JPH0289216A - magnetic recording medium - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording medium and a magnetic recording device using the same, and particularly to an improvement of a magnetic recording medium having a base layer on a substrate and a magnetic layer above the base layer. Regarding.

[Conventional technology]

In recent years, the importance of magnetic disks as external storage devices in computer systems has increased, and the recording density of magnetic disks has been significantly improved year by year. Conventionally, magnetic recording media have been developed mainly by thinning coating-type media, which are made by spin-coating a viscous material in which acicular r-F8203 fine particles are dispersed in an organic binder onto an aluminum alloy substrate, and then firing it. It is used.

However, in order to achieve higher density, K requires a thinner medium, but current coated media are considered to have technical limits, and as an alternative to this high-density magnetic disk, thinner media are needed. Magnetic disks with metal magnetic thin film media that are easy to use are attracting attention.

A plated magnetic disk formed by this metal magnetic thin film media plating technique, a metal magnetic film (Co-Cr).

Co-Ni etc.) or metal oxides (r-Fe20
3, etc.) have been developed, and it is expected that the recording density will be greatly increased.

The general structure of a magnetic disk using such a thin film continuous medium is as follows. A high-purity aluminum alloy is used for the substrate, and a base layer is formed thereon. A magnetic layer is formed on the underlayer, and an intermediate layer may be formed between these two layers for the purpose of improving the adhesion between the two layers and improving the characteristics of the magnetic layer. A lubricating layer or a protective layer is formed on the magnetic layer.

This underlayer enables thinning of the magnetic layer, is required to have flatness and smoothness to ensure a stable head flying state at a low flying height, and is required to significantly reduce substrate defects. In addition to the basic properties such as mechanical strength, workability, and abrasiveness, the base layer/m also has the following properties:
As described in Japanese Patent Application No. 54, it is required that the underlayer is not magnetized even by heat treatment in the process of forming the magnetic layer, lubricating layer, or protective layer.

The base layer mentioned above is N1- formed by electroless plating method.
P film is generally used, but there are other methods, such as methods for forming a metal undercoat layer, as described in JP-A-57-169950, and JP-A-4
Methods of forming metal oxides, nitrides, etc. are known, as described in Japanese Patent Application Laid-Open No. 9-74911, Japanese Patent Application Laid-Open No. 57-50524, and Japanese Patent Application Laid-open No. 59-217225.

As a method of forming the magnetic layer, a method of forming the magnetic layer under vacuum, such as vapor deposition or sputtering, is generally used.

Furthermore, when a material with low hardness such as an At-Mg alloy is used as the magnetic recording medium, the surface of the magnetic recording medium will not be damaged by the impact caused by contact between the magnetic head and the magnetic recording medium. As the underlayer, an N1-P plating film, a nonmagnetic metal undercoat layer, or a gold scrap oxide or nitride layer is formed.

However, when an N1-P plating film is used as the underlayer, the surface needs to be polished or polished after the plating film is formed because its surface is poor in smoothness. Furthermore, a dry vacuum process is generally used to form magnetic layers, etc., and when producing magnetic recording media, it is a mixed process of wet and dry methods, which is not an economical production process. There is a problem. In contrast, a method has been proposed in which a nonmagnetic metal, metal oxide, or nitride layer is formed as an underlayer by a dry method.

[Problem to be solved by the invention]

In the conventional technology described above, sufficient consideration was not given to the adhesion between the underlayer and the substrate, and the underlayer was formed thick to absorb the impact when the magnetic head and the magnetic d-recording medium came into contact. In some cases, there is a problem in that peeling occurs between the substrate surface and the underlayer, resulting in damage to the magnetic recording medium.

An object of the present invention is to provide a magnetic recording medium that has performance equivalent to or better than magnetic recording media obtained by conventional techniques and also has excellent sliding resistance against a magnetic head, and an efficient method for manufacturing the same. It is in.

[Means to solve the problem]

In order to achieve the above object, the inventors of the present invention have made extensive studies and found that by providing a mixed layer with the substrate between the substrate and the underlayer, a magnetic recording medium with good adhesion between the underlayer and the substrate can be created. The present inventors have discovered that the present invention can be obtained, and have completed the present invention.

That is, the present invention is a magnetic recording medium having an underlayer on a substrate and a magnetic layer above the underlayer, which is characterized by having a mixed layer of the substrate and a nonmagnetic metal compound between the substrate and the underlayer. The present invention relates to a magnetic recording medium, and also relates to a method for manufacturing a magnetic recording medium in which the mixed layer is formed by irradiating a substrate with a gaseous metal and depositing the metal on the substrate. Furthermore, the present invention relates to a magnetic recording device having a magnetic head and a magnetic disk, in which the magnetic recording medium is incorporated into the magnetic disk.

Next, the present invention will be explained in more detail.

In the magnetic recording medium of the present invention, a non-magnetic metal compound layer of about n1 to 1.0 μm is formed as a mixed layer on the surface of a substrate using, for example, an ion beam, and then a physical atmosphere is applied on top of the core layer. Phase deposition method (PVD) and chemical vapor deposition method (CVD)
It can be manufactured by forming a nonmagnetic underlayer using a method such as the above, and forming a magnetic layer or the like using the substrate.

The above substrate is generally an At alloy, such as AA standard 5086, or Fe, 81 in the At alloy.
An At-MIJ alloy with a reduced impurity concentration, etc., can be used. Further, the surface of the substrate is coated with, for example, TiN, T10. After forming a mixed layer of metal compound layers such as Ti, Zr%, etc., Ti, Zr%
Hf, V, Nb, Ta, Cr.

A carbide, nitride, boride, or oxide layer of at least one metal selected from MO5W, At%Si, Mn, B, etc. can be formed to serve as an underlayer of a magnetic recording medium.

As mentioned above, a non-magnetic compound layer of various metals as described above can be formed on the upper layer of the interfacial mixed layer to form an underlayer of a magnetic recording medium. In addition to the above, there are no particular limitations on the material as long as it has enough strength to not damage the magnetic layer when the magnetic recording medium and the magnetic head come into contact, and there are no particular limitations on the method of forming the layer. However, in order to increase the throughput during manufacturing of magnetic recording media,
It is desirable to use a method that allows film formation as fast as possible.

In addition, the thickness of the above-mentioned non-magnetic metal compound is largely controlled by the physical properties of the substance, especially the hardness, and the higher the hardness, the smaller the film thickness. The thickness can also be small.

Next, the method for manufacturing the magnetic recording medium of the present invention will be explained in more detail.

Although At alloy, glass, ceramics, glass, etc. can be used as the substrate material of the magnetic recording medium of the present IJJ, At alloy is generally used. In forming the base layer on the At alloy substrate surface according to the present invention,
Argon, nitrogen, rR beam, etc. can be used as the type of ion beam to irradiate the substrate surface. When nitrogen and oxygen are used as ion evaporators, metal nitridation can be achieved by simultaneously depositing metal on the substrate surface. and oxide layers can be formed. By controlling the energy of the ion beam used above, it is possible to control the thickness of the mixed layer with the substrate formed on the substrate surface.

For magnetic recording media, it is desirable to form the above mixed layer on both sides of the substrate at the same time.For example, by sputtering a non-magnetic metal while irradiating both sides of the substrate with an ion beam, A non-magnetic metal compound layer can be formed on the magnetic layer. In this case, the energy of the ion beam irradiated onto the substrate surface is converted into thermal energy on the substrate surface, so forming a thick layer using the above method will lead to a decrease in the flatness of the substrate surface or deformation. This is not a desirable thing.

In a preferred embodiment of the present invention, the film thickness is such that the temperature rise on the substrate surface is suppressed as much as possible using the above method, for example, 1 μm.
After forming the film to the following thickness, a non-magnetic and highly hard underlayer is formed on top of the above layer using a high-speed film formation method such as chemical vapor deposition (CVD) or physical vapor deposition (PVD). It is desirable to form a

FiTi, Zr%Hf, and V are used as materials for the underlayer.

A film having the following structure composed of Nb, Ta, Cr%MO%W1k1%Si, Mn, etc. can be used.

For example, the general formula TX9 or TMX(T%M:'ri,
Zr%Hf%V1Nb, Ta, Cr, Mo, W,
However, T\M1X: C, N, B, O), A3MX
(A: Ti, Mn, M: At, 81, X: C, N
), A4MX (A: Ti, V%Cr.

M: At%Si, X: C, N), AMDX (A:
'ri, M:V, D: Carbon, X:N)
etc.

The magnetic recording device that can be used in the present invention can be any device that has a conventional magnetic head and magnetic disk, and for example, the device shown in FIG. 3 can be used. Fig. 5 is a partial plan schematic diagram showing the structure of a fin recording device, number 11.
12 is a magnetic disk, 12 is a magnetic herad slider, 15 is a gimbal, 14 is a rotating shaft, 15 is a carriage, and 16 is a helad arm. The magnetic recording medium of the present invention is incorporated into the magnetic disk 1 of the above magnetic recording apparatus.

〔Example〕

The present invention will be explained below using specific examples with reference to the drawings, but the present invention is not limited to these examples.

FIG. 2 is a sectional view showing the structure of a conventional magnetic recording medium, and FIG. 1 is a sectional view showing the structure up to the underlayer, which is a feature of the present invention.

In a typical magnetic recording medium, as shown in FIG. 2, a base film 2, an intermediate layer 3, a magnetic layer 4, a protective layer 5,
Although a lubricating layer 6 is formed, the magnetic recording medium of the present invention has a mixed layer 7 provided on a substrate to form an underlayer, as shown in FIG.

Next, a specific example will be described with reference to the above-mentioned drawings.

Example 1 As the substrate 1, A/ of 5.25#φ, alloy (Mg about 4 w
The surface was processed in advance so that it had a predetermined acceleration and straightness. Furthermore, minute grooves (referred to as texture processing) were formed on the surface of the substrate 1 along the circumferential direction of the substrate 1 using a diamond lathe, tape, or the like. The above-mentioned grooves do not need to be continuous in the circumferential direction, and there is no need to control the groove width to be constant. The surface roughness measured along the radial direction of the disc is preferably Ra (center line average roughness) of 2 to 50 nm K, and grooves with sharp convexities are not preferred.

At the same time, metal T1 is sputtered onto the substrate surface by irradiating the target with an Ar ion beam (acceleration voltage + 500 eV, 57 mA) using gold [Ti as a target]. A TiN film was formed on the substrate surface by irradiating an N2 ion beam (acceleration voltage: 200 ev, amA) from an ion beam source. The pressure during film formation was 5×10” Torr.

By the above method, a mixed layer 7 is formed on one side of the substrate.
(After forming to a thickness of L 5 am, the above mixture/#
The substrate on which No. 7 was formed was moved to a film forming chamber for the next step via a gate pulp by a substrate transport system. In the next step, 81H44H is used as a raw material gas by electron cyclotron resonance plasma chemical vapor deposition method (ECR plasma CVD method).
A SiC film having a thickness of 2.0 μm was formed as an underlayer 2 on the substrate using a mixed gas of 2 and C, H4+H, and a mixed gas of 2.0 μm.

ECR plasma is microwave (z, 45 GHz)
and a magnetron to generate a pressure of 1×10'''Tor.
It was set as r. The substrate temperature was approximately room temperature.

After the above steps, the substrate on which the mixed layer 7 and base film 2 have been formed is transported to a DC bipolar sputtering reaction chamber, and the intermediate layer 5 (
Cr), magnetic layer 4 (Co-Ni system) and protective layer 5 (C
) was formed. The pressure is 5 X + 0-3 TOrr,
Output 2kW, thickness of each layer α2μm 150n
m and 50 nm. After this step, a perfluoroalkyl ether liquid lubricant was applied to form a magnetic recording medium.

Sliding resistance was evaluated using the above magnetic recording medium. A Mn-Zn ferrite head is used as the magnetic head,
Normal CSS exam (Contact 8tart/5t
OP test), no scratches were observed on the surface of the magnetic recording medium even after about 50,000 CSS cycles, and it was found that the magnetic recording medium had excellent resistance to m-dynamics.

The above magnetic recording medium has a conventional configuration, that is, an N1-P layer is formed as the underlayer 2 on one surface of the substrate by electroless plating, and then a magnetic layer, etc. is formed in exactly the same manner as described above. In comparison, the sliding resistance was completely comparable, and the magnetic recording properties were also the same. In this manner, as in the conventional method, after forming the underlayer 2 on the substrate 1 by wet plating, its surface is polished, and then transferred to a vacuum reaction chamber and a magnetic layer is formed by sputtering or the like. In contrast, in the present invention, it is possible to form a high-strength base/#2 with good adhesion to the substrate by a dry method on the substrate 1, so the process is consistent and quality control is easy. It has the advantage of high throughput.

Furthermore, compared to the conventional case where a high-hardness underlayer such as SIC' is directly formed on the substrate 1ililr, in the present invention, as shown in FIG. 1, the mixed layer 7t-
Since the high hardness base layer 2 is formed after the formation, the adhesion between the substrate and the base layer 2 is excellent.

Here, after forming TiN as the mixed layer 7 on the At alloy substrate 1, the composition analysis in the depth direction of this mixed layer 7 was performed using secondary ion mass spectrometry (SIMS). As shown in the figure. In FIG. 4, the horizontal axis indicates sputtering time (h), and the vertical axis indicates signal intensity (arbitrary unit), which indicates the distribution of Ti'' and At4'' in the depth direction from the surface of the sample. This figure shows that there is a layer in which both T1+ and At'' elements are detected simultaneously, so T1+ is present in the surface layer of the At substrate.
It can be seen that a mixed layer with iN is formed.

FIG. 5 shows the change in hardness depending on the thickness of the high-hardness base layer 2 formed on the mixed layer 7. The horizontal axis in Figure 5 is film thickness (μm)
The vertical axis shows the Knoop hardness (kgf/g"). From the graph in Figure 5, it can be seen that in order to make the base layer high hardness,
It can be seen that in the case of SiC, the thickness is preferably about 2 μm or more.

Example 2 After forming a TiN layer as the mixed layer 7 on the substrate 1 in the same manner as in Example 1, an 813N4 layer was formed as the base layer 2 by using 5iH44N as the raw material gas and a mixed gas by EcR plasma CVD. Formed to 3 μm. Thereafter, a magnetic layer and the like were formed in the same structure as in Example 1 to produce a magnetic recording medium.

The above magnetic recording medium was also found to be a recording medium with excellent sliding resistance, similar to that obtained in Example 1.

Example 3 As in Example 1, using a 525″φ At alloy substrate, TiN was first applied to the substrate 1ifi in the same manner as in Example 1.
After forming the layer, the next step is to perform sputtering using a T1-Zr alloy target in a mixed gas of Ar+N2 (N2/Ar ratio α2) by reactive sputtering using a DC two-pole sputtering device. A TiZrN layer having a thickness of 2.0 μm was formed as a base layer 2 on the TiN layer. The sputtering pressure was 5 mTOrr, and the substrate temperature was 150°C.

Example 1 Using the substrate 1 on which the base layer 2 described above was formed,
A magnetic recording medium was obtained by forming the magnetic layer 4 and the like having the same structure using the same apparatus.

This magnetic recording medium also has C
It was found that the magnetic recording medium had excellent sliding resistance according to the SS test.

Although the present invention has been specifically explained using the above examples, the present invention is not limited thereto. In the above example, a nitrogen ion beam was used to form the interfacial mixed layer of a metal compound on the substrate surface using an ion beam, but it is possible to form a metal oxide layer by using an oxygen ion beam. Needless to say. Furthermore, it is also possible to use an inert gas such as Ar as the ion beam.

〔Effect of the invention〕

In the magnetic recording medium of the present invention, a mixed layer consisting of a metal compound layer is first formed as an underlayer while irradiating the substrate surface with an ion beam, so that the metal compound layer is mixed with the elements of the substrate at the boundary with the substrate. Formed while mixing. Therefore, the metal compound layer described above has extremely excellent adhesion to the substrate.

In the present invention, after forming the above-mentioned metal compound layer, a base layer of a non-magnetic high-hardness material is formed by a method that allows film formation at higher speed, and the obtained magnetic recording medium is made of these metal compound layers. Compared to forming the underlayer directly on the substrate,
An underlayer for a magnetic recording medium having excellent adhesion to a substrate can be formed. The obtained magnetic recording medium is a magnetic recording medium that is not damaged even when the magnetic head and the magnetic recording medium come into contact, has excellent adhesion to the substrate, and has an extremely long service life.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the underlayer of the present invention, FIG. 2 is a sectional view showing the structure of a conventional magnetic recording medium, FIG. 3 is a partial plan schematic view showing the structure of a magnetic recording device, and FIG. The figure is a graph showing the element distribution in the depth direction of the mixed layer, and FIG. 5 is a graph showing the relationship between the hardness of the underlying layer material and the film thickness. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Base layer, 5... Intermediate layer, 4...
...magnetic layer, da, spear 5...protective layer, 6...lubricating layer, 7...mixed layer,...
...Magnetic disk, 12...Magnetic head slide 1'5
--Gimbal, 14...Rotation axis, 15...Kick, 16...Head arm Patent applicant Hitachi, Ltd.

Claims (1)

[Claims] 1. A magnetic recording medium having an underlayer on a substrate and a magnetic layer above it, characterized by having a mixed layer of the substrate and a non-magnetic metal compound between the substrate and the underlayer. magnetic recording media. 2. The magnetic recording medium according to claim 1, further comprising the underlayer of at least one type selected from nitride, carbide, boride, and oxide of nonmagnetic metals on the mixed layer. 3. The non-magnetic metal is Ti, Zr, Hf, V, Nb,
3. The magnetic recording medium according to claim 2, comprising at least one of Ta, Cr, Mo, W, Al, and Si. 4. The magnetic recording medium according to claim 1, wherein the substrate has controlled grooves along the circumferential direction on the substrate surface. 5. In a method for manufacturing a magnetic recording medium that has an underlayer on a substrate and a magnetic layer above it, a mixed layer consisting of a non-magnetic metal compound is formed by depositing a gaseous metal on the substrate by irradiating the substrate with an ion beam. 1. A method for manufacturing a magnetic recording medium, comprising: forming a magnetic recording medium, and forming the underlayer thereon. 6. The mixed layer is formed by depositing a gaseous metal onto the substrate by irradiating it with an ion beam using nitrogen or oxygen to form a non-magnetic metal nitride or oxide layer. 6. The method for producing a magnetic recording medium according to claim 5, wherein the method is carried out by: 7. After forming the mixed layer, a metal selected from nitrides, carbides, borides and oxides is deposited on the mixed layer by physical vapor deposition (PVD) or chemical vapor deposition (CVD). 7. The method for manufacturing a magnetic recording medium according to claim 5, further comprising forming a base layer. 8. The formation of the base layer is performed while irradiating the mixed layer with an ion beam of an inert gas.
Method for manufacturing the magnetic recording medium described. 9. A magnetic recording device having a magnetic head and a magnetic disk, in which a magnetic recording medium having the structure according to claim 1 is incorporated into the magnetic disk.