JP2768066B2 - Method for laminating upper thin film on oxide superconducting thin film - Google Patents
Method for laminating upper thin film on oxide superconducting thin filmInfo
- Publication number
- JP2768066B2 JP2768066B2 JP3198641A JP19864191A JP2768066B2 JP 2768066 B2 JP2768066 B2 JP 2768066B2 JP 3198641 A JP3198641 A JP 3198641A JP 19864191 A JP19864191 A JP 19864191A JP 2768066 B2 JP2768066 B2 JP 2768066B2
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- oxide superconducting
- superconductor
- oxide
- superconducting thin
- 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.)
- Expired - Lifetime
Links
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)
Description
【０００１】[0001]
【産業上の利用分野】本発明は基板上に予め成膜した酸
化物超電導薄膜上に他の薄膜を積層する方法に関するも
のであり、特に、上層の薄膜をエピタキシャル成長させ
るのに適した状態にするために下層の酸化物超電導薄膜
の表面の結晶性を改善する方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laminating another thin film on an oxide superconducting thin film previously formed on a substrate, and more particularly to a method for forming an upper thin film suitable for epitaxial growth. Therefore, the present invention relates to a method for improving the crystallinity of the surface of a lower oxide superconducting thin film.
【０００２】[0002]
【従来の技術】酸化物超電導体を各種電子デバイス等に
応用する場合には、酸化物超電導体を薄膜化して積層す
る必要がある。特に、トンネル型ジョセフソン接合とい
われる超電導体−非超電導体−超電導体接合を酸化物超
電導体を用して実現する場合には、第１の酸化物超電導
薄膜／非超電導体薄膜／第２の酸化物超電導薄膜をこの
順番で順次積層しなければならない。トンネル型ジョセ
フソン接合では、非超電導体層の厚さは超電導体のコヒ
ーレンス長によって決まる。しかし、酸化物超電導体は
コヒーレンス長が数ｎｍと非常に短いため、酸化物超電
導体を使用したトンネル型ジョセフソン接合では、非超
電導体薄膜の厚さを数ｎｍ程度にしなければならない。
換言すれば、このような極めて薄い薄膜を作ることが要
求される。一方、この非超電導体薄膜には高い品質も要
求される。すなわち、超電導電子素子としての特性を考
慮した場合には、上記の各薄膜は結晶性が良くなければ
ならず、全ての薄膜が単結晶であることが好ましい。い
ずれかの薄膜が多結晶またはアモルファスである場合に
は、ジョセフソン素子の性能が悪化またはジョセフソン
素子として動作しない場合もある。こうした結晶性が良
く、しかも、超電導特性にも優れた薄膜が要求されるの
はトンネル型ジョセフソン素子に限らず、酸化物超電導
体と半導体を組み合わせた超電導トランジスタ等の素子
でも同様である。2. Description of the Related Art When an oxide superconductor is applied to various electronic devices and the like, it is necessary to make the oxide superconductor thinner and stack it. In particular, when a superconductor-non-superconductor-superconductor junction called a tunnel-type Josephson junction is realized using an oxide superconductor, the first oxide superconducting thin film / non-superconducting thin film / second superconducting film is used. Oxide superconducting thin films must be sequentially laminated in this order. In a tunnel-type Josephson junction, the thickness of the non-superconductor layer is determined by the coherence length of the superconductor. However, an oxide superconductor has a very short coherence length of several nanometers. Therefore, in a tunnel-type Josephson junction using an oxide superconductor, the thickness of the non-superconductor thin film must be about several nanometers.
In other words, it is required to produce such an extremely thin thin film. On the other hand, high quality is also required for the non-superconductor thin film. That is, in consideration of the characteristics as a superconducting element, each of the above thin films must have good crystallinity, and all the thin films are preferably single crystals. When any of the thin films is polycrystalline or amorphous, the performance of the Josephson device may be deteriorated or the device may not operate as a Josephson device. The need for a thin film having good crystallinity and excellent superconducting properties is not limited to a tunnel-type Josephson device, but also applies to a device such as a superconducting transistor in which an oxide superconductor and a semiconductor are combined.
【０００３】しかし、全ての薄膜層が優れた結晶性を有
するような超電導体−非超電導体−超電導体接合の積層
構造を、酸化物超電導薄膜の超電導特性を低下させずに
作るのは従来方法では困難である。事実、酸化物超電導
薄膜は空気に触れると、表面から約１ｎｍ程度の部分の
超電導性および結晶性はともに消失する。通常、酸化物
超電導薄膜の成膜と、その上に積層する上層の成膜は互
いに異なる成膜装置で行われるため、一方のチャンバー
から他方のチャンバーへ基板を搬送する際に酸化物超電
導薄膜が空気に触れるのは避けられない。そのため、従
来法では、酸化物超電導薄膜上に他の薄膜を積層する前
に、酸化物超電導薄膜を１×10-9Torr程度の超高真空中
で約700 ℃まで加熱する熱処理を行っていた。上記の熱
処理を行った酸化物超電導薄膜は表面の結晶性が改善さ
れ、その上に積層される薄膜はエピタキシャル成長する
が、上記のような超高真空中で酸化物超電導薄膜を加熱
した場合には、薄膜を構成している酸化物超電導体結晶
中の酸素が失われるため、薄膜の超電導特性が悪化した
り、薄膜が超電導性を示さなくなる。上記の熱処理を酸
素中で行えば、薄膜の超電導特性に問題が生じることは
ないが、薄膜表面の結晶性は改善されない。However, it is a conventional method to form a superconductor-non-superconductor-superconductor junction laminated structure in which all the thin film layers have excellent crystallinity without deteriorating the superconducting characteristics of the oxide superconducting thin film. Is difficult. In fact, when the oxide superconducting thin film comes into contact with air, both the superconductivity and the crystallinity of a portion of about 1 nm from the surface disappear. Usually, the formation of the oxide superconducting thin film and the formation of the upper layer laminated thereon are performed by different film forming apparatuses. Therefore, when the substrate is transferred from one chamber to the other chamber, the oxide superconducting thin film is Touching the air is inevitable. Therefore, in the conventional method, before laminating another thin film on the oxide superconducting thin film, a heat treatment for heating the oxide superconducting thin film to about 700 ° C. in an ultra-high vacuum of about 1 × 10 −9 Torr was performed. . The oxide superconducting thin film subjected to the above heat treatment has improved surface crystallinity, and the thin film laminated thereon grows epitaxially, but when the oxide superconducting thin film is heated in an ultra-high vacuum as described above, Since oxygen in the oxide superconductor crystal constituting the thin film is lost, the superconductivity of the thin film deteriorates and the thin film does not show superconductivity. If the above heat treatment is performed in oxygen, there is no problem in the superconductivity of the thin film, but the crystallinity of the thin film surface is not improved.
【０００４】[0004]
【発明が解決しようとする課題】本発明の目的は従来技
術の問題点を解決して、酸化物超電導薄膜の表面の結晶
性を超電導特性を損なわずに改善する方法を提供するこ
とにある。SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art and to provide a method for improving the crystallinity of the surface of an oxide superconducting thin film without impairing the superconducting characteristics.
【０００５】[0005]
【課題を解決するための手段】本発明は、基板上に予め
成膜された酸化物超電導薄膜上に上層の薄膜を積層する
方法において、上層の薄膜を成膜する前に圧力１×10-6
Torr以下の高真空中、好ましくは１×10-8Torr以下の超
高真空中で上記酸化物超電導薄膜表面にパルスレーザ光
を照射し、上記酸化物超電導薄膜表面を結晶性表面とす
る工程を含むことを特徴とする。The present invention SUMMARY OF] is a method for laminating the upper layer of the thin film in advance formed oxide superconducting thin film on a substrate, the pressure 1 × 10 before forming the upper layer of the thin film - 6
The surface of the oxide superconducting thin film is irradiated with a pulsed laser beam in a high vacuum of not more than Torr, preferably in an ultrahigh vacuum of not more than 1 × 10 −8 Torr , to make the surface of the oxide superconducting thin film a crystalline surface.
The process is characterized by including the step of.
【０００６】[0006]
【作用】本発明方法で使用するパルスレーザ光は１回の
発光時間が非常に短い、高出力のレーザ光、例えばエキ
シマレーザ等のパルスが好ましい。本発明方法では、こ
のような高出力のパルスレーザ光を表面に照射すること
によって、酸化物超電導薄膜を極めて短い時間で瞬間的
に加熱し、極めて短い時間で冷却する。「加熱」とは広
い意味で、何らかの形でエネルギが加えられることを意
味する。The pulse laser beam used in the method of the present invention is preferably a high-output laser beam having a very short emission time, for example, a pulse of an excimer laser. In the method of the present invention, the surface of the oxide superconducting thin film is instantaneously heated in a very short time and cooled in a very short time by irradiating the surface with such a high-power pulsed laser beam. "Heating" in a broad sense means that some form of energy is applied.
【０００７】本発明方法では、高真空中で上記処理を行
う従来の加熱処理と同様に、結晶性が改善される。しか
し、従来法とは違って、加熱で非常に短時間であるた
め、薄膜内部の酸化物超電導体結晶の酸素が拡散して表
面から失われることはない。従って、上記処理を行った
酸化物超電導薄膜は超電導特性に優れ、しかも、表面の
結晶性も良くなる。その結果、この酸化物超電導薄膜表
面上に成膜する他の薄膜はエピタキシャル成長する。In the method of the present invention, the crystallinity is improved as in the case of the conventional heat treatment in which the above treatment is performed in a high vacuum. However, unlike the conventional method, heating is performed in a very short time, so that oxygen in the oxide superconductor crystal inside the thin film is not diffused and lost from the surface. Therefore, the oxide superconducting thin film that has been subjected to the above treatment has excellent superconducting properties and also has good surface crystallinity. As a result, another thin film formed on the surface of the oxide superconducting thin film grows epitaxially.
【０００８】本発明方法で使用するレーザはエキシマレ
ーザに代表されるパルス発振の高出力レーザが好まし
く、照射される酸化物超電導薄膜表面上での１パルス当
たりのエネルギ密度は0.01〜0.1 Ｊ／cm2 にするのが好
ましい。レーザ光の１パルス当たりのエネルギ密度が0.
01Ｊ／cm2 未満ではエネルギが小さすぎて薄膜表面の結
晶性を改善することができず、エネルギ密度が１パルス
当たり0.1 Ｊ／cm2 を超えるレーザ光を照射すると、薄
膜表面が損傷を受ける。また、酸化物超電導薄膜の同一
箇所に照射するパルスの数はレーザ光のエネルギー密
度、レーザ光の入射角度、被処理薄膜の表面状態を含む
種々のファクターによって決まる。上記のエネルギ密度
の範囲内では、１〜100 パルスのレーザ光を照射するこ
とが好ましい。実際には、ＲＨＥＥＤ、ＬＥＥＤ等で照
射部分の結晶状態をモニタしながらレーザ光を照射する
のが好ましい。また、同一箇所にパルスレーザ光を複数
回照射する場合には、短時間に連続して複数のパルスを
照射するのは好ましくない。これは、薄膜の照射部分の
温度が高温になって、結晶中の酸素が失われるためであ
る。The laser used in the method of the present invention is preferably a high-power laser of pulse oscillation typified by an excimer laser, and the energy density per pulse on the surface of the oxide superconducting thin film to be irradiated is 0.01 to 0.1 J / cm. Preferably it is 2 . The energy density per pulse of laser light is 0.
When the energy is less than 01 J / cm 2 , the energy is too small to improve the crystallinity of the surface of the thin film. When a laser beam having an energy density exceeding 0.1 J / cm 2 per pulse is applied, the surface of the thin film is damaged. The number of pulses applied to the same portion of the oxide superconducting thin film is determined by various factors including the energy density of the laser light, the incident angle of the laser light, and the surface condition of the thin film to be processed. Within the above energy density range, it is preferable to irradiate 1 to 100 pulses of laser light. Actually, it is preferable to irradiate the laser beam while monitoring the crystal state of the irradiated portion with RHEED, LEED or the like. In the case where the same location is irradiated with the pulse laser beam a plurality of times, it is not preferable to irradiate a plurality of pulses continuously in a short time. This is because the temperature of the irradiated portion of the thin film becomes high and oxygen in the crystal is lost.
【０００９】本発明方法は任意の酸化物超電導体に適用
できるが、ＹＢＣＯ系超電導材料、例えばＹ1Ba2Cu3Ｏ
7-X 、Bi系複合酸化物、例えばBi2Sr2Ca2Cu3Ｏx 、Tl系
複合酸化物、例えばTl2Ba2Ca2Cu3Ｏx にすることができ
る。Ｙ1Ba2Cu3Ｏ7-X は高品質の結晶性のよい薄膜を安
定に成膜できるので好ましく、また、Bi系複合酸化物超
電導体は超電導臨界温度Ｔc が高いので好ましい。これ
らの複合酸化物の薄膜はスパッタリング、レーザ蒸着
法、真空蒸着法で成膜することができる。これらの成膜
法の操作条件自体は公知である。Although the method of the present invention can be applied to any oxide superconductor, a YBCO-based superconducting material such as Y 1 Ba 2 Cu 3 O
7-X , Bi-based composite oxides such as Bi 2 Sr 2 Ca 2 Cu 3 O x and Tl-based composite oxides such as Tl 2 Ba 2 Ca 2 Cu 3 O x can be used. Y 1 Ba 2 Cu 3 O 7 -X is preferable because a high-quality thin film having good crystallinity can be stably formed, and a Bi-based composite oxide superconductor is preferable because the superconducting critical temperature Tc is high. These composite oxide thin films can be formed by sputtering, laser evaporation, or vacuum evaporation. The operating conditions per se of these film forming methods are known.
【００１０】酸化物超電導体上に成膜される他の薄膜は
非超電導体の薄膜であるのが好ましく、特に、酸化物超
電導体に類似した結晶構造または格子定数を有する非超
電導材料であるのが好ましい。例としては、BaＦ2 やMg
Ｏ、SrTiＯ3 等の酸化物を挙げることができる。この非
超電導体薄膜の膜厚は用いる酸化物超電導体のコヒーレ
ンス長さによって決まり、一般には数ｎｍである。The other thin film formed on the oxide superconductor is preferably a non-superconductor thin film, particularly a non-superconductor material having a crystal structure or lattice constant similar to that of the oxide superconductor. Is preferred. For example, BaF 2 or Mg
Oxides such as O and SrTiO 3 can be mentioned. The thickness of the non-superconductor thin film is determined by the coherence length of the oxide superconductor used, and is generally several nm.
【００１１】本発明方法を用いてジョセフソン接合を作
る場合には、上記非超電導体薄膜の上に第２の酸化物超
電導体の薄膜を成膜する。この第２の酸化物超電導体の
薄膜は上記の酸化物超電導薄膜と同じような方法で成膜
することができる。本発明では、下地の非超電導体薄膜
が優れた結晶性を有しているので、その上に成膜される
第２の酸化物超電導体はエピタキシャル成長して優れた
品質の薄膜となる。以下、本発明の実施例を説明する
が、本発明が下記実施例に限定されるものではない。When a Josephson junction is formed using the method of the present invention, a thin film of a second oxide superconductor is formed on the non-superconductor thin film. The thin film of the second oxide superconductor can be formed in the same manner as the above-described oxide superconducting thin film. In the present invention, since the underlying non-superconductor thin film has excellent crystallinity, the second oxide superconductor formed thereon is epitaxially grown into a thin film of excellent quality. Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples.
【００１２】[0012]
【実施例】実施例１ 本発明方法で、MgＯ基板上に第１の酸化物超電導薄膜、
非超電導体層としてのBaＦ2 薄膜、第２の酸化物超電導
薄膜をこの順番で積層してジョセフソン接合を作製し
た。先ず、スパッタリング法でMgＯ(100) 基板 (寸法：
８×10 mm)上に第１の超電導体層となるｃ軸配向の単結
晶に似たＹ1Ba2Cu3Ｏ7-X超電導薄膜を成膜した。 主な成膜条件は下記の通り： ターゲット組成 ： Ｙ：Ba：Cu＝１：２：３ 基板温度 ： 700 ℃ スパッタリングガス： Ar 90％ ＋ Ｏ2 10％ 圧力 ： ３×10-2Torr 膜厚 ： 300 nm 次に、この酸化物超電導薄膜を形成したMgＯ基板を真空
蒸着装置に移動して下記の条件でレーザ光を照射して表
面を処理した： 圧力（真空度） ： １×10-9Torr レーザ光 ： KrＦエキシマレーザ 波長 ： 248 nm エネルギ密度 ： 0.02 Ｊ／cm2 （薄膜表面上） １箇所に照射したパルス数： ３〜５パルス（ＬＥＥＤ
で観察して決定） この表面処理時には、レーザ光のパルスが酸化物超電導
薄膜上の異なる位置に照射されるようにレーザ光を走査
した。１箇所に照射するパルスの数は、酸化物超電導体
薄膜の表面の状態が良くなるように、ＬＥＥＤで酸化物
超電導体薄膜を観察しながら決定した。上記の処理の
後、基板温度が200 ℃になるまで加熱し、酸化物超電導
薄膜上にBaＦ2 薄膜を真空蒸着法で形成した。主な成膜
条件を以下に示す。 基板温度 ： 200 ℃ 圧力（真空度） ： １×10-9Torr 膜厚 ： ５nm その場のＬＥＥＤ観察で、BaＦ2 薄膜の結晶状態を確認
したところ、ほぼ単結晶の良好な結晶状態であった。酸
化物超電導体薄膜の臨界温度 Tc を求めるために、BaＦ
2 薄膜の一部を取り除き、酸化物超電導体薄膜上に電極
を銀ペーストで固定した。通常の４端子法で測定した下
地のＹ1Ba2Cu3Ｏ7-X薄膜の超電導臨界温度は85Ｋであっ
た。EXAMPLES Example 1 The present invention method, the first oxide superconducting thin film on a MgO substrate,
A Josephson junction was fabricated by laminating a BaF 2 thin film as a non-superconductor layer and a second oxide superconducting thin film in this order. First, a MgO (100) substrate (dimensions:
8 × 10 mm) was formed a first Y 1 Ba 2 Cu 3 O 7 -X superconducting thin film, similar to the single crystal of c-axis orientation of the superconductor layer on. The main film forming conditions are as follows: Target composition: Y: Ba: Cu = 1: 2: 3 Substrate temperature: 700 ° C. Sputtering gas: Ar 90% + O 2 10% Pressure: 3 × 10 −2 Torr Film thickness : 300 nm Next, the MgO substrate on which the oxide superconducting thin film was formed was moved to a vacuum evaporation apparatus and irradiated with laser light under the following conditions to treat the surface: Pressure (degree of vacuum): 1 × 10 -9 Torr laser light: KrF excimer laser Wavelength: 248 nm Energy density: 0.02 J / cm 2 (on the surface of the thin film) Number of pulses applied to one location: 3 to 5 pulses (LEED)
At the time of this surface treatment, the laser beam was scanned so that the pulse of the laser beam was applied to different positions on the oxide superconducting thin film. The number of pulses applied to one location was determined while observing the oxide superconductor thin film with LEED so that the surface condition of the oxide superconductor thin film was improved. After the above treatment, the substrate was heated until the substrate temperature reached 200 ° C., and a BaF 2 thin film was formed on the oxide superconducting thin film by a vacuum evaporation method. The main film forming conditions are shown below. Substrate temperature: 200 ° C. Pressure (degree of vacuum): 1 × 10 −9 Torr Film thickness: 5 nm When the crystal state of the BaF 2 thin film was confirmed by in-situ LEED observation, the single crystal was in a good single crystal state. . In order to determine the critical temperature Tc of the oxide superconductor thin film, BaF
A part of the two thin films was removed, and the electrodes were fixed on the oxide superconductor thin film with silver paste. The superconducting critical temperature of the underlying Y 1 Ba 2 Cu 3 O 7-X thin film measured by a usual four-terminal method was 85K.
【００１３】実施例２ 実施例１を繰り返したが、下地のＹ1Ba2Cu3Ｏ7-X薄膜の
膜厚を300ｎｍから200ｎｍに変え、非超電導体のBaＦ2
薄膜の膜厚を５ｎｍから３ｎｍに変え、さらに、下記の
操作を追加した。BaＦ2 薄膜を成膜した後に、同じチャ
ンバー内で、このBaＦ2 薄膜上に第２の酸化物超電導体
薄膜層としてのＹ1Ba2Cu3Ｏ7-X超電導薄膜をエキシマレ
ーザを用いたレーザ蒸着法で成膜した。成膜条件は下記
の通り： 基板温度 ： 700 ℃ 圧力（真空度） ： ３×10-9Torr 膜厚 ： 200 nm 他の条件は実施例１と同じにした。実施例１と同じ方法
で測定したこの第２の酸化物超電導体Ｙ1Ba2Cu3Ｏ7-X薄
膜の超電導臨界温度は80Ｋであった。 Example 2 Example 1 was repeated, except that the thickness of the underlying Y 1 Ba 2 Cu 3 O 7-X thin film was changed from 300 nm to 200 nm, and the non-superconductor BaF 2
The thickness of the thin film was changed from 5 nm to 3 nm, and the following operation was added. After a BaF 2 thin film is formed, a Y 1 Ba 2 Cu 3 O 7-X superconducting thin film as a second oxide superconducting thin film layer is formed on the BaF 2 thin film in the same chamber using an excimer laser. The film was formed by a vapor deposition method. The film forming conditions are as follows: Substrate temperature: 700 ° C. Pressure (degree of vacuum): 3 × 10 −9 Torr Film thickness: 200 nm Other conditions were the same as in Example 1. The superconducting critical temperature of the second oxide superconductor Y 1 Ba 2 Cu 3 O 7 -X thin film measured by the same method as in Example 1 was 80K.
【００１４】[0014]
【発明の効果】本発明方法を用いることによって、酸化
物超電導薄膜上に結晶性の良い薄膜を成膜することがで
きる。従って、この薄膜上に成膜される他の酸化物超電
導薄膜層は優れた結晶性を有し、従って、優れた超電導
特性を示すので、本発明方法は高性能なトンネル型のジ
ョセフソン接合を酸化物超電導体で作る場合に有利であ
る。According to the present invention, a thin film having good crystallinity can be formed on an oxide superconducting thin film. Therefore, since the other oxide superconducting thin film layer formed on this thin film has excellent crystallinity, and therefore exhibits excellent superconducting properties, the method of the present invention provides a high-performance tunnel-type Josephson junction. This is advantageous when made of an oxide superconductor.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) H01L 39/00 ZAA H01L 39/22 - 39/24 ZAA C01B 13/14 ZAA C01G 1/00 H01B 13/00 565 H01B 12/06 ZAA──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 6 , DB name) H01L 39/00 ZAA H01L 39/22-39/24 ZAA C01B 13/14 ZAA C01G 1/00 H01B 13/00 565 H01B 12/06 ZAA
Claims (2)
上に上層の薄膜を積層する方法において、上層の薄膜を
成膜する前に、圧力１×10-6Torr以下の高真空中で上記
酸化物超電導薄膜表面にパルスレーザ光を照射し、上記
酸化物超電導薄膜表面を結晶性表面とする工程を含むこ
とを特徴とする方法。In a method of laminating an upper thin film on an oxide superconducting thin film formed in advance on a substrate, prior to forming the upper thin film, the film is placed in a high vacuum at a pressure of 1 × 10 −6 Torr or less. Irradiating the surface of the oxide superconducting thin film with pulsed laser light ,
A method comprising a step of making a surface of an oxide superconducting thin film a crystalline surface .
とを特徴とする請求項１に記載の方法。The method of claim 1, wherein:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3198641A JP2768066B2 (en) | 1990-07-12 | 1991-07-12 | Method for laminating upper thin film on oxide superconducting thin film |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18486790 | 1990-07-12 | ||
| JP2-184867 | 1990-07-12 | ||
| JP3198641A JP2768066B2 (en) | 1990-07-12 | 1991-07-12 | Method for laminating upper thin film on oxide superconducting thin film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH057028A JPH057028A (en) | 1993-01-14 |
| JP2768066B2 true JP2768066B2 (en) | 1998-06-25 |
Family
ID=26502758
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3198641A Expired - Lifetime JP2768066B2 (en) | 1990-07-12 | 1991-07-12 | Method for laminating upper thin film on oxide superconducting thin film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2768066B2 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01203203A (en) * | 1988-02-08 | 1989-08-16 | Fujitsu Ltd | Formation of superconducting material layer |
| JPH01205579A (en) * | 1988-02-12 | 1989-08-17 | Nippon Telegr & Teleph Corp <Ntt> | Superconductive thin film and formation of superconductive thin film |
-
1991
- 1991-07-12 JP JP3198641A patent/JP2768066B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH057028A (en) | 1993-01-14 |
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