JPH017728Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a film forming apparatus for an amorphous silicon photoreceptor, which forms an amorphous silicon photoreceptor film on a conductive substrate using a plasma state of a gas containing at least Si. .

[Technical background of the invention and its problems]

A conventional amorphous silicon photoreceptor film forming apparatus supports a conductive substrate in a high vacuum chamber, introduces SiH ₄ or a mixed gas containing SiH ₄ into the chamber, and adjusts the pressure to a predetermined pressure. Furthermore, while heating and holding the conductive substrate at a predetermined temperature, a voltage is applied to the counter electrode provided opposite the conductive substrate, thereby creating a mixture containing SiH ₄ between the counter electrode and the conductive substrate. This method generates a plasma state using gas to form an a-Si photoreceptor film on the surface of a conductive substrate.

However, in conventional a-Si photoreceptor film deposition equipment, the asymmetry of the equipment shape causes unstable plasma conditions, so in addition to the metallic a-Si deposited on the conductive substrate, SiH ₄ polymerizes to produce powdered Si.
Therefore, after the a-Si photoreceptor is deposited on the conductive substrate, a large amount of powdered Si accumulates in the chamber. Therefore, the conventional a-Si photoreceptor film forming apparatus requires a long time to remove the powdered Si after each film forming process, which poses a problem in mass productivity.

[Purpose of invention]

The present invention was developed based on the above-mentioned circumstances, and it is possible to efficiently recover powdered Si generated in the chamber during film formation on an a-Si photoreceptor. Another object of the present invention is to provide a film forming apparatus for an a-Si photoreceptor that does not require removing powdered Si in a chamber and has excellent mass productivity.

[Summary of the idea]

In the present invention, a dust trap for recovering powdered Si is provided between the chamber and the exhaust system for discharging the SiH ₄ waste gas inside the chamber to the outside of the chamber. In other words, powdered Si is discharged out of the chamber together with SiH ₄ waste gas by the exhaust force of the exhaust system, and SiH ₄ is released in the dust trap.
The waste gas is allowed to pass through, and only the powdered Si is efficiently recovered.

[Example of idea]

Next, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a cross-sectional side view of a film forming apparatus 1 for an a-Si photoreceptor, which is an embodiment of the present invention, and FIG. 2 is a cross-sectional plan view thereof.

The a-Si photoreceptor film forming apparatus 1 forms a film of the a-Si photoreceptor on the surface of a conductive drum-shaped substrate by creating a plasma state with SiH ₄ gas in a sealed chamber 2. The chamber 2 is annular. The chamber 2 is fixed by a chamber stand 3, and a support stand 5 for supporting the conductive drum-shaped substrate 4 is provided inside the chamber 2. The support stand 5 has a small-diameter disk shape at the top and a large-diameter disk shape at the bottom, and the large-diameter disk-like portion at the bottom is the chamber stand 3.
It is rotatably supported via a bearing 11 at the peripheral end portion. This large-diameter disc-shaped part has 4
A sector-shaped hole 6 is bored, and the edge of the inner wall 6a of the hole 6 is aligned with the edge of the inner wall 3a of the chamber stand 3. Also, a gear groove 6b is provided on the outer wall of the large-diameter disk-shaped portion.
is engraved, and a gear 7 is engaged in this gear groove 6b (Fig. 3). The gear 7 is connected to a drive motor 8 located below it,
Therefore, when the gear 7 is driven by the driving force of the drive motor 8, the support base 5 is rotated. Further, a heater 9 is fixed to a small-diameter disk-shaped portion at the top of the support base 5, and the conductive drum-shaped substrate 4 is attached and supported by the small-diameter disk-shaped portion in a state surrounding the heater 9. Furthermore, in chamber 2, SiH ₄
Introduction pipe 1 for introducing gas into the chamber 2
0 is drawn in through a valve 19 and connected to a cylindrical gas introduction pipe/counter electrode 10a disposed opposite to the conductive drum-shaped substrate 4 supported by the support stand 5. This gas introduction pipe and counter electrode 10
A is for generating a plasma state of SiH ₄ gas between it and the conductive drum-shaped substrate 4 by applying a voltage from the power source 30, and the inner wall thereof has a
It has a plurality of holes 10b for sending SiH ₄ gas into the chamber 2. On the other hand, the opening of the chamber stand 3 is communicated with a dust trap 13 disposed below the chamber 2 through a conical exhaust pipe 12. The dust trap 13 is for collecting the powdered Si accumulated in the chamber 2, and the mesh 1 for capturing the powdered Si inside the dust trap 13.
4 is detachably attached. The dust trap 13 is also connected to an exhaust system 17 consisting of a mechanical booster pump 15 and a rotary pump 16 through an exhaust pipe 18 via a valve 20, and the SiH ₄ gas in the chamber 2 is exhausted to the atmosphere through this exhaust system 17. It is becoming more and more common.

In the a-Si photoreceptor film forming apparatus 1 configured as described above, first, a conductive drum-shaped substrate 4 is attached and supported on a support stand 5 in a chamber 2, and valves 19, 20 are installed.
is closed. In this state, the inside of chamber 2 is operated by a rotary pump and a diffusion pump (not shown).
After drawing a high vacuum of 10 ^-6 torr, valve 19 is opened. When the valve 19 is pulled, the gas introduction pipe 1
SiH ₄ gas flows into the gas introduction pipe/counter electrode 10a at a flow rate of 0 to 100 to 500 SCCM, and is introduced into the chamber 2 through the plurality of holes 10b of the gas introduction pipe/counter electrode 10a. At this time, the valve 20 is also opened, and by opening the valve 20, the exhaust force of the exhaust system 17 consisting of the mechanical booster pump 15 and the rotary pump is adjusted, and the pressure inside the chamber 2 is maintained at 0.01 to 1.0 torr. Here, a power supply 30 is connected to the gas introduction pipe/counter electrode 10a.
13.56MHz radio frequency power is 20W
When ~5Kw is applied, the gas introduction pipe and counter electrode 10
A plasma state of SiH ₄ gas is generated between a and the conductive drum-shaped substrate 4, and film formation of the a-Si photoreceptor onto the conductive drum-shaped substrate 4 is started. At this time, the conductive drum-shaped substrate 4 is heated to 150°C by the heater 9.
It is maintained at ~300°C, and in order to make the temperature distribution uniform in the circumferential direction of the conductive drum-shaped substrate 4,
The conductive drum-shaped substrate 4 is rotated together with the support base 5 by a drive motor 8 .

On the other hand, in the chamber 2 during film formation, other than the metallic a-Si film formed on the conductive drum-shaped substrate 4
Powdered Si is produced by the polymerization of SiH ₄ , but
This powdered Si falls between the gas introduction tube/counter electrode 10a and the conductive drum-shaped substrate 4 due to gravity, passes through the hole 6 of the support base 5, or falls onto the frame between the holes 6. However, since the support stand 15 is being rotated, it is thrown off and reaches the inclined surface of the exhaust pipe 17.
Here, the powdered Si is sucked into the dust trap 13 together with the SiH ₄ waste gas in the chamber 2 by the exhaust force of the exhaust system 17, and is captured by the mesh 14 inside the dust trap 13. The SiH ₄ waste gas passes through the mesh 14, and then passes through the mechanical booster pump 15 and the rotary pump 16.
After passing through a combustion tower and water shower (not shown), it is discharged into the atmosphere.

Therefore, after the film is formed, the powdered Si does not remain in the chamber 2, but is collected in the mesh 14 in the dust trap 13. On the other hand, if a sufficient amount of powdered Si has accumulated in the dust trap 13, the inside of the dust trap 13 can be easily cleaned by removing and replacing the mesh 14.

As described above, according to this embodiment, the powdered Si generated in the chamber 2 is efficiently collected into the dust trap 13 during the film formation of the a-Si photoreceptor, and the powder is returned to the chamber 2 after the film is formed. There is no accumulation of Si.
Further, by removably installing the mesh 14 for capturing powdered Si in the dust trap 13, the powdered Si accumulated in the dust trap 13 can be easily removed.

In addition, in this embodiment, as described above, the support base 5 is attached at the peripheral end of the annular chamber base 3.
is supported and fixed, and a drive motor 8 for rotating this support stand 5 is disposed below the peripheral end of the chamber stand 3. Further, the large-diameter disk-shaped portion of the support base 5 has a sector-shaped hole, and the opening of the chamber base 3 is communicated with the dust trap through a conical exhaust pipe 17. By doing this, the passage space for the powdered Si produced in the chamber 2 to be collected into the dust trap 13 becomes larger, and the powdered Si does not accumulate in various parts of the chamber 2 and is smoothly transferred to the dust trap 13. It gets sucked in. However, the arrangement positions and shapes of the members constituting the film forming apparatus 1 for these a-Si photoreceptors are not limited to those of the present invention, and in this embodiment,
Although the support table 5 is described as rotating, the present invention can also be applied to a film forming apparatus for an a-Si photoreceptor in which the support table 5 does not rotate.

[Effect of idea]

As explained above, according to the present invention, it is possible to efficiently recover the powdered Si generated in the chamber during film formation on an amorphous silicon photoreceptor, and therefore, the powdered Si is collected in the chamber after each film formation. It is possible to provide a film forming apparatus for an amorphous silicon photoreceptor that does not require the removal of Si and is excellent in mass production.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view showing an embodiment of the present invention;
FIG. 2 is a sectional plan view showing the same example, and FIG. 3 is a plan view showing essential parts of the same example. 1... Amorphous silicon photoreceptor film forming apparatus, 2... Chamber, 12, 18... Exhaust pipe,
13...Dust trap, 14...Mesh, 1
5... Mechanical booster pump, 16... Rotary pump, 17... Exhaust system.

Claims (1)

[Claims for Utility Model Registration] (1) In a film forming apparatus for an amorphous silicon photoreceptor that forms a film on a substrate using a plasma state of a material gas containing at least Si in a chamber, the chamber a gas introduction means for introducing the material gas into the film; an exhaust system for discharging gas including waste gas generated during the film forming process; 1. A film forming apparatus for an amorphous silicon photoreceptor, characterized in that it is equipped with a trapping means that allows gas to pass through and captures and recovers powdered Si generated in the chamber. (2) The film forming apparatus for an amorphous silicon photoreceptor according to claim 1, wherein the capturing means is composed of a removable mesh.