JPH046108A - Insulator, production of insulating thin film, superconducting thin film and production thereof - Google Patents
Insulator, production of insulating thin film, superconducting thin film and production thereofInfo
- Publication number
- JPH046108A JPH046108A JP2105931A JP10593190A JPH046108A JP H046108 A JPH046108 A JP H046108A JP 2105931 A JP2105931 A JP 2105931A JP 10593190 A JP10593190 A JP 10593190A JP H046108 A JPH046108 A JP H046108A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- elements
- alkaline earth
- oxide
- group iia
- 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.)
- Granted
Links
- 239000010409 thin film Substances 0.000 title claims abstract description 80
- 239000012212 insulator Substances 0.000 title claims abstract description 25
- 238000004519 manufacturing process Methods 0.000 title claims description 27
- 239000002887 superconductor Substances 0.000 claims abstract description 28
- 238000000034 method Methods 0.000 claims abstract description 23
- 239000000758 substrate Substances 0.000 claims abstract description 18
- 229910052802 copper Inorganic materials 0.000 claims abstract description 15
- 229910052797 bismuth Inorganic materials 0.000 claims abstract description 8
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims abstract description 6
- 150000001342 alkaline earth metals Chemical class 0.000 claims abstract description 6
- 239000010949 copper Substances 0.000 claims description 29
- 238000004544 sputter deposition Methods 0.000 claims description 23
- 230000008020 evaporation Effects 0.000 claims description 14
- 238000001704 evaporation Methods 0.000 claims description 14
- 150000002603 lanthanum Chemical class 0.000 claims description 11
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 9
- 229910052727 yttrium Inorganic materials 0.000 claims description 5
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims description 2
- 239000002648 laminated material Substances 0.000 claims 6
- 239000000463 material Substances 0.000 abstract description 17
- 229910052747 lanthanoid Inorganic materials 0.000 abstract 1
- 150000002602 lanthanoids Chemical class 0.000 abstract 1
- 239000010408 film Substances 0.000 description 55
- 238000010438 heat treatment Methods 0.000 description 15
- 239000000203 mixture Substances 0.000 description 12
- 230000007704 transition Effects 0.000 description 12
- 239000013078 crystal Substances 0.000 description 11
- 238000010586 diagram Methods 0.000 description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 230000000737 periodic effect Effects 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 5
- 238000009792 diffusion process Methods 0.000 description 5
- 238000003475 lamination Methods 0.000 description 5
- 238000001755 magnetron sputter deposition Methods 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 229910052779 Neodymium Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 3
- 229910052791 calcium Inorganic materials 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010030 laminating Methods 0.000 description 3
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- 229910052692 Dysprosium Inorganic materials 0.000 description 2
- 229910052693 Europium Inorganic materials 0.000 description 2
- 229910052688 Gadolinium Inorganic materials 0.000 description 2
- 229910052772 Samarium Inorganic materials 0.000 description 2
- -1 T Bi for b Inorganic materials 0.000 description 2
- 229910052769 Ytterbium Inorganic materials 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- NFFYXVOHHLQALV-UHFFFAOYSA-N copper(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Cu].[Cu] NFFYXVOHHLQALV-UHFFFAOYSA-N 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000005477 sputtering target Methods 0.000 description 2
- 229910052712 strontium Inorganic materials 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 229910004247 CaCu Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910002480 Cu-O Inorganic materials 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910052689 Holmium Inorganic materials 0.000 description 1
- 229910052765 Lutetium Inorganic materials 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- 229910052771 Terbium Inorganic materials 0.000 description 1
- 229910052775 Thulium Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 229910052740 iodine Inorganic materials 0.000 description 1
- 238000001659 ion-beam spectroscopy Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium oxide Inorganic materials [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 238000001947 vapour-phase growth Methods 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
- Inorganic Compounds Of Heavy Metals (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
- Physical Vapour Deposition (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Inorganic Insulating Materials (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、酸化物高温超伝導体等の６００〜９００℃の
比較的高い生成過程を経る材料をデバイス化する際に不
可欠な絶縁体、および絶縁薄膜の製造方法と、また、よ
り高性能な超伝導薄膜、および超伝導薄膜の製造方法に
関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to insulators, which are indispensable when making devices from materials that undergo a relatively high generation process at 600 to 900°C, such as oxide high-temperature superconductors. The present invention also relates to a method for producing an insulating thin film, a higher performance superconducting thin film, and a method for producing a superconducting thin film.
（従来の技術）
現在、最も応用が急がれている材料の１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−Ｌａ−Ｃｕ−０系の高温超伝導体が提案された［Ｊ
、Ｇ、Ｂｅｄｎｏｒｚ ａｎｄ Ｋ、Ａ。(Prior Art) One of the materials that is currently most urgently being applied 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-La-Cu-0 was proposed [J
, G., Bednorz and K., A.
Ｍｕｌｌｅｒ、ツァイトシュリフト・フユア・フィジー
ク（Ｚｅｔｓｈｒｉｆｔ Ｆｕｒ Ｐｈｙｓｉｋ Ｂ）
−ＣｏｎｄｅｎｓｅｄＭａｔｔｅｒ、 Ｖｏｌ、６４．
１８９−１９３ （１９８６） ］。さらに、］Ｂ１−
８ｒ−Ｃａ−Ｃｕ−○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。Muller, Zetshrift Fur Physik B
-CondensedMatter, Vol, 64.
189-193 (1986)]. Furthermore, ]B1-
It has also been discovered that the material 8r-Ca-Cu-○ exhibits a transition temperature above 100' [H, Maeda.
Ｙ、Ｔａｎａｋａ、 Ｍ、Ｆｕｋｕｔｏｍｉ 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 Ｊｏｕｒ
ｎａｌ ｏｆ ＡｐｐｌｉｅｄＰｈｙｓｉｃｓ）Ｖｏｌ
、２７． Ｌ２０９−２１０ （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
用が期待されている。Y., Tanaka, M., Fukutomi and
T, Asano, Japanese Journal of Applied Physics
nal of Applied Physics) Vol.
, 27. L209-210 (1988)]. The details of the superconducting mechanism of this type of material are not clear, but the transition temperature may be higher than room temperature, and it is expected to be used as a high-temperature superconductor in the electronic device field rather than conventional binary compounds. has been done.
そして、これらの酸化物超伝導体の開発と相俟って、こ
の材料を電子デバイスへの応用を考え、酸化物超伝導体
を作製する際に経る高熱過程に対しても安定な絶縁体お
よび絶縁簿膜の開発が行われている［ Ｙ 、 Ｉ ｃ
ｈｉｋａｗａ 、 Ｈ、Ａ ｄａｃｈｉ 。Along with the development of these oxide superconductors, we are considering the application of this material to electronic devices, and are developing stable insulators and materials that can withstand the high-temperature processes that go through when producing oxide superconductors. Insulating films are being developed [Y, Ic
hikawa, H., and A dachi.
Ｔ、Ｍｉｔｓｕｙｕ ａｎｄ Ｋ、Ｗａｓａ、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 Ｊｏｕｒｎａｌ ｏｆ Ａｐｐｌｉ
ｅｄ Ｐｈｙｓｉｃｓ）Ｖｏｌ、２７． ＬａＢ５−３
８３ （１９８ｇ）］。T, Mitsuyu and K, Wasa, Japanese Journal of Applied Physics (
Japanese Journal of Appli
ed Physics) Vol. 27. LaB5-3
83 (198g)].
さらに超伝導体と絶縁体とを交互に積層することにより
、より高い超伝導転移温度が従来から期待されていた［
Ｍ、Ｈ，Ｃｏｈｅｎ ａｎｄ Ｄ、Ｈ，Ｄｏｕｇｌａｓ
ｓ、 Ｊｒ、、フィジカル・レビュー・レターズ（Ｐｈ
ｙｓｉｃａｌ Ｒｅｖｉｅｗ Ｌｅｔｔｅｒｓ） Ｖｏ
ｌ、１９． Ｌｉ２Ｓ−１，２１（１９６７）］。Furthermore, by alternately stacking superconductors and insulators, higher superconducting transition temperatures have been expected [
M, H, Cohen and D, H, Douglas
S, Jr., Physical Review Letters (Ph.
ysical Review Letters) Vo
l, 19. Li2S-1, 21 (1967)].
（発明が解決しようとする課題）
しかしながら、酸化物超伝導体の材料は、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、そのため絶縁体の結
晶性が崩れ、絶縁体および絶縁薄膜と超伝導体との間で
各元素の相互拡散が起こり、超伝導体の特性劣化並びに
絶縁体の特性劣化が起こり、特に高温酸化物超伝導体と
絶縁膜との周期的な積層構造を得ることは極めて困難で
あり、ジョセフソンデバイスが代表応用例としてあげら
れるこの構造を利用した集積化デバイスを構成不可能に
近いものとしていた。(Problems to be Solved by the Invention) However, in order to obtain good superconducting properties, oxide superconductor materials require heat treatment at least at 600°C or higher or heating during formation. The crystallinity collapses and mutual diffusion of elements occurs between the insulator and the insulating thin film and the superconductor, resulting in deterioration of the properties of the superconductor and of the insulator. It is extremely difficult to obtain a periodic stacked structure with films, making it nearly impossible to construct an integrated device using this structure, of which the Josephson device is a typical application example.
さらに、高温超伝導体および薄膜にとって最適な絶縁薄
膜が得られていないため、超伝導体と絶縁体との有効な
積層構造が達成されないために、超伝導材料そのものの
超伝導転移温度の上昇は望めないのが現状であった。Furthermore, since the optimal insulating thin film for high-temperature superconductors and thin films has not been obtained, and an effective stacked structure of superconductors and insulators is not achieved, the increase in the superconducting transition temperature of the superconducting material itself is The current situation was hopeless.
本発明の目的は、従来の欠点を解消し、酸化物高温超伝
導体等の比較的高い生成過程を経る材料をデバイス化す
る際に不可欠な絶縁体、および絶縁薄膜の製造方法と、
また、より高性能な超伝導薄膜、および超伝導薄膜の製
造方法を提供することである。The purpose of the present invention is to eliminate the conventional drawbacks and provide a method for producing an insulator and an insulating thin film, which are essential when making devices from materials that undergo a relatively high production process such as oxide high-temperature superconductors.
Another object of the present invention is to provide a superconducting thin film with higher performance and a method for manufacturing the superconducting thin film.
（課題を解決するための手段）
第１の発明の絶縁体は、主体成分が少なくともビスマス
（Ｂｉ）、銅（Ｃ，ｕ）、アルカリ土類（ＩＩａ族）。(Means for Solving the Problems) The insulator of the first invention has at least bismuth (Bi), copper (C, u), and alkaline earth (group IIa) as main components.
Ｌｎから成るものである。It consists of Ln.
さらに第２の発明の絶縁薄膜の製造方法は、第１の発明
の絶縁体の薄膜化に関するものであり、基体上に、少な
くともＢｉを含む酸化物、少なくとも銅およびアルカリ
土類（ＩＩａ族）を含む酸化物、少なくとも銅およびＬ
ｎを含む酸化物を周期的に積層させて形成させて得るも
のである。Furthermore, the method for producing an insulating thin film according to the second invention relates to thinning the insulator according to the first invention, and includes applying an oxide containing at least Bi, at least copper and alkaline earth (group IIa) on the substrate. oxides containing at least copper and L
It is obtained by periodically stacking n-containing oxides.
さらに第３の発明の超伝導薄膜は、基体上に、主体成分
が少なくともＢｉ、 Ｃｕ、アルカリ土類（ＩＩａ族）
から成る層状酸化物超伝導薄膜と、主体成分が少なくと
もＢｉ、 Ｃｕ、アルカリ土類（ＩＩａ族Ｌ Ｌｎから
成る層状酸化物絶縁体薄膜が交互に積層された構造を持
つものである。Further, in the superconducting thin film of the third invention, the main components are at least Bi, Cu, and alkaline earth (group IIa) on the substrate.
It has a structure in which layered oxide superconducting thin films consisting of oxides and layered oxide insulating thin films whose main components are at least Bi, Cu, and alkaline earth (IIa group Ln) are laminated alternately.
さらに第４の発明の超伝導薄膜の製造方法は、基体上に
、少なくともＢｉを含む酸化物と少なくともＣｕおよび
アルカリ土類（ＩＩａ族）を含む酸化物とを周期的に積
層させて形成する酸化物薄膜と、少なくともＢｉを含む
酸化物と少なくともＣｕおよびアルカリ土類（ＩＩａ族
）、Ｌｎを含む酸化物とを周期的に積層させて形成する
酸化物薄膜とを、交互に積層させて得るものである。Furthermore, a method for producing a superconducting thin film according to a fourth aspect of the present invention includes an oxide film formed by periodically stacking an oxide containing at least Bi and an oxide containing at least Cu and alkaline earth (group IIa) on a substrate. An oxide thin film formed by periodically laminating an oxide containing at least Bi and an oxide containing at least Cu, alkaline earth (group IIa), and Ln, which are obtained by alternately laminating It is.
ここでＡはアルカリ土類であり、ｎａ族元素のうちの少
なくとも一種あるいは二種以上の元素、ＬｎはＹもしく
はランタン系列にある元素の少なくとも一種以上の元素
を示す。Here, A is alkaline earth, and represents at least one or more elements of the Na group elements, and Ln represents Y or at least one element of the lanthanum series elements.
（作 用）
第１の発明による絶縁体は、熱的にも極めて安定なり１
２０２酸化膜層またはこれを主体とした層により覆われ
た結晶構造を有しており、酸化物超伝導体とほぼ等しい
生成温度であることから、特に酸化物高温超伝導体と接
触させても高温熱処理等の過程を経ても本発明による絶
縁体、酸化物超伝導体の結晶性および特性が互いに劣化
させあうことがない。さらに第１の発明による絶縁体の
結晶構造は酸化物超伝導体のそれと同じペロブスカイト
構造であり、特にａおよびｂ軸の長さがほぼ等しいこと
からも酸化物超伝導体と絶縁体の安定な連続積層が可能
である６
さらに第２の発明においては上記構造を達成するため、
少なくともＢＩを含む酸化物と、少なくとも銅およびア
ルカリ土類（ＩＩａ族）を含む酸化物あるいはＹとラン
タン系にある元素を少なくとも一種以上含む酸化物とを
、周期的に積層させて分子レベルの制御による薄膜の作
製を行うことによって、再現性良（Ｂｉ系超伝導薄膜と
絶縁膜との積層が得られ、またジョセフソンデバイス設
計に必要とされる厚さ数百Å以下の層間絶縁膜の安定形
成を可能にするものである。(Function) The insulator according to the first invention is extremely stable thermally.
It has a crystal structure covered with a 202 oxide film layer or a layer mainly composed of this, and its formation temperature is almost the same as that of oxide superconductors, so it can be used even when brought into contact with oxide high-temperature superconductors. The crystallinity and properties of the insulator and oxide superconductor according to the present invention do not mutually deteriorate even after undergoing processes such as high-temperature heat treatment. Furthermore, the crystal structure of the insulator according to the first invention is a perovskite structure, which is the same as that of the oxide superconductor, and in particular, the lengths of the a and b axes are almost equal, which makes it possible for the oxide superconductor and the insulator to be stable. Continuous lamination is possible6 Furthermore, in the second invention, in order to achieve the above structure,
An oxide containing at least BI and an oxide containing at least copper and alkaline earth (group IIa) or an oxide containing at least one element in the lanthanum series and Y are layered periodically to control the molecular level. By fabricating a thin film using It is what makes it possible to form.
さらに第３の発明においては、Ｂｉ、０．酸化膜層また
はこれを主体とした層によりともに覆われた結晶構造と
なっているところの、Ｂｉ系超伝導薄膜と第１の発明に
よる絶縁体の薄膜とが、交互に積層された構造をとるこ
とによって、超伝導薄膜と絶縁膜との間での元素の相互
拡散の積層が可能になり、その結果Ｂｉ系超伝導薄膜に
おける超伝導転移温度が安定に再現性よく実現されたも
のである。Furthermore, in the third invention, Bi, 0. A structure in which a Bi-based superconducting thin film and an insulating thin film according to the first invention are alternately laminated, the Bi-based superconducting thin film having a crystal structure covered with an oxide film layer or a layer mainly composed of the same. This makes it possible to achieve layered mutual diffusion of elements between the superconducting thin film and the insulating film, and as a result, the superconducting transition temperature in the Bi-based superconducting thin film can be stably achieved with good reproducibility.
さらに第４の発明においては第３の発明の極めて安定に
、しかも微細スケールでの構造を達成するため、少なく
ともＢｉを含む酸化物と、少なくとも銅およびアルカリ
土類（ＩＩａ族）を含む酸化物あるいは、少なくとも銅
およびアルカリ土類（ＩＩａ族）とＬｎを含む酸化物と
を、周期的に積層させて分子レベルの制御による薄膜の
作製を行うことによって、再現性よ＜Ｂｉ系超伝導薄膜
と絶縁膜との積層を実現させるものである。Furthermore, in the fourth invention, in order to achieve the extremely stable and fine-scale structure of the third invention, an oxide containing at least Bi and an oxide containing at least copper and alkaline earth (group IIa) or By periodically stacking at least copper, alkaline earth metals (group IIa), and oxides containing Ln to create thin films under control at the molecular level, reproducibility is improved. This realizes lamination with membranes.
（実施例）
通常、Ｂ ｉ−Ｓ ｒ−Ｃａ−Ｃｕ−０系等の酸化物超
伝導薄膜は６００〜７００℃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、そののち７００〜９５０℃の熱処理を施し、超伝導
特性を向上させる。(Example) Generally, a B i-S r-Ca-Cu-0 based oxide superconducting thin film is obtained by vapor deposition on a substrate heated to 600 to 700°C. After deposition, the thin film exhibits superconducting properties as it is, but is then subjected to heat treatment at 700 to 950°C to improve its superconducting properties.
しかしながら、基体温度が高いときに絶縁膜を酸化物超
伝導薄膜に続いて積層したり、絶縁膜を形成後熱処理を
行った場合、超伝導膜と絶縁膜との間で、元素の相互拡
散が起こり超伝導特性が大きく劣化することが判明した
。相互拡散を起こさないためには、超伝導膜、絶縁膜の
結晶性が優れていること、超伝導膜、絶縁膜間での格子
の整合性が優れていること、絶縁膜が７００〜９５０℃
の熱処理に対して安定であることが不可欠と考えられる
。However, if an insulating film is laminated next to an oxide superconducting thin film when the substrate temperature is high, or if heat treatment is performed after forming the insulating film, mutual diffusion of elements will occur between the superconducting film and the insulating film. It was found that this phenomenon caused a significant deterioration of superconducting properties. In order to prevent mutual diffusion, the crystallinity of the superconducting film and insulating film must be excellent, the lattice matching between the superconducting film and the insulating film must be excellent, and the temperature of the insulating film must be maintained at 700 to 950°C.
It is considered essential that the material be stable against heat treatment.
まず、Ｂｉ２Ｏ２酸化物層に挟まれた構造を持つＢｉ系
超伝導体が高温の熱処理に対して、極めて安定であるた
め、］］３ｉ−８ｒ−Ｃａ−Ｃｕ−を構成する各元素を
他の元素と部分置換していった場合に超伝導体の電気特
性がどのように変化していくかを調べ、その結果、Ｂ
ｉ、 Ｓ ｒ、 Ｃａ２Ｃｕｚ○８においてＣａの一部
をＬｎ置換していくとき、Ｗ検量にしたがって、試料を
抵抗率が室温において、上昇することを見い出した。こ
こでＬｎはＹとランタン系列にある元素とする。First, since the Bi-based superconductor, which has a structure sandwiched between Bi2O2 oxide layers, is extremely stable against high-temperature heat treatment, each element constituting ]]3i-8r-Ca-Cu- is We investigated how the electrical properties of superconductors change when elements are partially substituted, and as a result, we found that B
It was found that when part of Ca was replaced with Ln in i, S r, Ca2Cuz○8, the resistivity of the sample increased at room temperature according to W calibration. Here, Ln is an element in the lanthanum series with Y.
第１〜第４の発明をより明確に理解するために。To understand the first to fourth inventions more clearly.
以下の実施例１から４に具体的に示す。Specific examples are shown in Examples 1 to 4 below.
（実施例１）
ここでは、バルク焼成体についてＬｎ＝Ｎｄを用いた場
合の発明の実施例を示す。まず、Ｂ １２０ ｚ ＋５
ｒＣＯ，、ＣａＣ○、、Ｎｄ２Ｏ３，ＣｕＯの酸化物粉
体を混ぜ合わせる。続いてこの混合粉体の炭素分子を取
り除くために、空気中で７００℃で５時間の熱処理を施
した。さらに熱処理後の前記混合粉体を直径８ｍｍ、厚
さ２ｍｎのディスクにプレス加工する。このプレスを酸
素雰囲気中において、９００℃で５時間熱処理を施した
。Ｂｉ２５ｒ２Ｃａ、−ｙＮｄｙＣｕ２０８の材料を作
成するために、上記酸化物粉体混合の段階でＢｉ： Ｓ
ｒ： Ｃａ： Ｎｄ： Ｃｕ＝２ ：２ ： １−ｙ
： ｙ： ２になるように秤量する。さらに電気特性を
測定するために、前記熱処理後のディスク上の白金（ｐ
ｔ）電極をパターニングして高周波マグネトロンスパッ
タ法により蒸着させる。(Example 1) Here, an example of the invention in which Ln=Nd is used for a bulk fired body is shown. First, B 120 z +5
Mix oxide powders of rCO, CaC○, Nd2O3, and CuO. Subsequently, in order to remove carbon molecules from this mixed powder, heat treatment was performed at 700° C. for 5 hours in air. Further, the mixed powder after heat treatment is pressed into a disk having a diameter of 8 mm and a thickness of 2 mm. This press was heat treated at 900° C. for 5 hours in an oxygen atmosphere. In order to create the material Bi25r2Ca, -yNdyCu208, Bi:S was added at the stage of mixing the oxide powder.
r: Ca: Nd: Cu=2:2:1-y
: Y: Weigh so that it becomes 2. Furthermore, in order to measure the electrical properties, platinum (p) on the disk after the heat treatment was
t) Patterning the electrode and depositing it by high frequency magnetron sputtering.
Ｂ ｉ２Ｓ ｒ２Ｃａ、−ｙ Ｎｄ、 Ｃｕ２ｏｘの抵
抗率の温度特性を第１図に示す。ｙを増やすにしたがっ
て、電気特性は半導体的になり、ｙ≧０．５のとき超伝
導現象が消滅することがわかった。特にＣａが完全置換
されたとき、すなわちｙ ＝ １ ； Ｂｉ２５ｒ２Ｌ
ｎＣｕ２０８のとき抵抗率は室温で１０”０口以上の極
めて大きいものとなることがわかった。このＢ ｉ、
Ｓ ｒ、 ＬｎＣｕ２０８の結晶構造をＢ ｉ２Ｓ ｒ
２Ｃａ２Ｃｕ２０ｘのそれと比較して第２図に示す。FIG. 1 shows the temperature characteristics of resistivity of B i2S r2Ca, -y Nd, and Cu2ox. It was found that as y increases, the electrical properties become semiconducting, and when y≧0.5, the superconductivity phenomenon disappears. Especially when Ca is completely substituted, i.e. y = 1; Bi25r2L
It was found that the resistivity of nCu208 was extremely large, exceeding 10"0 at room temperature.
S r, the crystal structure of LnCu208 is B i2S r
A comparison with that of 2Ca2Cu20x is shown in FIG.
Ｂ ｉ、 Ｓ ｒ、 Ｃａ、 Ｃｕ２Ｏ３は２つのピミ
ツド型Ｃｕ−０がＳｒ−〇、Ｃａ−０とともにＢｉ、０
２層に挟まれたペロブスカイト構造をしている（第２図
（ａ））。B i, S r, Ca, Cu2O3 has two pimid type Cu-0 together with Sr-〇, Ca-0 and Bi, 0
It has a perovskite structure sandwiched between two layers (Figure 2(a)).
方、Ｂｉ２５ｒ２ＬｎＣｕ２０８はＸ線回折等の分析か
らＢｉ、５ｒｚＣａ２Ｃｕ２０８のＣａがＬｎに完全置
換したものであることがわかった（第２図（ｂ））。On the other hand, analysis of Bi25r2LnCu208 by X-ray diffraction etc. revealed that Bi and Ca in 5rzCa2Cu208 were completely replaced by Ln (Fig. 2(b)).
Ｂｉ２５ｒ２ＬｎＣｕ２０ｘがＢ ｉ２Ｓ ｒ２Ｃａ２
Ｃｕ２０８に比べてはるかに高い抵抗率を示す原因は今
のところよくわかっていないが、およそ次のように解釈
される。すなわち電気伝導はＣｕ−○のネットワークで
行われるが、Ｃａ”があるＢｉ２５ｒ２ＣａＣｕ２０゜
のときにはＣｕ−○ネットワークにホールが供給され、
Ｃａ２＋を価数の異なるＬｎ”に置換することによって
ホールの供給はなくなり、１３ｉ２Ｓｒ２ＬｎＣｕ２０
８は絶縁体となるもの考えられる。さらに、Ｂ１−５ｒ
−Ｌｎ−Ｃｕ−０の材料をＢｉ２Ｓｒ、−、Ｌｎ、Ｃｕ
２０ｘと記述した場合、ｙ≠１のときには電気伝導性が
現れることがわかった。ｙ＜１のときには、その結晶構
造はＢ ｉ、 Ｓ ｒ、 ＣａＣｕｚ○、と同しであり
、ＣａをＳｒとＬｎで置き換えたかたちとなっている。Bi25r2LnCu20x is B i2S r2Ca2
The reason for the much higher resistivity than Cu208 is not well understood at present, but it can be interpreted as follows. In other words, electrical conduction takes place in the Cu-○ network, but when Bi25r2CaCu20° with Ca'', holes are supplied to the Cu-○ network,
By replacing Ca2+ with Ln'' with a different valence, the supply of holes is eliminated, and 13i2Sr2LnCu20
8 is considered to be an insulator. Furthermore, B1-5r
-Ln-Cu-0 materials are Bi2Sr, -, Ln, Cu
It was found that when described as 20x, electrical conductivity appears when y≠1. When y<1, the crystal structure is the same as B i, S r, CaCuz○, with Ca replaced by Sr and Ln.
一方、ｙ＞１のときには、その結晶構造が電気伝導性を
持つＢｉ２５ｒ２ＣｕＯ２に変化することがわかった。On the other hand, it was found that when y>1, the crystal structure changes to Bi25r2CuO2, which has electrical conductivity.
なお、Ｂ１−８ｒ−Ｌｎ−Ｃｕ−０において、絶縁性を
得るためには正確に１３１２ Ｓ ｒ２． Ｌ ｎ Ｃ
ｕ２０８となる組成は調整が必要であるが、通常、超伝
導転移が発現するのはおよそ１２０玉以下であることか
ら、Ｂｉ２５ｒ２Ｃａ、−、Ｎｄ、Ｃｕ２Ｏ３において
１≧ｙ≧０．５の範囲であれば絶縁体として機能できる
。In addition, in B1-8r-Ln-Cu-0, in order to obtain insulation, exactly 1312 S r2. L n C
Although the composition that becomes u208 needs to be adjusted, since the superconducting transition usually occurs at approximately 120 or less atoms, it is necessary to adjust the composition in the range of 1≧y≧0.5 for Bi25r2Ca, -, Nd, and Cu2O3. It can function as an insulator.
なお、絶縁体として適用できるＬｎに種類について検討
を行った。その結果、Ｌｎ：Ｃｅ、Ｙ。In addition, we investigated the types of Ln that can be applied as an insulator. As a result, Ln:Ce, Y.
Ｐｒ、 Ｎｄ、 Ｐｍ、 Ｓｍ、 Ｅｕ、 Ｇｄ、 Ｔ
ｂ、 Ｄｙ、 ＨｏｔＴｍ、Ｙｂ、ＬｕについてＢｉ、
５ｒ２ＬｎＣｕ２０Ｘは絶縁体になることを見いだした
。Pr, Nd, Pm, Sm, Eu, Gd, T
Bi for b, Dy, HotTm, Yb, Lu,
It has been found that 5r2LnCu20X becomes an insulator.
種々の検討を行った結果、上記Ｂ１□５ｒ２ＬｎＣｕ２
０ｘが絶縁体として優れていることを見いだした。この
理由として、この材料はＢｉ２Ｏ２酸化物層がＳｒ、Ｌ
ｎ、Ｃｕおよび酸素等の元素からなる構造体を挟み込ん
だ層状ペロブスカイトを示し、このＢｉ２Ｏ２層は同種
の結晶構造の物質の界面に対して高温の熱処理において
も非常に安定であり、一連の酸化物超伝導体とのその結
晶におけるａ軸。As a result of various studies, the above B1□5r2LnCu2
It was discovered that 0x is an excellent insulator. The reason for this is that this material has a Bi2O2 oxide layer of Sr, L
It shows a layered perovskite sandwiching a structure consisting of elements such as n, Cu, and oxygen. a-axis in a superconductor and its crystal.
ｂ軸の長さがほぼ等しいことから、格子の整合性がきわ
めて優れており、この材料を薄膜化した場合、酸化物超
伝導体上へＢｉ２５ｒ２ＬｎＣｕ２０ｘ、さらにＢｉ２
５ｒ２ＬｎＣｕ２０８上への酸化物超伝導体の連続エピ
タキシャル成長が可能であることがあげられる。そこで
Ｂｉ２５ｒ２ＬｎＣｕ２０８の薄膜化を試み、薄膜化に
は高周波マグネトロンスパッタリング法を用いた。スパ
ッタリングターゲットとして、空気中において８５０℃
、５時間焼成した混合酸化物を用い、Ａｒと０□混合ガ
ス雰囲気中でスパッタリングを行うことによって、Ｂｉ
２５ｒ２ＬｎＣｕ２０ｘの薄膜化が可能であることがわ
かった。しかし、酸化物高温超伝導体を電子デバイスに
応用する場合、絶縁膜の厚みは数百人程度であることが
要求されること、またこの絶縁体の結晶構造は第２図（
ｂ）に示すような構造を持ち、結晶はＢ１−０，５ｒ−
Ｃｒ−０，Ｌｎ−Ｃｕ−０の各部分を順次積層した形と
なっていることから、第２の発明に至った。Since the lengths of the b-axes are almost equal, the lattice matching is extremely good, and when this material is made into a thin film, Bi25r2LnCu20x and further Bi2
It is possible to continuously epitaxially grow an oxide superconductor on 5r2LnCu208. Therefore, an attempt was made to make Bi25r2LnCu208 a thin film, and high frequency magnetron sputtering was used to make the film thin. 850℃ in air as a sputtering target
By using a mixed oxide fired for 5 hours and performing sputtering in an atmosphere of Ar and 0
It was found that it is possible to make a thin film of 25r2LnCu20x. However, when applying oxide high-temperature superconductors to electronic devices, the thickness of the insulating film is required to be on the order of several hundred layers, and the crystal structure of this insulator is shown in Figure 2 (
It has the structure shown in b), and the crystal is B1-0,5r-
Since each part of Cr-0 and Ln-Cu-0 is sequentially laminated, the second invention has been achieved.
第２の発明の実施例を以下の実施例２に示す。An example of the second invention is shown in Example 2 below.
（実施例２）
第３図に本実施例で用いた３元マグネトロンスパッタ装
置の概略図を示す。第３図において、１１はＢｉターゲ
ット、１２は５ｒＣｕ合金ターゲット、１３はＮｄＣｕ
合金ターゲット、１４はシャッター、１５はスリット、
１６は基体、１７は基体加熱用ヒーターを示す。計３個
のターゲット１１．１２．１３は第３図に示すように配
置される。すなわち、ＭｇＯ（１００）基体１７に焦点
を結ぶように各ターゲットが約３０゜傾いて設置されて
いる。ターゲットの前方には回転するシャッター１４が
あり、パルスモータで駆動することによりその中に設け
られたスリット１５の回転が制御され、各ターゲットの
サイクルおよびスパッタ時間を設定することができる。(Example 2) FIG. 3 shows a schematic diagram of a ternary magnetron sputtering apparatus used in this example. In Fig. 3, 11 is a Bi target, 12 is a 5rCu alloy target, and 13 is a NdCu target.
Alloy target, 14 is a shutter, 15 is a slit,
16 is a substrate, and 17 is a heater for heating the substrate. A total of three targets 11, 12, and 13 are arranged as shown in FIG. That is, each target is installed at an angle of approximately 30° so as to focus on the MgO (100) substrate 17. In front of the target is a rotating shutter 14, which is driven by a pulse motor to control the rotation of a slit 15 provided therein, allowing the cycle and sputtering time of each target to be set.
基体１６のヒーター１７で約６００℃に加熱し、アルゴ
ン・酸素（５：１）混合雰囲気３Ｐａのガス中で各ター
ゲットのスパッタリングを行なった。各ターゲットのス
パッタ電流を、Ｂ ｉ ： ３０ｍＡ 、 Ｓ ｒＣｕ
： ８０ｍＡ 。The substrate 16 was heated to about 600° C. by the heater 17, and each target was sputtered in a mixed atmosphere of argon and oxygen (5:1) at 3 Pa. The sputtering current of each target is B i: 30 mA, S rCu
: 80mA.
ＮｄＣｕ：３００ｍＡにして実験を行った。Ｂｉ→５ｒ
Ｃｕ−＋ＮｄＣｕ−＋Ｂｉのサイクルでスパッタし。NdCu: The experiment was conducted at 300 mA. Bi→5r
Sputtering was performed using a cycle of Cu-+NdCu-+Bi.
Ｂ１−５ｒ−Ｎｄ−Ｃｕ−０膜の元素の組成比率がＢｉ
：Ｓｒ： Ｎｄ： Ｃｕ＝２ ： ２ ： １ ： ２
となるように各ターゲットのスパッタ時間を調整し、上
記サイクルを７周期行った。このままの状態でもこのＢ
１−５ｒ−Ｎｄ−Ｃｕ−〇薄膜はＣ軸配向膜となり、安
定な絶縁膜の形成が可能となったが、さらに酸素中で６
５０℃、１時間の熱処理を行うと非常に結晶性のよい膜
となった。The elemental composition ratio of the B1-5r-Nd-Cu-0 film is Bi
:Sr:Nd:Cu=2:2:1:2
The sputtering time of each target was adjusted so that the above cycle was repeated seven times. Even in this state, this B
The 1-5r-Nd-Cu-〇 thin film became a C-axis oriented film, making it possible to form a stable insulating film, but it was further
After heat treatment at 50° C. for 1 hour, a film with very good crystallinity was obtained.
なお、Ｂｊ−３ｒ−Ｎｄ−Ｃｕ−０の絶縁膜薄は、単一
蒸発源を用いた蒸着法によっても得ることは可能である
が、この種の材料からの場合組成の調節が極めて困難で
あることから、第２の発明の方法き有効である。Although it is possible to obtain a thin insulating film of Bj-3r-Nd-Cu-0 by a vapor deposition method using a single evaporation source, it is extremely difficult to control the composition when using this type of material. For this reason, the method of the second invention is more effective.
さらに、絶縁薄膜と超伝導薄膜との有効な積層を試み、
第３の発明に至った。Furthermore, we attempted to effectively stack insulating thin films and superconducting thin films,
This led to the third invention.
第３の発明の具体的実施例を実施例３として以下に示す
。A specific example of the third invention will be shown below as Example 3.
（実施例３）
第４図に本発明で作製した薄膜の断面図を模式的に表す
。第４図において、基体上にＢ ｉ−Ｓ ｒ−Ｃａ−Ｃ
ｕ−０膜とＢ１−５ｒ−Ｎｄ−Ｃｕ−０膜を交互に積層
した。積層の方法としては、Ｂ ｉ−Ｓ ｒ−Ｃａ−Ｃ
ｕ○膜は単一ターゲットの高周波マグネトロンスパッタ
法で蒸着し、さらに実施例２で示した方法でＢ１−５ｒ
−Ｎｄ−Ｃｕ−○膜を蒸着した。、Ｂ１−８ｒ−Ｃａ−
Ｃｕ−０膜の膜厚は約１０００人であり、Ｂ１−５ｒ−
Ｎｄ−Ｃｕ−○膜の膜厚すなわち実施例２で用いた第３
図の実験装置における積層の周期の数を変化させ、薄膜
の抵抗率の変化を調べ、結果を第５図に示す。(Example 3) FIG. 4 schematically shows a cross-sectional view of a thin film produced according to the present invention. In FIG. 4, B i-S r-Ca-C
The u-0 film and the B1-5r-Nd-Cu-0 film were alternately laminated. As a lamination method, B i-S r-Ca-C
The u○ film was deposited by single-target high-frequency magnetron sputtering, and then B1-5r was deposited by the method shown in Example 2.
-Nd-Cu-○ film was deposited. , B1-8r-Ca-
The thickness of the Cu-0 film is about 1000, and the thickness of the Cu-0 film is about 1000.
The thickness of the Nd-Cu-○ film, that is, the third film used in Example 2
The number of lamination cycles in the experimental apparatus shown in the figure was varied to examine changes in the resistivity of the thin film, and the results are shown in FIG.
ここで周期数をｍとする。ｍ＝６のとき、最も高い超伝
導転移温度およびゼロ抵抗温度、すなわち特性３２が得
られる。特性３２の超伝導転移温度、ゼロ抵抗温度はＢ
ｉ−Ｓ ｒ−Ｃａ−Ｃｕ−０膜本来のそれらの値より
も約８’に高いものであった。この結果の詳細な理由に
ついては未だ不明であるが、第４図に示すように、Ｂ１
−５ｒ−Ｃａ−Ｃｕ−〇膜とＢ１−８ｒ−Ｎｄ−Ｃｕ−
０膜とを周期的に積層することによって、Ｂ１−５ｒ−
Ｃａ−Ｃｕ−０膜とＢ１−５ｒ−Ｎｄ−Ｃｕ−Ｏ膜が互
いにＢｉ２Ｏ，層を介してエピタキシャル成長している
ことにより積層界面での元素の相互拡散の影響がなく、
かつ結晶性に優れた薄いＢ１５ｒ−Ｎｄ−Ｃｕ−○膜を
介して同じく結晶性に優れたＢ１−５ｒ−Ｃａ−Ｃｕ−
０膜を積層することによりＢ１−５ｒ−Ｃａ−Ｃｕ−〇
膜において超伝導機構になんらかの変化が引き起こされ
たことが考えられるが、機構はまだあきらかにできない
。Here, the number of cycles is assumed to be m. When m=6, the highest superconducting transition temperature and zero resistance temperature, property 32, is obtained. The superconducting transition temperature and zero resistance temperature of property 32 are B
These values were approximately 8' higher than those of the original i-S r-Ca-Cu-0 film. Although the detailed reason for this result is still unknown, as shown in Figure 4, B1
-5r-Ca-Cu-〇 film and B1-8r-Nd-Cu-
B1-5r-
Since the Ca-Cu-0 film and the B1-5r-Nd-Cu-O film are epitaxially grown through the Bi2O layer, there is no effect of mutual diffusion of elements at the laminated interface.
And B1-5r-Ca-Cu- which also has excellent crystallinity through a thin B15r-Nd-Cu-○ film which has excellent crystallinity.
It is conceivable that some change was caused in the superconducting mechanism in the B1-5r-Ca-Cu-〇 film by stacking the 0 film, but the mechanism is not yet clear.
なお、超伝導転移温度が上昇する効果は、Ｂｉ−＋５ｒ
Ｃｕ−＋ＮｄＣｕ−＋Ｂｉのサイクルが４〜１０の範囲
でとくに有効であることを１本発明者らは確認した。Note that the effect of increasing the superconducting transition temperature is Bi-+5r
The present inventors have confirmed that the cycle of Cu-+NdCu-+Bi is particularly effective in the range of 4 to 10 cycles.
なお、Ｂ１−８ｒ−Ｎｄ−Ｃｕ−〇膜の代わりに、 Ｂ
ｉＳ ｒ−Ｌ ｎ−Ｃｕ−○（Ｌｎ＝Ｃｅ、ＹＩ Ｐｒ
、Ｎｄ、Ｐｍ。In addition, instead of the B1-8r-Nd-Cu-〇 film, B
iS r-L n-Cu-○ (Ln=Ce, YI Pr
, Nd, Pm.
Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｔｍ、Ｙｂ、Ｉ
ｃｒ）膜を用いたときも第３の発明が有効であることを
確認した。また、Ｂｉ： Ｓｒ： Ｌｎ： Ｃｕ＝２
： ２ ：１：２のとき第１の発明で示したように、最
も絶縁性が高く、その組成を用いた第３の発明の超伝導
体が、最も超伝導特性の向上、安定性を示した。Sm, Eu, Gd, Tb, Dy, Ho, Tm, Yb, I
It was confirmed that the third invention is also effective when using a cr) film. Also, Bi: Sr: Ln: Cu=2
:2 :1:2 As shown in the first invention, the superconductor of the third invention using this composition has the highest insulating properties and shows the most improved superconducting properties and stability. Ta.
第４の発明の実施例を以下実施例４に示す。An example of the fourth invention is shown below in Example 4.
（実施例４）
第６図は、本実施例で用いた四元マグネトロンスパッタ
装置内部の概略図であり、４１はＢｉメタ−ット、４２
は５ｒＣｕターゲツト、４３はＣａ Ｃｕターゲット、
４４はＮｄＣｕターゲット、４５はシャッター４６はス
リット、４７は基体、４Ｂは基体加熱用ヒーターを示す
。ターゲット４Ｉは金属のターゲット、ターゲット４２
．４３．４４は元素比率Ｓｒ（もしくはＣａ、もしくは
Ｎｄ）： Ｃｕ＝１ ： １の合金ターゲットであり、
第６図に示すように配置させた。すなわち、ＭｇＯ（１
００）基体４７に焦点を結ぶように各ターゲットが約３
０°傾いて設置されている。ターゲットの前方には回転
するシャッター４５があり、その中に設けられたスリッ
ト４６の回転をパルスモータ−で制御することにより、
（Ｂｉ→５ｒＣｕ−）ＮｄＣｕ−＋５ｒＣｕ−＋Ｂｉ）
のサイクルと（Ｂｉ−＋５ｒＣｕ−）ＣａＣｕ−５ｒＣ
ｕ→Ｂｉ）のサイクルでスパッタ蒸着を行うことができ
る。積層の様子を概念的に第７図に示したが、ターゲッ
ト４１．４２．４３．４４への入力電力、それぞれのタ
ーゲットのスパッタ時間を制御することにより、基体４
７上に蒸着するＢ ｉ−Ｓ ｒ−Ｎ ｄ−Ｃｕ−０膜、
Ｂ１−５ｒ−Ｃａ−Ｃｕ−０膜の膜厚を変えることがで
きる。基体４７をヒーター４８で約７００℃に加熱し、
アルゴン・酸素（１： １）混合雰囲気０．５Ｐａのガ
ス中で各ターゲットのスパッタリングを行なった。薄膜
作製後は酸素雰囲気中において、８５０℃の熱処理を５
時間前した。(Example 4) FIG. 6 is a schematic diagram of the inside of the quaternary magnetron sputtering apparatus used in this example, where 41 is a Bi metal, 42
is 5rCu target, 43 is CaCu target,
44 is a NdCu target, 45 is a shutter 46 is a slit, 47 is a substrate, and 4B is a heater for heating the substrate. Target 4I is a metal target, target 42
．． 43.44 is an alloy target with an element ratio of Sr (or Ca or Nd):Cu=1:1,
They were arranged as shown in FIG. That is, MgO(1
00) Each target has approximately 3
It is installed at an angle of 0°. There is a rotating shutter 45 in front of the target, and by controlling the rotation of a slit 46 provided in the shutter with a pulse motor,
(Bi→5rCu-)NdCu-+5rCu-+Bi)
cycle and (Bi-+5rCu-)CaCu-5rC
Sputter deposition can be performed in a cycle of u→Bi). The state of lamination is conceptually shown in FIG.
B i-S r-N d-Cu-0 film deposited on 7;
The thickness of the B1-5r-Ca-Cu-0 film can be changed. The base body 47 is heated to about 700°C with a heater 48,
Sputtering of each target was performed in a mixed atmosphere of argon and oxygen (1:1) at 0.5 Pa. After thin film fabrication, heat treatment at 850°C was performed in an oxygen atmosphere for 55 minutes.
It was an hour ago.
本実施例では、Ｂ１−５ｒ−Ｃａ−Ｃｕ−０膜の元素の
組成比率がＢｉ： Ｓｒ： Ｃａ： Ｃｕ＝２ ： ２
： ２ ： ３゜Ｂ１−８ｒ−Ｎｄ−Ｃｕ−○膜の元
素の組成比率がＢｉ：Ｓｒ：Ｎｄ：Ｃｕ＝２：２：１：
２になるよう、スパッタ時間スパッタ電流を調節した。In this example, the elemental composition ratio of the B1-5r-Ca-Cu-0 film is Bi:Sr:Ca:Cu=2:2
: 2 : 3゜The composition ratio of the elements of the B1-8r-Nd-Cu-○ film is Bi:Sr:Nd:Cu=2:2:1:
The sputtering time and sputtering current were adjusted so that the sputtering time was 2.
さらに、結晶性を維持したまま、薄くできる膜厚の限界
は数十人であると思われる。絶縁膜はできるだけ薄い方
が好ましいので、ｋ ・（Ｂ ｉ−＋ Ｓ ｒＣｕ−＋
ＣａＣｕ−＋５ｒＣｕ−＋Ｂｉ）→Ｑ ・（Ｂ ｉ−
＋ Ｓ ｒＣｕ−＋ ＮｄＣｕ−） Ｓ ｒＣｕ→Ｂｉ
）と書き表せる周期を２０周期行なった。Furthermore, the limit on how thin a film can be made while maintaining crystallinity is believed to be several dozen. Since it is preferable that the insulating film be as thin as possible, k ・(B i−+ S rCu−+
CaCu-+5rCu-+Bi)→Q ・(Bi-
+ S rCu-+ NdCu-) S rCu→Bi
) was performed for 20 cycles.
なお、良好な結晶構造を保ったまま作製できるＢ１−８
ｒ−Ｎｄ−Ｃｕ−０膜の膜厚はＱ＝２が限度であった。In addition, B1-8 can be produced while maintaining a good crystal structure.
The maximum thickness of the r-Nd-Cu-0 film was Q=2.
そこで、Ｑ＝２のとき、玉を変化させできあがった薄膜
の抵抗率の温度変化を調べ、そのときの結果を第８図に
示す。第８＠において、８Ｉは玉＝２．８２は’に＝６
．８３はＸ＝１０のときの結果を示す。この図かられか
るように、’に＝６のとき最も超伝導転移温度並びにゼ
ロ抵抗温度が絶縁膜Ｂ１−５ｒ−Ｎｄ−Ｃｕ−〇と積層
しない場合に比べ上昇することがわかった。この物理的
な原因はよくわからないが、第４の発明により、Ｂ１−
５ｒ−Ｃａ−Ｃｕ−○薄膜とＢ１−８ｒ−Ｎｄ−Ｃｕ−
０薄膜の両方をきわめて制御性よく積層できたことによ
るものと考えられる。Therefore, when Q=2, the temperature change in the resistivity of the thin film obtained by changing the beads was investigated, and the results are shown in FIG. In the 8th @, 8I = 2.82 = 6
．． 83 shows the result when X=10. As can be seen from this figure, when '=6, the superconducting transition temperature and the zero resistance temperature are most elevated compared to the case where the insulating film B1-5r-Nd-Cu-〇 is not laminated. The physical cause of this is not well understood, but with the fourth invention, B1-
5r-Ca-Cu-○ thin film and B1-8r-Nd-Cu-
This is thought to be due to the fact that both the zero and zero thin films could be laminated with extremely good controllability.
さらに第２．第４の発明においてスパッタリング法を用
いなくても、Ｂｉの酸化物と、Ｓｒ、 Ｃａ。Furthermore, the second. In the fourth invention, Bi oxide, Sr, and Ca can be formed without using a sputtering method.
Ｃｕ、Ｎｄの酸化物を異なる蒸発源から真空中で別々に
蒸発させ、同様の構造を周期的に積層させた場合、（実
施例４）に示したスパッタリングを用い、積層構造作製
方法と同じく制御性良く、安定した膜質の、薄膜をうろ
ことが可能である。Ｂ１−０゜５ｒ−Ｃｕ−０，Ｃａ−
Ｃｕ−○、Ｎｄ−０を周期的に積層させる方法としては
、いくつか考えられる。一般的に、ＭＢＥ装置あるいは
多元のＥＢ蒸着装置で蒸発源の前を開閉シャッターで制
御したり、気相成長法で作製する際にガスの種類を切り
替えたりすることにより、周期的積層を達成することが
できる。しかしこの種の非常に薄い層の積層には従来ス
パッタリング蒸着は不向きとされていた。この理由は、
成膜中のガス圧の高さに起因する不純物の混入およびエ
ネルギーの高い粒子によるダメージと考えられている。When Cu and Nd oxides are evaporated separately in vacuum from different evaporation sources and similar structures are periodically stacked, sputtering as shown in (Example 4) is used and controlled in the same way as the stacked structure fabrication method. It is possible to coat thin films with good properties and stable film quality. B1-0゜5r-Cu-0,Ca-
There are several possible methods for periodically stacking Cu-○ and Nd-0. In general, periodic stacking is achieved by controlling the opening and closing shutters in front of the evaporation source in an MBE device or multi-source EB evaporation device, or by switching the type of gas during production using the vapor phase growth method. be able to. However, sputtering deposition has traditionally been considered unsuitable for this type of extremely thin layer stacking. The reason for this is
It is believed that the damage is caused by the inclusion of impurities and high-energy particles due to the high gas pressure during film formation.
しかしながら、このＢｉ系酸化物超伝導体また。絶縁薄
膜に対してスパッタリングにより異なる薄い層の積層を
行なってところ、以外にも良好な積層膜作製が可能であ
ることを発見した。スパッタ中の高い酸素ガス圧および
スパッタ放電により、膜内への酸素導入がより促進され
、超伝導特性の再現性、安定化が図られ、Ｂｉ系の１０
０ ’に以上の臨界温度を持つ相の形成、および絶縁薄
膜の形成に都合がよいためではなかろうかと考えられる
。However, this Bi-based oxide superconductor also By laminating different thin layers on an insulating thin film by sputtering, we discovered that it is possible to produce a good laminated film in other ways. The high oxygen gas pressure and sputter discharge during sputtering promote the introduction of oxygen into the film, which improves the reproducibility and stabilization of superconducting properties.
It is thought that this is because it is convenient for the formation of a phase having a critical temperature of 0' or higher and for the formation of an insulating thin film.
スパッタ蒸着で異なる物質を積層させる方法としては、
組成分布を設けた１個のスパッタリングターゲットの放
電位置を周期的に制御するという方法があるが、組成の
異なる複数個のターゲットのスパッタリングという方法
を用いると比較的簡単に達成することができる。この場
合、複数個のターゲットの各々のスパッタ量の周期的に
制御したり、あるいはターゲットの前にシャッターを設
けて周期的に開閉したりして、周期的積層膜を作製する
ことができる。また基板を周期的運動させて各々ターゲ
ットの上を移動させる方法でも作製が可能である。レー
ザースパッタあるいはイオンビームスパッタを用いた場
合には、複数個のターゲットを周期運動させてビームの
照射するターゲットを周期的に変えれば、周期的積層膜
が実現される。このように複数個のターゲットを用いた
スパッタリングによる比較的簡単にＢｉ系酸化物の周期
的積層が作製可能となる。（実施例２，４）で示したよ
うにＢ１−０，５ｒ−Ｃｕ−○、 Ｃａ−Ｃｕ−〇。The method of layering different materials using sputter deposition is as follows:
There is a method of periodically controlling the discharge position of one sputtering target with a composition distribution, but this can be achieved relatively easily by using a method of sputtering multiple targets with different compositions. In this case, a periodic laminated film can be produced by periodically controlling the amount of sputtering for each of a plurality of targets, or by providing a shutter in front of the target and opening and closing it periodically. Alternatively, it can be manufactured by a method in which the substrate is moved periodically and moved over each target. When laser sputtering or ion beam sputtering is used, periodic laminated films can be realized by periodically moving a plurality of targets and periodically changing the targets irradiated with the beam. In this way, periodic stacks of Bi-based oxides can be produced relatively easily by sputtering using a plurality of targets. As shown in (Examples 2 and 4), B1-0,5r-Cu-○, Ca-Cu-○.
Ｎｄ−０を別々の蒸発源から蒸発させ、 Ｂｉ−５ｒ−
Ｃａ−Ｃｕ−０超伝導薄膜とＢＢｌ−５ｒ−Ｎｄ−Ｏ縁
膜を周期的に積層したとき、極めて制御住良＜ｒｎ（Ｂ
ｉ−５ｒ−Ｃａ−Ｃｕ−０） ・ｎ（Ｂｉ−５ｒ−Ｎｄ
−０）の周期構造を持つ薄膜を形成できることを見いだ
した。ここで、ｍ、ｎは正の整数を示す。また、蒸発源
としてＢ１−３ｒ−Ｃａ−Ｃｕ−○、 Ｂ１−５ｒ−Ｎ
ｄ−〇の複合酸化物を用いても、簡単な方法で薄膜を作
製できる。別々の蒸発源を用いると、より結晶性が優れ
、組成制御性がきわめて良い１作製方法となる。超伝導
転移温度、臨界電流密度等の特性に勝っていることも併
せて見いだした。さらに、上記の方法で作製したＢ１−
５ｒ−Ｃａ−Ｃｕ−０超伝導薄膜とＢ１５ｒ−Ｎｄ−Ｃ
ｕ−０絶縁膜はともに薄膜表面が極めて平坦であること
を見いだした。これは、それぞれ層状構造を構成する異
なる元素を別々に順次積層していくことにより、基体表
面に対し平行な面内だけで積層された蒸着元素が動くだ
けで、基体表面に対し垂直方向への元素の移動がないこ
とによるものと考えられる。さらに、この組成の絶縁薄
膜は層状ペロブスカイト構造の結晶であり、ａ軸の長さ
は、Ｂ１−５ｒ−Ｃａ−Ｃｕ−０のそれとほぼ等しく、
連続的にエピタキシャル成長が可能であることによるも
のと考えられる。Nd-0 is evaporated from separate sources and Bi-5r-
When a Ca-Cu-0 superconducting thin film and a BBL-5r-Nd-O film are periodically laminated, extremely controlled Sumiri<rn(B
i-5r-Ca-Cu-0) ・n(Bi-5r-Nd
We have discovered that it is possible to form a thin film with a periodic structure of −0). Here, m and n indicate positive integers. In addition, B1-3r-Ca-Cu-○, B1-5r-N are used as evaporation sources.
A thin film can be produced by a simple method using the composite oxide d-〇. Using separate evaporation sources provides a manufacturing method with better crystallinity and extremely good composition controllability. It was also discovered that it has superior properties such as superconducting transition temperature and critical current density. Furthermore, B1- produced by the above method
5r-Ca-Cu-0 superconducting thin film and B15r-Nd-C
It has been found that both u-0 insulating films have extremely flat thin film surfaces. This is achieved by stacking different elements that make up a layered structure separately and sequentially, so that the stacked elements move only in a plane parallel to the substrate surface, and the stacked elements move in a direction perpendicular to the substrate surface. This is thought to be due to the lack of movement of elements. Furthermore, the insulating thin film with this composition is a crystal with a layered perovskite structure, and the length of the a-axis is approximately equal to that of B1-5r-Ca-Cu-0.
This is thought to be due to the fact that continuous epitaxial growth is possible.
さらに以外にも、良好な超伝導特性を得ることに必要な
基体の温度、熱処理温度も、従来より低いことを見いだ
した。Furthermore, we have also discovered that the substrate temperature and heat treatment temperature required to obtain good superconducting properties are lower than conventional ones.
（発明の効果）
以上のように第１の発明の絶縁体は、酸化物超伝導薄膜
のデバイス構成にかかせない要素部を提供するものであ
り、第２の絶縁薄膜の製造方法は第１の発明をより効果
的に実現し、デバイス等の応用には必須の低温でのプロ
セス確立したものであり、第３の発明の超伝導薄膜は、
酸化物超伝導薄膜の高性能化を実現し、提供するもので
あり、第４の超伝導薄膜の製造方法は第４の発明をより
効果的に実現し、デバイス等の応用には必須の低温での
プロセス確立したものであり、本発明の工業的価値は大
きい。(Effects of the Invention) As described above, the insulator of the first invention provides an essential element for the device configuration of the oxide superconducting thin film, and the second method of manufacturing the insulating thin film is the same as that of the first invention. The superconducting thin film of the third invention more effectively realizes the invention and establishes a low-temperature process that is essential for applications such as devices.
The fourth method for producing superconducting thin films realizes and provides higher performance of oxide superconducting thin films, and the fourth method for producing superconducting thin films more effectively realizes the fourth invention, and provides low-temperature production, which is essential for applications such as devices. The process of this invention has been established, and the industrial value of the present invention is great.
第１図は第１の発明の実施例における絶縁体の抵抗率の
温度特性図、第２図は第１の発明の実施例における構造
概念図、第３図は第２の発明の実施例における絶縁薄膜
の製造方法に用いた装置の概略図、第４図は第３の発明
で作製した薄膜の断面図、第５図は第３の実施例におけ
る超伝導薄膜の抵抗の温度依存性を示す図、第６図は第
４の発明の実施例における超伝導薄膜の製造方法にもち
いた装置の概略図、第７図は第４の発明の薄膜作製の構
造概念図、第８図は第４の発明実施例で得られた薄膜の
抵抗率の温度特性図である。
１１、１２．１３．４１．４２．４３．４４・・・ ス
パンタリングターゲット、１４．４５・・・シャッター
、１５．４６・・・スリット、１７．４７・・ＭｇＯ基
体、 １７．４８・・・ ヒーター、 ３１゜３２、３
３．８１．８２．８３・・・薄膜の抵抗の温度特性。
第１図
特許出願人 松下電器産業株式会社
５に贋（＠Ｋ）Fig. 1 is a temperature characteristic diagram of the resistivity of the insulator in the embodiment of the first invention, Fig. 2 is a structural conceptual diagram in the embodiment of the first invention, and Fig. 3 is a diagram of the temperature characteristic of the resistivity of the insulator in the embodiment of the second invention. A schematic diagram of the apparatus used in the method for producing an insulating thin film, FIG. 4 is a cross-sectional view of the thin film produced in the third invention, and FIG. 5 shows the temperature dependence of the resistance of the superconducting thin film in the third embodiment. Figure 6 is a schematic diagram of the apparatus used in the method for manufacturing a superconducting thin film in the embodiment of the fourth invention, Figure 7 is a conceptual diagram of the structure for manufacturing the thin film of the fourth invention, and Figure 8 is the FIG. 3 is a temperature characteristic diagram of the resistivity of a thin film obtained in an embodiment of the invention. 11, 12.13.41.42.43.44... Spanning target, 14.45... Shutter, 15.46... Slit, 17.47... MgO base, 17.48... Heater, 31°32,3
3.81.82.83...Temperature characteristics of thin film resistance. Figure 1 Patent applicant Matsushita Electric Industrial Co., Ltd. 5 fake (@K)
Claims (14)
ｕ）、およびアルカリ土類（IIａ族）、およびＬｎから
成ることを特徴とする絶縁体。 ここでアルカリ土類は、IIａ族元素のうち少なくとも一
種あるいは二種以上の元素、ＬｎはＹとランタン系列の
少なくとも一種以上の元素を示す。(1) The main components are at least bismuth (Bi) and copper (C).
u), an alkaline earth metal (group IIa), and Ln. Here, alkaline earth represents at least one or more elements of group IIa elements, and Ln represents at least one element of Y and the lanthanum series.
なくとも一種あるいは二種以上の元素を示す、ＬｎはＹ
もしくはランタン系列にある元素の少なくとも一種以上
の元素を示す。(2) The insulator according to claim (1), wherein the ratio of elements constituting the main components is Bi:A:Ln:Cu:2:2:1:2. Here, A is alkaline earth and represents at least one or two or more elements of group IIa elements, and Ln is Y
Or it indicates at least one element in the lanthanum series.
とも銅およびアルカリ土類（IIａ族）を含む酸化物、少
なくとも銅およびＬｎを含む酸化物を周期的に積層させ
て形成させて得ることを特徴とする絶縁薄膜の製造方法
。 ここでアルカリ土類は、IIａ族元素のうちの少なくとも
一種あるいは二種以上の元素、ＬｎはＹもしくはランタ
ン系列の少なくとも一種以上の元素を示す。(3) Formed by periodically stacking an oxide containing at least Bi, an oxide containing at least copper and alkaline earth (group IIa), and an oxide containing at least copper and Ln on a substrate. Characteristic method for manufacturing insulating thin films. Here, alkaline earth represents at least one or more elements of group IIa elements, and Ln represents Y or at least one element of the lanthanum series.
製造方法。 ここでＡはアルカリ土類であり、IIａ族元素のうちの少
なくとも一種あるいは二種以上の元素を示す。ＬｎはＹ
もしくはランタン系列にある元素の少なくとも一種以上
の元素を示す。(4) The method for producing an insulating thin film according to claim (3), wherein the ratio of elements constituting the main components is Bi:A:Ln:Cu=2:2:1:2. Here, A is alkaline earth and represents at least one or two or more elements of group IIa elements. Ln is Y
Or it indicates at least one element in the lanthanum series.
行うことを特徴とする請求項（３）記載の絶縁薄膜の製
造方法。(5) The method for producing an insulating thin film according to claim (3), wherein the evaporation of the laminated material is performed using at least two types of evaporation sources.
徴とする請求項（３）記載の絶縁薄膜の製造方法。(6) The method for manufacturing an insulating thin film according to claim (3), wherein the evaporation of the laminated material is performed by sputtering.
ルカリ土類（IIａ族）から成る層状酸化物超伝導薄膜と
、主体成分が少なくともＢｉ、Ｃｕ、アルカリ土類（I
Iａ族）、Ｌｎから成る層状酸化物絶縁体薄膜が交互に
積層された構造を持つことを特徴とする超伝導薄膜。 ここでアルカリ土類は、IIａ族元素のうちの少なくとも
一種あるいは二種以上の元素、ＬｎはＹもしくはランタ
ン系列の少なくとも一種以上の元素を示す。(7) A layered oxide superconducting thin film whose main components are at least Bi, Cu, and alkaline earth (group IIa);
1. A superconducting thin film characterized by having a structure in which layered oxide insulating thin films consisting of Group Ia) and Ln are alternately laminated. Here, alkaline earth represents at least one or more elements of group IIa elements, and Ln represents Y or at least one element of the lanthanum series.
の比率が Ｂｉ：Ａ：Ｌｎ：Ｃｕ＝２：２：１：２ であることを特徴とする請求項（７）記載の超伝導薄膜
。 ここでＡはアフレカリ土類であり、IIａ族元素のうちの
少なくとも一種あるいは二種以上の元素を示す。Ｌｎは
Ｙもしくはランタン系列にある元素の少なくとも一種以
上の元素を示す。(8) The superconducting thin film according to claim (7), wherein the ratio of elements constituting the main components in the oxide insulating thin film is Bi:A:Ln:Cu=2:2:1:2. Here, A is aphrekaline earth, and represents at least one or two or more elements of group IIa elements. Ln represents Y or at least one element in the lanthanum series.
する元素の比率が Ｂｉ：Ａ：Ｌｎ：Ｃｕ＝２：２：１：２ であることを特徴とする請求項（７）記載の超伝導薄膜
。 ここでＡはアルカリ土類であり、IIａ族元素のうちの少
なくとも一種あるいは二種以上の元素を示す。ＬｎはＹ
もしくはランタン系列にある元素の少なくとも一種以上
の元素を示す。(9) The superconductor according to claim (7), characterized in that the ratio of elements constituting the main components in the oxide thin film per layer is Bi:A:Ln:Cu=2:2:1:2. Thin film. Here, A is alkaline earth and represents at least one or two or more elements of group IIa elements. Ln is Y
Or it indicates at least one element in the lanthanum series.
で行うことを特徴とする請求項（７）記載の超伝導薄膜
。(10) The superconducting thin film according to claim (7), wherein the laminated material is evaporated using at least two types of evaporation sources.
特徴とする請求項（７）記載の超伝導薄膜。(11) The superconducting thin film according to claim (7), wherein the evaporation of the laminated material is performed by sputtering.
くともＣｕおよびアルカリ土類（IIａ族）を含む酸化物
とを周期的に積層させて形成する酸化物薄膜と、少なく
ともＢｉを含む酸化物と少なくともＣｕおよびアルカリ
土類（IIａ族）、Ｌｎを含む酸化物とを周期的に積層さ
せて形成する酸化物薄膜とを、交互に積層させて得るこ
とを特徴とする超伝導薄膜の製造方法。 ここでアルカリ土類は、IIａ族元素のうちの少なくとも
一種あるいは二種以上の元素、ＬｎはＹもしくはランタ
ン系列の少なくとも一種以上の元素を示す。(12) An oxide thin film formed by periodically stacking an oxide containing at least Bi and an oxide containing at least Cu and alkaline earth (group IIa) on a substrate; A method for producing a superconducting thin film, which is obtained by alternately stacking an oxide thin film formed by periodically stacking an oxide containing at least Cu, an alkaline earth metal (group IIa), and Ln. Here, alkaline earth represents at least one or more elements of group IIa elements, and Ln represents Y or at least one element of the lanthanum series.
で行うことを特徴とする請求項（１２）記載の超伝導薄
膜の製造方法。(13) The method for producing a superconducting thin film according to claim (12), wherein the evaporation of the laminated material is performed using at least two types of evaporation sources.
特徴とする請求項（１２）記載の超伝導薄膜の製造方法
。(14) The method for producing a superconducting thin film according to claim (12), wherein the evaporation of the laminated material is performed by sputtering.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2105931A JP2979422B2 (en) | 1990-04-21 | 1990-04-21 | Method of manufacturing insulator and insulating thin film, and method of manufacturing superconducting thin film and superconducting thin film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2105931A JP2979422B2 (en) | 1990-04-21 | 1990-04-21 | Method of manufacturing insulator and insulating thin film, and method of manufacturing superconducting thin film and superconducting thin film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH046108A true JPH046108A (en) | 1992-01-10 |
| JP2979422B2 JP2979422B2 (en) | 1999-11-15 |
Family
ID=14420602
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2105931A Expired - Fee Related JP2979422B2 (en) | 1990-04-21 | 1990-04-21 | Method of manufacturing insulator and insulating thin film, and method of manufacturing superconducting thin film and superconducting thin film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2979422B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0465320A (en) * | 1990-06-29 | 1992-03-02 | Matsushita Electric Works Ltd | Superconducting thin film and its production |
| JPH04198026A (en) * | 1990-11-29 | 1992-07-17 | Chodendo Hatsuden Kanren Kiki Zairyo Gijutsu Kenkyu Kumiai | Bi-sr-ca-cu-o superconductor material |
| JP2015170705A (en) * | 2014-03-06 | 2015-09-28 | 国立研究開発法人産業技術総合研究所 | resistor material |
-
1990
- 1990-04-21 JP JP2105931A patent/JP2979422B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0465320A (en) * | 1990-06-29 | 1992-03-02 | Matsushita Electric Works Ltd | Superconducting thin film and its production |
| JPH04198026A (en) * | 1990-11-29 | 1992-07-17 | Chodendo Hatsuden Kanren Kiki Zairyo Gijutsu Kenkyu Kumiai | Bi-sr-ca-cu-o superconductor material |
| JP2015170705A (en) * | 2014-03-06 | 2015-09-28 | 国立研究開発法人産業技術総合研究所 | resistor material |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2979422B2 (en) | 1999-11-15 |
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