JP2011138689A - Method of manufacturing superconductivity fine wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of carrying out formation of a groove part on a superconducting layer and making a fine wire reliably by etching without requiring an expensive photomask. <P>SOLUTION: This invention relates to a method of manufacturing a superconductive fine wire which has a superconducting layer formed on a substrate through an intermediate layer and has separating grooves to cut and separate the superconducting layer at least into a plurality of parts. The manufacturing method includes: a step in which grooves which reach from a protective layer to at least the surface of the superconducting layer are formed along the length direction of a superconductor on the superconductor having the intermediate layer, the superconducting layer, and the protective layer on a substrate; a step in which a photosensitive resin layer of negative type is formed; and a step in which exposure and development are carried out so as to form a connection groove continuing to the grooves on the photosensitive resin layer by removing the photosensitive resin layer at the position corresponding to the grooves, while leaving the photosensitive resin layer on the protective layer. The separating grooves are formed by removing by etching an oxide superconducting layer located at the lower part of these through the grooves and the connection groove. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a superconducting thin wire used under alternating current.

A superconductor such as an oxide is maintained in a superconducting state within a condition range defined by a critical temperature, a critical current, and a critical magnetic field. On the other hand, depending on the state of the superconductor, it is known that a part of the region becomes a normal conducting state during energization and generates heat, and further, a so-called quenching phenomenon occurs in which the entire superconductor is transferred to the normal conducting state. Yes. If the quench phenomenon occurs during energization, the superconductor may be burned out. Therefore, in order to prevent this, a stabilization layer (metal stabilization layer) made of a metal having good thermal conductivity and conductivity is placed in contact with the superconducting layer to form a composite.
As a method of providing a stabilization layer, a method of forming a stabilization layer (silver stabilization layer) made of silver (Ag) by sputtering or vapor deposition (see Patent Document 1), or on a silver stabilization layer via solder. Discloses a method of forming a stabilization layer (copper stabilization layer) made of inexpensive copper (Cu) (see Patent Document 2).

On the other hand, in order to use a superconductor for practical use such as a cable and a transformer, it is necessary to reduce AC loss. On the other hand, in a coil using a superconducting wire, a groove reaching the metal substrate is formed in the superconducting layer, and the superconducting layer is divided into a plurality of thin lines, so that AC is inversely proportional to the number of divisions. It is known that loss can be reduced (see Patent Document 3). Laser irradiation, photolithography, etching, etc. are usually applied as the thinning technique.
As described above, in a superconducting wire provided with a metal stabilizing layer, it has become an important technique to thin the superconducting wire in order to reduce AC loss.

JP 2006-236652 A JP 2008-060074 A JP 2007-141688 A

As described above, attempts have been made to make the superconducting wire thinner in order to reduce the AC loss of the superconducting wire.
Here, the oxide superconducting conductor is generally formed by laminating an intermediate layer and a cap layer on a base material such as a heat-resistant metal tape for the purpose of controlling crystal orientation and suppressing element diffusion, and then laminating an oxide superconducting layer thereon. Further, a structure provided with a highly conductive stabilization layer is generally used. Therefore, in order to thin the oxide superconducting conductor having such a laminated structure, it is necessary to subdivide the oxide superconducting layer by forming a plurality of grooves in the length direction of the oxide superconducting conductor.
FIG. 3A shows an example of the structure in the case of thinning. The oxide superconducting conductor 100 in the example of this figure is formed on an IBAD (Ion-Beam-Assisted) on a long base material 101 made of a refractory metal. An intermediate layer 102 having excellent crystal orientation is formed by an orientation control technique such as Deposition (ion beam assist) method, and a cap layer 103 capable of self-orientation such as CeO ₂ is formed on the intermediate layer 102 to be close to a single crystal. In addition to ensuring crystal orientation, an oxide superconducting layer 105 is formed, and a protective layer 106 is stacked thereon.

In order to thin the oxide superconducting conductor 100 having the laminated structure shown in FIG. 3A, a plurality of grooves 110 are formed so as to reach the oxide superconducting layer 105 from the protective layer 106 as shown in FIG. Thus, the oxide superconducting layer 105 can be divided into a plurality of superconducting layers 105A, whereby the superconducting thin wire 100A can be obtained. In superconducting thin wire 100A, adjacent superconducting layers 105A through grooves 110 must be mutually insulated.
In the case where the groove 110 is formed in the oxide superconducting layer 105, the groove 110 that divides the protective layer 106 and the oxide superconducting layer 105 can be formed as shown in FIG. As described above, the protective layer 106, the oxide superconducting layer 105, the cap layer 103, and the intermediate layer 102 can be divided to form the grooves 111 so as to reach the upper surface of the substrate 101.

A first method known as a method of forming a groove in the oxide superconducting layer 105 is a method of forming a groove by a technique such as etching using a photolithography technique, and a second method is a method using a mechanical blade. This is a method of physically forming and dividing the groove by using. As another method, a CO ₂ laser is irradiated to cause a compositional displacement in the oxide superconducting layer 105 at a position corresponding to the previous groove, thereby converting the superconducting portion into an insulator, and an insulator formed at a position corresponding to the groove. There is also known a method of dividing the oxide superconducting layer 105 into a plurality of layers.

However, the dividing method using the photolithography technique according to the first method described above has a problem that an expensive apparatus is required, for example, a photomask called an expensive reticle is required for exposure. Further, in the cutting method using the mechanical blade according to the second method described above, it is possible to process a plurality of grooves at a time by using a plurality of blades, and the throughput at the time of grooving is fast, There was a problem that the residue could easily remain inside the groove after processing, and there was an influence of the residue, so that the insulation resistance between the superconducting layers formed by division could not be increased. Therefore, it is necessary to remove these residues by a technique such as etching, but it is necessary to perform further etching after cutting with a mechanical blade. In this case also, a groove is formed by forming a photoresist. Since it is necessary to protect the oxide superconducting layer other than, there is a problem that the process becomes complicated.
Further, in the method using the third CO ₂ laser described above, when thin oxide superconducting wire is thinned, the superconducting wire wound around the reel or the like is not rewound by the number of times for forming the insulating portion. Therefore, there is a problem that throughput increases as the number of divisions is increased in order to reduce AC loss.

  It is an object of the present invention to provide a method of manufacturing a superconducting thin wire that can be formed in a superconducting layer by etching without requiring an expensive photomask, can be surely thinned of the superconducting wire, and is preferable for alternating current use. And

The present invention has the following configuration in order to solve the above problems.
The present invention is a method for producing a superconducting wire, wherein a superconducting layer is formed on a base material through an intermediate layer, and includes at least a separation groove that divides and separates the superconducting layer into a plurality in the wire width direction. Forming a groove portion that reaches at least the surface of the superconducting layer from the protective layer along the length direction of the superconducting conductor, and a step of forming the groove portion reaching the surface of the superconducting layer from the protective layer. Forming a negative photosensitive resin layer so as to cover the surface, and the photosensitive resin layer on the protective layer remains, and the photosensitive resin layer at a position corresponding to the groove portion is removed to continuously connect the groove portion. Steps of exposing and developing so as to form a groove in the photosensitive resin layer, and removing the oxide superconducting layer located under the groove and the connecting groove by etching to divide the oxide superconducting layer Forming separation grooves The features.
In the present invention, at least the surface of the protective layer is formed from a light-reflective material, and the amount of light that the photosensitive resin layer is exposed to when exposed to a negative photosensitive resin layer formed on the protective layer. The exposure is performed with a low amount of light, the photosensitive resin layer on the groove is in an underexposed state, and the photosensitive resin layer on the protective layer is developed in a photosensitive sufficient state, and then development is performed.

In the present invention, when the photosensitive resin layer is exposed with a light amount lower than the light amount that the photosensitive resin sensitizes, the exposure time is selected to be shortened, the light intensity is decreased, the exposure time is shortened, and the light is reduced. It is characterized in that both of the reductions in strength are selected and implemented.
The present invention is characterized in that the groove formed in the protective layer is formed with a mechanical blade.
The present invention is a method for producing a superconducting wire, wherein a superconducting layer is formed on a base material through an intermediate layer, and includes at least a separation groove that divides and separates the superconducting layer into a plurality in the wire width direction. Forming a resin-made second protective layer on the protective layer, and forming a groove in the second protective layer with respect to the length of the superconductive conductor. A step of forming with a mechanical blade along the length direction, and an oxide superconducting layer located under the groove is removed by etching to form a separation groove for dividing the oxide superconducting layer. And

According to the present invention, it is possible to form the separation groove for dividing the oxide superconducting layer without using an exposure apparatus equipped with an expensive photomask such as an exposure reticle, so that a superconducting thin wire is manufactured at low cost. be able to. In addition, since the separation groove for separating the superconducting layer is formed by etching, the problem that a residue is generated on the inner side of the groove as in the case of mechanical groove processing or laser groove processing does not occur in the present invention. .
Therefore, it is possible to manufacture a superconducting thin wire having a plurality of superconducting layers having a divided structure that has no insulating material in the separation groove and in which insulation is ensured.

In addition, at least the surface of the protective layer is made of a light-reflective material, and when the photosensitive resin layer is exposed, even if it is exposed in a state where the amount of light is insufficient, the protective layer is utilized using reflected light from the surface of the protective layer The photosensitive resin layer present on the substrate can be sufficiently exposed, whereas the photosensitive resin layer on the protective layer where the groove is formed has no reflection from the protective layer and remains underexposed. Therefore, if the photosensitive resin layer in this state is developed, it becomes possible to remove only the portion of the photosensitive resin layer that has become underexposed and leave other portions that have been exposed, By using the remaining portion of the photosensitive resin layer as a mask, a separation groove for dividing the superconducting layer can be formed by etching, and an objective photomask without using an expensive photomask or an expensive exposure apparatus using the same can be formed. Processing of the separation groove of the superconducting layer It can be formed by etching. Therefore, a superconducting thin wire having a structure obtained by subdividing the superconducting layer can be manufactured at low cost.
The method of forming the groove in the protective layer can also be physically performed using a mechanical blade, in which case a plurality of grooves are formed at a time by using a plurality of blades, and the length direction of the superconducting conductor. It is possible to form a plurality of grooves by one cutting process at a time, and it is possible to divide the superconducting layer into a plurality of parts with good production efficiency. Further, the groove portion is formed by the mechanical blade with respect to the protective layer, and the separation groove is formed by etching on the superconducting layer itself, so that there is little possibility that a mechanical load acts on the superconducting layer. A separation groove can be formed without physically damaging the superconducting layer itself, and a superconducting thin wire can be manufactured. In addition, residues such as cutting scraps are likely to remain in the groove formed using the mechanical blade, but since etching is performed after the groove is formed, the residue in the groove can be easily removed.

FIG. 1 is a diagram for explaining a manufacturing method of an oxide superconducting thin wire according to a first embodiment of the present invention in the order of steps, and FIG. 1 (A) shows an intermediate layer, a cap layer, a superconducting layer, and a protective layer on a substrate. 1B is a cross-sectional view showing a state in which a groove is formed in the protective layer, FIG. 1C is a cross-sectional view showing a state in which a resist layer is formed, and FIG. Is a cross-sectional view showing a state after exposure and development, FIG. 1E is a cross-sectional view showing a state where a groove reaching the oxide superconducting layer is formed, and FIG. 1F shows a groove reaching the base material. FIG. 1G is a cross-sectional view showing a state where a resist layer is removed, and FIG. 1H is a cross-sectional view showing a state where a resist is removed from a state where a groove reaching a base material is formed. FIG. 2 is a view for explaining a manufacturing method of an oxide superconducting thin wire according to a second embodiment of the present invention in the order of steps, and FIG. 2 (A) shows an intermediate layer, a cap layer, a superconducting layer, and a protective layer on a substrate. 2B is a cross-sectional view illustrating a state in which a second protective layer is formed on the protective layer, and FIG. 2C is a state in which grooves are formed in the second protective layer. 2D is a cross-sectional view showing a state in which a groove reaching the oxide superconducting layer is formed, FIG. 2E is a cross-sectional view showing a state in which a groove reaching the base material is formed, FIG. FIG. 1F is a cross-sectional view showing a state where the resist layer is removed, and FIG. 1G is a cross-sectional view showing a state where the resist is removed from a state where a groove reaching the base material is formed. 3A and 3B are diagrams for explaining groove processing of a general oxide superconducting wire. FIG. 3A is a perspective view showing an example structure of an oxide superconducting conductor, and FIG. 3B is an oxide superconducting conductor. The perspective view which shows the state which formed the groove | channel. FIG. 4 is a cross-sectional view showing a state in which a groove reaching an oxide superconducting layer is formed in an example structure of an oxide superconducting conductor. FIG. 5 is a cross-sectional view showing a state in which a groove reaching the base material is formed in an example structure of an oxide superconducting conductor.

Embodiments of the present invention will be described below.
FIG. 1 is a diagram for explaining an embodiment of a method of manufacturing a superconducting thin wire according to the present invention in the order of steps. FIG. 1A is a superconducting structure in which an intermediate layer, a superconducting layer, and a protective layer are laminated on a long base material. 1B is a cross-sectional view showing a state in which a groove is formed in the protective layer, FIG. 1C is a cross-sectional view showing a state in which a resist layer is formed on the protective layer, and FIG. ) Is a cross-sectional view showing a state after the resist layer is exposed and developed, FIG. 1E is a cross-sectional view showing a state in which grooves reaching the cap layer surface and dividing the superconducting layer are formed, and FIG. ) Is a cross-sectional view showing a state in which the resist layer is removed.

In the manufacturing method according to the first embodiment of the present invention, as shown in FIG. 1 (G), an intermediate layer 2, a cap layer 3, a superconducting divided layer 5A, and a protective layer are formed on a long tape-like base material 1. Superconductivity having a structure in which divided layers 6A are laminated, and a structure in which a plurality of superconducting divided layers 5A and protective divided layers 6A are divided by a plurality of separation grooves 7 formed at predetermined intervals in the width direction of the substrate 1 One of the purposes is to manufacture the thin wire 9. The superconducting thin wire 9 is a long superconducting wire, and FIG. 1 (G) shows the laminated structure of the cross section, so that the divided conductor portion 8 in which the superconducting divided layer 5A and the protective divided layer 6A are laminated. Is also extended along the length direction of the superconducting thin wire 9.
The superconducting thin wire 9 having the above structure is formed by laminating the intermediate layer 2, the cap layer 3, the superconducting layer 5, and the protective layer 6 on the base material 1 as shown in FIG. It is manufactured by thinning the oxide superconducting conductor A in a state by a method described later.
Here, the structure of the oxide superconducting conductor A will be described before the description of the thinning method.

  In the oxide superconducting conductor A, what is used as a material constituting the base material 1 is a metal such as Cu, Ni, Ti, Mo, Nb, Ta, W, Mn, Fe, or Ag, which is excellent in strength and heat resistance. These alloys can be used. Particularly preferred are stainless steel, hastelloy, and other nickel-based alloys that are excellent in corrosion resistance and heat resistance. Of course, in addition to these, a ceramic substrate, an amorphous alloy substrate, or the like may be used.

In the oxide superconductor A, the intermediate layer 2 can be applied by selecting one layer or a multilayer structure. In the case where the intermediate layer 2 has a multilayer structure, the intermediate layer 2 having a laminated structure in which a diffusion prevention layer and a bed layer are laminated on the base material 1 and an orientation control layer is combined can be formed. The diffusion prevention layer and the bed layer can be omitted.
<Diffusion prevention layer>
The diffusion prevention layer is formed for the purpose of preventing the diffusion of the constituent elements of the base material 1 and is made of silicon nitride (Si ₃ N ₄ ), aluminum oxide (Al ₂ O ₃ , also referred to as “alumina”) or the like. It is preferable.
<Bed layer>
As the bed layer, a rare earth oxide layer can be applied, and for example, it can be composed of Y ₂ O ₃ . By forming this bed layer, a later-described IBAD-MgO orientation control layer formed thereon can be made more highly oriented.
<Orientation control layer>
The orientation control layer is a main component of the intermediate layer 2 and is, for example, a deposited film formed by an ion beam assisted sputtering method (IBAD method), and includes a substrate 1 and an oxide superconducting layer described later. It functions as a buffer layer that relaxes differences in physical characteristics (thermal expansion coefficient, lattice constant, etc.), and also functions as an orientation control film that controls the crystal orientation of the cap layer 3 formed thereon. When forming this orientation control layer, it is preferable to use an ion beam assisted sputtering apparatus and perform an ion beam assisted sputtering method to adjust the crystal orientation. However, the orientation control layer is not limited to the orientation control layer by the IBAD method. The orientation control layer obtained by the method may be applied.

As the material constituting the orientation control layer which is the main component of the intermediate layer 2, those whose physical characteristics indicate intermediate values between the substrate 1 and an oxide superconducting layer described later are used. Examples of such a material for the orientation control layer include MgO, yttria stabilized zirconium (YSZ), Gd ₂ Zr ₂ O ₇ , CeO _2, etc., in addition, pyrochlore structure, rare earth-C structure, perovskite An appropriate compound having a mold structure or a fluorite structure can be used. Among these, it is preferable to use MgO, YSZ, or Gd ₂ Zr ₂ O ₇ as the material of the orientation control layer. In particular, MgO and Gd ₂ Zr ₂ O ₇ are particularly suitable as materials for the orientation control layer because ΔΦ (FWHM: full width at half maximum), which is an index representing the degree of orientation in the IBAD method, can be reduced.

<Cap layer>
The cap layer 3 has a function of controlling the orientation of the oxide superconducting layer provided thereon, diffusion of elements constituting the oxide superconducting layer, and reaction between the gas used during film formation and the intermediate layer 2 It has a function to suppress.
In particular, the cap layer 3 is epitaxially grown on the surface of the intermediate layer 2 (surface of the orientation control layer), and then grows in the lateral direction (plane direction) (overgrowth), so that the crystal grains are in the in-plane direction. More preferably, the film is formed through a process of selective growth. The cap layer 3 that is selectively grown in this way can have a higher in-plane orientation than the intermediate layer 2.
The material constituting the cap layer 3 is not particularly limited as long as it can exhibit such a function. For example, CeO ₂ , LaMnO ₃ , SrTiO ₃ , Y ₂ O ₃ , Al ₂ O _{3 and the} like are used. It is preferable.
When CeO ₂ is used as the constituent material of the cap layer 3, the cap layer 3 does not need to be entirely composed of CeO ₂ , and Ce-M in which a part of Ce is substituted with another metal atom or metal ion. -O type oxide may be included.

<Oxide superconducting layer>
As a material for the oxide superconducting split layer 5A, an RE-123 oxide superconductor (REBa ₂ Cu ₃ O _7-n : RE is a rare earth element such as Y, La, Nd, Sm, Eu, Gd) is used. Can do. Y123 (YBa ₂ Cu ₃ O _7-n ) or Gd123 (GdBa ₂ Cu ₃ O _7-n ) or the like is preferable as the RE-123-based oxide.
A stabilizing layer made of a highly conductive metal material such as Ag or an Ag alloy may be separately formed on the oxide superconducting layer 5A for the purpose of stabilizing the superconducting characteristics.
<Protective layer>
Examples of the material of the protective dividing layer 6A include noble metals such as Ag, Au, and Pt, and are preferably made of a metal having good electrical conductivity and high light reflectivity. In order to stabilize the superconducting dividing layer 5A in the superconducting wire, good conductive Ag is often applied. Therefore, when the protective dividing layer 6A of Ag is used, the protective dividing layer 6A used in this embodiment is used. This is preferable because it can be used as it is as the base layer of the metal stabilizing layer. The stabilization layer of the superconducting wire conductor A can be obtained by laminating a copper layer having a necessary thickness on the Ag base layer.

If the oxide superconducting conductor A having a laminated structure shown in FIG. 1A is prepared, a plurality of grooves 6 a formed by cutting a surface of the protective layer 6 using a mechanical blade in the width direction of the oxide superconducting conductor A. The oxide superconductor A is formed over the entire length in the length direction. The number of groove portions 6a formed here is formed in accordance with the number of oxide superconducting layers 5 to be divided. Therefore, the groove portions 6a are formed in the range of about 1 or more and about 20 though it depends on the width of the oxide superconducting conductor A. Can be provided. Of course, the number of grooves 6a is not limited to this range. By forming the groove 6a, the protective layer 6 is separated into a plurality of protective dividing layers 6A.
Once the groove 6a is formed, the surface of the protective layer 6 and the inside of the groove 6a are cleaned by means such as degreasing or chemical polishing, and then, after forming the groove 6a, a negative type is formed so as to cover the surface of the groove 6a and the protective layer 6. A photosensitive resin layer 10 is formed. The photosensitive resin layer 10 is coated with a photosensitive resin on the protective layer 6 and the groove portion 5 by a coating method such as a dipping method, a spray method, or a roll coater method, and then a hot air dryer or a far infrared irradiation device is used. It can be obtained by performing a drying process such as pre-baking treatment and drying.
As the negative photosensitive resin 10 used here, Nippon Paint Co., Ltd., trade name OPTO-ER, N series (OPTO is a registered trademark), Kansai Paint Co., Ltd., trade name Sonne LDI series, etc. can be used. .

  Next, it exposes from the photosensitive resin layer 10 using the exposure apparatus which uses an ultrahigh pressure mercury lamp, a metal halide mercury lamp, etc. as a light source. At the time of this exposure, the light intensity from the light source or the exposure time is adjusted, and either or both of the relations between the light intensity and the time required to completely expose the photosensitive resin layer 10 However, exposure is performed under conditions that are insufficient for complete exposure. When the light intensity is decreased, the output from the light source is decreased, and the irradiation time is reduced in order to shorten the exposure time. Here, as a relationship of light intensity × time = light quantity, it is preferable to set the exposure amount to 50% to less than 100% of the light quantity necessary for complete exposure. In other words, it is necessary to adjust the parameter of either the light amount or the time to make the underexposure state.

  Here, since at least the surface of the protective layer 6 is made of a light-reflective metal, the protective resin layer 10 located on the protective layer 6 has the protective layer 6 even under the above-described underexposure conditions. By reflecting light, the photosensitive resin layer 10 located on the protective layer 6 is satisfactorily exposed, whereas the photosensitive resin layer 10 located on the groove 6a is underexposed. It becomes a state. Since at least the surface of the protective layer 6 only needs to be light-reflective, the protective layer 6 may be a multilayer structure and only the outermost surface layer may be formed from a material having low light reflectivity.

From this state, development is performed for 30 seconds to 120 seconds at a liquid temperature of about 25 ° C. to 35 ° C. using a developer such as sodium carbonate, and then a rinse solution is spray applied to complete the development. By this development process, only the region of the photosensitive resin layer 10 that has been underexposed is removed, and a connection hole 10a is formed in the portion corresponding to the groove 6a of the photosensitive resin layer 10 as shown in FIG. As a result, the photosensitive resin layer 10 is divided into a plurality of photosensitive resin dividing layers 10A. After the connection hole 10a is formed, the surface of the oxide superconductor A is rinsed and cleaned, and then an etching process is performed.
After cleaning, the oxide superconducting layer 5 is divided by wet etching using the photosensitive resin dividing layer 10A and the protective dividing layer 6A existing therebelow as a mask. As an etchant used here, nitric acid or ammonia water + hydrogen peroxide water can be used. The oxide superconducting layer 5 can also be divided by physical etching.

The oxide superconducting layer 5 is etched by the above-described etching process, and the oxide superconducting layer 5 located under the groove 6a and the connection hole 10a is partially selectively removed to form the separation groove 5a in the oxide superconducting layer 5. When the separation groove 5a reaches the cap layer 6 underlying the oxide superconducting layer 5, the etching process is finished. By this etching step, the oxide superconducting divided layer 5A having a structure in which the oxide superconducting layer 5 is divided by the separation groove 7 can be formed.
After the etching step is finished, the photosensitive resin dividing layer 10A is peeled off from the protective dividing layer 6A by immersing in an aqueous sodium hydroxide solution (3 to 5%, liquid temperature 40 to 55 ° C.) for about 60 to 90 seconds. The superconducting thin wire 9 having the cross-sectional structure shown in FIG. 1G and having the oxide superconducting divided layer 5A divided into a plurality by the separation groove 7 can be obtained.

In the superconducting thin wire 9 manufactured by the method described above, the superconducting layer 5 is divided into a plurality of superconducting divided layers 5A by the separation groove 7 and is thinned, so that AC loss can be reduced during AC energization. Has characteristics.
Moreover, in the manufacturing method of this embodiment demonstrated based on FIG. 1 (A)-(G), the groove part 6a formed in the protective layer 6 mechanically using the blade, and the light of the protective division layer 6A By using the reflection, the entire photosensitive resin dividing layer 10A formed on the protective dividing layer 6A is exposed with a light intensity or exposure time that is less than the conditions for completing the exposure. By selectively classifying the photosensitive resin layer 10 positioned above into an exposure complete state and the photosensitive resin layer 10 above the groove 6a into an underexposed state, selective exposure processing can be performed without requiring an expensive photomask such as a reticle. it can. Then, the under-exposed portion formed at this time is removed by development to form a connection hole 10a in the photosensitive resin layer 10, and a continuous hole reaching the surface of the oxide superconducting layer 5 together with the groove portion 6a positioned therebelow. Since the other portions can be covered with the photosensitive resin dividing layer 10A and the protective dividing layer 6A, the oxide superconducting layer 5 is selectively etched using these as a mask to form the separation groove 7. The oxide superconducting layer 5 can be formed into a plurality of oxide superconducting divided layers 5A.
That is, according to the method of the present embodiment, the oxide superconducting layer 5 can be selectively etched without requiring an expensive photomask such as a reticle, so that the superconducting thin wire 9 can be manufactured at low cost.

  Next, in the manufacturing method according to the present invention, as shown in FIG. 1 (H), an intermediate layer 2A, a cap layer 3A, a superconducting split layer 5A, and a protective split layer 6A are formed on a long tape-shaped substrate 1. The intermediate layer 2A, the cap layer 3A, the superconducting dividing layer 5A, and the protective dividing layer 6A are divided into a plurality by the separation grooves 11 formed at predetermined intervals in the width direction of the substrate 1. It is also possible to manufacture a superconducting thin wire 13 having a split conductor portion 12 having a different shape. The superconducting wire 13 is a long superconducting wire, and FIG. 1 (H) shows the laminated structure of the cross section. Therefore, the divided conductor portion 12 and the separation groove 11 are both the length of the superconducting wire 13. Extended in the direction.

Next, in the manufacturing method according to the second embodiment of the present invention, the oxide superconducting A having the same structure as that used in the first embodiment described above is used, and the process shown in FIG. The oxide superconducting wire 22 having the laminated structure shown in FIG. 2 or the oxide superconducting wire 25 shown in FIG. 2G can be manufactured.
Using the oxide superconducting conductor A shown in FIG. 2 (A), a second protective layer 20 made of resin is laminated on the protective layer 6, and thereafter, the same as that used in the previous first embodiment. Grooves 20a are formed in the second protective layer 20 in a mechanical manner using a blade in the required width and the required number in the length direction of the oxide superconducting conductor A, and the second protective layer 20 is defined as a divided protective layer 20A. .
Thereafter, an etching with an etching solution is performed through the groove 20a of the second protective layer 20 to separate the protective layer 6, the oxide superconducting layer 5, the cap layer 6 and the intermediate layer 2 located below the groove 20a. 21 is formed, and then the second protective layer 20A is peeled and removed, whereby the oxide superconducting thin wire 22 having the cross-sectional structure shown in FIG. 1F can be obtained.

  In the manufacturing method of the second embodiment, the separation groove 24 is formed by etching so as to reach the surface of the substrate 1 from the state shown in FIG. 2C, and the protective layer 6 is formed on the protective dividing layer 6A. It is also possible to manufacture the superconducting thin wire 25 with the superconducting layer 5 as the oxide superconducting divided layer 5A and the cap layer 3 and the intermediate layer 2 as divided structures.

  Even in the process of manufacturing the oxide superconducting thin wires 22 and 25 by the method described above, the oxide superconducting layer can be divided by etching without using an expensive photomask and without using an expensive exposure apparatus. In addition, the oxide superconducting thin wires 22 and 25 can be manufactured.

Specific examples of the present invention will be described below, but the present invention is not limited to these examples.
An Al ₂ O ₃ diffusion-preventing layer was formed by sputtering on a tape-like Hastelloy metal substrate having a length of 10 cm and a length of 10 m. The film formation temperature of the Al ₂ O ₃ layer was room temperature and the film thickness was 100 nm.
Next, a Y ₂ O ₃ bed layer was formed on the Al ₂ O ₃ diffusion prevention layer by ion beam sputtering. The thickness of this bed layer was 20 nm.
Subsequently, an IBAD method was used to irradiate the MgO target with an ion beam while irradiating an assist ion beam at an incident angle of 45 ° using an MgO target, and the target particles were knocked out. An intermediate layer of IBAD-MgO was formed on the bed layer A film was formed (film thickness 5 nm).
Next, a CeO ₂ cap layer having a thickness of 500 nm was formed at 800 ° C. on the intermediate layer of IBAD-MgO by a pulse laser deposition method (PLD method).
Further, an oxide superconducting layer having a composition of Y123 (YBa ₂ Cu ₃ O _7-n ) was formed on the cap layer by a PLD method (pulse laser deposition method). (Thickness 1μm)

With respect to the oxide superconducting conductor obtained as described above, an Ag protective layer having a thickness of 5 μm was formed on the oxide superconducting layer by plating to form an Ag protective layer.
With respect to this protective layer, four separation grooves with a width of 100 μm and a cutting device having a rotating disk-shaped blade are formed over the entire length of the oxide superconducting conductor at equal intervals in the width direction of the oxide superconducting conductor. Divided into two protective separation layers.
Next, a photosensitive resin layer made of a negative photosensitive resist (OPTO-ER, N) was applied by spray coating, prebaked at 150 ° C. for 1 minute, and then exposed to 45 mJ / cm ² with an ultrahigh pressure mercury lamp. . Since this photosensitive resin has an exposure amount of 60 mJ / cm ² that is completely exposed, in this embodiment, the exposure is set to 75%.

Next, the exposed photosensitive resin layer is developed using 1% sodium carbonate (1: 7 dilution), and the oxide superconducting layer under the separation groove formed by the cutting device is removed, and the structure is divided into five parts. An oxide superconducting thin wire having an oxide superconducting split layer having a width of 2 mm was obtained.
The inter-line insulation between adjacent oxide superconducting split layers located on one end of the oxide superconducting wire in the width direction and divided by the groove can be confirmed to have an insulation resistance of 1 MΩ or more. It was confirmed that an oxide superconducting thin wire excellent in insulation between lines could be manufactured.

  A ... oxide superconducting conductor, 1 ... substrate, 2, 2A ... intermediate layer, 3A ... cap layer, 5 ... oxide superconducting layer, 6 ... protective layer, 7, 11 ... separation groove, 8, 12 ... divided Conductor part, 9, 13 ... superconducting thin wire,

Claims (5)

A method for producing a superconducting wire comprising a superconducting layer formed on an intermediate layer on a substrate, and comprising a separation groove for dividing and separating at least the superconducting layer into a plurality of wires in the width direction,
For the superconducting conductor provided with an intermediate layer, a superconducting layer, and a protective layer on the substrate, a step of forming a groove from the protective layer to at least the surface of the superconducting layer along the length direction of the superconducting conductor;
Forming a negative photosensitive resin layer so as to cover the protective layer and the groove,
A process of performing exposure and development so that the photosensitive resin layer on the protective layer remains, the photosensitive resin layer at a position corresponding to the groove is removed, and a connection groove continuous to the groove is formed in the photosensitive resin layer. When,
A method for producing a superconducting thin wire, comprising: forming a separation groove for separating the oxide superconducting layer by removing the oxide superconducting layer located under the groove and the connecting groove by etching.   At least the surface of the protective layer is formed from a light-reflective material, and when exposed to a negative photosensitive resin layer formed on the protective layer, exposure is performed with a light amount lower than the light amount that the photosensitive resin layer is exposed to. 2. The method for producing a superconducting thin wire according to claim 1, wherein the development is performed after the photosensitive resin layer on the groove portion is in an under-exposed state and the photosensitive resin layer on the protective layer is in a photosensitive sufficient state.   When exposing the photosensitive resin layer with a light amount that is lower than the light amount that the photosensitive resin sensitizes, select whether to shorten the exposure time, select a decrease in light intensity, reduce the exposure time, and decrease the light intensity. 3. The method of manufacturing a superconducting thin wire according to claim 2, wherein both are selected and executed.   The method for producing a superconducting thin wire according to claim 1, wherein the groove formed in the protective layer is formed with a mechanical blade. A method for producing a superconducting wire comprising a superconducting layer formed on an intermediate layer on a substrate, and comprising a separation groove for dividing and separating at least the superconducting layer into a plurality of wires in the width direction,
Forming a second protective layer made of resin on the protective layer for a superconducting conductor having an intermediate layer, a superconducting layer and a protective layer on the substrate;
Forming a groove in the second protective layer with a mechanical blade along the length direction of the superconducting conductor;
A method for producing a superconducting thin wire, wherein the oxide superconducting layer located under the groove is removed by etching to form a separation groove for dividing the oxide superconducting layer.

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