JP2598640B2 - Glow discharge decomposition equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glow discharge decomposition apparatus for manufacturing an electrophotographic photosensitive drum made of, for example, amorphous silicon, and more particularly, to a glow discharge decomposition apparatus over the peripheral surface of the drum. The present invention relates to a glow discharge decomposition apparatus capable of forming a uniform film.

[Prior art and its problems]

Today, electrophotographic photoreceptors using amorphous silicon as a photoconductive layer have been put to practical use, and are rapidly penetrating the market due to their excellent abrasion resistance, heat resistance, photosensitivity characteristics, and pollution-free properties.

The electrophotographic photosensitive member is formed by a glow discharge decomposition method, and has a drum shape. Therefore, a uniform amorphous silicon layer (hereinafter, amorphous silicon is abbreviated as a-Si) over the entire peripheral surface of the drum. It is difficult to form the image, and thus, the electrophotographic characteristics are not uniform over the entire peripheral surface of the photosensitive drum, and there is a problem that a screen obtained by forming an image has uneven quality.

This problem will be described below with reference to the glow discharge decomposition apparatus shown in FIG.

That is, 1 is a cylindrical reaction vessel, 1a is its lid, 1b is its peripheral wall, 2 is a cylindrical glow discharge electrode plate, 3 is a cylindrical conductive substrate support, and 4 is The substrate 4 is a cylindrical substrate for a film, and the substrate 4 is placed on the flange 3a of the substrate support 3, and the peripheral surfaces of both are loosely in contact with each other and are electrically connected to each other. The substrate support 3 is rotationally driven via a rotation shaft 6 by a motor 5 mounted on the substrate, and accordingly, the cylindrical substrate 4 is also rotatable. Also,
The substrate support 3, the rotating shaft 6, the base 1a and the peripheral wall 1b are electrically conductive, and the power input terminal 7 attached to the peripheral wall 1b and the power input terminal 8 attached to the glow discharge electrode plate are The glow discharge is generated between the glow discharge electrode plate 2 and the substrate 4 under such a power application system. Reference numerals 10 and 11 denote ring bodies for electrically insulating the electrode plate 2 and the reaction vessel 1 from each other.

Reference numeral 12 denotes a gas inlet, and 13 denotes a gas outlet. A gas for forming an a-Si film is introduced into the reaction vessel 1 through the gas inlet 12, and then a plurality of gas formed through the electrode plate 2. Gas spout
It is blown out toward the substrate 4 through 14.

When an a-Si photosensitive drum is manufactured, the substrate 4 is driven to rotate under the above-described power application system and gas flow system, and the substrate 4 is further fixed by a heater 15 formed inside the substrate support 3. And an a-Si film is vapor-phase grown on the substrate 4 by glow discharge decomposition. Then, the gas decomposition residual gas generated by the vapor phase growth is discharged through the gas discharge port 13. The arrows in the figure indicate the direction of the gas flow.

However, according to the glow discharge decomposition apparatus as described above, an abnormal discharge occurs in the space region 16 between the substrate 4 and the lid 1a, and this discharge is caused by a discharge in the upper region 4a of the substrate 4 during film formation.
There is a problem that it affects the film formation of Si, whereby a uniform a-Si film is not formed over the entire film formation surface of the substrate, and uniform electrophotographic characteristics cannot be obtained over the entire surface. .

Further, according to the glow discharge decomposition device, the contaminants generated by the glow discharge adhere to the lower surface of the lid 1a or the like as a film or powder, and the contaminants are formed during the formation of the a-Si film. It falls off and enters the film, which causes abnormal growth of the a-Si film or generation of pinholes.

[Object of the invention]

Therefore, an object of the present invention is to solve the above-mentioned problems, to form a uniform film on a substrate surface, and to prevent foreign matter from being mixed during the film formation, whereby a high-performance and highly reliable film formation can be achieved. It is an object of the present invention to provide a glow discharge decomposition device which can be used.

[Means for solving the problem]

According to the present invention, a cylindrical substrate is erected in a reaction chamber into which a film-forming gas is introduced, and a circular glow discharge electrode plate is concentrically arranged so as to include the cylindrical substrate. Yes,
In a glow discharge decomposition apparatus for forming a film on the outer surface of a cylindrical substrate by a glow discharge generated between the envelope substrate and the electrode plate, the upper end of the cylindrical substrate has a length of 5 mm or more and is substantially the same as the cylindrical substrate. placing the auxiliary substrate has a cylindrical with the same diameter, further an insulating disc area S ₂ above the auxiliary substrate, the ratio S ₂ / S ₁ to the cross-sectional area S ₁ of the inner diameter of the electrode plate 90% A glow discharge decomposition device is provided, which is installed as follows.

Hereinafter, the present invention will be described in detail by taking a glow discharge decomposition apparatus capable of manufacturing an a-Si photosensitive drum as an example.

FIG. 1 shows a glow discharge decomposition apparatus according to the present invention, and the same parts as those in FIG.

The glow discharge decomposition apparatus shown in FIG. 1 is a cylindrical auxiliary base having an inner diameter substantially the same as that of the substrate as compared with the apparatus shown in FIG.
17 is placed on the upper end of the upright cylindrical substrate 4, and a disc-shaped insulating member (insulating disc) 18 is provided above the auxiliary base 17. In this way, the auxiliary base 17 and the insulating member 18 are installed in combination as described above, and if there is a proper interval between the insulating member 18 and the electrode plate 2, a uniform film formation is performed over the entire outer surface of the substrate 4. I found that I could do it.

That is, when the insulating member 18 is interposed between the substrate 4 and the reaction chamber upper lid 1a, the glow discharge electrode plate 2 and the substrate 4 are placed under the same power application system as the glow discharge decomposition device shown in FIG.
When a glow discharge is generated between the substrate 4 and the upper surface 1a
No abnormal discharge is generated between them, so that the film forming discharge area near the peripheral surface of the substrate 4 is not affected by the abnormal discharge. However, if only the insulating member 18 is interposed, distortion occurs in the discharge space near the upper part of the substrate, and the same discharge space is not formed between the upper region 4a of the substrate 4 and the other film forming regions. Problems arise. Therefore,
When the auxiliary base 17 is placed on the substrate 4, the substrate 4 and the insulating member 18
Can be separated at appropriate intervals, which allows the upper area
4a and the other film formation areas can be the same discharge space.

The present inventors have repeatedly conducted experiments on the length of the auxiliary base 17 and obtained an appropriate size. As a result, they have found that at least 5 mm or more is required, and preferably 10 mm or more.

Further, when the auxiliary base member 17 and the insulating member 18 are provided as described above, when the disk-shaped insulating member 18 having substantially the same diameter as the inner diameter of the electrode plate 2 is brought into contact with each other, the upper region of the substrate It was found that 4a had a higher deposition rate than the other deposition areas.

To explain this point in detail, according to experiments by the present inventors, as shown in FIG. 3, the cross-sectional area S at the inner diameter of the circular electrode plate 2 that encloses the substrate 4 and is arranged concentrically is shown in FIG. ₁
The ratio of the area S ₂ in the insulating member 18 to S, ie, S ₂ / S ₁
When the a-Si film forming speed of each of the upper region 4a and the central region 4b was measured by changing the number of times, the results shown in FIG. 4 were obtained.

FIG. 4 shows a substrate 4 having a total length of 358 mm and an outer diameter of 108 mm and an inner diameter of 190 mm.
Placed in the interior of the electrode plates 2, further shows the measurement results when placing the auxiliary base 17 of length 60mm on the substrate 4, in the figure, the horizontal axis represents the S ₂ / S ₁ ratio, vertical The axis is the growth rate of the a-Si film at each part of the substrate, and the circles are plots of the film formation rate in the upper region 4a of the substrate (measurement points: 50 mm below the upper end of the substrate). Area 4b and lower area 4c
(Measurement location: the central region 4b is the center of the entire length of the substrate, and the lower region 4c is 50 mm above the lower end of the substrate). The plots of the film formation rates are substantially the same for both 4b and 4c. A and B are respective characteristic curves.

As is clear from the results, it is found that when S ₂ / S ₁ exceeds 90%, a remarkable difference occurs in the growth rate in each substrate region.

According to experiments repeatedly performed by the present inventors, depending on the size of the substrate or the electrode plate, if S ₂ / S ₁ is set in the range of 60 to 90%, preferably 70 to 85%, It has been found that it is advantageous for uniform film formation.

In the present invention, as the material of the insulating member 18, there are ceramics, heat-resistant plastics, glass, and the like. Among them, ceramics are excellent in heat resistance, abrasion resistance, corrosion resistance, insulation resistance against high-frequency current, and the like. Is desirable.

When the insulating member 18 is provided, reactive species are easily deposited on the lower surface 18a of the insulating member 18 due to the glow discharge, and the above-described film formation defect occurs. This problem can be solved by heating within the temperature range.

That is, in the apparatus of the present invention, the insulating member 18 can be brought close to or in contact with the heater 15 disposed inside the substrate support 3, whereby the insulating member 18 can be heated to an appropriate temperature. As a result, the film on the lower surface 18a does not peel off.

According to experiments performed by the present inventors, the temperature of the insulating member 18 was reduced.
It has been found that the above object can be advantageously achieved by setting the temperature within the range of 140 to 400 ° C., preferably 200 to 300 ° C.

〔The invention's effect〕

As described above, according to the glow discharge decomposition device of the present invention,
An auxiliary substrate and an insulating member are provided so that a uniform film can be formed over the entire surface of the substrate, and foreign matter is prevented from being mixed during the film formation by heating the insulating member. A glow discharge decomposition apparatus capable of forming a reliable film is provided.

The present invention is not limited to the above embodiment,
Various changes, improvements, etc. may be made without departing from the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a schematic view of a glow discharge decomposition apparatus of the present invention, FIG. 2 is a schematic view of a conventional glow discharge decomposition apparatus, and FIG. 3 is an internal sectional area of a glow discharge decomposition electrode plate and a disc-shaped insulating member. FIG. 4 is a diagram showing the film formation rate of each part of the substrate with respect to the ratio of the relationship shown in FIG. DESCRIPTION OF SYMBOLS 1 ... Reaction container 2 ... Glow discharge electrode plate 3 ... Conductive substrate support 4 ... Film forming cylindrical substrate 17 ... Auxiliary base 18 ... Insulating member

Claims (1)

(57) [Claims] 1. A tubular substrate is erected in a reaction chamber into which a film forming gas is introduced, and a cylindrical glow discharge electrode plate is concentrically arranged so as to include the tubular substrate. In a glow discharge decomposition apparatus that forms a film on the outer surface of the cylindrical substrate by a glow discharge generated between the cylindrical substrate and the electrode plate,
The upper end of the tubular substrate was placed an auxiliary substrate that the tubular substrate and substantially the same diameter of the cylindrical length 5mm or more, a further insulating disc area S ₂ above the auxiliary substrate A glow discharge decomposition apparatus, wherein the ratio S ₂ / S ₁ to the cross-sectional area S _{1 at} the inner diameter of the electrode plate is set to 90% or less.