JP2010163639A - Sputtering apparatus and method for manufacturing magnetic recording medium using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sputtering apparatus in which adhesibility between a target and a backing plate is enhanced without using any sheet, and the cooling efficiency of the target is enhanced. <P>SOLUTION: The sputtering apparatus includes a reaction vessel, and a water-cooled cathode which is arranged in the reaction vessel and has a target 117 being fixed on one surface thereof. The water-cooled cathode has a constitution in which two metal plates are separated from each other with an elastic material. A cooling water passage is formed between the two metal plates. The metal plate for fixing the target 117 out of the two metal plates constituting the water-cooled cathode forms a projecting surface on the target 117 side during the sputtering. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a sputtering apparatus built in an in-line type film forming apparatus or the like and a method for manufacturing a magnetic recording medium using the same.

  In recent years, the application range 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. Especially in HDD (Hard Disk Drive), since the introduction of MR head and PRML technology, the increase in surface recording density has become more severe. Continues to increase.

  Such a magnetic recording medium is configured to have a plurality of thin films, and an in-line type in which a plurality of film forming apparatuses for forming each thin film constituting the magnetic recording medium are connected in a row through a gate valve. In general, it is manufactured using a film forming apparatus.

Here, examples of the film forming apparatus include a sputtering apparatus, a reaction container having a pair of electrodes, a gas supply means for supplying gas into the reaction container, a vacuum pump for exhausting the gas in the reaction container, and the like. It is comprised.
In this in-line type film forming apparatus, a film forming substrate is sequentially transferred into each sputtering apparatus, and a predetermined thin film is formed in each sputtering apparatus. Therefore, the same number of thin films as the number of sputtering apparatuses can be formed on the deposition substrate by making a round of the in-line film deposition apparatus.

By the way, such a sputtering apparatus is normally used continuously for about two weeks.
For this reason, if the target is not cooled, the target temperature gradually increases and the target and the backing plate to which the target is attached are dissolved.

  In order to eliminate such inconvenience, a sputtering apparatus using a backing plate having a water cooling mechanism has been conventionally known (Patent Document 1).

Japanese Patent Laid-Open No. 2000-169962

  However, in the conventional sputtering apparatus, in order to increase the cooling efficiency, it is necessary to improve the adhesion between the target and the backing plate. Therefore, it is necessary to sandwich a sheet having a thickness of about 1 mm formed of indium or carbon. there were.

As a result, when the sheet is made of carbon, the sheet is liable to collapse, which causes a problem of dust.
In addition, when the sheet is made of indium, the sheet is melted by heat, so that there is a disadvantage that the required power cannot be applied.

  Under such a background, there has been a demand for a sputtering apparatus that improves the adhesion between the target and the backing plate without using a sheet. However, it is effective and appropriate to improve the adhesion without using a sheet. The fact is that nothing is provided.

  The present invention has been made in view of such circumstances, and its purpose is to increase the adhesion between the target and the backing plate without using a sheet, and to increase the cooling efficiency of the target. Is to provide a device.

In order to achieve the above object, the present invention provides the following means.
(1) A sputtering apparatus having a reaction vessel and a water-cooled cathode disposed in the reaction vessel and having a target fixed on one surface, wherein the two metal plates are separated by an elastic material. The cooling water channel is formed between the two metal plates, and the metal plate for fixing the target among the two metal plates constituting the water-cooled cathode is formed by sputtering. A sputtering apparatus characterized in that a convex surface is formed on the target side.
(2) The sputtering apparatus according to (1), wherein the cooling water channel is formed of the elastic material that separates the two metal plates.
(3) The sputtering apparatus according to (1) or (2), wherein the elastic material is an O-ring.
(4) The sputtering apparatus according to any one of (1) to (3), wherein a magnet for generating a magnetic field on the surface of the target is disposed on the other surface side of the water-cooled cathode.
(5) A method for producing a magnetic recording medium, comprising producing a magnetic recording medium using the sputtering apparatus according to any one of (1) to (4).

In the present invention, since the backing plate is configured to form a convex surface on the target side during sputtering, the adhesion between the backing plate and the target is improved despite the fact that no sheet is used.
In addition, since the cooling water channel is formed by partitioning the cooling water with an elastic material, the cooling water channel can be easily changed, and the backing plate and thus the target in close contact with the backing plate can be selectively and locally cooled.

FIG. 1 is a perspective view of the backing plate as viewed from the side opposite to the target fixing surface. FIG. 2 is a cross-sectional view taken along the line A-A ′ when the target is fixed to the backing plate of FIG. 1. FIG. 3 is a cross-sectional view taken along the line A-A ′ of FIG. 1. FIG. 4 is a perspective view of the cooling water channel forming plate as viewed from the surface side in close contact with the backing plate. 5 is a cross-sectional view taken along the line B-B ′ when the O-ring is buried in the groove of the cooling water channel forming plate of FIG. 4. FIG. 6 is a diagram in which the backing plate and the cooling water channel forming plate are fitted together. FIG. 7 is a longitudinal sectional view showing a perpendicular magnetic recording medium. FIG. 8 is a longitudinal sectional view showing the processing apparatus of this embodiment. FIG. 9 is a side view of the processing apparatus shown in FIG. 8 as viewed from the right side in FIG.

  Hereinafter, a sputtering apparatus according to an embodiment of the present invention will be described with reference to the drawings.

<Configuration of processing device>
1 is a perspective view of the backing plate as viewed from the opposite side of the target fixing surface, FIG. 2 is a cross-sectional view taken along the line AA ′ when the target is fixed to the backing plate of FIG. 1, and FIG. FIG. 2 is a cross-sectional view taken along the line AA ′ in FIG. 1. 4 is a perspective view of the cooling water channel forming plate as viewed from the side close to the backing plate, and FIG. 5 is a cross-sectional view of the cooling water channel forming plate shown in FIG. FIG. FIG. 6 is a diagram in which the backing plate and the cooling water channel forming plate are fitted together. FIG. 7 is a longitudinal sectional view showing a perpendicular magnetic recording medium. FIG. 8 is a longitudinal sectional view showing the processing apparatus of this embodiment, and FIG. 9 is a side view of the processing apparatus shown in FIG. 8 viewed from the right side in FIG.

  A processing apparatus 100 as a sputtering apparatus shown in FIGS. 8 and 9 includes a vertical and thin reaction vessel 101 and a gas supply means (not shown) for supplying an inert gas and / or a reactive gas into the reaction vessel 101. And vacuum pumps 130, 131, 132 for exhausting the gas in the reaction vessel 101, and an upper vacuum pump mounting chamber 134 and a lower vacuum pump mounting chamber 135 to which these vacuum pumps 130, 131, 132 are mounted, are carried in from the outside. And a substrate transfer device 105 for transferring the two substrates to be processed 200 to a predetermined position.

  A pair of water-cooled cathodes (electrodes for plasma generation) 113 and 115 are disposed on the pair of side walls 106 and 107 of the reaction vessel 101 with their one surfaces (electrode surfaces) 113a and 115a facing each other. 7, a pair of water-cooled cathodes 114 are arranged side by side with the pair of water-cooled cathodes 113 and 115 and their one surfaces (electrode surfaces) face each other. That is, this processing apparatus 100 is a type having two pairs of water-cooled cathodes.

<Reaction vessel>
The reaction vessel 101 is a vessel that partitions the outside and the reaction space 101a, has airtightness, and has pressure resistance because the inside is in a high vacuum state.
In the following description, in this reaction vessel 101, the right side wall in FIG. 8 is the “first side wall 106”, the left side wall is the “second side wall 107”, and the depth side wall in FIG. The third side wall 108 ”and the front side wall are referred to as“ fourth side wall 109 (see FIG. 9) ”.

<Sidewall>
As shown in FIG. 9, the first side wall 106 and the second side wall 107 have a slightly vertically long rectangular shape that is close to a square when viewed from the front. Moreover, between these side walls, the space | interval is mutually arrange | positioned narrowly so that the flat vertically long space as shown in FIG. 8 may be comprised.
A narrow third side wall 108 and a fourth side wall 109 are connected to the left and right sides of the first side wall 106 and the second side wall 107, and both the upper and lower sides of the side walls 106 to 109 are connected to each other. The top plate 142 and the bottom plate 143 are connected.
A vertically long flat space surrounded by the side walls 106 to 109, the top plate 142, and the bottom plate 143 constitutes an internal space of the reaction vessel 101.

<Window part>
The first side wall 106 of the reaction vessel 101 is provided with a first window 127 to which a first water-cooled cathode 113 and a second water-cooled cathode 114 described later are attached. The second side wall 107 is provided with a second window 128 to which a third water-cooled cathode 115 and a fourth water-cooled cathode described later are attached so as to face the first window 127.
The first window portion 127 and the second window portion 128 have a racetrack shape that is horizontally long as viewed from the side, as shown in FIG. 9, and are formed at the same height so as to face each other.
The first side wall 106 is provided with a small third window 116 for mounting a substrate transfer apparatus chamber 136 (described later) below the first window 127.

 On the other hand, the top plate 142 is provided with a fourth window 144 for mounting an upper vacuum pump mounting chamber 134 to be described later, and the bottom plate 143 has a fifth window for mounting a lower vacuum pump mounting chamber 135 to be described later. A window portion 145 is provided.

<Water-cooled cathode>
The first water-cooled cathode 113 to the fourth water-cooled cathode are all configured in the same manner, and two sets are arranged side by side on the first window 127 and two sets are arranged on the second window 128 side by side. ing. In FIGS. 8 and 9, some parts are omitted.
Specifically, as shown in FIG. 9, the first water-cooled cathode 113 and the second water-cooled cathode 114 are arranged in the lateral direction, and the horizontally long first window provided on the first side wall 106. The portion 127 is hermetically joined via a frame.
In addition, the third water-cooled cathode 115 and the fourth water-cooled cathode are hermetically joined to the second window 128 provided on the second side wall 107 through a frame in a state of being arranged in the lateral direction. The

The first water-cooled cathode 113 to the fourth water-cooled cathode are in a vertically placed state in which one surface (electrode surface) is substantially orthogonal to the horizontal plane. The third water-cooled cathode 115 faces the surfaces 113a and 115a on the reaction space 101a side, and the second water-cooled cathode 114 and the fourth water-cooled cathode face each other on the reaction space 101a side. It has become a relationship. That is, in this embodiment, the first water-cooled cathode 113 and the third water-cooled cathode 115 make a pair, and the second water-cooled cathode 114 and the fourth water-cooled cathode make a pair.
Each of the first water-cooled cathode 113 to the fourth water-cooled cathode is connected to a power source (not shown), and power is supplied by these power sources.

In addition, targets 117 and 118 are fixed to the respective surfaces 113a and 115a of the first water-cooled cathode 113 to the fourth water-cooled cathode 113, respectively. Each of the targets 117 and 118 has a plate shape and has a composition corresponding to the composition of the target thin film.
Further, magnets 161 for generating a magnetic field on the surfaces of the targets 117 and 118 may be disposed on the other surfaces of the first water-cooled cathode 113 to the fourth water-cooled cathode.
By arranging the magnets in this way, the target material (sputtered particles) can be easily ejected from the targets 117 and 118.

Each target 117, 118 may be a single unit or may be composed of a plurality of target pieces. Further, the planar shape of each of the targets 117 and 118 is not particularly limited. In the case of a single target, for example, it is desirable that the target is a circular shape or an annular shape, and it is desirable that the target be arranged coaxially with each cathode.
For example, when a magnetic layer having a granular structure is formed by the processing apparatus 100, as the targets 117 and 118, a semicircular target piece containing Co, Cr and Pt, respectively, and a half containing SiO ₂ are used. A circular oxide target piece or the like can also be used in combination.

Further, the first water-cooled cathode 113 to the fourth water-cooled cathode and each of the targets 117 and 118 are configured to be in direct contact with no sheet formed of indium, carbon, or the like interposed therebetween.
Hereinafter, although the configuration of the first water-cooled cathode 113 will be described in detail, the first water-cooled cathode 113 to the fourth water-cooled cathode all have the same configuration.

The first water-cooled cathode 113 includes a backing plate (metal plate) 11 shown in FIG. 1 and a cooling water channel forming plate (metal plate) 12 shown in FIG.
As shown in FIG. 2, a target 117 is directly disposed on one surface (target fixing surface) 11 a of the backing plate (metal plate) 11. A target holding jig 13 is disposed in the vicinity of the periphery of the target 117, and the target 117 is pressed so as to be in close contact with the backing plate 11.
The backing plate is made of stainless alloy, aluminum alloy, copper alloy or the like, and has a thickness of about 1 mm to 30 mm. However, the material and thickness of the backing plate are not limited to those described above, and as long as they are configured to form a convex surface on the target 117 side during sputtering as will be described later, an appropriate material is used. I do not care.

The backing plate 11 is configured to form a convex surface on the target 117 side during sputtering.
That is, although the backing plate 11 is water-cooled as will be described later, the backing plate 11 becomes hot and thus thermally expands. Further, the backing plate 11 has a small thickness and expands due to a cooling water pressure described later.
As described above, the backing plate 11 expands during sputtering, and at this time, as shown by a two-dot chain line 14 in FIG. 3, a convex surface is formed on the target 117 side. Note that a two-dot chain line 14 in FIG. 3 highlights the convex deformation. The actual amount of deformation depends on the size of the backing plate 11, but is about 0.5 mm to 2 mm for the target 117 having a diameter of about 200 mm.
With this configuration, the backing plate 11 expands in a convex shape toward the target 117 during sputtering, so that the adhesion between the backing plate 11 and the target 117 is improved despite the fact that no sheet is used. .
This eliminates the inconvenience that the sheet collapses and dust is generated, or that the sheet melts into heat.

  Further, the backing plate 11 is formed of, for example, SUS304 or the like, and is configured in a substantially circular plate shape in plan view, and a recess 15 is provided on a surface where the target 117 is not fixed. The concave portion 15 includes a substantially circular concave portion 15a when viewed in plan, and a concave portion 15b formed in a substantially triangular shape outward at two opposite points on the circumference.

  The water channel forming plate (metal plate) 12 is configured in a substantially circular plate shape in plan view that is substantially the same shape as the banking plate 11. Further, a convex portion 21 is provided on one surface 12 a of the water channel forming plate 12, and the convex portion 21 is configured to be fitted to the concave portion 15 of the backing plate 11. That is, the convex portion 21 is composed of a substantially circular convex portion 21a and a convex portion 21b formed in a substantially triangular shape outward at two points facing each other on the circumference when viewed in plan. The parts 21a and 21b are configured to fit into the recesses 15a and 15b, respectively.

At this time, as shown in FIG. 6, the backing plate 11 and the cooling water channel forming plate 12 are arranged so as to be fitted with a predetermined distance apart by O-rings 62, 63, 64 which are elastic materials. These spaces become the cooling water channels 51 and 52.
Specifically, as shown in FIGS. 4 and 5, a groove 22 is formed around the entire periphery of the cooling water channel forming plate 12, and at the center of the cooling water channel forming plate 12. In addition, the grooves 23 and 24 are formed so as to form a water channel in which the cooling water meanders.
Then, O-rings 62, 63, 64, which are elastic materials, are fitted in these grooves 22, 23, 24.
The water channel forming plate 12 having such a shape is arranged so that the convex portion 21 fits into the concave portion 15 of the backing plate 11, and the screw hole 31 provided in the peripheral portion of the backing plate 11 and the cooling water channel forming plate 12. 32, the backing plate 11 and the cooling water channel forming plate 12 are fixed by screwing screws (not shown).

The cooling water channel forming plate 12 is provided with inflow ports 41 and 42 and discharge ports 43 and 44, and the cooling water introduced from the inflow ports 41 and 42 by a cooling water supply means (not shown) is O-ring. The water is discharged from the discharge ports 43 and 44 through the cooling water channels 51 and 52 partitioned by 62, 63 and 64.
That is, the cooling water flowing in from the inflow port 41 passes through the cooling water passage 51 partitioned by the O-ring 62 fitted in the groove 22 and the O-ring 63 fitted in the groove 23, so that the outer periphery of the backing plate 11 is removed. Cooled and discharged from the outlet 43.
Further, the cooling water flowing in from the inlet 42 passes through the cooling water passage 52 partitioned by the O-ring 63 fitted in the groove 23 and the O-ring 64 fitted in the groove 24, so that the central portion of the backing plate 11 is obtained. Is cooled and discharged from the outlet 44.
At this time, since the backing plate 11 is thin, the backing plate 11 expands toward the target 117 side by the water pressure of the cooling water. Thereby, the adhesiveness between the backing plate 11 and the target 117 is improved.
In addition, since the cooling water passage 52 is formed with the grooves 23 and 24 so as to meander, the central portion of the backing plate 11 can be locally and efficiently cooled.

  Thus, in the present embodiment, the cooling water channels 51 and 52 are formed by partitioning with the O-rings 62, 63, and 64, which are elastic materials, so that the cooling water channels 51 and 52 can be easily changed, and the backing plate 11 As a result, the target 117 adhered to the target 117 can be selectively and locally cooled.

<Gas inlet pipe>
Inside the reaction vessel 101, four gas inflow pipes 126 are provided for allowing the gas supplied from a gas supply means (not shown) to flow out toward the surfaces of the targets 117 and 118, respectively.

<Vacuum pump installation room>
The upper vacuum pump mounting chamber 134 has a lower end attached to the periphery of the fourth window 144 of the reaction vessel 101, and its inside communicates with the space in the reaction vessel 101.
The upper vacuum pump mounting chamber 134 includes a pair of upper vacuum pump mounting walls 134a and 134b and a frame portion 134c that surrounds the gap between the pair of upper vacuum pump mounting walls 134a and 134b except for the fourth window 144 side. Have.

The upper vacuum pump mounting walls 134a and 134b are vertically mounted on the outer side of the right end and the outer side of the left end of the fourth window 144 (each upper end surface of the first side wall 106 and the second side wall 107), respectively. The surface direction is substantially parallel to the first side wall 106 and the second side wall 107.
As shown in FIG. 9, each of the upper vacuum pump mounting walls 134 a and 134 b has a semicircular shape at the upper side and a length substantially equal to the length in the depth direction of the fourth window 144 at the lower end as viewed from the side. It has a straight shape, and its lower end is attached to the upper ends of the first side wall 106 and the second side wall 107. The first upper vacuum pump mounting wall 134a is provided with an opening that communicates with a suction port of a first vacuum pump 130, which will be described later, and the second upper vacuum pump mounting wall 134b has a second, which will be described later. An opening communicating with the suction port of the vacuum pump 131 is provided.

The lower vacuum pump mounting chamber 135 has an upper end fixed around the fifth window 145 of the reaction vessel 101, and its inside communicates with the space in the reaction vessel 101.
The lower vacuum pump mounting chamber 135 includes a pair of lower vacuum pump mounting walls 135a and 135b and a frame portion 135c surrounding a gap between the pair of lower vacuum pump mounting walls 135a and 135b except for the fifth window 145 side. Have.

The lower vacuum pump mounting walls 135a and 135b are vertically mounted on the outside of the right end and the outside of the left end of the fifth window 145, and the surface direction thereof is the first side wall 106 and the second side wall. 107 and substantially parallel.
As shown in FIG. 9, each lower vacuum pump mounting wall 135a, 135b has a substantially square shape in which the length of each side is substantially equal to the length in the depth direction of the fifth window portion in a side view. Of these, the first lower vacuum pump mounting wall 135a is provided with an opening communicating with a suction port of a third vacuum pump 132 described later.

<Exhaust means>
The first vacuum pump (exhaust means) 130 to the third vacuum pump (exhaust means) 132 are respectively a suction mechanism, a suction port communicating with a gas passage of the suction mechanism, and a flange provided around the suction port. 130a to 132a and a gate valve (not shown) provided inside the suction port. The gate valve is configured to be opened and closed by a control mechanism (not shown).

Among these, the first vacuum pump 130 has a flange 130 a attached around the opening provided in the first upper vacuum pump attachment wall 134 a and is fixed to the upper vacuum pump attachment chamber 134. The flange 131a of the second vacuum pump 131 is attached around the opening provided in the second upper vacuum pump mounting wall 134b, and is fixed to the upper vacuum pump mounting chamber 132. Further, the flange 132a of the third vacuum pump 132 is attached around the opening provided in the first lower vacuum pump attachment wall 135a, and is fixed to the lower vacuum pump attachment chamber 135.
Each of the vacuum pumps 130 to 132 exhausts the gas in the reaction container 101 at a predetermined flow rate when the inside of the reaction container 101 is depressurized or when the processing is performed on the substrate 200 to be processed.

<Substrate transfer device>
The substrate transfer apparatus 105 processes the substrate 200 that has been loaded from the outside between the first cathode 113 and the third cathode 115 and between the second cathode 114 and the fourth cathode. The substrate 200 is conveyed so that both surfaces of the substrate 200 face the electrode surfaces 113a, 115a or the electrode surface 114a and are in a vertically placed state.
The substrate transfer device 105 includes a substrate transfer device chamber 136, a carrier transfer device 137, and a first carrier 138 and a second carrier held by the carrier transfer device 137.
Note that the second carrier and the second carrier holding unit have the same configuration as the first carrier 138 and the first carrier holding unit 140 described later, and are not shown.

As shown in FIGS. 8 and 9, the substrate transport apparatus includes a drive mechanism 141 that drives the carrier 138 in a non-contact state as a transport mechanism for transporting the carrier 138 as described above.
The drive mechanism 141 includes a plurality of magnets 202 arranged below the carrier 138 so that N poles and S poles are alternately arranged along the moving direction of the carrier 138, and a carrier 138 transport direction (see FIG. 8 and a rotating magnet 203 arranged along the vertical direction of the drawing sheet (left and right direction in FIG. 9). N and S poles are alternately arranged in a double spiral on the outer peripheral surface of the rotating magnet 203. It is formed with.

  A vacuum partition wall 204 is interposed between the plurality of magnets 202 and the rotating magnet 203. The vacuum partition wall 204 is formed of a material having a high magnetic permeability so that the plurality of magnets 202 and the rotating magnet 203 are magnetically coupled. The vacuum partition wall 204 surrounds the periphery of the rotating magnet 203 to isolate the inside of the reaction vessel 101 from the atmosphere side.

  The rotating magnet 202 is connected to a rotating shaft 206 that is driven to rotate by a rotating motor 205 via a plurality of gears that mesh with each other. As a result, it is possible to rotate the rotating magnet 204 around the axis while transmitting the driving force from the rotating motor 205 to the rotating magnet 204 via the rotating shaft 206.

  The substrate transport apparatus configured as described above rotates the carrier 138 by rotating the rotating magnet 203 around the axis while magnetically coupling the magnet 202 on the carrier 138 side and the rotating magnet 204 in a non-contact manner. Linear driving is performed along the axial direction of the magnet 203 (perpendicular to the plane of FIG. 8, left and right in FIG. 9).

  Further, in the reaction vessel 101, as a guide mechanism for guiding the carrier 138 to be transported, a plurality of main bearings 175 supported so as to be rotatable about the horizontal axis are transported in the transport direction of the carrier 138 (the direction perpendicular to the plane of FIG. They are arranged side by side in the left-right direction in FIG. On the other hand, the carrier 138 has a guide rail 176 with which a plurality of main bearings 175 are engaged on the lower side of the support base 226, and the groove portion of the guide rail 176 extends along the longitudinal direction of the support base 226. Is formed.

  In the reaction vessel 101, a pair of sub-bearings 177 supported so as to be rotatable about a vertical axis are provided so as to sandwich the carrier 138 therebetween. Similar to the plurality of main bearings 175, a plurality of the pair of sub bearings 177 are provided side by side in the conveying direction of the carrier 138.

The main bearing 175 and the sub-bearing 177 are bearings that reduce the friction of machine parts and ensure a smooth rotational movement of the machine. Specifically, the main bearing 175 and the sub-bearing 177 are rolling bearings and are provided in the reaction vessel 101. It is rotatably attached to a support shaft (not shown) fixed to the (attachment member).
The carrier 138 moves on the plurality of main bearings 175 in a state where the plurality of main bearings 175 are engaged with the guide rails 176 and is sandwiched between the pair of sub bearings 177 so that the inclination of the carrier 138 is increased. In other words, the substrate 200 to be processed can be transported while being held vertically.

<< Processor Operation >>
Next, the operation of this processing apparatus will be described by taking as an example the case of manufacturing a magnetic recording layer of a magnetic recording medium.
"Magnetic recording media"
FIG. 7 is a longitudinal sectional view showing a perpendicular magnetic recording medium having a magnetic layer formed in the present invention.
The perpendicular magnetic recording medium 1 having the form shown in FIG. 7 has at least a soft magnetic backing layer 3 on each side of a nonmagnetic substrate 2, an orientation control layer 4 and an underlayer 5 for controlling the orientation of the film immediately above, and a magnetic layer. The recording layer (magnetic layer) 6, the protective layer 7, and the lubricating layer 8 are sequentially stacked. The magnetic recording layer 6 is a perpendicular magnetic recording layer having a granular structure containing at least Co and Cr.

<Non-magnetic substrate>
Examples of the nonmagnetic substrate 2 used for the perpendicular magnetic recording medium 1 include an Al alloy substrate such as an Al—Mg alloy mainly composed of Al, ordinary soda glass, aluminosilicate glass, amorphous glass, silicon Any nonmagnetic substrate such as a substrate made of titanium, ceramics, sapphire, quartz, or various resins can be used.
Of these, glass substrates such as Al alloy substrates, crystallized glass, and amorphous glass are often used.
In the case of a glass substrate, a substrate subjected to mirror polishing, a low Ra substrate having a surface roughness (Ra) <1 (Å), or the like is preferable.
Further, the non-magnetic substrate 2 may be scratched if it is light.

In the manufacturing process of the perpendicular magnetic recording medium 1, the nonmagnetic substrate 2 is usually first cleaned and dried. In the present invention, the nonmagnetic substrate 2 includes a nonmagnetic substrate 2 from the viewpoint of ensuring adhesion with each layer. It is desirable that washing and drying are performed before forming each layer. Cleaning includes not only water cleaning but also cleaning by etching (reverse sputtering).
Moreover, the size of the nonmagnetic substrate 2 is not particularly limited, and is appropriately determined according to the application.

<Soft magnetic backing layer>
The soft magnetic backing layer 3 serves to guide a recording magnetic field from the head and efficiently apply a perpendicular component of the recording magnetic field to the magnetic recording layer 6 when recording a signal on the medium.

As a material of the soft magnetic backing layer 3, a material having so-called soft magnetic characteristics such as an FeCo alloy, a CoZrNb alloy, or a CoTaZr alloy can be used.
It is particularly preferable that the soft magnetic backing layer 3 has an amorphous structure. This is because the amorphous structure prevents the surface roughness (Ra) from increasing, reduces the flying height of the head, and further increases the recording density.

The soft magnetic underlayer 3 may have a single layer structure of such a soft magnetic layer, but an extremely thin nonmagnetic thin film such as Ru is sandwiched between two soft magnetic layers, and the soft magnetic layer 3 A structure with antiferromagnetic coupling may be used.
Further, the total thickness of the soft magnetic backing layer 3 is generally preferably about 20 (nm) to 120 (nm), and is appropriately determined depending on the balance between the recording / reproducing characteristics and the writing characteristics.

<Orientation control layer>
In the present invention, it is preferable to provide an orientation control layer 4 for controlling the orientation of the magnetic recording layer 6 on the soft magnetic backing layer 3. As the material of the orientation control layer 4, Ni alloys such as Ni, Ni—Nb, Ni—Ta, Ni—V, and Ni—W that are oriented with Ta or fcc (111) crystal plane are preferable.
Even when the soft magnetic backing layer 3 has an amorphous structure, the surface roughness Ra may increase depending on the material and film forming conditions. In such a case, the soft magnetic backing layer 3 and the orientation control layer 4 It is preferable to form a nonmagnetic amorphous layer between them.
Thereby, the surface roughness Ra of the surface on which the magnetic recording layer 6 is formed can be reduced, and the orientation of the magnetic recording layer 6 can be improved.

<Underlayer>
An underlayer 5 is provided on the soft magnetic backing layer 3 or the orientation control layer 4.
As the material of the underlayer 5, Ru, Re, or an alloy thereof having an hcp structure like the magnetic recording layer 6 is preferable.
The function of the intermediate layer (orientation control layer 4) is to control the orientation of the magnetic recording layer 6, so that any material that can control the orientation of the magnetic recording layer 6 without taking the hcp structure can be used. Can be used.
The total thickness of the underlayer 5 is preferably 5 (nm) or more and 20 (nm) or less from the balance between the recording / reproducing characteristics and the writing characteristics.

<Perpendicular magnetic recording layer>
The perpendicular magnetic recording medium 1 of this embodiment includes a perpendicular magnetic recording layer 6 having a granular structure including at least Co and Cr as magnetic particles and including at least chromium oxide at the grain boundary portion of the magnetic particles. The magnetic particles preferably contain Pt.
In addition to the Cr oxide, the oxide constituting the grain boundary part includes at least one of Si oxide, Ti oxide, W oxide, Co oxide, Ta oxide, and Ru oxide. Those are preferred. Examples of ferromagnetic materials to which these oxides are added include CoCrPt—Si oxide, CoCrPt—Ti oxide, CoCrPt—W oxide, CoCrPt—Co oxide, CoCrPt—Ta oxide, CoCrPt—Ru oxide, Examples thereof include CoRuPt—Si oxide and CoCrPtRu—Si oxide.
In these compositions, CoCrPt alloy, CoRuPt alloy, and CoCrPtRu alloy mainly constitute magnetic particles, and Cr oxide, Si oxide, Ti oxide, W oxide, Co oxide, Ta oxide and Ru oxidation A thing comprises a grain boundary part. Further, an oxide may be mixed in a part of the magnetic particles, and an alloy may be mixed in a part of the grain boundary part.
Two or more of these oxides can be added to the magnetic recording layer 6.

The average particle diameter of the magnetic particles forming the perpendicular magnetic recording layer 6 having a granular structure containing at least Co and Cr is preferably 1 nm or more and 12 nm or less. The average grain boundary width is preferably 0.3 nm or more and 2.0 nm or less. The average crystal grain size and the average grain boundary width can be calculated using a planar TEM observation image.
The total amount of oxides present in the perpendicular magnetic recording layer 6 having a granular structure containing at least Co and Cr is preferably 3 to 15 mol%. When the total amount of oxide added is within this range, a good granular structure can be formed using the method for forming a magnetic layer of the present invention.

<Protective layer>
The protective layer 7 is for protecting the medium from damage due to contact between the head and the medium, and a carbon film, a SiO ₂ film, or the like is used, but a carbon film is preferably used.
A sputtering method, a plasma CVD method, or the like is used to form these films, but it is preferable to use a plasma CVD method. A magnetron plasma CVD method can also be used.
The thickness of the protective layer 7 is about 1 nm to 10 nm, preferably about 2 nm to 6 nm, and more preferably 2 nm to 4 nm.
After forming the protective layer 7, it is preferable to apply the lubricating layer 8 to the surface.

“Deposition of magnetic layers by reactive sputtering”
Next, the operation of the processing apparatus of the present invention will be described by taking as an example the case where the perpendicular magnetic recording layer 6 is formed by reactive sputtering.
First, the first target 117 to the fourth target are attached to each surface (electrode surface) of the first water-cooled cathode 113 to the fourth water-cooled cathode, respectively. Specifically, the target is directly fixed to one surface of the backing plate without sandwiching a sheet therebetween.
In this embodiment, in order to form a magnetic layer having a so-called granular structure in which magnetic crystal grains are surrounded by a grain boundary region containing a large amount of oxide, Co, Cr, Pt are used as the targets 117 and 118, respectively. And a semicircular target piece containing SiO ₂ and a semicircular oxide target piece containing SiO ₂ are used in combination.

In addition, two substrates (substrates to be processed) 200 are prepared. As the substrate to be processed 200, a substrate in which the soft magnetic backing layer 3, the orientation control layer 4, and the underlayer 5 are already formed on the nonmagnetic substrate 2 is used.
Then, each substrate to be processed 200 is mounted on the first carrier 138 and the second carrier, respectively.
When the substrate 200 to be processed is mounted on the first carrier 138 and the second carrier, the substrate transport apparatus 105 moves each carrier 138 to the first target 117 and the third target 118 by the operation of the drive mechanism 141. And a space between the second target and the fourth target. As a result, the target substrate 200 mounted on the first carrier 138 is positioned between the first target 117 and the third target 118, and both surfaces of the target substrate 200 face the surfaces of the targets 117 and 118. And is conveyed so as to be in a vertically placed state. Further, the substrate 200 to be processed mounted on the second carrier is placed between the second target and the fourth target so that both surfaces of the substrate to be processed 200 face the surface of each target. It is transported so as to be placed.

Next, the gate valve of each vacuum pump 130-132 is opened, and the inside of the reaction vessel 101 is depressurized by the operation of each vacuum pump 130-132 (first exhaust process).
Here, in this processing apparatus 100, the vacuum pumps 130 to 132 are respectively attached to the first upper vacuum pump mounting wall 134a, the second upper vacuum pump mounting wall 134b, and the first lower vacuum pump mounting wall 135a. . For this reason, the two vacuum pumps 130 and 131 attached on the upper side work together, and the periphery of the carrier transfer device 137 is efficiently exhausted by the vacuum pump 132 attached on the lower side. Thereby, the reaction vessel 101 can be brought into a predetermined reduced pressure state in a short time.

  Next, a mixed gas of a reactive gas and an inert gas is supplied through the gas inflow pipe 126 using a gas supply unit (not shown). Thereafter, the gate valves of the vacuum pumps 130 to 132 are controlled to adjust the flow rate of the gas exhausted from the upper side and the flow rate of the gas exhausted from the lower side to a predetermined flow rate.

Next, a voltage is applied to the first water-cooled cathode 113 to the fourth water-cooled cathode.
Thereby, in the space corresponding to each water-cooled cathode, the mixed gas is turned into plasma, and ions of the inert gas generated in this plasma collide with each target 117, 118, and the target material ( Sputtered particles are ejected. Part of the sputtered particles reacted with the activated reactive gas, and the other part of the sputtered particles is deposited on each surface of each substrate 200 in a state of not reacting with the reactive gas.
At this time, each backing plate 11 constituting the first water-cooled cathode 113 to the fourth water-cooled cathode expands so as to form a convex surface on each target 117, 118 side by heat and water pressure of the cooling water. Thereby, the adhesiveness between each backing plate 11 and each target 117, 118 is improved.
In addition, since the sheet is not sandwiched between each backing plate 11 and each target 117, 118, there is no inconvenience that the sheet collapses and dust is generated or the sheet is melted by heat.
Further, since the cooling water cooling channels 51 and 52 are formed by partitioning with O-rings 62, 63 and 64, which are elastic materials, each backing plate 11 and thus each target 117 and 118 can be locally and efficiently cooled. it can.

Then, the film formation ends when the layers of the sputtered particles (perpendicular magnetic recording layer 6) have a predetermined thickness on both surfaces of each substrate 200 to be processed.
As described above, the perpendicular magnetic recording layers 6 are formed in parallel on both surfaces of the two substrates to be processed 200.
Each perpendicular magnetic recording layer 6 formed in this way is formed by uniform deposition of sputtered particles, so that it has uniform magnetic characteristics in the plane direction and obtains stable recording / reproducing characteristics. be able to.

  Next, the gate valves of the first vacuum pump 130 to the third vacuum pump 132 are opened, and the gas after the reaction in the reaction vessel 101 is exhausted by the operations of the vacuum pumps 130 to 132 (second exhaust process). ).

Next, after the inside of the reaction vessel 101 is brought into an atmospheric pressure state, the first carrier 138 and the second carrier are moved from the lower side of the reaction space 101a to the vicinity of the opening 139 of the substrate transfer apparatus chamber 136 by the operation of the drive mechanism 141. Move to. Then, the door is opened, and each substrate to be processed 200 mounted on the first carrier 138 and the second carrier is carried out from the opening 139 to the outside.
As described above, the substrate to be processed 200 having the perpendicular magnetic recording layer 6 formed on both surfaces is obtained.

The operation of the processing apparatus 100 of the present invention has been described above by taking the case where the perpendicular magnetic recording layer 6 is formed by reactive sputtering as an example. However, the usage mode of the processing apparatus of the present invention is not limited to this.
For example, the processing apparatus of the present invention can also be used as each film forming apparatus constituting an inline processing apparatus.

  The present invention can be widely used in the manufacturing industry for manufacturing magnetic recording media.

  DESCRIPTION OF SYMBOLS 11 ... Backing plate, 11a ... One side of backing plate, 12 ... Water channel formation board, 22, 23, 24 ... Groove, 101 ... Reaction container, 113, 114, 115 ... Water cooling Cathode, 117, 118 ... Target

Claims (5)

A reaction vessel;
A sputtering apparatus having a water-cooled cathode disposed in the reaction vessel and having a target fixed on one surface,
The water-cooled cathode is configured such that two metal plates are arranged apart by an elastic material,
A cooling water channel is formed between the two metal plates,
Of the two metal plates constituting the water-cooled cathode, the metal plate for fixing the target is configured to form a convex surface on the target side during sputtering.   The sputtering apparatus according to claim 1, wherein the cooling water channel is formed of the elastic material that separates the two metal plates.   The sputtering apparatus according to claim 1, wherein the elastic material is an O-ring.   The sputtering apparatus according to any one of claims 1 to 3, wherein a magnet for generating a magnetic field on the surface of the target is disposed on the other surface side of the water-cooled cathode.   A method for manufacturing a magnetic recording medium, comprising manufacturing a magnetic recording medium using the sputtering apparatus according to claim 1.

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