials 0.000 description 4
- 229910002244 LaAlO3 Inorganic materials 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000012212 insulator Substances 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 229910002480 Cu-O Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 229910014454 Ca-Cu Inorganic materials 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910002331 LaGaO3 Inorganic materials 0.000 description 1
- 229910003200 NdGaO3 Inorganic materials 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical group [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- XDFCIPNJCBUZJN-UHFFFAOYSA-N barium(2+) Chemical compound [Ba+2] XDFCIPNJCBUZJN-UHFFFAOYSA-N 0.000 description 1
- 235000010216 calcium carbonate Nutrition 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000005566 electron beam evaporation Methods 0.000 description 1
- 238000001659 ion-beam spectroscopy Methods 0.000 description 1
- 238000010884 ion-beam technique Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000003746 solid phase reaction Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 229910001427 strontium ion Inorganic materials 0.000 description 1
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 description 1
- 238000000427 thin-film deposition Methods 0.000 description 1
- 229910001233 yttria-stabilized zirconia Inorganic materials 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/60—Superconducting electric elements or equipment; Power systems integrating superconducting elements or equipment
Landscapes
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、高性能な特性を有する超伝導薄膜およびその
製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a superconducting thin film having high performance characteristics and a method for manufacturing the same.
［従来の技術］
現在量も応用が急がれている材料のひとつに酸化物高温
超伝導体がある。このペロブスカイト系化合物は、金属
化合物超伝導体よりさらに高い転移温度が期待され、Ｂ
ａ−Ｌ ａ−Ｃｕ−０系の高温超伝導体が提案された
［Ｊ、Ｇ、 Ｂｅｄｎｏｒｘ ａｎｄ Ｋ、 Ａ、 Ｍ
ｕｌｌｅｒ。[Prior Art] One of the materials that is currently in urgent need of application is an oxide high-temperature superconductor. This perovskite compound is expected to have a higher transition temperature than metal compound superconductors, and B
A high-temperature superconductor based on a-L a-Cu-0 was proposed [J, G, Bednorx and K, A, M
uller.
ツァイトシュリフト・フユア・フィジーク（２ｅｉｔｓ
ｈｒｉｆｔ Ｆｕｒ Ｐｈ７ｓｉｋ Ｂ）−Ｃｏｎｄｅ
ｎｓｅｄ Ｍａｔｔｅｒ Ｖｏｌ、５４゜１８９−１９
３ （１９８６） Ｉ。さらに、Ｂ ｉ−８ｒ−Ｃｘ−
Ｃｕ−０系の材料が１００に以上の転移温度を示すこと
も発見された［Ｈ，Ｍａｅｄａ、 Ｙ、 Ｔａｎａｋａ
、 Ｍ、Ｆｏｋｕｔｏｍｉ ａｎｄ Ｔ。Zeitschrift Fuyur Physik (2eits
hrift Fur Ph7sik B)-Conde
nsed Matter Vol, 54°189-19
3 (1986) I. Furthermore, B i-8r-Cx-
It was also discovered that Cu-0 based materials exhibit a transition temperature of over 100 [H, Maeda, Y, Tanaka
, M., Fokutomi and T.
Ａｓａｎｏ、ジャパニーズ・ジャーナル・オブ・アプラ
イド・フィジックス（Ｊａｐａｎｅｓｅ Ｊｏｕｒｎａ
ｌ ｏｆ Ａｐｐｌｉｅｄ Ｐｋｙｓｉｃｓ）Ｖｏｌ、
２７． Ｌ２０９−Ｌ２１０（１９８８）］。Asano, Japanese Journal of Applied Physics
l of Applied Dynamics) Vol.
27. L209-L210 (1988)].
この種の材料の超伝導機構の詳細は明らかではないが、
転移温度が室温以上に高くなる可能性があり、高温超伝
導体として従来の２元系化合物より、電子デバイス分野
での応用が期待されており、そのためにも膜厚が１００
ＯＡ以下の薄膜化技術の確立が叫ばれている。Although the details of the superconducting mechanism of this type of material are not clear,
The transition temperature may be higher than room temperature, and as a high-temperature superconductor, it is expected to be applied in the field of electronic devices rather than conventional binary compounds.
There is a call for the establishment of thin film technology below OA.
［発明が解決しようとする課題］
膜厚が数１００Ａの極薄膜は、その結晶性、超伝導特性
などを考えた場合、基体表面からエピタキシャル（ヘテ
ロ・エピタキシャル）成長したものが望ましい。しかし
ながら、酸化物超伝導体の薄膜材料は、良好な超伝導特
性を得るためには少なくとも６００℃以上の熱処理ある
いは形成時の加熱が必要であり、さらに酸化物超伝導体
の薄膜化には選択した基体の特性（結晶の格子定数、融
点など）、表面状態（汚れ、凹凸など）に極めて大きく
依存する。すなわち、基体の融点が低い場合に起こる基
体から酸化物超伝導薄膜中への元素−の拡散により特に
基体との界面で酸化物超伝導薄膜の結晶性の劣化、基体
の表面が凸凹であるために酸化物超伝導体を堆積した場
合に、結晶が基体表面に島状粒（アイランド）が発生し
、さらにその島状粒が酸化物超伝導薄膜へと成長するの
で結晶粒界を数多く含む超伝導臨界電流密度の低い薄膜
へといたり、膜厚数１００Ａの酸化物超伝導薄膜の形成
を不可能に近いものとしていた。さらには、酸化物超伝
導薄膜をシリコンデバイスと組み合わせることによって
、その応用範囲の広がることが期待されているが、一般
にシリコンは融点が低く、シリコン基体上への酸化物超
伝導薄膜の形成が困難であった。[Problems to be Solved by the Invention] Considering its crystallinity, superconductivity, etc., an extremely thin film with a thickness of several hundred amps is preferably grown epitaxially (hetero-epitaxially) from the surface of a substrate. However, thin film materials for oxide superconductors require heat treatment at least at 600°C or higher during formation in order to obtain good superconducting properties, and furthermore, thin film materials for oxide superconductors require It depends extremely on the properties of the substrate (crystal lattice constant, melting point, etc.) and surface conditions (dirt, unevenness, etc.). In other words, the crystallinity of the oxide superconducting thin film deteriorates, especially at the interface with the substrate, due to the diffusion of elements from the substrate into the oxide superconducting thin film, which occurs when the melting point of the substrate is low, and the surface of the substrate is uneven. When an oxide superconductor is deposited on a crystal substrate, island-like grains (islands) are generated on the surface of the substrate, and these island-like grains further grow into an oxide superconducting thin film. This made it nearly impossible to create a thin film with a low conduction critical current density or to form an oxide superconducting thin film with a thickness of several hundred amps. Furthermore, by combining oxide superconducting thin films with silicon devices, it is expected that their range of applications will expand; however, silicon generally has a low melting point, making it difficult to form oxide superconducting thin films on silicon substrates. Met.
本発明は、前記従来技術の課題を解決するため、基体の
上にバリヤー層を設けることにより、均一かつ高性能な
酸化物超伝導薄膜を得ることを目的とする。In order to solve the problems of the prior art, an object of the present invention is to obtain a uniform and high-performance oxide superconducting thin film by providing a barrier layer on a substrate.
［課題を解決するための手段］
前記目的を達成するため、本発明の超伝導薄膜は、基体
上に、主成分としてカルシウム（Ｃａ）、ストロンチウ
ム（Ｓ ｒ）およびバリウム（Ｂａ）から選ばれる少な
くともｉ種以上の元素を含む酸化物薄膜層を存在させ、
前記酸化物薄膜層上に、主成分として少なくとも銅（Ｃ
ｕ）を含む酸化物超伝導薄膜層を存在させたことを特徴
とする。[Means for Solving the Problems] In order to achieve the above object, the superconducting thin film of the present invention has at least one selected from calcium (Ca), strontium (Sr) and barium (Ba) as main components on a substrate. Presence of an oxide thin film layer containing i or more elements,
On the oxide thin film layer, at least copper (C
It is characterized by the presence of an oxide superconducting thin film layer containing u).
前記構成においては、基体が、ＭｇＯ，ＳｒＴｉＯ３、
サファイア（ａ−Ａ１２０３） 、ＭｇＡｌ２Ｏ４、Ｙ
ＳＺＸＬａＧａＯ３、ＬａＡｌＯ３、ＮｄＧａ０ａ 、
ＹＡ １０３ 、Ｓ ｉ、ＧａＡｓの結晶性基体のいず
れかであることが好ましい。In the above structure, the substrate is made of MgO, SrTiO3,
Sapphire (a-A1203), MgAl2O4, Y
SZXLaGaO3, LaAlO3, NdGa0a,
It is preferably a crystalline substrate of YA 103 , Si, or GaAs.
また本発明方法は、基体上に、主成分としてカルシウム
（Ｃａ）、ストロンチウム（Ｓ ｒ）およびバリウム（
Ｂａ）から選ばれる少なくとも一種以上の元素を含む成
分を分子堆積して酸化物薄膜層を設け、次いで熱処理し
、次に主成分として少な（とも銅（Ｃｕ）を含む酸化物
超伝導薄膜層をエピタキシャル成長させて堆積し、しか
る後熱処理することを特徴とする。In addition, the method of the present invention allows calcium (Ca), strontium (S r), and barium (
An oxide thin film layer is formed by molecularly depositing a component containing at least one element selected from Ba), followed by heat treatment, and then an oxide superconducting thin film layer containing a small amount (copper (Cu)) as the main component is formed. It is characterized by being epitaxially grown and deposited, followed by heat treatment.
前記構成においては、酸化物薄膜層の堆積時に、基体を
５００℃以上に加熱することが好ましい。In the above configuration, the substrate is preferably heated to 500° C. or higher during deposition of the oxide thin film layer.
［作用］
前記した本発明の超伝導薄膜の構成によれば、基体と主
成分として少なくとも銅（Ｃｕ）を含む酸化物超伝導薄
膜との間に、主成分としてＣａ、ＳｒおよびＢａから選
ばれる少なくとも一種以上の元素を含む酸化物薄膜層を
存在させたので、酸化物超伝導薄膜層に基体の元素成分
が拡散することを防止でき、結晶性に優れた酸化物超伝
導薄膜を形成することができる。[Function] According to the above-described structure of the superconducting thin film of the present invention, between the base and the oxide superconducting thin film containing at least copper (Cu) as the main component, a layer selected from Ca, Sr and Ba as the main component is provided. Since the oxide thin film layer containing at least one or more elements is present, it is possible to prevent the elemental components of the substrate from diffusing into the oxide superconducting thin film layer, thereby forming an oxide superconducting thin film with excellent crystallinity. I can do it.
また、基体がＭｇα、５ｒＴｉ０３、サファイア（α−
Ａ１２０３）、ＭｇＡｌ２Ｏ４、ＹＳＺ１ＬａＧａＯ３
、ＬａＡｌＯ３、ＮｄＧａＯ３、ＹＡ １０３ 、Ｓ
ｉ Ｎ Ｇ ａ Ａ ｓの結晶性基体のいずれかである
という本発明の好ましい構成によれば、電子デバイスと
して好ましいものとすることができる。In addition, the base material is Mgα, 5rTi03, sapphire (α-
A1203), MgAl2O4, YSZ1LaGaO3
, LaAlO3, NdGaO3, YA 103 , S
According to the preferred configuration of the present invention, in which the substrate is any of the crystalline substrates of iNGaAs, it can be preferably used as an electronic device.
また前記した本発明方法の構成によれば、基体上に主成
分としてＣａ、ＳｒおよびＢａから選ばれる少なくとも
一種以上の元素を含む成分を分子堆積して酸化物薄膜層
を設け、次いで熱処理し、次に主成分として少なくとも
銅（Ｃｕ）を含む酸化物超伝導薄膜層をエピタキシャル
成長させて堆積し、しかる後熱処理するので、結晶性に
優れた酸化物超伝導薄膜を効率よく合理的に形成するこ
゛とができる。Further, according to the configuration of the method of the present invention described above, an oxide thin film layer is provided by molecularly depositing a component containing at least one element selected from Ca, Sr, and Ba as a main component on the substrate, and then heat-treated, Next, an oxide superconducting thin film layer containing at least copper (Cu) as a main component is epitaxially grown and deposited, followed by heat treatment, making it possible to efficiently and rationally form an oxide superconducting thin film with excellent crystallinity. I can do it.
さらに、酸化物薄膜層の堆積時に、基体を５００℃以上
に加熱するという本発明方法の好ましい構成によれば、
基体上に酸化物薄膜層をエピタキシャル成長させること
ができる。Furthermore, according to a preferred configuration of the method of the present invention, the substrate is heated to 500° C. or higher during the deposition of the oxide thin film layer.
A thin oxide layer can be epitaxially grown on the substrate.
［実施例コ
以下一実施例を用いて本発明をさらに具体的に説明する
。 ′
まず、酸化物薄膜層としてＣａ１−ニーｙ Ｓ ｒ
Ｂ！
ａＯを用いた場合について説明する。[Example] The present invention will be described in more detail below using an example. ′ First, as an oxide thin film layer, Ca1−ny S r
B! The case where aO is used will be explained.
Ｃａ ５ｒｘＢａ、Ｏは格子定数が酸化物−ｘ−
ｙ
超伝導体のａ軸、ｂ軸のそれに近く、ＮａＣ１型の単純
立方格子構造の結晶構造を有する絶縁体であり、融点が
２０００℃程度と高く、またその結晶格子定数はＸおよ
びｙを変え、連続的に変えることができる。従って基体
にＣａ１ヤ、 エｒ Ｂ
ａＯ絶縁体（半導体であってもよい）薄膜を自在にエピ
タキシャル成長させることは容易であり、さらにＣａ
Ｓｒ Ｂａ Ｏ絶縁体薄膜上に１−ｘ−７ｘ
７
酸化物超伝導薄膜を堆積する際にもエピタキシャル界面
を容易に得ることができ、結果的に結晶性に優れた酸化
物超伝導薄膜を形成することができる。さらに、基体と
Ｃａ Ｓｒ Ｂａ Ｏ絶１−ｘ−ｙ ｘ
ｙ
縁体薄膜、およびＣＣａ Ｓｒ Ｂａ Ｏ絶
１−ｘ−７Ｘｌ
縁体薄膜と酸化物超伝導薄膜との界面は連続エピタキシ
ャル面であり、酸化物超伝導薄膜の数１００Ａ単位の極
薄膜化が可能である。Ca 5rxBa, O has a lattice constant of oxide -x-
y It is an insulator with a NaC1-type simple cubic lattice crystal structure, close to that of the a-axis and b-axis of superconductors, and has a high melting point of about 2000°C, and its crystal lattice constant varies with X and y. , can be changed continuously. Therefore, it is easy to epitaxially grow a CaO insulator (which may be a semiconductor) thin film on the substrate, and also
1-x-7x on SrBaO insulator thin film
7. An epitaxial interface can be easily obtained when depositing an oxide superconducting thin film, and as a result, an oxide superconducting thin film with excellent crystallinity can be formed. Furthermore, the substrate and Ca Sr Ba O separation 1-x-y x
y Edge thin film and CCa Sr Ba O isolation 1-x-7Xl The interface between the edge thin film and the oxide superconducting thin film is a continuous epitaxial plane, making it possible to make the oxide superconducting thin film extremely thin in the order of several hundred amperes. It is.
次に酸化物超伝導薄膜層について説明する。Next, the oxide superconducting thin film layer will be explained.
通常、酸化物超伝導薄膜は４００〜７００℃に加熱した
基体上に蒸着して得る。蒸着後、そのままでも薄膜は超
伝導特性を示すが、その後７００〜９５０℃の熱処理を
施し、超伝導特性を向上させる。Generally, oxide superconducting thin films are obtained by vapor deposition on a substrate heated to 400 to 700°C. After vapor deposition, the thin film exhibits superconducting properties as it is, but it is then subjected to heat treatment at 700 to 950°C to improve its superconducting properties.
しかしながら、通常、膜厚が１００ＯＡ以下の酸化物超
伝導薄膜については、バルク焼成体とほぼ等しい超伝導
転移温度を示すが、ゼロ抵抗温度がバルク焼成体の場合
より低い。例えば、Ｂ １−８ｒ−Ｃａ−Ｃｕ−０系の
超伝導体はバルク焼成体ではゼロ抵抗温度が１０５に程
度であるのに対し、膜厚数１００Ａの薄膜では最高８０
にであった。本発明者らはこの原因を多面的に追求した
ところ、基体上に酸化物超伝導薄膜を形成した場合、基
体と薄膜との界面で基体の元素が薄膜に拡散し、薄膜の
結晶構造を破壊していることを見いだした。However, normally, an oxide superconducting thin film with a film thickness of 100 OA or less exhibits a superconducting transition temperature almost equal to that of a bulk fired body, but a zero resistance temperature lower than that of a bulk fired body. For example, the B1-8r-Ca-Cu-0 system superconductor has a zero resistance temperature of about 105 in a bulk fired body, but a maximum of 80 in a thin film with a thickness of several hundred amps.
It was. The present inventors pursued the cause of this problem from multiple angles and found that when an oxide superconducting thin film is formed on a substrate, elements from the substrate diffuse into the thin film at the interface between the substrate and the thin film, destroying the crystal structure of the thin film. I found out what I was doing.
Ｂ１−８ｒ−Ｃａ−Ｃｕ−０系超伝導体結晶のａ軸（ま
たはｂ軸）長にそれが比較的近いと考えられるＬａ Ｇ
ａ Ｏ３（ａ ＝５．−４８２人、ｂ＝５．５２６Ａ
、 Ｂ１−３ｒ−Ｃａ−Ｃｕ−０系ではａ・５．４Ａ）
を基体として選んだ場合、界面でＧａがＢ ｉ−３ｒ−
Ｃａ−Ｃｕ−０薄膜へ拡散しその距離は約５００Ａであ
った。本発明者らの実験によるとＢ ｉ−８ｒ−Ｃａ−
Ｃｕ−０薄膜の膜厚が約１０００Å以下の薄膜では、−
様に超伝導転移温度がバルク焼成体より低かった。この
ような現象はどの様な基体を選んでも起こる。LaG, which is considered to be relatively close to the a-axis (or b-axis) length of the B1-8r-Ca-Cu-0-based superconductor crystal
a O3 (a = 5.-482 people, b = 5.526A
, a・5.4A for B1-3r-Ca-Cu-0 system)
is selected as the substrate, Ga at the interface becomes B i-3r-
It diffused into the Ca-Cu-0 thin film and the distance was about 500A. According to the experiments of the present inventors, B i-8r-Ca-
In a Cu-0 thin film with a thickness of about 1000 Å or less, -
Similarly, the superconducting transition temperature was lower than that of the bulk sintered body. This phenomenon occurs no matter what kind of substrate is chosen.
一般に酸化物超伝導薄膜の形成方法は次の３つに大別さ
れる。In general, methods for forming oxide superconducting thin films are broadly classified into the following three types.
（１，）薄膜を加熱温度４００℃以下の基体上に（アモ
ルファス状態で）堆積させ、後に結晶化温度以上の雰囲
気にて熱処理を施す。(1,) A thin film is deposited (in an amorphous state) on a substrate at a heating temperature of 400° C. or lower, and then heat-treated in an atmosphere at a crystallization temperature or higher.
（２）結晶化温度で基体上に薄膜を堆積する。(2) Depositing a thin film on a substrate at the crystallization temperature.
（３）結晶化温度以上に加熱した基体上に薄膜を堆積し
、後に熱処理を施す。(3) A thin film is deposited on a substrate heated above the crystallization temperature, and then heat treated.
しかしながら、前記（１） 、（３）の方法では薄膜を
結晶化温度（５００℃）以上に基体温度を加熱するため
、基体の凹凸を反映した結晶粒界の多い薄膜が形成され
たり、（２） 、（３）の方法では薄膜堆積時の基体温
度が高いために基体・薄膜間で元素の相互拡散が生じる
ことが、本発明者らの検討実験で明らかになった。この
ような問題は酸化物超伝導薄膜の形成・結晶化温度を下
げることで回避できるが、Ｎ２０、ＮＯ２、オゾン、酸
素ラジカルを基体に吹き付けながら薄膜を形成するなど
して、結晶化温度を下げても、基板の凹凸、蒸着粒子の
エネルギーの高さなどから結晶性に優れた膜厚数１００
人の酸化物超伝導薄膜は得ることができなかった。However, in the methods (1) and (3) above, since the substrate temperature is heated above the crystallization temperature (500°C) of the thin film, a thin film with many grain boundaries reflecting the irregularities of the substrate is formed, or (2) ), In the method (3), the present inventors have found through experiments that mutual diffusion of elements occurs between the substrate and the thin film due to the high substrate temperature during thin film deposition. Such problems can be avoided by lowering the formation/crystallization temperature of the oxide superconducting thin film. However, due to the unevenness of the substrate and the high energy of the deposited particles, a film thickness of several hundred nanometers with excellent crystallinity is required.
No human oxide superconducting thin film could be obtained.
そこで、基体上に酸化物超伝導薄膜を基体・酸化物超伝
導薄膜間の界面で元素の相互拡散の無いエピタキシャル
成長を実現するため、基体上にエピタキシャル成長し、
さらにその上に酸化物超伝導薄膜がエピタキシャル成長
するバッファーの絶縁膜を見いだしたのである。Therefore, in order to realize epitaxial growth of an oxide superconducting thin film on a substrate without mutual diffusion of elements at the interface between the substrate and the oxide superconducting thin film,
Furthermore, they discovered a buffer insulating film on which an oxide superconducting thin film is epitaxially grown.
まず、Ｂ１２ｏ２酸化物層に挟まれた構造を持つＢｉ系
超超伝導体高温の熱処理に対して、極めて安定であるこ
と１．そしてＣａＯ１ＳｒＯ，ＢａＯの材料が高融点で
、安定であり、（Ｃａ、 Ｓ ｒ。First, the Bi-based superconductor, which has a structure sandwiched between B12o2 oxide layers, is extremely stable against high-temperature heat treatment.1. The materials CaO1SrO and BaO have a high melting point and are stable (Ca, Sr.
Ｂａ）−０についてはＣａ、Ｓｒ、Ｂａの比率を変える
ことにより結晶の格子定数が自在に変化させることがで
きることに着目し、Ｂ ｉ−８ｔ−Ｃａ−Ｃａ−０超伝
導薄膜用の基体上の絶縁膜としての検討を行なった。Regarding Ba)-0, we focused on the fact that the lattice constant of the crystal can be freely changed by changing the ratio of Ca, Sr, and Ba. We investigated its use as an insulating film.
第１図に（Ｃａ、Ｓｒ、Ｂａ）Ｏ結晶の構造概略図を示
す。結晶は単純立方格子でＮａＣ１構造を持ち、ＳｒＯ
の場合ａ＝５．１４［１，Ｊであり、融点２４６０℃、
熱膨張係数１１×１０−６膜℃である。主に、格子定数
はＳｒ をＣａ２＋またはＢａ２＋で一装置２＋
換することによって、変化させることができる。FIG. 1 shows a schematic structural diagram of a (Ca, Sr, Ba)O crystal. The crystal has a simple cubic lattice, NaCl structure, and SrO
In the case a=5.14[1,J, melting point 2460℃,
The coefficient of thermal expansion is 11×10 −6 °C. Primarily, the lattice constant can be changed by replacing Sr with Ca2+ or Ba2+.
Ｃａｂ、ＳｒＯ，ＢａＯを単独に、あるいは固溶体を電
子ビーム加熱し、蒸発させＭｇＯ基体上に堆積させ、そ
の結晶性をＸ線回折法、電子線回折法にて解析、検討し
た。その結果、この種の材料は６００〜８００℃の形成
温度で結晶化することがわかった。また、Ｂｉ系を初め
とする酸化物高温超伝導体結晶のａ軸、ｂ軸長はほぼ５
゜４人であることから、この種の材料を絶縁膜として考
えた場合、ａ軸長がそれぞれ５．１４０人、５．５４２
Ａの５ｒＯ１ＢａＯを固相反応的に組み合わせれば、酸
化物超伝導薄膜に最適な絶縁膜の形成が実現できるもの
と考えＳ ｒ １−８Ｂ ａ工ＯのＸによる結晶構造の
変化を実験検討した結果、５ｒ１−よりａＸＯはＸ＝Ｏ
〜１に対してａ軸長が５．１４〜５゜５４の間で連続的
に変化することがわかった。Cab, SrO, and BaO alone or as a solid solution were heated with an electron beam, evaporated, and deposited on a MgO substrate, and their crystallinity was analyzed and examined using X-ray diffraction and electron beam diffraction. As a result, it was found that this type of material crystallizes at a formation temperature of 600-800°C. In addition, the a-axis and b-axis lengths of oxide high-temperature superconductor crystals including Bi-based crystals are approximately 5
Since there are 4 people, if this type of material is considered as an insulating film, the a-axis length will be 5.140 people and 5.542 people, respectively.
We thought that by combining A's 5rO1BaO in a solid-phase reaction manner, we could form an insulating film that is optimal for oxide superconducting thin films, and experimentally investigated the change in the crystal structure of S r 1-8B a-O by X. As a result, from 5r1-, aXO is X=O
It was found that the a-axis length varied continuously between 5.14 and 5.54° for 1.
さらに発明をより明確に理解されるために、以下の実施
例に具体的に示す。In order that the invention may be more clearly understood, it is illustrated in the following examples.
前段階の実験としては、（Ｃａ、Ｓｒ、Ｂａ）０薄膜形
成を電子ビーム蒸着法にて行ったが、Ｂｉ系超伝導薄膜
を形成するために、イオンビームスパッタリング法を用
い実験を行った。In the preliminary experiment, a (Ca, Sr, Ba) 0 thin film was formed by electron beam evaporation, but in order to form a Bi-based superconducting thin film, an experiment was conducted using ion beam sputtering.
第２図に本実施例で用いた真空装置の概略図を示す。第
２図において、２１はＢ ｉ−８ｒ−Ｃａ−Ｃｕ−Ｏ焼
成ディスクターゲット、２２はイオンガン、２３はＳｒ
Ｏを蒸発させる電子ビーム加熱蒸発装置、２４はＢａＯ
を蒸発させる電子ビーム加熱蒸発装置、２５．２６．２
７はシャッター、２８はＭｇＯ基体、２９は基体加熱用
ヒーターを示す。FIG. 2 shows a schematic diagram of the vacuum apparatus used in this example. In FIG. 2, 21 is a B i-8r-Ca-Cu-O firing disk target, 22 is an ion gun, and 23 is an Sr
An electron beam heating evaporator for evaporating O, 24 is BaO
Electron beam heating evaporation device for evaporating, 25.26.2
7 is a shutter, 28 is an MgO substrate, and 29 is a heater for heating the substrate.
ＭｇＯ（１００）基体２８にイオンガン２２からのＡｒ
イオンビームでスパッタされたＢ ｉ−８ｒ−Ｃａ−Ｃ
ｕ−０焼成デイスクターゲツトからのＢ ｉ−８ｒ−Ｃ
ａ−Ｃｕ−０粒子、電子ビーム加熱蒸発装置２３．２４
からのＳｒ０粒子、ＢａＯ粒子が焦点を結ぶように各蒸
発源の仰角が調整されている。Ar from the ion gun 22 is applied to the MgO (100) substrate 28.
B i-8r-Ca-C sputtered with ion beam
B i-8r-C from u-0 firing disc target
a-Cu-0 particles, electron beam heating evaporation device 23.24
The elevation angle of each evaporation source is adjusted so that the Sr0 particles and BaO particles from the evaporation source are focused.
Ｂ１−８ｔ−Ｃａ−Ｃｏ−０焼成デイスクターゲツト２
１は組成比がＢｉ ：Ｓｒ ：Ｃａ ：Ｃｕ＝２
：１：１：１．５になるようＢ ｉ２０３ 、Ｓ ｒ
Ｃ０３、ＣａＣＯ３、ＣｕＯ粉体を秤量し、空気中で９
００℃、５時間焼成・粉砕した粉体を直径６０ｍｍのデ
ィスク状に成形されたものである。基体２８上の（Ｓｒ
、Ｂａ）Ｏ薄膜で組成比がＳｒ ： Ｂａ＝３ ：
７になるようシャッター２６．２７の開閉サイクル調節
してＳｒ０粒子、ＢａＯ粒子の堆積量を調節した。基体
２８をヒーター２９で約６５０℃に加熱し、基体２８上
に（Ｓｒ、Ｂａ）Ｏ薄膜を１００人、さらにＢ ｉ−８
ｒ−Ｃａ−Ｃｕ−０薄膜を５００Ａ堆積した。B1-8t-Ca-Co-0 fired disk target 2
1 has a composition ratio of Bi:Sr:Ca:Cu=2
:1:1:1.5 B i203 , S r
Weigh C03, CaCO3, CuO powder, and store it in air at 9
The powder was calcined and pulverized at 00°C for 5 hours and molded into a disk shape with a diameter of 60 mm. (Sr
, Ba)O thin film with a composition ratio of Sr:Ba=3:
The amount of deposited Sr0 particles and BaO particles was adjusted by adjusting the opening and closing cycles of the shutters 26 and 27 so that the amount of Sr0 particles and BaO particles was 7. The substrate 28 is heated to about 650° C. with a heater 29, and a (Sr, Ba)O thin film is formed on the substrate 28 by 100 people, and then Bi-8
An r-Ca-Cu-0 thin film was deposited at 500A.
第３図の本実施例で行った積層膜概略図を示す。FIG. 3 shows a schematic diagram of a laminated film formed in this example.
Ｓ ｒ−Ｂ ａ−０膜を堆積させた場合、堆積させない
場合の薄膜の抵抗率の変化を調べ、その結果を第４図に
示す。薄膜はスパッタリング蒸着終了後でも超伝導転移
を起こすが、結晶性を更によくするために酸素ガス雰囲
気中において、８００℃、５時間の熱処理を施した。第
４図において４１．４２はそれぞれＳ ｒ−Ｂ ａ−０
薄膜を堆積した場合、堆積しない場合の薄膜試料の抵抗
率の温度特性を示す。抵抗率の温度特性４１．４２の超
伝導転移温度はともに１２０にであったが、ゼロ抵抗温
度は特性４１でｌｌ０Ｋ、特性４２で８８にであった。Changes in the resistivity of the thin film were investigated when the S r-B a-0 film was deposited and when it was not deposited, and the results are shown in FIG. The thin film undergoes superconducting transition even after sputtering deposition, but in order to further improve crystallinity, it was heat-treated at 800° C. for 5 hours in an oxygen gas atmosphere. In Fig. 4, 41.42 are respectively S r-B a-0
The temperature characteristics of the resistivity of a thin film sample with and without a thin film deposited are shown. The superconducting transition temperatures of resistivity temperature characteristics 41 and 42 were both 120, but the zero resistance temperature was 10K for characteristic 41 and 88 for characteristic 42.
この原因はおよそ次のように説明することができる。す
なわち、Ｓ ｒ−Ｂ ａ−０薄膜はＭｇＯ基体上に格子
定数が等しく基体上にエピタキシャル成長し、Ｂ１−８
ｒ−Ｃａ−Ｃｕ−０膜とＳ ｒ−Ｂ ａ−０膜との界面
では、Ｂ ｉ−８ｒ−Ｃａ−Ｃｕ−０結晶の格子定数に
一致するよっＳｒ イオンとＢａ２＋イオンとが適当
−２＋
に固相反応的に入れ替わり、Ｂ ｉ−８ｒ−Ｃａ−Ｃｕ
−０薄膜をＳ ｒ−Ｂ ａ−０薄膜上にエピタキシャル
成長させたものと考えら・れる。さらに、Ｓ ｒ−Ｂ
ａ−０結晶は融点が充分高く安定であるため、ＭｇＯ基
体とＳ ｒ−Ｂ ａ−０膜、あるいはＳ ｒ−Ｂ ａ−
０膜とＢ ｉ−８ｒ−Ｃａ−Ｃｕ−０膜との界面での元
素の相互拡散は起こらないことによるものと考えられる
。The reason for this can be roughly explained as follows. That is, the S r-B a-0 thin film is epitaxially grown on the MgO substrate with the same lattice constant, and the B1-8
At the interface between the r-Ca-Cu-0 film and the S r-B a-0 film, Sr ions and Ba2+ ions are appropriately -2+ because they match the lattice constant of Bi-8r-Ca-Cu-0 crystal. B i-8r-Ca-Cu
It is considered that the -0 thin film was epitaxially grown on the Sr-B a-0 thin film. Furthermore, S r-B
Since the a-0 crystal has a sufficiently high melting point and is stable, it can be used to form an MgO substrate and an S r-B a-0 film, or an S r-B a-
This is thought to be due to the fact that mutual diffusion of elements does not occur at the interface between the 0 film and the Bi-8r-Ca-Cu-0 film.
上記実施例によれば、Ｂ ｉ−８ｒ−Ｃａ−Ｃｕ−０膜
とＳ ｒ−Ｂ ａ−０膜を基体上に積層することで確認
されたが、酸化物超伝導体のＹ −Ｂ ａ−Ｃｕ−０系
、Ｐｂ−８ｒ−（Ｃａ、Ｙ） −Ｃｕ−０系、Ｔ Ｉ−
Ｂ ａ−Ｃａ−Ｃｕ−Ｏ系についても同様に有効である
ことを確認した。According to the above example, it was confirmed by stacking the B i-8r-Ca-Cu-0 film and the S r-B a-0 film on the substrate, but the Y-B a of the oxide superconductor -Cu-0 series, Pb-8r- (Ca, Y) -Cu-0 series, T I-
It was confirmed that the B a-Ca-Cu-O system is similarly effective.
なお、酸化マグネシウム（ＭｇＯ）以外の種々の基体に
ついても本発明の効果を実験・検討した結果、チタン酸
ストロンチウム（ＳｒＴｉＯ３）、サファイア（α−Ａ
１２０３、ＭｇＡｌ２Ｏ４、ＹＳＺ、ＬａＧａＯ３、Ｌ
ａＡ １０３ 、ＮｄＧａ０ ＸＹＡｌＯ３、Ｓｉ、
ＧａＡｓの結晶性基体についても本発明が有効であるこ
とを確認した。In addition, as a result of experiments and examination of the effects of the present invention on various substrates other than magnesium oxide (MgO), we found that strontium titanate (SrTiO3), sapphire (α-A
1203, MgAl2O4, YSZ, LaGaO3, L
aA 103 , NdGa0 XYAlO3, Si,
It was confirmed that the present invention is also effective for GaAs crystalline substrates.
以上のように本発明の超伝導薄膜は、酸化物超伝導薄膜
の高性能化、および極薄膜化を実現し、提供するもので
、デバイス等の応用には必須の技術を確立したものであ
り、本発明の工業的価値は大きい。As described above, the superconducting thin film of the present invention realizes and provides an oxide superconducting thin film with improved performance and ultrathin film thickness, and has established a technology that is essential for applications such as devices. , the industrial value of the present invention is great.
［発明の効果コ
以上説明したように本発明によれば、基体と主成分とし
て少なくとも銅（Ｃｕ）を含む酸化物超伝導薄膜との間
に、主成分としてＣａ、ＳｒおよびＢａから選ばれる少
なくとも一種以上の元素を含む酸化物薄膜層を存在させ
たので、酸化物超伝導薄膜に基採の元素成分が拡散する
ことを防止でき、結晶性に優れた酸化物超伝導薄膜を形
成することができる。[Effects of the Invention] As explained above, according to the present invention, at least one selected from Ca, Sr, and Ba as a main component is formed between the substrate and the oxide superconducting thin film containing at least copper (Cu) as the main component. Since the oxide thin film layer containing one or more elements is present, it is possible to prevent the basic elemental components from diffusing into the oxide superconducting thin film, and it is possible to form an oxide superconducting thin film with excellent crystallinity. can.
また、基体がＭｇＯ，ＳｒＴｉＯ３、サファイア（α−
Ａ１２０３）、ＭｇＡｌ２Ｏ４、ＹＳＺ１ＬａＧａ０３
、ＬａＡｌＯ３、ＮｄＧａｏ３、ＹＡｌＯ３、Ｓｉ、Ｇ
ａＡｓの結晶性基体ノイずれかであるという本発明の好
ましい構成によれば、電子デバイスとして好適なものと
することができる。In addition, the substrate is MgO, SrTiO3, sapphire (α-
A1203), MgAl2O4, YSZ1LaGa03
, LaAlO3, NdGao3, YAlO3, Si, G
According to the preferred configuration of the present invention in which the crystalline base material is an aAs crystalline substrate, it can be suitable as an electronic device.
また前記した本発明方法によれば、基体上に主成分とし
てＣａ、ＳｒおよびＢａから選ばれる少なくとも一種以
上の元素を含む成分を分子堆積して酸化物薄膜層を設け
、次いで熱処理し、次に主成分として少なくとも銅（Ｃ
ｕ）を含む酸化物超伝導薄膜をエピタキシャル成長させ
て堆積し、しかる後熱処理するので、結晶性に優れた酸
化物超伝導薄膜を効率よく合理的に形成することができ
る。Further, according to the method of the present invention described above, a component containing at least one element selected from Ca, Sr, and Ba as a main component is molecularly deposited on a substrate to form an oxide thin film layer, then heat treated, and then At least copper (C
Since the oxide superconducting thin film containing u) is epitaxially grown and deposited and then heat-treated, the oxide superconducting thin film with excellent crystallinity can be efficiently and rationally formed.
さらに、酸化物薄膜層の堆積時に、基体を５００℃以上
に加熱するという本発明方法の好ましい構成によれば、
基体上に酸化物薄膜層をエピタキシャル成長させること
ができる。Furthermore, according to a preferred configuration of the method of the present invention, the substrate is heated to 500° C. or higher during the deposition of the oxide thin film layer.
A thin oxide layer can be epitaxially grown on the substrate.
第１図は（Ｃａ、Ｓｒ、Ｂａ）Ｏ結晶の構造概略図、第
２図は本発明の実施例における真空装置の構造概略図、
第３図は本発明の実施例における超伝導薄膜作製構造概
念図、第４図は本発明の実施例で得られた薄膜の抵抗率
の温度特性。
２１− Ｂ ｉ−８ｒ−Ｃａ−Ｃｕ−０焼成デイスクタ
ーゲツト、 ２２・・・イオンガン、 ２３．２４・・
・電子ビーム加熱蒸発装置、 ２５．２６．２７・・・
シャッター、２８・・・ＭｇＯ基体、 ２９・・・ヒー
ター、４１．４２・・・薄膜の抵抗率の温度特性。
第１図
２８・・・ＭｇＯ基体
２９・・・ヒーター
第３図
Ｍ（Ｋ）
第４図FIG. 1 is a schematic structural diagram of a (Ca, Sr, Ba)O crystal, and FIG. 2 is a structural schematic diagram of a vacuum device in an embodiment of the present invention.
FIG. 3 is a conceptual diagram of a superconducting thin film fabrication structure in an example of the present invention, and FIG. 4 is a temperature characteristic of resistivity of the thin film obtained in an example of the present invention. 21- Bi-8r-Ca-Cu-0 fired disc target, 22... Ion gun, 23.24...
・Electron beam heating evaporation device, 25.26.27...
Shutter, 28... MgO substrate, 29... Heater, 41.42... Temperature characteristics of resistivity of thin film. Fig. 1 28...MgO base 29... Heater Fig. 3 M(K) Fig. 4
Claims (4)
トロンチウム（Ｓｒ）およびバリウム（Ｂａ）から選ば
れる少なくとも一種以上の元素を含む酸化物薄膜層を存
在させ、前記酸化物薄膜層上に、主成分として少なくと
も銅（Ｃｕ）を含む酸化物超伝導薄膜層を存在させたこ
とを特徴とする超伝導薄膜。(1) An oxide thin film layer containing at least one element selected from calcium (Ca), strontium (Sr), and barium (Ba) as a main component is present on the substrate, and on the oxide thin film layer, A superconducting thin film characterized by having an oxide superconducting thin film layer containing at least copper (Cu) as a main component.
α−Ａｌ＿２Ｏ＿３）、ＭｇＡｌ＿２Ｏ＿４、ＹＳＺ、
ＬａＧａＯ＿３、ＬａＡｌＯ＿３、ＮｄＧａＯ＿３、Ｙ
ＡｌＯ＿３、Ｓｉ、ＧａＡｓの結晶性基体のいずれかで
ある請求項１記載の超伝導薄膜。(2) The substrate is MgO, SrTiO_3, sapphire (
α-Al_2O_3), MgAl_2O_4, YSZ,
LaGaO_3, LaAlO_3, NdGaO_3, Y
The superconducting thin film according to claim 1, which is a crystalline substrate of AlO_3, Si, or GaAs.
トロンチウム（Ｓｒ）およびバリウム（Ｂａ）から選ば
れる少なくとも一種以上の元素を含む成分を分子堆積し
て酸化物薄膜層を設け、次いで熱処理し、次に主成分と
して少なくとも銅（Ｃｕ）を含む酸化物超伝導薄膜層を
エピタキシャル成長させて堆積し、しかる後熱処理する
ことを特徴とする超伝導薄膜の製造方法。(3) A thin oxide film layer is provided on the substrate by molecularly depositing a component containing at least one element selected from calcium (Ca), strontium (Sr), and barium (Ba) as a main component, and then heat-treated. . A method for producing a superconducting thin film, which comprises: epitaxially growing and depositing an oxide superconducting thin film layer containing at least copper (Cu) as a main component; and then heat-treating.
加熱する請求項３記載の超伝導薄膜の製造方法。(4) The method for producing a superconducting thin film according to claim 3, wherein the substrate is heated to 500° C. or higher during the deposition of the oxide thin film layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2300395A JPH04170394A (en) | 1990-11-05 | 1990-11-05 | Superconducting thin film and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2300395A JPH04170394A (en) | 1990-11-05 | 1990-11-05 | Superconducting thin film and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04170394A true JPH04170394A (en) | 1992-06-18 |
Family
ID=17884275
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2300395A Pending JPH04170394A (en) | 1990-11-05 | 1990-11-05 | Superconducting thin film and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04170394A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1221708A2 (en) * | 1995-12-15 | 2002-07-10 | Matsushita Electric Industrial Co., Ltd. | Plasma display panel suitable for high-quality display and production method |
-
1990
- 1990-11-05 JP JP2300395A patent/JPH04170394A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1221708A2 (en) * | 1995-12-15 | 2002-07-10 | Matsushita Electric Industrial Co., Ltd. | Plasma display panel suitable for high-quality display and production method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6027826A (en) | Method for making ceramic-metal composites and the resulting composites | |
| US5972845A (en) | High critical temperature superconductors in the system La3-z . Me.subz Ba3 Ca1-v Ncv Cu7 O16+x where Me=a rare earth or alkaline metal ION and Nc is a Mg, Cd ION | |
| US5361720A (en) | Epitaxial deposition | |
| US5141917A (en) | Multilayer deposition method for forming Pb-doped Bi-Sr-Ca-Cu-O Superconducting films | |
| JP3037514B2 (en) | Thin film superconductor and method of manufacturing the same | |
| JPH04170394A (en) | Superconducting thin film and its production | |
| US5939361A (en) | Method of fabricating Tl or Hg-containing oxide superconductor film | |
| JP2979422B2 (en) | Method of manufacturing insulator and insulating thin film, and method of manufacturing superconducting thin film and superconducting thin film | |
| US5296455A (en) | Process for preparing superconductor of compound oxide of Bi-Sr-Ca-Cu system | |
| JP2555477B2 (en) | Superconducting thin film and manufacturing method thereof | |
| US5962373A (en) | Method for producing mixed metal oxide compounds | |
| JPH075313B2 (en) | Method for producing oxide superconducting thin film | |
| JP2669052B2 (en) | Oxide superconducting thin film and method for producing the same | |
| US5260267A (en) | Method for forming a Bi-containing superconducting oxide film on a substrate with a buffer layer of Bi2 O3 | |
| EP0640994B1 (en) | Superconductor thin film and manufacturing method | |
| JP2741277B2 (en) | Thin film superconductor and method of manufacturing the same | |
| JPH05170448A (en) | Production of thin ceramic film | |
| JP3041529B2 (en) | Bi-based oxide superconducting thin film | |
| Kobayashi et al. | Chemi-physical diagnosis of BiSrCaCuO thin film preparation | |
| JP3025891B2 (en) | Thin film superconductor and method of manufacturing the same | |
| Tauber et al. | High critical temperature superconductors in the system La 3-z. Me. subz Ba 3 Ca 1-v Nc v Cu 7 O 16+ x where Me= a rare earth or alkaline metal ION and Nc is a Mg, Cd ION | |
| JPH0388725A (en) | Oxide superconductor | |
| JPH04300272A (en) | Thin oxide superconducting film and its production | |
| JPH02196006A (en) | Formation of superconducting thin film | |
| JPH0437609A (en) | Oxide superconducting thin film and its production |