JPH04310504A - Production of laminated film - Google Patents
Production of laminated filmInfo
- Publication number
- JPH04310504A JPH04310504A JP3103955A JP10395591A JPH04310504A JP H04310504 A JPH04310504 A JP H04310504A JP 3103955 A JP3103955 A JP 3103955A JP 10395591 A JP10395591 A JP 10395591A JP H04310504 A JPH04310504 A JP H04310504A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- oxide superconducting
- superconducting thin
- oxide
- film
- 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
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 12
- 239000010409 thin film Substances 0.000 claims abstract description 138
- 239000002887 superconductor Substances 0.000 claims abstract description 35
- 239000010408 film Substances 0.000 claims abstract description 29
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 239000001301 oxygen Substances 0.000 claims description 7
- 238000000034 method Methods 0.000 abstract description 28
- 239000000758 substrate Substances 0.000 abstract description 7
- 229920002120 photoresistant polymer Polymers 0.000 abstract description 4
- 238000010438 heat treatment Methods 0.000 abstract description 3
- 238000001020 plasma etching Methods 0.000 abstract description 3
- 238000004544 sputter deposition Methods 0.000 abstract description 3
- 238000007740 vapor deposition Methods 0.000 abstract description 3
- 230000015572 biosynthetic process Effects 0.000 abstract description 2
- 239000002184 metal Substances 0.000 description 5
- 229910009203 Y-Ba-Cu-O Inorganic materials 0.000 description 4
- 239000004020 conductor Substances 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 239000004065 semiconductor Substances 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
- 238000004140 cleaning Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- 238000010884 ion-beam technique Methods 0.000 description 2
- 238000009751 slip forming Methods 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000000608 laser ablation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000009257 reactivity Effects 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)
- Oxygen, Ozone, And Oxides In General (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】本発明は、積層膜の作製方法に関
する。より詳細には、酸化物超電導薄膜と、該酸化物超
電導薄膜上の一部に積層された、絶縁体膜、常電導体膜
または前記酸化物超電導薄膜と結晶の状態が異なる酸化
物超電導薄膜等、特定の形状の上層の薄膜を具備する積
層膜の作製方法に関する。
【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。
【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。
【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、半導体薄膜上に酸化物超電導薄膜を積層す
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。
【０００５】上記の積層膜を使用して、超電導素子、超
電導集積回路を作製する場合、各薄膜の機能、特性によ
り、それぞれの薄膜の大きさおよび形状を変えなければ
ならない。例えば、酸化物超電導薄膜に外部から電流を
供給する電極となる、例えばボンディングパッドのよう
な金属膜は、酸化物超電導薄膜上の一部の所定の位置に
形成される。また、超電導集積回路等で、酸化物超電導
薄膜に接する抵抗体となる金属膜も酸化物超電導薄膜上
の一部の所定の位置に形成されなければならない。この
ような金属膜は、 １００ｎｍ以下の厚さでもよいが、
酸化物超電導薄膜との間に不要な電気抵抗を生じること
なく形成されていなければならない。さらに、電流路に
酸化物超電導薄膜を使用した素子、集積回路等を作製す
る場合には、酸化物超電導薄膜を所定の電流路の形状に
しなければならない。酸化物超電導体は、組成、結晶構
造が容易に変化し、それにより超電導特性が大幅に低下
するので、酸化物超電導薄膜を使用した上記の積層膜を
作製する場合には、酸化物超電導薄膜に悪影響を与えな
いようにしなければならない。
【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
表面に形成された自然酸化物等により境界に不必要な弱
結合が発生したり、これらの異物により一様な成長が行
われず、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。
【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、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。
【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。
【０００９】また、上層の薄膜の材料、上層の薄膜を形
成する条件によっては、下層の酸化物超電導薄膜中に上
層の薄膜に含まれる元素が拡散し、界面が急峻に形成さ
れないだけでなく、酸化物超電導薄膜が劣化してしまう
。さらに、積層膜を構成する薄膜をそれぞれ異なる形状
にする場合にも、酸化物超電導薄膜を劣化させないよう
に注意しなければならない。特に、酸化物超電導薄膜の
直上の薄膜を、この酸化物超電導薄膜上の一部に形成さ
れた構成とする場合に、酸化物超電導薄膜を劣化させる
危険性が高い。即ち、リフトオフ法ではフォトレジスト
、エッチング液等の影響を受け、また、反応性イオンエ
ッチングではＣｌイオン等により、電子ビーム、イオン
ビーム等で酸化物超電導薄膜上に形成された薄膜を加工
する方法では、電子ビーム、イオンビーム等により、酸
化物超電導薄膜が侵されてしまう。
【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、酸化物超電導薄膜と、該酸化物超電
導薄膜上の一部に積層された所定の形状の上層の薄膜と
を具備する積層膜を作製する方法を提供することにある
。
【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た酸化物超電導薄膜と、該酸化物超
電導薄膜上の一部に積層された所定の形状の第２の薄膜
とを具備する積層膜を作製する方法において、前記酸化
物超電導薄膜を成膜した後、該酸化物超電導薄膜の温度
を、該酸化物超電導薄膜を構成する酸化物超電導体が酸
素を取り込む温度以下で、該温度との差が１００ ℃以
内の温度にして、該酸化物超電導薄膜を高真空中に保持
し、前記第２の薄膜を連続して成膜し、該第２の薄膜を
前記所定の形状に加工することを特徴とする積層膜の作
製方法が提供される。
【００１２】本発明では、上記の酸化物超電導薄膜を上
記の第２の薄膜と共に所定の形状に加工することも好ま
しい。
【００１３】
【作用】本発明では、酸化物超電導薄膜と、この酸化物
超電導薄膜上の一部に積層された所定の形状の第２の薄
膜とを具備する積層膜を作製する方法として、以下の方
法が提供される。即ち、上記の積層膜を作製する場合に
、下層の酸化物超電導薄膜を成膜後、この酸化物超電導
薄膜の温度をこの酸化物超電導薄膜を構成する酸化物超
電導体が酸素を取り込む温度以下で、該温度との差が１
００ ℃以内の温度にして、該酸化物超電導薄膜を高真
空中に保持して第２の薄膜を連続して成膜し、この第２
の薄膜を前記所定の形状に加工するところにそれぞれ主
要な特徴がある方法である。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、常電導体薄膜また
は下層の酸化物超電導薄膜と結晶の状態が異なる酸化物
超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。
【００１４】上記本発明の方法では、下層の酸化物超電
導薄膜を成膜した後、同一の装置内で連続して上層の薄
膜を成膜するので、下層の酸化物超電導薄膜が空気に触
れたりすることがない。従って、下層の酸化物超電導薄
膜の表面が汚染されたり、空気中の水分等と反応して劣
化することがない。また、上記本発明の方法では、下層
の酸化物超電導薄膜を成膜後、この酸化物超電導薄膜を
構成する酸化物超電導体が酸素を取り込む温度以下で、
該温度との差が１００ ℃以内の温度にして、上層の薄
膜を成膜する。この温度で上層の薄膜の成膜を行うと、
下層の酸化物超電導薄膜から酸素が抜けることがなく、
且つ上層の薄膜に含まれる元素が下層の酸化物超電導薄
膜内に拡散するのを抑制することができる。例えば、下
層の酸化物超電導薄膜が、Ｙ−Ｂａ−Ｃｕ−Ｏ系酸化物
超電導体で構成されている場合、Ｙ−Ｂａ−Ｃｕ−Ｏ系
酸化物超電導薄膜を３５０〜４００℃にして上層の薄膜
を成膜する。
【００１５】本発明では、上記の方法で酸化物超電導薄
膜上に第２の薄膜を積層した後、第２の薄膜を所定の形
状に加工する。また、このとき、酸化物超電導薄膜を第
２の薄膜と共に所定の形状に加工することも好ましい。
本発明の方法では、加工時に酸化物超電導薄膜の表面が
露出していないので、酸化物超電導薄膜が劣化すること
がない。また、酸化物超電導薄膜と第２の薄膜との間の
界面の状態が良好であるので、本発明の積層膜を使用し
て素子、集積回路を作製すると、安定した動作を行う。
さらに、この界面における接触抵抗が低減されており、
機械的強度も向上している。
【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。
【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
。
【００１８】
【実施例】本発明の方法により、Ｙ１Ｂａ２Ｃｕ３Ｏ７
−Ｘ酸化物超電導薄膜上にＡｕ薄膜が積層された積層膜
を作製した。
図１を参照して本発明の方法で積層膜を作製する手順を
説明する。
【００１９】まず、図１（ａ）に示すようなＭｇＯ（１
００）基板３を超高真空チャンバ内に入れ、１×１０−
６Ｔｏｒｒまで排気する。次いで、チャンバ内に酸素お
よびＡｒを導入し、ＭｇＯ（１００）基板３の表面に図
１（ｂ）に示すよう厚さ ３００ｎｍのｃ軸配向のＹ１
Ｂａ２Ｃｕ３Ｏ７−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。
【００２０】成膜後、基板温度を４００
℃にしてＹ１Ｂａ２Ｃｕ３Ｏ７−Ｘ酸化物超電導薄膜１
を構成するＹ１Ｂａ２Ｃｕ３Ｏ７−Ｘ酸化物超電導体に
酸素を取り込ませる熱処理を行ってもよい。この熱処理
の後、Ｙ１Ｂａ２Ｃｕ３Ｏ７−Ｘ酸化物超電導薄膜１の
温度を３７５ ℃にし、チャンバ内を１×１０−９Ｔｏ
ｒｒまで排気する。次いで、Ｙ１Ｂａ２Ｃｕ３Ｏ７−Ｘ
酸化物超電導薄膜１上に図１（ｃ）に示すよう厚さ ２
００ｎｍのＡｕ薄膜２を蒸着法で成膜する。次に、図１
（ｄ）に示すようＡｕ薄膜２上に、加工するパターンに
合わせてフォトレジスト５を積層し、図１（ｅ）に示す
ようＡｕ薄膜２とＹ１Ｂａ２Ｃｕ３Ｏ７−Ｘ薄膜１とを
反応性イオンエッチング法で加工する。
ここまでの工程は全て同一のチャンバ内で連続的に処理
した。上記本発明の方法により作製された積層膜は、加
工後も各薄膜の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。また、界面におい
て、相互拡散は生じていなかった。
【００２１】
【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所定の形状の第２の薄膜が積層さ
れた積層膜の作製方法が提供される。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。Description: FIELD OF THE INVENTION The present invention relates to a method for producing a laminated film. More specifically, an oxide superconducting thin film, and an insulator film, a normal conductor film, or an oxide superconducting thin film having a crystal state different from that of the oxide superconducting thin film, which is laminated on a part of the oxide superconducting thin film. , relates to a method for producing a laminated film having an upper layer thin film having a specific shape. [0002] 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] 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. 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 the oxide superconductor thin film on the semiconductor 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 laminated. [0005] When producing a superconducting element or a superconducting integrated circuit using the above laminated films, the size and shape of each thin film must be changed depending on the function and characteristics of each thin film. For example, a metal film such as a bonding pad, which serves as an electrode for supplying current to the oxide superconducting thin film from the outside, is formed at a predetermined position on a portion of the oxide superconducting thin film. Furthermore, in a superconducting integrated circuit or the like, a metal film serving as a resistor in contact with the oxide superconducting thin film must also be formed at a predetermined position on a portion of the oxide superconducting thin film. Such a metal film may have a thickness of 100 nm or less, but
It must be formed without creating unnecessary electrical resistance between it and the oxide superconducting thin film. Furthermore, when producing elements, integrated circuits, etc. that use oxide superconducting thin films for current paths, the oxide superconducting thin films must be shaped into predetermined current path shapes. The composition and crystal structure of oxide superconductors change easily, which significantly reduces their superconducting properties. Therefore, when producing the above laminated film using oxide superconducting thin films, We must ensure that there are no negative effects. [0006] 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, unnecessary weak bonds may occur at the boundary due to contaminants deposited on the surface of the underlying thin film, natural oxides formed on the surface of the underlying thin film, etc. Due to the foreign matter, uniform growth is not performed, and a portion 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. In particular, oxide superconductors have a very short coherence length, so when stacking further thin films on top of an oxide superconducting thin film, special care must be taken to the surface condition of the oxide superconducting thin film. have to pay. 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. 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] Furthermore, depending on the material of the upper thin film and the conditions for forming the upper thin film, elements contained in the upper thin film may diffuse into the lower oxide superconducting thin film, and not only will the interface not be formed steeply, The oxide superconducting thin film deteriorates. Furthermore, even when the thin films constituting the laminated film are formed into different shapes, care must be taken not to deteriorate the oxide superconducting thin film. In particular, when a thin film directly above an oxide superconducting thin film is formed on a portion of the oxide superconducting thin film, there is a high risk of deteriorating the oxide superconducting thin film. In other words, the lift-off method is affected by photoresist, etching solution, etc., reactive ion etching is affected by Cl ions, etc., and methods that process thin films formed on oxide superconducting thin films with electron beams, ion beams, etc. , electron beams, ion beams, etc., can attack the oxide superconducting thin film. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an oxide superconducting thin film and an upper thin film of a predetermined shape laminated on a portion of the oxide superconducting thin film, which solves the problems of the prior art. An object of the present invention is to provide a method for producing a laminated film that has the following properties. [0011] According to the present invention, there is provided an oxide superconducting thin film made of an oxide superconductor, and a second layer having a predetermined shape laminated on a portion of the oxide superconducting thin film. After forming the oxide superconducting thin film, the temperature of the oxide superconducting thin film is adjusted such that the oxide superconductor constituting the oxide superconducting thin film takes in oxygen. The oxide superconducting thin film is maintained in a high vacuum at a temperature below the above temperature and the difference from the above temperature is within 100 °C, and the second thin film is continuously formed. There is provided a method for producing a laminated film, characterized by processing the film into the predetermined shape. In the present invention, it is also preferable that the oxide superconducting thin film described above is processed into a predetermined shape together with the second thin film described above. [Operation] In the present invention, as a method for producing a laminated film comprising an oxide superconducting thin film and a second thin film of a predetermined shape laminated on a part of the oxide superconducting thin film, the following method is used. A method is provided. That is, when producing the above-mentioned laminated film, after forming the lower layer oxide superconducting thin film, the temperature of this oxide superconducting thin film is kept below the temperature at which the oxide superconductor constituting this oxide superconducting thin film takes in oxygen. , the difference from the temperature is 1
A second thin film is continuously formed by keeping the oxide superconducting thin film in a high vacuum at a temperature of 0.00°C or less;
The main feature of each method is that the thin film is processed into the predetermined shape. The method of the present invention includes, for example,
It can be applied to the case where a superconducting element is manufactured by laminating an insulator thin film, a normal conductor thin film, or an oxide superconducting thin film having a different crystal state from the underlying oxide superconducting thin film on an oxide superconducting thin film. In the method of the present invention, after forming the lower layer oxide superconducting thin film, the upper layer thin film is successively formed in the same apparatus, so that the lower layer oxide superconducting thin film does not come into contact with air. There's nothing to do. Therefore, the surface of the underlying oxide superconducting thin film is not contaminated or deteriorated due to reaction with moisture in the air. In addition, in the method of the present invention, after forming the lower oxide superconducting thin film, at a temperature below the temperature at which the oxide superconductor constituting this oxide superconducting thin film takes in oxygen,
The upper thin film is formed at a temperature within 100° C. from the above temperature. When the upper thin film is formed at this temperature,
Oxygen does not escape from the underlying oxide superconducting thin film,
In addition, it is possible to suppress elements contained in the upper thin film from diffusing into the lower oxide superconducting thin film. For example, when the lower layer oxide superconducting thin film is composed of a Y-Ba-Cu-O based oxide superconductor, the Y-Ba-Cu-O based oxide superconducting thin film is heated to 350 to 400°C. Deposit a thin film. In the present invention, after the second thin film is laminated on the oxide superconducting thin film by the method described above, the second thin film is processed into a predetermined shape. Moreover, at this time, it is also preferable to process the oxide superconducting thin film together with the second thin film into a predetermined shape. In the method of the present invention, since the surface of the oxide superconducting thin film is not exposed during processing, the oxide superconducting thin film does not deteriorate. Furthermore, since the interface between the oxide superconducting thin film and the second thin film is in good condition, devices and integrated circuits manufactured using the laminated film of the present invention will operate stably. Furthermore, the contact resistance at this interface is reduced,
Mechanical strength has also been improved. 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] 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. [Example] By the method of the present invention, Y1Ba2Cu3O7
A laminated film in which an Au thin film was laminated on a -X oxide superconducting thin film was fabricated. The procedure for producing a laminated film by the method of the present invention will be explained with reference to FIG. First, MgO (1
00) Place the substrate 3 in an ultra-high vacuum chamber and
Exhaust to 6 Torr. Next, oxygen and Ar are introduced into the chamber, and a c-axis oriented Y1 layer with a thickness of 300 nm is deposited on the surface of the MgO (100) substrate 3 as shown in FIG. 1(b).
A Ba2Cu3O7-X oxide superconducting thin film 1 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. After film formation, the substrate temperature was increased to 400°C.
Y1Ba2Cu3O7-X oxide superconducting thin film 1 at °C
A heat treatment may be performed to incorporate oxygen into the Y1Ba2Cu3O7-X oxide superconductor constituting the Y1Ba2Cu3O7-X oxide superconductor. After this heat treatment, the temperature of the Y1Ba2Cu3O7-X oxide superconducting thin film 1 is set to 375°C, and the inside of the chamber is heated to 1×10-9To
Exhaust to rr. Then Y1Ba2Cu3O7-X
As shown in FIG. 1(c), the thickness of the oxide superconducting thin film 1 is 2.
00 nm thick Au thin film 2 is formed by vapor deposition. Next, Figure 1
As shown in (d), a photoresist 5 is layered on the Au thin film 2 according to the pattern to be processed, and as shown in FIG. 1(e), the Au thin film 2 and the Y1Ba2Cu3O7-X thin film 1 are separated by reactive ion etching. Process. All the steps up to this point were performed continuously in the same chamber. It was found that the laminated film produced by the above method of the present invention not only has excellent crystallinity of each thin film even after processing, but also has good consistency at the interface. Furthermore, no mutual diffusion occurred at the interface. Effects of the Invention As explained above, according to the present invention,
A method for manufacturing a laminated film in which a second thin film having a predetermined shape is laminated on an oxide superconducting thin film is provided. 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 create a high-performance superconducting device that has not been previously available.
【図１】本発明の方法で、積層膜を作製する工程を説明
する図である。FIG. 1 is a diagram illustrating the process of producing a laminated film using the method of the present invention.
１ 酸化物超電導薄膜 ２ Ａｕ薄膜 ３ 基板 ５ フォトレジスト 1 Oxide superconducting thin film 2 Au thin film 3 Substrate 5 Photoresist
Claims (2)
電導薄膜と、該酸化物超電導薄膜上の一部に積層された
所定の形状の第２の薄膜とを具備する積層膜を作製する
方法において、前記酸化物超電導薄膜を成膜した後、該
酸化物超電導薄膜の温度を、該酸化物超電導薄膜を構成
する酸化物超電導体が酸素を取り込む温度以下で、該温
度との差が１００ ℃以内の温度にして、該酸化物超電
導薄膜を高真空中に保持し、前記第２の薄膜を連続して
成膜し、該第２の薄膜を前記所定の形状に加工すること
を特徴とする積層膜の作製方法。1. A method for producing a laminated film comprising an oxide superconducting thin film made of an oxide superconductor and a second thin film having a predetermined shape laminated on a portion of the oxide superconducting thin film. After forming the oxide superconducting thin film, the temperature of the oxide superconducting thin film is set to a temperature below the temperature at which the oxide superconductor constituting the oxide superconducting thin film takes in oxygen, and the difference from the temperature is 100°C. The oxide superconducting thin film is kept in a high vacuum at a temperature within Method for producing a laminated film.
膜と共に加工することを特徴とする請求項１に記載の積
層膜の作製方法。2. The method for producing a laminated film according to claim 1, wherein the oxide superconducting thin film is processed together with the second thin film.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3103955A JP2647277B2 (en) | 1991-04-09 | 1991-04-09 | Manufacturing method of laminated film |
| EP92401006A EP0509886B1 (en) | 1991-04-09 | 1992-04-09 | Process for patterning layered thin films including a superconductor layer |
| DE69216138T DE69216138T2 (en) | 1991-04-09 | 1992-04-09 | Process for structuring multilayer thin films with a superconducting layer |
| US07/865,498 US5326747A (en) | 1991-04-09 | 1992-04-09 | Process for patterning layered thin films including a superconductor |
| CA002065625A CA2065625C (en) | 1991-04-09 | 1992-04-09 | Process for patterning layered thin films including a superconductor layer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3103955A JP2647277B2 (en) | 1991-04-09 | 1991-04-09 | Manufacturing method of laminated film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04310504A true JPH04310504A (en) | 1992-11-02 |
| JP2647277B2 JP2647277B2 (en) | 1997-08-27 |
Family
ID=14367832
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3103955A Expired - Lifetime JP2647277B2 (en) | 1991-04-09 | 1991-04-09 | Manufacturing method of laminated film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2647277B2 (en) |
-
1991
- 1991-04-09 JP JP3103955A patent/JP2647277B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2647277B2 (en) | 1997-08-27 |
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