JP5216699B2 - Laser deposition equipment - Google Patents

Description

  The present invention irradiates a target with laser light, knocks or evaporates the vapor deposition particles of the target, and deposits the vapor deposition particles on a substrate to form a thin film such as an oxide superconducting layer. More particularly, the present invention relates to a laser vapor deposition apparatus capable of improving the productivity of an oxide superconducting wire using a long base material.

In order to use an oxide superconductor as a conductor, it is necessary to form a thin film of an oxide superconductor with good crystal orientation on a tape-like long base material. It is difficult to form a thin film of an oxide superconductor having a good crystal orientation directly on a metal tape because it is a polycrystal and its crystal structure is significantly different from that of an oxide superconductor. Therefore, an intermediate layer such as yttria-stabilized zirconia (YSZ) excellent in crystal orientation is formed on a long base material made of a metal tape such as hastelloy tape, and Y ₁ Ba ₂ Cu is formed on the intermediate layer. Attempts have been made to form a thin film of a rare earth oxide superconductor such as ₃ O _x, and when forming a thin film of this oxide superconductor, a method of forming a thin film by a laser vapor deposition method has been adopted. Yes.

In the conventional method for forming a thin film by laser vapor deposition, scanning is performed by reciprocating the laser beam along the path on the surface of the target. As a result, the flying direction of the vapor deposition particles struck from the target is biased, the vapor deposition particles cannot be deposited uniformly on the intermediate layer, and the thickness, film quality and crystal orientation of the resulting thin film vary. This causes problems such as deterioration of superconducting characteristics such as critical current density.
Therefore, the present applicant has passed the tape-shaped substrate a plurality of times within the deposition particle deposition region as a method of forming a thin film by laser vapor deposition that can uniformly deposit the vapor-deposited particles on the surface of the tape-shaped substrate. Thus, an apparatus for depositing vapor deposition particles on a tape-shaped substrate every time it passes through a deposition region and forming a thin film composed of a plurality of layers on the substrate is proposed (for example, Patent Document 1). reference.).

In the apparatus described in Patent Document 1, a reel-shaped winding member that winds the tape-shaped substrate is used as a means for passing the tape-shaped substrate through the deposition particle deposition region a plurality of times. A plurality of coaxially arranged pairs of winding member groups are disposed opposite to each other in the processing container, and a plurality of base members wound around the pair of winding member groups are circulated in the deposition region of the vapor deposition particles. Thin film formation is performed as a configuration in which the rows are aligned. According to this apparatus, a thin film consisting of a plurality of layers can be efficiently formed on the surface of the base material, but when the base material is circulated, the radiant heat easily escapes from the base material, and the temperature of the base material becomes uneven. There was a problem that it was easy.
Therefore, the present applicant encloses the circulating tape-shaped substrate with a heater box for heat insulation, provides an opening in a part of the heater box, places a target below the opening, and irradiates the target with laser light. A film forming apparatus capable of depositing vapor deposition particles by flying to the substrate side through the opening of the heater box is proposed. (See Patent Document 2)

JP 2004-263227 A JP 2006-233266 A

  FIG. 4 shows a configuration of a main part of the film forming apparatus described in Patent Document 2. A target 101 is bonded to the upper surface side of a copper backing plate 100 arranged horizontally, and a tape is placed above the target 101. The base materials 102 are arranged in a lane shape so as to be reciprocated in a state where a plurality of the base materials 102 are arranged, and the heater boxes 103 are arranged so as to cover the whole of the base materials 102. In an actual apparatus, a plurality of reel-shaped winding members are arranged at a coaxial position to form a winding member group. Two winding member groups are arranged opposite to each other, and the base material 102 is reciprocated between them. In FIG. 4, only the positional relationship on the target of the base material 102 arranged so as to be able to reciprocate is shown, and the winding member supporting the base material 102 is omitted.

  In the laser vapor deposition apparatus shown in FIG. 4, a laser beam is scanned in order to deposit vapor deposition particles on each of a plurality of arrayed base materials 102 that are reciprocating. For example, as shown in FIG. 4, in order to fly target particles across the entire area of the plurality of base materials 102 that are arranged and reciprocated, the surface of the target 101 facing the base material 102 is Laser vapor deposition is performed while scanning the laser beam in the range indicated by the arrow a (from the end to the end of the plurality of lanes formed by the plurality of base materials 102 reciprocating). When the target 101 is irradiated with the laser beam, the constituent particles are ejected as a jet from the target or evaporated to generate a jet called a plume. FIG. 4 shows a flame type plume P depending on the irradiation position of the laser beam. A conceptual illustration of the situation where

However, in the laser vapor deposition apparatus shown in FIG. 4, the laser beam is irradiated only to a narrow area facing the base material 102 with respect to the target 101 having a large area. Only a region having a width corresponding to the arrow a in FIG. 4 is used, and most of the target is wasted, which contributes to an increase in cost when an oxide superconductor is manufactured.
Therefore, the present inventor conducted a test in which laser deposition is performed by using a target 104 having a width corresponding to only the region a to be irradiated with laser light as shown in FIG. 5 and attaching the target 104 only to the central portion of the backing plate 100. When the oxide superconducting conductor was manufactured, problems such as a decrease in the critical current density of the obtained oxide superconducting conductor occurred.

  This is because when a target is present in a region not irradiated with laser light when the target particle is beaten or evaporated by condensing and irradiating the target with laser light, radiant heat is generated from the target at that position. Then, heat is applied to the film formation atmosphere and the temperature distribution is adjusted. However, if the backing plate 100 is present in the region not irradiated with the laser light but the backing plate 100 exists, the backing plate 100 is cooled with water and the temperature is low. Therefore, since the generation state of radiant heat is significantly different from the case where the target is present, the variation in heat distribution becomes large, and this causes the surface temperature of the tape-like base material 102 to be in the center lane side. As a result, it seems that the generation of the oxide superconducting layer was affected.

The present invention is directed to a laser vapor deposition apparatus capable of reducing the cost of film formation by reducing the waste of a target in the case of laser vapor deposition, and forming a stable thin film with uniform heat distribution in the film formation region. The purpose is to provide.
In the present invention, when an oxide superconducting layer is formed on a long substrate by laser vapor deposition, the cost of forming the oxide superconducting layer is reduced by reducing waste of an expensive target and the film forming region. An object of the present invention is to provide a laser vapor deposition apparatus capable of forming a superconducting layer having a stable film quality by making the heat distribution uniform.

The present invention has the following configuration in order to solve the above problems.
The present invention is provided with a processing container that accommodates a long base material, a heater box that is disposed in the processing container and that retains heat around the long base material, and is provided adjacent to the opening of the heater box. A target holder, a laser beam emitting means for irradiating a target held by the target holder with a laser beam, and provided in the processing container to support the winding of the long base material in a plurality of rows in a lane shape. A long base material comprising: a plurality of winding members; and irradiating the surface of the target with the laser light, and vapor deposition particles struck or evaporated from the target and supported by the winding members in the heater box A laser vapor deposition apparatus for depositing on a surface, wherein a target having a width corresponding to an installation range in a width direction of a long base material supported by being divided into a plurality of rows between the winding members is installed. A backing plate wider than the target is installed on the back side of the target, a heat-resistant metal dummy plate supported by the backing plate is installed on both sides in the width direction of the target, and the dummy plate An oxide film is formed on the backing plate side.

The present invention is characterized in that the dummy plate is a light-reflective heat-resistant metal dummy plate.
The present invention is characterized in that the target is an oxide superconductor material and the thin film is an oxide superconducting thin film.
In the present invention, a plurality of the winding members are coaxially arranged to form a winding member group, and the winding member group is disposed so as to face at least one pair in the heater box, and the long base material is wound around these winding members. The rotating member group is arranged in a plurality of lanes by a plurality of turns.

According to the apparatus of the present invention, since the target having a width corresponding to the installation range in the width direction of the long base material supported by being divided into a plurality of rows between the winding members in the heater box is installed and laser deposited, A smaller target having a narrower width can be used, and the unit price of the target can be lowered, so that the film formation cost can be reduced. In particular, when a film having a high target such as an oxide superconducting layer is produced, the reduction of the target cost contributes to the cost reduction during the production of the superconducting conductor.
In addition, since heat-resistant metal dummy plates are installed on both sides of the target in the width direction, both the radiant heat from the target and the radiant heat from the dummy plate can be used for laser deposition on the substrate after achieving a thermal balance. In any row of the substrates supported by being divided into a plurality of rows, the temperature can be equalized and a film can be formed with a uniform film quality without any temperature difference. For example, in the case where an oxide superconducting layer is formed by laser vapor deposition, it is possible to realize high-quality oxide superconducting conductors in which superconducting characteristics such as critical current density are not deteriorated at a low cost.

  In addition, when the backing plate is cooled and used by forming an oxide film on the backing plate side of the dummy plate, the oxide film suppresses heat conduction, and the temperature of the dummy plate is more than necessary due to the backing plate. Since it is possible to suppress the lowering, as a result of being able to balance the radiant heat that the dummy plate gives to the substrate side with the radiant heat that the target gives to the substrate side, it is possible to suppress the disturbance of the heat distribution on the long substrate side, Thereby, a film with uniform characteristics can be formed.

FIG. 1 is a configuration diagram showing a main part of a laser deposition apparatus according to a first embodiment of the present invention. FIG. 2 is a configuration diagram showing the overall configuration of the laser vapor deposition apparatus. FIG. 3 is a perspective view showing the overall configuration of the laser deposition apparatus. FIG. 4 is a block diagram showing a main part of a conventional laser vapor deposition apparatus. FIG. 5 is a block diagram showing a state where a part of a conventional laser vapor deposition apparatus is improved.

Embodiments of the present invention will be described below.
1 to 3 are views showing a first embodiment of a laser vapor deposition apparatus according to the present invention. FIG. 1 (A) is a configuration diagram of a main part of the laser vapor deposition apparatus, and FIG. FIG. 3 is a perspective view of the laser deposition apparatus 10.
In the present embodiment, as shown in FIG. 1B, the present invention is applied to a long base material 12 in which an intermediate layer 3 and a cap layer 4 are formed on a tape-shaped metal base material 2. The case where the oxide superconducting conductor A formed by forming the oxide superconducting layer 6 with the laser deposition apparatus 10 is described as an example.

<Metal base material>
As a material constituting the long tape-shaped metal substrate 2 constituting a part of the oxide superconductor A described above, Cu, Ni, Ti, Mo, Nb, Ta, excellent in strength and heat resistance, Metals such as W, Mn, Fe, and Ag, or alloys thereof can be used. Particularly preferred are stainless steel, hastelloy, and other nickel-based alloys that are excellent in corrosion resistance and heat resistance. Alternatively, in addition to these, a ceramic substrate, an amorphous alloy substrate, or the like may be used.
<Intermediate layer>
The intermediate layer 3 is a deposited film formed by an IBAD method or the like, and functions as a buffer layer that alleviates the difference in physical characteristics (thermal expansion coefficient, lattice constant, etc.) between the metal substrate 2 and the oxide superconducting layer 6. In addition, it functions as an orientation control film that controls the orientation of the cap layer 4 formed thereon. Examples of the material of the intermediate layer 3 include an example in which yttria-stabilized zirconium (YSZ), MgO, SrTiO ₃ , Gd ₂ Zr ₂ O _{7 and the} like are applied in a single layer or a multilayer.

<Cap layer>
The cap layer 4 has a function of controlling the orientation of the oxide superconducting layer 6 provided thereon, and is epitaxially grown on the surface of the intermediate layer 3 and grain growth (overgrowth) in the lateral direction (plane direction). Thus, it is preferable that the film is formed through a process in which crystal grains are selectively grown in the in-plane direction. For example, CeO ₂ , Y ₂ O ₃ , Al ₂ O _3, or the like can be used.
<Oxide superconducting layer>
As a material for the oxide superconducting layer 6, an RE-123 oxide superconductor (REBa ₂ Cu ₃ O _7-X : RE is a rare earth element such as Y, La, Nd, Sm, Eu, Gd, etc.) is used. it can. The RE-123-based oxide is preferably Y123 (YBa ₂ Cu ₃ O _7-X ) or Gd123 (GdBa ₂ Cu ₃ O _7-X ), but other oxide superconductors can be used. Of course.

<Laser deposition system>
The laser vapor deposition apparatus 10 of the present embodiment includes a processing container 11 that houses a long base 12, a heater box 13 with an opening that is placed in the processing container 11 and that keeps the long base 12 warm, A target holder 16 provided adjacent to the opening 14 of the heater box 13 and a laser light emitting means 17 for irradiating the target 15 held by the target holder 16 with the laser light 18 are configured. Is irradiated on the surface of the target 15, and a jet of evaporated particles struck or evaporated from the target 15 (hereinafter referred to as plume 19) is directed toward the surface of the long base 12 in the heater box 13. Can be deposited.

  In the processing container 11, a delivery reel 20 around which the long base material 12 is wound, and a take-up reel 21 that houses the oxide superconducting conductor 28 that has finished forming the oxide superconducting layer 6 are provided. Yes. In the heater box 13 provided between the delivery reel 20 and the take-up reel 21, a pair of a plurality of winding members such as reels for winding the long base material 12 are coaxially arranged. The winding member groups 22 and 23 are spaced apart from each other, and the long base material 12 wound around the pair of winding member groups 22 and 23 circulates around the winding member groups 22 and 23. Thus, the plurality of lanes are arranged in the deposition region of the vapor deposition particles.

  The heater box 13 that accommodates the winding member groups 22 and 23 has a plurality of heaters (not shown) on the inner wall surface, and the long base 12 is made uniform by energizing these heaters. It can be heated and kept warm. An opening 14 for introducing a plume 19 generated on the surface of the target 15 into the heater box 13 is formed in the center of the bottom surface of the heater box 13.

In the vicinity (downward) of the opening 14, a backing plate 16 to which the target 15 is fixed is provided so as to reciprocate along a plane parallel to the opening 14 of the heater box 13. The backing plate 16 is provided with a water channel for water cooling, other piping, etc., and is configured as a target holder. In FIGS. 2 and 3 of this specification, these are abbreviated and only the backing plate 16 is provided. I'm drawing.
The backing plate 16 is wound around the winding member groups 22 and 23 a plurality of times and arranged to form a plurality of rows of lanes (the case of 5 lanes is illustrated in FIG. 1A) on the target 15. With respect to the long base material 12, it is formed in the width | variety about 3 times the width b of all the lanes which the long base material 12 comprises. A target 15 having a width approximately equal to the width b of all the lanes formed by the long base 12 is mounted at the center of the backing plate 16, and on the backing plates 16 on both sides in the width direction of the target 15. A dummy plate 30 having the same width as the target 15 is mounted.

The dummy plate 30 is made of a heat-resistant and oxidation-resistant metal material having light reflectivity, low ultraviolet absorption rate, low absorption rate of the laser beam 18, and hardly receiving heat by the laser beam 18. . As a metal material satisfying such conditions, the dummy plate 30 is preferably made of, for example, stainless steel, Ni alloy hastelloy, inconel, silver, gold, platinum, or the like. Since the dummy plate 30 is heated from the heater box 13 side and cooled from the backing plate 16 side, the dummy plate 30 is preferably made of the above-described material that is difficult to crack even if it receives a temperature difference from these.
The thickness of the dummy plate 30 is preferably about the same as that of the target 30. For example, if the target 15 is about 5 mm thick, the thickness can be about 5 mm. If it is made of the above-mentioned material and has a thickness of this level, it will not crack even if it is heated and cooled as described above, and it will absorb almost no ultraviolet light even if it is exposed to laser light, and particles will evaporate from the surface. Therefore, the particles constituting the dummy plate 30 do not jump out to the long substrate 12 side, and unnecessary elements are not mixed into the oxide superconducting layer side to be generated.

An oxide film 31 is formed on the back side of the dummy plate 30. The oxide film 31 preferably has a heat insulating property, and is preferably made of an Al ₂ O ₃ layer, SiO ₂ , ZrO ₂ or the like. The oxide layer 31 is preferably made of a material that is interposed between the backing plate 16 and the dummy plate 30 and has an effect of suppressing heat conduction. The oxide layer 31 is made of the aforementioned material and has a thickness of about 100 μm to 10000 μm. It is preferable.

The target 15 placed on the backing plate 16 has a composition equivalent to or close to that of the superconducting layer 6 to be formed, or a sintered or oxidized complex oxide containing many components that are easily escaped during film formation. It consists of a plate material such as a superconductor. Therefore, the oxide superconductor target 15 has the same composition as the target oxide superconductor represented by Gd ₁ Ba ₂ Cu ₃ O _x , Y ₁ Ba ₂ Cu ₃ O _x, or the like, or a composition similar to that of the target oxide superconductor. It is preferable to use one.

As the laser beam emitting means 17 for irradiating the target 15 with the laser beam 18, Ar-F (193 nm), Kr-F can be used as long as it can generate the laser beam 18 that can knock out the deposited particles from the target 15. Any excimer laser such as (248 nm), YAG laser, CO ₂ laser, etc. may be used. Laser light 18 emitted from the laser light emitting means 17 enters the container through a transparent window (not shown) provided at an appropriate position of the processing container 11 and is irradiated onto the surface of the target 15. Between the laser light emitting means 17 and the transparent window, an optical system (not shown) such as a reflection mirror or a condenser lens is provided as necessary.
The adjustment of the laser irradiation output can be performed by adjusting the output of an amplifying device (not shown) that supplies power to the laser light emitting means 17. The laser irradiation frequency indicates the number of laser pulses oscillated intermittently per second, and this adjustment supplies power to the laser light emitting means 17 intermittently at a constant frequency. Alternatively, it can be adjusted by providing a mechanical shutter such as a rotating sector somewhere in the path through which the laser beam 18 passes and operating the mechanical shutter at a constant frequency.

In order to form the oxide superconducting layer 6 on the long base 12 using the laser vapor deposition apparatus 10 having the configuration shown in FIGS. 1 to 3, the long base 12 wound around the feed reel 20. Is drawn into the heater box 13 and wound around the pair of winding member groups 22 and 23 accommodated therein, and then the leading end is led out from the heater box 13 and wound around the take-up reel 21. Removably attach.
As a result, the long base material 12 wound around the pair of winding member groups 22 and 23 circulates around the winding member groups 22 and 23 so as to move in a plurality of rows at a position desired for the opening 14. Become. Further, the target 15 and the dummy plate 30 are installed on the backing plate 16 adjacent to the opening 14. Thereafter, the exhaust device 24 is driven to depressurize the inside of the processing container 11. At this time, oxygen gas may be introduced into the processing container 11 as necessary to create an oxygen atmosphere in the container.

  After the long base 12 is set as described above, the heater provided on the inner wall of the heater box 13 is energized at an appropriate time before the target 15 is irradiated with the laser beam 18 to start film formation. The long substrate 12 and the pair of winding member groups 22 and 23 in the heater box 13 are preferably heated as a whole and kept at a constant temperature. The temperature control of the long base 12 in the heater box 13 is performed by installing a plurality of temperature sensors at appropriate positions in the heater box 13 so that the temperature of the long base 12 in the heater box 13 is uniform. This is preferably performed by individually controlling a plurality of heaters ON / OFF.

Next, the laser beam 18 is generated from the laser beam emitting means 17 while feeding the long base material 12 from the delivery reel 20, the laser beam 18 is introduced into the processing container 11 through the transparent window, and the target 15 is irradiated. At this time, the laser beam 18 is irradiated to the target 15 while performing scanning for moving the irradiation position of the laser beam 18 on the surface of the target 15 as described later. The target 15 is reciprocated along a plane parallel to the opening 4 by a target moving mechanism (not shown). Thereby, the vapor deposition particles of the target 15 at different locations are knocked out or evaporated.
Vapor-deposited particles that have been knocked out or evaporated from the target 15 become a plume 19 having an enlarged radial sectional area, and are introduced into the heater box 13 through the opening 14 formed in the heater box 13. In the vicinity of the opening 14, the long base material 12 moves in a plurality of rows. By introducing the plume 19 into the heater box 13, vapor deposition particles can be deposited on the surface of the long base material 12 moving in a plurality of rows in the vicinity of the openings 14. The oxide superconducting layer 6 is repeatedly formed while being wound around the winding member groups 22 and 23 and laminated to a required thickness. After the formation of the oxide superconducting layer 6, the obtained oxide superconducting conductor A is led out from the heater box 13 and taken up on the take-up reel 21.

As described above, when the plume 19 is generated by irradiating the target 30 with the laser beam 18, the oxide superconducting layers 6 that are as uniform as possible for each of the long substrates 12 arranged in a lane shape are formed as long as possible. In order to form a film over the entire length of the target 15, the laser beam 18 is sequentially scanned over the entire width in the width direction of the target 15 as shown in FIG. Film formation is performed for a long time so that the entire length of the long substrate 12 can be accommodated. Further, by reciprocating the target 30 together with the backing plate 16 in the direction of the arrow in FIG. 2, the laser beam 18 is also irradiated to the entire region perpendicular to the width direction of the target 30, resulting in the surface of the target 30 as a result. Plumes 19 can be generated sequentially from the entire area to knock out or evaporate target particles.
During the scanning of the laser beam 18 and the target movement, the laser beam 18 is also irradiated to the vicinity of the dummy plate 30 on both end sides of the target 15, and the scanned laser beam 18 is sometimes applied to the dummy plate 30. However, since the dummy plate 30 is made of a metal material that is light-reflective and has a low absorption rate of the laser beam 18, the constituent particles of the dummy plate 30 are not knocked out. There is no evaporation. Therefore, the constituent elements of the dummy plate 30 are not mixed into the oxide superconducting layer 6. As a specific example, if the stainless steel dummy plate 30 is used, the laser beam absorbability is low, and even when the laser beam is irradiated, generation of particles or the like hardly occurs from the surface.

  The dummy plate 30 is cooled from the backing plate 16 side and heated from the heater box 13 side. However, since the dummy plate 30 is made of a heat-resistant metal, there is no risk of cracking. Furthermore, even if there is cooling from the backing plate 16 side, since the oxide layer 31 is formed on the back side of the dummy plate 30 and heat transfer is suppressed, the dummy plate 30 is excessively cooled. Since the radiant heat from the dummy plate 30 heated from the heater on the heater box 13 side is generated to the same extent as the target 30, it is evenly distributed on the long base material 12 moving in a plurality of rows in the vicinity of the opening 14. As a result of applying radiant heat, the radiant heat can be equalized for any part of the long base material 12 moving in parallel. As a result, the radiant heat can be applied more uniformly to the long base 12 than when the backing plate 16 is exposed without the dummy plate 30, and as a result, the oxide superconducting layer 6 can be formed in a uniform heating state. A homogeneous oxide superconducting layer 6 with good characteristics can be formed.

An MgO intermediate layer having a thickness of 500 μm is formed by ion beam assisted sputtering and ion beam sputtering on the surface of a Hastelloy metal substrate having a width of 10 mm, a thickness of 0.1 mm, and a length of 10 m, and then CeO ₂ by laser deposition. What formed the cap layer of this was used as a long base material.
Next, an oxide superconducting layer having a thickness of 1 μm made of Gd ₁ Ba ₂ Cu ₃ O _x was formed on the surface of the long base material by a laser vapor deposition apparatus having the configuration shown in FIGS.

As the target, a plate-like oxide target having a composition of Gd ₁ Ba ₂ Cu ₃ O _x (length and width: 150 mm × 100 mm: thickness 5 mm) was used, and stainless steel of the same size was formed on the backing plate on both sides of the oxide target. A dummy plate having a thickness of 5 mm was installed and subjected to laser vapor deposition. On the back side of the dummy plate, a 1 μm thick Al ₂ O ₃ layer coated by a welding method was used.
Next, in the structure in which the central oxide target and the dummy plates on both sides are arranged, dummy plates in which the film thickness of the Al ₂ O ₃ layer formed on the back side of the dummy plate is 10 μm, 100 μm, 1000 μm, and 10,000 μm are respectively produced. Then, laser vapor deposition was also performed when each was used to produce an oxide superconductor.

For comparison, laser deposition was similarly performed using a plate-shaped target having a Gd ₁ Ba ₂ Cu ₃ O _x composition having a size including an oxide target and dummy plates on both sides thereof. Similarly, for comparison, laser deposition is similarly performed using a plate target having the same size of Gd ₁ Ba ₂ Cu ₃ O _x composition instead of the dummy plate, and the dummy plate is omitted and only the oxide target is backed up. Laser deposition was performed in the center.

  During film formation by the above laser vapor deposition, the surface temperature of the long base material in the heater box was measured, the temperature distribution difference was measured, and the use limit time was measured. Further, the critical current density (Jc) of the obtained oxide superconducting conductor was measured.

In Table 1, all Gd123 indicates a case where a plate-shaped target having a Gd ₁ Ba ₂ Cu ₃ O _x composition having a size including an oxide target and dummy plates on both sides thereof is used. Instead, a case where a plate-like target having the same size and having a Gd ₁ Ba ₂ Cu ₃ O _x composition is simply installed without being bonded to the backing plate is shown. In each test, the stainless steel dummy plate is simply placed on the backing plate.
From the results shown in Table 1, when a plate-like target having a Gd ₁ Ba ₂ Cu ₃ O _x composition is bonded to the entire backing plate, target cracks do not become a problem, and film formation can be performed for 40 hours at the limit of use. . Further, in this case, a difference in temperature distribution is small and a high-quality oxide superconducting layer can be produced, but the cost becomes high. That is, what is deposited is a rare earth oxide superconducting layer, and the target is originally expensive, and only the central portion of this expensive target is consumed, which is disadvantageous in terms of manufacturing cost.
On the other hand, when a plate-like target having a Gd ₁ Ba ₂ Cu ₃ O _x composition is simply installed on both sides of the target joined to the center of the backing plate, the dummy plate breaks in a short time due to heat shock, No longer serves as a dummy plate. Furthermore, if the target is placed only in the center of the backing plate and the backing plate is exposed on both sides of the target, the difference in the temperature distribution of the long base material for each lane increases due to the difference in emissivity. The critical current density (Jc value) of the resulting oxide superconductor was lowered.

Next, according to the present invention, it was found that the sample in which the stainless steel plate was installed as a dummy plate had a small temperature distribution difference, a high Jc value, and a long use time when the Al ₂ O ₃ layer was 100 μm or more. . A sample having an Al ₂ O ₃ layer of 10 μm or less cannot suppress heat conduction between the backing plates, the emissivity is lowered, and the temperature distribution is not improved, so the Jc value seems to be lowered.
Note that the film thickness of the Al ₂ O ₃ layer is easily affected by heat shock and does not serve as a dummy plate due to peeling, but even a 10000 μm thick sample is more limited than the Gd123 sample. Improved. Note that when the Al ₂ O ₃ layer is peeled off, diffusion of unnecessary elements to the generated oxide superconducting layer may become a problem.
Based on the above results, the target unit price can be reduced if a target with a width corresponding to the film formation region of the long base material is used, and dummy plates lined with an oxide layer are provided on both sides of the target. In addition, the deposition time can be lengthened. In addition, by optimizing the thickness of the oxide layer provided on the back of the dummy plate, the laser can reduce the film formation cost, increase the laser deposition time, and produce a superconducting conductor that does not degrade the superconducting properties. It has been found that a vapor deposition apparatus can be provided.

  A ... oxide superconducting conductor, 2 ... metal substrate, 3 ... intermediate layer, 4 ... cap layer, 6 ... oxide superconducting layer, 11 ... treatment vessel, 12 ... long substrate, 10 ... laser deposition apparatus, 13 ... Heater box, 14 ... opening, 15 ... target, 16 ... backing plate, 17 ... laser light emitting means, 18 ... laser light, 19 ... plume, 22, 23 ... winding member group, 30 ... dummy plate, 31 ... oxide layer .

Claims (4)

A processing container that accommodates the long base material, a heater box with an opening that is disposed in the processing container and that keeps warm around the long base material, a target holder provided adjacent to the opening of the heater box, Laser light emitting means for irradiating the target held by the target holder with laser light, and a plurality of windings provided in the processing container and supporting the long base material in a plurality of rows in a lane shape. With members,
A laser vapor deposition apparatus that irradiates the surface of the target with the laser light and deposits vapor particles that have been beaten or evaporated from the target on the surface of a long substrate supported by the winding member in the heater box. And
A target having a width corresponding to the installation range in the width direction of the long base material supported in a plurality of rows between the winding members is installed, and a backing plate wider than the target is installed on the back side of the target A laser vapor deposition apparatus, wherein a dummy plate made of a refractory metal is installed on a backing plate on both sides in the width direction of the target, and an oxide film is formed on the backing plate side of the dummy plate .   The laser deposition apparatus according to claim 1, wherein the dummy plate is a light-reflective heat-resistant metal dummy plate.   The laser vapor deposition apparatus according to claim 1 or 2, wherein the target is an oxide superconductor material, and the thin film is an oxide superconducting thin film. A plurality of the winding members are coaxially arranged to form a winding member group, and at least a pair of the winding member groups are disposed to face each other in the heater box, and the long base member includes these winding member groups. The laser deposition apparatus according to any one of claims 1 to 3, wherein the laser deposition apparatus is arranged in a plurality of lanes by a plurality of rounds.

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