JPH05239630A - Ion plating method and apparatus - Google Patents

Abstract

(57) [Abstract] [Purpose] A ceramic film having a desired chemical composition is obtained by ion-plating a ceramic film on a wide strip at high speed for a long time and at a high ionization rate. A material in a crucible 3 is evaporated by an electron beam 7, and a hood-shaped electrode 9 having a diaphragm opening 8 through which vaporized particles pass is installed above the crucible. Reactive gas inlets 15a, 15b on top
Then, by applying a positive voltage to the electrode 9, the evaporated particles and the reaction gas are ionized and reacted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strip running in a vacuum,
In particular, the present invention relates to a method and apparatus for stably ion-plating a ceramic film such as a nitride or carbide on a wide strip at a high speed.

[0002]

2. Description of the Related Art As a method for plating a ceramic film in vacuum, there are techniques such as ion plating and sputtering. However, of these, sputtering has a slow film formation rate, and it is economically disadvantageous to apply it to equipment on a real production scale.

Ion plating has attracted attention as a technique for continuously treating a strip plate because it can form a ceramic film at a relatively high speed. When forming a ceramics film by the ion plating method, the ceramics film is formed on the substrate by heating and evaporating the main metal material, ionizing it, and reacting it with the reaction gas introduced at the same time. ..

In the ion plating, HCD for simultaneously evaporating and ionizing the material by using a plasma gun
There is a (hollow cathode discharge) method. Since this method has a high ionization rate, it is widely used as a reactive ion plating method. However, the film formation speed is 1/10 μm
Since it can be obtained only on the order of about 1 / min, it is mostly used for small-scale batch processing, and it is still economically inevitable to apply it to continuous processing equipment for strips.

Therefore, a method of ion plating using an electron gun has been proposed as a method for heating and evaporating a material. Since the electron gun has a higher energy density than the plasma gun, it is suitable for vaporizing the material at a high speed. However, it is difficult to maintain high-speed plasma with an electron gun and high-density plasma necessary for reaction at the same time stably for a long time.
The fact is that a method for stably ion-plating the ceramic coating at high speed using an electron gun has not been established yet, which is a reality.

Japanese Patent Publication No. 57-57553 proposes a method of forming a compound film by using an electron gun as a heating source, arranging electrodes in the vicinity of the crucible and ionizing the evaporation material. However, in this method, the discharge becomes unstable due to the disturbance of the evaporation material surface during high-speed film formation, and abnormal discharge tends to occur, so it can only be applied to small-scale batch processing using a small crucible, and a wide width It is difficult to perform stable and high speed ion plating on the strip plate.

In Japanese Patent Laid-Open No. 63-125673, a material is heated and evaporated by an electron gun, and an anode electrode and a corresponding ground electrode are placed between a substrate and a crucible, and an electron beam current and an anode current are made to flow above a certain value. Have proposed an ion plating method and apparatus for a ceramic film. However, with this configuration, Japanese Patent Publication No. 57-575
As with No. 53, instability of discharge during discharge at high speed and occurrence of abnormal discharge are unavoidable, and it is difficult to stably ion-plat a strip running continuously for a long time.

Japanese Patent Laid-Open No. 63-45365 discloses that the entire crucible 3 is covered with an internal chamber 6 having an opening 8 upward so that the steam flow ejected from the opening 8 can be opened. A method for forming a ceramic film by ionizing the positive electrode 9 on the upper part of the portion 8 and ejecting a reaction gas from the gas inlets 14a and 14b in the inner chamber and on the upper part of the opening is proposed. Is trying to stabilize. According to this method, the internal chamber 6 suppresses the disturbance of the surface of the evaporation material during high-speed evaporation and stabilizes the discharge. However, since the electrode 9 above the inner chamber 6 is far from the crucible 3 and does not directly face the crucible, the thermoelectrons generated from the evaporation material 4 cannot be sufficiently accelerated, and particularly during high-speed film formation. When the vapor pressure and the reaction gas pressure in the vicinity of the crucible increase and the mean free path of the electrons becomes shorter, the ionization rate sharply decreases, which causes the reaction rate control and there is a problem that a film having a desired chemical composition cannot be obtained. It was

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and a ceramic coating on a strip plate, particularly a wide strip plate, is stable at high speed for a long time and has high ionization. Ion plating at a rate
It is an object to obtain an ion plating method and apparatus for obtaining a ceramic film having a desired chemical composition.

[0010]

Means for Solving the Problems The inventors of the present invention, as a result of earnest research in line with the above object, have a function of evaporating a material in a crucible by an electron beam and converging a vapor flow above the crucible. A hood-shaped electrode is placed, a positive voltage is applied to it, and a reaction gas is introduced into and inside the hood-shaped electrode, so that a stable ceramic film can be produced without abnormal discharge during high-speed film formation. The present invention has been completed by finding out that the ion plating can be performed.

[0011]

In other words, by placing the hood-like electrode above the crucible, diffusion of the vapor flow is suppressed, and in particular, turbulence of vapor due to changes in the surface of the evaporation material during high-speed film formation is suppressed, so that discharge is stabilized. Furthermore, even when the vapor pressure on the surface of the evaporation material and the pressure of the reaction gas rise significantly during high-speed film formation, and the mean free path of the thermoelectrons and the reflected electrons of the electron beam generated from the surface of the evaporation material becomes short, the hood-like electrode Since one end is close to the crucible, the electrons can be sufficiently accelerated, and the high ionization rate is maintained, which promotes the reaction.

[0012]

The present invention will be described below with reference to the embodiment shown in FIG. The illustrated ion plating device is arranged in a vacuum chamber 1 that holds a vacuum atmosphere, and a strip plate 11 runs through the vacuum seal portion 14 above the inside thereof. The vacuum seal 14 is not particularly required as long as the pressure of the vacuum chamber adjacent to the vacuum chamber 1 is about the same as that of the vacuum chamber 1. Examples of the strip 11 include a low carbon steel plate, a stainless steel plate, a magnetic steel plate, a Fe—Ni alloy thin plate, an Al thin plate, a metal thin plate such as a Ti thin plate, and the like, but a polymer film or the like if it has an appropriate cooling mechanism. It is also applicable to, and is not particularly limited.

A crucible 3 is arranged in the lower part of the vacuum chamber 1,
The evaporation material 4 is contained in this. The evaporation material is a component constituting the ceramics of the present invention, and includes Ti and H
f, Ta, W, V, Zr, Ni, Co, Fe, Cr, A
Examples thereof include 1, Mn, Mg, and Zn. Among them, a refractory metal that generates a large amount of thermoelectrons during heating and evaporation is suitable. However, the evaporation materials are not limited to these, and for example, compounds other than metals (nitrides, oxides, carbides, etc.)
Can also be used directly. Further, the number of crucibles is not necessarily one, and it is possible to deposit a plurality of crucibles in close proximity to each other and evaporate different kinds of materials at the same time to form a ceramic film having two or more kinds of metal components. is there. When there is one crucible, it is desirable that the widthwise dimension of the crucible 3 be equal to or larger than that of the strip plate.

An electron gun 12 is mounted on one side of the vacuum chamber 1, and the electron beam 7 is bent in a crucible direction by a deflection magnetic field generated by a magnetic field generator (not shown here) to irradiate the surface of the evaporation material 4. It is supposed to be done.
The electron gun 12 is preferably a pierce-type electron gun that operates stably even if the pressure inside the vacuum chamber 1 is increased by introducing a reactive gas.

A hood-shaped electrode 9 is arranged between the crucible 3 and the strip 11. The material of the electrode 9 is preferably copper having a water cooling mechanism in order to sufficiently withstand radiant heat from the crucible and heat generated by ionization. The electrode 9 partially has an opening on the side through which the electron beam 7 passes, and has an opening 8 at the top. However, the opening on the side through which the electron beam 7 passes is not essential.
Is not required when the evaporation material 4 is irradiated through the gap between the electrode 9 and the crucible. The dimension of the upper opening 8 in the width direction is equal to or larger than the width of the strip plate. The electrode 9 is connected to the positive electrode side of the DC power supply 13, the crucible 3 is connected to the negative electrode side of the DC power supply 13, and the crucible 3 is simultaneously connected to the ground.

The reaction gas inlets 15a and 15b are provided at the side and upper portions of the hood-shaped electrode 9 so that the reaction gas can be introduced into and inside the hood-shaped electrode. The tips of the gas inlets 15a and 15b are preferably made of metal having a throttling mechanism, have a water cooling mechanism if necessary, and the gas pipes to the gas inlets are made of insulating material.
The reaction gas introduced from the gas inlets 15a and 15b is
A component constituting from ceramics of interest, the type, including the like _{N 2, O 2, CH 4} , C 2 H 2, H 2,
It can be arbitrarily selected according to the ceramics to be formed, and it is not always required to be one kind, and it is also possible to mix two or more kinds of gases to form a composite compound film such as a carbonitride film. Is. Suitable film-forming ceramics in the present invention include TiN, TiC, CrN, TiAlN, and T.
Examples thereof include iCrN and TiCN.

In this apparatus, the evaporation material 4 in the crucible 3 arranged in the vacuum chamber 1 is irradiated with the electron beam 7 from the electron gun 12 to evaporate the evaporation material 4. The electron beam 7 is emitted in a scanning mode optimized in advance so that the film thickness distribution in the width direction of the strip becomes uniform. The thermoelectrons generated from the evaporation material 4 are accelerated by the electrode 9 to which a positive voltage is applied,
It is ionized by colliding with vaporized particles and reaction gas. At this time, the deflection magnetic field of the electron beam has an effect of increasing the probability of collision with the vaporized particles and the reaction gas by trapping thermoelectrons and promoting ionization. The ionized material vapor and the reaction gas are converged by the hood-shaped electrode 9 and become a reacted compound, which adheres to the strip 11. At this time, applying a negative voltage to the strip plate 11 accelerates the ionized vaporized particles and the reaction gas toward the strip plate 11, so that not only the reaction is promoted but also the adhesion and workability of the film are improved. Also has the effect of improving.

In this apparatus, since the hood-shaped electrode 9 is provided above the crucible 3, diffusion of vapor flow is prevented,
In particular, since the turbulence of the vapor due to the change in the surface of the evaporation material during high-speed evaporation is suppressed, the discharge is stabilized. Also, since one end of the hood-shaped electrode is located near the crucible, the vapor pressure and reaction gas pressure on the surface of the evaporation material rises during high-speed film formation, and the average of the reflection electrons of the thermoelectrons and electron beams generated from the surface of the evaporation material Even if the free path becomes short, the electrons can be sufficiently accelerated, the high ionization rate is maintained, and the reaction between the vaporized particles and the reaction gas is promoted.

Next, the result of ion plating the compound film using the apparatus shown in FIG. 1 will be described in comparison with the case of using the apparatus shown in FIG. Here, a stainless steel plate was used as the strip plate, Ti was used as the evaporation material, and N ₂ was used as the reaction gas. The voltage of the electrode 9 was + 50V, and a voltage of -100V was applied to the strip.

The output 120 of the electron gun in the apparatus of the present invention
When ion plating was performed at kW and an electrode current of 1250 A, a gold-colored film which was the original color of TiN was formed at a film formation rate of 9 μm / min. During film formation for 3 hours, abnormal discharge did not occur and the discharge was stable. Observation by SEM (scanning electron microscope) revealed that the film had a smooth and dense structure. Peel strength by scratch test is 7kgf, Vickers hardness is 2200kg / mm ² Met.

On the other hand, when the film was formed at the same film forming rate using the conventional apparatus shown in FIG. 2, the electrode current reached a peak at 750 A and the film became dark brown. According to SEM observation, the surface had a rough and brittle structure. Peel strength in scratch test is 3.5kgf, Vickers hardness is 850kg / mm
² Both were inferior to the coatings according to the examples of the present invention.

[0022]

As described above, according to the present invention, it becomes possible to stably ion-plat a strip, particularly a wide-width strip, of a ceramic film having excellent film quality at high speed and for a long time. As a result, it becomes possible to manufacture the ceramic coating material on an industrial scale.

[Brief description of drawings]

FIG. 1 is a schematic view of an ion plating apparatus according to the present invention.

FIG. 2 is a schematic diagram of a conventional ion plating apparatus.

[Explanation of symbols]

1 ... Vacuum tank, 2 ... Exhaust system, 3 ... Crucible, 4 ... Evaporation material, 7
... Electron beam, 8 ... Aperture, 9 ... Electrode, 11 ... Strip plate, 1
2 ... Electron gun, 13 ... DC power supply, 14 ... Vacuum seal, 15
a ... Gas inlet, 15b ... Gas inlet, 16 ... Reaction gas

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[Procedure amendment]

[Submission date] March 23, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

The reaction gas inlets 15a and 15b are provided at the side and upper portions of the hood-shaped electrode 9 so that the reaction gas can be introduced into and inside the hood-shaped electrode. Gas inlets 15a, it is desirable 15b the tip of which is made of metal having a diaphragm mechanism having a water cooling system as required, the gas pipe to the gas inlet is a material of the insulating properties.
The reaction gas introduced from the gas inlets 15a and 15b is
In the components constituting the ceramics of interest, the _type, including _the like _{N 2, O 2, CH 4} , C 2 H 2, H 2,
It can be arbitrarily selected according to the ceramics to be formed, and it is not always required to be one kind, and it is also possible to mix two or more kinds of gases to form a composite compound film such as a carbonitride film. Is. Suitable film-forming ceramics in the present invention include TiN, TiC, CrN, TiAlN, and T.
Examples thereof include iCrN and TiCN.

Claims (4)

[Claims] 1. A device for ion-plating a compound film on a strip traveling in vacuum, and a crucible containing a material for forming the compound film, and an electron beam irradiation device for evaporating the material in the crucible. A hood-shaped electrode installed above the crucible and having a diaphragm opening in the upper part through which evaporated particles pass, an application device for applying a positive voltage to the hood-shaped electrode, and a reaction gas introduction arranged in the hood-shaped electrode. An ion plating device for a ceramic film having a mouth. 2. The apparatus according to claim 1, further comprising a magnetic field generating mechanism for deflecting the electron beam toward the crucible. 3. A method of ion-plating a ceramic film on a strip running in a vacuum, comprising the step of preparing the ion-plating device according to claim 1, and the material in the crucible being irradiated with electrons from the electron-beam irradiation device. Irradiation of a beam to evaporate this material, a step of introducing a reaction gas into the hood-shaped electrode from a reaction gas inlet, and a positive voltage is applied to this electrode by an application device to evaporate particles and reaction gas. An ion plating method for a ceramic film, comprising a step of ionizing and reacting and a step of applying a ceramic obtained by the reaction to a strip plate. 4. The method according to claim 3, wherein a voltage of −50 V to 1000 V is applied to the strip.