JP2009093710A - Method of manufacturing magnetic recording medium and magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a magnetic recording medium using a vacuum deposition apparatus, which reduces the number of cleaning operations by obtaining a sufficient peeling prevention effect and improves the yield, and to provide the magnetic recording medium. <P>SOLUTION: In the method of manufacturing the magnetic recording medium, at least a magnetic recording layer 22 and a medium protection layer 26 are formed on a substrate 1 using the vacuum deposition apparatus. In this case, one or a plurality of coating layers 150 comprising metal or alloy having an intermediate thermal expansion coefficient between the thermal expansion coefficient of a deposition material and the thermal expansion coefficient of a material constituting components 108, 112 are provided on the surfaces of components 108, 112 exposed to a deposition atmosphere of the vacuum deposition apparatus. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a magnetic recording medium mounted on an HDD (hard disk drive) or the like, and a magnetic recording medium.

  Various information recording techniques have been developed with the recent increase in information processing capacity. In particular, the surface recording density of HDDs using magnetic recording technology continues to increase at an annual rate of about 100%. Recently, an information recording capacity exceeding 160 GB has been demanded for a 2.5-inch diameter magnetic disk used for HDDs and the like, and in order to meet such a demand, per square inch. It is required to realize an information recording density exceeding 250 GBit.

  In recent years, a perpendicular magnetic recording type magnetic disk (perpendicular magnetic recording disk) has been proposed in order to achieve a high recording density in a magnetic disk used for an HDD or the like. In the conventional in-plane magnetic recording method, the easy axis of magnetization of the magnetic recording layer is oriented in the plane direction of the substrate surface, but in the perpendicular magnetic recording method, the easy magnetization axis is adjusted to be oriented in the direction perpendicular to the substrate surface. ing. In the perpendicular magnetic recording method, the demagnetizing field (Hd) increases and the coercive force Hc improves as the magnetic grains become finer than the in-plane recording method, and the thermal fluctuation phenomenon can be suppressed. It is suitable for.

  The above-described in-plane magnetic recording system and perpendicular magnetic recording system magnetic disks are formed by sequentially forming a plurality of layers having predetermined properties on a substrate using a vacuum film forming apparatus such as a sputtering apparatus or a CVD (Chemical Vapor Deposition) apparatus. It is manufactured by forming a film.

  By the way, in the above-described vacuum film forming apparatus such as a sputtering apparatus and a CVD apparatus, when forming a film on a substrate, the film forming material is also attached to various parts arranged in the apparatus and exposed to the film forming atmosphere. End up. The deposited film forming material is deposited and eventually peeled off from various components. If the peeled film forming material adheres to the substrate during film formation, a problem may occur and the yield may be reduced.

Therefore, by blasting various parts exposed to the film forming atmosphere in the vacuum film forming equipment, the surface is roughened and the anchor effect is obtained, thereby improving the adhesion between the deposited film forming material and the surface of the various parts. And a method for reducing the peeling has been proposed (for example, Patent Document 1).
Japanese Patent Laid-Open No. 2001-140054

  The method of blasting the surface of a component described in Patent Document 1 is not perfect, although a certain degree of peeling prevention effect can be obtained. Therefore, when peeling is likely to occur, a method has been adopted in which the vacuum of the vacuum film forming apparatus is released, the deposits adhering to various parts are washed, and the blasting process is performed again.

  However, if multiple blasting processes are performed, the shape of the part cannot be maintained, and the part must be reworked or renewed. Moreover, since it takes a long time to stop the apparatus, the productivity is lowered.

  The present invention has been made in view of the problems of conventional peeling prevention methods, and an object of the present invention is to newly provide a layer having good adhesion to deposits on the surfaces of various parts of a vacuum film forming apparatus. It is an object of the present invention to provide a method of manufacturing a magnetic recording medium and a magnetic recording medium that can prevent peeling of a deposited film and improve the productivity by reducing the number of cleanings.

  In order to solve the above-mentioned problems, the inventors of the present invention diligently studied, and as a result, the peeling of the deposit is caused by the thermal expansion coefficient of the deposit formed by the film forming material and the materials of various parts of the vacuum film forming apparatus. The present invention has been completed by finding out that the difference is large and conducting further research.

  That is, in order to solve the above problems, a typical configuration of the method for manufacturing a magnetic recording medium according to the present invention is a magnetic film in which at least a magnetic recording layer and a medium protective layer are formed on a substrate using a vacuum film forming apparatus. A method of manufacturing a recording medium, wherein a surface of a part of the vacuum film forming apparatus exposed to a film forming atmosphere of a vacuum film forming apparatus has a coefficient of thermal expansion of a film forming material and a material of the material constituting the part. It is characterized by comprising one or more coating layers made of a metal or alloy having a thermal expansion coefficient in the middle of the rate.

  With the above configuration, the film forming material adheres to the surfaces of various parts exposed to the film forming atmosphere of the vacuum film forming apparatus via the coating layer. The coating layer is a metal or alloy having a thermal expansion coefficient intermediate between the thermal expansion coefficient of the film forming material and the material constituting the various parts of the vacuum film forming apparatus, and therefore the adhesion with the film forming material is Improved compared to when directly attached to the surface of the part. For the above reason, the coating layer and the parts of the vacuum film forming apparatus are also in intimate contact. In other words, the film forming material comes into close contact with the components of the vacuum film forming apparatus through the coating layer, and it is possible to make it difficult for the deposited film forming material to be peeled off.

  Moreover, the material which comprises the components of a vacuum film-forming apparatus may be aluminum. Aluminum is lighter in specific gravity and more malleable than other metals, so it can be easily processed. Furthermore, since an oxide film is formed on the surface, it is possible to create a component having excellent corrosion resistance.

  The coating layer may be composed of a single element selected from manganese, silver, copper, gold, nickel, platinum, titanium, and ruthenium, or an alloy containing the element.

  The thermal expansion coefficient of manganese, silver, copper, gold, nickel, platinum, titanium, and ruthenium is the thermal expansion coefficient of the film forming material of the magnetic recording medium and the thermal expansion coefficient of aluminum that is the material of the parts of the vacuum film forming apparatus. Since it is in the middle, the adhesion to both is good.

  Another typical configuration of the method for manufacturing a magnetic recording medium according to the present invention is a method for manufacturing a magnetic recording medium in which at least a magnetic recording layer and a medium protective layer are formed on a substrate using a vacuum film forming apparatus. The surface of the part of the vacuum film forming apparatus exposed to the film forming atmosphere of the vacuum film forming apparatus is made of a metal or alloy having a Young's modulus smaller than the Young's modulus of the material constituting the part. One or more coating layers are provided.

  That is, a film made of a metal or alloy that is softer than the part is formed on the surface of the part exposed to the film forming atmosphere of the vacuum film forming apparatus. As a result, even if the component and the deposited coating material are deformed due to thermal expansion or stress, the coding layer causes dislocation to relieve the stress based on the deformation and prevent the peeling.

  One or a plurality of coating layers may be individually formed by one method selected from the group of thermal spraying, plating, and pressure bonding.

  Thereby, a coating layer can be installed uniformly and reliably on the surface of the component of a vacuum film-forming apparatus. In particular, when formed by thermal spraying, unevenness is formed on the surface, so that an anchor effect is obtained between the surface of the coating layer and the deposited film material, and the peeling of the film material from the coating layer is reduced. It becomes possible.

  Further, the surface of the coating layer may be blasted. As a result, unevenness is formed on the surface of the coating layer, so that an anchor effect is obtained between the surface of the coating layer and the deposited film material, and it is possible to reduce peeling of the film material from the coating layer. It becomes.

  In addition, the vacuum film forming apparatus may be any one of a sputtering apparatus, a CVD apparatus, an etching apparatus, and an ion implantation apparatus. The sputtering apparatus, the CVD apparatus, the etching apparatus, and the ion implantation apparatus can use the present invention suitably because the film peeling of the film forming material is particularly remarkable.

  Further, when the vacuum film forming apparatus is a sputtering apparatus, the components of the vacuum film forming apparatus include at least a shield and / or a substrate that focuses the film forming material released from the target on the substrate and prevents scattering to other than the substrate. A carrier to be held may be included.

  In the sputtering apparatus, the shield is placed in the vicinity of the substrate, which is the target for film formation, so that the effects of the present invention can be sufficiently exerted.

  Further, a typical configuration of the magnetic recording medium according to the present invention is characterized by being manufactured using the above-described method for manufacturing a magnetic recording medium.

  The components based on the technical idea of the magnetic recording medium manufacturing method described above and the description thereof can be applied to the magnetic recording medium.

  As described above, according to the method of manufacturing a magnetic recording medium of the present invention, it is possible to reduce the number of cleanings and improve the yield by obtaining a sufficient peeling prevention effect.

(Example)
An example of a perpendicular magnetic recording medium as a magnetic recording medium according to the present invention will be described. FIG. 1 is a diagram for explaining the configuration of a perpendicular magnetic recording medium according to this embodiment. FIG. 2 is a diagram for explaining the construction of a sputtering apparatus that is a vacuum film forming apparatus used in the method for manufacturing a perpendicular magnetic recording medium according to this embodiment. FIG. 3, FIG. 3 is a diagram showing the thermal expansion coefficient of the film forming material, the material constituting the components of the vacuum film forming apparatus and the material constituting the coating layer, and FIG. 4 is a diagram for explaining the structure of the coating layer. Note that dimensions, materials, and other specific numerical values shown in the following examples are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified.

  The perpendicular magnetic recording medium shown in FIG. 1 includes a disk substrate 1, an adhesion layer 12, a first soft magnetic layer 14a, a spacer layer 14b, a second soft magnetic layer 14c, an orientation control layer 16, a first underlayer 18a, and a second lower layer. The base layer 18b, the miniaturization promoting layer 20, the magnetic recording layer 22, the continuous layer 24, the medium protective layer 26, and the lubricating layer 28 are formed. The first soft magnetic layer 14a, the spacer layer 14b, and the second soft magnetic layer 14c together constitute the soft magnetic layer 14. The first base layer 18a and the second base layer 18b together constitute the base layer 18.

  First, an amorphous aluminosilicate glass was formed into a disk shape by direct pressing to produce a glass disk. The glass disk was ground, polished, and chemically strengthened in order to obtain a smooth nonmagnetic disk substrate 1 made of a chemically strengthened glass disk.

  Using the DC magnetron sputtering apparatus 100, which is a sputtering apparatus as a vacuum film forming apparatus, a film is sequentially formed on the obtained disk substrate 1 from the adhesion layer 12 to the continuous layer 24, and the medium protective layer 26 is obtained. The film was formed by a CVD apparatus as a vacuum film forming apparatus. Thereafter, the lubricating layer 28 was formed by dip coating. Note that it is also preferable to use an in-line film forming method in terms of high productivity. Hereinafter, the configuration of the DC magnetron sputtering apparatus 100, the configuration of each layer, and the manufacturing method will be described.

  A DC magnetron sputtering apparatus 100 shown in FIG. 2 includes a chamber 102 that forms a vacuum chamber, an introduction port 104 that is provided in the chamber 102 and introduces gas (Ar) from the outside, and an exhaust port for performing vacuum exhaust from the chamber 102. 106, a carrier 108 that holds the substrate 1, a target 110 that is a film forming material for forming the substrate 1, and a film forming material that is released from the target 110 is focused on the substrate 1 to prevent scattering to other than the substrate 1. And a magnet 114 for increasing the film formation speed and performing low-temperature film formation.

  In this embodiment, the carrier 108 and the shield 112 which are parts exposed to the film forming atmosphere of the DC magnetron sputtering apparatus 100 are made of aluminum. Aluminum is lighter in specific gravity and more malleable than other metals, so it can be easily processed. Furthermore, since an oxide film is formed on the surface, it is possible to create a component having excellent corrosion resistance.

  In the film formation from the adhesion layer 12 to the continuous layer 24 using the DC magnetron sputtering apparatus 100, first, plasma is generated between the target 110 and the shield 112 in the chamber 102. Then, Ar ions generated by the plasma are accelerated by an electric field and irradiated to the target 110 made of a film forming material. Ar ions repel atoms or molecules on the surface of the target 110 from the surface. The ejected atoms and / or molecules of the film forming material are deposited on the substrate 1 to form a thin film (layer). The target 110 in each layer will be described in detail below.

  At this time, the film forming material ejected from the target 110 adheres not only to the substrate 1 but also to the carrier 108 and the shield 112 installed in the vicinity of the substrate 1. In this embodiment, the coating layer 150 is provided on the surfaces of the target 110 and the shield 112 by thermal spraying. Further, the surface of the coating layer 150 is blasted. In this embodiment, the coating layer 150 has a two-layer structure of manganese and copper.

As shown in FIG. 3, the carrier 108 and the shield 112 are made of aluminum having a thermal expansion coefficient of 23.1E ⁻⁶ / ° C. On the other hand, a material of the main targets 110, Ni, Co, Pt, Ti, Ru, Cr, Ta, Zr, coefficient of thermal expansion of W is the 13.3E ^-6 /℃~4.5E ^-6 / ℃ . Even for nickel Ni having the largest thermal expansion coefficient among the materials of the target 110, the difference from aluminum is as large as about 10E- ⁶ / ° C. On the other hand, at the time of film formation in the magnetron sputtering apparatus 100, the film formation material ejected from the target and peripheral components are instantaneously at a high temperature. Therefore, when the film forming material of the target 110 adheres and deposits directly on the surface of the part exposed to the film forming atmosphere of the vacuum film forming apparatus, the deposits from the part easily peel off.

  As shown in FIG. 4, in this embodiment, a manganese layer 150a is provided on the surface of the chamber 102, the carrier 108 and the shield 112, and a nickel Ni layer 150b is provided on the surface of the manganese layer 150a to form the coating layer 150. .

The coefficient of thermal expansion of manganese is 23.0E- ⁶ / ° C, which is almost the same as the coefficient of thermal expansion of 23.1E- ⁶ / ° C of aluminum constituting the carrier 108 and the shield 112. Accordingly, the manganese layer 150a has a small thermal strain generated between the carrier 108 and the shield 112 and other parts.

By providing a nickel layer 150b having a thermal expansion coefficient of 13.3E ⁻⁶ / ° C. on the manganese layer 150a, the nickel layer 150b and the manganese layer 150a are formed more than the nickel layer directly on aluminum. Thermal strain is small.

  Since the thermal expansion coefficient of nickel is little different from the thermal expansion coefficient of the film forming material of the target 110, the nickel layer 150b has a small thermal strain with respect to the film forming material constituting the target 110 and does not easily peel off. For these reasons, when film formation is performed with a vacuum film formation apparatus, even if a film formation material is deposited by repeated film formation, it is possible to prevent peeling from the components of the vacuum film formation apparatus through the coating layer. it can.

  In this embodiment, the coating layer is made of manganese and nickel, but is not limited to this, and it is sufficient if the coating layer has a thermal expansion coefficient intermediate between the thermal expansion coefficients of the components of the vacuum film forming apparatus and the film forming material. One layer may be sufficient and it may be comprised with the simple substance of silver, copper, gold | metal | money, platinum, titanium, and ruthenium, and the alloy containing two or more among manganese, silver, copper, gold | metal | money, nickel, platinum, titanium, and ruthenium.

  In the present embodiment, the coating layer 150 is formed by thermal spraying, but is not limited thereto, and plating or pressure bonding may be used.

  Further, since the surface of the nickel layer 150b is blasted, irregularities are formed on the surface of the nickel layer 150b. For this reason, an anchor effect is obtained between the surface of the nickel layer 150b and the deposited film material, and peeling of the film material from the nickel layer 150b can be reduced.

  In the present embodiment, the coding layer has a thermal expansion coefficient that is intermediate between the thermal expansion coefficients of the vacuum film forming apparatus component and the film forming material, but is less than the Young's modulus of the material constituting the vacuum film forming apparatus component. One or a plurality of coating layers made of a metal or alloy having a small Young's modulus may be used. In this case, the coding layer can generate dislocations to relieve stress based on deformation (thermal strain) and prevent the peeling.

  In this embodiment, a sputtering apparatus is mentioned as a vacuum film forming apparatus provided with the coating layer 150, but it can also be suitably used for a CVD apparatus, an etching apparatus, and an ion implantation apparatus.

  Below, the structure and manufacturing method of each layer are explained in full detail.

  The adhesion layer 12 was formed using a Ti alloy target so as to be a 10 nm Ti alloy layer. By forming the adhesion layer 12, the adhesion between the disk substrate 1 and the soft magnetic layer 14 can be improved, so that the soft magnetic layer 14 can be prevented from peeling off. As a material of the adhesion layer 12, for example, a CrTi alloy can be used.

  The soft magnetic layer 14 includes AFC (Antiferro-magnetic exchange coupling) by interposing a nonmagnetic spacer layer 14b between the first soft magnetic layer 14a and the second soft magnetic layer 14c. It was configured as follows. As a result, the magnetization direction of the soft magnetic layer 14 can be aligned along the magnetic path (magnetic circuit) with high accuracy, and the perpendicular component of the magnetization direction is extremely reduced, so that noise generated from the soft magnetic layer 14 is reduced. Can do. Specifically, the composition of the first soft magnetic layer 14a and the second soft magnetic layer 14c was CoFeTaZr, and the composition of the spacer layer 14b was Ru (ruthenium).

  The orientation control layer 16 has an action of protecting the soft magnetic layer 14 and an action of promoting alignment of crystal grains of the underlayer 18. The material of the orientation control layer can be selected from Ni, Cu, Pt, Pd, Zr, Hf, and Nb. Furthermore, it is good also as an alloy which contains these metals as a main component and contains any one or more additional elements of Ti, V, Ta, Cr, Mo, and W. For example, NiW, CuW, or CuCr can be suitably selected.

  The underlayer 18 has an hcp structure, and the crystal of the hcp structure of the magnetic recording layer 22 can be grown as a granular structure. Therefore, the higher the crystal orientation of the underlayer 18 is, the more the orientation of the magnetic recording layer 22 can be improved. The material of the underlayer can be selected from RuCr and RuCo in addition to Ru. Ru has an hcp structure and can satisfactorily orient a magnetic recording layer containing Co as a main component.

  In this embodiment, the underlayer 18 has a two-layer structure made of Ru. When forming the second base layer 18b on the upper layer side, the Ar gas pressure is set higher than when forming the first base layer 18a on the lower layer side. When the gas pressure is increased, the free movement distance of the plasma ions to be sputtered is shortened, so that the film formation rate is reduced and the crystal orientation can be improved. Further, by increasing the pressure, the size of the crystal lattice is reduced. Since the size of the Ru crystal lattice is larger than that of the Co crystal lattice, if the Ru crystal lattice is made smaller, it approaches that of Co, and the crystal orientation of the Co granular layer can be further improved.

The miniaturization promoting layer 20 is a nonmagnetic granular layer. A nonmagnetic granular layer is formed on the hcp crystal structure of the underlayer 18, and the granular layer of the first magnetic recording layer 22 a is grown thereon, so that the magnetic granular layer can be grown from the initial growth stage (rise). Has the effect of separating. The composition of the miniaturization promoting layer 20 was nonmagnetic CoCr—SiO ₂ .

The magnetic recording layer 22 was formed of a CoCrPt—SiO ₂ hcp crystal structure of 10 nm using a hard magnetic target made of CoCrPt containing silicon oxide (SiO ₂ ) as an example of a nonmagnetic substance. In the magnetic recording layer 22 as well, the magnetic grains formed a granular structure.

  Here, the atmospheric gas pressure of the magnetic recording layer 22 was set to a low pressure of 0.6 Pa to 3 Pa. Thus, high impact resistance was able to be obtained by forming into a film by low pressure atmospheric gas.

  The continuous layer 24 forms a thin film (auxiliary recording layer) exhibiting high perpendicular magnetic anisotropy on the granular magnetic layer to constitute a CGC structure (Coupled Granular Continuous). Thereby, in addition to the high density recording property and low noise property of the granular layer, the high heat resistance of the continuous film can be added. The composition of the continuous layer 24 was CoCrPtB.

  The medium protective layer 26 is formed by depositing carbon by CVD while maintaining a vacuum and including diamond-like carbon. The medium protective layer 26 is a protective layer for protecting the perpendicular magnetic recording layer from the impact of the magnetic head. In general, carbon deposited by the CVD method has improved film hardness compared to that deposited by the sputtering method, so that the perpendicular magnetic recording layer can be protected more effectively against the impact from the magnetic head.

  The lubricating layer 28 was formed by dip coating using PFPE (perfluoropolyether). The film thickness of the lubricating layer 28 is about 1 nm.

  Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the present embodiment, the perpendicular magnetic recording medium has been described as the magnetic recording medium, but the present invention can also be suitably used for an in-plane magnetic recording medium.

  The present invention can be used as a magnetic recording medium mounted on an HDD (hard disk drive) or the like.

It is a figure explaining the structure of the perpendicular magnetic recording medium based on an Example. It is a figure explaining the structure of the sputtering device which is a vacuum film-forming apparatus used with the manufacturing method of the perpendicular magnetic recording medium based on an Example. It is a figure showing the thermal expansion coefficient of the film-forming material, the material which comprises the components of a vacuum film-forming apparatus, and the material which comprises a coating layer. It is a figure explaining the structure of a coating layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Disk base | substrate 100 ... DC magnetron sputtering apparatus 102 ... Chamber 104 ... Inlet port 106 ... Exhaust port 108 ... Carrier 110 ... Target 112 ... Shield 114 ... Magnet 12 ... Adhesion layer 14 ... Soft magnetic layer 14a ... 1st soft magnetic layer 14b ... spacer layer 14c ... second soft magnetic layer 150 ... coating layer 150a ... manganese layer 150b ... nickel layer 16 ... orientation control layer 18 ... underlayer 18a ... first underlayer 18b ... second underlayer 20 ... Layer 22 ... Magnetic recording layer 24 ... Continuous layer 26 ... Medium protective layer 28 ... Lubricating layer

Claims (8)

A method of manufacturing a magnetic recording medium using a vacuum film forming apparatus to form at least a magnetic recording layer and a medium protective layer on a substrate,
The surface of the parts of the vacuum film forming apparatus exposed to the film forming atmosphere of the vacuum film forming apparatus has a coefficient of thermal expansion intermediate between the thermal expansion coefficient of the film forming material and the material constituting the part. A method of manufacturing a magnetic recording medium, comprising one or more coating layers made of a metal or an alloy having the same.   2. The method of manufacturing a magnetic recording medium according to claim 1, wherein the material constituting the parts of the vacuum film forming apparatus is aluminum. The coating layer is
2. The method of manufacturing a magnetic recording medium according to claim 1, wherein the element is made of a single element selected from manganese, silver, copper, gold, nickel, platinum, titanium, and ruthenium, or an alloy containing the element. .   2. The method of manufacturing a magnetic recording medium according to claim 1, wherein the one or more coating layers are individually formed by one method selected from the group of thermal spraying, plating, and pressure bonding.   The method of manufacturing a magnetic recording medium according to claim 1, wherein the surface of the coating layer is subjected to blasting.   The method of manufacturing a magnetic recording medium according to claim 1, wherein the vacuum film forming apparatus is one of a group of a sputtering apparatus, a CVD apparatus, an etching apparatus, and an ion implantation apparatus. When the vacuum film forming apparatus is a sputtering apparatus,
The components of the vacuum film forming apparatus are at least
7. A magnetic recording medium according to claim 6, further comprising a shield for focusing the film-forming material released from the target on the substrate and preventing scattering of the film-forming material other than the substrate and / or a carrier for holding the substrate. Manufacturing method.   A magnetic recording medium manufactured using the method for manufacturing a magnetic recording medium according to claim 1.

Images