JP5328462B2 - Magnetron sputtering apparatus, in-line film forming apparatus, and method for manufacturing magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extend the life of a target by generating highly uniform erosion on a target surface. <P>SOLUTION: A magnetic circuit 11 for generating a magnetic field on the surface of a target includes: a first cylindrical magnet 40 having a magnetization direction parallel to an axis, and a second cylindrical or columnar second magnet 41 concentric-circularly disposed inside the first magnet 40 and having a magnetization direction anti-parallel to that of the first magnet 40. While the axes of the first and second magnets 40 and 41 are parallel to the axis of the target, the magnetic circuit is freely rotated in a plane parallel to the surface of the target. In a magnetic field M generated between the first magnet 40 and the second magnet 41, a Bz-0 line connecting points where the vertical components Bz of a magnetic flux density on the surface of the target is 0[T] draws a curve L1 having a plurality of inflection points C1 and C2 in the plane parallel to the surface of the target. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to a magnetron sputtering apparatus that performs processing such as film formation on a substrate to be processed under a reduced pressure atmosphere, an inline film forming apparatus including such a magnetron sputtering apparatus, and such an inline film forming apparatus. relates to the method of manufacturing have the magnetic recording medium.

  In recent years, the range of application of magnetic recording devices such as magnetic disk devices, flexible disk devices, and magnetic tape devices has been remarkably increased, and the importance has increased, and the recording density of magnetic recording media used in these devices has increased. Significant improvements are being made. Particularly in HDD (Hard Disk Drive), since the introduction of MR head and PRML technology, the increase in surface recording density has become more severe, and in recent years, GMR heads and TuMR heads have also been introduced, and about 100 per year. The surface recording density continues to increase at a pace of%.

  On the other hand, as a magnetic recording system for HDDs, the so-called perpendicular magnetic recording system has been rapidly used in recent years as a technique to replace the conventional in-plane magnetic recording system (recording system whose magnetization direction is parallel to the substrate surface). In this perpendicular magnetic recording system, crystal grains in the recording layer for recording information have an easy axis of magnetization in the direction perpendicular to the substrate. The easy magnetization axis means a direction in which the magnetization is easily oriented. In the case of a commonly used Co alloy, it is an axis (c axis) parallel to the normal line of the (0001) plane of the Co hcp structure. In the perpendicular magnetic recording method, since the easy axis of magnetization of such magnetic crystal grains is in the perpendicular direction, the influence of the demagnetizing field between the recording bits is small even when the high recording density is advanced, and also in magnetostatic manner. It is characterized by being stable.

  A perpendicular magnetic recording medium is generally formed on a nonmagnetic substrate in the order of an underlayer, an intermediate layer (orientation control layer), a recording magnetic layer, and a protective layer. Further, in many cases, a lubricating film is applied to the surface after forming a protective layer. In many cases, a magnetic film called a soft magnetic underlayer is provided under the underlayer. The underlayer and the intermediate layer are formed for the purpose of further improving the characteristics of the recording magnetic layer. Specifically, it functions to adjust the crystal orientation of the recording magnetic layer and at the same time to control the shape of the magnetic crystal.

  The magnetic recording medium described above is configured by laminating a plurality of thin films formed mainly using a sputtering method. For this reason, the magnetic recording medium is manufactured using an in-line type film forming apparatus in which a plurality of chambers (processing apparatuses) for forming each thin film constituting such a magnetic recording medium are connected in a row through a gate valve. It is common to be done. In this in-line film forming apparatus, the substrate to be processed is sequentially transferred into each chamber, and a predetermined thin film is formed in each chamber. Therefore, in the in-line type film forming apparatus, the number of thin films corresponding to the number of chambers can be formed on the substrate by circulating the substrate.

  Further, in the in-line type film forming apparatus, a magnetron sputtering apparatus is suitably used as the above-described processing apparatus for sputtering. Specifically, in this magnetron sputtering apparatus, a target is disposed opposite to a substrate disposed in a reaction vessel, and a magnetic circuit is disposed on the back surface of the target to generate a magnetic field in the vicinity of the target surface. A high voltage such as radio frequency (RF) is applied between the substrate and the target in a gas atmosphere, and an electron ionized by the high voltage collides with an inert gas to form plasma, and sputtering is performed by positive ions in the plasma. The deposited target particles are deposited on the substrate surface to perform a film forming process. The magnetic circuit arranged on the back of the target generally has a magnet with a magnetization direction in a direction perpendicular to the surface of the target inside, and a magnet with a magnetization direction opposite to this magnet. It is configured by placing it outside.

  By the way, in the magnetron sputtering apparatus, erosion (erosion) occurring on the surface of the target may proceed in a non-uniform shape depending on the magnetic field generated on the target surface side. In other words, erosion occurs in a region on the target surface where a horizontal component of the magnetic field with respect to the target exists, and the larger the same component of the magnetic field, the deeper the shape.

  The life of the target is determined at a portion where erosion progresses strongly. For this reason, attempts have been made to make the erosion uniform and improve the utilization efficiency of the target. For example, as one method for equalizing erosion, it has been proposed that the magnetic circuit disposed on the back surface of the target is in an appropriate state (see, for example, Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 7-157875 JP 2001-279439 A JP 2008-106330 A

  However, even if the above-described erosion countermeasure is performed, there is still a region where erosion progresses earlier than other portions on the surface of the target, which shortens the life of the target. Also, due to the non-uniform erosion shape of the target surface, the leakage magnetic field becomes non-uniform, and as a result, it becomes difficult to stably maintain the discharge state, or the in-plane distribution of the magnetic properties of the magnetic film Defects such as worsening occur. In particular, the latter is an important problem to be solved in a magnetic recording medium in which a higher recording density is required and the magnetic layer is made thinner.

The present invention has been proposed in view of such a conventional situation. The erosion generated on the target surface is highly uniformed, the life of the target is increased, and the target particles struck from the target by sputtering are covered. A magnetron sputtering apparatus capable of increasing the uniformity of in-plane distribution when forming a thin film by depositing on a processing substrate, an in-line type film forming apparatus equipped with such a processing apparatus, and such an in-line type forming apparatus. It is an object of the present invention to provide a method for manufacturing a magnetic recording medium using a film device.

  In order to solve the above problems, the present inventor has conducted intensive research. As a result, the Bz = 0 line connecting the points where the vertical component Bz of the magnetic flux density on the target surface of the magnetic field generated by the magnetic circuit becomes 0 [T]. However, by drawing a specific curve in a plane parallel to the target surface, it was found that the erosion generated on the target surface can be made highly uniform and the life of the target can be remarkably increased, and the present invention has been completed. .

That is, the present invention provides the following means.
(1) A reaction vessel in which a substrate to be processed is disposed, a vacuum evacuation unit that evacuates the inside of the reaction vessel, and a processing unit that processes the substrate to be processed. A backing plate that holds the target oppositely, and a magnetic circuit that is located on the opposite side of the backing plate from the target and generates a magnetic field on the surface of the target, the magnetic circuit having a magnetization direction A cylindrical first magnet that is parallel to the axis, and a cylindrical magnet that is disposed so as to have the same center inside the first magnet, and whose magnetization direction is antiparallel to the first magnet. The first and second magnets are in front of each other in a state where the axis of the first and second magnets and the axis of the target are parallel to each other. The vertical component Bz of the magnetic flux density on the surface of the target of the magnetic field generated between the first magnet and the second magnet is 0 [0] while being rotatable in a plane parallel to the surface of the target. Bz = 0 line connecting the points T] draws a similar shape of a curve represented by polar coordinates (r, θ) in a plane parallel to the surface of the target, and the first magnet and the first Corresponding to the shape of the magnet 2, the curve represented by the polar coordinates (r, θ) changes at θ = π in a graph in which the horizontal axis is θ (0 ≦ θ ≦ 2π) and the vertical axis is r. It has inflection points, has at least one inflection point at a position that is axially symmetric with respect to the inflection point, and draws a straight line or a curve connecting these inflection points Magnetron sputtering equipment.
(2) The first magnet is provided with at least one or more projecting portions projecting from the inner side surface thereof at least from one end side facing the backing plate in the axial direction. The magnetron sputtering apparatus according to (1) above.
(3) The position according to (2), wherein the second magnet is provided with at least one slit at a position facing the protruding portion so that the protruding portion faces the inside. Magnetron sputtering equipment.
(4) The second magnet is provided with at least one or more projecting portions projecting from an outer surface thereof extending at least from one end side facing the backing plate in the axial direction. The magnetron sputtering apparatus according to any one of (1) to (3) above.
(5) The position according to (4), wherein at least one slit is provided at a position facing the protruding portion of the first magnet so that the protruding portion faces the inside. Magnetron sputtering equipment.
(6) The preceding items (1) to (5), wherein at least one or more corners protruding outward are provided at positions where the first and second magnets face each other. The magnetron sputtering apparatus according to any one of the above.
(7) The magnetic circuit includes a yoke that forms a magnetic path together with the first and second magnets, and the yoke is opposite to a surface of the first and second magnets facing the backing plate. The magnetron sputtering apparatus according to any one of (1) to (6), wherein the magnetron sputtering apparatus is attached in a state of being abutted against a side surface.
(8) The magnetron sputtering apparatus according to any one of (1) to (7), wherein the first magnet and the second magnet have substantially the same volume.
(9) A plurality of chambers, a carrier that holds a substrate to be processed in the plurality of chambers, and a transport mechanism that sequentially transports the carrier between the plurality of chambers, and at least one of the plurality of chambers. One is an in-line film forming apparatus characterized by being configured by the apparatus according to any one of (1) to (8).
(10) A method for producing a magnetic recording medium, comprising a step of forming at least a magnetic layer on a nonmagnetic substrate using the in-line film forming apparatus according to (9).

  As described above, according to the present invention, the generation of non-uniform erosion on the target surface is prevented, the use efficiency of the target is improved, and the in-plane distribution when forming a thin film by sputtering on the surface of the substrate to be processed. It is possible to increase the uniformity. Therefore, when such a magnetron sputtering apparatus is used, it is possible to uniformly form a magnetic film or the like having a small in-plane distribution of magnetic characteristics, and thereby a magnetic recording medium corresponding to high recording density In addition, it is possible to provide a magnetic recording / reproducing apparatus including such a magnetic recording medium.

It is a partially cutaway sectional view showing an example of a magnetron sputtering apparatus to which the present invention is applied. It is a front view of the magnetron sputtering apparatus shown in FIG. It is a top view of the gas inflow tube with which the magnetron sputtering device shown in FIG. 1 is provided. It is the side view which looked at the carrier and conveyance mechanism with which the magnetron sputtering apparatus shown in FIG. 1 is provided from the direction orthogonal to the conveyance direction. It is the side view which looked at the carrier and conveyance mechanism with which the magnetron sputtering device shown in FIG. 1 is provided from the conveyance direction side. FIG. 6 is a cross-sectional view showing the configuration of the processing unit. FIG. 7 is a perspective view showing the configuration of the magnetic circuit. FIG. 8 is a plan view schematically showing the magnetic field generated by the magnetic circuit and the Bz = 0 line. FIG. 9 is a side view schematically showing the magnetic field generated by the magnetic circuit and the Bz = 0 line. FIG. 10 is a characteristic diagram showing the Bz = 0 line by a curve L1 on polar coordinates. FIG. 11 is a graph showing the curve L1 represented by polar coordinates (r, θ) with the horizontal axis converted to θ (0 ≦ θ ≦ 2π) and the vertical axis converted to r. FIG. 12 is a characteristic diagram showing the Bz = 0 line of the present invention with the curves L2 and L3 on the polar coordinates. FIG. 13 is a graph showing the curves L2 and L3 shown in FIG. 12 with the horizontal axis converted to θ (0 ≦ θ ≦ 2π) and the vertical axis converted to r. FIG. 14 is a characteristic diagram showing the Bz = 0 line of the present invention by a curve L4 on polar coordinates. FIG. 15 is a graph showing the curve L4 shown in FIG. 14 with the horizontal axis converted to θ (0 ≦ θ ≦ 2π) and the vertical axis converted to r. FIG. 16 is a plan view showing a modification of the magnetic circuit. It is a block diagram which shows an example of the in-line type film-forming apparatus to which this invention is applied. It is a side view which shows the case where it processes alternately with respect to two process substrates in the in-line type film-forming apparatus shown in FIG. It is sectional drawing which shows an example of the magnetic recording medium manufactured by applying this invention. It is sectional drawing which shows an example of the discrete type magnetic recording medium manufactured by applying this invention. It is a perspective view which shows one structural example of a magnetic recording / reproducing apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the present embodiment, a case where a magnetic recording medium mounted on a hard disk device (magnetic recording / reproducing device) is manufactured using an in-line film forming apparatus including a magnetron sputtering apparatus to which the present invention is applied will be described as an example. .

(Magnetron sputtering equipment)
First, an example of a magnetron sputtering apparatus 1 to which the present invention shown in FIG. 1 is applied will be described.
A magnetron sputtering apparatus 1 to which the present invention is applied is an in-line type film forming apparatus that performs film forming processing and the like while sequentially transferring a substrate (target substrate) W to be formed between a plurality of chambers to be described later. One processing chamber is constituted.

  Specifically, as shown in FIG. 1, the magnetron sputtering apparatus 1 includes a reaction vessel 2 in which a substrate to be processed W is disposed, and a holder 3 for holding the substrate to be processed W is provided in the reaction vessel 2. An attached carrier 4 and a transport mechanism 5 for transporting the carrier 4 are arranged.

  In the magnetron sputtering apparatus 1, it is possible to simultaneously perform film formation on both surfaces of the two substrates to be processed W. Although not shown in FIG. 1, two holders 3 are attached to the carrier 4 side by side in a straight line in the transport direction. Further, the two holders 3 hold the substrate W to be processed vertically (a state where the main surface of the substrate W to be processed is parallel to the direction of gravity).

  As shown in FIGS. 1 and 2, the reaction vessel 2 is a vacuum vessel (chamber) that is hermetically configured by a pressure-resistant partition wall so that the interior thereof is in a high vacuum state. A flat internal space 7 is formed between 6a and the back-side partition wall 6b. The carrier 4 that holds the substrate W to be processed is disposed in the center of the internal space 7, and the transport mechanism 5 is disposed below the carrier 4.

  Also, before and after the reaction container 2 in the transport direction, a substrate carry-in / out port (not shown) through which the carrier 4 passes between adjacent reaction vessels (chambers) and a pair of gates that open and close these substrate carry-in / out ports A valve 2A is provided. That is, the reaction vessel 2 is connected to the adjacent chamber via the gate valve 2A.

  The magnetron sputtering apparatus 1 includes a processing unit (processing unit) 1A that performs film formation processing on both surfaces of the substrate W to be processed held on the carrier 4 on the front partition 6a and the back partition 6b of the reaction vessel 2, respectively. It has.

  The processing unit 1 </ b> A is disposed to face both surfaces of the two substrates to be processed W held by the holder 3. Specifically, a total of four backing plates 8 are arranged in the reaction container 2 so as to face both surfaces of two substrates to be processed W held by the carrier 4. And the target T is attached to the surface (surface) which opposes the to-be-processed substrate W of these four backing plates 8. FIG. Each backing plate 8 is connected to a high-frequency power source (or microwave power source) (not shown), and a high-frequency voltage can be applied to the target T from the high-frequency power source via the backing plate 8. Yes.

  As shown in FIGS. 1 and 3, the processing unit 1 </ b> A includes a gas introduction pipe (gas introduction means) 9 that introduces gas into the reaction vessel 2. The gas introduction pipe 9 has an annular portion 9a formed in a ring shape corresponding to the disk-shaped substrate W, and the gas supply source 10 is connected to the gas supply source 10 via a connecting portion 9b connected to the annular portion 9a. It is connected. Further, the annular portion 9 a of the gas introduction pipe 9 is arranged so as to surround the periphery of the reaction space R formed between the substrate to be processed W and the target T. Further, a plurality of gas discharge ports 9c are arranged in the circumferential direction on the inner peripheral portion of the annular portion 9a, and the gas introduction pipe 9 is to be processed inside the plurality of gas discharge ports 9c. It is possible to release the gas G supplied from the gas supply source 10 toward the substrate W.

  In addition, about the aperture of the gas discharge port 9c, in order to make constant the quantity of the gas G discharged | emitted from each gas discharge port 9c, it is preferable to set it as the structure which changed the diameter of each gas discharge port 9c. Specifically, it is preferable to increase the diameter of the gas discharge port 9c according to the distance from the connecting portion 9b so that the amount of gas G discharged from each gas discharge port 9c is constant.

  An adjustment valve (not shown) is provided on the pipe between the gas introduction pipe 9 and the gas supply source 10. In the magnetron sputtering apparatus 1, it is possible to control the opening and closing of the adjustment valve and to adjust the flow rate of the gas G supplied to the gas introduction pipe 9 through the adjustment valve.

  The processing unit 1A includes a magnetic circuit (magnet generation means) 11 that is located on the opposite side of each backing plate 8 from the target T and generates a magnetic field. Each magnetic circuit 11 is attached to a rotation shaft 12 a of a drive motor 12 and is driven to rotate in a plane parallel to the surface of the target T by the drive motor 12.

  The front side partition 6a and the back side partition 6b of the reaction vessel 2 are provided with an opening 13 facing the inside of the reaction vessel 2. The opening 13 is formed so that the backing plate 8 to which the target T described above is attached, the gas introduction pipe 9, and the magnetic circuit 11 are disposed at positions facing both surfaces of the two substrates to be processed W held by the holder 3. The processing unit 1A including the attached drive motor 12 is formed in an oval shape (race track shape) with a size sufficient to arrange the processing unit 1A.

  A cylindrical housing 14 that hermetically seals the periphery of the opening 13 is attached to the front-side partition wall 6a and the back-side partition wall 6b, and the processing unit 1A is held inside the housing 14. At the same time, in order to adjust the facing distance between the target substrate W and the target T, the substrate 14 is supported so as to be movable within the housing 14. This makes it possible to easily adjust the facing distance between the target substrate W and the target T in order to optimize the film formation conditions. The front-side partition wall 6a and the back-side partition wall 6b are attached to the reaction vessel 2 so as to be openable and closable in order to open the reaction vessel 2 during maintenance or the like.

  As shown in FIG. 1, the magnetron sputtering apparatus 1 is arranged as a vacuum exhaust means for vacuum exhausting the inside of the reaction vessel 2, and a first vacuum pump 15 arranged above the reaction vessel 2 and below the reaction vessel 2. The second vacuum pump 16 is provided.

  The first vacuum pump 15 is a turbo molecular pump attached via an upper pump chamber 17 </ b> A disposed above the reaction vessel 2. Since this turbo molecular pump does not use lubricating oil, it has a high cleanliness (cleanness) and a high exhaust speed, so that a high degree of vacuum can be obtained. Furthermore, it is suitable for exhausting highly reactive gas.

  The upper pump chamber 17 </ b> A is airtightly configured by a pressure-resistant partition wall, and is attached to the upper portion of the reaction vessel 2 to form an internal space 7 </ b> A continuous with the internal space 7 of the reaction vessel 2. And the 1st vacuum pump 15 is attached in the state which each opposed to the both side surfaces of this upper pump chamber 17A.

  On the other hand, the second vacuum pump 16 is a cryopump attached via a lower pump chamber 17B disposed below the reaction vessel 2. The cryopump creates a very low temperature and condenses or adsorbs the gas inside to obtain a high degree of vacuum, and is particularly superior to a turbo molecular pump in terms of pumping speed and cleanliness.

  The lower pump chamber 17B is hermetically configured by a pressure-resistant partition, and communicates with the internal space 7 of the reaction vessel 2 through a hole 6d formed in the bottom wall 6c of the reaction vessel 2. The second vacuum pump 16 is connected to the side surface of the lower pump chamber 17B.

  In the magnetron sputtering apparatus 1, the inside of the reaction vessel 2 is depressurized and the gas introduced into the reaction vessel 2 is exhausted while controlling the driving of the first vacuum pump 15 and the second vacuum pump 16. It is possible.

  In the present embodiment, two first vacuum pumps 15 are disposed on both side surfaces of the reaction vessel 2 and one second vacuum pump 16 is disposed below the reaction vessel 2, The arrangement and number of the vacuum pumps 15 and 16 can be changed as appropriate. For example, the time required to evacuate the reaction vessel 2 under reduced pressure decreases as the number of vacuum pumps 15 and 16 increases, but if the number of first and second vacuum pumps 15 and 16 increases, the magnetron In order to increase the size of the sputtering apparatus 1 and increase the power consumption, it is desirable to determine the number of the first and second vacuum pumps 15 and 16 from such a viewpoint.

  Also, the cryopump used for the second vacuum pump 16 is different from a turbo molecular pump having a structure for discharging to the outside, and needs to be maintained at regular intervals because it is stored inside. When the gas introduced into the reaction vessel 2 is a highly reactive gas, the first vacuum pump 15 composed of the above-described turbo molecular pump is used to exhaust the gas to the outside of the reaction vessel 2. Is desirable. As a result, the reaction container 2 is kept clean while preventing the gas after reaction from flowing below the reaction space 7 and corroding metal parts such as the bearings 28 and 30 constituting the transport mechanism 5. It is possible to keep on. Note that a turbo molecular pump can be used as the second vacuum pump 16 instead of the cryopump.

  As shown in FIGS. 1 and 4, the carrier 4 has a structure in which two holders 3 are attached in parallel to the support base 18 on an upper part of a support base 18 having a plate shape. In the holder 3, a circular hole 3 b having a diameter slightly larger than the outer diameter of the substrate to be processed W is formed in the plate material 3 a having a thickness of about 1 to several times the thickness of the substrate to be processed W. Thus, the substrate to be processed W is held inside the hole 3b.

  Specifically, a plurality of support arms 19 that support the substrate W to be processed are attached around the hole 3b of the holder 3 so as to be elastically deformable. The plurality of support arms 19 have a lower fulcrum positioned at the lowest position on the outer periphery of the substrate W to be processed disposed inside the hole 3b, and a gravity direction passing through the lower fulcrum. Three are arranged at predetermined intervals around the hole 3b of the plate member 3a so as to support at three points with a pair of upper side fulcrum located on the upper side on the outer periphery that is symmetrical with respect to the center line. It has been.

  Each support member 19 is made of a leaf spring bent in an L shape, and its base end side is fixedly supported by the holder 3, and its tip end side protrudes toward the inside of the hole 3b. 3 is disposed in a slit 3c formed around the hole 3b. In addition, although not shown in the drawings, a groove portion with which the outer peripheral portion of the substrate to be processed W is engaged is provided at the distal end portion of each support member 19.

  The holder 3 can detachably hold the target substrate W fitted inside each of the support arms 19 while bringing the outer peripheral portion of the target substrate W into contact with the three support arms 19. It has become. In addition, attachment / detachment of the to-be-processed substrate W with respect to the holder 3 can be performed by pushing down the support arm 19 of a lower side fulcrum.

As shown in FIGS. 1, 4, and 5, the transport mechanism 5 includes a drive mechanism 20 that drives the carrier 4 in a non-contact state, and a guide mechanism 21 that guides the carrier 4 to be transported.
The drive mechanism 20 includes a plurality of magnets 22 arranged so that N poles and S poles are alternately arranged below the carrier 4, and a rotating magnet 23 arranged below the magnets 22 along the conveying direction of the carrier 4. In addition, on the outer peripheral surface of the rotating magnet 23, N poles and S poles are alternately formed in a double spiral shape.

  The drive mechanism 20 is provided with a vacuum partition wall 24 surrounding the rotary magnet 22, and the rotary magnet 22 is arranged in a space (atmosphere side) isolated from the internal space 7 of the reaction vessel 2 by the vacuum partition wall 24. doing. The vacuum partition 24 is formed of a material having high magnetic permeability so that the plurality of magnets 22 and the rotating magnet 23 are magnetically coupled.

  The rotating magnet 22 is connected to a rotating shaft 26 that is rotationally driven by a rotating motor 25 via a gear mechanism 27 that meshes with the rotating shaft 26. As a result, it is possible to rotate the rotating magnet 23 around the axis while transmitting the driving force from the rotating motor 25 to the rotating magnet 23 via the rotating shaft 26 and the gear mechanism 27.

  The drive mechanism 20 rotates the rotating magnet 23 around the axis while magnetically coupling the plurality of magnets 22 and the rotating magnet 23 in a non-contact manner, thereby moving the carrier 4 in the axial direction of the rotating magnet 23. Drive along a straight line.

  The guide mechanism 21 has a plurality of main bearings 28 supported so as to be rotatable about a horizontal axis, and the plurality of main bearings 28 are arranged in a straight line in the transport direction of the carrier 4. On the other hand, the carrier 4 has a guide rail 29 in which a groove portion with which a plurality of main bearings 28 are engaged is formed on the lower side of the support base 18.

  The guide mechanism 21 has a pair of sub-bearings 30 supported so as to be rotatable about a vertical axis, and the pair of sub-bearings 30 are arranged to face each other so as to sandwich the carrier 4 therebetween. Further, like the plurality of main bearings 28, a plurality of the pair of sub bearings 30 are provided side by side in a straight line in the transport direction of the carrier 4.

  The guide mechanism 21 guides the carrier 4 moving on the plurality of main bearings 28 in a state where the plurality of main bearings 28 are engaged with the grooves of the guide rails 29, and a pair of sub bearings 30. By sandwiching the carrier 4 between the two, the carrier 4 is prevented from tilting during movement.

  The main bearing 28 and the sub-bearing 30 are constituted by rolling bearings in order to reduce friction of machine parts and ensure a smooth rotational movement of the machine. The rolling bearing is rotatably attached to a support shaft fixed to a frame provided in the reaction vessel 2 although not shown.

  In the magnetron sputtering apparatus 1 having the above structure, the magnetic circuit 11 applies a high frequency voltage to the target T through the backing plate 8 while generating a magnetic field on the surface of the target T, and is introduced from the gas introduction tube 9. The target gas ejected from the target T is covered by causing the ions in the plasma to collide with the surface of the target T while ionizing the gas and generating plasma around the target T (reaction space R). It is possible to form a thin film by depositing on the processing substrate W.

  In this magnetron sputtering apparatus 1, when a cathode electrode is disposed instead of the backing plate 8 to which the target T is attached, a bias voltage is applied to the substrate W to be processed and introduced from the gas introduction tube 9. The exposed region can be modified by exposing the surface of the substrate W to the plasma while ionizing the gas and generating plasma around the substrate W to be processed (reaction space R). is there.

  By the way, in the magnetron sputtering apparatus 1 to which the present invention is applied, the Bz = 0 line connecting the points where the vertical component Bz of the magnetic flux density on the surface of the target T of the magnetic field generated by the magnetic circuit 11 becomes 0 [T], By drawing a specific curve in a plane parallel to the surface of the target T, erosion generated on the surface of the target T can be made highly uniform, and the life of the target T can be significantly increased.

(Magnetic circuit)
Specifically, the configuration of the magnetic circuit 11 which is a characteristic part of the magnetron sputtering apparatus 1 to which the present invention is applied will be described.
As shown in FIGS. 6 and 7, the magnetic circuit 11 includes a cylindrical first magnet (outer magnet) 40 whose magnetization direction is parallel to the axis, and a concentric arrangement inside the first magnet 40. The first magnet 40 has a cylindrical second magnet (inner magnet) 41 whose magnetization direction is antiparallel. Three corner portions 40a and 41b that protrude outward are provided at equal intervals in the circumferential direction at positions where these first and second magnets 40 and 41 face each other. And between the corner | angular parts 40a and 40b of these 1st and 2nd magnets 40 and 41, the side surface curved toward the outer side is formed.

  Further, between the corner portions 40a of the first magnet 40, three protruding portions 42 protruding from the inner side surface are provided side by side at equal intervals in the circumferential direction. These protrusions 42 are provided at least from one end side facing the backing plate 8 in the axial direction. Further, these protruding portions 42 are formed to protrude from the inner surface of the first magnet 40 toward the center thereof with a certain width and height.

  Correspondingly, three slits 43 are provided at equal positions in the circumferential direction at positions facing the protrusions 42 of the second magnet 41 so that the protrusions 42 face each other. These slits 43 have a larger width than the projecting portion 42 and are cut out in the axial direction from at least one end side facing the backing plate 8 in parallel with the projecting portion 42.

  In the present embodiment, each protrusion 42 is formed so as to protrude linearly between one end and the other end of the first magnet 40. Further, the tip of each protrusion 42 is positioned in front of the center of the first magnet 40. Correspondingly, each slit 43 is formed in a linear notch between one end and the other end of the second magnet 41 so as to divide a part of the second magnet 41. Yes. Thereby, each projecting portion 42 projecting from the inner surface of the first magnet 40 is disposed so as to face the inside of the second magnet 41 from between each slit 43, and the tip thereof is the second magnet 41. It is located in front of the center.

  The magnetic circuit 11 has a yoke 44 that forms a magnetic path together with the first and second magnets 40 and 41. The yoke 44 is made of a plate-like soft magnetic material, and the first and second magnets 40 and 41 are backed so as to close the opening on the other end side of the first and second magnets 40 and 41. The plate 8 is attached in a state of being abutted against the surface (back surface) opposite to the surface (front surface) facing the plate 8. Further, the yoke 44 is formed in a circular shape projecting outward from the first magnet 40 with the rotation center of the magnetic circuit 11 as the center, so that the rotation of the magnetic circuit 11 can be made more stable.

  As a result, the magnetic circuit 11 is configured, and the first and second magnets 40 and 41 are arranged from one end side of the first and second magnets 40 and 41 as shown in FIGS. An arc-shaped leakage magnetic field (magnetic field) M is generated around the entire circumference.

  The magnetic circuit 11 is attached to the rotating shaft 12a of the drive motor 12 in a state where the axes of the first and second magnets 40 and 41 and the axis of the target T are parallel to each other. It can rotate in a plane parallel to the surface. Since the processing unit 1A generates a horizontal magnetic field M near the surface of the target T, the facing distance between the target T and the magnetic circuit 11 can be adjusted.

  Further, it is preferable that the first magnet 40 and the second magnet 41 have substantially the same volume. By making the volume of the first magnet 40 and the second magnet 41 equal, the leakage magnetic field other than the leakage magnetic field generated between the first magnet 40 and the second magnet 41 described above is reduced, It is possible to make the erosion generated on the surface of the target T uniform and to control the erosion shape at a high level.

  In the magnetic circuit 11 having the above structure, the vertical component Bz of the magnetic flux density on the surface of the target T of the magnetic field M generated between the first magnet 40 and the second magnet 41 is 0 [T]. A locus connecting the points (hereinafter referred to as a Bz = 0 line) draws a curve L1 having a plurality of inflection points C1 and C2 as shown in FIG. 8, for example, in a plane parallel to the surface of the target T. become.

  In the magnetron sputtering apparatus 1 to which the present invention is applied, the Bz = 0 line of the magnetic field M generated by the magnetic circuit 11 draws the curve L having such a shape, thereby generating non-uniform erosion on the surface of the target T. It is possible to improve the utilization efficiency of the target T and improve the uniformity of the in-plane distribution when a thin film is formed on the surface of the substrate W to be processed by sputtering.

(Bz = 0 line)
Here, the Bz = 0 line of the present invention will be described.
The Bz = 0 line of the present invention draws a similar shape of a curve represented by polar coordinates (r, θ) in a plane parallel to the surface of the target T, and a curve represented by the polar coordinates (r, θ). However, in the graph in which the horizontal axis is θ (0 ≦ θ ≦ 2π) and the vertical axis is r, there is an inflection point at θ = π, and at least at a position that is axially symmetric with respect to the inflection point. It is characterized by having one or more inflection points and drawing a straight line or a curve connecting these inflection points.

  In polar coordinates (r, θ), “r” represents the distance of a half line (referred to as a moving radius) extending from the origin (0, 0) on the XY coordinate plane, and “θ” is the positive axis of the Y axis. Represents the angle measured counterclockwise of the angle (referred to as declination) formed by this starting line and the radius vector.

  Specifically, the Bz = 0 line of the present invention is shown when the origin (0, 0) is set as the rotation center of the magnetic circuit 11 in polar coordinates (r, θ) in a plane parallel to the surface of the target T. 10 can be expressed as a curve L1 on polar coordinates (r, θ) as shown in FIG.

  In the polar coordinates (θ, r) shown in FIG. 10, the direction in which θ = 0 is the 0 o'clock direction on the coordinate plane, and θ is 0 to 2π [rad] counterclockwise from this 0 o'clock direction. It is assumed that r [mm] is taken within a range. FIG. 11 shows a graph in which the horizontal axis is converted to θ (0 ≦ θ ≦ 2π) and the vertical axis is converted to r for the curve L1 represented by the polar coordinates (r, θ).

  As shown in FIG. 10, the curve L1 representing the Bz = 0 line of the present invention turns from decreasing to increasing counterclockwise when θ = 0 (2π), 2 / 3π, and 4 / 3π, respectively. An inflection point (cusp) C1 and an inflection point (cusp) C2 at which r turns from increasing to decreasing counterclockwise when θ = 1 / 3π, π, 5 / 3π, and The inflection points C1 and C2 adjacent to each other are connected by curved lines (arc lines) that protrude outward. Further, the inflection points C1 and C2 do not pass through the rotation center (origin) of the magnetic circuit 11, and the curve L1 has a line-symmetric shape with respect to the vertical axis passing through the rotation center (origin) of the magnetic circuit 11. Have. Further, the curve L1 has a point-symmetric shape with respect to the rotation center (origin) of the magnetic circuit 11.

  In the graph shown in FIG. 11, the curve L1 representing the Bz = 0 line of the present invention has an inflection point C2 at θ = π, and a position that is axially symmetric with respect to the inflection point C2. It has two inflection points C1 and one inflection point C2, and can be represented by a straight line (broken line) connecting these inflection points C1 and C2.

  In the present invention, the erosion of the target T can be made uniform because the Bz = 0 line draws such a curve L1. In the present invention, since the Bz = 0 line does not pass through the rotation center of the magnetic circuit 11, erosion at the center of the target T does not proceed excessively, and as a result, the life of the target T can be increased. In particular, when manufacturing a magnetic recording medium, a disk-shaped substrate W having an opening in the center is used, so that the lifetime of the target can be significantly increased by reducing erosion near the center of the target. It is.

  When the inflection points C1 and C2 pass through the origin (0, 0), the Bz = 0 line always passes through the rotation center of the magnetic circuit 11, and the erosion at the center of the target T proceeds excessively. Therefore, it is not preferable.

  As described above, in the magnetron sputtering apparatus 1 to which the present invention is applied, the generation of non-uniform erosion on the surface of the target T is prevented, the utilization efficiency of the target T is improved, and the thin film is formed on the surface of the substrate W to be processed by sputtering. It is possible to improve the uniformity of the in-plane distribution when forming the film. Therefore, when such a magnetron sputtering apparatus 1 is used, it is possible to form a magnetic film or the like having a small in-plane distribution of magnetic characteristics, and thus a magnetic recording medium corresponding to high recording density can be obtained. In addition, it is possible to provide a magnetic recording / reproducing apparatus including such a magnetic recording medium.

  In addition, this invention is not necessarily limited to the thing of the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

  Specifically, in the present invention, the erosion range at the center of the target T can be controlled by changing the shape of the curve L1 drawn by the Bz = 0 line. For example, in the present invention, as shown in FIGS. 12 and 13, the Bz = 0 line can be represented as curves L2 and L3 obtained by correcting the curve L1.

  That is, in the graph shown in FIG. 13, the curve L2 draws a convex arc line between the inflection points C1 and C2, and therefore the shape of the curve L2 shown in FIG. 12 is a shape curved outside the curve L1. It becomes. On the other hand, in the graph shown in FIG. 13, since the curve L3 draws a downwardly protruding arc line between the inflection points C1 and C2, the shape of the curve L3 shown in FIG. 12 is a shape curved inside the curve L1. It becomes.

  As described above, in the present invention, the distribution of the film deposited on the substrate W to be processed at the time of sputtering can be linearly changed by adjusting the shape of the curve drawn by the Bz = 0 line. Therefore, in the present invention, even when a difference occurs in the film thickness distribution in the surface of the substrate W to be processed due to the influence of the apparatus factor and the like, this surface is corrected by correcting the shape of the curve drawn by the Bz = 0 line. It is possible to improve the uniformity of the internal distribution.

  In addition, the shape of the curve drawn by the Bz = 0 line of the present invention is not limited to the shape of the above-described curves L1 to L3, and can be appropriately changed and implemented within a range that satisfies the conditions of the present invention. For example, the Bz = 0 line of the present invention is shown in FIG. 14 when the origin (0, 0) is set to the rotation center of the magnetic circuit 11 in polar coordinates (r, θ) in a plane parallel to the surface of the target T. It can also be expressed as a curve L4 on the polar coordinates (r, θ) as shown.

  As shown in FIG. 14, the curve L4 representing the Bz = 0 line of the present invention has an inflection point (where r changes from decreasing to increasing counterclockwise when θ = 1 / 2π and 3 / 2π, respectively). An inflection point having a cusp point C1 and an inflection point (cusp point) C2 at which r turns from increasing to decreasing counterclockwise when θ = 0 (2π), π, and adjacent to each other It has a shape in which C1 and C2 are connected by a curved line (arc line) that protrudes outward. The inflection points C1 and C2 do not pass through the rotation center (origin) of the magnetic circuit 11, and the curve L4 has a line-symmetric shape with respect to the vertical axis passing through the rotation center (origin) of the magnetic circuit 11. Have.

  In the graph shown in FIG. 15, the curve L4 representing the Bz = 0 line of the present invention has an inflection point C1 at θ = π and is axisymmetric with respect to the inflection point C1. 1 has an inflection point C2 and one inflection point C1, and can be represented by a straight line (a broken line) connecting these inflection points C2 and C1.

  In the present invention, the Bz = 0 line draws such a curve L4, thereby preventing the generation of non-uniform erosion on the surface of the target T, improving the utilization efficiency of the target T, and improving the use efficiency of the target T. It is possible to improve the uniformity of in-plane distribution when a thin film is formed by sputtering.

  Further, the present invention is not necessarily limited to the configuration of the magnetic circuit 11 shown in FIGS. 7 to 9, and the first and second components constituting the magnetic circuit 11 are drawn to draw the Bz = 0 line of the present invention. The shapes of the second magnets 40 and 41, the protrusions 42, and the slits 43 can be changed as appropriate.

  For example, as in the magnetic circuit 11A shown in FIG. 16A, instead of the cylindrical second magnet 41, a columnar second magnet 41A provided with a slit 43A is used as the first magnet 40. It is also possible to adopt a configuration in which they are arranged concentrically on the inner side.

  Further, as in the magnetic circuits 11B and 11C shown in FIGS. 16B and 16C, instead of the second magnet 41 provided with the slit 43, a cylindrical or columnar first having the slit 43 omitted is provided. It is also possible to adopt a configuration in which the two magnets 41B and 41C are arranged inside the first magnet 40.

  Also, as in the magnetic circuits 11D and 11E shown in FIGS. 16D and 16E, the first magnet 40 provided with the protruding portion 42 and the second magnet 41 provided with the slit 43 are provided. Instead, a configuration in which the second magnet 41D in which the protruding portion 42 protrudes from the outer surface is disposed inside the first magnet 41D in which the protruding portion 42 is omitted, or a first magnet in which the slit 43 is provided. It is also possible to adopt a configuration in which the second magnet 41E in which the protruding portion 42 protrudes from the outer surface is disposed inside 41E.

(In-line deposition system)
Next, the configuration of the in-line film forming apparatus 50 provided with the magnetron sputtering apparatus 1 shown in FIG. 17 will be described.
As shown in FIG. 17, the in-line film forming apparatus 50 is adjacent to the substrate transfer robot chamber 51, the substrate transfer robot 52 installed on the substrate transfer robot chamber 51, and the substrate transfer robot chamber 51. A substrate mounting robot chamber 53, a substrate mounting robot 54 disposed in the substrate mounting robot chamber 53, a substrate replacement chamber 55 adjacent to the substrate mounting robot chamber 53, and a substrate adjacent to the substrate replacement chamber 55. A removal robot chamber 56, a substrate removal robot 57 disposed in the substrate removal robot chamber 56, and a plurality of processing chambers 58 to 55 disposed side by side between the entry side and the exit side of the substrate exchange chamber 55. 70 and spare chamber 71, a plurality of corner chambers 72 to 75, and the respective chambers 58 to 71 and the corner chambers 72 to 75 from the entrance side to the exit side of the substrate exchange chamber 55 are sequentially conveyed. It is schematically configured with a plurality of the carrier 4.

  Further, openable and closable gate valves 76 to 93 are provided between the chambers from the entrance side to the exit side of the substrate exchange chamber 55. The chambers 58 to 71 can form independent sealed spaces by closing the gate valves 76 to 93.

  The substrate transfer robot 52 supplies the substrate to be processed W to the substrate mounting robot chamber 54 from a cassette (not shown) in which the non-processed substrate W before film formation is stored, and the substrate removal robot chamber 56. This is for recovering the substrate W after film formation. Gate portions 94 and 95 that can be freely opened and closed are provided between the substrate transfer robot chamber 51 and the substrate mounting and substrate removal robot chambers 53 and 56, respectively. Furthermore, openable and closable gate portions 96 and 97 are also provided between the substrate exchange chamber 55 and the substrate mounting and substrate removal robot chambers 53 and 56, respectively.

  The substrate attachment robot 54 attaches the substrate W to be processed before film formation to the carrier 4 in the substrate exchange chamber 55, while the substrate removal robot 57 performs film formation from the carrier 4 in the substrate exchange chamber 55 after film formation. The substrate W to be processed is removed.

  The plurality of processing chambers 58 to 70 and the spare chamber 71 basically have the same configuration as the reaction vessel 2 of the magnetron sputtering apparatus 1, and the carrier 4 is provided on both sides of each processing chamber 58 to 70. A processing unit 1A corresponding to the processing content for the substrate W to be processed held in is disposed. Although not shown, the chambers 58 to 71 are connected to the above-described vacuum pumps, and each chamber 58 to 71 can be individually evacuated by the operation of the vacuum pumps. . Each corner chamber 72 to 75 is provided with a rotation mechanism (not shown) for changing the moving direction of the carrier 4.

  In the inline-type film forming apparatus 50, each carrier 4 is sequentially transported between the chambers 58 to 71 and the corner chambers 72 to 75 from the entrance side to the exit side of the substrate exchange chamber 55. A film forming process or the like can be performed on the substrate W to be processed (not shown in FIG. 17) held on the substrate.

  In this embodiment, it is possible to process two substrates to be processed W held on the holder 3 of the carrier 4 at the same time. However, only the substrate to be processed W held on one holder 3 is processed. In the case of the configuration to be performed, for example, as shown by the solid line in FIG. 18, after processing is performed on the target substrate W <b> 1 held by one holder 3 </ b> A of the carrier 4, the broken line in FIG. As described above, the position of the carrier 4 is shifted in the reaction container 2, and the processing is performed on the substrate W <b> 2 that is held by the other holder 3 </ b> B (indicated by a broken line in FIG. 17) of the carrier 4. Thereby, it is possible to alternately process the two substrates to be processed W1 and W2 held by the holder 3 of the carrier 4.

(Method of manufacturing magnetic recording medium)
Next, a method for manufacturing a magnetic recording medium to which the present invention is applied will be described.
In the method of manufacturing a magnetic recording medium to which the present invention is applied, a nonmagnetic substrate to be processed W held by the carrier 4 is placed between the plurality of processing chambers 58 to 70 using the in-line film forming apparatus 50. A magnetic layer composed of a soft magnetic layer, an intermediate layer, and a recording magnetic layer, and a protective layer are sequentially laminated on both surfaces of the nonmagnetic substrate while being sequentially conveyed. Furthermore, after using the inline-type film forming apparatus 50, a lubricating film is formed on the outermost surface of the substrate W after film formation using a coating apparatus (not shown), whereby the magnetic recording medium is obtained. To manufacture.

  In the method for manufacturing a magnetic recording medium to which the present invention is applied, it is possible to increase the production capacity of the magnetic recording medium and to manufacture a high-quality magnetic recording medium by using the in-line film forming apparatus 50.

(Magnetic recording medium)
Specifically, a magnetic recording medium manufactured using the inline-type film forming apparatus 50 includes, for example, a soft magnetic layer 101 on both surfaces of a nonmagnetic substrate 100 to be processed substrate W, as shown in FIG. The intermediate layer 102, the recording magnetic layer 103, and the protective layer 104 are sequentially stacked, and the lubricating film 105 is further formed on the outermost surface. The soft magnetic layer 81, the intermediate layer 82, and the recording magnetic layer 83 constitute a magnetic layer 106.

  Examples of the nonmagnetic substrate 100 include an Al alloy substrate mainly composed of Al, such as an Al—Mg alloy, a glass substrate such as soda glass, aluminosilicate glass, or crystallized glass, a silicon substrate, a titanium substrate, a ceramic substrate, Various substrates such as a resin substrate can be mentioned, and among them, an Al alloy substrate, a glass substrate, and a silicon substrate are preferably used. Further, the average surface roughness (Ra) of the nonmagnetic substrate 100 is preferably 1 nm or less, more preferably 0.5 nm or less, and further preferably 0.1 nm or less.

The magnetic layer 106 can be broadly divided into a horizontal magnetic layer for in-plane magnetic recording media and a perpendicular magnetic layer for perpendicular magnetic recording media. In order to achieve a higher recording density, a perpendicular magnetic layer is used. Is preferably used. The magnetic layer 106 is preferably made of a Co alloy containing Co as a main component. Specifically, in the case of the perpendicular magnetic layer, for example, soft magnetic FeCo alloys (FeCoB, FeCoSiB, FeCoZr, FeCoZrB, FeCoZrBCu, etc.), FeTa alloys (FeTaN, FeTaC, etc.), Co alloys (CoTaZr, CoZrNB, CoB, etc.) ) and the soft magnetic layer 101 made of such as an intermediate layer 102 made of Ru or the like, be used such as those formed by laminating a recording magnetic layer 103 made of 60Co-15Cr-15Pt alloy or 70Co-5Cr-15Pt-10SiO ₂ alloy Can do. Further, an orientation control film made of Pt, Pd, NiCr, NiFeCr or the like may be interposed between the soft magnetic layer 81 and the intermediate layer 82. On the other hand, in the case of a horizontal magnetic layer, for example, a nonmagnetic CrMo underlayer and a ferromagnetic CoCrPtTa magnetic layer laminated can be used.

  Further, the magnetic layer 106 needs to be formed with a thickness that can provide sufficient input / output characteristics of the magnetic head in accordance with the type of magnetic alloy used and the laminated structure. On the other hand, the magnetic layer 106 needs to have a certain thickness in order to obtain a certain output during reproduction, but various parameters representing recording / reproduction characteristics usually deteriorate as the output increases. Therefore, it is necessary to set an optimum thickness. Specifically, the total thickness of the magnetic layer 106 is preferably 3 nm or more and 20 nm or less, and more preferably 5 nm or more and 15 nm or less.

The protective layer 104 may be made of a material usually used in magnetic recording media. Examples of such a material include carbon (C), hydrogenated carbon (HXC), nitrogenated carbon (CN), and alumocarbon. Examples thereof include carbonaceous materials such as silicon carbide (SiC), SiO ₂ , Zr ₂ O ₃ , and TiN. The protective layer 104 may be a stack of two or more layers. If the thickness of the protective layer 104 exceeds 10 nm, the distance between the magnetic head and the magnetic layer 106 increases, and sufficient input / output characteristics cannot be obtained.

  The lubricating film 105 can be formed, for example, by applying a lubricant made of a fluorine-based lubricant, a hydrocarbon-based lubricant, a mixture thereof, or the like on the protective layer 104. The film thickness of the lubricating film 105 is usually about 1 to 4 nm.

  In addition, for the magnetic recording medium, the recording magnetic layer 103 is subjected to reactive plasma treatment or ion irradiation treatment using the in-line film forming apparatus 50 to improve the magnetic characteristics of the recording magnetic layer 103. Can do. For example, the magnetic recording medium shown in FIG. 20 is a so-called discrete type magnetic recording medium in which magnetic recording patterns 103a formed in the recording magnetic layer 103 are separated by nonmagnetic regions 103b.

  As for the discrete type magnetic recording medium, for example, a patterned medium in which the magnetic recording pattern 103a is arranged with a certain regularity for each bit, a medium in which the magnetic recording pattern 103a is arranged in a track shape, and a magnetic recording pattern A medium 103a includes a servo signal pattern or the like.

  Also, in order to increase the recording density of the discrete magnetic recording medium, the width L1 of the portion that becomes the magnetic recording pattern 103a of the recording magnetic layer 103 is 200 nm or less, and the width L2 of the portion that becomes the non-magnetized region 103b. Is preferably 100 nm or less. The track pitch P (= L1 + L2) of this magnetic recording medium is preferably 300 nm or less, and is preferably as narrow as possible in order to increase the recording density.

  In such a discrete type magnetic recording medium, a mask layer is provided on the surface of the recording magnetic layer 103, and a portion not covered with the mask layer is exposed to a reactive plasma treatment or an ion irradiation treatment. Thereby, the magnetic characteristics of a part of the recording magnetic layer 103 can be modified, and preferably obtained by forming the nonmagnetic region 103b modified from a magnetic material to a nonmagnetic material.

  Here, the modification of the magnetic characteristics of the recording magnetic layer 103 means that the coercive force, residual magnetization, etc. of the recording magnetic layer 103 are partially changed in order to pattern the recording magnetic layer 103, and the change This means that the coercive force is lowered and the residual magnetization is lowered.

  Specifically, when the magnetic characteristics of the recording magnetic layer 103 are modified, the magnetization amount of the recording magnetic layer 103 at a location exposed to reactive plasma or reactive ions is set to 75% or less of the initial (unprocessed). The coercive force is preferably 50% or less and the initial coercive force is preferably 50% or less, more preferably 20% or less. As a result, writing blur at the time of magnetic recording can be eliminated and a high surface recording density can be obtained.

  Further, the magnetic property is modified by exposing the already formed recording magnetic layer 103 to reactive plasma, reactive ions, etc., and separating the magnetic recording track and the servo signal pattern (nonmagnetic region 103b) from amorphous. It can also be realized by improving the quality.

  Here, making the recording magnetic layer 103 amorphous means modifying the crystal structure of the recording magnetic layer 103, and the atomic arrangement of the recording magnetic layer 103 is changed to an irregular atomic arrangement having no long-range order. Say to state. Specifically, when the recording magnetic layer 103 is amorphized, it is preferable that the atomic arrangement of the recording magnetic layer 103 is in a state where microcrystalline grains having a particle diameter of less than 2 nm are randomly arranged. Note that such an atomic arrangement state of the recording magnetic layer 103 can be confirmed by an analysis technique such as X-ray diffraction or electron beam diffraction as a state where no peak representing a crystal plane is observed and only a halo is recognized. It is.

(Magnetic recording / reproducing device)
An example of the magnetic recording / reproducing apparatus using the magnetic recording medium is a hard disk drive (HDD) as shown in FIG. This magnetic recording / reproducing apparatus includes a magnetic disk 200 that is the magnetic recording medium, a medium driving unit 201 that rotationally drives the magnetic disk 200, a magnetic head 202 that performs recording and reproducing operations on the magnetic disk 201, and a magnetic head A head driving unit 203 that moves 202 in the radial direction of the magnetic disk 200 and a signal processing system 204 for performing signal input to the magnetic head 202 and reproduction of output signals from the magnetic head 202 are provided.

  In this magnetic recording / reproducing apparatus, when the discrete track type magnetic recording medium is used as the magnetic disk 200, it is possible to eliminate writing blur when performing magnetic recording on the magnetic disk 200 and to obtain a high surface recording density. It is. That is, by using the discrete track type magnetic recording medium, a magnetic recording / reproducing apparatus having a high recording density can be obtained.

  Also, in this magnetic recording / reproducing apparatus, by conventionally processing the recording track magnetically discontinuously, the reproducing head width is conventionally made narrower than the recording head width in order to eliminate the influence of the magnetization transition region at the track edge. The corresponding ones can be operated with substantially the same width, which makes it possible to obtain a sufficient reproduction output and a high SNR.

  Further, in this magnetic recording / reproducing apparatus, it is possible to obtain a sufficient signal intensity even at a high recording density by configuring the reproducing unit of the magnetic head 202 with a GMR head or a TMR head. Furthermore, by raising the magnetic head 202 lower than before, specifically, by setting the flying height of the magnetic head 202 in the range of 0.005 μm to 0.020 μm, a higher SNR can be obtained by improving the output. Therefore, a magnetic recording / reproducing apparatus having a large capacity and high reliability can be obtained.

  Further, when the signal processing circuit based on the maximum likelihood decoding method is combined, it is possible to further improve the recording density. For example, a sufficient SNR can be obtained even when recording / reproducing is performed at a recording density of 100 kbit / inch or more, a linear recording density of 1000 kbit / inch or more, and a recording density of 100 Gbit or more per square inch.

  Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement.

In this example, a magnetic recording medium was actually manufactured using an in-line film forming apparatus equipped with the magnetron sputtering apparatus of the present invention.
Specifically, in this example, a target having a diameter of 110 mm and a thickness of 8 mm was used, and the magnetic circuit arranged on the back side of the target was of the shape shown in FIG. That is, the Bz = 0 line by this magnetic circuit draws a curve having the shape shown in FIG.

  In this magnetic circuit, first and second magnets made of NdFeB-based sintered magnets having a height of 30 mm and a width of 5 mm to 8 mm are attached to one surface of a yoke made of a stainless steel plate (SS300) having a diameter of 110 mm and a thickness of 8 mm. The first magnet and the second magnet have substantially the same volume, and when viewed from the target side, the first magnet has an N pole and the second magnet has an S pole. Arranged. The distance from the magnetic circuit to the surface of the target was 17.7 mm, and the rotation speed of the magnetic circuit was 60 rpm. For the magnetic circuits facing each other with the substrate to be processed interposed therebetween, the phases of the Bz = 0 lines are shifted by π.

When manufacturing a magnetic recording medium, first, a substrate holder is attached to a cleaned glass substrate (manufactured by Konica Minolta, substrate outer diameter: 65 mm, substrate thickness: 1.27 mm, center hole diameter: 20 mm). The glass substrate is held by the carrier, accommodated in the chamber of an in-line film forming apparatus (C-3040 manufactured by Anelva), and evacuated to the ultimate vacuum of 1 × 10 ⁻⁵ Pa. On top of this, a 10 nm thick adhesion layer was formed using a Cr target. In addition, on this adhesion layer, using a target of Co-20Fe-5Zr-5Ta {Fe content 20at%, Zr content 5at%, Ta content 5at%, balance Co}, a soft magnetic layer with a thickness of 25 nm After forming a layer and forming a Ru layer with a thickness of 0.7 nm thereon, a soft magnetic layer of Co-20Fe-5Zr-5Ta is further formed with a thickness of 25 nm. It was a stratum.

  Next, Ni-6W {W content 6 at%, balance Ni} target and Ru target were sequentially formed on the soft magnetic underlayer with a layer thickness of 5 nm and 20 nm, respectively, and this was formed into an orientation control layer. It was. The Ru layer was formed with a sputtering pressure of 0.8 Pa and a thickness of 10 nm, and then with a sputtering pressure of 1.5 Pa and a thickness of 10 nm.

Then, on the orientation control _{layer, (Co15Cr16Pt) 91- (SiO 2} ) 6- (TiO 2) 3 {Cr content 15 at%, Pt content of 18 at%, the alloy of the balance Co 91 mol%, of SiO ₂ A magnetic layer having a composition of 6 mol% of an oxide and 3 mol% of an oxide of TiO ₂ was formed with a sputtering pressure of 2 Pa and a layer thickness of 9 nm.

Next, on the magnetic layer was deposited at a layer thickness of 0.3nm nonmagnetic layer composed of _{(Co30Cr) 88- (TiO 2)} 12.

Next, a magnetic layer made of (Co11Cr18Pt) 92- (SiO ₂ ) 5- (TiO ₂ ) 3 was formed on the nonmagnetic layer with a sputtering pressure of 2 Pa and a layer thickness of 6 nm.

  Next, a nonmagnetic layer made of Ru was formed with a layer thickness of 0.3 nm on the magnetic layer.

  Next, a magnetic layer is formed on the nonmagnetic layer using a target composed of Co20Cr14Pt3B {Cr content 20 at%, Pt content 14 at%, B content 3 at%, balance Co} and a sputtering pressure of 0.6 Pa. The film was formed with a layer thickness of 7 nm.

  Next, a protective layer having a thickness of 3.0 nm was formed by a CVD method, and then a lubricating layer made of perfluoropolyether was formed by a dipping method to produce a magnetic recording medium.

  Then, with respect to this magnetic recording medium, each of the recording / reproduction characteristics, that is, the S / N ratio, the recording characteristics (OW), and the thermal fluctuation characteristics are evaluated using a read / write analyzer RWA1632 and spin stand S1701MP manufactured by GUZIK. went. As the magnetic head, a head using a single pole magnetic pole on the writing side and a TMR element on the reading side was used.

  The S / N ratio was measured as a recording density of 750 kFCI.

  On the other hand, as for the recording characteristics (OW), first, a 750 kFCI signal was written, then a 100 kFCI signal was overwritten, a high frequency component was taken out by a frequency filter, and the data writing ability was evaluated by the residual ratio.

  On the other hand, with respect to thermal fluctuation characteristics, after writing at a recording density of 50 kFCI under the condition of 70 ° C., the output attenuation rate with respect to the playback output one second after writing is (So−S) × 100 / (So). Calculated based on In this equation, So represents a reproduction output when 1 second has elapsed after writing, and S represents a reproduction output after 10,000 seconds.

  Further, the recording / reproduction characteristics of the magnetic recording medium obtained in this example were evaluated for the outermost track, the innermost track, and the middle track. As a result, the S / N was 17.9 dB on average, the OW was 37.5 dB on average, and the thermal fluctuation was 0.3% on average, but the variation between tracks of each characteristic was within 3% in S / N. The OW was within 2% and the thermal fluctuation was within 0.05%, and almost no in-plane distribution was observed. The distribution of erosion generated on the target surface was such that the width of erosion in the cross section of all targets was within ± 2 mm in the manufacture of 20,000 magnetic recording media. The reproducibility of the occurrence of erosion when the same test was repeated was within ± 0.5 mm.

DESCRIPTION OF SYMBOLS 1 ... Magnetron sputtering apparatus 1A ... Processing unit 2 ... Reaction vessel 2A ... Gate valve 3 ... Holder 3 4 ... Carrier 5 ... Carrier mechanism 6a ... Front side partition 6b ... Back side partition 6c ... Bottom wall 6d ... Hole 7 ... Internal space DESCRIPTION OF SYMBOLS 8 ... Backing plate (cathode electrode) 9 ... Gas introduction pipe (gas introduction means) 10 ... Gas supply source 11 ... Magnetic circuit (magnetic field generation means) 12 ... Drive motor 13 ... Opening part 14 ... Housing 15 ... 1st vacuum pump (Pressure reduction exhaust means) 16 ... second vacuum pump (another pressure reduction exhaust means) 17 ... pump chamber 18 ... support base 19 ... support arm 20 ... drive mechanism 21 ... guide mechanism 22 ... magnet 23 ... rotary magnet 24 ... vacuum partition DESCRIPTION OF SYMBOLS 25 ... Rotary motor 26 ... Rotating shaft 27 ... Gear mechanism 28 ... Main bearing 29 ... Guide rail 30 ... Sub bearing W ... Substrate to be processed T ... Tar G R ... Reaction space G ... Gas H ... Suction port 40 ... First magnet 41 ... Second magnet 42 ... Projection 43 ... Slit 44 ... Yoke M ... Magnetic field L1-L4 ... Curve representing Bz = 0 line 50 In-line type film forming apparatus 51 ... Substrate transfer robot chamber 52 ... Substrate transfer robot 53 ... Substrate mounting robot chamber 54 ... Substrate mounting robot 55 ... Substrate replacement chamber 56 ... Substrate removal robot chamber 57 ... Substrate removal robot 58-70 ... processing chamber 71 ... spare chamber 72-75 ... corner chamber 76-93 ... gate valve 94-97 ... gate part 100 ... nonmagnetic substrate 101 ... soft magnetic layer 102 ... intermediate layer 103 ... recording magnetic layer 103a ... magnetic Recording pattern 103b Non-magnetized region 104 ... Protective layer 105 ... Lubricating film 106 ... Magnetic layer 107 ... Mask layer 108 ... Strike layer 109 ... stamp 200 ... magnetic disk 201 ... medium driving unit 202 ... magnetic head 203 ... head driver 204 ... signal processing system

Claims (10)

A reaction vessel in which a substrate to be processed is disposed;
Reduced pressure exhaust means for evacuating the reaction vessel;
Processing means for processing the substrate to be processed;
The processing means includes a backing plate that holds a target facing the substrate to be processed, and a magnetic circuit that is located on the opposite side of the backing plate from the target and generates a magnetic field on the surface of the target. And
The magnetic circuit is arranged to have a cylindrical first magnet whose magnetization direction is parallel to the axis, and to have the same center inside the first magnet, and the first magnet has a magnetization direction. In a state where the axis of the first and second magnets and the axis of the target are parallel to each other. The two magnets are rotatable in a plane parallel to the surface of the target,
The Bz = 0 line connecting the points where the perpendicular component Bz of the magnetic flux density on the surface of the target of the magnetic field generated between the first magnet and the second magnet is 0 [T] is In the plane parallel to the surface, draw a similar shape of the curve represented by polar coordinates (r, θ),
Corresponding to the shape of the first magnet and the second magnet,
The curve represented by the polar coordinates (r, θ) has an inflection point at θ = π in a graph in which the horizontal axis is θ (0 ≦ θ ≦ 2π) and the vertical axis is r. A magnetron sputtering apparatus characterized by having at least one or more inflection points at positions that are axially symmetric with respect to the inflection points, and drawing a straight line or a curve connecting these inflection points.   The at least one projecting portion projecting from the inner surface of the first magnet is provided at least from one end side facing the backing plate in the axial direction. 2. The magnetron sputtering apparatus according to 1.   3. The magnetron sputtering apparatus according to claim 2, wherein at least one slit is provided at a position facing the protruding portion of the second magnet so that the protruding portion faces the inside. 4.   The at least one or more projecting portions projecting from the outer surface of the second magnet are provided at least from one end side facing the backing plate in the axial direction. The magnetron sputtering apparatus as described in any one of 1-3.   5. The magnetron sputtering apparatus according to claim 4, wherein at least one slit is provided at a position facing the protruding portion of the first magnet so that the protruding portion faces the inside. 6.   The at least 1 or more corner | angular part which becomes convex toward the outer side is provided in the mutually opposing position of the said 1st and 2nd magnet, The any one of Claims 1-5 characterized by the above-mentioned. The magnetron sputtering apparatus described in 1.   The magnetic circuit has a yoke that forms a magnetic path together with the first and second magnets, and the yoke is a surface opposite to the surface of the first and second magnets facing the backing plate. The magnetron sputtering apparatus according to any one of claims 1 to 6, wherein the magnetron sputtering apparatus is attached in a state of being abutted against each other.   The magnetron sputtering apparatus according to claim 1, wherein the first magnet and the second magnet have substantially the same volume. Multiple chambers;
A carrier for holding a substrate to be processed in the plurality of chambers;
A transport mechanism for sequentially transporting the carrier between the plurality of chambers,
An in-line type film forming apparatus, wherein at least one of the plurality of chambers is configured by the apparatus according to claim 1.   A method for manufacturing a magnetic recording medium, comprising: forming at least a magnetic layer on a nonmagnetic substrate using the in-line film forming apparatus according to claim 9.

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