JPH01208327A - Production of thin film of superconductor - Google Patents
Production of thin film of superconductorInfo
- Publication number
- JPH01208327A JPH01208327A JP63032238A JP3223888A JPH01208327A JP H01208327 A JPH01208327 A JP H01208327A JP 63032238 A JP63032238 A JP 63032238A JP 3223888 A JP3223888 A JP 3223888A JP H01208327 A JPH01208327 A JP H01208327A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- substrate
- vapor deposition
- film superconductor
- superconductor
- 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
- 239000002887 superconductor Substances 0.000 title claims abstract description 40
- 239000010409 thin film Substances 0.000 title claims abstract description 30
- 238000004519 manufacturing process Methods 0.000 title claims description 21
- 239000010408 film Substances 0.000 claims abstract description 36
- 238000000034 method Methods 0.000 claims abstract description 35
- 238000004544 sputter deposition Methods 0.000 claims abstract description 24
- 238000000576 coating method Methods 0.000 claims abstract description 21
- 239000011248 coating agent Substances 0.000 claims abstract description 19
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 18
- 239000013078 crystal Substances 0.000 claims abstract description 16
- 229910052712 strontium Inorganic materials 0.000 claims abstract description 13
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 11
- 239000007789 gas Substances 0.000 claims abstract description 11
- 239000001301 oxygen Substances 0.000 claims abstract description 11
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052797 bismuth Inorganic materials 0.000 claims abstract description 10
- 229910052802 copper Inorganic materials 0.000 claims abstract description 10
- 239000000758 substrate Substances 0.000 claims description 51
- 150000001875 compounds Chemical class 0.000 claims description 25
- 239000000463 material Substances 0.000 claims description 18
- 239000002131 composite material Substances 0.000 claims description 17
- 238000010438 heat treatment Methods 0.000 claims description 13
- 238000000151 deposition Methods 0.000 claims description 9
- 238000007740 vapor deposition Methods 0.000 claims description 9
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims description 6
- 239000000395 magnesium oxide Substances 0.000 claims description 6
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical group [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 claims description 6
- -1 1_2O_3) Substances 0.000 claims description 5
- 238000005229 chemical vapour deposition Methods 0.000 claims description 5
- 230000008021 deposition Effects 0.000 claims description 5
- 238000005240 physical vapour deposition Methods 0.000 claims description 5
- 229910052573 porcelain Inorganic materials 0.000 claims description 5
- 229910052596 spinel Inorganic materials 0.000 claims description 5
- 239000011029 spinel Substances 0.000 claims description 5
- 229910052710 silicon Inorganic materials 0.000 claims description 4
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 claims description 3
- 229910001218 Gallium arsenide Inorganic materials 0.000 claims description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 3
- 239000010703 silicon Substances 0.000 claims description 3
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 claims description 3
- 238000002207 thermal evaporation Methods 0.000 claims description 3
- 229910052839 forsterite Inorganic materials 0.000 claims description 2
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 claims description 2
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims description 2
- 229910052594 sapphire Inorganic materials 0.000 claims description 2
- 239000010980 sapphire Substances 0.000 claims description 2
- 229910001928 zirconium oxide Inorganic materials 0.000 claims description 2
- LTPBRCUWZOMYOC-UHFFFAOYSA-N Beryllium oxide Chemical compound O=[Be] LTPBRCUWZOMYOC-UHFFFAOYSA-N 0.000 claims 2
- 238000001505 atmospheric-pressure chemical vapour deposition Methods 0.000 claims 1
- 238000004518 low pressure chemical vapour deposition Methods 0.000 claims 1
- 230000007704 transition Effects 0.000 abstract description 10
- 239000000126 substance Substances 0.000 abstract description 3
- 229910015901 Bi-Sr-Ca-Cu-O Inorganic materials 0.000 abstract 2
- 239000011247 coating layer Substances 0.000 abstract 2
- 238000001465 metallisation Methods 0.000 abstract 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 239000012071 phase Substances 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000001755 magnetron sputter deposition Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000007790 solid phase Substances 0.000 description 2
- 239000011882 ultra-fine particle Substances 0.000 description 2
- 241001156002 Anthonomus pomorum Species 0.000 description 1
- 229910002480 Cu-O Inorganic materials 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910000750 Niobium-germanium Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- CFJRGWXELQQLSA-UHFFFAOYSA-N azanylidyneniobium Chemical compound [Nb]#N CFJRGWXELQQLSA-UHFFFAOYSA-N 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005566 electron beam evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- RTRWPDUMRZBWHZ-UHFFFAOYSA-N germanium niobium Chemical compound [Ge].[Nb] RTRWPDUMRZBWHZ-UHFFFAOYSA-N 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 238000005477 sputtering target Methods 0.000 description 1
- 238000001947 vapour-phase growth 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
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は超電導体の製造方法に関するものである。特に
化合物薄膜超電導体の製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing superconductors. In particular, it relates to a method for manufacturing compound thin film superconductors.
従来の技術
高温超電導体として、Ａ１５型２元系化合物として窒化
ニオブ（ＮｂＮ）やゲルマニウムニオブ（ＮｂｓＧｅ）
などが知られていたが、これらの材料の超電導転移温度
はたかだか２４°にであった。一方、ペロブスカイト系
３元化合物は、さらに高い転移温度が期待され、Ｂａ−
Ｌａ−Ｃｕ−０系の高温超電導体が提案された［ Ｊ、
Ｇ、 Ｂｅｎｄ。Conventional technology Niobium nitride (NbN) and germanium niobium (NbsGe) are used as A15 type binary compounds as high-temperature superconductors.
were known, but the superconducting transition temperature of these materials was at most 24°. On the other hand, perovskite-based ternary compounds are expected to have even higher transition temperatures, and Ba-
A La-Cu-0-based high-temperature superconductor was proposed [J,
G. Bend.
ｒｚ ａｎｄ Ｋ、Ａ、Ｍｕｌｌｅｒ、ツァイト シコ
リフト フェアフィジーク（Ｚｅ ｔｓｈｒｉｆｔ ｆ
（Ｉ ｒｐｈｙｓｉｋ Ｂ）−Ｃｏｎｄｅｎｓｅｄ
Ｍａｔｔｅｒ ６４．１８９−１９３ （１９８６）
］。さらに、］Ｙ−Ｂａ−Ｃｕ−０がより高温の超電導
材料であることが最近提案された。（文献） ［８，
Ｋ、 Ｗｕ 等。rz and K, A, Muller, Ze tshrift f.
(I rphysik B)-Condensed
Matter 64.189-193 (1986)
]. Furthermore, ]Y-Ba-Cu-0 was recently proposed to be a higher temperature superconducting material. (Reference) [8,
K., Wu et al.
フィジカルレビュー レターズ（Ｐｈｙｓｉｃａｌ Ｒ
ｅｖｉｅｗ Ｌｅｔｔｅｒｓ） Ｖｏｌ、５８ Ｎｏ９
．９０８−９１０ （１９８７） ］さらに、］Ｂ１−
８ｒ−Ｃａ−Ｃｕ−０の材料が１００に以上の転移温度
を示すことも発見された。Physical Review Letters (Physical R
(view Letters) Vol, 58 No9
．． 908-910 (1987)]Furthermore,]B1-
It has also been discovered that the 8r-Ca-Cu-0 material exhibits a transition temperature of over 100°C.
この種の材料の超電導機構の詳細は明らかではないが、
転移温度が液体窒素温度以上に高くなる可能性があり、
高温超電導体として従来の３元系化合物より、より有望
な特性が期待される。Although the details of the superconducting mechanism of this type of material are not clear,
The transition temperature can be higher than liquid nitrogen temperature,
It is expected to have more promising properties as a high-temperature superconductor than conventional ternary compounds.
発明が解決しよとする課題
しかしながら、Ｂ１−５ｒ−Ｃａ−Ｃｕ Ｏ系の材料
は、現在の技術では焼結という過程でしか形成できない
ため、セラミックの粉末あるいはブロックの形状でしか
得られない。一方、この種の材料を実用化する場合、薄
膜状に加工することが強（要望されているが、従来の技
術では、薄膜化は非常に困難とされている。Problems to be Solved by the Invention However, B1-5r-Ca-CuO-based materials can only be formed through the process of sintering using current technology, and therefore can only be obtained in the form of ceramic powder or blocks. On the other hand, if this type of material is to be put to practical use, it is highly desirable to process it into a thin film, but with conventional techniques, it is considered extremely difficult to process the material into a thin film.
本発明者らは、この種の材料の薄膜をイオンプロセスに
より付着させると、薄膜状の高温超電体が形成されるこ
とを発見し、これにもとづいて薄膜超電導体の製造方法
を発明した。The present inventors have discovered that when a thin film of this type of material is deposited by an ion process, a thin film-like high temperature superconductor is formed, and based on this discovery, they have invented a method for producing a thin film superconductor.
課題を解決するための手段
本発明の製造方法で形成する薄膜超電導体の基本構成は
、基体表面に主成分がＢｉ、Ｓｒ、Ｃａｌ Ｃｕ、Ｏの
４元化合物被膜を付着させた層状構造を特徴としている
。本発明者らこの種の層状構造超電導体は、加熱された
基体上に、主成分がＢｉ、Ｓｒ、Ｃａ、Ｃｕ、Ｏである
複合化合物被膜を例えば蒸着というプロセスで付着させ
、さらに酸化性雰囲気で熱処理することにより、形成さ
れることを見い出し発明に致ったものである。Means for Solving the Problems The basic structure of the thin film superconductor formed by the manufacturing method of the present invention is characterized by a layered structure in which a quaternary compound coating containing Bi, Sr, Cal Cu, and O as main components is adhered to the surface of the substrate. It is said that The present inventors have developed this type of layered structure superconductor by depositing a composite compound film containing Bi, Sr, Ca, Cu, and O as main components on a heated substrate, for example, by a process called vapor deposition, and then depositing it in an oxidizing atmosphere. The present invention was based on the discovery that it can be formed by heat treatment.
作用
本発明にかかる薄膜超電導体の製造方法は、特定の組成
の超電導体を薄膜化している所に大きな特色がある。す
なわち、薄膜化は超電導体の素材を原子状態という極微
粒子に分解してから基体上に堆積させるから、形成され
た超電導体の組成は本質的に、従来の焼結体に比べて均
質である。したがってＢｉ、Ｓｒ、Ｃａ、Ｃｕ、Ｏ薄膜
よりなる非常に高精度の超電導体が本発明の方法を用い
て実現される。Function: The method for manufacturing a thin film superconductor according to the present invention is characterized in that a superconductor having a specific composition is made into a thin film. In other words, because film thinning involves decomposing the superconductor material into ultrafine particles in the atomic state and then depositing them on the substrate, the composition of the formed superconductor is essentially more homogeneous than that of conventional sintered bodies. . Therefore, very high precision superconductors consisting of Bi, Sr, Ca, Cu, O thin films are realized using the method of the invention.
実施例 本発明の実施例を図面とともに説明する。Example Embodiments of the present invention will be described with reference to the drawings.
、 第１図において、４元化合物被膜１２は、例えばス
パッタリング法で形成する。この場合、基体１１は、超
電導を示す４元化合物被膜１２の保持を目的としている
。したがって、本発明の超電導体は本質的に層状構造か
らなっている。この層状構造は通常数８００〜９００℃
の高温で形成し、超電導を例えば液体窒素温度（−１９
５°Ｃ）の低温で動作させるため、特に基体１１と被膜
１２の密着性が悪（なり、しばしば層状構造が破損され
ることを本発明者らは確認した。さらに本発明者らは、
詳細な基体の熱的特性を各種の材質について調べた結果
、基体の線熱彫版係数α＞１０−’／ｅであれば、上記
層状構造の破損がな（、実用されることを確認した。例
えばα＜ １０−６／ｅの石英ガラスを基体に用いると
、被膜１２は無数の亀裂が入り不連続な被膜となり、実
用に供しにくいことを本発明者らは確認した。In FIG. 1, the quaternary compound film 12 is formed by, for example, a sputtering method. In this case, the substrate 11 is intended to hold a quaternary compound coating 12 exhibiting superconductivity. The superconductor of the invention therefore essentially consists of a layered structure. This layered structure usually has a temperature of several 800 to 900 degrees Celsius.
For example, superconductivity is formed at high temperatures of liquid nitrogen (-19
The present inventors have confirmed that due to the operation at a low temperature of 5° C., the adhesion between the substrate 11 and the coating 12 is particularly poor, and the layered structure is often damaged.
As a result of examining the detailed thermal characteristics of the substrate for various materials, it was confirmed that if the linear thermal engraving coefficient α>10-'/e of the substrate, the layered structure described above would not be damaged (and could be used in practical use). For example, the present inventors have confirmed that if quartz glass with α<10-6/e is used as the substrate, the coating 12 will have numerous cracks and become a discontinuous coating, making it difficult to put it to practical use.
さらに、本発明者らは、第１図の層状構造の基体１１に
機能性から見て、最適の材料があることを見い出した。Furthermore, the present inventors have discovered that there is an optimal material for the layered structure substrate 11 shown in FIG. 1 from the viewpoint of functionality.
すなわち、結晶性の高い４元化合物被膜１２を基体１１
の表面１３に形成させるためには、単結晶の基体が有効
である。本発明者らは詳細に最適基体材料を調べた結果
、基体１１として、酸化マグネシウム、サファイア（α
−Ａｌ２Ｏ３）、スピネル、チタン酸ストロンチウユウ
ム、シリコン、ガリウム砒素等の単結晶が有効であるこ
とを確認した。もっとも、これは表面１３に効果的に結
晶性の高い被膜１２を成長させるためのものであるから
、少なくとも基体表面１３が単結晶であればよい。That is, the highly crystalline quaternary compound coating 12 is applied to the substrate 11.
A single crystal substrate is effective for forming it on the surface 13 of. As a result of detailed investigation into the optimal substrate material, the present inventors found that the substrate 11 was made of magnesium oxide, sapphire (α
-Al2O3), spinel, strontium titanate, silicon, gallium arsenide, and other single crystals were confirmed to be effective. However, since this is for effectively growing a highly crystalline coating 12 on the surface 13, it is sufficient if at least the substrate surface 13 is a single crystal.
本発明者らは、この種の超電導体を任意の形状例えば円
筒状に加工する場合、基体としては単結晶よりも、所謂
焼結磁器が有効であることを確認するともに、最適の磁
器材料を見い出した。すなわち、磁器基体として、アル
ミナ、酸化マグルシウム、酸化ヂルコニウム、ステアタ
イト、ホルステライト、ヘリリア、スピネル等が基体の
加工等、超電導被膜１２の基体１１への密着性が最適で
あることを本発明者らは確認した。この場合も単結晶と
同様に、基体の表面さえこの種の磁器で構されていると
よい。The present inventors have confirmed that so-called sintered porcelain is more effective as a substrate than a single crystal when processing this type of superconductor into an arbitrary shape, such as a cylinder, and have also found the most suitable porcelain material. I found it. That is, the present inventors have found that alumina, maglucium oxide, zirconium oxide, steatite, forsterite, heliaria, spinel, etc. are used as the porcelain substrate to provide optimal adhesion of the superconducting coating 12 to the substrate 11 during processing of the substrate. confirmed. In this case as well, it is preferable that even the surface of the substrate is made of this type of porcelain, as in the case of single crystals.
薄膜超電導体の形成には、まずＢｉ、Ｓｒ、Ｃａ、Ｃｕ
、Ｏ成分の複合化合物被膜をスパッタリング蒸着あるい
は熱蒸着例えば電子ビーム蒸着、レーザビーム蒸着等の
物理的気相成長法で基体上に付着させる。この場合、複
合化合物被膜は、成・分Ｂｉ、Ｓｒ、ＣａおよびＣｕの
化学量論比さえ合致していればよ（、酸素量は特に重要
ではなとことを本発明者らは確認した。その結果複合化
合物被膜の形成法は物理的気相成長法に限定されたもの
ではなく、化学的気相成長法例えば常圧あるいは減圧化
学的気相成長法、プラズマ化学的気相成長法、光化学的
気相成長法も、合致させれば、有効であることを本発明
者らは確認した。To form a thin film superconductor, first Bi, Sr, Ca, Cu
, O component is deposited on the substrate by physical vapor deposition methods such as sputtering deposition or thermal evaporation, such as electron beam evaporation or laser beam evaporation. In this case, the composite compound film only needs to match the stoichiometric ratios of the components Bi, Sr, Ca, and Cu (the present inventors have confirmed that the amount of oxygen is not particularly important). As a result, methods for forming composite compound films are not limited to physical vapor deposition, but also chemical vapor deposition, such as atmospheric or reduced pressure chemical vapor deposition, plasma chemical vapor deposition, photochemical vapor deposition, and photochemical vapor deposition. The present inventors have confirmed that a chemical vapor phase growth method is also effective if matched.
本発明者らは複合化合物被膜を基体１１の表面１３に付
着させる場合、基体の最適の温度範囲が存在することを
本発明者らは確認した。すなわち基体最適温度範囲は１
００〜１０００℃である。The present inventors have confirmed that when a composite compound coating is applied to the surface 13 of the substrate 11, there is an optimum temperature range for the substrate. In other words, the optimum temperature range for the substrate is 1
00-1000°C.
なお、１００℃以下では、基体表面への複合酸化物被膜
の付着性が悪くなる。また、１０００℃以上では複合酸
化物被膜中の成分３ ｉ、Ｓ ｒ、ＣａおよびＣｕの化
学量論比からのずれが太き（なる。Note that below 100°C, the adhesion of the composite oxide film to the substrate surface deteriorates. Further, at temperatures above 1000°C, the deviation from the stoichiometric ratio of components 3i, Sr, Ca, and Cu in the composite oxide film becomes large.
ところで、このＢｉ、Ｓｒ、Ｃａ、Ｃｕ、Ｏ系複合化合
物の超電導特性は、その組成と作製条件により転移温度
が１００ Ｋ以下の相と１００に以上の相を示す。これ
らの相は、複合化合物被膜を付着させる時の基体の温度
を６００℃以上とすることにより、１００に以上の複合
酸化物被膜の特性に対する再現性が良くなることを本発
明者らは確認した。By the way, the superconducting properties of this Bi, Sr, Ca, Cu, O-based composite compound exhibit a phase with a transition temperature of 100 K or less and a phase with a transition temperature of 100 K or more, depending on its composition and manufacturing conditions. The present inventors have confirmed that the reproducibility of the properties of the composite oxide film of 100 or higher can be improved by setting the temperature of the substrate at 600°C or higher when attaching the composite compound film to these phases. .
しかしながら作製した被膜は、そのままは良好な超電導
転移特性を示さない。However, the produced film does not exhibit good superconducting transition characteristics as it is.
本発明者らはこの種の複合化合物被膜をさらに空気、ア
ルゴンと酸素チッソお酸素の混合ガスあるいは純酸素な
どの酸化性雰囲気で熱処理することにより、超電導が発
生することを発見した。この場合最適の熱処理温度は６
００〜１０００ ’Ｃ。The present inventors have discovered that superconductivity can be generated by further heat-treating this type of composite compound film in an oxidizing atmosphere such as air, a mixed gas of argon, oxygen, nitrogen, and oxygen, or pure oxygen. In this case, the optimal heat treatment temperature is 6
00-1000'C.
熱処理時間は１〜１００時間である。The heat treatment time is 1 to 100 hours.
以下本発明の内容をさらに深く理解されるために、さら
に具体的な具体実施例を示す。In order to further understand the content of the present invention, more specific examples will be shown below.
（具体実施例）
酸化マグネシウム単結晶（１００）面を基体１１として
用い、高周波ブレナーマグネトロンスパッタにより、焼
結したＢ １−３ｒ−Ｃａ−Ｃｕ−０ターゲツトをＡｒ
と酸素の混合ガス雰囲気でスパッタリング蒸着して、上
記基体上に結晶性のＢｉ −８ｒ−Ｃａ−Ｃｕ−０被膜
として付着させ７１状構造を形成した。(Specific Example) Using a magnesium oxide single crystal (100) plane as the substrate 11, a sintered B1-3r-Ca-Cu-0 target was sputtered with Ar by high-frequency Brenner magnetron sputtering.
A crystalline Bi-8r-Ca-Cu-0 film was deposited on the substrate by sputtering in a mixed gas atmosphere of and oxygen to form a 71-shaped structure.
この場合、Ａｒと酸素の混合ガス圧力は０．５Ｐａ、ス
パッタリング電力１５０Ｗ、スパッタリング時間１時間
、被膜の膜厚０．５μｍ、基体温度７００℃であった。In this case, the mixed gas pressure of Ar and oxygen was 0.5 Pa, the sputtering power was 150 W, the sputtering time was 1 hour, the film thickness was 0.5 μm, and the substrate temperature was 700° C.
形成された被膜に対し、その温度を７００°Ｃとし、形
成装置内に酸素を含んだガスを引き継ぎ導入して、１時
間熱処理した。The formed film was heat-treated for 1 hour at a temperature of 700° C. and an oxygen-containing gas was introduced into the forming apparatus.
又同様に形成された被膜を装置より取り出し、空気中で
８８０℃ １時間熱処理後３時間で除冷した。Further, a similarly formed film was taken out from the apparatus, heat-treated in air at 880° C. for 1 hour, and then slowly cooled for 3 hours.
この実施例では被膜の膜厚は０．５μｍであるが、膜厚
は０．１μｍかそれ以下の薄い場合、ｌＯμ−以上の厚
い場合も超電導が発生することを確認した。In this example, the film thickness of the film is 0.5 μm, but it was confirmed that superconductivity occurs even when the film thickness is as thin as 0.1 μm or less, or as thick as 10 μm or more.
本発明者らは、酸化マグネシウム以外の結晶性基体につ
いての有効性を詳細に実験的に調べた。The present inventors experimentally investigated in detail the effectiveness of crystalline substrates other than magnesium oxide.
スピネル単結晶基体上に、Ｂｉ、Ｓｒ、Ｃａ、Ｃｕ、Ｏ
系の被膜を、酸化マグネシウム単結晶の場合と同様にス
パッタリング蒸着法で付着させ、これらの被膜を空気中
で８８０℃１時間熱処理後３時間除冷するといずれも超
電導を示すことが確認された。また、チタン酸ストロン
チュウム、シリコン、ガリウム砒素単結晶についても同
様の結果が得られた。Bi, Sr, Ca, Cu, O on spinel single crystal substrate
The system coatings were deposited by sputtering vapor deposition in the same manner as the magnesium oxide single crystal, and when these coatings were heat-treated in air at 880°C for 1 hour and then slowly cooled for 3 hours, it was confirmed that they all exhibited superconductivity. Similar results were also obtained for strontium titanate, silicon, and gallium arsenide single crystals.
Ｂ ＋ ＋ Ｓ ｒ ｒ Ｃａ ｅ Ｃｕ ｅ Ｏ系の
超電導材料の構造は複雑であり、まだわかっていない。The structure of B + + S r r Ca e Cu e O-based superconducting materials is complex and not yet understood.
単結晶基体に基体温度をエピタキシャル温度以上にあげ
た場合１作製条件により意図した結晶相が得られない場
合が多い。したがって、基体温度はむしろ低い範囲に選
らびアモルファスないしは微結晶構造の複合化合物被膜
を形成した後熱処理により結晶化する方が再現性よ（超
電導特性が得られることを本発明者らは実験的に確認し
た。When the temperature of a single-crystal substrate is raised above the epitaxial temperature, the intended crystal phase cannot be obtained in many cases depending on the manufacturing conditions. Therefore, it is better to select the substrate temperature in a low range, form a complex compound film with an amorphous or microcrystalline structure, and then crystallize it by heat treatment. confirmed.
この場合、単結晶構造の基体は熱処理過程において、被
膜の固相エピタキシャル成長を助は有効である。特に基
体上にアモルファス状態の被膜をあらかじめ形成し、こ
れを熱処理すると基板単結晶材料を適切に選択すること
により、結晶性基体表面に効果的に結晶性の被膜が固相
エピタキシャルし、超電導特性の優れた薄膜の形成に有
効であることを本発明者らは確認した。なお、超電導被
膜の結晶性が特に要求されない場合（急峻な超電導転位
が不要の時）は、多結晶の磁器基体が有効である。In this case, the substrate having a single crystal structure is effective in assisting the solid phase epitaxial growth of the coating during the heat treatment process. In particular, by forming an amorphous film on the substrate in advance and heat-treating it, by appropriately selecting the single crystal material of the substrate, the crystalline film can be effectively solid-phase epitaxially formed on the surface of the crystalline substrate, and the superconducting properties can be improved. The present inventors have confirmed that this method is effective in forming an excellent thin film. Note that when crystallinity of the superconducting film is not particularly required (when steep superconducting dislocations are not required), a polycrystalline ceramic substrate is effective.
この種の酸化物被膜のスパッタリング蒸着では例えばＡ
ｒと０２との混合ガスをスパッタリングガスに用いる。In sputtering deposition of this type of oxide film, for example, A
A mixed gas of r and 02 is used as the sputtering gas.
このほか実験的に、Ａ ｒ 、Ｘ ｅ ＊Ｎｅ、Ｋｒの
ような不活性ガスあるいはこれらの不活性ガスの混合ガ
スがスパッタリングガスとして有効であることを本発明
者らは確認した。In addition, the present inventors have experimentally confirmed that inert gases such as Ar, Xe*Ne, and Kr, or a mixed gas of these inert gases, are effective as sputtering gases.
スパッタリング蒸着方式も、二極スパッタ、高周波二極
スパッタ、直流二極スパッタ、マグネトロンスパッタい
ずれも有効であることを本発明者らは確認した。特に直
流スパッタの場合、スパッタリングターゲラ、トの抵抗
率を１０−３Ω備以下に低くする事が必要で、これ以上
の抵抗率では、充分なスパッタリング放電が発生しない
。なお、ターゲットの抵抗率の調整は通常ターゲットの
焼結条件によって行う。The present inventors have confirmed that all sputtering vapor deposition methods such as bipolar sputtering, high-frequency bipolar sputtering, DC bipolar sputtering, and magnetron sputtering are effective. Particularly in the case of DC sputtering, it is necessary to lower the resistivity of the sputtering target layer to less than 10@-3 Ω; if the resistivity is higher than this, sufficient sputtering discharge will not occur. Note that the resistivity of the target is usually adjusted by adjusting the sintering conditions of the target.
特にこの種の装置では、直流スパッタがスパッタ電力等
の精密制御に有効であり、また直′流マグネトロンスパ
ッタ、あるいは直流マグネトロンスパッタガンなどが特
に有効であることを本発明者らは確認した。Particularly in this type of apparatus, the present inventors have confirmed that DC sputtering is effective for precise control of sputtering power, etc., and that DC magnetron sputtering or a DC magnetron sputter gun is particularly effective.
なお、基体表面に′複合化合物被膜の形成法として、金
属主成分を物理的気相成長法で基体上に付着させ、さら
に酸素ビームあるいは酸素イオンを被膜形成中に被膜に
照射し、基体表面で金属主成分を酸化させることも可能
である。物理的気相成長法としては、スパッタリング以
外に熱蒸着例えば電子ビームを照射しながら、複合酸化
物被膜の合金主成分をターゲットとしてスパッタリング
蒸着する。この場合複合酸化物ターゲットとしてスパッ
タリング蒸着するよりも被膜形成速度が１桁以上速い特
長を示し、工業的により有効である。In addition, as a method for forming a composite compound film on the surface of a substrate, the main component of the metal is deposited on the substrate by physical vapor deposition, and then an oxygen beam or oxygen ions are irradiated onto the film during film formation. It is also possible to oxidize the metal main component. In addition to sputtering, the physical vapor deposition method includes thermal evaporation, for example, sputtering deposition using the main alloy component of the composite oxide film as a target while irradiating with an electron beam. In this case, the film formation rate is more than an order of magnitude faster than sputtering vapor deposition using a composite oxide target, and it is industrially more effective.
この種の被膜の結晶構造など詳細な特性は、基体上に被
膜が拘束されているため、被膜内には通常の焼結体では
存在しない様な大きな歪とか欠陥が存在する。このため
、焼結体の製造方法から被膜の製造方法を類推できるも
のでない。なお、被膜の熱処理の物理的な意味の詳細は
明らかではないが、おおよそつぎにように考えられる。The detailed characteristics of this type of coating, such as its crystal structure, are such that because the coating is constrained on the substrate, there are large strains and defects within the coating that do not exist in ordinary sintered bodies. For this reason, it is not possible to infer the method of manufacturing the coating from the method of manufacturing the sintered body. Although the details of the physical meaning of the heat treatment of the film are not clear, it can be roughly considered as follows.
すなわち、スパッタリング蒸着等で基体上に付着させた
複合化合物被膜では、Ｂ１−８ｒ−Ｃａ−Ｃｕ −Ｏの
化合物を形成していない。この場合、例えば（Ｓｒ、Ｃ
ａ）Ｃｕｂ３正方晶のペロブスカイト構造のネットワー
ク中にＡ元素の酸化物が分散した複合酸化物を形成して
いる。超電導は、層状ペロブスカイト構造の発生に起因
し、この過程が熱処理に関連する。なお、熱処理時間が
１時間以下で超電導性が得られないのは、転移温度１０
０に以上の結晶相の生成が不充分であった事に起因して
いると考えられる。なお、熱処理は通常のヒータ加熱炉
により行なったが、レーザ光、赤外線等の工学的熱処理
方法あるいは電子線による加熱方法等が応用可能である
。That is, the composite compound film deposited on the substrate by sputtering vapor deposition or the like does not form the compound B1-8r-Ca-Cu-O. In this case, for example (Sr, C
a) A complex oxide is formed in which the oxide of element A is dispersed in a network of Cub3 tetragonal perovskite structure. Superconductivity results from the generation of layered perovskite structures, and this process is associated with heat treatment. It should be noted that superconductivity cannot be obtained when the heat treatment time is less than 1 hour because the transition temperature is 10
This is thought to be due to insufficient formation of crystalline phases of 0 or more. Although the heat treatment was carried out using an ordinary heater heating furnace, it is also possible to apply an engineering heat treatment method using laser light, infrared rays, etc., or a heating method using an electron beam.
この種の４元化合物超電導体Ｂ１−８ｒ−Ｃａ−Ｃｕ−
０の構成元素Ｂｉ、ＳｒおよびＣａの変化による超電導
特性の変化の詳細は明らかではない。ただＢは、３価＋
Ｓ ｒ ＋ Ｃａは２価を示しているのは事実ではあ
る。This type of quaternary compound superconductor B1-8r-Ca-Cu-
The details of changes in superconducting properties due to changes in the constituent elements Bi, Sr, and Ca of 0 are not clear. However, B is trivalent +
It is true that S r + Ca indicates divalence.
発明の効果 とりわけ、本発明にかかる超電導体は、Ｂｉ。Effect of the invention In particular, the superconductor according to the present invention is made of Bi.
Ｓｒ、Ｃａ、Ｃｕ、Ｏよりなる超電導体を薄膜化してい
る所に大きな特色がある。すなわち、薄膜化は超電導体
の素材を原子状態という極微粒子に分解してから、基体
上に堆積させるから、形成された超電導体の組成は本質
的に、従来の焼結体に比べて均質である。したがって、
非常に高精度の超電導体が本発明で実現される。A major feature is that the superconductor made of Sr, Ca, Cu, and O is made into a thin film. In other words, in thin film formation, the superconductor material is decomposed into ultrafine particles in the atomic state and then deposited on the substrate, so the composition of the formed superconductor is essentially more homogeneous than that of conventional sintered bodies. be. therefore,
Superconductors of very high precision are realized with the present invention.
以上の説明のごとく本発明の薄膜超電導体の製造方法に
よると、例えば結晶性基体上に薄膜状で形成されるので
焼結体より本質的により精度が高い上ＳｉあるいはＧａ
Ａｓなどのデバイスとの集積化が可能であるとともに、
ジョセフソン素子など各種の超電導デバイスの製造に実
用される。特にこの種の化合物超電導体の転移温度が室
温になる可能性もあり、従来の実用の範囲は広（、本発
明の工業的価値は高い。As explained above, according to the method for producing a thin film superconductor of the present invention, it is formed in the form of a thin film on a crystalline substrate, so it is essentially more accurate than a sintered body, and is made of Si or Ga.
It is possible to integrate devices such as As, and
It is used in the production of various superconducting devices such as Josephson elements. In particular, the transition temperature of this type of compound superconductor may be room temperature, so the range of conventional practical use is wide (and the industrial value of the present invention is high).
図は本発明の一実施例の薄膜超電導体の製造方法で形成
した薄膜超電導体の基本構成図である。
１１・・・基体、１２・・・４元化合物被膜。The figure is a basic configuration diagram of a thin film superconductor formed by a method for manufacturing a thin film superconductor according to an embodiment of the present invention. 11... Substrate, 12... Quaternary compound coating.
Claims (8)
ある複合化合物被膜を付着させ、さらに上記被膜を熱処
理することを特徴とする薄膜超電導体の製造方法。(1) A method for producing a thin film superconductor, which comprises depositing a composite compound coating whose main components are Bi, Sr, Ca, Cu, and O on a substrate, and further heat-treating the coating.
で構成したことを特徴とする特許請求の範囲第１項記載
の薄膜超電導体の製造方法。(2) The method for manufacturing a thin film superconductor according to claim 1, wherein the substrate is made of a material having a coefficient of linear expansion α>10^-^6/°C.
ｌ＿２Ｏ＿３）、スピネル、チタン酸ストロンチュウム
、シリコン、ガリウム砒素等の単結晶の少なくとも一種
で構成したことを特徴とする特許請求の範囲第１項記載
の薄膜超電導体の製造方法。(3) The substrate is magnesium oxide, sapphire (α-A
2. The method for producing a thin film superconductor according to claim 1, wherein the thin film superconductor is made of at least one of single crystals such as 1_2O_3), spinel, strontium titanate, silicon, and gallium arsenide.
コニウム、ステアタイト、ホルステライト、ベリリア、
スピネル等の磁器で構成したことを特徴とする特許請求
の範囲第１項記載の薄膜超電導体の製造方法。(4) The base material is alumina, magnesium oxide, zirconium oxide, steatite, forsterite, beryllia,
A method for manufacturing a thin film superconductor according to claim 1, characterized in that the thin film superconductor is made of porcelain such as spinel.
等の物理的気相成長法もしくは、常圧あるいは減圧化学
的気相成長法、プラズマ化学的気相成長法、光化学的気
相成長法等の化学的気相成長法で基体上に付着させるこ
とを特徴とする特許請求の範囲第１項記載の薄膜超電導
体の製造方法。(5) The composite compound film is formed by physical vapor deposition methods such as sputtering vapor deposition or thermal evaporation, or by atmospheric or low pressure chemical vapor deposition methods, plasma chemical vapor deposition methods, photochemical vapor deposition methods, etc. 2. A method for producing a thin film superconductor according to claim 1, wherein the thin film superconductor is deposited on a substrate by chemical vapor deposition.
度を６００℃以上に設定することを特徴とする特許請求
の範囲第５項記載の薄膜超電導体の製造方法。(6) A method for manufacturing a thin film superconductor according to claim 5, characterized in that in sputtering deposition, the substrate temperature is set at 600° C. or higher during film deposition.
く形成工程に引き継ぎ少なくとも酸素を含むガスを被膜
形成装置に導入し、基体温度を２００〜９００℃の範囲
内に設定することを特徴とする特許請求の範囲第５項記
載の薄膜超電導体の製造方法。(7) The formed composite compound film is transferred to the forming process without being exposed to air, and a gas containing at least oxygen is introduced into the film forming apparatus, and the substrate temperature is set within the range of 200 to 900°C. A method for manufacturing a thin film superconductor according to claim 5.
含むガスを用い、基板温度を６００℃以上に設定するこ
とを特徴とする特許請求の範囲第１項記載の薄膜超電導
体の製造方法。(8) The method for manufacturing a thin film superconductor according to claim 1, wherein in the heat treatment, a gas containing at least oxygen is used as an atmosphere, and the substrate temperature is set at 600° C. or higher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63032238A JPH01208327A (en) | 1988-02-15 | 1988-02-15 | Production of thin film of superconductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63032238A JPH01208327A (en) | 1988-02-15 | 1988-02-15 | Production of thin film of superconductor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01208327A true JPH01208327A (en) | 1989-08-22 |
Family
ID=12353409
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63032238A Pending JPH01208327A (en) | 1988-02-15 | 1988-02-15 | Production of thin film of superconductor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01208327A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01212227A (en) * | 1988-02-17 | 1989-08-25 | Nippon Telegr & Teleph Corp <Ntt> | Oxide superconducting material |
| JPH01235103A (en) * | 1988-03-15 | 1989-09-20 | Toray Ind Inc | Superconducting material |
| JPH01252534A (en) * | 1988-03-31 | 1989-10-09 | Mitsui Mining & Smelting Co Ltd | Laminate of superconducting ceramics and production thereof |
| JPH01252536A (en) * | 1988-03-31 | 1989-10-09 | Matsushita Electric Ind Co Ltd | Superconductor |
| JPH0288773A (en) * | 1988-09-27 | 1990-03-28 | Fujitsu Ltd | Formation of oxide superconducting film using chemical vapor growth |
| WO1990003453A1 (en) * | 1988-09-28 | 1990-04-05 | Oki Electric Industry Co., Ltd. | Process for forming superconducting thin film |
-
1988
- 1988-02-15 JP JP63032238A patent/JPH01208327A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01212227A (en) * | 1988-02-17 | 1989-08-25 | Nippon Telegr & Teleph Corp <Ntt> | Oxide superconducting material |
| JPH01235103A (en) * | 1988-03-15 | 1989-09-20 | Toray Ind Inc | Superconducting material |
| JPH01252534A (en) * | 1988-03-31 | 1989-10-09 | Mitsui Mining & Smelting Co Ltd | Laminate of superconducting ceramics and production thereof |
| JPH01252536A (en) * | 1988-03-31 | 1989-10-09 | Matsushita Electric Ind Co Ltd | Superconductor |
| JP2517055B2 (en) * | 1988-03-31 | 1996-07-24 | 松下電器産業株式会社 | Superconductor |
| JPH0288773A (en) * | 1988-09-27 | 1990-03-28 | Fujitsu Ltd | Formation of oxide superconducting film using chemical vapor growth |
| JP2551983B2 (en) * | 1988-09-27 | 1996-11-06 | 富士通株式会社 | Preparation method of oxide superconducting film using chemical vapor deposition |
| WO1990003453A1 (en) * | 1988-09-28 | 1990-04-05 | Oki Electric Industry Co., Ltd. | Process for forming superconducting thin film |
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