JPH04275918A - Thin laminated superconductive film and its production - Google Patents
Thin laminated superconductive film and its productionInfo
- Publication number
- JPH04275918A JPH04275918A JP3053504A JP5350491A JPH04275918A JP H04275918 A JPH04275918 A JP H04275918A JP 3053504 A JP3053504 A JP 3053504A JP 5350491 A JP5350491 A JP 5350491A JP H04275918 A JPH04275918 A JP H04275918A
- Authority
- JP
- Japan
- Prior art keywords
- superconducting
- thin film
- laminated thin
- substrate
- oxide layer
- 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 12
- 239000010409 thin film Substances 0.000 claims description 46
- 239000000203 mixture Substances 0.000 claims description 10
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- 229910052804 chromium Inorganic materials 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 229910052748 manganese Inorganic materials 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 229910052758 niobium Inorganic materials 0.000 claims description 2
- 229910052697 platinum Inorganic materials 0.000 claims description 2
- 229910052719 titanium Inorganic materials 0.000 claims description 2
- 238000001771 vacuum deposition Methods 0.000 claims description 2
- 229910052720 vanadium Inorganic materials 0.000 claims description 2
- 229910052725 zinc Inorganic materials 0.000 claims description 2
- 239000002887 superconductor Substances 0.000 abstract description 24
- 238000007740 vapor deposition Methods 0.000 abstract description 10
- 238000009792 diffusion process Methods 0.000 abstract description 3
- 230000006866 deterioration Effects 0.000 abstract description 2
- ZLHLYESIHSHXGM-UHFFFAOYSA-N 4,6-dimethyl-1h-imidazo[1,2-a]purin-9-one Chemical compound N=1C(C)=CN(C2=O)C=1N(C)C1=C2NC=N1 ZLHLYESIHSHXGM-UHFFFAOYSA-N 0.000 abstract 5
- 230000001788 irregular Effects 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 41
- 239000000758 substrate Substances 0.000 description 30
- 239000000463 material Substances 0.000 description 13
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 12
- 238000010438 heat treatment Methods 0.000 description 9
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 8
- 229910001882 dioxygen Inorganic materials 0.000 description 8
- 239000013078 crystal Substances 0.000 description 7
- 238000000151 deposition Methods 0.000 description 7
- 238000001704 evaporation Methods 0.000 description 6
- 230000008020 evaporation Effects 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 238000010894 electron beam technology Methods 0.000 description 5
- 239000004809 Teflon Substances 0.000 description 3
- 229920006362 Teflon® Polymers 0.000 description 3
- 230000008021 deposition Effects 0.000 description 3
- 239000010453 quartz Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 239000002356 single layer Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910002370 SrTiO3 Inorganic materials 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910002244 LaAlO3 Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002003 electron diffraction Methods 0.000 description 1
- 238000004453 electron probe microanalysis Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000003507 refrigerant Substances 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000000427 thin-film deposition Methods 0.000 description 1
- 238000007738 vacuum evaporation 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
- Laminated Bodies (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は高い臨界温度（Ｔｃ）を
有するＹ系超伝導酸化物層により非超伝導酸化物中間層
を挟んだ構造を持つ超伝導積層薄膜およびその製造方法
に関するものである。[Field of Industrial Application] The present invention relates to a superconducting laminated thin film having a structure in which a non-superconducting oxide intermediate layer is sandwiched between Y-based superconducting oxide layers having a high critical temperature (Tc), and a method for manufacturing the same. be.
【０００２】0002
【従来の技術】高いＴｃを持つＹ系酸化物超伝導体の発
見以来、その高いＴｃをもたらす超伝導機構の解明のた
めの基礎研究や電子素子等への応用研究が活発に行われ
ている。Ｙ系超伝導体は９０Ｋという高いＴｃを持つた
め、その使用に際しては、７７Ｋの沸点を持つ安価な液
体窒素を冷媒として使用でき、またその低温の維持のた
めの設備も簡単なものですむという長所を持っている。
このため、従来の低いＴｃを持つ物質を用いて実現した
超伝導磁石や超伝導電子素子等を、高いＴｃを持つＹ系
超伝導体を用いて実現することは産業上大きな貢献とな
る。[Prior Art] Since the discovery of Y-based oxide superconductors with high Tc, basic research to elucidate the superconducting mechanism that provides the high Tc and applied research to electronic devices, etc. have been actively conducted. . Y-based superconductors have a high Tc of 90K, so when using them, inexpensive liquid nitrogen with a boiling point of 77K can be used as a refrigerant, and the equipment required to maintain the low temperature is simple. has advantages. Therefore, it would be a great contribution to industry to realize superconducting magnets, superconducting electronic devices, etc., which were realized using conventional materials with low Tc, using Y-based superconductors with high Tc.
【０００３】0003
【発明が解決しようとする課題】このＹ系超伝導体を用
いて超伝導電子素子を作製する際、この素子の重要な構
成部分であるジョセフソントンネル接合やジョセフソン
弱接合を制御性良く作製する必要がある。このための方
法として、非超伝導体中間層を超伝導体で挟んだ積層構
造を作製する技術が一般的である。この中間層を構成す
る非超伝導物質としては、Ｙ系超伝導体と結晶構造が似
ていること、Ｙ系超伝導体との相互拡散が小さいこと、
低温で比抵抗が充分高いことなどの条件を満足する必要
がある。したがって、Ｙ系超伝導積層薄膜の中間層とし
て、従来の低Ｔｃ超伝導積層構造で用いられていたＡｌ
酸化物等の非超伝導物質をそのまま用いると、相互拡散
やＹ系超伝導薄膜の結晶配向性の乱れ等の問題が発生し
、超伝導積層薄膜の作製が不可能となる。本発明の目的
は、Ｙ系超伝導積層薄膜で用いられる中間層としてＹ系
超伝導体に良く適した物質を選択することによって、相
互拡散やＹ系超伝導薄膜の結晶配向性の乱れ等のないＹ
系超伝導積層薄膜およびその製造方法を提供することに
ある。[Problem to be solved by the invention] When fabricating a superconducting electronic device using this Y-based superconductor, it is possible to fabricate Josephson tunnel junctions and Josephson weak junctions, which are important components of this device, with good controllability. There is a need to. A common method for this purpose is to create a laminated structure in which a non-superconductor intermediate layer is sandwiched between superconductors. The non-superconducting material constituting this intermediate layer has a similar crystal structure to the Y-based superconductor, and has low interdiffusion with the Y-based superconductor.
It is necessary to satisfy conditions such as sufficiently high resistivity at low temperature. Therefore, as the intermediate layer of the Y-based superconducting laminated thin film, Al, which has been used in the conventional low Tc superconducting laminated structure,
If a non-superconducting substance such as an oxide is used as is, problems such as interdiffusion and disordered crystal orientation of the Y-based superconducting thin film will occur, making it impossible to fabricate a superconducting laminated thin film. The purpose of the present invention is to prevent mutual diffusion, disturbance of crystal orientation, etc. of the Y-based superconducting thin film by selecting a material well suited for the Y-based superconductor as the intermediate layer used in the Y-based superconducting laminated thin film. No Y
An object of the present invention is to provide a system superconducting laminated thin film and a method for manufacturing the same.
【０００４】0004
【課題を解決するための手段】本発明は 、ＹａＢａｂ
ＣｕｃＯｘ なる式で表され、ａは０．５≦ａ≦１．５
，ｂは１．５≦ｂ≦２．５，ｃは２．５≦ｃ≦３．５，
ｘは６．５≦ｘ≦７．０である組成の超伝導酸化物層に
より、ＰｒｄＢａｅＣｕｆＯｙ なる式で表され、ｄは
０．７≦ｄ≦２．０，ｅは１．８≦ｅ≦３．３，ｆは２
．０≦ｆ≦３．２，ｙは６．５≦ｙ≦７．０である組成
の非超伝導酸化物、またはＰｒｇＢａｈ（Ｃｕ１−ＲＭ
Ｒ）ｉＯＺなる式（ＭはＡｌ，Ｔｉ，Ｖ，Ｃｒ，Ｍｎ，
Ｆｅ，Ｃｏ，Ｎｉ，Ｚｎ，Ｎｂ，Ｐｔの中の少なくとも
１種）で表され、Ｒは０＜Ｒ≦０．２，ｇは０．８≦ｇ
≦１．８，ｈは１．９≦ｈ≦２．９，ｉは２．２≦ｉ≦
３．０，ｚは６．５≦ｚ≦７．０である組成の非超伝導
酸化物、またはＰｒｊ（Ｂａ１−ｓＬｓ）ｋＣｕｍＯｗ
なる式（ＬはＳｒ，Ｃａの中の少なくとも１種）で表さ
れ、Ｓは０＜Ｓ≦０．５，ｊは０．９≦ｊ≦１．６，ｋ
は１．９≦ｋ≦２．６，ｍは２．４≦ｍ≦３．０，ｗは
６．５≦ｗ≦７．０である組成の非超伝導酸化物よりな
る中間層の両側を挟んだ構造を持つことを特徴とする超
伝導積層薄膜である。[Means for Solving the Problems] The present invention is based on YaBab
It is expressed by the formula CucOx, where a is 0.5≦a≦1.5
, b is 1.5≦b≦2.5, c is 2.5≦c≦3.5,
x is represented by the formula PrdBaeCufOy due to the superconducting oxide layer having a composition of 6.5≦x≦7.0, d is 0.7≦d≦2.0, and e is 1.8≦e≦3. .3, f is 2
．． A non-superconducting oxide with a composition of 0≦f≦3.2, y being 6.5≦y≦7.0, or PrgBah (Cu1-RM
R) iOZ formula (M is Al, Ti, V, Cr, Mn,
Fe, Co, Ni, Zn, Nb, Pt), R is 0<R≦0.2, g is 0.8≦g
≦1.8, h is 1.9≦h≦2.9, i is 2.2≦i≦
3.0, z is a non-superconducting oxide with a composition of 6.5≦z≦7.0, or Prj(Ba1-sLs)kCumOw
(L is at least one of Sr and Ca), S is 0<S≦0.5, j is 0.9≦j≦1.6, k
is 1.9≦k≦2.6, m is 2.4≦m≦3.0, and w is 6.5≦w≦7.0. This is a superconducting laminated thin film characterized by a sandwiched structure.
【０００５】また、上記の超伝導積層薄膜の製造方法は
、非超伝導酸化物よりなる中間層を作製する際、超伝導
酸化物層を作製するときより低い温度で真空蒸着法によ
り作製することを特徴とする。[0005] Furthermore, in the method for producing the superconducting laminated thin film described above, when producing the intermediate layer made of a non-superconducting oxide, it is produced by a vacuum evaporation method at a lower temperature than when producing the superconducting oxide layer. It is characterized by
【０００６】[0006]
【作用】Ｙ系超伝導体であるＹａＢａｂＣｕｃＯｘにお
いて、ａの範囲を０．５≦ａ≦１．５、ｂの範囲を１．
５≦ｂ≦２．５、ｃの範囲を２．５≦ｃ≦３．５、ｘの
範囲を６．５≦ｘ≦７．０と限定したのは、この範囲を
はずれると、作製された薄膜中に超伝導相以外の第２相
が高い割合で生成してしまい、Ｔｃの値の著しい低下や
、表面平坦性の悪化等の問題が生じるためである。[Operation] In YaBabCucOx, which is a Y-based superconductor, the range of a is 0.5≦a≦1.5, and the range of b is 1.5≦a≦1.5.
5≦b≦2.5, the range of c is limited to 2.5≦c≦3.5, and the range of x is limited to 6.5≦x≦7.0. This is because a high proportion of a second phase other than the superconducting phase is generated in the thin film, causing problems such as a significant decrease in the Tc value and deterioration of surface flatness.
【０００７】さらに、Ｐｒ−Ｂａ−Ｃｕ系酸化物である
ＰｒｄＢａｅＣｕｆＯｙ、ＰｒｇＢａｈ（Ｃｕ１−ＲＭ
Ｒ）ｉＯＺまたはＰｒｊ（Ｂａ１−ｓＬｓ）ｋＣｕｍＯ
ｗにおいて、ｄの範囲を０．７≦ｄ≦２．０、ｅの範囲
を１．８≦ｅ≦３．３、ｆの範囲を２．０≦ｆ≦３．２
、ｇの範囲を０．８≦ｇ≦１．８、ｈの範囲を１．９≦
ｈ≦２．９、ｉの範囲を２．２≦ｉ≦３．０、ｊの範囲
を０．９≦ｊ≦１．６、ｋの範囲を１．９≦ｋ≦２．６
、ｍの範囲を２．４≦ｍ≦３．０、ｙの範囲を６．５≦
ｙ≦７．０、ｚの範囲を６．５≦ｚ≦７．０、ｗの範囲
を６．５≦ｗ≦７．０、Ｒの範囲を０＜Ｒ≦０．２、Ｓ
の範囲を０＜Ｓ≦０．５と限定したのは、この範囲をは
ずれると、作製された薄膜中にＰｒ−Ｂａ−Ｃｕ系酸化
物以外の第２相が高い割合で生成してしまい、表面平坦
性が悪化するためである。Furthermore, PrdBaeCufOy, PrgBah(Cu1-RM
R) iOZ or Prj(Ba1-sLs)kCumO
In w, the range of d is 0.7≦d≦2.0, the range of e is 1.8≦e≦3.3, and the range of f is 2.0≦f≦3.2.
, the range of g is 0.8≦g≦1.8, the range of h is 1.9≦
h≦2.9, the range of i is 2.2≦i≦3.0, the range of j is 0.9≦j≦1.6, the range of k is 1.9≦k≦2.6
, m range is 2.4≦m≦3.0, y range is 6.5≦
y≦7.0, z range is 6.5≦z≦7.0, w range is 6.5≦w≦7.0, R range is 0<R≦0.2, S
The reason why the range of is limited to 0<S≦0.5 is that if this range is exceeded, a high proportion of second phases other than Pr-Ba-Cu-based oxides will be generated in the produced thin film. This is because the surface flatness deteriorates.
【０００８】また、Ｐｒ−Ｂａ−Ｃｕ系酸化物を中間層
として用いたのは、Ｙ系超伝導体と同じ結晶構造を持っ
ているうえ、格子定数の差も小さく、Ｙ系超伝導体層の
上にＰｒ−Ｂａ−Ｃｕ系酸化物層をエピタキシャル成長
させ得ること、および逆にＰｒ−Ｂａ−Ｃｕ系酸化物層
の上にＹ系超伝導体層をエピタキシャル成長させること
が可能であること、Ｙ系超伝導体層との間の相互拡散が
小さいこと、低温で充分高い比抵抗を持つことが理由で
ある。[0008] Furthermore, the use of Pr-Ba-Cu-based oxide as the intermediate layer has the same crystal structure as the Y-based superconductor, and the difference in lattice constant is small. It is possible to epitaxially grow a Pr-Ba-Cu based oxide layer on the Pr-Ba-Cu based oxide layer, and conversely, it is possible to epitaxially grow a Y-based superconductor layer on the Pr-Ba-Cu based oxide layer, Y This is because mutual diffusion with the system superconductor layer is small and the resistivity is sufficiently high at low temperatures.
【０００９】さらに、Ｐｒ−Ｂａ−Ｃｕ系酸化物の構成
元素のうち、Ａｌ等でＣｕを、またはＳｒ等でＢａを一
部置換すれば、Ｐｒ−Ｂａ−Ｃｕ系酸化物の比抵抗をさ
らに高めることができ、ジョセフソントンネル接合への
応用を考えるとより好ましい。また、真空蒸着法により
５００〜７５０℃の温度でＹ系超伝導積層薄膜を作製す
れば、作製後において約９００℃での高温熱処理をしな
くてもＹ系酸化物の超伝導性が得られ、平坦な表面を持
つ超伝導積層薄膜が得られる。また、Ｙ系酸化物に比べ
、Ｐｒ−Ｂａ−Ｃｕ系酸化物は第２相が生成しやすいの
で、Ｙ系超伝導積層薄膜作製の際、Ｐｒ−Ｂａ−Ｃｕ系
酸化物層作製時にＹ系超伝導体層作製時より作製温度を
低くすると、比抵抗がより低くなるものの、Ｐｒ−Ｂａ
−Ｃｕ系酸化物層の表面平坦性が向上し、良質の積層薄
膜が作製できる。Furthermore, among the constituent elements of the Pr-Ba-Cu oxide, if Cu is partially replaced with Al or the like, or Ba is partially replaced with Sr or the like, the specific resistance of the Pr-Ba-Cu oxide can be further increased. This is more preferable when considering application to Josephson tunnel junctions. Furthermore, if a Y-based superconducting laminated thin film is produced at a temperature of 500 to 750°C by vacuum evaporation, the superconductivity of the Y-based oxide can be obtained without the need for high-temperature heat treatment at about 900°C after production. , superconducting laminated thin films with flat surfaces can be obtained. In addition, compared to Y-based oxides, Pr-Ba-Cu-based oxides are more likely to generate a second phase. Although the specific resistance becomes lower when the fabrication temperature is lower than that during superconductor layer fabrication, Pr-Ba
- The surface flatness of the Cu-based oxide layer is improved, and a high-quality laminated thin film can be produced.
【００１０】0010
【実施例】次に、本発明の実施例について説明する。図
１は本発明によるＹ系超伝導積層薄膜の概略断面図であ
る。基板１には（００１）ＳｒＴｉＯ３単結晶基板を用
いた。基板としてはＳｒＴｉＯ３基板の他の方位の結晶
や、ＬａＡｌＯ３、ＭｇＯ等、他の材質を用いてもさし
つかえない。基板の大きさは１５ｍｍ角で、厚さは０．
５ｍｍである。基板１上に、まずＹ系超伝導体層２を堆
積させ、その上にＰｒ−Ｂａ−Ｃｕ系酸化物層３を、最
後にその上にＹ系超伝導体層４を堆積させて作製する。[Example] Next, an example of the present invention will be described. FIG. 1 is a schematic cross-sectional view of a Y-based superconducting laminated thin film according to the present invention. As the substrate 1, a (001) SrTiO3 single crystal substrate was used. As the substrate, crystals in other orientations of the SrTiO3 substrate, LaAlO3, MgO, and other materials may be used. The size of the board is 15 mm square, and the thickness is 0.
It is 5mm. First, a Y-based superconductor layer 2 is deposited on a substrate 1, a Pr-Ba-Cu-based oxide layer 3 is deposited thereon, and finally a Y-based superconductor layer 4 is deposited thereon. .
【００１１】図２は図１に示したＹ系超伝導積層薄膜を
作製するために本実施例で用いた多元蒸着装置の概略構
成図である。真空槽１１には電子線加熱装置１３，１４
，１５，１６，１７，１８が備え付けられており、６種
類の蒸着材料Ｙ１９，Ｐｒ２０，Ｂａ２１，Ｃｕ２２，
Ａｌ等２３、Ｓｒ等２４をそれぞれ独立に加熱し、各成
分原子を独立に蒸発させる。この際、加熱装置としては
抵抗加熱装置等、他の加熱装置を用いてもさしつかえな
い。さらに蒸着材料として、例えばＢａの代わりにＢａ
ＣＯ３、Ｙの代わりにＹ２Ｏ３を用いる等、他の組み合
わせを採用してもさしつかえない。積層薄膜作製中、基
板４２はヒ−タ３７によって９００℃まで加熱すること
ができる。また積層薄膜の均一性を高めるため、積層薄
膜作製中に基板を基板回転機構３８によって回転させる
ことができる。酸素ガスをオゾン発生装置３９に導入し
てオゾンを含む酸素ガスを作製し、これをテフロン製チ
ュ−ブ４０および石英管４１を通して積層薄膜作製中基
板に向けて吹き付けることができる。FIG. 2 is a schematic diagram of a multi-component vapor deposition apparatus used in this example to fabricate the Y-based superconducting laminated thin film shown in FIG. 1. The vacuum chamber 11 is equipped with electron beam heating devices 13 and 14.
, 15, 16, 17, 18, and six types of vapor deposition materials Y19, Pr20, Ba21, Cu22,
Al, etc. 23 and Sr, etc. 24 are each independently heated to evaporate each component atom independently. At this time, other heating devices such as a resistance heating device may be used as the heating device. Furthermore, as a vapor deposition material, for example, Ba can be used instead of Ba.
Other combinations may be used, such as using Y2O3 instead of CO3 or Y. During the production of the laminated thin film, the substrate 42 can be heated to 900° C. by the heater 37. Further, in order to improve the uniformity of the laminated thin film, the substrate can be rotated by the substrate rotation mechanism 38 during the production of the laminated thin film. Oxygen gas is introduced into the ozone generator 39 to produce an oxygen gas containing ozone, which can be blown through the Teflon tube 40 and the quartz tube 41 toward the substrate during the production of the laminated thin film.
【００１２】薄膜作製に際しては、まず真空槽１１を真
空排気系１２により１０−７Ｔｏｒｒ台まで排気する。
この後、真空槽１１内の真空度が４×１０−４Ｔｏｒｒ
程度になるように、酸素ガスをオゾン発生装置３９、テ
フロン製チュ−ブ４０および石英管４１を通して真空槽
１１内に導入する。この際、真空槽１１内の真空度は１
０−５Ｔｏｒｒ台〜１０−３Ｔｏｒｒ台の範囲内であれ
ば、他の真空度でもさしつかえない。オゾン発生装置３
９でオゾンを発生させると、オゾンを含む酸素ガスを基
板４２に向けて吹き付ける。オゾン発生装置３９を稼働
させず、酸素ガスのみを基板に向けて吹き付けた場合は
、良質のＹ系超伝導体が得られず、目的の超伝導積層薄
膜を作製することはできない。なお、本実施例ではオゾ
ン発生装置を用いてオゾンを含んだ酸素ガスを基板に吹
き付け薄膜を酸化したが、酸素ガスを高周波（ＲＦ）や
マイクロ波で活性化させ、薄膜の酸化を行っても同じよ
うに良質の超伝導積層薄膜を作製することができる。基
板４２はヒ−タ３７によって加熱され、その温度は約６
００℃に保持されている。なおこの基板温度は５００〜
７５０℃の範囲であれば他の温度でもさしつかえない。
また積層薄膜作製中、基板４２は基板回転機構３８で約
１０ｒｐｍの速度で回転している。この状態で電子線加
熱装置１３，１４，１５，１６，１７，１８で各蒸着材
料１９，２０，２１，２２，２３，２４を加熱し、各原
子を蒸発させる。ただしＹ系超伝導体層を堆積させる際
は、Ｐｒ用シャッタ２６、Ａｌ等用シャッタ２９および
Ｓｒ等用シャッタ３０を閉じて不要な原子が基板に到達
しないようにし、Ｐｒ−Ｂａ−Ｃｕ系酸化物層を堆積さ
せる際にはＹ用シャッタ２５、Ａｌ等用シャッタ２９お
よびＳｒ等用シャッタ３０を閉じて不要な原子が基板に
到達しないようにする。また例えば、Ｐｒ−Ｂａ−Ｃｕ
系酸化物層のＣｕをＡｌで一部置換したい場合は、蒸着
材料２３としてＡｌを置き、Ｐｒ−Ｂａ−Ｃｕ系酸化物
層堆積時にシャッタ２９もあわせて開ければよい。When producing a thin film, first, the vacuum chamber 11 is evacuated to a pressure of about 10 -7 Torr using the vacuum evacuation system 12 . After this, the degree of vacuum in the vacuum chamber 11 is set to 4 x 10-4 Torr.
Oxygen gas is introduced into the vacuum chamber 11 through the ozone generator 39, the Teflon tube 40, and the quartz tube 41 so that the temperature is at a certain level. At this time, the degree of vacuum in the vacuum chamber 11 is 1
Other degrees of vacuum may be used as long as they are within the range of 0-5 Torr to 10-3 Torr. Ozone generator 3
When ozone is generated in step 9, oxygen gas containing ozone is blown toward the substrate 42. If the ozone generator 39 is not operated and only oxygen gas is blown toward the substrate, a high quality Y-based superconductor cannot be obtained and the desired superconducting laminated thin film cannot be produced. Note that in this example, an ozone generator was used to spray oxygen gas containing ozone onto the substrate to oxidize the thin film, but it is also possible to activate the oxygen gas using radio frequency (RF) or microwaves to oxidize the thin film. Similarly, high-quality superconducting laminated thin films can be produced. The substrate 42 is heated by the heater 37, and its temperature is about 6
The temperature is maintained at 00°C. Note that this substrate temperature is 500~
Other temperatures within the range of 750°C are also acceptable. Further, during the production of the laminated thin film, the substrate 42 is rotated at a speed of about 10 rpm by the substrate rotation mechanism 38. In this state, each vapor deposition material 19, 20, 21, 22, 23, 24 is heated by electron beam heating devices 13, 14, 15, 16, 17, 18 to evaporate each atom. However, when depositing a Y-based superconductor layer, close the Pr shutter 26, the Al etc. shutter 29, and the Sr etc. shutter 30 to prevent unnecessary atoms from reaching the substrate. When depositing a material layer, the shutter 25 for Y, the shutter 29 for Al, etc., and the shutter 30 for Sr, etc. are closed to prevent unnecessary atoms from reaching the substrate. For example, Pr-Ba-Cu
If it is desired to partially replace Cu in the Pr-Ba-Cu based oxide layer with Al, Al may be placed as the vapor deposition material 23 and the shutter 29 may be opened at the same time when the Pr-Ba-Cu based oxide layer is deposited.
【００１３】なお、各材料の蒸発速度は蒸発速度計３１
，３２，３３，３４，３５，３６で常に測定し、その測
定値をもとに電子線加熱装置を制御し、蒸発速度を制御
している。各材料の蒸発速度が目的組成の酸化物層を堆
積するのに適した値になったことを確認してから基板シ
ャッタ４３を開け、薄膜の堆積を開始する。なお各蒸着
材料の蒸発速度、すなわち各酸化物層の組成は、Ｙ系酸
化物およびＰｒ−Ｂａ−Ｃｕ系酸化物の各単層薄膜をあ
らかじめ作製し、その組成をもとに決定した。単層薄膜
の組成は電子線励起Ｘ線微小分析装置（ＥＰＭＡ）で決
定した。各蒸発原子は酸素分子またはオゾン分子と反応
し、加熱された基板上で酸化物層として堆積する。堆積
速度は約０．５オングストロ―ム／ｓである。作製した
積層薄膜の各層の厚さは、いずれも約３００オングスト
ロ―ムである。[0013] The evaporation rate of each material is measured using an evaporation rate meter 31.
, 32, 33, 34, 35, and 36, and based on the measured values, the electron beam heating device is controlled to control the evaporation rate. After confirming that the evaporation rate of each material has reached a value suitable for depositing an oxide layer of the desired composition, the substrate shutter 43 is opened and thin film deposition is started. The evaporation rate of each vapor deposition material, that is, the composition of each oxide layer, was determined based on the compositions of single-layer thin films of Y-based oxide and Pr-Ba-Cu-based oxide prepared in advance. The composition of the single-layer thin film was determined using an electron beam excited X-ray microanalyzer (EPMA). Each evaporated atom reacts with an oxygen or ozone molecule and is deposited as an oxide layer on the heated substrate. The deposition rate is about 0.5 angstroms/s. The thickness of each layer of the produced laminated thin film was approximately 300 angstroms.
【００１４】積層薄膜作製後は、各シャッタ２５，２６
，２７，２８，２９，３０および基板シャッタ４３を閉
じて堆積を終了させる。次にヒ−タ３７での加熱をやめ
、基板４２およびその上に作製された積層薄膜を自然冷
却する。この冷却の際も、オゾンを含む酸素ガスは基板
に向けて吹き付け続ける。約１時間の冷却で基板温度は
約１００℃にまで下がる。ここで基板４２を大気中に取
り出す。After producing the laminated thin film, each shutter 25, 26
, 27, 28, 29, 30 and the substrate shutter 43 are closed to complete the deposition. Next, heating by the heater 37 is stopped, and the substrate 42 and the laminated thin film formed thereon are naturally cooled. Even during this cooling, oxygen gas containing ozone continues to be blown toward the substrate. After about 1 hour of cooling, the substrate temperature drops to about 100°C. Here, the substrate 42 is taken out into the atmosphere.
【００１５】こうして作製したＹ系超伝導積層薄膜を２
次イオン質量分析装置（ＳＩＭＳ）で分析すると、各層
は相互拡散せず堆積されており、良質の積層薄膜が作製
されていることが確認された。また、この積層薄膜をＸ
線回折法および電子線回折法で調べると、各層ともｃ軸
が基板表面に垂直で、基板の［１００］方向と各酸化物
の［１００］方向とが平行なエピタキシャル成長してい
ることが確認された。なおＸ線回折法で調べた結果、Ｙ
系酸化物相およびＰｒ−Ｂａ−Ｃｕ系酸化物相以外の相
は薄膜中に存在していないことが確認された。積層薄膜
の表面および同条件で作製した各単層薄膜の表面を２次
電子顕微鏡で観察したところ、表面は５０オングストロ
―ム以下の精度で平坦であることが確認された。４端子
法でＹ系超伝導体層２，４の抵抗の温度変化を測定した
ところ、いずれの層ともに８５Ｋ以上のＴｃを持つこと
が確認され、良質のＹ系超伝導体層が作製されているこ
とがわかった。また、室温でのＹ系酸化物層間の抵抗値
は充分に高く、Ｐｒ−Ｂａ−Ｃｕ系酸化物層３がＹ系酸
化物層間に均一に存在していることが確認された。また
、Ｐｒ−Ｂａ−Ｃｕ系酸化物の比抵抗は、Ａｌ等による
Ｃｕの一部置換およびＳｒ等によるＢａの一部置換によ
り、置換無しの場合に比べて２倍以上高くすることがで
きた。[0015] The Y-based superconducting laminated thin film thus produced was
Analysis using a subsequent ion mass spectrometer (SIMS) confirmed that each layer was deposited without interdiffusion, and that a high-quality laminated thin film had been produced. In addition, this laminated thin film is
When examined by line diffraction and electron diffraction, it was confirmed that the c-axis of each layer was perpendicular to the substrate surface, and the [100] direction of the substrate and the [100] direction of each oxide were epitaxially grown parallel to each other. Ta. Furthermore, as a result of investigation using X-ray diffraction method, Y
It was confirmed that no phases other than the Pr-Ba-Cu-based oxide phase and the Pr-Ba-Cu-based oxide phase were present in the thin film. When the surface of the laminated thin film and the surface of each single-layer thin film produced under the same conditions were observed using a secondary electron microscope, it was confirmed that the surface was flat with an accuracy of 50 angstroms or less. When the temperature change in the resistance of Y-based superconductor layers 2 and 4 was measured using the four-probe method, it was confirmed that both layers had a Tc of 85K or more, indicating that a high-quality Y-based superconductor layer had been fabricated. I found out that there is. Furthermore, it was confirmed that the resistance value between the Y-based oxide layers at room temperature was sufficiently high, and the Pr-Ba-Cu-based oxide layer 3 was uniformly present between the Y-based oxide layers. In addition, the specific resistance of the Pr-Ba-Cu oxide could be made more than twice as high as that without substitution by partially replacing Cu with Al etc. and partially replacing Ba with Sr etc. .
【００１６】以上のように良質なＹ系超伝導積層薄膜が
多元蒸着法で作製できたが、Ｐｒ−Ｂａ−Ｃｕ系酸化物
層３を堆積中に限って基板温度を約５５０℃に下げると
、Ｐｒ−Ｂａ−Ｃｕ系酸化物層の表面平坦性が向上し、
より良質な積層薄膜を作製することができた。なおこの
Ｐｒ−Ｂａ−Ｃｕ系酸化物層を堆積する際の基板温度は
５００〜７５０℃の範囲内であれば他の温度でも差し支
えない。As described above, a high-quality Y-based superconducting laminated thin film was fabricated by the multi-component vapor deposition method, but if the substrate temperature was lowered to about 550° C. only during the deposition of the Pr-Ba-Cu-based oxide layer 3, , the surface flatness of the Pr-Ba-Cu-based oxide layer is improved,
We were able to create a laminated thin film of better quality. Note that the substrate temperature when depositing this Pr--Ba--Cu based oxide layer may be any other temperature within the range of 500 to 750°C.
【００１７】[0017]
【発明の効果】以上、詳細に説明したように、本発明に
よるＹ系超伝導積層薄膜は、相互拡散やＹ系超伝導薄膜
の結晶配向性の乱れ等のない良質なもので、Ｙ系超伝導
体の超伝導電子素子への応用上効果が大きい。Effects of the Invention As explained above in detail, the Y-based superconducting laminated thin film according to the present invention is of good quality without interdiffusion or disorder of crystal orientation of the Y-based superconducting thin film, and is of good quality. This is highly effective in applying conductors to superconducting electronic devices.
【図１】本発明によるＹ系超伝導積層薄膜の概略断面図
である。FIG. 1 is a schematic cross-sectional view of a Y-based superconducting laminated thin film according to the present invention.
【図２】本発明による実施例で使用した多元蒸着装置の
一例の概略構成図である。FIG. 2 is a schematic configuration diagram of an example of a multi-component vapor deposition apparatus used in an example according to the present invention.
１，４２ 基板
２，４ Ｙ系超伝導体層
３ Ｐｒ−Ｂａ−Ｃｕ系酸化物層 １
１ 真空槽１２ 真空排気系
１３，１４，１５，１６，１７，１８ 電子線加熱装
置１９，２０，２１，２２，２３，２４ 蒸着材料２
５，２６，２７，２８，２９，３０ シャッタ３１，
３２，３３，３４，３５，３６ 蒸発速度計３７
ヒ−タ
３８ 基板回転機構
３９ オゾン発生装置
４０ テフロン製チュ−ブ
４１ 石英管
４３ 基板シャッタ1,42 board
2,4 Y-based superconductor layer 3 Pr-Ba-Cu-based oxide layer 1
1 Vacuum chamber 12 Vacuum exhaust system 13, 14, 15, 16, 17, 18 Electron beam heating device 19, 20, 21, 22, 23, 24 Vapor deposition material 2
5, 26, 27, 28, 29, 30 shutter 31,
32, 33, 34, 35, 36 Evaporation rate meter 37
heater
38 Substrate rotation mechanism 39 Ozone generator
40 Teflon tube 41 Quartz tube
43 Board shutter
Claims (4)
れ、ａは０．５≦ａ≦１．５，ｂは１．５≦ｂ≦２．５
，ｃは２．５≦ｃ≦３．５，ｘは６．５≦ｘ≦７．０で
ある組成の超伝導酸化物層により、ＰｒｄＢａｅＣｕｆ
Ｏｙ なる式で表され、ｄは０．７≦ｄ≦２．０，ｅは
１．８≦ｅ≦３．３，ｆは２．０≦ｆ≦３．２，ｙは６
．５≦ｙ≦７．０である組成の非超伝導酸化物よりなる
中間層の両側を挟んだ構造を持つことを特徴とする超伝
導積層薄膜。[Claim 1] Represented by the formula YaBabCucOx, where a is 0.5≦a≦1.5, and b is 1.5≦b≦2.5.
, c is 2.5≦c≦3.5, x is 6.5≦x≦7.0, and PrdBaeCuf
Oy is expressed by the formula, d is 0.7≦d≦2.0, e is 1.8≦e≦3.3, f is 2.0≦f≦3.2, y is 6
．． A superconducting laminated thin film characterized by having a structure in which both sides of an intermediate layer made of a non-superconducting oxide having a composition of 5≦y≦7.0 are sandwiched.
、ＰｒｇＢａｈ（Ｃｕ１−ＲＭＲ）ｉＯＺなる式（Ｍは
Ａｌ，Ｔｉ，Ｖ，Ｃｒ，Ｍｎ，Ｆｅ，Ｃｏ，Ｎｉ，Ｚｎ
，Ｎｂ，Ｐｔの中の少なくとも１種）で表され、Ｒは０
＜Ｒ≦０．２，ｇは０．８≦ｇ≦１．８，ｈは１．９≦
ｈ≦２．９，ｉは２．２≦ｉ≦３．０，ｚは６．５≦ｚ
≦７．０である組成の非超伝導酸化物よりなる中間層の
両側を挟んだ構造を持つことを特徴とする超伝導積層薄
膜。2. The superconducting oxide layer according to claim 1 has the formula PrgBah(Cu1-RMR)iOZ (M is Al, Ti, V, Cr, Mn, Fe, Co, Ni, Zn
, Nb, Pt), and R is 0
<R≦0.2, g is 0.8≦g≦1.8, h is 1.9≦
h≦2.9, i is 2.2≦i≦3.0, z is 6.5≦z
A superconducting laminated thin film characterized by having a structure in which both sides of an intermediate layer made of a non-superconducting oxide having a composition of ≦7.0 are sandwiched.
、Ｐｒｊ（Ｂａ１−ｓＬｓ）ｋＣｕｍＯｗなる式（Ｌは
Ｓｒ，Ｃａの中の少なくとも１種）で表され、Ｓは０＜
Ｓ≦０．５，ｊは０．９≦ｊ≦１．６，ｋは１．９≦ｋ
≦２．６，ｍは２．４≦ｍ≦３．０，ｗは６．５≦ｗ≦
７．０である組成の非超伝導酸化物よりなる中間層の両
側を挟んだ構造を持つことを特徴とする超伝導積層薄膜
。3. The superconducting oxide layer according to claim 1 is represented by the formula Prj(Ba1-sLs)kCumOw (L is at least one of Sr and Ca), and S is 0<
S≦0.5, j is 0.9≦j≦1.6, k is 1.9≦k
≦2.6, m is 2.4≦m≦3.0, w is 6.5≦w≦
A superconducting laminated thin film characterized by having a structure in which both sides of an intermediate layer made of a non-superconducting oxide having a composition of 7.0 are sandwiched.
する際、超伝導酸化物層を作製するときより低い温度で
真空蒸着法により作製することを特徴とする請求項１〜
３のいずれかに記載の超伝導積層薄膜の製造方法。4. The intermediate layer made of a non-superconducting oxide is produced by a vacuum evaporation method at a lower temperature than the superconducting oxide layer is produced.
3. The method for producing a superconducting laminated thin film according to any one of 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3053504A JPH04275918A (en) | 1991-02-27 | 1991-02-27 | Thin laminated superconductive film and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3053504A JPH04275918A (en) | 1991-02-27 | 1991-02-27 | Thin laminated superconductive film and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04275918A true JPH04275918A (en) | 1992-10-01 |
Family
ID=12944658
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3053504A Pending JPH04275918A (en) | 1991-02-27 | 1991-02-27 | Thin laminated superconductive film and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04275918A (en) |
-
1991
- 1991-02-27 JP JP3053504A patent/JPH04275918A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Naito et al. | MgB2 thin films for superconducting electronics | |
| JP3207058B2 (en) | Superconductor thin film and method of manufacturing the same | |
| JP2004530046A (en) | Method and apparatus for fabricating buffer layer and structure of crystalline thin film with biaxial texture | |
| JP2004071359A (en) | Oxide superconductor wire material | |
| JP3188358B2 (en) | Method for producing oxide superconductor thin film | |
| Xu et al. | Synthesis of La2− xSrxCuO4 films via atomic layer-by-layer molecular beam epitaxy | |
| US5567673A (en) | Process of forming multilayered Tl-containing superconducting composites | |
| US7871663B1 (en) | Minute doping for YBCO flux pinning | |
| JPH0297427A (en) | Production of oxide superconducting thin film | |
| JP3001273B2 (en) | Superconducting laminated thin film | |
| JP2720665B2 (en) | Superconducting laminated thin film and manufacturing method thereof | |
| JPH04275918A (en) | Thin laminated superconductive film and its production | |
| JP3579690B2 (en) | A method and apparatus for producing a composite oxide thin film and a composite oxide thin film produced by the method. | |
| US5244873A (en) | Process for preparing a thin film of bi-type oxide superconductor | |
| US5462921A (en) | Method of forming Hg-containing oxide superconducting films | |
| JPS63225599A (en) | Preparation of oxide superconductive thin film | |
| JP3353871B2 (en) | Oxide superconductor thin film laminate and method for producing oxide superconductor thin film laminate | |
| JPH02175613A (en) | Production of oxide superconducting thin film | |
| JPH057027A (en) | Oxide superconducting thin film and manufacture thereof and superconducting tunnel junction and manufacture thereof | |
| Naito et al. | Growth and properties of superconducting MgB2 thin films | |
| Braginski et al. | In-situ fabrication, processing and characterization of superconducting oxide films | |
| JPH06196760A (en) | Superconductive lamination thin film | |
| JPH05170448A (en) | Production of thin ceramic film | |
| JP2577056B2 (en) | Preparation method of composite oxide superconducting thin film | |
| JPS63236794A (en) | Production of superconductive thin film of oxide |