JP3529922B2 - Thin film manufacturing method and thin film manufacturing apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a thin film such as a magnetic tape.

[0002]

2. Description of the Related Art The role of thin films in modern society is extremely widespread, and thin films are used in various parts of daily life. Among these, wrapping paper, magnetic tape,
In applications such as capacitors, continuous winding vacuum deposition is performed, which is advantageous for high-speed mass production. That is, as shown in FIG. 6, various thin films can be mass-produced by performing electron beam evaporation while a long substrate is running along the peripheral surface of the cylindrical can. The evaporation material and the material for the substrate are selected according to the purpose of forming the thin film, and at the same time, desired gas is introduced by introducing a reaction gas into the vacuum chamber or by forming the thin film with the potential applied to the substrate. It is possible to form a thin film having the characteristics of. For example, in the production of a magnetic recording medium, a long magnetic recording medium is obtained by using an evaporation material containing a magnetic element such as Co, Ni, and Fe and performing reactive vapor deposition while introducing oxygen gas into a vacuum chamber. Can be done.

Further, as a method for further improving the productivity of the continuous winding vacuum vapor deposition method, there is a belt vapor deposition method using a belt instead of a can (Japanese Patent Laid-Open No. 217524/1985). That is, as shown in FIG. 7, if vapor deposition is performed using a belt instead of a can, a geometric vapor deposition angle condition almost similar to that when a very large can is used can be realized with a compact device. As the material for the belt, various materials such as an endless metal band can be applied. That is, the long substrate 4 unwound from the unwinding roll 3 along the rotation direction 12 in the vacuum chamber 2 evacuated by the exhaust system 1 is running along the surface of the endless belt (belt) 17. After receiving vapor deposition at the opening of the shielding plate 9 from the evaporation crucible 7 which is being irradiated with the electron beam 6, the take-up roll 10
To be wound up. Furthermore, reactive vapor deposition is also possible by directing a gas such as oxygen from the gas introduction nozzle 8 at the vapor deposition terminal side of the opening of the shielding plate to the substrate. Further, in order to enhance the adhesion between the polymer substrate and the endless belt, the polymer substrate is pressed against the endless belt by the nip roll 15,
It is also possible to irradiate the contact electron beam 14 from the contact electron gun 13 prior to forming the thin film. Further, the surface treatment of the substrate can be performed using the ion source. The electron beam for adhesion and the ion source can be omitted if unnecessary.
Thus, the belt deposition method is geometrically extremely suitable for mass production of thin films.

[0004]

However, this method has some problems to be solved. That is, in the can system, the can having a large heat capacity serves as a support, and the polymer substrate runs on it, so that the substrate is less likely to be damaged by heat during vapor deposition, whereas in the belt system, the heat capacity of the belt as a support is small. . Therefore, in order to prevent the heat damage to the substrate, it is necessary to devise more than the can method, and if this problem is not solved, the high productivity of the belt method cannot be utilized.

In order to solve the above problems, it is an object of the present invention to provide a manufacturing method capable of preventing a substrate from being damaged by heat and stably obtaining a thin film with high productivity, and a manufacturing apparatus for carrying out the manufacturing method.

[0006]

[Means for Solving the Problems]

[0007]

[0008] To achieve the above object, manufacturing method of the present invention, the production of a thin film for forming a thin film in an elongated substrate traveling along the endless belt that rotates along a plurality of rollers in vacuo In the method, at least one of the rollers is cooled, and at the same time, the endless belt is rotated while being heated, and then heating is terminated to cool the roller to form a thin film. At this time, the roller can be cooled by circulating a refrigerant inside the roller.

[0009]

[0010]

[0011] manufacturing apparatus of the present invention then, the state and conveying means for moving the elongated substrate along the surface of the endless belt circulating in a vacuum, which is the substrate to the endless belt along A thin film manufacturing apparatus comprising means for forming a thin film on a substrate, characterized by comprising heating means for preheating the endless zone. Examples of the heating means include a far infrared lamp.

[0012]

DETAILED DESCRIPTION OF THE INVENTION

[0013]

[0014]

According to manufacturing method of the present invention, in the manufacturing method of a thin film for forming a thin film on the elongated substrate traveling along the endless belt that rotates along a plurality of rollers in a vacuum, the When at least one of the rollers is cooled and at the same time the endless belt is rotated while being heated, heating is terminated and a thin film is formed while continuing to cool the roller, whereby a rapid thermal load change at the initial stage of thin film formation. Since it is possible to prevent the deformation of the endless belt due to, it is possible to prevent the substrate from being thermally deformed.

Next, according to the manufacturing apparatus of the present invention, the manufacturing method of the present invention can be effectively implemented. In the manufacturing apparatus of the present invention , it is preferable that the heating means for preheating the endless zone is a far-infrared lamp because heating can be performed with a simple configuration.

[0017]

EXAMPLES The present invention will be specifically described with reference to the following examples. A description will be given of a first reference example (Reference Example 1) The present invention. Figure 1 is for reference
It is a schematic diagram showing composition of an example manufacturing device. The vacuum chamber 2 is evacuated by the exhaust system 1. The size of the vacuum chamber 2 is 1000 cm in length, 1500 cm in width, and 2000 cm in height. The polyethylene terephthalate long substrate 4 having a width of 30 cm and a thickness of 10 μm is fed from the unwinding roll 3 in the rotation direction 1
It is unwound along 2 and runs along the surface of the endless belt 17. The endless belt 17 has a circumference of 4000 cm and a width of 600 cm.
Is. The traveling speed of the long substrate 4 was 50 m / min.
Three main rollers 18A, 18B that support the endless belt 17,
Of the rollers 1 and 18C closest to the vapor deposition start portion
8A was cooled. Cooling was performed by introducing oil, which is a refrigerant, from a rotating shaft in the roller and circulating the oil. An endless auxiliary belt 19 having a shorter circumference than that of the endless belt 17 was provided inside the endless belt 17, but the positional relationship was such that the endless belt bulges outward by 5 mm due to the auxiliary belt. The auxiliary belt has a circumference of 1500 cm and a width of 550 cm. Three rollers 20D, 20E supporting the auxiliary belt,
Of 20 and 20F, near the endless belt, roller 20D
And 20E were cooled by internal circulation of the refrigerant. The cooling method is the same as that of the roller 18A. In order to enhance the adhesion between the polymer substrate and the endless belt, the polymer substrate is pressed against the endless belt by the nip rolls 15, and then the electron beam for adhesion 14 is irradiated from the electron gun for adhesion 13 prior to the formation of the thin film. did.

The running long substrate 4 is vapor-deposited at the opening of the shield plate 9 from the evaporation crucible 7 which is being irradiated with the electron beam 6. The vapor incident angle on the polymer substrate was in the range of 80 to 45 degrees from the substrate normal. The gas introduction nozzle 8 was oriented so that the extension line of the nozzle was parallel to the endless belt 17. Then, the long substrate 4 is wound up by the winding roll 10. Further, reactive vapor deposition was performed by directing oxygen gas toward the substrate from the vapor deposition terminal side of the opening of the shield plate 9. The degree of vacuum in the deposition chamber during film formation is about 5 × 10 ^-5 torr
Is.

In this reference example , a Co—O magnetic layer having a layer thickness of 150 nm used for a thin film magnetic tape was formed on a polymer substrate. The film thickness of the magnetic layer was controlled by adjusting the input power of the electron gun by observing the film thickness using a transmitted light type film thickness meter 23 installed between the guide rollers 16 while adjusting the film thickness. The transmitted light type film thickness meter was constructed using a visible light source and a CdS photoelectric conversion element 24. Of the length of the endless zone, the length of the part involved in vapor deposition (deposition area) is set to 80 cm, and the contact length between the auxiliary belt and the endless zone, the temperature of the main roller 18A, and the refrigerant temperatures of the rollers 20D and 20E are changed. Evaporation was performed to examine the substrate for thermal damage. The results are shown in Table 1. The contact portion between the auxiliary belt and the endless belt was the central portion of the vapor deposition zone. Table 1 also shows the results when the auxiliary belt was not used (Nos. 1 to 3). As shown in Table 1, when the auxiliary belt was not used, heat damage to the substrate occurred unless the main roller 18A was cooled to -20 ° C. On the other hand, when the auxiliary belt is used, the cooling of the main roller can be weakened. Further, since the effect of preventing thermal damage is different when the contact length is 10 cm and 20 cm, it seems that there is a difference in the temperature rise prevention of the endless zone during vapor deposition depending on the contact length. It can be seen from Table 1 that the use of the cooled auxiliary belt has the effect of preventing heat damage and that the contact length is preferably 25% or more of the vapor deposition area.

[0020]

[Table 1]

[0021] describes a second reference example (Example 2) The present invention. Figure 2 is for reference
It is a schematic diagram showing composition of an example manufacturing device. The long substrate 4 unwound from the unwinding roll 3 along the rotation direction 12 in the vacuum chamber 2 evacuated by the evacuation system 1 emits the electron beam 6 while traveling along the surface of the endless belt 17. After being vaporized at the opening of the shielding plate 9 from the radiating evaporation crucible 7, it is wound around the winding roll 10. Three main rollers 18A, 18B and 1 supporting the endless belt
Of 8C, the roller 18A closest to the vapor deposition start portion was cooled by internal circulation of the refrigerant. The cooling member 21 was arranged inside the endless belt. The cooling member 21 has the same width as the vapor deposition width, and the endless band is pushed outward by pressing it.
The position was set so as to swell by mm. The endless belt was slid along the cooling member 21, and molybdenum disulfide was applied between the cooling member and the endless belt as a solid lubricant for preventing wear. Here, a copper block was used as the cooling member. This copper block was cooled with cooling water or helium. Stainless steel (SUS) besides copper block
It may be a plate. In addition to molybdenum disulfide, graphite, WS ₂ (tungsten disulfide), W or the like may be used as the solid lubricant. Further, reactive vapor deposition was performed by directing oxygen gas toward the substrate from the vapor deposition terminal side of the opening. Further, in order to enhance the adhesion between the polymer substrate and the endless belt, the polymer substrate is pressed against the endless belt 17 by the nip roll 15, and then the contact electron gun 13 is used to form a thin film prior to the formation of the thin film. 14 were irradiated.

As a polymer substrate, polyethylene terephthalate having a width of 30 cm and a thickness of 10 μm was used to form a Co—O magnetic layer having a layer thickness of 150 nm used for a thin film magnetic tape.
The vapor incident angle on the polymer substrate was in the range of 80 to 45 degrees from the substrate normal. The gas introduction nozzle 8 was oriented so that the extension line of the nozzle was parallel to the endless belt 17. The degree of vacuum in the vapor deposition chamber during film formation is about 5 × 10 ⁻⁵ torr. The film thickness of the magnetic layer was controlled by adjusting the input power of the electron gun by observing the film thickness using a transmitted light type film thickness meter 23 installed between the guide rollers 16 while adjusting the film thickness. The transmitted light type film thickness meter was constructed using a visible light source and a CdS photoelectric conversion element 24.

Of the length of the endless zone, the length of the portion involved in vapor deposition (vapor deposition zone) is 80 cm, the contact length between the cooling member 21 and the endless zone 17, the temperature of the main roller 18A, and the coolant of the cooling member. Vapor deposition was performed at different temperatures, and the heat damage of the substrate was examined. The temperature of the cooling member was changed by changing the temperature of the refrigerant inside the cooling member. The contact portion was the central portion of the vapor deposition area. The results are shown in Table 2. Table 1 also shows the results when the cooling member was not used (Nos. 1 to 3).

As can be seen from Table 2, thermal damage to the substrate can be effectively prevented by using the cooling member, and under the conditions of this embodiment , the contact length is stable at 25% or more of the deposition area. Was completed. It was found that when the solid lubricant was not applied, the inner surface of the endless belt was seriously damaged by sliding and was not suitable for practical use. Similar results were also obtained when other types of lubricants were used. It can be seen from Table 2 that the combination of the cooling member and the lubricant is effective in preventing thermal damage to the substrate even when the endless belt and the cooling member are in sliding contact, and it is desirable that the contact length is 25% or more of the vapor deposition area. I know there is.

[0025]

[Table 2]

[0026] describes a third reference example (Example 3) The present invention. Figure 3 is for reference
It is a schematic diagram showing composition of an example manufacturing device. The long substrate 4 unwound from the unwinding roll 3 along the rotation direction 12 in the vacuum chamber 2 evacuated by the evacuation system 1 emits the electron beam 6 while traveling along the surface of the endless belt 17. After being vaporized at the opening of the shielding plate 9 from the radiating evaporation crucible 7, it is wound around the winding roll 10. Further, reactive vapor deposition was performed by directing oxygen gas toward the substrate from the vapor deposition terminal side of the opening. Further, in order to enhance the adhesion between the polymer substrate and the endless belt, the polymer substrate is pressed against the endless belt 17 by the nip roll 15, and then the contact electron gun 13 is used to form a thin film prior to the formation of the thin film. 14 were irradiated.

As the polymer substrate, polyethylene terephthalate having a width of 30 cm and a thickness of 10 μm is used, and the layer thickness is 150 to 3
A 00 nm Co-O magnetic layer was formed. The vapor incident angle on the polymer substrate was in the range of 80 to 45 degrees from the substrate normal. The gas introduction nozzle 8 was oriented so that the extension line of the nozzle was parallel to the endless belt 17. Among the rollers supporting the endless belt, the roller 18A closest to the vapor deposition start portion was cooled by the internal circulation of the refrigerant. The degree of vacuum in the vapor deposition chamber during film formation is about 5 × 10 ⁻⁵ torr.

The film thickness of the magnetic layer was observed by using a transmitted light type film thickness meter 23 installed between the guide rollers 16 during vapor deposition, and was controlled by adjusting the electric power supplied to the electron gun. The transmitted light type film thickness meter includes a visible light source and a CdS photoelectric conversion element 2
4 was used.

The emissivity of the inner surface of the endless belt was changed within the range of 10 to 40% by finely adjusting the color or gloss of the inner surface of the endless belt by painting or plating. The emissivity was measured using a commercially available emissometer using a small piece of the same material as the endless band. By evaporating while changing the temperature of the main roller 18A, the relationship between the emissivity and the thermal damage during vapor deposition was examined. The results are shown in Table 3. As you can see from Table 3,
The higher the emissivity, the less likely thermal damage will occur during vapor deposition. For example, when the emissivity is 10%, heat damage to the substrate occurs when the magnetic layer thickness is 300 nm even when the temperature of the main roller 18A is set to -20 ° C, but when the emissivity is 20%, heat damage occurs. Does not occur. It is considered that this is because the heat load during vapor deposition can be released to some extent by radiation from the belt surface. Especially when the emissivity is 40% or more, the main roller is cooled by 10 ° C.
Since it can be weakened, it has great industrial value.

[0030]

[Table 3]

[0031] For real施例 (Example) The present invention will be described. FIG. 4 is a schematic diagram showing the configuration of the manufacturing apparatus of this embodiment. The long substrate 4 unrolled along the rotational direction 12 from the unwinding roll 3 in the vacuum chamber 2 evacuated by the exhaust system 1 is the endless belt 17.
After being vapor-deposited at the opening of the shielding plate 9 by the evaporation crucible 7 which is being irradiated with the electron beam 6 while traveling along the surface of, the film is taken up by the take-up roll 10. Of the rollers supporting the endless belt, the roller 18 closest to the vapor deposition start portion
A was cooled by internal circulation of the refrigerant. Prior to vapor deposition, the main roller 18A was cooled by internal circulation of the solvent, and the endless belt was rotated while being heated by using the heater of the preheating source 22. A far infrared lamp was used for the heater. After that, the heating of the heater was completed and the formation of the thin film was started while continuing the cooling of the main roller 18A. Further, reactive vapor deposition was performed by directing oxygen gas toward the substrate from the vapor deposition terminal side of the opening. Further, in order to enhance the adhesion between the polymer substrate and the endless belt, the polymer substrate is pressed against the endless belt by the nip roll 15, and then the electron gun 14 for adhesion is used before the thin film is formed. Was irradiated.

As a polymer substrate, polyethylene terephthalate having a width of 30 cm and a thickness of 10 μm was used to form a Co—O magnetic layer having a layer thickness of 150 nm used for a thin film magnetic tape.
The vapor incident angle on the polymer substrate was in the range of 80 to 45 degrees from the substrate normal. The gas introduction nozzle 8 was oriented so that the extension line of the nozzle was parallel to the endless belt 17. The degree of vacuum in the vapor deposition chamber during film formation is about 5 × 10 ⁻⁵ torr.

The film thickness of the magnetic layer was observed while performing vapor deposition using a transmitted light film thickness meter 23 installed between the guide rollers 16, and was controlled by adjusting the electric power input to the electron gun. The transmitted light type film thickness meter includes a visible light source and a CdS photoelectric conversion element 2
4 was used.

A thin film was formed by changing the heater power and the film thickness of the vapor deposition film, and the relationship with heat damage was investigated. The result is shown in FIG. As can be seen from FIG. 5, the heating of the heater in advance makes it difficult for the substrate to be damaged by heat. The reason for this is considered as follows. That is, when vapor deposition is started without preheating, the thermal load rapidly increases, so that thermal deformation of the endless zone also rapidly occurs. As a result, the adhesion between the substrate and the endless belt is lowered, and thermal damage is likely to occur. On the other hand, when preheating is performed, thermal deformation of the endless zone occurs due to preheating, and thus a steady state after thermal deformation is reached by the start of vapor deposition. Therefore, it is possible to reduce a rapid increase in heat load and thermal deformation at the start of vapor deposition, and the substrate is less likely to be damaged by heat.

The above Oite the embodiment has been described only for the case of using polyethylene terephthalate as the substrate, polyethylene naphthalate, polyesters, polyamides, and other various substrate materials, including polyimide and other polymeric substrate Can be used. Further, as an example, only the case of forming a Co—O magnetic layer as a thin film has been described, but similar results are obtained when a Co—Ni—O magnetic layer is formed. Since the present invention solves the problem of the endless zone and the heat load applied to the polymer substrate, it is not limited to the presence or absence of the reaction gas atmosphere and its type. Therefore, the present invention is effective not only when forming a thin film magnetic layer but also when forming another thin film.
The configuration of this embodiment is also effective when the thin film is formed after another underlayer is formed prior to the formation of the thin film. Therefore, the present embodiment can be applied not only to magnetic materials but also to reactive vapor deposition of various materials such as Si and a reaction gas such as oxygen, and for example, formation of liquid crystal alignment film, transparent electrode film, capacitor, etc. In this regard, by applying this embodiment, it is possible to stably supply a thin film with high productivity, which cannot be obtained by the conventional vacuum deposition. Also, regarding the incident angle of vapor deposition, the effect of the present invention is not limited to the angle shown in the embodiment, and by applying the present embodiment after appropriately optimizing the incident angle according to the intended use. Productivity can be improved.

[0036]

As described above, according to the thin film manufacturing method and the thin film manufacturing apparatus of the present invention, it is possible to prevent the substrate from being damaged by heat and to stably obtain a thin film with high productivity.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a manufacturing apparatus of Reference Example 1 of the present invention.

FIG. 2 is a schematic diagram showing a manufacturing apparatus of Reference Example 2 of the present invention.

FIG. 3 is a schematic view showing a manufacturing apparatus of Reference Example 3 of the present invention.

FIG. 4 is a schematic view showing a manufacturing apparatus according to an embodiment of the present invention.

FIG. 5 is a graph showing the relationship between preheating and thermal damage in the example of the present invention.

FIG. 6 is a schematic view showing an apparatus for producing a thin film by a continuous vapor deposition method using a conventional can.

FIG. 7 is a schematic view showing an apparatus for producing a thin film by a continuous vapor deposition method using a conventional endless zone.

[Explanation of symbols]

1 exhaust system 2 vacuum chamber 3 Unrolling roll 4 long board 5 can 6 electron beam 7 evaporation crucible 8 gas introduction nozzles 9 Shield 10 winding roll 11 Guide roll 12 rotation direction 13 Adhesion electron gun 14 Contact electron beam 15 Nip roll 16 Guide roller 17 endless belt 18 Main roller 19 Auxiliary belt 20 Auxiliary roller 21 Cooling member 22 Preheating source 23 Transmitted light type film thickness meter 24 CdS photoelectric conversion element

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-61-159573 (JP, A) JP-A-57-179952 (JP, A) JP-A-6-231457 (JP, A) JP-A-6- 145982 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C23C 14/00-14/58

Claims (3)

(57) [Claims] 1. A method of manufacturing a thin film, wherein a thin film is formed on a long substrate that runs along an endless belt that rotates along a plurality of rollers in a vacuum, and at least one of the rollers is cooled at the same time. A method for producing a thin film, comprising: rotating the endless belt while heating it, then ending the heating and cooling the roller to form the thin film. 2. A conveying means for moving a long substrate along the surface of an endless belt that circulates in a vacuum, and a means for forming a thin film on the substrate with the substrate along the endless belt. A thin film manufacturing apparatus comprising: a heating means for preheating the endless zone. 3. The heating means is a far-infrared lamp.
2. The thin film manufacturing apparatus described in 2 .