JPH0794794A - Manufacture of superconducting josephson device - Google Patents
Manufacture of superconducting josephson deviceInfo
- Publication number
- JPH0794794A JPH0794794A JP5261935A JP26193593A JPH0794794A JP H0794794 A JPH0794794 A JP H0794794A JP 5261935 A JP5261935 A JP 5261935A JP 26193593 A JP26193593 A JP 26193593A JP H0794794 A JPH0794794 A JP H0794794A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- superconducting thin
- metal mask
- superconducting
- forming surface
- 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.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 17
- 239000010409 thin film Substances 0.000 claims abstract description 72
- 229910052751 metal Inorganic materials 0.000 claims abstract description 51
- 239000002184 metal Substances 0.000 claims abstract description 51
- 238000005530 etching Methods 0.000 claims abstract description 23
- 238000010884 ion-beam technique Methods 0.000 claims abstract description 18
- 229920002120 photoresistant polymer Polymers 0.000 claims abstract description 18
- 238000000034 method Methods 0.000 claims abstract description 13
- 230000015572 biosynthetic process Effects 0.000 claims description 14
- 238000000059 patterning Methods 0.000 claims description 6
- 238000000992 sputter etching Methods 0.000 claims description 3
- 239000010408 film Substances 0.000 claims 1
- 239000000758 substrate Substances 0.000 abstract description 24
- 238000001020 plasma etching Methods 0.000 abstract description 9
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 8
- 239000010955 niobium Substances 0.000 description 5
- 229910052758 niobium Inorganic materials 0.000 description 5
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 5
- 229910052786 argon Inorganic materials 0.000 description 4
- 238000004891 communication Methods 0.000 description 4
- 230000008878 coupling Effects 0.000 description 4
- 238000010168 coupling process Methods 0.000 description 4
- 238000005859 coupling reaction Methods 0.000 description 4
- 230000006866 deterioration Effects 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 239000002887 superconductor Substances 0.000 description 4
- 238000011160 research Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 2
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- PXBRQCKWGAHEHS-UHFFFAOYSA-N dichlorodifluoromethane Chemical compound FC(F)(Cl)Cl PXBRQCKWGAHEHS-UHFFFAOYSA-N 0.000 description 1
- 235000019404 dichlorodifluoromethane Nutrition 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- MZLGASXMSKOWSE-UHFFFAOYSA-N tantalum nitride Chemical compound [Ta]#N MZLGASXMSKOWSE-UHFFFAOYSA-N 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 238000001039 wet etching Methods 0.000 description 1
Landscapes
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は超伝導ジョセフソン素子
の製造方法に関する。FIELD OF THE INVENTION The present invention relates to a method of manufacturing a superconducting Josephson device.
【０００２】[0002]
【従来の技術】図５に従来の作製プロセスとして、電子
情報通信学会技術研究報告超伝導エレクトロニクスＳＣ
Ｅ９２−５０において示された高温超伝導ジョセフソン
素子作製プロセス（以下、第１の従来例という。）を示
す。2. Description of the Related Art FIG. 5 shows a conventional manufacturing process, a research report of the Institute of Electronics, Information and Communication Engineers Superconducting Electronics
A high temperature superconducting Josephson device manufacturing process (hereinafter referred to as a first conventional example) shown in E92-50 is shown.
【０００３】図５において、誘電体基板１０上にフォト
レジスト１１がつけられる（Ａ）。紫外線露光でフォト
レジスト１１がパターニングされる（Ｂ）。イオンビー
ムエッチングで誘電体基板１０がエッチングされる
（Ｃ）。レジスト１１が剥離され（Ｄ）、誘電体基板１
０に段差が形成される。この誘電体基板１０を洗浄した
後、誘電体基板１０の上に高温超伝導薄膜１２が堆積さ
れる（Ｅ）。必要な段差の部分にジョセフソン接合を作
るため、レジストを塗り、それをパターニングし、エッ
チングで高温超伝導薄膜１２を加工し、高温超伝導ジョ
セフソン素子ができあがる。In FIG. 5, a photoresist 11 is applied on the dielectric substrate 10 (A). The photoresist 11 is patterned by ultraviolet exposure (B). The dielectric substrate 10 is etched by ion beam etching (C). The resist 11 is peeled off (D), and the dielectric substrate 1
A step is formed at 0. After cleaning the dielectric substrate 10, a high temperature superconducting thin film 12 is deposited on the dielectric substrate 10 (E). In order to form a Josephson junction in a necessary step portion, a resist is applied, the resist is patterned, and the high temperature superconducting thin film 12 is processed by etching to form a high temperature superconducting Josephson device.
【０００４】なお、パターニングとは、薄膜に対して電
極を形成するとか、配線のパターンを作る等のように、
所定の型のあるパターンを形成することを意味する。The patterning means, for example, forming an electrode on a thin film or forming a wiring pattern.
It means forming a certain pattern of a predetermined pattern.
【０００５】図６に電子情報通信学会論文誌ｖｏｌ．Ｊ
７６−Ｃ−〓 Ｎｏ．６、ｐ３６４において示される誘
電体基板に段差をエッチングする際のマスクとして金属
マスクを使用した例（以下、第２の従来例という。）を
示す。まず、誘電体基板１０上に金属マスク１３を堆積
させる（Ａ）。このときの金属マスクとしてはタンタル
を使用している。フォトレジスト１１をぬり（Ｂ）、フ
ォトレジスト１１を紫外線露光でパターニングする
（Ｃ）。アルゴンイオンビームエッチングで金属マスク
１３をエッチングする（Ｄ）。レジスト１１を剥離した
後（Ｅ）、窒素イオンビームエッチングにより基板に段
差をつける（Ｆ）。残ったマスク１３は剥離する
（Ｇ）。この誘電体基板を洗浄した後、高温超伝導薄膜
１２を堆積させる。必要な部分に接合を作るため、レジ
ストを塗り、それをパターニングし、エッチングで高温
超伝導薄膜１２を加工し、高温超伝導ジョセフソン素子
ができあがる。第１の従来例のように有機レジストであ
るフォトレジストを用いてマスクとする場合、形成され
た誘電体基板の段差部はレジストの熱膨張等でなだらか
なものとなる。これに反し、第２の従来例では金属マス
クを用いることにより急峻な段差を形成することができ
る。FIG. 6 shows the Institute of Electronics, Information and Communication Engineers journal vol. J
76-C-〓 No. 6, p364 shows an example of using a metal mask as a mask when etching a step on the dielectric substrate (hereinafter referred to as a second conventional example). First, the metal mask 13 is deposited on the dielectric substrate 10 (A). Tantalum is used as the metal mask at this time. The photoresist 11 is wetted (B), and the photoresist 11 is patterned by ultraviolet exposure (C). The metal mask 13 is etched by argon ion beam etching (D). After removing the resist 11 (E), a step is formed on the substrate by nitrogen ion beam etching (F). The remaining mask 13 is peeled off (G). After cleaning the dielectric substrate, the high temperature superconducting thin film 12 is deposited. In order to form a bond in a necessary portion, a resist is applied, the resist is patterned, and the high temperature superconducting thin film 12 is processed by etching to complete a high temperature superconducting Josephson device. In the case of using a photoresist which is an organic resist as a mask as in the first conventional example, the stepped portion of the formed dielectric substrate becomes gentle due to thermal expansion of the resist and the like. On the contrary, in the second conventional example, a steep step can be formed by using a metal mask.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、第１の
従来例においては、基板に段差をつける際、イオンビー
ムエッチングを使用しているため、熱の影響があり、エ
ッチング時にレジストの熱膨張等が伴い、誘電体基板の
側壁の角度制御を厳密に行うことが困難であり、特性の
そろったジョセフソン素子を作製することができない。
また、段差の側壁の形状の平坦度も良くなく、側壁自身
に凹凸をもってしまい、側壁でも弱結合ができてしま
い、不要なジョセフソン接合ができてしまうことや、側
壁面での超伝導体の劣化が起こり、臨界温度が下がり、
特性の劣化を引き起こす。However, in the first conventional example, since ion beam etching is used when forming a step on the substrate, it is affected by heat, and thermal expansion of the resist during etching is caused. Accordingly, it is difficult to strictly control the angle of the side wall of the dielectric substrate, and it is not possible to fabricate a Josephson device with uniform characteristics.
Further, the flatness of the shape of the side wall of the step is not good, and the side wall itself has irregularities, weak coupling can be formed even on the side wall, and unnecessary Josephson junction can be formed. Deterioration occurs, the critical temperature decreases,
Causes deterioration of characteristics.
【０００７】また、イオンビームエッチングの代わりに
ウエットエッチングを使用したとしても、熱の影響はな
くなるが、サイドエッチングのため段差部の平坦度は悪
くなる。Even if wet etching is used instead of ion beam etching, the influence of heat disappears, but the flatness of the step portion deteriorates due to side etching.
【０００８】また、第２の従来例においては、金属マス
クを使用することにより、第１の従来例におけるフォト
レジストの熱膨張の問題点は解決しているが、金属マス
クの側壁の形状については全く考慮せず、垂直にしてい
る。このため第２の従来例では段差の部分は急峻な側壁
をもつ。この場合は、超伝導体が切り立った構造になっ
ていて、段差上部と段差下部の部分の超伝導体がつなが
って、この結合部に弱結合ができ、ジョセフソン接合が
できると考えられる。この方法では、急峻な側壁の部分
での超伝導体の堆積の再現性に問題があり、多くの弱結
合ができてしまう可能性がある。Further, in the second conventional example, the problem of thermal expansion of the photoresist in the first conventional example is solved by using the metal mask, but the shape of the side wall of the metal mask is Vertically without any consideration. Therefore, in the second conventional example, the step portion has a steep side wall. In this case, it is considered that the superconductor has a raised structure, the superconductors at the upper part of the step and the superconductor at the lower part of the step are connected to each other, a weak bond can be formed at this joint, and a Josephson junction can be formed. This method has a problem in the reproducibility of the deposition of the superconductor on the steep side wall portion, and may cause many weak couplings.
【０００９】本発明の目的は上述の問題点を解決し、従
来のものに比較し超伝導薄膜形成面の段差の側壁の角度
の制御を再現性良く行い、側壁の形状の平坦度を上げる
ことにより、特性的に優れた再現性の良い超伝導ジョセ
フソン素子を作製することである。An object of the present invention is to solve the above-mentioned problems, to control the angle of the side wall of the step of the superconducting thin film formation surface with good reproducibility, and to improve the flatness of the side wall shape, as compared with the conventional one. To produce a superconducting Josephson device with excellent characteristics and good reproducibility.
【００１０】[0010]
【問題を解決するための手段】本発明に係る請求項記載
の超伝導ジョセフソン素子の製造方法は、超伝導薄膜形
成面の所要部分に段差を形成し、上記超伝導薄膜形成面
に堆積された超伝導薄膜をパターニングし、上記超伝導
薄膜形成面の段差部にジョセフソン接合を形成された超
伝導ジョセフソン素子の製造方法において、上記超伝導
薄膜形成面上に段差部を形成するためのマスクとなる金
属薄膜層を形成し、上記金属薄膜層の上面にパターニン
グしたフォトレジストを被着し、反応性イオンエッチン
グを行うことによって、パターニングに応じて上記金属
マスクに形成されるパターンの側壁に任意の角度をもつ
金属マスクを形成し、上記金属マスク上に残留するフォ
トレジストを除去し、イオンビームエッチングにより、
上記金属マスクの側壁の角度に応じた傾斜状の段差を上
記超伝導薄膜形成面に転写し、該傾斜状の段差に跨るよ
うに超伝導薄膜をパターニングするようにしたことを特
徴とする。According to the method for manufacturing a superconducting Josephson device according to the present invention, a step is formed on a required portion of a superconducting thin film forming surface, and the step is deposited on the superconducting thin film forming surface. In the method of manufacturing a superconducting Josephson device in which a Josephson junction is formed on the step portion of the superconducting thin film forming surface by patterning the superconducting thin film, a step for forming the step portion on the superconducting thin film forming surface is provided. A metal thin film layer to be a mask is formed, a patterned photoresist is deposited on the upper surface of the metal thin film layer, and reactive ion etching is performed to form a sidewall of the pattern formed on the metal mask according to the patterning. By forming a metal mask with an arbitrary angle, removing the photoresist remaining on the metal mask, by ion beam etching,
It is characterized in that an inclined step corresponding to the angle of the side wall of the metal mask is transferred to the superconducting thin film forming surface, and the superconducting thin film is patterned so as to extend over the inclined step.
【００１１】[0011]
【作用】上記構成によれば、超伝導薄膜形成面にイオン
ビームエッチングで段差を形成しようとするとき、金属
マスクと超伝導薄膜形成面のエッチングは同時に進行す
る。金属マスクは、金属薄膜層のパターニングの際、反
応性イオンエッチングを用いているため、パターンの側
壁には任意の角度がついている。そのため、イオンビー
ムは側壁部もエッチングしていき、金属マスクはイオン
ビームによる熱膨張が生じないので、一定の側壁の角度
を保持したまま、金属マスクの側壁は後退していく。こ
のとき、徐々に超伝導薄膜形成面に当たるイオンビーム
の面は側壁が後退していくに連れ、増加していく。この
側壁の後退に従い、超伝導薄膜形成面にも任意の角度の
側壁を有する段差部を形成できる。この時、金属マスク
の耐熱性により、超伝導薄膜形成面の側壁の平坦度が良
くなる。According to the above structure, when a step is formed on the superconducting thin film forming surface by ion beam etching, the etching of the metal mask and the superconducting thin film forming surface proceed at the same time. Since the metal mask uses reactive ion etching when patterning the metal thin film layer, the side wall of the pattern has an arbitrary angle. Therefore, the side wall of the metal mask is also etched, and the metal mask does not undergo thermal expansion due to the ion beam. Therefore, the side wall of the metal mask recedes while maintaining a constant side wall angle. At this time, the surface of the ion beam that gradually hits the superconducting thin film formation surface increases as the side wall recedes. As the side wall recedes, a step portion having a side wall with an arbitrary angle can be formed on the superconducting thin film formation surface. At this time, the heat resistance of the metal mask improves the flatness of the side wall of the superconducting thin film formation surface.
【００１２】超伝導薄膜の特性は超伝導薄膜形成面に大
きく左右されるため、超伝導薄膜形成面の側壁の平坦度
を良くする事は、超伝導薄膜形成面の段差の側壁に堆積
される超伝導薄膜の劣化をおさえることにつながり、側
壁での臨界温度の低下や、不要な粒界接合を作ってしま
うようなことはなくなる。Since the characteristics of the superconducting thin film are largely influenced by the surface on which the superconducting thin film is formed, it is necessary to improve the flatness of the side wall on the surface on which the superconducting thin film is formed by depositing on the side wall of the step on the surface on which the superconducting thin film is formed. The deterioration of the superconducting thin film is suppressed, and the lowering of the critical temperature on the side wall and the formation of unnecessary grain boundary junction are eliminated.
【００１３】[0013]
【実施例】以下、図面を参照して、本発明による実施例
について説明する。Embodiments of the present invention will be described below with reference to the drawings.
【００１４】図１に本発明に係る実施例である超伝導素
子の作製プロセスを示す。まず、超伝導薄膜形成面をも
つ基板１６上に金属マスク１３を堆積させる（Ａ）。フ
ォトレジスト１１をぬり（Ｂ）、フォトレジスト１１を
パターニングする（Ｃ）。金属マスク１３をエッチング
する（Ｄ）。この時、超伝導薄膜形成面の段差の側壁の
角度を制御するため、反応性イオンエッチングで金属マ
スク１３のパターンの側壁に角度がつけられる。フォト
レジスト１１を剥離した後（Ｅ）、イオンビームエッチ
ングにより、超伝導薄膜形成面に任意の角度がついた段
差をつける（Ｆ）。残った金属マスク１３は剥離する
（Ｇ）。この超伝導薄膜形成面に、超伝導薄膜１５を堆
積させる。必要な段差部分にジョセフソン接合を作るた
め、フォトレジストをぬり、パターニングし、エッチン
グで薄膜を加工し、最終的に超伝導ジョセフソン素子の
完成となる。段差の部分で配向性の違いにより粒界がで
き、ジョセフソン接合ができる。FIG. 1 shows a manufacturing process of a superconducting element which is an embodiment according to the present invention. First, the metal mask 13 is deposited on the substrate 16 having the superconducting thin film formation surface (A). The photoresist 11 is applied (B), and the photoresist 11 is patterned (C). The metal mask 13 is etched (D). At this time, in order to control the angle of the side wall of the step on the surface on which the superconducting thin film is formed, the side wall of the pattern of the metal mask 13 is angled by reactive ion etching. After removing the photoresist 11 (E), a step having an arbitrary angle is formed on the superconducting thin film formation surface by ion beam etching (F). The remaining metal mask 13 is peeled off (G). The superconducting thin film 15 is deposited on this superconducting thin film forming surface. In order to form a Josephson junction at a necessary step portion, a photoresist is applied, patterning is performed, and a thin film is processed by etching. Finally, a superconducting Josephson device is completed. A grain boundary is formed at the step portion due to the difference in orientation, and a Josephson junction can be formed.
【００１５】なお、段差とは超伝導薄膜形成面のエッチ
ングされた部分とエッチングされていない面との間の部
分を意味する。The step means a portion between the etched portion and the non-etched portion of the superconducting thin film forming surface.
【００１６】図２に金属のパターンの側壁の角度に対し
て超伝導薄膜形成面をイオンビームエッチング後の超伝
導薄膜形成面の段差の側壁の角度の関係を示す。この図
において、超伝導薄膜形成面をもつ基板はＭｇＯ、金属
マスクはニオブ、イオンビームはアルゴンイオンビーム
を用いた。この場合、ＭｇＯとニオブのアルゴンイオン
ビームに対するエッチング速度の違いにより、金属マス
クのパターンの側壁の角度は超伝導薄膜形成面の段差の
側壁の角度と同じにはならないが、再現性良くこの角度
は得られる。FIG. 2 shows the relationship between the angle of the side wall of the metal pattern and the angle of the side wall of the step of the superconducting thin film forming surface after the ion beam etching of the superconducting thin film forming surface. In this figure, MgO was used for the substrate having the superconducting thin film formation surface, niobium was used for the metal mask, and argon ion beam was used for the ion beam. In this case, the angle of the side wall of the pattern of the metal mask does not become the same as the angle of the side wall of the step on the superconducting thin film formation surface due to the difference in the etching rates of MgO and niobium with respect to the argon ion beam, but this angle has good reproducibility. can get.
【００１７】ＭｇＯ基板でアルゴンイオンエッチングと
ニオブ金属マスクの組み合わせでは段差の角度が４０度
までのものしか得られない。しかし、この組み合わせを
変えることにより大きな角度も可能となる。例えば、金
属マスクと超伝導薄膜形成面のエッチングレートが同程
度のものを用いれば、大きな角度の段差をつけることが
可能となる。With a combination of argon ion etching and a niobium metal mask on a MgO substrate, only a step angle of up to 40 degrees can be obtained. However, a large angle is possible by changing this combination. For example, if the metal mask and the superconducting thin film formation surface have the same etching rate, a step having a large angle can be formed.
【００１８】上述のプロセスにおいては金属マスクとし
てニオブを用いているが、金属マスクは高融点金属であ
ればどのようなものでも使用可能である。Although niobium is used as the metal mask in the above process, any metal mask can be used as long as it is a refractory metal.
【００１９】また、反応性イオンエッチングガスとして
ＣＦ4 、金属マスクはニオブを使用しているが、反応性
イオンエッチングで削ることのできる金属であればどん
なものでも使用可能である。たとえば、反応性イオンエ
ッチングガスとしてＣＦ4 を用いれば、金属としてシリ
コン、窒化シリコン、モリブデン、タンタル、窒化タン
タル、タングステン等が、反応性イオンエッチングガス
としてＣＣｌ4 を用いれば、金属としてシリコン、アル
ミニウム、クロム、チタン等が、反応性イオンエッチン
グガスとしてＣＣｌ2Ｆ2を用いれば、ＧａＡｓ等を用い
ることが可能である。Although CF4 is used as the reactive ion etching gas and niobium is used as the metal mask, any metal that can be removed by reactive ion etching can be used. For example, if CF4 is used as the reactive ion etching gas, silicon, silicon nitride, molybdenum, tantalum, tantalum nitride, tungsten, etc. are used as the metal, and if CCl4 is used as the reactive ion etching gas, silicon, aluminum, chromium, If titanium or the like uses CCl2F2 as the reactive ion etching gas, GaAs or the like can be used.
【００２０】図３に完成した超伝導ジョセフソン素子を
示す。段差をつけられた超伝導薄膜形成面をもつ基板１
６の上に、加工された超伝導薄膜１４があり、エッチン
グされた超伝導薄膜形成面と段差の側壁の部分と、エッ
チングされていない超伝導薄膜形成面と段差の側壁の部
分の２箇所で弱接合が形成されている。FIG. 3 shows the completed superconducting Josephson device. Substrate 1 having a stepped superconducting thin film formation surface
There is a processed superconducting thin film 14 on top of 6, and the superconducting thin film forming surface that has been etched and the side wall of the step, and the unetched superconducting thin film forming surface and the side wall of the step have two locations. A weak bond is formed.
【００２１】以上のように構成された実施例の超伝導ジ
ョセフソン素子の製造方法により製造された超伝導ジョ
セフソン素子において、超伝導薄膜１４にマイクロ波信
号を入力することにより接合部にマイクロ波電流が誘起
される。それによりマイクロ波の検出ができる。In the superconducting Josephson device manufactured by the method for manufacturing the superconducting Josephson device of the embodiment configured as described above, the microwave signal is input to the superconducting thin film 14 so that the microwave is applied to the junction. An electric current is induced. Thereby, the microwave can be detected.
【００２２】上述の方法で作成した素子は、段差角度が
１０度以下では粒界接合が作製されず、４０度以上では
きれいな電流電圧特性は得られない。典型的な素子の電
流電圧特性のオシログラフの写真を図４に示す。これ
は、超伝導薄膜をＹ1Ｂａ2Ｃｕ3０7、超伝導薄膜形成面
をもつ基板をＭｇＯ、段差角度を２０度としたもので、
４．２Ｋでの特性である。若干のヒステリシスを伴って
いるがＲＳＪモデルに非常に近い特性となっている。こ
の素子は臨界電流の減少はあるものの、７０Ｋでも動作
する。In the element produced by the above method, grain boundary junction is not produced when the step angle is 10 degrees or less, and clear current-voltage characteristics cannot be obtained when the step angle is 40 degrees or more. An oscillograph photograph of the current-voltage characteristics of a typical device is shown in FIG. In this, the superconducting thin film is Y1Ba2Cu307, the substrate having the superconducting thin film forming surface is MgO, and the step angle is 20 degrees.
It is a characteristic at 4.2K. Although it has some hysteresis, it has characteristics very close to the RSJ model. This device operates at 70K, although there is a reduction in critical current.
【００２３】なお、上記実施例においては、誘電体基板
であるＭｇＯを超伝導薄膜形成面をもつ基板としたが、
薄膜を多層化した場合、超伝導薄膜の下に形成される面
に上述の方法と同様に金属マスクを用いてイオンビーム
エッチングを行えば、同様に超伝導の弱結合ができ、薄
膜層間の配線を行うと同時にジョセフソン接合を作るこ
とができる。In the above embodiment, the dielectric substrate MgO is used as the substrate having the superconducting thin film forming surface.
When the thin film is multi-layered, if the surface formed under the superconducting thin film is subjected to ion beam etching using a metal mask as in the above method, weak coupling of superconductivity can be similarly generated and wiring between thin film layers can be formed. At the same time you can make a Josephson junction.
【００２４】[0024]
【発明の効果】以上、詳述したように、本発明に係る超
伝導ジョセフソン素子の製造方法によれば、超伝導薄膜
形成面に段差をつけるためのマスクとして、金属マスク
を用いて、金属マスクのエッチングの際、反応性イオン
ビームで金属マスクのパターンの側壁に角度をつけ、超
伝導薄膜形成面の段差の側壁の角度を制御よく作り、側
壁の平坦性を上げた超伝導ジョセフソン素子の製造方法
において、超伝導薄膜形成面の段差の側壁の平坦性を上
げることにより、側壁での超伝導特性の劣化を抑えるこ
とができる。As described above in detail, according to the method for manufacturing a superconducting Josephson device according to the present invention, a metal mask is used as a mask for forming a step on the superconducting thin film formation surface. When etching the mask, a reactive ion beam is used to angle the side wall of the pattern of the metal mask to control the angle of the side wall of the step of the superconducting thin film formation surface, making the side wall flat and superconducting Josephson device. In the manufacturing method described above, by increasing the flatness of the side wall of the step on the surface on which the superconducting thin film is formed, deterioration of the superconducting property on the side wall can be suppressed.
【００２５】また、この製造方法により、金属マスクの
パターンの側壁の角度に応じて超伝導薄膜形成面の段差
の側壁の角度は再現性よく得られ、安定した超伝導ジョ
セフソン素子を作製することができる。By this manufacturing method, the angle of the side wall of the step of the superconducting thin film forming surface can be obtained with good reproducibility according to the angle of the side wall of the pattern of the metal mask, and a stable superconducting Josephson element can be manufactured. You can
【００２６】超伝導高周波素子の集積化に向けて、本発
明を使用することにより、素子作成の制御性を上げるこ
とができる。特性のばらつきが少ないことは集積化の設
計上必要なことであり、アンテナ等との結合の時のマッ
チングやアレイ化の時などに利点を有する。By using the present invention for the integration of superconducting high frequency devices, the controllability of device fabrication can be improved. The small variation in characteristics is necessary in the design of integration, and has an advantage in matching at the time of coupling with an antenna or the like, or at the time of forming an array.
【図１】本発明に係る実施例の超伝導ジョセフソン素子
の作製プロセスを示す説明図である。FIG. 1 is an explanatory diagram showing a manufacturing process of a superconducting Josephson device according to an example of the present invention.
【図２】金属マスクのパターンの側壁の角度と超伝導薄
膜形成面の段差の側壁の角度との関係を示す特性図であ
る。FIG. 2 is a characteristic diagram showing the relationship between the angle of the side wall of the pattern of the metal mask and the angle of the side wall of the step on the surface on which the superconducting thin film is formed.
【図３】図１でのプロセスにより作製された超伝導ジョ
セフソン素子の斜視図である。3 is a perspective view of a superconducting Josephson device manufactured by the process of FIG.
【図４】実施例により作製された超伝導ジョセフソン素
子の電流電圧特性を示すオシログラフの写真である。FIG. 4 is a photograph of an oscillograph showing the current-voltage characteristics of the superconducting Josephson device manufactured according to the example.
【図５】第１の従来例の超伝導ジョセフソン素子作成プ
ロセスを示す説明図である。FIG. 5 is an explanatory view showing a superconducting Josephson device manufacturing process of a first conventional example.
【図６】第２の従来例の超伝導ジョセフソン素子作成プ
ロセスを示す説明図である。FIG. 6 is an explanatory view showing a second conventional example superconducting Josephson device manufacturing process.
１０ 誘電体基板 １１ フォトレジスト １２，１４ 高温超伝導薄膜 １３ 金属マスク １５ 超伝導薄膜 １６ 基板 10 Dielectric Substrate 11 Photoresist 12,14 High Temperature Superconducting Thin Film 13 Metal Mask 15 Superconducting Thin Film 16 Substrate
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成６年５月１８日[Submission date] May 18, 1994
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】図面[Document name to be corrected] Drawing
【補正対象項目名】図４[Name of item to be corrected] Fig. 4
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【図４】 [Figure 4]
───────────────────────────────────────────────────── フロントページの続き (72)発明者 小宮山牧兒 東京都小金井市貫井北町４丁目２番１号 郵政省通信総合研究所内 (72)発明者 中條 渉 東京都小金井市貫井北町４丁目２番１号 郵政省通信総合研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Makimasa Komiyama 4-2-1, Nakaikita-cho, Koganei-shi, Tokyo Inside Communication Research Laboratory, Ministry of Posts and Telecommunications (72) Wataru Nakajo 4-2-1, Nakaikita-cho, Koganei-shi, Tokyo No. 1 Communication Research Laboratory, Ministry of Posts and Telecommunications
Claims (1)
導薄膜形成面に堆積された超伝導薄膜をパターニング
し、上記超伝導薄膜形成面の段差部にジョセフソン接合
を形成する超伝導ジョセフソン素子の製造方法におい
て、上記超伝導薄膜形成面上に段差部を形成するための
マスクとなる金属薄膜層を形成し、上記金属薄膜層の上
面にパターニングしたフォトレジストを被着し、反応性
イオンエッチングを行うことによって、パターニングに
応じて上記金属マスクに形成されるパターンの側壁に任
意の角度をもつ金属マスクを形成し、上記金属マスク上
に残留するフォトレジストを除去し、イオンビームエッ
チングにより、上記金属マスクの側壁の角度に応じた傾
斜状の段差を上記超伝導薄膜形成面に転写し、該傾斜状
の段差に跨るように超伝導薄膜をパターニングするよう
にしたことを特徴とする超伝導ジョセフソン素子の製造
方法。A superconducting Joseph that forms a step on a required portion of the superconducting thin film forming surface, patterns the superconducting thin film deposited on the superconducting thin film forming surface, and forms a Josephson junction on the step portion of the superconducting thin film forming surface. In the method for manufacturing the Son element, a metal thin film layer serving as a mask for forming a step portion is formed on the superconducting thin film forming surface, and a patterned photoresist is deposited on the upper surface of the metal thin film layer to form a reactive film. By performing ion etching, a metal mask having an arbitrary angle is formed on the side wall of the pattern formed on the metal mask according to patterning, the photoresist remaining on the metal mask is removed, and ion etching is performed by ion beam etching. , A sloped step corresponding to the angle of the side wall of the metal mask is transferred to the superconducting thin film formation surface, and is superposed so as to straddle the sloped step. Method for producing a superconducting Josephson device characterized in that the conductive thin film to be patterned.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5261935A JP2526402B2 (en) | 1993-09-24 | 1993-09-24 | Method of manufacturing superconducting Josephson device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5261935A JP2526402B2 (en) | 1993-09-24 | 1993-09-24 | Method of manufacturing superconducting Josephson device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0794794A true JPH0794794A (en) | 1995-04-07 |
| JP2526402B2 JP2526402B2 (en) | 1996-08-21 |
Family
ID=17368736
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5261935A Expired - Lifetime JP2526402B2 (en) | 1993-09-24 | 1993-09-24 | Method of manufacturing superconducting Josephson device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2526402B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000016414A1 (en) * | 1998-09-14 | 2000-03-23 | Commonwealth Scientific And Industrial Research Organisation | Method of fabrication of step edge |
| CN102092673A (en) * | 2010-12-31 | 2011-06-15 | 上海集成电路研发中心有限公司 | Method for forming slowly changed side wall of micro-electro-mechanical system (MEMS) |
| CN111682096A (en) * | 2020-05-12 | 2020-09-18 | 中国科学院上海微系统与信息技术研究所 | Preparation method of planar superconducting nano bridge junction |
| CN115148890A (en) * | 2022-05-17 | 2022-10-04 | 南京大学 | Preparation method of niobium-aluminum Josephson junction based on metal mask |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61124137A (en) * | 1984-11-20 | 1986-06-11 | Fujitsu Ltd | Method of forming ultrafine hole pattern |
| JPS6224628A (en) * | 1985-07-24 | 1987-02-02 | Matsushita Electronics Corp | Formation of photoresist pattern |
| JPH01241874A (en) * | 1988-03-23 | 1989-09-26 | Mitsubishi Electric Corp | Josephson junction element |
-
1993
- 1993-09-24 JP JP5261935A patent/JP2526402B2/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61124137A (en) * | 1984-11-20 | 1986-06-11 | Fujitsu Ltd | Method of forming ultrafine hole pattern |
| JPS6224628A (en) * | 1985-07-24 | 1987-02-02 | Matsushita Electronics Corp | Formation of photoresist pattern |
| JPH01241874A (en) * | 1988-03-23 | 1989-09-26 | Mitsubishi Electric Corp | Josephson junction element |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000016414A1 (en) * | 1998-09-14 | 2000-03-23 | Commonwealth Scientific And Industrial Research Organisation | Method of fabrication of step edge |
| GB2357917A (en) * | 1998-09-14 | 2001-07-04 | Commw Scient Ind Res Org | Method of fabrication of step edge |
| GB2357917B (en) * | 1998-09-14 | 2002-05-08 | Commw Scient Ind Res Org | Method of fabrication of step edge |
| US6514774B1 (en) | 1998-09-14 | 2003-02-04 | Commonwealth Scientific And Industrial Research Organisation | Method of fabrication of step edge |
| CN102092673A (en) * | 2010-12-31 | 2011-06-15 | 上海集成电路研发中心有限公司 | Method for forming slowly changed side wall of micro-electro-mechanical system (MEMS) |
| CN111682096A (en) * | 2020-05-12 | 2020-09-18 | 中国科学院上海微系统与信息技术研究所 | Preparation method of planar superconducting nano bridge junction |
| CN115148890A (en) * | 2022-05-17 | 2022-10-04 | 南京大学 | Preparation method of niobium-aluminum Josephson junction based on metal mask |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2526402B2 (en) | 1996-08-21 |
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