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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