JP2000199065A - Formation of coating film of carbon or essentially consisting of carbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the film quality and adhesion of a coating film by generating the plasma of oxygen to remove a carbon film adhered to the unrequired part in a reaction chamber, carrying a magnetic recording medium into the reaction chamber and forming a coating film on the magnetic recording medium. SOLUTION: By etching gas, a coating film of carbon or essentially consisting of carbon adhered to the place other than the coating film forming face in a substrate at the inside of a reaction vessel or the like is removed by generating the plasma of gaseous oxygen or fluoride. After that, plasma cleaning treatment, e.g. by Ar or active gas such as H2 is executed, and O, O2, CO, CO2 or the like remaining in the inner wall is removed or substituted to clean the inside of the reaction chamber. A magnetic recording medium is carried into the reaction chamber to form a coating film of carbon or essentially consisting of carbon on the magnetic recording medium. Thus, at the tim of the film formation, O, O2, CO, CO2 or the like drops off from the inner wall, is autodoped into the film or is trapped on the boundary and does not deteriorate the film quality and boundary characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning an apparatus for forming a coating containing carbon or carbon as a main component.

[0002]

2. Description of the Related Art Conventionally, carbon films are superior in wear resistance, high smoothness, insulating properties and chemical resistance, and are expected to be applied as materials having many characteristics. As a coating technique, Japanese Patent Application Laid-Open No. 56-146930
A gazette is known.

However, it is difficult to form a film a plurality of times in the same reactor due to a decrease in the degree of vacuum, a problem of flakes, and the like. After forming the film once or twice, the inside of the reactor needs to be cleaned. The gas used for conventional cleaning is
From the components of the solid coating, for example, hydrogen, oxygen, and fluoride gases are used in the case of a carbon-based material in order to generate a volatile gas by a plasma reaction.

[0004]

The technique of etching a carbon film or a film containing a carbon film as a main component is a major problem in applying a carbon film. For example, a method of causing a hydrocarbon gasification reaction to produce a C _x H _y or the like is reacted with carbon film with hydrogen during the etching, although the contamination in the reactor is reduced, the etching speed slower mass There are many problems in terms of gender.

On the other hand, most of the gases used for plasma etching of the carbon film are those in which O ₂ is the simplest and is exhausted as CO, CO _2, etc. by a volatile gasification reaction. O, O ₂ or CO, CO ₂ is adsorbed on the inner wall of the reaction chamber as a film, and when forming a film after cleaning, they are separated from the inner wall, out-phase in the gas phase, and are auto-doped in the film or trapped at the interface , Film quality and interface characteristics (mainly adhesion).

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method for removing a carbon-based coating deposited on a substrate or a substrate other than a coating forming surface of a reaction vessel by a conventional etching gas. The inside of the reaction chamber is cleaned by performing a plasma cleaning process using an inert gas, for example, Ar or an active gas, for example, H ₂ to remove or replace O, O ₂ , CO, CO _2, etc. remaining on the inner wall. It is characterized by the following.

FIG. 1 shows NF ₃ , which is an etching gas,
Using H _2, O ₂ Vickers hardness 1000 kg / mm ² and 2000k
The etching rate and the self-bias generated on the high-frequency application electrode side when a g / mm ² hard carbon film was etched are shown.

In the figure, 図 represents self-bias, □ represents Vickers hardness of 1000 kg / mm ² , Δ represents Vickers hardness of 2000 kg
/ Mm ² represents the etching rate. In this case, the high-frequency energy is 60 W and the flow rate of the etching gas is 50 SC.
CM was carried out at room temperature and at a reaction pressure of 3 Pa.

Next, in the present invention, examples of combinations of etching, cleaning and replacement methods inside the reaction vessel will be described below. [1] O ₂ plasma etching + Ar plasma cleaning [2] NF ₃ plasma etching + Ar plasma cleaning [3] O ₂ plasma etching + H ₂ plasma cleaning [4] NF ₃ plasma etching + H ₂ plasma cleaning [5] H ₂ plasma etching + H ₂ Plasma cleaning

[0010]

EXAMPLES The present invention will be described below with reference to examples.
FIG. 2 shows an outline of a parallel plate type plasma apparatus for performing plasma cleaning after etching and removing carbon or a film containing carbon as a main component used in the present invention.

In the drawing, in the gas system (1), hydrogen as a carrier gas is a gas for etching a carbon film from (2), and a hydrocarbon gas as a reactive gas such as methane and ethylene is a gas from (3). A fluoride gas, for example, NF ₃ from (3), and an etching and cleaning gas such as argon, hydrogen, oxygen, etc. from (4) through a valve (6) and a flow meter (7) into a reaction system (8). In the reaction system (8) introduced from the nozzle (9), a carbon film was formed or the carbon film was etched under reduced pressure.

The reaction chamber (8) has a first electrode (10) and a second electrode (11), and has a pair of electrodes (10), (1).
During 1), a high frequency power source (12) applies a matching transformer (13) and a DC bias power source (14) applies electric energy to generate plasma.

In order to further analyze the reactive gas, a microwave excitation (15) of 200 w to 2 kW may be provided by a microwave of 2.45 GHz. As a result, the amount of the active reactive gas could be increased, and for example, the etching rate of the carbon-based film with oxygen could be improved about four times.

These reactive gases form a reaction space (16).
To 0.01 Torr, for example, 0.1 Torr, and 50 w to 5 kW of energy is applied by electromagnetic energy of high frequency. A DC bias is applied to the film forming surface from -200 to 600 V (substantially -400 to 400 V). Because, when the DC bias is zero, the self-bias is -200 V (second
Is used as the ground level).

A substrate using a Si wafer as a substrate and an Al substrate
After the reaction chamber was cleaned by the method of the present invention using γFe ₂ O ₃ , which is a magnetic recording medium, on the plate of No. 1 above, a carbon-based film was formed by a known method as shown in FIG. A method using only O ₂ plasma process and an etching gas using only H ₂ plasma etching gas as cleaning method of the reaction chamber in this embodiment, then in H ₂ plasma using O ₂ plasma etching gas Cleaning method was performed.

The particle size of the carbon-based film formed in Table 1 was 1
The results of an abrasive test using a diamond paste of 2 μm are shown.

The evaluation was performed in five stages of ○, ○ △, Δ, Δ ×, ×. As a result, a remarkable difference was observed as compared with the case of using only the oxygen plasma etching.

[0018]

[Table 1]

As shown in Table 1, since γFe ₂ O ₃ and a carbon-based film usually form a CO bond at the interface, the adhesiveness may be extremely reduced, and when applied as a protective film for a magnetic disk or the like. It is a big problem.

Therefore, as a result of comparison as shown in Table 1, it is considered that a process not using O ₂ is basically good. However, even if it is used, a process of performing a plasma treatment with H ₂ for replacement is adopted. For example, it was found that the adhesion was greatly improved. In the case of a Si wafer, the chemical bond at the interface is Si-
C, so there is no big difference, but oxygen atoms,
When molecules, radicals, and the like are adsorbed, they cause a decrease in adhesion.

Since the etching rate of the H ₂ plasma etching is extremely low, the throughput is increased, and from the viewpoint of mass productivity, it is considered that a method using both the O ₂ plasma etching and the H ₂ plasma cleaning is good at present.

[0022]

According to the present invention, the reaction chamber can be cleaned using a cleaning gas such as Ar or H ₂ after removing carbon or a film containing carbon as a main component. In addition, when a normal film was formed after cleaning by the above method, a great improvement in adhesion was observed.

For this reason, it has become possible for the first time to use it for a final passivation film of a magnetic recording medium such as a magnetic tape or a magnetic disk. Further, it can be used as an insulating film of a final coating such as a semiconductor integrated circuit.

[Brief description of the drawings]

FIG. 1 is a diagram showing an etching rate and a self-bias in each etching gas.

FIG. 2 is a diagram showing a schematic view of a plasma apparatus used in the present invention.

FIG. 3 is a view showing a substrate used in an example and a carbon-based film formed on the substrate.

Claims (7)

[Claims] 1. A method for forming a coating containing carbon or carbon as a main component on a magnetic recording medium in a reaction chamber, comprising generating oxygen plasma to remove carbon or carbon attached to unnecessary portions in the reaction chamber. Removing the film containing the main component, loading the magnetic recording medium into the reaction chamber, and forming the coating containing the carbon or carbon as the main component on the magnetic recording medium. A method for forming a coating as a component. 2. A method for forming a coating containing carbon or carbon as a main component on a magnetic recording medium in a reaction chamber, comprising generating plasma of a fluoride gas to remove carbon or carbon adhering to an unnecessary portion in the reaction chamber. Removing the film containing carbon as a main component, carrying the magnetic recording medium into the reaction chamber, and forming a film containing carbon or carbon as a main component on the magnetic recording medium. A method for forming a coating mainly composed of 3. A method for forming a carbon or carbon-based coating film on a semiconductor integrated circuit body in a reaction chamber, the method comprising generating oxygen plasma and depositing carbon or carbon adhered to an unnecessary portion in the reaction chamber. Removing the film containing carbon as a main component, carrying the semiconductor integrated circuit into the reaction chamber, and forming a film containing carbon or carbon as a main component on the semiconductor integrated circuit. A method for forming a coating as a main component. 4. A method for forming a film containing carbon or carbon as a main component on a semiconductor integrated circuit body in a reaction chamber, the method comprising generating plasma of a fluoride gas to remove carbon adhering to an unnecessary portion in the reaction chamber. Or removing the film containing carbon as a main component, carrying the semiconductor integrated circuit into the reaction chamber, and forming the film containing carbon or carbon as a main component on the semiconductor integrated circuit. A method for forming a coating mainly composed of carbon. 5. The method according to claim 1, wherein:
A method for forming a carbon- or carbon-based coating film, comprising forming the carbon- or carbon-based coating film by generating a hydrocarbon gas plasma. 6. The method according to claim 1, wherein:
A method for forming a carbon- or carbon-based coating, characterized by forming the carbon- or carbon-based coating by generating plasma by applying high-frequency energy to a hydrocarbon gas. 7. The method according to claim 1, wherein:
2. A method of forming a carbon or carbon-based film by applying energy to the hydrocarbon gas by microwaves of 2.45 GHz to generate plasma. Forming method. Forming a film containing carbon or carbon as a main component.