JPH026303A - Formation of superconducting thin film with protecting film - Google Patents
Formation of superconducting thin film with protecting filmInfo
- Publication number
- JPH026303A JPH026303A JP15776488A JP15776488A JPH026303A JP H026303 A JPH026303 A JP H026303A JP 15776488 A JP15776488 A JP 15776488A JP 15776488 A JP15776488 A JP 15776488A JP H026303 A JPH026303 A JP H026303A
- Authority
- JP
- Japan
- Prior art keywords
- film
- thin film
- superconducting
- layer
- composition
- 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
- 239000010408 film Substances 0.000 title claims abstract description 99
- 239000010409 thin film Substances 0.000 title claims abstract description 84
- 230000015572 biosynthetic process Effects 0.000 title abstract description 12
- 239000000203 mixture Substances 0.000 claims abstract description 56
- 239000000758 substrate Substances 0.000 claims abstract description 41
- 238000000137 annealing Methods 0.000 claims abstract description 29
- 238000000034 method Methods 0.000 claims description 42
- 239000010410 layer Substances 0.000 claims description 39
- 230000001681 protective effect Effects 0.000 claims description 28
- 239000011241 protective layer Substances 0.000 claims description 10
- 239000000126 substance Substances 0.000 claims description 10
- 239000002887 superconductor Substances 0.000 claims description 6
- 238000000151 deposition Methods 0.000 claims description 4
- 239000012298 atmosphere Substances 0.000 abstract description 11
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 229910052814 silicon oxide Inorganic materials 0.000 abstract 1
- 238000004544 sputter deposition Methods 0.000 description 30
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 22
- 239000001301 oxygen Substances 0.000 description 22
- 229910052760 oxygen Inorganic materials 0.000 description 22
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 14
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 10
- 238000005755 formation reaction Methods 0.000 description 9
- 238000010438 heat treatment Methods 0.000 description 9
- 229910052786 argon Inorganic materials 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 7
- 239000012300 argon atmosphere Substances 0.000 description 6
- 229910052681 coesite Inorganic materials 0.000 description 6
- 229910052906 cristobalite Inorganic materials 0.000 description 6
- 239000013078 crystal Substances 0.000 description 6
- 229910052682 stishovite Inorganic materials 0.000 description 6
- 229910052905 tridymite Inorganic materials 0.000 description 6
- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Inorganic materials O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 4
- 235000012239 silicon dioxide Nutrition 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 3
- 238000002845 discoloration Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 229910044991 metal oxide Inorganic materials 0.000 description 3
- 150000004706 metal oxides Chemical class 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000005546 reactive sputtering Methods 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000002178 crystalline material Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000010884 ion-beam technique Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000002715 modification method Methods 0.000 description 1
- 238000005019 vapor deposition process Methods 0.000 description 1
Landscapes
- Oxygen, Ozone, And Oxides In General (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Physical Vapour Deposition (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は超伝導薄膜の形成法に関し、さらに詳しくは、
表面に保護膜を有する安定な超伝導薄膜の改善された形
成法に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for forming a superconducting thin film, and more specifically,
This invention relates to an improved method for forming stable superconducting thin films with a protective film on the surface.
［従来の技術］
超伝導薄膜の形成法としては、室温または高温の真空中
、または酸素を含み、もしくは含まざる不活性ガス雰囲
気中で、基板上に超伝導組成（超伝導体となり得る化学
組成）を持つ薄膜を形成した後、これを空気中または酸
素中で加熱処理（アニーリング）して超伝導薄膜とする
方法や酸素を含む不活性ガス雰囲気中で加熱した単結晶
基板上に超伝導組成の結晶体をエピタキシャル成長させ
て直接超伝導薄膜を形成する方法などが知られている。[Prior art] A method for forming a superconducting thin film involves depositing a superconducting composition (a chemical composition that can become a superconductor) on a substrate in vacuum at room temperature or high temperature, or in an inert gas atmosphere that may or may not contain oxygen. ) and then heat-treating (annealing) it in air or oxygen to form a superconducting thin film. A known method is to directly form a superconducting thin film by epitaxially growing a crystalline material.
たとえば、ＹＢａＣｕＯ系の超伝導体を例にとって説明
すれば、第一の方法による場合はＹ。For example, if we take a YBaCuO-based superconductor as an example, in the case of the first method, Y.
ＢＢ、Ｃｕの各金属元素をそれぞれ別個に真空中等で蒸
着あるいはスパッタリングによってＹ二ＢＢ：Ｃｕの原
子比が１：２：３となるように基板上に付むさせるか、
あるいはそのような原子比を持つＹＢａＣｕ系合金を用
いて基板上に上記の原子比のＹ、ＢａおよびＣｕを蒸着
またはスパッタリングすることによって超伝導組成の薄
膜を形成した後、これを空気中または酸素中で加熱処理
（アニーリング）することによって、Ｙ１Ｂａ２Ｃｕ３
Ｏ７−ｘの組成を持つ超伝導薄膜を形成している。上記
の変形または改良法の一つとして、蒸着工程で直接酸素
を導入して上記組成比の各金属元素を含む複合的金属酸
化物の膜を超伝導組成膜として形成する方法もある。こ
の変形方法は、一般にスパッタリング法で成膜する場合
に使われることが多い。別の方法として、Ｙ。Each of the metal elements BB and Cu is separately deposited on the substrate by vapor deposition or sputtering in a vacuum or the like so that the atomic ratio of Y2BB:Cu is 1:2:3, or
Alternatively, a thin film having a superconducting composition is formed by vapor depositing or sputtering Y, Ba, and Cu having the above atomic ratios on a substrate using a YBaCu alloy having such an atomic ratio, and then this is exposed to air or oxygen. By heat treatment (annealing) in Y1Ba2Cu3
A superconducting thin film having a composition of O7-x is formed. As one of the above-mentioned modifications or improvements, there is also a method of directly introducing oxygen in the vapor deposition process to form a composite metal oxide film containing each metal element in the above-mentioned composition ratio as a superconducting composition film. This modification method is generally used when forming a film by sputtering. Alternatively, Y.
ＢａおよびＣｕ各々の酸化物をそれぞれスパッタリング
して基板上にＹ：Ｂａ：Ｃｕの原子比が１：２：３とな
る組成膜をつくる方法もある。また、Ｙ、Ｂａ、Ｃｕの
３金属をすべて含む酸化物として合成したターゲットを
用いて、Ｙ：Ｂａ：Ｃｕの原子比が１：２：３となって
いる組成膜を形成する方法もある。スパッタリング法、
蒸管法以外にイオンビーム法、イオンクラスタービーム
法等の方法もあり、同様に成膜することができる。上記
の成膜は通常基板を加熱しないで行なうが、結晶化しな
い程度の温度に基板を加熱して行なうこともできる。こ
れらの方法で成膜された超伝導組成膜は通常アモルファ
ス形態であって、そのま＼ではまだＹ１Ｂａ２Ｃｕ３Ｏ
７□の組成を持つ結晶質の超伝導薄膜ではない。超伝導
薄膜とするためには、上記種々の方法のいずれかで成膜
した超伝導組成の薄膜を、支持している基板と共に、空
気中または酸素中でアニーリングしてアモルファス組織
を結晶化させ超伝導薄膜とする反応を完成させなければ
ならない。すなわち、第一の方法で超伝導薄膜を形成す
るためには、超伝導組成薄膜の形成工程と該組成薄膜を
アニーリングする工程という２種類のプロセスを経る必
要がある。There is also a method of sputtering Ba and Cu oxides to form a composition film on a substrate with an atomic ratio of Y:Ba:Cu of 1:2:3. There is also a method of forming a composition film having an atomic ratio of Y:Ba:Cu of 1:2:3 using a target synthesized as an oxide containing all three metals: Y, Ba, and Cu. sputtering method,
In addition to the steam tube method, there are also methods such as an ion beam method and an ion cluster beam method, which can similarly form a film. The above film formation is usually performed without heating the substrate, but it can also be performed by heating the substrate to a temperature that does not cause crystallization. The superconducting composition films formed by these methods are usually in an amorphous form, and are still Y1Ba2Cu3O.
It is not a crystalline superconducting thin film with a composition of 7□. In order to make a superconducting thin film, a thin film with a superconducting composition formed by one of the various methods mentioned above is annealed together with a supporting substrate in air or oxygen to crystallize the amorphous structure and form a superconducting thin film. The reaction to create a conductive thin film must be completed. That is, in order to form a superconducting thin film using the first method, it is necessary to go through two types of processes: a step of forming a superconducting composition thin film and a step of annealing the composition thin film.
第二の方法によるＹＢａＣｕＯ系超伝導薄膜の形成は、
通常、スパッタリング装置を用いて行なう。すなわち、
たとえば装置内に保持したＭｇＯまたはＳ ｒ Ｔ ｌ
Ｏｓ等の単結晶からなる基板の温度を８００℃以上に
保ち、酸素を含むアルゴン等の不活性ガスの雰囲気中で
、超伝導となる組成で各成分元素が付着成膜するように
スパッタリングを行なう。この方法では、成膜体を改め
てアニーリング処理する必要はなく、加熱基板上に直接
に超伝導薄膜を形成することができる。Formation of YBaCuO-based superconducting thin film by the second method is as follows:
This is usually carried out using a sputtering device. That is,
For example, MgO or S r T l held in the device
The temperature of a substrate made of a single crystal such as Os is maintained at 800°C or higher, and sputtering is performed in an atmosphere of an inert gas such as argon containing oxygen so that each component element is deposited and formed into a film with a superconducting composition. . In this method, there is no need to re-anneal the film-formed body, and a superconducting thin film can be directly formed on the heated substrate.
［発明が解決しようとする課題］
上記第一、第二いずれの方法で形成するにせよ、たとえ
ば組成Ｙ １Ｂ ａ ２ Ｃｕ ａ ０７−Ｘの超伝導
体の薄膜は、そのままでは不安定であり、水や二酸化炭
素と反応しやすく、室温で空気中に放置すると劣化して
遂には超伝導特性が失なわれてしまう。したがって、従
来方法でつ（られたいかなるＹＢａＣｕＯ系超伝導薄膜
も、該超伝導薄膜の上に保護膜を形成して安定化しなけ
れば実用上役立つものとはならなかった。[Problems to be Solved by the Invention] Regardless of whether it is formed by the first or second method described above, a thin film of a superconductor having a composition of, for example, Y 1B a 2 Cu a 07-X is unstable as it is, It easily reacts with water and carbon dioxide, and if left in the air at room temperature, it will deteriorate and eventually lose its superconducting properties. Therefore, any YBaCuO-based superconducting thin film produced by the conventional method would not be of practical use unless a protective film was formed on the superconducting thin film to stabilize it.
第一の方法でＹＢａＣｕＯ系の超伝導薄膜を形成する場
合に例をとって説明すると、まず基板上に超伝導組成の
薄膜を形成し、これをアニーリングして結晶化した超伝
導薄膜を形成した後、該超伝導薄膜の上に、ＳｉＯまた
はＡｇ２Ｏ３等の金属酸化物からなる薄層を、蒸着また
はスパッタリング等の方法で成膜して保護膜としていた
。このような保護膜の形成方法はＹＢａＣｕＯ系以外の
酸化物超伝導体、たとえばＢ１５ｒＣａＣｕＯ系、Ｌａ
Ｓ ｒｃｕｏ系等の薄膜の上に保護層を形成するために
も使用されている。To explain the case of forming a YBaCuO-based superconducting thin film using the first method, first, a thin film with a superconducting composition is formed on a substrate, and this is annealed to form a crystallized superconducting thin film. Thereafter, a thin layer of a metal oxide such as SiO or Ag2O3 was formed on the superconducting thin film by a method such as vapor deposition or sputtering to serve as a protective film. The method for forming such a protective film is based on oxide superconductors other than YBaCuO, such as B15rCaCuO and La.
It is also used to form a protective layer on thin films such as Srcuo-based films.
第二の方法で同じ組成の超伝導薄膜とその保護層をつく
るためには、ＭｇＯやＳ ｒ Ｔ ｉ ０３等の単結晶
基板の温度を６００℃以上に保って該加熱基板の上にス
パッタリングによってＹ１Ｂａ２Ｃｕ３Ｏ７−ｘの超伝
導薄膜をエピタキシャル成長させて形成し、−度冷却し
て温度を下げた後にＳｉＯやＡｇ２Ｏ３等からなる保護
膜を形成する必要があった。In order to create a superconducting thin film and its protective layer with the same composition using the second method, a single crystal substrate such as MgO or S r Ti 03 is kept at a temperature of 600°C or higher and sputtered onto the heated substrate. It was necessary to epitaxially grow a superconducting thin film of Y1Ba2Cu3O7-x, cool it by -degrees to lower the temperature, and then form a protective film made of SiO, Ag2O3, or the like.
すなわち、これらの方法には、それぞれ次のような課題
があった。まず第一の方法による場合、スパッタリング
装置等の真空チャンバー内で、超伝導組成薄膜の形成と
、保護膜の形成とを連続的に行なった後にアニーリング
処理して一挙に保護膜付き超伝導薄膜を形成するという
ことはできなかった。そのようにすると、アニーリング
過程で超伝導組成膜と保護膜との間に相互の反応が起っ
てそれぞれの膜の組成が変化してしまうためである。こ
のため、超伝導組成薄膜形成後にアニリングを行なって
超伝導薄膜を形成した後、−度冷却してから該超伝導薄
膜の上に保護膜を形成することが必要であった。このた
め成膜工程が複雑となり、連続的操業で保護膜付き超伝
導薄膜を製造することは困難であった。一方、第二の方
法による場合も、超伝導薄膜をエピタキシャル成長させ
るときに、ＣＦ結晶基板の温度を６００℃以上にする必
要があるため、超伝導薄膜形成後、−度冷却して温度を
下げてから保護膜を形成する必要があり、第一の方法の
場合と同様、成膜工程が複雑となり、連続工程で一挙に
保護膜付き超伝導薄膜を形成することはできなかった。That is, each of these methods has the following problems. In the case of the first method, the formation of a superconducting composition thin film and the formation of a protective film are sequentially performed in a vacuum chamber such as a sputtering device, and then an annealing treatment is performed to form a superconducting thin film with a protective film at once. It was not possible to form it. If this is done, a mutual reaction will occur between the superconducting composition film and the protective film during the annealing process, resulting in a change in the composition of each film. For this reason, it has been necessary to perform annealing to form a superconducting thin film after forming a superconducting composition thin film, and then forming a protective film on the superconducting thin film after cooling the superconducting thin film by -0. This complicates the film formation process, making it difficult to manufacture a superconducting thin film with a protective film in continuous operation. On the other hand, in the case of the second method, it is necessary to raise the temperature of the CF crystal substrate to 600°C or higher when epitaxially growing a superconducting thin film. As with the first method, the film formation process was complicated, and it was not possible to form a superconducting thin film with a protective film all at once in a continuous process.
［課題を解決するための手段］
上記の課題を解決するため鋭意研究を行なった結果、本
発明者等は、ある種の金属の酸化物の薄層（接合層と呼
ぶ）を、基板上に成膜したＹＢａＣｕＯ系超伝導組成薄
膜の上に成膜し、さらにその上に従来保護層として使用
されてきたＳｉ 、Ａｌ２．Ｚｒ等の元素の酸化物の薄
層を成膜した後アニーリングして組成ＹＩＢａ２Ｃｕ３
０７−ｘの超伝導薄膜を形成する場合には、超伝導薄膜
と接合層相互間にも、また接合層と保護層相互間にも、
アニーリング処理に際して各含有成分の反応現象は起ら
ず、安定な保護膜付き超伝導薄膜を、−度のアニーリン
グ処理で一挙に製造できることを見出した。この方法に
よれば、たとえばスパッタリング装置内でＹＢａＣｕＯ
系ターゲットを用いて超伝導組成薄膜を基板上に形成し
た後、引き続き同じ装置内でＭｇＯターゲットを用いて
前記超伝導組成薄膜上にＭｇＯの薄層からなる接合層を
成膜し、さらにその上に、ＳｉＯ２ターゲットを用いて
Ｓ ｉＯ２薄層からなる保護層を成膜し、これらすべて
の成膜を終えた後に、得られた多層成膜体をスパッタリ
ング装置から取り出してアニーリング炉内に装填してア
ニーリング処理するようにすれば一連の工程を連続化で
きしかも一度に多層の処理をすることができるので、非
常に生産効率が向上する。[Means for Solving the Problems] As a result of intensive research in order to solve the above problems, the present inventors have developed a thin layer (referred to as a bonding layer) of a certain type of metal oxide on a substrate. A film of Si, Al2. After depositing a thin layer of oxide of an element such as Zr, it is annealed to obtain a composition of YIBa2Cu3.
When forming the superconducting thin film of 07-x, between the superconducting thin film and the bonding layer, and between the bonding layer and the protective layer,
It has been found that no reaction phenomenon occurs among the contained components during the annealing treatment, and that a stable superconducting thin film with a protective film can be produced all at once with a -degree annealing treatment. According to this method, for example, YBaCuO
After forming a superconducting composition thin film on a substrate using a system target, a bonding layer consisting of a thin layer of MgO is subsequently deposited on the superconducting composition thin film using an MgO target in the same apparatus, and then Next, a protective layer consisting of a thin SiO2 layer was formed using a SiO2 target, and after all of these film formations were completed, the obtained multilayered film was taken out of the sputtering device and loaded into an annealing furnace. If annealing is used, a series of steps can be made continuous, and multiple layers can be processed at once, which greatly improves production efficiency.
接合層という介在層を用いる本発明の技術思想は前記第
二の方法にも有効に応用できる。すなわち、ＭｇＯ等の
単結晶基板をたとえば６５０℃に加熱して、スパッタリ
ング装置内でＹＢａＣｕＯ系ターゲットを用いて基板上
にＹ１Ｂａ２Ｃｕ３Ｏ７−ｘをエピタキシャル成長させ
た後に、ＭｇＯターゲットを用いてＭｇＯ薄層からなる
接合層を成膜し、さらにその上に、Ｓ ｌ ０２ターゲ
ツトを用いてＳ ｉＯＺ薄層からなる保護膜を成膜する
ようにすれば、同一のスパッタリング装置内ですべての
成膜と超伝導組成薄膜の結晶化とを一挙に行なうことが
でき、別途にアニーリング処理する必要なくして、保護
膜付き超伝導膜を好都合に製造することができる。この
ため、第一の方法の場合と同様に生産性が著しく向上す
る。The technical concept of the present invention using an intervening layer called a bonding layer can also be effectively applied to the second method. That is, after heating a single crystal substrate of MgO or the like to, for example, 650° C. and epitaxially growing Y1Ba2Cu3O7-x on the substrate using a YBaCuO target in a sputtering device, a bond consisting of a thin MgO layer is formed using an MgO target. If a layer is formed and then a protective film made of a thin SiOZ layer is formed on top of it using a S102 target, all the film formation and the superconducting composition thin film can be performed in the same sputtering equipment. and crystallization can be performed all at once, and a superconducting film with a protective film can be conveniently manufactured without the need for a separate annealing treatment. Therefore, productivity is significantly improved as in the case of the first method.
［作 用］
基板上に成膜した超伝導組成薄膜の上に保護膜を成膜し
た後、これらの成膜体をアニーリングして保護膜付きの
超伝導薄膜を一挙に製造しようとする試みは成功しなか
った。アニーリング処理時に両膜間に相互に反応が起っ
て製品の薄膜が超伝導組成でなくなってしまうからであ
る。そこで、成膜時に、両膜の中間に、特定の物質から
なる薄層をもう１層特別に設けて、その多層成膜体をア
ニーリングする方法をとれば、上記の拡散を防止できる
という作用をもつ特定物質が存在し得るのではないかと
いつ石想を持ち、研究を進めた。その結果、少なくとも
Ｍｇ、Ｔａ、Ｎ１ 、Ｗ、ＣａおよびＴｉの酸化物が、
そのような作用を示す物質であることをつきとめた。そ
のような物質の存在が証明された以上、今後の研究によ
り、さらに多くのそのような作用を示す物質が次々と発
見されるに違いない。したがって、最も広い意味での本
発明の技術思想は、超伝導組成膜およびその保護膜のい
ずれとも、加熱処理（アニーリング）時に相互に反応せ
ず、しかもアニーリング後において、超伝導膜と保：ａ
膜との中間に介在してそれら両膜の強固な結合の妨げと
ならない接合層の使用を着想しその有効性を確認したこ
とである。特に、超伝導体がＹ１Ｂａ２Ｃｕ３Ｏ７−ｘ
であり、保訛層がＳｉ、ＡΩおよびＺｒからなる群から
選ばれる少なくとも１種の元素の酸化物であるとき、Ｍ
ｇ、Ｔａ、Ｎ１ 、Ｗ、ＣａおよびＴｉからなる群から
選ばれる少なくとも１種の元素の酸化物からなる薄層が
上述の接合層として有効であることを確認した。さらに
、上記のごとき接合層の使用は、加熱した基板上に超伝
導薄膜をエピタキシャル成長させ、その上に接合層をス
パッタリングで形成した後、さらに保護膜をスパッタリ
ングによって形成するという方法においても、有利に応
用できることがｌｉＩ認された。[Operation] After forming a protective film on a superconducting composition thin film formed on a substrate, an attempt is made to manufacture a superconducting thin film with a protective film all at once by annealing these film deposits. Not successful. This is because a mutual reaction occurs between the two films during the annealing process, and the thin film of the product no longer has a superconducting composition. Therefore, if a method is used in which a thin layer made of a specific substance is specially provided between the two films during film formation and the multilayer film is annealed, the above-mentioned diffusion can be prevented. I first had the idea that there might be a specific substance that possesses this, and I proceeded with my research. As a result, oxides of at least Mg, Ta, N1, W, Ca and Ti are
It was discovered that this substance exhibits such an effect. Now that the existence of such substances has been proven, future research will no doubt lead to the discovery of many more substances that exhibit such effects. Therefore, the technical idea of the present invention in the broadest sense is that neither the superconducting composition film nor its protective film react with each other during heat treatment (annealing), and that the superconducting film and its protective film do not react with each other after annealing.
The idea was to use a bonding layer that is interposed between the membranes and does not interfere with the strong bond between the two membranes, and its effectiveness was confirmed. In particular, the superconductor is Y1Ba2Cu3O7-x
and when the protective layer is an oxide of at least one element selected from the group consisting of Si, AΩ and Zr, M
It was confirmed that a thin layer made of an oxide of at least one element selected from the group consisting of g, Ta, N1, W, Ca, and Ti is effective as the above-mentioned bonding layer. Furthermore, the use of the bonding layer as described above is also advantageous in a method in which a superconducting thin film is epitaxially grown on a heated substrate, a bonding layer is formed thereon by sputtering, and then a protective film is further formed by sputtering. It has been confirmed that it can be applied.
以下実施例により説明する。This will be explained below using examples.
［実施例１］
全圧４ Ｘ １Ｏ−３ｔｏｒｒ、アルゴン対酸素のモル
比３対１ （Ａｒ ： ０２−３ ： １ ）の稀薄な
酸素含有アルゴン雰囲気中で、Ｚ「０２基板上にＭｇＯ
をスパッタリングして、厚さ１膜１ｍのＭｇＯ膜を形成
した。次いで所定組成のＹＢａＣｕＯ系ターゲットを用
いて同様な条件の下でスパッタリングを行ない、上記Ｍ
ｇＯ膜の上にＹ１Ｂａ２Ｃｕ３Ｏ７−、ｇの超伝導組成
薄膜を２μｓの厚さに成膜した。さらにその組成膜の上
に、同様な条件の下でスパッタリングしてＭｇＯを１−
の厚さに成膜し、さらにその上に、ＺｒＯ２ターゲット
を用いてＺ ｒ Ｏ２を同様の条件の下でスパッタリン
グすることにより、厚さＩＩＥａのＺ ｒ ０２膜を成
膜した。このようにしてつくった超伝導組成薄膜を基板
と共に酸素中でアニーリング処理することにより保護膜
付き超伝導薄膜を作成した。この超伝導薄膜の臨界温度
（Ｔ ）は８０にであり、室温における抵抗値は３
Ｘ １０’Ωであった。この超伝導膜を基板と共に、１
００℃の水に１時間浸漬したが変色等はみられず、超伝
導特性が安定に保持されていることが確認された。[Example 1] MgO was deposited on a Z'02 substrate in a dilute oxygen-containing argon atmosphere with a total pressure of 4 X 1O-3 torr and a molar ratio of argon to oxygen of 3:1 (Ar: 02-3:1).
was sputtered to form an MgO film with a thickness of 1 m. Next, sputtering was performed under the same conditions using a YBaCuO target with a predetermined composition, and the above M
A superconducting composition thin film of Y1Ba2Cu3O7-, g was formed to a thickness of 2 μs on the gO film. Furthermore, 1-MgO was added on top of the composition film by sputtering under the same conditions.
A Z r 02 film with a thickness of IIEa was further formed thereon by sputtering Z r O 2 using a ZrO 2 target under the same conditions. A superconducting thin film with a protective film was created by annealing the superconducting composition thin film thus produced together with a substrate in oxygen. The critical temperature (T) of this superconducting thin film is 80, and the resistance value at room temperature is 3.
X 10'Ω. This superconducting film together with the substrate, 1
Although it was immersed in water at 00°C for 1 hour, no discoloration was observed, confirming that the superconducting properties were stably maintained.
［実施例２］
全圧４ Ｘ ｌＯ’Ｌｏｒｒ、アルゴン対酸素のモル比
３対１ （Ａｒ：０２−３ ： １ ）の稀薄な酸素含
有アルゴン雰囲気中でＭｇＯ単結晶（１１０）基板を６
００〜８００℃に加熱し、所定組成のＹＢａＣｕＯ系タ
ーゲットを用いてスパッタリングすることにより、上記
基板上にＹ ｒ Ｂ ａ ２ Ｃｕ ａ Ｏｙ□の組成
をもつ超伝導薄膜を厚さ２虜に成膜した。さらにＴ１タ
ーゲットを用いて同じ雰囲気中で反応性スパッタリング
を行なうことにより、上記超伝導薄膜の上にＴｉＯの膜
を厚さ１ｔｌｒｎに成膜した。さらにＳ ｚ Ｏ２ター
ゲツトを用いて同じ雰囲気中でスパッタリングすること
により、ＴｉＯＪ１％の上にＳ ｌ ０２膜を厚さ１４
に成膜した。このようにして得られた保護膜付き超伝導
薄膜の室温における抵抗はＩ Ｘ １０’Ω程度であり
、臨界温度Ｔ は８０に近い値であった。この超伝導薄
膜を基板ごと１００℃の水に１時間つけたが変色等は見
られなかった。[Example 2] An MgO single crystal (110) substrate was grown in a dilute oxygen-containing argon atmosphere with a total pressure of 4 X lO'Lorr and a molar ratio of argon to oxygen of 3:1 (Ar:02-3:1).
A superconducting thin film having a composition of Y r Ba 2 Cu a Oy □ is formed to a thickness of 2 mm on the above substrate by heating to 00 to 800 °C and sputtering using a YBaCuO target with a predetermined composition. did. Further, by performing reactive sputtering in the same atmosphere using a T1 target, a TiO film with a thickness of 1 tlrn was formed on the superconducting thin film. Furthermore, by sputtering using a SzO2 target in the same atmosphere, a S102 film with a thickness of 14% was formed on 1% TiOJ.
The film was deposited on The resistance of the superconducting thin film with a protective film thus obtained at room temperature was about I x 10'Ω, and the critical temperature T was close to 80. This superconducting thin film, together with the substrate, was soaked in water at 100°C for 1 hour, but no discoloration was observed.
［実施例３］
全圧４ Ｘ ｌｏ’Ｌｏｒｒ、アルゴン対酸素のモル比
３対１（Ａｒ：Ｏ３−３＝１）の稀薄な酸素含有アルゴ
ン雰囲気中で、出力４００ＷにてＭｇＯターゲットを用
いてスパッタリングを行ない、Ｓ ｉ Ｏ２ガラス基板
上にＭｇＯを１μｓの厚さに成膜した。同じ雰囲気中で
所定組成のＹＢａＣｕＯ系ターゲットを用いてスパッタ
リングすることにより、上ｉｅ Ｍ ｇ Ｏ膜の上に組
成Ｙ１Ｂａ２Ｃｕ３Ｏ７−８の超伝導組成膜を２−の厚
さに成膜した。同じ雰囲気中でさらにこの上に、Ｎｌ
ターゲットを用いて反応性スパッタリングを行なうこと
により、上記超伝導組成膜の上にＮｉＯを１ｕｒａの厚
さに成膜し、さらにＡΩ２０３ターゲットを用いてスパ
ッタリングすることにより、上記ＮｉＯ膜の上にＡｇ２
Ｏ３膜を１ｕｒｎの厚さに成膜した。このようにしてつ
くった超伝導組成膜を基板ごと酸素中でアニーリング処
理することにより、保護膜付き超伝導薄膜を作製した。[Example 3] Using an MgO target at a power of 400 W in a dilute oxygen-containing argon atmosphere with a total pressure of 4 x lo'Lorr and a molar ratio of argon to oxygen of 3 to 1 (Ar: O3-3 = 1). Sputtering was performed to form a film of MgO to a thickness of 1 μs on the SiO2 glass substrate. A superconducting composition film having a composition of Y1Ba2Cu3O7-8 was formed to a thickness of 2-2 on the upper ie MgO film by sputtering using a YBaCuO target of a predetermined composition in the same atmosphere. Further on top of this in the same atmosphere, Nl
By performing reactive sputtering using a target, NiO is deposited to a thickness of 1 ura on the superconducting composition film, and by further sputtering using an AΩ203 target, Ag2 is deposited on the NiO film.
An O3 film was formed to a thickness of 1 urn. A superconducting thin film with a protective film was fabricated by annealing the thus-prepared superconducting composition film together with the substrate in oxygen.
これを１００℃の水に１時間浸漬したが、変色等の変化
は見られず超伝導特性は安定に保持されていることが確
認された。This was immersed in water at 100° C. for 1 hour, but no changes such as discoloration were observed, confirming that the superconducting properties were stably maintained.
［比較例１］
全圧４ Ｘ １Ｏ−３Ｌｏｒｒ、アルゴン対酸素のモル
比３対１ （Ａ ｒ ： ０２−３ ： １ ）の稀
薄な酸素含有アルゴン雰囲気中で、Ｚ ｒ ０２基板上
にＭｇＯをスパッタリングして、厚さ１膜ｍのＭｇＯ膜
を形成した。次いで所定組成のＹＢａＣｕＯ系ターゲッ
トを用いて同様な条件の下でスパッタリングを行ない、
上記ＭｇＯ膜の上にＹＩＢａ２Ｃｕ３０７□の超伝導組
成薄膜を２庫の厚さに成膜した。[Comparative Example 1] MgO was deposited on a Zr02 substrate in a dilute oxygen-containing argon atmosphere with a total pressure of 4 x 1O-3Lorr and a molar ratio of argon to oxygen of 3:1 (Ar: 02-3:1). A MgO film having a thickness of 1 m was formed by sputtering. Next, sputtering was performed under the same conditions using a YBaCuO target with a predetermined composition,
A superconducting thin film of YIBa2Cu307□ was formed on the MgO film to a thickness of 2 cm.
さらにその上に、Ｚ ｒ Ｏ２ターゲツトを用いてＺ
ｒ Ｏ２を同様の条件の下でスパッタリングすることに
より、厚さ１郁のＺ ｒ Ｏ２膜を成膜した。Furthermore, on top of that, Z r O2 target is used.
By sputtering rO2 under the same conditions, a ZrO2 film with a thickness of 1 layer was formed.
このようにしてつくった超伝導組成膜を基板と共に酸素
中でアニーリング処理することにより保護膜付き超伝導
薄膜をつくろうとしたが、Ｚ ｒ Ｏ２膜とＹＢａＣｕ
Ｏ膜との間に反応が生じたため超伝導薄膜はできなかっ
た。An attempt was made to create a superconducting thin film with a protective film by annealing the superconducting composition film thus produced together with the substrate in oxygen, but the ZrO2 film and YBaCu
A superconducting thin film could not be formed because a reaction occurred with the O film.
［比較例２］
全圧４Ｘ１０″″３ｔｏｒｒ、アルゴン対酸素のモル比
３対１ （Ａｒ：０゜−３＝１）の稀薄な酸素含有アル
ゴン雰囲気中でＭ ｇ ＯＩｌｌ結晶（＋１０）基板を
６００〜８００℃に加熱し、所定組成のＹＢａＣｕＯ系
ターゲットを用いてスパッタリングすることにより、上
記基板上にＹ１Ｂａ２Ｃｕ３Ｏ７□の組成をもつ超伝導
薄膜を厚さ２虜に成膜した。さらにＳ ｔ Ｏ２ターゲ
ツトを用いて同じ雰囲気中でスパッタリングすることに
より、ＹＩＢａ２Ｃｕ３０７□膜の上にＳ ｉＯ２膜を
厚さ１ｔＨａに成膜した。[Comparative Example 2] A M g OIll crystal (+10) substrate was grown at a dilute oxygen-containing argon atmosphere with a total pressure of 4 x 10''3 torr and a molar ratio of argon to oxygen of 3 to 1 (Ar: 0° - 3 = 1). A superconducting thin film having a composition of Y1Ba2Cu3O7□ was formed to a thickness of 2 cm on the above substrate by heating to ~800°C and sputtering using a YBaCuO target having a predetermined composition. Furthermore, by sputtering using an S t O 2 target in the same atmosphere, a SiO 2 film was formed to a thickness of 1 tHa on the YIBa 2 Cu 30 7 □ film.
このようにして、保護膜付き超伝導薄膜を形成しようと
したが、両膜間に反応が生じたためＹＢａＣｕＯ系の組
成が変化してしまい、超伝導薄膜は得られなかった。Although an attempt was made to form a superconducting thin film with a protective film in this manner, a reaction occurred between the two films, resulting in a change in the composition of the YBaCuO system, and a superconducting thin film could not be obtained.
［比較例３］
全圧４ Ｘ ｌＯ’ｔｏｒｒ、アルゴン対酸素のモル比
３対１ （Ａｒ：０２−３ ： １ ）の稀薄な酸素含
有アルゴン雰囲気中で、出力４００ＷにてＭｇＯターゲ
ットを用いてスパッタリングを行ない、ＳｉＯ２ガラス
基板上にＭｇＯを１−の厚さに成膜した。同じ雰囲気中
で所定組成のＹＢａＣｕＯ系ターゲットを用いてスパッ
タリングすることにより、上記ＭｇＯ膜の上に組成ＹＩ
Ｂａ２Ｃｕ３０７□の超伝導組成膜を２μｍの厚さに成
膜した。さらにＡｌ１２０３ターゲツトを用いてスパッ
タリングすることにより、上記ＹＢａＣｕＯ薄膜の上に
へｇ２０３膜を１扉の厚さに成膜した。このようにして
つくった多層成膜体を基板ごと酸素中でアニーリング処
理することにより、保護膜付き超伝導薄膜をつくろうと
したがアニーリング時に層間に反応が生じたため超伝導
薄膜は得られなかった。[Comparative Example 3] Using an MgO target at an output of 400 W in a dilute oxygen-containing argon atmosphere with a total pressure of 4 X lO'torr and a molar ratio of argon to oxygen of 3:1 (Ar:02-3:1). Sputtering was performed to form a film of MgO to a thickness of 1-1 on the SiO2 glass substrate. By sputtering using a YBaCuO target with a predetermined composition in the same atmosphere, the composition YI is deposited on the MgO film.
A superconducting composition film of Ba2Cu307□ was formed to a thickness of 2 μm. Further, by sputtering using an Al1203 target, a Heg203 film was formed to a thickness of one door on the YBaCuO thin film. An attempt was made to create a superconducting thin film with a protective film by annealing the multilayer film formed in this way together with the substrate in oxygen, but a superconducting thin film could not be obtained because a reaction occurred between the layers during annealing.
［比較例４］
保護膜を成膜しないことを除き上記比較例１〜３の各々
と同じことを、それぞれくり返した。いずれの場合も超
伝導薄膜が得られたが、これらの膜は１００℃の水につ
けると、いずれも数分で青色に変色し、一部白色に変化
した。変色した膜は超伝導特性を有していなかった。[Comparative Example 4] The same procedures as in Comparative Examples 1 to 3 above were repeated except that no protective film was formed. Superconducting thin films were obtained in all cases, but when these films were immersed in water at 100°C, the color changed to blue within a few minutes, and partially to white. The discolored film did not have superconducting properties.
［発明の効果］
本発明の方法によれば、基板上に超伝導組成薄膜を形成
すること、その上に接合層を成膜することおよびさらに
その上に保護層を成膜することを同一の雰囲気の中で連
続的に行なうことができ、その後、１回の加熱処理（ア
ニーリング）で直ちに超伝導薄膜を形成することができ
るので、製造工程が簡単となり、生産性が向上する。基
板を加熱して直接結晶化した超伝導薄膜をつくる場合に
も、超伝導膜形成のときと同じ雰囲気中で、基板が加熱
された状態のま＼、次々と接合層および保護層をスパッ
タリングによって成膜できるので上記と事情は同じであ
り生産性が向上する。[Effects of the Invention] According to the method of the present invention, forming a superconducting composition thin film on a substrate, forming a bonding layer thereon, and further forming a protective layer thereon can be performed in the same process. This can be carried out continuously in an atmosphere, and then a superconducting thin film can be formed immediately with one heat treatment (annealing), which simplifies the manufacturing process and improves productivity. When directly crystallizing a superconducting thin film by heating a substrate, the bonding layer and protective layer are successively sputtered while the substrate is heated in the same atmosphere as when forming the superconducting film. Since a film can be formed, the situation is the same as above, and productivity is improved.
Claims (1)
む薄層からなる超伝導組成薄膜を成膜し、該超伝導組成
薄膜の上に、アニーリング処理時に該超伝導組成薄膜と
相互に反応しない物質の薄層からなる接合層を成膜し、
該接合層の上に、アニーリング処理時に該接合層と相互
に反応しない物質の薄層からなる保護層を成膜すること
によって多層成膜体を形成し、該多層成膜体をアニーリ
ング処理することからなる保護膜付き超伝導薄膜の形成
方法。 ２、成膜装置内で、加熱された基板表面に、超伝導とな
る組成で各成分元素を薄層状に付着せしめて超伝導薄膜
を成膜し、該超伝導薄膜表面に、基板を加熱した状態に
おいても該超伝導薄膜と相互に反応しない物質の薄層か
らなる接合層を成膜し、該接合層表面に、該接合層と相
互に反応しない物質の薄層からなる保護層を成膜するこ
とからなる保護膜付き超伝導薄膜の形成方法。 ３、前記接合層がＭｇ、Ｔａ、Ｎｉ、Ｗ、ＣａおよびＴ
ｉからなる群から選ばれる少なくとも１種の元素の酸化
物からなる薄層であり、保護層がＳｉ、ＡｌおよびＺｒ
からなる群から選ばれる少なくとも１種の元素の酸化物
からなる薄層であることを特徴とする請求項１または２
のいずれかに記載の方法。[Claims] 1. A superconducting composition thin film consisting of a thin layer containing each component element with a composition that becomes a superconductor is formed on the substrate surface, and the superconducting composition thin film is coated with the superconducting composition thin film during annealing treatment. A bonding layer consisting of a thin layer of a substance that does not react with the superconducting composition thin film is formed,
Forming a multilayer film body by forming a protective layer made of a thin layer of a substance that does not react with the bonding layer during annealing treatment on the bonding layer, and subjecting the multilayer film body to an annealing treatment. A method for forming a superconducting thin film with a protective film. 2. A superconducting thin film was formed by depositing each component element in a thin layer with a superconducting composition onto the heated substrate surface in a film forming apparatus, and the substrate was heated on the superconducting thin film surface. A bonding layer made of a thin layer of a substance that does not react with the superconducting thin film even under the conditions is formed, and a protective layer made of a thin layer of a substance that does not react with the bonding layer is formed on the surface of the bonding layer. A method for forming a superconducting thin film with a protective film. 3. The bonding layer is made of Mg, Ta, Ni, W, Ca and T.
It is a thin layer made of an oxide of at least one element selected from the group consisting of i, and the protective layer is made of Si, Al and Zr.
Claim 1 or 2, characterized in that the thin layer is made of an oxide of at least one element selected from the group consisting of
The method described in any of the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15776488A JPH026303A (en) | 1988-06-26 | 1988-06-26 | Formation of superconducting thin film with protecting film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15776488A JPH026303A (en) | 1988-06-26 | 1988-06-26 | Formation of superconducting thin film with protecting film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH026303A true JPH026303A (en) | 1990-01-10 |
Family
ID=15656803
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15776488A Pending JPH026303A (en) | 1988-06-26 | 1988-06-26 | Formation of superconducting thin film with protecting film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH026303A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6454615A (en) * | 1987-08-25 | 1989-03-02 | Furukawa Electric Co Ltd | Manufacture of ceramic superconductive wire |
| JPH01115009A (en) * | 1987-10-28 | 1989-05-08 | Furukawa Electric Co Ltd:The | Oxide superconducting compact and manufacture thereof |
| JPH01179779A (en) * | 1988-01-11 | 1989-07-17 | Sumitomo Electric Ind Ltd | Method for protecting multi-ply oxide superconductor |
| JPH01246354A (en) * | 1988-03-28 | 1989-10-02 | Oki Electric Ind Co Ltd | Production of passivation film on thin film of high temperature oxide superconductor |
-
1988
- 1988-06-26 JP JP15776488A patent/JPH026303A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6454615A (en) * | 1987-08-25 | 1989-03-02 | Furukawa Electric Co Ltd | Manufacture of ceramic superconductive wire |
| JPH01115009A (en) * | 1987-10-28 | 1989-05-08 | Furukawa Electric Co Ltd:The | Oxide superconducting compact and manufacture thereof |
| JPH01179779A (en) * | 1988-01-11 | 1989-07-17 | Sumitomo Electric Ind Ltd | Method for protecting multi-ply oxide superconductor |
| JPH01246354A (en) * | 1988-03-28 | 1989-10-02 | Oki Electric Ind Co Ltd | Production of passivation film on thin film of high temperature oxide superconductor |
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