JPH0216029B2 - - Google Patents
Info
- Publication number
- JPH0216029B2 JPH0216029B2 JP59131706A JP13170684A JPH0216029B2 JP H0216029 B2 JPH0216029 B2 JP H0216029B2 JP 59131706 A JP59131706 A JP 59131706A JP 13170684 A JP13170684 A JP 13170684A JP H0216029 B2 JPH0216029 B2 JP H0216029B2
- Authority
- JP
- Japan
- Prior art keywords
- constriction
- thin film
- microbridge
- metal thin
- josephson
- 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.)
- Expired
Links
- 239000002184 metal Substances 0.000 claims description 19
- 229910052751 metal Inorganic materials 0.000 claims description 19
- 239000010409 thin film Substances 0.000 claims description 17
- 239000000758 substrate Substances 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 7
- 230000005668 Josephson effect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 238000000059 patterning Methods 0.000 description 2
- 238000002788 crimping Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N60/00—Superconducting devices
- H10N60/01—Manufacture or treatment
- H10N60/0912—Manufacture or treatment of Josephson-effect devices
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はジヨセフソン素子等に用いられるサブ
ミクロン級のくびれ部を有するマイクロブリツジ
にバンプ（導電層の隆起部）を形成する方法に関
する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for forming bumps (protrusions of a conductive layer) on microbridges having submicron constrictions used in Josephson devices and the like.
第３図は従来例によるマイクロブリツジの斜視
図である。
FIG. 3 is a perspective view of a conventional microbridge.
図において、基板１上にサブミクロン程度の厚
さの超伝導金属薄膜２を蒸着し、中央部にサブミ
クロン程度の長さＬと幅Ｗのくびれを有する図示
の形状のマイクロブリツジを電子線露光を用いた
パターニングにより形成する。 In the figure, a superconducting metal thin film 2 with a thickness of about submicron is deposited on a substrate 1, and a microbridge having the shape shown in the figure, which has a constriction of length L and width W of about submicron in the center, is formed with an electron beam. Formed by patterning using exposure.
くびれの両側にインジウムを圧着して電流端子
３，４と、電圧端子５，６を形成する。 Current terminals 3 and 4 and voltage terminals 5 and 6 are formed by crimping indium on both sides of the constriction.
上記構造のマイクロブリツジ型のジヨセフソン
素子を臨界温度以下に下げ、くびれ部にマイクロ
波を照射するとジヨセフソン効果があらわれ、第
４図のようにジヨセフソン素子の電流Ｉ−電圧Ｖ
特性はジヨセフソン・ステツプまたはShappiro
Stepと呼ばれる階段状の特性を示す。この場合
各ステツプの電圧ｖは次式に示されるように、照
射したマイクロ波の周波数により一義的に決ま
るので、電圧標準として用いられる。 When the microbridge-type Josephson element with the above structure is lowered to below the critical temperature and the constriction is irradiated with microwaves, the Josephson effect appears, and as shown in Figure 4, the electric current I - voltage V of the Josephson element.
Characteristics: Josephson Stepp or Shappiro
It exhibits a step-like characteristic called a step. In this case, the voltage v at each step is uniquely determined by the frequency of the irradiated microwave, as shown in the following equation, and is therefore used as a voltage standard.
ｖ＝h／2e，
ここに、ｈはPlanck常数、ｅは素電荷をあら
わす。 v=h/2e, where h represents the Planck constant and e represents the elementary charge.
このようなマイクロブリツジ構造においては、
くびれ部で超伝導が保持できなくなつて常伝導に
なりジヨセフソン効果をあらわす。ジヨセフソン
効果は常伝導領域が長くなると起きなくなり、ま
たくびれの形状によつてあらわれるジヨセフソ
ン・ステツプの数が異なる。 In such a microbridge structure,
At the constriction, superconductivity can no longer be maintained and normal conduction occurs, resulting in the Josephson effect. The Josephson effect no longer occurs as the normal conduction region becomes longer, and the number of Josephson steps that appear differs depending on the shape of the constriction.
例えば超伝導材料として鉛（Pb）を用いると、
臨界温度7.2K以下で、照射したマイクロ波の周
波数が10GHzで20μV毎のステツプが得られる。
ステツプ数が100であれば、100倍の2mVの電圧
標準が得られる。 For example, if lead (Pb) is used as a superconducting material,
When the critical temperature is below 7.2K and the frequency of the irradiated microwave is 10GHz, steps of 20μV can be obtained.
If the number of steps is 100, a voltage standard of 2 mV will be obtained, which is 100 times larger.
あるいは逆にステツプの電圧ｖを測定して照射
したマイクロ波の周波数を正確に知ることがで
きる。 Alternatively, the frequency of the irradiated microwave can be accurately determined by measuring the voltage v of the step.
さらにSQID（Super Quantum Interference
Device）として生体等よりでる微少磁場の測定
に利用できる。 Furthermore, SQID (Super Quantum Interference)
It can be used as a device to measure minute magnetic fields emitted from living organisms, etc.
以上のようにマイクロブリツジ型のジヨセフソ
ン素子は種々の用途に用いられるが、ジヨセフソ
ン・ステツプの数が多くなるような構造が望まれ
る。そのためにはくびれ部の両側を厚くし、従来
の１次元的なくびれを２次元的なくびれにすれば
よいことが確かめられている。 As described above, the microbridge type Josephson device is used for various purposes, but a structure in which the number of Josephson steps is increased is desired. It has been confirmed that this can be achieved by increasing the thickness on both sides of the constriction and changing the conventional one-dimensional constriction into a two-dimensional constriction.
マイクロブリツジ構造において、くびれ部の微
少寸法を保持して、その両側を厚くする製造技術
的に効果のある簡易な方法はなかつた。
In the microbridge structure, there has been no simple method that is effective in terms of manufacturing technology to maintain the minute dimensions of the constriction and thicken both sides of the constriction.
上記問題点の解決は、マイクロブリツジ型ジヨ
セフソン素子形成に際し、基板上に金属薄膜を被
着し、該金属薄膜をパターニングして中央部にく
びれを有する金属パターンを形成し、真空中で該
金属パターンに電流を流して該くびれ部分を溶断
して溶断部の両側に該金属薄膜からなるバンプを
形成する工程を有するバンプ形成方法により達成
される。
The solution to the above problem is to deposit a metal thin film on a substrate, pattern the metal thin film to form a metal pattern with a constriction in the center, and then deposit the metal thin film on the substrate in a vacuum. This is achieved by a bump forming method that includes the step of passing an electric current through the pattern to fuse the constricted portion to form bumps made of the metal thin film on both sides of the fused portion.
金属薄膜よりなるマイクロブリツジのくびれ部
を、真空中で電流を流してジユール熱により溶断
すると、溶融した金属は表面張力により、くびれ
の両側に２個のバンプを形成する。
When the constriction of a microbridge made of a thin metal film is fused by Joule heat by passing an electric current in a vacuum, the molten metal forms two bumps on both sides of the constriction due to surface tension.
形成された２個のバンプを覆つて金属薄膜を被
着してパターニングすれば３次元のくびれは簡単
に形成できる。 A three-dimensional constriction can be easily formed by covering the two formed bumps with a metal thin film and patterning it.
また本発明により形成されたマイクロブリツジ
のバンプはジヨセフソン素子の他に基板上のコネ
クタとして利用できる。 Further, the microbridge bump formed according to the present invention can be used not only as a Josephson device but also as a connector on a substrate.
第１図は本発明によるマイクロブリツジの斜視
図である。
FIG. 1 is a perspective view of a microbridge according to the present invention.
図において、基板１上に金属薄膜２としてサブ
ミクロン程度の厚さの超伝導薄膜を蒸着し、中央
部にサブミクロン程度の長さと幅を有するくびれ
の両側にバンプ７，８が形成されている。 In the figure, a superconducting thin film with a thickness of about submicrons is deposited as a metal thin film 2 on a substrate 1, and bumps 7 and 8 are formed on both sides of a constriction having a length and width of about submicrons in the center. .
第２図は本発明によるマイクロブリツジの製造
方法を工程順に示す断面図である。図は第１図の
Ａ−Ａ断面を示す。 FIG. 2 is a cross-sectional view showing the method for manufacturing a microbridge according to the present invention in the order of steps. The figure shows a cross section taken along line AA in FIG.
第２図ａにおいて、基板１の上に、レジスト９
を被着し、電子線露光を用いてくびれ部の長さと
幅がそれぞれ5000Åのマイクロブリツジの形状に
パターニングする。 In FIG. 2a, a resist 9 is placed on the substrate 1.
is deposited and patterned using electron beam exposure into the shape of a microbridge with a constriction length and width of 5000 Å.
第２図ｂにおいて、金属薄膜２として厚さ1000
Åの超伝導Pb薄膜を蒸着し、５×10-6の真空中
でくびれ部に0.5Aのステツプ状電流を流してく
びれ部を溶断してバンプ７，８を形成する。 In Fig. 2b, the metal thin film 2 has a thickness of 1000 mm.
A superconducting Pb thin film having a thickness of 1.5 Å is deposited, and a step current of 0.5 A is passed through the constriction in a vacuum of 5×10 -6 to fuse the constriction to form bumps 7 and 8.
第２図ｃにおいて、マイクロブリツジ部を覆つ
て金属薄膜１０として厚さ1000Åの超伝導Pb薄
膜を蒸着し、レジスト９の上の金属薄膜１０をリ
フトオフすると第１図に示されるマイクロブリツ
ジを得ることができる。 In FIG. 2c, a superconducting Pb thin film with a thickness of 1000 Å is deposited as a metal thin film 10 to cover the microbridge part, and when the metal thin film 10 on the resist 9 is lifted off, the microbridge shown in FIG. 1 is formed. Obtainable.
以上詳細に説明したように本発明によれば、マ
イクロブリツジ構造において、くびれ部の微少寸
法を保持して、その両側を厚くする簡易で確実な
方法が得られる。
As described in detail above, according to the present invention, a simple and reliable method for maintaining the minute dimensions of the constriction and thickening both sides of the constriction in a microbridge structure can be obtained.
第１図は本発明により製造されたマイクロブリ
ツジの斜視図、第２図は本発明によるマイクロブ
リツジの製造方法を工程順に示す断面図、第３図
は従来例によるマイクロブリツジの斜視図、第４
図はジヨセフソン素子の電流−電圧特性を示す図
である。
図において、１は基板、２，１０は金属薄膜、
３，４は電流端子、５，６は電圧端子、７，８は
バンプ、９はレジストを示す。
FIG. 1 is a perspective view of a microbridge manufactured according to the present invention, FIG. 2 is a sectional view showing the method for manufacturing a microbridge according to the present invention in order of steps, and FIG. 3 is a perspective view of a conventional microbridge. , 4th
The figure is a diagram showing the current-voltage characteristics of the Josephson device. In the figure, 1 is a substrate, 2 and 10 are metal thin films,
3 and 4 are current terminals, 5 and 6 are voltage terminals, 7 and 8 are bumps, and 9 is a resist.
Claims (1)
際し、基板上に金属薄膜を被着し、該金属薄膜を
パターニングして中央部にくびれを有する金属パ
ターンを形成し、真空中で該金属パターンに電流
を流して該くびれ部分を溶断して溶断部の両側に
該金属薄膜からなるバンプを形成する工程を有す
ることを特徴とするバンプ形成方法。1. When forming a micro bridge type Josephson device, a metal thin film is deposited on a substrate, the metal thin film is patterned to form a metal pattern having a constriction in the center, and a current is passed through the metal pattern in a vacuum. A bump forming method comprising the step of fusing the constricted portion and forming bumps made of the metal thin film on both sides of the fusing portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59131706A JPS6110286A (en) | 1984-06-26 | 1984-06-26 | Formation of bump |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59131706A JPS6110286A (en) | 1984-06-26 | 1984-06-26 | Formation of bump |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6110286A JPS6110286A (en) | 1986-01-17 |
| JPH0216029B2 true JPH0216029B2 (en) | 1990-04-13 |
Family
ID=15064296
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59131706A Granted JPS6110286A (en) | 1984-06-26 | 1984-06-26 | Formation of bump |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6110286A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170088682A1 (en) * | 2014-05-21 | 2017-03-30 | Toyobo Co., Ltd. | Biaxially stretched polybutylene terephthalate film, manufacturing method therefor, and gas barrier laminate film |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01183177A (en) * | 1988-01-18 | 1989-07-20 | Agency Of Ind Science & Technol | Superconducting ceramic element |
-
1984
- 1984-06-26 JP JP59131706A patent/JPS6110286A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170088682A1 (en) * | 2014-05-21 | 2017-03-30 | Toyobo Co., Ltd. | Biaxially stretched polybutylene terephthalate film, manufacturing method therefor, and gas barrier laminate film |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6110286A (en) | 1986-01-17 |
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