JPH04349197A - Apparatus for forming thin film - Google Patents

Abstract

PURPOSE:To prevent the peeling of a film laminated on the wall face of a film forming chamber and to form a thin film good in properties and uniformity with good reproducibility. CONSTITUTION:At the inside of the inner wall parts of a film forming chamber 3 and a plasma generating chamber 2, protective sheets 18... 18 for the wall faces made of high purity graphite coated with glassy carbon are set, and a holder 11 and a shutter 16 are formed by high purity graphite coated with glassy carbon. The high purity graphite coated with glassy carbon has high adhesion for a hard diamond like carbon film, so that the peeling of a carbon film can be eliminated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus for forming hard diamond-like carbon films used for surface protection materials, hard materials, acoustic materials, heat conductive materials, etc.

0002

[Prior Art] Apparatus for forming hard diamond-like carbon films include sputtering equipment, microwave plasma carbon film, etc.
There are VD equipment, ECR plasma CVD equipment, etc.

0003

[Problems to be Solved by the Invention] Hard diamond-like carbon films have high internal stress and are chemically stable substances, so they have poor adhesion to other substances, especially in the main film forming chamber of conventional manufacturing equipment. Because the stainless steel material used as the constituent material did not have good adhesion, the diamond-like carbon film deposited on the walls of the deposition chamber peeled off during vacuum evacuation, gas introduction, or deposition, and floated in the deposition chamber. Moreover, problems have arisen in the properties, uniformity, and reproducibility of the obtained films. The present invention was devised to solve the above problems, and provides a thin film forming apparatus capable of forming a thin film such as a hard diamond-like carbon film with good characteristics and uniformity with good reproducibility. With the goal.

0004

[Means for Solving the Problems] In order to achieve the above object, the thin film forming apparatus of the present invention uses high purity graphite coated with glassy carbon for the inner wall portion of the film forming chamber and the substrate mounting holder portion. It is characterized by forming.

[0005]

[Action] High-purity graphite coated with glassy carbon has excellent characteristics such as plasma resistance, heat resistance, oxidation resistance, and low dust generation rate. It has high adhesion to. Therefore, if the part of the thin film forming apparatus exposed to plasma is formed using this material, the carbon film will not peel off from the wall surface, and a high quality hard diamond-like carbon film etc. can be formed.

[0006]

Embodiment FIG. 1 shows an embodiment in which the present invention is applied to an ECR plasma CVD type hard diamond-like carbon film forming apparatus. This hard diamond-like carbon film forming apparatus 1 includes a plasma chamber 2 and a film forming chamber 3, and the plasma chamber 2 is configured to act as a cavity resonator for microwaves introduced therein. A waveguide 5 for introducing microwaves is connected to the upper part of the plasma chamber 2 via a microwave introduction window 4 made of quartz or the like. Further, around the plasma chamber 2, electromagnetic coils 6a and 6 are provided as a magnetic circuit for plasma generation.
b is provided. The strength of the magnetic field generated by the electromagnetic coils 6a and 6b is determined so that the conditions for electron cyclotron resonance due to microwaves are established inside the plasma chamber 2. Furthermore, a diverging magnetic field that diverges downward can be formed by the electromagnetic coils 6a and 6b.

Furthermore, one end of a gas introduction pipe 7 is connected to the upper part of the plasma chamber 2, and the gas introduction pipe 7 has a control valve 8, and the other end is connected to a gas cylinder 9 filled with a film-forming gas. It is connected. Note that, as the film-forming gas, for example, a single gas such as ethylene gas or benzene gas, a mixed gas of methane gas and hydrogen gas, a mixed gas of methane gas, hydrogen gas, and carbon dioxide gas, etc. are used.

The film forming chamber 3 is located below the plasma chamber 2, and a communication port 10 communicating with the plasma chamber 2 is provided in the upper part of the film forming chamber 3. A holder 11 is arranged below the communication port 10, and a substrate 12 is placed on this holder 11.
It is designed to be able to hold. The holder 11 is a support shaft 13
A high frequency power source 14 is connected via the support shaft 13 and the alignment device 15. Note that the holder 11 is equipped with a jacket (not shown) through which cooling water circulates.

In the film forming chamber 3, a shutter 16 that can be opened and closed is provided between the communication port 10 and the holder 11, and the degree of opening of the shutter 16 can be adjusted. Also,
An exhaust port 17 is provided at the bottom of the film forming chamber 3, and this exhaust port 17 is connected to an exhaust system (not shown). Wall protection plates 18 made of high-purity graphite coated with glassy carbon are installed inside the inner wall portions of the film forming chamber 3 and the plasma generation chamber 2. Further, the holder 11 and the shutter 16 are made of high-purity graphite itself coated with glassy carbon.

Next, a method for forming a hard diamond-like carbon film using this thin film forming apparatus will be explained. first,
The inside of the plasma chamber 2 and the film forming chamber 3 are set to a vacuum state by an exhaust system (not shown). Next, the control valve 8 is opened, and a film-forming gas is introduced into the plasma chamber 2 from the gas cylinder 9 through the introduction pipe 7. Here, the gas is introduced while controlling the flow rate of the film-forming gas by adjusting the control valve 8.

On the other hand, the electromagnetic coils 6a and 6b provided around the plasma chamber 2 are energized to set the magnetic flux density within the plasma chamber 2 to, for example, 875 Gauss. And the waveguide 5
Microwaves with a frequency of 2.45 GHz are introduced into the plasma chamber 2 through the plasma chamber 2.

[0012] Through this operation, in the plasma chamber 2, the frequency of the electrons rotated by the magnetic field of 875 Gauss matches the frequency of the microwave of 2.45 GHz, and electron cyclotron resonance occurs. As a result, in the plasma chamber 2, electrons efficiently absorb energy from microwaves, and high-density plasma is generated at low gas pressure. This plasma is a plasma of film-forming gas. The plasma generated in the plasma chamber 2 is transferred to the electromagnetic coils 6a and 6b.
The plasma flow M flows along the lines of magnetic force of the divergent magnetic field formed by the plasma flow, and is drawn out into the film forming chamber 3 through the communication port 10.

When the shutter 16 in the film forming chamber 3 is opened, the plasma flow M from the plasma chamber 2 is irradiated onto the substrate 12 while the flow rate is adjusted by the shutter 16. Here, since a high frequency voltage is applied to the substrate 12 from the high frequency power source 14 via the alignment device 15, the support shaft 13, and the holder 11, positive and negative potentials are applied periodically. As a result, the substrate 12
negative self-bias occurs. Due to this negative self-bias, positive ions in the plasma of the film-forming gas are transferred to the substrate 12.
A hard diamond-like carbon film is formed on the substrate 12.

At this time, as described above, on the inside of the inner wall of the film forming chamber 3 and the inner wall of the plasma generation chamber 2, there are wall protection plates 18 made of high purity graphite coated with vitreous carbon. installed, holder 11 and shutter 1
6 is made of high-purity graphite itself coated with glassy carbon, and this high-purity graphite coated with glassy carbon has high adhesion to hard diamond-like carbon films, so it is difficult to form There is no peeling of the carbon film from the inner wall portions of the film chamber 3, the plasma generation chamber 2, the holder 11, and the shutter 16, and a high-quality hard diamond-like carbon film can be formed.

In the above embodiment, the case where the wall protection plate 18 made of high-purity graphite coated with glassy carbon was separately installed was explained. It is also possible to form the inner wall portion of the generation chamber 2. In addition, the hard diamond-like carbon film forming apparatus other than the above-mentioned embodiments can also be used to form thin films without shutters other than the ECR plasma CVD type by covering all the parts exposed to plasma with high-purity graphite coated with glassy carbon. The present invention can also be applied to a forming device. Furthermore, the present invention can be applied to thin film forming apparatuses other than hard diamond-like carbon films, as long as the film has good adhesion to high-purity graphite coated with glassy carbon, for example, W, SiNx, SiOx, etc. The present invention can also be applied to a thin film forming apparatus.

[0016]

[Effects of the Invention] As described above, in the thin film forming apparatus according to the present invention, the inner wall portion of the film forming chamber and the substrate mounting holder portion are formed using high purity graphite coated with vitreous carbon. There is no peeling of the carbon film from the inner wall portion and the holder, and a thin film such as a hard diamond-like carbon film with good characteristics and uniformity can be formed with good reproducibility.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to an ECR plasma CVD type hard diamond-like carbon film forming apparatus.

[Explanation of symbols]

2... Plasma chamber, 3... Film forming chamber, 4... Microwave introduction window, 6a, 6b... Electromagnetic coil, 11... Holder, 1
2... Board, 13... Support shaft, 14... High frequency power supply, 16
...Shutter, 18...Wall surface protection plate

Claims (1)

[Claims] 1. A thin film forming apparatus characterized in that an inner wall portion of a film forming chamber and a substrate mounting holder portion are formed using high purity graphite coated with vitreous carbon.