JP4366636B2 - Superconducting magnetic field generator and sputtering film forming apparatus using the same - Google Patents

Description

  The present invention is a superconductivity that can be used in various devices that require a strong magnetic field such as a magnetizing device, a magnetic separation device, a magnetic field press, a nuclear magnetic resonance device, a generator, a motor, and a sputtering film forming device for film formation. The present invention relates to a magnetic field generator by a body. The present invention also relates to a sputtering film forming apparatus using a magnetic field generator as a part of a sputtering gun.

As a superconductor, a conventional superconducting magnetic field generator equipped with a bulky (bulky) high-temperature superconductor such as a Y-system manufactured by a melt solidification method will be described as an example. Bulk-type high-temperature superconductors such as Y-systems produced by the melt-solidification method become powerful magnets that generate Tesla-class magnetic fields by applying a magnetic field, so a strong magnetic field for various applications Application as a generator is being studied. For example, Patent Literature 1 and Patent Literature 2 disclose a superconducting magnet device in which a superconductor is cooled by a refrigerator and integrated with a vacuum exhaust device or the like. Patent Documents 3 and 4 disclose a magnetron sputtering film forming apparatus using a superconducting magnet device as a sputtering gun. Patent Documents 5 and 6 disclose a superconducting magnetic field generating element that can generate a strong magnetic field by surrounding a superconductor with a reinforcing ring.
JP-A-11-283822 JP 2001-68338 A Japanese Patent Laid-Open No. 10-72667 JP 2002-146529 A JP-A-11-284238 JP 11-335120 A

  In order to generate a large magnetic field from the superconductor described above, it is preferable to efficiently cool the superconductor. However, according to the above-described publication technique, it is not always sufficient to efficiently cool the superconductor. There is a need for improvement.

  In addition, a superconducting magnetic field generator 1X shown in FIG. 14 has been recently developed. According to this, the superconductor 2X, the cold head 31X that functions as a cold generating part of the refrigerator 30X, and the mounting member 4X are accommodated in the heat insulating container 5X that is evacuated to vacuum. A cooling unit 33X is provided that extends from the cold head 31X to the superconductor 2X side through an extension.

  The attachment member 4X has a top hat shape with a hole in the ceiling, and has a cylindrical body 40X having a chamber, and a ring hook-shaped pressing portion 41X extending radially inward from one end of the cylindrical body 40X. In addition, it has a ring flange-shaped outer flange portion 42X extending radially outward from the other end of the cylindrical body 40X. An indium sheet 29X is disposed between the superconductor 2X and the cooling unit 33X in order to improve the thermal contact between them. By screwing the bolt member 7X inserted into the insertion hole of the outer flange portion 42X into the female screw hole 34X of the cooling portion 33X in a state where the bulk superconductor 2X is accommodated in the chamber of the top hat-shaped attachment member 4X, The superconductor 2X is fixed to the cooling part 33X by the mounting member 4X. The head portion 70X of the bolt member 7X presses the outer flange portion 42X. The magnetic field generating surface 21X of the superconductor 2X is pressed in the direction of the arrow Y1 by the ring-shaped pressing portion 41X of the mounting member 4X, and the back surface of the superconductor 2X contacts the cooling unit 33X via the indium sheet 29X.

  According to the superconducting magnetic field generator 1X described above, there is an advantage that the superconductor 2X can be easily attached to the cooling unit 33X. However, although the side surface 25X of the superconductor 2X is surrounded by the cylindrical body 40X of the mounting member 4X, the side surface 25X of the superconductor 2X is not necessarily sufficiently in contact with the inner wall surface of the cylindrical body 40X of the mounting member 4X. . That is, because the method of pressing the magnetic field generating surface 21X of the superconductor 2X with the pressing portion 41X of the mounting member 4X by pressing the outer flange portion 42X with the head portion 70X of the bolt member 7X, the superconductor is employed. When the side surface 25X of the 2X and the inner wall surface of the cylindrical body 40X of the attachment member 4X come into contact with each other, when the bolt member 7X is screwed into the female screw hole 34X of the cooling portion 33X, the pressing portion 41X of the attachment member 4X is superconductor. This is because the pressing force for pressing the 2X magnetic field generating surface 21X cannot be obtained sufficiently. For this reason, a minute gap 48X is formed between the side surface 25X of the superconductor 2X and the cylindrical body 40X of the mounting member 4X. Thus, according to the conventional example shown in FIG. 14, the side surface 25X of the superconductor 2X cannot be positively cooled, and the mounting member 4X does not necessarily contribute sufficiently to cooling the superconductor 2X. Thus, when the clearance gap 48X is formed, even if the attachment member 4X is cooled, the degree to which the attachment member 4X contacts the side surface 25X of the superconductor 2X is small.

  In addition, as a superconducting magnetic field generator for generating a strong magnetic field, it is preferable that a magnetic field as large as possible can be generated as a magnetic pole outside the heat insulating container 5X that accommodates the superconductor 2X. However, according to the superconducting magnetic field generator 1X described above, as shown in FIG. 14, the mounting member 4X needs to have the pressing portion 41X that presses and fixes the magnetic field generating surface 21X of the superconductor 2X. Due to the influence of the 4X pressing portion 41X, the distance between the magnetic field generating surface 21X of the superconductor 2X and the distal end portion 52X of the heat insulating container is increased accordingly, the gap width ta of the gap 53X therebetween increases, and the magnetic field captured by the superconductor 2X. However, the magnetic field that can actually be used outside the heat insulating container 5X is so small that the superconducting magnetic field generator 1X has a limit to fully exhibit the original performance.

  In order to generate a magnetic field from the superconductor 2X, it is necessary to magnetize the superconductor 2X in advance. As a magnetizing method, a heat insulating container 5X containing the superconductor 2X is inserted into the bore of the ring-shaped superconducting magnet 100 and a static magnetic field is applied, and a ring shape is formed around the heat insulating container 5X containing the superconductor 2X. There is a method in which the superconductor 2X is magnetized by a pulse magnetic field generated by applying a pulse current from a pulse power source constituted by a capacitor or the like. However, according to the superconducting magnet device 1X, the outer flange portion 42X of the mounting member 4X is fixed from above with the bolt member 7X, so that the diameter of the superconductor 2X is reduced due to the influence of the outer flange portion 42X of the mounting member 4X. The diameter of the magnetic pole increases. As a result, the diameter of the heat insulating container 5X accommodating the superconductor 2X becomes large. For this reason, there has been a problem that the diameter of the superconducting magnet 100 necessary for magnetization, the diameter of the magnetizing coil, and the pulse power source are increased. In addition, since the magnetic poles are large, there are problems such as restrictions on the mounting method and location when a plurality of magnetic poles are combined or incorporated in an apparatus.

  It has been found that these problems are caused by fixing the superconductor 2X by pressing the superconductor 2X against the cooling portion 33X with the top hat-shaped mounting member 4X as shown in FIG.

  The present invention has been made in view of these problems, and can effectively cool a superconductor, and further, a device necessary for magnetization (for example, a superconducting magnet, a magnetizing coil, a pulse power source, etc.) can be small. It is an object of the present invention to provide a high-performance superconducting magnet device having a compact magnetic pole capable of generating a strong magnetic field and a sputtering film forming apparatus using the same.

The invention of aspect 1 includes a superconductor that is cooled below the superconducting transition temperature and generates a magnetic field to the outside, a cooling device that has a cooling portion that cools the superconductor, and a cooling attachment member that holds the superconductor in the cooling portion of the cooling device; In the superconducting magnetic field generating device comprising the superconductor and the heat insulating container for accommodating the cooling attachment member, the cooling attachment member comprises a side surface fixing portion for fixing the superconductor from the side surface thereof, and the cooling attachment member is disposed on the cooling device. It has the fixing mechanism which pulls and fixes toward the cooling unit side. According to this, compared with the method of fixing from the normal superconductor side, it is advantageous to position the mounting mechanism more inside, and it is advantageous to reduce the outer diameter of the cooling mounting member disposed around the superconductor. Become. Therefore, it is advantageous to obtain a compact magnetic pole having a small diameter.
For example, as a mechanism for fixing the cooling mounting member to the cooling portion, if the cooling mounting member has a structure having a male screw portion, the male screw portion is passed through a part of the cooling portion and the male screw portion is fastened with a nut member, thereby superconducting. The body can be pulled and fixed from the cooling part side.
The superconductor is not necessarily limited to the superconducting substance itself, and the superconductor may be subjected to surface treatment such as resin impregnation, a metal film, or reinforcement by a metal ring as in the above reference. The cooling device can be a refrigerator having a cooling unit, and a GM refrigerator, a pulse tube refrigerator, a Stirling refrigerator, or the like can be used. In this case, the cooling part may be the cold head itself of the refrigerator or may be a part extended from the cold head by a copper block or the like. Moreover, it is preferable that the above-described cooling attachment member is formed of a material having both strength as an attachment member for attaching the superconductor and thermal conductivity as a cooling member for cooling the superconductor .

Further, as a mechanism for fixing the cooling mounting member to the cooling part, if the cooling mounting member has a structure having a female screw hole, by fastening the female screw hole with a bolt member with a part of the cooling part sandwiched from the cooling part side, it can be fixed taut Tsu pull the superconductor from the cooling unit side. In this case, the position of the screw can be made more inside, and at the same time, the cooling mounting member can be made into a simple cylindrical shape without a protrusion, and can be attached and detached integrally with the superconductor. In particular, the cooling mounting member can also serve as a reinforcing ring that surrounds the periphery of the superconductor, so that the magnetic pole structure can be simplified, and at the same time, a magnetic field generator excellent in durability and reliability can be obtained .
Next, according to the invention of aspect 2 , the cooling attachment member does not protrude forward from the magnetic field generation surface of the superconductor. The distance between the inner surface of the tip of the heat insulating container and the magnetic field generating surface of the superconductor can be reduced. Therefore, attenuation due to the distance of the magnetic field captured by the superconductor can be reduced, and the magnetic field generated from the magnetic pole can be strengthened.
Next, according to the invention of aspect 3 , at least a part of the side surface of the superconductor is tapered in cross section, and the side surface fixing portion of the cooling mounting member engages with the taper portion of the superconductor and has a cross section. In this case, by bringing the cooling attachment member closer to the cooling portion, the superconductor is moved through the engagement of the tapered restriction surface of the cooling attachment member and the tapered portion of the superconductor. It is fixed from the side. In this case, the superconductor can be fixed from the side surface of the superconductor through the taper portion of the superconductor by bringing the cooling attachment member closer to the cooling portion. In this case, since the superconductor can be fixed from the side surface only by bringing the cooling attachment member close to the cooling portion, the fixing is easy and the operation such as detachment is easy.
Next, according to the invention of aspect 4 , the side surface fixing portion of the cooling attachment member is characterized in that the superconductor is fixed from the side surface through a material having higher thermal conductivity than the superconductor. When the superconductor is a brittle material such as ceramics, it is preferable not to be mechanically, but to be fixed via a soft material having good thermal conductivity in order to avoid damage to the superconductor. Further, when a gap is formed between the superconductor and the cooling attachment member, the superconductor can be fixed using a heat conductive material as a filler for the gap between the two. Examples of the thermally conductive material include soft low melting point metals such as In, Al, Cu, solder, and wood metal. Moreover, the resin etc. which mixed at least 1 sort (s) of these metals, heat conductive particle | grains, and heat conductive fiber are illustrated.

Next, according to the invention of aspect 5 , the superconductor is manufactured by a melt solidification method, and its main component is RE-Ba-Cu-O (RE is Y, La, Nd, Sm, Eu, Gd, Er, One or more of Yb, Dy, and Ho) are preferable. The RE-Ba-Cu-O-based superconductor synthesized by the melt-solidification method that once heated above the melting point and melted and solidified again has coarse crystal grains and a fine insulating phase in the superconducting parent phase. Has a distributed organization. Since this insulating phase acts as a pinning point for the magnetic field, it becomes easy to obtain a superconductor having a large trapping magnetic field, and the performance as a magnetic field generator is improved.

Furthermore, as in the invention of aspect 6 , it is desirable that the superconductor includes at least one of Ag, Au, Pt, Rh, and Ce. Ag and Au do not react with the superconducting phase and precipitate in the superconducting parent phase, and the mechanical strength of the RE-Ba-Cu-O superconductor, which is a ceramic, is reduced without impairing superconducting properties such as the superconducting transition temperature. Improve. Therefore, the reliability as a magnetic field generator is improved. In addition, the RE-Ba-Cu-O-based superconductor containing Pt, Rh, and Ce has a finer dispersion of the insulating phase in the superconducting phase that is the parent phase, and exhibits a stronger pinning force. Accordingly, the trapping magnetic field of the superconductor is increased and the performance as a magnetic field generator is improved.

Next, the invention of aspect 7 includes a decompression chamber having a target holder for holding a target containing a thin film raw material, a film formation target holder for holding a film formation target, and a magnetic field held in the pressure reduction chamber. And a sputter gun for concentrating plasma near the surface of the target by the action of
Sputtering is performed by concentrating plasma near the surface of the target by the action of a magnetic field emitted from the sputtering gun, and a thin film material emitted from the target is deposited on the surface of the film formation target to form a thin film on the film formation target. In the sputtering film forming apparatus, the sputtering gun is a sputtering film forming apparatus in which a superconducting magnetic field generation device having any one of the various aspects is incorporated.

  As described above, the superconducting magnetic field generator according to each aspect of the invention has a feature that the magnetic field generated from the magnetic pole is extremely strong. By incorporating this into the sputtering gun, the magnetic field on the target surface is strengthened, and a high-performance sputtering film forming apparatus can be realized. The number of sputter guns attached to the sputtering film forming apparatus is not limited to one, but can be applied to a so-called multi-source sputtering film forming apparatus having a plurality of types of targets, and a plurality of sputter guns can be attached. Further, the present invention can also be applied to an opposed sputtering film forming apparatus configured such that a plurality of targets are opposed to each other.

  According to the present invention, since the cooling mounting member includes the side surface fixing portion that fixes the side surface of the superconductor from the outside, the superconductor can be effectively cooled from the side surface, and is further necessary for magnetization. Equipment (superconducting magnet, magnetizing coil, pulse power supply, etc.) can be small, and a high-performance superconducting magnet device having a compact magnetic pole capable of generating a strong magnetic field and a sputtering film forming apparatus using the same can be provided.

  Hereinafter, the best mode for carrying out the invention will be described based on examples.

  FIG. 1 shows a superconducting magnetic field generator 1 according to Embodiment 1 of the present invention. In order to avoid complications, there are parts where hatching is omitted. The superconducting magnetic field generator 1 includes a bulk superconductor 2 that emits a magnetic field by capturing a magnetic field when cooled to a superconducting transition temperature or lower, a cooling device 3 that cools the superconductor 2, and a superconductor 2. The cooling attachment member 4 held in the cooling part 33 of the cooling device 3, and the heat insulating container 5 that accommodates the superconductor 2, the cooling attachment member 4, and the cooling part 33 and has a vacuum heat insulating chamber 50. According to the present embodiment, since the superconductor 2 is coaxially arranged in the heat insulating container 5, the center axis PA of the heat insulating container 5 is aligned with the center axis P of the superconductor 2. The superconductor 2 is manufactured by a melt solidification method, and its main component is RE-Ba-Cu-O (RE is Y, La, Nd, Sm, Eu, Gd, Er, Yb, Dy, Ho. 1 type or more). The superconductor 2 includes at least one of Ag, Au, Pt, Rh, and Ce.

  The superconductor 2 has a cylindrical shape with a required thickness, and has a flat magnetic field generating surface 21 and a flat back surface 23 which are front end surfaces. The magnetic field generating surface 21 of the superconductor 2 faces the inner wall surface of the distal end portion 52 of the heat insulating container 5 through a minute gap 53 that becomes a vacuum, and faces away from the cooling surface 34 of the cooling unit 33. Since the back surface 23 of the superconductor 2 faces the cooling surface 34 of the cooling unit 33, the back surface 23 of the superconductor 2 is cooled. As shown in FIG. 1, the side surface 25 of the superconductor 2 is a cross section passing through the central axis P of the superconductor 2 and is linearly inclined with respect to the central axis P of the superconductor 2 and becomes tapered. Yes. That is, the tapered side surface 25 of the superconductor 2 is formed as a conical inclined surface so that the outer diameter gradually decreases toward the magnetic field generating surface 21 of the superconductor 2. The side surface 25 of the superconductor 2 can be defined as a surface parallel to or parallel to the central axis P perpendicular to the magnetic field generating surface 21 of the superconductor 2.

  As shown in FIG. 1, the cooling device 3 is connected to the cold generator 30, a cold generator 31 called a cold head cooled to a low temperature by the refrigerator 30, and the cold generator 31 via an extension 32. And a cooling unit 33. As the refrigerator 30, a GM refrigerator, a pulse tube refrigerator, a Stirling refrigerator, or the like can be used. The heat insulating container 5 includes a cylindrical wall portion 51 having a cylindrical shape, and a distal end portion 52 that faces the magnetic field generating surface 21 of the superconductor 2 through a gap 53 that becomes a vacuum. The vacuum heat insulation chamber 50 of the heat insulation container 5 is evacuated by a vacuum exhaust system (not shown) and maintained in a high vacuum state, and heat insulation is ensured with respect to the outside.

  The cooling attachment member 4 has a ring-shaped side surface fixing portion 40 that goes around the central axis P of the superconductor 2 so as to fix the side surface 25 of the superconductor 2 from the outside thereof. The cooling attachment member 4 has a flat tip surface 41 that forms a ring shape facing the cooling surface 34 of the cooling unit 33, and a flat facing surface 42 that forms a ring shape that faces the cooling surface 34 of the cooling unit 33. . The cooling attachment member 4 is formed of a material that is larger in thermal contraction due to cooling than the superconductor 2 that is ceramic, generally a metal material (stainless steel or the like). This metal material is non-magnetic so as to form a good magnetic path by the superconductor 2.

  Here, the heat shrinkage amount of the metal cooling attachment member 4 is larger than the heat shrinkage amount of the ceramic superconductor 2. Therefore, based on the difference in heat shrinkage between the cooling mounting member 4 and the superconductor 2 during cooling, the superconductor 2 can be restrained and fixed from the side surface 25 by the side surface fixing portion 40 of the cooling mounting member 4. . In addition, since the outer wall surface 49 of the cooling attachment member 4 is along the central axis P of the superconductor 2 and the cylindrical wall part 51 of the heat insulation container 5, the increase in the diameter of the heat insulation container 5 can be suppressed.

  As shown in FIG. 1, the cooling attachment member 4 does not have a portion that covers the magnetic field generating surface 21 of the superconductor 2. That is, the front end surface 41 of the cooling attachment member 4 and the magnetic field generation surface 21 of the superconductor 2 are the same or substantially the same surface, and the cooling attachment member 4 is more than the magnetic field generation surface 21 of the superconductor 2. It does not protrude forward (arrow Y2 direction) or does not substantially protrude. This is different from the prior art shown in FIG. Here, the front means the direction of magnetic field dissipation from the magnetic field generation surface 21 of the superconductor 2.

  As shown in FIG. 1, the side surface fixing portion 40 of the cooling attachment member 4 has a conical tapered constraining surface 43 that forms an inner peripheral surface. The constraining surface 43 is linearly tapered in a cross section passing through the central axis P of the superconductor 2. The taper angle of the constraining surface 43 of the cooling attachment member 4 and the taper angle of the tapered side surface 25 of the superconductor 2 are set to be the same or substantially the same. Therefore, the taper-shaped restraining surface 43 of the cooling mounting member 4 can be brought into close contact with the taper-shaped side surface 25 of the superconductor 2 and can be brought into close contact with each other, thereby improving the thermal contact property. A thermal contact member such as indium may be interposed between the side surface 25 and the constraining surface 43.

  The cooling attachment member 4 includes a fixing mechanism 45 that pulls and fixes the cooling attachment member 4 toward the cooling unit 33 of the cooling device 3 in the arrow Y1 direction. The fixing mechanism 45 is formed by an attachment portion 46 provided integrally with the cooling attachment member 4 and a nut member 47 as a fastening member that is a separate member from the cooling attachment member 4. As shown in FIG. 1, the mounting portion 46 is a central axis of the superconductor 2 from the facing surface 42 (for example, the lower surface) facing the cooling surface 34 of the cooling portion 33 of the cooling mounting member 4 toward the cooling portion 33. A plurality of protrusions are provided along P. The attachment portion 46 has a male screw portion. For example, the mounting portion 46 can be formed by fixing a bolt member having a male screw portion to the facing surface 42 of the cooling mounting member 4 by welding or the like.

  When the superconductor 2 is held on the cooling surface 34 of the cooling portion 33, first, the attachment portion 46 of the cooling attachment member 4 is inserted into the insertion hole 33 a of the cooling portion 33. Next, the nut member 47 is inserted into the male thread portion of the attachment portion 46 exposed from the insertion hole 33 a via the washer member 48, and the nut member 47 is rotated and fastened to the attachment portion 46. Thereby, the cooling attachment member 4 is detachably fixed to the cooling part 33. Here, when the amount of rotational operation of the nut member 47 is increased to increase the fastening force for fastening the nut member 47 to the attachment portion 46 of the cooling attachment member 4, the direction in which the cooling attachment member 4 approaches the cooling portion 33 (arrow) Y1 direction). As a result, the tapered restraining surface 43 of the cooling mounting member 4 and the tapered side surface 25 of the superconductor 2 can be engaged with each other while enhancing the thermal contact property. As a result, the cooling property of the superconductor 2 can be enhanced through this engagement, and the superconductor 2 can be fixed by the cooling attachment member 4 from the side surface 25 thereof.

  In the state where the superconductor 2 is fixed to the cooling portion 33 as described above, as shown in FIG. 1, the inner end 47 i and the attachment portion 46 of the nut member 47 are in the radial direction (arrow R direction) of the superconductor 2. The cooling attachment member 4 is located on the inner side in diameter than the outer wall surface 49. This is advantageous in reducing the diameter of the magnetic pole. In addition, since the nut member 47 is not located on the outer peripheral side of the cooling attachment member 4 but is located on the lower side of the cooling attachment member 4, this is also advantageous in reducing the diameter of the magnetic pole.

  As shown in FIG. 1, a sheet-like thermal contact member 29 is interposed between the back surface 23 of the superconductor 2 and the cooling surface 34 of the cooling unit 33, thereby improving the thermal contact property between the two. Cooling is promoted. The thermal contact member 29 also extends between the cooling surface 34 of the cooling unit 33 and the opposing surface 42 of the cooling attachment member 4. The thermal contact member 29 has higher thermal conductivity than the superconductor 2 and is made of a soft material (for example, indium).

  In order to generate a magnetic field from the superconductor 2, it is necessary to magnetize the superconductor 2 in advance. As described above, as described above, as described above, the heat insulating container 5 containing the superconductor 2 is inserted into the bore of the ring-shaped superconducting magnet 100 and a static magnetic field is applied. The heat insulating container 5 containing the superconductor 2 is used. There is a method of magnetizing the superconductor 2 with a pulse magnetic field generated by supplying a pulse current from a pulse power source constituted by a capacitor or the like by arranging a ring-shaped magnetizing coil around the coil. In this regard, according to the present embodiment, the cooling mounting member 4 shown in FIG. 1 is different from the above-described superconducting magnet device 1X shown in FIG. The diameter can be reduced, and consequently the diameter of the heat insulating container 5 can be reduced. Therefore, there is an advantage that the diameter of the superconducting magnet 100 necessary for magnetization, the diameter of the magnetizing coil, and the pulse power source can be reduced. In addition, since the magnetic poles can be reduced in size, there can be obtained an advantage that the mounting method and location are not easily restricted when a plurality of magnetic poles are combined or incorporated in an apparatus.

  According to the present embodiment, the cooling attachment member 4 described above has both a function of attaching the superconductor 2 and a function of cooling the superconductor 2. Accordingly, the superconductor 2 is not only cooled from the back surface 23 by the cooling surface 34 of the cooling unit 33 but also from the side surface 25 of the superconductor 2 via the cooling attachment member 4 to the cooling surface 34 of the cooling unit 33. The superconductor 2 can be cooled efficiently and quickly. In addition, as the fixing force of the superconductor 2 is increased by rotating the nut member 47 constituting the fixing mechanism 45 in the screwing direction, the cooling mounting member 4 and the superconductor 2 are moved in the direction of the cooling unit 33 (the direction of the arrow Y1). Therefore, it is possible to obtain a merit that is advantageous in increasing the cooling ability of the superconductor 2.

  Also, when the superconductor 2 is a RE-Ba-Cu-O system, a strong magnetic field can be generated on the c-axis, whereas the thermal conductivity and thermal diffusion coefficient are on the a-axis and b-axis. Is bigger. According to the present embodiment, as shown in FIG. 1, since the restraining surface 43 of the cooling mounting member 4 faces the a and b axes of the superconductor 2, the superconductor 2 can be efficiently cooled. Therefore, the heat generated by the magnetic field change of the superconductor 2 can be quickly removed from the side surface 25 of the superconductor 2 through the cooling attachment member 4, and the superconductor 2 can be efficiently cooled. However, in some cases, the constraining surface 43 of the cooling attachment member 4 may not be opposed to the a-axis and b-axis directions.

  Further, according to the present embodiment, since the cooling attachment member 4 has the fixing mechanism 45 that fixes the cooling attachment member 4 toward the cooling portion 33 side of the cooling device 3 in the arrow Y1 direction, the nut member 47 of the fixing mechanism 45 is rotated. By doing so, the thermal contact property between the tapered constraining surface 43 of the cooling mounting member 4 and the tapered side surface 25 of the superconductor 2 can be enhanced, which is advantageous for cooling the side surface 25 of the superconductor 2.

  In addition, according to the present embodiment, since the mounting portion 46 is connected to the opposing surface 42 (lower surface) of the cooling mounting member 4, the mounting portion 46 is arranged as much as possible inside the cooling mounting member 4 together with the nut member 47. This is advantageous. As a result, the diameter of the cylindrical wall portion 51 of the heat insulating container 5 that accommodates the superconductor 2 and the cooling attachment member 4 can be reduced.

  Further, according to this embodiment, as shown in FIG. 1, the cooling mounting member 4 does not protrude forward (in the direction of the arrow Y <b> 2) from the magnetic field generation surface 21 of the superconductor 2, so the magnetic field generation surface 21 of the superconductor 2. And the tip 53 of the heat insulating container 5 can be made as narrow as possible, and the magnetic field emitted from the superconductor 2 to the outside of the heat insulating container 5 can be strengthened.

  Furthermore, according to the present embodiment, when the fastening force for fastening the cooling member to the attachment part 46 of the cooling attachment member 4 is increased by rotating the nut member 47, the direction in which the cooling attachment member 4 approaches the cooling part 33 (arrow Y1 direction). ). As a result, not only can the thermal contact between the tapered constraining surface 43 of the cooling mounting member 4 and the tapered side surface 25 of the superconductor 2 be improved, but also in the radially inward direction from the cooling mounting member 4 toward the superconductor 2 side. A compressive force toward (in the direction of arrow R1) acts on the side surface 25 of the superconductor 2. Therefore, it is advantageous to suppress the expansion acting on the superconductor 2 by capturing the magnetic field. As a result, generation of cracks in the superconductor 2 can be suppressed, and a higher magnetic field can be generated in the superconductor 2 with high reliability. In particular, as shown in FIG. 1, the tip end surface 41 that covers the magnetic field generation surface 21 side of the cooling attachment member 4 is thick and can exert a large compressive force. Therefore, in the magnetic field generation surface 21 that is likely to start a crack. Contributes to increasing the compression force.

  In addition, according to the present embodiment, since the cooling attachment member 4 is formed of a material that has a larger thermal contraction due to cooling than that of the superconductor 2, when the superconductor 2 is cooled below the critical temperature of the superconductor 2, the cooling attachment member 4 is cooled. Based on the difference in heat shrinkage between the cooling mounting member 4 and the superconductor 2 at the time, the side fixing part 40 of the cooling mounting member 4 can tighten the side surface 25 of the superconductor 2 and the side fixing of the cooling mounting member 4 It is advantageous to increase the degree of fixing the side surface 25 of the superconductor 2 by the portion 40, and also to suppress the expansion acting on the superconductor 2 by capturing the magnetic field.

  A superconducting magnetic field generator 1 according to Embodiment 2 of the present invention is shown in FIGS. The present embodiment basically has the same configuration and operational effects as the first embodiment. Parts having common functions are denoted by common reference numerals. Hereinafter, the description will focus on the different parts. According to this embodiment, the side surface 25 of the superconductor 2 and the restraining surface 43 of the cooling mounting member 4 are along the central axis P. As shown in FIG. 2, the cooling attachment member 4 is formed so as to protrude radially outward at one end of the C-shaped ring-shaped side surface fixing portion 40 having a slit-like gap 40 p and the side surface fixing portion 40. The tongue-shaped first attachment piece 71, the tongue-shaped second attachment piece 72 formed so as to protrude radially outward from the other end of the side surface fixing portion 40, and the insertion hole of the first attachment piece 71 are inserted. A male screw member 73 that functions as a fastening member, and a female screw hole 74 as an attachment hole formed in the second attachment piece 72 so as to screw the male screw member 73 together. A plurality of protrusions 49s distributed in the circumferential direction are formed on the outer wall surface 49 of the side surface fixing portion 40 of the cooling attachment member 4. A mounting portion 46 is connected to the protrusion 49s by welding or the like.

  By screwing the male screw member 73 into the female screw hole 74, the side surface fixing portion 40 of the cooling mounting member 4 contracts in the radially inward direction (arrow R1 direction). Thus, the side surface 25 of the superconductor 2 is tightened, and the superconductor 2 is fixed. The side surface 25 of the superconductor 2 and the constraining surface 43 that is the inner peripheral surface of the cooling attachment member 4 are along the central axis P of the superconductor 2.

  The cooling attachment member 4 includes a fixing mechanism 45 that pulls and fixes the cooling attachment member 4 toward the cooling unit 33 of the cooling device 3 in the arrow Y1 direction. The fixing mechanism 45 is formed by a mounting portion 46 formed of a bolt member provided integrally with the cooling mounting member 4 and a nut member 47 that is a separate body from the cooling mounting member 4. The mounting portion 46 is connected to the protrusion 49s of the cooling mounting member 4 by welding or the like.

  According to this embodiment, between the side surface 25 of the superconductor 2 and the side surface fixing portion 40 of the cooling mounting member 4, the thermal contact member 29B having a soft and high thermal conductivity such as indium is disposed over the entire circumference. Has been. For this reason, when the male screw member 73 for fastening shown in FIG. 2 is fastened to the female screw hole 74 of the cooling attachment member 4, the thermal contact between the superconductor 2 and the cooling attachment member 4 is improved. Further, it is possible to prevent the superconductor 2 from being damaged by mechanical tightening.

  According to the present embodiment, if the fastening force of the male screw member 73 is adjusted, the force for fixing the superconductor 2 from the side surface 25 can be adjusted. In addition, the attachment portion 46 generates a force for fixing the back surface 23 of the superconductor 2 in close contact with the cooling surface 34 of the cooling portion 33. Since the mounting portion 46 and the male screw member 73 are independent of each other, the force for fixing the superconductor 2 from the side surface 25 using the male screw member 73 and the back surface 23 of the superconductor 2 are cooled using the mounting portion 46. It is possible to independently control the force to be brought into close contact with the cooling surface 34 of the portion 33 and fix.

  Also in the present embodiment, the cooling attachment member 4 does not protrude forward (in the direction of the arrow Y2) from the magnetic field generation surface 21 of the superconductor 2. For this reason, the clearance gap 53 maintained between the magnetic field generating surface 21 of the superconductor 2 and the front-end | tip part 52 of the heat insulation container 5 maintained by the vacuum can be made as narrow as possible, and the magnetic field which comes out of the heat insulation container 5 is shown. Can be strengthened.

  FIG. 4 shows a superconducting magnetic field generator 1 according to Embodiment 3 of the present invention. The present embodiment basically has the same configuration and operational effects as the first embodiment. Parts having common functions are denoted by common reference numerals. Hereinafter, the description will focus on the different parts. A ring-shaped cooling attachment member 4 made of a material having a thermal contraction rate larger than that of the superconductor 2 is provided. The cooling attachment member 4 is fitted to the outside of the side surface 25 of the superconductor 2. A thermal contact member 29 </ b> B having good thermal conductivity is disposed between the restraining surface 43 that is the inner peripheral surface of the cooling attachment member 4 and the side surface 25 of the superconductor 2. The cooling attachment member 4 and the superconductor 2 are integrated with a thermal contact member 29 </ b> B interposed therebetween. That is, the cooling attachment member 4 is integrated with the superconductor 2 as a reinforcing member for reinforcing the ceramic superconductor 2 from the outside, and can be handled as a single component. The side surface 25 of the superconductor 2 and the constraining surface 43 of the cooling attachment member 4 are along the central axis P of the superconductor 2.

  The cooling attachment member 4 is formed of a material (for example, stainless steel) that has a larger thermal contraction due to cooling than the superconductor 2. The cooling attachment member 4 includes a fixing mechanism 45 that pulls and fixes the cooling attachment member 4 toward the cooling unit 33 of the cooling device 3 in the arrow Y1 direction. The fixing mechanism 45 includes a female screw hole 77 as a mounting hole formed on the opposing surface 42 of the cooling mounting member 4 that faces the cooling portion 33 and spaced in the circumferential direction of the cooling mounting member 4, and a female screw hole 77. And a mounting portion 46 having a head portion 46a formed of a bolt member having a male screw portion to be screwed together. The mounting portion 46 is separable from the cooling mounting member 4. When the superconductor 2 is held by the cooling portion 33, the male screw portion of the attachment portion 46 is screwed into the female screw hole 77 of the cooling attachment member 4 via the washer member 48, and the head portion 46 a of the attachment portion 46 is turned to attach the attachment portion. 46 male screw portions are detachably fastened to the female screw hole 77.

  In this state, if the superconductor 2 and the cooling mounting member 4 are cooled to a low temperature by the cooling unit 33 of the cooling device 3, the cooling mounting member 4 is thermally contracted in the radial direction (arrow R1 direction). Based on the difference in thermal shrinkage between the member 4 and the superconductor 2, the side surface 25 of the superconductor 2 can be restrained and fixed by the restraining surface 43 of the side surface fixing portion 40 of the cooling attachment member 4. When the cooling attachment member 4 is cooled in this way, a compressive force directed from the cooling attachment member 4 toward the superconductor 2 in the radially inward direction (arrow R1 direction) acts on the side surface 25 of the superconductor 2. Therefore, it becomes advantageous to cancel the expansion force acting on the superconductor 2 by capturing the magnetic field, and a higher magnetic field can be generated more reliably in the superconductor 2.

  Note that the material of the mounting portion 46 can be the same as or similar to the material of the cooling mounting member 4 in order to make the thermal contraction rate of the mounting portion 46 and the cooling mounting member 4 close to each other. Absent.

  In the state where the superconductor 2 is fixed by the cooling mounting member 4 as described above, as shown in FIG. 4, the inner end 46 i of the head portion 46 a of the mounting portion 46 is further in the radial direction of the superconductor 2. In the (arrow R direction), the cooling mounting member 4 is located on the inner side of the outer wall surface 49, and the magnetic pole diameter size can be reduced. As a result, the diameter of the cylindrical wall portion 51 of the heat insulating container 5 can be reduced. Is planned.

  Also in the present embodiment, if the head portion 46a of the attachment portion 46 is turned, the cooling attachment member 4 can be pulled and urged from the cooling portion 33 side in the direction of the arrow Y1, whereby the heat contact member 29 can be urged. The adhesion between the cooling surface 34 of the cooling unit 33 and the cooling attachment member 4 can be increased. Similarly, the adhesion between the cooling surface 34 of the cooling unit 33 and the back surface 23 of the superconductor 2 through the thermal contact member 29 can be increased.

  The cooling attachment member 4 is integrated with the superconductor 2 as a reinforcing member that reinforces the ceramic superconductor 2 from the outside. For this reason, handling of the superconductor 2 becomes easy, and attachment of the superconductor 2 to the cooling part 33 is also easy. Further, the cooling mounting member 4 has a ring shape, and since the shape thereof is simple, the manufacturing cost can be reduced and the advantage of a large cost countermeasure effect can be obtained.

  Also in the present embodiment, as shown in FIG. 4, the cooling attachment member 4 does not have a portion that covers the magnetic field generation surface 21 that is the tip surface of the superconductor 2. That is, the cooling attachment member 4 does not protrude forward (in the direction of the arrow Y2) from the magnetic field generation surface 21 of the superconductor 2. For this reason, the gap 53 between the magnetic field generating surface 21 of the superconductor 2 and the distal end portion 52 of the heat insulating container 5 can be made as narrow as possible, and the magnetic field emitted to the outside of the heat insulating container 5 can be strengthened.

  When the use conditions such as making the magnetic field considerably strong are severe, cracks are often generated on the magnetic field generating surface 21 of the superconductor 2. In this regard, according to the present embodiment, as shown in FIG. 4, the female screw hole 77 that functions as a mounting hole formed in the cooling mounting member 4 is open to the facing surface 42 of the cooling mounting member 4. This is a non-through hole that does not reach the front end surface 41 of the cooling mounting member 4. For this reason, when the cooling mounting member 4 is cooled, when the cooling mounting member 4 exerts a compressive force for tightening the superconductor 2 based on thermal contraction, a compressive force in the vicinity of the front end surface 41 of the cooling mounting member 4 is secured. It is advantageous. For this reason, it is advantageous in suppressing cracks in the magnetic field generating surface 21 that tends to be the starting point of cracks in the superconductor 2.

  Further, although the female screw hole 77 opens at the facing surface 42 of the cooling mounting member 4, the mounting portion 46 enters and is loaded into the hollow female screw hole 77. Therefore, when the cooling mounting member 4 is cooled, when the side surface fixing portion 40 of the cooling mounting member 4 exerts a compressive force that tightens the superconductor 2 inward in the radial direction based on the thermal contraction, the opposing surface 42 of the cooling mounting member 4. It is also advantageous to secure the compression force in the vicinity. Therefore, the compressive force acting on the side surface 25 of the superconductor 2 can contribute to making it act as uniformly as possible in the axial length direction of the superconductor 2, which is advantageous for improving the durability of the superconductor 2.

  The principal part of the superconducting magnetic field generator 1 according to Embodiment 4 of the present invention is shown in FIG. The present embodiment basically has the same configuration and effect as the third embodiment. Parts having common functions are denoted by common reference numerals. Hereinafter, a description will be given centering on portions different from the third embodiment. The cooling attachment member 4 includes a fixing mechanism 45 that pulls and fixes the cooling attachment member 4 toward the cooling unit 33 of the cooling device 3 in the arrow Y1 direction. The fixing mechanism 45 is screwed into the female screw hole 77 and a female screw hole 77 formed on the opposing surface 42 of the cooling mounting member 4 facing the cooling portion 33 and spaced in the circumferential direction of the cooling mounting member 4. And a mounting portion 46 formed of a bolt member having a male screw portion.

  According to the present embodiment, the female screw hole 77 penetrates from the facing surface 42 of the cooling attachment member 4 toward the distal end surface 41, and has an opening 77 m in the distal end surface 41. Therefore, when the vacuum heat insulating chamber 50 of the heat insulating container 5 is exhausted by a vacuum exhaust device (not shown), even if air remains in the boundary area between the female screw hole 77 and the mounting portion 46 of the cooling mounting member 4, the air is discharged. It is advantageous to make it. As a result, it is advantageous for maintaining the degree of vacuum and the vacuum heat insulating property of the vacuum heat insulating chamber 50 of the heat insulating container 5 high.

  Further, as shown in FIG. 5, the tip 46 u of the attachment portion 46 reaches the opening 77 m of the female screw hole 77. That is, the mounting portion 46 enters and is loaded throughout the entire length direction of the hollow female screw hole 77 as the mounting hole. Therefore, when the cooling mounting member 4 is cooled, when the side surface fixing portion 40 of the cooling mounting member 4 exerts a compressive force that tightens the superconductor 2 inwardly based on the thermal contraction, the compressive force is applied to the axis of the superconductor 2. It is possible to contribute to making it work as uniformly as possible in the long direction, which is advantageous for improving the durability of the superconductor 2.

  The principal part of the superconducting magnetic field generator 1 according to Embodiment 5 of the present invention is shown in FIGS. The present embodiment basically has the same configuration and operational effects as the first embodiment. Hereinafter, a description will be given centering on portions different from the first embodiment. Parts having common functions are denoted by common reference numerals. The cooling attachment member 4 includes an extension portion 4e that also serves as a cold head extension portion that extends toward the cooling portion 33, a side surface fixing portion 40 that forms a ring shape that is integrally formed at the tip (upper end) of the extension portion 4e, and an extension. It is formed with a hook-shaped fixing portion 4f formed integrally with the other end of the portion 4e. The outer diameter of the side surface fixing portion 40 of the cooling attachment member 4 is larger than the outer diameter of the extension portion 4e. The fixing part 4f of the cooling attachment member 4 is fixed to the cooling part 33 by a fixing tool 4h. The cooling attachment member 4 is made of a material having a larger thermal contraction rate than the superconductor 2 and has a holding hole 80 having a shape corresponding to the superconductor 2. The holding hole 80 opens toward the tip 52 of the heat insulating container 5 and has a bottom wall surface 80b and a circular inner wall surface 80f.

  When the superconductor 2 is attached, the superconductor 2 is fitted into the holding hole 80 of the side surface fixing portion 40 of the cooling attachment member 4. In this case, in consideration of the fitting property of the superconductor 2, it is preferable that a minute gap 80 k is formed between the inner wall surface 80 f of the holding hole 80 and the side surface 25 of the superconductor 2. At the time of mounting, when the cooling mounting member 4 and the superconductor 2 are cooled by the cooling device 3 with the superconductor 2 fitted in the holding hole 80, the side surface fixing portion 40 of the cooling mounting member 4 is in the radial direction (the direction of the arrow R1). And the superconductor 2 can be fixed from the side surface 25 by the restraining surface 43 of the side surface fixing portion 40. The superconductor 2 has a center axis P at the intersection of the center lines M1 and M2.

  When the superconductor 2 is removed from the cooling attachment member 4, if the cooling attachment member 4 is heated to a normal temperature region or the like, the side surface fixing portion 40 of the cooling attachment member 4 expands in the radially outward direction (arrow R2 direction). Since the thermal expansion amount of the metal cooling attachment member 4 is larger than the thermal expansion amount of the ceramic superconductor 2, the superconductor 2 can be removed from the side surface fixing portion 40 of the cooling attachment member 4.

  Furthermore, as shown in FIG. 7, since the cooling attachment member 4 is formed with a communication hole 81 that allows the inside and outside of the holding hole 80 of the cooling attachment member 4 to communicate with each other, the inside / outside communication of the holding hole 80 is ensured. The operation of removing the cooling attachment member 4 from the holding hole 80 of the cooling attachment member 4 becomes easy. Further, when the superconductor 2 is fitted into the holding hole 80 of the cooling attachment member 4, the air remaining in the holding hole 80 can be discharged out of the holding hole 80 through the communication hole 81, and the vacuum insulation of the heat insulating container 5 is achieved. This is advantageous for maintaining the degree of vacuum and the vacuum heat insulation of the chamber 50 high. If the inner diameter of the communication hole 81 is a required amount, a needle-like jig is inserted into the communication hole 81 from the outside of the holding hole 80, and the back surface 23 of the superconductor 2 in the holding hole 80 is pressed by the jig. In this case, the work of removing the superconductor 2 can be further facilitated.

  Also in the present embodiment, as shown in FIG. 7, the cooling attachment member 4 does not have a portion that covers the magnetic field generation surface 21 of the superconductor 2. That is, the cooling attachment member 4 does not protrude forward (in the direction of the arrow Y2) from the magnetic field generation surface 21 of the superconductor 2. For this reason, the gap 53 between the magnetic field generating surface 21 of the superconductor 2 and the distal end portion 52 of the heat insulating container 5 can be made as narrow as possible, and the magnetic field emitted to the outside of the heat insulating container 5 can be strengthened.

  The principal part of the superconducting magnetic field generator 1 according to Embodiment 6 of the present invention is shown in FIGS. The present embodiment basically has the same configuration and operational effects as the first embodiment. Parts having common functions are denoted by common reference numerals. Hereinafter, a description will be given centering on portions different from the first embodiment. According to the present embodiment, in the cross section passing through the central axis PA of the heat insulating container 5, the magnetic field generating surface 21 of the superconductor 2 is directed in a direction intersecting with the central axis PA of the heat insulating container 5 (for example, an orthogonal direction). ing. That is, as shown in FIG. 8, the central axis P of the superconductor 2 and the central axis PA of the heat insulating container 5 intersect each other.

  The cooling attachment member 4 includes an extension portion 4e that also serves as a cold head extension portion that extends toward the cooling portion 33, a side surface fixing portion 40 that forms a ring shape integrally formed with one end (upper end) of the extension portion 4e, and an extension. It is formed with a fixing portion 4f having a hook shape formed integrally with the other end (lower end) of the portion 4e. As shown in FIG. 9, the side surface fixing part 40 has a bifurcated shape, and has a first piece part 40a and a second piece part 40b that form a gap 40p in a part in the circumferential direction. The constraining surface 43 of the first piece 40a and the constraining surface 43 of the second piece 40b each have a semicircular shape. The mounting portion 46, which is a bolt member inserted through the insertion hole 40c of the first piece portion 40a, is screwed into the female screw hole 40d of the second piece portion 40b, and the gap 40p is shortened to connect the first piece portion 40a and the second piece portion 40b. By bringing them close to each other, the cylindrical superconductor 2 is fixed from the side surface 25 thereof. As shown in FIG. 8, the superconductor 2 is fixed only by the side surface 25 thereof, and the surface of the cooling mounting member 4 does not protrude outward from the magnetic field generating surface 21 of the superconductor 2.

  As shown in FIG. 8, the heat insulating container 5 includes a cylindrical first cylindrical wall portion 51 a having a relatively large diameter and a second cylindrical wall portion 51 b having a distal end portion 52 and a relatively small size. According to the present embodiment, the magnetic field generating surface 21 of the superconductor 2 is oriented in a direction intersecting with the central axis PA of the heat insulating container 5 (for example, a direction orthogonal thereto). A strong magnetic field can be generated on both sides of the portion 51b. As shown in FIG. 8, the second cylindrical wall portion 51 b has a flat cylindrical shape, and includes a wall 51 s facing the magnetic field generating surface 21 of the superconductor 2 and a wall 51 t facing the back surface 23 of the superconductor 2. Have.

  In the embodiment described above, the root portion of the first piece portion 40a and the root portion of the first piece portion 40b are integrated as shown in FIG. 9, but as in the other embodiment shown in FIG. The one piece portion 40a and the second piece portion 40b may be separated from each other to have a separable structure. In this case, as shown in FIG. 11, the mounting portion 46, which is a bolt member inserted into the insertion hole 40c of the first piece 40a, is screwed into the female screw hole 40d of the second piece 40b, and the first piece 40a Another mounting portion 46B, which is a bolt member inserted through the insertion hole 40m, is screwed into the female screw hole 40n of the second piece 40b. Thus, the first piece portion 40a and the second piece portion 40b are brought close to each other, and the superconductor 2 is fixed from the side surface 25 thereof. In this state, both the magnetic field generating surface 21 and the back surface 23 of the superconductor 2 face the vacuum heat insulating chamber 50.

  Embodiment 7 of the present invention is shown in FIG. This embodiment is an example applied to a magnetron sputtering film forming apparatus. The present embodiment basically has the same configuration and operational effects as the first embodiment. Parts having common functions are denoted by common reference numerals. Hereinafter, a description will be given centering on portions different from the first embodiment. As shown in FIG. 12, the sputtering film forming apparatus 200 includes a base 202, a decompression chamber 204 having a film forming chamber 203 installed on the upper side of the base 202 and maintained in a decompressed state by a pump (not shown), and a magnetic field. Thus, the superconducting magnetic field generator 1 serving as a sputter gun for concentrating the plasma 310 near the surface of the target 206 is provided. The decompression chamber 204 is provided at the upper part of the film forming chamber 203 so as to hold the target holder 207 provided at the lower part of the film forming chamber 203 so as to hold the target 206 containing the thin film raw material and the film forming object 208. A film formation object holder 209. An insertion space 212 is formed below the target 206.

  The superconducting magnetic field generator 1 cools the superconductor 2 with a superconductor 2 that generates a magnetic field outside by supplementing the magnetic field below the superconducting transition temperature, a heat insulating container 5 having a vacuum heat insulating chamber 50 that accommodates the superconductor 2. A cooling device 3 having a cooling unit 33 for performing the above operation, and a ferromagnetic body 9 for correcting the distribution shape of the magnetic field emitted from the superconductor 2. The cooling device 3 is provided in the lower part of the heat insulating container 5, and an elevating part 38 having a traveling wheel or 38 x is provided in the lower part of the cooling device 3. The raising / lowering part 38 raises / lowers the heat insulation container 5 which accommodates the superconductor 2 in the arrow Y1, Y2 direction, and is comprised with the jack.

  As shown in FIG. 12, the ferromagnetic body 9 is formed by a ring yoke 91 disposed on the outer peripheral side of the superconductor 2 and a back yoke 92 disposed on the back surface 23 side of the superconductor 2. The ring yoke 91 is held in the decompression chamber 204. The back yoke 92 is attached to the back surface 23 side of the superconductor 2 in the superconducting magnetic field generator 1. Examples of the material of the ring yoke 91 and the back yoke 92 include permendur (Fe—Co—V system), electromagnetic soft iron (Fe), silicon steel sheet (Fe—Si system), sendust (Fe—Si—Al), and the like. .

  As shown in FIG. 12, although the wall portion of the heat insulating container 5 exists between the inner peripheral surface of the ring yoke 91 and the outer peripheral surface of the superconductor 2, other members such as magnetized coils are interposed. Absent. For this reason, the inner peripheral surface of the ring yoke 91 is brought close to the outer peripheral surface of the superconductor 2 in the radial direction thereof, or the inner peripheral surface of the ring yoke 91 is separated from the outer peripheral surface of the superconductor 2 in the radial direction thereof. The degree of freedom of arranging the ring yoke 91 with respect to the superconductor 2 can be increased.

  When the above-described superconducting magnetic field generator 1 is detachably assembled to the sputtering film forming apparatus 200, the superconducting magnetic field generator 1 having the superconductor 2 made of a superconducting bulk magnet is inserted into the decompression chamber 204 as shown in FIG. It is arranged below the space 212. Next, the elevating part 38 is moved up to raise the heat insulating container 5 together with the superconductor 2 in the direction of the arrow Y2, the distal end 52 of the heat insulating container 5 is inserted into the insertion space 212, and the front end 52 of the heat insulating container 5 is moved to the target holder. Approach or contact 207. In this way, the magnetic circuit 300 by the magnetic field of the superconductor 2 is formed in the vicinity of the target 206 in the film forming chamber 203.

At the time of film formation, first, the film formation chamber 203 is evacuated to a high vacuum (for example, 10 ⁻⁶ Torr level) by an unillustrated vacuum exhaust system so that no impurity gas remains. Next, while evacuating, a sputtering gas is introduced from a gas introduction port (not shown) to make an atmosphere of a sputtering gas of, for example, several millitorr. In this state, a predetermined voltage (for example, several KV) is applied between the target 206 and the film formation target 208. In this case, generally, a voltage is applied so that the target 206 is negative and the film formation target 208 is positive. Thereby, plasma discharge is generated in the film forming chamber 203. Electrons in the plasma 310 move by a magnetic field and ionize sputter gas molecules (generally, but not limited to argon). Since the plasma-like sputter gas ions are focused on the surface of the target 206 under the influence of the magnetic field, they are accelerated and collide with the surface of the target 206. Thus, the target material is sputtered from the surface of the target 206 and deposited on the surface of the film formation target 208, and a thin film can be formed on the film formation target 208 at a high film formation rate. In this case, there is an advantage that the plasma 310 can be concentrated near the target 206 by the strong magnetic field of the superconductor 22. Therefore, high-vacuum discharge is possible in the film formation chamber 203, the film formation speed can be improved, impurities in the thin film are reduced, the film formation quality of the thin film is improved, and the productivity is improved. Can do.

  As shown in FIG. 12, also in the present embodiment, the cooling attachment member 4 does not substantially protrude forward (in the direction of the arrow Y <b> 2) from the magnetic field generation surface 21 of the superconductor 2. For this reason, the gap 53 between the magnetic field generating surface 21 of the superconductor 2 and the tip 52 of the heat insulating container 5 can be made as small as possible, the magnetic field emitted to the outside of the heat insulating container 5 can be strengthened, and plasma-like sputtering is performed. It is advantageous to focus the gas ions near the surface of the target 206. Note that the voltage is applied so that the target 206 is negative and the film formation target 208 is positive. However, the present invention is not limited to this, and an AC voltage is applied between the target 206 and the film formation target 208. May be.

  FIG. 13 shows a cooling attachment member 4 in which the superconductor 2 mounted on the sputtering film forming apparatus 200 is integrated. As shown in FIG. 13, the gap between the side surface 25 of the superconductor 2 and the cooling mounting member 4 is filled with a heat conductive member 65 (trade name: stycast), and the superconductor 2 is fixed from the side surface 25 thereof. The superconductor 2 and the cooling attachment member 4 are integrated. The heat conductive member 65 is made by mixing a ceramic or a fine metal such as alumina having a good heat conductivity in a resin. In some cases, the heat conductive member 65 may be formed of indium.

  At the time of cooling, the amount of heat shrinkage of the metal cooling attachment member 4 is larger than the amount of heat shrinkage of the ceramic superconductor 2, so that when the cooling attachment member 4 heat shrinks in the radial direction (arrow R1 direction), the heat shrinkage occurs. The compressive force accompanying the above acts from the side surface 25 of the superconductor 2. A female screw hole 77 is formed in the cooling attachment member 4. The female screw hole 77 penetrates from the facing surface 42 to the front end surface 41 of the side surface fixing portion 40 of the cooling attachment member 4.

  According to the present embodiment, as shown in FIG. 12, the mounting portion 46 formed of a bolt member is inserted into the insertion hole of the cooling portion 33 and the mounting hole 92m of the back yoke 92, and the male screw portion of the mounting portion 46 is cooled. By screwing into the female screw hole 77 of the mounting member 4, the cooling mounting member 4 is pulled in the direction of the arrow Y <b> 1 by the screwing operation of the mounting portion 46 from the cooling unit 33 side and fixed together with the superconductor 2.

  This magnetron sputtering film forming apparatus is an apparatus that forms a thin film by performing sputtering by concentrating the plasma 310 near the surface of the target 206 by the action of a magnetic field. The stronger the magnetic field, the more concentrated the plasma in the vicinity of the target 206. As a result, the film deposition speed is improved, the film is formed at a high vacuum, and the damage of the thin film formed on the film formation object is reduced. Is obtained.

  The distribution of magnetic lines of force in the vicinity of the surface of the target 206 is as shown in FIG. 12, and applying as strong a magnetic field as possible to the surface of the target 206 leads to improved performance as a sputtering film forming apparatus. For this reason, the magnetic poles and yokes that generate the magnetic field are arranged as close to the target 206 as possible so that as much magnetic flux as possible is generated on the target 206.

  Problems of the sputtering film forming apparatus using the conventional superconducting magnetic field generator 1X shown in FIG. 14 are as follows. Since the ring yoke 91 is disposed outside the heat insulating container 5, the ring yoke 91 can be brought close to the back surface of the target holder 207 to which the target 206 is attached. On the other hand, since the superconductor 2 is accommodated in the heat insulating container 5, it cannot approach the back surface of the target holder 207 by the thickness of the heat insulating container 5 and the gap 53. According to the conventional superconducting magnetic field generator 1 shown in FIG. 14, the gap 53 between the magnetic field generating surface 21 of the superconductor 2, the heat insulating container 5, and the tip 52 is wide, so that of the magnetic field generated from the superconductor 2, The ratio of being absorbed by the ring yoke 91 without increasing on the surface of the target 206 increases. Therefore, there is a problem that the magnetic field on the surface of the target 206 is not so strong although a large magnetic field is captured in the superconductor 2. Therefore, the magnetic field trapped by the superconductor 2 cannot be used effectively for plasma concentration.

  In this respect, according to the present embodiment, as described above, the gap 53 between the magnetic field generating surface 21 of the superconductor 2 and the tip 52 of the heat insulating container 5 can be narrowed, so that the magnetic field on the surface of the target 206 is made stronger. can do. That is, the magnetic field captured by the superconductor 2 can be effectively used for the concentration of the plasma 310, and the performance of the sputtering film forming apparatus can be improved.

(Confirmation experiment)
A sputtering film forming apparatus equipped with a superconducting magnetic field generator according to a conventional example shown in FIG. 14 using an Sm-based superconductor 2 having a diameter of 60 mm and magnetized under the same conditions, and a sputtering film forming apparatus shown in FIG. The horizontal magnetic field strength of the surface of the target 206 was compared. Although it was 0.9T (Tesla) in the conventional example, it improved to 1.0T (Tesla) in this example. As a result, the magnetic field captured by the superconductor 2 can be effectively used for plasma concentration, and the performance of the sputtering film forming apparatus can be improved.

(Other examples)
According to the first embodiment described above, the cooling attachment member 4 does not protrude forward (in the direction of the arrow Y2) from the magnetic field generation surface 21 of the superconductor 2 or does not substantially protrude, but the cooling attachment member Since the fact that the front end surface does not protrude forward from the magnetic field generating surface of the superconductor corresponds to claim 2, the side fixing portion 40 of the cooling mounting member 4 is provided on the side surface 25 of the superconductor 2 as the invention of claim 1. As long as it contacts and fixes this, the cooling attachment member 4 may protrude from the magnetic field generating surface 21 of the superconductor 2 as long as it is a minute amount (in the direction of the arrow Y2). In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within a range not departing from the gist.

  The superconducting magnetic field generator of the present invention is not limited to a sputtering film forming apparatus, but can also be used for a strong magnetic field utilization apparatus such as a magnetic separation apparatus, a magnetic field press machine, a nuclear magnetic resonance apparatus, a generator, and a motor.

1 is a cross-sectional view schematically showing a superconducting magnetic field generator according to Example 1. FIG. It is a top view which shows typically the cooling attachment member of the state which concerns on Example 2 and attached the superconductor. FIG. 4 is a cross-sectional view of the superconducting magnetic field generation device according to the second embodiment and is a cross-sectional view taken along arrows W3-W3 in FIG. FIG. 9 is a cross-sectional view schematically showing a superconducting magnetic field generator according to Example 3. It is sectional drawing which concerns on Example 4 and shows typically the principal part of a superconducting magnetic field generator. It is a top view of the cooling attachment member in the state which concerns on Example 5 and attached the superconductor. FIG. 10 is a cross-sectional view schematically showing a superconducting magnetic field generator according to Example 5. FIG. 10 is a cross-sectional view schematically showing a superconducting magnetic field generator according to Example 6. It is sectional drawing of a different direction concerning the Example 6 in the principal part of a superconducting magnetic field generator. FIG. 10 is a cross-sectional view schematically showing the main part of a superconducting magnetic field generator viewed from the direction of arrow W10 in FIG. 9 according to Example 6. It is sectional drawing which shows typically the principal part of the superconducting magnetic field generator which concerns on the other form of Example 6. FIG. It is sectional drawing which shows typically the state which concerns on Example 7 and was assembled | attached to the sputtering film-forming apparatus so that attachment or detachment of the superconducting magnetic field generator was possible. It is a perspective view of the cooling attachment member of the state which attached the superconductor. It is sectional drawing which shows typically the superconducting magnetic field generator which concerns on a prior art example.

Explanation of symbols

  In the figure, 1 is a superconducting magnetic field generator, 2 is a superconductor, 21 is a magnetic field generating surface, 23 is a back surface, 25 is a side surface, 3 is a cooling device, 33 is a cooling unit, 4 is a cooling mounting member, and 40 is a side fixing unit. , 41 is a front end surface, 42 is an opposing surface, 45 is a fixing mechanism, 5 is a heat insulating container, 50 is a vacuum heat insulating chamber, 51 is a cylindrical wall portion, 52 is a front end portion, 200 is a sputtering film forming apparatus, 202 is a base, Reference numeral 203 denotes a film formation chamber, 204 denotes a decompression chamber, 206 denotes a target 206, 207 denotes a target holder, 208 denotes a film formation target, and 209 denotes a film formation target holder.

Claims (7)

A superconductor that cools below the superconducting transition temperature and emits a magnetic field to the outside;
A cooling device having a cooling unit for cooling the superconductor;
A cooling attachment member for holding the superconductor in the cooling part of the cooling device;
In a superconducting magnetic field generator comprising a heat-insulating container that houses the superconductor and the cooling mounting member,
The cooling mounting member is
A superconducting magnetic field generation device comprising a side fixing portion for fixing the superconductor from a side surface, and having a fixing mechanism for fixing the cooling attachment member by pulling it toward the cooling portion of the cooling device. 2. The superconducting magnetic field generation device according to claim 1, wherein the front end surface of the cooling attachment member does not protrude forward from the magnetic field generation surface of the superconductor. In claim 1 or claim 2, at least a part of the side surface of the superconductor is tapered in cross section, and
  The side fixing portion of the cooling mounting member engages with a tapered portion of the superconductor and has a constraining surface tapered in cross section,
  Fixing the superconductor from the side surface of the cooling attachment member by engaging the tapered constraining surface and the tapered portion of the superconductor by bringing the cooling attachment member closer to the cooling portion. A superconducting magnetic field generator. In any one of Claims 1-3, the said side surface fixing | fixed part of the said cooling attachment member is the said superconductor from this side via the material whose heat conductivity is higher than the said superconductor. A superconducting magnetic field generator characterized by being fixed. 5. The superconductor according to claim 1, wherein the superconductor is manufactured by a melt solidification method, and a main component thereof is RE-Ba-Cu-O (RE is Y, La, Nd, Sm). , Eu, Gd, Er, Yb, Dy, and Ho)). 6. The superconducting magnetic field generator according to claim 5, wherein the superconductor includes at least one of Ag, Au, Pt, Rh, and Ce. A decompression chamber having a target holder for holding a target containing a thin film material, and a film formation target holder for holding a film formation target;
  A sputtering gun for concentrating the plasma near the surface of the target by the action of a magnetic field held in the decompression chamber;
  Sputtering is performed by concentrating plasma in the vicinity of the surface of the target by the action of a magnetic field emitted from the sputter gun, and a thin film material released from the target is deposited on the surface of the film formation target to form the film formation target. In a sputtering film forming apparatus for forming a thin film on an object,
  A sputtering film forming apparatus, wherein the sputter gun incorporates a superconducting magnetic field generating apparatus according to any one of claims 1 to 6.

Images