JPH05182192A - Thin film forming method and device therefor - Google Patents

Abstract

PURPOSE:To suppress the sticking of deposited materials to undesired points by using a mask member which has an aperture to regulate a deposition region and has the high sticking force to the deposited materials at the time of depositing a 2nd thin film by a deposition method from gaseous phase. CONSTITUTION:The component particles of a target 88 are driven out by a sputtering gas, such as Ar, and are deposited on a substrate B through the aperture 92 of the mask 93 at the time of sputtering, by which a protective film is formed on the magnetic thin film on the substrate B. The flying particles stick onto the mask 93 at the time of the sputtering but the sticking force of the flying particles is increased by heating the mask 93 to prevent the stuck particles from falling. At least the target side of the surface of the mask 93 is subjected to a surface treatment to increase the sticking force of the particles. The sticking of the flying particles to the undesired points is prevented by providing the mask 93 having the high sticking force to the particles. The falling of the particles sticking to the mask 93 onto the target 88 by peeling and the consequent generation of discharge abnormality are prevented.

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 an apparatus thereof, and more particularly to a method and an apparatus suitable for forming a protective film on a metal magnetic thin film such as a vapor deposition tape.

[0002]

2. Description of the Related Art In video tape recorders, image quality is being improved by high density recording, and in order to cope with this, a so-called metal magnetic thin film is used as a magnetic layer as a magnetic recording medium for 8 mm VTR, for example. Vapor-deposited tape has been put to practical use.

The vapor-deposited tape is superior in magnetic properties to the widely used coating type magnetic tape and has a thin magnetic layer, so that it is superior to the coating type magnetic tape in terms of electromagnetic conversion characteristics. It is expected to perform well.

In order to improve the durability of the metal magnetic thin film in such a vapor deposition tape, it has been conventionally known to provide a protective film by ECR plasma CVD, ion plating, sputtering or the like.

However, when forming the above-mentioned protective film, flying particles knocked out from a target in a sputtering apparatus, for example, are deposited in a predetermined region on a film substrate (nonmagnetic support) and other than the deposition region. It will also adhere to the mounting members. For example, when the substrate is guided while being contacted and supported by a drum-shaped can, both sides of the can are covered with a can mask, and the above particles adhere to the can mask.

[0006] Such adhered particles are likely to be peeled off and fall, and when adhered to the target, abnormal discharge may occur. This tendency becomes stronger as the input power is increased and the film formation speed is increased, which makes it difficult to increase the input power and also becomes a factor of lowering productivity.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for depositing a deposition material in a predetermined area and reducing the fall of the deposition material when forming a second thin film such as the above-mentioned protective film. To provide a device.

[0008]

That is, according to the present invention, when the second thin film is formed on the first thin film formed on the support by the deposition method from the vapor phase, it has an opening for defining a deposition region. In addition, the present invention relates to a method for forming a thin film, in which a mask member having a large adherence of deposited substances is arranged near the support.

Further, according to the present invention, a mask having an opening near the support on which the first thin film is formed and defining a deposition region for forming the second thin film and having a large adhesive force of the deposited substance. The present invention also provides a thin film forming apparatus in which members are arranged.

In the method and apparatus of the present invention, the mask member can be arranged in the vicinity of the can mask covering both edges of the can for guiding the support.

In order to further improve the effect of preventing the particles from adhering, the mask member is heated, or at least a part of the surface of the mask substrate is subjected to a treatment for increasing the adhering force of the deposited substance. Is desirable.

Further, in the present invention, the first thin film can be formed as a metal magnetic thin film by a vacuum deposition method, and the second thin film can be formed as a protective film by sputtering.

[0013]

EXAMPLES Examples of the present invention will be described below.

FIG. 1 schematically shows a sputtering apparatus for forming a protective film on a vapor deposition tape having a magnetic metal thin film as a magnetic layer. This sputter device has a can 87 and a partition plate arranged in the center for guiding and cooling the substrate.
It has vacuum tanks 81a and 81b divided by 82, and each vacuum tank 81
Vacuum exhaust systems 83a and 83b are connected to a and 81b, respectively.

Further, one of the vacuum chambers 81a is provided with a supply roll 84 and a take-up roll 85 for the base film B having a metal magnetic thin film. Further, the base film B is placed along the cooling can 87. Guide rolls 86a and 86b for traveling are installed.

In the vacuum chamber 81b, a target 88 of carbon or the like faces a cathode 90, facing the cooling can 87.
It's actually installed on the backing plate,
A high frequency voltage (not shown) or a DC voltage is applied to the can 87. In this case, a magnetron type sputtering method may be adopted to efficiently concentrate the electrons in the vicinity of the target.

Then, a can mask 91 is arranged on the target 88 side at both side edge positions of the can 87 so that extra particles due to sputtering are not scattered in the can width direction along the carrying direction of the substrate B.

Further, on the target 88 side of the can mask 91, a mask 93 having an opening 92 for defining a deposition region of flying particles by sputtering is arranged according to the present invention. The opening portion 92 of the mask 93 is formed so as to define the particle deposition region on the substrate B as clearly shown in FIG. 2 and has a width size corresponding to the width of the substrate B. The target is located immediately below the opening 92, as shown by the phantom line 88.

The mask 93 is made of metal, and may be made of, for example, stainless steel (SUS) processed into a plate shape. Further, since the mask 93 is used to deposit the flying particles from the target 88 only in a predetermined area, it is possible to effectively prevent the particles from adhering to other undesired areas. Therefore, the mask 93 is located directly above the target 88 and is formed in a size larger than the glow discharge region during sputtering. Therefore, the flying particles are masked
It does not substantially scatter to the area other than 93, and the adhesion to the can mask 91 is small, which is not a problem.

At the time of sputtering, the component particles of the target 88 are blown out by the sputtering gas such as Ar, and the mask 93
And is deposited on the substrate B (actually a metal magnetic thin film) through the opening 92 of the. FIG. 3 shows a state in which the protective film 103 is formed by sputtering on the metal magnetic thin film 102 on the substrate B. Materials for the protective film 103 include SiO ₂ , Si ₃ N ₄ , and SiN.
x, BN, ZnO ₂ , carbon, TiN, etc. The thickness of the protective film 103 is preferably 50 Å or more, and is preferably 300 Å or less in terms of spacing loss during reproduction.

At the time of the above-mentioned sputtering, flying particles adhere to the mask 93, but the following measures are taken to prevent the adhered particles from falling (that is, in order to increase the adhesive force of the particles). Is desirable. (1) To increase the adhesive force of flying particles by heating the mask 93 without cooling it. The heating temperature is preferably 70 ° C or higher, more preferably 150 ° C or higher. However, the heating temperature is set to be equal to or lower than the melting point of the mask 93. (2) At least the target side of the surface of the mask 93 is subjected to a surface treatment for enhancing the adhesive force of particles.

As for the above (1), as shown in FIG. 4, a stainless steel pipe 94 is fixed to the peripheral portion of the mask 93 by welding or the like, and hot water 95 is passed through the pipe to keep the mask 93 at a predetermined temperature. Can be heated to This heating temperature is 100 ℃
When it is desired to set the above, steam or heated oil can be passed through the pipe 94. Further, instead of the pipe 94, electric heating with a heater or the like made of a resistance heating wire is also possible.

Regarding the above item (2), as shown in FIG. 5, Zn, in advance, is formed on the surface of the mask substrate (for example, made of SUS).
A copper foil 96, which is surface-treated with Pb or the like by plating, is adhered, which facilitates attachment of flying particles. Alternatively, a mask substrate whose surface is directly treated with Zn, Pb, or the like may be used.

The metal magnetic thin film 102 is previously formed by vacuum vapor deposition on the substrate B on which the above-mentioned sputtering is performed. For this vacuum vapor deposition, the apparatus shown in FIG. 6 can be used.

The structure of the upper part of the vacuum vapor deposition apparatus including the cooling can 87 in FIG. 6 may be the same as that of the sputtering apparatus of FIG. Omit it. However, the lower vacuum chamber 81b
An evaporation source 188 is installed in the
A shield plate 190 for controlling the incident angle of the evaporated metal and an oxygen gas introduction pipe 191 for finely and stably depositing vapor deposition particles are provided in the vicinity of the position. The evaporation source 188 is a single metal of iron, cobalt, and nickel, Co-Ni.
It is possible to use alloys such as series alloys, and also mixtures with other elements. Reference numeral 193 in the figure is a preheating heater.

Therefore, by running the base film B along the cooling can 87 and heating and evaporating the evaporation source 188 by the electron beam 189 from the electron gun 192, the metal magnetic thin film is obliquely vapor-deposited on the base film. It θ min represents the incident angle (minimum value) of the evaporated metal on the base film.

As explained above, according to the present invention,
When depositing the protective film on the metal magnetic thin film by the sputtering method, since the mask 93 having a large particle adhesion is provided,
It is possible to prevent the sputtered flying particles from adhering to an undesired portion, and to suppress the particles adhering to the mask from falling onto the target due to peeling and causing the discharge abnormality as described above.

In particular, by heating the mask 93 or surface-treating Zn or the like, the flying particles are easily attached to the mask 93, and therefore the attached particles are more effectively prevented from falling. It is possible to achieve stable film formation by drastically reducing falling objects.

Next, a specific experimental example of the above thin film formation will be described. Each prescription carried out was as follows.

1. Formation of Metallic Magnetic Thin Film In the continuous winding type vapor deposition apparatus shown in FIG. 6, Co ₈₀ Ni ₂₀ was obliquely vapor-deposited in oxygen gas on a polyethylene terephthalate base having a thickness of 10 μm under the following conditions. Degree of vacuum: 1 × 10 ^-4 Torr Incident angle of vaporized metal on the base θmin: 45 ° Oxygen gas introduction rate: 250cc / min Deposition film thickness: 2000Å

2. Formation of Protective Film In the continuous winding type sputtering apparatus shown in FIG. 1, a protective film was formed on the base with the metal magnetic thin film formed above under the following conditions. Sputtering method: DC magnetron sputtering Gas pressure (Ar): 10 mTorr Power density: 6.8 W / cm ² Protective film thickness: 0.01-0.015 μm Target-base distance: 8 cm Target material: Carbon cooling can: Fig. 2 Mask shape: as shown in Figure 2

The base on which the above-mentioned magnetic layer is formed is coated with a back coat made of, for example, carbon and an epoxy binder, and a lubricant top coat made of perfluoropolyether. A magnetic tape can be created by cutting.

When the mask type and the discharge power were changed in the above, the results shown in the following table were obtained.

As is clear from the above results, a stable discharge can be secured by disposing a mask on the target side of the base and forming a film without cooling this mask.
High-speed film formation became possible. Furthermore, by applying a surface treatment with Zn etc. to increase the adhesive force, a faster and more stable film formation was possible and the productivity was improved.

In the above-described example, the can mask 91 and the mask 93 are separately arranged as shown in FIG. 2, but these can be integrated into one and have the same function.

FIG. 7 shows such an example, so to speak, the mask 93 is extended over the area of the original can mask to exert the function of the can mask, and the opening 92 defines the deposition area. The points are the same as the above-mentioned example. Also in this case, the sputtering can be stably performed by subjecting the mask 93 to the treatment for increasing the adhesive force of the flying particles as in the above-described example. In addition, since both masks are used in common, the mask can be easily installed and the structure is simplified.

Although the embodiments of the present invention have been described above, the above embodiments can be variously modified based on the technical idea of the present invention.

For example, although the above-mentioned protective film is formed by sputtering, another deposition method such as ECR plasma CV is used.
The protective film can be formed by D, ion plating, vacuum deposition or the like. Further, the material of this protective film may be formed as the second-layer magnetic film other than the above-mentioned materials. Further, the protective film may have a plurality of layers (for example, the lower layer is a corrosion-resistant metal such as Ni, the upper layer is carbon, SiO _2, etc.).

The shape and material of the mask used for depositing this protective film are not limited to those described above. Even if FIG. 7 is further modified and the conventional can mask itself is subjected to the above-described treatment for increasing the adhesion force of the deposited material, it is within the scope of the present invention. Further, although one mask is provided for each target in the above example, a plurality of pairs may be arranged along the can.

Further, in the above-mentioned example, the processing in the vacuum vapor deposition apparatus and the processing in the sputtering apparatus are carried out separately and in a batch system, but the base film is continuously passed between the respective apparatuses to carry out each processing. Can also be performed sequentially.

[0041]

As described above, according to the present invention, when depositing the second thin film by the deposition method from the vapor phase, the mask member has an opening for defining a deposition region and has a large adhesive force for the deposited substance. Since it is used, it is possible to prevent the deposited substance from adhering to an undesired portion and dropping onto the target or the like due to peeling to cause the discharge abnormality as described above.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a sputtering apparatus for forming a protective film according to an embodiment of the present invention.

FIG. 2 is a bottom view of the mask used in the sputtering apparatus as seen from below.

FIG. 3 is an enlarged cross-sectional view of a vapor deposition tape.

FIG. 4 is a plan view of an example of a preferred mask.

FIG. 5 is a cross-sectional view of another preferred mask.

FIG. 6 is a schematic sectional view of a vacuum vapor deposition apparatus for forming a metal magnetic thin film on the vapor deposition tape.

FIG. 7 is a bottom view showing another example of the mask.

[Explanation of symbols]

 81a, 81b ... Vacuum chamber 82 ... Partition plate 84 ... Supply roll 85 ... Winding roll 87 ... Can 88 ... Target 91 ... Can mask 92 ... Opening 93・ ・ ・ Mask 94 ・ ・ ・ Pipe 95 ・ ・ ・ Hot water 96 ・ ・ ・ Copper foil 102 ・ ・ ・ Metal magnetic thin film 103 ・ ・ ・ Protective film 188 ・ ・ ・ Evaporation source 189 ・ ・ ・ Electron beam 190 ・ ・ ・ Shielding Board B: Base film (substrate)

Claims (10)

[Claims] 1. When forming a second thin film on a first thin film formed on a support by a vapor deposition method,
A method for forming a thin film, comprising arranging a mask member having an opening defining a deposition region and having a large adhesion force of a deposition substance in the vicinity of the support. 2. A mask member is arranged in the vicinity of a can mask which covers both edges of a can for guiding a support.
The method described in. 3. The method according to claim 1, wherein the mask member is heated.
The method described in. 4. The method according to claim 1, wherein the substrate of the mask member is subjected to a treatment for increasing the adhesion of the deposited substance. 5. The method according to claim 1, wherein the first thin film is formed as a metal magnetic thin film by a vacuum vapor deposition method, and the second thin film is formed as a protective film by sputtering. 6. The vicinity of the support on which the first thin film is formed,
A thin film forming apparatus in which a mask member having an opening defining a deposition region for forming a second thin film and having a large adhesive force of a deposited substance is arranged. 7. A mask member is arranged in the vicinity of a can mask which covers both edges of the can for guiding the support.
The device according to. 8. The apparatus according to claim 6, wherein the mask member is heated. 9. The apparatus according to claim 6, wherein the substrate of the mask member is subjected to a treatment for increasing the adhesion of the deposited substance. 10. The protective film is formed by sputtering on the metal magnetic thin film formed by the vacuum deposition method.
The device described in any of 1.