JPS598142A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve the orientation of a vertical magnetized film, by converging thermoelectrons in the direction vertical to the surface of a supporting material after colliding thermoelectrons in a place, where the density of a Co-Cr steam current is high, to ionize them. CONSTITUTION:While holding the inside of a casing 1 in a high degree of vacuum through a vacuum exhaust system 2, an evaporating source 4 is heated to generate the steam of Co and Cr metallic particles. Said steam current collides concentratively against thermoelectrons discharged by heating of a thermoelectron discharging source 11 provided near the evaporating source 4, and said metallic particles are ionized efficiently. These ionized metallic particles has the distribution converged by an ion beam converging means 7, and a desired vertical incidence angle is given to them, and they are vapor-deposited to the surface of a supporting material 10 efficiently after passing through a netlike space. Thus, the Co-Cr vertical magnetized film is formed at a low temperature in a proper vapor deposition speed with a high orientability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a so-called non-coating type magnetic recording medium, in which a thin film such as a magnetic film is deposited on a non-magnetic support in a vacuum atmosphere.

Most conventional magnetic recording media belong to what is generally called a coating type, and are usually coated with 7-Fe on a non-magnetic support.
20B, Co-doped 1-Fe2O3°Fe3O4, Co-doped Fe3O4, 7-F
Magnetic powder consisting of bertolide compounds of e2O3 and Fe304, Co-doped bertolide compounds, oxide magnetic powders such as 0r02, or alloy magnetic powders whose main components are Fθ, Ni, Co, etc.; It has been manufactured using a manufacturing method and apparatus in which a coating liquid made by dispersing in an organic binder such as a copolymer, styrene-butadiene copolymer, epoxy resin, or polyurethane resin is applied and dried to form a magnetic film.

In recent years, as the amount of information to be recorded has increased, there has been a strong desire to put magnetic recording media suitable for high-density recording into practical use.
Attention has been paid to so-called non-coated magnetic recording media in which a ferromagnetic metal film is formed on the support by methods such as vacuum evaporation, sputtering, and ion blating without using the binder described above. As development and research progresses, various proposals are being made for practical application.

Recently, the perpendicular magnetization method has been attracting attention as a method for further increasing the recording density, and one of these types of recording media is Co-
Or vapor-deposited films or sputtered films are being developed, and various reports have been made.

As a method for producing such a Co-0r perpendicularly magnetized film, the vacuum evaporation method, sputtering method, ion blating method, etc. as described above are used. Although the film formation speed is fast in the vacuum evaporation method, the orientation of the film is It has the disadvantage that it has poor elasticity, and that it curls more than 10 degrees. When using the sputtering method, the orientation and coercive force (Hc) of the film are good, but the film formation rate is low. Ion brating can be considered as a method to eliminate these drawbacks. However, in the conventional method, the ionization rate of metal vapor was poor, and good film formation efficiency could not be obtained.

As an ion brating method that improves this point, for example, Japanese Patent Application Laid-open Nos. 50-119779 and 53-57494
Various methods have been proposed in Japanese Patent No. 54-141111 and the like. When using these methods, promotion of ionization is improved, but there are limits to improving magnetic properties such as adhesion to the support and coercive force, and there are also limitations when forming a Co-Or perpendicularly magnetized film. However, there were drawbacks such as the need to maintain the support at a high temperature of about 300°C.

The present inventors investigated various methods for obtaining a Co-Or perpendicular magnetization film, and found that a Co-Or perpendicular magnetization film was obtained using the high-vacuum ion grating method (M application No. 185669/1983) proposed earlier by the present invention. Surprisingly, it was possible to obtain an OO-Or perpendicularly magnetized film with improved film orientation without the above-mentioned drawbacks, thus achieving the present invention.

That is, in the present invention, a vapor flow obtained by heating and evaporating a Co-0r based evaporation source in a vacuum atmosphere is provided at a separate location where the vapor flow density near the oxidation source is relatively high. After thermionic electrons emitted from the thermionic emission source are impinged on the rfiii to promote ionization of the vapor flow, the evaporation distribution of the ionized vapor flow is directed perpendicularly to the non-magnetic support that is the object to be evaporated. This is a magnetic recording medium whose motive is to form an OOOr-based perpendicular magnetization film on the support by convergence.

In the present invention, the orientation can be further improved by placing a magnetic pole near the support which is the object to be deposited during vapor deposition and applying a magnetic field perpendicularly to the support. Introduce a coil, for example 13.56 MI! By applying an RF wave with a frequency of approximately z, the time fluctuation in the ionization rate can be suppressed to ±15% or less.

Hereinafter, the implementation mode of the present invention will be described in detail with reference to the accompanying drawings.

Figures 1 and 1 are explanatory diagrams showing one example of an ion blating apparatus for carrying out the present invention, which is connected to an IVi vacuum evacuation system 2 and whose internal vacuum degree is generally 10'-'
Torr or more, preferably), 110-4 to 1 o-aT
The casing, 3, is maintained at a level in the range of orr, for example, W, Ta, O, Ou, Mo, Al-2
There is an open hearth made of 0B, BN, etc., and 4 is a Co-Or type evaporation source housed within the hearth. As the evaporation source, one hearth 3 made of Co-Or gold alloy may be used, but considering the difference in evaporation rate between CO and Or, two hearths 3 are provided as shown in the figure, and each Preferably, the CO source and (3r source) are housed separately.

0o(75-80%)-Or(1
It is preferable to select so that an alloy film of 5 to 20 cm) can be obtained.

Note that the evaporation source may include Rh, W, and M as necessary.

A small amount of a third component such as the like may also be added.

Reference numeral 5 denotes an evaporation source heating means of an electron beam heating type arranged near the hearth 3.

Note that the hearth 3 described above is not limited to the so-called open type in which the evaporation source 4 has an upper opening that allows evaporation over a relatively wide area; It may be a closed hearth.

Further, the evaporation source heating means 5 is not limited to only the electron beam heating method, and other known methods such as resistance heating, high frequency induction heating, etc. can be adopted.

However, in the heating means 5 made of any of the heating methods described above, the amount of ions produced in the steam flow is extremely small (for example, 10 or less of the total steam flow).
In the present invention, an ionization promoting means 6 is provided above the evaporation source 4.

The ion promoting means 6 consists of a thermionic emission source 11 and an ionization electrode 12, and the thermionic emission source 11 includes W, Ta.
A DC or AC voltage is applied to a straight rod-shaped filament made by spirally winding a high melting point material such as Mo, Mo, or an alloy containing them, to emit thermionic electrons.

Furthermore, the thermionic emission source 11 is connected to the evaporation source heating means 5.
If the heating method is an electron beam heating method, the evaporation source 4 should be placed as close to the evaporation surface of the evaporation source 4 as possible within a range that does not obstruct the passage of the electron beam (indicated by the broken line), and the evaporation distribution boundary of the vapor flow. Or install one so that it faces slightly within the distribution area.

In cases other than the electron beam heating method, the filament may be placed closer to the evaporation source 4.

Further, the ionization electrode 12 is made of Ag, Cu, W, Ta,
A rod-shaped, flat-shaped, or ring-shaped electrode having conductivity such as Mo, stainless steel, etc. is disposed above and close to the emission source 11 at a position that does not significantly impede the evaporation distribution of the vapor flow, and is further provided with a direct current or alternating current voltage. is applied.

Reference numeral 7 denotes an ion beam focusing means disposed between the ionization promoting means 6 and the lower surface of the cylindrical cooling can 9 rotatably supported above the ionization promoting means 6.

The ion beam focusing means 7 comprises a focusing assisting coil 13 and a focused electrodeposition 14 to which direct current or alternating current is supplied.

The convergence assisting coil 13 is arranged above the ionization electrode 12 to prevent the vapor flow from spreading beyond a predetermined evaporation area and to deflect or direct the center of the vapor flow toward the center of a predetermined evaporation area. They each have an auxiliary effect.

The focusing electrode 14 is disposed above the focusing assisting coil 13 and near a predetermined vapor deposition surface on the lower surface of the non-magnetic support 10 supported and guided in a curved manner by the cooling can 9. For example, W, Ta, λ
4o, A mesh electrode made of stainless steel or the like, to which a negative potential is applied.

Note that the effective action area of the focusing electrode 14 is the same as that of the support 1.
It is positioned so as not to deviate from the predetermined deposition area on the lower surface of the 0.

8 is below the cooling can 9, and the □
A mask is provided on the lower surface of the support 10 to prevent the vapor flow from depositing at angles other than vertical.

The nonmagnetic support used in the present invention is preferably a plastic base such as polyethylene terephthalate (pmT), polyimide, polyamide, polyvinyl chloride, cellulose triacetate, polycarbonate, or polyethylene naphthalate, but At.

Non-magnetic metals such as Cu and ETIB, and inorganic substrates such as glass and ceramics can also be used.

In the apparatus of the present invention, the main parts of which are constructed as described above, first, the inside of the casing 1 is brought to a desired degree of vacuum within the range of 10-' to 10-6 Torr via the evacuation system 22. When the evaporation source 4 in the hearth 3 is continuously heated by supplying electricity to the evaporation source heating means 5 while maintaining the evaporation source 4, a vapor flow of Co and Or metal particles is gradually formed from the evaporation surface of the evaporation source 4. It evaporates and goes to 7. Incidentally, during the evaporation, a very small portion of the metal particles are ionized and emit and rise together with other metal particles.

Next, the vapor flow is directed to the thermionic emission source 11 in the vicinity of the evaporation source 4, where the evaporation distribution is not relatively expanded.
When the metal particles are heated, they collide intensively with thermionic electrons whose motion path is appropriately controlled by the ionizing electrode 12, and the metal particles are efficiently ionized (positive). Note that the thermionic emission source 11 and the ionization electrode 12
Even if the vertical positional relationship is reversed to that described above, that is, the ion specific gravity and the dowel 12 are placed below the thermionic emission point 11, the ionization rate will not be lowered, and the heating method described above will not be caused. The most advantageous vertical positional relationship may be determined depending on layout conditions.

If there is an excess or deficiency in the voltage applied to the ionization electrode 12, the ionization rate will decrease, so it is usually preferable to set the voltage in the range of 30 to 500V.

Even if the entire vapor flow that has been efficiently ionized by the ionization accelerator 6 is deposited perpendicularly to the support 10, the evaporation distribution described above will spread more than necessary and the deposition incident angle will become uneven. Since no improvement in vapor deposition efficiency or magnetic properties can be expected, the next step of the present invention is to process the ionized vapor flow, that is, the ions and some of them using the ion and some of the ions and convergence means 7.

When the ion beam first passes through the aperture area of the convergence assisting coil 13 to which a positive DC voltage in the range of 100 to 2 KV is applied, the evaporation distribution up to that point is significantly converged, and the In the ion beam according to the center of the aperture area of the coil 13, if the gap or displacement between the predetermined evaporation area of the support 100 and the evaporation source 4 is relatively small, the focusing assisting coil 13 may be removed. On the other hand, if the gap or the amount of displacement is quite large, the ion beam is decelerated or It is also possible to achieve convergence.

Next, the ion beam that has passed through the focusing auxiliary coil 16 is directed to the focusing electrode 14, which is disposed close to a predetermined deposition area of the support 10 and does not deviate from the deposition area.
When the evaporation distribution finally converges, the desired perpendicular incident angle is determined, and after passing through the net-like voids, the vapor is efficiently deposited on the surface of the support 10. Incidentally, instead of the convergence assisting coil 13, it is also possible to apply a phantom, ring-shaped, or rod-shaped convergence assisting N1 pole.

Furthermore, if there is too much or too little voltage applied to the focusing electrode 14, there will be too much or too little speed of the ion beam, and as a result, the focusing effect will be significantly reduced or the deposited film will be sputtered. It is desirable to set it within the range of -100V to -3000V within the song.

FIG. 2 shows another embodiment of the ion blating apparatus used in the present invention. In the apparatus shown in FIG. 1, a magnetic pole 21 is provided close to the support 1o to support the ion beam during deposition. By applying a magnetic field perpendicular to the body, the orientation of the deposited film can be further improved.

FIG. 3 shows still another embodiment of the ion blating device used in the present invention, in which the RF coil 22 is provided in the device shown in FIG.
．． By applying a high frequency of 56 MHz and 500 watts, time fluctuations in the ionization rate can be reduced.

As mentioned above, according to the present invention, IgL at a low temperature of the support similar to general ion blating is used.
And Co-C! An r-thread perpendicularly magnetized film can be formed with an appropriate deposition rate and good orientation.

Example 1: Using an ion blating device of the type shown in Figure 1, metal Co and metal Cr were used as evaporation sources, respectively, and 2
A 5μ thick PET base is used as a support and the vacuum level is 5X.
10'-' Torr, deposition rate 1ooooX/
Vapor deposition was carried out perpendicularly to the support using sea, and the film thickness was 5000.
A magnetic recording material having a (3o-Or (ss: 15)) perpendicular magnetization film of A was obtained.The deposition efficiency was 60 degrees and the orientation was 6 degrees.

Example 2゜Using the ion blating device shown in Fig. 2, metal C was
O and metal Or were used as evaporation sources, a 25 μ thick polyamide (Kapton, 2 product name) base was used as a support, and a magnetic field was applied at a vacuum level of 5 x 10' TOrr.

Vapor deposition was performed at a deposition rate of 5000 A/see, and the thickness was 400 A/see.
A magnetic recording medium having a perpendicular magnetization film of 0A Co-(3r (75:15)) was obtained.The orientation was 4°.

Example 6 2p Using the ion brating device shown in Figure 3, 0
O-Or gold alloy evaporation source (In this case, Or evaporates faster, so we carried out the process while supplying Or source), At
Using the sheet as a support 1, argon gas pressure 1×1 [1'
Torr, deposition rate 300 nA/eec, RF
Vapor deposition was performed while applying high frequency power of 13.56 MHz and 500 watts to the coil, and a Co-
A magnetic recording sand body having a first product magnetization value ψ of 0r (75: 15) was obtained. At The fluctuation of the current flowing through the sheet is ±1
It was as low as 5%.

[Brief explanation of drawings]

FIGS. 1 to 5 are explanatory diagrams showing each embodiment of an ion blating apparatus that implements the present invention. 4... Evaporation source, 5... Evaporation heating means, 6... Ionization promoting means, 7... Ion beam focusing means, Q
ass mask, 9@・9 Cooling Can, 10@@I
I support, 21---magnetic pole, 2'2@*++RF:ff
Ile @ Figure 1 Figure 2 Figure 3 Drawing Procedure Amendment Showa M 571 January - 1 - Otsu 11 1982 Permanent Application No. 115551 2, Title of invention Method for manufacturing magnetic recording media 3, Person making the amendment 1 '1 Relationship with "l"J'tt'l Applicant name (52
0) Fuji Photo Film Co., Ltd. Kasumigaseki Building Post Office iQ','l'f) No. 49) 8. Contents of amendment 1) As per the attached sheet 2) (1) of ``Revision of invention + q1 + explanation'' as shown below (sode 1 [''ro. ... Details 'i'1' 2 r'y 5 f Enoki 1 (1 line '1
, ``Kengyoku'' is 1 magnet'' and sleeve IF-4).・・・ Same immediately, 6L"], 6th line, 19 after "Dan N"
Mg (adds the moon. ・) Same page 6, lines 10-11, 1-Co (75-80
%)-Cr(15-20%)J! i: rco(75
~90 at%) -Cr(10-25 at%). Q In line 802 of the same, delete "1 piece" by 1. () Same 14th. @6th line from the bottom, “(75:15)
-1 is corrected to 1-(80:20).・) Same page 15, line 9, "(75:15)" is changed to [(a
o:2o)j. 6) Add the reference numerals in Figure 1 of the drawings as if they were attached. Above 1) For the vapor 3fj obtained by heating and evaporating a Co-Cr based evaporation source in a vacuum atmosphere, separate Heat emitted from the thermionic emission source provided in 1. After the ionization of the vapor flow is progressed, the evaporation distribution of the ionized vapor flow is covered in a direction perpendicular to the non-magnetic support, which is a 6-magnetic body. By convergence, a KC magnetized film of Co--Cr yarn is formed on the support. A method of manufacturing a magnetic recording medium, which particularly comprises forming a magnetic recording medium. 2) Magnetic recording according to claim (1), in which a magnet is provided close to the support and evaporation is performed while applying a magnetic field to the ionized vapor flow in a force direction perpendicular to the support. Method of manufacturing media. 3) An RF coil is provided between the support and the evaporation source, and the RF coil is placed between the support and the evaporation source. A method for manufacturing an arsenic gas recorder according to claim 1 or claim 2, 0-j, in which vapor deposition is performed while applying pressure.

Claims (1)

[Scope of Claims] 1) For a vapor flow obtained by heating and evaporating a Co-0r-based evaporation source in a vacuum atmosphere, separate After promoting the ionization of the vapor flow by colliding thermionic electrons emitted from the provided thermionic emission source, the evaporation distribution of the ionized vapor flow is adjusted in a direction perpendicular to the non-magnetic support that is the deposition target. A method for manufacturing a magnetic recording medium, characterized in that a perpendicularly magnetized film of (!o-Or system) is formed on the support by convergence. 2) Magnetism is provided in the vicinity of the support and ionization A method for manufacturing a magnetic recording medium according to claim 11, in which vapor deposition is performed while applying a magnetic field perpendicular to the support. 5) Between the support and the evaporation source. The method for producing a magnetic recording material according to claim 1, wherein the evaporation is carried out while depositing sand through an RF coil and applying a high-frequency voltage.