JPH07102362A - Formation of film - Google Patents

Abstract

PURPOSE:To form a film high in adhesion with a substrate and excellent in surface roughness by forming a film under low pressure conditions by an ion mixing method, and then executing. arc ion plating under high pressure conditions. CONSTITUTION:A substrate 2 impressed with a negative bias voltage is arranged in a vacuum vessel whose atmosphere is comprised of a reaction gas such as N2 from a gas feeding source 6. A target 11 of Ti or the like from an arc evaporating source 10 is melted to evaporate by arc discharge and is deposited on the substrate 2. Besides, the substrate 2 is subjected to ion implantation by accelerating ions from a cathode of Ti or the like from a metallic ion beam source 20 by a drawing electrode system 25. At the time of forming films of TiN or the like on the substrate 2 by jointly using the arc ion plating method and ion implanting method, at first, a film is formed under low pressure conditions by the ion mixing method in which both method are executed simultaneously or alternately, and next, a film forming substance is moreover formed thereon under high pressure conditions by the arc ion plating method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a compound coating film of ceramics or the like by an ion mixing method, and in particular, it forms a coating film having a high effect of adhering to a base material and an excellent surface condition. Regarding the method.

[0002]

2. Description of the Related Art As a method for forming a film on a substrate, there is an ion plating method in which a film-forming substance is vaporized and ionized to be deposited on the substrate. However, the coating film formed by the ion plating method has a drawback that it generally has poor adhesion to the substrate.

On the other hand, as a method for forming a coating film having high adhesion to a substrate, for example, in Japanese Patent Laid-Open No. 61-96721, a coating film-forming substance may be applied at the same time or alternately by applying an ion plating method. An ion mixing method has been proposed in which ions are injected into the formed film.

[0004]

In the above-mentioned prior art, heating means such as electron beam type, high frequency heating, resistance heating or the like is used to evaporate the metal element which is one of the constituent materials of the coating film. When evaporating the refractory metal, a large amount of electric power is required and the efficiency is low. Further, since the metal of the evaporation source is in a molten state, the position of the evaporation source is limited to the lower part of the vacuum container,
Since the positional relationship with the base material is also restricted, there is a problem that uniform coating is difficult with a base material having a complicated shape.

As a dynamic mixing apparatus capable of solving such a problem, instead of ionization by a heating type evaporation source and a high frequency coil in the prior art, metal is vaporized and ionized from a target by arc discharge, and a metal is formed on the surface of a substrate. By using the vacuum arc evaporation method (arc ion plating method) to form a film, refractory metal ions can be generated efficiently, and the restriction on the mounting position of the metal evaporation source is eliminated, making it possible to achieve uniform deposition on substrates with complex shapes. Can enable coating.

However, in the ion mixing method using such an apparatus, the adhesion between the base material and the coating is improved by using the ion plating method and the ion implantation together, but the surface roughness of the formed coating is increased for the following reasons. There is a problem of inferiority. That is, the ion implantation method is a method of implanting accelerated high-speed ions into the formed vapor deposition film, but from the viewpoint of preventing dielectric breakdown of the extraction electrode system for acceleration, a high vacuum of 10 ⁻⁴ Torr or less is used. Must be done in a state. On the other hand, when a film is formed by the ion plating method, macro particles (melt particles) are inevitably produced at a constant rate as ions (Ti ions in the case of TiN film) for forming the film are generated from the evaporation source as the film material. ) Is a byproduct. The by-product ratio of the macro particles (molten particles) increases as the degree of vacuum increases. When the film was formed using only the ion plating method, the degree of vacuum was maintained at about 10 ^-2 Torr, so the by-product of macroparticles did not pose such a problem, but in the case of the ion mixing method, Due to the limitation in the ion implantation method, it is necessary to perform the treatment under a vacuum of 10 ⁻⁴ Torr or less, and thus the formed coating contains macro particles (molten particles). Then, the mixing of macro particles disturbs the deposition at the molecular level, resulting in a so-called inferior surface roughness film.

The present invention has been made in view of the above circumstances, and an object thereof is to make up for the drawbacks of the ion mixing method and the ion plating method, to have a high adhesive force with a substrate and to have a surface. An object of the present invention is to provide a film forming method capable of forming a film having excellent roughness.

[0008]

A film forming method of the present invention is a film forming method using a combination of an arc ion plating method and an ion implantation method in a reaction gas atmosphere.
Forming a first coating by depositing a film-forming substance by an ion mixing method in which an arc ion plating method and an ion implantation method are performed simultaneously or alternately under low pressure conditions.
And a second step of depositing a film-forming substance on the first film by an arc ion plating method under a high pressure condition.

The film-forming substance used in the present invention can be appropriately selected depending on the purpose of use. Specifically, Periodic Table IV
a, Va, VIa group metal carbides, nitrides, borides,
The film can be formed from an oxide, a sulfide, or a mutual solid solution thereof, or a compound such as aluminum nitride, boride, or oxide. The kind of gas introduced into the reaction chamber in the first step and the second step is one of the constituents of the film-forming substance, for example, a nitrogen-containing gas such as nitrogen or ammonia in the case of nitride and acetylene in the case of carbide. , Hydrocarbon gas such as methane, and oxygen-containing gas such as oxygen and water in the case of oxide.

The ion mixing method performed in the first step is a method in which the arc ion plating method and the ion implantation method are used in combination, and when the arc ion plating and the ion implantation are simultaneously performed, and the ion plating method. And the case where the ion implantation method is performed alternately. The ion mixing method in the first step is performed under low pressure conditions. That is, a pressure of 10 ⁻⁴ Torr or less is appropriately selected so that ion implantation can be performed without problems.

The ions implanted in the ion implantation in the first step are ion species having a predetermined ion acceleration energy, and have an ion mixing effect at the interface between the base material and the vapor deposition film formed by ion plating. It should be something that can be demonstrated. For example, metal ions of the film-forming substance; inert gas ions such as argon ions and neon ions; other non-metal ions (nitrogen ions, carbon ions, etc.) can be appropriately selected according to the purpose and the type of the film.

The thickness of the first coating formed in the first step is
It is sufficient if the film thickness is sufficient to increase the adhesion with the base material,
For example, in dynamic mixing, 1
The thickness is preferably about / 3 or less. If the thickness of the first coating exceeds ⅓ of the total thickness, the deposition of the constituent molecules of the coating disturbed by the inclusion of molten particles in the first coating affects the subsequently formed coating. Influence
This is because the surface roughness is reduced.

After forming the first coating film in the first step, the ion implantation is stopped, and only the arc ion plating is performed in the second step. As the condition of the second step, a pressure condition suitable for arc ion plating is set. Ie 1
It may be carried out at about 0 ^-2 Torr until the desired film thickness is obtained.

[0014]

In the coating film forming method of the present invention, first, the first coating film having excellent adhesion to the substrate is formed by the ion mixing effect performed in the first step. Next, in the second step, film formation is performed by ion plating alone under high pressure conditions in which there are few by-products of the molten particles, and therefore mixing of the molten particles into the formed film can be reduced.

Therefore, the coating film formed by the method of the present invention is a coating film in which molten particles are not mixed on the first coating film, so that the finally formed coating film has good adhesion to the substrate. Excellent and excellent in surface roughness.

[0016]

EXAMPLES The formation of a TiN film will be described below as an example of the film forming method of the present invention. First, Fig. 1
An example of an apparatus used in the film forming method of the present invention is shown in FIG. In FIG. 1, reference numeral 1 denotes a vacuum container, and a base material 2 as an object to be coated is placed on a rotary table 3 below the vacuum container 1. The turntable 3 is connected to a bias power source 4, and a bias voltage is applied to the substrate 2 via the turntable 3 to make it a negative potential. In the figure, 5 is an exhaust port for exhausting the inside of the vacuum container 1, and 6 is a gas supply source for supplying gas into the container 1.

An arc discharge evaporation source 10 for performing ion plating is attached to the upper right side of the vacuum container 1, and an arc discharge type metal ion beam source 20 for performing ion implantation is attached to the upper left side. . In the arc discharge evaporation source 10, a target 11 made of a film forming material metal (for example, Ti) is connected as a cathode to a cathode of an arc power supply 13, and an anode 12 is connected to an anode of the arc power supply 13. In this ion plating device 10, when an ignition device (not shown) is brought into contact with a target 11 which is a cathode to generate an arc discharge, the target 11 is partially melted and evaporated at an arc spot, It becomes a film-forming substance ion.

The ion beam source 20 is provided with a metal ion source cathode 22 connected to a cathode of an arc power source 21 and a trigger electrode 23 for ignition on one side of the arc chamber, and a cathode of an arc chamber 24. The extraction electrode system 15 is formed on the side facing the. The ion beam source 20 is attached so that the extraction electrode system 25 is on the vacuum container side. In the ion beam source 20 having such a configuration, when the cathode 22 is ignited by the trigger electrode 23 to generate arc discharge, the metal (for example, Ti) forming the cathode 22 is vaporized and ionized from the arc spot, The metal ions are extracted and accelerated by the acceleration voltage applied between the extraction electrodes 15, and are emitted as a high energy ion beam.

Example 1 In the apparatus shown in FIG. 1, the pressure of nitrogen gas in the vacuum container 1 was set to 5
It was set to × 10 ^-4 Torr. Bias voltage -50 on substrate 2
V was applied. In this state, first, as the first step,
The arc discharge evaporation source 10 and the ion beam source 20 were simultaneously operated under the following conditions to form a TiN film having a thickness of about 0.5 μm on the base material 2 as the first coating.

Arc current of evaporation source 100A Deposition rate 1-3 nm / s
ec Ion beam source acceleration voltage 50 kV Ion beam source current density 10-20 μA
/ Cm ² Then, the operation of the ion beam source 20 is stopped, nitrogen gas is supplied into the vacuum vessel 1, and the nitrogen gas pressure is set to 1 × 10 ^-2.
Torr. In the second step, TiN is further deposited on the first coating by ion plating to obtain T
The total thickness of the iN film was set to about 3 μm.
The setting of the ion plating device in the second step is the same as in the first step.

The surface roughness of the coating film thus formed was measured and found to be Ra 0.1 to 0.2 μm. On the other hand, the surface roughness of the coating when the entire coating was formed only by the ion mixing method was Ra 0.5 to 0.6 μm. The surface roughness when the entire coating was formed by the ion plating method was Ra 0.1 to 0.2 μm. Therefore, according to the method of the present invention, it can be seen that a film having a surface roughness as high as that of the case where the whole is formed only by the ion plating method can be formed.

Example 2 As a first step, a film was formed by ion mixing in which ion plating and ion implantation were performed alternately. While maintaining the N ₂ gas pressure in the vacuum vessel at 5 × 10 ⁻⁴ Torr and applying a bias voltage of −50 V to the substrate 2, the evaporation source 10 was operated while operating the ion beam source 20 under the following conditions. The operation and stop under the following conditions were repeated 10 times at regular intervals. Ion plating and ion implantation for forming a film having a thickness of about 500 Å each time were alternately performed to form a TiN film with a total thickness of about 0.5 μm.

Conditions for ion implantation: Ion beam source acceleration voltage: 50 kv Ion beam source current density: 10-20 μA
/ Cm ² Conditions of ion plating Arc current of evaporation source 100A Deposition rate 1-3 nm / s
ec Operating time 20-50se
c Stop Time (Ion Implantation Time) 10 min Next, ion implantation is stopped, nitrogen gas is again supplied into the vacuum container 1 to increase the pressure to 1 × 10 ⁻² Torr, and then the second
Total film thickness of about 3μm due to process ion plating
The coating was formed to a certain extent. The conditions for ion plating are the same as the conditions for ion plating in the first step.

The surface roughness of the obtained coating was measured. As a result, it was possible to form a coating having a surface roughness Ra of 0.1 to 0.2 μm and an excellent surface roughness comparable to the case where the entire surface was formed only by ion plating. . Although Ti ions are implanted in the above embodiment, the present invention is not limited to this, and N ions that are the other ions of the film-forming substance or other inert ions may be implanted.

In the apparatus shown in FIG. 1, an arc discharge type apparatus is used as the ion beam source 20, but the present invention is not limited to this, and other conventional Freeman type ion sources, Kauffman type ion sources, etc. It is also possible to use an ion beam source of this type. In addition, although the TiN coating film is formed in the above-described embodiment, other types of compound coating films may be appropriately selected according to the purpose of use.

[0026]

According to the method for forming a coating film of the present invention, after the first coating film having excellent adhesion to the substrate is formed by the ion mixing in the first step, the ion plating in which the molten particles are less by-produced in the second step. By carrying out only the coating method, it is possible to grow a coating film containing almost no molten particles.

Therefore, according to the method of the present invention, it is possible to obtain a coating film having excellent adhesion to the substrate and excellent surface roughness.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an apparatus for carrying out the method of the present invention.

[Explanation of symbols]

 1 Vacuum container 2 Substrate 10 Arc discharge evaporation source 20 Ion beam source

Front page continued (72) Inventor Noriyuki Inuishi 1-5-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Kobe Steel Works Seishin Research Area

Claims (1)

[Claims] 1. In a coating forming method using both an arc ion plating method and an ion implantation method in a reaction gas atmosphere, the arc ion plating method and the ion implantation method are simultaneously or alternately performed under a low pressure condition. First, a first film is formed by applying a film-forming substance by an ion mixing method.
And a second step of depositing a film-forming substance on the first film by an arc ion plating method under a high pressure condition.