JPS6383271A - Production of diamond-like carbon film - Google Patents

Abstract

PURPOSE:To form the title diamond-like carbon film having high hardness and an excellent insulating property on the surface of a substrate with good productivity by introducing an active species formed by an electron cyclotron resonance method and a carbon-contg. gas into a vacuum vessel wherein the film forming substrate is arranged. CONSTITUTION:Gaseous H2 is introduced from an inlet pipe 7 into a plasma producing chamber 1-1 provided with a magnet 3 as a carrier gas, and an H2 plasma active species formed by an electron cyclotron resonance method using a microwave generator 2 and the magnet 3 is introduced into the vacuum reaction chamber 1-2. The substrate 4 heated to about 300 deg.C by a heater 5 is arranged in the vacuum reaction chamber 1-2, and a carbon-contg. gas such as CH4 is supplied directly before the substrate. Diamond-like carbon film having high hardness and extremely low electric conductivity is formed on the substrate 4 by the reaction with the H2 plasma active species.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a diamond-like carbon film used as a decorative coating, a coating for workpieces, and a coating for electronic devices.

[Prior art] One of the methods for manufacturing diamond-like carbon films is low-pressure synthesis, and the methods that have been proposed so far include thermal CV
D method, plasma CVD method (PCVD method), ion beam method (IB method), ion plate ink method (IP method), etc.

In these methods, carbon-containing gas is introduced into the film-forming space using hydrogen gas as a carrier gas, and the substrate is heated to approximately 600 to 1,300°C.
Alternatively, the introduced gas is brought into a plasma state in the film forming space to generate carbon-containing active species (C), and the active species or other active species derived from the active species are applied to the substrate surface. (PCVD method), active species of ionized carbon or carbon-containing gas are generated, and the active species are accelerated and collided with the surface of the substrate by an electric field to form an r& film (IB method and IP Law).

Another method is to manufacture a diamond-like carbon film by electron cyclotron resonance (ECR). For example, E
A method for producing a diamond-like carbon film by applying an accelerating voltage to the CR plasma outlet to draw out ions (Unexamined Japanese Patent Publication No. 6O
-103099), method for producing diamond-like carbon film in ECR plasma generation chamber (JP-A-6O-103098)
, a method of intermittently directing charged particles to a deposition chamber (Unexamined Japanese Patent Publication No. 6)
0-195092 etc. are known.

[Problems to be Solved] However, in the conventional method described above, carbon-containing gas and hydrogen gas are introduced into the film forming space in a mixed state, and these gases are simultaneously activated and decomposed in the mixed state. Active species generated from hydrogen gas (hereinafter referred to as "active species (H)", meaning excited molecules, ion species, and radical species).

) and carbon-containing active species (hereinafter referred to as "active species (C)", meaning excited molecules, ionic species, and radical species) occur simultaneously, and the production rate and activity of each active species It is not possible to independently control the degree of oxidation, and there are considerable restrictions on the degree of freedom in membrane design.

In the case of the thermal CVD method and PCVD method, the degree of vacuum during film formation is relatively low, and in the case of the IB method and IP method, the distance from the position where active species are generated to the substrate surface for film formation is Because of the long distance, the generated carbon-containing active species (C) collide with each other before reaching the substrate surface, resulting in a tire cent-like carbon film (mainly containing carbon with sp3 structure). In the formation of a carbon film), undesirable active species are generated, and this causes the formation of a carbon film (high electrical conductivity, low Vickers hardness) that mainly contains SP2 structure or SP structure carbon. easy to be Also, depending on the type of raw material gas, carbon-containing active species with a large molecular weight are generated, and these active species collide with the surface of the film formed on the substrate for film formation, causing etching or sputtering of the film surface. Another problem is that the film formation rate is suppressed.

In addition, carbon-containing active species (C
) and film formation are performed in the same space, the inner wall surface of the vacuum deposition chamber that forms the space becomes contaminated with adhesion of soot, etc., and this contamination may cause the desired film properties to deteriorate. Even if it is not possible to form a film with a 100% active species, or if the active species generation chamber and film formation chamber are separated from each other as in the IB method, contamination of the inner wall surface of the active species generation chamber is unavoidable. . For this reason, it is necessary to clean the inner wall surface of the vacuum deposition apparatus each time a film is formed, which poses problems in terms of productivity and mass production.

The above points were also a problem in the ECR method.

[Purpose] The present invention has been made in view of the above points, and its main purpose is to propose a method for producing a tire cent-like carbon film that can solve the conventional problems.

Another object of the present invention is to suppress the inclusion of SP2 structure and sp structure carbon, and to easily create a carbon film containing mainly SP3 structure carbon, with extremely low electrical conductivity and high Vickers hardness. The purpose of the present invention is to propose a method for manufacturing a diamond-like carbon film that can be produced using a diamond-like carbon film.

Still another object of the present invention is to propose a method for manufacturing a diamond-like carbon film with excellent productivity and mass production.

[Means for Solving the Problems] The object of the present invention is to introduce active species generated by an electron cyclotron resonance method into a film forming space in which a film forming substrate is arranged by a first introducing means. This is achieved by introducing a carbon-containing gas from the second introducing means and forming a film.

[Function] According to the above-described method for producing a tire cent-shaped carbon film of the present invention, the content of carbon having the SP2 structure and the SP structure is extremely small compared to conventional carbon films, and the carbon film mainly contains carbon having the sp' structure. can be produced with higher efficiency and better reproducibility than in the past, and there is no need to clean the vacuum deposition apparatus itself as in the past.

Furthermore, since the produced film mainly contains carbon with an SP'' structure, it is comparable in hardness to diamond-like carbon films produced by conventional methods. Good electrical quality and IQ electrical conductivity
Extremely small decorative coatings, coatings for workpieces, and passivation coatings for semiconductors, which are as small as -IIΩ-Icm″′ or less,
Furthermore, it is suitable for films constituting new electronic devices.

The present invention will be explained in detail below.

The method for producing a diamond-like carbon film according to the present invention is characterized by the above points, and more specifically, as a preferred embodiment, the active species produced by the ECR method include the active species produced from hydrogen gas ( H) is used, the active species is introduced into the film forming chamber from the inlet of the first introducing means, and separately from this, a carbon-containing gas is introduced into the film forming chamber from the inlet of another introducing means, These are mixed near the substrate surface to form a diamond-like carbon film on the substrate surface, and the mean free path (also) of the carbon-containing active species (C) at that time or the inlet of the carbon-containing gas introduction means is The pressure in the vacuum deposition chamber during film formation is adjusted so that the distance is longer than the distance from the substrate. This pressure adjustment is carried out by controlling the flow rates of the introduced active species (H), the carbon-containing raw material gas, the exhaust speed of the exhaust system, and the like.

In the present invention, by applying a negative electric field to the substrate for film formation, positive ion plasma is efficiently extracted.
By applying a voltage of 200 V), the plasma can be stabilized and a uniform film can be formed.

Furthermore, by pulsing the carbon-containing gas, it is possible to remove the sp and sp2 hybrid carbon in the film using hydrogen gas plasma. The carbon-containing gas used in the present invention is CHs
, C2H6, C:l HA, linear and alicyclic hydrocarbons such as C6H12, CH, OH.

Alcohols such as C, H, OH, halides such as CF, C2F6, aldehydes, ketones, organometallic compounds, etc. can be used alone or in combination of two or more.

笥 Next, a practical example of the present invention will be shown.

Spider Example 1 Figure 1 consists of a vacuum container 1, a micro generator 2, and a magnet 8. Furthermore, the vacuum vessel is comprised of a plasma generation chamber 1-1 and a reaction chamber 1-2. The magnitude of the magnetic field generated by the magnet 3 was made to satisfy the relationship between the microwave frequency V and v-e-B/2 m. m and e are the mass and charge of an electron, respectively.

First, chamber 1 was evacuated and the temperature of the substrate was set at 300°C. 200 SCCM of H2 gas was introduced into the gas line, and 5 CCM of methane gas was introduced through the gas line 8. The pressure is 2.
Once the flow rate was stabilized at 0.times.torr, microwaves of 600 W at a frequency of 2.degree. 45 GHz and a magnetic field of 875 Gauss were applied. The introduction position of methane activated by H2 plasma was set just before the substrate. The deposition rate was on average 10 pm/h. Also, the dark conductivity is 1
0-9Ω-'cm-', the optical bandgap is 2
．． It was 3 eV. Also, the Raman spectrum is 133
It was confirmed that the peak belonged to diamond at 2 cm-'. Compared to other plasma CVD methods, this method has a faster deposition rate (deposition rate ~1) of 1 m/h, methane concentration of 1%), and is comparable in terms of hardness, optical band gap, electrical conductivity, etc. Ta.

[Comparative Example 1] Methane was placed at the same position 8 as hydrogen gas under the same conditions as Example 1.
' and plasma outlet 8''. The properties of the film are shown in Table 1 along with the results of Example 1.

[Example 2] Under the same conditions as in Example 1, a negative potential 9 was applied to the substrate 4. The deposition speed was 8 μm/h, which was lower than that in Example 1, and the dark conductivity was lower, and from the 10th to the 10th -1″Ω″ I c
m''' I. The optical gap was 2.8 eV, and the film was colorless.

[Example 3] A film was formed under the same film forming conditions as in Example 1. The gas was introduced with a period of 20 s and a pulse iJ 10 s.

After 4 hours of deposition, IΔ conductivity IQ-12 to IQ-+4Ω
A film with an optical gap of -1 cm and an optical gap of 3.2 eV was produced. The Raman spectrum also showed a decrease in the intensity attributable to graphite at 1580 cm-'.

[Example 41 A film was formed under the same conditions as in Example 1. Then, 60.01 mol% of 82H was mixed into the methane gas.

Photoconduction was observed in this film, and the dark conductivity was 10-1'~
10-'Ω-ICIn-1, photoconductivity ratio is 103~1O
"There was.

(Effects of the Invention) As explained below, by devising the introduction position of the carbon-containing gas, applying voltage to the substrate, and pulsing the introduction of the carbon-containing gas, diamonds with a high concentration of carbon-containing gas were produced. It becomes possible to deposit carbon films at high speed, and furthermore, sp, s
It has now become possible to deposit a film with a wide optical gap, with less contribution from p2-enhanced carbon atoms. Photoconductive films have also been produced by introducing elements other than carbon atoms into the film.

[Brief explanation of the drawing]

FIG. 1 shows an ECR apparatus for synthesizing a diamond grown elementary film. 1 vacuum container, 1-1 plasma generation chamber, 1-2 reaction chamber. 2 Microwave oscillator 3 81 stones 4 Substrate 5 Substrate overheating heater 6 Exhaust system 7 Hydrogen gas introduction pipe 8.8', 8'', carbon-containing gas introduction pipe 9 DC power supply

Claims (1)

[Claims] Active species generated by electron cyclotron resonance are introduced into a film forming space in which a film forming substrate is placed through a first introducing means, and a carbon-containing gas is introduced through a second introducing means to form a film. A method for producing a diamond-like carbon film.