JP2004300486A - Carbon protection film, method for depositing the same, magnetic recording medium having the carbon protection film, magnetic head, and magnetic storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon protection film of excellent smoothness and film quality and high hardness which can be thinned, and a method for depositing the same. <P>SOLUTION: An arc discharge plasma jet film deposition apparatus 10 comprises a plasma torch 11, a vacuum chamber 12, a substrate holding stand 14 to hold a substrate 13 provided facing the plasma torch 11 in the vacuum chamber 12, and a powder feeder 15 to feed carbon particles as raw material of a carbon protection film to the plasma torch 11. Arc discharge is generated in the plasma torch 11, and carbon particles are fed into the generated plasma together with carrier gas. Carbon particles are converted into carbon ions, and radiated on the substrate 13 as plasma jet to deposit the carbon protection film thereon. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a carbon protective film and a method for forming the same, and a magnetic recording medium, a magnetic head, and a magnetic storage device provided with the carbon protective film, and in particular, has good smoothness and film quality, and can be thinned with high hardness. And a method for forming the same.
[0002]
2. Description of the Related Art In recent years, due to the rapid spread of the Internet and an increase in communication speed, the amount of data has increased dramatically, and storage devices having a storage capacity of the order of one hundred gigabytes have been mounted on personal computers and image recording devices. I have. As the need for a storage device having a larger storage capacity increases, the same durability as before has been required. In storage devices, it has become increasingly difficult to achieve both high recording density and improved durability.
[0003]
[Prior art]
In a storage device, for example, a hard disk drive, it is necessary to reduce a distance between a recording layer of a magnetic recording medium and a recording / reproducing element of a magnetic head in order to improve recording density. Examples of the method include reducing the thickness of a protective film covering the recording layer of the magnetic recording medium and the recording / reproducing element of the magnetic head, and reducing the flying height of the magnetic head from the magnetic recording medium. However, when the thickness of the protective film is reduced, problems such as mechanical weakening of the protective film and deterioration of corrosion resistance occur.
[0004]
Therefore, conventionally, a DLC film (diamond-like carbon film) having a high mechanical strength and being chemically inactive by a sputtering method or a CVD method (chemical vapor deposition method) has been used for these protective films (for example, And Patent Document 1). However, it is considered that the required performance cannot be satisfied because the hardness is insufficient for a demand for further thinning in the future.
[0005]
As a method for obtaining a DLC film having extremely high hardness, there is an FCA method (Filtered Cathodic Arc method). In this method, carbon ions are generated by an arc discharge from a carbon material cathode target, and simultaneously, neutral carbon particles that are incidentally are illuminated on the substrate by selecting only carbon ions using a magnetic deflection type mass analyzer. It is. Since this method is formed only by carbon ions, it does not contain hydrogen, and therefore has no hydrocarbon bond (CH bond) which causes a decrease in hardness. ³ A DLC film with high hardness and rich in bonding can be obtained (for example, see Patent Document 2).
[0006]
[Patent Document 1]
JP-A-11-45429
[0007]
[Patent Document 2]
JP-A-2002-285328
[0008]
[Problems to be solved by the invention]
By the way, in order to form a DLC film stably by the FCA method, it is necessary to precisely control the amount of carbon evaporation at the discharge point (cathode point) on the surface of the cathode target. However, the amount of carbon evaporation at the discharge point cannot be practically controlled. That is, the surface of the cathode target is peeled off due to a rapid temperature rise of the cathode target, and large-sized graphite particles are generated. The graphite particles generated in this manner cannot be completely removed by reflection on the wall of the magnetic deflector or the like even through the magnetic deflector, and reach the surface of the substrate and adhere thereto. If the DLC film with the graphite particles attached thereto is used as a hard disk medium or a protective film for a magnetic head, the magnetic head collides with the magnetic disk due to the projections of the graphite particles, causing a head crash or breaking the protective film.
[0009]
Such graphite particles can be suppressed by devising strict filtering with a multi-stage magnetic deflector, but the film forming apparatus becomes complicated and large, and furthermore, the carbon protective film is formed. There are problems such as a decrease in speed.
[0010]
Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a carbon protective film having good smoothness and film quality, high hardness, capable of being thinned, a method for forming the same, and a method for forming the carbon protective film. An object of the present invention is to provide a magnetic recording medium, a magnetic head, and a magnetic storage device having a film.
[0011]
[Means for Solving the Problems]
According to one aspect of the present invention, there is provided a method for forming a carbon protective film that emits a plasma containing carbon ions and deposits the carbon protective film on a substrate, comprising forming a plasma and supplying carbon particles into the plasma. To form a carbon protective film that converts the carbon ions into carbon ions and radiates plasma containing the carbon ions to the substrate.
[0012]
According to the present invention, carbon particles are supplied into plasma formed by arc discharge or the like, and are sublimated and dissociated to be converted into carbon ions, so that carbon (graphite) in the form of particles is mixed into the carbon protective film. And a smooth carbon protective film can be formed. In addition, since carbon ions are formed by deposition, the film quality is dense and good. Therefore, a carbon protective film having high hardness and being chemically inert can be formed.
[0013]
According to another aspect of the present invention, there is provided a carbon protective film for depositing a carbon protective film on a substrate by radiating the plasma containing the carbon ions, wherein the optical gap of the carbon protective film ranges from 3.6 eV to 3.0. A carbon overcoat that is 7 eV is provided. According to the present invention, by setting the optical gap in the range of 3.6 eV to 3.7 eV, a smooth carbon protective film containing no particulate carbon (graphite) is realized.
[0014]
According to another aspect of the present invention, there is provided a magnetic recording medium including a substrate and a carbon protective film formed by the above-described forming method or the carbon protective film described above above the substrate. According to the present invention, the carbon protective film is dense and excellent, has high hardness, is chemically inert, and is smooth, so that it can be thinned. Therefore, a magnetic recording medium capable of high-density recording can be realized.
[0015]
According to another aspect of the present invention, a magnetic recording medium is contacted or floated on a magnetic recording medium to perform recording or reproduction, and a slider and carbon formed on a side of the slider facing the magnetic recording medium A magnetic head including a protective film, wherein the carbon protective film is a carbon protective film formed by the formation method described in the above item, or a magnetic head that is the carbon protective film described above. According to the present invention, the carbon protective film is dense and excellent, has high hardness, is chemically inert, and is smooth, so that it can be thinned. Therefore, a magnetic recording medium capable of high-density recording can be realized. Further, it is most suitable as a protective film for a contact type magnetic head because of its high hardness and chemical inertness.
[0016]
According to another aspect of the present invention, there is provided a magnetic storage device including the magnetic recording medium and / or the magnetic head. According to the present invention, a high-capacity and long-life magnetic storage device can be realized because high-density recording is possible and durability is good by using the magnetic recording medium and the protective film of a magnetic head. Can be.
[0017]
FIG. 1 is a diagram for explaining the principle of the present invention. Referring to FIG. 1, a thermal plasma region 2 is formed in a vacuum chamber 1 to which a discharge gas is supplied by arc discharge or inductive coupling discharge, and ultrafine carbon particles are transported to the thermal plasma region 2 by a carrier gas. Supply. In the thermal plasma region 2, the carbon particles sublime, and are further dissociated by ions forming the discharge gas and converted into carbon ions. In the conventional case using a carbon target, there was a problem that carbon particles separated from the carbon target were deposited on the substrate without being converted into carbon ions. However, such a problem was caused by using ultrafine carbon particles as a carbon source. Can be prevented.
[0018]
Further, in the present invention, when the plasma jet is ejected from the thermal plasma region 2 toward the substrate 3, the plasma flow path is once narrowed, and then the jet outlet 4 has a divergent opening. 5 is formed, and the carbon ions reach the substrate 3 by the flow of the plasma jet 5 to form the carbon protective film 6. In the present invention, there is no need to apply a bias voltage for guiding carbon ions to the substrate unlike the ion beam deposition method, so that excessive kinetic energy is not added to carbon ions. Therefore, the carbon protective film 6 having good film quality and high uniformity can be formed. As a result, the carbon protective film of the present invention has high hardness and can be made thin.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
(First Embodiment)
First, a film forming apparatus for forming a carbon protective film according to an embodiment of the present invention will be described.
[0021]
FIG. 2 is a schematic sectional view of an arc discharge plasma jet film forming apparatus for forming a carbon protective film according to an embodiment of the present invention. FIG. 3 is an enlarged view of the plasma torch shown in FIG. Referring to FIGS. 2 and 3, the arc discharge plasma jet film forming apparatus 10 holds a plasma torch 11, a vacuum chamber 12, and a substrate 13 provided in the vacuum chamber 12 so as to face the plasma torch 11. It comprises a substrate holder 14, a powder feeder 15 for supplying carbon particles as a raw material of a carbon protective film to the plasma torch 11, and the like.
[0022]
The plasma torch 11 includes a cathode 22, an anode 26 formed coaxially with the cathode 22 so as to surround the cathode 22, and disposed through a gap that serves as a discharge gas flow path 23 through which a discharge gas flows. A nozzle 28 provided at the tip of the anode 26 via an insulating ring 29, a carbon particle supply channel 30 for supplying carbon particles formed in the nozzle 28, and a direct current between the cathode 22 and the anode 26. It comprises a first power supply 27 for applying voltage to form arc discharge.
[0023]
The cathode 22 has a cylindrical shape with a tip 22-1 that is pointed in a conical shape, and is made of tungsten, graphite, or the like. The tip 26-1 of the anode 26 is made of a conductive material such as graphite or copper. From the viewpoint of preventing impurities from being mixed into the plasma, the material of the tip 26-1 of the anode 26 is preferably graphite. Even if the material of the anode 26 is sputtered due to the abnormal discharge of the arc discharge, it is possible to prevent impurities from being mixed.
[0024]
A voltage for causing arc discharge is applied between the cathode 22 and the anode 26 by the first power supply 27. Although the voltage varies depending on the distance between the cathode 22 and the anode 26 and the like, for example, preferable ranges are set to an applied voltage of 100 V to 190 V and a current of 50 A to 70 A.
[0025]
The discharge gas is supplied through a discharge gas channel 23 formed between the cathode 22 and the anode 26 provided coaxially. The flow rate varies depending on the dimensions of the tapered portion 26A and the ejection port 28A, which will be described later, but is preferably set to, for example, 0.5 SLM to 5 SLM and the pressure is set to 0.3 MPa or less.
[0026]
In the discharge gas flow path 23, a rectifying plate 43 is provided upstream of the cathode 22 so as to use the discharge gas as a swirling flow. FIG. 4 is a sectional view taken along line XX of FIG. Referring to FIG. 4, openings 44A and 44B are provided on the upstream side and the downstream side of the current plate 43, and a flow path 44C communicating with the openings 44A and 44B is provided substantially coaxially with the cathode 22. ing. The discharge gas flows from the upstream opening 44A of the rectifying plate 43, flows in the flow path 44C in the substantially coaxial circumferential direction, and is ejected from the downstream opening 44B. Therefore, the discharge gas reaches the cathode 22 and the anode 26 as a swirling flow. The anode spot formed on the surface of the cathode 26 due to the DC arc discharge is concentrated at one point, and it is possible to prevent the material from evaporating abnormally due to a high temperature. In FIG. 4, the direction of the swirling flow is counterclockwise, but it may be clockwise. Note that the rectifying plate 43 is not essential and does not need to form a swirling flow.
[0027]
The anode 26 is formed with a tapered tapered portion 26A that tapers from the cathode 22 toward the substrate holding table 14. Here, the discharge gas is narrowed down to increase the pressure of the discharge gas.
[0028]
The insulation ring 29 insulates between the nozzle 28 and the anode 26. For the insulating ring 29, for example, Teflon (registered trademark), alumina, quartz glass, or the like can be used.
[0029]
The nozzle 28 is made of copper or graphite, and has an ejection port 28A that widens toward the downstream. After the discharge gas is once narrowed down by the tapered portion 26A formed on the anode 26, the discharge gas is adiabatically expanded and radiated to the substrate 13 as a plasma jet 40 containing carbon ions by the jet port 28A formed divergently. . In the present invention, since the radiation is performed only by the gas flow due to the adiabatic expansion, the carbon ions can be deposited on the substrate 13 without giving excessive kinetic energy to the carbon ions.
[0030]
Since the cathode 22, the anode 26, and the nozzle 28 are exposed to the plasma of tens of thousands of degrees and have a high temperature, cooling water is circulated therein.
[0031]
The nozzle 28 is provided with a carbon particle supply channel 30. The powder supply device 15 is connected to the carbon particle supply channel 30 as a carbon particle source. The powder supply device 15 includes a rotor 31 for agitating the carbon particles, a carrier gas introduction channel 33 for injecting a carrier gas from a cylinder 32, and a delivery channel 34 for delivering the agitated powder mixed with the carrier gas. And a motor 35 for rotating the rotor. The powder feeder 15 is filled with carbon particles 36, for example, a solid carbon material such as fullerene, carbon black, and cluster diamond. As the carrier gas, an inert gas, for example, a rare gas such as He or Ar is used. The carrier gas is controlled to a predetermined gas flow rate by the flow regulator 38 and the valve 39, and the carbon particles 36 are converted into plasma through the carbon particle supply flow path 30. Supplied. The flow rate of the carrier gas is preferably 0.1 SLM to 0.8 SLM. If the flow rate is excessive, the plasma may be destabilized and the arc discharge may stop (misfire). Note that a hydrocarbon gas may be added to the carrier gas. A small amount of hydrogen is added to the carbon protective film, and the wettability and adhesion with a lubricant for a magnetic recording medium described later are improved. As the hydrocarbon gas, a gas composed of a saturated hydrocarbon or an unsaturated hydrocarbon having 1 to 4 carbon atoms is preferable from the viewpoint of handling since it is in a gaseous state. ₄ ), Ethane (C ₂ H ₆ ), Propane (C ₃ H ₈ ), Butane (C ₄ H ₁₀ ) Or ethylene (C ₂ H ₄ ), Propylene (C ₃ H ₆ ), Butylene (C ₄ H ₈ ), Acetylene (C ₂ H ₂ ) Are particularly preferred.
[0032]
Here, the maximum particle size of the carbon particles is set to 0.5 nm to 100 nm. If it is larger than 100 nm, it may not be sufficiently sublimated and may be deposited on the substrate in the form of particles. The smaller the maximum particle size of the carbon particles, the better, but if it is smaller than 0.5 nm, the carbon particles are stably obtained as solid carbon particles. Because there is no. A carbon particle suitable as the carbon particle material is a spherical fullerene, and particularly a C60 spherical fullerene having a particle size of about 0.7 nm to 0.8 nm is preferable. As the carbon particle material, for example, a fullerene mixture from Frontier Carbon Co., Ltd. can be used. The supply amount of the carbon particles is set to, for example, 0.01 mg / sec to 0.09 mg / sec. Note that the maximum particle size of the carbon particles is observed on a photograph by SEM or HRTEM by enlarging it to, for example, about 20 mm. The diameter was taken as the maximum particle size.
[0033]
The carbon particles flow through the carbon particle supply channel 30 together with the carrier gas, and are supplied into the plasma between the anode 26 and the nozzle 28 from the carbon particle supply nozzle 45. FIG. 5 is a sectional view taken along the line YY shown in FIG. Referring to FIG. 5, the carbon particle supply nozzle 45 communicates with the upstream opening 46 communicating with the carbon particle supply flow path 30 and the upstream opening 46A, and has a substantially coaxial circumferential shape with the anode 26. It is composed of a formed flow channel 46C and a downstream opening 46B communicating with the flow channel. Therefore, the carrier gas containing the carbon particles flowing through the carbon particle supply nozzle 45 forms a swirling flow and is jetted into the discharge gas, that is, into the plasma. When the discharge gas is supplied as a swirling flow, it is better to set the ejection direction to the same direction as the rotation direction of the swirling flow of the discharge gas. The carbon particles can be injected into the plasma without disturbing the swirling flow of the discharge gas and consequently without disturbing the plasma. Note that the carbon particle supply nozzle 45 may be configured by a plurality of spiral partition walls. A swirling flow can be formed, and maintenance and cleaning are easy.
[0034]
The substrate holding table 14 is provided such that the substrate 13 faces substantially perpendicularly to the flow of the plasma jet 40, and is provided with a cooling water channel 41 for cooling the substrate 13. The substrate temperature is set in the range of 0 ° C. to 100 ° C., which is preferable in that the quality of the carbon protective film is densified.
[0035]
The discharge of the discharge gas and the like from the carbon protective film is performed from the substrate holder side, and a vacuum pump such as a molecular turbo pump (not shown) is used.
[0036]
A discharge gas, such as Ar gas, is supplied between the cathode 22 and the anode 26 through the discharge gas flow path 23, and an arc column 42 is formed between the cathode 22 and the anode 24 by the arc discharge. A plasma region is formed. Carbon particles are supplied to the plasma region together with the carrier gas from the carbon particle supply channel 30. The carbon particles are pulverized and sublimated by electrons or Ar ions in plasma and dissociated into carbon ions. In the plasma containing carbon ions, the discharge gas has a discharge port 28A diverging from the cathode 22 toward the substrate holding table 13, so that the plasma ions 40 are emitted to the substrate 13 and the carbon ions are irradiated on the substrate 13. Then, a carbon protective film is formed. Since such a carbon protective film does not include a hydrocarbon bond (CH bond), the bond between carbon atoms is sp ³ Ta-amorphous carbon having a high bonding ratio is formed, and a carbon protective film having good film quality and high hardness can be formed.
[0037]
Next, a method for forming a carbon protective film using the above arc discharge plasma jet film forming apparatus will be described.
[0038]
First, for example, a substrate 13 on which a magnetic disk, which will be described later, is formed up to a magnetic layer is transported between vacuum chambers without being exposed to the outside air and set on a substrate holder 14. Next, a discharge gas of Ar gas or the like flows at a predetermined flow rate. Next, a DC voltage is applied between the cathode 22 and the anode 26 to ignite and generate an arc discharge to generate plasma. Next, a carrier gas is supplied to the powder supply device 15 to supply the carbon particles to the plasma region, convert the carbon particles into carbon ions, and radiate a plasma jet to the substrate to form a carbon protective film. At this time, it is preferable to provide a shutter or the like between the plasma torch 11 and the substrate holding table 13 to continue the arc discharge with the shutter closed, and to open the film when forming the film. Since the arc discharge is stabilized and the plasma is stabilized, the uniformity of the film quality is further improved.
[0039]
(Second embodiment)
FIG. 6 is a schematic sectional view of an arc discharge plasma jet film forming apparatus for forming a carbon protective film according to an embodiment of the present invention. FIG. 7 is an enlarged view of the plasma torch shown in FIG. In the figure, parts corresponding to the parts described above are denoted by the same reference numerals, and description thereof will be omitted.
[0040]
Referring to FIGS. 6 and 7, an arc discharge plasma jet film forming apparatus 50 includes a plasma torch 51 and a substrate holding table 14 that holds a substrate 13 provided in the vacuum chamber 12 so as to face the plasma torch 51. And a powder supply unit 15 for supplying a carbon particle serving as a raw material of the carbon protective film to the plasma torch 51.
[0041]
The plasma torch 51 includes a cathode 22, an anode 26 formed coaxially with the cathode 22 so as to surround the cathode 22, and disposed through a gap serving as a discharge gas channel 23 through which a discharge gas flows. A DC voltage is applied between the cathode 22 and the anode 26 and a nozzle 52 having a function as a second anode disposed around the insulating ring 29 through insulating rings 29A and 29B and the carbon particle supply channel 30. A first power supply 27 for forming an arc discharge, a second power supply 53 for applying a DC voltage between the cathode 22 and the nozzle 52 to form an arc discharge, and an insulating ring 29A between the anode 26 and the nozzle 52. , 29B, and the like. The arc discharge plasma jet film forming apparatus 50 has an arc column 54B formed between the cathode 22 and the nozzle 52 in addition to the arc column 54A formed between the cathode 22 and the anode 26. Is supplied to the space surrounded by the arc columns 54A and 54B, and is the same as the arc discharge plasma jet film forming apparatus 10 described in the first embodiment. Note that the rectifying plate 43 and the carbon particle supply nozzle 45 may or may not be provided.
[0042]
The nozzle 52 is made of the same conductive material as the anode 26, and is preferably made of copper or graphite. The nozzle 52 is electrically insulated from the anode 26 by the insulating rings 29A and 29B and the carbon particle supply channel 30. Further, the carbon particle supply channel 30 is also electrically insulated from the anode 26 and the nozzle 52.
[0043]
A second power supply 53 is provided in addition to the first power supply 27, and a voltage is applied between the cathode 22 and the nozzle 52. An arc discharge is generated between the cathode 22 and the nozzle 52 to extend to the tip 52A of the nozzle 52 and to form an arc column 54B widened at the tip 52A of the nozzle 52. The voltages of the first power supply 27 and the second power supply 53 vary depending on the distance between the cathode 22 and the anode 26, the distance between the anode 26 and the nozzle 52, and the like. For example, a preferable range is that the voltage applied by the first power supply is about 50V. The constant current is set to 20A to 40A, the applied voltage by the second power supply is set to 100V to 250V, and the current is set to 40A to 70A.
[0044]
The carbon particles are supplied from the carbon particle supply flow path 30 together with the carrier gas to the space between the arc column 54A that spreads near the tip of the anode 26 and the arc column 54B that spreads at the nozzle tip. This space has a high plasma density, and the carbon particles are efficiently sublimated and dissociated and converted into carbon ions. Therefore, a high quality carbon protective film is formed.
[0045]
Here, the same material as in the first embodiment can be used for the carbon particles, but the maximum particle size of the carbon particles is set to 0.5 nm to 100 nm. Further, compared to the arc discharge plasma jet film forming apparatus of the first embodiment, even if the maximum particle size or a large amount of carbon particles is in the above range, the plasma density is high, It can be converted into ions, and as a result, the film formation rate can be improved.
[0046]
The method for forming the carbon protective film by the arc discharge plasma jet film forming apparatus according to the present embodiment is the same as the method described in the first embodiment.
[0047]
According to the present embodiment, the carbon particles are supplied to the space between the arc columns between the arc column 54A expanding near the tip of the anode and the arc column 54B expanding near the tip of the nozzle. It is easy to convert and a good quality carbon protective film is formed, and the film forming speed can be improved.
[0048]
(Third embodiment)
FIG. 8 is a schematic sectional view of an arc discharge plasma jet film forming apparatus for forming a carbon protective film according to the embodiment of the present invention. In the figure, parts corresponding to the parts described above are denoted by the same reference numerals, and description thereof will be omitted. The illustration of the powder supply device 15 (shown in FIG. 2) for supplying carbon particles is omitted.
[0049]
Referring to FIG. 8, an arc discharge plasma jet film forming apparatus 60 according to the present embodiment includes a plasma torch 11, a film forming chamber 62 provided with a substrate holder, a plasma torch 11, and a film forming chamber 62. And an electric field deflection type filter 61 for selecting carbon ions in the plasma jet. The plasma torch 11 is the same as the plasma torch 11 of the arc discharge plasma jet film forming apparatus according to the first embodiment.
[0050]
The electric field deflection filter unit 61 uses a 1 / 8-circle type filter, and includes a pair of filtering electrodes 63 and a filtering power supply 64 for applying a DC voltage to the filtering electrodes 63.
[0051]
9A is an enlarged view of a main part of the electric field deflection filter unit shown in FIG. 8, and FIG. 9B is a sectional view taken along line XX of FIG. 9A. Referring to FIGS. 8, 9A and 9B, the filtering electrode 63 is provided on the inside of the vessel wall 12A of the vacuum chamber 12 so as to be opposed to each other via an insulator 64 which is electrically insulated. . Further, a cooling tube 65 is wound around the outer wall 12A of the vacuum chamber so as not to be heated by the plasma jet.
[0052]
The voltage applied between the filtering electrodes 63 by the filtering power supply 64 is appropriately selected according to the flow rate of the plasma jet and the like, and is specifically set to 30 V to 300 V. The filtering electrode 63 is provided, for example, in a range of 1/8 circle of a radius of 500 mm, and the distance between the electrodes is set to 120 mm.
[0053]
In the plasma jet radiated from the ejection port 28A of the plasma torch 11, only the charged particles receive Lorentz force by the electric field applied by the filtering electrode 63, and the flow direction is bent toward the film forming chamber. The voltage between the filtering electrodes 63 is set such that only carbon ions of the charged particles reach the substrate. On the other hand, neutral carbon particles collide with the inner surface of the container wall 12A and the filtering electrode 63 and cannot reach the film forming chamber 62. Therefore, a smooth and high quality carbon protective film can be formed without mixing neutral carbon particles (graphite particles) into the carbon protective film formed on the substrate 13.
[0054]
The filtering electrode 63 is not limited to one pair, and may be divided into two or more along the direction of the plasma jet flow. Further, instead of the plasma torch 11, a plasma torch 51 (shown in FIG. 6) of the arc discharge plasma jet film forming apparatus according to the second embodiment may be used.
[0055]
(Fourth embodiment)
FIG. 10 is a schematic sectional view of an arc discharge plasma jet film forming apparatus according to an embodiment of the present invention. In the figure, parts corresponding to the parts described above are denoted by the same reference numerals, and description thereof will be omitted. The illustration of the powder supply device 15 (shown in FIG. 2) for supplying carbon particles is omitted.
[0056]
Referring to FIG. 10, an arc discharge plasma jet film forming apparatus 70 for forming a carbon protective film according to the present embodiment includes a plasma torch 11, a film forming chamber 62 provided with a substrate holder 14, A magnetic field deflection type filter unit 71 for selecting carbon ions in the plasma jet 73 is provided between the plasma torch 11 and the film forming chamber 62. The plasma torch 11 is similar to the plasma torch 11 of the arc discharge plasma jet film forming apparatus according to the first embodiment.
[0057]
As the magnetic field deflection type filter unit 71, a 45 ° vent type filter having two filter coils 72 is used. By applying a magnetic field perpendicular to the direction of the flow of the plasma jet 73 by the filter coil 72 (perpendicular to the plane of the drawing), the carbon ions in the plasma jet 73 are moved toward the film forming chamber 62 by Lorentz force. Then, neutral carbon particles and the like are trapped on the inner surface of the container wall 12A and the fins 74 provided on the container wall 12A, and are prevented from reaching the film forming chamber 62. Therefore, a smooth and high-quality carbon protective film can be formed without mixing neutral carbon particles into the carbon protective film formed on the substrate 13.
[0058]
Although not shown, a cooling tube is wound around the outside of the chamber wall 12A of the vacuum chamber by the plasma jet 73 so as not to reach a high temperature.
[0059]
Further, instead of the plasma torch 11, a plasma torch 51 (shown in FIG. 6) of the arc discharge plasma jet film forming apparatus of the second embodiment may be used.
[0060]
(Fifth embodiment)
FIG. 11 is a schematic cross-sectional view of an inductively coupled plasma jet film forming apparatus for forming a carbon protective film according to an embodiment of the present invention. In the figure, parts corresponding to the parts described above are denoted by the same reference numerals, and description thereof will be omitted.
[0061]
Referring to FIG. 11, the inductively coupled plasma jet film forming apparatus according to the present embodiment holds inductively coupled plasma torch 81 and substrate 13 provided in vacuum chamber 12 so as to face the plasma generating unit. And a powder supply unit 15 for supplying carbon particles serving as a raw material of the carbon protective film to the plasma generating unit.
[0062]
The inductively-coupled plasma torch 81 is formed of a cylindrical body 82 made of a ceramic insulator such as quartz glass that isolates a space for forming plasma from the outside, and a conductive material spirally wound around the wall of the cylindrical body 82. A high-frequency coil 83, a plasma-excited high-frequency power supply 84 connected to the high-frequency coil 83, a nozzle 28 provided at a narrowed distal end portion 82A of the cylindrical body 82 via an insulating ring 29, and formed in the nozzle 28. And a carbon particle supply channel 30 for supplying the carbon particles.
[0063]
The discharge gas described above is introduced into the cylindrical body 82, and a high frequency current of, for example, 1 MHz to 8 MHz and 100 A to 200 A is applied to the high frequency coil 83 by the plasma excitation high frequency power supply 84, thereby dissociating the ions and electrons of the discharge gas. Thermal plasma having a high temperature and a plasma temperature of 10,000 ° C. or more is formed.
[0064]
The distal end portion 82A of the cylindrical body 82 is narrowed down similarly to the anode (26A shown in FIG. 3) according to the first embodiment. Further, since the nozzle 28 and the carbon particle supply channel 30 are the same as in the first embodiment, the plasma generated in the cylindrical body 82 is once narrowed down. Further, the carbon particles are supplied into the plasma narrowed down from the carbon particle supply channel 30, and the carbon particles are converted into carbon ions. The plasma containing the carbon ions is radiated onto the substrate 13 as a plasma jet 85 from the divergent injection port 28A of the nozzle.
[0065]
According to the present embodiment, high-density plasma is formed by high-frequency induction plasma, and carbon particles are efficiently converted into carbon ions, so that a carbon protective film having good film quality can be formed. Hereinafter, examples will be described.
[0066]
[First embodiment]
A 30 nm-thick carbon protective film is formed on a silicon substrate by using the arc discharge plasma jet film forming apparatus according to the first embodiment shown in FIG. ₂ A carbon protective film having a thickness of 30 nm was formed on the substrate.
[0067]
The film forming conditions were as follows: Ar gas at a flow rate of 1 SLM, Ar gas at a carrier gas of 0.5 SLM, a pressure in the vacuum chamber of 6.7 Pa (0.05 Torr), a voltage of the first power supply of 150 V, and a discharge current of 70A and the substrate temperature was 40 ° C. The material of the anode was copper.
[0068]
Further, carbon black having a maximum particle diameter of 100 nm was supplied. The above-described method was used for measuring the maximum particle size of the carbon particles.
[0069]
[Second embodiment]
The carbon protective film of this example was produced under the same conditions as those of the first example, except that spherical fullerene having a maximum particle diameter of 0.8 nm (C60 / C70 mixture manufactured by MTR) was used as carbon particles.
[0070]
[Third embodiment]
The carbon protective film of this example was manufactured under the same conditions as those of the first example except that He gas was used instead of Ar gas as the carrier gas.
[0071]
[Fourth embodiment]
In the carbon protective film of the present embodiment, the carrier gas is methane gas (CH) instead of Ar gas. ₄ ) Was manufactured under the same conditions as those of the first example except that ()) was used.
[0072]
[First Comparative Example]
The carbon protective film of this comparative example was produced under the same conditions as those of the first example except that carbon particles having a maximum particle size of 300 nm (trade name of carbon black manufactured by Mitsubishi Chemical Corporation) were supplied.
[0073]
[Fifth embodiment]
A carbon protective film having a thickness of 30 nm is formed on a silicon substrate by using the arc discharge plasma jet film forming apparatus according to the second embodiment shown in FIG. ₂ A carbon protective film having a thickness of 30 nm was formed on the substrate.
[0074]
The film forming conditions are as follows: discharge gas is Ar gas at a flow rate of 1 SLM, carrier gas is Ar gas at 0.5 SLM, pressure in a vacuum chamber is 6.7 Pa (0.05 Torr), first power is 50 V, 40 A, and second power is Was set to 150 V, 70 A, and the substrate temperature was set to 40 ° C. The material of the anode and the nozzle was graphite. As the carbon particles, carbon black having a maximum particle size of 100 nm was supplied.
[0075]
[Sixth embodiment]
A carbon protective film having a thickness of 30 nm is formed on a silicon substrate by using the arc discharge plasma jet film forming apparatus according to the third embodiment shown in FIG. ₂ A carbon protective film having a thickness of 30 nm was formed on the substrate.
[0076]
The film forming conditions are as follows: discharge gas is Ar gas at a flow rate of 1 SLM, carrier gas is 0.5 SLM Ar gas, the pressure in the vacuum chamber is 6.7 Pa (0.05 Torr), the first power supply is 150 V, 70 A, and the substrate temperature is 40 ° C. The material of the anode was graphite. As the carbon particles, carbon black having a maximum particle size of 100 nm was supplied.
[0077]
Further, a voltage to be applied to the filtering electrode is selected in advance so that only carbon ions reach the substrate.
[0078]
[Seventh embodiment]
A carbon protective film having a thickness of 30 nm is formed on a silicon substrate using the arc discharge plasma jet film forming apparatus according to the fourth embodiment shown in FIG. ₂ A carbon protective film having a thickness of 30 nm was formed on the substrate.
[0079]
The film forming conditions are as follows: discharge gas is Ar gas at a flow rate of 1 SLM, carrier gas is 0.5 SLM Ar gas, the pressure in the vacuum chamber is 6.7 Pa (0.05 Torr), the first power supply is 150 V, 70 A, and the substrate temperature is 40 ° C. The material of the anode was graphite. As the carbon particles, carbon black having a maximum particle size of 100 nm was supplied. Further, a voltage to be applied to the filter coil is selected in advance so that only carbon ions reach the substrate.
[0080]
[Eighth embodiment]
A carbon protective film having a thickness of 30 nm was formed on a silicon substrate using the inductively coupled plasma jet film forming apparatus according to the fourth embodiment shown in FIG. Also, for the optical gap measurement described later, MgF ₂ A carbon protective film having a thickness of 30 nm was formed on the substrate.
[0081]
The film formation conditions were as follows: discharge gas: Ar gas at a flow rate of 1 SLM; carrier gas: Ar gas at 0.5 SLM; pressure in a vacuum chamber: 6.7 Pa (0.05 Torr); plasma excitation high frequency power supply: 40 kHz; current: 100 A; The temperature was 40 ° C. The material of the anode was graphite. As the carbon particles, carbon black having a maximum particle size of 100 nm was supplied.
[0082]
(Evaluation of carbon protective film)
The optical gap and the hardness of the carbon protective films according to the first to eighth examples and the first comparative example were evaluated.
[0083]
It has been reported that when graphite particles are locally present in the carbon protective film, the optical gap of the carbon protective film decreases (Teo et al., J. Appl. Phys. 89 (2001) p. 3706-p). .3710).
The evaluation method described in this report is useful as a method for evaluating the presence or absence of graphite particles over a wide range of a carbon protective film. Using this method, the optical gap was determined by measuring the visible absorption spectrum of the graphite particles in the carbon protective film according to the first to fourth examples and the first comparative example. The measurement of the visible absorption spectrum was performed using a U3200 spectrophotometer manufactured by Hitachi, Ltd. under the following measurement conditions.
[0084]
Measurement mode: Transmission method
Beam slit size: 10mm x 0.1mm
Then, using the absorbance α (E) and light energy E obtained by the measurement, [α (E) × E] ^1/2 The optical gap was determined from the slope and intercept of the relationship between Ta and E (Tauc plot).
[0085]
Further, the hardness of the carbon protective film was measured. For the measurement, a nano indentation method (a method of using a diamond indenter as a probe of an atomic force microscope (AFM) to push the diamond indenter into a carbon protective film and measure the repulsive force and displacement amount at the time of pushing). The measurement was performed under the following measurement conditions.
[0086]
Measuring device: Triboscope (manufactured by Hysitron)
Tip shape of diamond indenter: radius of curvature 40 nm or less, 90 ° Tip
Pushing force: 70μN
FIG. 12 is a diagram illustrating optical gaps and hardnesses of the carbon protective films according to the first to eighth examples and the first comparative example. In the figure, the maximum particle size of the carbon particles used is also shown.
[0087]
Referring to FIG. 12, first, when the first to third examples using the arc discharge plasma jet film forming apparatus of the first embodiment are compared with the first comparative example, carbon particles having a maximum particle size of 300 nm are obtained. The optical gap of the first comparative example formed by using 2.8 eV was lower than the optical gap of the first to third examples, and the carbon protective film according to the first comparative example contained graphite particles. You can see that.
[0088]
Also, comparing the first and third examples formed using carbon particles having a maximum particle size of 100 nm and the second example formed using carbon particles having a maximum particle size of 0.8 nm, It can be seen that the optical gap of the example is as high as 3.70 eV, and a carbon protective film containing no graphite particles is formed.
[0089]
In the fourth embodiment using methane gas as the carrier gas, the optical gap is slightly lower than in the first to third embodiments, but the hardness is reduced to 40 GPa. It is presumed that a hydrocarbon bond (CH bond) component was formed in the carbon protective film. Although the hardness of the carbon protective film of the fourth embodiment was relatively low, the wettability and adhesion of a lubricant having perfluoropolyether as a main chain were improved.
[0090]
Next, when the first embodiment is compared with the fifth to eighth embodiments, although the carbon particles having the same maximum particle size are used, the optical gap of the fifth to eighth embodiments is 3.70 eV. This indicates that a carbon protective film containing no graphite particles was formed.
[0091]
FIG. 13 is a diagram showing the relationship between the optical gap of the carbon protective film and the maximum particle size of the supplied carbon particles.
[0092]
Referring to FIG. 13, as another comparative example not according to the present invention, a carbon protective film having a maximum particle diameter of 200 nm or more was supplied in the first example to form a carbon protective film. did. It can be seen that the optical gap sharply decreases when the maximum particle size exceeds 100 nm.
[0093]
(Sixth embodiment)
FIG. 14 is a sectional view of the magnetic recording medium according to the embodiment of the present invention. Referring to FIG. 14, a magnetic recording medium 90 includes a substrate 91 and an underlayer 92, a nonmagnetic intermediate layer 93, a stabilizing layer 94, a nonmagnetic coupling layer 95, a recording layer 96, and a carbon protective film 98 on the substrate 91. Are sequentially laminated, and a lubricating layer 99 is further formed on the carbon protective film 98.
[0094]
As the substrate 91, a glass substrate, a NiP-plated aluminum alloy substrate, a silicon substrate, a ceramics substrate, or the like can be used. A NiP layer or the like may be formed on a glass substrate, a silicon substrate, a ceramics substrate, or the like by a sputtering method or the like. It is possible to impart conductivity and apply a bias during sputtering, and to orient the underlying layer 92 described below in a desired crystal direction.
[0095]
As the underlayer 92, a Cr layer grown in the (002) plane direction with a thickness of 40 nm by setting the substrate temperature to 200 ° C. by a sputtering method or an evaporation method is formed. Specifically, the underlayer 92 has a thickness of 10 nm to 100 nm and is not limited to the Cr layer. For example, a Cr alloy layer, for example, CrW, CrMo, CrTi, or the like is used instead of the Cr layer. By adding W or the like to Cr, the lattice constant is controlled to achieve lattice matching with the non-magnetic intermediate layer formed on the underlayer 92, and the epitaxial growth of the non-magnetic intermediate layer 93 is made more complete. it can. It is preferable that the thickness of the underlayer 92 be 2 nm or more and 50 nm or less. If the thickness is larger than 50 nm, the crystal grains of the underlayer 92 grow, the size (for example, the diameter) of the crystal grains in the in-plane direction becomes excessive, and the crystal grains are successively taken over by the layers grown on the underlayer 92, and finally. The crystal grains of the recording layer 96 become excessively large and increase the medium noise. If it is smaller than 2 nm, the crystallinity of the non-magnetic intermediate layer 93 will be reduced.
[0096]
The nonmagnetic intermediate layer 93 is formed by a sputtering method or a vapor deposition method, and is made of a CoCr alloy or a CoCrTa alloy or the like grown at a substrate temperature of 180 ° C. and growing in a (11-20) plane direction with a thickness of 20 nm. Specifically, the nonmagnetic intermediate layer 93 is made of a CoCr alloy having a thickness of 1 nm to 10 nm (Cr content is 25 atomic% or more) or an alloy obtained by adding Ta, Pt, W, or the like to a CoCr alloy. The nonmagnetic intermediate layer 93 functions as a buffer layer for alleviating the lattice mismatch between the underlayer 92 and the stabilizing layer 94 (and the recording layer 96). It has a function of improving the in-plane orientation of the c-axis of the CoCrPt alloy of the 94 (and the recording layer 96).
[0097]
The stabilizing layer 94 and the recording layer 96 have a non-magnetic coupling layer 95 between these layers, and the c-axis is oriented in the in-plane direction (for example, grown in the (11-20) plane direction). It has a laminated ferrimagnetic structure in which the magnetizations of the stabilizing layer 94 and the recording layer 96 are antiparallel to each other. Each of the stabilizing layer 94 and the recording layer 96 is a ferromagnetic layer. For example, ferromagnetic layers having the same composition and different thicknesses are formed. Specifically, the stabilizing layer 94 and the recording layer 96 are made of CoCrPt (Cr: 10 to 25 atomic%, Pt: 3 to 15 atomic%), CoCrPtB (B: 2 to 10 atomic%). , CoCrPtTa, CoCrPtTaNb, or the like, and has a composition in which CoCrPt is a main component and fourth and fifth elements are added thereto. Of these, CoCrPtB can increase the coercive force with a smaller Pt content than, for example, CoCrPtTa, and is therefore preferable from the viewpoint of higher recording density and lower cost. CoCrPtB is also suitable from the viewpoint of miniaturization of crystal grains. A fifth element may be further added to CoCrPtB.
[0098]
The thickness of the stabilizing layer 94 and the recording layer 96 is determined by the residual magnetic flux density Mr of the recording layer 96. ₁ And film thickness δ ₁ The product Mr of ₁ δ ₁ (Magnetic layer) is the Mr of the stabilizing layer 94 ₂ δ ₂ (Stabilizing layer) Set larger. That is, Mr ₁ δ ₁ -Mr ₂ δ ₂ > 0. The magnetic head senses this difference and reproduces information recorded on the magnetic recording medium 90. Therefore, the volume V of the magnetic grains, which are magnetic units, can be increased without excessively increasing the leakage magnetic field from the magnetic recording medium 90 on which information is recorded, and the thermal stability of magnetization KV / k can be increased. _B T can be increased. For example, when the compositions of the stabilizing layer 94 and the recording layer 96 are the same, ₁ = Mr ₂ Is the difference δ between the thicknesses of the stabilizing layer 94 and the recording layer 96. ₁ −δ ₂ A leakage magnetic field proportional to Here, K is an anisotropic constant, k _B Is Boltzmann's constant and T is absolute temperature.
[0099]
The nonmagnetic coupling layer 95 is formed between the stabilizing layer 94 and the recording layer 96 by a sputtering method or an evaporation method, and has a thickness of 0.4 nm to 1.0 nm (preferably 0.6 nm to 0.8 nm) of Ru or Rh. , Ir, Ru-based alloys, Rh-based alloys, and Ir-based alloys are used. By setting the film thickness in such a range, the magnetization directions of the stabilizing layer 94 and the recording layer 96 can be made antiparallel.
[0100]
The carbon protective film 98 is formed on the recording layer 96 by the formation method according to the first to fifth embodiments described above. The bond between carbons is sp ³ Ta-amorphous carbon having a high bonding ratio is formed, and since graphite particles are not mixed, a carbon protective film 98 having high smoothness, good film quality and high hardness is formed.
[0101]
The lubricating layer 99 is formed on the carbon protective film 98 with a thickness of 0.5 nm to 3 nm by an immersion method or a spin coating method. Specifically, the lubricant is prepared by diluting ZDOL, Z25 having a main chain of perfluoropolyether, AM3001 (trade name, manufactured by Ausimont) or the like into a chlorofluorocarbon-based solvent (eg, Fluorinert (trade name, manufactured by 3M)). Then, an immersion method, for example, a pulling method in which the thickness of the lubricating layer is controlled by the speed at which the substrate is pulled can be used. Of course, the thickness of the lubricating layer may be controlled by lowering the level of the fluorocarbon solvent containing the lubricant at a predetermined speed. The use of the above-described carbon protective film 98 doped with nitrogen or hydrogen can improve the adhesion of the lubricating layer 99. In particular, methane gas (CH ₄ The carbon protective film 98 formed by using ()) is preferably ZDOL and AM3001. Good wettability and adhesion of lubricant.
[0102]
According to this embodiment, since the carbon protective film is formed by the forming method according to the first to fifth embodiments, it is smooth, has good film quality, and has high hardness. Therefore, a magnetic recording medium having excellent durability and corrosion resistance can be realized.
[0103]
(Seventh embodiment)
The embodiment of the present invention relates to a magnetic head provided with the carbon protective film of the present invention.
[0104]
FIG. 15 is a diagram showing how the magnetic head according to the embodiment of the present invention flies above the magnetic recording medium. FIG. 16 is a perspective view of the magnetic head shown in FIG. 15 as seen from the side facing the magnetic recording medium. Referring to FIGS. 15 and 16, the magnetic head 100 is moved from the magnetic recording medium 101 at the outflow end of the air flow by the pressure of the air flow flowing in the arrow AIR direction generated by the magnetic recording medium 101 moving in the arrow ME direction. The recording / reproducing is performed on the magnetic recording medium 101 by flying up to a height of 10 nm. At the outflow end of the airflow of the magnetic head 100, a composite magnetic head element 102 for performing recording / reproduction is provided (indicated by a dot because it is minute).
[0105]
The medium facing surface 103-1 of the slider of the magnetic head 100 includes three pads 104 for generating a positive pressure against the airflow, a concave portion 105 for generating a negative pressure surrounded by the three pads 104, and a pad. It is composed of a composite magnetic head element 102 provided at the outflow end of 104L.
[0106]
The slider 103 is made of AlTiC (ceramics of alumina and TiC), and a carbon protective film 106 is provided on the medium facing surface 103-1 of the slider 103 as shown in FIG. Specifically, the surfaces of the three pads 104 shown in FIG. 16 are covered with a carbon protective film 106 having a thickness of 0.5 nm to 20 nm formed by the formation method according to the first to fifth embodiments. ing. Wear and scratches due to contact with the magnetic recording medium 101 can be prevented, and the flying characteristics of the magnetic head 100 can be prevented from deteriorating. The conditions for forming the carbon protective film 106 are the same as in the first embodiment.
[0107]
Here, the outflow end of the pad 104L or the pad 104R, particularly the outflow end of the pad 104L on which the composite magnetic head element 102 is formed, has the smallest spacing with the magnetic recording medium when the magnetic head 100 flies. . Since the carbon protective film 106 has no protrusions and is excellent in smoothness, spacing can be reduced, and since the carbon protective film 106 has excellent wear resistance and scratch resistance, the thickness of the carbon protective film 106 can be reduced. As a result, spacing can be further reduced, and higher recording density can be achieved.
[0108]
FIG. 17 is an enlarged view showing the structure of the medium facing surface of the composite magnetic head element 102. In FIG. 17, the opposing magnetic recording medium moves from the lower side to the upper side. Referring to FIG. 17, the composite magnetic head element 102 includes an inductive recording element 108 for performing recording and a reproducing element 109 for performing reproduction. The inductive recording element 108 includes an upper magnetic pole layer 111 separated by a recording gap 110 made of a nonmagnetic insulating material such as alumina, a lower magnetic pole layer 112 having a lower auxiliary magnetic pole 112-1, and an upper magnetic pole layer 111. A coil (not shown) for generating a head magnetic field between the lower auxiliary magnetic pole 112-1 and the like is provided. The reproducing element 109 includes a spin-valve GMR element 113 which is a magnetic sensing element, an upper shield layer 114 and a lower shield layer 115 which sandwich the spin-valve GMR element 113 via a non-magnetic insulating material. .
[0109]
The upper magnetic pole layer 111, the lower auxiliary magnetic pole 112-1, the lower magnetic pole layer 112, the spin valve type GMR element 113, the upper shield layer 114, and the lower shield layer 115 are made of a soft magnetic material such as NiFe (permalloy) or CoFeB. , An antiferromagnetic material such as FeMn or CoPtPd, or a conductive material such as Cu or Al. Therefore, these materials have relatively low hardness and are easily damaged when they come into direct contact with the protrusions or the like of the magnetic recording medium 101. Further, the magnetic recording medium 101 is easily corroded by an acid or an alkali attached to the surface. On the other hand, as shown in FIGS. 15 and 16, the magnetic head of the present embodiment is formed on the surface of the composite magnetic head element 102 by the forming methods according to the first to fifth embodiments. A carbon protective film 107 having a thickness of 0.5 nm to 5 nm is formed. Therefore, it is excellent in scratch resistance and corrosion resistance.
[0110]
Returning to FIGS. 15 and 16, the carbon protective film may be formed on the entire surface including the concave portion 105 of the medium facing surface 103-1 of the slider 103. The adhesion of the lubricant migrating from the lubricating layer of the magnetic recording medium 101 to the medium facing surface 103-1 can be prevented.
[0111]
According to the present embodiment, since a high hardness and high density carbon protective film is formed on the medium facing surface 103-1 of the magnetic head 52, for example, the surface of the pad 104 and the composite magnetic head element 102, the durability and the durability are improved. Excellent corrosion resistance. In particular, since the carbon protective film has excellent smoothness, the spacing between the magnetic head and the magnetic recording medium 101 can be further reduced.
[0112]
(Eighth embodiment)
The embodiment of the present invention relates to a magnetic storage device including the magnetic recording medium according to the sixth embodiment and / or the magnetic head according to the seventh embodiment.
[0113]
FIG. 18 is a diagram showing a main part of the magnetic storage device according to the embodiment of the present invention. Referring to FIG. 18, the magnetic storage device 120 generally includes a housing 121. Inside the housing 121, a hub 122 driven by a spindle (not shown), a magnetic recording medium 123 fixed to and rotated by the hub 122, an actuator unit 124, and attached to the actuator unit 124 in a radial direction of the magnetic recording medium 123 An arm 125 to be moved, a suspension 126, and a magnetic head 128 supported by the suspension 126 are provided.
[0114]
The magnetic storage device 120 according to the present embodiment is characterized by a magnetic recording medium 123 and a magnetic head 128. For example, the magnetic recording medium 123 is the magnetic recording medium according to the sixth embodiment. The magnetic head 128 is, for example, the magnetic head of the seventh embodiment. It is sufficient that at least one of the magnetic recording medium 123 and the magnetic head 128 has such a feature.
[0115]
The basic configuration of the magnetic storage device 120 is not limited to that shown in FIG. The magnetic recording medium 123 used in the present invention is not limited to a magnetic disk but may be a magnetic tape.
[0116]
According to the present embodiment, the magnetic storage device 120 has a long period of time even if the magnetic recording medium 123 has a low flying height at high density recording or a contact recording method since the magnetic recording medium 123 has excellent smoothness, durability, and corrosion resistance. It has a long operation reliability. Further, the magnetic head 128 has long-term flying stability in addition to excellent smoothness, durability, and corrosion resistance, and has long-term operation reliability.
[0117]
Although the preferred embodiment of the present invention has been described in detail, the present invention is not limited to the specific embodiment, and various modifications and changes may be made within the scope of the present invention described in the claims. It is possible.
[0118]
For example, although a magnetic disk has been described as an example of the magnetic recording medium according to the embodiment, the magnetic recording medium is not limited to a magnetic disk, and may be, for example, a vapor-deposited tape in which a metal thin film is formed on a tape-shaped substrate. The same effect as in the embodiment is obtained.
[0119]
In addition, the following supplementary notes are disclosed with respect to the above description.
(Supplementary Note 1) A method for forming a carbon protective film, wherein plasma containing carbon ions is emitted to deposit the carbon protective film on a substrate,
A method for forming a carbon protective film, comprising: forming plasma, supplying carbon particles into the plasma, converting the particles into carbon ions, and radiating a plasma containing the carbon ions to the substrate.
(Supplementary Note 2) The method for forming a carbon protective film according to Supplementary Note 1, wherein the carbon particles have a maximum particle size of 0.5 nm or more and 100 nm or less.
(Supplementary Note 3) The method for forming a carbon protective film according to Supplementary Note 1 or 2, wherein the carbon particles are spherical fullerenes.
(Supplementary Note 4) The carbon particles are supplied together with a carrier gas. ₂ 4. The method for forming a carbon protective film according to any one of Supplementary notes 1 to 3, wherein the method comprises at least one of the group consisting of He, Ne, Ar, Kr, and Xe.
(Supplementary note 5) The method for forming a carbon protective film according to supplementary note 4, wherein the carrier gas further includes a hydrocarbon gas.
(Supplementary Note 6) The plasma introduces a discharge gas into the vacuum chamber, and a cathode provided in the vacuum chamber and a discharge gas introduction flow path for introducing the discharge gas substantially coaxially with the cathode. The method for forming a carbon protective film according to any one of supplementary notes 1 to 5, wherein the carbon protective film is formed by applying a direct current voltage between the anode and the provided anode to cause arc discharge.
(Supplementary note 7) The method for forming a carbon protective film according to Supplementary note 6, wherein the discharge gas introduction flow path has an injection port that expands in a tapered shape from the anode toward the base.
(Supplementary note 8) The method for forming a carbon protective film according to Supplementary note 6 or 7, wherein the discharge gas introduction flow path has a tapered portion narrowed toward the substrate at the anode.
(Supplementary note 9) The method for forming a carbon protective film according to supplementary note 8, wherein the carbon particles are supplied between the tapered portion and the injection port through a carbon particle supply channel.
(Supplementary Note 10) The method for forming a carbon protective film according to any one of Supplementary Notes 6 to 9, wherein the anode and the cathode are made of graphite.
(Supplementary Note 11) The method for forming a carbon protective film according to any one of Supplementary Notes 1 to 10, wherein the discharge gas forms a swirling flow and is supplied into the plasma.
(Supplementary Note 12) Any of Supplementary Notes 1 to 11, wherein the carrier gas containing the carbon particles is supplied into the plasma from the carbon particle supply channel along the flow direction of the swirling flow of the discharge gas. The method for forming a carbon protective film according to claim 1.
(Supplementary note 13) The method for forming a carbon protective film according to any one of Supplementary notes 1 to 12, wherein the emitted plasma is deflected by an electric field or a magnetic field to select carbon ions.
(Supplementary note 14) The method for forming a carbon protective film according to any one of Supplementary notes 1 to 5, and 13, wherein the plasma is inductively coupled plasma.
(Supplementary Note 15) A carbon protective film for depositing a carbon protective film on a substrate by radiating a plasma containing carbon ions,
The carbon protective film has an optical gap in a range of 3.6 eV to 3.7 eV.
(Supplementary Note 16) A substrate, and a carbon protective film formed by the forming method according to any one of Supplementary Notes 1 to 14 or the carbon protective film according to Supplementary Note 15 above the substrate. Magnetic recording medium.
(Supplementary Note 17) Recording or reproduction is performed by contacting with or floating above the magnetic recording medium,
In a magnetic head including a slider and a carbon protective film formed on a side of the slider facing the magnetic recording medium,
A magnetic head, wherein the carbon protective film is a carbon protective film formed by the forming method according to any one of Supplementary notes 1 to 14 or the carbon protective film according to Supplementary note 15.
(Supplementary note 18) A magnetic storage device comprising the magnetic recording medium according to supplementary note 16 and / or the magnetic head according to supplementary note 17.
(Supplementary Note 19) A carbon protective film forming apparatus that radiates a plasma containing carbon ions to a substrate to form a carbon protective film on the substrate.
A vacuum vessel defined by an outer wall and having a holding table for holding the substrate,
On the vacuum vessel, a plasma generator provided so as to face the substrate on the holding table,
A discharge gas supply unit that supplies a discharge gas to the plasma generation unit,
The plasma generation unit is provided so as to surround the cathode and a cathode coaxially with the cathode through a gap that is a discharge gas flow path connected to the discharge gas supply unit, and has an anode opening coaxially therewith. An anode having a nozzle adjacent to the anode and having a nozzle opening for emitting plasma together with a discharge gas in the vacuum vessel, and a carbon particle supply channel provided between the anode and the nozzle. Become
The discharge gas flow path, the anode opening and the nozzle opening communicate with each other,
A power supply for arc discharge is connected between the cathode and the anode,
A plasma region is formed by arc discharge between the cathode and the anode at the anode opening,
An apparatus for forming a carbon protective film, wherein carbon particles are supplied into the plasma region from the carbon particle supply channel.
(Supplementary Note 20) Another power supply for arc discharge is connected between the cathode and the nozzle,
Another plasma region continuous with the plasma region is formed by arc discharge between the cathode and the nozzle,
An apparatus for forming a carbon protective film, wherein carbon particles are supplied into the other plasma region.
(Supplementary note 21) The carbon protective film forming apparatus according to supplementary note 19 or 20, wherein a deflector that deflects the radiated plasma by an electric field or a magnetic field is provided between the plasma generation unit and the holding table. .
[0120]
【The invention's effect】
As is apparent from the details described above, according to the present invention, a hard carbon protective film having good smoothness and film quality, high hardness, and capable of being thinned, a method for forming the same, and the hard carbon protective film are provided. A magnetic recording medium, a magnetic head, and a magnetic storage device.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining the principle of the present invention.
FIG. 2 is a schematic sectional view of an arc discharge plasma jet film forming apparatus according to the first embodiment of the present invention.
FIG. 3 is an enlarged view showing a main part of the plasma torch shown in FIG. 2;
FIG. 4 is a sectional view taken along line XX shown in FIG. 3;
FIG. 5 is a sectional view taken along line YY shown in FIG. 3;
FIG. 6 is a schematic sectional view of an arc discharge plasma jet film forming apparatus according to a second embodiment of the present invention.
FIG. 7 is an enlarged view showing a main part of the plasma torch shown in FIG. 6;
FIG. 8 is a schematic sectional view of an arc discharge plasma jet film forming apparatus according to a third embodiment of the present invention.
9A is an enlarged view of a main part of the electric field deflection filter unit shown in FIG. 8, and FIG. 9B is a sectional view taken along line XX of FIG. 9A.
FIG. 10 is a schematic sectional view of an arc discharge plasma jet film forming apparatus according to a fourth embodiment of the present invention.
FIG. 11 is a schematic sectional view of an inductively coupled plasma jet film forming apparatus according to a fifth embodiment of the present invention.
FIG. 12 is a diagram illustrating optical gaps and hardnesses of carbon protective films according to first to eighth examples and a first comparative example.
FIG. 13 is a diagram showing the relationship between the optical gap of the carbon protective film and the maximum particle size of the supplied carbon particles.
FIG. 14 is a sectional view of a magnetic recording medium according to a sixth embodiment of the present invention.
FIG. 15 is a diagram showing how a magnetic head according to a seventh embodiment of the present invention flies above a magnetic recording medium.
16 is a perspective view of the magnetic head shown in FIG. 15 as viewed from a side facing a magnetic recording medium.
FIG. 17 is an enlarged view showing a structure of a medium facing surface of the composite magnetic head element.
FIG. 18 is a diagram illustrating a main part of a magnetic storage device according to an eighth embodiment of the present invention.
[Explanation of symbols]
10, 50, 60, 70 arc discharge plasma jet film forming apparatus
11,51,81 Plasma torch
12 vacuum chamber
13 Substrate
14 Substrate holder
15 Powder feeder
22 Cathode
23 Discharge gas flow path
26 Anode
27 1st power supply
28, 52 nozzles
28A spout
29, 29A, 29B Insulation ring
30 carbon particle supply channel
30A Opening of carbon particle supply channel
36 carbon particles
38 Flow controller
42, 54A, 54B Arc column
43 Rectifier plate
45 Nozzle for supplying carbon particles
53 Second power supply
61 Electric field deflection type filter
71 Magnetic field deflection type filter section
80 Inductively coupled plasma jet film forming system
90 Magnetic recording medium
98, 106, 107 Carbon protective film
100 magnetic head
102 Composite magnetic head element
120 Magnetic storage device

Claims (10)

A method for forming a carbon protective film that emits plasma containing carbon ions and deposits a carbon protective film on a substrate,
A method for forming a carbon protective film, comprising: forming plasma, supplying carbon particles into the plasma, converting the particles into carbon ions, and radiating a plasma containing the carbon ions to the substrate. 2. The method according to claim 1, wherein the carbon particles are spherical fullerenes. The plasma introduces a discharge gas into a vacuum chamber, and a cathode provided in the vacuum chamber and an anode provided substantially coaxially with the cathode through a discharge gas introduction flow path for introducing a discharge gas. The method for forming a carbon protective film according to claim 1, wherein the carbon protective film is formed by applying a DC voltage between the first and second layers to generate an arc discharge. 4. The method according to claim 3, wherein the discharge gas introduction flow path has a tapered portion narrowed toward a substrate at the anode. The method for forming a carbon protective film according to claim 1, wherein the emitted plasma is deflected by an electric or magnetic field to select carbon ions. 6. The method according to claim 1, wherein the plasma is an inductively coupled plasma. A carbon protective film that emits plasma containing carbon ions and deposits a carbon protective film on a substrate,
The carbon protective film has an optical gap of 3.6 eV to 3.7 eV. A substrate, and a carbon protective film formed by the method according to any one of claims 1 to 6 or a carbon protective film according to claim 7 above the substrate. Magnetic recording medium. Contacting the magnetic recording medium, or floating on the magnetic recording medium to perform recording or reproduction,
In a magnetic head including a slider and a carbon protective film formed on a side of the slider facing the magnetic recording medium,
A magnetic head, wherein the carbon protective film is a carbon protective film formed by the forming method according to any one of claims 1 to 6, or a carbon protective film according to claim 7. A magnetic storage device comprising the magnetic recording medium according to claim 8 and / or the magnetic head according to claim 9.

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