JP2019199635A - Deposition film forming apparatus - Google Patents

Abstract

To provide a deposition film forming apparatus capable forming a high-quality deposition film excellent in uniformity of film thickness and film characteristics and at the same time increasing the productivity.SOLUTION: The deposition film forming apparatus having a reaction vessel 101 which can be decompressed and in which a cylindrical base body 102A is installed, and a plurality of raw material gas discharge holes 142 provided therein, comprises: a cylindrical and metallic first electrode 106 provided between the raw material gas discharge holes and the cylindrical base body and having a plurality of holes in its side wall; voltage application means 118 provided between a second electrode 104 which includes the cylindrical base body and the first electrode and applying an alternating voltage with a frequency of 3 kHz or more and 300 kHz or less; and piping 130 in which a first opening is coupled to an outer peripheral surface of the first electrode and a second opening is coupled to an exhaust port. The piping is configured to exhaust gas flowing into the piping from the first electrode through the plurality of holes.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a deposition film forming apparatus for forming a deposition film on a substrate to be processed, particularly a non-single-crystal deposition film such as amorphous or polycrystalline. The present invention particularly relates to a deposited film forming apparatus for forming a deposited film by a plasma CVD (Chemical Vapor Deposition) method.

Conventionally, various deposited films composed of non-single crystal materials such as amorphous materials have been proposed. For example, an amorphous silicon (hereinafter also referred to as “a-Si”) film is used as a deposited film for an electrophotographic photoreceptor.
A plasma CVD (Chemical Vapor Deposition) method is used to manufacture an electrophotographic photosensitive member (hereinafter also referred to as “a-Si photosensitive member”) on which an a-Si deposited film is formed. In particular, a manufacturing method in which a source gas is excited with high-frequency power (mainly 13.56 MHz) to generate glow discharge and a deposited film is formed on a cylindrical substrate has been put into practical use.

In recent years, there has been a strong demand for higher image quality in electrophotographic apparatuses. Corresponding to this, the uniformity of deposited films (thickness of deposited films and the uniformity of film quality) of electrophotographic photoreceptors has been increased. There is a strong demand for improvements and improved characteristics of deposited films.
Regarding the uniformization of the deposited film, for example, with respect to the introduction method of the source gas, a plurality of tubular cavities serving as a path for the source gas are provided inside the cylindrical electrode constituting the reaction vessel, and gas holes communicating with the tubular cavities are provided. An apparatus for forming a deposited film is disclosed. (See Patent Document 1)
In addition, a technique is disclosed in which a deposited film is formed by applying a crossing voltage having a frequency of 3 kHz or more and 300 kHz or less between an electrode and a cylindrical substrate in place of the high-frequency power (see Patent Document 2).

JP 2001-323375 A Japanese Patent No. 4959029

With the technique as described above, it has become possible to obtain an a-Si photoreceptor in which the thickness of the deposited film and the uniformity of the film characteristics are improved.
However, the market demand level for products using an electrophotographic photosensitive member is increasing day by day, and a higher quality electrophotographic photosensitive member is required.
For example, it has been found that there is room for improvement in the thickness of the deposited film and the uniformity of the film characteristics when a relatively low frequency voltage as described in Patent Document 2 is used.

  In plasma CVD, active species generated by generating plasma between electrodes are deposited on a substrate to form a desired deposited film. At this time, a deposited film is also deposited on the electrode surface exposed to the plasma. When a deposited film is formed by plasma CVD using the one-sided polar discharge disclosed in Patent Document 2, only positive or negative charged particles reach the electrode, so that deposition occurs on the electrode. Charges accumulate on the electrode surface due to the effect of the deposited film. Due to the accumulated electric charge, a spark is generated in a part of the electrode, and strong plasma emission may be generated starting from the spark generation portion.

Due to this strong plasma emission, the plasma intensity around the spark generating portion becomes high, so that the plasma distribution in the discharge space becomes non-uniform, and the uniformity of the deposited film formed on the substrate may be reduced.
It has been frequently observed that this strong plasma emission is generated in the vicinity of a source gas discharge hole for supplying a source gas used for plasma CVD into the reaction vessel.

In addition, when the deposited film having a relatively large thickness is formed as in the above-described electrophotographic photosensitive member, or when the flow rate of the source gas used for plasma CVD is increased, the above strong plasma emission occurs. Cheap. When strong plasma emission occurs, film thickness unevenness occurs, and it may be difficult to form a deposited film with high film thickness uniformity.
When such an electrophotographic photosensitive member is used, image density unevenness due to film thickness unevenness may occur.

The adverse effect caused by the strong plasma emission caused by the accumulation of electric charges in the deposited film on the electrode during the formation of such an electrophotographic photosensitive member is that the low voltage portion disclosed in Patent Document 2 is set to 0 V, and charged particles Even by intermittently stopping the incidence of light, it has not been sufficiently improved.
In addition, during the formation of the deposited film, when dust adheres to the surface of the formed deposited film (hereinafter also referred to as “deposited film forming surface”), abnormal growth occurs on the deposited film starting from the dust. May occur. When abnormal growth occurs in the deposited film of the electrophotographic photosensitive member, the image output from the electrophotographic apparatus is described as an image defect (black spots (“black spots” for convenience even when toner other than black is used). ) Or white spots) may occur.

Further, in the electrophotographic photosensitive member, it is required to improve the quality as described above and at the same time reduce the manufacturing cost of the deposited film.
One effective means for reducing the manufacturing cost is to improve the utilization efficiency of the source gas. The utilization efficiency of the source gas here refers to the rate at which the source gas is used for the deposited film on the substrate. When a predetermined film thickness is formed, if the utilization efficiency is high, a deposited film can be formed in a relatively short time, and the amount of source gas used can be reduced. However, if the utilization efficiency is low, it is difficult to form a deposited film in a short time, and the amount of source gas used increases.

  In particular, when a deposited film having a relatively large film thickness is formed, such as an electrophotographic photosensitive member, the cost of the source gas occupying the manufacturing cost is relatively high, and therefore it is required to reduce the amount of the source gas used. ing. An object of the present invention is made in view of the above-described problems, and provides a deposited film forming apparatus capable of forming a high-quality deposited film excellent in uniformity of film thickness and film characteristics at a low cost. There is to do.

In order to achieve the above-mentioned object, according to the present invention,
A deposition film forming apparatus having a reaction vessel capable of being depressurized and having a cylindrical substrate installed therein, and a plurality of source gas discharge holes provided inside the reaction vessel,
A cylindrical metal first electrode provided between the source gas discharge hole and the cylindrical substrate and having a plurality of holes on a side wall;
Means for applying a cross-seeding voltage having a frequency of 3 kHz or more and 300 kHz or less provided between the second electrode including the cylindrical substrate and the first electrode;
A first port connected to the outer peripheral surface of the first electrode, and a second port connected to the exhaust port;
The pipe is provided with a deposited film forming apparatus that exhausts gas that has passed through the plurality of holes and has flowed into the pipe from the inside of the first electrode.

  According to the present invention, it is possible to provide a deposited film forming apparatus capable of forming a deposited film having excellent uniformity in film thickness and film characteristics and having high utilization efficiency of a source gas when forming the deposited film. It becomes possible.

It is a schematic diagram which shows the example of the manufacturing apparatus for manufacturing the electrophotographic photosensitive member in connection with this invention. It is a schematic diagram which shows the example of the 1st electrode and piping in the manufacturing apparatus for manufacturing the electrophotographic photosensitive member in connection with this invention. It is a schematic diagram which shows an example of the voltage waveform used with the manufacturing apparatus for manufacturing the electrophotographic photoreceptor concerning this invention. It is a schematic diagram which shows the example of the manufacturing apparatus for manufacturing the electrophotographic photosensitive member in connection with the comparative example of this invention. It is a schematic diagram which shows the example of the manufacturing apparatus for manufacturing the electrophotographic photosensitive member in connection with this invention. It is a schematic diagram which shows the example of the manufacturing apparatus for manufacturing the electrophotographic photosensitive member in connection with the comparative example of this invention. It is a schematic diagram which shows the example of the 1st electrode and piping in the manufacturing apparatus for manufacturing the electrophotographic photosensitive member in connection with this invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
1A and 1B are schematic views showing an example of a deposited film forming apparatus for manufacturing an a-Si photosensitive member. FIG. 1A is a longitudinal sectional view, and FIG. 1B is a transverse sectional view.

A second electrode 104 including cylindrical base bodies 102A and 102B and auxiliary base bodies 103A and 103B is installed inside a reaction vessel 101 that can be decompressed and is grounded. The upper wall 108 and the lower wall 109 of the reaction vessel 101 are grounded.
Between the reaction vessel 101 and the second electrode 104, a cylindrical metal first electrode 106 having a plurality of holes on the side surface is provided. The first electrode 106 is grounded via the inner surface of the lower wall 109 of the reaction vessel 101 and the inner surface of the upper wall 108 of the reaction vessel 101.

FIG. 2 is a schematic diagram showing an example of the first electrode 106 and an example in which a pipe 130 is attached to the exhaust surface 106A of the first electrode 106. FIG. A plurality of holes 201 are provided on the side surface of the first electrode 106. (A) is a perspective view, (b) is a plan view, and (c) is a bottom view.
As for piping, one opening (1st opening) is connected with the peripheral face of the 1st electrode.

  As shown in FIG. 1, the other port (second port) of the pipe 130 attached to the exhaust surface 106 </ b> A of the first electrode 106 is an exhaust port 107 provided on the side wall inside the reaction vessel 101. Is connected to the reaction vessel 101 so as to surround the. The gas that has passed through the plurality of holes 201 from the inside of the first electrode 106 and has flowed into the first port side of the pipe 130 passes through the pipe 130 and is discharged from the second port side of the pipe 130 to the exhaust port 107. It is exhausted through.

As described above, the space inside the reaction vessel 101 is divided by the first electrode 106 and the pipe 130 as follows.
Space A-Internal space of the piping 130 Space B-Space surrounded by the inner peripheral surface of the first electrode 106, the upper wall 108 and the lower wall 109 Space C-The inner peripheral surface of the reaction vessel 101, the upper wall 108 and the lower A space surrounded by the wall 109 and other than the space A and the space B.

The second electrode 104 is connected to the power source 118 via the rotating shaft 111. The rotating shaft 111 is insulated from the reaction vessel 101 grounded by the insulating member 105.
The rotation motor 110, the motor gear portion 120, and the rotation shaft gear portion 121 constitute a rotation support mechanism for the cylindrical base bodies 102A and 102B and the auxiliary base bodies 103A and 103B.
A gas block 140 is installed on the side wall of the reaction vessel 101. The gas block 140 is grounded via the reaction vessel 101.

  A plurality of gas blocks 140 are provided so as to surround the first electrode 106 (seven in this embodiment, equidistant from a position facing the exhaust port 107). The gas block 140 has a tubular cavity 141 serving as a path for the source gas, and the source gas discharge hole 142 communicating with the tubular cavity 141 has a shaft on the surface facing the first electrode 106 of the gas block 140. A plurality are formed in the direction. Further, the gas block 140 is connected to a gas supply system including a mixing device 145 including a mass flow controller (not shown) for adjusting the flow rate of the raw material gas and the raw material gas introduction valve 146 via the supply pipe 144. Yes. As a result, the source gas can be supplied into the reaction vessel 101.

  An exhaust port 107 for exhausting the inside of the reaction vessel 101 is provided on the side wall inside the reaction vessel 101. The exhaust system of the reaction vessel 101 includes an exhaust pipe 115 communicated with an exhaust port 107, an exhaust main valve 116, and a vacuum pump 117. The vacuum pump 117 is, for example, a rotary pump or a mechanical booster pump. By using the vacuum gauge 112 to feedback control the exhaust system, the inside of the reaction vessel 101 is maintained at a predetermined pressure.

Hereinafter, an example of a method for producing an electrophotographic photoreceptor using the apparatus of FIG. 1 will be described.
For example, cylindrical bases 102A and 102B and auxiliary bases 103A and 103B whose surfaces are mirror-finished using a lathe are rotatably installed on a base holder (not shown). Next, the source gas introduction valve 146 is also opened to serve as the exhaust in the gas supply system, the exhaust main valve 116 is opened, and the exhaust in the reaction vessel 101 and the gas block 140 is started. Confirm that the pressure is 0.67 Pa or less.

Next, an inert gas for heating, for example, argon gas, is introduced from the mixing device 145 into the reaction vessel 101 through the gas block 140.
The argon gas introduced from the gas block 140 passes through the space C, then passes through the space B, then passes through the space A, and is exhausted out of the reaction vessel 101.
The inside of the reaction vessel 101 is maintained at a predetermined pressure by performing feedback control using a vacuum gauge 112 provided in the reaction vessel 101.

Thereafter, a substrate heater (not shown) is operated to heat the cylindrical substrates 102A and 102B, and the temperature of the cylindrical substrates 102A and 102B is controlled to a predetermined temperature of 20 ° C to 500 ° C. When the cylindrical base bodies 102A and 102B are heated to a predetermined temperature, the inert gas is gradually stopped. At the same time, a predetermined raw material gas for film formation, for example, a material gas such as monosilane (SiH ₄ ), disilane (Si ₂ H ₆ ), methane (CH ₄ ), ethane (C ₂ H ₆ ), or diborane ( A doping gas such as B ₂ H ₆ ) or phosphine (PH ₃ ) is mixed by the mixing device 145 and then gradually introduced into the reaction vessel 101.

The raw material gas introduced from the gas block 140 passes through the space C, then passes through the space B, then passes through the space A, and is exhausted out of the reaction vessel 101 in the same manner as the argon gas described above. Is done.
Next, each source gas is adjusted to a predetermined flow rate by a mass flow controller (not shown) in the mixing device 145. At that time, the opening ratio of the exhaust main valve 116 or the exhaust speed of the vacuum pump 117 is adjusted while looking at the vacuum gauge 112 so that the inside of the reaction vessel 101 is maintained at a predetermined pressure.

After completing the film formation preparation by the above procedure, a laminated film is deposited on the cylindrical substrates 102A and 102B in the order of the lower injection blocking layer, the photoconductive layer, the upper injection blocking layer, and the surface layer. By means of the power source 118, a cross-seeding voltage with a frequency of 3 kHz or more and 300 kHz or less is applied to the second electrode 104 and the first electrode so that the other potential with respect to one potential of the second electrode 104 and the first electrode 106 alternately becomes positive and negative. Applied between the first electrode 106 and the first electrode 106.
Accordingly, plasma is generated in the space between the second electrode 104 and the first electrode 106. Each source gas introduced into the reaction vessel 101 is decomposed by the plasma energy, and a predetermined film is formed on the cylindrical substrates 102A and 102B.

FIG. 3 is a diagram illustrating an example of a voltage waveform applied from the power supply 118.
The potential of the second electrode 104 with respect to the potential of the first electrode 106 is shown with the potential of the first electrode 106 being constant at the ground potential.
In FIG. 3, the range A is a period in which the voltage has an absolute value greater than or equal to the absolute value of the discharge start voltage, and the range B in FIG. 3 is a period in which the voltage has an absolute value less than the absolute value of the discharge sustain voltage. It is. In FIG. 3, T represents a voltage period and is determined by the frequency.
Further, (t / T) × 100 is defined as the duty ratio (%).

  In the deposited film forming apparatus of the present invention, a cross seeding voltage is applied between the second electrode 104 and the first electrode 106. As a result, the plasma is confined in the space B formed by the second electrode 104, the first electrode 106, the upper wall 108 and the lower wall 109. Further, as described above, the raw material gas passes through the space C, then passes through the space B, then passes through the space A, and is exhausted out of the reaction vessel 101. Therefore, since only a few active species diffused from the space B to the space C reach the surface of the gas block 140, the deposits deposited on the surface of the gas block 140 are greatly reduced.

As a result, the above-mentioned strong plasma emission that occurred near the source gas discharge hole 142 on the surface of the gas block 140 was greatly reduced.
This cause is presumed as follows.
The cause of the strong plasma emission is considered as follows.
When a deposited film is formed by plasma CVD using one-sided polar discharge as described above, only charged particles of either positive or negative polarity reach the electrode, so the deposited film deposited on the electrode Electric charges accumulate on the electrode surface due to the influence. For example, when a negative voltage is applied to the second electrode 104, electrons accumulate in the opposing first electrode 106. At this time, the state of charge accumulation varies depending on the deposit on the electrode surface of the first electrode 106 that is opposed.

  In the case where the deposit on the surface of the opposing first electrode 106 is a deposit made of an a-Si film that is deposited on the surfaces of the cylindrical substrates 102A and 102B constituting the second electrode 104, the resistivity Is relatively small, charge accumulation is suppressed. On the other hand, in the case of a deposit in the form of a polymer powder called polysilicon, for example, like the surface of the gas block 140, since the resistivity is relatively large, charge accumulation is promoted. Furthermore, as the thickness of the deposit increases, the resistance increases and charges are more likely to accumulate. Thus, it is considered that a spark is generated in a part of the electrode due to the accumulated electric charge, and strong plasma emission is generated starting from the spark generation portion.

  It has been frequently observed that this strong plasma emission is generated in the vicinity of a source gas discharge hole for supplying a source gas used for plasma CVD into the reaction vessel. Furthermore, when the flow rate of the source gas used for plasma CVD is increased, it may be observed more frequently. For this reason, it is considered that the discharge pressure of the raw material gas is related to the generation of strong plasma emission.

The structure of the deposit changes depending on the temperature of the surface on which the deposit is deposited. In the gas block 140, normal temperature source gas flows inside, and the back side is in contact with the normal temperature atmosphere, so that the surface on the inner surface side of the reaction vessel 101 of the gas block 140 is cooled by heat conduction, and the surface temperature is relatively high. Is low. Therefore, the deposit is likely to be polymerized, and the resistivity is relatively high.
According to the present invention, deposits deposited on the surface of the gas block 140 are greatly reduced, so that charge accumulation is suppressed and strong plasma emission generated near the source gas discharge holes 142 can be significantly suppressed. It has become possible.

  On the other hand, a deposit is deposited relatively thick on the inner surface of the first electrode 106. However, the first electrode 106 is provided with a plurality of holes 201 on the side surface of the first electrode 106 as shown in FIG. Therefore, since there is almost no pressure difference between the space C and the space B, the discharge pressure of the raw material gas supplied to the space B from the plurality of holes 201 is greatly reduced. Furthermore, since the first electrode 106 is installed in a decompressed space, the temperature of the surface is decreased only by heat radiation (heat release), but the temperature decrease due to heat radiation is extremely small. Further, since the gas block 140 is installed between the cylindrical bases 102A and 102B, the surface is easily affected by radiant heat from the cylindrical bases 102A and 102B whose surface is heated and temperature-controlled, and the surface is relatively The temperature is high. Therefore, since a film-like deposit is deposited on the surface of the first electrode 106, the resistivity is relatively low and charge accumulation is suppressed. It is considered that strong plasma emission does not occur on the first electrode 106 due to the above action. Furthermore, according to the present invention, the utilization efficiency of the source gas can be improved.

FIG. 4 shows an apparatus for comparison. The apparatus shown in FIG. 4 is different from the apparatus of the present invention shown in FIG. 1 in that a pipe 130 is not installed on the exhaust surface 106A.
In the case of the apparatus shown in FIG. 4, the source gas introduced from the gas block 140 is first released into the space C. However, a part of the source gas discharged from the space C is exhausted outside the reaction vessel 101 without passing through the space B where the plasma is formed. Such a source gas is unlikely to contribute to the formation of a deposited film deposited on the cylindrical bases 102A and 102B, and thus contributes to reducing the utilization efficiency of the source gas.

  On the other hand, the apparatus of the present invention shown in FIG. 1 has a pipe 130 for exhausting the inside of the reaction vessel 101 connected to the exhaust surface 106A of the first electrode. The raw material gas introduced from the gas block 140 by the pipe 130 passes through the space C, then passes through the space B, then passes through the space A, and is exhausted out of the reaction vessel 101. Therefore, it is possible to reduce the raw material gas that is exhausted outside the reaction vessel 101 without passing through the space B in which the plasma is formed. As a result, the utilization efficiency of the source gas is improved.

In the present invention, the position where the first electrode 106 is installed is not particularly limited as long as it is between the source gas discharge hole 142 and the second electrode 104. The distance between the first electrode 106 and the second electrode 104 may be determined as appropriate depending on the formation conditions (for example, internal pressure in the reaction vessel 101) when forming the deposited film.
In the present invention, the material of the cylindrical first electrode 106 is not particularly limited as long as it is made of metal, but is preferably made of aluminum or stainless steel from the viewpoint of ease of processing and cost.

The thickness of the cylindrical first electrode 106 is not particularly limited as long as the cylindrical shape is not deformed by the stress of the deposited film or heat. From the viewpoint of strength and ease of processing, the thickness is preferably 0.3 mm to 5.0 mm.
The cross-sectional area S1 of the plurality of holes 201 provided on the side surface of the cylindrical first electrode 106 may include different cross-sectional areas, but the same cross-sectional area is preferable from the viewpoint of ease of processing.

The size of the single sectional area S1 of the plurality of holes 201 is not particularly limited. However, when the maximum cross-sectional area of the source gas discharge hole 142 is S2 from the viewpoint of reducing the discharge pressure compared to the source gas discharge hole 142, S1 and S2 are expressed by the following formula (1). It is preferable to satisfy.
S1 ≧ S2 × 10 (1)
In addition, the cross-sectional area S1 is preferably 7 mm ² or more from the viewpoint of further reducing the discharge pressure.

  If the ratio of the area occupied by the plurality of holes 201 on the side surface of the first electrode 106 (hereinafter also referred to as “opening ratio”) is too small, the differential pressure between the space C and the space B described above increases. For this reason, the discharge pressure of the source gas from the plurality of holes 201 is increased. On the other hand, if the aperture ratio is too large, the effect of confining the plasma in the space B is weakened, so that deposits deposited on the gas block 140 increase. Therefore, the opening ratio on the side surface of the cylindrical first electrode 106 is preferably 20% or more and 50% or less.

  Further, the film-like deposit deposited on the surface of the first electrode 106 may not be uniform on the peripheral surface depending on the formation conditions of the deposited film. Specifically, the deposit that is deposited on the exhaust surface 106A where the source gas is directed to the exhaust port may be different from the deposit that is deposited on a region other than the exhaust surface 106A. More specifically, the deposit deposited on the exhaust surface 106A on the space B side where the plasma is formed may become a polymer deposit more than the other regions. Such a phenomenon becomes more apparent when the pressure in the reaction vessel is high as the formation condition of the deposited film, and this polymer deposit floats in the plasma space depending on the case and rarely appears on the deposited film formation surface. It may adhere and become a dust source. This is because the source gas heading from the space B where the plasma is formed to the space A causes stagnation in the peripheral portions of the plurality of hole ends of the first electrode, and as a result, the gas phase reaction is promoted and the polymer deposition is performed. This is because things are generated.

In order to reduce the stagnation of the raw material gas and suppress the formation of polymer deposits, it is preferable to improve the flow of the raw material gas around the hole of the first electrode provided on the exhaust surface 106A. Specifically, as shown in the partially enlarged view of the cross section in FIG. 7C or 7D, the inner peripheral surface side (space B side) of the plurality of holes provided in the first electrode 106 is provided. The end is preferably chamfered.
FIG. 7A is a perspective view showing an overview of the first electrode 106 and the pipe 130, and FIGS. 7B to 7D are partially enlarged views of the cross section of the first electrode 106. FIGS. 3E to 3F are diagrams for specifically explaining the chamfering method.
FIG. 7B shows an example of the hole 201 in which the end portion 201A is not chamfered, and FIGS. 7C and 7D show examples of the hole 201 in which the end portion 201A is chamfered.
The chamfering method applied to the end of the hole is not particularly limited, and may be C chamfering as shown in FIG. 7C or R chamfering as shown in FIG.

The arrangement method of the plurality of holes 201 provided on the side surface of the cylindrical first electrode 106 is not particularly limited, and may be arranged randomly, for example, a 60 ° zigzag type, a square zigzag type, or a parallel type. You may arrange | position with regularity like.
The method of forming the plurality of holes 201 provided on the side surface of the cylindrical first electrode 106 is not particularly limited, and drilling may be performed by a drill, or punching metal processing in which holes are formed by a punching press die. But it ’s okay.

In the present invention, the attachment position (exhaust surface 106A) on the peripheral surface of the first electrode 106 of the pipe 130 will be described with reference to FIG.
FIG. 5 is a cross-sectional view of the deposited film forming apparatus in which a part of the cross-sectional view shown in FIG.
The center of the exhaust port 107 is set to “P”, the center of the second electrode 104 including the cylindrical base bodies 102A and 102B is set to “O”, and the source gas discharge closest to the exhaust port 107 in the source gas discharge hole 142 is performed. The center of the hole 142 is “E”. In the example shown in FIG. 5, seven gas blocks 140 and one exhaust port 107 are arranged at equal intervals at each position obtained by dividing the reaction vessel 101 into eight equal parts in the circumferential direction. Existing.

  Further, when the intersection of PO and the second electrode 106 is “Q” and the intersection of EO and the second electrode 106 is “F”, the region indicated by the arrow 501 in FIG. The pipe 130 is provided in the region from F to F and including Q. This is preferable because the piping 130 does not exist on the straight line in the traveling direction of the source gas ejected from the source gas discharge hole 142 and the distribution of the source gas in the reaction vessel 101 is not disturbed. In addition, it is preferable in terms of symmetry of the distribution of the raw material gas in the circumferential direction that each gas block 140 is provided at a position that is symmetric with respect to a straight line passing through OQP.

In view of improving the utilization efficiency of the source gas, the source gas passes through the space B surrounded by the second electrode 106 and then passes through the space A surrounded by the pipe 130 to be exhausted. preferable. Therefore, it is more preferable that the piping 130 has no hole or the like through which the source gas passes because the source gas exhausted directly from the space C to the space A is reduced.
The attachment position on the exhaust port 107 side of the pipe 130 is not particularly limited as long as a flow of the source gas is formed so that the source gas passes through the space B from the space C and is exhausted from the space A. A part and the piping 130 should just be connected.

  However, it is more preferable to provide the pipe 130 so as to surround the exhaust port 107 in terms of improving the utilization efficiency of the raw material gas because the raw material gas directly exhausted from the space A is reduced. Furthermore, when enclosing the exhaust port 107, it is more preferable that there is no gap or the like through which the source gas passes at the connection portion between the reaction vessel 101 and the pipe 130. For example, it is preferable that the width of the pipe 130 and the width of the exhaust port 107 are substantially equal, and the height of the pipe 130 and the height of the exhaust port 107 are substantially equal.

The material of the pipe 130 is not particularly limited and may be metal or non-metal. However, if the material is the same as the material of the metal cylindrical first electrode 106, the thermal expansion coefficient is the same, and the first electrode 106 is the same. Since it becomes easy to maintain the connection with the pipe 130, it is preferable.
In the present invention, as described above, the deposit deposited on the first electrode 106 is preferably a film rather than a powder in terms of suppressing strong plasma emission. Therefore, in order to keep the surface temperature of the first electrode 106 high as described above, it is preferable that the first electrode 106 has no cooling means.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not restrict | limited at all by these.

<Example 1>
As the cylindrical substrate, an aluminum cylindrical substrate having an outer diameter of 84 mm, a length of 381 mm, and a mirror finish with a thickness of 3 mm was used.
Deposited films (photoconductive layers) for calculating the raw material gas utilization efficiency were formed on the surfaces of the cylindrical substrates 102A and 102B by the method described above using the conditions shown in Table 1 and the voltage waveforms shown in FIG.

Next, the layers shown in Table 2 are formed on the surfaces of the cylindrical substrates 102A and 102B by the method described above using the conditions shown in Table 2 and the voltage waveforms shown in FIG. A photoreceptor was manufactured.
In this embodiment, the first electrode 106 has an inner diameter φ of 3.0 mm, a hole interval (pitch) of 5.0 mm, and an aperture ratio of 28.3 (%). A punching metal of material SUS304 having a thickness of 2.0 mm was used. The “hole interval (pitch)” means the distance between the center of the adjacent first hole and the center of the second hole.
And the said punching metal was made into the cylindrical shape of internal diameter (phi) 150mm as shown in FIG.

The pipe 130 is made of a material SUS304 and a thickness of 2.0 mm, and has a rectangular parallelepiped shape (square tube shape) surrounding the entire exhaust port 107 as shown in FIG.
In addition, as shown in FIG. 5, seven gas blocks 140 and one exhaust port 107 were arranged at equal intervals at each position obtained by dividing the reaction vessel 101 into eight equal parts in the circumferential direction. The width of the pipe 130 is the same as the width of the exhaust port 107, and the height of the pipe 130 is the same as the height of the exhaust port 107. Then, the entire circumference of the end portion of the pipe 130 on the first electrode 106 side was attached to the outer peripheral surface of the first electrode 106 by welding.

At this time, the end on the first electrode 106 side of the upper wall 130-1 (FIG. 2 (a)) constituting the pipe 130 is located on the outer peripheral surface of the first electrode 106 as shown in FIG. 2 (b). Processing was performed so as to match the shape, and welding was performed. By doing in this way, it attached so that there might be no gap as much as possible in the connection part of the outer peripheral surface of the 1st electrode 106, and the upper wall 130-1 of the piping 130. FIG. As shown in FIG. 2C, the lower wall 130-2 of the pipe 130 was also processed into the same shape as the upper wall 130-1 at the end on the first electrode 106 side.
Similarly, the exhaust port 107 side of the piping 130 was similarly attached so that there was no gap as much as possible at the connecting portion.
Further, as shown in FIG. 1, seven gas blocks 140 are arranged at equal intervals from the position facing the exhaust port 107. The source gas discharge holes 142 with a hole diameter of φ0.8 mm were arranged at equal intervals.
In this example, ten cylindrical substrates each having a deposited film for calculating the raw material gas utilization efficiency and ten electrophotographic photosensitive members for evaluating axial charging unevenness were manufactured.

<Comparative Example 1>
In Comparative Example 1, except that the apparatus shown in FIG. 4 was used, a cylindrical substrate on which a deposited film for calculating the raw material gas utilization efficiency was formed and an axial charging unevenness evaluation was performed in the same manner as in Example 1. Ten electrophotographic photoreceptors were produced each.
The apparatus shown in FIG. 4 is the same as the apparatus shown in FIG. 1 except that the pipe 130 is not installed as compared with the apparatus shown in FIG.

<Comparative Example 2>
In Comparative Example 2, a cylindrical substrate on which a deposited film for calculating the raw material gas utilization efficiency was formed in the same manner as in Example 1 except that the apparatus shown in FIG. Ten electrophotographic photoreceptors were produced each.
The apparatus shown in FIG. 6 is the same as the apparatus shown in FIG. 1 except that the first electrode 106 and the pipe 130 are not installed as compared with the apparatus shown in FIG.

<Evaluation of Example 1 and Comparative Examples 1 and 2>
Using the deposited film for calculating the raw material gas utilization efficiency prepared in Example 1 and Comparative Examples 1 and 2, the following items were evaluated for the utilization efficiency of the raw material gas.

(Raw material gas utilization efficiency)
The thickness of the produced deposited film was measured at the following measurement points.
As for the axial direction, the central position of the electrophotographic photosensitive member was set to 0 cm, and a total of 5 points of 0 cm, ± 10 cm, and ± 18 cm were used.
Further, at each axial position, two points were set at 180 ° intervals in the circumferential direction, and a total of 10 points were set as measurement positions. The average value of the film thickness at each measurement point obtained was divided by the deposition film formation time to calculate the deposition film formation rate.
The film thickness was measured by an eddy current method with a probe ETA3.3H attached to FISCHERSCOPE mms (manufactured by HELMUT FISCHER).

Since Example 1 and Comparative Examples 1 and 2 form a deposited film under the same conditions, the higher the deposited film formation rate obtained, the higher the utilization efficiency of the source gas, and the lower the deposited film formation rate. However, the utilization efficiency of the raw material gas is low.
The obtained deposited film formation rates were ranked according to the following criteria. It was judged that the effect of this invention was acquired by D or more.

A: 1.25 times or more compared with Comparative Example 2 B: 1.20 times or more and less than 1.25 times compared with Comparative Example 2 C: 1. Compared with Comparative Example 2 15 times or more and less than 1.20 times D: 1.05 times or more and less than 1.15 times compared with Comparative Example 2 E: Less than 1.05 times compared with Comparative Example 2

(Axial charging unevenness)
The axial charging unevenness of the electrophotographic photosensitive member produced in Example 1 and Comparative Examples 1 and 2 was evaluated as follows.
The manufactured electrophotographic photosensitive member was installed in a modified machine of a copying machine (trade name: iRC6800) manufactured by Canon Co., Ltd., which was modified to have a negative charging and reversal development system. Further, the black developing unit of the copying machine is removed, and a surface potential meter (surface potential meter (trade name: Model 344) manufactured by Trek) and a probe (trade name: Model 555-P)) are installed, and an electrophotographic photosensitive member is installed. The surface potential in the axial direction of the body was measured. First, the electrophotographic photosensitive member was charged under the conditions of a process speed of 265 mm / sec, a pre-exposure (LED with a wavelength of 660 nm) light amount of 4 μJ / cm ^2, and a current value of the main charger of 1000 μA. At this time, the surface potential of the dark part of the electrophotographic photosensitive member was measured with the above-described surface potential meter. The dark portion surface potential was an average value of a total of 360 points at intervals of 1 degree in the circumferential direction.

A total of 8 points (± 2 cm, ± 4 cm, ± 6 cm, ± 8 cm, ± 10 cm, ± 12 cm, ± 14 cm, ± 16 cm) at 2 cm intervals on both sides in the axial direction, with the center position of the electrophotographic photosensitive member being 0 position Measurements were made on 17 points. Then, the obtained potential difference between the maximum value and the minimum value of the dark portion surface potential at each position was defined as charging unevenness.
For each of the 10 electrophotographic photoreceptors produced, charging unevenness was determined, and the average value thereof was defined as axial charging unevenness.
The obtained axial charging unevenness was ranked according to the following criteria. It was judged that the effect of this invention was acquired by D or more.

A: Less than 0.75 times compared with Comparative Example 2 B: 0.75 times or more and less than 0.80 times compared with Comparative Example 2 C: 0.0 compared with Comparative Example 2 80 times or more and less than 0.85 times D: 0.85 times or more and less than 0.95 times compared with Comparative Example 2 E: 0.95 times or more compared with Comparative Example 2

(Overall)
Ranking was performed according to the following criteria based on the evaluation result of (source gas utilization efficiency) and the evaluation result of (axial charging unevenness). It was judged that the effect of this invention was acquired by D or more.
A ... all A
B ... C, D, E are not included, but there is at least one B.
C ... D and E are not included, but there is at least one C.
D ... E is not included, but there is at least one D.
E ... E even one.
Table 3 shows the evaluation results of the items described above.

  From the results shown in Table 3, it was found that the use efficiency of the source gas can be improved by using the deposited film forming apparatus of the present invention. Further, in Comparative Example 2, there was a lot in which strong plasma emission was generated in a part of the gas discharge hole 142, but in the deposited film forming apparatus of the present invention, there was no lot in which strong plasma emission was generated. It was found that uneven charging in the direction can be reduced.

<Examples 2-1 to 2-7>
In Examples 2-1 to 2-7, the cylindrical base on which the deposited film for calculating the raw material gas utilization efficiency was formed by using the apparatus shown in FIG. Ten electrophotographic photosensitive members for each were manufactured and evaluated in the same manner.
However, in this embodiment, the sectional area S1 of the single hole 201 and the aperture ratio of the first electrode 106 were changed by changing the diameter of the hole 201 on the first electrode 106.
Further, the maximum cross-sectional area S2 in the source gas discharge hole 142 was not changed, but the cross-sectional area ratio (S1 / S2) was changed by changing the cross-sectional area S1.
In the present embodiment, all of the source gas discharge holes 142 have the same shape, and the cross-sectional area S2 is 0.502 mm ² .
The evaluation results are shown in Table 4.

From the results shown in Table 4,
The aperture ratio of the first electrode 106 is set to 20% or more and 50% or less, and the single sectional area S1 of the plurality of holes 201 on the first electrode 106 is set to the largest sectional area S2 among the source gas discharge holes. On the other hand, by making it 10 times or more,
It was found that the raw material gas utilization efficiency can be greatly improved and the axial charging unevenness can also be improved (Examples 2-3 to 2-6).
Furthermore, it turned out that it is more effective in the cross-sectional area S1 of the single body of the hole 201 being 7 mm < ² > or more (Examples 2-4 to 2-6).

<Examples 3-1 to 3-7>
In Examples 3-1 to 3-7, by using the apparatus shown in FIG. 1, the cylindrical substrate on which the deposited film for calculating the raw material gas utilization efficiency was formed and the axial charging unevenness evaluation was performed in the same manner as in Example 2. Ten electrophotographic photoconductors were manufactured and evaluated in the same manner.
Also in this example, by changing the diameter of the hole 201 on the first electrode 106, the single sectional area S1 of the hole 201 and the aperture ratio of the first electrode 106 were changed.
Further, the maximum cross-sectional area S2 in the source gas discharge hole 142 was not changed, but the cross-sectional area ratio (S1 / S2) was changed by changing the cross-sectional area S1.
Further, all the source gas discharge holes 142 have the same shape.
However, in this example, the diameter of the source gas discharge hole 142 was 0.5 mm, and the cross-sectional area S2 was 0.196 mm ² .
The evaluation results are shown in Table 5.

From the results shown in Table 5,
The aperture ratio of the first electrode 106 is set to 20% or more and 50% or less, and the single sectional area S1 of the plurality of holes 201 on the first electrode 106 is set to the largest sectional area S2 among the source gas discharge holes. On the other hand, by making it 10 times or more,
It was found that good results were obtained (Examples 3-3 to 3-6).
Furthermore, it turned out that it is more effective in the cross-sectional area S1 of the single body of the hole 201 being 7 mm < ² > or more (Examples 3-4 to 3-6).

<Example 5>
In Example 5, a cylindrical substrate on which a deposited film for calculating the raw material gas utilization efficiency was formed in the same manner as in Example 1 except that the conditions shown in Table 6 were used instead of the conditions shown in Table 2. Ten electrophotographic photoreceptors for evaluation of uneven charging in the axial direction were manufactured and evaluated in the same manner as in Example 1. Further, ten electrophotographic photoreceptors for image defect evaluation described later were produced in the same manner.

  However, in this embodiment, as shown in the partially enlarged view of the cross section of FIG. 7C, the plurality of holes 201 on the exhaust surface 106A surrounded by the pipe 130 for exhausting the inside of the first electrode. A chamfering process was performed on the end portion 201A of the steel plate. The C chamfering process was performed on the end 201A of the hole 201 on the side opposite to the outer peripheral surface to which the pipe 130 is connected (the inner peripheral surface side of the first electrode; the space B side where plasma is formed). Specifically, the C chamfering process was a C0.7 chamfering process for a punching metal having a thickness of 2.0 mm constituting the first electrode 106. As shown in FIG. 7E, C0.7 chamfering means a process in which the shape of the cross-section of the portion to be scraped becomes a right isosceles triangle having an equilateral length of 0.7 mm.

(Evaluation of Example 5)
In addition to the evaluation performed in Example 1, Example 5 was also evaluated by the following method.
(Image defect)
The image defect was evaluated as follows.
The manufactured electrophotographic photosensitive member was installed in a modified machine of a copying machine (trade name: iRC6800) manufactured by Canon Co., Ltd., which was modified to have a negative charging and reversal development system. In addition, the black developing device of the copying machine is removed, and a surface potential meter (a surface potential meter (trade name: Model 344) and a probe (trade name: Model 555-P) manufactured by Trek) is installed, and an electrophotographic photosensitive member is installed. The surface potential was measured.

First, without exposing the laser beam for forming the electrostatic latent image, a solid white image is output, the dark part potential of the surface of the electrophotographic photosensitive member is measured, and the primary current and the grid voltage of the primary charger are adjusted. The dark portion potential on the surface of the electrophotographic photosensitive member was adjusted to −450V.
In order to strictly evaluate the image defects, the images were output under conditions that make it easy for spots to appear. Specifically, by adjusting the DC bias condition of the cyan development condition, an image in which fog (a phenomenon in which toner adheres to a portion that should originally become a non-image area by the development operation) is output. Development at the time of image output was performed only with a developing device using cyan toner.

The fog density was measured according to the following procedure, and an image for evaluation was output under development conditions where the fog density was in the range of 0.4 to 0.8%. The reflectance of the evaluation image was measured, and the reflectance of unused paper was further measured. The value obtained by the following formula was defined as the fog density.
Fog density = (Reflectance value of unused paper) − (Reflectance value of evaluation image)
The reflectance was measured by attaching an amber filter to a white photometer (trade name: TC-6DS) manufactured by Tokyo Denshoku.
The image output was performed in a normal temperature and humidity environment with a temperature of 23 ° C. and a relative humidity of 60%. The same applies to the following.

Using Canon Marketing Japan Co., Ltd. paper and A3 paper (trade name: CS-814 (81.4 g / m ² )) as output paper, 10 solid white images (Laser for forming electrostatic latent image) (Non-exposure) was output and the last two sheets were used for evaluation.
One round of the electrophotographic photosensitive member of the image (= about 264 mm from the front end in the paper conveyance direction) × the size of a circle having a diameter of 0.05 mm or more present within an image area width of 292 mm (a circle having a diameter of 0.05 mm) We counted the number of cyan spots that had a part that protruded from the circle when they were stacked.

Two images were output for each of the two electrophotographic photoreceptors, and the number of spots was counted for each of the four output images. A value obtained by dividing the total count of these spots by 4 and rounding up the decimal point to an integer was used as an evaluation value.
Furthermore, ranking was performed according to the following criteria based on evaluation values.
A ... 2 or less B ... 3 or more and 8 or less C ... 9 or more and 16 or less D ... 17 or more and 29 or less E ... 30 or more

(Overall)
Based on the evaluation results of (raw material gas utilization efficiency), (axial charging unevenness) and (image defect), ranking was performed according to the following criteria. It was judged that the effect of this invention was acquired by D or more.
A ... all A
B ... C, D, E are not included, but there is at least one B.
C ... D and E are not included, but there is at least one C.
D ... E is not included, but there is at least one D.
E ... E even one.
Table 7 shows the evaluation results of the items described above.

<Example 6>
In Example 6, the apparatus shown in FIG. 1 and the method similar to Example 5 were used to form a cylindrical substrate on which a deposited film for calculating the raw material gas utilization efficiency was formed, and an electrophotographic photosensitive member for evaluating axial charging unevenness. And 10 electrophotographic photoreceptors for image defect evaluation were manufactured. And evaluation similar to Example 5 was performed.

However, in this embodiment, as shown in the partially enlarged view of the cross section of FIG. 7D, the plurality of holes 201 on the exhaust surface 106A surrounded by the pipe 130 for exhausting the inside of the first electrode. An end chamfering process was applied to the end portion 201A of the steel plate. The R chamfering process was performed on the end 201A of the hole 201 on the side opposite to the outer peripheral surface to which the pipe 130 is connected (the inner peripheral surface side of the first electrode; the space B side where plasma is formed). Specifically, the R chamfering process was an R0.9 chamfering process for a punching metal having a thickness of 2.0 mm constituting the first electrode 106. R0.9 chamfering means machining in which the shape of the cross section of the portion remaining after machining becomes an arc having a radius of 0.9 mm, as shown in FIG.
Table 7 shows the evaluation results.

From the results shown in Table 7,
Ends of a plurality of holes on the exhaust surface 106A (the inner peripheral surface side of the first electrode) surrounded by the first electrode side port (first port) of the pipe for exhausting the inside of the first electrode By chamfering as in Example 5 or R chamfering as in Example 6.
It has been found that the gas utilization efficiency and the uneven charging in the axial direction are good, and the image defects are also improved.

101 ... Reaction vessel 102A 102B ... Cylindrical substrate 104 ... Second electrode 106 ... First electrode 107 ... Exhaust port 130 ... Pipe 140 ... Gas block 142 ... Raw material gas discharge hole 201 ... Hole 201A ... Chamfered part of hole end

Claims (5)

A deposition film forming apparatus having a reaction vessel capable of being depressurized and having a cylindrical substrate installed therein, and a plurality of source gas discharge holes provided inside the reaction vessel,
A cylindrical metal first electrode provided between the source gas discharge hole and the cylindrical substrate and having a plurality of holes on a side surface;
Means for applying a cross-seeding voltage having a frequency of 3 kHz or more and 300 kHz or less provided between the second electrode including the cylindrical substrate and the first electrode;
A first port connected to the outer peripheral surface of the first electrode, and a second port connected to the exhaust port;
The deposited film forming apparatus, wherein the pipe exhausts gas that has passed through the plurality of holes and has flowed into the pipe from the inside of the first electrode. When the opening ratio of the outer peripheral surface is 20% or more and 50% or less, the sectional area of the single hole is S1, and the largest sectional area of the source gas discharge holes is S2. The deposited film forming apparatus according to claim 1, wherein the S2 satisfies the following expression (1):
S1 ≧ S2 × 10 Expression (1). The deposited film forming apparatus according to claim 2, wherein the cross-sectional area S1 is 7 mm ² or more.   The deposited film forming apparatus according to claim 1, wherein the first electrode has no cooling means. Among the plurality of holes of the first electrode, the plurality of holes surrounded by the first port of the pipe are chamfered at the end of the hole on the inner peripheral surface side of the first electrode. The deposited film forming apparatus according to claim 1, wherein the deposited film forming apparatus is applied.

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