JPH11209868A - Production of carbon nitride film and device for producing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reactivity between carbon and nitrogen and to synthe size a carbon nitride film excellent in wear resistance on a substrate with tight adhesion by irradiating the surface of a base material held in a vacuum vessel with ions contg. nitrogen by specified irradiating energy and simultaneously irradiating it with carbon vapor. SOLUTION: In a vacuum vessel 11, a substrate 13 composed of a high speed tool steel or the like is held via a substrate holder 12. This substrate 13 is irradiated with nitrogen ions 19 from an ion impregnating device. The irradiating energy from the ions is regulated to the value of 20 to 150 keV in which the ions are not etched and are not impregnated into the substrate. Simultaneously with this, carbon 15 as an evaporating source 14 is heated by the irradiation of an elecron beam 16, and the surface of the substrate is irradiated with the generated carbon vapor 17. At this time, the evaporating quantity of the carbon 15 is controlled via a monitor 18, and the ratio of it to nitrogen ions 19 is regulated. In this way, a mixed layer of a carbon nitrogen film formed by the energy of the irradiating ions and the substrate 13 is formed to improve the adhesion between the carbon nitrogen film and the base material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to sliding members such as bearings and sliders of various rotary machines, storage devices of information equipment, and the like.
The present invention relates to a method for producing a carbon nitride film applied to a member requiring abrasion resistance.

[0002]

The carbon nitride has a β
-C_ThreeN_FourWhen adopting a structure, hardness exceeding diamond
It is said to have high wear resistance. Also,
The carbon nitride is the β-C _ThreeN_FourFor composition and structure other than structure
In addition to lubrication, thermal stability, chemical resistance,
Is expected to have excellent mechanical stability.
Sliding members such as bearings and sliders for various types of rotary machines and information devices
Is expected to be applied to storage devices and the like. Such nitrided carbon
As a method of synthesizing a base film, conventionally, the synthesis by the following method has been tried.
Has been seen.

That is, as the above method, there are a sputtering method, a plasma CVD method, a laser vapor deposition method, an ion implantation method and the like, but there is no confirmed example of synthesizing a carbon nitride film having a β-C ₃ N ₄ structure. Further, in the above conventional method, when attention is paid only to the composition ratio in the carbon film, the carbon / nitrogen composition ratio in the carbon nitride film is also the stoichiometric composition ratio of β-C ₃ N ₄ (carbon: Nitrogen = 3: 4) was not obtained, and the film compositions were all excessive in carbon, and the nitrogen content was at most 30%. Furthermore, in the prior art, the performance of the synthesized carbon nitride film is hardly clarified, and a carbon nitride film having sufficient adhesiveness has not been synthesized.

As described above, in the conventional method for manufacturing a carbon nitride film, the intended composition and structure of the carbon nitride film cannot be obtained, because the reactivity between carbon and nitrogen is extremely low. In addition, since β-C ₃ N ₄ is a non-equilibrium substance, it is extremely difficult to control the composition and structure. Another reason is that since carbon nitride is a non-equilibrium substance, the internal stress accumulated in the film is large and sufficient adhesion cannot be obtained. Therefore, in order to synthesize β-C ₃ N ₄ , it is necessary to improve the reactivity between carbon and nitrogen and also to improve the adhesion between the carbon nitride film and the substrate.

An object of the present invention is to provide a method of synthesizing a carbon nitride film which can improve the reactivity between carbon and nitrogen and improve the adhesion between the carbon nitride film and a substrate.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems. The first invention is to irradiate nitrogen-containing ions onto a substrate held in a vacuum vessel and simultaneously apply carbon vapor to the substrate. And a method for producing a carbon nitride film.

In the above-mentioned manufacturing method, it is preferable that the irradiation energy of the ions is set to 20 keV to 150 keV.

The second invention also relates to an apparatus for carrying out the manufacturing method according to the first invention, wherein a vacuum container having a base material for forming a carbon nitride film therein is provided, and A carbon nitride film, which is provided below the base material and includes an evaporation source for heating and evaporating carbon by an electron beam or the like, and an ion implanter for generating nitrogen ions and irradiating the base material with the ions. In the manufacturing equipment.

According to the ion vapor deposition method of the present invention, in which the irradiation of nitrogen or nitrogen-containing ions and the irradiation of carbon vapor are performed at the same time, the energy of the ions to be irradiated can be changed. This is a means for improving the reactivity between carbon and nitrogen. Further, by changing the irradiation amount of nitrogen or ion irradiation containing nitrogen and the amount of evaporation of carbon, the carbon / nitrogen composition ratio in the carbon nitride film can be changed. At this time, by increasing the energy of the irradiation ions sufficiently, a mixed layer of the carbon nitride film and the substrate is formed by the kinetic energy, and the adhesion between the carbon nitride film and the substrate can be improved. .

Here, the reason why the ion irradiation energy is set to 20 keV to 150 keV in the second invention is that when the energy of ions containing nitrogen is 20 keV or less, the carbon nitride film formed by the ion etching effect is shaved. As a result, when a carbon nitride film cannot be formed and the energy of the nitrogen-containing ions exceeds 150 keV, nitrogen ions are implanted into the inside of the base material, so that nitrogen does not remain on the surface of the base material. This is because a carbon nitride film cannot be formed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a configuration diagram of a vacuum chamber of a carbon nitride film production apparatus used for synthesizing a carbon nitride film by a carbon nitride production method according to an embodiment of the present invention, FIG. 2 is an overall configuration diagram of the carbon nitride film production apparatus, FIG. 3 is a performance comparison diagram of the carbon nitride film.

As shown in FIG. 2, the above-mentioned carbon nitride film manufacturing apparatus includes a vacuum chamber 10 and an ion implantation apparatus 20. In FIG. 2, the ion implantation apparatus 20 is an apparatus for generating and implanting high-energy ions.
2, an extraction electrode 23 for extracting nitrogen ions from the ion source 22, a mass separator 24 for selecting a predetermined nitrogen ion in the nitrogen ions, an acceleration tube 25 for accelerating the nitrogen ions to increase the energy, described later. A scanning tube 26 and the like are provided for scanning the entire substrate in the vacuum chamber 10 to be irradiated with the nitrogen ions.

The vacuum chamber 10 is constructed as shown in FIG. 1. Numeral 11 denotes a vacuum vessel, the inside of which is maintained at a vacuum. Reference numeral 13 denotes a substrate, and 12 denotes a substrate holder for mounting the substrate 13. Reference numeral 14 denotes an evaporation source provided at the bottom of the vacuum vessel 11 for evaporating carbon 15 by an electron beam 16. Reference numeral 31 denotes an ion injection path connecting the vacuum tank 10 and the ion implantation apparatus 20, 32 denotes an exhaust port, and 18 denotes a monitor for measuring the amount of carbon vapor evaporated from the evaporation source 14.

Next, a method for manufacturing a carbon nitride film using the carbon nitride film manufacturing apparatus shown in FIGS. 1 and 2 will be described.

In FIG. 2, nitrogen ions ionized by the ion source are extracted by the extraction electrode 23 into the ion source 2.
2 and guided to the mass separator 24, where a predetermined nitrogen ion (for example, N ₂ ⁺ ) is selected. After the selected nitrogen ions are accelerated to a predetermined energy by the accelerating tube 25, they are scanned by the scanning tube 26 so as to irradiate the entire substrate 13 in the vacuum chamber 10 serving as a nitrogen ion beam injection target.

In FIG. 1, nitrogen ions 19 supplied from an ion implanter 20 are provided in the vacuum chamber 10.
Is irradiated on the substrate 13 attached to the substrate holder 12 in the vacuum container 11, and at the same time, the carbon 15 in the evaporation source 14 installed at the lower part in the vacuum container 11 is evaporated by the electron beam 16, Thereby, the carbon vapor 17 is deposited on the base material 13. Then, the amount of evaporation of the carbon vapor 17 to the substrate 13 is measured by the monitor 18.

Next, a method of synthesizing a carbon nitride film using the apparatus for manufacturing a carbon nitride film shown in FIGS. 1 and 2 will be described.
First, the base material 13 made of high-speed tool steel or the like is subjected to ultrasonic cleaning with an organic solvent (for example, acetone).
Attached to the substrate holder 12 of the inner and pre-evacuation below 2 _X 10 ^-6 torr. Next, the nitrogen gas supplied to the ion source 22 is ionized in the ion source 22, accelerated by an acceleration tube 25, mass-separated by a mass separator 24, and the nitrogen ions 19 passing through a scanning tube 26 are converted into the base material 13. Irradiation. At the same time, the carbon vapor 17 is evaporated from the evaporation source 14 by the electron beam 16 and deposited on the substrate 13.

Here, for example, the energy of the nitrogen ions 19 is 70 keV, and the evaporation rate of the carbon vapor 17 is 1.0 ° /
sec, a carbon nitride film having a carbon / nitrogen composition ratio of 1 can be synthesized by the above process.
Energy of 70 keV and evaporation rate of carbon vapor 17 of 2.
When 0 ° / sec, a carbon nitride film having a carbon / nitrogen composition ratio of 2 can be synthesized. Thus, by changing the evaporation rate of the carbon vapor 17 while keeping the energy of the nitrogen ions 19 constant, the carbon / nitrogen composition ratio in the carbon nitride film can be changed. The energy of the nitrogen ions 19 is 20
In the range of keV to 150 keV, the same ion 1
Even when the energy of No. 9 is other than 70 keV, the carbon / nitrogen composition ratio of the carbon nitride film can be adjusted in the same manner as described above.

To explain the basis of the above range, when the energy of ions containing nitrogen is 20 keV or less, the carbon nitride film formed by the ion etching effect is shaved, so that a carbon nitride film cannot be formed. When the energy of the ions containing nitrogen exceeds 150 keV, nitrogen ions are implanted into the base material 13 so that the base material 1
This is because nitrogen remains on the surface of No. 3 and a carbon nitride film cannot be formed.

The energy of the nitrogen ions 19 is 2
By setting the voltage between 0 keV and 150 keV, the adhesion between the carbon nitride film and the base material 13 can be improved. FIG. 3 shows a comparison of the adhesion between the carbon nitride film and the base material 13 with and without high energy nitrogen ion irradiation when synthesizing the carbon nitride film. The adhesion was evaluated by a scratch test, and was evaluated based on the force when the carbon nitride film was peeled off from the substrate 13. From the results shown in FIG. 3, those subjected to the high-energy nitrogen ion irradiation shown in FIG. B have approximately twice the adhesive strength as those without irradiation shown in FIG.

The carbon nitride film produced by the above method was examined by photoelectron spectroscopy. As a result, a bond between carbon and nitrogen was recognized, and it was confirmed that carbon nitride was synthesized. Furthermore, as a result of examining the interface between the carbon nitride film and the base material 13 by the same analysis method, nitrogen and carbon, which are constituent elements of the carbon nitride film, entered the base material 13 and mixed with the carbon nitride and the base material 13. It became clear that a layer was formed.

The substrate 1 on which the carbon nitride film is synthesized
As a result of the SUS ball / carbon nitride film sliding test using No.3, it was found that the coefficient of friction was lower than that of the high-speed tool steel as the base material 13 and the wear width was smaller, resulting in excellent wear resistance. It was also confirmed that.

[0023]

The present invention is configured as described above.
According to the present invention, by simultaneously irradiating the base material with nitrogen-containing ions and carbon vapor, a compound of low reactivity carbon and nitrogen can be synthesized and carbon nitride having high adhesion A membrane can be obtained. As a result, a carbon nitride film product having high adhesion to the substrate and high wear resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a vacuum tank of a carbon nitride film manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of the carbon nitride film manufacturing apparatus.

FIG. 3 is a performance comparison diagram of a carbon nitride film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vacuum tank 11 Vacuum container 12 Substrate holder 13 Substrate 14 Evaporation source 15 Carbon 18 Monitor 20 Ion implantation apparatus 22 Ion source 23 Extraction electrode 24 Mass separator 25 Acceleration tube 26 Scanning tube 31 Ion injection path

[Procedure amendment]

[Submission date] September 1, 1998

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

Claims (3)

[Claims] 1. A method for producing a carbon nitride film, comprising irradiating a substrate held in a vacuum vessel with ions containing nitrogen and simultaneously irradiating it with carbon vapor. 2. An ion irradiation energy of 20 keV or more.
The method for producing a carbon nitride film according to claim 1, wherein the voltage is set to 150 keV. 3. A vacuum vessel in which a base material for forming a carbon nitride film is provided, and an evaporation source provided below the base material in the vacuum vessel and heating and evaporating carbon by an electron beam or the like. And an ion implantation apparatus for generating nitrogen ions and irradiating the substrate with the nitrogen ions.