JPH02257681A - Machining method of superconductive thin-film - Google Patents
Machining method of superconductive thin-filmInfo
- Publication number
- JPH02257681A JPH02257681A JP1078975A JP7897589A JPH02257681A JP H02257681 A JPH02257681 A JP H02257681A JP 1078975 A JP1078975 A JP 1078975A JP 7897589 A JP7897589 A JP 7897589A JP H02257681 A JPH02257681 A JP H02257681A
- Authority
- JP
- Japan
- Prior art keywords
- film
- oxide
- thin film
- thin
- metallic layer
- 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
- 239000010409 thin film Substances 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000003754 machining Methods 0.000 title 1
- 239000002184 metal Substances 0.000 claims abstract description 25
- 229910052751 metal Inorganic materials 0.000 claims abstract description 25
- 239000002887 superconductor Substances 0.000 claims abstract description 18
- 239000010408 film Substances 0.000 claims abstract description 10
- 230000009257 reactivity Effects 0.000 claims abstract description 7
- 238000000206 photolithography Methods 0.000 claims description 9
- 238000010849 ion bombardment Methods 0.000 abstract description 4
- 239000000463 material Substances 0.000 abstract description 2
- 229910052709 silver Inorganic materials 0.000 abstract description 2
- 229910052782 aluminium Inorganic materials 0.000 abstract 1
- 229910052738 indium Inorganic materials 0.000 abstract 1
- 238000005530 etching Methods 0.000 description 11
- 238000010438 heat treatment Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 5
- 239000000758 substrate Substances 0.000 description 5
- 239000013078 crystal Substances 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000010884 ion-beam technique Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000004544 sputter deposition Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 206010016654 Fibrosis Diseases 0.000 description 2
- 230000004761 fibrosis Effects 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 206010011732 Cyst Diseases 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 208000031513 cyst Diseases 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 238000001459 lithography Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 238000001020 plasma etching Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000007261 regionalization Effects 0.000 description 1
- WGTYBPLFGIVFAS-UHFFFAOYSA-M tetramethylammonium hydroxide Chemical compound [OH-].C[N+](C)(C)C WGTYBPLFGIVFAS-UHFFFAOYSA-M 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/60—Superconducting electric elements or equipment; Power systems integrating superconducting elements or equipment
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
- Superconductors And Manufacturing Methods Therefor (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、酸化物超電導薄膜の加工方法に関する。より
詳細には、フォトリソグラフィ技術を用いて酸化物超電
導薄膜を加工する方法に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for processing oxide superconducting thin films. More specifically, the present invention relates to a method of processing an oxide superconducting thin film using photolithography technology.
従来の技術
各種酸化物超電導体が発見されて以来、超電導電子デバ
イスおよび回路配線に応用することが試みられている。BACKGROUND OF THE INVENTION Since the discovery of various oxide superconductors, attempts have been made to apply them to superconducting electronic devices and circuit wiring.
すでに、ジョセフソン素子、５ＱＵＩＤ、超電導トラン
ジスタ、超電導回路配線等を酸化物超電導体で作製した
報告がなされている。Reports have already been made on fabricating Josephson elements, 5QUIDs, superconducting transistors, superconducting circuit wiring, etc. using oxide superconductors.
これらのデバイスを酸化物超電導体で作製する場合、そ
の加工にはフォトリソグラフィ技術が用いられている。When manufacturing these devices using oxide superconductors, photolithography technology is used for processing.
すなわち、酸化物超電導薄膜表面にレジスト膜を、形成
し、加工する形状に合わせたマスクを形成し、エツチン
グを行ってデバイ゛スを作製していた。That is, a resist film is formed on the surface of an oxide superconducting thin film, a mask is formed to match the shape to be processed, and etching is performed to fabricate a device.
発明が解決しようとする“課題
上記従来の加工方法では、レジスト膜を酸化物超電導薄
膜表面に直接形成していたので、界面で反応が起こり、
酸化物超電導体の特性が劣化するという問題があった。Problems to be Solved by the Invention In the conventional processing method described above, the resist film was formed directly on the surface of the oxide superconducting thin film, so a reaction occurred at the interface.
There was a problem that the characteristics of the oxide superconductor deteriorated.
また、フォトリンゲラフィブロセスにおいて、酸化物超
電導体が、アルカリ性の現像液、レジスト剥離液および
洗浄用の水に触れ、さらに特性が劣化することがあった
。Furthermore, in the photoringer fibrosis process, the oxide superconductor comes into contact with an alkaline developer, resist stripping solution, and cleaning water, and its properties sometimes deteriorate.
一方、ドライエツチング法によりエツチングを行う場合
には、酸化物超電導体にイオン（ＫＭによるダメージが
生じ、超電導特性が劣化することもあった。On the other hand, when etching is performed using a dry etching method, the oxide superconductor is damaged by ions (KM), resulting in deterioration of superconducting properties.
そこで本発明の目的は、上記従来技術の問題点を解決し
た酸化物超電導体の特性を劣化させない酸化物超電導薄
膜の加工方法を提供することにある。なお、本明細書で
、酸化物超電導薄膜とは、膜厚が１００μｍ以下の薄膜
および厚膜を意味する。SUMMARY OF THE INVENTION An object of the present invention is to provide a method for processing an oxide superconducting thin film that solves the problems of the prior art described above and does not deteriorate the characteristics of the oxide superconductor. In addition, in this specification, the oxide superconducting thin film means a thin film and a thick film having a film thickness of 100 μm or less.
課題を解決するだめの手段
本発明に従うと、酸化物超電導薄膜をフォトリソグラフ
ィにより加工する方法おいて、酸化物超電導薄膜の表面
に該薄膜を構成する酸化物超電導体との反応性が低い金
属層を形成し、該金属層上にレジスト膜を形成すること
を特徴とする超電導薄膜の加工方法が提供される。Means for Solving the Problems According to the present invention, in a method of processing an oxide superconducting thin film by photolithography, a metal layer having low reactivity with the oxide superconductor constituting the thin film is formed on the surface of the oxide superconducting thin film. A method for processing a superconducting thin film is provided, which comprises forming a resist film on the metal layer.
作用
本発明の方法は、酸化物超電導薄膜の表面に反応性が低
い金属層を形成し、その上にレジスト膜を形成するとこ
ろにその主要な特徴がある。すなわち、本発明の方法に
従うと、酸化物超電導薄膜は、直接レジスト、現像液等
に触れることがなく、また、イオン衝撃も受けないため
、特性が劣化しない。Function The main feature of the method of the present invention is that a metal layer with low reactivity is formed on the surface of an oxide superconducting thin film, and a resist film is formed thereon. That is, according to the method of the present invention, the oxide superconducting thin film does not come into direct contact with the resist, developer, etc., and is not subjected to ion bombardment, so its properties do not deteriorate.
前記金属層材料としてはＡｇが反応性が低いことおよび
接触抵抗が低いこと、密着性がよいことで優れているが
、Ａｌｓ Ｉ ｎ ％ Ｚｎ 、ＳＣｕ 、、ＮＩ Ｓ
Ａｕ １Ｐ ｔ ＳＴ＋、Ｐｄ等、酸化物超電導体との
反応性が低い金属ならば使用可能である。また、この金
属層は蒸着法等により形成することができる。As the metal layer material, Ag is excellent because of its low reactivity, low contact resistance, and good adhesion, but Als I n % Zn, SCu, NI S
Any metal that has low reactivity with the oxide superconductor can be used, such as Au 1P t ST+ and Pd. Further, this metal layer can be formed by a vapor deposition method or the like.
本発明の方法では金属層形成後に加熱して密着性を向上
させることが好ましい。この加熱温度は、３００〜４０
０℃の範囲が好ましい。加熱温度が３００℃未満では密
着性向上に効果がなく、４００℃を超える温度に加熱す
ると反応層を生じて酸化物超電導体の特性が劣化する。In the method of the present invention, it is preferable to heat the metal layer after forming it to improve adhesion. This heating temperature is 300 to 40
A range of 0°C is preferred. If the heating temperature is less than 300°C, there will be no effect on improving adhesion, and if it is heated to a temperature exceeding 400°C, a reaction layer will be formed and the properties of the oxide superconductor will deteriorate.
また、加熱を酸素雰囲気中で行うと、さらに効果がある
。Furthermore, heating in an oxygen atmosphere is more effective.
本発明の方法では、上記金属層上にさらに他の金属で第
２の金属層を形成することも好ましい。In the method of the present invention, it is also preferable to further form a second metal layer of another metal on the metal layer.
この第２の金属層は、酸化物超電導薄膜表面に形成した
第１の金属層を電極としても用いる場合に、加熱工程で
表面が酸化されないよう保護する目的で設けるものであ
る。第２の金属層は、Ａｕ、 ｐｔなどで形成すること
が好ましい。従って、第２の金属層を形成する場合、上
記の加熱工程は、第２の金属層形成後に実行する。This second metal layer is provided for the purpose of protecting the surface from being oxidized during the heating process when the first metal layer formed on the surface of the oxide superconducting thin film is also used as an electrode. The second metal layer is preferably formed of Au, PT, or the like. Therefore, when forming the second metal layer, the above heating step is performed after forming the second metal layer.
上記第１および第２の金属層の厚さは、それぞれ０．０
１〜１μｍ、０．０５〜１μｍが好ましい。第１の金属
層の厚さが、０．０１μｍ未満では、酸化物超電導体を
保護する効果がなく、１μｍを超えていてもその効果に
変わりがなく、フォトリンゲラフィブロセス後に不要部
分の金属層の剥離に長時間を要するためである。また、
第２の金属層についても同様に厚さが、０．０５μｍ未
満では第１の金属層を保護する効果がなく、１μｍを超
えていると不要部分の剥離に長時間を要するため、上記
の範囲の厚さが好ましい。The thickness of the first and second metal layers is each 0.0
1 to 1 μm, preferably 0.05 to 1 μm. If the thickness of the first metal layer is less than 0.01 μm, it has no effect of protecting the oxide superconductor, and even if it exceeds 1 μm, the effect remains the same. This is because it takes a long time to peel off. Also,
Similarly, for the second metal layer, if the thickness is less than 0.05 μm, it will not have the effect of protecting the first metal layer, and if it exceeds 1 μm, it will take a long time to peel off the unnecessary parts, so it is within the above range. A thickness of .
また、上記の金属層は、フォトリソグラフィ後のエツチ
ング工程で、イオンビームエツチング、ＥＣＲエツチン
グ、ＲＦプラズマエツチング等を用いる場合に、荷電粒
子から酸化物超電導体を保護する。すなわち、上記の各
エツチング法では、従来、荷電粒子によるイオン衝撃の
ため、酸化物超電導体の特性が劣化したが、本発明の方
法ではこれも防げるものである。The metal layer also protects the oxide superconductor from charged particles during post-photolithographic etching steps such as ion beam etching, ECR etching, RF plasma etching, etc. That is, conventionally, in each of the above etching methods, the characteristics of the oxide superconductor deteriorated due to ion bombardment by charged particles, but this can also be prevented with the method of the present invention.
以下、本発明を実施例により、さらに詳しく説明するが
、以下の開示は本発明の単なる実施例に過ぎず、本発明
の技術的範囲をなんら制限するものではない。EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the following disclosure is merely an example of the present invention and does not limit the technical scope of the present invention in any way.
実施例
各種酸化物超電導薄膜に、フォ） ＩＪソグラフィで第
１図に示したパターンを形成した。それぞれ、本発明の
方法と従来の方法とでパターンの形成を行い、パターン
形成前後で超電導特性を比較した。EXAMPLES Patterns shown in FIG. 1 were formed on various oxide superconducting thin films by IJ lithography. Patterns were formed using the method of the present invention and the conventional method, respectively, and the superconducting properties were compared before and after pattern formation.
実施例ｌ
ＭｇＯ単結晶基板上にスパッタリング法により作製した
ＹＩＢａ２Ｃｕ３０ｘ薄膜を使用した。本発明の方法で
は、以下の条件で真空蒸着法により薄膜表面にＡｇおよ
びＡｕを重ねて蒸着した。Example 1 A YIBa2Cu30x thin film produced by sputtering on an MgO single crystal substrate was used. In the method of the present invention, Ag and Au were deposited in layers on the surface of the thin film by vacuum evaporation under the following conditions.
（蒸着条件）
基板加熱なし
真空度 １〜３ Ｘ １０−’Ｔｏｒｒ蒸着速
度 ２〜３八／へｅｃ
Ａｇ （下層）膜厚 ０，１５μｍ
Ａｕ （上層）膜厚 ０．１０μｍ
このサンプルを酸素フロー中の大気圧炉で３００℃×１
０分間の加熱を行った。(Deposition conditions) Vacuum degree without substrate heating: 1 to 3 300℃ x 1 in an atmospheric pressure furnace
Heating was performed for 0 minutes.
次に、以下の条件でフォトリンゲラフィブロセスを実施
してパターニングを行った。Next, patterning was performed by performing photoringer fibrosis under the following conditions.
（フォトリソグラフィプロセス）
レジスト塗布スピンナー速度４０００ｒｐｍ ｘ２０秒
レジスト ポジレジスト
９５℃×３０分
８秒 マスク
ＮＭＤ−３（東京応化）１分３０秒
流水で３分間
プリベーク
露光
現像
水洗
Ｎ２ ブロー
次に、カウフマン式イオンガンによるＡｒイオンビーム
エツチングによりエツチングを行った。(Photolithography process) Resist coating spinner speed 4000 rpm x 20 seconds Resist Positive resist 95°C x 30 minutes 8 seconds Mask NMD-3 (Tokyo Ohka) 1 minute 30 seconds Pre-bake with running water for 3 minutes Exposure Developing Washing with N2 Blow Next, Kaufman ion gun Etching was performed by Ar ion beam etching.
加速電圧 ： ５００ Ｖ
電流 ： ３０ｍＡ
基板温度 ：５〜１０℃
真空度 ： ４ ＸＬＯ−’Ｔｏｒｒエツチング
時間：１０分
エツチングの後、Ｉ／シスト膜をアセトンに５分間浸漬
することにより剥離した。Accelerating voltage: 500 V Current: 30 mA Substrate temperature: 5 to 10° C. Degree of vacuum: 4 XLO-'Torr etching time: 10 minutes After etching, the I/cyst film was peeled off by immersing it in acetone for 5 minutes.
第１表に結果を示す。測定はＤＣ帯磁率の測定により測
定した。Table 1 shows the results. The measurement was performed by measuring DC magnetic susceptibility.
第１表
（体積率はフォトリソグラフィ前を１００％とした）超
電導の転移温度が、比較例では８０．ＯＫに低下してい
るが、本発明の方法では９０． ＯＫであり、はとんど
低下していない。これは、本発明の方法ではイオンビー
ムエツチング時のイオン衝撃がほとんどないからと考え
られる。また、本発明の方法では、薄膜表面に反応層が
生じないので、体積率もフォトリソグラフィ前後でまっ
たく変っていな実施例２
１、Ｉｇｏ単結晶基板上にスパッタリング法により作製
したＢｉ。５ｒ２Ｃａ２Ｃｕ３０）１薄膜を用いて、実
施例１と同じ条件で、金属層の形成およびパターニング
を行い、同様の方法で測定を行った。第２表に結果を示
す。Table 1 (The volume fraction is 100% before photolithography) The transition temperature of superconductivity is 80. However, with the method of the present invention, it is 90. It is OK and has not decreased at all. This is thought to be because the method of the present invention causes almost no ion bombardment during ion beam etching. Further, in the method of the present invention, since no reaction layer is formed on the surface of the thin film, the volume fraction does not change at all before and after photolithography.Example 2 1: Bi fabricated by sputtering on an Igo single crystal substrate. Using the 5r2Ca2Cu30)1 thin film, a metal layer was formed and patterned under the same conditions as in Example 1, and measurements were performed in the same manner. Table 2 shows the results.
とＴｃ 、体積率ともに、はとんど低下しない。Both Tc and volume fraction hardly decrease.
実施例３
）４ｇＯ単結晶基板上にスパッタリング法により作製し
たＴＩ。Ｂａ２Ｃａ、Ｃｕ３０Ｍ薄膜を用いて、実施例
１と同じ条件で金属層の形成およびパターニングを行い
、同様の方法で測定を行った。第３表に結果を示す。Example 3) TI produced by sputtering on a 4gO single crystal substrate. Using Ba2Ca and Cu30M thin films, metal layers were formed and patterned under the same conditions as in Example 1, and measurements were performed in the same manner. Table 3 shows the results.
第３表
第２表
（体積率はフォトリソグラフィ前を１００％とした）実
施例１の結果と同様に、本発明の方法によるとＴｃ 、
体積率ともに、はとんど低下しない。Table 3 Table 2 (The volume fraction is 100% before photolithography) Similar to the results of Example 1, according to the method of the present invention, Tc,
Both volume fractions hardly decrease.
（体積率はフォトリソグラフィ前を１００％とした）実
施例１の結果と同様１ご、本発明の方法による以上の結
果、本発明の方法で、酸化物超電導薄膜を加工しても、
酸化物超電導体の特性が劣化しないことが証明された。(The volume fraction was 100% before photolithography) Same as the result of Example 11. The above results obtained by the method of the present invention show that even if an oxide superconducting thin film is processed by the method of the present invention,
It was proven that the properties of oxide superconductors do not deteriorate.
発明の効果
本発明の方法を用いることにより、酸化物超電導薄膜を
超電導特性を劣化させることなく各種超電導デバイスに
加工することが可能となる。本発明により、高性能な超
電導デバイスを作製することができ、超電導技術はさら
に発展する。Effects of the Invention By using the method of the present invention, it becomes possible to process oxide superconducting thin films into various superconducting devices without deteriorating their superconducting properties. According to the present invention, a high-performance superconducting device can be manufactured, and superconducting technology will further develop.
第１図は、実施例で超電導薄膜を加工したパターンを示
す。FIG. 1 shows a pattern obtained by processing a superconducting thin film in an example.
Claims (1)
方法おいて、酸化物超電導薄膜の表面に該薄膜を構成す
る酸化物超電導体との反応性が低い金属層を形成し、該
金属層上にレジスト膜を形成することを特徴とする超電
導薄膜の加工方法。In a method of processing an oxide superconducting thin film by photolithography, a metal layer having low reactivity with the oxide superconductor constituting the thin film is formed on the surface of the oxide superconducting thin film, and a resist film is formed on the metal layer. A method for processing a superconducting thin film, characterized by forming a superconducting thin film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1078975A JPH02257681A (en) | 1989-03-30 | 1989-03-30 | Machining method of superconductive thin-film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1078975A JPH02257681A (en) | 1989-03-30 | 1989-03-30 | Machining method of superconductive thin-film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02257681A true JPH02257681A (en) | 1990-10-18 |
Family
ID=13676902
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1078975A Pending JPH02257681A (en) | 1989-03-30 | 1989-03-30 | Machining method of superconductive thin-film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02257681A (en) |
-
1989
- 1989-03-30 JP JP1078975A patent/JPH02257681A/en active Pending
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| JPH02257681A (en) | Machining method of superconductive thin-film | |
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| JPH03124077A (en) | Manufacture of superconducting element | |
| JPS6258676B2 (en) | ||
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| JPS6143488A (en) | Manufacture of superconductive contact | |
| JPH03794B2 (en) | ||
| JPS60208874A (en) | Manufacture of josephson junction element | |
| JPH0448788A (en) | Formation of pattern of josephson junction element | |
| JPH0530310B2 (en) | ||
| JPS6167975A (en) | Manufacture of josephson junction element | |
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