JP2936790B2 - Thin film forming equipment - Google Patents

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 a hard diamond-like carbon film used for a surface protective material, a hard material, an acoustic material, a heat conductive material, and the like.

[0002]

2. Description of the Related Art An apparatus for forming a hard diamond-like carbon film or the like includes a sputtering apparatus and a microwave plasma C.
There are a VD apparatus, an ECR plasma CVD apparatus, and the like.

[0003]

The hard diamond-like carbon film has a high internal stress and is a chemically stable material, so that it has poor adhesion to other materials. The stainless steel material, which is a constituent material, did not have good adhesion, so the diamond-like carbon film deposited on the wall of the deposition chamber peeled off during evacuation, gas introduction, or deposition, and floated in the deposition chamber. In addition, there were problems in the characteristics, uniformity, and reproducibility of the obtained film. The present invention has been made in order to solve the above problems, and to provide a thin film forming apparatus capable of forming a thin film such as a hard diamond-like carbon film having good characteristics and uniformity with good reproducibility. With the goal.

[0004]

In order to achieve the above object, a thin film forming apparatus according to the present invention uses a high-purity graphite in which an inner wall portion of a film forming chamber and a substrate mounting holder portion are coated with glassy carbon. It is characterized by forming.

[0005]

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

[0006]

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. The 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 be a cavity resonator for microwaves to be introduced. A microwave introduction waveguide 5 is connected to the upper part of the plasma chamber 2 via a microwave introduction window 4 made of quartz or the like. In addition, around the plasma chamber 2, electromagnetic coils 6a,
6b is provided. The strength of the magnetic field generated by the electromagnetic coils 6a and 6b is determined so that the conditions of electron cyclotron resonance by microwaves are satisfied inside the plasma chamber 2. Further, a diverging magnetic field diverging downward can be formed by the electromagnetic coils 6a and 6b.

Further, one end of a gas introduction pipe 7 is connected to the upper part of the plasma chamber 2, 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. 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, or a mixed gas of methane gas, hydrogen gas, and carbon dioxide gas is used.

The film forming chamber 3 is disposed below the plasma chamber 2, and a communication port 10 for communicating with the plasma chamber 2 is provided above the film forming chamber 3. A holder 11 is disposed below the communication port 10, and a substrate 12 is placed on the holder 11.
Can be held. Holder 11 is spindle 13
, And a high-frequency power supply 14 is connected via a support shaft 13 and a matching device 15. The holder 11 is provided with a jacket (not shown) through which cooling water circulates.

In the film forming chamber 3, an openable and closable shutter 16 is provided between the communication port 10 and the holder 11, and the opening of the shutter 16 can be adjusted. Also,
An exhaust port 17 is provided at a lower portion of the film forming chamber 3, and the exhaust port 17 is connected to an exhaust system (not shown). Inside the inner wall portion of the film forming chamber 3 and the inner wall portion of the plasma generating chamber 2, there are provided wall protection plates 18 made of high-purity graphite coated with glassy carbon. Further, the holder 11 and the shutter 16 are formed of high-purity graphite itself coated with glassy carbon.

Next, a method of forming a hard diamond-like carbon film using the thin film forming apparatus will be described. First,
The inside of the plasma chamber 2 and the film forming chamber 3 is 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 via the introduction pipe 7. Here, the gas is introduced while adjusting the control valve 8 to control the flow rate of the film forming gas.

On the other hand, the magnetic coils 6a and 6b provided around the plasma chamber 2 are energized to set the magnetic flux density in the plasma chamber 2 to, for example, 875 gauss. And the waveguide 5
, A microwave having a frequency of 2.45 GHz is introduced into the plasma chamber 2.

By such an operation, in the plasma chamber 2, the frequency of the electrons rotating by the 875 Gauss magnetic field coincides with the microwave frequency 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 a low gas pressure. This plasma is a plasma of a film forming gas. The plasma generated in the plasma chamber 2 is supplied to the electromagnetic coils 6a and 6a.
The plasma flow M flows along the lines of magnetic force of the divergent magnetic field formed by b, and is drawn 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 supply 14 via the matching device 15, the support shaft 13, and the holder 11, positive and negative potentials are applied periodically. As a result, the substrate 1
2 has a negative self-bias. Due to this negative self-bias, positive ions in the plasma of the deposition gas
It is drawn to the second side to form a hard diamond-like carbon film on the substrate 12.

At this time, as described above, inside the inner wall portion of the film forming chamber 3 and the inner wall portion of the plasma generating chamber 2, the wall protection plates 18 made of high-purity graphite covered with glassy carbon are provided. Installed, holder 11 and shutter 1
6 is formed of high-purity graphite coated with glassy carbon itself. This high-purity graphite coated with glassy carbon has high adhesion to a hard diamond-like carbon film. Peeling of the carbon film from the film chamber 3, the inner wall portion of the plasma generation chamber 2, the holder 11 and the shutter 16 is eliminated, 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 covered with glassy carbon is separately attached has been described. An inner wall portion of the generation chamber 2 may be formed. In addition, the hard diamond-like carbon film forming apparatus other than the above-mentioned embodiment also covers the portion exposed to the plasma with high-purity graphite covered with glass-like carbon, thereby forming a thin film having no shutter other than the ECR plasma CVD type. The present invention can be applied to a forming apparatus. Furthermore, the present invention can be applied to a thin film forming apparatus other than a hard diamond-like carbon film as long as the film has good adhesion to high-purity graphite coated with glass-like carbon. For example, W, SiNx, SiOx, etc. The present invention can be applied to a thin film forming apparatus.

[0016]

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 by using high-purity graphite covered with glassy carbon. Peeling of the carbon film from the inner wall portion and the holder is eliminated, and a thin film such as a hard diamond-like carbon film having good characteristics and uniformity can be formed with good reproducibility.

[Brief description of the drawings]

FIG. 1 is a view 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 formation chamber, 4 ... microwave introduction window, 6a, 6b ... electromagnetic coil, 11 ... holder, 1
2 ... board, 13 ... spindle, 14 ... high frequency power supply, 16
...... Shutter, 18 ... Wall protection plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C30B 1/00-35/00 H01L 21/205

Claims (1)

(57) [Claims] 1. A thin film forming apparatus, wherein an inner wall portion of a film forming chamber and a substrate mounting holder portion are formed by using high-purity graphite coated with glassy carbon.