JPH01255663A - Method and device for vacuum deposition - Google Patents

Abstract

PURPOSE:To efficiently form a vapor deposition film excellent in film quality by separately arranging an evaporation target consisting of either the same component as the substance forming the vapor deposition film or one component thereof and evaporating arc in vacuum and vapor-depositing the produced ions toward a base plate. CONSTITUTION:A cathode (target) 21 consisting of the same component as vapor deposition source substance 4 is arranged to the lower part slanted toward a base plate 7 in a vacuum chamber 1. An anode 22 is provided in the vicinity of the base plate 7 side and both the anode 22 and the cathode 21 are connected with an arc power source 23. Then the vapor deposition source substance 4 in a crucible 3 is heated and evaporated by utilizing the above-mentioned device according to an ordinary method and vacuum-deposited on the base plate 7. On the other hand, the vapor generated from the cathode 21 is ionized with high efficiency by generating arc between the anode 22 and the cathode 21 and the surface of the base plate 7 is irradiated by the generated ion beams 9. As a result, the particles on the film are activated by allowing the ions having large energy such as 10-50eV to collide against the film being vapor-deposited on the base plate 7. Thereby the vacuum deposition film which is high quality and excellent in adhesion to the base plate 7 is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vacuum evaporation method and an apparatus therefor which are carried out with the support of ions generated by vacuum arc discharge, and in particular, to a vacuum evaporation method and an apparatus thereof that have good film quality and operational stability. This article relates to an excellent vacuum evaporation method and its equipment.

[Prior Art] The vacuum evaporation method is one of the most well-known and widely used thin film forming techniques, in which a substance to be evaporated is heated with an electron beam (EB).

This is a technique in which the material is heated and evaporated using a method such as resistance heating or induction heating, and then deposited on a substrate. This method has high industrial value because it can be carried out using relatively simple equipment, and is applied to a wide range of film formation from large-scale products to small-scale products.

However, this method has the disadvantage that the evaporated particles are hardly ionized, so the activity is low, and the properties and adhesion of the film deposited on the substrate are poor.

Therefore, various improvement methods have been proposed to overcome these drawbacks of vacuum evaporation, and one such technique is so-called ionization, in which ions of an inert gas such as Ar are irradiated onto the substrate during vacuum evaporation. A beam-assisted vacuum evaporation method is mentioned. In this method, as illustrated in FIG. 3, a crucible 3. Substrate holder 6, substrate 7. After arranging the ion source 8, etc., and adjusting the vacuum chamber 1 to a predetermined degree of vacuum by reducing the pressure inside the vacuum chamber 1 using the vacuum pump 2, the evaporation source material in the crucible 3 is heated and evaporated by an electron beam, etc. The evaporated particles are deposited on a substrate 7 placed opposite to the substrate 7 . On the other hand, Ar is introduced from a gas supply system 10 into an ion source 8 arranged separately to generate an ion beam 9 and irradiate the substrate 7 with it. As a result, the board 7
The ion beam that has reached the top collides with the film being grown on the substrate and gives activation effects such as migration, resulting in a significant improvement in the properties of the deposited film.

[Problems to be Solved by the Invention] However, although the above-mentioned ion beam assisted vacuum evaporation method achieves considerable effects in terms of improving film quality, it has the following drawbacks.

■Introducing the gas that serves as the ion beam source into the vacuum chamber reduces the degree of vacuum within the vacuum chamber, making evaporation difficult under high vacuum conditions. That is, the evaporation rate decreases and the mean free path of the evaporated particles decreases, resulting in a significant deterioration of the evaporation rate. Moreover, the load on the vacuum pump increases. Furthermore, when an EB gun is used as a heating device, a decrease in the degree of vacuum adversely affects its operation.

■Inert gas is used as the ion beam gas, but even though it is an inert gas, substances other than the vapor deposition substance are irradiated onto the substrate, so the irradiated ion substances are incorporated into the substrate as impurities, which adversely affects the film quality. Get out.

(2) Even if the ion beam generator has a large output, the output current is about IA, and - most of the ion beam generators have a current of about 100 mA, so the irradiation area is small. To increase the irradiation area, a large ion beam generator can be used, but large ion beam generators are very expensive and difficult to apply to large area films.

The present invention has been made in view of these circumstances, and is capable of efficiently forming a vapor-deposited film with excellent film quality.
The present invention aims to provide a vacuum evaporation method and apparatus that can be applied to large-area films if necessary.

[Means for Solving the Problems] The method of the present invention, which achieves the above object, is a vacuum evaporation method in which one or more vapor-deposited film-forming substances are vapor-deposited on a substrate. The gist is that an evaporation target consisting of one component is separately arranged and evaporated in a vacuum arc, and the generated ions are irradiated toward the substrate for evaporation. In a vacuum evaporation apparatus in which sources are arranged facing each other, the gist lies in that a vacuum arc evaporation target for irradiating ions toward a substrate is arranged so as to be directed toward the substrate surface.

[Function] In the method of the present invention, a vacuum arc evaporation target is arranged separately from a vacuum evaporation mechanism consisting of an evaporation source for vacuum evaporation and a substrate placed opposite thereto, and the evaporation target is used as a cathode and the evaporation target is used as a cathode. A vacuum arc is generated to generate plasma particles consisting of ions and neutrons from a vacuum arc evaporation target, and the plasma particles are irradiated onto the substrate. That is, as a result of irradiating plasma particles from a vacuum arc onto the deposition surface of a substrate that is being vacuum-deposited according to a conventional method, the deposition material that is being deposited on the substrate is activated by the impact of the plasma particles. A vacuum-deposited film that is dense and has excellent adhesion to the substrate can be obtained.

Since the method of the present invention employs a vacuum arc evaporation technique for plasma particle irradiation, it is not necessary to introduce gas into the vacuum chamber, and ion-assisted vacuum deposition can be performed under high vacuum. Furthermore, for the same reason, the load on the vacuum pump is small, and economical vacuum deposition can be carried out using a small vacuum pump. Furthermore, as the target for vacuum arc evaporation, the same component as the evaporation material for vacuum evaporation, or if the evaporation film formed on the substrate is a reactive evaporation film, one of the components is used as the evaporation target. Even if plasma particles generated from the evaporation film are taken into the deposited film, they do not introduce impurities, and a vacuum-deposited film with less impurities can be obtained.

As described above, the method of the present invention can enjoy various excellent effects, and furthermore, in vacuum arc evaporation, it is very easy to obtain an ion current of IA or more, and there is no particular problem when increasing the size of the apparatus. As a result, the ion current density of plasma particles irradiated onto the substrate can be made much higher than in the past, and a high quality film can be formed.

[Example] Example 1 FIG. 1 is a schematic diagram showing an apparatus for carrying out the method of the present invention, and since the vacuum evaporation mechanism is the same as the conventional one, the same reference numerals are used. In this apparatus, a cathode (target) 21 having the same composition as the evaporation source material 4 is placed in a vacuum chamber 1 diagonally below a substrate 17, an anode 22 is provided near the substrate 17, and the anode 22 and cathode 21 to arc power supply 23
It is connected with Note that 23 is an arc containment ring made of BN or the like.

When performing vacuum evaporation using the above equipment,
According to a conventional method, the evaporation source material 4 in the crucible 3 is heated and evaporated, and vacuum-deposited onto the substrate 17. On the other hand, anode 22 and cathode 2
When an arc is generated between 1 and 1, the vapor generated from the negative 8i21 is ionized with a high efficiency of 50 to 100%, and an ion beam is generated.The ion beam 19 is irradiated onto the surface of the substrate 17. As a result, the film being deposited on the substrate is bombarded with ions with high energy (10 to 50 eV), activating the film particles.
We were able to obtain a vacuum-deposited film of high quality and excellent adhesion to the substrate.

In the above embodiment, the cathode 21 is cooled by a cooling structure (not shown) and supported within the vacuum chamber 1 by a support mechanism having an insulating structure. Further, in the embodiment, the anode 22 was installed on the substrate 17 side of the cathode 21, but the vacuum container may be used as the anode without installing a special anode, or one of the cathode and the anode may be connected directly to the wall of the vacuum chamber or through a resistor. May be connected. Of course, both may be floating. Furthermore, in the above embodiment, an evaporation source material having the same composition as the evaporation source material in the crucible 3 was used for the cathode 21.
The material forming the cathode 21 may be different from the source material in the crucible 3. That is, if the component is necessary as a film component to be vapor deposited on the substrate, the film component of the vapor deposited film may be used as the cathode material since no impurities will be mixed in. Furthermore, by employing vacuum arc evaporation, it is possible to evaporate high melting point metals that are difficult to evaporate with normal heating and evaporation, such as W and Mo.

While using high melting point metals such as Cr as a cathode material, it is possible to obtain a deposited film containing these high melting point metals as one of the composition components.

Further, a vacuum arc evaporation source generally operates with an arc discharge current of 50 to several hundreds of amperes, and it is said that about 8% of this current becomes an evaporation ion current.

Therefore, the evaporation ion current changes from 4A to more than IOA, and a large amount of ions are generated. If this ion beam is irradiated onto a substrate with the same area as before, it is possible to obtain a much higher current density than before, making it possible to obtain a deposited film of higher quality and also applicable to large-area deposition. can do.

Embodiment 2 FIG. 2 shows an embodiment in which the substrate is a long object such as a steel plate. In this embodiment, a steel plate roll 33 is placed stretched between rollers 31 and 32 in the vacuum chamber 1, and the roller 31,
Vacuum deposition is carried out while running between rollers 32 and 32.
It is wrapped around.

In the case of this example, the material to be evaporated is quite large-scale and must be vacuum-deposited continuously on the moving steel plate, so it is necessary to supply the evaporation material and ion beam sufficiently continuously to the steel plate. .

The amount of evaporation from the crucible 3 can be adjusted by increasing the output of the heat source such as an electron beam, and the amount of ion beam irradiation can be increased to a required amount by increasing the vacuum arc current. In this way, vacuum deposition can be performed on steel plates as wide as 1 m in width.

In addition, in order to increase the energy of the ion beam when it reaches the substrate and increase the ion irradiation effect, a negative bias voltage is applied to the substrate 7 via the substrate holder 6, and the ions are caused to correspond to the bias applied voltage just before the substrate. It is effective to accelerate by the amount of energy. In a similar way, a positive bias voltage is applied to the vacuum arc evaporation target (cathode), but a higher positive voltage is applied to the anode), and ions are accelerated by the energy equivalent to the bias voltage to It is also effective to irradiate the ions, and when combined with the application of a negative bias voltage to the substrate, the effect of ion irradiation can be further enhanced.

[Effects of the Invention] The present invention is configured as described above, and can obtain the effects summarized below.

(1) Since there is no need to introduce ion species gas, ion-assisted vacuum deposition can be performed under high vacuum by irradiating the deposited film with ions generated by a vacuum arc without causing deterioration of the degree of vacuum. can.

(2) The load on the vacuum pump can be reduced.

(3) There is no decrease in membrane purity due to ionic species gas.

(4) By employing vacuum arc evaporation, the ion beam output current can be increased, making it possible to respond to higher speeds and larger areas.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing an embodiment of the present invention, and FIG. 3 is a schematic diagram showing a conventional example. 1... Vacuum chamber 2... Vacuum pump 3...
Crucible 4... Evaporation source material 5... Evaporated particles 6... Substrate holder 7... Substrate
8...Ion source 9...Ion beam 10...
・Gas supply system 21...Anode 23...Arc power source 24...Arc containment ring 31.32...Roller 33...Steel plate Fig. 1 Fig. 2 Fig. 3

Claims (2)

[Claims] (1) In a vacuum evaporation method in which one or more vapor-deposited film-forming substances are vapor-deposited on a substrate, an evaporation target consisting of the same component or one component as the vapor-deposited film-forming substance is separately arranged and vacuum arc evaporation is performed. A vacuum evaporation method characterized by performing evaporation while irradiating ions toward the substrate. (2) In a vacuum evaporation apparatus in which a substrate and an evaporation source are arranged facing each other in a vacuum chamber, a vacuum arc evaporation target for irradiating ions toward the substrate is arranged to face the substrate surface. A vacuum evaporation device featuring: