JPH075433B2 - Method for synthesizing diamond or hard carbon film and method for holding organic compound as raw material thereof - Google Patents

Description

The present invention relates to a method for synthesizing a diamond or hard carbon film suitable for producing a diamond or hard carbon film by a chemical vapor deposition method, and at least methyl alcohol. The present invention relates to a method for holding an organic compound which contains and is suitable for holding an organic compound which is a raw material for a diamond or hard carbon film.

[Outline of Invention]

The present invention relates to a method for synthesizing a diamond or hard carbon film suitable for producing a diamond or hard carbon film by a chemical vapor deposition method, and in particular, it etches non-diamond carbon that is simultaneously formed when diamond is formed, Without supplying a carrier gas for etching other impure carbon and regasifying and removing the non-diamond carbon or other impure carbon so that a good quality hard carbon film is produced even when the carbon film is produced. , An organic compound containing methyl alcohol is used as a substance for forming a diamond or a hard carbon film and as an etching substance, which makes it possible to easily and efficiently form a diamond or a hard carbon film, and a device for forming a diamond or the like. Is designed to be simplified.

Further, the present invention relates to a method for holding an organic compound suitable for holding an organic compound which is a raw material for a diamond or hard carbon film, and in particular, a liquid organic material containing methyl alcohol in a porous body arranged in a reaction vessel. By impregnating and holding the compound, the handling of the organic compound is facilitated, and it is possible to avoid the occurrence of a disaster such as a fire due to the spillage of the organic compound.

[Conventional technology]

For example, JP-A-61-286299, JP-A-61-183198, JP-A-62-202896, JP-A-62-113796 and "Chemistry and Education" Vol. 37, separate volume (1989) Published), etc., describes a diamond synthesis method by a vapor phase growth method.

In this type of diamond synthesizing method, as a diamond-forming substance, a mixed gas of hydrocarbon and hydrogen, an organic compound containing methyl group (gas phase or liquid phase), an oxygen-containing compound containing oxygen, carbon and hydrogen (one kind) Alternatively, two or more kinds are subjected to a gas phase reaction), or those obtained by adding a small amount of an inert gas such as argon to these substances are used.

Also, as decomposition energy, heat, arc discharge, glow plasma, laser light, electron beam, plasma, etc. are used, and further potential is applied, acetylene oxygen flame plasma (within the feather flame) alone, or their energy May be combined and added.

Then, in any of the above-mentioned methods, hydrogen, oxygen, or an inert gas is supplied as a carrier gas to produce diamond, and the carrier gas etches non-diamond carbon produced at the same time as diamond and re-produces it. It is indispensable for gasification and removal.

On the other hand, for example, various raw materials mixed with a small amount of methyl alcohol or other organic compounds used in the production of diamond of this kind are handled as liquid or gas.

[Problems to be Solved by the Invention]

However, when the carrier gas is supplied, the amount of supply of the carrier gas greatly affects the diamond production time, the quality of the produced diamond, etc., and in the worst case, diamond may not be produced.

Therefore, there is a problem that it is difficult to control a good carrier gas supply amount and the device for diamond production becomes complicated in order to supply the carrier gas.

Further, in order to handle a raw material such as methyl alcohol as a liquid or as a liquid, a storage tank or the like is required, which is difficult to handle, and there is a risk of spilling and causing a disaster such as a fire.

The present invention has been made in view of the above conventional problems,
The purpose is that the supply of carrier gas is unnecessary and the production of diamond etc. can be performed easily and with high efficiency.
An object of the present invention is to provide a method for synthesizing a diamond or hard carbon film, which can simplify a device for producing diamond and the like.

In addition, another object of the present invention is to facilitate the handling of an organic compound containing methyl alcohol that is used as a production substance such as diamond, and to provide a raw material for a diamond or hard carbon film capable of avoiding a disaster such as a fire. Another object of the present invention is to provide a method for retaining an organic compound.

[Means for Solving the Problems]

In order to achieve the above object, a method for synthesizing a diamond or hard carbon film according to the present invention is to introduce an organic compound containing methyl alcohol into a reaction container for producing a diamond or hard carbon film, and to carry a carrier in the reaction container. It is characterized in that the methyl alcohol introduced into the reaction vessel is heated or plasma-reacted without supplying gas to generate a diamond or hard carbon film.

Further, the method for holding an organic compound which is a raw material of a diamond or a hard carbon film according to the present invention, a reaction container for producing a diamond or a hard carbon film, salt, glass wool, asbestos, ceramic particles, carbon particles, carbon wool ,
Ceramics adsorbent, inert metal particles, hydrogen storage alloy,
A porous body made of a substance containing at least one of cloth-like glass wool, ceramics wool, fiber or metal fiber is arranged, and a liquid organic compound containing methyl alcohol, which is a raw material for a diamond or hard carbon film, is porous. It is characterized in that it is impregnated into a body and held.

[Action]

In the method for synthesizing a diamond or hard carbon film according to the present invention, an organic compound containing methyl alcohol is used as a raw material for producing a diamond or hard carbon film,
Without supplying a carrier gas into the reaction vessel, methyl alcohol is heated or plasma-reacted in the reaction vessel to form a diamond or hard carbon film.

Further, in the method for holding an organic compound as a raw material of a diamond or hard carbon film according to the present invention, a liquid organic compound containing methyl alcohol as a raw material for producing a diamond or hard carbon film is a porous material arranged in a reaction vessel. Since the material is impregnated and retained, the liquid organic compound can be easily handled, and inconveniences such as spilling of the organic compound can be avoided.

〔Example〕

Hereinafter, preferred embodiments of a method for synthesizing a diamond or hard carbon film and a method for holding an organic compound as a raw material thereof according to the present invention will be described with reference to the drawings.

FIG. 1 shows a diamond synthesizing apparatus (1) used in the present embodiment. This diamond synthesizing apparatus (hereinafter simply referred to as “apparatus”) (1) is a reaction for producing diamond. The container (3), a tank (5) in which liquid methyl alcohol showing a specific example of the organic compound introduced into the reaction container (3) is sealed, and the reaction container (3) are filled with hydrogen. It has a hydrogen check part (7) for confirming the above, and an exhaust confirmation bubbler (9) for confirming that unnecessary gas generated in the reaction vessel (3) during diamond formation is exhausted. ing. The reaction vessel (3) consists of a glass cylindrical body with a rubber stopper (14),
This reaction container (3) is formed by arranging (16).
A substrate support portion (11) on which a plate-like substrate (13) such as molybdenum or silicon that produces diamond is placed.
And a filament (15) is provided, and the filament (1
Current is supplied to 5) from a power supply (17) having a variable resistor.

Further, hydrogen is introduced into the reaction vessel (3) from a hydrogen tank (not shown) via the flow rate control valve (10) and the rubber pipe (12). This hydrogen is for exhausting the air remaining in the reaction vessel (3) before starting the synthesis reaction. Further, methyl alcohol in the tank (5) is introduced into the reaction container (3) through the rubber tube (5a).

In this case, the end portion (5b) of the rubber tube (5a) protruding into the reaction container (3) is filled with a core material (porous body (P)) made of a non-combustible porous body such as glass wool or asbestos. This prevents the methyl alcohol in the tank (5) from flowing out into the tank (5) at the self-confident liquid pressure, and the methyl alcohol molecules are diffused from the larger surface area. This is because the liquid moves through the core material to the heating section due to the capillary phenomenon. As a result, the methyl alcohol molecules are set to diffuse sufficiently and uniformly in the reaction vessel (3) so that better diamond production can be performed.

When diffusing methyl alcohol molecules for such a purpose, as understood from FIG. 2, salt, glass wool, asbestos, ceramic particles, carbon particles, carbon are placed in a cylindrical container (23) with a bottom. A porous body (P) made of wool, a ceramics adsorbent, an inert metal particle, a hydrogen storage alloy, a cloth-like glass wool, a ceramics wool, a substance containing at least one of fibers or metal fibers, or a mixture thereof is prepared. It is also preferable to provide the porous body (P) and impregnate it with methyl alcohol.

In this case, in addition to better diamond production, methyl alcohol can be easily handled.

The method of impregnating the porous body (P) with methyl alcohol is widely applicable when methyl alcohol is used.

The same effect can be obtained by forming the container (23) itself with the porous body (P) or forming the lid of the container (23) with the porous body (P).

Further, the rubber tube (5a) is provided with a vibration imparting means (100) such as an ultrasonic oscillator and a high-frequency vibrating body. Since vibration is applied to methyl alcohol, the methyl alcohol becomes a fine spray to form a reaction container ( 3) is diffused in. As a result, the diamond generation speed is increased, diamond is generated even when the temperature inside the reaction vessel (3) is relatively low, and plasma or the like added to methyl alcohol may have low energy.

In addition, the vibration applying means (100) is the whole reaction container (3),
A configuration in which the tank (5) or the porous body (P) is vibrated is also suitable.

Next, a method for producing diamond using the device (1) will be described.

First, the pitch cock (20) and the flow rate control valve (10) are operated to introduce hydrogen into the reaction vessel (3), and as a result, the air in the reaction vessel (3) is exhausted. At this time, the hydrogen introduced into the reaction vessel (3) is only for exhausting the air in the reaction vessel (3), and this hydrogen does not serve as a conventional carrier gas.

That is, when air is mixed in the reaction container (3), diamond is not generated, and when the amount of air is large, the temperature of the filament (15) and the introduced methyl alcohol cause reaction in the reaction container (3). This is because there is a risk of explosion. Therefore, the air in the reaction vessel (3) is replaced with hydrogen, an inert gas, or the like, or the inside of the reaction vessel (3) is evacuated. Further, when the air in the reaction container (3) is not replaced with the above gas, the filament (15) in the reaction container (3) is slowly heated to remove unnecessary gas generated in the reaction container (3). Is
It is introduced into the exhaust confirmation bubbler (9) through the rubber pipe (3a), the pinch cock (21) and the rubber pipe (9a) and is exhausted. It is also necessary to take care so that air does not leak into the reaction vessel (3) during diamond formation.

Further, whether the air in the reaction vessel (3) has been replaced with hydrogen or not is determined by warming the pinch cock (19) in the test tube (7a) of the hydrogen check section (7) and by arranging the rubber tubes (3a), ( It can be carried out by introducing air in the reaction vessel (3) through 7b), igniting the gas in the test tube (7a), and confirming the explosion sound peculiar to hydrogen. This confirmation work is unnecessary if hydrogen is not used for the first replacement.

Next, the flow rate control valve (10) is closed and the pinch cock (19) is closed, while energization of the filament (15) is started with the pinch cock (21) opened and vibration is applied. The means (100) is driven. When hydrogen is not used for the first replacement, the pinch cock (21) remains open.

As a result, when the filament (15) is heated, its thermal energy causes the methyl alcohol in the tank (5) to be introduced into the reaction vessel (3) through the rubber tube (5a).

At this time, methyl alcohol gradually sublimes and diffuses from the porous body (P), and diamond is formed on the substrate (13) arranged near the filament (15).

Unwanted gas generated in the reaction vessel (3) during the heating of the filament (15) passes through the rubber pipe (3a), the pinch cock (21) and the rubber pipe (9b) and the exhaust confirmation bubbler (9). ), The introduced gas passes through the water in the container (9a) and is then discharged to the outside from the rubber pipe (9c).

Here, when the diamond is formed, the generation process proceeds without introducing a carrier gas such as hydrogen into the reaction vessel (3), and methyl alcohol is introduced by bubbling with hydrogen. Nor. In this case, if the pressure in the reaction vessel (3) is increased by a small amount than the normal pressure or is decreased by a small amount than the normal pressure, the reaction can be performed better.

The substance thus formed on the base body (13) is not affected by delicate synthesis conditions such as the temperature of the filament (15) and the state of the base body (13) (surface treatment, etc.), As can be seen from FIG. 3, the Raman shift value
A laser Raman spectrum unique to diamond having a peak at 1333 [cm ^-1 ] is obtained, and it is confirmed that the product substance on the substrate (13) is diamond.

Further, as can be understood from FIG. 4, it is confirmed that the produced substance is diamond also by its crystal structure.

In this embodiment, the filament (15) has a diameter of 0.
A tungsten wire of 2 [mm] is applied, but by supplying heat energy to methyl alcohol from another secondary heating source that heats the filament (15) to the primary heating source, the filament (15) It is also suitable to reduce the power consumption of the.

And the temperature of the filament (15) is 2000 [℃] -2400
[° C.] is preferable, but according to the present invention, even if the temperature is 1600 [° C.] to 1800 [° C.], diamond can be produced well.

Further, in this embodiment, a filament (15) formed by forming a tungsten wire having a diameter of 0.2 [mm] into a coil having a diameter of 1 [mm] is used, and the number of peaks in the coil portion is
It has been found that 5 to 12 pieces are optimal per 1 cm of the longitudinal direction of the coil, but the volume of the reaction vessel (3), the current value passing through the filament (15), or plasma is used as the energy supply source. It is preferable to appropriately change it in the case of combined use.

Furthermore, according to the present invention, the formation of diamond is favorably performed without the filament (15) being deformed during heating, and, for example, immediately below the filament (15) where the largest diamond crystal is produced, The particle size of diamond can be set to about 50 [μm] to 100 [μm] in 1 hour, and the work for 18 to 20 hours or more can be continuously performed.

In this case, the consumption of methyl alcohol is related to the volume of the reaction vessel (3), the reaction temperature, etc., and was about 3 [ml] to 4 [ml] per hour in this example,
This value changes depending on the energy supplied during the reaction.

On the other hand, the temperature of the substrate (13) was about 500 [° C] to 1000 [° C], but about 900 [° C] is suitable for increasing the reaction rate.

In this case, when plasma or the like is used as the energy source, this temperature is set to be low corresponding to the amount of the energy used in combination.

In order to generate diamond more favorably, the surface of the substrate (13) is previously polished with diamond powder or the like, and the surface of the substrate (13) is etched with desired particles, chemicals, oxygen plasma, etc. Examples of such methods include that a diamond case is generated on the substrate (13) by a flame combustion method using acetylene gas, and the surface of the substrate (13) is plated with a substance that easily produces diamond.

Then, when polishing with a diamond powder, a particle size of about 100 [μm] can be generated in a relatively short time, and by previously generating a diamond case, the diamond layer can be generated during the reaction. .

As described above, when air is mixed in the reaction vessel (3) at the time of diamond formation, it causes an explosion, which is dangerous. Therefore, in the apparatus (1) of FIG. 1 and FIG. If an explosion occurs, the comb stopper (1
When 4) and (16) fall off, they function as a safety valve and are constructed so as not to harm workers.

Further, since the synthesis is performed under normal pressure, it is not necessary to configure the device (1) with a pressure resistant material such as stainless steel, and the device (1)
Can be manufactured at a low price.

In preparation for such an explosion, as is understood from FIG. 5, a through hole (27) is formed in the reaction vessel (3), and a plug (29) is pressure fitted into the through hole (27). It is also preferable to have the configuration.

In this case, a pipe (25) through which cooling water passes is built in the substrate supporting portion (11) of the reaction vessel (3) shown in FIG. 5, and the substrate (13) itself is cooled by the cooling water. The temperature is lowered so that the substrate (13) does not change physically or chemically.

Furthermore, the device (1), as can be seen from FIG.
As a teaching material for chemical experiments conducted at junior high school, high school, etc.
It is possible to configure it simply and compactly. In this case, the container (23) is inserted into the cavity (3A) projecting from the reaction vessel (3) and screwed onto the outer peripheral side surface of this cavity (3A). Supported by the nut member (31).

Alternatively, the porous body (P) impregnated with methyl alcohol may be directly placed inside the nut member (31) without using the container (23).

When manufacturing the device (1) as a teaching material kit,
Since the substrate (3) is made of quartz glass, an expensive metal microscope is not required.
It can also be widely applied as a part of education.

Further, by configuring the device (1) as shown in FIG. 6, even if an explosion occurs in the reaction container (3), it is possible to prevent methyl alcohol from spilling to the outside, so that a fire or the like can be prevented. The danger of can be avoided.

As described above, in this embodiment, a carrier gas such as hydrogen is not supplied at the time of diamond production, and methyl alcohol is used as a diamond producing substance. Therefore, it is not necessary to manage the device for supplying the carrier gas and the supply amount thereof. As a result, diamond can be easily and efficiently produced and the apparatus (1) can be simplified.

Further, since methyl alcohol is impregnated and retained in the porous body (P) made of salt or the like, it is easy to handle and avoids accidents such as fire due to spillage of methyl alcohol. It becomes possible.

The hard carbon film is synthesized in the same manner as in the above embodiment. In addition to methyl alcohol, an organic compound obtained by mixing methyl alcohol with another organic compound (for example, ethyl alcohol, acetone) may be used as the substance for producing diamond or the like, and the porous material may be used. It is also preferable to impregnate (P) with such an organic compound.

Further, as the vibration applying means (100), a structure in which metal, ceramics, semiconductor or the like is irradiated with light to vibrate and the vibration is applied to methyl alcohol is also suitable.

In this case, light from an infrared heating furnace, a far infrared heating lamp, an ultraviolet laser, an infrared laser or an ultraviolet lamp, or light of another wavelength can be condensed and applied.

〔The invention's effect〕

As can be understood from the above description, in the method for synthesizing a diamond or hard carbon film according to the present invention, methyl alcohol is used as a substance for forming a diamond or hard carbon film, and a carrier gas is supplied at all when diamond or the like is formed. Not done. Therefore, it becomes unnecessary to manage the supply amount of the carrier gas and to use the device used for the supply. As a result, it becomes possible to easily and efficiently produce diamond and the like, and it is possible to simplify the apparatus for producing diamond and the like.

Further, in the method for holding an organic compound as a raw material of a diamond or a hard carbon film according to the present invention, since methyl alcohol is impregnated and held in the porous body, the handling of methyl alcohol becomes easy and the methyl alcohol spills out. The effect of avoiding a disaster such as a fire can be obtained.

[Brief description of drawings]

FIG. 1 is an overall schematic view of a diamond synthesizing apparatus according to a preferred embodiment of the present invention, FIG. 2 is an overall schematic view of a diamond synthesizing apparatus according to another embodiment, and FIG. 3 is an example of a laser Raman spectrum (Raman spectrum). (Shift)-(Raman light intensity) curve, FIG. 4 is a photograph showing the structure of a diamond crystal, and FIG. 5 is a block diagram showing an example of the explosion-proof structure of the above device,
FIG. 6 is a schematic configuration diagram of a diamond synthesizing apparatus in still another embodiment. (1) is a diamond synthesizer, (3) is a reaction vessel,
(5) is a methyl alcohol tank, (9) is an exhaust confirmation bubbler, (11) is a base support portion, (13) is a base, (15)
Is a filament, (23) is a container, (100) is a vibration applying means, and (P) is a porous body.

Front Page Continuation (72) Inventor Masafumi Koji 4-3-15 Shinjuku, Shinjuku-ku, Tokyo Reifrat Shinjuku 601 Toyoshin Kagaku Sangyo Co., Ltd. (56) References JP-A-61-163195 (JP, A) JP 63-2897 (JP, A) JP 2-153895 (JP, A)

Claims (3)

[Claims] 1. An organic compound containing methyl alcohol is introduced into a reaction vessel for producing a diamond or hard carbon film, and a carrier gas is not supplied into the reaction vessel.
A method for synthesizing a diamond or a hard carbon film, characterized in that the methyl alcohol introduced into the reaction vessel is heated or plasma-reacted to form a diamond or a hard carbon film. 2. The synthesis of a diamond or hard carbon film according to claim 1, wherein the organic compound is diffused while being vibrated by a vibrating means including an ultrasonic oscillator or a high frequency vibrating body. Method. 3. A reaction vessel for producing a diamond or hard carbon film, containing salt, glass wool, asbestos, ceramic particles, carbon particles, carbon wool, a ceramic adsorbent, an inert metal particle, a hydrogen storage alloy, and a cloth. A porous body made of a substance containing at least one of glass wool, ceramics wool, fibers or metal fibers is provided, and a liquid organic compound containing methyl alcohol, which is a raw material for a diamond or hard carbon film, is added to the porous body. A method for holding an organic compound which is a raw material for a diamond or hard carbon film, characterized in that it is impregnated with and held.