JPH01283884A - Josephson element array and manufacture thereof - Google Patents
Josephson element array and manufacture thereofInfo
- Publication number
- JPH01283884A JPH01283884A JP63113101A JP11310188A JPH01283884A JP H01283884 A JPH01283884 A JP H01283884A JP 63113101 A JP63113101 A JP 63113101A JP 11310188 A JP11310188 A JP 11310188A JP H01283884 A JPH01283884 A JP H01283884A
- Authority
- JP
- Japan
- Prior art keywords
- element array
- thin film
- metal oxide
- josephson
- sawtooth
- 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
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 239000010409 thin film Substances 0.000 claims abstract description 26
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 22
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 22
- 239000000758 substrate Substances 0.000 claims description 22
- 150000001875 compounds Chemical class 0.000 claims description 19
- 238000000034 method Methods 0.000 claims description 19
- 238000010894 electron beam technology Methods 0.000 claims description 15
- 239000010949 copper Substances 0.000 claims description 13
- 238000005530 etching Methods 0.000 claims description 12
- 229910052802 copper Inorganic materials 0.000 claims description 11
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 9
- 239000002905 metal composite material Substances 0.000 claims description 8
- 239000002131 composite material Substances 0.000 claims description 7
- 229910052746 lanthanum Inorganic materials 0.000 claims description 5
- 229910052727 yttrium Inorganic materials 0.000 claims description 4
- 229910052788 barium Inorganic materials 0.000 claims description 3
- 229910052706 scandium Inorganic materials 0.000 claims description 3
- 150000002736 metal compounds Chemical class 0.000 claims description 2
- 229910002480 Cu-O Inorganic materials 0.000 claims 2
- 239000000126 substance Substances 0.000 claims 1
- 239000002887 superconductor Substances 0.000 abstract description 12
- 239000010408 film Substances 0.000 abstract description 3
- 239000013078 crystal Substances 0.000 abstract description 2
- 230000000694 effects Effects 0.000 description 5
- 238000000992 sputter etching Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 3
- 239000000395 magnesium oxide Substances 0.000 description 3
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000001755 magnetron sputter deposition Methods 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000005668 Josephson effect Effects 0.000 description 1
- 229910000750 Niobium-germanium Inorganic materials 0.000 description 1
- 241000270666 Testudines Species 0.000 description 1
- VVTSZOCINPYFDP-UHFFFAOYSA-N [O].[Ar] Chemical compound [O].[Ar] VVTSZOCINPYFDP-UHFFFAOYSA-N 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000003491 array 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
- 239000000919 ceramic Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005566 electron beam evaporation Methods 0.000 description 1
- 238000000609 electron-beam lithography Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- RTRWPDUMRZBWHZ-UHFFFAOYSA-N germanium niobium Chemical compound [Ge].[Nb] RTRWPDUMRZBWHZ-UHFFFAOYSA-N 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000010884 ion-beam technique Methods 0.000 description 1
- 239000013081 microcrystal Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 210000002784 stomach Anatomy 0.000 description 1
Landscapes
- Crystals, And After-Treatments Of Crystals (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、酸化物超電導体を用いたジョセフソン素子ア
レイおよびその製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a Josephson element array using an oxide superconductor and a method for manufacturing the same.
従来の技術
高温超電導体として、人１６型２元系化合物として窒化
ニオブ（ＮｂＮ）やゲルマニウムニオブ（Ｗｂ３Ｇｅ）
などが知られていた。これらの材料の超電導転移温度は
たかだか２４°にであった。Conventional technology Niobium nitride (NbN) and germanium niobium (Wb3Ge) are used as high-temperature superconductors as binary compounds.
etc. were known. The superconducting transition temperature of these materials was at most 24°.
一方、ペロブスカイト系３元化合物は、さらに高い転移
温度が期待され、Ｂａ−Ｌａ−１ｕ−０系の高温超電導
体が提案された（Ｊ 、Ｇ、ＢｅｄｎｏｒｚａｎｄＫ、
人、Ｍｕｌ１６ｒ、ツァイト シュリフトフェア フイ
ジーク（ＺｅｔＳｈｒｉｆｔ ｆ’ｕｒｐｈｙｓｉｋ
Ｂ）−Ｃｏｎｄｅｎｓｅｄ Ｍａｔｔａｒ６４．
１８９−１９３（１９８６）’ｌ。On the other hand, perovskite-based ternary compounds are expected to have even higher transition temperatures, and Ba-La-1u-0-based high-temperature superconductors have been proposed (J, G, Bednorzand, K.
People, Mul16r, ZetShrift f'urphysik
B)-Condensed Matter64.
189-193 (1986)'l.
さらに、Ｙ−Ｂａ−Ｏｕ−０系がより高温の超電導体で
あることが最近提案された。［：Ｍ、Ｋ。Furthermore, it has recently been proposed that the Y-Ba-Ou-0 system is a higher temperature superconductor. [:M, K.
Ｗｕ等、フィジカルレピューレターズ
（Ｐｈｙｓｉｃａｌ Ｒｅｖｉｅｗ Ｌａｔｔｅｒ
ｓ）Ｖｏｌ、５Ｂ、Ｎｏ９，９０８−９１０（１９８７
））Ｙ−Ｂａ−Ｃｕ−０系の材料の超電導機構の詳細は
明らかではないが、転移温度が液体窒素温度以上に高く
なる可能性があり、高温超電導体とじて従来の２元系化
合物より、より有望な特性が期待される。Wu et al., Physical Review Latter
s) Vol, 5B, No. 9, 908-910 (1987
)) The details of the superconducting mechanism of Y-Ba-Cu-0-based materials are not clear, but the transition temperature may be higher than the liquid nitrogen temperature, making them more suitable as high-temperature superconductors than conventional binary compounds. , more promising properties are expected.
超電導現象を利用した素子としてジョセフソン接合素子
が知られている、この分野に関する従来技術は電気学会
ライオエレクトロニクス常温専門委員金繰の「ジョセフ
ソン効果く基礎と応用〉」電気学会発行コロナ社発売（
昭和６３年）に体系的かつ詳細に記述されている。The Josephson junction device is known as an element that utilizes superconducting phenomena, and the conventional technology in this field can be found in "Fundamentals and Applications of the Josephson Effect" by the Institute of Electrical Engineers of Japan's Lioelectronics Room Temperature Specialist Committee, published by the Institute of Electrical Engineers of Japan and published by Corona Publishing.
(1986), it was described systematically and in detail.
ジョセフソン接合には非常に薄い（数１０人）絶縁層と
はさんで両側に超電導体を配置したトンネル接合型や、
−木の超電導体を一部細か＜（１μｍ）（びれさせたブ
リッジ型、超電導材料の鋭い針を用いた点接触型があり
、これらの作成方法では上記の文献に詳細に報告されて
いるが、いずれのタイプでも超微細加工技術を必要とし
、際限性が悪いため歩留が低く、多数のジョセフソン接
合素子をアレイ状に集積化することは著しく困難であっ
た。Josephson junctions include a tunnel junction type in which superconductors are placed on both sides with a very thin (several 10 layers) insulating layer,
-There are bridge types in which wooden superconductors are made with fine (1 μm) fins, and point contact types in which a sharp needle of superconducting material is used, and these methods of creation are reported in detail in the above-mentioned literature. Both types require ultra-fine processing technology, have low yields due to poor limitability, and have been extremely difficult to integrate a large number of Josephson junction elements into an array.
発明が解決しようとする訝題
従来のジョセフソン接合は構造的に作りにくく、トンネ
ル型では絶縁層の界面の均一性やピンホールの問題、点
接触型では振動や温度変化に弱いという問題点があった
。ブリッジ型は作りやすいと言われるが、１μｍ以下の
加工技術が要求される。The problem that the invention aims to solve Conventional Josephson junctions are structurally difficult to fabricate, with tunnel-type junctions having problems with uniformity of the insulating layer interface and pinholes, and point-contact junctions having problems with vibration and temperature changes. there were. The bridge type is said to be easy to make, but requires processing technology of 1 μm or less.
特に良好なシャピロステップを得ようとすると０．１μ
ｍ程度の幅の長さのブリッジを形成する必要があった。Especially when trying to obtain a good Shapiro step, 0.1μ
It was necessary to form a bridge with a width and length of about m.
ところが高温超電導体としてしられている複合酸化物、
例えばＬａ、Ｓｒ、Ｃｕ、０系やＹ、Ｂａ、Ｃｕ、Ｏ系
の材料はセラミック状、薄膜状いずれの場合でも１μｍ
前後の微結晶の集合体で空孔率が大きく、１０μｍの微
細加工も困難とされ、ジョセフソン接合の形式できない
という問題点があった。However, complex oxides, which are known as high-temperature superconductors,
For example, La, Sr, Cu, 0-based materials, Y, Ba, Cu, O-based materials have a thickness of 1 μm in either ceramic or thin film form.
The porosity is large due to the aggregate of the front and back microcrystals, and microfabrication of 10 μm is difficult, which poses the problem that a Josephson junction cannot be formed.
課題を解決するための手段
本発明の第１の発明のジシセ７ソン素子アレイでは、鋸
歯状凹凸表面を有する基体上に金属酸化物超電導薄膜を
エピタキシャル成長させた構造を特徴とするものであり
、特に、金属酸化物超電導薄膜材料として、銅を含む金
属複合化合物であることを特徴とするものである。また
銅を含む金属複合化合物として、ム−Ｂ−Ｃｕ−０また
はム−Ｂ−Ｃｕ−０−３またはＡ−Ｏｕ−０−５−Ｆ複
合化合物を用いたものである。ここに人はＳｃ、Ｙ、Ｌ
ａおよびＬａ系列元素（原子番号６７゜６０．６２〜７
１）のうち少なくとも一種、ＢはＢａ、Ｓｒなどｌａ族
元素のうちのすくなくとも一種、かつ、人、Ｂ元素とＣ
ｕ元素の濃度は
寸だは銅を含む金属複合化合物として、Ｂ１−８ｒ−Ｃ
ａ−Ｃ：ｕ−０複合化合物であることを特徴とするもの
、あるいは銅を含む金属化合物として、Ｔ、５−Ｃａ−
Ｂａ−Ｃｕ−０複合化合物であることを特徴とするジコ
セフノン素子アレイである。Means for Solving the Problems The device array of the first aspect of the present invention is characterized by a structure in which a metal oxide superconducting thin film is epitaxially grown on a substrate having a sawtooth uneven surface. , the metal oxide superconducting thin film material is a metal composite compound containing copper. Further, as the metal composite compound containing copper, Mu-B-Cu-0, Mu-B-Cu-0-3, or A-Ou-0-5-F composite compound is used. The people here are Sc, Y, L
a and La series elements (atomic number 67゜60.62~7
1), B is at least one of the LA group elements such as Ba and Sr, and human, B element and C
The concentration of the u element is approximately B1-8r-C as a metal composite compound containing copper.
T, 5-Ca-
This is a dicosephnone element array characterized by being a Ba-Cu-0 composite compound.
本発明の第２の発明のジョセフノン素子アレイの製造方
法では基体上に電子ビームレジストを塗布し、電子ビー
ム露光法により鋸歯状レジストパターンを形成した後、
エツチングにより前記基体表面に鋸歯状凹凸形状を形成
した後、金属酸化物超電導薄膜をエピタキシャル成長さ
せたことを特徴とするジョセフソン素子アレイの製造方
法である。In the method for manufacturing a Josephnon element array according to the second aspect of the present invention, an electron beam resist is applied onto a substrate, a sawtooth resist pattern is formed by an electron beam exposure method, and then,
This method of manufacturing a Josephson element array is characterized in that a sawtooth-like uneven shape is formed on the surface of the substrate by etching, and then a metal oxide superconducting thin film is epitaxially grown.
作用
第１の発明のジョセフソン素子アレイにおいて、鋸歯状
凹凸表面を有する基体上に金属酸化物超電導薄膜をエピ
タキシャル成長させた構造にすることにより、金属酸化
物超電導体の臨界電流密度の結晶軸異方性が、鋸歯状凹
凸基体表面により反影されることを利用する。即ち鋸歯
状凹凸の凸部近傍即ち短斜面方向での金属酸化物超電導
体薄膜の膜厚が他の部分に比べて薄くなる事と、基体の
鋸歯状長斜面に沿って金属酸化物超電導薄膜が配向する
だめに、短斜面方向にグレインパウンダＩＪ −が形成
され弱結合ジョセフソン接合を形成することになり、自
然にジョセフソン接合がアレイ状に形成されることにな
るのを利用しているものである。Effects In the Josephson element array of the first invention, by forming a structure in which a metal oxide superconducting thin film is epitaxially grown on a substrate having a sawtooth-like uneven surface, crystal axis anisotropy of the critical current density of the metal oxide superconductor can be improved. This method takes advantage of the fact that the characteristics are reflected by the serrated uneven substrate surface. In other words, the thickness of the metal oxide superconductor thin film near the protrusions of the sawtooth unevenness, that is, in the short slope direction, is thinner than in other parts, and the metal oxide superconductor thin film is thinner along the sawtooth long slopes of the substrate. Due to the orientation, grain pounders IJ- are formed in the direction of the short slope, forming a weakly coupled Josephson junction, and this method takes advantage of the fact that Josephson junctions are naturally formed in an array. It is something.
また、第２の発明のジョセフソン素子プレイの製造方法
においては、電子ビーム描画法と、エツチング技術を用
いることにより鋸歯状凹凸を基体上に形成することが可
能となり同時にエツチングにより基体凹凸表面のクリー
ニングも併せて行なえるという特長がある。従ってこの
鋸歯状凹凸表面に金属酸化物超電導薄膜が容易にエピタ
キシャル可能となる作用がある。In addition, in the method for manufacturing a Josephson element plate according to the second invention, by using an electron beam lithography method and an etching technique, it is possible to form sawtooth-like unevenness on the substrate, and at the same time, the uneven surface of the substrate can be cleaned by etching. It has the advantage of being able to be used at the same time. Therefore, there is an effect that a metal oxide superconducting thin film can be easily epitaxially formed on this sawtooth-like uneven surface.
実施例
第１および第２の発明のジョセフソン素子アレイおよび
その製造方法の実施例を図を用いて以下に述べる。Examples Examples of Josephson element arrays and methods of manufacturing the same according to the first and second inventions will be described below with reference to the drawings.
第１図は水筒１の発明のジョセフソン素子アレイの一実
施例を示す断面図を示す。第２図は水筒２の発明のジョ
セフソン素子アレイの製造方法の一実施例を示す工程図
である。FIG. 1 shows a cross-sectional view of an embodiment of the Josephson element array of the water bottle 1 invention. FIG. 2 is a process diagram showing an embodiment of a method for manufacturing a Josephson element array according to the invention of Water Bottle 2.
本発明のジョセフソン素子アレイの構造は第１図に示す
ごとく、基体１上に形成された鋸歯状凹凸表面２上に、
金属酸化物超電導薄膜３がエピタキシャル成長された構
造となっており、金属酸化物超電導薄膜３の鋸歯状凹凸
表面の短斜面５の延長上近傍部分にグレインパウンダリ
ー４が形成されている。金属酸化物超電導薄膜３のグレ
インパウンダリー４部分は膜厚も薄くなっている。この
両者の効果で、グレインバウンダリー４部分が弱結合あ
るいはトンネル型シロセフノン接合を形成する。特に、
金属酸化物超電導薄膜材料が銅を含む金属複合化合物で
ある場合、例えば、ム−Ｂ−Ｃｕ−０またはム−Ｂ−Ｃ
ｕ−Ｓまたはム−Ｂ−Ｃｕ−Ｓ−Ｆ 複合化合物、ここ
にムはＳｃ、Ｙ、ＬａおよびＬａ系列元素（原子番号６
７゜６０．６２〜７１）のうち少なくとも一種、ＢはＢ
ａ、Ｓｒなど［ｌａ族元素のうちのすくなくとも一種、
かつ、Ａ、Ｂ元素とＣｕ元素の濃度は、
であるか１．または銅を含む金属複合化合物とし２て、
Ｂ１−８ｒ−Ｃａ−Ｃｕ−０複合化合物であるが、また
は銅を含む金属化合物として
Ｔｌ−Ｃａ−Ｂａ−Ｃｕ−０複合化合物である場合には
、高い臨界温度と強い臨界電流密度の異方性が現れるた
めに、前記グレインバウンダリー４部分での臨界電流密
度が弱くなり、良好なジョセフソン接合を形成する。As shown in FIG. 1, the structure of the Josephson element array of the present invention is as shown in FIG.
It has a structure in which a metal oxide superconducting thin film 3 is epitaxially grown, and a grain pounder 4 is formed in the vicinity of an extension of a short slope 5 on the sawtooth-like uneven surface of the metal oxide superconducting thin film 3. The grain pounder 4 portion of the metal oxide superconducting thin film 3 is also thinner. Due to both of these effects, the grain boundary 4 portion forms a weak bond or a tunnel type silocephnon junction. especially,
When the metal oxide superconducting thin film material is a metal composite compound containing copper, for example, Mu-B-Cu-0 or Mu-B-C
u-S or Mu-B-Cu-S-F complex compound, where Mu is Sc, Y, La and La series elements (atomic number 6
7゜60.62-71), B is B
a, Sr, etc. [at least one of the la group elements,
And, are the concentrations of A, B elements and Cu element as follows?1. Or as a metal composite compound containing copper2,
B1-8r-Ca-Cu-0 composite compound or Tl-Ca-Ba-Cu-0 composite compound as a metal compound containing copper, high critical temperature and strong critical current density anisotropy Because of this, the critical current density at the grain boundary 4 portion becomes weaker, forming a good Josephson junction.
次に第２図において、製造方法について説明する。基体
１上に電子ビームレジスト６を塗布し、電子ビーム７に
より、濃淡露光する（＆）。次に現像して、鋸歯状レジ
ストパターン８を形成する（ｂ）。Next, referring to FIG. 2, a manufacturing method will be explained. An electron beam resist 6 is applied onto the substrate 1 and exposed to light and dark light using an electron beam 7 (&). Next, development is performed to form a sawtooth resist pattern 8 (b).
その後エツチングを行う。エツチングは例えば、ムｒイ
オンミリングやムｒスパッタエツチング等の物理エツチ
ングを行うことにより、鋸歯状レジストパターン８の表
面形状が基体１表面に転写され、鋸歯状凹凸表面２が形
成できる（０）。この時、表面２はエツチングにより、
レジストも除去されると同時に、汚れもクリーニングさ
れている。次に、鋸歯状凹凸表面２上に金属酸化物超電
導薄膜３をエピタキシャル成長させる（ｄ）。成長には
Ｒｆプレーナーマグネトロンスパッタリング法を用いる
か、または、反応性電子ビーム蒸着法と熱処理により実
現できた。以上の様にしてジョセフソン素子アレイを製
造できた。Then perform etching. For example, the surface shape of the sawtooth resist pattern 8 is transferred to the surface of the substrate 1 by physical etching such as ion milling or sputter etching, thereby forming the sawtooth uneven surface 2 (0). At this time, surface 2 is etched,
At the same time as the resist is removed, dirt is also cleaned. Next, a metal oxide superconducting thin film 3 is epitaxially grown on the sawtooth uneven surface 2 (d). The growth could be achieved by using Rf planar magnetron sputtering method or by reactive electron beam evaporation method and heat treatment. A Josephson element array was manufactured in the manner described above.
理解を更に深めるために、以下に具体実施例を用いて説
明する。In order to further deepen understanding, specific examples will be described below.
（具体実施例）
第１図において、基体１には酸化マグネシウム（２１０
）面を用いた。これに、ネガ型電子ビームレジスト（Ｃ
ＭＳ■）ｅを０．６μｍ厚さにスピンコードした後、１
２０℃、３０分でプリベークを行った。電子ビームレジ
スト６に電子ビーム７でピッチ０．６μｍの濃淡描画を
行った（第２図（亀））。(Specific Example) In FIG. 1, the substrate 1 has magnesium oxide (210
) surface was used. This is coated with a negative electron beam resist (C
After spin-coding MS■)e to a thickness of 0.6 μm, 1
Prebaking was performed at 20°C for 30 minutes. Density drawing was performed on the electron beam resist 6 with an electron beam 7 at a pitch of 0.6 μm (Fig. 2 (turtle)).
これを露光した後にピッチ０．６μｍの鋸歯状レジスト
パターン８を得た（第２図（ｂ））。その後ムｒ＋イオ
ンミリングによりエツチングを行ないレジストパターン
８が完全になくなるまでエツチングを行い、レジストパ
ターン８の表面形状を基体１に０．６μｍ ピッチの鋸
歯状凹凸表面を転写した（第２図（Ｃ））。人、ｒガス
圧Ｉ Ｘｌ ０−’ ＴＯｒｌ： 、加速電圧５ｓｏＶ
、イオン電流密度０．６ｍム／ｄｈｒイオンビームの
入射は垂直とした。この際レジスト６のエツチングレー
トと基体１の酸化マグネシウムのエツチングレートが若
干具なるため、鋸歯状凹凸表面２の断面形状は、レジス
トパターン８のそれとは基体１の深さ方向に伸びている
。鋸歯状凹凸表面２の長斜面の基体１の元の表面と成す
角度は約２６．６°、短斜面（第１図６）のそれは、約
６３．４°であり、それぞれ（１ｏｏ）面、（ｏｌＱ）
面が出ているものと思われる。短斜面の段差は約０．３
μｍであった。エツチング後の基体１の鋸歯状凹凸表面
２上にそのままＲｆプレーナマグネトロンスパッタ法に
より焼結したＹ Ｂ ａ ２Ｃａ ａ、ｓ ｏＹメタ−
ットを用いてアルゴン酸素雰囲気中でスパッタを行い、
ＹＢａ２Ｃｕ３Ｏｘ超電導薄膜３をエピタキシャル成長
させてジョセフソン素子アレイを作製した（第２図（ｄ
））。基体１は６５０℃に保ち、アルゴンと酸素分圧比
を３＝２とし全圧０．４Ｐ２Ｌとした。高周波電力１５
０Ｗで、スパッタリング時間１時間とし、薄膜３の膜厚
は凹凸の短斜面６方向にほぼ一様に約ＳＯＯｎｍ程度あ
った。断面観察をすると、薄膜２の膜厚は鋸歯状凹凸表
面の凸部で約０．２μｍ、長斜面部分で基体１に垂直方
向に約ａｏｎｍ程度であった。まだ、薄膜３は短斜面５
方向にグレインパウンダリー４がみられた。これらのこ
とより、グレインバウンダリー４の近傍でジョセフソン
接合が得られているものと思われた。After exposing this, a sawtooth resist pattern 8 with a pitch of 0.6 μm was obtained (FIG. 2(b)). After that, etching was carried out by mr+ ion milling until the resist pattern 8 was completely removed, and the surface shape of the resist pattern 8 was transferred to the substrate 1 as a serrated uneven surface with a pitch of 0.6 μm (Fig. 2 (C)). ). Person, r Gas pressure I Xl 0-' TOrl: , Acceleration voltage 5soV
, the ion current density was 0.6 mm/dhr, and the incidence of the ion beam was vertical. At this time, since the etching rate of the resist 6 and the etching rate of magnesium oxide of the substrate 1 are slightly different, the cross-sectional shape of the serrated uneven surface 2 is different from that of the resist pattern 8 and extends in the depth direction of the substrate 1. The long slope of the serrated uneven surface 2 makes an angle of about 26.6° with the original surface of the base body 1, and the short slope (FIG. 1, 6) makes an angle of about 63.4°, respectively. (olQ)
It seems that the face is showing. The height difference on the short slope is approximately 0.3
It was μm. YB a 2Ca a,soY meta-- which was directly sintered by Rf planar magnetron sputtering on the serrated uneven surface 2 of the substrate 1 after etching.
Sputtering is performed in an argon oxygen atmosphere using a
A Josephson element array was fabricated by epitaxially growing a YBa2Cu3Ox superconducting thin film 3 (Fig. 2(d)
)). The substrate 1 was maintained at 650° C., the argon and oxygen partial pressure ratio was set to 3=2, and the total pressure was 0.4P2L. High frequency power 15
The sputtering time was 1 hour at 0 W, and the thickness of the thin film 3 was about SOO nm almost uniformly in the 6 directions of the short slopes of the unevenness. When cross-sectionally observed, the film thickness of the thin film 2 was about 0.2 μm at the convex portions of the sawtooth-like uneven surface, and about aonm at the long slope portions in the direction perpendicular to the substrate 1. Still, the thin film 3 has a short slope 5
Grain Pounder 4 was seen in the direction. From these facts, it was thought that a Josephson junction was obtained near the grain boundary 4.
鋸歯状凹凸（０，６μｍピッチ）を２００個形成して、
１０μｍ幅に制限して作製したシロセフノン素子アレイ
の直流電圧電流特性を第３図に示す。200 sawtooth irregularities (0.6 μm pitch) are formed,
FIG. 3 shows the DC voltage-current characteristics of a silosefnon element array manufactured with a width limited to 10 μm.
作製したジョセフノン素子の臨界温度はｓＯＫであった
。臨界電流は、７７にで４０μムであった。The critical temperature of the produced Josephnon element was sOK. The critical current was 77 and 40 μm.
これに、ｆ＝１０ＧＨｚのマイクロ波を照射した時の電
流電圧特性を第４図に示す。同図よ抄、４．１４ｍＶの
ステップ電圧が得られ、これはｈｆ／（２ｅｌ）＝ ２
０．７μＶ（ここでｈはブランクの定数６．６３Ｘ１０
−３’ Ｊ、Ｓ 、ｅは素電荷１．６０Ｘ １ ｏ−１
９ｑ）のちょうど２００個分となり、各々のジョセフノ
ン素子が有効に働いていることが確認できた。FIG. 4 shows the current-voltage characteristics when this was irradiated with microwaves of f=10 GHz. From the same figure, a step voltage of 4.14 mV was obtained, which is hf/(2el) = 2
0.7μV (here h is the blank constant 6.63X10
-3' J, S, e are elementary charges 1.60X 1 o-1
9q), and it was confirmed that each Josephnon element was working effectively.
なお、上記具体実施例では基体１に酸化マグネ Ａシウ
ムを用いて説明したが、何もこれに限定することはなく
、基体として金属酸化物超電導薄膜をエピタキシャル成
長できるものであればなんでも良いのは言うまでもない
。Although the above-mentioned specific example has been explained using magnesium oxide as the substrate 1, there is no limitation to this, and it goes without saying that any material that can epitaxially grow a metal oxide superconducting thin film can be used as the substrate. stomach.
また、電子ビームレジスト６にネガ型電子ピームレジス
）ＣＭＳ■を用いたが、これに限定するものではなく、
他のネガ型電子ビームレジストや、ポジ型の電子ビーム
レジストでも使用できるのは言うまでもない。In addition, although a negative type electron beam resist (CMS) was used as the electron beam resist 6, it is not limited to this.
Needless to say, other negative type electron beam resists and positive type electron beam resists can also be used.
また、エツチングにムｒイオンミリングを用いた例を示
したが、他に人ｒスパッタエツチング、ＫＣＲエツチン
グ等も使用できるのは言うまでもない。Further, although an example is shown in which ion milling is used for etching, it goes without saying that other methods such as human sputter etching and KCR etching can also be used.
発明の効果
本発明の実施例により、高い臨界温度例えば液体窒素温
度以上を示す金属酸化物超電導薄膜を用いたシロセフノ
ン素子アレイが、−度のエピタキシャルにより容易に形
成することが出来、その効果は大きい。Effects of the Invention According to the embodiments of the present invention, a silosephnon element array using a metal oxide superconducting thin film exhibiting a high critical temperature, for example, liquid nitrogen temperature or higher, can be easily formed by -degree epitaxial method, and the effect is large. .
第１図は本発明のシロセフノン素子アレイの一実施例を
示す断面図、第２図は本発明のジョセフソン素子アレイ
の製造方法の一実施例を示す工程図、第３図、第４図は
同実施例の特性図である。
１・・・・・・基体、２・・・・・・鋸歯状凹凸表面、
３・・・・・・金属酸化物超電導薄膜、４・・・・・・
グレインパウンダリー、６・・・・・・短斜面、６・・
・・・・電子ビームレジスト、７・・・・・・電子ビー
Ａ、８・・・・・・鋸歯状レジストパターン０
代理人の氏名 弁理士 中 尾 敏 男 ほか１名！
・・−茎 体
ト鋸ＩＩＩ状凹凸表面
３・・−全Ａ酸化惜趨電轟溝項
４・・−グレインパウンダリー
５−・−履舛■
第１図
１８四１１
９ フヘ
）
Ｑ ＋
第３図
第４図FIG. 1 is a cross-sectional view showing an embodiment of the silosefnon element array of the present invention, FIG. 2 is a process diagram showing an embodiment of the method for manufacturing the Josephson element array of the present invention, and FIGS. 3 and 4 are It is a characteristic diagram of the same example. 1... Base body, 2... Serrated uneven surface,
3...Metal oxide superconducting thin film, 4...
Grain pounder, 6...Short slope, 6...
...Electron beam resist, 7...Electron beam A, 8...Sawtooth resist pattern 0 Name of agent Patent attorney Toshi Nakao and 1 other person!
...-Stalk Body Saw III-shaped uneven surface 3...-Total A oxidation trend electric groove section 4...-Grain pounder 5---Trace ■ Fig. 1 18411 9
) Q + Figure 3 Figure 4
Claims (1)
導薄膜をエピタキシャル成長させたことを特徴とするジ
ョセフソン素子アレイ。 （２）金属酸化物超電導薄膜の材料として銅を含む金属
複合化合物であることを特徴とする特許請求の範囲第１
項記載のジョセフソン素子アレイ。 （３）銅を含む金属複合化合物として、Ａ−Ｂ−Ｃｕ−
ＯまたはＡ−Ｂ−Ｃｕ−Ｏ−ＳまたはＡ−Ｂ−Ｃｕ−Ｏ
−Ｓ−Ｆ複合化合物を用いたことを特徴とする特許請求
の範囲第２項記載のジョセフソン素子アレイ。 ここにＡはＳｃ、Ｙ、ＬａおよびＬａ系列元素（原子番
号５７、６０、６２〜７１）のうち少なくとも一種、Ｂ
は、Ｂａ、ＳｒなどIIａ族元素のうちのすくなくとも一
種、かつ、Ａ、Ｂ元素とＣｕ元素の濃度は、 ０．５≦▲数式、化学式、表等があります▼≦２．５ （４）銅を含む金属複合化合物として、 Ｂｉ−Ｓｒ−Ｃａ−Ｇｕ−Ｏ複合化合物であることを特
徴とする特許請求の範囲第２項記載のジヨセフソン素子
アレイ。 （５）銅を含む金属化合物として、 Ｔｌ−Ｃａ−Ｂａ−Ｃｕ−Ｏ複合化合物であることを特
徴とする特許請求の範囲第２項記載のジョセフソン素子
アレイ。 （６）基体上に電子ビームレジストを塗布し、電子ビー
ム露光法により鋸歯状レジストパターンを形成した後、
エッチングにより前記基体表面に鋸歯状凹凸形状を形成
した後、金属酸化物超電導薄膜をエピタキシャル成長さ
せたことを特徴とする特許請求の範囲第１項記載のジョ
セフソン素子アレイの製造方法。[Scope of Claims] (1) A Josephson element array characterized in that a metal oxide superconducting thin film is epitaxially grown on a substrate having a sawtooth uneven surface. (2) Claim 1, characterized in that the material of the metal oxide superconducting thin film is a metal composite compound containing copper.
The Josephson element array described in Section 1. (3) As a metal composite compound containing copper, A-B-Cu-
O or A-B-Cu-O-S or A-B-Cu-O
The Josephson element array according to claim 2, characterized in that a -S-F composite compound is used. Here, A is at least one of Sc, Y, La, and La series elements (atomic numbers 57, 60, 62-71), and B
is at least one type of Group IIa elements such as Ba and Sr, and the concentration of A, B elements and Cu element is 0.5≦▲There are mathematical formulas, chemical formulas, tables, etc.▼≦2.5 (4) Copper The di-Josephson element array according to claim 2, wherein the metal composite compound containing: Bi-Sr-Ca-Gu-O composite compound. (5) The Josephson element array according to claim 2, wherein the metal compound containing copper is a Tl-Ca-Ba-Cu-O composite compound. (6) After applying an electron beam resist on the substrate and forming a sawtooth resist pattern by electron beam exposure method,
2. The method of manufacturing a Josephson element array according to claim 1, wherein the metal oxide superconducting thin film is epitaxially grown after forming sawtooth irregularities on the surface of the substrate by etching.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63113101A JPH01283884A (en) | 1988-05-10 | 1988-05-10 | Josephson element array and manufacture thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63113101A JPH01283884A (en) | 1988-05-10 | 1988-05-10 | Josephson element array and manufacture thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01283884A true JPH01283884A (en) | 1989-11-15 |
Family
ID=14603507
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63113101A Pending JPH01283884A (en) | 1988-05-10 | 1988-05-10 | Josephson element array and manufacture thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01283884A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0244786A (en) * | 1988-08-05 | 1990-02-14 | Canon Inc | Manufacture of josephson element |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6065583A (en) * | 1983-09-20 | 1985-04-15 | Nippon Telegr & Teleph Corp <Ntt> | Josephson junction element and manufacture thereof |
| JPS62273782A (en) * | 1986-05-21 | 1987-11-27 | Nippon Telegr & Teleph Corp <Ntt> | Josephson junction device and manufacture thereof |
-
1988
- 1988-05-10 JP JP63113101A patent/JPH01283884A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6065583A (en) * | 1983-09-20 | 1985-04-15 | Nippon Telegr & Teleph Corp <Ntt> | Josephson junction element and manufacture thereof |
| JPS62273782A (en) * | 1986-05-21 | 1987-11-27 | Nippon Telegr & Teleph Corp <Ntt> | Josephson junction device and manufacture thereof |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0244786A (en) * | 1988-08-05 | 1990-02-14 | Canon Inc | Manufacture of josephson element |
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