JPH1112724A - Vapor deposition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that a base film is charged by the secondary electrons to be emitted from the surface of the material for vapor deposition and wrinkled, or that the members in the vapor deposition device are damaged by the reflected electrons having especially high energy among the secondary electrons in the vapor deposition device in which the material for vapor deposition is irradiated with the electronic beam to be emitted from an electron gun to achieve the heating and vapor deposition. SOLUTION: A plasma generating region is formed in the advancing route of the secondary electron. A means to generate the plasma comprises a pair of electrodes 18, 19 across the proceeding route of the secondary electron and a power source 20 to apply the AC power to the electrodes. In addition, at least one kind of gas among hydrogen gas, oxygen gas, and nitrogen gas is introduced between the electrodes, and the magnetic field is formed in the plasma generating region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor deposition apparatus, and more particularly, to a vapor deposition apparatus that heats and evaporates a vapor deposition material in a vacuum chamber using an electron beam emitted from an electron gun.

[0002]

2. Description of the Related Art The process of depositing a metal material mainly on a substrate made of a film or glass in a vacuum is generally widely carried out, and is used, for example, for manufacturing packaging materials and magnetic recording media. In this vapor deposition step, the vapor deposition material is heated and evaporated in a vacuum chamber to adhere to the substrate surface. Conventionally, as this heating means, for example,
A method of heating a container (hereinafter, referred to as a crucible) containing a vapor deposition material, such as resistance heating or induction heating, has been used, but when evaporating a metal material having a high melting point, the crucible has extremely high heat resistance. However, there is a problem that it is very difficult to produce a crucible satisfying such requirements.

In recent years, an electron gun has been used as a heating means. When the high-energy electron beam accelerated by the electron gun is irradiated on the deposition material in the crucible,
The material surface on which the electron beam is incident becomes particularly hot locally,
From there evaporation takes place. Therefore, the temperature of the vapor deposition material in the vicinity of the inner wall of the crucible does not rise so much as compared with the vapor deposition material surface region where the electron beam is incident, so that even when vapor deposition of a high melting point metal material is performed, it is formed of a general material. It becomes possible to use a crucible.

When electrons are incident on a metal surface as described above, electrons are emitted from the metal surface, that is, a so-called secondary electron emission phenomenon occurs. That is, as shown in FIG. 2, incident electrons 3 are applied to the surface of the evaporation material 2 in the crucible 1.
Is irradiated at various angles from the surface of the deposition material 2.
Next electrons 4 are emitted. Among these secondary electrons, there is an electron particularly called a reflected electron 4 ′, which is an electron having the same speed (energy) as the incident electron 3. The backscattered electrons not only have high energy, but also as if the incident electron beam reflected off a flat metal surface,
The light is emitted at a reflection angle θ equal to the incident angle θ. This means that high-energy electrons are emitted within a specific range from the surface of the crucible vapor deposition material in the vacuum chamber.

[0005]

In the vacuum chamber of the vapor deposition apparatus, the members in the traveling path of the reflected electrons are:
The problem arises of being damaged by the high energy. In order to prevent this, for example, in FIG. 2, it is considered to install a protective plate 5 made of ceramic or a water-cooled stainless steel plate in the traveling path of the backscattered electrons 4 ′. There is a problem that the protection plate 5 is damaged by high energy, its life is very short, and it must be replaced frequently.

Further, when a non-conductive material such as a polymer film is used as a base material on which vapor deposition is performed, charging by secondary electrons floating in a vacuum chamber is remarkable, and wrinkles of the film and damage due to discharge are observed. Is done. Therefore, in a vapor deposition apparatus equipped with an electron gun as a heating means,
It is necessary to take measures to prevent the influence of secondary electrons such as reflected electrons emitted from the surface of the metal material.

[0007]

The present inventor has studied various means for solving the above-mentioned problems, and as a result, found that secondary electrons floating in a vacuum chamber and particularly high energy among the secondary electrons are obtained. Capture some of the reflected electrons that have
Alternatively, the inventor has found that if the energy can be reduced, the influence of these electrons can be extremely reduced. That is, according to the present invention, as a means for heating and evaporating the vapor deposition material in the crucible, the vapor deposition device provided with an electron gun for irradiating the vapor deposition material with an electron beam emits when the electron beam is irradiated on the vapor deposition material surface. A plasma generation region is provided on the secondary electron traveling path.

In the above configuration, the means for generating plasma preferably comprises a pair of electrodes sandwiching a traveling path of secondary electrons, and an AC power supply for applying AC power to the electrodes. Moreover, providing a means for introducing at least one of hydrogen gas, oxygen gas and nitrogen gas between the electrodes is effective for stabilizing the state of plasma. Further, in the above configuration, when a magnetic field is formed in the plasma generation region, the plasma generation region can be limited to a very narrow space, which is effective for reducing the size of the apparatus.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of a specific structure of a vapor deposition apparatus according to the present invention will be described with reference to FIG.
In FIG. 1, only main parts of the present invention are shown, and other parts are omitted. Further, the same components as those in FIG. 2 are denoted by the same reference numerals. In FIG.
A cooling can roll 1 is placed in a vacuum chamber (not shown).
1. An unwind roll 12, a take-up roll 13, and guide rolls 14 to 17 are arranged, and a substrate, for example, a film 6, is wound between these rolls, and runs in the direction of the arrow in the figure. A crucible 1 containing a vapor deposition material 2 is provided below the cooling can roll 11 so that incident electrons 3 from an electron gun 7 are irradiated on the surface of the vapor deposition material 2. As described above, the secondary electrons 4 are emitted at various angles with respect to the incident angle φ of the incident electrons 3.
In particular, the protection plate 5 is disposed so as to block the traveling path of the reflected electrons 4 ′ emitted at the reflection angle φ equal to the incident angle φ of the incident electrons 3.

[0010] A plasma generating means is provided on the traveling path of the reflected electrons 4 '. Specifically, the plasma generation means includes, for example, a pair of electrodes sandwiching the traveling path of the reflected electrons 4 ′, for example, two plate electrodes 18 and 19,
An AC power supply 20 for applying AC power to the electrodes 18 and 19. By applying AC power to the electrodes 18 and 19 to form a plasma generation region A between the electrodes, a part of the reflected electrons 4 ′ having particularly high energy among the secondary electrons is captured, and The energy of those that are not performed is also weakened, so that the collision energy against the protection plate 5 becomes extremely small, and the life of the protection plate 5 is greatly increased. Further, since the secondary electrons floating in the vacuum chamber are also captured by the plasma generation region A, it is possible to prevent wrinkles due to charging of the film 6 and damage due to electric discharge.

Further, when one of hydrogen, nitrogen and oxygen or a mixture of two or more gases is introduced from a gas inlet (not shown) between the electrodes 18 and 19, the discharge between the electrodes is stabilized. Therefore, it is effective for maintaining the plasma state for a long time. The gas introduction amount is not particularly limited, and a sufficient effect can be obtained with a small amount of gas of, for example, about 1 to 50 cc / min. Further, in the vapor deposition apparatus having the above configuration, when a magnetic field is formed in the plasma region A, the effect of capturing reflected electrons is improved, so that the plasma region A can be reduced.
It is possible to reduce the size and shape of 8,19. Therefore, it is extremely effective for downsizing the device. This magnetic field forming means is, for example, as shown in FIG.
The coils 21 and 22 can be arranged in the vicinity of 8 and 19, and the coils 21 and 22 can be connected to DC power supplies 23 and 24, respectively. Thereby, the electrode 18,
The strength of the magnetic field formed between 19 is not particularly limited, and a sufficient effect can be obtained, for example, at about 100 [Oe].

<Embodiment> In the vapor deposition apparatus shown in FIG. 1, a P film having a width of 200 mm and a thickness of 10 μm was used as the film 6.
An ET film, a water-cooled copper crucible as the crucible 1 and cobalt as the vapor deposition material 2 were used, and the electron gun 7 was of a straight type. The protective plate 5 was a water-cooled stainless steel plate. By setting the output of the electron gun 7 to 10 kw and the running speed of the film 6 to 20 m / min, the film thickness on the film 6 could be reduced to about 1 μm. The following tests were performed using such an apparatus.

(1) Evaluation of Influence of Secondary Electrons and Reflected Electrons As the first embodiment, in the above-described apparatus, the flat electrode 18,
AC power was applied to 19 to generate plasma, and deposition on the film 6 was performed. At this time, as a result of examining the size of the plate electrodes 18 and 19 so as not to cause damage to the stainless steel plate 5, in the drawing, the width direction of the film, that is, the electrode depth is 30 cm, and the electrode width L is 2
A size of 6 cm was required, and it was found that a sufficient effect could be obtained with 1.2 kW when the power supply frequency was set to 50 Hz.

Under the above conditions, deposition was performed for a certain period of time.
During the vapor deposition, no phenomenon was observed in which the film was charged and stuck to the surface of the cooling can roll 11, and the state in which the film 6 was separated from the cooling can roll 11 was very stable. Also, the surface of the cobalt film was observed after film formation,
No streaks or wrinkles were found. Further, the surface of the stainless steel plate 5 was observed after the deposition was completed. The surface was deteriorated, specifically, the discoloration was slightly recognized, and it was apparent that the stainless steel plate 5 could be used for a long time. became.

As a comparative example, vapor deposition was performed for a certain period of time in the same manner as in Example 1 except that no plasma was generated. As a result, a phenomenon in which the film 6 sticks to the cooling can roll 11 during the vapor deposition occurs, and the state in which the film 6 separates from the cooling can roll 11 is unstable.
Wrinkling was observed particularly at the edge portion of the film 6.
Further, streaks in an unspecified direction were also observed on the cobalt film on the surface of the film 6. This is presumed to be due to a discharge phenomenon of secondary electrons floating in the chamber. Furthermore, after the vapor deposition was completed, the surface of the water-cooled stainless steel plate 5 was observed. As a result, even though the operation was performed for a very limited time, obvious damage was seen. Was predicted. Table 1 summarizes the above results.

[0016]

[Table 1] Peeling of the water-cooled stainless steel plate on the film deposition surface from the can roll Condition Damage Example 1 Good Good No Comparative Example Bad Streaks and wrinkles

As is clear from the above results, the generation of plasma in the traveling path of secondary electrons, particularly reflected electrons, makes it possible to prevent the effects thereof.

(2) Stability of Plasma When continuous vapor deposition was performed for 3 hours under the conditions of Example 1 above, there was no effect on the vapor deposition, but the discharge was interrupted four times in the middle, and the plasma state disappeared each time. . Then, various gases shown in Table 2 were introduced between the plate electrodes 18 and 19, plasma was continuously generated for 3 hours in the same manner, and the number of discharge stops was measured. The results are shown in Table 2. Examples 2-6). In addition, the introduction amount of the gas was about 3 cc / min.

[0019]

[Table 2]

As described above, by introducing the gas between the electrodes 18 and 19, the phenomenon that the discharge was interrupted and the plasma state disappeared was completely eliminated.

(3) Miniaturization of Electrodes In the second embodiment, the width L of the electrodes 18 and 19 needs to be 26 cm, but a current is applied to the coils 21 and 22 in FIG.
By forming a magnetic field having a magnetic field strength of 300 [Oe] between the electrodes 18 and 19, it was confirmed that the effect on secondary electrons and reflected electrons was sufficient even when the width L of the electrodes 18 and 19 was set to 12 cm. Example 7). Table 3 shows the above results.

[0022]

[Table 3]

As described above, when a magnetic field is formed between the electrodes 18 and 19, the required electrode length can be remarkably shortened, so that it has been proved to be extremely effective for miniaturization of the apparatus.

[0024]

As described above in detail, according to the present invention, by forming a plasma in the traveling path of secondary electrons, especially reflected electrons, the film is charged or discharged by the influence of these electrons. Damage can be prevented, and damage to structures in the chamber can also be prevented. Further, by introducing a gas into the plasma generation region, the state of the plasma can be stabilized, and by forming a magnetic field in the plasma generation region, it is effective for shortening the electrodes and, consequently, miniaturizing the device. is there.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of a configuration of a main part of a vapor deposition apparatus of the present invention.

FIG. 2 is a conceptual diagram showing a traveling path of incident electrons and reflected electrons.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crucible 2 Evaporation material (cobalt) 3 Incident electron 4 Secondary electron 4 'Reflection electron 5 Protective plate (water-cooled stainless steel plate) 6 Base material (film) 7 Electron gun 11 Cooling can roll 12 Unwind roll 13 Take-up roll 14, 15, 16, 17 Guide roll 18, 19 Plate electrode 20 AC power supply 21, 22 Coil 23, 24 DC power supply

Claims (4)

[Claims] 1. A vapor deposition apparatus having an electron gun for irradiating an electron beam to the vapor deposition material as means for heating and vaporizing the vapor deposition material in the crucible, wherein the electron beam is emitted when the surface of the vapor deposition material is irradiated with the electron beam. The traveling path of the secondary electron
An evaporation apparatus, wherein a plasma generation region is formed. 2. The vapor deposition apparatus according to claim 1, wherein said means for generating plasma includes a pair of electrodes sandwiching a traveling path of said secondary electrons, and a power supply for applying AC power to said electrodes. 3. The vapor deposition apparatus according to claim 2, further comprising means for introducing at least one of hydrogen gas, oxygen gas and nitrogen gas between said electrodes. 4. The deposition apparatus according to claim 1, wherein a magnetic field is formed in a region where the plasma is generated.