JPH01167221A - Production of superconducting thin film - Google Patents
Production of superconducting thin filmInfo
- Publication number
- JPH01167221A JPH01167221A JP62324708A JP32470887A JPH01167221A JP H01167221 A JPH01167221 A JP H01167221A JP 62324708 A JP62324708 A JP 62324708A JP 32470887 A JP32470887 A JP 32470887A JP H01167221 A JPH01167221 A JP H01167221A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- superconducting thin
- producing
- 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
- 239000010409 thin film Substances 0.000 title claims abstract description 65
- 238000004519 manufacturing process Methods 0.000 title claims description 34
- 238000004544 sputter deposition Methods 0.000 claims abstract description 39
- 239000000758 substrate Substances 0.000 claims abstract description 34
- 239000010408 film Substances 0.000 claims abstract description 22
- 238000010438 heat treatment Methods 0.000 claims abstract description 15
- 238000000034 method Methods 0.000 claims abstract description 15
- 229910052712 strontium Inorganic materials 0.000 claims abstract description 6
- 229910052788 barium Inorganic materials 0.000 claims abstract description 4
- 239000013078 crystal Substances 0.000 claims description 36
- 239000002131 composite material Substances 0.000 claims description 31
- 239000007789 gas Substances 0.000 claims description 14
- 239000002887 superconductor Substances 0.000 claims description 13
- 230000015572 biosynthetic process Effects 0.000 claims description 9
- 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
- 238000001755 magnetron sputter deposition Methods 0.000 claims description 4
- 238000001552 radio frequency sputter deposition Methods 0.000 claims description 3
- 238000010583 slow cooling Methods 0.000 claims 1
- 150000001875 compounds Chemical class 0.000 abstract 4
- 239000000463 material Substances 0.000 description 12
- 238000007796 conventional method Methods 0.000 description 9
- 238000005240 physical vapour deposition Methods 0.000 description 6
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
- 229910002370 SrTiO3 Inorganic materials 0.000 description 3
- 229910052746 lanthanum Inorganic materials 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
- 230000005668 Josephson effect Effects 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005291 magnetic effect Effects 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 241000282326 Felis catus Species 0.000 description 1
- 229910000750 Niobium-germanium Inorganic materials 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910052790 beryllium Inorganic materials 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 229910052593 corundum Inorganic materials 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
- 230000010354 integration Effects 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/60—Superconducting electric elements or equipment; Power systems integrating superconducting elements or equipment
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
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 as well as other excellent properties such as smoothness, and is particularly suitable as a wiring material for various electronic components such as integrated circuits. Useful.
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.
超電導現象の代表的な応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知られている。代表的な
ものとしては、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。また、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。Various superconducting elements are known in the field of electronics, which is a typical application field of superconducting phenomena. A typical example is an element that utilizes the Josephson effect, in which a quantum effect appears macroscopically due to an applied current when superconducting materials are weakly bonded together. Further, tunnel junction type Josephson devices are expected to be extremely high-speed switching devices with low power consumption because the energy gap of the superconducting material 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.
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 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Ｎｂ３Ｇｅの２３Ｋを
越えることができなかったが、昨年来、（Ｌａ、 Ｂａ
） ２ＣｕＯ４または［’Ｌａ、 Ｓｒ） ２ＣＩ０４
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Ｔ。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 of Nb3Ge for a long period of time.
) 2CuO4 or ['La, Sr) 2CI04
Sintered materials of oxides such as oxides have been discovered as superconducting materials with high Tc, greatly increasing the possibility of realizing non-low temperature superconductivity. These materials have a T of 30 to 50, which is dramatically higher than that of conventional materials. has been observed.
発明が解決しようとする問題点
従来、上記複合酸化物超電導体薄膜を作製する際には、
焼結等で生成した酸化物を蒸着源としてスパッタリング
法等の物理蒸着を行っていた。Problems to be Solved by the Invention Conventionally, when producing the above composite oxide superconductor thin film,
Physical vapor deposition such as sputtering was performed using oxides produced by sintering as a vapor deposition source.
しかしながら、こうして作製された従来の超電導体薄膜
は、臨界電流密度Ｊｃが小さいため、臨界温度Ｔｃが高
くても実際の電子回路として実用化することができなか
った。However, since the conventional superconductor thin film produced in this way has a small critical current density Jc, it has not been possible to put it into practical use as an actual electronic circuit even if the critical temperature Tc is 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スパッ
タリング法により作製する方法において、０２とＡｒと
を含むスパッタリングガスを使用し、該スパッタリング
ガス中の０２の比率を３０から９５分子％の範囲内とし
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;
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 sputtering, a sputtering gas containing 02 and Ar is used. , there is provided a method for producing a superconducting thin film, characterized in that the ratio of O2 in the sputtering gas is within the range of 30 to 95 molecule %.
好ましくは、上記スパッタリングガス中の０□の比率を
４０から８０分子％の範囲内とする。Preferably, the proportion of 0□ in the sputtering gas is within the range of 40 to 80 mol%.
上記スパッタリングとしては、ＲＦ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。The above sputtering is preferably RF sputtering, particularly RF magnetron sputtering.
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：
（Ｌａ ｌ−ｙ αｊ ２ ＣｏＯ２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 thought that the main component is type oxide.
上記元素αはＢａまたはＳｒから選択されるが、元素α
と、Ｌａと、Ｃｕの原子比は上記の式を満たすことが好
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
な超電導特性を示す場合がある。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
される原子比が上記以外のものも含むということを意味
する。The above element α is selected from Ba or Sr, but the element α
It is preferable that the atomic ratio of La, Cu, and La satisfies the above formula, but it is not necessarily strictly limited to this ratio. Even compositions with atomic ratios that are out of range may exhibit effective superconducting properties. In other words, in the claims, the expression "mainly contains a complex oxide represented by the above formula" means that the atomic ratio defined by the above formula also includes those other than the above. do.
さらに、上記の定義は上記以外の元素、すなわち、ｐｐ
ｍオーダーで混入する不可避的不純物と、他の特性を向
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。Furthermore, the above definition applies to elements other than the above, i.e. pp
This means that it may contain unavoidable impurities mixed in on the order of m and a third component added for the purpose of improving other properties.
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Ｓｒ、 Ｃａ、 Ｍｇ、 Ｂｅ、上記以外の周
期律表ｍａ族元素、周期律表Ｉｂ、■ｂ、Ｉｂ、ＩＶａ
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。Elements that can be added as the third component include ■a of the periodic table
Group elements Sr, Ca, Mg, Be, periodic table ma group elements other than the above, periodic table Ib, ■b, Ib, IVa
and ■ an element selected from group a, such as 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
〜ＩÅ／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
~I 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、０２とＡｒ とを含む
スパッタリングガス中の０２の比率すなわち０２／ （
０２＋Ａｒ）が９５分子％を超えても、３０分子％未満
でも、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。According to the experimental results of the present inventors, the ratio of 02 in the sputtering gas containing 02 and Ar, that is, 02/(
Even if 02+Ar) exceeds 95 mol % or less than 30 mol %, the critical current density of the obtained superconducting thin film will be significantly reduced, making it impossible to obtain a practical thin film.
上記スパッタリングを行う場合には、スパッタリングを
０．００１〜Ｑ、５ Ｔｏｒｒの圧力、さらに好ましく
は０．０１〜０．３ Ｔｏｒｒの圧力下でかつ高周波電
力を１、２７〜２．５５ Ｗ／ ｃｕｔの範囲内、特に
１．５３〜２．２９ Ｗ／Ｃｌｌ１の範囲内とすること
が好ましい。また、基板を２００〜９５０℃、さらに好
ましくは５００〜９２０℃に加熱しながらスパッタリン
グを行うのが好ましい。When performing the above sputtering, the sputtering is performed under a pressure of 0.001 to Q.5 Torr, more preferably a pressure of 0.01 to 0.3 Torr, and a high frequency power of 1.27 to 2.55 W/cut. It is preferably within the range of, particularly 1.53 to 2.29 W/Cll1. Moreover, it is preferable to perform sputtering while heating the substrate to 200 to 950°C, more preferably 500 to 920°C.
冊
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。Also, 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.
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、ＺｒＯ２
単結晶、ＹＳＺ単結晶、Ａｌ２Ｏ３単結晶、または多結
晶へ１２０３、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、ＭｇＯ単結
晶またはＳｒＴｉＯ３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, ZrO2
Single crystal, YSZ single crystal, Al2O3 single crystal, or polycrystal 1203, and furthermore, metal substrates or semiconductor substrates having film-forming surfaces formed of these materials are preferable. In particular, the film formation surface of the MgO single crystal or SrTiO3 single crystal substrate is (001
) plane or (110) plane is preferable.
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.
昨月
本発明の超電導薄膜の作製方法は、０２とＡｒとを含む
スパッタリングガスを使用して上記スパッタリングを行
い、該スパッタリングガス中の０２の比率を３０から９
５分子％の範囲内とし、好ましくは、上記スパッタリン
グガス中の０２の比率を４０から８０分子％の範囲内と
することをその主要な特徴としている。Last month, the method for producing a superconducting thin film of the present invention involves performing the above sputtering using a sputtering gas containing O2 and Ar, and increasing the ratio of O2 in the sputtering gas from 30 to 9.
Its main feature is that the proportion of 02 in the sputtering gas is preferably within the range of 40 to 80 mol%.
複合酸化物超電導体の薄膜を作製する場合には、従来複
合酸化物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、従来の方法で得られた
超電導薄膜は、臨界電流密度Ｊｃが低く、実用にはなら
なかった。When producing thin films of composite oxide superconductors, conventional physical vapor deposition, generally sputtering, has been performed using a sintered composite oxide as a target, but superconducting thin films obtained by conventional methods are Jc was low and it was not practical.
これは、複合酸化物超電導体が、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Ｍｇ Ｏ、Ｓｒｔ＋ ０３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, conventionally, in order to align the crystal directions, a specific surface of a single crystal such as MgO, Srt+ 03, or YSZ, which has a lattice spacing close to that of a composite oxide superconductor crystal, was used as the film-forming surface. I was using it.
本発明の方法では、従来の方法を改良して、スパッタリ
ングガス中の０２の比率を３０から９５分子％の範囲内
とし、好ましくは、上記スパッタリングガス中の０２の
比率を４０から８０分子％の範囲内としたことで、複合
酸化物の結晶方向を揃える。In the method of the present invention, the conventional method is improved so that the proportion of 02 in the sputtering gas is in the range of 30 to 95 molecule %, preferably, the proportion of 02 in the sputtering gas is in the range of 40 to 80 molecule %. By setting it within this range, the crystal directions of the composite oxide are aligned.
この結果、従来法と比較して、大幅にＪｃが向上した超
電導薄膜が得られる。As a result, a superconducting thin film with significantly improved Jc compared to conventional methods 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１０ｃｍφ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１．９．
Ｗ／ｃｉｆ程度から１００〜２００Ｗ１すなわち、単位
断面積当たり１．２７〜２．５４Ｗ／ｃｕｔ、さらに好
ましくは、１２０〜１８０ Ｗ、すなわち、単位断面積
当たり１．５３〜２．２９Ｗ／ｃａｔ印加することが好
ましい。In the case of RF magnetron sputtering, which is preferably used in the present invention, for example, when sputtering a target of 10 cmφ, high-frequency power is applied to a target of 1.9 cm.
Approximately W/cif to 100 to 200 W1, that is, 1.27 to 2.54 W/cut per unit cross-sectional area, more preferably 120 to 180 W, that is, 1.53 to 2.29 W/cat per unit cross-sectional area. It is preferable.
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、ＳｒＴ＋（）＋
単結晶またはＺｒＯ２単結晶基板が好ましく、特に、Ｍ
ｇＯ単結晶基板または５ｒＴｉ○３単結晶基板の（００
１）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 composite oxide superconducting thin film is formed is MgO single crystal, SrT+()+
Single crystal or ZrO2 single crystal substrates are preferred, especially M
gO single crystal substrate or 5rTi○3 single crystal substrate (00
It is preferable to use the 1) 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軸が基板底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
５ｒＴｉ○３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、（１１０３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、ＭｇＯ、ＳｒＴｉＯ３は、熱
膨脹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 bottom film surface of the substrate, 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 5rTi○3 single crystal substrate as the film forming surface. Also, (C using 1103 planes)
It is also possible to make the axis parallel to the substrate and specify a direction perpendicular to the C-axis. Furthermore, since MgO and SrTiO3 have a coefficient of thermal expansion close to that of the above-mentioned composite oxide superconductor, heating,
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、１０℃／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 in which heat treatment is performed by heating to 800 to 960°C, more preferably 850 to 950°C, and cooling at a cooling rate of 10°C/min or less in an oxygen-containing cloud atmosphere of ~10 atm. 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、以下の開示に何隻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.
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。使用した
ターゲットは、Ｌａと、ＳｒまたはＢａと、Ｃｕとの原
子比Ｌａ：α：Ｃ１の比を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複合酸化物
焼結体である。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。The method for producing a superconducting thin film of the present invention described above was carried out by RF magnetron sputtering. The target used was a composite made by sintering raw material powder with an atomic ratio of La, Sr or Ba, and Cu in an atomic ratio La:α:C1 of 1.8:0.2:1 according to a conventional method. It is an oxide sintered body. 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
０２／（０２＋Ａｒ） ５Ｑ％
基板温度 ７００℃
圧力 ０． Ｉ Ｔｏｒｒ
高周波電力 １５０Ｗ （１，９Ｗ／ｃｕｔ）時間
６時間
膜厚 ０．８８μｍ
（成膜速度 ０．３５ 人／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、成膜速度
を１．５人／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。これらの薄膜の緒特性
を第１表に示す。Substrate MgO (001) plane 02/(02+Ar) 5Q% Substrate temperature 700°C Pressure 0. I Torr High frequency power 150W (1.9W/cut) time
After 6 hours film thickness 0.88 μm (film forming rate 0.35 persons/sec), the temperature was kept at 900° C. for 1 hour in 02 atmospheric pressure and then cooled at a cooling rate of 5° C./min. For comparison, a composite oxide superconducting thin film was produced under exactly the same conditions except that the film formation rate was 1.5 people/second. The properties of these thin films are shown in Table 1.
尚、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、試料に電気抵
抗が検出されたときの電流量を、電流路の単位面積に換
算したものを記しすいる。Incidentally, the critical temperature Tc was measured by a four-terminal method according to a conventional method. In addition, the critical current density Jc was determined by increasing the amount of current while measuring the electrical resistance of the sample in 4.2, and converting the amount of current when electrical resistance was detected in the sample into the unit area of the current path. Write things down.
第１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。Table 1 As shown above, the superconducting thin film produced by the method of the present invention has 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, whereas the surface of the composite oxide superconducting thin film of the comparative example produced by the conventional method has dalein of several microns. The method of the present invention can also be inferred from the fact that when the surface is observed with an SEM at a 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
膜速度を小さくする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 (24)
但し、元素αは、ＢａまたはＳｒであり、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主として含有する複合酸化物超
電導体薄膜をスパッタリング法により作製する方法にお
いて、Ｏ＿２とＡｒとを含むスパッタリングガスを使用
し、該スパッタリングガス中のＯ＿２の比率を３０から
９５分子％の範囲内としたことを特徴とする超電導薄膜
の作製方法。(1) Formula: (L_1_−_xα_x)_2CuO_4(
However, element α is Ba or Sr, and x is 0.01
≦x≦0.2) In a method for producing a composite oxide superconductor thin film mainly containing a composite oxide represented by the following by a sputtering method, a sputtering gas containing O_2 and Ar is used, A method for producing a superconducting thin film, characterized in that the ratio of O_2 in the sputtering gas is within a range of 30 to 95 molecule %.
から８０分子％の範囲内としたこと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 ratio of O_2 in the sputtering gas is 40
The method for producing a superconducting thin film according to claim 1, wherein the content is within a range of 80 molecule %.
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 (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.
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 gas pressure during the sputtering is 0.001
5. The method for producing a superconducting thin film according to any one of claims 1 to 4, wherein the superconducting thin film is within a range of from 0.5 Torr to 0.5 Torr.
ら０．３Ｔｏｒｒの範囲内であることを特徴とする特許
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。(6) The superconducting thin film according to any one of claims 1 to 4, wherein the gas pressure during the sputtering is in the range of 0.01 to 0.3 Torr. Fabrication method.
特徴とする特許請求の範囲第１項から第６項のいずれか
一項に記載の超電導薄膜の作製方法。(7) The method for producing a superconducting thin film according to any one of claims 1 to 6, characterized in that the substrate is heated during the sputtering.
９５０℃であることを特徴とする特許請求の範囲第７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 7, wherein the substrate temperature during the sputtering is 200 to 950°C.
９２０℃であることを特徴とする特許請求の範囲第７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 claim 7, wherein the substrate temperature during the sputtering is 500 to 920°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９項のいずれか一項に記載の超電導薄膜の作
製方法。(10) The substrate is a substrate having a film-forming surface of an oxide single crystal having a lattice spacing close to that of the composite oxide crystal. The method for producing a superconducting thin film according to any one of Item 9.
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１０項に記載の超電導
薄膜の作製方法。(11) As the substrate, MgO single crystal, SrTiO_
3 single crystal, ZrO_2 single crystal, YSZ single crystal, Al_2
11. The method for producing a superconducting thin film according to claim 10, characterized in that 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１０項に記載の超電
導薄膜の作製方法。(12) The method for producing a superconducting thin film according to claim 10, 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.
ることを特徴とする特許請求の範囲第１項から第１２項
のいずれか一項に記載の超電導薄膜の作製方法。(13) The method for producing a superconducting thin film according to any one of claims 1 to 12, characterized in that the film is formed at a film formation rate in the range of 0.05 to 1 Å/sec.
することを特徴とする特許請求の範囲第１項から第１２
項のいずれか一項に記載の超電導薄膜の作製方法。(14) Claims 1 to 12, characterized in that the film is formed at a film forming rate in the range of 0.1 to 0.8 Å/sec.
A method for producing a superconducting thin film according to any one of paragraphs.
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) A method for producing a superconducting thin film according to any one of claims 1 to 14, 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１４項のいずれ
か一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 any one of claims 1 to 14, characterized in that the film is formed to a thickness in the range of 0.5 to 2 μm.
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１６項のいずれか一項に記載の超電導薄膜
の作製方法。(17) After the above film formation, the thin film is heated in an oxygen-containing atmosphere.
The method for producing a superconducting thin film according to any one of claims 1 to 16, 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１７項に記載の超電導薄膜の作製
方法。(18) The method for producing a superconducting thin film according to claim 17, 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１７項に記載の超電導薄膜の作製方法
。(19) The method for producing a superconducting thin film according to claim 17, 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１８項または１
９項に記載の超電導薄膜の作製方法。(20) Claim 18 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 9.
あることを特徴とする特許請求の範囲第１８項から第２
０項のいずれか一項に記載の超電導薄膜の作製方法。(21) Claims 18 to 2, characterized in that the oxygen partial pressure during the heat treatment is 0.1 to 10 atm.
A method for producing a superconducting thin film according to any one of item 0.
リングであることを特徴とする特許請求の範囲第１項か
ら第２１項のいずれか一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 any one of claims 1 to 21, wherein the sputtering method is magnetron sputtering.
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 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２２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 22, 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. .
Priority Applications (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62324708A JPH01167221A (en) | 1987-12-22 | 1987-12-22 | Production of superconducting thin film |
| CN88109261A CN1021175C (en) | 1987-12-20 | 1988-12-19 | Composite oxide superconductive film |
| CA 586516 CA1339020C (en) | 1987-12-20 | 1988-12-20 | Superconducting thin film and wire and a process for producing the same |
| 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 |
| EP19880403254 EP0322306B1 (en) | 1987-12-20 | 1988-12-20 | Process for producing a superconducting thin film |
| KR1019880017018A KR970005158B1 (en) | 1987-12-20 | 1988-12-20 | Superconducting thin film and wire and the process therefor |
| DE3854493T DE3854493T2 (en) | 1987-12-20 | 1988-12-20 | Method of manufacturing a thin film superconductor. |
| 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 |
|---|---|---|---|
| JP62324708A JPH01167221A (en) | 1987-12-22 | 1987-12-22 | Production of superconducting thin film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01167221A true JPH01167221A (en) | 1989-06-30 |
Family
ID=18168822
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62324708A Pending JPH01167221A (en) | 1987-02-17 | 1987-12-22 | Production of superconducting thin film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01167221A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10700339B2 (en) | 2017-09-09 | 2020-06-30 | Sateria Battery Innovation Group, Inc. | Method of manufacture of an energy storage device having an internal fuse |
| US10763481B2 (en) | 2017-09-09 | 2020-09-01 | Soteria Battery Innovation Group Inc. | Lithium storage device with improved safety architecture |
| US10804526B2 (en) | 2017-11-22 | 2020-10-13 | Contemporary Amperex Techology Co., Limited | Electrode member, electrode assembly and rechargeable battery |
| US10854868B2 (en) | 2017-09-09 | 2020-12-01 | Soteria Battery Innovation Group, Inc. | Lithium energy storage device with internal fuse |
| US10957956B2 (en) | 2017-09-09 | 2021-03-23 | Soteria Battery Innovation Group, Inc. | Energy storage device having a current collector with inherent current limitations |
| US11482711B2 (en) | 2017-09-09 | 2022-10-25 | Soteria Battery Innovation Group, Inc. | Tabless cell utilizing metallized film current collectors |
Citations (2)
| 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 |
| JPS6435819A (en) * | 1987-07-31 | 1989-02-06 | Matsushita Electric Ind Co Ltd | Manufacture of superconducting membrane |
-
1987
- 1987-12-22 JP JP62324708A patent/JPH01167221A/en active Pending
Patent Citations (2)
| 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 |
| JPS6435819A (en) * | 1987-07-31 | 1989-02-06 | Matsushita Electric Ind Co Ltd | Manufacture of superconducting membrane |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10700339B2 (en) | 2017-09-09 | 2020-06-30 | Sateria Battery Innovation Group, Inc. | Method of manufacture of an energy storage device having an internal fuse |
| US10763481B2 (en) | 2017-09-09 | 2020-09-01 | Soteria Battery Innovation Group Inc. | Lithium storage device with improved safety architecture |
| US10854868B2 (en) | 2017-09-09 | 2020-12-01 | Soteria Battery Innovation Group, Inc. | Lithium energy storage device with internal fuse |
| US10957956B2 (en) | 2017-09-09 | 2021-03-23 | Soteria Battery Innovation Group, Inc. | Energy storage device having a current collector with inherent current limitations |
| US11482711B2 (en) | 2017-09-09 | 2022-10-25 | Soteria Battery Innovation Group, Inc. | Tabless cell utilizing metallized film current collectors |
| US10804526B2 (en) | 2017-11-22 | 2020-10-13 | Contemporary Amperex Techology Co., Limited | Electrode member, electrode assembly and rechargeable battery |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2567460B2 (en) | Superconducting thin film and its manufacturing method | |
| JPH01163058A (en) | Supercoductive thin film and its preparation | |
| JPH01167221A (en) | Production of superconducting thin film | |
| KR970005158B1 (en) | Superconducting thin film and wire and the process therefor | |
| JPH01166419A (en) | Manufacture of superconductive membrane | |
| JP2545422B2 (en) | Composite oxide superconducting thin film and method for producing the same | |
| JP2544759B2 (en) | How to make a superconducting thin film | |
| JP2501035B2 (en) | Superconducting thin film | |
| JPH01100022A (en) | Preparation of superconducting thin film | |
| JPH0264021A (en) | Preparation of multiple oxide superconducting thin film | |
| JPH01167218A (en) | Production of superconducting thin film | |
| JP2545423B2 (en) | Composite oxide superconducting thin film and method for producing the same | |
| JP2544761B2 (en) | Preparation method of superconducting thin film | |
| JP2544760B2 (en) | Preparation method of superconducting thin film | |
| JPH01188661A (en) | Superconducting thin film of compound oxide and production thereof | |
| JP2525842B2 (en) | Superconducting wire and its manufacturing method | |
| JPH01188664A (en) | Production of superconducting thin film | |
| JPH01167220A (en) | Production of superconducting thin film | |
| JPH01167223A (en) | Production of superconducting thin film | |
| JPH01188663A (en) | Production of superconducting thin film | |
| JP2501609B2 (en) | Method for producing complex oxide superconducting thin film | |
| JPH01188662A (en) | Production of superconducting thin film | |
| JPH01167222A (en) | Production of superconducting thin film | |
| JPH01188665A (en) | Production of superconducting thin film | |
| JP2567416B2 (en) | Preparation method of superconducting thin film |