JPH01166419A - Manufacture of superconductive membrane - Google Patents
Manufacture of superconductive membraneInfo
- Publication number
- JPH01166419A JPH01166419A JP62324704A JP32470487A JPH01166419A JP H01166419 A JPH01166419 A JP H01166419A JP 62324704 A JP62324704 A JP 62324704A JP 32470487 A JP32470487 A JP 32470487A JP H01166419 A JPH01166419 A JP H01166419A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- producing
- superconducting thin
- film according
- sputtering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 39
- 239000012528 membrane Substances 0.000 title abstract 6
- 238000000034 method Methods 0.000 claims abstract description 16
- 239000002887 superconductor Substances 0.000 claims abstract description 14
- 239000010409 thin film Substances 0.000 claims description 67
- 239000000758 substrate Substances 0.000 claims description 38
- 239000013078 crystal Substances 0.000 claims description 37
- 239000010408 film Substances 0.000 claims description 36
- 238000004544 sputter deposition Methods 0.000 claims description 35
- 239000002131 composite material Substances 0.000 claims description 34
- 238000005240 physical vapour deposition Methods 0.000 claims description 19
- 239000007789 gas Substances 0.000 claims description 17
- 230000015572 biosynthetic process Effects 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 13
- 238000001816 cooling Methods 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- 239000001301 oxygen Substances 0.000 claims description 7
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 238000001552 radio frequency sputter deposition Methods 0.000 claims description 7
- 238000001755 magnetron sputter deposition Methods 0.000 claims description 4
- 238000010583 slow cooling Methods 0.000 claims 1
- 239000000463 material Substances 0.000 abstract description 11
- 238000001704 evaporation Methods 0.000 abstract 5
- 230000008020 evaporation Effects 0.000 abstract 5
- 238000007733 ion plating Methods 0.000 abstract 1
- 238000007738 vacuum evaporation Methods 0.000 abstract 1
- 238000007796 conventional method Methods 0.000 description 11
- 238000000151 deposition Methods 0.000 description 4
- 230000008021 deposition Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 230000000737 periodic effect Effects 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 230000005668 Josephson effect Effects 0.000 description 2
- 229910002370 SrTiO3 Inorganic materials 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005291 magnetic effect Effects 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000005292 diamagnetic effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000007704 transition Effects 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
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は超電導薄膜の製造方法に関するものであり、よ
り詳細には、高い超電導臨界温度を有する複合酸化物超
電導薄膜の臨界電流を大幅に向上させる超電導薄膜の作
製方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing a superconducting thin film, and more particularly, to a method for producing a superconducting thin film that significantly improves the critical current of a composite oxide superconducting thin film having a high superconducting critical temperature. This invention relates to a method for producing a thin film.
本発明により得られる超電導薄膜は高い臨界電流を持つ
と同時に、平滑性等の他の特性においても優れた特性を
有しており、集積回路を始めとする各種電子部品の配線
材料として特に有用である。The superconducting thin film obtained by the present invention has a high critical current and also has excellent properties such as smoothness, making it particularly useful as a wiring material for various electronic components including integrated circuits. be.
従来の技術
電子の相転移であるといわれる超電導現象は、特定の条
件下で導体の電気抵抗が零の状態となり完全な反磁性を
示す現象である。BACKGROUND OF THE INVENTION Superconductivity, which is said to be a phase transition of electrons, is a phenomenon in which the electrical resistance of a conductor becomes zero under certain conditions and exhibits complete diamagnetic properties.
超電導の代表的な利用分野であるエレクトロニクスの分
野では、各種の超電導素子が提案され、また開発されて
いる。この分野で代表的なものとして、超電導材料どう
しを弱く接合した場合に、印加電流によって量子効果が
巨視的に現れるジョセフソン効果を利用した素子が挙げ
られる。トンネル接合型ジョセフソン素子は、超電導材
料のエネルギーギャップが小さいことから、極めて高速
な低電力消費のスイッチング素子として期待されている
。さらに、電磁波や磁場に対するジョセフソン効果が正
確な量子現象として現れることから、ジョセフソン素子
を磁場、マイクロ波、放射線等の超高感度センサとして
利用することも期待されている。In the field of electronics, which is a typical field of application of superconductivity, various superconducting elements have been proposed and developed. A typical example in this field is an element that utilizes the Josephson effect, in which a quantum effect appears macroscopically depending on an applied current when superconducting materials are weakly bonded together. Tunnel junction type Josephson devices are expected to be extremely high-speed switching devices with low power consumption because the energy gap of superconducting materials is small. Furthermore, since the Josephson effect on electromagnetic waves and magnetic fields appears as a precise quantum phenomenon, it is expected that Josephson elements will be used as ultrasensitive sensors for magnetic fields, microwaves, radiation, etc.
また、超高速電子計算機では、単位面積当たりの消費電
力が冷却能力の限界に達してきているため超電導素子の
開発が要望されおり、さらに、電子回路の集積度が高く
なるにつれて電流ロスの無い超電導材料を配線材料とし
て用いることが要望されている。In addition, in ultra-high-speed electronic computers, the power consumption per unit area is reaching the limit of cooling capacity, so there is a demand for the development of superconducting elements.Furthermore, as the degree of integration of electronic circuits increases, superconducting There is a desire to use the material as a wiring material.
しかし、様々な努力にもかかわらず、超電導材料の超電
導臨界温度Ｔｃは長期間に亘ってＮｂ、Ｇｅの２３Ｋを
越えることができなかったが、昨年来、（Ｌａ、 Ｂａ
〕、（：ｕ○、または（Ｌａ、 Ｓｒ） ２ｃｕｏａ等
の酸化物の焼結材が高いＴＣをもつ超電導材料として発
見され、非低温超電導を実現する可能性が大きく高まっ
ている。これらの物質では、３０乃至５０にという従来
に比べて飛躍的に高いＴｃが観測されている。However, despite various efforts, the superconducting critical temperature Tc of superconducting materials has not been able to exceed 23K for Nb and Ge for a long time;
], (:u○, or (La, Sr) 2cuoa, etc., have been discovered as superconducting materials with high TC, and the possibility of realizing non-low temperature superconductivity is greatly increasing.These materials In this case, a significantly higher Tc of 30 to 50 has been observed compared to the conventional method.
尚、上述のような複合酸化物超電導体薄膜の作製は、わ
が国においては、焼結等で生成した酸化物を蒸着源とし
て用いた、スパッタリング法等の物理蒸着によって行う
ことが一般的である。In Japan, the above-described composite oxide superconductor thin film is generally produced by physical vapor deposition such as sputtering using an oxide produced by sintering or the like as a deposition source.
発明が解決しようとする問題点
ところで、上述のような複合酸化物系超電導体薄膜は、
臨界電流密度Ｊｃが小さいために、臨界温度Ｔｃが極め
て高いにも関わらず実際の電子回路として実用化するこ
とができなかった。Problems to be solved by the invention By the way, the above-mentioned composite oxide superconductor thin film has
Since the critical current density Jc was small, it could not be put to practical use as an actual electronic circuit even though the critical temperature Tc was extremely high.
そこで、本発明の目的は、上記従来技術の問題点を解決
し、高い臨界電流密度Ｊｃを有する複合酸化物超電導材
料の薄膜を作製する方法を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art described above and to provide a method for producing a thin film of a composite oxide superconducting material having a high critical current density Jc.
問題点を解決するための手段
本発明に従うと、下記の式：
％式％
（但し、元素αは、ＢａまたはＳｒであり、Ｘは０．０
１≦ｘ≦０．２を満たす数である）で表される複合酸化
物を主として含有する複合酸化物超電導体薄膜を物理蒸
着によって作製する方法において、
上記物理蒸着時の成膜速度を０．０５〜１Å／秒の範囲
としたことを特徴とする超電導薄膜の作製方法が提供さ
れる。Means for Solving the Problems According to the present invention, the following formula: % formula % (where the element α is Ba or Sr and X is 0.0
In a method for producing a composite oxide superconductor thin film mainly containing a composite oxide represented by the formula 1≦x≦0.2 by physical vapor deposition, the film forming rate during the physical vapor deposition is set to 0. Provided is a method for producing a superconducting thin film, characterized in that the heating rate is in the range of 0.05 to 1 Å/sec.
上記物理蒸着としては、スパッタリング、イオンブレー
ティング、真空蒸着等の減圧下での蒸着法の他を用いる
ことができるが、一般にはスパッタリング、特にＲＦマ
グネトロンスパッタリングが好ましい。As the above-mentioned physical vapor deposition, other vapor deposition methods under reduced pressure such as sputtering, ion blating, and vacuum vapor deposition can be used, but generally sputtering, particularly RF magnetron sputtering, is preferable.
本発明の方法で作製される複合酸化物超電導薄膜は、上
記一般式：
％式％
で示される複合酸化物を主として含んでおり、これらの
複合酸化物はペロブスカイト型または擬似ペロブスカイ
ト型酸化物を主体としたものと考えられ、上記元素αは
８ａまたはＳｒから選択される。The composite oxide superconducting thin film produced by the method of the present invention mainly contains a composite oxide represented by the above general formula: It is considered that the element α is selected from 8a or Sr.
上記ＢａまたはＳｒと、Ｌａと、Ｃｕとの原子比は上記
の式を満たす範囲であることが好ましいが、必ずしも厳
密にこの比に限定されるものではなく、これらの比から
±５０％の範囲、さらに好ましくは±２０％の範囲でず
れた原子比の組成のものでも有効な超電導現象を示す場
合がある。すなわち、特許請求の範囲において「上記の
式で表される複合酸化物を主として含有する」という表
現は上記のように上記の式で定義される原子比以外のも
のも含むということを意味し、更に、上記の定義は上記
の元素以外の元素、すなわち、ｐｐｍオーダーで混入す
る不可避的不純物や、製品の他の特性、例えば機械的な
特性等を向上させる目的で添加される第３成分を含有し
ていてもよいということを意味している。The atomic ratio of Ba or Sr, La, and Cu is preferably within a range that satisfies the above formula, but is not necessarily strictly limited to this ratio, and may be within ±50% of these ratios. Even if the composition has an atomic ratio that deviates within a range of, more preferably, ±20%, an effective superconducting phenomenon may be exhibited. That is, in the claims, the expression "mainly contains a composite oxide represented by the above formula" means that it also includes atomic ratios other than those defined by the above formula, as described above, Furthermore, the above definition includes elements other than the above elements, that is, unavoidable impurities mixed in on the order of ppm, and third components added for the purpose of improving other properties of the product, such as mechanical properties. This means that it is okay to do so.
第３成分として添加可能な元素としては、周期律表■ａ
族元素のＳｒＳＣａ５Ｍｇ、 Ｂｅ、上記以外の周期律
表ｍａ族元素、周期律表Ｉ ｂ、 ＩＩ ｂ、 ＩＩ［
ｂ。Elements that can be added as the third component include ■a of the periodic table
Group elements SrSCa5Mg, Be, periodic table ma group elements other than the above, periodic table I b, II b, II [
b.
ｒＶａおよび■ａ族から選択される元素、例えば、Ｔｉ
、 Ｖを挙げることが出来る。rVa and an element selected from the a group, for example, Ti
, V can be mentioned.
本発明の特徴は、上記物理蒸着時の成膜速度を０．０５
〜１Å／秒、さらに好ましくは０．１〜０．８Å／秒に
した点にある。The feature of the present invention is that the film formation rate during the above physical vapor deposition is 0.05
-1 Å/sec, more preferably 0.1 to 0.8 Å/sec.
本発明者達の実験結果によると、理蒸着時の成膜速度が
１Å／秒を超えると、得られた超電導薄膜の臨界電流密
度が大幅に低下して実用的な薄膜が得られない。また、
成膜速度を０．０５Å／秒未満にすると、成膜速度が極
端に遅くなるので、工業的でない。According to the experimental results of the present inventors, when the deposition rate during physical vapor deposition exceeds 1 Å/sec, the critical current density of the obtained superconducting thin film decreases significantly, making it impossible to obtain a practical thin film. Also,
If the film formation rate is less than 0.05 Å/sec, the film formation rate becomes extremely slow and is not industrially practical.
上記物理蒸着をスパッタリングで行う場合には、スパッ
タリングを０．００１〜０．５ Ｔｏｒｒの圧力、さら
に好ましくは０．０１〜０ＪＴｏｒｒの圧力下でかつ０
□を５〜９５分子％、さらに好ましくは１０〜８０分子
％含む雰囲気で行うのが好ましい。この０２以外と一緒
に用いることが可能な他のスパッタリングガスとしては
不活性ガスであるアルゴンが好ましい。When the above-mentioned physical vapor deposition is performed by sputtering, the sputtering is performed under a pressure of 0.001 to 0.5 Torr, more preferably under a pressure of 0.01 to 0 JTorr, and at a pressure of 0.001 to 0.5 Torr.
It is preferable to conduct the reaction in an atmosphere containing 5 to 95 mol %, more preferably 10 to 80 mol % of □. Argon, which is an inert gas, is preferably used as a sputtering gas other than 02.
また、基板を２００〜９５０℃、さらに好ましくは５０
０〜９２０℃に加熱しながらスパッタリングを行うのが
好ましい。In addition, the substrate is heated at 200 to 950°C, more preferably at 50°C.
It is preferable to perform sputtering while heating at 0 to 920°C.
上記のように物理蒸着をスパッタリングで行う場合には
、成膜速度を制御するファクタとしては、成膜ガス圧力
、０２／（０２＋Ａｒ）の比、更にＲＦスパッタリング
においてはＲＦパワーを挙げることができる。When physical vapor deposition is performed by sputtering as described above, factors for controlling the film formation rate include the film formation gas pressure, the ratio of 02/(02+Ar), and, in the case of RF sputtering, the RF power.
いずれの場合にも、スパッタリングガス中の０２の比率
が５から９５分子％であることが好ましい。In either case, the proportion of 02 in the sputtering gas is preferably 5 to 95 mol%.
そして、スパッタリングをＲＦスパッタリングで行う場
合には、高周波電力を０．０６４〜１．２７Ｗ／Ｃｒｌ
の範囲内、特に０．１２７〜０．７６Ｗ／ｃａ！の範囲
内とすることが好ましい。更に、スパッタリングガス中
０Ｏ２の比率が１０から８０分子％の範囲とし、成膜ガ
ス圧力を０．００１〜０．５ Ｔｏｒｒの圧力、特に０
．０１〜０．３ Ｔｏｒｒの範囲内とすることが好まし
い。When sputtering is performed by RF sputtering, the high frequency power is 0.064 to 1.27 W/Crl.
Within the range of 0.127 to 0.76 W/ca! It is preferable to set it within the range of. Furthermore, the ratio of 0O2 in the sputtering gas is in the range of 10 to 80 mol%, and the film forming gas pressure is 0.001 to 0.5 Torr, especially 0
．． It is preferable to set it within the range of 0.01 to 0.3 Torr.
成膜ガス圧力または０２／ （０２＋ Ａ ｒ）の比を
制御する場合には、上記スパッタリングをＲＦスパッタ
リングで行うときは、高周波電力を１．２７〜２，５５
Ｗ ／ ａｎ！の範囲内、特に１．５３〜２．２９Ｗ／
ｃａｆの範囲内とすることが好ましい。そして、０２／
（０２＋Ａ ｒ）の比を制御する場合には、スパッタ
リングガス中の０２の比率は、３０から９５分子％の範
囲内、特に４０から８０分子％の範囲内とすることが好
ましく、成膜ガス圧力を０．００１〜０．５Ｔｏｒｒの
圧力、特に０．０１〜Ｑ、３Ｔｏｒｒの範囲内とするこ
とが好ましい。When controlling the film forming gas pressure or the ratio of 02/(02+Ar), when performing the above sputtering by RF sputtering, the high frequency power should be set at 1.27 to 2,55.
W/an! within the range, especially 1.53 to 2.29 W/
It is preferable to set it within the range of caf. And 02/
When controlling the ratio of (02+A r), the ratio of 02 in the sputtering gas is preferably within the range of 30 to 95 mol%, particularly within the range of 40 to 80 mol%, and the deposition gas pressure It is preferable that the pressure is in the range of 0.001 to 0.5 Torr, particularly in the range of 0.01 to Q, 3 Torr.
一方、成膜ガス圧力を制御する場合には、スパッタリン
グガス中の０２の比率は、特に１０から８０分子％の範
囲内とすることが好ましく、成膜ガス圧力を０、ＯＯ１
〜０．５７ｏｒｒの圧力、特に０．０５〜０．５Ｔｏｒ
ｒの範囲内とすることが好ましい。On the other hand, when controlling the film-forming gas pressure, the ratio of 02 in the sputtering gas is preferably within the range of 10 to 80 mol%, and the film-forming gas pressure is set to 0, OO1.
~0.57 orr pressure, especially 0.05-0.5 Torr
It is preferable to set it within the range of r.
本発明の態様に従うと、上記の複合酸化物超電導薄膜を
形成する基板としては、ペロブスカイト型結晶の基板、
酸化物基板、またはそれらペロブスカイト型結晶または
酸化物がバッファ層として形成された金属基板や半導体
基板を使用することが可能である。好ましくは、基板と
しては、ＭｇＯ単結晶、ＳｒＴｉＯ３単結晶、ＺｒＯ，
単結晶、ＹＳＺ単結晶、Ａ１□（１３）単結晶、または
多結晶Ａ１□（１３）、更には、それら物質で成膜面が
形成された金属基板や半導体基板が好ましい。特に、Ｍ
ｇＯ単結晶または３ｒＴｉＯｓ単結晶基板の成膜面を、
（００１）面または（１１０）面とすることが好ましい
。According to an aspect of the present invention, the substrate on which the above composite oxide superconducting thin film is formed includes a perovskite crystal substrate,
It is possible to use an oxide substrate, or a metal substrate or semiconductor substrate on which a perovskite crystal or oxide is formed as a buffer layer. Preferably, the substrate is MgO single crystal, SrTiO3 single crystal, ZrO,
Single crystal, YSZ single crystal, A1□(13) single crystal, or polycrystalline A1□(13), as well as metal substrates and semiconductor substrates whose film-forming surfaces are formed of these materials are preferable. In particular, M
The film formation surface of the gO single crystal or 3rTiOs single crystal substrate is
It is preferable to use a (001) plane or a (110) plane.
さらに、本発明の態様では、成膜後の薄膜を酸素分圧０
．１〜１０気圧の酸素含有雰囲気で８００〜９６０℃で
０．５〜２０時間、さらに好ましくは８５０〜９５０℃
で１〜１０時間加熱し、１０℃／分以下の冷却速度で冷
却してアニールを行うことが好ましい。Furthermore, in an aspect of the present invention, the thin film after being formed has an oxygen partial pressure of 0.
．． 0.5 to 20 hours at 800 to 960°C in an oxygen-containing atmosphere of 1 to 10 atm, more preferably 850 to 950°C
It is preferable to perform annealing by heating for 1 to 10 hours and cooling at a cooling rate of 10° C./min or less.
また、膜厚を０．１〜１０μｍの範囲、さらに好ましく
は０．５〜２μｍの範囲となるように成膜する。Further, the film is formed to have a thickness in the range of 0.1 to 10 μm, more preferably in the range of 0.5 to 2 μm.
作用
本発明の超電導薄膜の作製方法は、上記物理蒸着を０．
０５〜１Å／秒、さらに好ましくは０．１〜０．８Å／
秒の成膜速度で行うことをその主要な特徴としている。Function: The method for producing a superconducting thin film of the present invention includes the above-mentioned physical vapor deposition at 0.
05-1 Å/sec, more preferably 0.1-0.8 Å/sec
Its main feature is that it can be formed at a deposition rate of seconds.
従来の方法による複合酸化物超電導体薄膜の作製におい
ては、焼結体をターゲットとして物理蒸着、一般にはス
パッタリングを行っていたが、得られた超電導薄膜の臨
界電流密度Ｊｃが低く、実用にはならなかった。In the conventional method of producing composite oxide superconductor thin films, physical vapor deposition, generally sputtering, was performed using a sintered body as a target, but the critical current density Jc of the obtained superconducting thin film was low, making it impractical. There wasn't.
これは、複合酸化物超電導体は、その臨界電流密度に結
晶異方性を有するためである。すなわち、結晶のａ軸お
よびｂ軸で決定される面に平行な方向に電流が流れ易い
が、従来の方法では、結晶方向を十分に揃えることがで
きなかったためである。This is because the composite oxide superconductor has crystal anisotropy in its critical current density. That is, although current tends to flow in a direction parallel to the plane determined by the a-axis and b-axis of the crystal, the conventional methods have not been able to align the crystal directions sufficiently.
そこで、従来は、結晶方向を揃えるために、基板として
、複合酸化物超電導体結晶の格子間隔に近い格子間隔を
有するＭｇＯ１ＳｒＴｉＯ，およびＹＳＺ等の単結晶の
特定な面を成膜面として用いていた。Therefore, in the past, in order to align the crystal directions, a specific surface of a single crystal such as MgO1SrTiO or YSZ, which has a lattice spacing close to that of a composite oxide superconductor crystal, was used as a substrate for film formation. .
本発明の方法では、従来の方法を改良して、上記物理蒸
着時の成膜速度を０．０５〜１Å／秒、さらに好ましく
は０．１〜０．８ Å／秒にしたことで、複合酸化物の
結晶方向を揃える。この結果、従来法と比較して、大幅
にＪｃが向上した超電導渭膜が得られる。In the method of the present invention, the conventional method is improved and the film formation rate during the physical vapor deposition is set to 0.05 to 1 Å/sec, more preferably 0.1 to 0.8 Å/sec. Align the crystal orientation of the oxide. As a result, a superconducting wave film with significantly improved Jc compared to the conventional method can be obtained.
本発明の方法では、上記の条件で、物理蒸着、好ましく
はスパッタリングにより成膜を行うが、この物理蒸着、
好ましくはスパッタリング時に基板温度を２００〜９５
０℃、さらに好ましくは５００〜９２０℃に加熱して物
理蒸着、好ましくはスパッタリングすることが好ましい
。基板温度が２００℃未満の場合には、複合酸化物の結
晶性が悪くアモルファス状になり、超電導薄膜は得られ
ない。また、基板温度が９５０℃を超えると、結晶構造
が変わってしまい、上記の複合酸化物は超電導体とはな
らない。In the method of the present invention, film formation is performed by physical vapor deposition, preferably sputtering, under the above conditions.
Preferably, the substrate temperature during sputtering is 200-95
It is preferable to perform physical vapor deposition, preferably sputtering, by heating to 0°C, more preferably 500 to 920°C. If the substrate temperature is less than 200° C., the composite oxide has poor crystallinity and becomes amorphous, making it impossible to obtain a superconducting thin film. Furthermore, if the substrate temperature exceeds 950° C., the crystal structure changes and the above-mentioned composite oxide does not become a superconductor.
本発明で好ましく用いられるＲＦマグネトロンスパッタ
リングの場合には、例えばｌＱｃｍφのターゲットに対
して、スパッタリング時に高周波電力を従来の１．９Ｗ
／ｃｎｆ程度から５〜１００ Ｗ、すなわち、単位断面
積当たり０．０６４〜１．２７Ｗ／ｃｏ！、さらに好ま
しくは、１０〜６０Ｗ１すなわち、単位断面積当たり０
．１２７〜０．７６Ｗ／ｃａｔ印加するするのが好まし
い。In the case of RF magnetron sputtering, which is preferably used in the present invention, for example, a high frequency power of 1.9 W is applied to a target of lQcmφ during sputtering, compared to the conventional method.
/cnf to 5 to 100 W, that is, 0.064 to 1.27 W/co per unit cross-sectional area! , more preferably 10 to 60 W1, that is, 0 per unit cross-sectional area.
．． It is preferable to apply 127 to 0.76 W/cat.
本発明の態様に従うと、上記の複合酸化物超電導薄膜を
形成する基板としては、ＭｇＯ単結晶、５ｒＴｉＯ，単
結晶またはＺｒ○２単結晶基板が好ましく、特に、Ｍｇ
Ｏ単結晶基板または５ｒＴｉ（１３）単結晶基板の（０
０１）面または（１１０）面を成膜面として用いること
が好ましい。さらには、上記の単結晶相を有する金属基
板あるいは半導体基板を用いることもできる。According to an aspect of the present invention, the substrate on which the above composite oxide superconducting thin film is formed is preferably an MgO single crystal, 5rTiO, single crystal, or Zr○2 single crystal substrate, particularly an MgO single crystal,
O single crystal substrate or 5rTi(13) single crystal substrate (0
It is preferable to use the 01) plane or the (110) plane as the film-forming plane. Furthermore, a metal substrate or a semiconductor substrate having the above-mentioned single crystal phase can also be used.
これは、既に説明したように本発明の複合酸化物超電導
体は、その電気抵抗に結晶異方性を有するためで、上記
の基板の上記成膜面上に形成された複合酸化物超電導薄
膜は、その結晶のＣ軸が基板成膜面に対し垂直または垂
直に近い角度となり、特に臨界電流密度Ｊｃが大きくな
るものと考えられる。従って、ＭｇＯ単結晶基板または
ＳｒＴｉＯ３単結晶基板の（００１）面を成膜面として
用いることが好ましい。また、（１１０１面を用いてＣ
軸を基板と平行にし、Ｃ軸と垂直な方向を特定して用い
ることもできる。さらに、ＭｇＯ１ＳｒＴｉＯ，は、熱
膨張率が上記の複合酸化物超電導体と近いため、加熱、
冷却の過程で薄膜に不必要な応力を加えることがなく、
薄膜を破損する恐れもない。This is because, as already explained, the composite oxide superconductor of the present invention has crystal anisotropy in its electrical resistance, and the composite oxide superconductor thin film formed on the film formation surface of the substrate is It is thought that the C-axis of the crystal is perpendicular or nearly perpendicular to the substrate film-forming surface, and the critical current density Jc becomes particularly large. Therefore, it is preferable to use the (001) plane of the MgO single crystal substrate or the SrTiO3 single crystal substrate as the film forming surface. Also, (C using the 1101 plane)
It is also possible to make the axis parallel to the substrate and specify a direction perpendicular to the C-axis. Furthermore, MgO1SrTiO, has a coefficient of thermal expansion close to that of the above-mentioned composite oxide superconductor, so when heated,
No unnecessary stress is applied to the thin film during the cooling process.
There is no risk of damaging the thin film.
本発明の態様に従うと、成膜後の薄膜を酸素分圧０．１
〜１０気圧の酸素含有雲囲気中で８００〜９６０℃、さ
らに好ましくは８５０〜９５０℃に加熱、ｌＯ℃／分以
下の冷却速度で冷却する熱処理を施すアニール処理を行
うことが好ましい。この処理は、上記の複合酸化物中の
酸素欠陥を調整するもので、この処理を経ない薄膜の超
電導特性は悪く、超電導性を示さない場合もある。従っ
て、上記の熱処理を行うことが好ましい。According to an aspect of the present invention, the thin film after being formed has an oxygen partial pressure of 0.1.
It is preferable to perform an annealing treatment by heating to 800 to 960° C., more preferably 850 to 950° C., in an oxygen-containing cloud atmosphere of 10 atm and cooling at a cooling rate of 10° C./min or less. This treatment is to adjust oxygen defects in the above-mentioned composite oxide, and a thin film that does not undergo this treatment will have poor superconducting properties, and may not exhibit superconductivity. Therefore, it is preferable to perform the above heat treatment.
実施例
以下に本発明を実施例により説明するが、本発明の技術
的範囲は、以下の開示に何等制限されるものではないこ
とは勿論である。EXAMPLES The present invention will be explained below using examples, but it goes without saying that the technical scope of the present invention is not limited to the following disclosure.
実施例１
上記で説明した本発明の超電導薄膜の作製方法をＲＦマ
グネトロンスパッタリングによって実施した。ターゲッ
トとしては、Ｌａ５ＢａＳＣｕの原子比Ｌａ：Ｂａ：Ｃ
ｕを１．８ ： ０．２ ： １とした原料粉末を常法
に従って焼結して作った１ａ−１３ａ−Ｃｕ−０複合酸
化物の焼結体と、Ｌａ５ＳｒＳＣｕの原子比Ｌａ：Ｓｒ
：Ｃｕを１．８ ： ０．２ ： １とした原料粉末を
常法に従って焼結して作ったＬａ−Ｂａ−Ｃｕ−０複合
酸化物の焼結体とをそれぞれ用いた。ターゲットは直径
が１００ｍｍφの円板とした。各々の場合の成膜条件は
同一とし、その成膜条件は以下の通りであった。Example 1 The method for producing a superconducting thin film of the present invention described above was carried out by RF magnetron sputtering. As a target, the atomic ratio La:Ba:C of La5BaSCu
A sintered body of 1a-13a-Cu-0 composite oxide made by sintering raw material powder with u of 1.8:0.2:1 and an atomic ratio of La:Sr of La5SrSCu.
: A sintered body of a La-Ba-Cu-0 composite oxide prepared by sintering a raw material powder containing Cu in a ratio of 1.8:0.2:1 according to a conventional method was used. The target was a disk with a diameter of 100 mm. The film forming conditions in each case were the same, and the film forming conditions were as follows.
基板 ＭｇＯ（００１）面
ｏ２／（ｏａ＋Ａｒ） ２０％
基板温度 ７００℃
圧力 ０． Ｉ Ｔｏｒｒ
高周波電力 ４０Ｗ （０，５１Ｗ／ｃｒｌ）時間
６時間
膜厚 ０．８８μｍ
（成膜速度 ０．３５ Ａ／秒）成膜後、大気圧
の０２中で９００℃の温度を１時間保った後、５℃／分
の冷却速度で冷却した。なお、比較のために、同じター
ゲットの場合の成膜速度を１．５ Å／秒としたこと以
外は、全く等しい条件で複合酸化物超電導薄膜を作製し
た場合の結果を第１表に比較例として示しである。Substrate MgO (001) plane o2/(oa+Ar) 20% Substrate temperature 700°C Pressure 0. I Torr High frequency power 40W (0.51W/crl) time
After film formation for 6 hours, film thickness 0.88 μm (film formation rate 0.35 A/sec), the temperature was maintained at 900° C. for 1 hour in 02 atmospheric pressure, and then cooled at a cooling rate of 5° C./min. For comparison, Table 1 shows a comparative example of the results obtained when a composite oxide superconducting thin film was fabricated under exactly the same conditions, except that the film formation rate was 1.5 Å/sec using the same target. It is shown as follows.
臨界温度Ｔｃは、常法に従って四端子法によって測定し
た。また、臨界電流密度Ｊｃは、４．２にで試料の電気
抵抗を測定しつつ電流量を増加し、試料の電気抵抗が検
出されたときの電流量を、電流路の単位面積に換算した
ものを記している。The critical temperature Tc was measured by a four-terminal method according to a conventional method. In addition, the critical current density Jc is the value obtained by increasing the amount of current while measuring the electrical resistance of the sample in 4.2, and converting the amount of current when the electrical resistance of the sample is detected into the unit area of the current path. is written.
第１表
実施例２
成膜条件は以下の通りであること以外、実施例１と同様
な条件で複合酸化物超電導薄膜を作製した。その結果を
第２表に示す。Table 1 Example 2 A composite oxide superconducting thin film was produced under the same conditions as in Example 1 except that the film forming conditions were as follows. The results are shown in Table 2.
基板 ＭｇＯ（００１）面
ｏ２／（ｏ２＋Ａｒ） ５０％
基板温度 ７００℃
圧力 Ｑ、１Ｔｏｒｒ
高周波電力 １５０Ｗ （１，９Ｗ／ｃｎｆ）時間
６時間
膜厚 ０．８８μｍ
（成膜速度 ０．３５ Ａ／秒）第２表
実施例３
成膜条件は以下の通りであること以外、実施例１と同様
な条件で複合酸化物超電導薄膜を作製した。その結果を
第３表に示す。Substrate MgO (001) surface o2/(o2+Ar) 50% Substrate temperature 700℃ Pressure Q, 1Torr High frequency power 150W (1,9W/cnf) Time
6 hours Film thickness: 0.88 μm (Film forming rate: 0.35 A/sec) Table 2 Example 3 A composite oxide superconducting thin film was formed under the same conditions as in Example 1 except that the film forming conditions were as follows. Created. The results are shown in Table 3.
基板 ＭｇＯ（００１）面
０２／（０２＋Ａｒ） ２０％
基板温度 ７００℃
圧力 ０．１５Ｔｏｒｒ
高周波電力 １５０Ｗ （１，９Ｗ／ｃｕｔ）時間
６時間
膜厚 ０．８８μｍ
（成膜速度 ０．３５ Å／秒）第３表
上記のように本発明の方法により作製された超電導薄膜
は、比較例より大幅に臨界電流が向上している。また、
本発明の方法で作製した複合酸化物超電導薄膜の組織が
一様でであることは、従来法により作製した比較例の複
合酸化物超電導薄膜の表面には、数ミクロンのダレイン
が存在するのに対し、本発明の方法によるものは、表面
をＳＥＭで１万倍に拡大して観察した場合に、その表面
の大部分の面積の所で凹凸が見られないことからも推測
できる。Substrate MgO (001) plane 02/(02+Ar) 20% Substrate temperature 700℃ Pressure 0.15Torr High frequency power 150W (1.9W/cut) Time
6 hours Film thickness: 0.88 μm (Film forming rate: 0.35 Å/sec) Table 3 As described above, the superconducting thin film produced by the method of the present invention has a significantly improved critical current compared to the comparative example. Also,
The structure of the composite oxide superconducting thin film produced by the method of the present invention is uniform, even though there are several micrometers of dalein on the surface of the composite oxide superconducting thin film of the comparative example produced by the conventional method. On the other hand, in the case of the method of the present invention, it can be inferred from the fact that when the surface is observed under SEM magnification of 10,000 times, no irregularities are observed over most of the surface area.
発明の効果
以上詳述のように、本発明の方法によって得られた超電
導薄膜は、従来の方法で作製されたものに較べ、高いＪ
ｃを示す。Effects of the Invention As detailed above, the superconducting thin film obtained by the method of the present invention has a higher J than that produced by the conventional method.
c.
本発明の方法は、従来法と較べ、単に、物理蒸着時の成
膜速度を小さくだけで安定に高性能な超電導薄膜を供給
することが可能となる。Compared to conventional methods, the method of the present invention makes it possible to stably supply a high-performance superconducting thin film simply by reducing the film formation rate during physical vapor deposition.
特許出願人 住友電気工業株式会社Patent applicant: Sumitomo Electric Industries, Ltd.
Claims (29)
１≦ｘ≦０．２を満たす数である） で表される複合酸化物を主として含有する複合酸化物超
電導体薄膜を物理蒸着によって作製する方法において、 ０．０５〜１Å／秒の範囲の成膜速度で上記物理蒸着を
実施することを特徴とする超電導薄膜の作製方法。(1) Formula: (La_1_-_xα_x)_2CuO_4 (However, element α is Ba or Sr, and x is 0.0
1≦x≦0.2) A method for producing a composite oxide superconductor thin film mainly containing a composite oxide represented by A method for producing a superconducting thin film, characterized in that the physical vapor deposition described above is performed at a film speed.
ることを特徴とする特許請求の範囲第１項に記載の超電
導薄膜の作製方法。(2) The method for producing a superconducting thin film according to claim 1, wherein the film is formed at a film forming rate in the range of 0.1 to 0.8 Å/sec.
Ｂａ＿ｘ）＿２ＣｕＯ＿４（ただしｘは０．０１≦ｘ≦
０．２を満たす数である）で表される複合酸化物を含む
ことを特徴とする特許請求の範囲第第１項または第２項
に記載の超電導薄膜の作製方法。(3) The composite oxide superconductor is (La_1_-_x
Ba_x)_2CuO_4 (where x is 0.01≦x≦
A method for producing a superconducting thin film according to claim 1 or 2, characterized in that the method comprises a composite oxide represented by a number satisfying 0.2.
Ｓｒ＿ｘ）＿２ＣｕＯ＿４ （ただしｘは０．０１≦ｘ≦０．２を満たす数である）
で表される複合酸化物を含むことを特徴とする特許請求
の範囲第第１項または第２項に記載の超電導薄膜の作製
方法。(4) The composite oxide superconductor is (La_1_-_x
Sr_x)_2CuO_4 (x is a number satisfying 0.01≦x≦0.2)
A method for producing a superconducting thin film according to claim 1 or 2, characterized in that the superconducting thin film contains a composite oxide represented by:
とする特許請求の範囲第１項から第４項のいずれか一項
に記載の超電導薄膜の作製方法。(5) The method for producing a superconducting thin film according to any one of claims 1 to 4, wherein the physical vapor deposition is sputtering.
グであること特徴とする特許請求の範囲第６項に記載の
超電導薄膜の作製方法。(6) The method for producing a superconducting thin film according to claim 6, wherein the sputtering is magnetron sputtering.
から０．５Ｔｏｒｒの範囲内であることを特徴とする特
許請求の範囲第５項または第６項に記載の超電導薄膜の
作製方法。(7) The gas pressure during the sputtering is 0.001
7. The method for producing a superconducting thin film according to claim 5 or 6, wherein the superconducting thin film is within a range of from 0.5 Torr to 0.5 Torr.
ら０．５Ｔｏｒｒの範囲内であることを特徴とする特許
請求の範囲第５項または第６項に記載の超電導薄膜の作
製方法。(8) The method for producing a superconducting thin film according to claim 5 or 6, wherein the gas pressure during the sputtering is within a range of 0.01 to 0.5 Torr.
する特許請求の範囲第１項から第８項のいずれか一項に
記載の超電導薄膜の作製方法。(9) The method for producing a superconducting thin film according to any one of claims 1 to 8, wherein the substrate is heated during the physical vapor deposition.
０℃であることを特徴とする特許請求の範囲第９項に記
載の超電導薄膜の作製方法。(10) The substrate temperature during the physical vapor deposition is from 200 to 95
The method for producing a superconducting thin film according to claim 9, wherein the temperature is 0°C.
０℃であることを特徴とする特許請求の範囲第９項に記
載の超電導薄膜の作製方法。(11) The substrate temperature during the physical vapor deposition is from 500 to 92
The method for producing a superconducting thin film according to claim 9, wherein the temperature is 0°C.
隔に近い格子間隔を有する酸化物単結晶の成膜面を有し
ている基板を用いることを特徴とする特許請求の範囲第
１項から第１０項のいずれか一項に記載の超電導薄膜の
作製方法。(12) The substrate is a substrate having a film-forming surface of an oxide single crystal having a lattice spacing close to the lattice spacing of the composite oxide crystal. The method for producing a superconducting thin film according to any one of Item 10.
３単結晶、ＺｒＯ＿２単結晶、ＹＳＺ単結晶、Ａｌ＿２
Ｏ＿３単結晶、または多結晶Ａｌ＿２Ｏ＿３を用いるこ
とを特徴とする特許請求の範囲第１２項に記載の超電導
薄膜の作製方法。(13) As the substrate, MgO single crystal, SrTiO_
3 single crystal, ZrO_2 single crystal, YSZ single crystal, Al_2
13. The method for producing a superconducting thin film according to claim 12, wherein O_3 single crystal or polycrystalline Al_2O_3 is used.
基板の｛００１｝面または｛１１０｝面を成膜面とする
ことを特徴とする特許請求の範囲第１３項に記載の超電
導薄膜の作製方法。(14) The method for producing a superconducting thin film according to claim 13, wherein the {001} plane or {110} plane of the MgO single crystal or SrTiO_3 single crystal substrate is used as the film formation surface.
徐冷する熱処理を行うことを特徴とする特許請求の範囲
第１項から第１４項のいずれか一項に記載の超電導薄膜
の作製方法。(15) After the above film formation, the thin film is heated in an oxygen-containing atmosphere.
15. The method for producing a superconducting thin film according to any one of claims 1 to 14, characterized in that a heat treatment of slow cooling is performed.
度で、０．５〜２０時間の範囲の時間行うことを特徴と
する特許請求の範囲第１５項に記載の超電導薄膜の作製
方法。(16) The method for producing a superconducting thin film according to claim 15, wherein the heat treatment is performed at a heating temperature in the range of 800 to 960°C for a time in the range of 0.5 to 20 hours.
度で、１〜１０時間の範囲の時間行うことを特徴とする
特許請求の範囲第１５項に記載の超電導薄膜の作製方法
。(17) The method for producing a superconducting thin film according to claim 15, wherein the heat treatment is performed at a heating temperature in the range of 850 to 950°C for a period of time in the range of 1 to 10 hours.
あることを特徴とする特許請求の範囲第１６項または１
７項に記載の超電導薄膜の作製方法。(18) Claim 16 or 1, characterized in that the cooling temperature during the heat treatment is 10°C/min or less.
The method for producing a superconducting thin film according to item 7.
あることを特徴とする特許請求の範囲第１６項から第１
８項のいずれか一項に記載の超電導薄膜の作製方法。(19) Claims 16 to 1, characterized in that the oxygen partial pressure during the heat treatment is 0.1 to 10 atm.
The method for producing a superconducting thin film according to any one of Item 8.
中のＯ＿２の比率が５から９５分子％であることを特徴
とする特許請求の範囲第５項から第８項のいずれか一項
に記載の超電導薄膜の作製方法。(20) The superconducting thin film according to any one of claims 5 to 8, wherein the ratio of O_2 in the sputtering gas during the sputtering is 5 to 95 molecule %. Fabrication method.
い、高周波電力を０．０６４〜１．２７Ｗ／ｃｍ＾２の
範囲内としたことを特徴とする特許請求の範囲第２０項
に記載の超電導薄膜の作製方法。(21) The method for producing a superconducting thin film according to claim 20, wherein the sputtering is performed by RF sputtering, and the high frequency power is within the range of 0.064 to 1.27 W/cm^2. .
い、高周波電力を０．１２７〜０．７６Ｗ／ｃｍ＾２の
範囲内としたことを特徴とする特許請求の範囲第２０項
に記載の超電導薄膜の作製方法。(22) The method for producing a superconducting thin film according to claim 20, wherein the sputtering is performed by RF sputtering, and the high frequency power is within the range of 0.127 to 0.76 W/cm^2. .
中のＯ＿２の比率が１０から８０分子％であることを特
徴とする特許請求の範囲第２２項に記載の超電導薄膜の
作製方法。(23) The method for producing a superconducting thin film according to claim 22, wherein the ratio of O_2 in the sputtering gas during the sputtering is 10 to 80 mol%.
い、高周波電力を１．２７〜２．５５Ｗ／ｃｍ＾２の範
囲内としたことを特徴とする特許請求の範囲第２０項に
記載の超電導薄膜の作製方法。(24) The method for producing a superconducting thin film according to claim 20, wherein the sputtering is performed by RF sputtering, and the high frequency power is within the range of 1.27 to 2.55 W/cm^2. .
い、高周波電力を１．５３〜２．２９Ｗ／ｃｍ＾２の範
囲内としたことを特徴とする特許請求の範囲第２４項に
記載の超電導薄膜の作製方法。(25) The method for producing a superconducting thin film according to claim 24, wherein the sputtering is performed by RF sputtering, and the high frequency power is within the range of 1.53 to 2.29 W/cm^2. .
中のＯ＿２の比率が１０から８０分子％であることを特
徴とする特許請求の範囲第２５項に記載の超電導薄膜の
作製方法。(26) The method for producing a superconducting thin film according to claim 25, wherein the ratio of O_2 in the sputtering gas during the sputtering is 10 to 80 molecule %.
中のＯ＿２の比率が４０から８０分子％であることを特
徴とする特許請求の範囲第２５項に記載の超電導薄膜の
作製方法。(27) The method for producing a superconducting thin film according to claim 25, wherein the ratio of O_2 in the sputtering gas during the sputtering is 40 to 80 mol%.
を特徴とする特許請求の範囲第１項から第２９項のいず
れか一項に記載の超電導薄膜の作製方法。(28) The method for producing a superconducting thin film according to any one of claims 1 to 29, characterized in that the film is formed to a thickness in the range of 0.1 to 10 μm.
特徴とする特許請求の範囲第１項から第２９項のいずれ
か一項に記載の超電導薄膜の作製方法。(29) The method for producing a superconducting thin film according to any one of claims 1 to 29, characterized in that the film is formed to a thickness in the range of 0.5 to 2 μm.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62324704A JPH01166419A (en) | 1987-12-22 | 1987-12-22 | Manufacture of superconductive membrane |
| KR1019880017018A KR970005158B1 (en) | 1987-12-20 | 1988-12-20 | Superconducting thin film and wire and the process therefor |
| DE19883854493 DE3854493T2 (en) | 1987-12-20 | 1988-12-20 | Method of manufacturing a thin film superconductor. |
| US07/286,860 US5028583A (en) | 1987-12-20 | 1988-12-20 | Superconducting thin film and wire and a process for producing the same |
| AU27099/88A AU615014B2 (en) | 1987-02-17 | 1988-12-20 | Superconducting thin film and wire and a process for producing the same |
| CA 586516 CA1339020C (en) | 1987-12-20 | 1988-12-20 | Superconducting thin film and wire and a process for producing the same |
| EP19880403254 EP0322306B1 (en) | 1987-12-20 | 1988-12-20 | Process for producing a superconducting thin film |
| US07/648,964 US5252543A (en) | 1987-12-20 | 1991-01-31 | Superconducting thin film and wire on a smooth substrate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62324704A JPH01166419A (en) | 1987-12-22 | 1987-12-22 | Manufacture of superconductive membrane |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01166419A true JPH01166419A (en) | 1989-06-30 |
Family
ID=18168779
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62324704A Pending JPH01166419A (en) | 1987-02-17 | 1987-12-22 | Manufacture of superconductive membrane |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01166419A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5653607A (en) * | 1994-07-27 | 1997-08-05 | Sumitomo Wiring Systems, Ltd. | Electric connection casing |
| US5718598A (en) * | 1994-12-29 | 1998-02-17 | Sumitomo Wiring Systems, Ltd. | Electrical connection box and contact bonding terminal used therefor |
| US5742005A (en) * | 1994-09-14 | 1998-04-21 | Sumitomo Wiring Systems, Ltd. | Electrical connection box |
| US5920034A (en) * | 1994-12-28 | 1999-07-06 | Sumitomo Wiring Systems, Ltd. | Electrical connection box |
| US5934929A (en) * | 1994-07-15 | 1999-08-10 | Sumitomo Wiring Systems, Ltd. | Electrical connection box |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6414814A (en) * | 1987-03-19 | 1989-01-19 | Nippon Telegraph & Telephone | Manufacture of oxide superconductive thin film |
| JPS6459973A (en) * | 1987-08-31 | 1989-03-07 | Semiconductor Energy Lab | Manufacture of superconducting material |
| JPS6463218A (en) * | 1987-09-03 | 1989-03-09 | Oki Electric Ind Co Ltd | Forming superconductive thin film |
-
1987
- 1987-12-22 JP JP62324704A patent/JPH01166419A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6414814A (en) * | 1987-03-19 | 1989-01-19 | Nippon Telegraph & Telephone | Manufacture of oxide superconductive thin film |
| JPS6459973A (en) * | 1987-08-31 | 1989-03-07 | Semiconductor Energy Lab | Manufacture of superconducting material |
| JPS6463218A (en) * | 1987-09-03 | 1989-03-09 | Oki Electric Ind Co Ltd | Forming superconductive thin film |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5934929A (en) * | 1994-07-15 | 1999-08-10 | Sumitomo Wiring Systems, Ltd. | Electrical connection box |
| US6168456B1 (en) | 1994-07-15 | 2001-01-02 | Sumitomo Wiring Systems, Ltd. | Electrical connection box |
| US5653607A (en) * | 1994-07-27 | 1997-08-05 | Sumitomo Wiring Systems, Ltd. | Electric connection casing |
| US5742005A (en) * | 1994-09-14 | 1998-04-21 | Sumitomo Wiring Systems, Ltd. | Electrical connection box |
| US5895277A (en) * | 1994-09-14 | 1999-04-20 | Sumitomo Wiring Systems, Ltd. | Electrical connection box with general and special circuits |
| US5920034A (en) * | 1994-12-28 | 1999-07-06 | Sumitomo Wiring Systems, Ltd. | Electrical connection box |
| US5718598A (en) * | 1994-12-29 | 1998-02-17 | Sumitomo Wiring Systems, Ltd. | Electrical connection box and contact bonding terminal used therefor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH01163058A (en) | Supercoductive thin film and its preparation | |
| KR970005158B1 (en) | Superconducting thin film and wire and the process therefor | |
| JPH01166419A (en) | Manufacture of superconductive membrane | |
| JPH01167221A (en) | Production of superconducting thin film | |
| JPH0286014A (en) | Composite oxide superconducting thin film and film forming method | |
| JP2545422B2 (en) | Composite oxide superconducting thin film and method for producing the same | |
| JP2544759B2 (en) | How to make a superconducting thin film | |
| JPH01167218A (en) | Production of superconducting thin film | |
| JP2545423B2 (en) | Composite oxide superconducting thin film and method for producing the same | |
| JPH0264021A (en) | Preparation of multiple oxide superconducting thin film | |
| JPH01100022A (en) | Preparation of superconducting thin film | |
| JP2544761B2 (en) | Preparation method of superconducting thin film | |
| JPH01188661A (en) | Superconducting thin film of compound oxide and production thereof | |
| JP2544760B2 (en) | Preparation method of superconducting thin film | |
| JPH01188662A (en) | Production of superconducting thin film | |
| JPH01188664A (en) | Production of superconducting thin film | |
| JPH01167223A (en) | Production of superconducting thin film | |
| JPH01167220A (en) | Production of superconducting thin film | |
| JP2525842B2 (en) | Superconducting wire and its manufacturing method | |
| JPH01188663A (en) | Production of superconducting thin film | |
| JP2501609B2 (en) | Method for producing complex oxide superconducting thin film | |
| JPH01188665A (en) | Production of superconducting thin film | |
| JPH01167222A (en) | Production of superconducting thin film | |
| JP2567416B2 (en) | Preparation method of superconducting thin film | |
| JPH01264911A (en) | Formation of thin composite oxide superconducting film |