JPH0741386A - Substrate coated with diamond-like film and formation thereof - Google Patents

Abstract

PURPOSE:To provide a substrate coated with a diamond-like film and formation thereof by which adhesion between the substrate such as an electric shaver blade and the diamond-like coating film has been improved and peeling of the diamond-like film is decreased. CONSTITUTION:A diamond like coating film with an intermediate layer essentially comprising Ru is formed on a substrate 7 essentially comprising Ni or Al or consisting of stainless steel in the following processes. In the first process, the substrate in a chamber 8 is radiated with ions of inert gas. Simultaneously, Ru atoms are radiated from a vapor source 13 to the substrate to form the intermediate layer comprising Ru on the surface of the substrate 7. In the second process, a reaction gas containing carbon is supplied to the vacuum chamber 8 and changed into plasma. This plasma is made to radiate the intermediate layer to form a diamond-like coating film on the surface of the intermediate layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diamond-like coating formed on the surface of a substrate such as an electric razor blade for the purpose of improving its characteristics and protecting the surface, and in particular the adhesion between the substrate and the diamond-like coating. The present invention relates to a diamond-like coated substrate excellent in heat resistance and a method for forming the same.

[0002]

2. Description of the Related Art Conventionally, in order to improve the adhesion between a substrate and a diamond-like coating, it has been proposed to form an intermediate layer between the substrate and the diamond-like coating,
For example, in JP-A-1-317197, plasma C
A technique is disclosed in which an intermediate layer containing silicon (Si) as a main component is formed on a substrate by the VD method, and a diamond-like coating is formed on the intermediate layer. This makes it possible to improve the adhesion of the diamond-like coating to the substrate as compared with the case where the diamond-like coating is directly formed on the substrate such as the ceramics substrate or the Si substrate.

[0003]

However, the above-mentioned prior art assumes the case where a diamond-like film is formed on a substrate such as a ceramic substrate or a Si substrate, and nickel (Ni) which is often used for electric razor blades and the like. The case of forming a diamond-like coating on aluminum, aluminum (Al), or stainless steel has not been studied. For example, an intermediate layer of SiC or Si ₃ N ₄ is formed on a Ni substrate, and the diamond-like coating is formed on the intermediate layer. When formed, the diamond-like coating may peel off due to insufficient adhesion strength.

Therefore, it was unclear what kind of intermediate layer is most suitable for a substrate such as an electric razor blade.

The present invention has been made in view of the above circumstances, and is a diamond-like film in which the adhesion between a substrate such as an electric razor blade and the diamond-like film is improved and the occurrence of peeling of the diamond-like film is reduced. An object is to provide a coated substrate and a method for forming the same.

[0006]

The diamond-like coating substrate of the present invention comprises a diamond-like coating on a substrate containing Ni or Al as a main component through an intermediate layer containing Ru as a main component, or made of stainless steel. It is characterized in that it is provided on the substrate, and that the intermediate layer is a mixed layer of Ru and C having a composition ratio gradient structure.

The first diamond-like coated substrate forming method according to the present invention comprises:
Alternatively, by radiating an inert gas ion toward a substrate containing Al as a main component or a substrate made of stainless steel, and simultaneously radiating Ru atoms from the evaporation source toward the substrate, Ru on the surface of the substrate. A first step of forming an intermediate layer consisting of: a reaction gas containing carbon supplied into the vacuum chamber is converted into a plasma, and the plasma is radiated toward the intermediate layer to form a diamond-like pattern on the surface of the intermediate layer. And a second step of forming a coating film.

Further, in the second diamond-like coated substrate forming method of the present invention, the reaction gas containing carbon supplied into the vacuum chamber is made into plasma so that the gas supply amount is gradually increased to a predetermined value, and the plasma is converted into the above-mentioned plasma. Radiate toward a substrate containing Ni or Al as a main component or a substrate made of stainless steel placed in a vacuum chamber and at the same time radiate an inert gas ion toward the substrate, and at the same time, from the evaporation source to Ru. A first step of forming an intermediate layer made of a mixed layer of Ru and C on the surface of the substrate by radiating atoms toward the substrate so that the evaporation rate is gradually reduced to zero; Forming a diamond-like coating on the surface of the intermediate layer by converting the reaction gas containing carbon supplied to the plasma into plasma and radiating the plasma toward the intermediate layer. It is characterized by comprising two steps.

[0009]

According to the present invention, the diamond-like coating which improves the adhesion between the substrate containing Ni or Al as a main component or the substrate made of stainless steel and the diamond-like coating and reduces the occurrence of peeling of the diamond-like coating. A coated substrate is formed.

Further, according to the method for forming a diamond-like coated substrate of the present invention, since the energy of ions is used for forming the intermediate layer in the first step, the intermediate layer is firmly adhered to the substrate by ion implantation.

Further, according to the second diamond-like coated substrate forming method of the present invention, the intermediate layer having the composition ratio gradient structure is formed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an embodiment thereof. FIG. 1 is a schematic sectional view showing an apparatus for forming a diamond-like coated substrate of the present invention.

In FIG. 1, reference numeral 1 denotes a microwave supply means, and the microwave generated by the microwave supply means 1 is guided to a plasma generation chamber 4 through a waveguide 2 and a microwave introduction window 3. . Reference numeral 5 is a discharge gas introduction tube for introducing a discharge gas such as argon (Ar) gas into the plasma generation chamber 4, and reference numeral 6 is a plasma magnetic field generator disposed around the plasma generation chamber 4, which is a high frequency magnetic field generated by microwaves and plasma. By applying a magnetic field from the magnetic field generator 6, high density plasma is formed in the plasma generation chamber 4. Then, this plasma is guided to the vacuum chamber 8 in which the substrate 7 is arranged along the divergent magnetic field generated by the plasma magnetic field generator 6.

Therefore, an ECR (electron cyclotron resonance) composed of the microwave supply means 1, the waveguide 2, the microwave introduction window 3, the plasma generation chamber 4, the discharge gas introduction pipe 5 and the plasma magnetic field generator 6 is provided. The plasma flow from the plasma CVD apparatus will be emitted to the substrate 7.

Here, the substrate 7 is mounted on the peripheral side surface of a cylindrical substrate holder 9 which is rotatably provided around an axis (not shown) pivotally mounted perpendicularly to the back surface of the vacuum chamber 8. This is a board, and a plurality of boards 7 are attached at equal intervals. In this embodiment, nickel (Ni) is used as the substrate 7.
Several tens of substrates are mounted on the peripheral side surface of the substrate holder 9. As a result, the number of substrates that can be processed by one evacuation can be increased.

Reference numeral 10 denotes a reaction gas introducing pipe for introducing methane (CH ₄ ) gas as a raw material gas into the vacuum chamber 8, which is composed of a gas introducing portion 10a and a gas releasing portion 10b, which will be described later, and the introduced CH. ₄ Gas is decomposed by the action of plasma. A high frequency power source (13.56 MHz) 11 applies a predetermined high frequency voltage (RF voltage) to the substrate holder 9 to generate a negative self-bias (-50 V) on the substrate 7. This is because the moving speed of the ions due to the electric field in the plasma is slower than that of the electrons, so that the electrons can follow the fluctuation of the potential while the RF voltage is applied, but the ions cannot. Therefore, when an RF voltage is applied to the substrate 7, many electrons are emitted to the substrate 7 and a negative self-bias is generated in the substrate 7,
Positive ions in the plasma are drawn in, and a diamond-like coating is formed on the substrate 7.

Reference numeral 12 denotes a metallic cylindrical shield cover provided at a predetermined distance so as to surround the peripheral side surface of the substrate holder 9, and is connected to the ground electrode. The shield cover 12 has an RF applied to the substrate holder 9 when the film is formed.
It is provided in order to prevent electric discharge from being generated between the substrate holder 9 and the vacuum chamber 8 other than the film forming portion due to the voltage, and the gap between the substrate holder 9 and the shield cover 12 is equal to or less than the mean free path of electrons. The distance is set to. This sets the gap between the substrate holder 9 and the shield cover 12 to be equal to or less than the mean free path of electrons, that is, equal to or less than the average distance that electrons generated for some reason are accelerated by the electric field and can move without colliding with gas atoms. This reduces the probability of electrons colliding with gas atoms and prevents avalanche ionization.

Therefore, in order to prevent the discharge from occurring at a place other than the film forming portion, it is necessary to set the gap between the substrate holder 9 and the shield cover 12 to a distance equal to or less than the mean free path of electrons, and especially the mean of electrons. It is effective when the distance is less than 1/10 of the free path. In this embodiment, the gap between the substrate holder 9 and the shield cover 12 is about 5 mm, which is 1/10 or less of the mean free path of electrons.

Reference numeral 13 denotes an evaporation source that evaporates ruthenium (Ru) atoms, which is a constituent material of the intermediate layer, by an electron beam and radiates the atoms toward the substrate 7, and 14 applies energy to the constituent material evaporated from the evaporation source 13. , Supply an inert gas,
It is an ion gun that emits the ions. In this embodiment, Ar gas is supplied as the inert gas.

Reference numeral 15 is a first opening provided in the upper part of the shield cover 12 below the plasma generation chamber 4, and the plasma flow extracted from the plasma generation chamber 4 through the first opening 15 is tubular. The substrate 7 mounted on the substrate holder 9 is radiated. Reference numeral 16 denotes a second opening provided in the lower part of the shield cover 12, and the constituent materials from the evaporation source 13 and the ion gun 14 and Ar ions are attached to the substrate holder 9 through the second opening 16. The radiation is emitted to the substrate 7.

As shown in FIG. 2, the reaction gas introducing pipe 10 is connected to the gas introducing portion 10a for introducing CH ₄ gas from the outside into the vacuum chamber 8 and a T-shaped connection to the introducing portion 10a. It is composed of a gas releasing portion 10b. The gas discharge part 10b is arranged perpendicularly to the rotation direction of the substrate holder 9 and is attached so as to be located on the upstream side in the rotation direction above the first opening 15. A plurality of holes 17 (eight in this embodiment) are formed in the gas discharge portion 10b in a direction of about 45 degrees downward in the rotation direction, and the pitch of the holes 17 is set to the gas introduction portion. It is the largest on the 10a side, and gradually decreases as it goes away from the gas introduction portion 10a. As a result, the CH introduced from the introduction unit 10a
_{The four} gases are evenly ejected from the holes 17 of the discharge part 10b.

As described above, since the surface of the substrate 7 has the film forming means by the ECR plasma CVD apparatus and the film forming means by the evaporation source 13 and the ion gun 14, the diamond-like film forming step and the intermediate layer forming step. Can be controlled individually, and a desired intermediate layer can be easily formed on the substrate.

Next, regarding the method of forming an intermediate layer containing Ru as the main component on the surface of the Ni substrate 7 using the apparatus of FIG. 1 and forming a diamond-like coating thereon, the Ru layer is used as the intermediate layer. The case of forming and the case of forming a mixed layer of Ru and carbon (C) will be described below as first and second examples, respectively.

First, as the first embodiment, R is formed on the surface of the substrate 7.
A case where an intermediate layer of the u layer is provided and a diamond-like film is formed on the intermediate layer will be described.

First, dozens of Ni substrates 7 are mounted on the peripheral side surface of the substrate holder 9 at equal intervals. Then, the inside of the vacuum chamber 8 is evacuated to 10 ⁻⁵ to 10 ⁻⁷ Torr, and the substrate holder 9 is moved to about 10 rp.
Rotate at a speed of m. Next, Ar gas is supplied to the ion gun 14 to take out Ar ions and irradiate them on the surface of the substrate 13. The acceleration voltage of Ar ions at this time is 400e
V and ion current density were set to 0.3 mA / cm ² . On the other hand, Ar
At the same time as the emission of ions, the evaporation source 13 is driven to evaporate Ru atoms and emit them to the surface of the substrate 7. The evaporation rate of Ru at this time was set to 420 Å / min in terms of the film formation rate on the substrate 7.

The above steps were carried out for about 5 minutes to form an intermediate layer of Ru layer having a film thickness of 200Å on the surface of the substrate 7.

Next, the emission of Ru atoms and Ar ions from the evaporation source 13 and the ion gun 14 is stopped, and the ECR plasma C
Flow rate of Ar gas from the discharge gas introduction pipe 5 of the VD device is 40 sccm
Microwave supply means 1 to 2.45GH
Microwaves of z and 100 W are supplied to irradiate the Ar plasma formed in the plasma generation chamber 4 on the surface of the substrate 7.
At the same time, the self-bias generated on the substrate 7 is -50V.
So that the RF voltage of 13.56 MHz is applied from the high frequency power source 11 to the substrate holder 12 so that CH ₄
Gas is supplied at a flow rate of 100 sccm.

The above steps were carried out for about 15 minutes to form a diamond-like film having a film thickness of 1200 Å on the intermediate layer formed on the substrate 7. Therefore, as a result of the above two steps, a diamond-like coating is formed on the surface of the substrate 7 via the intermediate layer of the Ru layer.

Next, as a second embodiment, R is formed on the surface of the substrate 7.
A case will be described in which an intermediate layer which is a mixed layer of u and C is provided and a diamond-like coating is formed thereon.

First, as in the case of the first embodiment, several tens of Ni substrates 7 are mounted on the peripheral side surface of the substrate holder 9 at equal intervals, and the inside of the vacuum chamber 8 is set to 10 ^-5 to 10 ^-7 Torr. Exhaust to
The substrate holder 9 is rotated at a speed of about 10 rpm.

Next, Ar gas is supplied from the discharge gas introduction pipe 5 of the ECR plasma CVD apparatus at a flow rate of 40 sccm, and microwaves of 2.45 GHz and 100 W are supplied from the microwave supply means 1 to the inside of the plasma generation chamber 4. Formed on Ar
Plasma is radiated onto the surface of the substrate 7. At the same time, an RF voltage of 13.56 MHz is applied from the high frequency power source 10 to the substrate holder 9 so that the self-bias generated on the substrate 7 becomes −50 V, and CH ₄ gas is supplied from the reaction gas introducing pipe 10.
At this time, the CH ₄ gas supply flow rate was gradually increased as time elapsed as shown in FIG. 3, and was set to 100 sccm after 5 minutes.

Then, in this ECR plasma CVD apparatus
Simultaneously with the film formation process by the ion gun on the surface of the substrate 7.
It emits Ar ions from 14 and the Ru source from the evaporation source 13.
Let the child radiate. The acceleration voltage of Ar ions at this time is 400e
V, ion current density 0.3mA / cm ²Set to, the evaporation rate of Ru
4 is converted into a film formation rate on the substrate 7 as shown in FIG.
From 420Å / min to 5 minutes
It was set to be 0 Å / min after passing. And Ru's
When the evaporation rate reaches 0Å / min, that is, after 5 minutes,
Stop the emission of Ar ions from Ongun 14.

The above steps are carried out for about 5 minutes to form a mixed layer structure of Ru and C having a total film thickness of 200 Å on the surface of the substrate 7, and the Ru content gradually decreases as the distance from the surface of the substrate 7 increases. An intermediate layer was formed whose amount gradually increased as the distance from the surface of the substrate 7 increased.

Next, CH supplied from the reaction gas introducing pipe 10
The supply flow rate of the ₄ gases is set to be constant at 100 sccm, and the film forming process by the ECR plasma CVD apparatus in the above step is continuously performed.

The above steps were carried out for about 15 minutes to form a diamond-like film having a film thickness of 1200 Å on the intermediate layer on which the substrate 7 was formed.

Therefore, as a result of the above two steps, the substrate 13
Thus, a diamond-like coating is formed on the surface of the intermediate layer of the mixed layer of Ru and C having a compositional gradient structure.

Next, in Table 1, (a) the first step of forming the intermediate layer in the above-mentioned first embodiment is not carried out, and only the second step of forming the diamond-like film is carried out for about 15 minutes, and the diamond is directly deposited on the Ni substrate. A case where a diamond-like coating is formed, (b) a case where the intermediate layer of the Ru layer is formed on the Ni substrate using the first embodiment described above, and a diamond-like coating is formed thereon, (c) the second embodiment
In the case where the intermediate layer of the mixed layer of Ru and C is formed on the Ni substrate and the diamond-like coating is formed on the Ni substrate by using the embodiment, and (d) in the first embodiment, the evaporation source 13 of Ru atoms Instead, Si atoms are evaporated to form an intermediate layer of the Si layer on the Ni substrate, and the diamond-like coating is formed on the intermediate layer. The evaluation test was carried out by a constant load (load = 1 kg) indentation test using a Vickers indenter. Table 1 shows the number of peeled diamond-like coatings on the Ni substrate due to this test. However, the number of test substrates for each coating treatment was 50.

[0038]

[Table 1]

From Table 1, in the case of the treatment (a), the number of peeling occurrences was as large as 43, and when the diamond-like coating was formed directly on the Ni substrate without providing the intermediate layer, the diamond-like coating was formed. It can be seen that the adhesion of the coating is poor. On the other hand, in the case of the treatments (b) to (d) in which the intermediate layer is formed and the diamond-like coating is formed on the intermediate layer, the number of peeling occurrences is 7, 0 and 16 respectively. The value is considerably lower than that in the above case, and it is clear that the adhesion of the diamond-like coating is improved. It is considered that one of the factors is to alleviate the thermal stress, which has conventionally been caused by the difference in thermal expansion coefficient between the substrate 7 and the diamond-like coating, due to the presence of the intermediate layer.

Further, in the case of the treatment (B) in which the intermediate layer of the Ru layer is formed on the Ni substrate and the diamond-like coating is formed thereon, the number of peeling occurrences is 7, whereas on the Ni substrate In the case of the treatment (d) in which the intermediate layer of the Si layer is formed on and the diamond-like coating is formed thereon, the number of peeling occurrences is 16, and conventionally, the diamond-like coating is formed on the ceramic substrate or the Si substrate. It can be seen that the Ru layer is superior in adhesion between the coatings to the Ni substrate as compared with the Si layer which is said to be most suitable as the intermediate layer. In particular, in the case of treatment (c), that is, an intermediate layer of a mixed layer of Ru and C having a composition ratio gradient structure is formed on a Ni substrate,
When a diamond-like coating is formed on it, the number of occurrences of peeling is 0, which shows that the adhesion between the coatings is excellent. It is considered that this is because the formation of the interface between the coatings is prevented by forming the intermediate layer as a mixed layer of Ru and C having a graded content ratio.

Further, the same evaluation test was carried out when Al and stainless steel were used as the substrate 7, but substantially the same results as in the case of the above Ni substrate were obtained.

Therefore, when a diamond-like coating is formed on a substrate made of Ni, Al, or stainless steel,
By providing the intermediate layer containing Ru and forming the diamond-like coating on it, the adhesion between the substrate and the diamond-like coating can be improved, and the occurrence of peeling of the diamond-like coating can be reduced. Furthermore, by forming the intermediate layer as a mixed layer of Ru and C having a compositional gradient structure, it becomes possible to further improve the adhesion between the substrate and the diamond-like coating.

In the above-mentioned embodiment, the case where the ECR plasma CVD apparatus is used for forming the diamond-like film is explained, but other various plasma CVD apparatuses,
For example, high-frequency plasma CVD device and DC plasma CVD
A device or the like may be used.

In the above embodiment, since the intermediate layer containing Ru as the main component is formed on the substrate, the ECR plasma CV is used.
The case of forming a film by using the evaporation source 13 and the ion gun 14 in addition to the D device has been described. In addition to this, an intermediate layer containing Ru as a main component is formed on the substrate by plating, or A source gas containing Ru may be supplied from the reaction gas introducing pipe 10 of the ECR plasma CVD apparatus to form an intermediate layer containing Ru as a main component on the substrate. However, in this case, it is more difficult to control the film quality of the intermediate layer than in the case of the above-mentioned embodiment, and there is a possibility that the adhesion is slightly inferior.

[0045]

As described above, according to the present invention, Ni,
Alternatively, since an intermediate layer containing Ru as a main component is interposed between the substrate containing Al as a main component or a substrate made of stainless steel and the diamond-like film, the adhesion between the two is improved and the diamond-like film is formed. It is possible to form a diamond-like coated substrate with reduced occurrence of peeling.

Further, according to the method for forming a diamond-like coated substrate of the present invention, since the energy of ions is used for forming the intermediate layer in the first step, the intermediate layer can be firmly adhered to the substrate by ion implantation. .

Further, according to the second diamond-like film substrate forming method of the present invention, since the intermediate layer having the composition ratio of the graded structure is formed, the adhesion between the substrate and the diamond-like film is further improved. It becomes possible.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an apparatus for forming a hard carbon film as one embodiment of the present invention.

FIG. 2 is a plan view of a reaction gas introducing pipe.

FIG. 3 shows time and reaction when using the apparatus of FIG. 1 embodiment.
CH supplied from gas inlet pipe 10 _FourThe relationship with the gas flow rate
FIG.

FIG. 4 is a diagram showing a relationship between time and an evaporation rate of Ru radiated from an evaporation source 13 when the apparatus of FIG. 1 embodiment is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microwave supply means 2 Waveguide 3 Microwave introduction window 4 Plasma generation chamber 5 Discharge gas introduction tube 6 Magnetic field generation means 7 Substrate 8 Vacuum chamber 9 Cylindrical substrate holder 10 Reactive gas introduction tube 11 High frequency power supply 12 Cylindrical shield cover 13 Evaporation source 14 Ion gun 15 First opening 16 Second opening

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[Procedure amendment]

[Submission date] February 18, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

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

Claims (4)

[Claims] 1. A diamond-like coating provided on a substrate containing Ni or Al as a main component or on a substrate made of stainless steel via an intermediate layer containing Ru as a main component. substrate. 2. The diamond-like coated substrate according to claim 1, wherein the intermediate layer is a mixed layer of Ru and C having a composition ratio gradient structure. 3. Irradiating an inert gas ion toward a substrate containing Ni or Al as a main component or a substrate made of stainless steel, which is placed in a vacuum chamber, and at the same time,
A first step of forming an intermediate layer of Ru on the surface of the substrate by radiating Ru atoms toward the substrate from an evaporation source; and converting the reaction gas containing carbon supplied into the vacuum chamber into plasma, A second step of forming a diamond-shaped coating film on the surface of the intermediate layer by radiating the plasma toward the intermediate layer, the method for forming a diamond-shaped coating substrate. 4. A reaction gas containing carbon, which is supplied into the vacuum chamber so as to gradually increase the gas supply amount to a predetermined value, is made into plasma, and the plasma is mainly composed of Ni or Al arranged in the vacuum chamber. To emit a substrate made of stainless steel or a substrate made of stainless steel and emit ions of an inert gas toward the substrate, and at the same time, to reduce Ru atoms from the evaporation source to a zero value. A first step of forming an intermediate layer composed of a mixed layer of Ru and C on the surface of the substrate by radiating toward the substrate; and converting the reaction gas containing carbon supplied into the vacuum chamber into plasma, A second step of forming a diamond-like coating on the surface of the intermediate layer by irradiating the intermediate layer with a diamond-like coating substrate.