JPH0382749A - Thin film superconductor and its production - Google Patents
Thin film superconductor and its productionInfo
- Publication number
- JPH0382749A JPH0382749A JP1220743A JP22074389A JPH0382749A JP H0382749 A JPH0382749 A JP H0382749A JP 1220743 A JP1220743 A JP 1220743A JP 22074389 A JP22074389 A JP 22074389A JP H0382749 A JPH0382749 A JP H0382749A
- Authority
- JP
- Japan
- Prior art keywords
- film
- thin film
- thin
- superconducting
- oxide
- 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 48
- 239000002887 superconductor Substances 0.000 title claims abstract description 17
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 238000000034 method Methods 0.000 claims abstract description 9
- 229910052797 bismuth Inorganic materials 0.000 claims abstract description 4
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 4
- 238000004544 sputter deposition Methods 0.000 claims description 17
- 239000000758 substrate Substances 0.000 claims description 13
- 239000010949 copper Substances 0.000 claims description 7
- 230000008020 evaporation Effects 0.000 claims description 6
- 238000001704 evaporation Methods 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 claims description 3
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 2
- 239000010937 tungsten Substances 0.000 claims description 2
- 239000002648 laminated material Substances 0.000 claims 2
- 239000010408 film Substances 0.000 abstract description 77
- 230000007704 transition Effects 0.000 abstract description 19
- 239000000203 mixture Substances 0.000 abstract description 9
- 239000000463 material Substances 0.000 abstract description 7
- 238000010030 laminating Methods 0.000 abstract description 4
- 238000003475 lamination Methods 0.000 abstract description 4
- 229910015901 Bi-Sr-Ca-Cu-O Inorganic materials 0.000 abstract 1
- 238000007740 vapor deposition Methods 0.000 abstract 1
- 230000000737 periodic effect Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 7
- 238000009792 diffusion process Methods 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 229910014454 Ca-Cu Inorganic materials 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 229910002480 Cu-O Inorganic materials 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 241000841159 Anaka Species 0.000 description 1
- 229910004247 CaCu Inorganic materials 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 241001670226 Equus caballus x asinus Species 0.000 description 1
- 229910000750 Niobium-germanium Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- CFJRGWXELQQLSA-UHFFFAOYSA-N azanylidyneniobium Chemical compound [Nb]#N CFJRGWXELQQLSA-UHFFFAOYSA-N 0.000 description 1
- 230000005493 condensed matter Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- RTRWPDUMRZBWHZ-UHFFFAOYSA-N germanium niobium Chemical compound [Ge].[Nb] RTRWPDUMRZBWHZ-UHFFFAOYSA-N 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000001659 ion-beam spectroscopy Methods 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000005477 sputtering target 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)
- Containers, Films, And Cooling For Superconductive Devices (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明ζ、ｔ、 １００Ｋ以上の高臨界温度が期待さ
れるビスマスを含む酸化物超電導体の薄膜の製造方法に
関するものであ翫
従来の技術
高温超電導体として、Ａ１５型２元系化合物として窒化
ニオブ（ＮｂＮ）やゲルマニウムニオブ（ＮｂｓＧｅ）
などが知られていた力丈 これらの材料の超電導転移温
度はたかだか２３にであっｔうＸ ペロプスカイト系化
合物（よ さらに高い転移温度が期待され Ｂａ−Ｌａ
−Ｃｕ−０系の高温超電導体が提案された ［シ２エイ
、シゝ−１へ゛ンドｌルッ及びケイ、ニー、ミューラ−
（Ｊ、Ｇ、Ｂｅｄｎｏｒｚ ａｎｄ ［、Ａ、Ｍｕ
ｌｌｅｒ） 、ファイトシュリフト−７ユア・フィシ
ゝ−り（Ｚｅｔｓｈｒｉｆｔ Ｆｕｒ Ｐｈｙｓｉ
ｋ Ｂ）−：Ｉ）Ｉテ”ｙスト′マター（Ｃｏｎｄｅ
ｎｓｅｄ Ｍａｔｔｅｒ） Ｖｏｌ、 ６４．１８９−
１９３（１９８６） Ｌさらに Ｂ１−３ｒ−Ｃａ−Ｃ
ｕ−０系の材料が１００Ｋ以上の転移温度を示すことも
発見された［エイチ、マエタ１、ワイ、タナ力、エム、
７クトミ及びデイ、アサノ （Ｈ，Ｍａｅｄａ、Ｙ、Ｔ
ａｎａｋａ、Ｍ。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing a thin film of an oxide superconductor containing bismuth, which is expected to have a high critical temperature of ζ, t, or 100 K or higher.Prior art High-temperature superconductor Niobium nitride (NbN) and germanium niobium (NbsGe) are used as A15 type binary compounds.
The superconducting transition temperature of these materials is at most 23X.
-A high-temperature superconductor based on Cu-0 was proposed.
(J, G, Bednorz and [, A, Mu
Zetshrift Fur Physi
k B)-:I) Ite”yst’matter (Conde
nsed Matter) Vol, 64.189-
193 (1986) L further B1-3r-Ca-C
It was also discovered that u-0-based materials exhibit a transition temperature of 100 K or higher [H, Maeta 1, Y, Tana Chikara, M,
7 Kutomi and Day, Asano (H, Maeda, Y, T
anaka, M.
Ｆｕｋｕｔｏｍｉ ａｎｄ Ｔ、Ａｓａｎｏ）
、シ＊、へｍ二−ス＊、 ９’ｙ−ナル・オフ０・
ア７＠ライド・フィシ＃７クス（Ｊａｐａｎｅｓｅ
Ｊｏｕｒｎａｌ ｏｆ Ａｐｐｌ−ｉｅｄ Ｐｈｙ
ｓｉｃｓ）Ｖｏｌ、 ２７． Ｌ２０９−２１０（１９
８８）１． この種の材料の超電導機構の詳細は明ら
かではない力ｔ 転移温度が室温以上に高くなる可能性
があり、高温超電導体として従来の２元系化合物より、
より有望な特性が期待されも
さらに超電導体と絶縁物とを交互に積層することにより
、より高い超電導転移温度が従来から期待されていた
［エム、エイチ、コーエン及びデ１イ、エイチ、ドゥク
”ラス、シコ：７ （Ｍ、Ｈ９Ｃｏｈｅｎ ａｎｄ
Ｄ、Ｈ，Ｄｏｕｇｌａｓｓ、Ｊｒ、） 、７（シ
リル−１／ヒ１ニー・レターＸ’（Ｐｈｙｓｉｃａｌ
Ｒｅｖｉｅｗ Ｌｅｔｔｅｒｓ）Ｖｏｌ、１９，１
１８−１２１（１９６７）コ。Fukutomi and T, Asano)
, s*, hem second*, 9'y-nal off 0.
A7 @ Ride Fish #7 Cus (Japanese)
Journal of Appl-ied Phy
sics) Vol, 27. L209-210 (19
88)1. The details of the superconducting mechanism of this type of material are not clear, but the force t transition temperature may be higher than room temperature, making it more difficult to use as a high-temperature superconductor than conventional binary compounds.
Although more promising properties are expected, higher superconducting transition temperatures have traditionally been expected by alternately layering superconductors and insulators.
[M, H9Cohen and D1I, H9Duc'rus, Siko: 7 (M, H9Cohen and
D, H, Douglas, Jr.), 7 (Cyril-1/Hinny Letter X' (Physical
Review Letters) Vol. 19, 1
18-121 (1967).
発明が解決しようとする課題
しかしながｆｉ Ｂ１−３ｒ−Ｃａ−Ｃｕ−０系の材
料（よ 現在の技術では主として焼結という過程でしか
形成できないた△ セラミックの粉末あるいはブロック
の形状でしか得られな（１−太 この種の材料を実用化
する場合、薄膜状に加工することが強く要望されている
力曳 従来の技術で（表 良好な超電導特性を有する薄
膜作製は難しいものであった すなわＬ Ｂ１−３ｒ
−Ｃａ−Ｃｕ−０系には超電導転移温度の異なるいくつ
かの相が存在することが知られている力ｔ 特に転移温
度が１００Ｋ以上の相を薄膜の形態で達成するの（友
非常に困難とされていたまた 従来このＢｉ系において
良好な超電導特性を示す薄膜を形成するためには少なく
とも７００℃以上の熱処理あるいは形成時の加熱が必要
であり、そのため高い超電導転移温度が期待される絶縁
膜との周期的な積層構造を得ることは極めて困難と考え
られ またこの構造を利用した集積化デバイスを構成す
ることもたいへん困難であるとされていｔら
本発明は このような従来技術の課題を解決することを
目的とすも
課題を解決するための手段
本発明者らによる第１の発明の薄膜超電導体ζ上主体成
分が少なくともビスマス（Ｂｉ）、銅（Ｃｕ）、および
アルカリ土類（Ｉ Ｉ ａ族）を含む層状酸化物超電導
薄膜と、主体成分が少なくともＢｉとタングステン（Ｗ
）を含む層状酸化物薄膜が交互に積層された構造を持つ
ことを特徴とする薄膜超電導体であも
さらに第２の発明の薄膜超電導体の製造方法１よ基体上
に 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Ｗを含む酸化物を周期的に積層させ
て形成する酸化物薄膜とを、さらに交互に積層させて得
ることを特徴とする薄膜超電導体の製造方法であも
ここでアルカリ土類（上 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。Problems to be Solved by the Invention However, fi B1-3r-Ca-Cu-0 materials (with current technology, they can only be formed mainly through the process of sintering). In order to put this kind of material into practical use, it is strongly desired to process it into a thin film.It was difficult to fabricate a thin film with good superconducting properties using conventional techniques. Sunawa L B1-3r
-It is known that there are several phases with different superconducting transition temperatures in the Ca-Cu-0 system.In particular, it is difficult to achieve a phase with a transition temperature of 100 K or higher in the form of a thin film (friends).
In addition, in order to form a thin film that exhibits good superconducting properties in this Bi system, which has been considered extremely difficult, heat treatment at at least 700°C or higher during formation is required, and therefore a high superconducting transition temperature is expected. It is considered to be extremely difficult to obtain a periodic laminated structure with an insulating film, and it is also considered to be extremely difficult to construct an integrated device using this structure. The main components of the thin film superconductor ζ of the first invention by the present inventors are at least bismuth (Bi), copper (Cu), and alkaline earth. A layered oxide superconducting thin film containing the group IIa (group IIa) and a layered oxide superconducting thin film containing at least Bi and tungsten (W) as main components.
) is characterized in that it has a structure in which layered oxide thin films are stacked alternately. and an oxide containing at least copper and an alkaline earth (group IIa) are periodically stacked, and an oxide containing at least Bi and an oxide containing at least W are stacked periodically. The method for producing a thin film superconductor is characterized in that the oxide thin films to be formed are further laminated alternately. shows.
作用
本発明者らによる第１の発明において（表 安定なりｉ
ｇ○２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ＱＢｉＢｉ系超電
導薄膜ＢｉとＷとを含む酸化物層状構造の絶縁体Ｓ膜と
パ 交互に積層された構造をとることによって、超電導
膜と絶縁膜との間での相互拡散の少ない積層が可能とな
り、その結果Ｂｉ系超電導薄膜における超電導転移温度
の上昇が実現されたものであも
さらに第２の発明においては上記構造を達成するた△
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Ｗ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、再現性良
＜Ｂｉ系超電導薄膜と絶縁膜との積層を得ることに成功
したものであも
実施例
ます 本発明者らはＢｉ系超電導薄膜と絶縁膜との周期
的な積層構造を実現するた＆ＢｉＢｉ系超電導薄膜々の
絶縁膜との相互作用について検討しｔも
通ｔＢｉ系超電導薄膜は６００〜７００℃に加熱した基
体上に蒸着して得も 蒸着機 そのままでも薄膜は超電
導特性を示すバ その後８５０〜９５０℃の熱処理を施
し 超電導特性を向上させもしかしながら、基体温度が
高い時に絶縁膜をＢｉ系超電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、超電導膜と絶縁
膜との開−元素の相互拡散が起こり超電導特性が大きく
劣化することが判明しｔも 相互拡散を起こさないた
めには 超電導膜 絶縁膜の結晶性が優れていること、
超電導膜・絶縁膜間での格子の整合性が優れていること
、絶縁膜が８５０〜９５０℃の熱処理に対して安定であ
ることが不可欠と考えられも種々の検討を行った語気
本発明者らζよ 少なくともＷを含むＢｉｉ化物層状構
造の薄膜が絶縁膜として適していることを見いだしｆ、
この理由として、Ｗを含むＢｉｉ状酸化物１’！、
Ｂｉｇｏｔｉ化物層がＷ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プスカイトを示すことが知ら
れており、このＢｉｚＯａ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
、またＢｉ系超電導体とＢｉ−Ｗ系酸化物との格子の整
合性がきわめて優れていることが考えられも
さらに本発明者らｉ！Ｂｉ系超電導薄膜とＢｉ−Ｗ系酸
化物薄膜を周期的に積層した時、Ｂｉ系超超電導薄膜本
来超電導転移温度が上昇することを見いだした
本発明者らによる第１の発明の内容を更に深く理解され
るために 第１図を用い具体的な実施例を示ｔ
（実施例１）
第１図（友 本実施例で用いた二元マグネトロンスパッ
タ装置内部の概略図であり、 １１はＢ１−８ｒ−Ｃａ
−Ｃｕ−０ターゲツト、 １２はＢ１４−０ターゲツト
、 １３はシャッター、 １４はアパーチャー、 １
５は基体 １６は基体加熱用ヒーターを示す。焼結体を
ブレス成形加工して作製した２個のターゲット１１、１
２を用１．ｋ 第１図に示すように配置させたすなわ
６ Ｍｇｏ（１００）基体１５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もターゲット
の前方には回転するシャッター１３があり、その中に設
けられたアパーチャー１４の回転をパルスモータ−で制
御することにより、Ｂ１−８ｒ−Ｃａ−Ｃｕ−０−＋
Ｂｉ−Ｗ−０−＋ Ｂ１−８ｒ−Ｃａ−Ｃｕ−０−＋Ｂ
ｉ−Ｗ−０−＋Ｂ１−３ｒ−Ｃａ−Ｃｕ−０のサイクル
でスパッタ蒸着が行なうことができ４ Ｂ１−３ｒ−
Ｃａ−Ｃｕ−ＯＷＬＢｉ−Ｗ−０膜の積層の様子を概念
的に第２図に示ｔ 第２図において、２１はＢ１−８ｒ
−Ｃａ−Ｃｕ−０風２２はＢｉ−Ｗ−０膜を示す。Effect In the first invention by the present inventors (Table Stable i
g○2 A place with a crystalline structure covered with an oxide film layer or a layer mainly composed of this. By adopting this structure, it becomes possible to stack layers with less mutual diffusion between the superconducting film and the insulating film, and as a result, an increase in the superconducting transition temperature in the Bi-based superconducting thin film is achieved. In order to achieve the above structure in the invention, △
By periodically laminating an oxide containing at least Bi and an oxide containing at least copper and alkaline earth (group IIa) or an oxide containing at least W to produce a thin film through control at the molecular level. , with good reproducibility<This example is also one in which we succeeded in obtaining a stack of a Bi-based superconducting thin film and an insulating film.The present inventors have realized a periodic stacked structure of a Bi-based superconducting thin film and an insulating film. We also investigated the interaction of BiBi-based superconducting thin films with insulating films. Afterwards, heat treatment at 850 to 950°C is performed to improve the superconducting properties. It has been found that mutual diffusion of open elements with the insulating film occurs, greatly deteriorating the superconducting properties.In order to prevent mutual diffusion, the superconducting film and the insulating film must have excellent crystallinity.
Although it is considered essential that the lattice matching between the superconducting film and the insulating film be excellent, and that the insulating film be stable against heat treatment at 850 to 950°C, various studies have been carried out.
The present inventors ζ have discovered that a thin film with a Bii compound layered structure containing at least W is suitable as an insulating film.
The reason for this is that Bii-like oxide 1'! ,
It is known that the BizOa layer exhibits a layered perovskite sandwiching a structure composed of elements such as W and oxygen, and this BizOa layer exhibits extremely high resistance to the interface of materials with the same crystal structure even when subjected to high-temperature heat treatment. It is considered that the lattice matching between the Bi-based superconductor and the Bi-W-based oxide is extremely excellent. Let's take a deeper look into the content of the first invention by the present inventors, who discovered that when a Bi-based superconducting thin film and a Bi-W-based oxide thin film are stacked periodically, the inherent superconducting transition temperature of the Bi-based superconducting thin film increases. For better understanding, a specific example will be shown using FIG. 1. (Example 1) FIG. 8r-Ca
-Cu-0 target, 12 is B14-0 target, 13 is shutter, 14 is aperture, 1
Reference numeral 5 indicates a base body, and 16 indicates a heater for heating the base body. Two targets 11 and 1 made by press molding a sintered body
Use 2 to 1. k Even though each target is installed at an angle of about 30 degrees so as to focus on the 6 Mgo (100) substrate 15 arranged as shown in FIG. 1, there is a rotating shutter 13 in front of the target. By controlling the rotation of the aperture 14 provided therein with a pulse motor, B1-8r-Ca-Cu-0-+
Bi-W-0-+ B1-8r-Ca-Cu-0-+B
Sputter deposition can be performed with a cycle of i-W-0-+B1-3r-Ca-Cu-04B1-3r-
Figure 2 conceptually shows how the Ca-Cu-OWLBi-W-0 film is stacked. In Figure 2, 21 is B1-8r.
-Ca-Cu-0 style 22 indicates a Bi-W-0 film.
ターゲットｌ１１１２への入力電九 Ｂ１−８ｒ−Ｃａ
−Ｃｕ−０およびＢｉ−Ｗ−０のスパッタ時間を制御す
ることにより、基体１５上に蒸着するＢ１−８ｒ−Ｃａ
−Ｃｕ−０膜２１、Ｂ１−３ｒ−Ｃａ−Ｃｕ−０膜２２
の膜厚を変えることができも 基体１５をヒーター１６
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
タリングを行なり？、 薄膜作製後は酸素雰囲気中に
おいて、８５０℃の熱処理を５時間施した 本実施例で
（よ各ターゲットのスパッタ電力を、Ｂ１−３ｒ−Ｃａ
−Ｃｕ−０：１５０ Ｗ、 Ｂｉ−Ｗ−０： １０
０ Ｗとし ターゲット１１１１２のスパッタ時間を制
御しｆ：、 Ｂ１−３ｒ−Ｃａ−Ｃｕ−０膜２１の元
素の組成比率がＢｉ：Ｓｒ：Ｃａ：Ｃｕ−２：２：２：
３． Ｂｉ−Ｗ−Ｏ膜２２の元素の組成比率がＢｉ：
Ｗ−２：１になるよう、ターゲット１１，１２の元素の
組成比率を調整し？、、、 Ｂ１−３ｒ−Ｃａ−Ｃｕ
−０膜２１をＢｉ−Ｗ−０膜２２と積層せずに基体１５
上に形成した場合、すなわちＢ１−３ｒ−Ｃａ−Ｃｕ−
０膜２１そのものの特性ｉ；Ｌ１１５にで超電導転移を
起こり、、９７にで抵抗がゼロになるものであっ１．
さらに本発明者らによると、結晶性を維持したまま、
薄くできる膜厚の限界はＢｉ−Ｗ−０膜２２については
約２０ＯＡであった 絶縁膜はできるだけ薄い方が好ま
しいので、膜厚２００ＡのＢ１４−０膜２２に対して、
Ｂ１−８ｒ−Ｃａ−Ｃｕ−０膜２１の膜厚を変え第２図
に示すような（Ｂｉ−３ｒ−Ｃａ−Ｃｕ−０膜−＋Ｂｉ
−Ｗ−０膜）の積層構造を２０周期作製し氾 そのとき
゛の超電導薄膜の抵抗の温度特性を第３図に示す。第３
図において、Ｂ１−８ｒ−Ｃａ−Ｃｕ−０膜２１の膜厚
が１００Ａ、３０ＯＡ、５００Ａのときのを特性をそれ
ぞれ 特性３１．３２、３３に示す。特性３１において
はゼロ抵抗温度が約３０にとＢ１−３ｒ−Ｃａ−Ｃｕ−
０膜２１（７）特性が劣化することがわかりｔも こ
の理由として、Ｂ１−８ｒ−Ｃａ−Ｃｕ−０膜２１とＢ
ｉ−Ｗ−０膜２２との間で元素の相互拡散による膜２１
、２２の結晶性の破壊が考えられも さらに特性３３に
おいてＩｔ Ｂｉ−Ｗ−０膜２２との周期的な積層な
しに基体１５上につけたときのＢ１−３ｒ−Ｃａ−Ｃｕ
−０膜２１本来の超電導特性とほとんど同じであり、絶
縁膜Ｂ１４−０膜２２との積層効果は確認されなかった
しかしなか板 本発明者らは特性３２において、超電
導転移温度 ゼロ抵抗温度がともに約５に上昇すること
を見いだした この効果の詳細な理由については未だ不
明であるパＢ１−３ｒ−Ｃａ−Ｃｕ−０膜２１とＢｉ−
Ｗ−０膜２２との積層界面での元素の相互拡散の影響が
少なく、かつ薄いＢｉ−Ｗ−Ｏｊｊｊ ２２を介して複
数のＢ１−３ｒ−Ｃａ−Ｃｕ−０膜２１を積層すること
によりＢ１−３ｒ−Ｃａ−Ｃｕ−０膜２１において超電
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
れも
な抵 超電導転移温度が上昇する効果に４ Ｂ１−３
ｒ−Ｃａ−Ｃｕ−０膜２１の膜厚が２００〜４００Ａの
範囲で有効であることを、本発明者らは確認したな抵
本発明者らはターゲット１１、もしくは１２に鉛（Ｐｂ
）を添加してスパッタしたとき、基体１５の温度が上記
実施例よりも約１００℃低くても、上記実施例と同等な
結果が得られることを見いだした
さらに本発明者ら１ｔＢｉの酸化物と、Ｓｒ、ＣＬ
Ｃｕの酸化物を異なる蒸発源から真空中で別々に蒸発さ
せ、基体上にＢ１−０４Ｓｒ−Ｃｕ−０−＋Ｃａ−Ｃｕ
−０−３ｒ−Ｃｕ−０−＋Ｂ１−０の順で周期的に積層
させた場合、さらにＢｉの酸化物と、Ｗの酸化物を異な
る蒸発源から真空中で別々に蒸発させ、Ｂ１−０→Ｗ−
０→Ｂ１−０の順で周期的に積層させた場合、 （実施
例１）に示した積層構造作製方法より極めて制御性良く
、安定した膜質Ｑ しかも膜表面が極めて平坦なり１−
３ｒ−Ｃａ−Ｃｕ−０超電導薄膜およびＢｉ−Ｗ−０絶
縁膜が得られることを見いだした
さらに本発明者らｉ；Ｌ Ｂ１−０，５ｒ−Ｃｕ−０
、Ｃａ−Ｃｕ−０゜トＯを別々の蒸発源から蒸発させ、
Ｂ１−５ｒ−Ｃａ−Ｃｕ−０超電導薄膜とＢｉ−Ｗ−０
絶縁膜を周期的に積層した隊極めて制御性良＜ ｍ （
Ｂｉ−Ｓｒ−Ｃａ−Ｃｕ−０） ・ｎ （Ｂｉ−Ｗ−
０）の周期構造を持つ薄膜を形成できることを見いだし
九 ここでｒＱ、ｎは正の整数を示丸 さらへ このｍ
（Ｂｉ−８ｒ−Ｃａ−Ｃｕ−０） ・ｎ （Ｂｉ−
Ｗ−０）薄膜は （実施例１）に示したＢ１−８ｒ−Ｃ
ａ−Ｃｕ−０を同時に蒸着して得る超電導薄膜と、Ｂｉ
−Ｗ−０を同時に蒸着して得る酸化物絶縁膜とを周期的
に積層して得た薄膜に比べて１．はるかに結晶性が優れ
超電導転移温度 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ｆ、 さらに本発明者らは 上
記の方法で作製したＢ１−８ｒ−Ｃａ−Ｃｕ−０超電導
薄膜とＢｉ−Ｗ−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
これらのことは第４図に示す積層の概念図を用いて説明
することができも すなわ板 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も さらに ＢｉとＷを
含む酸化物層状ペロブスカイト構造の結晶のａ軸の長さ
？＆Ｂ１−８ｒ−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
のと考えられも
さらに以外にＬ 良好な超電導特性を得るに必要な基体
の温度 熱処理温度Ｌ 従来より低いことを見いだした
Ｂ１−０．５ｒ−Ｃｕ−０，Ｃａ−Ｃｕ−０，Ｗ−０を
周期的に積層させる方法として（よ いくつか考えられ
も 一般番響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。Input telephone nine to target l1112 B1-8r-Ca
-B1-8r-Ca deposited on the substrate 15 by controlling the sputtering time of Cu-0 and Bi-W-0
-Cu-0 film 21, B1-3r-Ca-Cu-0 film 22
It is possible to change the film thickness of the substrate 15 and the heater 16.
Heat it to about 700℃ using argon and oxygen (1:1).
Sputtering was performed on each target in a mixed atmosphere of 0.5 Pa gas? In this example, the sputtering power of each target was changed to B1-3r-Ca
-Cu-0: 150 W, Bi-W-0: 10
0 W and controlling the sputtering time of the target 11112, f:, the composition ratio of the elements of the B1-3r-Ca-Cu-0 film 21 is Bi:Sr:Ca:Cu-2:2:2:
3. The composition ratio of the elements of the Bi-W-O film 22 is Bi:
Adjust the composition ratio of the elements of targets 11 and 12 so that it becomes W-2:1? ,, B1-3r-Ca-Cu
-0 film 21 and Bi-W-0 film 22 are not stacked on the base 15.
When formed on the top, that is, B1-3r-Ca-Cu-
0 Characteristics of the film 21 itself: A superconducting transition occurs at L115, and the resistance becomes zero at L115.1.
Furthermore, according to the present inventors, while maintaining crystallinity,
The limit of the film thickness that can be reduced is about 20OA for the Bi-W-0 film 22.Since it is preferable for the insulating film to be as thin as possible, for the B14-0 film 22 with a film thickness of 200A,
By changing the film thickness of the B1-8r-Ca-Cu-0 film 21, as shown in FIG.
Figure 3 shows the temperature characteristics of the resistance of the superconducting thin film. Third
In the figure, the characteristics when the thickness of the B1-8r-Ca-Cu-0 film 21 is 100A, 30OA, and 500A are shown in characteristics 31, 32, and 33, respectively. In characteristic 31, the zero resistance temperature is about 30 and B1-3r-Ca-Cu-
It was found that the properties of the B1-8r-Ca-Cu-0 film 21 and B1-8r-Ca-Cu-0 film 21 deteriorated.
The film 21 due to interdiffusion of elements with the i-W-0 film 22
, 22 crystallinity may be destroyed.Furthermore, in characteristic 33, B1-3r-Ca-Cu when deposited on the substrate 15 without periodic lamination with the It Bi-W-0 film 22.
-0 film 21 has almost the same superconducting properties as the original, and no stacking effect with insulating film B14-0 film 22 was confirmed. The detailed reason for this effect is still unknown.
By stacking a plurality of B1-3r-Ca-Cu-0 films 21 through the thin Bi-W-Ojjj 22, which has less influence of mutual diffusion of elements at the lamination interface with the W-0 film 22, the B1 -3r-Ca-Cu-0 film 21, it is unlikely that some change was caused in the superconducting mechanism due to the effect of increasing the superconducting transition temperature 4 B1-3
The present inventors have confirmed that the r-Ca-Cu-0 film 21 is effective when the film thickness is in the range of 200 to 400 A.
The present inventors set the target 11 or 12 to lead (Pb).
), the present inventors found that even if the temperature of the substrate 15 was about 100° C. lower than that of the above example, results equivalent to those of the above example could be obtained. , Sr, C.L.
The oxides of Cu were evaporated separately in vacuum from different evaporation sources, and B1-04Sr-Cu-0-+Ca-Cu was deposited on the substrate.
-0-3r-Cu-0-+B1-0 is stacked periodically in the order of B1-0, Bi oxide and W oxide are evaporated separately in vacuum from different evaporation sources, and B1-0 →W-
When laminated periodically in the order of 0→B1-0, the controllability is much better than the laminated structure manufacturing method shown in Example 1, and the film quality is stable.Moreover, the film surface is extremely flat.1-
Furthermore, the present inventors have discovered that a 3r-Ca-Cu-0 superconducting thin film and a Bi-W-0 insulating film can be obtained.
, Ca-Cu-0° and O are evaporated from separate evaporation sources,
B1-5r-Ca-Cu-0 superconducting thin film and Bi-W-0
The structure in which insulating films are periodically laminated provides extremely good controllability.
Bi-Sr-Ca-Cu-0) ・n (Bi-W-
We found that it is possible to form a thin film with a periodic structure of 0), where rQ and n are positive integers.
(Bi-8r-Ca-Cu-0) ・n (Bi-
W-0) The thin film is B1-8r-C shown in (Example 1)
A superconducting thin film obtained by simultaneously depositing a-Cu-0 and Bi
1. compared to a thin film obtained by periodically laminating an oxide insulating film obtained by simultaneously depositing -W-0. We also found that the crystallinity was far superior, and the properties such as superconducting transition temperature and critical current density were superior. Furthermore, the present inventors found that the B1-8r-Ca-Cu-0 superconducting thin film produced by the above method and It was found that both Bi-W-0 insulating films have extremely flat thin film surfaces.These things can be explained using the conceptual diagram of lamination shown in Figure 4.In other words, each plate has a layered structure. By stacking different elements separately and sequentially,
This may be due to the fact that the deposited elements move only in the plane parallel to the substrate surface, and there is no movement of elements in the direction perpendicular to the substrate surface. What is the length of the a-axis of the crystal structure? &B1-8r-Ca-Cu-0, almost equal to that of
This is thought to be due to the fact that continuous epitaxial growth is possible; , Ca-Cu-0, and W-0 (there are several methods that can be considered). Periodic stacking can be achieved by switching the type of gas during production using a phase growth method.
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ｆ、 この理由ば 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。しか
しなが板 本発明者らはこのＢｉ系酸化物超電導体に対
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
たとこム以外にも良好な積層膜作製が可能なことを発見
し九 スパッタ中の高い酸素ガス圧およびスパッタ放電
力＜、Ｂｉ系の１００Ｋ以上の臨界温度を持つ相の形成
およびＢｉ−Ｗ−０絶縁膜の形成に都合がよいためで
はなかろうかと考えられも
スパッタ蒸着で異なる物質を積層させる方法として（よ
組成分布を設けた１ケ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力丈 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
の塔載 複数個のターゲットの各々のスパッタ量を周期
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
することができも 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も
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ζ上 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
積層膜が実現されも 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り比較的簡単にＢｉ系酸化物
の周期的積層が作製可能となも
以下本発明者らによる第２の発明の内容をさらに深く理
解されるために 具体的な実施例を示す。However, sputtering deposition has traditionally been considered unsuitable for this type of extremely thin layer stacking, and the reason for this is thought to be damage caused by impurity contamination and high-energy particles caused by the high gas pressure during film formation. ing. However, the present inventors have discovered that it is possible to produce a good laminated film by laminating different thin layers on this Bi-based oxide superconductor by sputtering. This may be due to the high oxygen gas pressure and sputter discharge power <, which is convenient for the formation of a Bi-based phase with a critical temperature of 100 K or higher and the formation of a Bi-W-0 insulating film. One method of stacking layers is to periodically control the discharge position of one sputtering target with a composition distribution.This can be achieved relatively easily by sputtering multiple targets with different compositions. By periodically controlling the amount of sputtering for each of multiple targets, or by providing a shutter in front of the target and opening and closing it periodically, a periodic laminated film can be produced. However, it may also be possible to fabricate the substrate by periodically moving it over each target.
When using laser sputtering or ion beam sputtering, periodic laminated films can be achieved by periodically moving multiple targets on ζ and periodically changing the targets irradiated with the beam. It is possible to relatively easily produce a periodic stack of Bi-based oxides by sputtering.Specific examples will be shown below in order to provide a deeper understanding of the content of the second invention by the present inventors.
（実施例２）
第５図に本実施例で用いた４元マグネトロンスパッタ装
置の概略図を示も 第５図において、 ５１はＢｉツタ
−ット、 ５２は５ｒＣｕ合金ターゲット、５３はＣａ
Ｃｕ合金ターゲット、 ５４はＷターゲット、 ５５は
シャッター、 ５６はスリット、 ５７は基体 ５８は
基体加熱用ヒーターを示す。計４個のターゲット５１、
５２．５３．５４は第２図に示すように配置させた 即
’＆Ｍｇ０（１００）基体５７に焦点を結ぶように各タ
ーゲットカ文 約３０°傾いて設置されていも ターゲ
ットの前方には回転するシャッター５５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５６の回転が制御され 各ターゲットのサイクル及び
スパッタ時間を設定することができも 基体５７をヒー
ター５８で約８００℃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つｔも各ターゲットのスパッタ電流
を、Ｂｉ：３０ｍＡ、 ５ｒＣｕ：８０ｍＡ、ＣａＣｕ
：３００ｍＡ、 Ｗ：４００ｍＡにして実験を行ｊ １
％４Ｂｉ−＋ ５ｒＣｕ−＊ＣａＣｕ−ｅ Ｂｉのサイ
クルでスパッタＬ、 Ｂ１５ｒ−Ｃａ−Ｃｕ−０膜の
元素の組成比率が Ｂｉ：Ｓｒ：Ｃａ：Ｃｕ−２二２：
２：３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２０周期行った結電１００に以上の
臨界温度を持つ相を作製することができた このままの
状態でもこのＢ１−３ｒ−Ｃａ−Ｃｕ−Ｏ薄膜は１００
Ｋ以上の超電導転移を示した力交 さらに酸素中で６５
０ｔ、 １時間の熱処理を行なうと非常に再現性よく
なり、超電導転移温度は１２０凰抵抗がゼロになる温度
は１００Ｋになつｔも 超電導転移温度が１００Ｋを
越す相は金属元素がＢ１−８ｒ−Ｃｕ−Ｃａ−Ｃｕ−Ｃ
ａ−Ｃｕ−３ｒ−Ｂｉの順序で並んだ酸化物の層から成
り立っているとも言われており、本発明の製造方法がこ
の構造を作るのに非常に役だっているのではないかと考
えられも また 同様にＢｉ−＋Ｗ→Ｂｉのサイクルで
Ｂｉ−Ｗ−０膜の元素の組成比がＢｉ：Ｗ−２＋１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４サイクルまで少なくして、Ｂｉ−Ｗ〜Ｏ膜の膜
厚を薄くしてＬ 極めて結晶性に優れたＢｉ−Ｗ−０膜
が得られた
さらに本発明者らはｍｘ （Ｂｉ−＋５ｒＣｕ−＊Ｃａ
Ｃｕ−＊５ｒＣｕ−＋Ｂｉ） →ｎ Ｘ （Ｂｉ→Ｗ−
＋Ｂｉ）のサイクルで各ターゲットをスパッタｌ、、
ｍ （Ｂｉ−３ｒ−Ｃａ−Ｃｕ−０） ・ｎ（Ｂｉ
−Ｗ−０）薄膜を基体５７上に作製した ここで― ｎ
は正の整数を示す。本発明者らはｎ＝４のと１＝、ｍを
変化させて周期的に積層して得た膜の超電導特性を調べ
ｔも 第６図にｍ＝２、６、１６のときに得た膜の抵
抗の温度変化をそれぞれ特性６１．６２、６３に示す。(Example 2) Figure 5 shows a schematic diagram of the four-element magnetron sputtering apparatus used in this example. In Figure 5, 51 is a Bi target, 52 is a 5rCu alloy target, and 53 is a Ca
54 is a W target; 55 is a shutter; 56 is a slit; 57 is a base; 58 is a heater for heating the base. A total of 4 targets 51,
52, 53, and 54 were arranged as shown in Figure 2. Even though each target was placed at an angle of about 30 degrees, it rotated in front of the target so as to focus on the base 57. There is a shutter 55, which is driven by a pulse motor to control the rotation of a slit 56 provided therein.The cycle and sputtering time for each target can be set.The substrate 57 is heated to approximately 800°C by a heater 58. Argon/oxygen (5:
1) Perform sputtering for each target in a mixed atmosphere of 3 Pa gas.The sputtering current for each target is Bi: 30 mA, 5rCu: 80mA, CaCu
:300mA, W:400mA j 1
%4Bi-+5rCu-*CaCu-e In the Bi cycle, the elemental composition ratio of the sputtered L, B15r-Ca-Cu-0 film is Bi:Sr:Ca:Cu-22:
By adjusting the sputtering time of each target so that the ratio was 2:3 and repeating the above cycle 20 times, we were able to create a phase with a critical temperature higher than the B1-3r-Ca phase. -Cu-O thin film is 100
Force exchange that showed superconducting transition above K and 65 in oxygen
When the heat treatment is performed for 0t and 1 hour, the reproducibility becomes very good, and the superconducting transition temperature is 120, and the temperature at which the resistance becomes zero is 100K. Cu-Ca-Cu-C
It is said that it consists of layers of oxides arranged in the order a-Cu-3r-Bi, and it is thought that the manufacturing method of the present invention is extremely useful in creating this structure. Similarly, the sputtering time of each target was adjusted so that the elemental composition ratio of the Bi-W-0 film became Bi:W-2+1 in the Bi-+W→Bi cycle, and the above cycles were reduced to 4 cycles. By reducing the thickness of the Bi-W~O film, a Bi-W-0 film with extremely excellent crystallinity was obtained.
Cu-*5rCu-+Bi) →n X (Bi→W-
Sputter each target with cycles of +Bi).
m (Bi-3r-Ca-Cu-0) ・n(Bi
-W-0) A thin film was produced on the substrate 57, where - n
indicates a positive integer. The inventors investigated the superconducting properties of films obtained by periodically stacking films with n = 4 and 1 = varying m, and the t values obtained when m = 2, 6, and 16 are shown in Figure 6. The temperature changes in the resistance of the film are shown in characteristics 61, 62 and 63, respectively.
第６図において、ｍ＝６のとき、最も高い超電導転移温
度およびゼロ抵抗温度 すなわち特性６２が得られた
特性６２の超電導転移温度 ゼロ抵抗温度はＢ１−３ｒ
−Ｃａ−Ｃｕ−Ｏ膜本来のそれらの値よりも約８に高い
ものであったこの効果の詳細な理由については未だ不明
である力交 本実施例に示した方法でＢ１−３ｒ−Ｃａ
−Ｃｕ−０膜とＢｉ−Ｗ−０膜とを周期的に積層するこ
とによって、Ｂ１−８ｒ−Ｃａ−Ｃｕ−０膜とＢｉ−Ｗ
−０１１［が互いにＢｉ２Ｏを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Ｂｉ−Ｗ−０膜
を介して同じく結晶性に優れたＢ１−８ｒ−Ｃａ−Ｃｕ
−０膜を積層することによりＢ１５ｒ−Ｃａ−Ｃｕ−０
膜において超電導機構になんらかの変化が引き起こされ
たことが考えられも
な耘 超電導転移温度が上昇する効果（よ Ｂ１−３
ｒＣｕ−＋ ＣａＣｕ−＋ Ｂ ｉのサイクルが４〜Ｉ
Ｏの範囲で有効であることを、本発明者らは確認しｆＱ
。In Figure 6, when m = 6, the highest superconducting transition temperature and zero resistance temperature, that is, characteristic 62, was obtained.
Superconducting transition temperature of characteristic 62 Zero resistance temperature is B1-3r
The detailed reason for this effect, which was about 8 higher than those of the -Ca-Cu-O film, is still unknown.
-By periodically stacking the Cu-0 film and the Bi-W-0 film, the B1-8r-Ca-Cu-0 film and the Bi-W
-011[ are epitaxially grown through the Bi2O layer, so there is no effect of mutual diffusion of elements at the laminated interface, and the same crystallinity is achieved through the thin Bi-W-0 film with excellent crystallinity. Excellent B1-8r-Ca-Cu
By stacking -0 films, B15r-Ca-Cu-0
It is unlikely that some change was caused in the superconducting mechanism in the film.
The cycle of rCu-+ CaCu-+ B i is 4 to I
The inventors confirmed that fQ is effective in the range of O.
.
な抵 本発明者らはターゲット５１． もしくは５４
に鉛（Ｐｂ）を添加してスパッタしたとき、基体５７の
温度が上記実施例よりも約１００℃低くてｋ 上記実施
例と同等な結果が得られることを見いだした
発明の効果
以上のように第１の本発明の薄膜超電導体ζよりｉ系薄
膜超電導体の超電導転移温度を上昇させる構造を提供す
るものであり、第２の本発明の薄膜超電導体の製造方法
は第１の本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犬き鶏The present inventors target 51. Or 54
The effect of the invention is as follows: it was found that when lead (Pb) is added to and sputtered, the temperature of the substrate 57 is about 100° C. lower than in the above embodiment, and results equivalent to those in the above embodiment can be obtained. The second invention provides a structure that increases the superconducting transition temperature of the i-based thin film superconductor from the thin film superconductor ζ of the first invention. The industrial value of the present invention is that it has been realized more effectively and has established a process at low temperatures that is essential for the application of devices, etc.
第１図は第１の発明の一実施例における薄膜の製造装置
の概略を示す構造＠ 第２図は第１の発明の一実施例に
おける薄膜の構造概念は 第３図は第１図の装置により
得た薄膜における抵抗の温度特性は 第４図は第２の発
明の一実施例における薄膜の構造概念＠ 第５図は第２
の発明の一実施例における薄膜の製造装置の概略を示す
構造は第６図は第５ＦｙＪの装置により得た薄膜におけ
る抵抗の温度特性図である。Figure 1 shows the structure of the thin film manufacturing apparatus in an embodiment of the first invention. Figure 2 shows the structure of the thin film in an embodiment of the first invention. The temperature characteristics of the resistance in the thin film obtained by
FIG. 6 is a temperature characteristic diagram of resistance in a thin film obtained by the apparatus of No. 5FyJ.
Claims (4)
ｕ），およびアルカリ土類（ＩＩａ族）を含む層状酸化
物超電導薄膜と、主体成分が少なくともＢｉとタングス
テン（Ｗ）を含む層状酸化物薄膜が交互に積層された構
造を持つ（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を示す。）こ
とを特徴とする薄膜超電導体。(1) The main components are at least bismuth (Bi) and copper (C).
u), and has a structure in which layered oxide superconducting thin films containing alkaline earth (group IIa) and layered oxide thin films containing at least Bi and tungsten (W) as main components are laminated alternately (here, alkaline earth 1. A thin film superconductor characterized in that (1) indicates at least one or two or more elements of group IIa elements.
も銅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Ｗを含む酸化物を周期的
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を示す。）こと
を特徴とする薄膜超電導体の製造方法。(2) An oxide thin film formed by periodically stacking an oxide containing at least B and an oxide containing at least copper and alkaline earth (group IIa) on a substrate, and an oxide containing at least Bi. It is obtained by alternately stacking oxide thin films formed by periodically stacking oxides containing at least W. A method for producing a thin film superconductor, characterized in that:
行うことを特徴とする請求項２記載の薄膜超電導体の製
造方法。(3) The method for manufacturing a thin film superconductor according to claim 2, 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２記載の薄膜超電導体の製造方法。(4) The method for producing a thin film superconductor according to claim 2, wherein the evaporation of the laminated material is performed by sputtering.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1220743A JPH0822742B2 (en) | 1989-08-28 | 1989-08-28 | Thin film superconductor and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1220743A JPH0822742B2 (en) | 1989-08-28 | 1989-08-28 | Thin film superconductor and method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0382749A true JPH0382749A (en) | 1991-04-08 |
| JPH0822742B2 JPH0822742B2 (en) | 1996-03-06 |
Family
ID=16755837
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1220743A Expired - Fee Related JPH0822742B2 (en) | 1989-08-28 | 1989-08-28 | Thin film superconductor and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0822742B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5434126A (en) * | 1992-09-29 | 1995-07-18 | Matsushita Electric Industrial Co., Ltd. | Thin-film high Tc superconductor comprising a ferroelectric buffer layer |
-
1989
- 1989-08-28 JP JP1220743A patent/JPH0822742B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5434126A (en) * | 1992-09-29 | 1995-07-18 | Matsushita Electric Industrial Co., Ltd. | Thin-film high Tc superconductor comprising a ferroelectric buffer layer |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0822742B2 (en) | 1996-03-06 |
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