JPH1180954A - Thin film forming method and thin film forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin film forming method and a thin film forming apparatus for preventing the quality of a thin film from deteriorating due to a splash in a magnetic material thin film forming step. A thin film forming method and a thin film forming apparatus according to the present invention dissolve and evaporate at least a thin film forming material such as a magnetic material contained in a crucible in a reduced pressure atmosphere.
In a method / apparatus for forming a thin film by attaching to a support 2a such as a non-magnetic support, a thin film composed of a mesh or grid metal or ceramic is provided between a thin film forming material 7 and the support 2a. A method / apparatus for arranging means for preventing scattering of massive particles due to splash of the forming material 7 and preventing the massive particles from reaching the support 2a is characterized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming method and a thin film forming apparatus, and more particularly, to a method of forming a thin film by dissolving and evaporating a thin film forming material in a reduced-pressure atmosphere and applying the material to a support. The present invention relates to a thin film forming method and a thin film forming apparatus characterized in the means.

[0002]

2. Description of the Related Art In the field of magnetic recording, for example, in a video tape recorder, etc., high-density recording has been carried out in response to a demand for higher image quality. A magnetic recording medium of a metal magnetic thin film type is formed by directly forming a magnetic material such as a magnetic alloy such as Ni on a non-magnetic support by plating or a vacuum thin film forming technique such as a sputtering method or an ion plating method. Have been. This metal magnetic thin film type magnetic recording medium not only has excellent coercive force, squareness ratio, and electromagnetic conversion characteristics in a short wavelength region, but also has a magnetic layer that can be made thinner so that it can be used for recording demagnetization and reproduction. It has many advantages, such as extremely small thickness loss and the fact that the magnetic layer does not contain a nonmagnetic material such as a binder which is a nonmagnetic material, so that the packing density of the magnetic material can be increased.
A so-called vapor deposition tape on which a magnetic layer is formed by a vacuum vapor deposition method has already been commercialized as a high band 8 mm tape or digital micro tape because of its high productivity and stable characteristics.

[0003] The vapor deposition tape is provided with a cooling can rotatable in a predetermined direction in a vacuum chamber, and moves a non-magnetic support at a predetermined speed along the outer peripheral surface of the cooling can into the crucible. It is produced by dissolving and evaporating the stored magnetic material and continuously forming it on the surface of the support.
At this time, the magnetic material is dissolved by the irradiation of the electron beam. By the way, when the magnetic material is dissolved and evaporated by the electron beam, a phenomenon called so-called splash occurs, in which the magnetic material suddenly jumps out as mass particles. Lumped particles due to the splash reach and adhere to the support, and lumped out lump particles form scratches and pinholes on the support, increasing the number of dropouts and reducing electromagnetic conversion characteristics. Was. As described above, in the process of forming a thin film such as a magnetic recording medium, the quality of the thin film is deteriorated due to the splash of the material for forming the thin film, which has been an important problem to be solved in the thin film forming process.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a thin film forming method and a thin film forming apparatus for preventing the quality of a thin film from being deteriorated due to splash in a process of forming a thin film on a support. The task is to

[0005]

According to the thin film forming method of the present invention, a thin film forming material such as a magnetic material stored in a crucible or the like is dissolved and evaporated at least in a reduced-pressure atmosphere, and the material is supported on a non-magnetic support or the like. In a method for forming a thin film such as a magnetic recording medium such as a magnetic tape or a magnetic disk having a step of forming a thin film by attaching the thin film to a body, the step of forming the thin film includes a mesh or a thin film between the thin film forming material and the support. Made of lattice-shaped metal or ceramics,
Arrange means for preventing scattering of massive particles due to splash,
The method is characterized in that a thin film is formed while preventing the massive particles from reaching the support.

The thin film forming apparatus of the present invention comprises at least a thin film forming material such as a magnetic material as an evaporation source, heating means for dissolving and evaporating the thin film forming material in a reduced-pressure atmosphere, and a thin film forming material such as a non-magnetic support. A thin film forming apparatus for forming a thin film such as a magnetic recording medium such as a magnetic tape or a magnetic disk having a means for forming a thin film by attaching the thin film forming material to a support of the thin film forming material. And means for preventing scattering of massive particles made of metal or ceramics in a mesh or lattice shape for preventing the massive particles due to the splash from reaching the support.

In the method and apparatus for forming a thin film of the present invention, the steps and means for forming a thin film include an electron beam vapor deposition method / apparatus, an induction heating vapor deposition method / apparatus, a sputtering method / apparatus, an ion plating method / apparatus, and the like. It is effective to use any one of the laser heating evaporation method / apparatus. Here, the reduced pressure atmosphere refers to a vacuum and an atmosphere in which a reactive gas, an inert gas, and the like are introduced into the vacuum.

According to the above-mentioned means, the means for preventing the lumpy particles from scattering between the thin film forming material and the support are provided.
It is possible to prevent the massive particles from adhering to the support or forming scratches or pinholes. Therefore, a high-quality thin film can be formed on the support.

[0009]

DETAILED DESCRIPTION OF THE INVENTION A thin film forming method and a thin film forming apparatus according to the present invention form a thin film on a magnetic recording medium such as a metal thin film type magnetic tape or a magnetic disk in which a metal magnetic thin film is formed on a nonmagnetic support. It can be applied to a method and a thin film forming apparatus. An example in which the present invention is applied to a magnetic recording medium will be described.

A magnetic recording medium generally has a magnetic layer such as a metal magnetic thin film formed on a non-magnetic support. If necessary, an underlayer may be formed under the magnetic layer, and a backcoat layer may be formed on the surface opposite to the surface of the support having the topcoat layer or the magnetic layer formed on the magnetic layer. Non-magnetic supports include polyesters, polyolefins,
Examples thereof include polymer materials such as cellulose derivatives, vinyl resins, polyimides, polyamides, and polycarbonate. The magnetic layer, which is a metal magnetic thin film, is formed as a continuous film by a vacuum deposition method or the like, and includes metals such as Fe, Co and Ni, Co-Ni-based alloys, Co-Ni-Pb-based alloys, Fe- An in-plane magnetization recording metal magnetic thin film formed from a Co-Ni alloy, an Fe-Ni-B alloy, an Fe-Co-B alloy, an Fe-Co-Ni-B alloy, a Co-Cr alloy, Co-
A perpendicular magnetic recording metal magnetic thin film formed of an O-based compound or the like can be used. In particular, in the case of an in-plane magnetized recording metal magnetic thin film, Bi, Sb, P
A base layer of a low melting point non-magnetic material such as b, Sn, Ga, In, Si and Ti is formed beforehand, and a metal magnetic material is vapor-deposited or sputtered from a vertical direction, and these low melting point non-magnetic The material may be diffused to eliminate the orientation and secure the in-plane isotropy, while improving the coercive force. These metallic magnetic thin films are formed by an electron beam evaporation method / apparatus and a sputtering method / apparatus, and the magnetic material is stored in a crucible or dissolved and evaporated by a sputtering target or the like, and this is adhered to a non-magnetic support. Is done. The top coat layer may be a commonly used polymer material containing a rust inhibitor or a lubricant, and the back coat layer may be a commonly used polymer material containing an antistatic agent or the like.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thin film forming method and a thin film forming apparatus according to the present invention are applied to a thin film of a magnetic recording medium, and FIG. This will be described in more detail with reference to FIG. 2 of a schematic external perspective view, FIG. 3 of a schematic plan view thereof, and FIG. The present invention is not limited to the embodiments described below.

First, a schematic configuration of a magnetic recording medium will be described.
This will be described with reference to FIG. In the magnetic recording medium 2, an underlayer 2b is formed on a nonmagnetic support 2a as necessary,
A magnetic layer 2c such as a metal magnetic thin film is formed on the underlayer 2b, and a top coat layer 2d is formed as necessary. A back coat layer 2e is formed on the surface of the support 2a opposite to the surface on which the magnetic layer 2c is formed, if necessary.

[0013] For example, 10
A feed roll 3, a take-up roll 4, and a cooling can 5 rotating in the counterclockwise direction in the figure are disposed in a vacuum chamber 1 in a vacuum state of ^-3 Pa. The support 2a, which is a tape-shaped base film, is fed toward the outer peripheral surface of the cooling can 5 while being closely contacted with the outer peripheral surface of the cooling can 5 rotating at a predetermined rotation speed, and is sequentially driven at a constant speed. The cooling body 5 has a support 2
An internal cooling device (not shown) is provided so as to suppress deformation due to a temperature rise of “a”. The feed roll 3, the take-up roll 4, and the cooling can 5 are each formed in a cylindrical shape having a length substantially equal to the width of the support 2a.

A crucible 6 is provided below the cooling can 5, and a thin film forming material 7, which is a magnetic material, is stored in the crucible 6. The crucible 6 has the same width as the width of the cooling can 5. Further, an electron beam generator 8 for dissolving and evaporating the thin film forming material 7 stored in the crucible 6 is provided in the vacuum chamber 1. The electron beam generator 8 irradiates the thin film forming material 7 which is a magnetic material in the crucible 6 with the generated electron beam by a focusing device 9 and a scanning device 10 using a magnetic field. At this time, the thin film forming material 7 stored in the crucible 6
In order to prevent the agglomerate particles from scattering to the support 2a due to the splash generated when the material evaporates, the thin film forming material 7 is provided between the thin film forming material 7 and the support 2a, for example, at the opening of the crucible 6. Means for preventing scattering of massive particles 1 made of, for example, a mesh-like metal so as to cover the evaporation direction.
1 is arranged. This scattering prevention means 11 has a wire diameter of 3
It is made of a 15 mm × 15 mm mesh using a stainless steel material of 15 mm. Further, as shown in FIG. 3, the scattering prevention means 11 is provided with a window 12 at a portion irradiated with the electron beam from the scanning device 10 so as not to hinder the irradiation. The scattering prevention means 11 may be attached to the opening of the crucible 6 as shown in FIG. 2, may be integrated with the crucible 6, or may be provided between the crucible 6 and the support 2a. Further, the wire diameter and the size of the mesh are not particularly limited. For example, the occupied area of the mesh portion is approximately 7% of the entire occupied area of the scattering prevention means 11 in the above case. The thin film forming material 7 dissolved and evaporated by the electron beam generator 8 is deposited on the support 2a which runs at a constant speed while being in close contact with the outer peripheral surface of the cooling can 5 to form a magnetic layer 2c which is a metal magnetic thin film. It is preferable that the power of the electron beam is appropriately set according to the deposition rate. However, for example, about 8 kW or more is required as the power that can be used for manufacturing a normal deposition tape. In addition, at the time of such vapor deposition, oxygen gas is supplied to the vicinity of the surface on the support 2a through an inlet for oxygen gas or the like (not shown), and the magnetic properties, durability, and weather resistance of the resulting metal magnetic thin film are obtained. Improvements are being made.

The method of heating the thin film forming material 7 may be any one of an induction heating evaporation method, a sputtering method, an ion plating method, and a laser heating evaporation method. In a heating method other than the electron beam, the window 12 is not necessarily required for the scattering prevention means 11.

Using the vacuum evaporation apparatus 20 having the above structure,
7.2 μm thick polyethylene terephthalate (PE
T) a magnetic tape having a 0.5 μm thick magnetic layer 2c formed on a support 2a;
Each original sample of the magnetic tape on which the magnetic layer 2c was formed was produced by using the vacuum evaporation apparatus 20 in the case of using no. In this case, the electron beam power was set to, for example, 12 kW. Each raw sample was cut into a width of 8 mm to obtain a magnetic tape for evaluation. With respect to these evaluation magnetic tapes, the number of dropouts was measured by the following measurement method, and the results shown in [Table 1] were obtained.

Measurement of the number of dropouts A 7 MHz signal was recorded when the tape was run at a relative speed of 3.77 m / sec, and the degradation rate of the RF output level and the time when the tape was reproduced were measured by a Sony EV-S900. Then, it was counted with a dropout counter manufactured by Shibasoku Co., Ltd. Dropout is -16d
B / 10μs, -10dB / 10μs, -10db / 3
It was measured at each level of μs.

[0018]

[Table 1]

As shown in Table 1, the sample manufactured using the anti-scattering means 11 of the present embodiment is different from the sample of the comparative example in which the conventional anti-scattering means 11 is not used.
Clearly the number of dropouts has been reduced. This is because the provision of the scattering prevention means 11 so as to cover the opening of the crucible 6 reduced the amount of clumping particles generated by the splash of the thin film forming material 7 on the magnetic tape and the number of scratches and pinholes. It is inferred.

In the embodiment of the above case, the magnetic recording medium 2
However, the present invention can be applied to a magnetic disk.

[0021]

According to the thin film forming method and the thin film forming apparatus of the present invention, it is possible to provide a thin film forming method and a thin film forming apparatus capable of forming a high quality thin film on a support.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a vacuum evaporation apparatus which is an example of a thin film forming apparatus of the present invention.

FIG. 2 is a schematic external perspective view showing one example of scattering prevention means applied to the thin film forming apparatus of the present invention.

FIG. 3 is a schematic plan view showing one example of scattering prevention means applied to the thin film forming apparatus of the present invention.

FIG. 4 is a schematic sectional view of a magnetic recording medium.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum chamber, 2 ... Magnetic recording medium, 2a ... Support, 2b ...
Underlayer, 2c: magnetic layer, 2d: top coat layer, 2e ...
Back coat layer, 3 ... feed roll, 4 ... take-up roll, 5 ... cooling can, 6 ... crucible, 7 ... thin film forming material,
8 ... electron beam generator, 9 ... focusing device, 10 ...
Scanning device, 11: scattering prevention means, 12: window,
20 Vacuum evaporation equipment

Claims (12)

[Claims] 1. A method for forming a thin film, comprising: forming a thin film by attaching a thin film forming material dissolved and evaporated in at least a reduced-pressure atmosphere to a support, wherein the step of forming the thin film comprises the steps of: A step of arranging a means for preventing scattering of the aggregated particles due to the splash of the thin film forming material between the support and the thin film forming material, and forming a thin film while preventing the aggregated particles from reaching the support. A method for forming a thin film, comprising: 2. The thin film according to claim 1, wherein the scattering prevention means has one of a mesh shape and a grid shape and is made of one of a metal and a ceramic. Forming method. 3. The thin film forming method according to claim 1, wherein the thin film forming material is stored in a crucible. 4. The method according to claim 1, wherein the thin film forming material is at least one of a magnetic metal, a magnetic alloy, and a magnetic compound. 5. The method according to claim 1, wherein the step of forming the thin film is a step of forming any one of a magnetic tape and a magnetic disk. 6. The method of forming a thin film according to claim 1, wherein one of an electron beam evaporation method, an induction heating evaporation method, a sputtering method, an ion plating method, and a laser heating evaporation method is used. Item 2. The method for forming a thin film according to Item 1. 7. At least a thin film forming material as an evaporation source, heating means for dissolving and evaporating the thin film forming material in a reduced-pressure atmosphere, and means for forming a thin film by applying the thin film forming material to a support. In the thin film forming apparatus having the above, a scattering preventing means for preventing a mass of particles caused by a splash of the thin film forming material from reaching the support is disposed between the thin film forming material and the support. Thin film forming apparatus. 8. The thin film forming apparatus according to claim 7, wherein said scattering prevention means has one of a mesh shape and a lattice shape and is made of one of metal and ceramics. apparatus. 9. The thin film forming apparatus according to claim 7, wherein the thin film forming material is stored in a crucible. 10. The thin film forming apparatus according to claim 7, wherein the thin film forming material is at least one of a magnetic metal, a magnetic alloy, and a magnetic compound. 11. The thin film forming apparatus according to claim 7, wherein the means for forming the thin film is a means for forming any one of a magnetic tape and a magnetic disk. 12. The means for forming the thin film includes an electron beam evaporation apparatus, an induction heating evaporation apparatus, a sputtering apparatus,
8. The apparatus according to claim 7, wherein the apparatus is one of an ion plating apparatus and a laser heating evaporation apparatus.
2. The thin film forming apparatus according to 1.