JPH08175898A - Device for forming hard carbon coating film and method for forming coating film with the same - Google Patents

Abstract

PURPOSE: To obtain the hard carbon coating film-forming device capable of simultaneously subjecting coating film-forming treatments to plural substrates in a process and further capable of forming strong carbon coating films also to substrates comprising a material low in the adhesivity to the hard carbon coating films. CONSTITUTION: A plasma-generating chamber 4 is formed in a vacuum chamber 10, and a substrate holder 7 is rotatably disposed at a position faced to the plasma-generating chamber 4. A high frequency voltage is applied from the first high frequency source 9 to the substrate holder so that a self bias generated in the substrates 11 is negative. A target 18 containing the raw material atoms of an intermediate layer is disposed toward the surface of the substrate holder 7, and the second high frequency source 19 is connected to the target 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming a hard carbon coating on a substrate via an intermediate layer, and a coating forming method using the apparatus.

[0002]

2. Description of the Related Art Conventionally, electric razor blades, semiconductor materials,
In order to improve the characteristics and protect the surface of magnetic heads, piezoelectric materials, or sliding parts of various devices, coatings made of various materials are formed on these surfaces. For example, in the manufacturing process of electric razor blades, ECR
(Electron cyclotron resonance) Plasma CVD (chemical va
por deposition) device, stainless steel or N
A hard carbon coating (diamond-like coating) is formed on the surface of the substrate made of i.

FIG. 5 shows the structure of a conventional ECR plasma CVD apparatus (Japanese Patent Laid-Open No. 3-175620). In the ECR plasma CVD apparatus, a plasma generation chamber (4) and a reaction chamber in which the substrate (11) is to be installed are formed inside the vacuum chamber (10), and the plasma generation chamber (4) includes The microwave generator (1) is connected via the waveguide (2). A microwave introduction window (3) is provided at the connection between the waveguide (2) and the plasma generation chamber (4). A discharge gas introduction pipe (5) for introducing a discharge gas such as argon (Ar) into the plasma generation chamber (4) is connected to the plasma generation chamber (4). Further, a plasma magnetic field generator (6) is provided so as to surround the plasma generation chamber (4). A substrate holder (12) is installed in the reaction chamber in the vacuum chamber (10), and a reaction gas introduction pipe (14) is connected to the substrate holder (12). A high frequency power source (13) is connected to the substrate holder (12).

The microwave from the microwave generator (1) is guided to the plasma generation chamber (4) through the waveguide (2) and the microwave introduction window (3). High-density plasma is formed in the plasma generation chamber (4) by the action of the high frequency magnetic field generated by the microwave and the magnetic field from the plasma magnetic field generator (6). This plasma is guided to the reaction chamber along the divergent magnetic field generated by the plasma magnetic field generator (6).

In the reaction chamber, methane (CH ₄ ) gas as a source gas introduced from the reaction gas introduction pipe (14) is decomposed by the action of plasma, and carbon C is deposited on the substrate (11) on the substrate holder (12). Is deposited on the surface of. Here, a predetermined high-frequency voltage (RF voltage) is applied to the substrate holder (12) by a high-frequency power source (13), and a negative self-bias is generated in the substrate (11), which is a so-called bias plasma CVD method. Is carried out. That is, since the moving speed of ions in plasma is slower than that of electrons, the electrons can follow the potential fluctuation during the application of the RF voltage, but the ions cannot.
Therefore, when an RF voltage is applied to the substrate (11), many electrons are emitted toward the substrate (11), and a negative self-bias is generated in the substrate (11). As a result, positive ions in the plasma are drawn to the substrate (11) side, and as shown in FIG.
A diamond-like coating (15) is formed on (11).

[0006]

However, the conventional EC
In the R plasma CVD apparatus, the number of substrates 11 that can be mounted on the substrate holder 12 is limited to one or two. In the film forming process for these substrates (11), it is necessary to evacuate the inside of the vacuum chamber (10) first. Therefore, in order to form a film on a large number of substrates (11), it is frequent during the process. There was a problem of inefficiency because it had to be evacuated.

If a material having high adhesion to the hard carbon coating, such as Si or C, is selected as the material of the substrate, the hard carbon coating adheres strongly to the surface of the substrate. If a low material such as stainless steel or Ni is used, the adhesion of the hard carbon coating is low and there is a risk of peeling.

It is an object of the present invention to allow a plurality of substrates to be simultaneously subjected to a film forming treatment in a single process, and even a film made of a material having low adhesion to a hard carbon film is a strong film. To provide a hard carbon film forming apparatus and a film forming method capable of forming a film.

[0009]

A hard carbon film forming apparatus according to the present invention comprises a vacuum chamber, a plasma introducing means for introducing plasma into the vacuum chamber, and a reactive gas containing carbon into the vacuum chamber. In order to make the self-bias generated in the substrate holder and the substrate holder rotatably provided in the vacuum chamber with the surfaces facing each other in the plasma supply direction to become negative, First to apply high frequency voltage to substrate holder
It is provided with a high-frequency power source, a target that is disposed in the vacuum chamber toward the surface of the substrate holder, and includes a source atom of the intermediate layer, and a second high-frequency power source for applying a high-frequency voltage to the target.

In a specific structure, a plurality of electrodes insulated from each other are arranged on the surface of the substrate holder, and a brush to be brought into sliding contact with one electrode facing in the plasma supply direction as the substrate holder rotates. Is attached at a fixed position, and the brush is connected to the first high frequency power supply.

Here, the substrate holder is formed in a drum shape or a disk shape. The plasma introducing means is an electron cyclotron resonance plasma CVD apparatus.

The substrate is, for example, Ni, stainless steel, or ceramics, and the target contains, for example, Si, Ru, or C as a raw material atom of the intermediate layer.

In the method for forming a coating film according to the present invention, a substrate holder on which a plurality of substrates are to be mounted is rotatably arranged in a vacuum chamber, and the raw material atoms of the intermediate layer are directed toward the surface of the substrate holder. Place the target containing
A film forming apparatus is configured. Then, at the time of film formation, while rotating the substrate holder, a high frequency voltage is applied to the target to form an intermediate layer on the surface of the substrate on the substrate holder, and then a reaction gas is supplied into the vacuum chamber and plasma is generated. While introducing and rotating the substrate holder,
A high frequency voltage is applied to the substrate holder to form a hard carbon coating on the surface of the intermediate layer.

In another method for forming a coating film according to the present invention, a reaction gas is supplied into the vacuum chamber,
While introducing plasma and rotating the substrate holder, a high frequency voltage is applied to the target and at the same time, a high frequency voltage is applied to the substrate holder to gradually increase the flow rate of the reaction gas in the process of forming the coating film and at the same time to increase the target. By lowering the high frequency voltage to be applied to the
As the carbon content gradually increases toward the surface,
After forming the intermediate layer in which the content of the target atoms is gradually reduced, the application of the high frequency voltage to the target is stopped, and the hard carbon film is formed on the surface of the intermediate layer.

[0015]

In the above hard carbon film forming apparatus of the present invention, the plasma introducing unit, the reactive gas introducing unit, the substrate holder, and the first high-frequency power source constitute a plasma CVD apparatus, and the substrate holder, target, and (2) The high frequency power supply constitutes a high frequency sputtering apparatus, and the reaction chamber of the plasma CVD apparatus and the discharge chamber of the high frequency sputtering apparatus are formed in a common vacuum chamber. Therefore, after the intermediate layer is formed on the substrate by using the high frequency sputtering device, the hard carbon film can be continuously formed on the surface of the intermediate layer by using the plasma CVD device without evacuation.

Here, the substrate holder is formed in a drum shape or a disk shape, and in the case of a drum shape, on the outer peripheral surface thereof, and in the case of a disk shape, one or more surfaces are provided with a large number of 2 or 3 or more. The substrate can be placed around the center of rotation.
Further, in the case of a drum shape, the plasma CVD apparatus and the high frequency sputtering apparatus can be arranged opposite to each other on both sides of the substrate holder. In the case of a disc shape, the plasma CVD apparatus and the high frequency sputtering apparatus can be installed side by side so as to face the one surface.

Then, at the time of forming the film, by rotating the substrate holder, the substrates in the substrate holder shape are sequentially faced to the plasma CVD device and the high frequency sputtering device, and the intermediate layer or the hard carbon film can be formed. .

In a specific structure in which a plurality of electrodes are arranged on the surface of the substrate holder, the brush relatively slides on the electrodes as the substrate holder rotates, and the electrodes are sequentially arranged on the electrodes. A high frequency voltage is applied. Therefore, only the substrate on the electrode to which the high frequency voltage is applied is targeted, and the hard carbon film is selectively formed on the substrate.

If an electron cyclotron resonance plasma CVD apparatus is adopted as the plasma introducing means, the plasma density can be further increased and a high quality coating film can be formed at a low temperature.

When the substrate is made of, for example, Ni, stainless steel, or ceramics, the hard carbon film has low adhesion to the substrate and is easily peeled off, but Si, Ru, or C is used as the target atom. By including it, an intermediate layer containing these atoms is formed. The hard carbon coating has high adhesion to the intermediate layer and is firmly adhered. As a result, the adhesion of the hard carbon coating to the substrate can be enhanced.

In forming the intermediate layer, the plasma CV is used.
By adopting a method in which the D device and the high frequency sputtering device are simultaneously operated, it is possible to form an intermediate layer in which the carbon content gradually increases toward the surface and the target atom content gradually decreases. In this case, the adhesiveness between the intermediate layer and the hard carbon coating can be further enhanced.

[0022]

EFFECTS OF THE INVENTION According to the hard carbon film forming apparatus and the film forming method of the present invention, it is possible to simultaneously perform film forming treatment on a plurality of substrates in a single process, and the adhesion between the hard carbon film and the hard carbon film can be improved. A strong coating can be formed even on a substrate made of a material having a low heat resistance.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings. Apparatus Configuration In the film forming apparatus according to the present invention, as shown in FIG. 1, a plasma generating chamber (4) is provided inside a vacuum chamber (10).
And a reaction chamber in which the substrate (11) should be installed are formed, and the microwave generation device (1) is connected to the plasma generation chamber (4) through the waveguide (2). A microwave introduction window (3) is provided at the connection between the waveguide (2) and the plasma generation chamber (4). A discharge gas introduction pipe (5) for introducing a discharge gas such as argon (Ar) into the plasma generation chamber (4) is connected to the plasma generation chamber (4). Also, the plasma generation chamber (4)
A plasma magnetic field generator (6) is provided to surround the.
In the reaction chamber in the vacuum chamber (10), a drum-shaped substrate holder (7) is rotatably installed around a rotation axis O perpendicular to the paper surface of FIG. A motor (not shown) is linked.

A plurality (24 in this embodiment) of electrodes (8) are arranged at regular intervals on the outer peripheral surface of the substrate holder (7), and each electrode (8) has a surface. , Ni substrate (11)
Is attached. Further, the substrate holder (7) has one electrode facing the plasma generation chamber (4) side as the substrate holder (7) rotates.
A brush (17) to be brought into sliding contact with (8) is provided and fixed to the vacuum chamber (10). First on the brush (17)
A high frequency power supply (9) is connected. Therefore, when the substrate holder (7) rotates, the RF voltage from the first high frequency power source (9) is applied to the electrode (8) via the brush (17).

A reaction gas introducing pipe (16) for introducing a reaction gas such as methane (CH ₄ ) is connected to the reaction chamber. As shown in FIG. 2, a T-shaped gas releasing portion (16a) is formed at the tip of the reaction gas introducing pipe (16), and the gas releasing portion (16a) has a plurality of gasses. The emission hole (16b) is opened downward at 45 ° toward the surface of the substrate holder (7). Also, these gas discharge holes (16b) are the gas discharge parts.
The distance is gradually narrowed toward both ends of (16a),
As a result, the reaction gas is evenly discharged from each gas discharge hole (16b).

Further, in the reaction chamber, a Si target (18) is installed below the substrate holder (7) toward the outer peripheral surface of the substrate holder (7). Second to the target (18)
A high frequency power supply (19) is connected, which allows the target to
RF voltage is applied to (18).

Thus, the above microwave generator
(1), waveguide (2), plasma generation chamber (4), discharge gas introduction pipe (5), plasma magnetic field generator (6), reaction gas introduction pipe (1
6), the substrate holder (7), and the first high-frequency power source (9) constitute an ECR plasma CVD apparatus, and the substrate holder (7), target (18), and discharge gas introduction tube
A high frequency sputtering apparatus is constituted by (5) and the second high frequency power supply (19). Hereinafter, using the above film forming apparatus, a hard carbon film is formed on a Ni substrate through an intermediate layer.
The method for forming the (diamond-like coating) will be specifically described.

First Embodiment First, a total of 2 electrodes are placed on each electrode (8) on the surface of the substrate holder (7).
After attaching four Ni substrates (11) and evacuating the inside of the vacuum chamber (10) to 10 ⁻⁵ to 10 ⁻⁷ Torr, the substrate holder (7) is rotated at a speed of about 10 rpm. Next, Ar gas was supplied from the discharge gas introducing pipe (5) at 1.4 × 10 ⁻³ Tor.
The RF voltage of 13.56 MHz is applied from the second high frequency power source (19) to the Si target (18) while being supplied by r. At this time, the applied voltage was adjusted so that the self-bias generated in the target (18) was set to -200 V and the ion current flowing in the target (18) was set to 1.9 mA / cm ² .

The above process was performed for about 3 minutes to form an intermediate layer of Si on the surface of the Ni substrate to a film thickness of 100 Å.

Next, after the application of the RF voltage from the second high frequency power source (19) is stopped, Ar gas is supplied from the discharge gas introducing pipe (5) at 5.7 × 10 ⁻⁴ Torr and the microwave is generated. A microwave generated at 2.45 GHz and 100 W was supplied from the device (1) to generate A in the plasma generation chamber (4).
The r plasma is radiated to the surface of the substrate (11). At the same time, from the high frequency power supply (9) to the brush (17) 13.5
An RF voltage of 6 MHz is applied to generate a self-bias of -20 V on the Ni substrate (11) on the electrode (8) with which the brush (17) is in sliding contact.

At the same time, CH ₄ gas is supplied at 1.3 × 10 ⁻³ Torr from the reaction gas introducing pipe (14).
The CH ₄ gas supplied from the reaction gas introduction pipe (14) is decomposed by the action of plasma, and the carbon generated thereby becomes a highly reactive ion or a neutral active state,
It is emitted to the surface of the substrate (11).

The above steps are performed for about 25 minutes to obtain a Ni substrate.
On the surface of (11), a diamond-like coating having a film thickness of 2000 angstrom was formed via the intermediate layer.

Thus, by interposing the intermediate layer between the substrate (11) and the diamond-like coating, it is possible to relieve the thermal stress caused by the difference in thermal expansion coefficient between the substrate and the diamond-like coating. At the same time, the adhesion between the substrate and the diamond-like coating can be enhanced.

Second Embodiment In this embodiment, the source material atom Si of the target is used as the intermediate layer.
And a carbon C mixed layer are formed, and a diamond-like coating is formed on the surface of the intermediate layer. The film forming apparatus used here has the same structure as that of the first embodiment.

First, each electrode (8) on the surface of the substrate holder (7)
A total of 24 Ni substrates (11) were mounted on the top, the inside of the vacuum chamber (10) was evacuated to 10 ⁻⁵ to 10 ⁻⁷ Torr, and then the substrate holder (7) was rotated at a speed of about 10 rpm. Next, Ar gas was introduced through the discharge gas introduction pipe (5) at 5.7 ×.
Microwave generator with 10 ^-4 Torr
A microwave of 2.45 GHz and 100 W is supplied from (1) to irradiate the Ar plasma formed in the plasma generation chamber (4) on the surface of the Ni substrate (11). At the same time, 13.56MH from the high frequency power supply (9) for the brush (17)
An electrode with which the brush (17) is in sliding contact by applying an RF voltage of z
(8) Self-bias of -20 V is generated on the Ni substrate (11).

At the same time, CH ₄ gas is supplied from the reaction gas introducing pipe (14). Here, the supply amount of CH ₄ gas is increased with time as shown in FIG. 3, and 100 sccm after 5 minutes, that is, 1.3 × 10 ⁻³ Torr.
Set to.

In this embodiment, the above ECR plasma CV is used.
Simultaneously with the film forming process by the D apparatus, the intermediate layer is formed by the above high frequency sputtering apparatus. That is, 13.56M from the second high frequency power source (19) to the Si target (18)
By applying an RF voltage of Hz and gradually decreasing the RF voltage, as shown in FIG. 4, the self-bias generated in the target (18) is gradually increased from -200V, and after 5 minutes, 0V is applied. And

By performing the above steps for 5 minutes,
An intermediate layer made of a mixed layer of Si and C is formed on the surface of the Ni substrate to have a film thickness of 100 angstrom. In the intermediate layer, as a result of the film formation control shown in FIGS. 3 and 4, the content of C gradually increases and the content of Si gradually decreases from the substrate side toward the surface of the intermediate layer. Become.

Thereafter, the application of the RF voltage from the second high frequency power source (19) is stopped, and the partial pressure of the CH ₄ gas supplied from the reaction gas introducing pipe (16) is maintained at 1.3 × 10 ⁻³ Torr. hand,
Only the film forming process by the ECR plasma CVD apparatus is continued. The above steps are performed for about 25 minutes, and the Ni substrate
On the surface of (11), a diamond-like coating having a film thickness of 2000 angstrom was formed via the intermediate layer.

As described above, by changing the composition ratio of Si and C in the film pressure direction in the intermediate layer composed of the mixed layer of Si and C, the adhesion between the substrate and the diamond-like film can be further enhanced. I can.

In order to evaluate the effects of the present invention, the conventional diamond-like coating without the intermediate layer and the first
Fifty samples each of the diamond-like coating according to the example and the diamond-like coating according to the second example were prepared, and a load test using a Vickers indenter for these coatings.
(Load = 1 kg) was performed to measure the number of samples in which the diamond-like coating was peeled off. Table 1 below shows the results.

[0042]

[Table 1]

As is clear from these results, in the first example in which the intermediate layer is provided, the number of peelings is significantly reduced as compared with the comparative example in which the intermediate layer is not provided. The adhesion of can be improved. Further, in the second embodiment in which the composition of the intermediate layer is controlled, peeling is completely prevented, and the adhesion of the diamond-like coating can be dramatically improved.

In the film forming apparatus of FIG. 1, a plurality of electrodes insulated from each other are formed on the surface of the substrate holder (7).
(8) is arranged, and RF is sequentially applied to these electrodes (8).
Since the voltage is applied, only the substrate (11) on the electrode (8) to which the voltage is applied rises in temperature, and the other substrates drop in temperature due to heat radiation. Therefore, it is possible to perform film formation while the substrate is kept at a low temperature, and deterioration or deformation of the substrate due to overheating is prevented.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or limiting the scope. The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

For example, the substrate holder may have a disc shape as well as a drum shape. In this case, a plurality of substrates are arranged in a circle on the surface of the disc-shaped substrate holder. Then, facing the surface of the substrate holder, the plasma CV
D equipment and high frequency sputtering equipment are installed side by side.

The plasma CVD apparatus is not limited to the ECR plasma CVD apparatus, and various well-known plasma CVD apparatuses such as a high frequency plasma CVD apparatus and a DC plasma CVD apparatus can be adopted.

Further, as the high frequency sputtering device,
It is possible to dispose a plurality of targets to form two or more intermediate layers made of different elements, or to form a single intermediate layer made of a plurality of elements.

[Brief description of drawings]

FIG. 1 is a diagram showing a film forming apparatus according to the present invention.

FIG. 2 is a plan view showing a tip portion of a reaction gas introduction pipe.

FIG. 3 is a graph showing a relationship between a film forming time and a flow rate of a reaction gas in the second embodiment.

FIG. 4 is a graph showing the relationship between the film forming time and the bias voltage in the above.

FIG. 5 is a diagram showing a conventional device.

FIG. 6 is a sectional view showing a state in which a diamond-like coating is formed on a substrate.

[Explanation of symbols]

 (1) Microwave generator (2) Waveguide (3) Microwave introduction window (4) Plasma generation chamber (5) Discharge gas introduction pipe (6) Plasma magnetic field generator (7) Substrate holder (8) Electrode ( 9) First high frequency power supply (10) Vacuum chamber (11) Substrate (16) Reactive gas introduction pipe (17) Brush (18) Target (19) Second high frequency power supply

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiichi Kiyama 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (8)

[Claims] 1. An apparatus for forming a hard carbon film on a substrate via an intermediate layer, comprising: a vacuum chamber; a plasma introducing means for introducing plasma into the vacuum chamber; and a reaction containing carbon in the vacuum chamber. A reaction gas introduction means for introducing a gas, a substrate holder rotatably provided in the vacuum chamber with the surfaces facing each other in the plasma supply direction, and a self-bias generated on the substrate on the substrate holder is negative. As described above, a first high frequency power supply that applies a high frequency voltage to the substrate holder, a target that is disposed in the vacuum chamber toward the surface of the substrate holder, and that includes the source atom of the intermediate layer, and a high frequency voltage is applied to the target. And a second high-frequency power source for the hard carbon film forming apparatus. 2. A plurality of electrodes insulated from each other are arranged on the surface of the substrate holder, and a brush to be slidably contacted with one electrode facing in the plasma supply direction as the substrate holder rotates is fixed. The hard carbon coating forming apparatus according to claim 1, wherein the brush is attached to the first high frequency power source, and the brush is connected to the first high frequency power source. 3. The hard carbon film forming apparatus according to claim 1, wherein the substrate holder is formed in a drum shape. 4. The hard carbon film forming apparatus according to claim 1, wherein the substrate holder is formed in a disc shape. 5. The substrate according to claim 1, wherein the substrate is Ni, stainless steel, or ceramics, and the target contains Si, Ru, or C as a raw material atom of the intermediate layer. Hard carbon film forming equipment. 6. The plasma introducing means is an electron cyclotron resonance plasma CVD apparatus.
The hard carbon film forming apparatus according to any one of 1. 7. A method for forming a hard carbon coating on a substrate through an intermediate layer, wherein a substrate holder to which a plurality of substrates are to be mounted is rotatably disposed in a vacuum chamber, and the substrate holder is rotatably mounted. The target containing the raw material atoms of the intermediate layer is arranged toward the surface of the substrate to form a film forming apparatus. During film formation, a high frequency voltage is applied to the target while rotating the substrate holder, After forming the intermediate layer on the surface of the substrate, while supplying the reaction gas into the vacuum chamber and introducing plasma, while rotating the substrate holder, a high frequency voltage is applied to the substrate holder, and the surface of the intermediate layer. A method for forming a film, which comprises forming a hard carbon film on a substrate. 8. A method of forming a hard carbon coating on a substrate via an intermediate layer, wherein a substrate holder to which a plurality of substrates are to be mounted is rotatably arranged in a vacuum chamber, and the substrate holder is rotatably mounted. A target containing raw material atoms of the main component of the intermediate layer is arranged toward the surface of the substrate to form a film forming apparatus, and at the time of film formation, a reaction gas is supplied into the vacuum chamber and plasma is introduced to the substrate. While the holder is rotated, a high frequency voltage is applied to the target at the same time as a high frequency voltage is applied to the substrate holder, and the flow rate of the reaction gas is gradually increased during the film formation process, and at the same time, the high frequency voltage to be applied to the target. Is reduced to form an intermediate layer on the surface of the substrate in which the carbon content gradually increases toward the surface and the target atom content gradually decreases. After the formation, the application of the high frequency voltage to the target is stopped, and the hard carbon coating is formed on the surface of the intermediate layer.