JPH04299878A - Method for laminating thin films of different material on oxide superconducting thin film - Google Patents
Method for laminating thin films of different material on oxide superconducting thin filmInfo
- Publication number
- JPH04299878A JPH04299878A JP3089617A JP8961791A JPH04299878A JP H04299878 A JPH04299878 A JP H04299878A JP 3089617 A JP3089617 A JP 3089617A JP 8961791 A JP8961791 A JP 8961791A JP H04299878 A JPH04299878 A JP H04299878A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- oxide superconducting
- oxide
- superconducting thin
- laminating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000010409 thin film Substances 0.000 title claims description 100
- 238000000034 method Methods 0.000 title claims description 38
- 238000010030 laminating Methods 0.000 title claims description 13
- 239000000463 material Substances 0.000 title claims description 13
- 239000002887 superconductor Substances 0.000 claims description 35
- 238000010438 heat treatment Methods 0.000 claims description 19
- 239000010408 film Substances 0.000 claims description 14
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- 239000000356 contaminant Substances 0.000 claims description 7
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 239000001301 oxygen Substances 0.000 claims description 7
- 230000015572 biosynthetic process Effects 0.000 claims description 3
- 230000008020 evaporation Effects 0.000 claims description 2
- 238000001704 evaporation Methods 0.000 claims description 2
- 239000000758 substrate Substances 0.000 description 7
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 238000007740 vapor deposition Methods 0.000 description 4
- 239000002184 metal Substances 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 238000004544 sputter deposition Methods 0.000 description 3
- 229910015901 Bi-Sr-Ca-Cu-O Inorganic materials 0.000 description 2
- 229910002480 Cu-O Inorganic materials 0.000 description 2
- 229910009203 Y-Ba-Cu-O Inorganic materials 0.000 description 2
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 238000000608 laser ablation Methods 0.000 description 2
- 238000000004 low energy electron diffraction Methods 0.000 description 2
- 238000001069 Raman spectroscopy Methods 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000001039 wet etching 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
- Superconductors And Manufacturing Methods Therefor (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Containers, Films, And Cooling For Superconductive Devices (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【０００１】0001
【産業上の利用分野】本発明は、酸化物超電導薄膜上に
異なる材料の薄膜を積層する方法に関する。より詳細に
は、酸化物超電導体で構成された酸化物超電導薄膜上に
、異なる材料で構成された薄膜を積層する方法に関する
。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laminating thin films of different materials on an oxide superconducting thin film. More specifically, the present invention relates to a method of laminating a thin film made of a different material on an oxide superconducting thin film made of an oxide superconductor.
【０００２】0002
【従来の技術】酸化物超電導体は、従来の金属系超電導
体に比較して臨界温度が高く、実用性がより高いと考え
られている。例えば、Ｙ−Ｂａ−Ｃｕ−Ｏ系酸化物超電
導体の臨界温度は８０Ｋ以上であり、Ｂｉ−Ｓｒ−Ｃａ
−Ｃｕ−Ｏ系酸化物超電導体およびＴｌ−Ｂａ−Ｃａ−
Ｃｕ−Ｏ系酸化物超電導体の臨界温度は １００Ｋ以上
と発表されている。2. Description of the Related Art Oxide superconductors have a higher critical temperature than conventional metal-based superconductors and are considered to be more practical. For example, the critical temperature of Y-Ba-Cu-O based oxide superconductor is 80K or higher, and Bi-Sr-Ca
-Cu-O based oxide superconductor and Tl-Ba-Ca-
It has been announced that the critical temperature of Cu-O based oxide superconductors is 100K or higher.
【０００３】酸化物超電導体を各種電子デバイス等に応
用する場合、酸化物超電導体を薄膜化し、積層すること
が必要となる。例えば、トンネル型ジョセフソン接合と
称される超電導接合を酸化物超電導体を使用して実現す
る場合、第１の酸化物超電導薄膜、非超電導体の薄膜お
よび第２の酸化物超電導薄膜を順次積層しなければなら
ない。[0003] When oxide superconductors are applied to various electronic devices, it is necessary to form oxide superconductors into thin films and laminate them. For example, when realizing a superconducting junction called a tunnel Josephson junction using an oxide superconductor, a first oxide superconducting thin film, a non-superconducting thin film, and a second oxide superconducting thin film are sequentially laminated. Must.
【０００４】上記のジョセフソン接合を利用したジョセ
フソン素子は２端子の素子であり、論理回路を構成しよ
うとすると回路が複雑となる。そのため、各種の３端子
の超電導素子が考えられている。３端子の超電導素子の
うちで、超電導体と半導体とを組み合わせた超電導トラ
ンジスタの構成に関しては、各種のものが発表されてい
る。この超電導トランジスタに酸化物超電導体を使用す
る場合には、酸化物超電導薄膜上に半導体薄膜を積層す
る必要性が生じることがある。さらに、超電導体と常電
導体を組み合わせた超電導素子も考えられているが、こ
の超電導素子に酸化物超電導体を使用する場合には、酸
化物超電導薄膜上に金属等の常電導体の薄膜を積層する
ことがある。The Josephson element using the Josephson junction described above is a two-terminal element, and when a logic circuit is constructed, the circuit becomes complicated. Therefore, various three-terminal superconducting elements are being considered. Among three-terminal superconducting elements, various configurations of superconducting transistors that combine a superconductor and a semiconductor have been announced. When using an oxide superconductor in this superconducting transistor, it may be necessary to laminate a semiconductor thin film on the oxide superconducting thin film. Furthermore, superconducting elements that combine a superconductor and a normal conductor are being considered, but if an oxide superconductor is used in this superconducting element, a thin film of a normal conductor such as a metal is coated on the oxide superconducting thin film. May be stacked.
【０００５】上記の各種超電導素子は、いずれも近接さ
せて配置された超電導体間の非超電導体に流れる超電導
電流により動作する。この超電導体間の距離は、該超電
導体のコヒーレンス長によって決まる。酸化物超電導体
は、コヒーレンス長が非常に短いため、酸化物超電導体
を使用した上記の超電導素子では、超電導体間の距離を
数ｎｍ程度にしなければならない。一方、素子としての
特性を考慮すると、上記の超電導素子の各薄膜は結晶性
がよくなければならない。即ち、全ての薄膜が単結晶ま
たは単結晶に近い配向性を有する多結晶であることが好
ましく、結晶方向が全く揃っていない多結晶またはアモ
ルファスの薄膜がある場合には、一般に超電導素子の性
能は安定しない。[0005] The above-mentioned various superconducting elements are all operated by a superconducting current flowing between non-superconductors between superconductors placed close to each other. The distance between the superconductors is determined by the coherence length of the superconductors. Since an oxide superconductor has a very short coherence length, in the above-mentioned superconducting element using an oxide superconductor, the distance between the superconductors must be approximately several nm. On the other hand, in consideration of the characteristics of the device, each thin film of the superconducting device described above must have good crystallinity. That is, it is preferable that all thin films be single crystals or polycrystals with near-single crystal orientation, and if there is a polycrystalline or amorphous thin film whose crystal orientation is not aligned at all, the performance of the superconducting element will generally be poor. Not stable.
【０００６】[0006]
【発明が解決しようとする課題】一般に複数の薄膜を積
層する場合、下層の薄膜の表面を清浄にしてから上層の
薄膜を成長させる。下層の薄膜の表面を清浄にしないと
、下層の薄膜の表面に堆積した汚染物質、下層の薄膜の
表面に形成された酸化物等により界面が一様にならず、
上層の薄膜と下層の薄膜との界面の一部が不連続となっ
てしまう。従って、素子、集積回路の性能が所定の値に
ならなかったり、動作しなかったりすることがある。Generally, when a plurality of thin films are laminated, the surface of the lower thin film is cleaned before the upper thin film is grown. If the surface of the underlying thin film is not cleaned, the interface will not be uniform due to contaminants deposited on the surface of the underlying thin film, oxides formed on the surface of the underlying thin film, etc.
A part of the interface between the upper thin film and the lower thin film becomes discontinuous. Therefore, the performance of the element or integrated circuit may not reach a predetermined value or may not operate.
【０００７】特に酸化物超電導体は、コヒーレンス長が
非常に短いので超電導性が失われ易く、酸化物超電導薄
膜を下層の薄膜としてその上にさらに薄膜を積層する場
合には、酸化物超電導薄膜の表面状態に特に注意を払わ
なければならない。即ち、下層の薄膜として使用する酸
化物超電導薄膜の表面は、清浄であり、結晶性、超電導
性に優れていることが要求される。In particular, oxide superconductors have very short coherence lengths, so they tend to lose their superconductivity. Therefore, when an oxide superconducting thin film is used as a lower layer thin film and another thin film is laminated on top of it, the oxide superconducting thin film is Particular attention must be paid to the surface condition. That is, the surface of the oxide superconducting thin film used as the lower layer thin film is required to be clean and to have excellent crystallinity and superconductivity.
【０００８】従来の半導体を使用した素子、集積回路等
では、下層の薄膜の表面を清浄にするために、純水洗浄
、化学洗浄、ドライエッチング、ウェットエッチング等
の方法が使用されていたが、酸化物超電導体は反応性が
高いので上記の各方法は適用できない。酸化物超電導薄
膜の表面を上記の方法で処理すると、酸化物超電導薄膜
の表面で反応が起こり、かえって薄膜表面の清浄性、結
晶性、超電導性が失われてしまう。In conventional semiconductor elements, integrated circuits, etc., methods such as pure water cleaning, chemical cleaning, dry etching, and wet etching have been used to clean the surface of the underlying thin film. The above methods cannot be applied to oxide superconductors because of their high reactivity. When the surface of an oxide superconducting thin film is treated by the above method, a reaction occurs on the surface of the oxide superconducting thin film, and the cleanliness, crystallinity, and superconductivity of the thin film surface are rather lost.
【０００９】酸化物超電導薄膜を成膜した直後に、同一
の成膜装置を使用して連続的に上層の薄膜を積層する方
法も採用されているが、装置が大型化し、また、上層の
薄膜に使用可能な材料が限定される等の問題がある。Immediately after forming the oxide superconducting thin film, a method has also been adopted in which the upper thin film is successively deposited using the same film forming apparatus, but the apparatus becomes larger and the upper thin film is There are problems such as limitations on the materials that can be used.
【００１０】そこで、本発明の目的は、上記従来技術の
問題点を解決した、酸化物超電導薄膜上に、酸化物超電
導薄膜の各種特性を劣化させないで、さらに薄膜を積層
する方法を提供することにある。SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for laminating a thin film on an oxide superconducting thin film without deteriorating various properties of the oxide superconducting thin film, which solves the problems of the prior art described above. It is in.
【００１１】[0011]
【課題を解決するための手段】本発明に従うと、酸化物
超電導体で構成され、表面に汚染物質がある酸化物超電
導薄膜上に、前記酸化物超電導体と異なる材料で構成さ
れた第２の薄膜を積層する方法において、前記酸化物超
電導薄膜を、純度の高い酸素雰囲気中で、前記汚染物質
の蒸発温度から前記酸化物超電導薄膜の成膜温度までの
範囲の温度に加熱する熱処理を行った後、該酸化物超電
導薄膜上に前記第２の薄膜を成膜することを特徴とする
酸化物超電導薄膜上に異なる材料の薄膜を積層する方法
が提供される。[Means for Solving the Problems] According to the present invention, on an oxide superconducting thin film composed of an oxide superconductor having contaminants on its surface, a second film composed of a material different from the oxide superconductor is provided. In the method of laminating thin films, the oxide superconducting thin film is subjected to heat treatment in a high purity oxygen atmosphere to a temperature ranging from the evaporation temperature of the contaminant to the deposition temperature of the oxide superconducting thin film. There is also provided a method for laminating thin films of different materials on an oxide superconducting thin film, which comprises subsequently forming the second thin film on the oxide superconducting thin film.
【００１２】本発明では、上記酸化物超電導薄膜が、Ｙ
１Ｂａ２Ｃｕ３Ｏ７−Ｘ酸化物超電導体で構成されてい
る場合、前記加熱温度が ３５０〜７００ ℃であるこ
とが好ましい。In the present invention, the oxide superconducting thin film is made of Y
In the case of a 1Ba2Cu3O7-X oxide superconductor, the heating temperature is preferably 350 to 700°C.
【００１３】[0013]
【作用】本発明の方法は、酸化物超電導薄膜上に異なる
材料の薄膜を積層する場合に、下層の酸化物超電導薄膜
を純度の高い酸素中で熱処理して、表面を清浄にしてか
ら上層の薄膜を積層するところにその主要な特徴がある
。本発明の方法は、例えば、酸化物超電導薄膜上に、絶
縁体薄膜や常電導薄膜を積層して超電導素子を作製する
場合に適用できる。本発明の方法では、下層の酸化物超
電導薄膜に対して上層の薄膜を成膜する直前に上記の熱
処理を行う。この熱処理により、下層の酸化物超電導薄
膜の表面に堆積した汚染物質（炭化水素、金属炭化物）
が除去される。また、下層の酸化物超電導薄膜の表面の
結晶性が乱れた部分の結晶性が回復されるとともに、十
分な酸素が供給されて超電導特性も向上する。[Operation] When laminating thin films of different materials on top of an oxide superconducting thin film, the method of the present invention heat-treats the lower oxide superconducting thin film in high-purity oxygen to clean the surface before stacking the upper layer. Its main feature lies in the layering of thin films. The method of the present invention can be applied, for example, to the case where a superconducting element is manufactured by laminating an insulating thin film or a normal conducting thin film on an oxide superconducting thin film. In the method of the present invention, the above-described heat treatment is performed on the lower oxide superconducting thin film immediately before forming the upper thin film. Due to this heat treatment, contaminants (hydrocarbons, metal carbides) deposited on the surface of the underlying oxide superconducting thin film.
is removed. In addition, the crystallinity of the disordered portion of the surface of the underlying oxide superconducting thin film is restored, and sufficient oxygen is supplied, thereby improving the superconducting properties.
【００１４】本発明の方法で使用する高純度酸素は、具
体的には５Ｎ（９９．９９９％）以上の純度で、特にＨ
２ＯおよびＣＯ２が不純物として含まれないものが好ま
しい。
これは、Ｈ２ＯおよびＣＯ２が酸化物超電導体と反応し
易く、特性を劣化させるからである。また、上記の熱処
理の際の酸素分圧は、２０ｍＴｏｒｒ〜 １００Ｔｏｒ
ｒが好ましい。さらに、本発明の方法で、下層の酸化物
超電導薄膜にＹ１Ｂａ２Ｃｕ３Ｏ７−Ｘ薄膜を使用した
場合には、上記の熱処理の際の加熱温度を ３５０〜７
００℃とする。加熱温度が３５０℃未満では再結晶が起
こらず、加熱温度が７００ ℃を越えた場合には逆に薄
膜を構成する酸化物超電導体結晶の配向性が乱れてしま
う。本発明の方法において、上記の熱処理時間は、酸素
分圧および加熱温度により調整する必要があるが、概ね
数分〜数時間の範囲である。The high-purity oxygen used in the method of the present invention specifically has a purity of 5N (99.999%) or higher, and in particular H
Preferably, it does not contain 2O and CO2 as impurities. This is because H2O and CO2 tend to react with the oxide superconductor, deteriorating its properties. Further, the oxygen partial pressure during the above heat treatment is between 20 mTorr and 100 Torr.
r is preferred. Furthermore, in the method of the present invention, when a Y1Ba2Cu3O7-X thin film is used as the lower layer oxide superconducting thin film, the heating temperature during the above heat treatment is 350-7
00℃. If the heating temperature is less than 350°C, recrystallization will not occur, and if the heating temperature exceeds 700°C, the orientation of the oxide superconductor crystals constituting the thin film will be disturbed. In the method of the present invention, the heat treatment time needs to be adjusted by adjusting the oxygen partial pressure and heating temperature, but is generally in the range of several minutes to several hours.
【００１５】本発明の方法に従えば、例えば、空気に触
れるなどして表面が劣化した酸化物超電導薄膜の表面を
清浄にして、その上に異なる材料の薄膜を積層すること
が可能である。従って、酸化物超電導薄膜と他の材料の
薄膜とを、それぞれ異なる成膜装置を使用して最適な条
件で成膜することが可能であり、従来よりも特性の優れ
た積層膜を作製することができる。[0015] According to the method of the present invention, it is possible to clean the surface of an oxide superconducting thin film whose surface has deteriorated due to exposure to air, for example, and to laminate a thin film of a different material thereon. Therefore, it is possible to form an oxide superconducting thin film and a thin film of other materials under optimal conditions using different film forming apparatuses, and it is possible to create a laminated film with better properties than before. Can be done.
【００１６】本発明は、任意の酸化物超電導体に適用す
ることが可能であるが、特にＹ−Ｂａ−Ｃｕ−Ｏ系酸化
物超電導体、Ｂｉ−Ｓｒ−Ｃａ−Ｃｕ−Ｏ系酸化物超電
導体、Ｔｌ−Ｂａ−Ｃａ−Ｃｕ−Ｏ系酸化物超電導体に
適用することが好ましい。これらの酸化物超電導体は、
臨界温度を始めとする各種の超電導特性が現在のところ
最も優れているからである。The present invention can be applied to any oxide superconductor, but is particularly applicable to Y-Ba-Cu-O based oxide superconductors and Bi-Sr-Ca-Cu-O based oxide superconductors. It is preferable to apply the present invention to Tl-Ba-Ca-Cu-O based oxide superconductors. These oxide superconductors are
This is because various superconducting properties including critical temperature are currently the best.
【００１７】以下、本発明を実施例によりさらに詳しく
説明するが、以下の開示は本発明の単なる実施例に過ぎ
ず、本発明の技術的範囲をなんら制限するものではない
。[0017] Hereinafter, the present invention will be explained in more detail with reference to examples. However, the following disclosure is merely an example of the present invention, and is not intended to limit the technical scope of the present invention in any way.
【００１８】[0018]
【実施例】〔実施例１〕本発明の方法により、Ｙ１Ｂａ
２Ｃｕ３Ｏ７−Ｘ酸化物超電導薄膜上にＭｇＯ薄膜を積
層した。図１を参照して、本発明の方法で酸化物超電導
薄膜を積層する手順を説明する。[Example] [Example 1] By the method of the present invention, Y1Ba
A MgO thin film was laminated on the 2Cu3O7-X oxide superconducting thin film. Referring to FIG. 1, the procedure for laminating oxide superconducting thin films using the method of the present invention will be described.
【００１９】まず、図１（ａ）に示すようなＭｇＯ（１
００）基板３の表面に、図１（ｂ）に示すよう厚さ ３
００ｎｍのｃ軸配向のＹ１Ｂａ２Ｃｕ３Ｏ７−Ｘ酸化物
超電導薄膜１をオフアクシススパッタリング法、レーザ
アブレーション法、反応性蒸着法、ＭＢＥ法、ＣＶＤ法
等の方法で成膜する。
オフアクシススパッタリング法で酸化物超電導薄膜を成
膜する場合の成膜条件を以下に示す。First, MgO (1
00) The surface of the substrate 3 has a thickness of 3 as shown in FIG. 1(b).
A c-axis oriented Y1Ba2Cu3O7-X oxide superconducting thin film 1 with a thickness of 00 nm is formed by a method such as an off-axis sputtering method, a laser ablation method, a reactive vapor deposition method, an MBE method, or a CVD method. The film forming conditions for forming an oxide superconducting thin film by off-axis sputtering method are shown below.
【００２０】成膜後、チャンバから取り出すと酸化物超
電導薄膜１の表面は、空気中の水分と反応し、劣化した
部分１０が形成される。また、炭化水素、ＢａＣＯ３
、ＢａＣｕＯ２ 等で汚染されている。超高真空チャン
バに収容して１×１０−９Ｔｏｒｒ以下の高真空に排気
した後、ＬＥＥＤ（低速電子回折）、ＱＭＳ（４重極型
質量分析計）、ＸＰＳ（Ｘ線光電子分光）でモニタしな
がら以下の熱処理を行ったところ、汚染物質は除去され
、図１（ｃ）に示すよう劣化部分１０が消滅し、結晶性
の表面が出現した。
雰 囲 気 Ｏ２ （
５Ｎ以上、分圧２５Ｔｏｒｒ）
加 熱 温 度 ６００℃（基
板温度）処 理 時 間 １
０分間（その後Ｏ２ 雰囲気下で降温）When taken out from the chamber after film formation, the surface of the oxide superconducting thin film 1 reacts with moisture in the air, forming a degraded portion 10. In addition, hydrocarbons, BaCO3
, BaCuO2, etc. After placing it in an ultra-high vacuum chamber and evacuating it to a high vacuum of 1 x 10-9 Torr or less, it was monitored using LEED (low-energy electron diffraction), QMS (quadrupole mass spectrometer), and XPS (X-ray photoelectron spectroscopy). However, when the following heat treatment was performed, the contaminants were removed, the degraded portion 10 disappeared, and a crystalline surface appeared, as shown in FIG. 1(c). Atmosphere O2 (
5N or more, partial pressure 25 Torr) Heating temperature 600℃ (substrate temperature) Processing time 1
0 minutes (then lower temperature under O2 atmosphere)
【００２１】上記の熱処理により、表面が清浄となった
酸化物超電導薄膜１上に図１（ｄ）に示すよう厚さ２０
０ ｎｍのＭｇＯ薄膜を蒸着法で成膜する。成膜条件を
以下に示す。
圧 力 １
０Ｐａ基 板 温 度 ２
００℃上記本発明の方法により作製された積層膜は、下
層および上層いずれの薄膜も結晶性が優れているだけで
なく、界面における整合性がよいことがわかった。As shown in FIG. 1(d), a film with a thickness of 20 mm is deposited on the oxide superconducting thin film 1 whose surface has been made clean by the above heat treatment.
A 0 nm MgO thin film is formed by vapor deposition. The film forming conditions are shown below. pressure 1
0Pa substrate temperature 2
It was found that the laminated film produced by the above method of the present invention not only has excellent crystallinity in both the lower and upper thin films, but also has good consistency at the interface.
【００２２】〔実施例２〕実施例１と同様に本発明の方
法により、Ｙ１Ｂａ２Ｃｕ３Ｏ７−Ｘ酸化物超電導薄膜
上にＡｇ薄膜を積層した。まず、実施例１で使用したも
のと等しいＭｇＯ（１００）基板表面に、厚さ ３００
ｎｍのｃ軸配向のＹ１Ｂａ２Ｃｕ３Ｏ７−Ｘ酸化物超電
導薄膜をオフアクシススパッタリング法、レーザアブレ
ーション法、反応性蒸着法、ＭＢＥ法、ＣＶＤ法等の方
法で成膜する。成膜後、チャンバから取り出して表面が
劣化した酸化物超電導薄膜を超高真空チャンバに収容し
て１×１０−９Ｔｏｒｒ以下の高真空に排気した後、Ｌ
ＥＥＤ（低速電子回折）とＱＭＳ（４重極型質量分析計
）、ＲＡＭＡＮ分光、ＸＰＳ（Ｘ線光電子分光）とＱＭ
Ｓでモニタしながら以下の熱処理を行った。
雰 囲 気 Ｏ２ （
５Ｎ以上、分圧２５Ｔｏｒｒ）
加 熱 温 度 ６００℃（基
板温度）処 理 時 間 １
０分間（その後Ｏ２ 雰囲気下で降温）[Example 2] As in Example 1, an Ag thin film was laminated on a Y1Ba2Cu3O7-X oxide superconducting thin film by the method of the present invention. First, a layer of 300 mm thick was coated on the surface of an MgO (100) substrate, which was the same as that used in Example 1.
A Y1Ba2Cu3O7-X oxide superconducting thin film with a c-axis orientation of nm is formed by a method such as an off-axis sputtering method, a laser ablation method, a reactive vapor deposition method, an MBE method, or a CVD method. After film formation, the oxide superconducting thin film with a deteriorated surface is removed from the chamber and placed in an ultra-high vacuum chamber, and evacuated to a high vacuum of 1 x 10-9 Torr or less.
EED (low energy diffraction) and QMS (quadrupole mass spectrometer), RAMAN spectroscopy, XPS (X-ray photoelectron spectroscopy) and QM
The following heat treatment was performed while monitoring with S. Atmosphere O2 (
5N or more, partial pressure 25 Torr) Heating temperature 600℃ (substrate temperature) Processing time 1
0 minutes (then lower temperature under O2 atmosphere)
【００２３】上記の熱処理により、表面が清浄となった
酸化物超電導薄膜上に厚さ２００ ｎｍのＡｇ薄膜を蒸
着法で成膜する。成膜条件を以下に示す。
圧 力 １
０Ｐａ基 板 温 度 ２
００℃上記本発明の方法により作製された積層膜は、下
層および上層いずれの薄膜も結晶性が優れているだけで
なく、界面における整合性がよいことがわかった。A 200 nm thick Ag thin film is formed by vapor deposition on the oxide superconducting thin film whose surface has been made clean by the above heat treatment. The film forming conditions are shown below. pressure 1
0Pa substrate temperature 2
It was found that the laminated film produced by the above method of the present invention not only has excellent crystallinity in both the lower and upper thin films, but also has good consistency at the interface.
【００２４】[0024]
【発明の効果】以上説明したように、本発明に従えば、
酸化物超電導薄膜上に特性を損なわずに、異なる材料の
薄膜を積層する方法が提供される。本発明の方法により
作製される積層膜は、超電導特性が優れているだけでな
く、界面における整合性も優れている。本発明を超電導
素子、超電導集積回路の作製に応用することにより、従
来得られなかった高性能な超電導装置が作製可能である
。[Effects of the Invention] As explained above, according to the present invention,
A method is provided for stacking thin films of different materials on an oxide superconducting thin film without impairing its properties. The laminated film produced by the method of the present invention not only has excellent superconducting properties but also excellent consistency at the interface. By applying the present invention to the production of superconducting elements and superconducting integrated circuits, it is possible to produce high-performance superconducting devices that have not been previously available.
【図１】本発明の方法で、酸化物超電導薄膜上に異なる
材料の薄膜を積層する工程を説明する図である。FIG. 1 is a diagram illustrating the process of laminating thin films of different materials on an oxide superconducting thin film in the method of the present invention.
１ 酸化物超電導薄膜 ２ ＭｇＯ薄膜 ３ 基板 1 Oxide superconducting thin film 2 MgO thin film 3 Substrate
Claims (2)
染物質がある酸化物超電導薄膜上に、前記酸化物超電導
体と異なる材料で構成された第２の薄膜を積層する方法
において、前記酸化物超電導薄膜を、純度の高い酸素雰
囲気中で、前記汚染物質の蒸発温度から前記酸化物超電
導薄膜の成膜温度までの範囲の温度に加熱する熱処理を
行った後、該酸化物超電導薄膜上に前記第２の薄膜を成
膜することを特徴とする酸化物超電導薄膜上に異なる材
料の薄膜を積層する方法。1. A method of laminating a second thin film made of a material different from the oxide superconductor on an oxide superconducting thin film made of an oxide superconductor and having a contaminant on its surface, the method comprising: After performing a heat treatment in which the oxide superconducting thin film is heated in a high-purity oxygen atmosphere to a temperature ranging from the evaporation temperature of the contaminant to the film formation temperature of the oxide superconducting thin film, A method for laminating thin films of different materials on an oxide superconducting thin film, the method comprising forming the second thin film.
Ｃｕ３Ｏ７−Ｘ酸化物超電導体で構成され、前記加熱温
度が ３５０〜７００ ℃であることを特徴とする請求
項１に記載の酸化物超電導薄膜を積層する方法。2. The oxide superconducting thin film is Y1Ba2
The method for laminating oxide superconducting thin films according to claim 1, characterized in that the oxide superconducting thin film is made of a Cu3O7-X oxide superconductor, and the heating temperature is 350 to 700°C.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3089617A JP2710870B2 (en) | 1991-03-28 | 1991-03-28 | Method of laminating thin films of different materials on oxide superconducting thin film |
| EP92400855A EP0506572B1 (en) | 1991-03-28 | 1992-03-27 | Improved process for preparing a layered structure containing at least one thin film of oxide superconductor |
| DE69219192T DE69219192T2 (en) | 1991-03-28 | 1992-03-27 | Process for producing a layer structure with at least one thin layer of superconductor oxide |
| CA002064273A CA2064273C (en) | 1991-03-28 | 1992-03-27 | Improved process for preparing a layered structure containing at least one thin film of oxide superconductor |
| US08/381,278 US5534491A (en) | 1991-03-28 | 1995-01-31 | Process for preparing a layered structure containing at least one thin film of oxide superconductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3089617A JP2710870B2 (en) | 1991-03-28 | 1991-03-28 | Method of laminating thin films of different materials on oxide superconducting thin film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04299878A true JPH04299878A (en) | 1992-10-23 |
| JP2710870B2 JP2710870B2 (en) | 1998-02-10 |
Family
ID=13975715
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3089617A Expired - Lifetime JP2710870B2 (en) | 1991-03-28 | 1991-03-28 | Method of laminating thin films of different materials on oxide superconducting thin film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2710870B2 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0199269A (en) * | 1987-10-13 | 1989-04-18 | Nippon Telegr & Teleph Corp <Ntt> | Oxide superconductor tunnel junction and forming method thereof |
| JPH01106481A (en) * | 1987-10-20 | 1989-04-24 | Fujitsu Ltd | Superconductive material structure |
| JPH0226831A (en) * | 1988-07-15 | 1990-01-29 | Sumitomo Electric Ind Ltd | Method for manufacturing superconducting materials |
-
1991
- 1991-03-28 JP JP3089617A patent/JP2710870B2/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0199269A (en) * | 1987-10-13 | 1989-04-18 | Nippon Telegr & Teleph Corp <Ntt> | Oxide superconductor tunnel junction and forming method thereof |
| JPH01106481A (en) * | 1987-10-20 | 1989-04-24 | Fujitsu Ltd | Superconductive material structure |
| JPH0226831A (en) * | 1988-07-15 | 1990-01-29 | Sumitomo Electric Ind Ltd | Method for manufacturing superconducting materials |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2710870B2 (en) | 1998-02-10 |
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