JP3236848B2 - Electrical component - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for coating carbon or a carbon-based film having an optical energy bandwidth of 1.0 eV or more, particularly 1.5 to 5.5 eV, on a surface of a member for electric use. These solid surface reinforcements,
Alternatively, the present invention relates to a composite for obtaining a protective material against mechanical stress.

[0002]

2. Description of the Related Art Regarding the coating of a carbon film, a patent application “composite having a carbon film and a method for producing the same” filed by the present inventor (Japanese Patent Application No. 56-146930, filed on Sep. 17, 1981) It has been known. In addition, the carbon film has many characteristics such as high smoothness and high thermal conductivity at the same time as being a wear-resistant material, and is expected to be applied to electric parts and the like.

[0003] Carbon or carbon having an amorphous (amorphous) having a hardness similar to diamond or a semi-amorphous (semi-amorphous) structure having a microcrystalline size of 5 to 200 mm is formed on a surface to be formed. In the case of forming a film containing a main component, in the vicinity of a high-frequency application electrode provided with a substrate having a surface to be formed, positive ions accelerated by self-bias generated by accumulation of electrons in plasma at the high-frequency application electrode ( For example, by colliding H ⁺ ) with carbon or a film containing carbon as a main component, the carbon film containing carbon or carbon as a main component is formed into a carbon film having a higher hardness and a structure close to diamond. I've been making things. This is because positive ions collide with C
= C by reducing the proportion of carbon having a double bond such as C
By increasing the number of carbons that can be bonded to the --C bond or by eliminating hydrogen atoms bonded to carbon atoms, so-called three-way carbons having sp ² hybridized orbitals or so-called two-way carbons having sp hybridized orbitals are eliminated and sp ³ hybridized This is because diamond bonding is easily caused by increasing the ratio of so-called tetragonal carbon having orbits. Therefore, when an attempt is made to form carbon having a higher hardness or a coating containing carbon as a main component, the self-bias generated between the electrodes must be increased to increase the acceleration of positive ions. The methods used to increase this self-bias include:
First, there is a method of reducing the reaction pressure. This is because the number of hydrocarbon gas molecules contained in a unit volume is reduced by reducing the pressure of the hydrocarbon or the hydrocarbon gas used for forming a film containing carbon as a main component,
This is based on the fact that the output of the high-frequency energy applied to relatively decompose the gas increases and the electrons in the plasma increase and are accumulated in the high-frequency application electrode, so that the self-bias increases.

There is also a method of increasing the output of high-frequency energy. However, as described above, when the energy for decomposing gas increases, the electrons in the plasma increase. This is because the self-bias increases due to the increase.

[0005]

However, in the case of forming a carbon film having high hardness or a film containing carbon as a main component on the surface to be formed by such a method, the film is formed by increasing the self-bias. Therefore, positive ions having a large kinetic energy accelerated by a large self-bias collide with carbon or a film containing carbon as a main component during the film formation, and also collide with the surface to be formed. As a result of the sputtering, it has been difficult to form a carbon film having a high hardness or a film containing carbon as a main component without damaging the surface to be formed. In addition, a film having high hardness has poor consistency with the surface to be formed due to expansion, shrinkage, stress, or the like of the surface to be formed or carbon or a film containing carbon as a main component, and causes peeling or detachment. It was bad.

The present invention solves the above problems and has an optical energy bandwidth (Eg) of 1.0 eV or more, preferably 1.5 to 5.5 eV, and a Vickers hardness of 2000 kg / mm ² or more. preferably 4500 kg / mm ² or more, ideally amorphous with microcrystalline size of the amorphous or 5 to 200 DEG Å having insulation properties and hardness similar to diamond that 6500Kg / mm ² (semi-amorphous) It mainly contains carbon having a structure or so-called carbon in which hydrogen and halogen elements are 25 atomic% or less, or trivalent or V-valent impurities are 5 atomic% or less, and nitrogen is added at a concentration of N / C ≦ 0.05. The object is to provide carbon as a component on a surface to be formed with good adhesion and good consistency with the surface to be formed.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides direct current or high frequency energy between a first electrode and a second electrode provided in contact with a substrate having a surface to be formed. In addition, in the method of forming a coating containing carbon or carbon as a main component on the surface to be formed by causing a decomposition reaction of a hydrocarbon gas or an additive gas in addition to the generated gas with the generated plasma, When forming a film containing carbon as a main component, carbon or carbon formed by reducing the reaction pressure, increasing the high-frequency energy, changing the amount of additive gas added, or using a combination of these conditions is mainly used. The hardness of the coating film as a component is increased from the surface on which the film is formed toward the surface.

That is, the present invention is intended to coat carbon or a film containing carbon as a main component on the surface to be formed and to reinforce mechanical strength such as abrasion resistance on the surface.
For this purpose, instead of directly forming a carbon film having a hardness similar to diamond or a film containing carbon as a main component on the surface to be formed, the hardness is gradually increased from a portion close to the surface to be formed, and a desired hardness is obtained. It is characterized in that the reaction pressure is reduced, the high-frequency energy is increased, or the amount of additive gas is changed so that carbon or a carbon-based film having a desired hardness can be obtained when the film thickness is large.

In order to form a film having a hardness similar to diamond directly on the surface to be formed, the self-bias must be increased to form a film containing carbon or carbon as a main component. Sputtering on the surface to be formed cannot be avoided, but carbon or a film containing carbon as a main component that is close to the surface to be formed has a hardness of carbon that can be formed with a self-bias that does not damage the surface to be formed. Alternatively, a film containing carbon as a main component is formed, and a film whose hardness is gradually increased is laminated, and a carbon film having a desired hardness or a film containing carbon as a main component is formed on the surface. Carbon or a coating containing carbon as a main component, which has good close contact with carbon and has high hardness.

In this case, as shown in FIG. 6A, a method of laminating a film having a small hardness from a film having a small hardness into several layers, and a method of continuously increasing the hardness as shown in FIG. Alternately, there is a method of forming a carbon or a coating containing carbon as a main component whose hardness continuously changes in a single layer. In the present invention, as a method of increasing the self-bias, a method of reducing the reaction pressure, a method of increasing the high-frequency energy, a method of changing the amount of the additive gas, and a method of combining two or three of the above three methods There is.

The surface to be formed used in the present invention is P
ET (polyethylene terephthalate), PES, PMM
A, an organic resin base such as Teflon (registered trademark), epoxy, polyimide or the like, a metal mesh carrier, a tape carrier such as paper, glass, metal, ceramic, semiconductor, a member for a magnetic head, a magnetic disk, and the like. Hereinafter, the present invention will be described specifically with reference to Examples.

[0012]

[Embodiment 1] FIG. 1 shows an outline of a plasma CVD apparatus for forming carbon or a film containing carbon as a main component of the present invention. In the drawing, in the doping system (1), hydrogen as a carrier gas is converted from (2) to hydrocarbon gas as a reactive gas such as methane and ethylene from (3) to diborane (diluted with hydrogen) (III), ), V-impurity ammonia or phosphine from (5)
(6) is introduced into the reaction system (8) through the nozzle (9) through the flow meter (7). Before reaching the nozzle, it is effective to add microwave energy (10) to excite the reactive gas to activate it in advance.

The reaction system (8) was provided with a first electrode (11) and a second electrode (12). In this case, the condition of (first electrode area / second electrode area) <1 was satisfied. A pair of electrodes (1
A high frequency power supply (13) and a matching transformer (1)
4) Electric energy is applied from the DC bias power supply (15), and plasma is generated. Exhaust system (16) is pressure regulating valve
(17), unnecessary gas is exhausted through the turbo molecular pump (18) and the rotary pump (19). The reaction space
The pressure at (20) is 0.001 to 10 torr, typically 0.01 to 0.
With high frequency or DC energy under 5torr
0.1-5KW of energy is applied. Especially the excitation source is 1GH
_Z above, for example In the frequency of 2.45 GHz _Z, to separate hydrogen from the CH bond, further frequency source CC bonds In the frequency of 0.1 ～50MH _Z for example 13.56 MHz, to decompose the C = C bond, A -CC- bond is formed, and unpaired carbon atoms collide with each other to form a covalent bond, thereby forming a structure locally having a stable diamond structure.

The DC bias is -200 to 600 V (effectively -4
00 to + 400V). This is because when the DC bias is zero, the self-bias has -200 V (the second electrode is at the ground level). The reactive gas was partially diluted with hydrogen. For example, methane: hydrogen = 1: 1. The first electrode has a cooling means, and controls the temperature on the formation surface.
It was kept at 250--100 ° C.

In the present invention, the surface to be formed is placed on the cathode electrode. This is because when comparing the film quality of the carbon film formed when the surface to be formed is placed on the anode side and when the film surface is placed on the cathode side, the direction when the surface to be formed is placed on the cathode side as shown in FIG. This is because a carbon film having high hardness can be obtained at a high film forming rate. In FIG. 2, ○ indicates a stylus type surface roughness meter,
Indicates a film thickness measured by an ellipsometer, and △ indicates a refractive index of the film measured by an ellipsometer. The experimental conditions were: high frequency energy 60W, pressure 0.015torr, methane flow rate 100S
CCM was performed at a substrate temperature of room temperature and a film formation time of 180 minutes.

As described above, the Vickers hardness of 2000 kg / mm ² or more is formed on the surface to be formed by the plasma.
Amorphous carbon with a large number of CC bonds with thermal conductivity of 2.5 W / cm deg or higher was formed. In addition, this electromagnetic energy is 50
Supplying W ~1KW, it was added plasma energy 0.03~3W / cm ² per unit area.

FIG. 3 shows the film forming speed and the Vickers hardness of the film when the carbon film was formed by changing the high-frequency energy applied in the apparatus used in the present invention. The higher the applied high frequency energy, the harder the film is formed. FIG. 4 shows the film forming speed and the Vickers hardness of the film when the carbon film was formed by changing the reaction pressure. The smaller the reaction pressure, the harder the film is formed. FIG. 5 shows the relationship between the applied high frequency energy, the reaction pressure, and the self-bias. The higher the high-frequency energy, the greater the self-bias, and the lower the reaction pressure, the greater the self-bias. From FIG. 5, FIG. 3, and FIG. 4, it can be seen that the larger the self-bias, the harder the carbon film formed.

In the apparatus shown in FIG. 1, a carbon film was formed on a substrate having a surface to be formed by the method of the present invention.
First, methane to which hydrogen was added from the nozzle was added to the reaction system for 10 minutes.
Introduced at a flow rate of 0 SCCM, the pressure was maintained at 0.03 torr, high frequency energy of 50 W was applied to methane, and a 15 Ω potential was applied on a Si substrate maintained at room temperature under the condition of self-bias -150 V.
A film was formed for 0 minutes to form a first layer. Next, methane to which hydrogen was added was introduced from the nozzle at a flow rate of 100 SCCM, the pressure was maintained at 0.015 torr, and 100 W
Is applied, and the surface to be formed is maintained at 150 ° C. under the condition of self-bias of −200 V to form a film for 150 minutes to form a second layer. Then, methane added with hydrogen was introduced from the nozzle onto the second layer at a flow rate of 100 SCCM,
The reaction system was maintained at 0/015 torr, high-frequency energy of 200 W was applied to methane, and the surface to be formed was maintained at room temperature under the condition of self-bias of -280 V to form a film for 60 minutes to form a third layer. When the Vickers hardness of these three layers was measured, the first layer was 2200 kg / mm ² , and the second layer was 35 kg / mm ² .
00Kg / mm ^2, the third layer could be formed with good adhesion between the forming surface of carbon film having a surface hardness of and diamond-like a 4200Kg / mm ^2,.

Example 2 Hydrogen-added methane was introduced at a flow rate of 100 SCCM into a reaction system on which a substrate having a surface to be formed was placed, and the pressure was maintained at 0.03 torr.
A high-frequency energy of 0 W was applied to form a film for 150 minutes to form a first layer. Next, a second layer was formed on the first layer under the same conditions as the first layer except that the high-frequency energy for methane was 150 W. And the second
The layer was formed under the same conditions as the first layer except that a film was formed at a high frequency energy of 300 W for 60 minutes on the layer. As a result, 2200 kg / mm ² , 3800 kg / mm ² , 5000 kg / m
A carbon film comprising a first layer, a second layer, and a third layer having a Vickers hardness of m ² was formed. This carbon film had a surface hardness of 5000 kg / mm ² , similar to diamond, and was excellent in wear resistance, high thermal conductivity and high smoothness.

In this embodiment, the hardness of the carbon film is increased by increasing only the output of the high-frequency energy, but the same effect can be obtained by decreasing only the reaction pressure, as described above. In this embodiment, each carbon film layer is formed using one reaction chamber. However, each layer may be formed in a different reaction chamber by connecting a plurality of reaction chambers.

[Embodiment 3] In this embodiment, instead of laminating layers having different hardnesses on the surface to be formed, the high-frequency energy is continuously increased so that the carbon whose hardness is continuously changed is changed. A film was formed. First, film formation is started under the same conditions as those for forming the first layer in Example 1, and then the high-frequency energy is increased at a rate of 0.7 to 2 W / min to 300 W until the film is formed. A carbon film was formed on the surface. The formed carbon film had a Vickers hardness of 4000 Kg / mm ^{2 on} the surface and was excellent in wear resistance, high thermal conductivity, and high smoothness.

In this embodiment, only the high-frequency energy is continuously increased. However, only the reaction pressure may be continuously reduced. Alternatively, the high-frequency energy may be continuously increased and the reaction pressure may be continuously reduced. May be. Further, the amount of the additive to be added to the reactive gas may be continuously changed, and the method of the present invention can be carried out by combining the change of the additive with an increase in the high-frequency energy or a decrease in the reaction pressure. .

[Embodiment 4] In this embodiment, before forming a carbon film on a surface to be formed, the surface to be formed is disposed in an atmosphere of an inert gas or hydrogen activated by plasma. After removing contaminants or foreign substances such as oxides, carbides or nitrides, a carbon film was formed. Means for plasma of inert gas or hydrogen, 0.1 ~100MH _Z
Using a microwave frequency and 1 ~10GH _Z, energy applied is sufficient 10～1000W. The pressure of the reaction system at the time of plasma conversion is 10 ^-3 torr or more, typically 0.01 to 200 t
orr is preferably 1 to 10 torr. Under the above conditions, the inert gas or hydrogen is plasma-activated, and the activated hydrogen or the inert gas causes oxides, dirt, hydroxides, and / or the surface of these to be localized on the surface to be formed. Removed tension and physical adsorption force. After such a treatment, a carbon film was formed on the surface to be formed according to Example 1, Example 2, or Example 3. The obtained carbon film was excellent in adhesion to the surface to be formed.

[0024]

As described above, the carbon-based or carbon-based film produced by the method of the present invention has a close contact with the carbon-based or carbon-based film on the surface to be formed. A carbon or carbon-based coating with a hardness that can be made with a self-bias level that is as low as possible, a film with a gradually increased hardness is laminated, and carbon or carbon with the desired hardness is mainly deposited on the surface. Because it has a coating as a component, it has a hardness similar to diamond with excellent adhesion to the surface on which it is to be formed. It was very effective for an electrical member.

Particularly, the obtained carbon or a coating containing carbon as a main component has a thermal conductivity of 2.5 W / cm deg or more, typically 4.0 W / cm deg.
~ 6.0 W / cm deg and close to 60 W / cm deg of diamond, it is possible to uniformly dissipate the heat generated by friction, and furthermore, it has abrasion resistance, high thermal conductivity, high smoothness unique to carbon film, etc. It had characteristics.

Further, the method of the present invention comprises the steps of:
Since a magnetic material, a metal, a ceramic, a semiconductor, or the like can be used as a formation surface, the reaction is immeasurable.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of an apparatus used in the present invention.

FIG. 2 is a view showing the film quality of a carbon film.

FIG. 3 is a diagram showing an output of high-frequency energy, a film forming speed, and Vickers hardness.

FIG. 4 is a diagram showing a reaction pressure, a film formation rate, and Vickers hardness.

FIG. 5 is a diagram showing the relationship between high-frequency energy, reaction pressure, and self-bias.

FIG. 6 is a graph showing the relationship between the thickness and hardness of a carbon film.

[Description of Signs] 1 ... doping system 6 ... valve 7 ... flow meter 8 ... reaction system 9 ... nozzle 10 ... microwave energy 11 ... first electrode 12 ... ··· Second electrode 13 ··· High frequency power supply 14 ··· Matching transformer 15 ··· DC bias power supply 16 ··· Exhaust system 17 ··· Pressure regulating valve 18 ··· Turbo molecular pump 19 ··· Rotary Pump 20: reaction space

Claims (8)

(57) [Claims] Claims: 1. A carbon or carbon-based coating on the surface
The carbon or the coating containing carbon as a main component has a hardness that continuously increases toward the surface of the coating , and the surface has a hardness similar to diamond. , and the coating mainly containing carbon or a carbon, the electrical unit
The surface in contact with the surface of the product is
An electric component, wherein the absolute value of the fuse bias is formed to be 150 V or less . 2. A method in which carbon or a coating mainly composed of carbon is coated on the surface.
An electrical device in which the, coating stepwise increased hardness towards the surface of the coating film, and the hardness the surface of <br/> diamond-like mainly containing carbon or carbon , and the coating mainly containing carbon or a carbon, the electrical unit
The surface in contact with the surface of the product is
An electric component, wherein the absolute value of the fuse bias is formed to be 150 V or less . 3. The method according to claim 1, wherein the
The coating mainly composed of silicon or carbon has an amorphous structure
An electrical component, characterized by being a coating of: 4. The method according to claim 1, wherein the
The coating mainly containing silicon or carbon is 0.5 to 20 nm.
An electrical component, characterized in that it is a coating containing microcrystals of Any Te one odor <br/> of 5. A method according to claim 1 to claim 4, coating mainly the carbon or carbon Vickers hardness is equal to or is 2,000 Kg / mm ² or more Electrical components . 6. The film according to claim 1 , wherein the carbon or the film containing carbon as a main component contains nitrogen at a concentration of nitrogen / carbon ≦ 0.05. electrodeposition, characterized in that it comprises at
Damn parts . Any one odor <br/> Te, the electrical component of claim 7 according to claim 1 to claim 6, the electrical component, which is a magnetic head. Any one odor <br/> Te, the electrical component of claim 8 claims 1 to 6, the electrical component, which is a magnetic disk.