JP2006351592A - Superconducting magnetic field generator, its exciting method and sputtering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a superconducting magnetic field generator in which arcade-like magnetic field distribution is widely formed in front of a superconductor, and plasma can widely be distributed in front of the superconductor, and which is advantageous for improving the use efficiency of a target even if the generator is applied to a sputtering device, and to provide an exciting method of the superconducting magnetic field generator and the sputtering device. <P>SOLUTION: The superconducting magnetic field generator is provided with the superconductor 10 generating a magnetic field to an external part by cooling the generator to a temperature not higher than a superconductivity transition temperature and acquiring the magnetic field, a cooling means 202 for cooling the superconductor 10 and a heat insulation vessel 30 which stores the superconductor 10. In the superconductor 10, a first region 1 having supercurrent which flows back to one direction, and a second region 2 having supercurrent which flows back in a direction opposite to the first region alternately, exist as it goes outside from the center of the superconductor 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a superconducting magnetic field generator, a method for exciting a superconducting magnetic field generator, and a sputtering apparatus.

  Patent Documents 1 and 2 disclose a magnetron sputtering film forming apparatus using a superconducting bulk magnet as a sputtering gun instead of a permanent magnet.

  The feature of this equipment is that it generates a strong magnetic field 10 times or more on the target surface and concentrates the plasma on the target surface, thereby enabling high-speed film formation and low sputtering compared to sputtering equipment using permanent magnets. Gas pressure film formation, low damage film formation, etc. can be performed.

  In this case, an arcade-like magnetic field distribution is formed on the front surface of the target, exits from the center of the target, exits the front surface, draws a loop, and returns to the periphery. A high-density plasma is generated in this arcade-like strong magnetic field, and ions of the sputtering gas (usually argon gas) in the plasma collide with a target having a negative potential, and a portion facing the target plasma is sputtered.

In the sputter gun using the superconducting bulk disclosed in the above-mentioned document, a superconductor cooled by a refrigerator is magnetized in one direction, and this is used as a central electrode, and a ferromagnetic material is disposed around the central magnetic pole. An arcade-like magnetic field distribution that exits and enters the surrounding magnetic pole is realized.
JP 2004-91872 A JP 2003-289334 A

  However, this has the following problems. In other words, since the superconductor is the central magnetic pole and the ferromagnetic body is the surrounding magnetic pole, the arcade-like magnetic field connects the superconductor and the ferromagnetic body outside the superconductor when observed in the radial direction of the target. Formed. As a result, the consumable part used for sputtering out of the target area is mainly only the part outside in the radial direction from the outer peripheral edge of the superconductor, and the use efficiency of the target is poor, and the film forming speed is sufficient. It wasn't. The use efficiency of the target was poor in the area inside the outer periphery of the superconductor in the target area.

  The present invention has been made in view of the above situation, and an arcade-like magnetic field distribution is widely formed on the front surface of the superconductor, and plasma can be widely distributed on the front surface of the superconductor, and is applied to a sputtering apparatus. Even so, it is an object of the present invention to provide a superconducting magnetic field generator, an excitation method for the superconducting magnetic field generator, and a sputtering apparatus that are advantageous for increasing the use efficiency of the target.

  The superconducting magnetic field generator according to the present invention of aspect 1 includes a superconductor that is cooled to a superconducting transition temperature and captures the magnetic field to generate a magnetic field to the outside, a cooling means that cools the superconductor, and a heat insulation that houses the superconductor. In the superconducting magnetic field generator including the container, the superconductor includes a first region having a superconducting current circulating in one direction and a second region having a superconducting current circulating in the opposite direction to the first region. It is characterized by being alternately present from the center toward the outside. Circulation means that the superconducting current flows endlessly inside the superconductor. In this case, the first region having the superconducting current circulating in one direction and the second region having the superconducting current circulating in the opposite direction to the first region are alternately present from the center of the superconductor to the outside. Therefore, an arcade-like magnetic field distribution is widely formed on the front surface of the superconductor, and plasma can be widely distributed on the front surface of the superconductor.

  The exciting method of the superconducting magnetic field generator according to the present invention of aspect 2 is an exciting method for exciting the superconducting magnetic field generator according to any one of the above claims, wherein the magnetic field 1 in one direction and the A superconductor is magnetized by alternately applying a unidirectional magnetic field and a reverse magnetic field 2. In this case, the first region and the second region can be magnetized so as to be alternately present from the center of the superconductor toward the outside.

  A sputter gun according to the present invention of aspect 3 is a sputter gun using the superconducting magnetic field device according to any one of the above-mentioned claims, and is an arcade-like shape by a superconducting current circulating in the first region and the second region. Or a superconducting current circulating in the first region or the second region and an arcade-like magnetic field distribution by a ferromagnetic material is formed on the front surface of the target. In this case, an arcade-like magnetic field distribution is easily spread in the radial direction on the front surface of the superconductor. Therefore, when sputtering, the region inside the outer periphery of the superconductor of the target can be sputtered or a plurality of regions sputtered on the front surface of the target can be formed, so that the sputtered region (erosion region) on the front surface of the target is widened. be able to.

  The sputtering apparatus according to the present invention of aspect 4 has a target including a thin film raw material and a sputter gun, and performs sputtering by concentrating plasma near the surface of the target by the action of a magnetic field generated from the sputter gun. In a sputtering apparatus for forming a thin film by depositing a thin film raw material on the surface of a substrate, the superconducting magnetic field generator according to any one of the claims is incorporated in the sputter gun. It is a feature. In this case, an arcade-like magnetic field distribution is easily spread in the radial direction on the front surface of the superconductor. Therefore, when sputtering, the area (erosion area) sputtered on the front surface of the target can be expanded.

  According to the present invention, in the superconductor, a first region having a superconducting current that circulates in one direction and a second region having a superconducting current that circulates in a direction opposite to the first region are outward from the center of the superconductor. It exists alternately as you go. For this reason, an arcade-like magnetic field distribution is formed on the front surface of the superconductor, and plasma can be widely distributed on the front surface of the superconductor.

  The superconducting magnetic field generator according to the present invention includes a superconductor, a cooling means for cooling the superconductor, and a heat insulating container for housing the superconductor. In a superconductor, first regions having a superconducting current that circulates in one direction and second regions having a superconducting current that circulates in the opposite direction to the first region are alternately present from the center of the superconductor toward the outside. ing. Therefore, an arcade-like magnetic field distribution is widely formed on the front surface of the superconductor, and plasma can be widely distributed on the front surface of the superconductor. Here, the first region may be one of the inner region and the outer region in the superconductor, and the second region may be the other of the outer region and the inner region in the superconductor. As the cooling means, a liquid or gas refrigerant such as nitrogen, oxygen, argon, neon, hydrogen, or helium may be used, or a refrigerator such as a GM refrigerator, a pulse tube refrigerator, or a Stirling refrigerator may be used. Alternatively, a method of circulating the refrigerant by cooling with a refrigerator may be used.

  According to the present invention, the magnetic field generated from the superconductor has an arcade-like magnetic field distribution that extends from the first region to the second region and reaches the boundary between the first region and the second region. The form to form can be illustrated. Also, a plurality of boundaries between the first region and the second region are provided, and an arcade-like magnetic field distribution returning from the first region to one boundary and an arcade shape returning from one boundary to the other boundary A form in which another magnetic field distribution is formed outside the heat insulating container can be exemplified. Thus, an arcade-like magnetic field distribution is widely formed on the front surface of the superconductor, and plasma can be widely distributed on the front surface of the superconductor.

  According to the present invention, the ferromagnetic material is disposed around the superconductor, and at least a part of the ferromagnetic material is disposed in a ring shape so as to surround the side surface of the superconductor. Can be illustrated. In this case, an arcade-like magnetic field distribution region tends to expand in the radial direction on the front surface of the superconductor. Therefore, when applied to sputtering, a sputtered region (erosion region) is widened on the front surface of the target. Furthermore, since such a magnetic circuit is configured, the magnetic field distribution is enhanced on the front surface of the superconductor. Therefore, since the leakage magnetic field to the part other than the front surface of the superconductor is reduced, safety can be further increased. As a ferromagnetic material, the form which is accommodated in the inside of a heat insulation container and is a yoke which consists of a soft magnetic material can be illustrated. As a ferromagnetic material, the form which is accommodated in the inside of a heat insulation container and the ferromagnetic material part arrange | positioned so that the side surface of a superconductor among ferromagnetism may be surrounded can be illustrated.

  In exciting the above-described superconducting magnetic field generator, a form in which a superconductor is magnetized by alternately applying a magnetic field 1 in one direction and a magnetic field 2 in the opposite direction to the magnetic field can be exemplified. When the permanent magnet is disposed so as to surround the outer peripheral side surface of the superconductor, the magnetic field 1 in one direction and the magnetic field 2 in the opposite direction are alternately applied to attach the superconductor and the permanent magnet together. Can be magnetized. Here, after applying the magnetic field 1 in one direction, the superconductor can be magnetized by applying the magnetic field 2 in the opposite direction.

  A sputtering apparatus using the above-described superconducting magnetic field apparatus, wherein an arcade-like magnetic field distribution by a superconducting current circulating in the first region and the second region, or an arcade-like magnetic field by a superconducting current circulating in the first region or the second region. Examples include a magnetic field distribution, or a form in which a superconducting current circulating in the first region or the second region and an arcade-like magnetic field distribution by a ferromagnetic material are formed on the front surface of the target. Thereby, plasma can be widely distributed on the front surface of the superconductor. In this case, a form in which a plurality of target-like magnetic field distributions are formed on the front surface of the target can be exemplified.

  According to the present invention, there is provided a target including a thin film raw material and a sputter gun. The plasma is concentrated near the surface of the target by the action of a magnetic field emitted from the sputter gun, and the thin film raw material is released. In a sputtering apparatus in which a thin film is formed by being deposited on the surface of a material, the sputtering gun can be exemplified by a form in which the superconducting magnetic field generating apparatus described in any one of the above claims is incorporated. Plasma can be widely distributed on the front surface of the superconductor, which is advantageous in increasing the use efficiency of the target even when applied to a sputtering apparatus.

  Hereinafter, Example 1 of the present invention will be described in detail with reference to FIGS. The superconducting magnetic field generator includes a superconductor 10 that cools below the superconducting transition temperature and captures the magnetic field to generate an external magnetic field, a cooling means 20 that cools the superconductor 10, and a heat insulating container 30 that houses the superconductor 10. including. The heat insulating container 30 is cooled by the cooling means 20 and has a side wall 31 and a tip wall 32. P1 represents the center line of the superconductor 10.

  The cooling means 20 has a refrigerator 21 and a cold head 22 having a cooling function provided at the tip of the refrigerator 21 via a part 22a of the refrigerator component. The superconductor 10 has a cylindrical shape. In the superconductor 10, a first region 1 having a superconducting current that circulates in one direction and a second region 2 having a superconducting current that circulates in the opposite direction to the first region 1 are arranged in the radial direction from the center of the superconductor 10. As they go to the outside, that is, they are alternately adjacent in the radial direction of the superconductor 10. That is, the superconductor 10 includes an inner region composed of the first region 1 and an outer region composed of the second region 2. The “•” in the circle means that the superconducting current flows from the other side of the page of FIG. 1 to the front side of the page. The “x” mark in the circle means that it flows from the front side of the page of FIG. 1 to the other side of the page.

  As shown in FIG. 1, a superconductor 10 is accommodated in a heat-insulated container 30 evacuated to a vacuum, and the superconductor 10 is fixed to a cold head 22 of a refrigerator 21. The superconductor 10 is manufactured by a melting method, and its main component is RE-Ba-Cu-O (RE is one or more of Y, La, Nd, Sm, Eu, Gd, Er, Yb, Dy, and Ho. ) Is preferable. In this regard, the RE-Ba-Cu-O-based superconductor 10 synthesized by a melting method that is once heated to a melting point and melted and solidified again has an insulating phase as a parent phase that has coarse crystal grains and becomes superconductive. Has an organization. Since this insulating phase serves as a pinning point for the magnetic field, the superconductor 10 having a high captured magnetic field strength is obtained, and the performance as a magnetic field generator is improved. 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. 10 capture density increases. Moreover, when Ag and Au are contained, the mechanical strength of the RE-Ba-Cu-O-based superconductor is improved. Therefore, if at least one of Ag, Au, Pt, Rh, and Ce is included in the superconductor 10, the reliability as the superconducting magnetic field generator is improved.

  The magnetization of the superconductor 10 is performed with the magnetic pole (the heat insulating container 30 in which the superconductor 10 before magnetization) is placed in the bore of the ring-shaped superconducting magnet, as shown in FIG. Perform by operation. The horizontal axis of FIG. 2 indicates the radial direction of the superconductor 10, and the vertical axis indicates the strength of the magnetic field during magnetization. The zero point on the vertical axis indicates that the magnetic field strength is zero. The direction of the magnetic field is opposite above and below the vertical axis of zero. Here, the upper side is treated as a forward magnetic field, and the lower side is treated as a reverse magnetic field. The slope of the line α shown in FIG. 2 is proportional to the current density. The operation of magnetizing the superconductor 10 is as follows.

  (1) The superconductor 10 is cooled below the superconducting transition temperature in a state where a forward magnetic field having a predetermined magnitude B1 is applied in one direction.

  (2) The operation of “1” is performed to lower the applied forward magnetic field to zero. Furthermore, the operation “2” is performed to apply a reverse magnetic field up to B2 in the reverse direction.

  (3) The operation of “3” is performed to reduce the magnitude of the reverse magnetic field to zero. Thereafter, the magnetic pole (the heat insulating container 30 in which the superconductor 10 is accommodated) is taken out from the bore of the superconducting magnet.

  After magnetizing the superconductor 10 as described above, the current distribution and magnetic flux density of the superconductor 10 are as shown in FIG. That is, the superconductor 10 has a first region 1 having a superconducting current that circulates in one direction, and a second region 2 having a superconducting current that circulates in the opposite direction to the first region 1. Then, the first region 1 and the second region 2 exist in the superconductor 10 from the center of the superconductor 10 toward the outside, that is, in a state of being adjacent in the radial direction. However, FIG. 3 shows a current distribution in an ideal case where the superconductor 10 is near infinity. Since the actual sample has a finite length, the boundary of the current region is not completely straight. The front surface and the back surface of 10 are inwardly curved boundaries.

  A superconducting current is not induced in the central portion of the superconductor 10 where the magnetic field has not changed by the magnetization operation shown in FIG. 2, and the current density J in the central portion of the superconductor 10 becomes zero. As shown in FIG. 3, a first region 1 (inner region) in which the superconducting current circulates in a ring shape in one direction (counterclockwise as viewed from Z> 0) is formed around the central portion of the superconductor 10. . Further, a second region 2 (outer region) in which the superconducting current circulates in a reverse ring shape is formed around the outer periphery of the first region 1 (inner region). As a result, as shown in FIG. 3, the front surface of the superconductor 10 on the front end side, that is, the side facing the target 50, exits from the first region 1 (inner region) and the second region 2 (outer flow region). An arcade-like magnetic field distribution that returns to the boundary between the first region 1 (inner region) and the second region 2 (outer flow region) is formed widely.

  When this superconductor magnetic field device is used as a sputtering gun, the size of the target 50 is selected and arranged so that an arcade-like magnetic field distribution is formed on the front surface of the target 50. At the time of sputtering film formation, as shown in FIG. 1, the plasma P is widely distributed on the surface of the target 50 due to the magnetic field distribution described above. Due to the magnetic field distribution described above, the target 50 is sputtered on the inner side of the outer peripheral edge 10 f of the superconductor 10. As described above, since sputtering can be performed also on the inner side of the outer peripheral edge 10f of the superconductor 10, a sputtered region (erosion region) is widened on the front surface of the target 50, and the unnecessary portion of the target 50 that is not sputtered is reduced. Can do.

  According to the present embodiment, the above-described arcade-like magnetic field distribution can be widely obtained on the front surface of the superconductor 10 only by devising the above-described magnetization operations “1” to “3”. Therefore, it is not necessary to attach a ferromagnetic ring disposed outside the heat insulating container 30 and the start-up as a sputter gun is simplified. Also, since there is no ferromagnetic ring around the magnetic pole, the sputter gun is downsized and compact.

  4 to 6 show a second embodiment. In the following, the present embodiment has basically the same configuration and effects as the first embodiment. As shown in FIG. 4, the superconducting magnetic field generator includes a superconductor 10 that is cooled below the superconducting transition temperature and captures the magnetic field to generate a magnetic field to the outside, a cooling means 20 that cools the superconductor 10, and a superconductor 10. And a heat-insulating container 30 for housing the container. The superconductor 10 has a cylindrical shape, and includes a first region 1 provided on the center side, a second region 2 positioned on the outer peripheral side of the first region 1, and a second region 2 positioned on the outer peripheral side of the second region 2. 1 region 1 is provided.

  The magnetization of the superconductor 10 is performed by the operation shown in FIG. 5 with the magnetic pole (the heat insulating container 30 in which the superconductor 10 is accommodated) placed in the bore of the superconducting magnet. The horizontal axis in FIG. 2 indicates the radial direction, and the vertical axis indicates the strength of the magnetic field. The zero point on the vertical axis indicates that the magnetic field strength is zero. The direction of the magnetic field is opposite between above and below zero.

  (1) The superconductor 10 is cooled to a superconducting transition temperature or lower in a state where a predetermined forward magnetic field B1 is applied in one direction.

  (2) The operation of “1” is performed to reduce the magnitude of the applied forward magnetic field to zero. Furthermore, the operation “2” is performed to apply a reverse magnetic field up to the magnitude of B2 in the reverse direction.

  (3) The operation of “3” is performed to reduce the magnitude of the reverse magnetic field to zero. Thereafter, the operation of “4” is performed to apply a reverse magnetic field to the magnitude of B3 in the same direction as the forward magnetic field B1. In this embodiment, regarding the magnitude of the magnetic field, B3 is larger than B1, but the shape of the magnetic field distribution after magnetization can be controlled by changing the magnitudes of B1, B2, and B3. .

  (4) The operation of “5” is performed to reduce the magnitude of the forward magnetic field to zero. Thereafter, the magnetic pole is taken out from the bore of the superconducting magnet.

  The current density and magnetic flux distribution in the superconductor 10 after being magnetized as described above are as shown in FIG. However, FIG. 6 shows the distribution in an ideal case where the superconductor 10 is infinitely long. Since the actual sample has a finite length, the boundary of the current region is not straight, and the upper surface of the superconductor 10 On the lower surface, the boundary is curved inward.

  In the magnetizing operation of the superconductor 10 shown in FIGS. 5 and 6, there is no portion in the superconductor 10 where the magnetic field has not changed, and thus a superconducting current is induced in all regions of the superconductor 10. As shown in FIGS. 4 and 6, the first region 1 in which the superconducting current circulates in one direction (counterclockwise as viewed from Z> 0) is formed in the central region of the radial direction in the central region of the superconductor 10. . Around the first region 1, a second region 2 in which the superconducting current circulates in the opposite direction (clockwise) is formed. Around the second region 2 is formed a first region 1 in which the superconducting current circulates in the opposite direction. As a result, as shown in FIG. 4, the front surface of the superconductor 10 exits from the first region 1 and returns to the second region 2 and exits from the first region 1 to the first region 1 and the second region 2. The arcade-shaped magnetic field distribution M1 returning to the boundary and the arcade-shaped magnetic field distribution M2 exiting from the interface between the first region 1 and the second region 2 and returning to the boundary between the second region 2 and the first region 1 are substantially concentric. As a result, the magnetic field distribution is widely formed on the front surface of the superconductor 10. When used as a sputter gun, the size of the target 50 is selected and arranged so that a plurality of arcade-like magnetic field distributions M1 and M2 are formed on the front surface of the target 50. During film formation of the sputter gun, the plasma P is widely distributed on the surface of the target 50 due to the magnetic field distribution described above.

  As described above, a plurality of arcade-shaped magnetic field distributions M1 and M2 are formed substantially concentrically on the front surface of the superconductor 10, that is, on the front surface of the target 50, so that the magnetic field distribution is widened and the plasma P is widely distributed. The area (erosion area) to be sputtered on the front surface of the substrate spreads and the utilization efficiency of the target 50 is improved. That is, it is possible to reduce a waste portion of the target 50 that is not sputtered, which is advantageous for consuming the target 50 on average. In addition, the deposition rate is improved. Since the target 50 can be regarded as a planar evaporation source having a large area instead of the conventional ring shape, it is advantageous for uniform film formation with a large area.

  FIG. 7 shows a third embodiment. In the following, the present embodiment has basically the same configuration and effects as the first embodiment. As shown in FIG. 7, the present embodiment is a magnetic field generator in which a ring-shaped yoke 60 is disposed so as to surround the outer peripheral side surface of the superconductor 10. Also in this embodiment, the superconductor 10 includes a first region 1 having a superconducting current that circulates in one direction and a second region 2 having a superconducting current that circulates in the opposite direction to the first region 1. As it goes from the center to the outside in the radial direction, that is, in an adjacent state in the radial direction, it exists alternately.

  That is, the first region 1 forms an inner region of the superconductor 10. The second region 2 forms the outer region of the superconductor 10. Around the outer peripheral side surface of the superconductor 10, a ring-shaped yoke 60 is disposed as a ferromagnetic material. A lower yoke 60 u is formed on the back surface (lower surface) of the superconductor 10. The yoke 60 and the lower yoke 60u are made of a soft magnetic material made of a high permeability material such as permendur (Fe—Co—V), electromagnetic soft iron (Fe), silicon steel plate (Fe—Si), or the like. As described above, the ferromagnetic material such as the yoke 60 and the lower yoke 60 u forms a magnetic path between the outer peripheral side surface of the superconductor 10 and the back surface of the superconductor 10. For this reason, as shown in FIG. 7, a closed, wide arcade-like magnetic field distribution is formed so as to exit from the central portion of the superconductor 10 on the front surface of the superconductor 10 and return to the periphery of the superconductor 10.

  According to the present embodiment, the following effects can be obtained in addition to the effects described in the first embodiment. That is, a ring-shaped yoke 60 is disposed as a ferromagnetic material around the outer peripheral side surface of the superconductor 10. For this reason, the area of the arcade-like magnetic field distribution spreads in the radial direction on the front surface of the target 50. Therefore, a sputtered region (erosion region) on the front surface of the target 50 increases. Since such a magnetic circuit is configured, the magnetic field distribution on the front surface of the target 50 becomes strong. Therefore, since the leakage magnetic field to the part other than the front surface of the target 50 is reduced, the safety can be further increased.

  FIG. 8 shows a fourth embodiment. In the following, the present embodiment has basically the same configuration and effects as the first embodiment. According to the present embodiment, as shown in FIG. 8, a ring-shaped permanent magnet 70 is disposed as a ferromagnetic body disposed around the outer peripheral side surface of the superconductor 10 in the heat insulating container 30. . The permanent magnet 70 has magnetic poles on the front surface and the back surface. The permanent magnet 70 can be made of a known material. A lower yoke 60u is disposed below the superconductor 10 with the cold head 22 attached thereto. The magnetizing operation is the same as that shown in FIG. 2 as in the first embodiment, but differs from the first embodiment in the following points. That is, the permanent magnet 70 may be magnetized before the superconductor 10 is excited, or may be magnetized together with the superconductor 10. In this case, the superconductor as shown in FIG. 8 is set by setting the magnitude of the magnetic field of the reverse operation “3” applied in the reverse direction shown in FIG. 2 to exceed the holding force of the permanent magnet 70. 10 is magnetized. An arcade magnetic field distribution spreads in the radial direction of the superconductor 10 on the front surface of the target 50, and a region to be sputtered on the target 50 spreads. Furthermore, since the permanent magnet 70 is disposed as a ferromagnetic body around the outer peripheral side surface of the superconductor 10, the magnetic field strength near the target 50 is higher than when a yoke is used around the outer peripheral side surface of the superconductor 10. Become stronger.

  FIG. 9 shows a fifth embodiment. In the following, the present embodiment has basically the same configuration and effects as the first embodiment. A yoke 60 as a ferromagnetic material is arranged in a ring shape around the outer peripheral side surface of the superconductor 10. A disc-shaped lower yoke 60 u is disposed on the back surface of the superconductor 10 while being held by the cold head 22. Ferromagnetic materials such as the yoke 60 and the lower yoke 60 u form a magnetic path between the outer peripheral side surface of the superconductor 10 and the back surface of the superconductor 10. For this reason, a closed arcade magnetic field distribution is formed on the front surface of the superconductor 10 that exits from the center of the superconductor 10 and returns to the periphery of the superconductor 10.

  According to the present embodiment, the ring-shaped yoke 60 is disposed around the outer peripheral side surface of the superconductor 10 so as to form a gap 62 between the yoke 60 and the superconductor 10 in a ring shape. . Differences from the third embodiment shown in FIG. 7 are as follows.

  The yoke 60 disposed around the outer peripheral side surface of the superconductor 10 is disposed inside the heat insulating container 30 so that the gap 62 is formed in a ring shape with respect to the superconductor 10. Accordingly, as shown in FIG. 9, a plurality of arcade-like magnetic field distributions are formed on the front surface of the target 50.

  According to the present embodiment, in addition to the effects described in Embodiment 3 shown in FIG. A gap 62 is formed between the yoke 60 and the superconductor 10. For this reason, as shown in FIG. 9, an arcade-like magnetic field distribution that returns from the first region 1 to the second region 2 and returns from the first region 1 to the boundary between the first region 1 and the second region 2. A plurality of M1 and an arcade-shaped magnetic field distribution M2 that returns from the boundary between the first region 1 and the second region 2 and returns to the yoke 60 are formed substantially concentrically on the front surface of the target 50. Accordingly, a wide magnetic field distribution can be formed on the front surface of the superconductor 10. Therefore, a sputtered region (erosion region) on the front surface of the target 50 is widened, and an area of a useless portion of the target 50 that is not consumed can be reduced, and the utilization efficiency of the target 50 is improved. Moreover, the film formation speed in sputtering is improved. The width of the gap 62 is set as appropriate. Instead of the gap 62, a nonmagnetic material portion made of a nonmagnetic material such as ceramics or austenitic stainless steel may be disposed between the yoke 60 and the superconductor 10.

  FIG. 10 shows a sixth embodiment. In the following, the present embodiment has basically the same configuration and effects as the first embodiment. Differences from the first embodiment are as follows. As shown in FIG. 10, a ferromagnetic ring 72 having a permanent magnet 70 is disposed outside the heat insulating container 30 that houses the superconductor 10. The ring 72 includes a ring-shaped yoke 60 and a permanent magnet 70 held by the yoke 60. The ferromagnetic ring 72 is attached to the outer peripheral side of the heat insulating container 30 after magnetizing the superconductor 10 in the heat insulating container 30.

  According to the present embodiment, in addition to the effects described in the third embodiment, the following effects can be given. That is, a plurality of arcade magnetic field distributions are formed on the front surface of the superconductor 10, that is, on the front surface of the target 50. A gap 62 is formed between the yoke 60 and the superconductor 10. For this reason, as shown in FIG. 10, an arcade-like magnetic field distribution that returns from the first region 1 to the second region 2 and returns from the first region 1 to the boundary between the first region 1 and the second region 2. A plurality of arc-shaped magnetic field distributions M2 that return from the boundary between the first region 1 and the second region 2 and return to the yoke 60 are formed substantially concentrically on the front surface of the target 50. Accordingly, a wide magnetic field distribution can be formed on the front surface of the superconductor 10. For this reason, the area of the useless part which is not consumed among targets 50 can be made small, and the utilization efficiency of target 50 improves. For this reason, the area of the useless part which is not consumed among the targets 50 can be reduced, and the utilization efficiency of the targets 50 is improved. Moreover, the film formation speed in sputtering is improved. The width of the gap 62 is set as appropriate. A nonmagnetic material portion made of a nonmagnetic material instead of the gap 62 may be disposed between the yoke 60 and the superconductor 10.

  FIG. 11 shows a seventh embodiment. In the following, the present embodiment has basically the same configuration and effects as the first embodiment. Differences from the first embodiment are as follows. As shown in FIG. 11, the first region 1 having a superconducting current that circulates in one direction and the second region 2 having a superconducting current that circulates in the opposite direction to the first region 1 It exists from the center toward the outside, that is, in a state of being adjacent in the radial direction. As shown in FIG. 11, a first region 1 (inner region) where the superconducting current circulates in one direction is formed around the central portion of the superconductor 10. Further, around the first region 1 (inner region), a second region 2 (outer region) in which the superconducting current circulates in the opposite direction is formed.

  According to the present embodiment, the magnitude B2 of the magnetic field performed by the operation “3” is set larger than that in the first embodiment. As a result, the volume of the first region 1 inside the superconductor 10 decreases, and the volume of the second region 2 on the outer peripheral side of the superconductor 10 increases. Therefore, as shown in FIG. 11, the first region 1 and the second region exit from the first region 1 (inner region) on the front surface on the front end side of the superconductor 10, that is, on the side facing the target 50. An arcade-like magnetic field distribution returning to the boundary with 2 (outer basin) is formed, and a magnetic field distribution extending upward away from the superconductor 10 from the boundary between the first region 1 and the second region 2 has a heat insulating container 30. Formed on the outside. Here, the magnetic field generated from the outer periphery of the superconductor 10 extends in a direction away from the superconductor 10 as compared to the magnetic field generated from the inside of the superconductor 10.

  A strong magnetic field distribution in the second region 2 located on the outer peripheral side of the superconductor 10 can be realized by the above-described magnetization operation. Therefore, the total amount of magnetic flux outside the superconductor 10 can be made stronger than the total amount of magnetic flux in the central portion of the superconductor 10. When the superconducting generator is used as a sputter gun, an unbalanced magnetron gun is realized in which the magnetic field of the surrounding magnetic pole is stronger than the magnetic field of the central magnetic pole. Therefore, high-density plasma P is formed in the space between the target 50 and the base material. Therefore, a denser and better adhesive film is formed as compared with a magnetron sputtering apparatus using a normal permanent magnet. In addition, when a magnetron gun having a strong magnetic field is used in the plasma apparatus as in this embodiment, the object to be processed can be irradiated with plasma having a higher density than an apparatus using a normal coil or permanent magnet.

  FIG. 12 shows Example 8 in which the superconducting magnetic field generator according to Example 5 is applied to a magnetron sputtering apparatus. Hereinafter, the present embodiment has basically the same configuration and operational effects as the fifth embodiment. In the superconductor 10, the first region 1 having a superconducting current that circulates in one direction and the second region 2 having a superconducting current that circulates in the opposite direction to the first region 1 are separated from the center of the superconductor 10 in the radial direction. As they go outward, that is, they are alternately adjacent in the radial direction.

  The cooling means 20 is provided in the lower part of the heat insulating container 30. An elevating unit 300 that elevates and lowers the superconductor 10 is provided below the cooling means 20. The elevating unit 300 is placed on a carriage 301. The elevating unit 300 is equipped with a superconducting magnetic field generator, and moves the superconducting magnetic field generator that accommodates the superconductor 3 in the directions of the arrows Y1 and Y2, and is composed of a jack having an expandable and contractible pantograph structure. Yes.

As shown in FIG. 12, the sputter deposition apparatus 200 is installed in a reduced pressure state (for example, by a pump not shown) while introducing a sputter gas (generally argon gas) installed on the upper side of the base 201 and the base 201. A depressurization chamber 203 having a film formation chamber 202 maintained at about 10 ⁻⁴ to 10 ⁻⁵ Torr) and generation of a superconducting magnetic field that serves as a sputter gun for concentrating the plasma P in a region near the surface of the target 50 by the action of the magnetic field. Device. The decompression chamber 203 includes a plate 52 that functions as a target holder that is provided below the film formation chamber 202 so as to hold the target 50 containing the film forming raw material and holds the target 50, and a base material 210 as a film formation target. A film formation object holder 211 provided on the upper part of the film formation chamber 202 so as to be held.

  When assembling the superconducting magnetic field generating apparatus described above into the sputter film forming apparatus, as shown in FIG. 12, the superconducting magnetic field generating apparatus having the superconductor 10 formed as a superconducting bulk magnet is disposed below the insertion space of the decompression chamber 203. . Next, the elevating unit 300 of the superconducting magnetic field generator is moved up to raise the heat insulating container 30 together with the superconductor 10 in the direction of the arrow Y1, so that the tip wall 32 of the heat insulating container 30 faces the plate 52 as shown in FIG. The tip of the superconductor 10 is brought close to or in contact with the plate 52. In this way, a magnetic circuit of a superconducting bulk magnet formed of the superconductor 10 is formed in the vicinity of the target 50 in the film forming chamber 202.

At the time of film formation, first, the film formation chamber 202 is evacuated to a high vacuum (for example, 10 ⁻⁶ Torr level) by an unillustrated vacuum exhaust apparatus 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 50 and the film formation target 210. In this case, generally, a voltage is applied so that the target 50 is negative and the film formation target 210 is positive. Thereby, plasma discharge is generated in the film forming chamber 202. Electrons in the plasma P ionize sputter gas molecules (generally, but not limited to, argon) while moving by a magnetic field. Since the plasma P-shaped sputtering gas ions are focused on the surface of the target 50, they are accelerated and collide with the surface of the target 50. Accordingly, the constituent material of the target 50 is sputtered from the surface of the target 50 and deposited on the surface of the film formation target 210, and a thin film can be formed on the film formation target 210 at a high film formation rate. In this case, there is an advantage that the plasma P can be concentrated near the target 50 by the strong magnetic field of the superconductor 10. Therefore, high-vacuum discharge is possible in the film formation chamber 202, 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. The target 50 is negative and the voltage is applied so that the target 50 is positive. However, the present invention is not limited to this, and an AC voltage may be applied between the target 50 and the film formation target 210. .

  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 as necessary.

  The present invention can be used in a field having a magnetic field generation source using a superconductor. For example, the superconducting magnetic field generator is not limited to the sputter film forming apparatus and the etching apparatus, and for example, the superconducting magnetic field generating apparatus can be used in 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 of a superconducting magnetic field generator according to Example 1. FIG. It is a block diagram which shows the magnetic field distribution in the radial direction of a superconductor when Example 1 concerns on exciting a superconductor. FIG. 3 is a configuration diagram illustrating a current density distribution in an excited superconductor according to the first embodiment. FIG. 6 is a cross-sectional view of a superconducting magnetic field generator according to a second embodiment. It is a block diagram which shows the magnetic field distribution in the radial direction of a superconductor when Example 2 concerns on exciting a superconductor. FIG. 10 is a configuration diagram illustrating a current density distribution in an excited superconductor according to the second embodiment. FIG. 6 is a cross-sectional view of a superconducting magnetic field generator according to Example 3. It is sectional drawing of a superconducting magnetic field generator concerning Example 4. FIG. 10 is a cross-sectional view of a superconducting magnetic field generator according to Example 5. FIG. 10 is a cross-sectional view of a superconducting magnetic field generator according to Example 6. FIG. 10 is a cross-sectional view of a superconducting magnetic field generator according to Example 7. FIG. 10 is a cross-sectional view illustrating a superconducting magnetic field generator applied to a magnetron sputtering apparatus according to an eighth embodiment.

Explanation of symbols

  1 is a first region, 2 is a second region, 10 is a superconductor, 20 is a cooling means, 21 is a refrigerator, 22 is a cold head, 30 is a heat insulating container, 50 is a target, 62 is a gap, 70 is a permanent magnet Show.

Claims (16)

In a superconducting magnetic field generator including a superconductor that cools below a superconducting transition temperature and generates a magnetic field by capturing the magnetic field, cooling means that cools the superconductor, and a heat insulating container that houses the superconductor.
In the superconductor, the first region having a superconducting current that circulates in one direction and the second region having a superconducting current that circulates in the opposite direction to the first region are alternately arranged toward the outside from the center of the superconductor. A superconducting magnetic field generator characterized by being present in   2. The first region according to claim 1, wherein the first region is one of an inner region and an outer region in the superconductor, and the second region is one of an outer region and an inner region in the superconductor. Superconducting magnetic field generator.   3. The heat insulating container according to claim 1, wherein the magnetic field generated from the superconductor has an arcade-like magnetic field distribution that comes out of the first region and reaches a vicinity of a boundary between the first region and the second region. A superconducting magnetic field generator characterized in that it is formed outside.   3. The arcade-like magnetic field distribution according to claim 1 or 2, wherein a plurality of boundaries between the first region and the second region are provided, the arcuate magnetic field distribution returns from the first region and returns to the vicinity of one boundary, and the one A superconducting magnetic field generator characterized in that another arcade-like magnetic field distribution that exits from the vicinity of the boundary and returns to the vicinity of the other boundary is formed outside the heat insulating container.   In any one of Claims 1-4, while a ferromagnetic body is arrange | positioned around the said superconductor, at least one part of the said ferromagnetic body has the side surface of the said superconductor. A superconducting magnetic field generator characterized by being arranged in a ring shape so as to surround it.   6. The superconducting magnetic field generating device according to claim 5, wherein the ferromagnetic body is a yoke housed in the heat insulating container and made of a soft magnetic body.   7. The ferromagnetic body according to claim 5, wherein the ferromagnetic body is housed inside the heat insulating container, and the ferromagnetic body portion disposed so as to surround a side surface of the superconductor is permanent. A superconducting magnetic field generator characterized by being a magnet.   The magnetic field generated from the superconductor according to any one of claims 5 to 7, wherein the magnetic field is generated from the first region, from the second region, or between the first region and the second region. A superconducting magnetic field generating device characterized in that an arcade-like magnetic field distribution returning to the ferromagnetic material from outside is formed outside the heat insulating container.   In any one of Claims 1-8, compared with the magnetic field emitted from the outer peripheral part of the said superconductor, the magnetic field emitted from the outer peripheral part of the said superconductor is the direction away from the said superconductor. A superconducting magnetic field generator characterized by extending.   The superconductor according to any one of claims 1 to 9, wherein the superconductor is manufactured by a melting method, and a main component thereof is RE-Ba-Cu-O (RE is Y, La, Nd, Sm, Eu). , Gd, Er, Yb, Dy, and Ho).   An excitation method for exciting the superconducting magnetic field generator according to any one of claims 1 to 10, wherein a magnetic field 1 in one direction and a magnetic field 2 in a direction opposite to the magnetic field in one direction are alternately applied. A method of exciting a superconducting magnetic field generator characterized by magnetizing the superconductor.   In Claim 11, the permanent magnet is arrange | positioned so that the side surface of the outer peripheral side of the said superconductor may be enclosed, The said magnetic field 1 and the said reverse magnetic field 2 are applied alternately, and the said superconductor and An excitation method for a superconducting magnetic field generator, wherein the permanent magnet is magnetized.   13. The method of exciting a superconducting magnetic field generator according to claim 11 or 12, wherein after applying the magnetic field 1, the magnetic field 2 is applied to magnetize the superconductor.   A sputter gun using the superconducting magnetic field device according to any one of claims 1 to 13, wherein an arcade-like magnetic field distribution by a superconducting current circulating in the first region and the second region, or the first A sputter gun, wherein a superconducting current circulating in the region or the second region and an arcade-like magnetic field distribution by the ferromagnetic material are formed on the front surface of the target.   15. The sputter gun according to claim 14, wherein a plurality of arcade-like magnetic field distributions are formed substantially concentrically on the front surface of the superconductor. A target including a thin film raw material and a sputter gun are provided, and plasma is concentrated in the vicinity of the surface of the target by the action of a magnetic field emitted from the sputter gun, and the thin film raw material to be released is applied to the surface of the substrate. In a sputtering apparatus for depositing and forming a thin film,
A sputtering apparatus comprising the superconducting magnetic field generator according to any one of claims 1 to 10 incorporated in the sputtering gun.

Images