JP2654555B2 - Superconducting device manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic-based superconducting thin film (also referred to as superconducting, but also referred to as superconducting). The present invention, by covering the material formed is thinned on the base body provided with a non-superconductive material, allowed the multi-layer wiring of a superconducting material, it is an does make a superconducting electronic device using such configuration .

[0002]

Conventionally, superconducting materials metallic material Nb-Ge (e.g. _Nb 3 Ge) is used. Since this material is a metal, it has high ductility and malleability, and can be used for winding coils for superconducting magnets, etc. In addition, since there is no anisotropy in the structure, electronic devices can be used without considering orientation. Was possible.

However, superconducting materials using these metallic materials have a small Tc (the superconducting critical temperature is hereinafter simply referred to as Tc), which is only 23 K or less. On the other hand, if industrial application is considered, it is more effective that Tc is 77 K, preferably room temperature or higher.

[0004]

Therefore, ceramic materials, especially oxide ceramic materials, have attracted attention as materials having a high Tc, instead of metals. However, despite the high Tc of the ceramic-based superconducting material which has been attracting attention, the ceramic superconducting material has poor bendability, ductility, and malleability, and is slightly bent. It has been said that it is impossible at all to form a thin film having a thickness of 0.1 to 30 μm on a cylindrical or disk-shaped substrate and selectively remove part or all of the thin film. In particular, it has been impossible at all to perform multilayer wiring using the same photolithography technology as that of a semiconductor integrated circuit or to make a new electronic device using this thin film superconductivity.

Further, in the case where a multilayer wiring, particularly a coil or the like, is to be provided, it is important to match the coefficient of thermal expansion by preventing the cracks and the like by making the entire assembly the same main component. For this reason, using the substrate itself as a material different from the oxide superconducting material and actually using it under long-term use conditions has posed a serious problem in reliability.

[0006]

According to the present invention, an electronic device is formed by using a thin film of such an oxide superconducting material and an interlayer separation film of an oxide non-superconducting material of the same main component sandwiching the thin film. is there. The properties of the oxide non-superconducting material include semiconducting properties and insulating properties depending on its composition and the like. Needless to say, the properties are selected depending on the desired electronic device.

According to the present invention, when a superconducting coil having a desired shape is prepared in advance, for example, a superconducting coil as an electronic device, the same main component material as the oxide superconducting material is formed on the surface of the cylindrical or disc-shaped base on which the superconducting coil is formed. Form a non-superconducting material.
This material is used as a substrate. Further, by removing the original base after the formation, only the non-superconducting material may be used as the base. Of course, when the material used as the base material itself is a material having a thermal expansion coefficient close to that of the superconducting material, it can be used as it is as the base. The present invention provides an oxide superconducting material or a starting material having superconductivity after annealing in an oxidizing atmosphere on a substrate having a surface to be formed of such an oxide non-superconducting material or the like. A film of a superconducting material) is formed by a sputtering method, a printing method such as a screen printing method, a spray method, a plasma spray method, an electron beam evaporation method, a plasma CVD method, or another method.

For example, the substrate is formed by magnetron sputtering at a substrate temperature of 650 ° C. in an Ar (20% oxygen mixed) atmosphere. At this time, the ab plane (c
(I.e., a plane perpendicular to the c-axis).
Therefore, when a film is formed on the substrate, a magnetic field is applied in a direction perpendicular to the surface on which the film is to be formed (the surface tangential to the circle in the case of a cylindrical shape). Then, the oxide superconducting material having a modified perovskite structure used in the present invention has a
A plane parallel to the b-plane is configured to be parallel to the formation surface. This magnetic field is applied to a film formed by the sputtering method at 850 ° C., 8 ° C. in oxygen.
During the slow cooling at a rate of 4 ° C./min, the annealing is also applied during the annealing at 400 ° C. for 2 hours.

The present invention has experimentally discovered that such an oxide superconducting material has sublimability and can be easily scribed (cut) by an excimer laser or a YAG laser. For this reason, the present invention selectively irradiates the formed superconducting thin film with a laser beam before or after firing, and further performs scanning (scanning) as necessary, so as to form a strip having a certain area, for example, a certain width. This oxide superconducting material is removed. Then, a band of the superconducting thin film having a constant Tc can be formed only in a portion other than the portion where the groove is formed by the laser irradiation.

In a film formed by a sputtering method or the like, a target is adjusted, and the formed oxide superconducting material is, for example, (A
_1-x Bx) yCuzOw where x = 0.1 to 1, preferably 0.6 to 0.7, y = 2.0 to 4.0, preferably 2.
5 to 3.5, z = 1.0 to 4.0, preferably 1.5 to
3.5, w = 4.0 to 10.0, preferably 6 to 8, wherein A is one or more elements selected from Group 3a of the periodic table, particularly yttrium (Y) or a lanthanoid, and B is Ba (barium), Sr of group 2a of the periodic table
(Strontium) or one or more elements selected from Ca (calcium), for example, barium (B
a).

Further, an interlayer separation film (in a superconducting coil, the interlayer separation film needs to be an interlayer insulating film)
((A'pA " _1- p) _1-x (B'qB"
_1- q) x) y (CurX1 _-r ) zOwx = 0-1.
0, y = 2.0-4.0, z = 1.0-4.0, w =
4.0 to 10.0, and A ′ is Y (yttrium),
Gd (gadolinium), Yb (ytterbium), Eu
(Europium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Lu (lutetium), Sc
(Scandium) and one or more elements selected from other lanthanoids, and B 'has an element selected from Ba (barium), Sr (strontium) and Ca (calcium), and A'' ,
B ″ and X are Mg (magnesium) Be (beryllium), Al (aluminum), Fe (iron), Co (cobalt), Ni (nickel), Cr (chromium), Ti (titanium), Mn (manganese), An oxide superconducting material made of one or more elements selected from Zr (zirconium) was used. At this time, as an additive for making this non-superconducting material, 1 to 20% by volume (0.99 to 0.80 as a value of p, q or r) was added. In particular, Mg and Al, which have a large extent as oxide insulators, are added in an amount of 1 to 5%.
It was convenient.

When laser scribing using an excimer laser is performed to form an insulating region, a pulse width of 20
Since it is as small as n seconds, it is easier to control the region to be removed in the depth direction. In the present invention, a circular (diameter: 10 to 100 μm) laser beam can be formed by squeezing an excimer laser with an optical system, and the substrate or the substrate and the laser beam light are moved while irradiating the oxide superconducting film with the laser beam. I do. Then, the oxide superconducting thin film at a desired position is removed by sublimation or flying.

For the region to be removed, Mg (magnesium), Be (beryllium), A
l (aluminum), Fe (iron), Co (cobalt),
i (nickel), Cr (chromium), Ti (titanium), M
One or more kinds selected from n (manganese) may be selectively implanted by an ion implantation method or the like for insulation. This has the feature that the upper surfaces of the insulating region and the superconducting region can be made smooth and flat to each other, but the injection amount is large and the productivity is not sufficient.

As described above, the present invention uses the oxide superconducting material and the oxide non-superconducting material of the same main component as the base or the upper part thereof and the interlayer separator, thereby obtaining the same thermal expansion coefficient as that of the oxide superconducting material. An oxide non-superconducting material having a similar structure is used as an interlayer film for electrical isolation. Then, after that, a second oxide superconducting thin film was laminated, and unnecessary substances were selectively removed again by a laser scribe method or the like in the same manner as the first oxide superconducting material. This was repeated to form a multilayer wound coil.

In the present invention, when the substrate material is to remain thereafter, alumina, YSZ (yttria stabilized zircon), magnesium oxide (Mg)
O), zirconia, yttria, strontium titanate (SrTiO ₃ ), glass, or a non-superconducting material of the same main component as the oxide superconducting material was used. Further, a composite substrate may be used by forming an oxide non-superconducting thin film on a substrate such as a metal.

[0016] The substrate provided on the mother, when removing after constituting the base used was melted organic resin with an organic solvent as a matrix.

[0017]

Conventionally, when a metal superconducting material is used, a wire rod is first formed as a process. This was applied to a predetermined base to form a coil.

However, for a coil using the oxide superconductor of the present invention, a substrate having a final shape, for example, a disk or a cylindrical (bobbin) structure is used. After heat treatment of the superconductivity in a strip shape on the substrate, an oxide superconducting material to be provided with superconductivity is formed in a film shape. By selectively performing the first patterning on this film, a band-shaped coil is formed by the remaining region of the other portion. Further, an oxide non-superconducting material having the same main component as the oxide superconducting material is formed on the upper surface. Then, since they are the same main component, cracks and the like hardly occur, and high reliability can be obtained. Furthermore, while connecting at the connecting portion of this oxide non-superconducting material,
A second oxide superconducting thin film is formed. For this thin film,
Perform second patterning. The thermal annealing or oxidation treatment of the oxide superconducting material and the non-superconducting material may be performed after performing all the steps, or may be performed for each step.

The present invention will be described below with reference to examples.

[0020]

FIG. 1 shows an embodiment of the present invention.

In FIG. 1A, a material that can be removed later, for example, a material that does not dissolve the superconducting material and can dissolve the mother material, may be used for the matrix (1). Further mother (1)
On top of ((A'pA " _1- p) _1-x (B'qB"
_1- q) x) y (CurX1 _- r) zOwx = 0.1-
1.0, y = 2.0-4.0, z = 1.0-4.0, w
= 4.0 to 10.0, and A ′ represents Y (yttrium), Gd (gadolinium), Yb (ytterbium), Eu (europium), Tb (terbium), D
y (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Lu (lutetium),
Sc (scandium) and one or more elements selected from other lanthanoids, B 'is Ba
(Barium), Sr (strontium), and Ca (calcium).
B ″ or X is Mg (magnesium), Be (beryllium), Al (aluminum), Fe (iron), Co (cobalt), Ni (nickel), Cr (chromium), Ti
(Titanium), Mn (manganese), Zr (zirconium)
An oxide non-superconducting film (1 ′) containing 1 to 20% by volume of one or more elements selected from about 10 to 5000 μm
m, for example, 20 μm thick. Then, on the upper surface, it is almost the same as the oxide superconducting thin film (± 50%
) Can be made. If this difference is too large, it has stress strain after annealing, the temperature at which superconductivity is exhibited is low, and superconductivity is no longer observed due to cracks generated in the film. In this embodiment, an oxide non-superconducting film (1 ') is formed on a disk-shaped base (1).
Is used as a substrate. On this substrate , a sputtering method or a printing method, for example, 0.1 to
The oxide superconducting thin film (2) was formed to a thickness of 50 μm, for example, 20 μm.

It was subjected to a heat treatment in an oxygen atmosphere. 5
The test was performed at 00 to 1000 ° C, for example, at 900 ° C for 15 hours. Thereafter, it was gradually cooled at a temperature of 200 ° C./min or less, for example, at 10 ° C./min, and further stored at 450 ° C. for 1 hour to perform an oxidation treatment. Thus, an oxide superconducting film was formed. Thereafter, an excimer laser (254 nm) (4) was applied to perform laser scribe. This laser beam (4) is shown in FIG.
Scanning was performed from the left end to the center as shown by the arrow (11) , and the disk-shaped substrate was rotated as shown by the arrow (12) . Thus, a groove (3) was prepared. Laser light has peak output of 10
^{It was 6} to 10 ⁸ W / sec. Care must be taken if this is too strong, since it will damage the substrates (1) and (1 ').

FIG. 1B shows that ((A′pA ″ ₁ -p)) is formed on the entire surface after the one-layer wiring of FIG.
_1−x (B′qB ″ ₁₋ q) x) y (CurX
_1- r) zOwx = 0-1.0, y = 2.0-4.0,
z = 1.0 to 4.0, w = 4.0 to 10.0,
A 'is Y (yttrium), Gd (gadolinium), Y
b (ytterbium), Eu (europium), Tb
(Terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), L
u (lutetium), Sc (scandium) and other lanthanoids, and one or more elements selected from the group consisting of Ba (barium), Sr (strontium) and Ca (calcium). A '', B '' or X is Mg (magnesium), Be (beryllium), Al (aluminum), F
e (iron), Co (cobalt), Ni (nickel), Cr
(Chromium), Ti (titanium), Mn (manganese), Zr
Oxide non-superconducting thin film containing 1 to 20% by volume of one or more elements selected from (zirconium) (6)
Is formed as an interlayer separation film (9), and a hole is formed in the connection portion (8).
I do. Further, the second (A ₁ -xBx) yCuzOw
x = 0-1.0, y = 2.0-4.0, z = 1.0-
4.0, w = 4.0 to 10.0, and A is Y (yttrium), Gd (gadolinium), Yb (ytterbium), Eu (europium), Tb (terbium), D
y (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Lu (lutetium),
Sc (scandium) and one or more elements selected from other lanthanoids, B is Ba
(Barium), Sr (strontium), one or more elements selected from Ca (calcium) is added
Oxide superconductor thin film (7) was laminated, laser scribing was
(7-1), (7-2) ...
And corresponds to the section taken along line AA ′ of FIG. 1 (A).

As is clear from the drawing, the first oxide superconducting thin film (2) remains as a strip (5-1), (5-2)... To form a coil (5) . The coil (5) is connected to the coil (7) obtained by laser scribing the second oxide superconducting thin film at the connecting portion (8).

Thus, the strip-shaped wires are wired in a disk shape, and the multilayer winding can be performed.

A multilayer film having a metal such as silver provided above or below the first and second strip-shaped superconducting thin films may be used.

Embodiment 2 FIG. 2 shows another embodiment of the present invention.

In the drawings, the substrate is cylindrical (bobbin shape)
Having. Here, the oxide superconducting material (2) is formed in a film-like manner as in the first embodiment.

This production is performed by a spray method and a cylindrical base (1).
On top of ((A'pA " _1- p) _1-x (B'qB"
_1- q) x) y (CurX1 _- r) zOwx = 0.1-
1.0, y = 2.0-4.0, z = 1.0-4.0, w
= 4.0 to 10.0, and A ′ represents Y (yttrium), Gd (gadolinium), Yb (ytterbium), Eu (europium), Tb (terbium), D
y (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Lu (lutetium),
Sc (scandium) and one or more elements selected from other lanthanoids, B 'is Ba
(Barium), Sr (strontium), and Ca (calcium).
B ″ and X are Mg (magnesium), Be (beryllium), Al (aluminum), Fe (iron), Co (cobalt), Ni (nickel), Cr (chromium), Ti (titanium), Mn (manganese) , Zr (zirconium), an oxide non-superconducting material (1 ′) (not shown in FIG. 2A) made of one or more elements. After this, this mother (1) is removed,
Cylindrical substrate made only of oxide non-superconducting material (1 ')
It may be. Further, the oxide superconducting material (2) may be deposited while rotating the substrate as shown by the arrow (12).

In this spray method, nitrates, bromates or hydrochlorides of the elements constituting the superconducting material are sufficiently mixed with water,
Ultrafine particles neutralized with ammonia are formed. These are coated on the surface to be coated, dried, and fired.

It is effective to lower the temperature by performing this firing in ozone. Furthermore, this spraying operation may be formed on the surface to be coated in ozone or active oxygen to which a magnetic field has been applied to form a film.

Next, after these films are thermally annealed, the laser light is gradually transferred in the direction of arrow (11) while irradiating the films with a YAG laser (4) beam (diameter: 50 μm). At the same time, the cylindrical body (1) is rotated in the direction of the arrow (12). Then, one continuous band-shaped scribe line (3) can be formed on the cylindrical substrate. Due to this groove, each oxide superconducting material (2)
Are formed as strips (5-1) and (5-2), which are electrically separated from each other to form the superconducting region (5) . Here, the superconducting region (5) had a coil shape, and could substantially constitute a superconducting magnet coil.

In this embodiment, after these steps, all of them are calcined in oxygen, and (A _1-x Bx) yCuzOwx =
0.1-1.0, y = 2.0-4.0, z = 1.0-
4.0, w = 4.0 to 10.0, and A is Y (yttrium), Gd (gadolinium), Yb (ytterbium), Eu (europium), Tb (terbium), D
y (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Lu (lutetium),
Sc (scandium) and one or more elements selected from other lanthanoids, B is Ba
The oxide superconducting material was transformed from one or more elements selected from (barium), Sr (strontium), and Ca (calcium). And it could be made a superconducting magnet. By connecting the start point and the end point of this coil with a superconducting wire, it is possible to provide an energy storage device.

FIG. 2B corresponds to a cross-sectional view taken along the line AA ′ of FIG. FIG. 2A shows only the first layer to avoid complication of the drawing, and is formed on the surface of the mother body (1).
The oxide non-superconducting thin film (1 ') was omitted . In the present invention, this is multi-layered. In FIG. 2 (B),
((A'pA " _1- p) _1-X (B'qB"
_1- q) x) y (CurX1 _- r) zOwx = 0-1.
0, y = 2.0-4.0, z = 1.0-4.0, w =
4.0 to 10.0, and A ′ is Y (yttrium),
Gd (gadolinium), Yb (ytterbium), Eu
(Europium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Lu (lutetium), Sc
(Scandium) and one or more elements selected from other lanthanoids, and B 'has an element selected from Ba (barium), Sr (strontium) and Ca (calcium), and A'' ,
B ″ and X are Mg (magnesium), Be (beryllium), Al (aluminum), Fe (iron), Co (cobalt), Ni (nickel), Cr (chromium), Ti (titanium), Mn (manganese) , Zr on maternal having an oxide non-superconducting thin film made of one or more kinds of elements selected from zirconium () (1 ') (1), FIG. 2 (a)
The first superconducting region (5) is formed by shaping the first oxide superconducting material (2) as shown in FIG. Further, an oxide non-superconducting thin film having the same element is entirely formed as an interlayer separation film (6) by a spray method of the same method. After the opening is made at the connecting portion (8), a second oxide superconducting thin film is formed on the whole of these, and the second oxide superconducting thin film is formed at the connecting portion (8).
1 to the oxide superconducting region (5) . Further, laser scribe is performed in the same manner as the first superconducting thin film to form a strip (7).
-1), (7-2) ... molded second superconducting region
Make (7) . Further, a second oxide non- superconducting thin film (6 ′) is formed as an interlayer separation film (9), and the second oxide non- superconductive thin film is
Make a hole . Further, a third oxide superconducting material was formed, connected to the second superconducting region (7) at the connecting portion (8 ') , and formed in a belt shape. External take-out, interlayer separation membrane
(6), (9) opening reaching the first superconducting region (5)
Is formed, and an extraction electrode (10) is formed there. By repeating this, not only three layers but also an arbitrary multilayer can be obtained.

The other parts are the same as in the first embodiment.

[0036]

According to the present invention, it has become possible to manufacture an electronic device using an oxide superconducting material which has been impossible at all.

Thus, the ceramic superconducting material, which breaks off immediately upon bending, could be formed into a film or band by performing isolation for forming a conductor, an electrode or a superconducting element.

In this specification, an example in which the present invention is applied to a coil is shown. However, it is needless to say that the present invention can be applied to other electronic devices. For example, a device using a proximity effect in which the electrical characteristics of the interlayer isolation film are semiconductive and superconducting-semiconductor-superconducting can be used. In that case, after forming a superconducting thin film, it is sufficient to form a superconducting element or a superconducting wiring by performing predetermined patterning using a known photolithography technique or the like.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a superconducting coil using the oxide superconducting material of the present invention.

FIG. 2 shows an embodiment of a superconducting coil using the oxide superconducting material of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base body 2 ... Oxide superconducting material 3 ... Groove 4 ... Laser beam 5 ... Region exhibiting superconductivity 6, 9- Interlayer separation film 7 ... 2nd oxide superconductivity material

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-B-61-61555 (JP, B2) IEICE Technical Report Vol. 87 No. 137 p. 49-54 Japanese Journal of Applied Physics Vol. 26 No. 3 (1987). P. L203-205

Claims (1)

(57) [Claims] 1. A method according to claim 1, wherein (A _1-x BX) yCuzOw is formed on the substrate.
x = 0.1-1.0, y = 2.0-4.0, z = 1.0
~ 4.0, w = 4.0 ~ 10.0, having a perovskite structure as the structure, A is Y (yttrium),
Gd (gadolinium), Yb (ytterbium), Eu
(Europium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Lu (lutetium), Sc
(Scandium) and one or more elements selected from other lanthanoids, and B has one or more elements selected from Ba (barium), Sr (strontium), and Ca (calcium). Forming an oxide superconducting thin film; and ((A′pA ″,
_1- p), _1-x (B'qB " _1- q) x) y (Cu
rX1 _-r ) zOwx = 0-1.0, y = 2.0-4.
0, z = 1.0 to 4.0, w = 4.0 to 10.0, and A ′ is Y (yttrium), Gd (gadolinium), Yb (ytterbium), Eu (europium), Tb ( Terbium), Dy (dysprosium),
Ho (holmium), Er (erbium), Tm (thulium), Lu (lutetium), Sc (scandium) and other elements selected from a plurality of lanthanoids, and B 'is Ba ( Barium), Sr (strontium), Ca (calcium)
A ″, B ″ or X is Mg (magnesium), Be
(Beryllium), Al (aluminum), Fe (iron),
It has non-superconducting properties to which one or more elements selected from Co (cobalt), Ni (nickel), Cr (chromium), Ti (titanium), Mn (manganese), and Zr (zirconium) are added. Laminating a material having a perovskite structure similar to that of the oxide superconducting material, and forming the oxide superconducting thin film, wherein a magnetic field is applied in a direction perpendicular to a surface on which the oxide superconducting thin film is formed. A method for manufacturing a superconducting electron device, comprising: