JPH0322067B2 - - Google Patents
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- Publication number
- JPH0322067B2 JPH0322067B2 JP56103066A JP10306681A JPH0322067B2 JP H0322067 B2 JPH0322067 B2 JP H0322067B2 JP 56103066 A JP56103066 A JP 56103066A JP 10306681 A JP10306681 A JP 10306681A JP H0322067 B2 JPH0322067 B2 JP H0322067B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode body
- superconductor
- josephson junction
- niobium
- layer
- Prior art date
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- Expired - Lifetime
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Classifications
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10P95/00—Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass
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- Superconductor Devices And Manufacturing Methods Thereof (AREA)
Description
【発明の詳細な説明】
本発明は、論理回路や記憶装置を構成するスイ
ツチング素子、微小磁場測定素子、電圧標準器な
どに用いられるジヨセフソン接合素子の構造に関
するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of Josephson junction elements used in switching elements, minute magnetic field measuring elements, voltage standards, etc. that constitute logic circuits and memory devices.
従来開発されてきたジヨセフソン接合素子は、
鉛合金／鉛合金の酸化物／鉛合金の構造をもつも
のが主であつた。しかし、これらの鉛合金系ジヨ
セフソン接合素子は、動作温度である液体ヘリウ
ム温度と室温との間の熱サイクルを経ることによ
つて接合が破壊され易く、特性の劣化が著しいと
いう欠点がある。これに代つて、熱サイクルや経
時変化による特性の劣化がほとんど生じないジヨ
セフソン接合素子として、機械的に鉛より硬いニ
オブもしくはニオブ化合物を電極とするニオブ系
ジヨセフソン接合素子の開発が行なわれている。
窒化ニオブを電極としたジヨセフソン接合素子で
は、熱サイクルや経時変化による特性の劣化がほ
とんどないことが、東海林等により電子通信学会
技術研究報告CPM80−90（1981年２月17日発行）
に述べられている。このジヨセフソン接合素子の
接合層には、アモルフエスシリコン及びその酸化
物が用いられている。 The Josephson junction device that has been developed so far is
The main ones had the structure of lead alloy/lead alloy oxide/lead alloy. However, these lead alloy type Josephson junction elements have the disadvantage that the junction is easily destroyed by undergoing a thermal cycle between the operating temperature of liquid helium and room temperature, resulting in significant deterioration of characteristics. As an alternative to this, a niobium-based diosefson junction element that uses niobium or a niobium compound as an electrode, which is mechanically harder than lead, is being developed as a diosefson junction element whose characteristics hardly deteriorate due to thermal cycles or changes over time.
Tokairin et al. reported in IEICE technical research report CPM80-90 (published February 17, 1981) that there is almost no deterioration in characteristics due to thermal cycles or changes over time in Josephson junction devices using niobium nitride as electrodes.
It is stated in Amorphous silicon and its oxide are used for the bonding layer of this Josephson junction element.
ニオブは、ゲツタ作用が非常に強く、酸素や
種々の物質を吸着し易いという特徴がある。よつ
てニオブをジヨセフソン素子の電極体として用い
る場合、接合層の形成時に酸素などが余分に電極
体のニオブに拡散するという現象や、接合層の形
成後接合層中の酸素等が同様にして電極体のニオ
ブ中に拡散し易いという欠点があつた。このた
め、接合層の厚さの制御が非常に困難になるとい
う問題が生じた。ジヨセフソン接合素子の接合層
の厚さは、素子の電気的特性に大きく影響するた
め、接合層の厚さを数パーセント以下に制御する
必要があるが、従来のニオブを電極体として用い
たジヨセフソン接合素子では、この接合層の厚さ
の制御が困難であつた。しかも、経時変化により
接合層の等価的な厚さが変化するため、素子の電
気的特性が劣化するという欠点があつた。 Niobium has a very strong wicking effect and is characterized by its ability to easily adsorb oxygen and various substances. Therefore, when using niobium as the electrode body of a Josephson element, there is a phenomenon that oxygen etc. diffuses into the niobium of the electrode body during the formation of the bonding layer, and that oxygen etc. in the bonding layer similarly diffuses into the electrode body after the bonding layer is formed. The drawback is that it easily diffuses into the niobium in the body. For this reason, a problem arose in that it became very difficult to control the thickness of the bonding layer. The thickness of the bonding layer in a Josephson junction device greatly affects the electrical characteristics of the device, so it is necessary to control the thickness of the bonding layer to a few percent or less. In devices, it has been difficult to control the thickness of this bonding layer. Moreover, since the equivalent thickness of the bonding layer changes over time, there is a drawback that the electrical characteristics of the device deteriorate.
一方窒化ニオブなどのニオブ化合物は、ニオブ
が既に窒素などと化合物として結合しているので
ゲツタ作用が著しく低下し、酸素などの吸着や化
合物中への拡散が著しく少くなるという特徴があ
る。よつてニオブ化合物には接合層の形成におい
て、厚さの制御が容易になり、かつ、経時変化が
減少するという長所がある。しかし、窒化ニオブ
などのニオブ化合物は、ニオブに比べて、超伝導
状態での磁界侵入の深さが400〜500ナノメータで
４〜５倍大きいため、信号の転送時間が長くなる
と共に、磁場感度が低下するという欠点がある。 On the other hand, niobium compounds such as niobium nitride have the characteristic that because niobium is already combined with nitrogen etc. as a compound, the gettering effect is significantly reduced, and the adsorption of oxygen etc. and diffusion into the compound is significantly reduced. Therefore, the niobium compound has the advantage that the thickness can be easily controlled in forming the bonding layer, and changes over time are reduced. However, in niobium compounds such as niobium nitride, the depth of magnetic field penetration in the superconducting state is 400 to 500 nanometers, which is 4 to 5 times larger than that of niobium, resulting in longer signal transfer times and lower magnetic field sensitivity. The disadvantage is that it decreases.
この窒化ニオブの欠点を除くため、窒化ニオブ
とニオブの２層膜をベース電極（第１の電極体）
とし、鉛合金をカウンタ電極（第２の電極体）と
するジヨセフソン接合素子の構造が幸坂等により
第28回応用物理学関係連合講演会の予稿集の第
444頁（講演番号29P−Ｕ−12）に述べられてい
る。 In order to eliminate this drawback of niobium nitride, a two-layer film of niobium nitride and niobium is used as the base electrode (first electrode body).
The structure of a Josephson junction element with a lead alloy as the counter electrode (second electrode body) was described by Kosaka et al. in the proceedings of the 28th Joint Conference on Applied Physics.
It is stated on page 444 (lecture number 29P-U-12).
このジヨセフソン接合素子のカウンタ電極（第
２の電極体）には、鉛合金が用いられているので
前述した熱サイクルや経時変化による素子の電気
的特性の劣化が生じるという欠点は、完全には除
かれていない。 Since a lead alloy is used for the counter electrode (second electrode body) of this Josephson junction element, the above-mentioned drawback of deterioration of the electrical characteristics of the element due to thermal cycles and changes over time can be completely eliminated. It's not clear.
本発明の目的は、熱サイクルや経時変化による
素子の電気的特性の劣化がほとんどなく、高速で
磁場感度の良好なジヨセフソン接合素子を提供す
ることにある。 It is an object of the present invention to provide a Josephson junction device that is fast and has good magnetic field sensitivity, with almost no deterioration in the electrical characteristics of the device due to thermal cycles or changes over time.
本発明によれば、ニオブ化合物からなる第１の
超伝導体と超伝導状態での磁場侵入の深さが第１
の超伝導より小さいニオブからなる第２の超伝導
体からなる第１の電極体と、前記第１の超伝導体
と前記第２の超伝導体からなる第２の電極体と、
前記第１の電極体と前記第２の電極体との間に介
在して超伝導トンネル効果を生じさせる接合層と
から構成されることを特徴とするジヨセフソン接
合素子が得られる。 According to the present invention, the first superconductor made of a niobium compound and the depth of magnetic field penetration in the superconducting state are the first
a first electrode body made of a second superconductor made of niobium, which is smaller than the superconductivity of , and a second electrode body made of the first superconductor and the second superconductor;
A Josephson junction element is obtained, comprising a junction layer that is interposed between the first electrode body and the second electrode body and causes a superconducting tunnel effect.
本発明の好ましい実施の態様によれば、前記第
１の電極体の第１の超伝導体と前記第２の電極体
の第１の超伝導体で前記接合層をはさみ、前記第
１の電極体の第２の超伝導体と前記第２の電極体
の第２の超伝導体を、前記第１の電極体の第１の
超伝導体と前記第２の電極体と第１の超伝導体の
外側にそれぞれ配置するジヨセフソン接合素子が
得られる。 According to a preferred embodiment of the present invention, the bonding layer is sandwiched between the first superconductor of the first electrode body and the first superconductor of the second electrode body, and a second superconductor of the second electrode body and a second superconductor of the second electrode body; A Josephson junction element is obtained, each placed on the outside of the body.
さらに本発明の好ましい実施の態様によれば、
前記ニオブ化合物として窒化ニオブを用いたこと
を特徴とする前述のジヨセフソン接合素子が得ら
れる。 Further, according to a preferred embodiment of the present invention,
The aforementioned Josephson junction device is obtained, characterized in that niobium nitride is used as the niobium compound.
さらに本発明の好ましい実施の態様によれば、
前記接合層として窒化シリコン，シリコン，シリ
コンの酸化物又はシリコンとシリコンの酸化物を
用いたジヨセフソン接合素子が得られる。 Further, according to a preferred embodiment of the present invention,
A Josephson junction element using silicon nitride, silicon, silicon oxide, or silicon and silicon oxide as the junction layer is obtained.
以下図面により本発明のさらに詳細な説明を行
なう。 The present invention will be explained in more detail below with reference to the drawings.
第１図は、従来のジヨセフソン接合素子の構造
を示したものである。第１の電極体１１と第２の
電極体１２とには、鉛合金、ニオブ又はニオブ化
合物などが用いられる。接合層１３には、第１の
電極体１１の酸化物，アモルフアスシリコン，ア
モルフアスシリコンとその酸化物又は窒化ニオブ
などの絶縁物が通常用いられる。第１の電極体１
１と第２の電極体１２とを絶縁する絶縁層１４に
はSiOやSiO2などのシリコン酸化膜又は窒化シリ
コンなどが通常用いられている。 FIG. 1 shows the structure of a conventional Josephson junction element. For the first electrode body 11 and the second electrode body 12, a lead alloy, niobium, a niobium compound, or the like is used. For the bonding layer 13, an insulator such as the oxide of the first electrode body 11, amorphous silicon, amorphous silicon and its oxide, or niobium nitride is usually used. First electrode body 1
For the insulating layer 14 that insulates the electrode body 1 and the second electrode body 12, a silicon oxide film such as SiO or SiO 2 or silicon nitride is usually used.
第２図は、前述した２層膜ベース電極構造を持
つ従来のジヨセフソン接合素子の構造を示したも
のである。第１の電極体は、窒化ニオブ膜２１と
ニオブ膜２２とから構成される。第２の電極体１
２には鉛合金が、接合層１３にはアモルフアスシ
リコン又はその酸化物が、絶縁層１４にはシリコ
ンの酸化膜がそれぞれ用いられている。ニオブ膜
２２の膜厚を300ナノメータとし、窒化ニオブ膜
２１の膜厚を60ナノメータとすることにより、磁
界侵入の深さが100ナノメータに減少され、磁場
感度が大幅に改善されている。しかし、第２の電
極体１２に鉛合金が用いられているので、第１図
の場合と同じく、熱サイクルや経時変化による素
子の電気的特性の劣化が生じるという欠点は除か
れていない。なお、第１図、第２図とも、ジヨセ
フソン接合素子のスイツチを制御する制御線や、
ブランドプレーン及びその絶縁層膜などの実用の
ための付加機能部は、説明を簡単にするために省
略した。 FIG. 2 shows the structure of a conventional Josephson junction device having the above-mentioned two-layer membrane base electrode structure. The first electrode body is composed of a niobium nitride film 21 and a niobium film 22. Second electrode body 1
A lead alloy is used for 2, amorphous silicon or its oxide is used for the bonding layer 13, and a silicon oxide film is used for the insulating layer 14. By setting the thickness of the niobium film 22 to 300 nanometers and the thickness of the niobium nitride film 21 to 60 nanometers, the depth of magnetic field penetration is reduced to 100 nanometers, and the magnetic field sensitivity is greatly improved. However, since a lead alloy is used for the second electrode body 12, the disadvantage that the electrical characteristics of the element deteriorate due to thermal cycles and changes over time is not eliminated, as in the case of FIG. 1. In addition, in both FIG. 1 and FIG. 2, the control line that controls the switch of the Josephson junction element,
Additional functional parts for practical use, such as the brand plane and its insulating layer, have been omitted to simplify the explanation.
第３図は、本発明によるジヨセフソン接合素子
の第１の実施例を示したものである。第１図及び
第２図と同様、制御線やグランドプレーン等の実
用のための付加機能部は省略してある。第３図の
接合層１３と絶縁層１４とは第１図及び第２図の
従来技術と同様であるので同一番号で示してあ
る。本発明の第１の電極体は、第１の超伝導体３
１と超伝導状態での磁界侵入の深さが第１の超伝
導より小さい第２の超伝導体３２とから構成され
る。また、第２の電極体は、第１の超伝導体３３
と第２の超伝導体３４とから構成される。第１の
電極体の第１の超伝導体３１と第２の電極体の第
１の超伝導体３３は接合層１３をはさんで超伝導
トンネル効果を生じさせる。第１の電極体の第２
の超伝導体３２と第２の電極体の第２の超伝導体
３４とは、それぞれの電極体の第１の超伝導体３
１，３３の外側に配置される。第１の電極体の第
１の超伝導体３１と第２の電極体の第１の超伝導
体３３は接合層１３の形成を経時変化に対して、
第２の超伝導体３２，３４と接合層１３の相互作
用による前述の酸素の拡散等の影響を受けないよ
うな十分な厚さで形成される。第２の超伝導体３
２，３４は、少くとも超伝導状態での磁界侵入の
深さ以上の厚さで、製造可能な適当な厚さで形成
される。よつて、第１の電極体と第２の電極体の
等価的な超伝導状態での磁界侵入の深さは、第２
の超伝導体と同等になり、カイネテイツクインダ
クタンスの増加による信号の転送遅れや磁場感度
の低下を防ぐことができる。 FIG. 3 shows a first embodiment of a Josephson junction device according to the present invention. Similar to FIGS. 1 and 2, additional functional units for practical use such as control lines and ground planes are omitted. Since the bonding layer 13 and the insulating layer 14 in FIG. 3 are the same as those in the prior art shown in FIGS. 1 and 2, they are designated by the same numbers. The first electrode body of the present invention includes a first superconductor 3
1 and a second superconductor 32 in which the depth of magnetic field penetration in the superconducting state is smaller than that of the first superconductor. In addition, the second electrode body includes the first superconductor 33
and a second superconductor 34. The first superconductor 31 of the first electrode body and the first superconductor 33 of the second electrode body sandwich the bonding layer 13 to produce a superconducting tunnel effect. the second of the first electrode body
The superconductor 32 and the second superconductor 34 of the second electrode body are the first superconductor 3 of the respective electrode body.
1 and 33. The first superconductor 31 of the first electrode body and the first superconductor 33 of the second electrode body control the formation of the bonding layer 13 over time.
It is formed to have a sufficient thickness so as not to be affected by the aforementioned oxygen diffusion caused by the interaction between the second superconductors 32 and 34 and the bonding layer 13. Second superconductor 3
2 and 34 are formed to have a thickness at least equal to or greater than the depth of magnetic field penetration in the superconducting state, and are formed to have an appropriate thickness that can be manufactured. Therefore, the depth of magnetic field penetration in the equivalent superconducting state of the first electrode body and the second electrode body is
It becomes equivalent to a superconductor, and can prevent signal transfer delays and decreases in magnetic field sensitivity due to increases in kinetic inductance.
次に本実施例のジヨセフソン素子の製造方法を
簡単に述べる。 Next, a method for manufacturing the Josephson device of this example will be briefly described.
先ず第１の電極体の第２の超伝導体３２を蒸着
技術やスパツタ技術等を用いて成膜し、続けて、
第１の電極体の第１の超伝導体３１を前述と同様
な技術を用いて成膜する。第１の電極体をリフト
オフ技術等によりパターニングした後、絶縁層１
４としてSiOやSiO2などを蒸着技術やケミカル・
ベーパ・デイポジシヨン技術（CVD技術と称す
る）等を用いて成膜し、リフトオフ技術等により
パターニングする。接合層１３は、アモルフアス
シリコンをCVD技術で成膜した後、陽極酸化に
よりアモルフアスシリコン全体又は一部をSiOま
たはSiO2層に変える手法や、CVD技術により窒
化シリコン等の膜を成膜する手法や第１の電極体
の表面を陽極酸化する手法等によつて作られる。
続いて、第２の電極体の第１の超伝導体３３と、
第２の電極体の第２の超伝導体３４を前述と同様
の技術を用いて重ねて成膜する。第２の電極体の
パターニングは前述と同様のリフトオフ技術等に
より行なわれる。この時、接合層１３を形成する
時絶縁層１４上に同時に形成されるSiO，SiO2又
は窒化シリコンなどの薄層が残るが、これらは絶
縁層１４と同様の絶縁物であるので、素子の電気
的特性には影響しない。 First, the second superconductor 32 of the first electrode body is formed using vapor deposition technology, sputtering technology, etc., and then,
The first superconductor 31 of the first electrode body is formed using the same technique as described above. After patterning the first electrode body by lift-off technique etc., the insulating layer 1
4. SiO, SiO 2 , etc. can be deposited using vapor deposition technology or chemical
A film is formed using vapor deposition technology (referred to as CVD technology) and patterned using lift-off technology. The bonding layer 13 can be formed by forming amorphous silicon using CVD technology, and then converting all or part of the amorphous silicon into a SiO or SiO 2 layer by anodic oxidation, or by forming a film of silicon nitride or the like using CVD technology. The first electrode body is manufactured by a method such as a method of anodizing the surface of the first electrode body, or the like.
Subsequently, the first superconductor 33 of the second electrode body,
The second superconductor 34 of the second electrode body is deposited in an overlapping manner using the same technique as described above. Patterning of the second electrode body is performed by the same lift-off technique as described above. At this time, a thin layer of SiO, SiO 2 or silicon nitride, which is formed simultaneously on the insulating layer 14 when forming the bonding layer 13, remains, but since these are the same insulators as the insulating layer 14, Does not affect electrical characteristics.
第４図は、本発明の第２の実施例のジヨセフソ
ン接合素子の構造を示したものである。素子の接
合部の基本的な構造は第１の実施例と同一である
ので、第１の実施例と同一の効果が得られる。 FIG. 4 shows the structure of a Josephson junction device according to a second embodiment of the present invention. Since the basic structure of the joining portion of the element is the same as in the first embodiment, the same effects as in the first embodiment can be obtained.
但し、製造順序が一部異なるため、全体の構造
が異なつている。第２の実施例のジヨセフソン接
合素子は以下の手順で製造される。 However, because the manufacturing order is partially different, the overall structure is different. The Josephson junction device of the second embodiment is manufactured by the following procedure.
先ず、第１の電極体の第２の超伝導体４２が前
述と同様の技術により成膜され、パターニングさ
れる。次は、絶縁層１４が前述と同様の技術によ
り成膜され、パターニングされる。その後、第１
の電極体の第１の超伝導体４１が前述と同様の技
術を用いて成膜され、続いて接合層１３と第２の
電極体の第１の超伝導体４３と第２の電極体の第
２の超伝導体４４とが前述と同様の技術により順
次成膜される。最後に、前述と同様の技術を用い
て、第２の電極体がパターニングされる。 First, the second superconductor 42 of the first electrode body is formed and patterned using the same technique as described above. Next, the insulating layer 14 is formed and patterned using the same technique as described above. Then the first
The first superconductor 41 of the electrode body is formed using the same technique as described above, and then the bonding layer 13, the first superconductor 43 of the second electrode body, and the second superconductor 43 of the second electrode body are deposited. A second superconductor 44 is sequentially formed using the same technique as described above. Finally, the second electrode body is patterned using techniques similar to those described above.
第２の実施例では、第１の実施例と異なり、第
１の電極体の第１の超伝導体４１と、同一物質の
層４５を接合層１３と同一の物質の層４６が絶縁
層１４の上に残るという欠点がある。しかし製造
上、第１の電極体の第１の超伝導体４１と接合層
１３と第２の電極体の第１の超伝導体４３と第２
の電極体の第２の超伝導体４４が、真空を破壊す
ることなく作れるという特徴がある。よつて、第
１の電極体の第１の超伝導体４１と第２の電極体
の第１の超伝導体４３と接合層１３との間が空気
中の酸素等による汚染を受けることなく素子が製
造されるので、良質のジヨセフソン接合素子が得
られる。なお、絶縁層１４上の第１の超伝導体の
残りの層４５と接合層と同一物質の残りの層４６
は、絶縁層１４により第１の電極体の第１の超伝
導体４１から絶縁されているので、素子の電気的
特性には影響しない。 In the second embodiment, unlike the first embodiment, the first superconductor 41 of the first electrode body, the layer 45 of the same material, the bonding layer 13, and the layer 46 of the same material as the insulating layer 14. The disadvantage is that it remains on top of the However, in manufacturing, the first superconductor 41 and the bonding layer 13 of the first electrode body, the first superconductor 43 and the second superconductor of the second electrode body
The second superconductor 44 of the electrode body can be made without destroying the vacuum. Therefore, the space between the first superconductor 41 of the first electrode body, the first superconductor 43 of the second electrode body, and the bonding layer 13 can be maintained without being contaminated by oxygen in the air or the like. is manufactured, so that a high-quality Josephson junction device can be obtained. Note that the remaining layer 45 of the first superconductor on the insulating layer 14 and the remaining layer 46 of the same material as the bonding layer
Since it is insulated from the first superconductor 41 of the first electrode body by the insulating layer 14, it does not affect the electrical characteristics of the device.
第５図は、本発明の第３の実施例のジヨセフソ
ン接合素子の構造を示したものである。素子の接
合部の基本的な構造は、第１の実施例及び第２の
実施例と同一であるので、第１の実施例及び第２
の実施例と同一の効果が得られる。製造方法と第
１の電極体の第１の超伝導体５１と接合層１３と
第２の電極体の第１の超伝導体５３の構造が、第
１の実施例及び第２の実施例と異なる。第３の実
施例のジヨセフソン接合素子は以下の手順で製造
される。 FIG. 5 shows the structure of a Josephson junction device according to a third embodiment of the present invention. The basic structure of the junction part of the element is the same as that of the first embodiment and the second embodiment.
The same effect as in the embodiment can be obtained. The manufacturing method and the structure of the first superconductor 51 of the first electrode body, the bonding layer 13, and the first superconductor 53 of the second electrode body are the same as those in the first embodiment and the second embodiment. different. The Josephson junction device of the third embodiment is manufactured by the following procedure.
先ず第１の電極体の第２の超伝導体５２が、第
２の実施例と同様にして成膜され、パターニング
される。続いて絶縁層１４が前述と同様にして成
膜され、パターニングされる。次に、第１の電極
体の第１の超伝導体５１と接合層１３と第２の電
極体の第１の超伝導体５３とが、前述と同様の技
術により順次成膜される。ここで接合層１３のパ
ターンをリフトオフ技術等によりパターニングす
る。この時、第１の電極体の第１の超伝導体５１
と第２の電極体の第１の超伝導体５３も同時にパ
ターニングされる。従つて、絶縁層１４上には、
第１の電極体の第１の超伝導体５１と第２の電極
体の第１の超伝導体５３と、接合層１３に相当す
る膜は残らない。最後に、第２の電極体の第２の
超伝導体５４が前述と同様の技術により成膜され
パターニングされる。なお、第２の電極体の第１
の超伝導体５３は、第５図では絶縁層１４の接合
パターンの内側に凹状に配置されているが、絶縁
層１４上に凸状に突起した状態で配置されても素
子の電気的特性に影響しない。 First, the second superconductor 52 of the first electrode body is formed and patterned in the same manner as in the second embodiment. Subsequently, the insulating layer 14 is formed and patterned in the same manner as described above. Next, the first superconductor 51 of the first electrode body, the bonding layer 13, and the first superconductor 53 of the second electrode body are sequentially formed by the same technique as described above. Here, the bonding layer 13 is patterned using a lift-off technique or the like. At this time, the first superconductor 51 of the first electrode body
The first superconductor 53 of the second electrode body is also patterned at the same time. Therefore, on the insulating layer 14,
The first superconductor 51 of the first electrode body, the first superconductor 53 of the second electrode body, and the film corresponding to the bonding layer 13 do not remain. Finally, the second superconductor 54 of the second electrode body is formed and patterned using the same technique as described above. Note that the first electrode body of the second electrode body
In FIG. 5, the superconductor 53 is arranged in a concave manner inside the bonding pattern of the insulating layer 14, but even if it is arranged in a convex manner on the insulating layer 14, it will not affect the electrical characteristics of the device. It does not affect.
第３の実施例では、ジヨセフソン接合を形成す
る第１の電極体の第１の超伝導体５１と接合層１
３と第２の電極体の第１の超伝導体５３とが、接
合パターン部分のみに、しかも製造装置の真空を
破ることなく製造できるという特徴がある。よつ
て第３の実施例では、第２の実施例の利点と、絶
縁層１４上に不要なパターンが残らないので素子
の電気的特性が安定して得られるという利点があ
る。さらに第３の実施例では、通常、第１の電極
体と第２の電極体の製造時に同時に形成される電
極体間の配線パターンやインダクタンスループな
どの実用上必要な付加回路が、超伝導状態での磁
界侵入の深さが小さい第２の超伝導体のみで製造
できるので信号の転送遅れを他の実施例より小さ
くできるという利点がある。但し、接合パターン
のパターニングの工程を余分に必要とするという
欠点がある。 In the third embodiment, the first superconductor 51 of the first electrode body forming a Josephson junction and the bonding layer 1
3 and the first superconductor 53 of the second electrode body can be manufactured only in the bonding pattern portion and without breaking the vacuum of the manufacturing apparatus. Therefore, the third embodiment has the advantages of the second embodiment and the advantage that since no unnecessary pattern remains on the insulating layer 14, stable electrical characteristics of the device can be obtained. Furthermore, in the third embodiment, practically necessary additional circuits such as wiring patterns and inductance loops between the electrode bodies, which are usually formed at the same time when manufacturing the first electrode body and the second electrode body, are in a superconducting state. Since the second superconductor can be manufactured using only the second superconductor, which has a small depth of magnetic field penetration, it has the advantage that the signal transfer delay can be smaller than in other embodiments. However, there is a drawback that an extra step of patterning the bonding pattern is required.
以上述べた各実施例の製造手順の詳細や、実用
上必要なグランドプレーンや制御線等の付加機能
部の製造方法については、グレイナ（J.H.
Greiner）等によりアイ・ビー・エム・ジヤーナ
ル・オブ・リサーチ・アンド・デイベロプメント
（IBM Journal of Research and
Development）の第24巻第２号の第195頁から第
205頁に詳細に述べられている。 For details of the manufacturing procedure of each of the above-mentioned embodiments and the method of manufacturing additional functional parts such as ground planes and control lines that are necessary for practical use, please refer to Grayna (JH
IBM Journal of Research and Development (IBM Journal of Research and Development) by Greiner et al.
Development), Volume 24, No. 2, pages 195-
It is described in detail on page 205.
以上述べたように、本発明によれば、熱サイク
ルや経時変化による劣化がほとんどなく、かつ高
速で磁場感度の良好なジヨセフソン接合素子が得
られる。 As described above, according to the present invention, it is possible to obtain a Josephson junction element that is almost free from deterioration due to thermal cycles or changes over time, and has high speed and good magnetic field sensitivity.
第１図は従来のジヨセフソン接合素子の構造を
示す断面図、第２図は２層膜電極構造を持つ従来
のジヨセフソン接合素子の構造を示す断面図、第
３図は本発明による第１の実施例のジヨセフソン
接合素子の構造を示す断面図、第４図は本発明の
第２の実施例のジヨセフソン接合素子の構造を示
す断面図、第５図は本発明の第３の実施例のジヨ
セフソン接合素子の構造を示す断面図である。
１１……第１の電極体、１２……第２の電極
体、１３……接合層、１４……絶縁層、２１，３
１，４１，５１……第１の電極体の第１の超伝導
体、２２，３２，４２，５２……第１の電極体の
第２の超伝導体、３３，４３，５３……第２の電
極体の第１の超伝導体、３４，４４，５４……第
２の電極体の第２の超伝導体、４５……絶縁層上
の第１の超伝導体の残り、４６……絶縁層上の接
合層と同一物質の残り。
FIG. 1 is a cross-sectional view showing the structure of a conventional Josephson junction device, FIG. 2 is a cross-sectional view showing the structure of a conventional Josephson junction device having a two-layer membrane electrode structure, and FIG. 3 is a first embodiment according to the present invention. FIG. 4 is a cross-sectional view showing the structure of the Josephson junction element according to the second embodiment of the present invention, and FIG. 5 is a cross-sectional view showing the structure of the Josephson junction element according to the third embodiment of the present invention. FIG. 3 is a cross-sectional view showing the structure of the element. DESCRIPTION OF SYMBOLS 11... First electrode body, 12... Second electrode body, 13... Bonding layer, 14... Insulating layer, 21, 3
1, 41, 51...first superconductor of the first electrode body, 22,32,42,52...second superconductor of the first electrode body, 33,43,53...th 1st superconductor of the second electrode body, 34, 44, 54... Second superconductor of the second electrode body, 45... Rest of the first superconductor on the insulating layer, 46... ...Remains of the same material as the bonding layer on the insulating layer.
Claims (1)
トンネル効果を生じさせる接合層を介在させたジ
ヨセフソン接合素子において、前記電極体はニオ
ブ化合物からなる第１の超伝導体と超伝導状態で
の磁界侵入の深さがその第１の超伝導体より小さ
いニオブからなる第２の超伝導体との２層構造か
らなり、かつそれぞれ第１の超伝導体側において
前記接合層に接していることを特徴とするジヨセ
フソン接合素子。 ２ 前記ニオブ化合物として窒化ニオブを用いた
特許請求の範囲第１項記載のジヨセフソン接合素
子。 ３ 前記接合層として窒化シリコンを用いた特許
請求の範囲第１項に記載のジヨセフソン接合素
子。 ４ 前記接合層としてシリコン、シリコン酸化物
又はシリコンとシリコン酸化物を用いた特許請求
の範囲第１項に記載のジヨセフソン接合素子。[Claims] 1. A Josephson junction element in which a bonding layer that produces a superconducting tunnel effect is interposed between two electrode bodies made of a superconductor, wherein the electrode body is a first superconductor made of a niobium compound. It has a two-layer structure of a conductor and a second superconductor made of niobium in which the depth of magnetic field penetration in the superconducting state is smaller than that of the first superconductor, and each of the above-mentioned A Josephson junction element characterized by being in contact with a junction layer. 2. The Josephson junction device according to claim 1, wherein niobium nitride is used as the niobium compound. 3. The Josephson junction element according to claim 1, wherein silicon nitride is used as the junction layer. 4. The Josephson junction element according to claim 1, wherein silicon, silicon oxide, or silicon and silicon oxide is used as the junction layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56103066A JPS584931A (en) | 1981-07-01 | 1981-07-01 | Josephson junction device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56103066A JPS584931A (en) | 1981-07-01 | 1981-07-01 | Josephson junction device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS584931A JPS584931A (en) | 1983-01-12 |
| JPH0322067B2 true JPH0322067B2 (en) | 1991-03-26 |
Family
ID=14344287
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56103066A Granted JPS584931A (en) | 1981-07-01 | 1981-07-01 | Josephson junction device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS584931A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5390061A (en) | 1990-06-08 | 1995-02-14 | Hitachi, Ltd. | Multilayer magnetoresistance effect-type magnetic head |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5282090A (en) * | 1975-12-27 | 1977-07-08 | Fujitsu Ltd | Apparatus and manufacture for superconductor |
-
1981
- 1981-07-01 JP JP56103066A patent/JPS584931A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS584931A (en) | 1983-01-12 |
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