JPH02186682A - Josephson junction device - Google Patents
Josephson junction deviceInfo
- Publication number
- JPH02186682A JPH02186682A JP1004870A JP487089A JPH02186682A JP H02186682 A JPH02186682 A JP H02186682A JP 1004870 A JP1004870 A JP 1004870A JP 487089 A JP487089 A JP 487089A JP H02186682 A JPH02186682 A JP H02186682A
- Authority
- JP
- Japan
- Prior art keywords
- fluoride
- barrier layer
- josephson junction
- film
- junction device
- 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
- 230000004888 barrier function Effects 0.000 claims abstract description 28
- OYLGJCQECKOTOL-UHFFFAOYSA-L barium fluoride Chemical compound [F-].[F-].[Ba+2] OYLGJCQECKOTOL-UHFFFAOYSA-L 0.000 claims abstract description 12
- 229910001632 barium fluoride Inorganic materials 0.000 claims abstract description 12
- 239000000463 material Substances 0.000 claims abstract description 12
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 claims abstract description 5
- 229910001634 calcium fluoride Inorganic materials 0.000 claims abstract description 5
- FVRNDBHWWSPNOM-UHFFFAOYSA-L strontium fluoride Chemical compound [F-].[F-].[Sr+2] FVRNDBHWWSPNOM-UHFFFAOYSA-L 0.000 claims abstract description 4
- 229910001637 strontium fluoride Inorganic materials 0.000 claims abstract description 4
- 229940105963 yttrium fluoride Drugs 0.000 claims abstract description 4
- RBORBHYCVONNJH-UHFFFAOYSA-K yttrium(iii) fluoride Chemical compound F[Y](F)F RBORBHYCVONNJH-UHFFFAOYSA-K 0.000 claims abstract description 4
- 239000010410 layer Substances 0.000 claims description 40
- 239000002887 superconductor Substances 0.000 claims description 13
- 238000001755 magnetron sputter deposition Methods 0.000 claims description 5
- 239000011229 interlayer Substances 0.000 claims description 4
- 230000000694 effects Effects 0.000 claims description 3
- 239000000758 substrate Substances 0.000 abstract description 9
- 229920002120 photoresistant polymer Polymers 0.000 abstract description 8
- 238000000034 method Methods 0.000 abstract description 5
- 229910003097 YBa2Cu3O7−δ Inorganic materials 0.000 abstract description 4
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 abstract description 4
- 239000000395 magnesium oxide Substances 0.000 abstract description 4
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 abstract description 4
- 239000010408 film Substances 0.000 description 14
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 8
- 239000010409 thin film Substances 0.000 description 5
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 4
- 229910052786 argon Inorganic materials 0.000 description 4
- 229910052731 fluorine Inorganic materials 0.000 description 4
- 239000011737 fluorine Substances 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 238000009832 plasma treatment Methods 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 238000000992 sputter etching Methods 0.000 description 3
- 239000005751 Copper oxide Substances 0.000 description 2
- 229910021594 Copper(II) fluoride Inorganic materials 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 2
- BTGZYWWSOPEHMM-UHFFFAOYSA-N [O].[Cu].[Y].[Ba] Chemical compound [O].[Cu].[Y].[Ba] BTGZYWWSOPEHMM-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 229910000431 copper oxide Inorganic materials 0.000 description 2
- GWFAVIIMQDUCRA-UHFFFAOYSA-L copper(ii) fluoride Chemical compound [F-].[F-].[Cu+2] GWFAVIIMQDUCRA-UHFFFAOYSA-L 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 229910021521 yttrium barium copper oxide Inorganic materials 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- MQNFNBMBHDXUHQ-UHFFFAOYSA-N [Cu]=O.[Ba].[Ho] Chemical compound [Cu]=O.[Ba].[Ho] MQNFNBMBHDXUHQ-UHFFFAOYSA-N 0.000 description 1
- OSOKRZIXBNTTJX-UHFFFAOYSA-N [O].[Ca].[Cu].[Sr].[Bi] Chemical compound [O].[Ca].[Cu].[Sr].[Bi] OSOKRZIXBNTTJX-UHFFFAOYSA-N 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- 239000000109 continuous material Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- RQTATCNDOLOZTR-UHFFFAOYSA-N helium;hydrofluoride Chemical compound [He].F RQTATCNDOLOZTR-UHFFFAOYSA-N 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 1
- 238000001552 radio frequency sputter deposition Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 description 1
- SFZCNBIFKDRMGX-UHFFFAOYSA-N sulfur hexafluoride Chemical compound FS(F)(F)(F)(F)F SFZCNBIFKDRMGX-UHFFFAOYSA-N 0.000 description 1
- 229960000909 sulfur hexafluoride Drugs 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
- -1 yttrium - barium - Erbium-barium-copper oxide Chemical compound 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 1
- 229910001928 zirconium oxide Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は超電導装置に係り、特に酸化物超電導体を電極
として用いる場合に好適なジョセフソン接合装置の構造
に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a superconducting device, and particularly to a structure of a Josephson junction device suitable for using an oxide superconductor as an electrode.
［従来の技術］
従来、高温超電導体薄膜を用いてジョセフソントンネル
接合素子を形成することについては、例ば日刊工業新聞
昭和６３年８月２５日号に記載されている。上記従来技
術においては、高温超電導体としてはイツトリウム−バ
リウム−銅酸化物系薄膜を用い、約５８０℃の温度に保
持した酸化マグネシウム基板上にＲＦスパッタリング法
で上記超電導薄膜を形成、その表面をフッ素プラズマ処
理して極めて薄い高抵抗層をつくり、再びスパッタリン
ク法によって薄膜を成長させることが開示されている。[Prior Art] Conventionally, the formation of a Josephson tunnel junction element using a high-temperature superconductor thin film has been described, for example, in the August 25, 1988 issue of the Nikkan Kogyo Shimbun. In the above conventional technology, a yttrium-barium-copper oxide thin film is used as a high-temperature superconductor, and the superconducting thin film is formed by RF sputtering on a magnesium oxide substrate maintained at a temperature of about 580°C, and its surface is coated with fluorine. It is disclosed that a very thin high resistance layer is formed by plasma treatment and then the thin film is grown again by a sputter link method.
［発明か解決しようとする課題］
」１記従来技術において、トンネル障壁層の形成につい
ては、イツトリウム−バリウム−銅酸化物系薄膜の表面
をフッ素プラズマ処理することにより行なっている。と
ころか上述の如く形成されたＩ〜フンル障壁層を用いた
ジョセフソン接合装置において、ジョセフソン接合のリ
ーク電流が増大したり、ギャップ電圧が低下したりして
電流−電圧特性が劣化する恐れがあるとの問題点が我々
によって見出された。[Problems to be Solved by the Invention] In the prior art described in 1., the tunnel barrier layer is formed by subjecting the surface of the yttrium-barium-copper oxide thin film to fluorine plasma treatment. However, in the Josephson junction device using the I~Funru barrier layer formed as described above, there is a risk that the leakage current of the Josephson junction will increase or the gap voltage will decrease, resulting in deterioration of the current-voltage characteristics. We found some problems.
本発明の目的は、上記の問題点を解決し、良好な電流−
電圧特性を有するジョセフソン接合装置を提供すること
にある。The purpose of the present invention is to solve the above problems and provide a good current
An object of the present invention is to provide a Josephson junction device having voltage characteristics.
［課題を解決するための手段］
上記目的を達成するために本発明のジョセフソン接合装
置は、第１の酸化物超電導体層と、第２の酸化物超電導
体層と、上記第１．第２の酸化物超電導体層の間に形成
され超電導トンネル効果を生じさせる障壁層とを有し、
上記障壁層がフン化バリウム、フン化イツトリウム、フ
ッ化ス１〜ロンチウム、及びフッ化カルシウムからなる
材料群のうちの少なくとも一部で構成されることを特徴
とする。[Means for Solving the Problems] In order to achieve the above object, the Josephson junction device of the present invention includes a first oxide superconductor layer, a second oxide superconductor layer, and the first oxide superconductor layer. a barrier layer formed between the second oxide superconductor layers and causing a superconducting tunnel effect;
The barrier layer is characterized in that it is composed of at least a part of the material group consisting of barium fluoride, yttrium fluoride, sulfur fluoride to rontium fluoride, and calcium fluoride.
上記１〜フンル障壁層を構成する材料は、高周波マグネ
トロンスパッタ法により形成することができる。The materials constituting the barrier layers 1 to 1 above can be formed by high frequency magnetron sputtering.
」二記トンネル障壁層の厚さは、その厚さが最も薄い部
分において１０ｎｍ以下となるようにするのが好ましい
。The thickness of the tunnel barrier layer described in 2 above is preferably 10 nm or less at its thinnest portion.
［作用］
我々の検討によれは、」１記従来技術においてジョセフ
ソン接合装置の特性が劣化する原因は、」〕部組電極形
の際の高熱によってトンネル障壁層の一部が破壊された
り、トンネル障壁層中の元素が拡散してｌ−ンネル障壁
層に接する超電導電極の超電導特性が劣化するためであ
ると考えられる。特にイノトリウ１１−バリウムー銅酸
化物表面をプラズマ処理した際に生じるフッ化銅がこの
特性劣化の原因と考えられる。」二連した材料によって
構成された本発明に係るトンネル障壁層は、いずれも上
部電極形成時の温度よりも高い融点を示す。より具体的
には、上部電極形成時の温度が５００〜９５０℃である
のに対し、フッ化ハリウｌ＼は１３５３°Ｃ，フッ化イ
ツ１ヘリウムは１１５２℃。[Function] According to our investigation, the reason for the deterioration of the characteristics of the Josephson junction device in the prior art described in 1. is that part of the tunnel barrier layer is destroyed due to high heat during the assembly electrode type, This is considered to be because the elements in the tunnel barrier layer diffuse and the superconducting properties of the superconducting electrode in contact with the tunnel barrier layer deteriorate. In particular, copper fluoride produced when the surface of the inotrium 11-barium-copper oxide is subjected to plasma treatment is considered to be the cause of this characteristic deterioration. The tunnel barrier layer according to the present invention constituted by two continuous materials all exhibit a melting point higher than the temperature at which the upper electrode is formed. More specifically, the temperature at the time of forming the upper electrode is 500 to 950°C, whereas the temperature for halium fluoride is 1353°C, and the temperature for helium fluoride is 1152°C.
フッ化ストロンチウムは１４００°Ｃ，フッ化カルシウ
ムは］４０３°Ｃが各々その融点である。また上記各材
料を組み合せた材料もほぼ同等の高い融点を示す。これ
に対し、上記フッ化銅の融点は９５０°Ｃであり、上記
の上部電極形成時の温度とほぼ同等の価である。The melting points of strontium fluoride and calcium fluoride are 1400°C and 403°C, respectively. Furthermore, materials obtained by combining the above-mentioned materials also exhibit approximately the same high melting point. On the other hand, the melting point of the above-mentioned copper fluoride is 950°C, which is almost the same as the temperature at the time of forming the above-mentioned upper electrode.
したがって上述の材料によってトンネル障壁層を形成す
れば、」−細電極形成時に５００〜９５０℃の高温工程
を経たとしても、ｌ−ンネル障壁層が破壊されたり、係
るＩ−ンネル障壁層中の元素が拡散してトンネル障壁層
に接する超電導電極の超電導特性が劣化することがほと
んどない。従って、トンネル型ジョセフソン接合のリー
ク電流が増大したりギャップ電圧が低下したりすること
がなく、電流−電圧特性を良好なものにすることができ
る。Therefore, if the tunnel barrier layer is formed using the above-mentioned materials, even if a high-temperature process of 500 to 950°C is performed during the formation of the thin electrode, the tunnel barrier layer will not be destroyed or the elements in the tunnel barrier layer will not be destroyed. The superconducting properties of the superconducting electrode in contact with the tunnel barrier layer are hardly deteriorated due to diffusion of the superconducting material. Therefore, the leakage current of the tunnel Josephson junction does not increase or the gap voltage decreases, and the current-voltage characteristics can be improved.
［実施例コ 以下、本発明を、実施例により詳細に説明する。[Example code] Hereinafter, the present invention will be explained in detail with reference to Examples.
第１図は本発明の実施例によるジョセフソン接合装置の
一部を示す断面図である。まず酸化マグネシウム基板１
上に高周波マグネＩ・ロンスパッタ法によってフッ化バ
リウムを０．３μｍ堆積し、バッファ層２とする。この
バッファ層は必ずしも必要ではないが、特性改善のため
に通常設けられるものである。次に基板１を８００°Ｃ
に加熱しながら、高周波マグネトロンスパッタ法を用い
てＹＢａ２Ｃｕ３Ｏ７−δ膜を１μｍを堆積する。雰囲
気ガスとしては酸素を１０％混合したアルゴンガスを圧
力５．３Ｐａで用いる。係るＹＢａ２Ｃｕ。FIG. 1 is a sectional view showing a portion of a Josephson joining device according to an embodiment of the present invention. First, magnesium oxide substrate 1
A buffer layer 2 is formed by depositing barium fluoride to a thickness of 0.3 .mu.m thereon by high-frequency Magne-I Ron sputtering. Although this buffer layer is not necessarily required, it is usually provided to improve characteristics. Next, heat substrate 1 to 800°C.
A 1 μm thick YBa2Cu3O7-δ film is deposited using high-frequency magnetron sputtering while heating to . As the atmospheric gas, argon gas mixed with 10% oxygen is used at a pressure of 5.3 Pa. YBa2Cu concerned.
０７−６膜を、ホトレジストをマスクとしたアルゴンス
パッタエツチング法によって加工して下部電極３とする
。次に高周波マグネトロンスパッタ法によって膜厚１．
２μｍのフッ化バリウム膜を形成する。係るフッ化バリ
ウム膜を、ホトレジストをマスクとしたアルゴンスパッ
タエツチング法によって加工して層間絶縁膜４とする。The 07-6 film is processed to form the lower electrode 3 by argon sputter etching using a photoresist as a mask. Next, high-frequency magnetron sputtering was performed to achieve a film thickness of 1.
A 2 μm barium fluoride film is formed. The barium fluoride film is processed to form an interlayer insulating film 4 by argon sputter etching using a photoresist as a mask.
この眉間絶縁膜は、次に述べるトンネル障壁層によって
上部電極と下部電極とが電気的に絶縁される場合には必
ずしも必要ない。次にホトレジストを残したまま、高周
波マグネトロンスパッタ法によってフッ化バリウムを５
膜ｍ堆積し、リフトオフ法によって加工してトンネル障
壁Ｍ５とする。さらに、再び基板１を８００℃に加熱し
ながら、高周波マグネ１へロンスパッタ法を用いてＹＢ
ａ２Ｃｕ３Ｏ７，、δ膜を１．５ μｍ堆積する。係る
Ｙ Ｂ ａ ｚ Ｃｕ ３Ｏ７−６膜をホトレジストを
マスクとしたアルゴンスパッタエツチング法によって加
工して上部電極６とする。以上によって本発明の実施例
に係るジョセフソン接合装置を実現することができる。This glabellar insulating film is not necessarily necessary when the upper electrode and the lower electrode are electrically insulated by the tunnel barrier layer described below. Next, leaving the photoresist, 55% of barium fluoride was applied using high-frequency magnetron sputtering.
A film M is deposited and processed by a lift-off method to form a tunnel barrier M5. Furthermore, while heating the substrate 1 to 800° C. again, YB was applied to the high frequency magnet 1 using the Ron sputtering method.
A 1.5 μm thick a2Cu3O7, δ film is deposited. The YB az Cu 3O7-6 film is processed to form the upper electrode 6 by argon sputter etching using a photoresist as a mask. Through the above steps, the Josephson bonding device according to the embodiment of the present invention can be realized.
係るジョセフソン接合装置の電流−電圧特性は４．２Ｋ
において第２図の様なトンネル型ジョセフソン接合とし
ての性質を示す。ギャップ電圧は１７ｍＶであった。The current-voltage characteristic of the Josephson junction device is 4.2K.
2 shows the properties of a tunnel-type Josephson junction as shown in FIG. The gap voltage was 17mV.
一方、本発明の実施例におけるトンネル障壁層５を、フ
ッ化バリウムを堆積することによって作製するのではな
く、下部電極３の表面を１０分間フッ素プラズマにさら
すくとによって作製した、ジョセフソン接合装置の電流
−電圧特性は、第３図の様に、リーク電流が大きくなり
、ギャップ電圧が１．３ｍＶと低下する。従って本発明
により、トンネル型ジョセフソン接合装置のリーク電流
を低減させ、しかもジョセフソン接合のギャップ電圧を
高くして、高流−電圧特性の本来の理想的なものに近づ
けることができる。On the other hand, the tunnel barrier layer 5 in the embodiment of the present invention was not fabricated by depositing barium fluoride, but was fabricated by exposing the surface of the lower electrode 3 to fluorine plasma for 10 minutes in a Josephson junction device. As for the current-voltage characteristics, as shown in FIG. 3, the leakage current increases and the gap voltage decreases to 1.3 mV. Therefore, according to the present invention, the leakage current of the tunnel type Josephson junction device can be reduced, and the gap voltage of the Josephson junction can be increased to bring the high current-voltage characteristics closer to the originally ideal one.
なお、本実施例においては基板１の材料として酸化マグ
ネシウムを用いたが、これに替えて酸化ジルコニウム、
チタン酸ストロンチウム、酸化アルミニウム、シリコン
等を用いてもよい。また、本実施例においてはバッファ
層２２層間絶縁膜４゜トンネル障壁層５の材料としてフ
ッ化バリウムを用いたが、これに替えてフッ化イツトリ
ウム、フッ化ストロンチウム、フッ化カルシウムを用い
てもよい。また、本実施例においては下部電極３及び上
部電極６の材料としてＹＢａ２Ｃｕ３Ｏ７−δを用いた
が、イツトリウム、バリウム、銅、酸素の組成比が異な
るものを用いてもよい。またイツトリウム−バリウム−
銅酸化物に替えて、エルビウム−バリウム−銅酸化物、
ホルミウム−バリウム−銅酸化物、ビスマス−ストロン
チウム−カルシウム−銅酸化物、タリウム−バリウム−
カルシウム−銅酸化物等を用いてもよい。In this example, magnesium oxide was used as the material for the substrate 1, but instead of this, zirconium oxide,
Strontium titanate, aluminum oxide, silicon, etc. may also be used. Furthermore, in this embodiment, barium fluoride was used as the material for the buffer layer 22, interlayer insulating film 4, and tunnel barrier layer 5, but yttrium fluoride, strontium fluoride, and calcium fluoride may be used instead. . Further, in this embodiment, YBa2Cu3O7-δ was used as the material for the lower electrode 3 and the upper electrode 6, but materials having different composition ratios of yttrium, barium, copper, and oxygen may be used. Also, yttrium - barium -
Erbium-barium-copper oxide instead of copper oxide,
Holmium-barium-copper oxide, bismuth-strontium-calcium-copper oxide, thallium-barium-
Calcium-copper oxide or the like may also be used.
［発明の効果］
本発明によれば、下部電極及び上部電極の両方を酸化物
超電導体で構成したジョセフソン接合装置において、上
部電極膜形成時の高温工程が原因でトンネル障壁層が破
壊されることがなく、トンネル障壁層に接する超電導電
極の超電導特性が劣化することがない。従ってトンネル
型ジョセフソン接合装置としての電流−電圧特性を理想
的なものに近づけることができる。[Effects of the Invention] According to the present invention, in a Josephson junction device in which both the lower electrode and the upper electrode are made of oxide superconductors, the tunnel barrier layer is destroyed due to the high temperature process during the formation of the upper electrode film. Therefore, the superconducting properties of the superconducting electrode in contact with the tunnel barrier layer do not deteriorate. Therefore, the current-voltage characteristics of the tunnel type Josephson junction device can be made close to ideal.
第１図は本発明の実施例によるジョセフソン接合装置の
一部を示す断面図、第２図は本発明の実施例によるジョ
セフソン接合装置の電流−電圧時性を示す図、第３図は
トンネル障壁層をＹＢａ２Ｃｕ３Ｏ．−δ膜表面のフッ
素プラズマ処理で作製した場合の電流−電圧特性を示す
図である。
１・・・基板、２・・・バッファ層、３・・・下部電極
、４・・・層間絶縁膜、５・・・トンネル障壁層、６・
・・上部電極。FIG. 1 is a sectional view showing a part of a Josephson junction device according to an embodiment of the present invention, FIG. 2 is a diagram showing current-voltage characteristics of the Josephson junction device according to an embodiment of the present invention, and FIG. The tunnel barrier layer is made of YBa2Cu3O. FIG. 3 is a diagram showing current-voltage characteristics when the −δ film surface is produced by fluorine plasma treatment. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Buffer layer, 3... Lower electrode, 4... Interlayer insulating film, 5... Tunnel barrier layer, 6...
...Top electrode.
Claims (1)
層と、上記第１、第２の酸化物超電導体層の間に形成さ
れ超電導トンネル効果を生じさせる障壁層とを有するジ
ョセフソン接合装置であって、上記障壁層がフッ化バリ
ウム、フッ化イットリウム、フッ化ストロンチウム、及
びフッ化カルシウムからなる材料群のうちの少なくとも
一者で構成されることを特徴とするジョセフソン接合装
置。 ２、上記障壁層は高周波マグネトロンスパッタ法で形成
されることを特徴とする請求項１記載のジョセフソン接
合装置。 ３、上記障壁層はその厚さが最も薄い部分において１０
ｎｍ以下であることを特徴とする請求項１または２記載
のジョセフソン接合装置。 ４、上記第１、第２の酸化物超電導体層の間に層間絶縁
膜を有することを特徴とする請求項１ないし３の一に記
載のジョセフソン接合装置。 ５、上記第１、第２の酸化物超電体層がＹＢａ＿２Ｃｕ
＿３Ｏ＿７＿−＿δで構成されることを特徴とする請求
項１ないし３の一に記載のジョセフソン接合装置。[Claims] 1. A first oxide superconductor layer, a second oxide superconductor layer, and a superconducting layer formed between the first and second oxide superconductor layers to produce a superconducting tunnel effect. A Josephson junction device having a barrier layer comprising: a barrier layer comprising at least one of a material group consisting of barium fluoride, yttrium fluoride, strontium fluoride, and calcium fluoride; Characteristic Josephson joining device. 2. The Josephson junction device according to claim 1, wherein the barrier layer is formed by high frequency magnetron sputtering. 3. The barrier layer has a thickness of 10 at its thinnest part.
The Josephson junction device according to claim 1 or 2, characterized in that the diameter is less than nm. 4. The Josephson junction device according to claim 1, further comprising an interlayer insulating film between the first and second oxide superconductor layers. 5. The first and second oxide superconductor layers are YBa_2Cu
4. The Josephson bonding device according to claim 1, characterized in that the Josephson bonding device is comprised of _3O_7_-_δ.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1004870A JPH02186682A (en) | 1989-01-13 | 1989-01-13 | Josephson junction device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1004870A JPH02186682A (en) | 1989-01-13 | 1989-01-13 | Josephson junction device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02186682A true JPH02186682A (en) | 1990-07-20 |
Family
ID=11595711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1004870A Pending JPH02186682A (en) | 1989-01-13 | 1989-01-13 | Josephson junction device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02186682A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992005591A1 (en) * | 1990-09-21 | 1992-04-02 | The Regents Of The University Of California | Improved microelectronic superconducting devices and methods |
| JPH05167111A (en) * | 1991-12-16 | 1993-07-02 | Nec Corp | Tunnel type josephson junction element |
| US5274249A (en) * | 1991-12-20 | 1993-12-28 | University Of Maryland | Superconducting field effect devices with thin channel layer |
| US5291035A (en) * | 1990-03-09 | 1994-03-01 | The Regents Of The University Of California | Microelectronic superconducting crossover and coil |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61111589A (en) * | 1984-11-06 | 1986-05-29 | Nippon Telegr & Teleph Corp <Ntt> | Manufacture of tunnel type josephson element |
| JPS63308979A (en) * | 1987-06-11 | 1988-12-16 | Nippon Telegr & Teleph Corp <Ntt> | Forming method for junction of oxide superconductor |
-
1989
- 1989-01-13 JP JP1004870A patent/JPH02186682A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61111589A (en) * | 1984-11-06 | 1986-05-29 | Nippon Telegr & Teleph Corp <Ntt> | Manufacture of tunnel type josephson element |
| JPS63308979A (en) * | 1987-06-11 | 1988-12-16 | Nippon Telegr & Teleph Corp <Ntt> | Forming method for junction of oxide superconductor |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5291035A (en) * | 1990-03-09 | 1994-03-01 | The Regents Of The University Of California | Microelectronic superconducting crossover and coil |
| WO1992005591A1 (en) * | 1990-09-21 | 1992-04-02 | The Regents Of The University Of California | Improved microelectronic superconducting devices and methods |
| US5256636A (en) * | 1990-09-21 | 1993-10-26 | The Regents Of The University Of Calif. | Microelectronic superconducting device with multi-layer contact |
| JPH05167111A (en) * | 1991-12-16 | 1993-07-02 | Nec Corp | Tunnel type josephson junction element |
| US5274249A (en) * | 1991-12-20 | 1993-12-28 | University Of Maryland | Superconducting field effect devices with thin channel layer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS61206279A (en) | Superconductive element | |
| JPH0577347B2 (en) | ||
| JPH02186682A (en) | Josephson junction device | |
| JPH0714079B2 (en) | Oxide superconducting three-terminal device | |
| JPH104223A (en) | Oxide superconducting josephson element | |
| JPH04285012A (en) | Formation of oxide superconductor thin film | |
| JP2698364B2 (en) | Superconducting contact and method of manufacturing the same | |
| JP3155558B2 (en) | Oxide superconducting wire | |
| JP4104323B2 (en) | Method for fabricating Josephson junction | |
| JP2907831B2 (en) | Josephson element | |
| JPH03166776A (en) | Tunnel junction element and manufacture thereof | |
| JPH054828B2 (en) | ||
| JPH0262081A (en) | Superconductive parts | |
| JPS63318176A (en) | Manufacture of oxide superconductive junction | |
| JPS63194376A (en) | Josephson junction element | |
| JP2691065B2 (en) | Superconducting element and fabrication method | |
| JPH02308578A (en) | Manufacture of superconductor device | |
| JPH0613666A (en) | Nb josephson junction device and its manufacture | |
| JPH02271686A (en) | Josephson junction element and manufacture thereof | |
| JPH02271687A (en) | Manufacture of tunnel type josephson junction | |
| JPH0555649A (en) | Manufacture of superconducting electric field effect element | |
| JPS58108739A (en) | Josephson junction device | |
| JPH01207981A (en) | Oxide superconductor device and manufacture thereof | |
| JPH04171872A (en) | Josephson device and manufacture thereof | |
| JPH0558625A (en) | Oxide superconductor thin film having insulating layer and its production |