JPS63259079A - Production of diamondlike carbon - Google Patents

Abstract

PURPOSE:To efficiently produce diamondlike carbon at a high rate of deposition by bringing gas obtd. by exciting gas from an org. compd. contg. oxygen or nitrogen as a carbon source into contact with a heated substrate under reduced pressure. CONSTITUTION:Gas from an org. compd. contg. oxygen and/or an org. compd. contg. nitrogen as a carbon source or a mixture of the gas with gaseous hydrogen and/or an inert gas is excited by plasma CVD or other method. The resulting gas is brought into contact with a substrate kept at <=600 deg.C, preferably room temp. - about 400 deg.C under reduced pressure of 10<-9>-10<2>Torr to deposit and form diamondlike carbon on the substrate at a high rate of deposition. Satd. monohydric alcohol, aldehyde or ketone may be used as the org. compd. contg. oxygen and aliphat. nitrile, amine or amide as the org. compd. contg. nitrogen.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing diamond-like carbon, and more specifically, the present invention relates to a method for producing diamond-like carbon. The present invention relates to a method for producing diamond-like carbon that can efficiently produce diamond-like carbon at a high deposition rate.

[Prior art and its problems] In recent years, the technology for synthesizing diamond-like carbon has been making remarkable progress.

To date, we have developed a plasma CVD method that deposits diamond-like carbon by plasma decomposing hydrocarbons, a chemical transport method that deposits diamond-like carbon on the substrate surface using a nonuniform chemical reaction, a hot cathode PIG gun, and a cold cathode PIG gun. Various synthesis techniques have become known, such as ionized vapor deposition using a cathodic PIG gun or a sputter gun.

However, these conventional methods all use hydrocarbons or a mixed gas of hydrocarbons and inert gases such as hydrogen gas and/or argon gas as raw materials, so the deposition rate of diamond-like carbon is slow and production is slow. It was reported that he had a low gender.

[Object of the invention] The object of the invention is to solve the above-mentioned problems and to
A method for producing diamond-like carbon with high deposition rate and high efficiency, regardless of whether it is by method, CVD method, sputtering method, ionization vapor deposition method, or ion beam vapor deposition method. The goal is to provide the following.

[Means for achieving the above object] The outline of the present invention for achieving the above object is as follows: (1) a carbon source gas consisting of an oxygen-containing organic compound and/or a nitrogen-containing organic compound; (2) a carbon source gas and a hydrogen gas and/or A method for producing diamond-like carbon, characterized in that a gas obtained by exciting either a gas or a mixed gas with an inert gas is brought into contact with a substrate at a temperature of 600°C or less under a reduced pressure of 1O-9 to 102 torr. It is.

Examples of the oxygen-containing organic compound include saturated alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, and isobutyl alcohol; n-octanol and nonanol;
2, aliphatic alcohols such as n-decanol, undecanol-2, lauryl alcohol, myristyl alcohol, cetyl alcohol; allyl alcohol, glotyl alcohol, 2-buteno-1, 2-penteno-1
, unsaturated alcohols such as oleyl alcohol; polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polypropylene glycol, glycerin; phenol, cresol, p-torr-butylphenol, p-tert-amylphenol, Phenols such as o-5ec-amylphenol, p-nonylphenol, 0-phenylphenol; formic acid, acetic acid, propionic acid, acetic acid, U-formic acid, caproic acid, enanthic acid, caprylic acid, hexenoic acid, heptenoic acid, octenoic acid, Fats such as lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, and oleic acid: Esters such as decyl probionic acid, decyl butyrate, heptyl butyrate, octyl acetate, vinyl caproate, and propyl caproate: formaldehyde, acetaldehyde , aldehydes such as enantaldehyde, acrolein, crotonaldehyde, and benzaldehyde, ketones such as acetone, vinacolin, mesityl oxide, acetophenone, and benzophenone, and carbon monoxide and carbon dioxide. These may be used alone or in combination of two or more.

Among these, particularly preferred are saturated alcohols such as methanol and ethanol, aldehydes such as formaldehyde and acetaldehyde, and ketones such as acetone and vinacolin.

Examples of the nitrogen-containing organic compound include aliphatic nitriles such as capronitrile, enantonitrile, and caprylonitrile; hexylamine, isohexylamine, heptylamine, octylamine, 2-octylamine, decylamine, undecylamine, laurylamine, and Decylamine, dioctylamine, dioctylamine, dioctylamine, dinonylamine, N-methyl-hexylamine, N-methyl-hebutylamine, N-methyl-octylamine, N,N-dimethyl-hexylamine, N,N
-dimethyl-hebutylamine, N,N-dimethyl-octylamine, N,N-diethyl-laurylamine, N,
N-diethyl-tridecylamine, trimethylamine,
Amines such as triethylamine, trihexylamine, trioctylamine; amides such as hexyl 7mide, heptylamide, octylamide, nonylamide, decylamide, caprylic acid amide, capric acid amide, lauric acid amide, myristic acid amide, etc. It will be done.

These may be used alone or in combination of two or more.

Among these, amines such as trimethylamine and triethylamine are preferred.

In this invention, either the oxygen-containing organic compound or the nitrogen-containing organic compound may be used alone, or
One or more of the oxygen-containing organic compounds and one or more of the nitrogen-containing organic compounds may be used in combination.

The hydrogen gas can be used in combination with a carbon source gas made of the oxygen-containing organic compound and/or the nitrogen-containing organic compound, and in the plasma CVD method, plasma is formed by high frequency or microwave irradiation, and the CVD
In method D, atomic hydrogen is formed by heat or electric discharge.

This atomic hydrogen has the function of removing graphite-structured carbon that precipitates simultaneously with the precipitation of diamond-like carbon, and maintains the SP3 structure of carbon atoms in the precipitated diamond crystals even at high temperatures.

The inert gas is used in combination with the carbon source gas consisting of the oxygen-containing organic compound and/or nitrogen-containing organic compound, especially when a sputtering method, an ionization vapor deposition method, or an ion beam vapor deposition method is employed. It has the effect of ionizing carbon by knocking out carbon atoms by ionizing in the arc discharge space. Examples of this inert gas include argon gas, neon gas,
Examples include helium gas, xenon gas, and nitrogen gas. Further, this inert gas can also be used as a carrier gas in combination with the hydrogen gas when either the plasma CVD method or the CVD method is employed.

In the method of the present invention, the reaction proceeds under the following conditions, and diamond having an amorphous structure, that is, diamond-like carbon, is deposited on the surface of the substrate provided in the reaction chamber.

The mixing ratio of the hydrogen gas and the oxygen-containing organic compound and/or nitrogen-containing organic compound is usually 1,000% hydrogen gas/oxygen-containing organic compound and/or nitrogen-containing organic compound.
It is as follows.

When this mixing ratio exceeds 1000, the precipitation rate of diamond-like carbon may be slowed down or no diamond-like carbon may be precipitated.

The mixing ratio of the inert gas and the oxygen-containing organic compound and/or nitrogen-containing organic compound is usually 1000 or less.

If this mixing ratio exceeds 1000, diamond-like carbon may not be precipitated.

The reaction pressure in the method of this invention, that is, the pressure inside the reaction chamber, is usually 10-9 to 102 torr, preferably 10-9 to 10 torr.
When the temperature is lower than torr, the precipitation rate of diamond-like carbon may be slow or no diamond-like carbon may be precipitated.

The temperature of the substrate surface in this invention is usually room temperature to 80°C.
The temperature is 0°C, preferably room temperature to 400°C. This temperature is 6
Even if the temperature is higher than 00°C, a corresponding effect cannot be obtained.

The diamond-like carbon that can be obtained by the method of this invention is neither diamond crystal nor amorphous carbon or graphitic carbon, and this diamond-like carbon generally has the following physical properties. There is.

Density: approx. 2 g/c layer 3 Vickers hardness: too neoo.

Specific resistance; 1 (-9 to 1014 0 cm refractive index; 1.5 to 2.8 optical band gap; 1.0 to 2.8 eV light transmittance;
Good The diamond-like carbon obtained by the production method of the present invention has high hardness, so it can be used, for example, as a coating for cutting tools, and it has excellent heat dissipation and electrical insulation properties, so it can be used as an electronic material. It can be used for parts.

[Effects of the Invention] According to this invention, (1) the deposition rate of diamond-like carbon is extremely high compared to conventional methods, resulting in high productivity; (2) a wide variety of raw materials are available; 3) Furthermore, since the equipment used in the conventional method can be used as is, it is possible to provide a method for producing diamond-like carbon that has various effects such as the following, which is industrially advantageous.

〔Example〕

Next, Examples and Comparative Examples of the present invention will be shown to explain the present invention in more detail.

(Example 1) Using a 13.58 MHz high frequency power supply using parallel plate electrodes, the substrate temperature was 100°C and the pressure was 10-2 tarr (
F) The output was set to 300W under conditions.

Next, acetone was introduced into the reaction chamber at an i amount of 10 sc, and diamond-like carbon was synthesized by high frequency plasma CVD to obtain a deposit on the substrate controlled at the above temperature. Note that a silicon wafer was used as the substrate. Further, the deposition rate at this time was 470 A/min.

When the obtained deposit was subjected to Raman spectroscopic analysis, the Raman scattering spectrum showed a broad peak around 1500 cm-1, and it was confirmed that it was diamond-like carbon.

(Example 2) Example 1 was repeated except that methanol was used instead of acetone and the flow rate was 20 sccm.

Diamond-like carbon was synthesized by high-frequency plasma CVD in the same manner as in Example 1 above.

At this time, the deposition rate of diamond-like carbon is 360 per minute.
It was a person.

When the obtained deposit was subjected to Raman spectroscopic analysis, the Raman scattering spectrum showed a broad peak around 1500 cm-1, and it was confirmed that it was diamond-like carbon.

(Comparative Example 1) Example 1 except that methane was used instead of acetone and the flow rate was set to 20 scc layer.
Diamond-like carbon was synthesized using the high-frequency plasma CVD method in the same manner as described above.

As a result, the deposition rate of diamond-like) 5 elements was 80% per minute.
A, which was slower than both Examples 1 and 2.

(Example 3) Using a known ionization vapor deposition apparatus, the substrate temperature was 300°C,
Substrate voltage -600v, ion current 5mA, discharge current 0.
Diamond-like carbon was synthesized under the conditions of 4A, magnetic flux density of 200G, and gas pressure of 1O-2 torr using acetone as a carbon source gas. Note that a silicon wafer was used as the substrate. Also, the deposition rate at this time is ooo per molecule.
It was A.

When the obtained deposit was subjected to Raman spectroscopic analysis, the Raman scattering spectrum showed a broad peak around 1500 cm-1, and it was confirmed that it was diamond-like carbon.

(Comparative Example 2) Diamond-like carbon was synthesized in the same manner as in Example 3, except that methane was used instead of acetone.

As a result, the deposition rate of diamond-like carbon was 180 m/min.
A, which was slower than in Example 3.

Patent applicant: Idemitsu Petrochemical Co., Ltd. ・　7：・ Ino

Claims (1)

[Claims] [1] Obtained by exciting either (1) a carbon source gas consisting of an oxygen organic compound and/or a nitrogen-containing organic compound and (2) a mixed gas of a carbon source gas and a hydrogen gas and/or an inert gas Gas, 10^-^9~10^
A method for producing diamond-like carbon, which comprises bringing it into contact with a substrate at a temperature of 600° C. or less under a reduced pressure of 2 torr.