JP2009030088A - Deposited film forming equipment - Google Patents

Abstract

An electrophotographic photoreceptor manufacturing apparatus capable of manufacturing an electrophotographic photoreceptor having good electrophotographic characteristics with high productivity is provided.
A plurality of cylindrical substrates 105 are respectively installed in a reaction vessel and surrounded by a discharge electrode 101 that also serves as a side wall of the reaction vessel. The partition plate 104 is provided between the cylindrical substrates 105 so that the deposition surfaces of the cylindrical substrates 105 do not directly face each other, and is electrically connected to the discharge electrode 101. The partition plate 104 is detachable from the reaction vessel, and the shape of the partition plate 104 at the time of forming the deposited film is different from the shape of the partition plate 104 in a state where the partition plate 104 is removed from the reaction vessel.
[Selection] Figure 2

Description

  The present invention relates to a deposited film forming apparatus using high-frequency power, which is used for forming a deposited film in a semiconductor device, an electrophotographic photosensitive member, an image input line sensor, a photovoltaic device and the like. In particular, the present invention relates to an apparatus for producing an electrophotographic photosensitive member used in an electrophotographic apparatus. More specifically, the present invention relates to an apparatus for manufacturing an amorphous silicon electrophotographic photosensitive member using a glow discharge plasma CVD (Chemical Vapor Deposition) method.

  Conventionally, there has been proposed and put to practical use a technique in which an element member used for an electrophotographic photoreceptor is composed of various materials such as selenium, cadmium sulfide, zinc oxide, phthalocyanine, and amorphous silicon. Among them, a non-single crystalline deposited film containing silicon as a main component, for example, a photoreceptor using an amorphous silicon film compensated with hydrogen and / or halogen (for example, fluorine or chlorine) has high performance, high durability, and no pollution. Has characteristics. 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 the formation of an amorphous silicon deposited film for electrophotography, and many apparatuses have been proposed.

FIG. 6 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 600 and an exhaust device 616 for depressurizing the inside of the reaction vessel 600. In the reaction vessel 600, an auxiliary substrate 606 connected to the ground, a substrate heater 607 for heating the cylindrical substrate 605 installed on the auxiliary substrate 606, and a gas introduction pipe 608 are installed. Further, the side wall portion of the reaction vessel 600 is constituted by a discharge electrode 601 made of a conductive material, and the other portion of the discharge electrode 601 and the reaction vessel 600 is insulated by an insulator 610. A high frequency power supply 612 of 13.56 MHz is connected to the discharge electrode 601 through a matching box 611.

  Each cylinder constituting source gas supply means (not shown) is connected to a gas introduction pipe 608 in the reaction vessel 600 via a source gas introduction valve 613.

The reaction vessel 600 has an exhaust pipe 609 and is evacuated by an exhaust device 616 via a vacuum gauge 614 and a main valve 615.
Japanese Patent Laid-Open No. 10-63024

  With such a conventional deposited film forming apparatus, it is possible to obtain a deposited film having practical characteristics and uniformity to some extent. In particular, among the film formation methods by the plasma CVD method, the RF plasma CVD method using the RF band as the high-frequency power has a feature that a film having good characteristics can be easily obtained. Therefore, an electrophotographic photoreceptor using amorphous silicon. Widely used in the manufacture of

  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, the electrophotographic photosensitive member using amorphous silicon has been required not only to improve the electrical characteristics and the image quality as in the past, but also to have a lower cost and an inexpensive member. .

  However, an electrophotographic photosensitive member using amorphous silicon has to have a large film thickness in order to obtain sufficient charging ability due to the high dielectric constant of amorphous silicon. 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. 6, the conventional plasma CVD apparatus has many coaxial film forming apparatuses. In this case, the plasma state around the cylindrical substrate 605 is symmetrical, and a uniform film thickness and film quality can be obtained. There is a merit that However, this plasma CVD apparatus has a demerit that only one electrophotographic photosensitive member can be obtained per one film-forming furnace, and the production amount must be reduced.

  Conventionally, improvement of the deposition rate has been studied as an attempt to increase the production amount per film forming furnace. However, when the deposition rate is increased, the film quality of the deposited film is deteriorated and the characteristics as an electrophotographic photosensitive member are inferior, and there is a trade-off relationship between the production capacity and the characteristics.

  Accordingly, an object of the present invention is to solve various problems in the conventional electrophotographic photosensitive member, specifically, to reduce the manufacturing cost without sacrificing the electrical characteristics of the electrophotographic photosensitive member, and to stabilize the yield with high yield. It is an object of the present invention to provide a deposited film forming apparatus that can be manufactured.

  In order to achieve the above object, a deposited film forming apparatus according to the present invention is an apparatus for forming a deposited film on a plurality of cylindrical substrates, and includes a vacuum-tight reaction vessel equipped with exhaust means and source gas introduction means. An installation portion for installing a plurality of cylindrical substrates is provided in the reaction vessel, and a discharge electrode is provided so as to surround the plurality of cylindrical substrates as a side wall of the reaction vessel. A feature of this apparatus is that a partition plate is provided between the cylindrical substrates arranged in the installation unit so that the deposition surfaces of the cylindrical substrates installed in the installation unit do not directly face each other. There is. This partition plate is electrically connected to the discharge electrode. Furthermore, the partition plate can be removed from the reaction vessel, and the shape of the partition plate when the deposited film is formed is different from the shape of the partition plate in a state where the partition plate is removed from the reaction vessel.

  According to the present invention, the deposited film on the cylindrical substrate can reduce the manufacturing cost without sacrificing the electrical characteristics of the electrophotographic photosensitive member, and can produce a stable and uniform electrophotographic photosensitive member with a high yield. It becomes possible to provide the forming apparatus.

  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 intensive studies to achieve the above-described object, the present inventors have arranged a plurality of cylindrical substrates in place of the conventional coaxial-type deposited film forming apparatus so as to surround these cylindrical substrates. A deposited film forming apparatus having a configuration in which a discharge electrode is installed was considered. In this deposited film forming apparatus, a large number of electrophotographic photoreceptors 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, the number of photoconductors manufactured per film forming furnace is greatly increased, and at the same time, the utilization efficiency of the raw material gas is improved. As a result, a significant cost reduction can be expected.

  However, when we actually experimented, the electrophotographic photoreceptor obtained has good electrical characteristics only in a limited prescription range, and it is produced because the prescription selection range is narrow. It has been found that satisfactory results cannot always be obtained in order to provide for Furthermore, it has been found that there is a large variation in electrical characteristics between the obtained electrophotographic photosensitive members.

  In order to investigate the cause, film formation was performed while the cylindrical substrate was stationary, and the characteristic unevenness in the circumferential direction of the cylindrical substrate was examined. As a result, the characteristics of the deposited film on the surface of the cylindrical substrate facing the reaction vessel that also serves as the discharge electrode is a coaxial film forming furnace (hereinafter, one coaxial type) that obtains one photoconductor per furnace. A good result equal to or better than that of the furnace was obtained. However, it has been found that the characteristics of the deposited film on the other surface, that is, the surface where the cylindrical substrate and the cylindrical substrate are directly opposed to each other, may be considerably inferior to those of the coaxial single furnace. did. In this deposited film forming apparatus, since high frequency power is applied to the discharge electrode, a plurality of grounded cylindrical substrates arranged inside function as counter electrodes of the discharge electrode. That is, a sufficient high frequency electric field acts on the surface of each cylindrical substrate facing the discharge electrode, and a high quality deposited film is formed. However, high-frequency power from the discharge electrode does not sufficiently act on the surface of each cylindrical substrate facing the other cylindrical substrate adjacent to it, that is, the region where the grounded surfaces face each other, resulting in a weak electric field. For this reason, the decomposition and excitation of the raw material gas become insufficient, and it is estimated that the characteristics of the deposited film are inferior compared with the place facing the discharge electrode. Furthermore, it is presumed that the discharge becomes unstable in the region where the high frequency power from the discharge electrode does not sufficiently work, and thus the variation in the film characteristics of the deposited film becomes large.

  The present inventors considered that as a simple and inexpensive method for solving this problem, a partition plate may be provided between the cylindrical bases that face each other to be grounded so as to be blinded. . And the high frequency electric field was able to be effectively applied also to the surface which faces the other cylindrical base | substrate in each cylindrical base | substrate by making the partition plate contact with a discharge electrode and making it electrically conduct | electrically_connect. That is, when looking around the circumferential direction of the cylindrical substrate, the high frequency power from the discharge electrode was applied to all surfaces, and the ground planes were not facing each other. As a result, it was found that a deposited film having characteristics that are not inferior to those of a coaxial single furnace can be obtained over the entire circumference of the cylindrical substrate.

  Furthermore, the present inventors diligently studied the configuration of the partition plate. As a result, the partition plate can be removed, and the shape of the partition plate when forming the deposited film is different from the shape of the partition plate in a state where the partition plate is removed from the reaction vessel. By doing so, it has been found that it is advantageous in terms of apparatus cost and maintainability, and further, the uniformity of the obtained electrophotographic photosensitive member is improved.

  The reason why the uniformity of the resulting electrophotographic photosensitive member is improved by making the shape of the partition plate when forming the deposited film different from the shape of the partition plate when the partition plate is removed from the reaction vessel It is not clear, but at the moment I am imagining:

  In the present invention, the partition plate is detachable from the reaction vessel from the viewpoint of apparatus cost and maintainability. In addition, in a state where the partition plate is installed in the reaction vessel, the partition plate and the discharge electrode are brought into contact with each other to be electrically connected, so that each cylindrical substrate also has a surface facing the other cylindrical substrate. A high frequency electric field can be effectively applied. Therefore, depending on the contact state between the partition plate and the discharge electrode, there may be variations in the high-frequency electric field acting on each cylindrical substrate, and as a result, there may be variations in characteristics between the obtained electrophotographic photosensitive members. Conceivable. However, when the partition plate is installed in the reaction vessel by making the shape of the partition plate at the time of deposit film formation different from the shape of the partition plate in a state in which the partition plate is removed from the reaction vessel, Therefore, the pressing force against the discharge electrode acts. Therefore, it is considered that the contact between the partition plate and the discharge electrode during the formation of the deposited film can always be kept good, and the uniformity of the obtained electrophotographic photosensitive member may be improved.

  The present invention can of course be applied to the case where a plasma CVD method using a band other than the RF band, such as a microwave plasma CVD method or a VHF plasma CVD method, is used. However, the RF plasma CVD method is particularly effective. It was. Although the detailed reason is unknown at present, in the case of the RF plasma CVD method, the wavelength of the high frequency power is several tens of meters, and even if the discharge form is a complicated shape combining the discharge electrode and the partition plate, the standing wave etc. It is thought that it is because it is difficult to produce the influence of the above, and the power can be supplied uniformly.

  As described above, the RF plasma CVD method has a feature that it is easy to obtain a deposited film with good characteristics. Therefore, it is a widely used technique, but on the other hand, the deposition rate is low and the production cost is high. . However, according to the present invention, a large number of electrophotographic photosensitive members can be uniformly formed with good characteristics at a time, thereby realizing cost reduction. The present invention has been completed by the above process.

  Hereinafter, the 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 with extremely high productivity that can simultaneously form a plurality of electrophotographic photosensitive members according to the present invention. FIG. 1A is a schematic longitudinal sectional view thereof, and FIG. 1B is a schematic transverse sectional view taken along the line A-A ′ of FIG.

  In the deposited film forming apparatus of this embodiment, the reaction vessel 100 is configured to be vacuum-tight with a discharge electrode 101 that also serves as a reaction furnace wall, an upper lid 102, and a bottom plate 103, and can be depressurized. The discharge electrode 101, the upper lid 102, and the bottom plate 103 are insulated by an insulator 110. Inside the reaction vessel 100, there is an installation portion (not shown) for installing a plurality of cylindrical substrates on the same circumference. The discharge electrode 101 has a cylindrical shape, and the installation portions thereof are arranged so that a plurality of cylindrical substrates are installed on a circumference having the same central axis as the cylindrical discharge electrode 101. In each installation section, a cylindrical base body 105 and auxiliary base bodies 106 set on the upper and lower ends thereof are attached to a rotating shaft 107. A partition plate 104 that is electrically connected to the discharge electrode 101 is provided between the cylindrical substrate 105 and the cylindrical substrate 105 so that a high-frequency electric field can be effectively applied.

  An exhaust pipe 109 is connected to the lower part of the bottom plate 103, and the other end of the exhaust pipe 109 is connected to an unillustrated exhaust device (for example, a vacuum pump), whereby the inside of the reaction vessel 109 can be evacuated. In addition, the raw material gas is introduced into the reaction vessel through the gas introduction pipe 108. A high frequency power source 112 is connected to the discharge electrode 101 via a matching unit (matching box) 111.

  Then, the apparatus applies high frequency power to the discharge electrode 101 to generate glow discharge in the reaction vessel 100, thereby decomposing the source gas introduced into the reaction vessel 100 and depositing the cylindrical substrate 105. A deposited film is formed on the surface.

  The configuration of this deposited film forming apparatus will be described in more detail.

  In the present invention, a partition plate 104 is provided between the plurality of cylindrical base bodies 105 so that the grounding surfaces do not directly face each other. Since the partition plate 104 is attached to the discharge electrode 101, high frequency power is applied to the partition plate 104 via the discharge electrode 101. Therefore, the surrounding structure viewed from the cylindrical base 105 does not have a surface having a ground potential. In this respect, the environment is much closer to that of the conventional coaxial single furnace. Therefore, the deposited film forming apparatus of the present invention has a sensitivity equivalent to that of the electrophotographic photosensitive member obtained in the conventional coaxial single furnace. The body will be obtained.

  Further, in the deposited film forming apparatus of the present invention, the partition plate 104 can be detached from the discharge electrode 101 in consideration of the apparatus cost and the maintainability because the complicated shape is obtained by combining the discharge electrode 101 with the partition plate 104. It has a different form. Thereby, the manufacturing cost of the electrophotographic photosensitive member can be further reduced.

  Furthermore, the shape of the partition plate 104 when the deposited film is formed and the shape of the partition plate 104 when the partition plate 104 is detached from the reaction vessel 100 are different from each other, so that one of the electrophotographic photoreceptors obtained can be obtained. An effect of improving the appearance can be obtained.

  Moreover, as a structure of the connection part of the partition plate 104 and the discharge electrode 101, it is preferable to form the groove 201 on the discharge electrode 101 side and to fit the partition plate 104 into the groove 201. By setting it as such a structure, the contact of the partition plate 104 and the discharge electrode 101 can be kept more favorable, and the effect of this invention can be acquired more notably.

  FIG. 2 shows the shape of the partition plate 104 in a state attached to the reaction vessel (when the deposited film is formed) and the shape of the partition plate 104 in a state in which the partition plate 104 is detached from the reaction vessel 100 according to the present invention. An example of a different aspect is shown typically. 2A shows the shape of the partition plate 104 in a state attached to the reaction vessel (when the deposited film is formed), and FIG. 2B shows the partition plate in a state where the partition plate 104 is detached from the reaction vessel 100. 104 is shown. In FIG. 2A, a groove 201 is formed in the discharge electrode 101, and a partition plate is fitted into the groove portion. Further, FIG. 2C shows a deformation at the end of the partition plate between the state in which the partition plate 104 is attached to the reaction vessel (when the deposited film is formed) and the state in which the partition plate 104 is removed from the reaction vessel. Indicates the amount. The solid line in FIG. 2 (C) shows the shape of the partition plate when removed from the reaction vessel, and the broken line shows the shape of the partition plate attached in the reaction vessel. The partition plate 104 has a shape in which plate members are combined and intersected, and each plate member is rotationally displaced about the intersecting portion.

  Further, in the deposited film forming apparatus of the present invention, when the cleanliness in the reaction vessel 100 is considered, when the partition plate 104 is installed in the reaction vessel 100, the partition plate 104 and the discharge electrode 101 are in contact with each other and rubbed. It is important to prevent dust generation as much as possible. This is because dust generated when the partition plate 104 and the discharge electrode 101 come into contact with each other and rubs adhere to the cylindrical substrate 105, and as a result, abnormal growth of the deposited film that causes image defects may occur.

  From this point of view, it is more preferable that the partition plate 104 in the present invention has a shape that suppresses contact with the discharge electrode 101 as much as possible when the partition plate 104 is installed in the reaction vessel 100. In addition, it is more preferable that the shape of the partition plate 104 when forming the deposited film is different from the shape of the partition plate 104 when the partition plate 104 is detached from the reaction vessel 100. As the partition plate 104 satisfying such a condition, for example, as shown in FIG. 3, a configuration in which plate members 301 and 302 made of two materials having different thermal expansion coefficients are combined in a cross shape is used. Can be mentioned.

  When the partition plate 104 configured as described above is used, the cylindrical substrate 105 is heated and the partition plate 104 is also heated due to the influence of glow discharge generated in the reaction vessel 100 when the deposited film is formed. Therefore, the partition plate will bend. As a result, the shape of the partition plate 104 when forming the deposited film is different from the shape of the partition plate 104 in a state where the partition plate 104 is detached from the reaction vessel 100.

  Further, the state where the shape of the partition plate 104 at the time of deposit film formation and the shape of the partition plate 104 when the partition plate 104 is detached from the reaction vessel 100 are different from each other due to some expansion and contraction due to thermal expansion or the like. Similar changes are not included.

  Further, as described in FIG. 1, the length of the partition plate 104 (which means the length in the axial direction of the cylindrical substrate) is shorter than the discharge electrode 101 and is longer than the axial length of the cylindrical substrate 105. The length was effective. In particular, when the auxiliary base 106 is provided above and below the cylindrical base 105, the partition plate 104 is shorter than the total length of the auxiliary base 106 and the cylindrical base 105 and is longer than the axial length of the cylindrical base 105. It was effective.

  It has been found that by making the length of the partition plate 104 shorter than that of the discharge electrode 101, the amount of by-product called polysilane in the reaction furnace is suppressed, and the electrical characteristics of the electrophotographic photosensitive member are further improved.

  This is presumably because the distance between the partition plate 104 and the upper lid 102 or the bottom plate 103 is increased, and the electric discharge generated between them is reduced. As a result, the decomposition of the raw material gas in the excess region is suppressed and polysilane is reduced. In addition, the high frequency power is prevented from being consumed by the discharge between the partition plate 104 and the upper lid 102 or the bottom plate 103, and is effectively consumed between the cylindrical substrate 105, which helps to improve the photoreceptor characteristics. I believe that.

  Further, by making the partition plate 104 longer than the axial length of the cylindrical substrate 105, the plasma distribution on the cylindrical substrate 105 becomes uniform, and as a result, the film thickness and film quality of the deposited film become uniform. The effect of becoming.

  The partition plate 104, the discharge electrode 101, the upper lid 102, and the bottom plate 103 of this deposited film forming apparatus are made of a conductive material. These components can be any conductive material. In particular, when it is made of a metal material such as aluminum, iron, stainless steel, nickel, chromium, titanium, etc., it is easy to process and has high durability, and it is preferable in terms of convenience of reuse. In addition, composite materials composed of two or more of these materials are also preferably used. For example, the material etc. which bonded the stainless steel from which a thermal expansion coefficient differs are mentioned.

  At least a part of the surface of the partition plate 104 preferably has an arithmetic average roughness (Ra) determined in accordance with JIS B0601-1994 in a range of 1 μm or more and 20 μm or less. This is because Ra having a thickness of 1 μm or more has a favorable effect on the adhesion of the film deposited on the partition plate 104. On the other hand, when Ra is too large, it becomes easy to take in dust, and this may cause abnormal growth of the deposited film when it is discharged. Therefore, Ra is preferably in the range of 1 μm to 20 μm.

  The surface roughness Ra was measured using a foam tracer SV-C4000S4 (Mitutoyo Corporation). The measurement environment was an air temperature of 25 ° C. and a humidity of 65%. The tip of the stylus was a 60 ° conical shape with a tip radius of 2 μm. The measurement was performed with a measuring force of 0.75 mN and a scanning speed of 0.1 mm / sec. All other conditions not specifically described were performed based on JIS B0601-1994. Further, the specific measurement method using the foam tracer SV-C4000S4 was in accordance with the instruction manual attached to the apparatus.

  In order to control the surface roughness of the partition plate 104 within the above range, the partition plate may be blasted or the partition plate may be covered with a thermal spray material. Blasting and thermal spraying are preferable from the viewpoint of cost, high controllability of surface roughness, and difficulty in being limited by the size and shape of the coating target.

  There are no particular restrictions on the specific means of thermal spraying, but the surface may be coated by a coating method such as plasma spraying, low-pressure plasma spraying, high-speed flame spraying, or low-temperature spraying. Specific examples of the thermal spray material include aluminum, nickel, stainless steel, titanium dioxide, and the like, but aluminum is more preferable in terms of economy and durability.

The high frequency power used in the apparatus of the present invention can be used in any frequency band, but good electrophotographic characteristics are easily obtained in the RF band of 1 MHz to 20 MHz, typically 13.56 MHz. . This is because, as described above, the RF band has a wavelength of several tens of meters, and even if it is a discharge shape with a complicated shape combining the discharge electrode 101 and the partition plate 104, the influence of standing waves and the like is not likely to occur, and power can be evenly distributed. This is because the plasma uniformity and stability are high. Further, it is presumed that SiH ₃ that easily obtains good film quality as a decomposition species is likely to be stably obtained.

  FIG. 4 shows a schematic diagram when the number of installed cylindrical substrates 105 is different in the deposited film forming apparatus of the present invention. (A) is an example in the case of installing two cylindrical substrates, (B) is an example in the case of three, and (C) is an example in the case of six. The reference numerals are the same as those in FIG.

  In the apparatus of the present invention, two or more cylindrical substrates 105 are installed, but about 4 to 8 are suitable for obtaining an electrophotographic photosensitive member having good characteristics. When the number of the cylindrical base bodies 105 increases, the distance between the cylindrical base body 105 and the partition plate 104 becomes narrower. As a result, due to slight tilt or misalignment of the cylindrical substrate, axial unevenness (characteristic unevenness in the axial direction of the cylindrical substrate) and circumferential unevenness (characteristic unevenness in the circumferential direction of the cylindrical substrate). Is likely to occur, which may affect the manufacturing yield. Conversely, if the number of cylindrical substrates 105 is too small, the amount of raw material gas consumed per photoconductor increases, and the cost reduction effect is reduced. In addition, the “number of cylindrical bases” referred to here means the number of rotating shafts 107 to which the cylindrical bases 105 are attached. For example, in the deposited film forming apparatus configured to form the cylindrical substrate 105 in two layers, if the number of rotating shafts is four, for example, eight cylindrical substrates 105 are formed twice at a time. It will be possible.

  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 105 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 109 by an exhaust device (not shown). When the exhaust is sufficiently performed, an inert gas for heating, for example, argon is introduced into the reaction vessel 100 through a gas introduction pipe 108 from a gas supply device (not shown). 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 105 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 105 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, Si 2 H 6,} CH 4, the material gas such as C ₂ H ₆ or 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 a 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 several tens to several hundreds of 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 source 112 to the discharge electrode 101 via the matching box 111. At this time, the matching box 111 is adjusted so that the reflected wave is minimized, and the effective value is obtained by subtracting the reflected power from the high frequency incident power. This high frequency power causes glow discharge in the reaction vessel 100. At this time, the cylindrical substrate 105 is rotated by a rotating means (not shown) attached to the rotating shaft 107.

  Since discharge occurs between the cylindrical substrate 105, the discharge electrode 101, and the partition plate 104, uniform discharge is generated around the cylindrical substrate 105, and characteristic unevenness is minimized.

  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, after the formation of one layer is completed as described above, the gas flow rate, the pressure, and the high frequency power are changed to the gas flow rate and the pressure for the next layer after the setting is changed. The next layer may be formed by causing discharge again. 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.

  FIG. 5 shows a schematic diagram of another example of the deposited film forming apparatus of the present invention. 5A is a schematic longitudinal sectional view thereof, and FIG. 5B is a schematic transverse sectional view cut along the line AA ′ of FIG. 5A.

  In the deposited film forming apparatus of FIG. 5, the discharge electrode 501 that also serves as the reaction furnace wall has a square shape, and a plurality of cylindrical substrates 505 are arranged in a line. A partition plate 504 to which high-frequency power is applied via the discharge electrode 501 is provided between the cylindrical substrates 505 so that the cylindrical substrates 505 do not face each other directly. Other parts are the same as those of the deposited film forming apparatus of FIG. In FIG. 5, reference numeral 500 is a reaction vessel, reference numeral 502 is an upper lid, reference numeral 503 is a bottom plate, reference numeral 506 is an auxiliary base, reference numeral 507 is a rotating shaft, reference numeral 508 is a gas introduction pipe, reference numeral 509 is an exhaust pipe, reference numeral 510 is An insulator is shown.

  In the apparatus shown in FIG. 5, the partition plate 504 can be removed, and the shape of the partition plate 504 at the time of deposition film formation is different from the shape of the partition plate 504 in a state where the partition plate 504 is removed from the reaction vessel. I did it. By doing so, it is advantageous in terms of apparatus cost and maintainability, and an effect of improving the uniformity of the obtained electrophotographic photosensitive member can be obtained.

Example 1
In this example, a cylindrical aluminum cylinder having a diameter of 30 mm and a length of 358 mm was installed as the cylindrical substrate 105 in the deposited film forming apparatus shown in FIG. Then, while rotating the cylindrical substrate at 5 rpm, using the high frequency power source 112 with an oscillation frequency of 13.56 MHz, an electrophotographic photosensitive member comprising a lower blocking layer, a photoconductive layer, and a surface layer under the conditions shown in Table 1 was obtained. A total of 8 lots of 2 lots were produced.

  In the deposited film forming apparatus of this example, the partition plate 104 having the configuration shown in FIG. 2 was used, and the shape of the partition plate 104 when the deposited film was formed and the partition plate 104 were removed from the reaction vessel 100. The shape of the partition plate 104 in the state is different. The amount of deformation shown in FIG. 2C is 5 mm at the end.

In this embodiment, the length of the partition plate 104 is
Length of cylindrical substrate + (length of discharge electrode−length of cylindrical substrate) × 0.7
It was. However, the length of the cylindrical base body 105 here does not include the length of the auxiliary base body 106.

  In the present example, the surface of the partition plate 104 was untreated, and the arithmetic average roughness was 0.7 μm.

  The lengths of the cylindrical base body 105, the partition plate 104, and the discharge electrode 101 are the lengths in the axial direction of the cylindrical base body. The partition plate 104 is arranged so that the distance from the partition plate 104 to the upper lid 102 and the distance from the partition plate 104 to the bottom plate 103 are equal.

In the present embodiment, after one lot of electrophotographic photosensitive members is manufactured, the partition plate 104 is temporarily detached from the reaction vessel 100, and dry cleaning is performed on the inside of the reaction vessel 100, the partition plate 104, and the like with ClF ₃ gas to adhere them. The removed film is removed.

  After the cleaning is performed, the partition plate 104 is again installed in the reaction container 100, and the electrophotographic photosensitive member of the second lot is manufactured.

(Example 2)
In this example, a cylindrical aluminum cylinder having a diameter of 30 mm and a length of 358 mm was installed as the cylindrical substrate 105 in the deposited film forming apparatus shown in FIG. Then, while rotating the cylindrical substrate at 5 rpm, using the high frequency power source 112 with an oscillation frequency of 13.56 MHz, an electrophotographic photosensitive member comprising a lower blocking layer, a photoconductive layer, and a surface layer under the conditions shown in Table 1 was obtained. A total of 8 lots of 2 lots were produced.

  In the deposited film forming apparatus according to the present embodiment, as shown in FIG. 3, a partition plate 104 in which plate members of SUS304 and SUS316 having different thermal expansion coefficients are combined in a cross shape is used. And when installing the partition plate 104 in the reaction container 100, it was set as the structure which can suppress the contact between the partition plate 104 and the discharge electrode 101 as much as possible. In addition, the shape of the partition plate 104 when the deposited film is formed is different from the shape of the partition plate 104 when the partition plate 104 is detached from the reaction vessel 100. Regarding the deformation of the partition plate 104, in a preliminary experiment using the transparent quartz glass upper lid 102, the shape of the partition plate 104 under the deposited film formation conditions and the partition plate in a state where the partition plate 104 is detached from the reaction vessel 100. It was visually confirmed that the shape of 104 was different. Furthermore, it was confirmed visually that the partition plate 104 and the groove 201 were in contact with each other due to the deformation of the partition plate 104 under the deposited film formation conditions. The deformation amount of the partition plate is about 2 mm.

In this embodiment, the length of the partition plate 104 is
Length of cylindrical substrate + (length of discharge electrode−length of cylindrical substrate) × 0.7
It was. The length of the cylindrical base 105 mentioned here does not include the length of the auxiliary base 106. The lengths of the cylindrical substrate 105, the partition plate 104, and the discharge electrode 101 are the lengths of the cylindrical substrate 105 in the axial direction.

In the present example, the surface of the partition plate 104 was untreated, and the arithmetic average roughness was 0.7 μm.
In addition, the partition plate 104 is arranged so that the distance between the top lid 102 and the bottom plate 103 is uniform.

  Also in this example, as in Example 1, after one lot of electrophotographic photosensitive member was manufactured, the partition plate 104 was once removed from the reaction vessel 100, and a film attached to the reaction vessel 100, the partition plate 104, etc. Cleaning is in progress. After the cleaning is performed, the partition plate 104 is installed again in the reaction vessel 100, and the electrophotographic photosensitive member of the second lot is manufactured.

(Comparative Example 1)
Except for removing the partition plate 104 from the deposited film forming apparatus used in Example 1 and not using it, eight lots of electrophotographic photoreceptors were manufactured in the same procedure as in Example 1 under the conditions shown in Table 1.

(Comparative Example 2)
In this comparative example, a cylindrical aluminum cylinder having a diameter of 30 mm and a length of 358 mm was installed as the cylindrical substrate 605 in the conventional deposited film forming apparatus shown in FIG. Then, using a high frequency power source 612 having an oscillation frequency of 13.56 MHz, eight electrophotographic photosensitive members each including a lower blocking layer, a photoconductive layer, and a surface layer were manufactured under the conditions shown in Table 2.

(Evaluation of Example 1, Example 2, Comparative Example 1, and Comparative Example 2)
The electrophotographic characteristics of each of the eight electrophotographic photosensitive members produced in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 were evaluated by the method described below, and the electrophotographic photosensitive material produced in Comparative Example 2 was used. Comparisons were made based on the body.

"Electrophotographic characteristic evaluation method"
Each produced electrophotographic photosensitive member was installed in a copying machine GP55 (trade name) manufactured by Canon Co., Ltd., modified for this test, and evaluated. The evaluation items were five items of “chargeability”, “sensitivity”, “image evaluation”, “chargeability variation”, and “sensitivity variation”, and each item was evaluated by the following specific evaluation method.

"Charging ability"
The dark portion potential at the developing unit position when a constant current is supplied to the main charger of the copying machine is defined as “charging ability” (however, the average value of the circumference of the electrophotographic photosensitive member in the circumferential direction, and in this example, The middle position of the axial direction (hereinafter referred to as the generatrix direction) of the cylindrical substrate that becomes the photosensitive member is measured). Therefore, the larger the numerical value, the better. As the surface potential meter, Model 344 (trade name) manufactured by Trek Incorporated of the United States was used. The “charging ability” of each of the eight electrophotographic photoreceptors prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 was measured, and the average value of each of the eight electrophotographic photoreceptors was determined. Was classified into the following ranks.

A: 110% or more for Comparative Example 2 B: 105% or more and less than 110% for Comparative Example 2 C: 95% or more and less than 105% for Comparative Example 2 D: 90% or more for Comparative Example 2 95% or more 95 Less than% E: Less than 90% of Comparative Example 2 “Sensitivity”
After adjusting the current value of the main charger so that the dark portion potential at the developing unit position becomes a predetermined value, image exposure (semiconductor laser having a wavelength of 655 nm) is irradiated. Next, the light amount of the image exposure light source is adjusted so that the surface potential (bright potential) at the developing device position becomes a predetermined value, and the exposure amount at that time is defined as “sensitivity” (however, the electrophotographic photosensitive member circumferential direction) The average value of one round is used, and in this example, the middle position in the bus line direction is measured). Therefore, the smaller the value, the better. The “sensitivity” of each of the eight electrophotographic photoreceptors prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 was measured, and the average value of each of the eight electrophotographic photoreceptors was determined. It was classified into the following ranks.

A: Less than 90% for Comparative Example 2 B: 90% or more and less than 95% for Comparative Example 2 C: 95% or more and less than 105% for Comparative Example 2 D: 105% or more for Comparative Example 2 110 Less than% E: 110% or more with respect to Comparative Example 2 “Image Evaluation”
A solid black document of A3 size having a reflection density of 1.5 was placed on the document table, and white spots with a diameter of 0.1 mm or more within the same area of the copy image obtained when copying were counted, and the number was evaluated. Therefore, the smaller the value, the better. The “image evaluation” of each of the eight electrophotographic photoreceptors prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 was performed, and the average value of each of the eight was obtained. It was classified into the following ranks. In addition, A to D in this evaluation were practically satisfactory levels.

A: Less than 80% for Comparative Example 2 B: 80% or more and less than 95% for Comparative Example 2 C: 95% or more and less than 105% for Comparative Example 2 D: 105% or more for Comparative Example 2 120 Less than% E: 120% or more with respect to Comparative Example 2 “Chargeability variation”
The “charging ability” of each of the eight electrophotographic photoreceptors prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 was measured, and Example 1, Example 2, Comparative Example 1, and For each Comparative Example 2, eight average values Z, maximum values X, and minimum values Y are obtained. Then, in each of Example 1, Example 2, Comparative Example 1, and Comparative Example 2, (XY) / Z is obtained and evaluated as “chargeability variation”. Therefore, the smaller the value, the better. Moreover, it divided into the following ranks on the basis of the comparative example 2.

A: Less than 50% for Comparative Example 2 B: 50% or more and less than 90% for Comparative Example 2 C: 90% or more and less than 110% for Comparative Example 2 D: 110% or more for Comparative Example 2 150 Less than% E: 150% or more with respect to Comparative Example 2 “Sensitivity variation”
The “sensitivity” of each of the eight electrophotographic photoreceptors prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 was measured, and Example 1, Example 2, Comparative Example 1, and Comparative Example were measured. For every two, eight average values Z, maximum values X, and minimum values Y are obtained. In each of Example 1, Example 2, Comparative Example 1 and Comparative Example 2, (XY) / Z is obtained and evaluated as “sensitivity variation”. Therefore, the smaller the value, the better. Moreover, it divided into the following ranks on the basis of the comparative example 2.

A: Less than 50% for Comparative Example 2 B: 50% or more and less than 90% for Comparative Example 2 C: 90% or more and less than 110% for Comparative Example 2 D: 110% or more for Comparative Example 2 150 Less than% E: 150% or more with respect to Comparative Example 2

The results are shown in Table 3.

  As is clear from Table 3, by using the deposited film forming apparatus of the present invention, a plurality of electrophotographic photosensitive members are formed simultaneously, but the number of electrons is equal to or higher than that of a conventional coaxial single furnace. Realizes photographic photoreceptor characteristics. Moreover, it can be seen that the level of variation in image and electrophotographic characteristics is maintained at a level where there is no practical problem. Since the throughput per reactor is four times, it can be seen that there is a merit of significant cost reduction considering the equipment cost.

Example 3
In this example, in the deposited film forming apparatus used in Example 1, the length of the partition plate 104 was changed to the following five patterns to form four electrophotographic photosensitive members for each lot. The other conditions are the same as those in the first embodiment.
(B) Equivalent to the length of the discharge electrode (b) Length of the cylindrical substrate + (Length of discharge electrode−Length of cylindrical substrate) × 0.8
(C) Length of cylindrical substrate + (length of discharge electrode−length of cylindrical substrate) × 0.5
(D) Length of cylindrical substrate + (length of discharge electrode−length of cylindrical substrate) × 0.2
(E) A length equivalent to the length of the cylindrical substrate

However, the length of the cylindrical base body 105 here does not include the length of the auxiliary base body 106. The lengths of the cylindrical substrate 105, the partition plate 104, and the discharge electrode 101 are the lengths of the cylindrical substrate 105 in the axial direction. In addition, the partition plate 104 is arranged so that the distance between the top lid 102 and the bottom plate 103 is uniform.

(Evaluation of Example 3)
The electrophotographic characteristics of each of the four electrophotographic photoreceptors produced in Example 3 were evaluated by the method described below, and the comparison was performed using the electrophotographic photoreceptor produced in Comparative Example 2 as a reference.

"Electrophotographic characteristic evaluation method"
Each produced electrophotographic photosensitive member was installed in a copying machine GP55 (trade name) manufactured by Canon Co., Ltd., modified for this test, and evaluated. The evaluation items are “Charging Ability”, “Sensitivity”, “Charging Ability Axis Unevenness” and “Sensitivity Axis Unevenness”, and “Charging Ability” and “Sensitivity” are “Charging Ability Axis” as in Example 1. Each item was evaluated by the following specific evaluation method for “unevenness” and “sensitivity axis unevenness”.

“Charging capacity unevenness”
In each of the electrophotographic photosensitive members obtained in the patterns (i) to (e) of Example 3 and Comparative Example 2, the “charging ability” was measured in increments of 2 cm in the direction of the generatrix, and the average value for each electrophotographic photosensitive member. (XY) / Z is obtained from Z, the maximum value X, and the minimum value Y, and evaluated as “chargeability axis unevenness”. Therefore, the smaller the value, the better. For each of the patterns (A) to (E) of Example 3 and Comparative Example 2, the “charging ability axis unevenness” of each electrophotographic photosensitive member was measured to obtain an average value between the four, and the following values were obtained using Comparative Example 2 as a reference. Divided into ranks.
A: Less than 90% for Comparative Example 2 B: 90% or more and less than 95% for Comparative Example 2 C: 95% or more and less than 105% for Comparative Example 2 D: 105% or more for Comparative Example 2 110 Less than% E: 110% or more with respect to Comparative Example 2

"Sensitivity axis unevenness"
In each of the electrophotographic photoreceptors obtained in the patterns (i) to (e) of Example 3 and Comparative Example 2, the “sensitivity” was measured in increments of 2 cm in the direction of the generatrix, and the average value Z for each electrophotographic photoreceptor. Then, (XY) / Z is obtained from the maximum value X and the minimum value Y and evaluated as “sensitivity axis unevenness”. Therefore, the smaller the value, the better. The “sensitivity axis unevenness” of each electrophotographic photosensitive member is measured for each of the patterns (A) to (E) of Example 3 and Comparative Example 2, and the average value between the four is obtained. It was divided into.
A: Less than 90% for Comparative Example 2 B: 90% or more and less than 95% for Comparative Example 2 C: 95% or more and less than 105% for Comparative Example 2 D: 105% or more for Comparative Example 2 110 Less than% E: 110% or more with respect to Comparative Example 2

The results are shown in Table 4.

  As can be seen from the results in Table 4, the length of the partition plate is shorter than the discharge electrode, and the length is equal to or longer than the axial length of the cylindrical base body. It can be seen that an electrophotographic photosensitive member can be obtained.

Example 4
In this example, the deposited film forming apparatus shown in FIG. 4C is used instead of the deposited film forming apparatus used in Example 2, and the same method as in Example 2 is performed under the conditions shown in Table 5. Thus, a total of 12 electrophotographic photoreceptors were manufactured in 2 lots.

  The other conditions are the same as in the second embodiment.

The obtained electrophotographic photoreceptor was evaluated in the same manner as in Example 2, and the results are shown in Table 6.

  As can be seen from the results in Table 6, it can be confirmed that the effect of the present invention can be sufficiently obtained even when the number of cylindrical substrates is changed.

(Example 5)
In this example, the deposition film forming apparatus used in Example 4 was used, and the surface property of the partition plate 104 was changed to the following states (a) to (f). Using these procedures, a total of 12 electrophotographic photoreceptors in total of 12 lots were produced under the conditions shown in Table 5.
(A) The partition plate surface is untreated, and the arithmetic average roughness is 0.5 μm.
(B) The surface of the partition plate is blasted to an arithmetic average roughness of 1.2 μm (c) The surface of the partition plate is blasted to an arithmetic average roughness of 5.4 μm (d) The surface of the partition plate Is sprayed with aluminum to give an arithmetic average roughness of 9.8 μm
(E) The aluminum spray is applied to the partition plate surface, and the arithmetic average roughness is 19.6 μm. (F) The aluminum spray is applied to the partition plate surface, and the arithmetic average roughness is 21.3 μm.

In addition, the measurement of the surface roughness Ra of the partition plate 104 in a present Example is measured with foam tracer SV-C4000S4 (Mitutoyo Corporation) by the above-described method.

  The obtained electrophotographic photoreceptor was evaluated in the same manner as in Example 4, and the results are shown in Table 7.

  From the results of Table 7, it can be seen that the surface roughness of the partition plate is such that when the arithmetic average roughness (Ra) is 1 μm or more and 20 μm or less, white spots are particularly reduced, and a satisfactory image evaluation level is obtained.

It is a schematic diagram which shows an example of the deposited film formation apparatus used by this invention. It is a schematic diagram which shows an example of the partition plate used by this invention. It is a schematic diagram which shows an example of the partition plate used by this invention. It is a schematic diagram which shows another example of the deposited film formation apparatus used by this invention. It is a schematic diagram which shows another example of the deposited film formation apparatus used by this invention. It is a schematic diagram which shows an example of the conventional deposited film formation apparatus.

Explanation of symbols

100, 600 Reaction vessel 101, 601 Discharge electrode 104, 604 Partition plate 105, 605 Cylindrical substrate

Claims (13)

A vacuum-tight reaction vessel provided with exhaust means and source gas introduction means, an installation part for installing a plurality of cylindrical substrates in the reaction vessel, and a plurality of cylindrical shapes serving also as side walls of the reaction vessel A deposited film forming apparatus for forming a deposited film on the plurality of cylindrical substrates, comprising a discharge electrode provided so as to surround the substrate;
Provided between the cylindrical substrates installed in the installation unit so that the deposition surfaces of the cylindrical substrates installed in the installation unit do not directly face each other, and Further comprising an electrically connected partition plate,
The partition plate is configured to be removable from the reaction vessel, and the shape of the partition plate when the deposited film is formed is different from the shape of the partition plate when the partition plate is removed from the reaction vessel. A deposited film forming apparatus.   The deposited film forming apparatus according to claim 1, wherein a groove is formed in the reaction container, and the partition plate is attached to the reaction container by fitting the partition plate into the groove.   The deposited film forming apparatus according to claim 1 or 2, wherein the partition plate has a configuration in which plate members made of two materials having different coefficients of thermal expansion are bonded together.   2. A length of the partition plate in the axial direction of the cylindrical substrate is equal to or longer than an axial length of the cylindrical substrate, and is shorter than a length of the discharge electrode in the axial direction of the cylindrical substrate. 4. The deposited film forming apparatus according to any one of items 1 to 3.   The cylindrical base is installed in the installation portion with an auxiliary base at an end, and the partition plate is shorter than an axial length of the cylindrical base including the auxiliary base. 5. The deposited film forming apparatus according to any one of 1 to 4.   6. The deposited film forming apparatus according to claim 1, wherein an arithmetic average roughness Ra measured according to JIS B0601-1994 of the partition plate is 1 μm or more and 20 μm or less.   The deposited film forming apparatus according to claim 6, wherein a surface roughness of the partition plate is adjusted by blasting.   The deposited film forming apparatus according to claim 6, wherein the surface roughness of the partition plate is adjusted by thermal spraying.   The deposited film forming apparatus according to claim 8, wherein the thermal spray material used for thermal spraying of the partition plate is at least one material of aluminum, nickel, stainless steel, and titanium dioxide.   The deposited film forming apparatus according to claim 1, wherein the discharge electrode is cylindrical.   The deposited film forming apparatus according to claim 10, wherein the installation portion is arranged to install the plurality of cylindrical substrates on a circumference having the same central axis as the discharge electrode.   The deposited film forming apparatus according to any one of claims 1 to 11, further comprising means for applying high-frequency power to the discharge electrode, wherein the high-frequency power is an RF band of 1 MHz to 20 MHz.   13. The deposited film forming apparatus according to claim 1, which is used for manufacturing an electrophotographic photosensitive member.

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