JPH03297175A - Manufacture of thin film superconducting device - Google Patents
Manufacture of thin film superconducting deviceInfo
- Publication number
- JPH03297175A JPH03297175A JP2099705A JP9970590A JPH03297175A JP H03297175 A JPH03297175 A JP H03297175A JP 2099705 A JP2099705 A JP 2099705A JP 9970590 A JP9970590 A JP 9970590A JP H03297175 A JPH03297175 A JP H03297175A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- superconducting
- rays
- irradiation
- weak coupling
- 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
- 239000010409 thin film Substances 0.000 title claims abstract description 49
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 12
- 239000010949 copper Substances 0.000 claims abstract description 24
- 239000002131 composite material Substances 0.000 claims abstract description 23
- 229910052802 copper Inorganic materials 0.000 claims abstract description 21
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 18
- 230000008878 coupling Effects 0.000 claims abstract description 14
- 238000010168 coupling process Methods 0.000 claims abstract description 14
- 238000005859 coupling reaction Methods 0.000 claims abstract description 14
- 230000001678 irradiating effect Effects 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 11
- 229910052779 Neodymium Inorganic materials 0.000 claims description 4
- 229910052772 Samarium Inorganic materials 0.000 claims description 4
- 229910052684 Cerium Inorganic materials 0.000 claims description 3
- 229910052776 Thorium Inorganic materials 0.000 claims description 3
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 2
- 238000010894 electron beam technology Methods 0.000 abstract description 16
- 239000013078 crystal Substances 0.000 abstract description 13
- 239000000758 substrate Substances 0.000 abstract description 12
- 239000002887 superconductor Substances 0.000 abstract description 10
- 239000012212 insulator Substances 0.000 abstract description 7
- 239000004065 semiconductor Substances 0.000 abstract description 6
- 229920002120 photoresistant polymer Polymers 0.000 abstract description 5
- 229910052751 metal Inorganic materials 0.000 abstract description 4
- 239000002184 metal Substances 0.000 abstract description 3
- 230000000873 masking effect Effects 0.000 abstract description 2
- 239000000203 mixture Substances 0.000 abstract description 2
- 229910002480 Cu-O Inorganic materials 0.000 abstract 1
- 230000005641 tunneling Effects 0.000 abstract 1
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 9
- 239000005751 Copper oxide Substances 0.000 description 7
- 229910000431 copper oxide Inorganic materials 0.000 description 7
- 239000010408 film Substances 0.000 description 7
- 230000009467 reduction Effects 0.000 description 4
- 238000004544 sputter deposition Methods 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000005240 physical vapour deposition Methods 0.000 description 2
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 2
- 239000004926 polymethyl methacrylate Substances 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- 206010021143 Hypoxia Diseases 0.000 description 1
- 238000001505 atmospheric-pressure chemical vapour deposition Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- CFJRGWXELQQLSA-UHFFFAOYSA-N azanylidyneniobium Chemical compound [Nb]#N CFJRGWXELQQLSA-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 150000001879 copper Chemical class 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005566 electron beam evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 238000010884 ion-beam technique Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004518 low pressure chemical vapour deposition Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000002207 thermal evaporation Methods 0.000 description 1
- 230000007704 transition Effects 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)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は超電導素子、特に弱結合部を有するＮｄ２Ｃｕ
Ｏ，型結晶構造の銅複合酸化物薄膜超電導素子の製造方
法に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to superconducting elements, particularly Nd2Cu having weak coupling parts.
The present invention relates to a method for manufacturing a copper composite oxide thin film superconducting element having an O, type crystal structure.
従来の技術
超電導体としては、Ａ１５型２元系化合物として窒化ニ
オブ（ＮｂＮ）やニオブ３ゲルマニウム（Ｎｂ３Ｇｅ）
などが知られている。又これらの材料を用いた超電導素
子も種々提案されている。Conventional technology superconductors include niobium nitride (NbN) and niobium 3 germanium (Nb3Ge) as A15 type binary compounds.
etc. are known. Various superconducting elements using these materials have also been proposed.
一方、ペロブスカイト系化合物としては、Ｂａ −Ｐｂ
−Ｂｉ−０系（特開昭６０−１７３８８５号公報）が知
られており、この系の材料を用いた超電導素子も数多く
研究されている。Ｂａ−Ｌａ−Ｃｕ−０系［Ｊ、Ｇ、Ｂ
ｅｄｎｏｒｚ ａｎｄ Ｋ、Ａ、Ｍｕｌｌｅｒ、 ツ
アイト シュリフト フェア フィジーク（Ｚｅｉｔｓ
ｈｒｉｆｔ ｆｕｒｐｈｙｓｉｋ Ｂ）−Ｃｏｎｄｅｎ
ｓｅｄ Ｍａｔｔｅｒ ６４，１８９−１９３ （１９
８６）１に続いてＹ−Ｂａ−Ｃｕ−０系［Ｍ、に、 Ｗ
ｕ ｅｔ ａｌ、 フィジカル レビュー レターズ（
ＰｈｙｓｉｃａＩ Ｒｅｖｉｅｗ Ｌｅｔｔｅｒｓ）
Ｖｏｌ、 ５Ｂ、 Ｎｏ、 ９．９０８−９１０（１９
８７） ］などが発見された。更にこれまでのホールド
ープ型と異なる電子ドープ型の超電導体が発見された。On the other hand, as a perovskite compound, Ba-Pb
-Bi-0 series (Japanese Unexamined Patent Publication No. 173885/1985) is known, and many superconducting elements using materials of this series have been studied. Ba-La-Cu-0 system [J, G, B
ednorz and K, A, Muller, Zeits Schrift Fair Physique (Zeits
hrift furphysik B)-Conden
sed Matter 64, 189-193 (19
86) Following 1, Y-Ba-Cu-0 system [M, Ni, W
u et al, Physical Review Letters (
Physica I Review Letters)
Vol, 5B, No, 9.908-910 (19
87) ] were discovered. Furthermore, an electron-doped superconductor was discovered, which is different from the hole-doped type used up until now.
これはＮｄｚＣｕＯ，型結晶構造を持つ銅複合酸化物で
あり、（Ａ 、 Ｂ ）ｚｃｕＯｎ−ｘＦｘ （但し、
Ａ ： Ｎｄ、 Ｓｍ、 Ｐｒのうちの少なくとも一種
の元素、Ｂ ： Ｃｅ、 Ｔｈのうちの少なくとも一種
の元素、Ｘ：０≦Ｘ〈４）の一般式で表される。This is a copper composite oxide with a NdzCuO type crystal structure, and (A, B)zcuOn-xFx (however,
A: at least one element among Nd, Sm, and Pr; B: at least one element among Ce and Th; X: represented by the general formula 0≦X<4).
Ｎｄ−Ｃｅ−Ｃｕ−０系がその代表である。A typical example is the Nd-Ce-Cu-0 system.
Ｎｄ−Ｃｅ−Ｃｕ−０系に代表されるＮｄ、ＣｕＯ，型
結晶構造を持つ銅複合酸化物は、例えばスパッタリング
法などの薄膜形成手法を用いると、薄膜状の絶縁体又は
半導体として形成され得る。Copper composite oxides having a Nd, CuO, type crystal structure represented by the Nd-Ce-Cu-0 system can be formed as a thin film insulator or semiconductor by using a thin film formation method such as sputtering, for example. .
発明が解決しようとする課題
しかしながら従来は、この絶縁体又は半導体薄膜を利用
して超電導素子を作製するためのプロセス技術が確立し
ておらず、新規素子の実現は困難と考えられている。Problems to be Solved by the Invention However, until now, no process technology has been established for producing superconducting elements using this insulator or semiconductor thin film, and it is considered difficult to realize new elements.
これに対し本発明者らは、このＮｄｚＣｕ０４型結晶構
造を持つ銅複合酸化物結晶中の酸素原子量すなわち結晶
の酸化状態の精密制御によりその絶縁体又は半導体−超
電導体特性を制御できると考え、結晶中の酸素の欠損量
の制御技術を研究し、これに基いてＮｄ−Ｃｅ−Ｃｕ−
０系に代表されるＮｄｚＣｕＯ，型結晶構造を持つ銅複
合酸化物を用いた新しい超電導素子の製造方法を発明し
た。In contrast, the present inventors believed that by precisely controlling the amount of oxygen atoms in the copper composite oxide crystal having the NdzCu04 type crystal structure, that is, the oxidation state of the crystal, the insulator or semiconductor-superconductor properties of the crystal could be controlled. We researched the technology to control the amount of oxygen deficiency in Nd-Ce-Cu-
We have invented a new method for manufacturing superconducting elements using copper composite oxides with a NdzCuO type crystal structure, typically the 0-series.
課題を解決するための手段
本発明における銅複合酸化物薄膜を用いた超電導素子の
製造方法は、銅複合酸化物（Ａ、 Ｂ）ｚｃｕｏ４−ｘ
Ｆｘ （但し、Ａ ： Ｎｄ、 Ｓｍ、 Ｐｒのうちの
少なくとも一種の元素、Ｂ ： Ｃｅ、 Ｔｈのうちの
少なくとも一種の元素、Ｘ：０≦Ｘ〈４）の薄膜に、Ｘ
線、紫外線、電子線から選ばれたものを部分的に照射す
ることにより、少なくとも２つ以上の超電導電極部及び
弱結合部を有する構造を形成することを特徴としている
。Means for Solving the Problems The method of manufacturing a superconducting element using a copper composite oxide thin film in the present invention includes copper composite oxides (A, B) zcuo4-x
In a thin film of Fx (A: at least one element among Nd, Sm, and Pr, B: at least one element among Ce and Th, X: 0≦X<4),
It is characterized in that a structure having at least two or more superconducting electrode parts and weak coupling parts is formed by partially irradiating with radiation selected from radiation, ultraviolet rays, and electron beams.
つまりＮｄ−Ｃｅ−Ｃｕ −０’Ｆｉｇ膜に上記部分照
射を行うことにより、前記薄膜中に照射領域からなる超
電導部を形成すると同時に前記超電導部中に微少な非照
射領域を残して弱結合部とする。In other words, by performing the partial irradiation on the Nd-Ce-Cu -0'Fig film, a superconducting part consisting of an irradiated area is formed in the thin film, and at the same time a small non-irradiated area is left in the superconducting part to form a weak coupling part. shall be.
これにより超電導部を前記弱結合部によって少なくとも
２つの領域に分離した構造を形成する。This forms a structure in which the superconducting portion is separated into at least two regions by the weak coupling portion.
尚、弱結合部をマスクパターンを用いて形成する場合、
マスクパターンとしてＰＭＭＡなどのアクリル樹脂系や
ＣＭＳなどのスチレン樹脂系の電子線レジストあるいは
光りソグラフィ用のネガレジストなどを用いることがで
きる。In addition, when forming the weak coupling part using a mask pattern,
As the mask pattern, an acrylic resin-based resist such as PMMA, a styrene resin-based resist such as CMS, an electron beam resist, a negative resist for optical lithography, or the like can be used.
作用
本発明にかかる薄膜超電導素子の製造方法は銅複合酸化
物を薄膜化して用いるので、従来の焼結体に比べ均質な
超電導体である。Function: Since the method for producing a thin film superconducting element according to the present invention uses a thin film of copper composite oxide, the superconductor is more homogeneous than a conventional sintered body.
又この薄膜に対してＸ線、紫外線、電子線などを照射す
るとＣｕ−０結合軌道の価電子が励起され、０□−が中
性化されて結晶中から逃げ出しＣｕ酸化物が還元される
結果、Ｎｄ−Ｃｅ−Ｃｕ−０薄膜の照射領域で超電導性
が得られ、又その非照射領域は絶縁体又は半導体のまま
で残り弱結合部となり、非常に高精度な薄膜超電導素子
の製造が簡単に実現される。Also, when this thin film is irradiated with X-rays, ultraviolet rays, electron beams, etc., the valence electrons in the Cu-0 bond orbital are excited, and 0□- is neutralized and escapes from the crystal, resulting in the reduction of Cu oxide. , superconductivity is obtained in the irradiated region of the Nd-Ce-Cu-0 thin film, and the non-irradiated region remains an insulator or semiconductor and remains as a weak bond, making it easy to manufacture thin-film superconducting elements with extremely high precision. will be realized.
実施例 本発明の実施例を、第１図及び第２図に基き説明する。Example An embodiment of the present invention will be explained based on FIGS. 1 and 2.
第１図に示すように、ＮｄｚＣｕＯ，型結晶構造を持つ
Ｎｄ−Ｃｅ−Ｃｕ−０系の銅複合酸化物薄膜２を基体１
上に例えばスパッタリング法で形成する。薄膜２の一部
分に、第２図に示すように、Ｘ線３（紫外線、電子線な
どでも良い）を照射することにより超電導電極部４を形
成する。この超電導電極部４はＸ線３の照射量によって
絶縁体又は半導体から超電導体に性質が変化することを
本発明者らは確認した。この照射時にＮｄ −Ｃｅ−Ｃ
ｕ−Ｏｆｉ！膜２の微小部を金属、フォトレジスト、電
子線レジストなどでマスクすることにより幅が０．２μ
ｍ程度以下の微少な非照射領域を形成する。この非照射
領域は超電導電極部４．４間の弱結合部５となる。本実
施例のように超電導電極部４が２つ即ち二端子素子であ
ると、弱結合部５がトンネル形のジョセフソン素子とな
る。As shown in FIG.
It is formed on top by, for example, a sputtering method. As shown in FIG. 2, a superconducting electrode portion 4 is formed by irradiating a portion of the thin film 2 with X-rays 3 (ultraviolet rays, electron beams, etc.). The present inventors have confirmed that the properties of the superconducting electrode portion 4 change from an insulator or a semiconductor to a superconductor depending on the amount of X-ray 3 irradiation. During this irradiation, Nd-Ce-C
u-Ofi! By masking the minute part of the film 2 with metal, photoresist, electron beam resist, etc., the width is reduced to 0.2μ.
A minute non-irradiation area of about m or less is formed. This non-irradiated region becomes a weak coupling portion 5 between the superconducting electrode portions 4.4. When there are two superconducting electrode sections 4, that is, a two-terminal element as in this embodiment, the weak coupling section 5 becomes a tunnel-type Josephson element.
超電導体薄膜の形成には、他にＡ−Ｂ−ＣｕＯ系などの
銅複合酸化物を熱蒸着例えば電子ビ−ム蒸着、レーザビ
ーム蒸着などの物理的気相成長法で基体上に付着させる
ことができる。本発明者らは、銅複合酸化物（Ａ、 Ｂ
）ｚｃｕ０４−ＸＦｘ（但し、Ａ ： Ｎｄ、 Ｓｍ、
Ｐｒのうちの少なくとも−種の元素、Ｂ ： Ｃｅ、
Ｔｈのうちの少なくとも一種の元素、Ｘ：０≦Ｘ＜４）
ｆｊｌ膜において元素比率が、０．１４≦Ｂ／Ｃｕ≦０
．１８の範囲にあれば、臨界温度に多少の差があっても
超電導現象が見い出されることを確認した。この銅複合
酸化物薄膜の形成法は物理的気相成長法に限定されたも
のではなく、化学的気相成長法例えば常圧あるいは減圧
化学的気相成長法、プラズマ化学的気相成長法、光化学
的気相成長法も、成分Ａ、 Ｂ、ＣｕＯ比を合致させれ
ば有効であることを本発明者らは確認した。In addition, to form a superconductor thin film, a copper composite oxide such as A-B-CuO may be deposited on a substrate by physical vapor deposition methods such as thermal evaporation, e.g., electron beam evaporation, and laser beam evaporation. Can be done. The present inventors have developed copper composite oxides (A, B
)zcu04-XFx (A: Nd, Sm,
At least one element of Pr, B: Ce,
At least one element of Th, X: 0≦X<4)
In the fjl film, the element ratio is 0.14≦B/Cu≦0
．． It was confirmed that superconductivity can be observed even if there is a slight difference in critical temperature within the range of 18. The method for forming this copper composite oxide thin film is not limited to physical vapor deposition, but also includes chemical vapor deposition, such as atmospheric or low pressure chemical vapor deposition, plasma chemical vapor deposition, The present inventors have confirmed that the photochemical vapor deposition method is also effective if the ratios of components A, B, and CuO are matched.
本発明者らは銅複合酸化物薄膜２を基体１の表面に付着
させる際、基体１の最適の温度範囲が存在することを確
認した。即ち基体最適温度範囲は２００〜１０００°Ｃ
である。２００°Ｃ以下では複合銅酸化物薄膜２の基体
１表面への付着性が悪くなる。１０００°Ｃ以上では複
合銅酸化物薄膜２中の成分Ａ、Ｂ及びＣｕの化学量論比
からのずれが大きくなる。The present inventors have confirmed that there is an optimal temperature range for the substrate 1 when depositing the copper composite oxide thin film 2 on the surface of the substrate 1. In other words, the optimum temperature range for the substrate is 200 to 1000°C.
It is. At temperatures below 200°C, the adhesion of the composite copper oxide thin film 2 to the surface of the substrate 1 deteriorates. At temperatures above 1000°C, the deviation from the stoichiometric ratio of components A, B, and Cu in the composite copper oxide thin film 2 increases.
更に、銅複合酸化物薄膜２を付着させるときの基体１の
温度はとりわけ５００〜７００°Ｃの範囲がこの種の蒸
着装置の機能、銅複合酸化物薄膜の特性の再現性からみ
て最適であることを本発明者らは確認した。Furthermore, the temperature of the substrate 1 when depositing the copper composite oxide thin film 2 is particularly optimal in the range of 500 to 700°C from the viewpoint of the function of this type of vapor deposition apparatus and the reproducibility of the characteristics of the copper composite oxide thin film. The present inventors confirmed this.
本発明者らはこの種の銅複合酸化物薄膜２を減圧下又は
不活性雰囲気下でＸ線又は紫外線又は電子線などによる
照射処理を行うことにより前述のように半導体あるいは
絶縁体から超電導体へのの性質変化を示すように制御で
きることを見い出した。この照射処理は通常のＷ、Ｍｏ
、Ｒｈ、 Ｃｕ、 Ｆｅ、 Ｃｏ、 Ｃｒ、 ＡＬ Ｍ
ｇ、 ＺｒなとのＸ線管、又はＨ，Ｈｅ、 Ｎｅなどの
紫外線、又は電子線源を用いて行われる。この効果は最
適化された組成を持つ複合銅酸化物を還元し、結晶中の
酸素欠損量を制御して超電導対を形成するための電子を
結晶にドープするために得られるものと考えられる。The present inventors transformed this type of copper composite oxide thin film 2 from a semiconductor or an insulator into a superconductor as described above by irradiating this type of copper composite oxide thin film 2 with X-rays, ultraviolet rays, or electron beams under reduced pressure or an inert atmosphere. It was discovered that it can be controlled to show changes in the properties of . This irradiation treatment is carried out using ordinary W, Mo
, Rh, Cu, Fe, Co, Cr, AL M
It is carried out using an X-ray tube such as G, Zr, ultraviolet rays such as H, He, Ne, or an electron beam source. This effect is thought to be obtained by reducing the composite copper oxide with an optimized composition, controlling the amount of oxygen vacancies in the crystal, and doping the crystal with electrons to form superconducting pairs.
Ｘ線や紫外線、又は電子線の利用はイオンビームの利用
と異なり、金属元素同士の比率の変化や薄膜の結晶性の
低下などを引起こさずに均一性の良好な処理を可能とす
るので、薄膜２の非照射領域に大きな損傷を与えないと
いう利点を有する。又Ｘ線、紫外線、電子線などはその
波長が短く、加工する超電導薄膜の領域を微細に制御し
、精密、微細な銅酸化物薄膜の還元処理を可能とする。Unlike the use of ion beams, the use of X-rays, ultraviolet rays, or electron beams enables processing with good uniformity without causing changes in the ratio of metal elements or deterioration of the crystallinity of thin films. This has the advantage of not causing major damage to the non-irradiated area of the thin film 2. In addition, X-rays, ultraviolet rays, electron beams, etc. have short wavelengths, and the area of the superconducting thin film to be processed can be finely controlled, allowing precise and fine reduction treatment of the copper oxide thin film.
これにより、サブミクロン加工を必要とするジョセフソ
ンデバイスなどのデバイス作製を容易に行うことができ
る。This makes it possible to easily manufacture devices such as Josephson devices that require submicron processing.
（具体実施例）
ＳｒＴｉＯｉ単結晶（１００）面を基体に用い、高周波
プレナーマグネトロンスバッタにより、焼結したＮｄ１
．１ｓｃｅｏ、 １５ｃａ１．５０４． ｂターゲット
を計と０２の混合ガス雰囲気でスパッタリング蒸着して
、前記基体上に結晶性のＮｄ１１５Ｃｅｏ、 ＋５Ｃｕ
Ｏ＝薄膜として付着させ層状構造を形成した。本実施例
では、ガス圧力は０．３Ｐａ、スパッタリング電力は１
６０Ｗ、スパッタリング時間は１時間、薄膜の膜厚は０
．１μｍ、基体温度は６５０°Ｃであった。形成された
薄膜を更に９００°Ｃに加熱して８Ｘ １０− ’Ｔｏ
ｒｒの真空槽内で３０分保持した後、この薄膜に対して
レジストを用いてマスクパターンを形成し部分的にＨｅ
Ｉ［紫外線を照射することにより制御性良（照射領域か
らなる超電導電極部と非照射領域からなる弱結合部とを
形成することができた。この場合、レジストは有機溶剤
のみで現像できる紫外線３に対するＰＭＭＡ、あるいは
ネガレジストなどが適している。通常これらのレジスト
は２００°Ｃ以上に加熱されると変質してしまいレジス
トとしての機能を発揮できないものが多いが、本実施例
の紫外線照射はほとんど基板温度を上昇させることがな
く効果的である。(Specific Example) Using a SrTiOi single crystal (100) plane as a substrate, Nd1 was sintered by high-frequency planar magnetron scattering.
．． 1sceo, 15ca1.504. b Target is sputter-deposited in a mixed gas atmosphere of +02 to deposit crystalline Nd115Ceo, +5Cu on the substrate.
O=deposited as a thin film to form a layered structure. In this example, the gas pressure was 0.3 Pa, and the sputtering power was 1
60W, sputtering time 1 hour, thin film thickness 0
．． 1 μm, and the substrate temperature was 650°C. The formed thin film was further heated to 900°C to 8X 10-'To
After holding the thin film in a vacuum chamber of
I [By irradiating ultraviolet rays, it was possible to form a superconducting electrode part consisting of an irradiated area and a weak bonding part consisting of a non-irradiated area. PMMA or negative resists are suitable for resists.Normally, these resists change in quality when heated to 200°C or higher and are unable to function as a resist, but in this example, ultraviolet irradiation is almost impossible. This is effective without increasing the substrate temperature.
本実施例では被膜の膜厚は０．１μｍであるが、膜厚は
それ以下の薄い場合（０，０３μｍ）も超電導が発生す
ることを確認した。更に、前記薄膜に対して電子線レジ
ストなどを用いてマスクパターンを形成し３０ｋＶの電
子線を照射することにより制御性層（超超電導部と弱結
合部とを形成することができた。この場合、レジストは
有機溶剤のみで現像できる電子線に対するＰ−ＭＭＡ、
あるいはネガレジストなどが通している。In this example, the film thickness of the film is 0.1 μm, but it was confirmed that superconductivity occurs even when the film thickness is less than that (0.03 μm). Furthermore, by forming a mask pattern on the thin film using an electron beam resist or the like and irradiating it with a 30 kV electron beam, it was possible to form a controllable layer (a superconducting part and a weak coupling part. In this case , the resist is P-MMA for electron beams that can be developed only with organic solvents,
Or a negative resist etc. is used.
これ以外にも真空槽内にＸ線管を設置し、このＸ線の照
射可能領域内に部分的に金属マスクを設置し微細部分の
非照射領域を弱結合部、そのほかの照射領域を超電導体
とする銅酸化物薄膜の還元処理をすることもできる。こ
れは膜厚が０．５μｍ以上の場合非常ムこ有効であり実
用的である。In addition to this, an X-ray tube is installed in a vacuum chamber, and a metal mask is partially installed within the X-ray irradiation area, and the fine non-irradiation area is a weak coupling area, and the other irradiation area is a superconductor. It is also possible to perform a reduction treatment on a copper oxide thin film. This is extremely effective and practical when the film thickness is 0.5 μm or more.
発明の効果
本発明によれば、Ｘ線などの照射による銅酸化物薄膜の
還元処理は薄膜の温度上昇がなく。Effects of the Invention According to the present invention, the reduction treatment of a copper oxide thin film by irradiation with X-rays or the like does not cause a rise in the temperature of the thin film.
制御性もよく、且つ処理が簡単であるので、非常に高精
度の弱結合部を持つ均一性の良い薄膜超電導素子を容易
に得ることができる。Since the controllability is good and the processing is simple, it is possible to easily obtain a thin film superconducting element with good uniformity and weak coupling portions with very high precision.
上記薄膜超電導素子は例えばＳｉあるいはＧａＡｓなど
のデバイスとの集積化が可能となる。又本発明はジョセ
フソン素子などの各種超電導デバイスの製造方法に適用
することができる。本発明は、特にこの種の化合物超電
導体の転移温度が室温になる可能性もあり、実用の範囲
は広く工業的価値は高い。The thin film superconducting element described above can be integrated with devices such as Si or GaAs. Further, the present invention can be applied to methods of manufacturing various superconducting devices such as Josephson elements. The present invention has a wide range of practical application and high industrial value, especially since the transition temperature of this type of compound superconductor may be room temperature.
第１図は本発明の一実施例において基板上に薄膜が形成
された状態の縦断面図、第２図は照射処理された状態の
縦断面図である。
複合銅酸化物薄膜
・・Ｘ線又は紫外線
又は電子線
超電導電極部
一弱結合部FIG. 1 is a vertical cross-sectional view of a thin film formed on a substrate in an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of the thin film after irradiation treatment. Composite copper oxide thin film...X-ray or ultraviolet rays or electron beam superconducting electrode part weak bonding part
Claims (3)
Ｆ＿Ｘ（但し、Ａ：Ｎｄ、Ｓｍ、Ｐｒのうちの少なくと
も一種の元素、Ｂ：Ｃｅ、Ｔｈのうちの少なくとも一種
の元素、Ｘ：０≦Ｘ＜４）の薄膜に、Ｘ線、紫外線、電
子線から選ばれたものを部分的に照射することにより、
微小な非照射領域からなる弱結合部によって少なくとも
２つの領域に分離された超電導部を形成し、薄膜超電導
素子を得ることを特徴とする薄膜超電導素子の製造方法
。(1) Copper composite oxide (A, B)_2CuO_4_-_X
A thin film of F_X (A: at least one element among Nd, Sm, and Pr; B: at least one element among Ce and Th; X: 0≦X<4) is exposed to X-rays, ultraviolet rays, and By partially irradiating selected lines,
A method for manufacturing a thin film superconducting device, which comprises forming a superconducting portion separated into at least two regions by a weak coupling portion consisting of a minute non-irradiated region, and obtaining a thin film superconducting device.
を特徴とする請求項１記載の薄膜超電導素子の製造方法
。(2) The method for manufacturing a thin film superconducting element according to claim 1, characterized in that the width of the non-irradiated region is approximately 0.2 μm or less.
ことを特徴とする請求項１記載の薄膜超電導素子の製造
方法。(3) The method for manufacturing a thin film superconducting element according to claim 1, characterized in that the non-irradiation region is formed using a mask pattern.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2099705A JPH03297175A (en) | 1990-04-16 | 1990-04-16 | Manufacture of thin film superconducting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2099705A JPH03297175A (en) | 1990-04-16 | 1990-04-16 | Manufacture of thin film superconducting device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03297175A true JPH03297175A (en) | 1991-12-27 |
Family
ID=14254480
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2099705A Pending JPH03297175A (en) | 1990-04-16 | 1990-04-16 | Manufacture of thin film superconducting device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03297175A (en) |
-
1990
- 1990-04-16 JP JP2099705A patent/JPH03297175A/en active Pending
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