JP2007119839A - Method for forming deposition film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a deposition film, which reduces a production cost without sacrificing electrical characteristics and can stably produce the film in a high yield. <P>SOLUTION: An apparatus for forming the deposition film has a plurality of cylindrical substrates 107 arranged on the same circumference in a reaction vessel 100 and a discharge electrode 101 installed so as to surround a plurality of the cylindrical substrates 107. The method for forming the deposition film on a plurality of the cylindrical substrates 107 by using the film-forming apparatus and applying a high-frequency power includes setting a deposition rate on the surface of the cylindrical substrate 107 so that a deposition rate on a plane (position A) which faces to the center of a central space 111 surrounded by a plurality of the cylindrical substrates 107 has a ratio of 5% to 30% (both inclusive) with respect to a deposition rate on the plane (position B) which faces to the discharge electrode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus and method for forming a deposited film on a substrate by glow discharge plasma CVD (Chemical Vapor Deposition), and an electrophotographic photosensitive member. In particular, the present invention relates to a method for forming a functional film, particularly a deposited film used for a semiconductor device, an electrophotographic photoreceptor, an image input line sensor, a photographing device, a photovoltaic device, and the like.

  Conventionally, there has been proposed a technique in which an element member used for an electrophotographic photosensitive member is composed of various materials such as selenium, cadmium sulfide, zinc oxide, phthalocyanine, and amorphous silicon (hereinafter referred to as “a-Si”). In particular, non-single crystalline deposited films containing silicon atoms as a main component typified by a-Si, for example, amorphous deposited films such as a-Si compensated with hydrogen and / or halogen (such as fluorine and chlorine) have been proposed. ing. Such an amorphous deposited film is a high-performance, high-durability, non-polluting photoconductor, and some have been put into practical use. As a method for forming such a deposited film, there are a number of conventional methods such as sputtering, thermal CVD for decomposing source gas by heat, photo-CVD for decomposing source gas by light, and plasma CVD for decomposing source gas by plasma. The method is known. In the plasma CVD method, a raw material gas is decomposed by glow discharge such as direct current or high frequency (RF or VHF) or microwave, and is formed into a thin film on a conductive substrate such as glass, quartz, heat-resistant synthetic resin film, stainless steel or aluminum. A deposited film is formed. This plasma CVD method is currently in practical use in a method for forming an a-Si deposited film for electrophotography, and many apparatuses have been proposed.

  For example, a photoconductive member in which a surface protective layer is provided on a photoconductive layer described below is known. The photoconductive layer of the photoconductive member is made of an amorphous material mainly containing silicon atoms and containing at least one of hydrogen atoms and halogen atoms. The surface protective layer is made of a non-photoconductive amorphous material containing silicon atoms and carbon atoms as a base and containing hydrogen atoms.

  A method of forming a deposited film made of a-Si or the like by these conventional techniques is performed as follows, for example.

  FIG. 5 schematically shows an example of a deposited film forming apparatus (see Patent Document 1) that performs an RF plasma CVD method using a 13.56 MHz high-frequency power source, which is provided for producing an electrophotographic photosensitive member. Yes.

  This deposited film forming apparatus includes a reaction vessel 401 and an exhaust device 408 for depressurizing the inside of the reaction vessel 401. In the reaction vessel 401, a cylindrical substrate 402 is installed on a conductive pedestal 407 connected to ground, and further, a substrate heater 403 for the cylindrical substrate 402 and a source gas introduction pipe 405 are installed. ing. In addition, a discharge electrode 406 made of a conductive material is provided and insulated by an insulator 413. A high frequency power supply 412 of 13.56 MHz is connected to the discharge electrode 406 via a matching box 411.

  Each cylinder constituting source gas supply means (not shown) is connected to a gas introduction pipe 405 in the reaction vessel 401 via a source gas introduction valve 409.

  Hereinafter, an example of a conventional method for forming an electrophotographic photoreceptor using the apparatus of FIG. 5 will be described.

  For example, a cylindrical substrate 402 whose surface is mirror-finished using a lathe is attached to the conductive cradle 407 so as to surround the substrate heater 403 in the reaction vessel 401.

Next, the main valve 415 is opened to evacuate the reaction vessel 401 and the source gas introduction pipe 405. When the reading of the vacuum gauge 410 becomes 0.67 Pa or less, the source gas introduction valve 409 is opened, and an inert gas for heating, for example, argon is introduced into the reaction vessel 401 from the source gas introduction tube 405. Then, the flow rate of the inert gas for heating and the opening of the main valve 415 or the exhaust speed of the exhaust device 408 are adjusted so that the inside of the reaction vessel 401 has a desired pressure. Thereafter, a temperature controller (not shown) is operated to heat the cylindrical substrate 402 by the substrate heater 403, and the temperature of the cylindrical substrate 402 is controlled to a desired temperature of 20 ° C to 500 ° C. When the cylindrical substrate 402 is heated to a desired temperature, the inert gas is gradually stopped, and at the same time, a predetermined source gas for film formation is gradually introduced into the reaction vessel 401. Raw material gas is, for example, the material gas or the like _{SiH 4, Si 2 H 6,} CH 4, C 2 H 6, a doping gas such as B ₂ H _6, PH _3, is mixed by the gas supply means (not shown) After that, it is introduced into the reaction vessel 401. Next, the raw material gas is adjusted to a predetermined flow rate by a mass flow controller (not shown). At that time, the opening of the main valve 415 or the exhaust speed of the exhaust device 408 is adjusted while looking at the vacuum gauge 410 so that the pressure in the reaction vessel 401 is maintained at 0.1 Pa to several hundreds Pa.

  After completing the film formation preparation by the above procedure, a photoconductive layer is formed on the cylindrical substrate 402. After confirming that the internal pressure is stable, the high-frequency power source 412 is set to a desired power and high-frequency power is supplied to the discharge electrode 406 to cause a high-frequency glow discharge. At this time, the matching box 411 is adjusted so that the reflected wave is minimized, and the effective value obtained by subtracting the reflected power from the high frequency incident power is set to a desired value. With this discharge energy, the source gas introduced into the reaction vessel 401 is decomposed, and a predetermined deposited film is formed on the cylindrical substrate 402. During film formation, the cylindrical substrate 402 may be rotated at a predetermined speed by a driving device (not shown). After the deposition film having a desired thickness is formed, the supply of the high frequency power is stopped, the flow of the raw material gas into the reaction vessel 401 is stopped, the inside of the reaction vessel 401 is once raised to a high vacuum, and then the deposition film forming step Finish. The photoconductive layer is formed by repeating the above operation.

  Even when the a-Si-based surface protective layer of the present invention is formed, the same procedure as described above can be performed only by changing the necessary source gas.

These techniques improve electrical, optical, and photoconductivity characteristics, and further improve image quality.
Japanese Patent Laid-Open No. 10-63024 JP 60-168156 A JP-A-60-178457 JP-A-60-225854 JP-A-61-231561

  With such a conventional deposited film forming method and apparatus, a deposited film having practical characteristics and uniformity to some extent can be obtained. In particular, the RF plasma CVD method using the RF band as the high frequency power among the film formation methods by the plasma CVD method has a feature that a film having good characteristics can be easily obtained. Therefore, the electrophotographic photosensitive film using a-Si is used. Widely used in body production.

  However, in recent years, demands from the market for electrophotographic apparatuses have become stricter year by year, and not only higher image quality, higher speed, higher durability, and higher functionality are required, but also the cost of the main body and running cost are reduced. Price competition is also intensifying. As a result, electrophotographic photoreceptors using a-Si are required not only to improve electrical characteristics and image quality as in the past, but also to lower-cost and inexpensive members. It was.

  However, an electrophotographic photosensitive member using a-Si has to have a thick film in order to obtain sufficient charging ability because of the high dielectric constant of a-Si, and in some cases, the thickness is 10 μm to 100 μm. A deposited film having a thickness must be formed. However, in the manufacturing method using the RF plasma CVD method, since it is difficult to increase the deposition rate, the film forming process requires a long time, and the production cost tends to increase.

  In addition, as shown in FIG. 5, the conventional plasma CVD apparatus has many coaxial film forming apparatuses. In this case, the plasma state around the cylindrical substrate 402 is symmetrical, and a uniform film thickness and film quality can be obtained. There is a merit that However, this plasma CVD apparatus can obtain only one electrophotographic photosensitive member per one film-forming furnace, and there is a demerit that the production amount per one film-forming furnace inevitably becomes low.

  Conventionally, improvement of the deposition rate has been studied as one attempt to increase the production amount per film forming furnace. However, if the deposition rate is increased, the film quality of the deposited film will inevitably deteriorate, and the characteristics as an electrophotographic photosensitive member will deteriorate, resulting in a tradeoff between production capacity and characteristics, and satisfactory results have been obtained. There was no current situation.

  Accordingly, an object of the present invention is to solve the problems in the conventional electrophotographic photosensitive member described above, and specifically to reduce the manufacturing cost without sacrificing the electrical characteristics, and to achieve a stable production with a high yield. It is to provide a film forming method.

  A feature of the present invention is that a reaction vessel capable of depressurization, a plurality of cylindrical substrates disposed on the same circumference inside the reaction vessel, a raw material gas introducing means, and a plurality of cylindrical substrates are disposed so as to surround the plurality of cylindrical substrates. The discharge gas is applied to the discharge electrode, high-frequency power is applied to the discharge electrode, and glow discharge is generated in the reaction vessel, so that the raw material gas introduced into the reaction vessel is decomposed and deposited on a plurality of cylindrical substrates. The deposition rate on the surface of the cylindrical substrate is set to a surface facing the center of the central space surrounded by the plurality of cylindrical substrates with respect to the deposition rate on the surface facing the discharge electrode. The deposition rate ratio is set to be 5% or more and 30% or less.

  According to the present invention, it is possible to provide a method for forming a deposited film that can be manufactured stably with a high yield without reducing the manufacturing cost without sacrificing the electrical characteristics.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, the background to the present invention will be described. As a result of diligent studies to achieve the above-mentioned object, the present inventors abandoned the idea of the conventional coaxial-type deposited film forming apparatus, and arranged a plurality of cylindrical substrates at equal intervals on the same circumference, A deposited film forming apparatus having a configuration in which a discharge electrode surrounding the cylindrical substrate is installed was considered. In this deposited film forming apparatus, a large number of electrophotographic photosensitive members can be produced by a single film formation by applying a high frequency power to the discharge electrode to generate a glow discharge between the cylindrical substrate and the discharge electrode. In this case, since the number of photoconductors manufactured per film forming apparatus is greatly increased, a significant cost reduction can be expected as a result.

  However, when an experiment is actually performed, the electrical characteristics of the obtained electrophotographic photosensitive member are inferior to those of the photosensitive member obtained by the coaxial deposited film forming apparatus (single-removal furnace). It turned out to be difficult to obtain equivalent characteristics. In order to investigate the cause, film formation was performed with the cylindrical substrate stationary, and the unevenness in the characteristics in the circumferential direction was examined. As a result, the characteristics of the deposited film on the surface facing the outer side of the reaction vessel, that is, the surface facing the discharge electrode, were the same as or better than those of the coaxial single furnace. However, the characteristics of the deposited film on the surface facing the inner side of the reaction vessel, that is, the surface facing the center of the central space surrounded by the cylindrical substrate, are considerably inferior to those of the coaxial single furnace. Turned out to be. In this deposited film forming apparatus, high-frequency power is applied to the discharge electrode, and a plurality of cylindrical substrates installed inside function as counter electrodes of the discharge electrode. That is, a sufficient high-frequency electric field acts on the surface of the cylindrical substrate facing the discharge electrode, and a deposited film having a good film quality is formed. However, the high-frequency power from the discharge electrode does not work sufficiently on the opposite surface, that is, the region facing the central space surrounded by the cylindrical base body, resulting in a weak electric field. Therefore, it is assumed that the decomposition and excitation of the source gas are insufficient and the film characteristics of the deposited film are deteriorated.

  As a method for solving this problem, the present inventors have thought that the adhesion amount of the deposited film deposited in the region facing the space surrounded by the cylindrical substrate may be reduced as much as possible. That is, the inventors considered that the intervals between a plurality of cylindrical base bodies installed at equal intervals on the same circumference are made close to each other so that the plasma does not enter the inside (center space side). As a result, compared with the deposition rate on the surface facing the discharge electrode, the deposition rate in the region facing the central space surrounded by the cylindrical substrate could be considerably reduced.

  The “deposition rate on the surface facing the discharge electrode” means that a straight line connecting the center point of a circle where a plurality of cylindrical substrates are located on the circumference and the central axis of the cylindrical substrate, and the cylindrical substrate The deposition rate at the point where the surface on the discharge electrode side intersects. On the other hand, “the deposition rate on the surface facing the center of the central space surrounded by a plurality of cylindrical substrates” means that the straight line connecting the center point of the circle and the central axis of the cylindrical substrate, and the cylindrical shape It is the deposition rate at the point where the surface of the substrate intersects with the surface opposite to the discharge electrode. This can be said to have the same meaning as “deposition rate in a region facing a central space surrounded by a plurality of cylindrical substrates”.

  In the present invention, the ratio of the deposition rate on the surface facing the center of the central space surrounded by the cylindrical substrate to the deposition rate on the surface facing the discharge electrode of the cylindrical substrate, and the electrophotographic photosensitive member The relationship of characteristics was investigated in detail. As a result, it has been found that when the deposition rate ratio is 5% or more and 30% or less, a photoconductor having characteristics comparable to that of an electrophotographic photoconductor obtained in a coaxial single take-off furnace can be obtained. . Deposition with poor characteristics by setting the deposition rate of the deposition rate on the surface facing the center of the central space surrounded by a plurality of cylindrical substrates to 30% or less of the deposition rate on the surface facing the discharge electrode The film thickness can be reduced to eliminate its substantial effect. However, when the ratio of the deposition rates is less than 5%, the deposited film is almost entirely deposited on the portion of the cylindrical substrate formed while rotating and facing the central space surrounded by the plurality of cylindrical substrates. It does not adhere and a clear interface is formed there. This has an adverse effect on the running characteristics and may deteriorate the electrophotographic characteristics, particularly in the case of an electrophotographic photoreceptor in which carriers run in the film thickness direction. Therefore, in the present invention, good results can be obtained by setting the deposition rate ratio to 5% to 30%, more preferably 8% to 20%.

  Furthermore, the present inventors also examined a configuration in which a discharge electrode is installed at the center of a circle in which a plurality of cylindrical substrates are located on the circumference, contrary to the configuration described above. In this case, a discharge is caused in the central space surrounded by the plurality of cylindrical substrates. The electrical characteristics of the electrophotographic photoreceptor obtained in this case were found to be inferior to those of the photoreceptor obtained in a coaxial single-removal furnace. Moreover, the unevenness in the circumferential direction of the deposited film formed in a stationary state is deposited on the outside of the central space, although the characteristics of the cylindrical substrate facing the discharge electrode installed in the central space are good. It was found that the quality of the obtained film was inferior. Therefore, in the same way as described above, the gap between the cylindrical substrates is narrowed so that the discharge does not leak to the outside so that a film with poor film quality is not deposited. However, even in that case, the electrophotographic characteristics were not completely improved.

  As a cause of this, when the discharge electrode is provided inside a central space surrounded by a plurality of cylindrical substrates, it is better in the circumferential direction of the cylindrical substrate than when it is installed outside the plurality of cylindrical substrates. It is conceivable that the rate at which the film having the characteristic is deposited is small. This is considered to have caused a decrease in average electrophotographic characteristics during rotation of the cylindrical substrate. Accordingly, it has been found that for the purpose of the present invention to produce an electrophotographic photosensitive member having good characteristics at a low cost, it is desirable to adopt a configuration in which discharge electrodes are provided outside a plurality of cylindrical substrates.

  In addition, the present invention has a particularly great effect when the RF plasma CVD method is used, compared to the case where the plasma CVD method using other than the RF band such as the microwave plasma CVD method and the VHF plasma CVD method is used. . The detailed reason is currently unknown. However, the internal pressure during film formation is several tens to several hundreds of Pa in the RF plasma CVD method, whereas it is several Pa in the microwave plasma CVD method and the VHF plasma CVD method. It is possible that

  The RF plasma CVD method is characterized in that a film having good characteristics can be easily obtained, but the only drawback is that the deposition rate is low and the production cost is high. However, since the present invention makes it possible to form a large number of electrophotographic photosensitive members at once, this drawback is eliminated and the completeness as a manufacturing method is greatly increased.

  The present invention has been completed by the above process. Hereinafter, a deposited film forming method and a deposited film forming apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows an example of a deposited film forming apparatus according to the present invention that can form a plurality of electrophotographic photoreceptors at the same time and has extremely high productivity. FIG. 1A is a schematic longitudinal sectional view, and FIG. 1B is a schematic transverse sectional view taken along line XX of FIG.

  The deposited film forming apparatus of the present invention includes a reaction vessel 100, a plurality of cylindrical substrates 107 arranged on the same circumference inside the reaction vessel 100, a gas introduction pipe 106 as a raw material gas introduction means, a plurality of A discharge electrode 101 is provided so as to surround the cylindrical substrate 107. Then, high-frequency power is applied to the discharge electrode 101 to generate glow discharge in the reaction vessel 100, thereby decomposing the raw material gas introduced into the reaction vessel 100, and depositing films on the plurality of cylindrical substrates 107. To form. Further, the ratio of the deposition rate on the surface facing the center of the central space 111 surrounded by the plurality of cylindrical substrates 107 to the deposition rate on the surface of the cylindrical substrate 107 facing the discharge electrode 101 is 5%. Above and below 30%.

  The configuration of this deposited film forming apparatus will be described in more detail. The reaction vessel 100 includes a discharge electrode 101 that also serves as a reaction furnace wall, a base plate 102, and an upper lid 103, and can be decompressed. The discharge electrode 101, the base plate 102, and the upper lid 103 are insulated by an insulator 104. A gas introduction pipe 106 is installed inside the reaction vessel 100. An exhaust pipe 105 is connected to the lower part of the base plate 102, and the other end of the exhaust pipe 105 is connected to an unillustrated exhaust device (for example, a vacuum pump) so that vacuum exhaust is possible. A high frequency power source 109 is connected to the discharge electrode 101 via a matching unit (matching box) 110.

  Inside the reaction vessel 100, a plurality of cylindrical substrates 107 on which deposited films are formed are arranged on the same circumference so as to be parallel to each other and close to each other. The plurality of cylindrical base bodies 107 are respectively held by rotating shafts 108 including a base heater for heating (not shown). The rotating shaft 108 can be rotated by a driving device (not shown). Since the plurality of cylindrical substrates 107 are arranged close to each other, it is possible to prevent glow discharge generated between the discharge electrodes 101 from entering the central space 111 surrounded by the cylindrical substrate 107. As the cylindrical substrates 107 are brought closer to each other, the discharge that goes around to the central space 111 decreases, and adhesion of a deposited film having inferior characteristics to the surface of the cylindrical substrate 107 on the central space side can be prevented. The interval between the cylindrical substrates 107 differs depending on the shape of the deposited film forming apparatus and the size and number of the cylindrical substrates 107, but is approximately 10 mm or less and is a distance that does not contact each other (practical considering mechanical accuracy). 1 mm or more).

  Accordingly, in the present invention, the surface (A position) facing the center of the central space 111 surrounded by the plurality of cylindrical substrates 107 with respect to the deposition rate on the surface (position B) facing the discharge electrode 101. The deposition rate is 5% or more and 30% or less. More preferably, the deposition rate ratio is 8% or more and 20% or less. By forming the film so that the deposition rate ratio falls within this range, a photoconductor having characteristics equivalent to those of the electrophotographic photoconductor obtained in the coaxial single-removal furnace can be obtained.

  The discharge electrode 101, the base plate 102, and the upper lid 103 of this deposited film forming apparatus are made of a conductive material. Any conductive material can be used, but if it is made of a metal material such as aluminum, iron, stainless steel, gold, silver, copper, nickel, chromium, titanium, etc., it is easy to process and highly durable, and is convenient for reuse. This is also preferable. In addition, composite materials composed of two or more of these materials are also preferably used.

The high-frequency power used in the present invention may be in any frequency band, but good electrophotographic characteristics are easily obtained in the RF band of 1 MHz or more and 20 MHz or less, typically 13.56 MHz. This is presumed to be related to the fact that SiH _{3, which} is easy to obtain good film quality as a decomposition species, can be stably obtained, and plasma uniformity and stability. Any high frequency power supply 109 can be used as long as it can generate high frequency power suitable for the deposited film forming apparatus. Further, the output fluctuation rate of the high frequency power supply 109 is not particularly limited.

  The matching box 110 used in the present invention can be suitably used in any configuration as long as the high frequency power supply 109 and the load can be matched. In addition, as a method for matching the load, an automatically adjusted method is preferable in order to avoid the complexity at the time of manufacturing, but even the manually adjusted method completely affects the effect of the present invention. There is no. Further, regarding the position where the matching box 110 is disposed, there is no problem regardless of where the matching box 110 is installed within a range where the load can be matched. However, it is desirable to arrange the wiring from the matching box 110 to the discharge electrode 101 so that the inductance of the wiring is as small as possible because matching can be achieved under a wide load condition.

  Three or more cylindrical substrates 107 are installed so as to be arranged close to each other. However, in order to obtain an electrophotographic photosensitive member having good characteristics, it is important that the number of the cylindrical substrates 107 is not excessively increased. This is because as the number of cylindrical bases 107 increases, the volume of the central space 111 surrounded by the cylindrical bases 107 increases, so that plasma flows from a slight gap between the cylindrical bases 107 and discharges inside the central space 111. It is because it becomes easy to generate | occur | produce. Therefore, it is desirable that the number of cylindrical substrates 107 in the present invention is practically 6 or less, and optimally 4 or less. In addition, the “number of installations” referred to here means the number of rotating shafts 108 to which the cylindrical base body 107 is attached. For example, in the deposited film forming apparatus configured to form the cylindrical substrates 107 in a two-layered manner, when the number of installations is three, it is possible to form a film on the six cylindrical substrates 107 twice as much at a time. .

  The cylindrical substrate 107 used in the present invention may be conductive or electrically insulating. Examples of the conductive substrate include metals such as Al, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof such as stainless steel. Further, it is also possible to use a synthetic resin film or sheet, or a substrate obtained by conducting a conductive treatment on at least the surface on the deposition film forming side of an electrically insulating substrate such as glass or ceramic. Examples of the synthetic resin include polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, polyamide, and the like.

  The shape of the cylindrical substrate 107 used in the present invention may be a smooth surface or an uneven surface cylindrical shape, or a cylindrical shape composed of a plate-like endless belt. It is determined appropriately so that it can be formed. When flexibility as an electrophotographic photosensitive member is required, the thickness can be made as thin as possible within a range where the function as the cylindrical substrate 107 can be sufficiently exhibited. In general, however, the thickness of the cylindrical substrate 107 is usually 10 μm or more from the viewpoint of mechanical strength during manufacture and handling.

  In particular, when performing image recording using coherent light such as laser light, in order to more effectively eliminate image defects due to so-called interference fringe patterns that appear in a visible image, the surface of the cylindrical substrate 107 is uneven. It may be provided. The unevenness provided on the surface of the cylindrical substrate 107 may be created by a known method described in Patent Documents 2 to 4. Further, as another method for more effectively eliminating the image defect due to the interference fringe pattern when image recording is performed using coherent light such as laser light, unevenness due to a plurality of spherical trace depressions on the surface of the cylindrical substrate 107 A shape may be provided. In other words, the surface of the cylindrical substrate 107 may have unevenness that is slightly smaller than the resolution required for the electrophotographic light receiving member, and the unevenness may be due to a plurality of spherical trace depressions. The unevenness due to the plurality of spherical trace depressions provided on the surface of the substrate may be created by a known method described in Patent Document 5.

  Formation of the deposited film using the deposited film forming apparatus of FIG. 1 described above is performed, for example, as follows.

  For example, a plurality of cylindrical substrates 107 whose surfaces are mirror-finished using a lathe are installed in the reaction vessel 100, and the inside of the reaction vessel 100 is exhausted through an exhaust pipe 105 by an exhaust device (not shown). At a stage where exhaust is sufficiently performed, an inert gas for heating, for example, argon, is introduced into the reaction vessel 100 from a gas supply device (not shown) through a gas introduction pipe (gas introduction means) 106. Then, the flow rate of the heating gas or the exhaust speed of an exhaust device (not shown) is adjusted so that the inside of the reaction vessel 100 has a desired pressure. Subsequently, the cylindrical substrate 107 is heated by a substrate heating heater (not shown) and controlled to a desired temperature of 50 ° C. to 500 ° C.

When the cylindrical substrate 107 is heated to a desired temperature, the inert gas is gradually stopped, and at the same time, a predetermined source gas for film formation is gradually introduced into the reaction vessel 100. Raw material gas, for example SiH _4, and the material gas such as _{Si 2 H 6, CH 4,} C 2 H 6, a doping gas such as B ₂ H _6, PH _3, were mixed by the gas supply means (not shown) Later, it is introduced into the reaction vessel 100. Next, the flow rate of the raw material gas is adjusted to the set flow rate, and the exhaust speed of an exhaust device (not shown) is adjusted so that the pressure in the reaction vessel 100 becomes a desired pressure of 0.1 Pa to several hundred Pa. After confirming that the desired flow rate and pressure are obtained in this way, predetermined high frequency power is supplied from the high frequency power supply 109 to the discharge electrode 101 via the matching box 110. At this time, the matching box 110 is adjusted so that the reflected wave is minimized, and the effective value obtained by subtracting the reflected power from the high frequency incident power is set to a desired value. This high frequency power causes glow discharge in the reaction vessel 100. At this time, the cylindrical base 107 is rotated by a rotating means (not shown) attached to the rotating shaft 108.

  The discharge occurs between the cylindrical base body 107 and the discharge electrode 101, but no discharge occurs in the central space 111 surrounded by the plurality of cylindrical base bodies 107, or the discharge is very weak. . This is because since the cylindrical base body 107 is installed close to the discharge, it is difficult for the discharge to go into the central space 111. The decomposed species thus excited and dissociated are deposited on the outer peripheral surface of the cylindrical substrate 107. Since the cylindrical substrate 107 is rotated as described above, a uniform deposited film is formed over the entire circumference of the cylindrical substrate 107. Is formed.

  After the deposition film having a desired thickness is formed, the supply of the high frequency power is stopped, and then the supply of the source gas is stopped to finish the formation of the deposition film. When forming a multi-layered deposited film, the same operation is repeated a plurality of times. In this case, in each layer, as described above, once the formation of one layer is completed, the discharge is temporarily stopped, and after the setting is changed to the gas flow rate and pressure for the next layer, the discharge is performed again. It may occur to form the next layer. Alternatively, a plurality of layers may be continuously formed by gradually changing the gas flow rate, pressure, and high-frequency power to set values for the next layer over a certain time after the formation of one layer is completed. Further, once the residual gas in the reaction vessel 101 is sufficiently evacuated between the steps of forming each layer, contamination in the case of using different gas types for each layer can be minimized.

  By using the present invention, various a-Si electrophotographic light receiving members shown in FIGS. 2A to 2D, for example, can be formed.

  An electrophotographic photoreceptor 300 shown in FIG. 2A has amorphous silicon (a-Si: (H, X)) containing a hydrogen atom or a halogen atom as a constituent element on a support 301 and is photoconductive. The photoconductive layer 302 having a property is provided.

  An electrophotographic photoreceptor 300 shown in FIG. 2B includes a photoconductive layer 302 made of a-Si: (H, X) and having photoconductivity on a support 301, and amorphous silicon or amorphous carbon. A system surface layer 303 is provided.

  An electrophotographic photoreceptor 300 shown in FIG. 2C has a configuration in which an amorphous silicon-based lower blocking layer 304, a photoconductive layer 302, and a surface layer 303 are provided on a support 301. As described above, the photoconductive layer 302 is made of a-Si: (H, X) and has photoconductivity, and the surface layer 303 is an amorphous silicon-based or amorphous carbon-based layer.

  An electrophotographic photoreceptor 300 shown in FIG. 2D also has a structure in which a photoconductive layer 302 and a surface layer 303 are provided on a support 301. The photoconductive layer 302 includes a charge generation layer 305 and a charge transport layer 306 made of a-Si: (H, X), and the surface layer 303 is an amorphous silicon type or amorphous carbon type layer.

  Hereinafter, more specific examples of the present invention will be described in more detail. However, the present invention is not limited by these examples.

Example 1
In this example, four cylindrical aluminum cylinders having a diameter of 30 mm and a length of 358 mm were installed as the cylindrical substrate 107 (corresponding to the support 301 in FIG. 2) in the deposited film forming apparatus shown in FIG. Specifically, first, four cylindrical substrates 107 masked in part by attaching a heat-resistant tape having a width of 1 cm in the circumferential direction to the central portion in the axial direction were installed on the base plate 102. Then, in a stationary state, film formation was performed for 15 minutes under the conditions of the photoconductive layer 302 shown in Table 1.

  After the film formation was completed, the heat-resistant tape was peeled off to form a step between the portion where the deposited film did not adhere (the portion where the background of the cylindrical substrate 107 was exposed) and the portion where the film was deposited. Using this step, the deposition rate on the outside (position B in FIG. 1 (b)) and the deposition rate on the inside (position A in FIG. 1 (b)) are determined by the method described later, The ratio of inner deposition rate was investigated. In accordance with such a procedure, six conditions were selected in which the inner and outer deposition rate ratios were 5% or more and 30% or less while changing the interval between the cylindrical substrates 107 in various ways.

  After the above preparation is completed, the lower blocking layer 304, the photoconductive layer 302, and the surface layer 303 are subjected to each of the six conditions obtained above under the conditions shown in Table 1 while rotating the cylindrical member 107 at 5 rpm. An electrophotographic photosensitive member was formed. In this way, six types of electrophotographic photoreceptors were produced in which the inner and outer deposition rate ratios were 5% or more and 30% or less.

(Comparative Example 1)
Using the deposited film forming apparatus shown in FIG. 1, an electrophotographic photosensitive member was formed in the same procedure as in Example 1. In this comparative example, two types of electrophotographic photoreceptors were prepared under the condition that the deposition rate ratio between the inside and outside of the cylindrical substrate 107 was 3% and 40%.

(Evaluation of Example 1 and Comparative Example 1)
The a-Si electrophotographic photosensitive member produced in Example 1 and Comparative Example 1 was evaluated by the following method.

(Deposition rate ratio)
The thickness of the deposited film on the surface of the cylindrical substrate 107 formed in a stationary state is determined using a step between a portion where the deposited film is deposited and a portion where the deposited film does not adhere (a portion where the background of the cylindrical substrate 107 is exposed). Was measured. The measurement was performed under the measurement conditions described below using Alpha Step 500 (trade name) manufactured by KLA-Tencor Corporation.
Measurement conditions and measurement environment: temperature 25 ° C., humidity 60%, 1 atmosphere, stylus tip diameter: 5 μm
-Stylus pressing pressure: 8mg
・ Scan length: 400μm
・ Scanning speed: 50μm / sec
・ Scanning method: Continuous movement ・ Data sampling rate: 50Hz
・ Horizontal resolution: 1μm
・ Vertical resolution: 0.1 nm
・ Short wavelength cut-off filter: 12.5μm
・ Long wavelength cut-off filter: OFF
Under this measurement condition, calibration was performed in advance with a standard test piece. As a standard test piece, Step Height Standard model number: SHS-9400QC (trade name) manufactured by VLSI Standard Co., Ltd. was used. In the calibration mode of the alpha step 500, the calibration step is determined by measuring the calibrated level difference of the standard test piece and inputting the calibration value. By performing calibration, the film thickness can be easily and correctly measured. All other specific operations and measurement operations were performed according to the description in the instruction manual (Alpha Step 500 User's Manual October 1994, Software Version 1.7) attached to Alpha Step 500.

  Next, using the alpha step 500 under the measurement conditions described above, the stylus is scanned from the portion where the film at the central portion of the cylindrical substrate 107 is deposited to the portion where the cylindrical substrate 107 is exposed. The film thickness was measured. The measurement was performed 5 times, and the average value was obtained. The deposition rate can be obtained by dividing the film thickness thus obtained by the film formation time.

  In this way, at the central portion in the axial direction of the cylindrical substrate 107, the deposition rate on the surface (position B) facing the discharge electrode and the center of the central space 111 surrounded by the plurality of cylindrical substrates 107 are matched. The deposition rate on the surface (position A) was determined. And the deposition rate ratio was calculated | required by dividing the latter with the former. As a result, as described above, the deposition rate ratio of the six electrophotographic photoreceptors produced in Example 1 is in the range of 5% or more and 30% or less, and the two electrophotographic photoreceptors produced in Comparative Example 1 are deposited. The speed ratio was confirmed to be 3% and 40%, respectively.

(Chargeability)
The electrophotographic photosensitive member produced in Example 1 and Comparative Example 1 was set in an electrophotographic apparatus, a constant current (for example, 800 μA) was passed through the main charger, and the potential sensor of the surface electrometer set at the developing unit position. The dark potential was measured. Therefore, the larger the dark portion potential, the better the charging ability. In this embodiment, a Canon copier GP55 (trade name) modified for experiment is used as the electrophotographic apparatus, and Model 344 (trade name) manufactured by Trek Incorporated of the United States is used as the surface electrometer. Using. The chargeability measurement was performed at the central portion of the photoreceptor in the busbar direction. The evaluation results of the charging ability are shown by the following symbols in Table 2 on the basis of the result of the photoconductor of Comparative Example 1 having a deposition rate ratio of 40%.
◎… Better than 20% ○ ～ ◎… Better than 15% but less than 20% ○… Better than 10% but less than 15% Δ˜ ○… Better than 5% but less than 10% Δ… Less than 5% Improvement ... worsening

(sensitivity)
In the electrophotographic apparatus described above, after adjusting the current to the main charger so that the dark portion potential at the position of the developing device becomes a constant value (for example, 450 V), a predetermined white paper having a reflection density of 0.1 or less is used as a document. Sensitivity. Specifically, the sensitivity was evaluated based on the image exposure amount when the image exposure (semiconductor laser having a wavelength of 655 nm) was adjusted so that the bright portion potential at the developing unit position had a predetermined value (for example, 50 V). Therefore, the smaller the image exposure amount, the better the sensitivity. The sensitivity was measured at the center of the photoreceptor in the direction of the bus. The sensitivity evaluation results are indicated by the following symbols in Table 2 above based on the results of the photoconductor of Comparative Example 1 having a deposition rate ratio of 40%.
◎… Better than 20% ○ ～ ◎… Better than 15% but less than 20% ○… Better than 10% but less than 15% Δ˜ ○… Better than 5% but less than 10% Δ… Less than 5% Improvement x ... deterioration (residual potential)
The electrophotographic photosensitive member was charged to a constant dark portion surface potential (for example, 450 V) and immediately irradiated with a relatively strong light (for example, 1.5 μJ) of a fixed amount of image exposure (a semiconductor laser having a wavelength of 655 nm). At this time, the bright portion surface potential at the center of the electrophotographic photosensitive member in the direction of the generatrix was measured with a surface potential meter. Therefore, the smaller the bright part potential, the better the residual potential. The evaluation results of the residual potential are shown by the following symbols in Table 2 described above on the basis of the results of the photoconductor of Comparative Example 1 having a deposition rate ratio of 40%.
◎… Better than 40% ○ ˜ ◎… Better than 30% to less than 40% ○… Better than 20% to less than 30% Δ˜ ○… Better than 10% to less than 20% Δ ... less than 10% Improvement x ... deterioration (optical memory)
After adjusting the current value of the main charger so that the dark portion potential at the developing unit position becomes a predetermined value (for example, 450 V), the bright portion potential when the predetermined white paper is used as a document is set to a predetermined value (for example, 50 V). The amount of image exposure was adjusted so that A ghost chart in which a black circle having a reflection density of 1.1 and a diameter of 5 mm is pasted on a blank paper document having a length of 297 mm and a width of 80 mm is placed at the left end of the document table, and a halftone chart of A3 reflection density of 0.3 is placed on the ghost chart I made a copy of it. In this copy image, the optical memory was evaluated by measuring the difference between the reflection density of the black circle with a diameter of 5 mm in the ghost chart recognized on the halftone copy and the reflection density of the halftone portion. Therefore, the smaller the value, the better the optical memory. The optical memory was measured at the central portion in the axial direction of the photoreceptor. The evaluation result of this optical memory is indicated by the following symbols in the above-mentioned Table 2 based on the result of the photosensitive member of Comparative Example 1 having a deposition rate ratio of 40%.
◎… Better than 40% ○ ˜ ◎… Better than 30% to less than 40% ○… Better than 20% to less than 30% Δ˜ ○… Better than 10% to less than 20% Δ ... less than 10% Table 2 shows that the evaluation results of Example 1 and Comparative Example 1 show that the characteristics of the electrophotographic photosensitive member are improved by setting the deposition rate ratio to 5% or more and 30% or less. did. It was also found that even better characteristics can be obtained by setting the deposition rate ratio to 8% or more and 20% or less.

(Example 2)
In this embodiment, a deposited film forming apparatus (see FIG. 3C) similar to the deposited film forming apparatus shown in FIG. 1 but capable of processing six cylindrical substrates 107 is used. This deposited film forming apparatus is different from that shown in FIG. 1 only in the number of cylindrical bases 107 and rotating shafts 108, and the other configurations are the same. To do. In this example, six cylindrical aluminum cylinders having a diameter of 30 mm and a length of 358 mm were installed as the cylindrical substrate 107.

  Also in this example, as in Example 1, film formation was performed for 15 minutes under the conditions of the photoconductive layer 302 shown in Table 3 in a stationary state on the cylindrical base body 107 with a part of the axial central portion masked. It was.

  Then, the ratio of the deposition rate on the inner side to the deposition rate on the outer side of the cylindrical substrate 107 was examined by the same procedure as in Example 1. According to such a procedure, while changing the interval between the cylindrical substrates 107 in various ways, the conditions (interval between the cylindrical substrates 107) were determined so that the deposition rate ratio between the outside and the inside was 20%.

  After the above preparation was completed, an electrophotographic photosensitive member comprising a lower blocking layer 304, a photoconductive layer 302, and a surface layer 303 was formed under the conditions shown in Table 3 while rotating the cylindrical member at 1 rpm. At this time, according to the above-described conditions, the deposition rate ratio between the outer side and the inner side was set to 20%.

(Comparative Example 2)
As shown in FIG. 4, the deposited film forming apparatus used in this comparative example has a discharge electrode 511 in the center of a central space surrounded by six cylindrical substrates 507. On the outside, not a discharge electrode but a simple cylindrical outer wall 501 is provided. An exhaust pipe 505 and a gas introduction pipe 506 are installed inside the outer wall 501, and a high-frequency power source 509 and a matching box 510 connected to the discharge electrode 511 are installed outside the outer wall 501.

  In this comparative example, a cylindrical aluminum cylinder having a diameter of 30 mm and a length of 358 mm was used as the cylindrical substrate 507. In this deposited film forming apparatus, since the plasma discharge is excited in the central space surrounded by the cylindrical substrate 507, the deposition rate of the inner surface of the cylindrical substrate 507 is high and the deposition rate of the outer surface is low. ing. In this comparative example, an electrophotographic photosensitive member having an outer / inner deposition rate ratio of 20% was produced in the same manner as in Example 2.

(Evaluation of Example 2 and Comparative Example 2)
The characteristics (charging ability, sensitivity, residual potential, optical memory) of the electrophotographic photoreceptors produced in Example 2 and Comparative Example 2 were evaluated in the same manner as in Example 1 and Comparative Example 1. The results are shown in Table 4 in the same display method as in Table 2.

  According to Table 4, it can be seen that the characteristics when the discharge electrode is installed outside the cylindrical substrate are superior to those when the discharge electrode is installed inside the cylindrical substrate 107.

(Example 3)
In this example, a deposited film forming apparatus (see FIG. 3A) similar to the deposited film forming apparatus shown in FIG. 1 but capable of processing three cylindrical substrates 107 was used. This deposited film forming apparatus is different from that shown in FIG. 1 only in the number of cylindrical bases 107 and rotating shafts 108, and the other configurations are the same. To do. In this example, three cylindrical aluminum cylinders having a diameter of 30 mm and a length of 358 mm were installed as the cylindrical base body 107. The interval between the cylindrical substrates 107 was set to 1 mm. Also in this example, as in Example 1, film formation was performed for 15 minutes under the conditions of the photoconductive layer 302 shown in Table 5 in a stationary state on the cylindrical substrate 107 masked with a part of the central portion in the axial direction. It was. Then, the ratio of the deposition rate on the inner side to the deposition rate on the outer side of the cylindrical substrate 107 was examined by the same procedure as in Example 1.

  After the above preparation was completed, an electrophotographic photosensitive member including the lower blocking layer 304, the photoconductive layer 302, and the surface layer 303 was formed under the conditions shown in Table 5 while rotating the cylindrical member at 3 rpm.

Example 4
In the deposited film forming apparatus shown in FIG. 1, four cylindrical aluminum cylinders having a diameter of 30 mm and a length of 358 mm were installed as the cylindrical substrate 107. The interval between the cylindrical substrates 107 was set to 1 mm. Also in this example, as in Example 1, film formation was performed for 15 minutes under the conditions of the photoconductive layer 302 shown in Table 6 in a stationary state on the cylindrical substrate 107 masked with a part of the central portion in the axial direction. It was. Then, the ratio of the deposition rate on the inner side to the deposition rate on the outer side of the cylindrical substrate 107 was examined by the same procedure as in Example 1.

  After the above preparation was completed, an electrophotographic photosensitive member including the lower blocking layer 304, the photoconductive layer 302, and the surface layer 303 was formed under the conditions shown in Table 6 while rotating the cylindrical member at 3 rpm.

(Example 5)
In this embodiment, a deposited film forming apparatus (see FIG. 3B) that is similar to the deposited film forming apparatus shown in FIG. 1 but can process five cylindrical substrates 107 is used. This deposited film forming apparatus is different from that shown in FIG. 1 only in the number of cylindrical bases 107 and rotating shafts 108, and the other configurations are the same. To do. In this example, five cylindrical aluminum cylinders having a diameter of 30 mm and a length of 358 mm were installed as the cylindrical substrate 107. The interval between the cylindrical substrates 107 was set to 1 mm. Also in this example, similarly to Example 1, film formation was performed for 15 minutes on the cylindrical substrate 107 masked with a part of the central portion in the axial direction under the conditions of the photoconductive layer 302 shown in Table 7 in a stationary state. It was. Then, the ratio of the deposition rate on the inner side to the deposition rate on the outer side of the cylindrical substrate 107 was examined by the same procedure as in Example 1.

  After the above preparation was completed, an electrophotographic photosensitive member comprising the lower blocking layer 304, the photoconductive layer 302, and the surface layer 303 was formed under the conditions shown in Table 7 while rotating the cylindrical member at 3 rpm.

(Example 6)
In this embodiment, a deposited film forming apparatus (see FIG. 3C) similar to the deposited film forming apparatus shown in FIG. 1 but capable of processing six cylindrical substrates 107 is used. This deposited film forming apparatus is different from that shown in FIG. 1 only in the number of cylindrical bases 107 and rotating shafts 108, and the other configurations are the same. To do. In this example, six cylindrical aluminum cylinders having a diameter of 30 mm and a length of 358 mm were installed as the cylindrical substrate 107. The interval between the cylindrical substrates 107 was set to 1 mm. Also in this example, similarly to Example 1, film formation was performed for 15 minutes on the cylindrical substrate 107 masked with a part of the central portion in the axial direction under the conditions of the photoconductive layer 302 shown in Table 8 in a stationary state. It was. Then, the ratio of the deposition rate on the inner side to the deposition rate on the outer side of the cylindrical substrate 107 was examined by the same procedure as in Example 1.

  After the above preparation was completed, an electrophotographic photosensitive member including the lower blocking layer 304, the photoconductive layer 302, and the surface layer 303 was formed under the conditions shown in Table 8 while rotating the cylindrical member at 3 rpm.

(Example 7)
In this example, a deposited film forming apparatus (see FIG. 3D) similar to the deposited film forming apparatus shown in FIG. 1 but capable of processing seven cylindrical substrates 107 was used. This deposited film forming apparatus is different from that shown in FIG. 1 only in the number of cylindrical bases 107 and rotating shafts 108, and the other configurations are the same. To do. In this example, seven cylindrical aluminum cylinders having a diameter of 30 mm and a length of 358 mm were installed as the cylindrical substrate 107. The interval between the cylindrical substrates 107 was set to 1 mm. Also in this example, similarly to Example 1, film formation was performed for 15 minutes on the cylindrical substrate 107 masked with a part of the central portion in the axial direction under the conditions of the photoconductive layer 302 shown in Table 9 in a stationary state. It was. Then, the ratio of the deposition rate on the inner side to the deposition rate on the outer side of the cylindrical substrate 107 was examined by the same procedure as in Example 1.

  After the above preparation was completed, an electrophotographic photosensitive member comprising the lower blocking layer 304, the photoconductive layer 302, and the surface layer 303 was formed under the conditions shown in Table 9 while rotating the cylindrical member at 3 rpm.

(Evaluation of Examples 3-7)
The characteristics (deposition rate, charging ability, sensitivity, residual potential, optical memory) of the electrophotographic photoreceptors prepared in Examples 3 to 7 were evaluated in the same manner as in Example 1, and the results are shown in Table 10. ing.

  As can be seen from Table 10, good results were obtained in any case even when the number of cylindrical substrates per deposited film forming apparatus was changed in the range of 3 to 7. It was particularly effective to make it below this.

(Example 8)
In this example, a deposited film forming apparatus having an RF power source of 13.56 MHz was used as the high frequency power source 109 although it is substantially the same as the deposited film forming apparatus shown in FIG. Since this deposited film forming apparatus has the same configuration as that shown in FIG. 1 except for the high-frequency power supply 109, the same reference numerals are given and description thereof is omitted. In this example, four cylindrical aluminum cylinders having a diameter of 30 mm and a length of 358 mm were installed as the cylindrical substrate 107. Also in this example, as in Example 1, film formation was performed for 15 minutes under the conditions of the photoconductive layer 302 shown in Table 11 in a stationary state on the cylindrical substrate 107 with a portion of the axial central portion masked. It was. Then, the ratio of the deposition rate on the inner side to the deposition rate on the outer side of the cylindrical substrate 107 was examined by the same procedure as in Example 1. According to such a procedure, while changing the interval between the cylindrical substrates 107 in various ways, the five conditions in which the deposition rate ratio between the outside and the inside is 5% or more and 30% or less (the interval between the cylindrical substrates 107). Asked.

  After the above preparation was completed, an electrophotographic photosensitive member including the lower blocking layer 304, the photoconductive layer 302, and the surface layer 303 was formed under the conditions shown in Table 11 while rotating the cylindrical member at 10 rpm. At this time, in accordance with the above-described conditions, five types of electrophotographic photoreceptors were prepared in which the ratio between the outer and inner deposition rates was 5 to 30%.

(Comparative Example 3)
An electrophotographic photosensitive member was formed in the same procedure as in Example 8 using the deposited film forming apparatus shown in FIG. In this comparative example, an electrophotographic photosensitive member was produced under the condition that the deposition rate ratio between the inner side and the outer side of the cylindrical substrate 107 was 40%.

Example 9
In this embodiment, a deposited film forming apparatus having a 105 MHz VHF power source is used as the high frequency power source 109 although it is substantially the same as the deposited film forming apparatus shown in FIG. Since this deposited film forming apparatus has the same configuration as that shown in FIG. 1 except for the high-frequency power supply 109, the same reference numerals are given and description thereof is omitted. In this example, four cylindrical aluminum cylinders having a diameter of 30 mm and a length of 358 mm were installed as the cylindrical substrate 107. Also in this example, similarly to Example 1, film formation was performed for 15 minutes under the conditions of the photoconductive layer 302 shown in Table 12 in a stationary state on the cylindrical base body 107 with a part of the axial central portion masked. It was. Then, the ratio of the deposition rate on the inner side to the deposition rate on the outer side of the cylindrical substrate 107 was examined by the same procedure as in Example 1. According to such a procedure, while changing the interval between the cylindrical substrates 107 in various ways, the five conditions in which the deposition rate ratio between the outside and the inside is 5% or more and 30% or less (the interval between the cylindrical substrates 107). Asked.

  After the above preparation was completed, an electrophotographic photosensitive member including the lower blocking layer 304, the photoconductive layer 302, and the surface layer 303 was formed under the conditions shown in Table 12 while rotating the cylindrical member at 10 rpm. At this time, in accordance with the above-described conditions, five types of electrophotographic photoreceptors were prepared in which the ratio of the deposition rate between the outside and the inside was 5% or more and 30% or less.

(Comparative Example 4)
Using the deposited film forming apparatus shown in FIG. 1, an electrophotographic photosensitive member was formed in the same procedure as in Example 9. In this comparative example, an electrophotographic photosensitive member was produced under the condition that the deposition rate ratio between the inner side and the outer side of the cylindrical substrate 107 was 40%.

(Evaluation of Examples 8 and 9 and Comparative Examples 3 and 4)
About the electrophotographic photosensitive member produced in Example 8 and Comparative Example 3, and the electrophotographic photosensitive member produced in Example 9 and Comparative Example 4, the characteristics (deposition rate, charging ability, sensitivity, Residual potential, optical memory) were evaluated, and the results are shown in Tables 13 and 14, respectively.

  As is apparent from Tables 13 and 14, the present invention can obtain a particularly remarkable effect when the RF band high frequency power supply 109 is used in the deposited film forming apparatus.

(A) is a typical longitudinal cross-sectional view which shows an example of the deposited film formation apparatus of this invention, (b) is the typical cross-sectional view. (A)-(d) is typical enlarged drawing which shows the various examples of the layer structure of the electrophotographic photoreceptor formed based on this invention. (A)-(d) is typical sectional drawing which shows the various modifications of the deposited film forming apparatus of this invention. It is a typical cross-sectional view showing a comparative example of a deposited film forming apparatus. It is a typical longitudinal cross-sectional view which shows the prior art example of a deposited film formation apparatus.

Explanation of symbols

100 reaction vessel 101 discharge electrode 106 gas introduction tube (raw material gas introduction means)
107 Cylindrical substrate 111 Central space A Position indicating a surface facing the center of the central space surrounded by a plurality of cylindrical substrates B Position indicating a surface facing the discharge electrode

Claims (9)

A reaction vessel capable of being depressurized, a plurality of cylindrical substrates disposed on the same circumference inside the reaction vessel, a raw material gas introducing means, and a discharge electrode disposed so as to surround the plurality of cylindrical substrates; And applying a high frequency power to the discharge electrode to generate glow discharge in the reaction vessel, thereby decomposing the raw material gas introduced into the reaction vessel, and depositing a film on the plurality of cylindrical substrates In the deposited film forming method for forming
The ratio of the deposition rate on the surface of the cylindrical substrate to the deposition rate on the surface facing the discharge electrode is the ratio of the deposition rate on the surface facing the center of the central space surrounded by the plurality of cylindrical substrates. A method for forming a deposited film, which is set to be 5% or more and 30% or less.   2. The deposited film forming method according to claim 1, wherein the deposition rate ratio is set to be 8% or more and 20% or less.   The method for forming a deposited film according to claim 1, wherein the closest distance between the plurality of cylindrical substrates is 1 mm or more and 10 mm or less.   4. The deposited film forming method according to claim 1, wherein the high frequency power applied to the discharge electrode is an RF band of 1 MHz or more and 20 MHz or less. 5.   5. The deposited film forming method according to claim 4, wherein the high frequency power applied to the discharge electrode is 13.56 MHz.   6. The deposited film forming method according to claim 1, wherein the deposited film is made of a non-single crystal material containing silicon as a base material and containing at least hydrogen.   The deposited film forming method according to claim 1, wherein the number of the cylindrical substrates is three or four.   8. The deposited film forming method according to claim 1, wherein the film formation is performed while rotating the cylindrical substrate.   The deposited film forming method according to any one of claims 1 to 8, which is used for producing an electrophotographic photosensitive member.

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