CN101138025B - Production process of magnetic recording medium, magnetic recording medium, and magnetic recording and reproducing apparatus - Google Patents
Production process of magnetic recording medium, magnetic recording medium, and magnetic recording and reproducing apparatus Download PDFInfo
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- CN101138025B CN101138025B CN2006800079089A CN200680007908A CN101138025B CN 101138025 B CN101138025 B CN 101138025B CN 2006800079089 A CN2006800079089 A CN 2006800079089A CN 200680007908 A CN200680007908 A CN 200680007908A CN 101138025 B CN101138025 B CN 101138025B
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Abstract
A production process of magnetic recording media is provided in which, when using an oxide magnetic material as a perpendicular magnetic recording layer and forming a carbon protective layer using a plasma CVD method, stripping of the carbon protective layer and separation of a lubrication layer can be prevented, and satisfactory recording and reproduction characteristics can be obtained. In the production process of magnetic recording media, the magnetic recording media consists of, at least, a substrate 1 on which are provided a perpendicular magnetic recording layer and a carbon protective layer, in which the perpendicular magnetic recording layer consists of magnetic material containing a Co alloy and oxide material; the method includes a perpendicular magnetic recording layer formation process of forming the perpendicular magnetic recording layer on the substrate 1, a heating process of using a heating portion 28 to heat the substrate 1 on which the perpendicular magnetic recording layer has been formed, and a protective layer formation process of using a plasma CVD method to form a carbon protective layer on the substrate 1 on which the perpendicular magnetic recording layer has been formed.
Description
The cross reference of related application
The right of priority of the Japanese patent application 2005-077916 that submitted on March 17th, 2005 is enjoyed in request.This application is the application of submitting to according to 35U.S.C. § 111 (a), and it enjoys the applying date in the provisional application 60/665371 of submission on March 28th, 2005 according to 35U.S.C. § 111 (b) according to 35U.S.C. § 119 (e).
Technical field
The magnetic recording and the transcriber that the present invention relates to the manufacture method of a kind of magnetic recording media, this medium and adopt this magnetic recording media.
Background technology
The perpendicular magnetic recording method is to adopt the method for the magnetic recording layer that wherein easy magnetizing axis is vertical with substrate.Compare with the longitudinal magnetic recording method, near the demagnetized field the magnetic transitional region on border weakens between as recorded bit in perpendicular magnetic recording, thereby the high more recording status of recording density is magnetostatic more stable, and has improved the heat resistanceheat resistant undulatory property; Therefore this method is suitable for improving surface density.
Particularly, when the soft magnetism lining that is made of soft magnetic material is arranged between substrate and the perpendicular magnetic recording layer, can obtain the function of so-called vertical double-layer medium and good recording characteristic.At this moment, the soft magnetism lining is used to provide the recording magnetic field return path that begins from magnetic head, and improves record and reproduce efficient.
In perpendicular magnetic recording medium, in substrate, form soft magnetism lining, lining, perpendicular magnetic recording layer and protective seam usually.
Co-Cr system alloy is widely used as perpendicular magnetic recording materials.When adopting Co-Cr system alloy, usually the heating of the substrate between the film depositional stage cause in the magnetic recording layer magnetic mutually and the separating of non magnetic phase.
The carbon protective layer that forms by the plasma CVD method is widely used as protective seam.
In recent years, comprise Co alloy (for example Co-Cr-Pt) and SiO
2Perhaps the oxidate magnetic material of other oxide is gradually as the perpendicular magnetic recording layer material.
In oxidate magnetic material, the non magnetic segregation mutually of oxide is the magnetic phase around Co alloy or analog, thereby detachable magnetic crystal grain (magnetic phase) and make it thinner can make also the magnetic transitional region littler.Therefore, can reduce media noise (referring to non-patent literature 1 to 3).
Non-patent literature 1:Oikawa et al. " SiO
2Composition of CoPtCr-SiO
2/ Ruperpendicular magnetic recording media and grain isolation ", Journal ofthe Applied Magnetic Society Japan, 29,231-234 (2005).
Non-patent literature 2:Matsunuma et al. " CoCrPt alloy-oxide perpendicularmagnetic recording media with a new structure incorporating anintermediate layer ", Technical Report of the Institute of Electronic, Information and Communication Engineers, MR2004-10.
Non-patent literature 3:Ohtsuki and Uwazumi " Development of perpendicularmagnetic recording media for an HDD aiming at 400 Gbits/inch
2", NikkeiElectronics, January 19,2004.
Summary of the invention
But in the magnetic recording media that is obtained by the prior art manufacture method, carbon protective layer separates.And lubricating layer is relatively poor in the lip-deep adhesion of carbon protective layer, and uses a part of lubricating layer to stick to head-slider through long-time.
According to above-mentioned situation design the present invention; an one target is to provide magnetic recording medium manufacturing method, magnetic recording media and magnetic recording and transcriber; when in perpendicular magnetic recording layer, adopting oxidate magnetic material; and when forming carbon protective layer by the plasma CVD method; it can prevent that the separation of carbon protective layer and lubricant from sticking to magnetic head, and record and reproduction feature are met the requirements.
For obtaining above-mentioned target, the present invention adopts following configuration.
(1) the first kind of invention that addresses the above problem is a kind of method of making magnetic recording media, in described medium, perpendicular magnetic recording layer and carbon protective layer are provided in substrate at least, wherein said perpendicular magnetic recording layer is formed by the magnetic material that comprises Co alloy and oxide material, described method comprises: the perpendicular magnetic recording layer formation process forms perpendicular magnetic recording layer in described substrate; Heating process heats the described substrate that is formed with described perpendicular magnetic recording layer on it; And the protective seam forming process, be formed with thereon by the plasma CVD method in the described substrate of described perpendicular magnetic recording layer and form carbon protective layer.
(2) the second kind of invention that addresses the above problem for make as above-mentioned (1) as described in the method for magnetic recording media, it is characterized in that heating-up temperature in described heating process is higher than the film deposition temperature when the described carbon protective layer of formation in described protective seam forming process.
(3) the third invention that addresses the above problem is for making as above-mentioned (1) or (2) described magnetic recording media method; it is characterized in that in described perpendicular magnetic recording layer formation process; temperature during forming described perpendicular magnetic recording layer is less than 80 ℃; heating-up temperature in heating process is set to, and makes that the film deposition temperature during forming described carbon protective layer is 80 ℃ or higher.
(4) the 4th kind of invention that addresses the above problem is for making as any described magnetic recording media method of above-mentioned (1) to (3), it is characterized in that described perpendicular magnetic recording layer comprises a kind of structure, the nonmagnetic layer that is made of oxide material in described structure is around the magnetosphere that is made of the Co alloy.
(5) the 5th kind of invention that addresses the above problem is characterized in that for making as any described magnetic recording media method of above-mentioned (1) to (4) described oxide material is SiO
2, TiO, TiO
2, ZrO
2, Cr
2O
3, CoO, Ta
2O
5, and Al
2O
3In any or two kinds or more kinds of material.
(6) the 6th kind of invention that addresses the above problem is a kind of magnetic recording media, it is characterized in that this magnetic recording media is by any described magnetic recording medium manufacturing method manufacturing in (1) to (5).
(7) the 7th kind of invention that addresses the above problem is a kind of magnetic recording and transcriber, it is characterized in that having as (6) described magnetic recording media, and records information to magnetic recording media and from the magnetic head of magnetic recording media information reproduction.
According to the present invention; after forming perpendicular magnetic recording layer with oxidate magnetic material; heating substrate and using plasma CVD method are to form carbon protective layer; thereby the perpendicular magnetic recording layer that acquisition has good record and reproducing characteristic, and can form carbon protective layer with high density and good adhesion characteristic.
Description of drawings
Fig. 1 is the cross-sectional view that magnetic recording media first example of the present invention is shown;
Fig. 2 is the cross-sectional view that magnetic recording media second example of the present invention is shown;
Fig. 3 illustrates the manufacturing installation structure that is used to make magnetic recording media shown in Figure 1;
Fig. 4 totally illustrates the example of magnetic recording of the present invention and transcriber;
Fig. 5 is the figure that sample result is shown;
Fig. 6 is the figure that sample result is shown; And
Fig. 7 is for being the figure that sample result is shown.
Embodiment
Fig. 1 illustrates first example of magnetic recording media of the present invention.
By in substrate 1, forming first soft ferromagnetic layer 2 in order; Antiferromagnetic layer 3; Second soft ferromagnetic layer 4; Alignment control layer 5; Perpendicular magnetic recording layer 6; Carbon protective layer 7; Construct this magnetic recording media with lubricating layer 8.
Fig. 2 illustrates second example of magnetic recording media of the present invention.
This magnetic recording media and magnetic recording media shown in Figure 1 are similarly constructed, and different is between the substrate 1 and first soft ferromagnetic layer 2 pinning lining 9 and pinning layer 10 to be set.
As substrate, can use the metallic substrates that constitutes by aluminium, aluminium alloy or another kind of metal material; Perhaps adopt the non metallic substrate that constitutes by glass, stupalith, silicon, silit, carbon or another kind of nonmetallic materials.
Amorphous glass or glass ceramics can be used as substrate of glass; General soda-lime glass or alumina silicate glass are used as amorphous glass.The lithium glass ceramics is used as glass ceramics.The sinter etc. that with Main Ingredients and Appearance is general aluminium oxide, aluminium nitride, silicon nitride or analog and fiber strengthened these materials is as ceramic bases.
Size of foundation base can be any.For example can adopt diameter is the substrate of 95mm, 65mm, 48mm, 27.4mm, 21.6mm or similar size.
When the average surface roughness Ra of substrate is 2nm or still less is preferably 1nm or still less the time, can reduce the flying height of magnetic head, so this medium is suitable for high density recording.
In addition, the external waviness Wa in substrate surface remains on 0.3nm or lower, is preferably 0.25nm or when lower, can reduce magnetic head flight height, so this medium is suitable for high density recording.For example can external waviness Wa be measured as the average surface roughness of 80 μ m measurement ranges by surface finish measurement device P-12 (KLA-Tencor manufacturing).
For keeping the stabilized flight of magnetic head, preferably adopt a kind of substrate, wherein at least one the surperficial average surface roughness Ra in end face ramp and the lateral parts is 10nm or lower, more preferably 9.5nm or lower.
Provide the pinning lining so that the crystal structure of pinning layer to be set; Can be with Cr or Cr alloy material as the pinning lining.The example of Cr alloy comprises CrMo, CrTi, CrW, CrV, CrSi and CrNb system alloy.
For example Co-Cr-Pt-B alloy or Co-Sm alloy constitute pinning layer by retentive material.Because the coercive force of pinning layer, can suppress moving of the interior domain wall of soft ferromagnetic layer much larger than soft ferromagnetic layer.
The coercive force Hc of preferred pinning layer is 500Oe or bigger (more preferably coercive force is 1000Oe or bigger).One Oe is approximately equal to 79A/m.
Soft ferromagnetic layer is also referred to as the soft magnetism lining, and goes out corresponding first soft ferromagnetic layer 2 and second soft ferromagnetic layer 4 in the example illustrated in figures 1 and 2.
To comprise that material at least a among Fe, Ni and the Co is as the soft magnetic material that uses in soft ferromagnetic layer.As this material, can use FeCo alloy (FeCo, FeCoB, or analog), FeNi alloy (FeNi, FeNiMo, FeNiCr, FeNiSi, or analog), FeAl alloy (FeAl, FeAlSi, FeAlSiCr, FeAlSiTiRu, FeAlO, or analog), FeCr alloy (FeCr, FeCrTi, FeCrCu, or analog), FeTa alloy (FeTa, FeTaC, FeTaN, or analog), FeMg alloy (FeMgO or analog), FeZr alloy (FeZrN or analog), the FeC alloy, the FeN alloy, the FeSi alloy, the FeP alloy, the FeNb alloy, the FeHf alloy, the FeB alloy, the CoB alloy, the CoP alloy, CoNi alloy (CoNi, CoNiB, CoNiP or analog), FeCoNi alloy (FeCoNi, FeCoNiP, FeCoNiB, or analog) and other alloy.
To comprise that preferably Co alloy at least a in 80at% or more Co and Zr, Nb, Ta, Cr, Mo or the analog is as the soft ferromagnetic layer material.Can from CoZr, CoZrNb, CoZrTa, CoZrCr, CoZrMo or other alloy, choose this Co alloy suitably.
Also can adopt a kind of alloy material, this alloy comprises 60at% or more Fe (FeAlO, FeMgO, FeTaN, FeZrN or analog), and has fine crystals structure or granular structure.Granular structure is by the structure of mother metal around the fine crystals particle.
Preferred soft ferromagnetic layer has impalpable structure or fine crystals structure.This is because when soft ferromagnetic layer has impalpable structure or fine crystals structure, and surfaceness can variation, and the crystal orientation of perpendicular magnetic recording layer can variation yet.
The coercive force Hc of preferred soft ferromagnetic layer is 20Oe or littler (more preferably this be worth be 10Oe or littler).
The saturation magnetic flux density Bs of preferred soft ferromagnetic layer is 0.6T or bigger (more preferably this be worth be 1T or bigger).
The product Bst of preferred saturation magnetic flux density Bs and soft ferromagnetic layer layer thickness t is 20Tnm or bigger, and more preferably this is worth and is 40Tnm or bigger.When Bst is lower than above-mentioned scope, OW characteristic variation, this point is undesirable.
The layer thickness of preferred soft ferromagnetic layer is 120nm or lower, and more preferably this thickness is 80nm or lower.By soft ferromagnetic layer thickness is remained in the above-mentioned scope, character of surface is met the requirements, and prevent performance degradation and make the characteristic variation.
The part on the whole surface of soft ferromagnetic layer, oxidable the top.When the soft magnetism number of plies is for the moment, topmost soft ferromagnetic layer is unique soft ferromagnetic layer; When a plurality of soft ferromagnetic layer, uppermost soft ferromagnetic layer is a uppermost layer in these layers.In the example that goes out illustrated in figures 1 and 2, uppermost soft ferromagnetic layer is second soft ferromagnetic layer 4.
Provide antiferromagnetic layer with by with soft ferromagnetic layer between exchange coupling aim at direction of magnetization in the soft ferromagnetic layer.Preferred magnetization direction be substrate radially.
Preferred antiferromagnetism layer material is MnIr system alloy or MnFe system alloy.When adopting MnIr system alloy or MnFe system alloy, can between soft ferromagnetic layer and antiferromagnetic layer, produce exchange coupling by deposition soft ferromagnetic layer and antiferromagnetic layer in magnetic field, therefore needn't carry out the magnetic-field annealing process after deposition, cooling and the similar operations, this point is desired.
The thickness of preferred MnIr system alloy antiferromagnetic layer is 3nm or bigger and 10nm or littler.For MnFe system alloy, preferred thickness is 10nm or bigger and 30nm or littler.Particularly, when adopt MnIr system alloy and when the thickness of antiferromagnetic layer be 4nm or bigger and 7nm or more hour, can make exchange coupling magnetic field stronger, and can not produce the problem that layer thickness causes.
In the example that goes out illustrated in figures 1 and 2, only between first soft ferromagnetic layer 2 and second soft ferromagnetic layer 4, antiferromagnetic layer is set; Except this structure, also can below first soft ferromagnetic layer 2, form antiferromagnetic layer.
During when the deposition soft magnetic film and with the antiferromagnetism film of the former exchange coupling, preferred magnetic direction when adjusting deposition is so that the magnetic direction difference.For example, when the direction of magnetization of soft ferromagnetic layer and antiferromagnetic layer is in substrate radially and during antiparallel, help to make, this point is desired.
In the present invention, can replace antiferromagnetic layer and be arranged between two soft ferromagnetic layers being coupled with the middle layer to form demagnetized field.This middle layer is made of Ru or Ru alloy.
Soft ferromagnetic layer forms magnetic domain easily, and magnetic domain is the spike noise source; But the middle layer can suppress the formation of neticdomain wall in the soft ferromagnetic layer because demagnetized field is coupled by bias magnetic field, thereby reduces noise.
Can under antiferromagnetic layer, form the soft magnetism crystal lining that constitutes by soft magnetic material.For example, in example illustrated in fig. 1 and 2, can between the antiferromagnetic layer 3 and first soft ferromagnetic layer 2, form soft magnetism crystal lining.
Provide soft magnetism crystal lining to improve antiferromagnetic layer crystallographic and strengthen exchange coupling magnetic field.Preferred soft magnetism crystal lining is made of the material with fcc or hcp structure.Particularly, Ni-Fe system alloy and Co-Fe system alloy are desirable.
Because soft magnetism crystal lining is made of soft magnetic material, between antiferromagnetic layer that is provided with on the soft magnetism crystal lining of base side and soft ferromagnetic layer exchange coupling takes place.
Provide alignment control layer to aim at control perpendicular magnetic recording layer and crystal grain diameter.
As the alignment control layer material, preferred Ru or Ru alloy.
As the Ru alloy, can use the oxide bulk based material that comprises Ru and oxide.Oxide can be SiO
2, Al
2O
3, Cr
2O
3, CoO and Ta
2O
5In any, two or more.When adopting the oxide bulk based material, alignment control layer can comprise granular structure, wherein centers on the particle that comprises Ru by the mother metal as oxide material.It is desirable for the formation of determining alignment control layer, make and write down and reproducing characteristic the best.Can in alignment control layer, adopt magnetic material, but not restriction especially.
The saturation magnetization Ms of preferred alignment key-course from 0 to 200emu/cc.When the Ms of alignment control layer surpasses 200emu/cc, the noise that alignment control layer produced can cause record and reproducing characteristic variation.One emu/cc approximates 12.5710 greatly
-4Wb/m
2
Preferably, the thickness of alignment control layer is more than or equal to 3nm and smaller or equal to 30nm, and more preferably this thickness is more than or equal to 10nm and smaller or equal to 20nm.In the time of in alignment control layer thickness is in this scope, the aligning of perpendicular magnetic recording layer is good, and can make when record magnetic head and soft ferromagnetic layer between distance less, thereby can strengthen the resolution that record and reproducing characteristic still can not reduce reproducing signal.
Can below alignment control layer, form inculating crystal layer.
Preferred inculating crystal layer is NiTa alloy, NiNb alloy, NiTaC alloy, NiTaB alloy, CoNiTa alloy, NiFe alloy, NiFeMo alloy, NiFeCr alloy, NiFeV alloy or NiCo alloy.
By forming inculating crystal layer, the crystal orientation of alignment control layer is met the requirements, and can adjust the crystal structure of perpendicular magnetic recording layer.
The main aligned perpendicular of the easy magnetizing axis of perpendicular magnetic recording layer is in the direction of substrate.Make this main coercive force Hc (P) and vertical coercive force Hc (L) of meaning on the vertical direction of aiming at vertical direction satisfy relational expression Hc (P)＞Hc (L).
In perpendicular magnetic recording layer, adopt the magnetic material (oxide bulk magnetic material hereinafter referred to as) that comprises Co alloy and oxide at least.
Perpendicular magnetic recording layer is a granular structure, i.e. the non magnetic magnetic phase (magnetic-particle) that is made of the Co alloy that centers on mutually that is made of oxide material.In having the perpendicular magnetic recording layer of granular structure, a plurality of magnetic phase particulate dispersion non magnetic mutually in.So, make as the magnetic transitional region in media noise source as much as possible for a short time, and can reduce media noise.
Preferably with Co-Pt system alloy particularly Co-Cr-Pt system alloy as the Co alloy.
Preferably with SiO
2, TiO, TiO
2, ZrO
2, Cr
2O
3, CoO, Ta
2O
5And Al
2O
3Wherein a kind of, two kinds or more of material is as oxide material.
Preferably with Co-Cr-Pt-SiO
2Perhaps Co-Cr-Pt-Cr
2O
3As oxidate magnetic material.
Preferred Cr content is 5at% or higher and be 30at% or lower (more preferably this content is 8at% or higher and be 15at% or lower); And preferred Pt content is 10at% or higher and 22at% or lower (more preferably this content is 13at% or higher and 20at% or lower).
Preferred oxide material content is 2mol% or higher and 15mol% or lower (more preferably this content is 4mol% or higher and 12mol% or lower).
When Cr or oxide content were lower than above-mentioned scope, with the magnetic that is made of the Co alloy exchange coupling grow between (magnetic-particle) mutually, magnetic bunch diameter increased, and noise increases, and this point is undesirable.When Cr or oxide material content surpassed above-mentioned scope, coercive force and Mr/Ms reduced.Mr is remanent magnetization, and Ms is a saturated magnetization.
When Pt content is lower than above-mentioned scope, improve the effect deficiency of record and reproducing characteristic, and the Mr/Ms reduction, thereby heat resistanceheat resistant undulatory property variation.When Pt content surpassed above-mentioned scope, noise increased.
Perpendicular magnetic recording layer can be a single layer structure, and perhaps material constitutes different two-layer or sandwich constructions.
The thickness of perpendicular magnetic recording medium is 5nm or bigger and 20nm or meet the requirements more for a short time (and more preferably 10nm or bigger and 16nm or littler thickness).When the thickness of perpendicular magnetic recording layer is 5nm or when bigger, the magnetic flux deficiency of acquisition, and clear and output does not reduce in the reproduction period output waveform, thus medium is suitable for high density recording.When the perpendicular magnetic recording layer thickness is 20nm or when lower, can suppress magnetic phase (magnetic-particle) alligatoring, for example degenerate that noise increases thereby be difficult for occurrence record and reproducing characteristic.
The coercive force of preferred vertical magnetic recording layer is 4000Oe or bigger.When coercive force was lower than this scope, resolution and heat-resisting undulatory property reduced.
When the Mr/Ms of perpendicular magnetic recording layer is greater than or equal to 0.95, can obtain good heat-resisting undulatory property.
When the reverse magnetic domain nucleation magnetic field of perpendicular magnetic recording layer (is 1000 or when bigger Hn), can obtains good heat resistanceheat resistant undulatory property.
Preferably in perpendicular magnetic recording layer, the average particulate diameter of the magnetic phase (magnetic-particle) that is made of the Co alloy is more than or equal to 4nm and smaller or equal to 8nm.For example determine average particulate diameter by TEM (transmission electron microscope art) observation perpendicular magnetic recording layer and by Flame Image Process institute observed image.
Also can form a plurality of perpendicular magnetic recording layers.
Carbon protective layer prevents the corrosion of perpendicular magnetic recording layer, and prevents when the medium contact magnetic head destruction to dielectric surface, and carbon protective layer is formed by carbon.
Form carbon protective layer by the plasma CVD method.
The thickness of expectation carbon protective layer is more than or equal to 1nm and smaller or equal to 10nm; More than or equal to 1nm and smaller or equal to 5nm is desirable thickness.By the carbon protective layer thickness in this scope is set, the distance between magnetic head and the perpendicular magnetic recording layer is diminished, from the high density recording angle, this point is desired.
Can form carbon protective layer by plasma CVD method to small part, and can for example it be configured to comprise first carbon-coating that forms by the plasma CVD method and second carbon-coating that forms by sputtering method.
Preferred lubricating layer adopts PFPE, fluorinated alohol, fluoride carboxylate or similar lubricant.
Then explain the method for making magnetic recording media of the present invention.
Fig. 3 illustrates and can be used on the example of making the manufacturing installation in the magnetic recording media method of the present invention.This manufacturing installation is the film depositing system, and it comprises first soft ferromagnetic layer formation chamber 22 that is used for forming first soft ferromagnetic layer 2 in substrate 1; The antiferromagnetic layer that is used to form antiferromagnetic layer 3 forms chamber 23; Second soft ferromagnetic layer that is used to form second soft ferromagnetic layer 4 forms chamber 24; The alignment control layer that is used to form alignment control layer 5 forms chamber 25; The perpendicular magnetic recording layer that is used to form perpendicular magnetic recording layer 6 forms chamber 26; Heating part 28; Form chamber 27 with the protective seam that is used to form carbon protective layer 7.
Condition of work when adopting the sputtering method sedimentary deposit is for example as described below.
Substrate placed form the chamber, and will form the chamber and be evacuated to 10
-4To 10
-7The pressure of Pa.Ar or another kind of sputter gas are infiltrated the formation chamber, and by powering and sedimentary deposit to sputtering target.Can be with vacuum evaporation deposition, ion beam and similar approach as film deposition method.
Below, with the example that example is described manufacture method of the present invention that is fabricated to of magnetic recording media shown in Figure 1.
As shown in Figure 3, place first soft ferromagnetic layer to form in the chamber 22 substrate 1, use sputtering method or similar approach to form first soft ferromagnetic layer 2.
Then, after formation chamber 22, place antiferromagnetic layer to form chamber 23 substrate 1, and adopt sputter or another kind of method to form antiferromagnetic layer 3.
Then, after formation chamber 23, place second soft ferromagnetic layer to form chamber 24 substrate 1, and adopt sputter or another kind of method to form second soft ferromagnetic layer 4.
Then, after formation chamber 24, place alignment control layer to form chamber 25 substrate 1, and adopt sputter or another kind of method to form alignment control layer 5.
In forming chamber 22 to 25, between the film depositional stage, preferably when adopting the material different, when being in heated condition, substrate 1 deposits this layer with the oxide bulk based material.For example from 100 to 400 ℃ of heating-up temperatures.
Then,, place perpendicular magnetic recording layer to form in the chamber 26 substrate 1, and adopt sputter or another kind of method to form by oxide bulk magnetic material Co-Cr-Pt-SiO for example through forming after the chamber 25
2Perhaps Co-Cr-Pt-Cr
2O
3The perpendicular magnetic recording layer 6 that constitutes.
Can perhaps can utilize to contain the oxygen sputter gas by above-mentioned oxide bulk magnetic material is deposited perpendicular magnetic recording layer 6 as sputtering target, deposit this layer by reactive sputtering method as the oxide material raw material.The forming process of perpendicular magnetic recording layer 6 is called the perpendicular magnetic recording layer formation process.
Because can in perpendicular magnetic recording layer 6, use the oxide bulk magnetic material, needn't heating substrate 1 when deposition.Preferably the temperature of substrate 1 is less than 80 ℃ when forming perpendicular magnetic recording layer 6, and more preferably this temperature is less than 50 ℃.By this method, coercive force, gradient and other magnetic characteristic can meet the requirements, and can obtain good record and reproduce feature.
Perpendicular magnetic recording layer 6 has granular structure, wherein the non magnetic magnetic phase (magnetic-particle) that is made of the Co alloy that centers on mutually that is made of oxide material.
Then, through after forming chamber 26, substrate 1 is placed heating part 28, well heater 29 is used for heating.The process that heats in heating part 28 is called heating process.
Consider with substrate 1 from heating part 28 be sent to protective seam when forming chamber 27 temperature of substrate 1 may reduce, can heating-up temperature be set to be higher than above-mentioned film deposition temperature.Preferably heating-up temperature is set to be higher than for example 5 to 20 ℃ of film deposition temperatures.Particularly, can adopt for example 100 ℃ or higher temperature.
Consider the thermal resistance of substrate 1 or film deposition apparatus, for example heating-up temperature is set to 400 ℃ or lower.
Then, the substrate 1 that will heat in heating part 28 places protective seam to form chamber 27.
Protective seam forms chamber 27 for example to be had plasma electrode, provides the high frequency electric source of high frequency power and the reacting gas source that supplies raw material to carbon protective layer 7 to this electrode.
By substrate 1 being placed protective seam form in the chamber 27, be that raw material forms carbon protective layer 7 in substrate 1 with the reacting gas under the above-mentioned film deposition temperature by the plasma CVD method.For example acetylene, ethene or toluene are used as reacting gas with organic compound.The process that forms carbon protective layer 7 is called the protective seam forming process.
When carbon protective layer 7 successive sedimentations to perpendicular magnetic recording layer 6 time, being difficult to form carbon protective layer with very high density and good adhesion in low temperature using plasma CVD method; But with at above-mentioned film deposition temperature deposit carbon protective layer 7, can obtain the carbon protective layer 7 of high density and good adhesion by heating.
Then, adopt dipping method or another kind of method that lubricant is applied on the carbon protective layer 7 to form lubricating layer 8, to obtain above-mentioned magnetic recording media.
According to above-mentioned manufacture method, after forming the perpendicular magnetic recording layer 6 that constitutes by the oxide bulk magnetic material, heating substrate 1, and under above-mentioned film deposition temperature, form carbon protective layer 7 by the plasma CVD method.
When forming perpendicular magnetic recording layer 6, can prevent coercive force, gradient and the degeneration of other magnetic characteristic, and can obtain satisfied record and reproducing characteristic by maintenance low temperature.
Because with the material of oxidate magnetic material as perpendicular magnetic recording layer 6, compare with the situation that adopts Co-Cr system alloy or other non-oxidized substance material, can be in low temperature separation magnetic mutually with mutually non magnetic.
When forming carbon protective layer 7 by the plasma CVD method, be that high film deposition temperature carries out the film deposition at high temperature, thus bond with carbon strain minimum, and the carbon protective layer 7 of acquisition high density and good adhesion.
Therefore can obtain to have concurrently the magnetic recording media of good record and reproducing characteristic and excellent durability.
Fig. 4 illustrates magnetic recording and the transcriber example that adopts above-mentioned magnetic recording media.
Magnetic recording described here and transcriber have magnetic recording media 11, be used for the spindle drive motor 12 of rotating magnetic recording media 11, to magnetic recording media 11 recorded informations with from magnetic head 13, magnetic-head actuator 14 and record and the reproducing signal disposal system 15 of magnetic recording media 11 information reproductions.Record and reproducing signal disposal system 15 are handled the input data and are sent tracer signal to magnetic head 13, and handle signal and these data of output of reproducing from magnetic head 13.
(example 1)
Preparation is as the substrate 1 of crystallized glass substrate (diameter 48mm, bore portion diameter 12mm, thickness 0.508mm, average surface roughness Ra=0.5nm).Sample number is 50.
Adopt DC magnetron sputtering system (Anelva C-3010 type) as described below in substrate 1 deposited film.Be evacuated to 2 * 10 by at first forming the chamber
-5Pa, then Ar gas infiltrate to be formed the chamber and makes Ar gas bias voltage as sputter gas be 0.6Pa, comes deposited film.
(thickness 30nm) is deposited in the substrate 1 with Co-Cr-Pt-B pinning layer 10.
Then, deposition FeCo first soft ferromagnetic layer 2 (thickness 100nm).
Then, deposition Ru middle layer 3 (thickness 20nm).
Then, deposition Co-Cr-Pt-SiO
2Perpendicular magnetic recording layer 6 (thickness 10nm).
The temperature of substrate 1 is 40 ℃ when forming perpendicular magnetic recording layer 6.
Then, using plasma CVD method deposit carbon protective seam 7 (thickness 4nm).Temperature (film deposition temperature) when forming carbon protective layer 7 is 40 ℃.
Carbon protective layer 7 surfaces are subjected to being with polishing.The polishing block that is adopted is the oxidation aluminium strip that 3M makes; Revolving force is 30gf (290mN), and rotating speed is 1000rpm, and contact velocity is 0.3mm/s.
Then, dipping method is used to form the lubricating layer 8 that is made of PFPE.When forming lubricating layer 8, thereby the thickness of adjusting lubricant concentration and haulage speed lubricating layer 8 is 1.8nm.
(example 2)
Silicon base (diameter 48mm, bore portion diameter 12mm, thickness 0.508mm, average surface roughness Ra=0.5nm) is used as substrate 1; In addition, to be used to make magnetic recording media with example 1 similar condition.
(example 3 to 14)
After forming perpendicular magnetic recording layer 6 and before and then forming carbon protective layer 7, use the well heater 29 heating substrates 1 of heating part 28; In addition, to make magnetic recording media with example 2 similar conditions with example 1.Film deposition temperature when heating-up temperature in the heating part 28 and formation carbon protective layer 7 is shown in table 1 and 2.Adopt the infrared temperature measuring instrument to detect this temperature.
(reference example)
For doing reference, prepare the longitudinal magnetic recording medium that has magnetic recording layer but do not comprise oxide material.In this example, before preparing every layer substrate is heated to about 300 ℃, temperature is approximately 300 ℃ when using plasma CVD method forms carbon protective layer.
50 samples of each example are placed the Wen Du ﹠amp of 80 ℃ of temperature and humidity 90%; In the humidity chamber one hour.Then, one next these 50 samples are placed on the universal stage, and in ten seek operation, adopt magnetic head.
Table 1 shows adhesion rate, and it is for confirming to adhere in 50 samples the surperficial number of lubricant when adopting optical microscope observation head-slider surface.Because detect the both sides of each sample, so the surperficial number of these 50 samples is 100.
To each sample, adopt Heidon 14 type surface measurement devices, the load of 100gf (980mN) is applied to the adamas notcher (90 ° of cone angles, most advanced and sophisticated R25 μ m) that pulls 30mm from the teeth outwards; Form 1 illustrates the cut rate, the surperficial number that carbon protective layer 7 cut occurs or takes place to separate in its whole 100 surfaces.
Fig. 5 and Fig. 6 illustrate with the adhesion rate of the variation of the heating-up temperature in the heating process and the trend of cut rate.
Table 1
| Substrate | Medium | The substrate heating | Heating-up temperature (℃) | Film deposition temperature (℃) | Adhesion rate (%) | Cut rate (%) | |
| Example 1 | Glass ceramics | ? |
Not | -- | 40 | 43 | 17 |
| Example 2 | Silicon | ?PMRM | Not | -- | 40 | 36 | 12 |
| Example 3 | Glass ceramics | ?PMRM | Be | 50 | 50 | 10 | 6 |
| Example 4 | Silicon | ?PMRM | Be | 50 | 50 | 5 | 3 |
| Example 5 | Glass ceramics | ?PMRM | Be | 100 | 80 | 0 | 0 |
| Example 6 | Silicon | ?PMRM | Be | 100 | 80 | 0 | 0 |
| Substrate | Medium | The substrate heating | Heating-up temperature (℃) | Film deposition temperature (℃) | Adhesion rate (%) | Cut rate (%) | ||
| Example 7 | Glass ceramics | ?PMRM | Be | 150 | 130 | 0 | 0 | |
| Example 8 | Silicon | ?PMRM | Be | 150 | 130 | 0 | 0 | |
| Example 9 | Glass ceramics | ? | Be | 200 | 180 | 0 | 0 | |
| Example 10 | Silicon | ? | Be | 200 | 180 | 0 | 0 | |
| Example 11 | Glass ceramics | ? | Be | 300 | 280 | 0 | 0 | |
| Example 12 | Silicon | ? | Be | 300 | 280 | 0 | 0 | |
| Example 13 | Glass ceramics | ? | Be | 400 | 380 | 0 | 0 | |
| Example 14 | Silicon | ? | Be | 400 | 380 | 0 | 0 |
*The 1:PMRP=perpendicular magnetic recording medium
Can be clear from table 1, by when making the perpendicular magnetic recording medium that adopts the oxide bulk magnetic material, heating, can weaken the adhesion of lubricant on head-slider greatly.In addition, carbon protective layer 7 lip-deep cuts separate with it and are difficult for taking place, and find that the adhesion characteristics of carbon protective layer 7 improves.Think that this is because the hardness number of carbon protective layer 7 is suitable.
Find that when the substrate heating-up temperature is configured such that the film deposition temperature of carbon protective layer 7 be 80 ℃ or when higher, can obtain the measured medium of matter.Consider the thermal resistance of film deposition apparatus, the expectation heating-up temperature is 400 ℃ or lower.
For the quality of carbon protective layer 7 in the magnetic recording media of relatively this example and reference example, carry out the Raman spectral measurement.
To five samples from 50 samples, selecting at random, measure at three per 90 ° points of circumferencial direction of the position of 22mm radius, get the mean value of measuring for three times.
The Id/Ig of Raman spectral measurement is carbon sp2 key G band strength and sp3 key D band strength ratio, and is the bond with carbon state indices.Usually, Id/Ig is more little for value, and sp3 bonded carbon (micro-diamond lattic structure) increases many more.
B/A be defined as comprise the noise component peak height divided by peak height, and be organic principle index in this layer.The B/A value is more little, and the C-H amount is also more little.
The result of Raman spectral measurement is illustrated in the table 2.
Table 2
| Substrate | Medium | The substrate heating? | Heating-up temperature (℃) | Film deposition temperature (℃) | B/A | Id/Ig | ||
| Example 1 | | PMRM | ＊1 | Not | -- | 40 | 1.41 | 0.73 |
| Example 2 | Silicon | PMRM | Not | -- | 40 | 1.43 | 0.7 | |
| Example 9 | Glass | PMRM | Be | 200 | 180 | 1.4 | 1.33 | |
| Example 10 | | PMRM | Be | 200 | 180 | 1.42 | 1.34 | |
| Example 11 | Glass | PMRM | Be | 300 | 280 | 1.33 | 1.88 | |
| Example 12 | | PMRM | Be | 300 | 280 | 1.39 | 1.9 | |
| Reference example | | LMRM | ＊2 | Be | -- | 300 | 1.44 | 1.9 |
*The 1:PMRP=perpendicular magnetic recording medium
*2:LMRM=longitudinal magnetic recording medium
As known from Table 2, when heating substrate before the next-door neighbour forms carbon protective layer 7, the B/A value is almost constant.In addition, along with heating-up temperature raises, the Id/Ig value raises, and under about 300 ℃ heating-up temperature, realizes the degree suitable with the longitudinal magnetic recording medium.
Based on this, think that the Id/Ig value is not minimum when heating substrate, so layer hardness height, therefore the ply stress height can produce poor layer adhesion characteristics.When the heating substrate, along with film deposition temperature improves, the Id/Ig value increases, and layer becomes softer, realizes the degree suitable with the longitudinal magnetic recording medium.Therefore think and to obtain and the comparable layer of the longitudinal magnetic recording medium of current manufacturing adhesion characteristics.
(example 15 to 28)
Except being the material of perpendicular magnetic recording layer 6 with CoCrPtTa system alloy and example 1 to 14 is similarly made magnetic recording media.Assessment result is illustrated in the table 3.
Table 3
| Substrate | Medium | The substrate heating? | Heating-up temperature (℃) | Film deposition temperature (℃) | Adhesion rate (%) | Cut rate (%) | Coercive force (Oe) | |
| Example 15 | Glass ceramics | ? |
Not | -- | 40 | 39 | 15 | 1002 |
| Example 16 | Silicon | ?PMRM | Not | -- | 40 | 32 | 10 | 980 |
| Substrate | Medium | The substrate heating? | Heating-up temperature (℃) | Film deposition temperature (℃) | Adhesion rate (%) | Cut rate (%) | Coercive force (Oe) | ||
| Example 17 | Glass ceramics | ?PMRM | Be | 50 | 50 | 6 | 4 | 1110 | |
| Example 18 | Silicon | ?PMRM | Be | 50 | 50 | 3 | 2 | 1101 | |
| Example 19 | Glass ceramics | ?PMRM | Be | 100 | 80 | 0 | 0 | 1200 | |
| Example 20 | Silicon | ?PMRM | Be | 100 | 80 | 0 | 0 | 1240 | |
| Example 21 | Glass ceramics | ?PMRM | Be | 150 | 130 | 0 | 0 | 1301 | |
| Example 22 | Silicon | ?PMRM | Be | 150 | 130 | 0 | 0 | 1340 | |
| Example 23 | Glass ceramics | ? | Be | 200 | 180 | 0 | 0 | 1385 | |
| Example 24 | Silicon | ? | Be | 200 | 180 | 0 | 0 | 1384 | |
| Example 25 | Glass ceramics | ? | Be | 300 | 280 | 0 | 0 | 1459 | |
| Example 26 | Silicon | ? | Be | 300 | 280 | 0 | 0 | 1430 | |
| Example 27 | Glass ceramics | ? | Be | 400 | 380 | 0 | 0 | 1630 | |
| Example 28 | Silicon | ? | Be | 400 | 380 | 0 | 0 | 1590 |
*The 1:PMRP=perpendicular magnetic recording medium
As known from Table 3; when the Co-Cr-Pt-Ta system alloy that adopts as the non-oxidized substance magnetic material; similar with the situation that adopts oxidate magnetic material; the substrate heating that forms before tight at carbon protective layer produces good carbon protective layer adhesion and scratch resistance, and can suppress lubricant and stick on the head-slider.
But, when adopting the non-oxidized substance magnetic material, when at high temperature not carrying out the film deposition, can not promote being separated in this layer, and coercive force and other magnetic characteristic are insufficient.That is, when heating substrate after the deposition magnetic recording layer, can produce the friction advantage, but the magnetic characteristic variation.Therefore, can obtain favourable outcome from the perpendicular magnetic recording medium that adopts the oxide system perpendicular magnetic recording materials especially in the present invention.
(example 29 to 36)
Except before forming every layer, heating substrate (preheating hereinafter referred to as) in advance and example 1 similarly make perpendicular magnetic recording medium.
With 2 * 10
-5The pressure of Pa adopts the compound well heater of carbon to carry out preheating in forming the chamber.
Temperature (film deposition temperature of perpendicular magnetic recording layer) when table 4 shows preheat temperature and forms perpendicular magnetic recording layer 6.
Table 4 and Fig. 7 show in each example the measurement result of vertical direction coercive force Hc on the sample radius 15mm position.
Table 4
| Sample | Preheating | Preheat temperature (℃) | The film deposition temperature of perpendicular magnetic recording layer (℃) | Coercive force (Oe) |
| Example 29 | Not | -- | 50 | 4403 |
| Example 30 | Be | 100 | 80 | 3908 |
| Example 31 | Be | 150 | 130 | 3240 |
| Example 32 | |
200 | 180 | 2790 |
| Example 33 | Be | 250 | 230 | 2287 |
| Example 34 | |
300 | 280 | 1988 |
| Example 35 | Be | 350 | 330 | 1650 |
| Example 36 | |
400 | 380 | 1236 |
From table 4 and Fig. 7 as can be known, when at high temperature forming the perpendicular magnetic recording layer that constitutes by oxidate magnetic material, the coercive force variation.
In the magnetic recording media based on the perpendicular recording method, the expectation coercive force is 4000Oe or higher; But when at high temperature forming perpendicular magnetic recording layer, coercive force descends, record and reproduction feature variation.
Industrial applicability
According to the present invention; after oxidate magnetic material forms perpendicular magnetic recording layer; heating substrate and using plasma CVD method are to form carbon protective layer; thereby the perpendicular magnetic recording layer that acquisition has good record and reproducing characteristic, and can form the carbon protective layer with high density and good adhesion characteristic.
Claims (3)
1. method of making magnetic recording media, described medium is included in suprabasil perpendicular magnetic recording layer and carbon protective layer, and wherein said perpendicular magnetic recording layer is formed by the magnetic material that comprises Co alloy and oxide material, and described method comprises:
The perpendicular magnetic recording layer formation process forms perpendicular magnetic recording layer in described substrate;
Heating process heats the described substrate that is formed with described perpendicular magnetic recording layer on it; And
The protective seam forming process is formed with thereon by the plasma CVD method in the described substrate of described perpendicular magnetic recording layer and forms carbon protective layer,
Wherein,
In described perpendicular magnetic recording layer formation process, the temperature of the described substrate during forming described perpendicular magnetic recording layer is less than 80 ℃, and in described protective seam forming process, the film deposition temperature during forming described carbon protective layer is 80 ℃ or higher; And
The structure that described perpendicular magnetic recording layer has is, the non magnetic magnetic phase that constitutes by the Co alloy of surrounding mutually that constitutes by oxide material wherein, and wherein said oxide material is to be selected from SiO
2, TiO, TiO
2, ZrO
2, Cr
2O
3, CoO, Ta
2O
5, and Al
2O
3In any or two kinds or more kinds of material.
2. a magnetic recording media comprises
Substrate;
Described suprabasil perpendicular magnetic recording layer, the structure that described perpendicular magnetic recording layer has be, the non magnetic magnetic phase that constitutes by the Co alloy of surrounding mutually that constitutes by oxide material wherein, and wherein said oxide material is to be selected from SiO
2, TiO, TiO
2, ZrO
2, Cr
2O
3, CoO, Ta
2O
5, and Al
2O
3In any or two kinds or more kinds of material; And
Carbon protective layer on the described perpendicular magnetic recording layer,
Wherein, described magnetic recording media passes through the method manufacturing according to the manufacturing magnetic recording media of claim 1.
3. magnetic recording and transcriber comprise according to the magnetic recording media of claim 2 and are used for to described magnetic recording media recorded information with from the magnetic head of described magnetic recording media information reproduction.
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| JP2005077916 | 2005-03-17 | ||
| JP77916/2005 | 2005-03-17 | ||
| PCT/JP2006/305764 WO2006098504A1 (en) | 2005-03-17 | 2006-03-16 | Production process of magnetic recording medium, magnetic recording medium, and magnetic recording and reproducing apparatus |
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|---|---|---|---|---|
| US6455101B1 (en) * | 1999-07-28 | 2002-09-24 | Anelva Corporation | Method for depositing a protective carbon coating on a data recording disk |
| CN1487507A (en) * | 2002-07-12 | 2004-04-07 | 昭和电工株式会社 | Magnetic recording medium and producing method thereof, magnetic recording and reproducing equipment |
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| US6455101B1 (en) * | 1999-07-28 | 2002-09-24 | Anelva Corporation | Method for depositing a protective carbon coating on a data recording disk |
| CN1487507A (en) * | 2002-07-12 | 2004-04-07 | 昭和电工株式会社 | Magnetic recording medium and producing method thereof, magnetic recording and reproducing equipment |
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