JP2003501555A - Doped diamond-like carbon coating - Google Patents

Abstract

(57) SUMMARY The present invention relates to a diamond-like carbon coating doped with silicon-nitrogen. This type of coating is characterized by low surface energy, high hardness, and good adhesion to the substrate. Such a layer functions as a good adhesion promoting layer for the diamond-like carbon composition film. By alternately repeating the deposition of the deep diamond-like carbon layer and the diamond-like carbon composition layer, a thick film having good adhesion to the substrate and low internal stress can be obtained.

Description

Detailed Description of the Invention

FIELD OF THE INVENTION The present invention relates to doped diamond-like carbon coatings and methods of depositing such coatings on a substrate.

[0002] It is known as the background of the invention diamond-like carbon (DLC) amorphous hydrogenated carbon (a-C
: H) have various attractive properties. A coating having a diamond-like carbon composition is hard and is suitably used as a coating having excellent wear resistance, self-lubrication, and corrosion resistance. However, due to insufficient adhesion to the substrate, there is a high internal compressive stress (up to several GPa) in the material. This internal compressive stress limits the applications of the diamond-like carbon (hereinafter, carbon is also referred to as carbon) film.
For example, due to the presence of high internal stress, only a limited thickness of film can be formed. Another drawback of DLC coatings is that the coefficient of friction increases significantly with humidity. Therefore, the DLC film cannot be used as a low friction film in a high humidity environment or in water.

Various attempts have been made to improve the adhesion to the substrate. EP60
DLC on a substrate made of steel or iron, as described in Japanese Patent No. 0533.
Techniques are known in which an intermediate silicon layer is used to improve the adhesion of a coating having a composition. In addition, in WO98 / 33948, before depositing a DLC layer,
A technique for depositing a diamond-like microcomposite (DLN) layer on a substrate is described. DLN coatings usually consist of two interpenetrating networks a-C: H and a-Si: O. Such a DLN coating is known as "Dylyn" (R).

The object of the Summary of the Invention The present invention is a high hardness, and good adhesion to the substrate, the silicon further has a non-sticking property - to provide a diamond-like carbon film nitrogen (Si-N) doped It is in. Another object of the present invention is to provide a multi-layer coating that gives good adhesion to the substrate. Such a multilayer film has a low total internal stress even if it is a thick film. Furthermore, it is an object of the invention to provide a method for depositing a coating according to the invention on a substrate.

According to the first aspect of the present invention, a silicon-nitrogen-doped diamond-like carbon film is obtained. This coating consists of the elements C, H, Si, and N. C,
The concentrations of the elements C, Si, and N, which are represented by the ratio to the total of Si and N, are as follows. That is, the concentration of C is 30 to 90 atom%, the concentration of Si is 5 to 50 atom%, and the concentration of N is 5 to 40 atom%. Preferably C
Is 40 to 50 atomic%, Si is 15 to 40 atomic%, and N is 12 to 20 atomic%. The coating has been found to further contain a small amount of oxygen. However, the amount of oxygen is limited to a few percent or less, and becomes the highest in the portion that is closest to the outer surface of the coating layer.

The adhesion of the coating according to the invention, measured by the scratch test and represented by the critical load, is greater than 22N.

The doped diamond-like carbon coating can be considered a non-stick coating. The non-stick property of the coating can be represented by the surface energy. In most cases, lower surface energy can improve non-stick properties. Specifically, if the surface energy of the coating is less than 40 mN / m, the coating can be considered to have non-stick properties. More preferably, the surface energy is less than 33 mN / m, more preferably less than 30 mN / m.

In addition to non-stick properties, the coatings of the invention are characterized by high hardness. The hardness has been found to be higher than 12 GPa. Hardness is 15G in most cases
Even higher than Pa.

The coating of the present invention has a low surface energy, and thus is very suitably used as a coating for a substrate for applications where non-stickiness is desired. Applications include plastic injection molds, tablets and punches for powders, and implants such as stents (molds for oral structures).

The doped diamond-like carbon coating layer having both low surface energy and high hardness exhibits extremely excellent characteristics and has a possibility of being applied to many industrial applications.

The coating layer contains one or more other elements such as fluorine, W, Zr or Ti.
Can be doped with a transition metal. By doping with a metal element, the thermal conductivity and / or the electrical conductivity of the film can be changed. That is, the thermal conductivity and / or the electrical conductivity of the film can be controlled by adjusting the content of the metallic doping element. Further, the surface energy can be controlled by containing such a doping element.

An inert gas such as Ar, Kr or Ne can be included in the coating composition by introducing it into the vacuum chamber during deposition of the coating.

According to a second aspect of the invention, a multi-layer coating is provided. The multilayer coating has at least one layer structure. Such a layer structure has a first layer formed of a film of silicon-nitrogen-doped elements C, H, Si, and N formed closest to the substrate, and a diamond-like layer formed on the first layer. It comprises a second layer of carbon composition, a silicon-nitrogen-doped diamond-like carbon film formed between the first and second layers, and a transition layer of a mixture of diamond-like carbon compositions.

To form a coating of one or more layered structures, an intermediate layer of a mixture of a diamond-like carbon composition layer and a doped diamond-like carbon coating is sandwiched between each pair of successive layered structures.

The transition layer gradually changes from the composition of C, H, Si, and N to the diamond-like carbon composition layer. On the other hand, the intermediate layer is composed of C, H, Si, and N from the diamond-like carbon composition layer, and the composition gradually changes.

Adhesion measurements have revealed that the first layer functions as an excellent adhesion promoting layer for the DLC layer. The critical load of this adhesion promoting layer is significantly larger than the critical load of the DLC composition layer deposited directly on the substrate. Further, the adhesion promoting layer according to the present invention has an advantage that it has not only good adhesion but also a considerably high hardness as compared with other adhesion promoting layers such as a silicon layer. As a result, the multilayer coating can have a hardness close to that of the DLC coating layer.

By alternately repeating the deposition of the CLC, H, Si, and N layers and the DLC composition layer, for example, a film having a thickness of more than 10 μm can be formed. The number of layer structures can be varied within the range of 1 to 5000, preferably within the range of 5 to 50.

The internal stress of the multilayer coating according to the present invention is extremely low. This is because the Young's modulus (elasticity) of the silicon-nitrogen-doped diamond-like carbon coating layer sandwiching the DLC coating layer is low. Even with a thick multilayer coating, the total internal stress of the coating has a low value.

To control the thermal and / or electrical conductivity and / or surface energy of the multilayer coating, for example, fluorine or transition metals can be doped in any layer of the coating.

Depending on the properties required for the multilayer coating or the application of the multilayer coating, the outermost layers in the multilayer coating may be modified.

When the DLC layer is deposited on top of the multi-layer coating, the multi-layer coating exhibits high hardness and low wear properties represented by DLC coatings. That is, DL on top of the multilayer coating
By depositing the C layer, it is possible to obtain a coating excellent in abrasion resistance and scratch resistance. According to this method, a thick film can be formed while having characteristics comparable to those of the conventional DLC film. Applications of such coatings include coatings on metal forming tools and textile needles. When a doped diamond-like carbon coating consisting of the elements C, H, Si, and N is deposited on top, the multilayer coating exhibits low surface energy and low coefficient of friction. Such coatings, i.e. coatings with non-stick properties, are suitable as coatings for many applications, especially for plastic injection molds and powder pressure tools.

As an outer layer other than the above layers of the multilayer coating, a layer composed of C, H, Si, and O, a-
Si-C doped layer, aC-F doped layer, a-Si-F-C doped layer, or a
-Si-F-O-C doped layer is mentioned.

According to a third aspect of the invention, there is provided a substrate coated with the doped diamond-like carbon coating or multilayer coating of the invention. The material of the substrate to be coated may be rigid or flexible. As a substrate, hardened steel (for example, 100Cr-
6), aluminum, silicon, titanium, glass, or the like can be used.

According to yet another aspect of the invention, there is provided a method of coating at least a portion of a substrate. The substrate is placed in a vacuum chamber and secured to the substrate plate by any suitable means. Preferably, the surface of the substrate is cleaned before the film is deposited.
Cleaning can be performed by bombarding the substrate with an inert gas such as Ar, Kr, or Ne. By this pretreatment, the surface of the substrate can be activated and residual impurities can be removed.

A precursor of the elements C, H, Si, and N or a mixture of different precursors is introduced into the vacuum chamber, a plasma is formed from the introduced precursor, and the composition of the plasma is negatively biased. It is deposited on a substrate to which a voltage is applied.

After being coated with an adhesive film of sufficient thickness, the substrate is further processed as follows. That is, the composition of the precursor is gradually switched to hydrocarbon without stopping the glow discharge. A plasma is then formed from the mixture of precursor and hydrocarbon,
From the mixture, a transition layer is deposited on the substrate with a negative bias voltage applied. The composition of this mixture gradually changes from a composition consisting of elements C, H, Si, and N to a diamond-like carbon composition consisting only of elements C and H.

Even after the composition of the film is switched to the diamond-like carbon composition, the plasma deposition is continued as it is, and the diamond-like carbon composition layer is deposited from hydrocarbon until a predetermined thickness is obtained.

In the case of forming a multi-layer coating having a layer structure of one or more layers, in addition to the above steps, the hydrocarbon is gradually switched to a precursor containing the elements C, H, Si, and N, and the hydrocarbon and the precursor are combined. Forming a continuous plasma and depositing an intermediate layer from the mixture, continuing plasma deposition from a precursor containing the elements C, H, Si and N, and gradually switching the precursor to a hydrocarbon. And each layer structure is formed by performing the step of depositing a DLC composition layer from hydrocarbons.

[0029]   The plasma is generated by various methods and deposited on the substrate.

As a first method of generating plasma, there is a method of adding capacitively coupled radio frequency glow discharge (RF) to the substrate. The frequency is in the range of 1MHz to 28MHz,
Preferably, it is set to 13.56 MHz. A bias voltage in the range of 50 to 1000V may be applied to the substrate.

Another way to generate plasmas is to use a negative DC in the range of 200 to 1200V.
A method of applying a bias or MF (medium frequency) bias voltage to the substrate can be mentioned. The frequency of the MF bias is preferably set to a value within the range of 30 to 1000 kHz.

More preferably, plasma is generated by electron auxiliary discharge. The filament current may be set in the range of 50 to 150 A, the negative filament bias DC voltage may be set in the range of 50 to 300 V, and the plasma current may be set in the range of 0.1 to 20 A.

Yet another method of generating plasma is to use a bipolar pulsed DC source. The term "bipolar" means alternating negative and positive voltage pulses. Either a symmetric bipolar pulse (the amplitude of the positive and negative pulses is equal) or an asymmetric bipolar pulse (the amplitude of the negative pulse voltage is higher than the amplitude of the positive pulse voltage) Can be used.

The plasma can be further enhanced by applying a magnetic field during deposition of the coating. The magnetic field may be added by an induction coil. Preferably, the magnetic field is set within the range of 10 to 30 Gauss.

High frequency, eg 13.56 MHz capacitively coupled radio frequency glow discharge (RF)
It has been found that silicon-nitrogen-doped diamond-like carbon coatings deposited with s.p. exhibit very good non-stick properties.

A liquid or gaseous component consisting of the deposited elements C, H, Si and N in suitable proportions can be used as a precursor. Examples of preferred precursors are 1,1,3
, 3 Tetramethyldisilazane or hexamethyldisilazane. As a modification of the precursor, a mixture of different components, for example silane,
And mixtures obtained by mixing hydrocarbons and nitrogen gas such that the elements C, H, Si and N are contained in suitable proportions.

The hydrocarbon may be a saturated or unsaturated cyclic or acyclic hydrocarbon having a carbon number within the range of 1 to 20. Substitutional hydrocarbons are also suitably used as precursors. Specific examples include methane, propane, butane, pentane, cyclopentane, ethylene, acetylene, and aromatic or substituted aromatic hydrocarbons such as benzene and substituted benzene.

[0038]   The pressure in the vacuum chamber is 1 x 10^-3To 1 mbar, preferably 5 × 10 ^-3 From 1 × 10^-1Values in the mbar range, especially 2 × 10^-2Set to millibar
It is good. The flow rate of the precursor is within the range of 0.1 g / hour to 25 g / hour, preferably
It may be set to a value within the range of 1 g / hour to 3 g / hour. Inert gas, eg
, The flow rate of argon should be set to a value within the range of 10 to 500 mL / min.
. Preferably, the precursor and argon gas are in a controlled vapor deposition / mixing system (CEM).
Therefore, it may be introduced into the vacuum chamber while being controlled. CEM system is a precursor
And the flow rate of argon gas can be controlled independently of each other. this
The CEM system allows easy control of the deposition process. Also,
The deposition time may be selected according to the required film thickness.

[0039]   The present invention will be described in more detail with reference to the accompanying drawings.

Description of Embodiments of the Invention Some examples of suitable coatings will be described with reference to the drawings.

In FIG. 1, a substrate 11 is coated with a silicon-nitrogen-doped diamond-like carbon film 12 by RF glow discharge. The coating was performed as follows. First, the substrate is placed in a vacuum chamber and fixed to the substrate plate. Then, the surface of the substrate was cleaned by plasma etching with Ar ions for 10 minutes. After the washing, 1,1,3,3-tetramethyldisilazane is introduced into the vacuum chamber at a flow rate of 1.8 g / hour, and Ar is introduced into the vacuum chamber at a flow rate of 75 mL / min.
The disilazane precursor and argon were introduced into the vacuum chamber while controlling their flow rate by a controlled vapor deposition / mixing system (CEM). A high frequency of 13.56 MHz was applied to the substrate plate to generate plasma. Bias voltage is 3
The pressure in the vacuum chamber was set to 1.6 × 10 ^-2 mbar. Deposition was carried out for 60 minutes.

The composition of the coating layer deposited on the substrate was measured by X-ray photoelectron spectroscopy (XPS). The coating contained 43 atom% carbon, 40 atom% silicon, and 14 atom% nitrogen. The hydrogen concentration is not taken into consideration. It was found that only a small amount of oxygen, for example 3%, was present in the coating.

The non-stick property of the coating was evaluated by measuring the surface energy of the coating and the contact angle of a water drop on the coated surface. The contact angle of the water droplet on the coated substrate was 81 °. The surface energy of the deposited film was 30.5 mN / m, the dispersed component of the surface energy was 24.9 mN / m, and the polar component was 5.8 mN / m. Then
The hardness of the coating was measured by the microindentation hardness test. The indentation depth was 300 nm. This test method revealed that the microhardness of the coating was 15.8 ± 0.4 GPa. Further, the adhesion of the film was measured by a scratch test. The scratch test was carried out on a 4 cm ² M2 steel plate. The critical load (Lc ₂ ) at which the first sign of delamination appears was 22N. The coating is further characterized by a high elasticity represented by Young's modulus. As a result of measuring Young's modulus, 125 ± 2
The value of GPa is shown.

In one variation of the method of the present invention, the coating layer consisting of the elements C, H, Si, and N shown in FIG. Is deposited. The film layer was deposited as follows. First, argon was introduced into the vacuum chamber in order to clean and activate the substrate surface. Next, 1,1,3,3-tetramethyldisilazane is introduced into the vacuum chamber at a flow rate of 7.2 g / hour, and Ar is introduced into the vacuum chamber at a flow rate of 500 mL / min. These flow rates were controlled by the CEM system. A plasma was generated by the combination of applying a DC bias to the substrate and a heating filament. Bias voltage to the substrate is 6
It was set to 00V. Also, the plasma current is 1 A, negative filament bias DC
The voltage was set to 100V. The plasma was strengthened by applying a magnetic field.
The magnetic current was set to 5A. The pressure inside the vacuum chamber was set to 8.5 × 10 ⁻³ mbar. A film layer was formed by depositing for 60 minutes under such conditions.

The composition of the deposited layer was measured by XPS. The composition of the film is as follows. That is, it contained 45.2 atomic% C, 15.2 atomic% N, and 39.7 atomic% Si. This concentration is expressed as a ratio to the total of C, N, and Si.

A similar experiment was conducted using the following parameters. Flow rate of tetramethyldisilazane: 10.3 g / hour Flow rate of argon: 500 mL / min Bias voltage: 200 V Filament bias: 100 V Magnetic current: 5 A Pressure: 8.5 × 10 ⁻³ mbar Deposition time: 60 minutes

By XPS analysis, the film contains 46.0 atomic% C, 16.1 atomic% N, and 37.9 atomic% Si in proportion to the sum of C, N, and Si. It turned out that

FIG. 2 shows the substrate 11 covered by the multilayer coating 13. This film is
It comprises a first layer 14 of C, H, Si and N formed closest to the substrate and a second DLC composition layer 15. Between these first and second layers, C, H
A transition layer 16 gradually changing from a layer composed of Si, N, and N to a DLC composition layer is interposed.

The first layer of this two-layer coating was deposited as follows. Tetramethyldisilazane was introduced into the vacuum chamber at a flow rate of 1.8 g / hr, and argon was introduced into the vacuum chamber at a flow rate of 75 mL / hr. Then 13.56 MHz RF was applied to the substrate.
The bias voltage was set to 300V. The pressure inside the vacuum chamber was set to 1.6 × 10 ^-2 mbar. Under such conditions, the deposition was performed for 30 minutes to form the first layer. After deposition of the first layer, the precursor consisting of 1,1,3,3-tetramethyldisilazane was gradually switched to CH ₄ . To deposit a DLC composition layer, CH ₄ is added to 80
It was introduced into the vacuum chamber at a flow rate of mL / hr with H ₂ at a flow rate of 20 mL / hr. The bias voltage was set to 350 V and the pressure in the vacuum chamber was set to 1 × 10 ^-2 mbar. The deposition time of the DLC composition layer is 120 minutes. The total thickness of the multilayer film thus formed was 2.5 μm.

The two-layer coating had a hardness of 21.4 ± 0.7 GPa. As a result of a scratch test performed on a 4 cm ² M2 steel plate, the critical load Lc ₂ of the two-layer coating was 25.
It was 7 ± 4N. The Young's modulus of the two-layer coating was 135 ± 2 GPa.

As a result of measuring the adhesion, it was found that the first layer gave good adhesion to the substrate. The critical load of the bilayer coating is much higher than that of the DLC layer deposited directly on the substrate. The two-layer coating is further characterized by high hardness.

A modification of the method for depositing a two-layer coating as shown in FIG. 2 will be described. A precursor consisting of tetramethyldisilazane was introduced into the vacuum chamber at a flow rate of 7.2 g / hour. Further, as a carrier gas, argon having a flow rate of 500 mL / hour was introduced into the vacuum chamber. A bias voltage of 500V was then applied to the substrate. The plasma current was set to 1 A, the filament bias was set to 100 V, and the magnetic current was set to 5 A. The pressure inside the vacuum chamber was set to 8.5 × 10 ⁻³ mbar. In this way, the deposition was performed for 30 minutes to form the first layer. Then, the precursor composed of tetramethyldisilazane was switched to the precursor composed of C ₄ H ₁₀ . A bias voltage of 600 V was applied to form the DLC composition layer. In this way, the deposition is carried out for 3 hours,
A DLC composition layer was formed. The thickness of the film was 1.3 μm.

The two-layer coating thus obtained had a high hardness (21 GPa). Four
The result of the adhesion measurement by the scratch test performed on the M2 steel plate of cm ² is 2
The critical load of the layer coating was 28 ± 0.7N.

FIG. 3 shows the substrate 11 covered by the multilayer coating 13. This film is
Of the same composition as the first layer 14 of C, H, Si and N, the second layer 15 of diamond-like composition deposited on the first layer, and the first layer deposited on the second layer The third layer 18 is provided. The transition layer 16 is interposed between the first layer and the second layer. Further, an intermediate layer is interposed between the second layer and the third layer. The first layer formed closest to the substrate functions as an adhesion promoting layer.

The DLC composition layer deposited on this adhesion promoting layer provides the multilayer coating with the required hardness. Also, the outer layer ultimately deposited on the DLC composition layer provides the coating with certain non-stick properties. Such coatings have low total internal stress.

FIG. 4 shows a multilayer coating 13 consisting of a two-layer structure 19. Each layer structure has a first coating layer 14 composed of elements C, H, Si, and N deposited closest to the substrate.
And a second DLC composition layer 15 deposited on the first layer and a transition layer formed between the first layer and the second layer. The intermediate bonding layer 17 is formed between the two continuous layer structures.

By repeating the above steps, it is possible to form a multilayer film including more layers.

[Brief description of drawings]

FIG. 1 shows a substrate coated with a silicon-nitrogen doped diamond-like carbon layer.

2, 3 and 4 are diagrams showing substrates coated with different types of multilayer coatings.

[Procedure for Amendment] Submission for translation of Article 34 Amendment of Patent Cooperation Treaty

[Submission date] May 9, 2001 (2001.5.9)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Contents of correction]

[Claims]

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ , CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, K E, LS, MW, SD, SL, SZ, TZ, UG, ZW ), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, C N, CR, CU, CZ, DE, DK, DM, DZ, EE , ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, K P, KR, KZ, LC, LK, LR, LS, LT, LU , LV, MA, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, S G, SI, SK, SL, TJ, TM, TR, TT, TZ , UA, UG, US, UZ, VN, YU, ZA, ZW (72) Inventor Narink, Dominic             Belgium 8820 Herzberge, Belgium             Velbinding Strath 21 F-term (reference) 4G046 CA02 CB03 CC02 CC06                 4K030 AA09 AA17 AA18 BA24 BA28                       BB12 FA01 JA18 KA20 LA21                 4K044 AA01 AA11 AB10 BA18 BB01                       BB02 BB03 BB04 BB05 BB06                       BB17 BC01 BC05 BC06 CA07                       CA14 CA57

Claims (27)

[Claims] 1. In a silicon-nitrogen-doped diamond-like carbon film (12), the composition of the film is from 30 to 30 at a concentration expressed as a ratio to the total of all elements other than H constituting the film. 90 atom% carbon, 5 to 50
A coating consisting of atomic% silicon and 5 to 40 atomic% nitrogen, characterized in that the adhesion of said coating, measured by scratch test and expressed by the critical load, is greater than 22N. 2. The composition of the coating is 40 to 50 atomic% carbon and 15 to 4 at a concentration expressed as a ratio to the total of all elements other than H constituting the coating.
The coating of claim 1 comprising 0 atomic% silicon and 5 to 40 atomic% nitrogen. 3. The coating according to claim 1, which has a hardness of more than 15 GPa. 4. The coating according to claim 1, which has a surface energy of less than 40 mN / m. 5. The film according to claim 1, which has a surface energy of less than 33 mN / m. 6. The surface energy is less than 33 mN / m and the hardness is 15 G.
It is larger than Pa, The film of Claim 1 or 2 characterized by the above-mentioned. 7. The coating according to claim 1, wherein the coating is doped with fluorine and / or at least one transition metal. 8. A multi-layer coating (13) comprising at least one layer structure (19).
8. The first layer (14) comprising a silicon-nitrogen-doped diamond-like carbon film according to any one of claims 1 to 7, wherein each layer structure is formed closest to the substrate.
And a second layer (1) made of a diamond-like carbon composition formed on the first layer.
5), and a transition layer (16) formed between the first layer and the second layer, the transition layer (16) including a mixture of the doped diamond-like carbon film and the diamond-like carbon composition. Multi-layer coating. 9. An intermediate layer (17) comprising at least two layer structures and comprising a mixture of said doped diamond-like carbon coating and said diamond-like carbon composition.
9. The multilayer coating according to claim 8, characterized in that (4) is sandwiched between each pair of successive layer structures. 10. A silicon-nitrogen-doped diamond-like carbon coating (18) according to claim 1, which is formed on top of the multilayer coating. Item 10. The multilayer film according to Item 8 or 9. 11. Multilayer coating according to claim 8 or 9, characterized in that at least one of the layers is doped with fluorine and / or transition metals. 12. The multi-layer coating according to claim 8, wherein the total thickness of the multi-layer coating is in the range of 2 to 20 μm. 13. A substrate at least partially coated with a coating according to any one of claims 1-12. 14. A method of coating at least a part of a substrate in a vacuum chamber, the step (a) of plasma etching the substrate by bombarding the substrate with ions of an inert gas, and C as a deposition target element. , H, Si, and N in an appropriate ratio are introduced into the vacuum chamber, a plasma is formed from the introduced precursor, and a composition of the plasma is applied with a negative bias voltage. And a step (b) of depositing on a substrate. 15. The method of coating a substrate of claim 14, wherein the precursor is gradually switched to a hydrocarbon to form a plasma of a mixture of the precursor and the hydrocarbon, and a transition layer from the mixture to a negative layer. (C) depositing on the substrate to which the bias voltage of 1 is applied, and (d) continuing plasma deposition of the diamond-like carbon composition layer with the hydrocarbon. 16. The method according to claim 15, for additionally forming each layer structure (19).
The method of claim 1, wherein the hydrocarbon is gradually switched to a precursor containing the elements C, H, Si, and N, a plasma is formed from the hydrocarbon and the precursor, and an intermediate layer is deposited from the mixture ( e), a step (f) of continuing plasma deposition from the precursor containing the elements C, H, Si, and N, a step (g) of gradually switching the precursor to a hydrocarbon, and A step (h) of depositing a diamond-like carbon composition layer, the method further comprising: 17. The method according to claim 14, wherein a high frequency of 1 to 28 MHz is applied to the substrate. 18. The method according to claim 14, wherein a negative DC bias or MF bias voltage of 200 to 1200V is applied to the substrate. 19. A method as claimed in any one of claims 14 to 16, characterized in that a pulsed DC bias voltage is applied to the substrate. 20. The method of claim 18, wherein the frequency of the MF bias voltage is in the range of 30 to 1000 Hz. 21. The method according to claim 18, wherein the plasma is an induced plasma using electron emission from a filament. 22. The electron emission is a filament current of 50 to 150 A,
3. Obtained by an electronic auxiliary discharge using a negative filament bias voltage of 50 to 300 V and a plasma current of 0.1 to 20 A.
The method according to 1. 23. The method according to claim 18, wherein a magnetic field is applied to enhance the plasma. 24. The method according to any one of claims 14 to 23, wherein the precursor containing C, H, Si and N is silazane. 25. The method of claim 24, wherein the silazane is 1,1,3,3-tetramethyldisilazane or hexamethyldisilazane. 26. The method of claim 25, wherein the hydrocarbon is selected from the group of saturated and unsaturated acyclic or cyclic hydrocarbons containing 1 to 20 carbon atoms. 27. The method of claim 26, wherein the cyclic hydrocarbon is benzene or substituted benzene.