JP2005264232A - Plasma treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma treatment apparatus which inhibits a defect in a deposited film from occurring due to the scattering of a film which has been once deposited on various members in a reaction vessel and then peeled off, onto a substrate to be film-formed, when forming a deposition film with the use of a plasma CVD method, and which improves the yield. <P>SOLUTION: A plasma treatment apparatus is provided with at least the reaction vessel capable of being depressurized, a means for storing a cylindrical substrate in the reaction vessel, a gas introduction means for introducing a gas into the reaction vessel, a power-feeding means for feeding a high-frequency power so as to generate plasma in the reaction vessel, and an exhaust means for exhausting the gas in the reaction vessel through an outlet of the reaction vessel. This plasma treatment apparatus further has a plasma-leakage-preventing means having a plurality of openings which have a larger diameter in the vicinity of the side face of the reaction vessel than in other portions and can pass the gas therethrough, installed between a plane having the outlet of the reaction vessel and the cylindrical substrate, so as to cover the whole plane having the outlet of the reaction vessel. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vacuum processing apparatus using plasma, and more particularly to an apparatus suitable for forming a deposited film by a plasma CVD method.

  Conventionally, a deposited film forming method, which is a manufacturing method of element members used for semiconductor devices, electrophotographic photoreceptors, image input line sensors, imaging devices, photovoltaic devices, and other various electronic elements, is a vacuum deposition method. Many methods are known, such as sputtering, ion plating, thermal CVD, photo-CVD, and plasma CVD. Also, a deposited film forming apparatus used for these various deposited film forming methods has been put into practical use. Among them, a plasma CVD method, that is, a method of decomposing a source gas by direct current, high frequency or microwave glow discharge to form a thin deposited film on a substrate is, for example, hydrogenated amorphous silicon (hereinafter a-Si). The method is most practically used as a method suitable for forming a deposited film. Along with this, various apparatuses for forming a deposited film by the plasma CVD method have been proposed in accordance with actual applications.

  FIG. 4 shows an example of a conventional plasma CVD apparatus generally used for forming an a-Si: H film. 4A is a longitudinal sectional view of the deposited film forming apparatus, and FIG. 4B is a transverse sectional view of the deposited film forming apparatus.

  A deposited film forming apparatus 400 shown in FIG. 4A is an apparatus based on a VHF plasma CVD method using a high frequency in the VHF band as a high frequency power source, and mainly deposits an a-Si: H film on a cylindrical substrate. An apparatus for producing an electrophotographic photoreceptor.

  In the deposited film forming apparatus 400 shown in FIG. 4A, the depressurized reaction vessel 403 includes a cylindrical side wall made of a dielectric member, and a top plate 420 and a bottom plate 417 that are in close contact with both ends of the side wall 403. Yes. Inside the reaction vessel 403, a cylindrical substrate 401 is installed on a substrate support 406 and attached to a rotating shaft 410. The side wall 403 is made of, for example, a ceramic material. The rotating shaft 410 is provided on the bottom plate 417 via a rotating mechanism (not shown) driven by a motor and has a heating element (not shown). Can be heated and rotated.

  The cathode electrode 404 for generating plasma uses a metal rod electrode and is installed outside the reaction vessel 403. High frequency power supplies 408 and 415 are connected to the cathode electrode 404 via matching circuits 409 and 416.

  On the other hand, the bottom plate 417 is at ground potential, and the rotating shaft 410 provided on the bottom plate 417 holds the cylindrical base body 401, so that the cylindrical base body 401 is substantially the counter electrode of the cathode electrode. The bottom plate 417 is provided with an opening for exhausting the reaction vessel 403, and an exhaust pipe 407 is connected to the opening. A vacuum exhaust means (not shown) is connected to the other end of the exhaust pipe 407, and the reaction vessel 403 is evacuated.

  Between the opening of the bottom plate 417 and the cylindrical base 401, plasma leakage prevention means 418 is installed to prevent plasma from leaking to the exhaust pipe 407 side and reducing the plasma density in the discharge space. . The plasma leakage prevention means 418 is a punching metal having a plurality of openings. The plasma leakage preventing means 418 is fixed to the bottom plate 417. As a result, the plasma leakage preventing means 418 is in close contact with the bottom plate 417 that is at the ground potential. Therefore, the plasma leakage prevention means 418 is also kept at the ground potential.

  A gas supply means 402 is attached to the reaction vessel 403, and the source gas is supplied into the reaction vessel 403 from this.

  The formation of the a-Si: H film using the conventional film forming apparatus as shown in FIG. 4 is generally performed by the following procedure.

First, the inside of the reaction vessel 403 is exhausted to a high vacuum by a vacuum exhaust means (not shown) connected to the other end of the exhaust pipe 407. Thereafter, while further evacuating, the gas supply means 402 uses silane gas (SiH ₄ ), disilane gas (Si ₂ H ₆ ), diborane gas (B ₂ H ₆ ), methane gas (CH ₄ ), ethane gas (C ₂ H ₆ ), etc. The source gas is introduced to maintain the inside of the reaction vessel 403 at a predetermined pressure. High frequency power supplies 408 and 415 are set to desired power, and VHF power is introduced into reaction vessel 403 made of a dielectric member through matching circuits 409 and 416 and cathode electrode 404. With this VHF power, plasma is generated between the cathode electrode 404 and the cylindrical substrate 401 serving as the counter electrode, and the source gas is decomposed by the plasma. The cylindrical substrate 401 is heated by a heating element (not shown) to a predetermined temperature of 200 to 400 ° C., and an a-Si: H film is deposited on the cylindrical substrate 401.

  In order to prevent plasma from leaking from the reaction vessel as in the deposited film forming apparatus 400 described above, other deposited film forming apparatuses having plasma leakage preventing means using punching metal or the like have been proposed ( For example, see Patent Document 1).

  An a-Si: H-based electrophotographic photosensitive member having good characteristics is formed by a conventional deposited film forming apparatus and is put into practical use.

JP 2001-335948 A

  However, in order to further improve the overall characteristics, there is still room for improvement. For example, in recent years, the performance of copying machine bodies has been improved, and digital machines and color machines have become popular. Accordingly, electrophotographic photoreceptors are required to further improve image characteristics such as higher image quality and higher quality than ever. For this reason, it is necessary to suppress the occurrence of minute image defects that have not been a significant problem in the past.

  The image defects are caused by defects in the deposited film on the electrophotographic photoreceptor. The main causes for the occurrence of defects in the deposited film are as follows.

  That is, as the film forming operation is repeated, the deposited film is laminated on various members and inner walls arranged in the reaction vessel. Since the deposited film is peeled off from each member in the subsequent film forming operation and pulled in the exhaust direction of the exhaust means provided at the lower part of the vertical reaction vessel, plasma leakage prevention at the bottom of the vertical reaction vessel is prevented. Get down on the means. In some cases, the deposited film pieces may stay and scatter due to the gas flow accompanying the supply or exhaust of the film formation gas and adhere to the lower part of the cylindrical substrate.

  Therefore, it is necessary to take measures to prevent film fragments that cause image defects from flying on the cylindrical substrate.

  The object of the present invention is to prevent defects in the deposited film caused by peeling off the film deposited on various members in the reaction vessel and scattering on the deposition substrate when the deposited film is formed by applying the plasma CVD method. An object of the present invention is to provide a plasma processing apparatus capable of suppressing the generation and dramatically improving the yield.

  In order to achieve the above object, the invention described in claim 1 includes at least a reaction vessel that can be depressurized, means for housing a cylindrical substrate in the reaction vessel, and gas introduction means for introducing gas into the reaction vessel. A plasma processing apparatus comprising: high-frequency power supply means for supplying high-frequency power for generating plasma in the reaction container; and exhaust means for exhausting the gas in the reaction container through an exhaust port of the reaction container. The opening diameter is larger in the second region on the side surface of the reaction vessel than the first region on the side of the central portion of the reaction vessel, and has a plurality of openings that allow the gas in the reaction vessel to flow. The plasma leakage prevention means is provided between the surface having the exhaust port and the cylindrical base so as to cover the entire surface having the exhaust port.

  According to a second aspect of the present invention, in the first aspect of the present invention, the second region of the plasma leakage prevention means is between the side surface of the reaction vessel and the gas introduction means.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the individual opening area of the opening of the first region of the plasma leakage preventing means is 0.8 mm ² or more and 80 mm ² or less. And

The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the individual opening area of the opening of the second region of the plasma leakage preventing means is more than 80 mm ² and 140 mm ² or less. It is characterized by that.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the plasma leakage preventing means is made of a punching metal or a metal mesh.

  According to a sixth aspect of the invention, in the invention according to any one of the first to fifth aspects, the high-frequency power supply means is means for simultaneously supplying at least two different high-frequency frequencies to the same high-frequency electrode. Features.

  The invention according to claim 7 is the deposited film of the invention according to any one of claims 1 to 6, which is made of a non-single crystal material containing at least silicon having a function as an electrophotographic photoreceptor on the cylindrical substrate. It is characterized by forming.

  As a result of intensive studies on the above-described problems in the conventional method and apparatus, the present inventors have confirmed that image defects are concentrated in the vertical direction of the cylindrical base body arranged upside down in the lower part of the cylindrical base body. . As a result of examining the image defects concentrated on the lower part of the cylindrical substrate, it was estimated that the concentration of image defects occurred due to the following phenomenon.

  When a deposited film is formed on a cylindrical substrate, the deposited film is also formed at a site in contact with plasma other than the cylindrical substrate in the reaction vessel. The conditions for forming the deposited film are the film quality and stress of the film deposited on the cylindrical substrate. In consideration of the above, the input power of the high frequency power and the heating setting of the cylindrical substrate are selected. Therefore, the film quality and stress of the film deposited on other than the cylindrical substrate are different from the film deposited on the cylindrical substrate.

  As a result, minute film peeling occurs due to the stress of the film as the temperature changes during the formation of the deposited film, the lamination conditions, and the thickness of the deposited film increases. Since the film pieces generated by this minute film peeling are drawn in the exhaust direction of the exhaust means provided at the lower part of the vertical reaction vessel, they are deposited on the plasma leakage preventing means 418 provided on the exhaust port surface of the reaction vessel. In some cases, the deposited film pieces may stay and scatter due to the gas flow accompanying the supply or exhaust of the film formation gas and adhere to the lower part of the cylindrical substrate. In particular, the plasma leak prevention means 418 is provided with a plurality of openings in the vicinity of the side surface on the lower side of the reaction vessel 403 and on the plasma leak prevention means 418 on the lower side of the gas introduction means 402. The accompanying gas flow causes gas stagnation, and the amount of film pieces deposited on the gas tends to increase.

  Further, a deposited film is also formed on the film piece that has fallen on the plasma leakage prevention means 418 provided on the exhaust port surface of the reaction vessel, but the film deposited on the minute film piece is further peeled off. It is presumed that the film is likely to occur, the film peeling further proceeds, and the minute film pieces adhering to the lower part of the cylindrical substrate may increase at an accelerated rate.

  That is, reducing the number of film pieces that accumulate on the plasma leakage prevention means 418 provided on the exhaust port surface of the reaction vessel prevents the film pieces from scattering and adhering to the cylindrical substrate surface. It is necessary to prevent the container 403 from getting on the side of the lower side of the container 403 or the lower side of the gas introduction means 402. As a result of studying the means, the reaction container is provided between the surface having the exhaust port of the reaction container and the cylindrical substrate. The plasma leakage preventing means having a region having a plurality of openings through which gas can be circulated on the side surface side covers the entire surface having the exhaust port of the reaction vessel. Proved to be effective.

  The opening of the plasma leakage preventing means having a plurality of openings through which the gas can flow is prevented by preventing the plasma leakage by making the opening diameter larger than the central portion between the side surface of the reaction vessel and the gas introducing means. And the suppression of the deposition of film pieces are compatible, and the effect of the present invention is remarkable.

The individual opening area of the opening in the first region at the center of the plasma leakage preventing means having a plurality of openings through which the gas can flow is 0.8 mm ² or more and 80 mm ² or less. The effect was remarkable.

If the area of each opening in the first region opening in the central portion of the plasma leakage prevention means is smaller than 0.8 mm ² , the opening is closed by the deposited film deposited in the opening, and the reaction vessel is maintained at a predetermined pressure. In view of improving the quality and reproducibility of the deposited film and preventing image defects, the individual opening area of the plasma leakage preventing means is preferably 0.8 mm ² or more.

In addition, when the individual opening area of the opening in the first region is larger than 80 mm ² , the plasma density is high at the center of the reaction vessel, and the plasma leaks to the exhaust tube side, and the plasma density in the discharge space decreases. In this case as well, the individual opening area of the opening in the first region of the shielding plate is preferably 80 mm ² or less from the viewpoint of improving the quality and reproducibility of the deposited film and preventing image defects. .

Opening area of the central portion of the plasma leakage prevention means is to appropriately set within a range of 0.8 mm ² or more 80 mm ² or less as described above.

The individual opening area of the opening in the second region where the opening diameter is large on the side surface of the reaction vessel of the plasma leakage prevention means having a plurality of openings through which the gas can flow is more than 80 mm ² and 140 mm ² or less. As a result, the effects of the present invention were more remarkable.

When the individual opening area of the opening portion of the second region whose opening diameter is large on the side surface side of the reaction vessel of the plasma leakage prevention means is smaller than 80 mm ^2, the opening in the vicinity of the side surface of the reaction vessel or on the lower side of the gas introduction means When the membrane pieces that have accumulated on the part cannot be sufficiently discharged, and the individual opening areas of the openings are larger than 140 mm ² , the vicinity of the side of the reaction vessel and the lower side of the gas introduction means are Although the plasma density is lower than that at the center, the plasma may leak to the exhaust pipe and the plasma density in the discharge space may decrease, improving the quality and reproducibility of the deposited film and preventing image defects from the viewpoint of the individual opening area of the second region opening aperture diameter in a reaction vessel side surface is larger is to appropriately set within a range of 140 mm ² or less than the 80 mm ²

  Moreover, it is preferable that the ratio of the whole opening to the area of the whole plasma leakage preventing means, that is, the opening ratio is in the range of 20% to 80%. When the aperture ratio is less than 20%, the decrease in conductance is large, and the exhaust capacity is greatly decreased accordingly. In the experiments conducted by the inventors, for the reasons described above, depending on the raw material gas flow rate, the pressure in the reaction vessel cannot be maintained at a desired value, and therefore, good film quality may not be obtained.

  On the other hand, when the aperture ratio is greater than 80%, the plasma leakage prevention capability is reduced depending on the shape and the opening area (size) of each opening (hole), and the plasma generated in the reaction vessel under the desired conditions. Leakage becomes significant. If the plasma leakage is significant, the plasma density and stability are lowered, and the deposited film speed is lowered. In addition, the deposited film characteristics often deteriorate with plasma destabilization.

  For the above reasons, it is preferable to select the aperture ratio of the plasma leakage preventing means in the range of 20 to 80%.

  Moreover, it is preferable for the present invention that the plasma leakage preventing means is a punching metal or a metal mesh.

  Examples of the material for the plasma leakage prevention means include metals such as Al, Ni, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof such as stainless steel. Of these, Al, stainless steel, Ni, and Cr are suitable in terms of ease of punching and cost.

  The surface of the plasma leakage prevention means is preferably blasted or sprayed with nickel, aluminum, stainless steel or the like.

  Moreover, it is preferable for the present invention that the high-frequency power supply means is means for simultaneously supplying at least two different high-frequency frequencies to the same high-frequency electrode.

  In the present invention, it is necessary to supply a plurality of high-frequency powers into such a vacuum processing container from the same electrode. When high-frequency power having different frequencies is supplied from different electrodes, a standing wave depending on the frequency of the high-frequency power is generated for each electrode. As a result, the plasma characteristics in the vicinity of the electrode have a distribution shape corresponding to this standing wave, and the type / ratio of the generated active species and the energy of ions vary depending on the position.

  In the present invention, the relationship between the plurality of high frequency powers supplied to the electrodes, that is, the frequency and the power ratio may be determined while actually confirming the uniformity of the vacuum processing characteristics. If it is small, it becomes substantially the same as when high-frequency power of the same frequency is applied, and the standing wave suppression position cannot be obtained sufficiently because the node position and antinode position of each standing wave are close. . If the difference is too large, the wavelength of the high-frequency electric field standing wave of the high-frequency power having the smaller frequency is too large relative to the wavelength of the high-frequency electric field standing wave of the high-frequency power having the larger frequency. A sufficient standing wave suppression effect cannot be obtained.

  In the present invention, it is necessary for obtaining the effect of the present invention that the plurality of high-frequency wave powers supplied to the electrodes include at least two high-frequency powers having a frequency of 10 MHz to 250 MHz.

  When the frequency is lower than 10 MHz, it is difficult to obtain a high processing speed. More preferably, it is 30 MHz or more from the viewpoint of the deposition rate.

  On the other hand, when the frequency is higher than 250 MHz, the attenuation of the high-frequency power in the traveling direction becomes significant, and the deviation of the attenuation rate from the high-frequency power having a different frequency becomes remarkable, so that a sufficient uniformity effect can be obtained. It will disappear. Therefore, it is preferable to set the frequency to 250 MHz or less because the superposition effect can be effectively obtained.

  In addition, regarding the power ratio of the high frequency power supplied to the electrodes, when supplying two high frequency powers of the above frequency, the first high frequency power is P1, and the second high frequency power having a frequency lower than this is P2. The ratio of the second high-frequency power P2 to the total power (P1 + P2) is preferably in the range of 0.1 to 0.9 in order to obtain the effects of the present invention.

  If the second high-frequency power is smaller than this range with respect to the total power, the component resulting from the first high-frequency power is dominant in the high-frequency electric field, and the standing wave suppressing effect cannot be obtained.

  On the other hand, as the second high-frequency power is increased, the influence of the second high-frequency power on the raw material gas decomposition in the reaction vessel is increased, becoming closer to the case where the second high-frequency power is used alone. The suppression effect is reduced. Therefore, it is necessary for at least one of the high frequency powers to be 10% or more with respect to the two total powers in order to reliably obtain the standing wave suppressing effect.

  According to the present invention, at least a pressure-reducible reaction vessel, a means for accommodating a cylindrical substrate in the reaction vessel, a gas introduction means for introducing a gas into the reaction vessel, and plasma generation in the reaction vessel A vacuum processing apparatus comprising a high-frequency power supply means for supplying high-frequency power to cause a gas in the reaction vessel to be exhausted through the exhaust port of the reaction vessel, and the exhaust port of the reaction vessel is provided The opening diameter is larger in the second region on the side surface of the reaction vessel than the first region on the center side of the reaction vessel between the surface and the cylindrical substrate, and the gas in the reaction vessel A plasma leakage prevention means having a plurality of openings that can be circulated is provided between the surface having the exhaust port of the reaction vessel and the cylindrical substrate so as to cover the entire surface having the exhaust port. Discharge Qualitative, it is possible to reduce image defects in high uniformity device configuration of vacuum processing characteristics, it can be improved reproducibility and productivity of the electrophotographic characteristics.

  In addition, the present invention provides a high-quality electrophotographic photosensitive member that does not vary in the film thickness, electrophotographic characteristics, etc. within or between lots of electrophotographic photosensitive members even in a mass production apparatus that takes many products. It is possible.

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

<Embodiment 1>
Embodiment 1 of the present invention is shown in FIG.

  FIG. 1 is a schematic view showing an example of an amorphous silicon photoconductor manufacturing apparatus using the present invention. FIG. 1A is a schematic cross-sectional view, and FIG. 1B is a schematic cross-sectional view taken along a cutting line A-A ′ in FIG.

  An opening is provided in the bottom surface 117 of the cylindrical reaction vessel 103 for exhausting the inside of the reaction vessel 103, and an exhaust pipe 107 is installed in the opening. The other end of the exhaust pipe 107 is connected to an exhaust device (not shown). At the center of the reaction vessel 103, a single cylindrical substrate 101 on which a deposited film is formed is arranged in a state of being placed on a substrate support 106.

  A plurality of high frequency powers from two VHF power sources 108 and 115 having oscillation frequencies f1 and f2 are applied to feeding points of the power branch plate 113 after passing through the matching boxes 109 and 116, and are installed outside the reaction vessel 103. In this configuration, power is supplied from the high-frequency electrode 104 into the reaction vessel 103 to generate plasma in the reaction vessel 103 to form a deposited film.

  Ceramic that is a dielectric is used on the side wall of the cylindrical reaction vessel 103.

  The power branch plate 113 is installed in a shield 114 that substantially confines electromagnetic waves while being electrically insulated from the shield 114. That is, it has the structure fixed to the reaction apparatus through the insulator. Furthermore, in order to improve the vacuum processing stability in the initial stage of discharge, the power branch plate 113 and the high-frequency electrode 104 may be connected via a capacitor.

  Plasma leakage prevention means 118 having a plurality of openings is provided between the lower end of the cylindrical substrate 101 and the bottom surface 117, and the plasma leakage prevention means 118 is fixed to the bottom plate 117.

  The plasma leakage prevention means 118 is provided so as to cover the entire surface having the exhaust port of the reaction vessel by a combination of the small opening portion 119a and the large opening portion 119b, and the opening diameter is large near the side surface of the reaction vessel 103. It has become.

<Embodiment 2>
Next, Embodiment 2 of the present invention is shown in FIG.

  FIG. 2 shows an amorphous silicon photoconductor manufacturing apparatus in which a cathode electrode is installed outside a reaction vessel and a plurality of cylindrical substrates are installed in the reaction vessel. FIG. 2B shows a cross section taken along the line A-A ′ of FIG.

  The reaction apparatus shown in FIG. 2 has a configuration in which six cylindrical substrates 201 are installed in the reaction vessel 203 at equal intervals on the same circumference. Six gas introduction pipes 202 for introducing gas are installed at equal intervals on the same circumference outside the arrangement circle of the cylindrical base body.

  The high frequency powers having different frequencies oscillated from the high frequency power sources 208 and 215 having the oscillation frequencies f1 and f2 are applied to the feeding point of the power branch plate 213 through the matching boxes 209 and 216, respectively, and installed outside the reaction vessel 203. Electric power is supplied into the reaction vessel 203 from a plurality of high-frequency electrodes 204, and plasma is generated in the reaction vessel 203 to form a deposited film.

  In order to efficiently introduce the high-frequency power emitted from the high-frequency electrode 204 into the reaction vessel 203, ceramic which is a dielectric is used on the side wall of the cylindrical reaction vessel 203.

  Plasma leakage prevention means 218 having a plurality of openings is provided between the lower end of the cylindrical base 201 and the bottom surface 217, and the plasma leakage prevention means 218 is fixed to the bottom plate 217.

  The plasma leakage prevention means 218 is provided so as to cover the entire surface having the exhaust port of the reaction vessel by a combination of a small opening portion 219a and a large opening portion 219b, and the opening diameter is large on the side surface side of the reaction vessel 203. It has become.

  Specific ceramic materials for the cylindrical reaction vessel used in FIG. 1 and FIG. 2 are alumina, titanium dioxide, aluminum nitride, boron nitride, zircon, cordierite, zircon cordierite, silicon oxide, beryllium mica type Ceramics etc. are mentioned. Of these, alumina, aluminum nitride, and boron nitride are preferable from the viewpoint of suppression of impurity contamination during heat treatment and heat resistance.

  An outline of the formation of the deposited film when the apparatus shown in FIGS. 1 and 2 is used will be described below by taking the apparatus of FIG. 1 as an example.

  A cylindrical base 101 is installed in the reaction vessel 103, and exhaust is performed to the exhaust pipe 107 via a plasma leakage prevention means 118 provided between the lower end and the bottom surface 117 of the base support 106 by an exhaust device (not shown). Then, the reaction vessel 103 is evacuated. Subsequently, the cylindrical substrate 101 is heated and controlled to a predetermined temperature of about 200 ° C. to 300 ° C. by a heater (not shown).

  When the cylindrical substrate 101 reaches a predetermined temperature, a source gas is introduced into the reaction vessel 103 via a source gas supply means (not shown). After confirming that the flow rate of the source gas is the set flow rate and the pressure in the reaction vessel 103 is stable, two high frequency powers are supplied from the high frequency power sources 108 and 115 to the high frequency electrode 104 via the matching boxes 109 and 116. To do.

  As a result, high-frequency power of two different frequencies is introduced into the reaction vessel 103, glow discharge occurs in the reaction vessel 103, the source gas is excited and dissociated, and a deposited film is formed on the cylindrical substrate.

  After the formation of the desired film thickness, 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 deposited film. By repeating the same operation a plurality of times, a desired multilayered light-receiving layer is formed.

  During the formation of the deposited film, the cylindrical substrate 101 is rotated at a predetermined speed by the motor 111 via the rotation shaft 110, whereby a deposited film is formed over the entire surface of the cylindrical substrate 101.

  FIGS. 3A to 3C are diagrams schematically showing an example of an opening pattern of the plasma leakage prevention means 118 and 218 according to the present invention.

  Incidentally, the shape of the openings provided in the plasma leakage preventing means 118 and 218 may be any of various shapes such as round holes and squares at a constant pitch, but a round shape is preferable from the viewpoint of workability.

  FIG. 5 is a schematic configuration diagram for explaining a layer configuration of an electrophotographic photosensitive member made of a non-single crystal material containing at least silicon produced according to the present invention.

  FIG. 5A shows an electron in which a charge injection blocking layer 502, a photoconductive layer 503 made of a-Si containing at least hydrogen, and a surface layer 504 having a visible image holding capability in an electrophotographic apparatus are stacked in this order on a substrate 501. It is a photographic photoreceptor.

  FIG. 5B shows an electrophotographic photoreceptor in which a charge injection blocking layer 502, a photoconductive layer 503, and a surface layer 504 are sequentially laminated on a substrate 501, and the photoconductive layer 503 and the charge transport layer 505 generate charge. This is a function-separated electrophotographic photoreceptor having a configuration including a layer 506. When the electrophotographic photoreceptor is irradiated with light, carriers generated mainly in the charge generation layer 506 pass through the charge transport layer 505 and reach the conductive substrate 501.

  Hereinafter, the deposited film forming apparatus of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples described below.

  Using the apparatus having the configuration shown in FIG. 1, high-frequency power having two types of oscillation frequencies of 105 MHz (f1) and 60 MHz (f2) is supplied to the electrode 104 on a cylindrical aluminum cylinder having a diameter of 80 mm and a length of 358 mm. An electrophotographic photoreceptor was prepared under the conditions shown in Table 1. In the present embodiment, the plasma leakage prevention means 118 is formed of the punching metal shown in FIG. 3A and has a portion 119b having a large opening diameter from the wall surface of the reaction vessel 103 to the gas introduction means 102, and the individual openings of the openings. The area of the 119a portion was 80 mm and the aperture ratio was 50%, and the individual opening area of the opening portion of the 119b portion was changed to the values shown in Table 2. At this time, the aperture ratio of the portion 119b was also set to 50%.

  The surface of the plasma leakage prevention means was blasted.

The following evaluation was performed on the produced electrophotographic photoreceptor. The results are shown in Table 2.
(Peeling situation)
After producing the electrophotographic photoreceptor, the adhesion state of the film deposited on the plasma leakage preventing means was visually observed.

  The evaluation criteria were as follows.

◎… Very good with no peeling at all ○… Slightly fuzzy but good with no peeling △… Slightly peeled off (a level that is not a problem in practical use)
(Image defect)
The produced electrophotographic photoconductor was mounted on a modified machine of Canon Copier iR-5000, and a Canon full black chart was placed on the document table and copied. The white spots having a diameter of 0.2 mm or more in the same area of the obtained copy image were counted, and the evaluation value of the image defect was determined by the number. Therefore, the smaller the numerical value, the fewer image defects and the better.

  The evaluation criteria are as follows.

◎… Very good with less than 3 ○… Good with 3 or more and less than 5 △… Standard level (chargeability) with 5 or more and less than 10
The produced electrophotographic photosensitive member was installed in a modified machine of Canon Copier iR-5000, and a high voltage of +6 kV was applied to the charger to perform corona charging. Then, the surface potential of the dark portion of the electrophotographic photoreceptor was measured with a surface potential meter installed at the developing device position.

  The evaluation criteria were as follows.

◎… Good at 460V or more ○… Standard level at 420V or more and less than 460V △… Slightly low chargeability at 380V or more and less than 420V (residual potential)
After the electrophotographic photosensitive member was charged to a constant dark portion surface potential (for example, 400 V), it was immediately irradiated with a relatively strong light (for example, 1.5 Lux · sec) of a certain amount of light. At this time, the residual potential of the electrophotographic photoreceptor was measured with a surface potential meter installed at the position of the developing device.

  The evaluation criteria are as follows.

◎… Less than 20V, good ○… 20V or more, less than 30V, standard level △… 30V or more, less than 40V, slightly higher residual potential <Comparative Example 1>
An electrophotographic photoreceptor was produced with the apparatus configuration shown in FIG. 4 under the conditions shown in Table 1 in the same manner as in Example 1.

このとき、プラズマ漏れ防止手段４１８はパンチングメタルから成る形状で開口部の個々の開口面積を８０ｍｍ²で開口率５０％とした。

At this time, the plasma leakage preventing means 418 is made of a punching metal, and each opening area of the opening is 80 mm ² and the opening ratio is 50%.

  The surface of the plasma leakage prevention means was blasted.

  Evaluation similar to Example 1 was implemented with respect to the produced electrophotographic photoreceptor.

  The evaluation results are shown in Table 2 together with Example 1.

表２から明らかなように、プラズマ漏れ防止手段１１８の開口径が大きい第２の領域１１９ｂの開口部の個々の開口面積を中央部側の第１の領域１１９ａの開口部の個々の開口面積より大きくすることで良好な結果が得られた。１１９ｂの開口部の個々の開口面積が１４０ｍｍ²を超えると反応容器内のプラズマが排気管側に漏れて放電空間のプラズマ密度が低下してしまうことにより、帯電能、残留電位といった電気特性が悪化してしまった。

As is clear from Table 2, the individual opening area of the opening of the second region 119b where the opening diameter of the plasma leakage preventing means 118 is large is larger than the individual opening area of the opening of the first region 119a on the center side. Good results were obtained by increasing the size. If the individual opening area of the opening portion of 119b exceeds 140 mm ² , the plasma in the reaction vessel leaks to the exhaust pipe side, and the plasma density in the discharge space decreases, resulting in deterioration of electrical characteristics such as charging ability and residual potential. have done.

Using the apparatus shown in FIG. 1, high-frequency power having two oscillation frequencies of 105 MHz (f1) and 60 MHz (f2) is supplied to the electrode 104 on a cylindrical aluminum cylinder having a diameter of 80 mm and a length of 358 mm. In addition, an electrophotographic photoreceptor was produced under the conditions shown in Table 1. In the present embodiment, the plasma leakage prevention means 118 is formed of the punching metal shown in FIG. 3A and has a portion 119b having a large opening diameter from the wall surface of the reaction vessel 103 to the gas introduction means 102, and the individual openings of the openings. The area of the 119a part was 50 mm ² and the aperture ratio was 50%, and the individual opening area of the 119b part opening was changed to the values shown in Table 3. At this time, the aperture ratio of the portion 119b was also set to 50%.

  Evaluation similar to Example 1 was implemented with respect to the produced electrophotographic photoreceptor.

  The results are shown in Table 3.

＜比較例２＞
図４に示した装置構成で実施例２と同様にして表１に示した条件で電子写真用感光体を作製した。

<Comparative example 2>
An electrophotographic photoreceptor was produced with the apparatus configuration shown in FIG. 4 under the conditions shown in Table 1 in the same manner as in Example 2.

At this time, the plasma leakage preventing means 418 is made of a punching metal, and each opening area of the opening is 50 mm ² and the opening ratio is 50%.

  The surface of the plasma leakage prevention means was blasted.

  Evaluation similar to Example 1 was implemented with respect to the produced electrophotographic photoreceptor.

  The evaluation results are shown in Table 3 together with Example 2.

As is clear from Table 3, good results were obtained by making the individual opening areas of the portions 119b where the opening diameter of the plasma leakage preventing means 118 is larger than the individual opening areas of the central portion 119a. Also, even when the individual opening area of 19 b was 80 mm ² or less, the plasma leakage prevention means 118 was peeled off well, but there were some film pieces that fell on the plasma leakage prevention means 118. . Therefore, it is suitable for the present invention that the individual opening area of the opening portion of the portion 119b where the opening diameter of the plasma leakage preventing means 118 is large is larger than 80 mm ² . On the other hand, if the individual opening area of the opening portion of 119b exceeds 140 mm ² , the plasma in the reaction vessel leaks to the exhaust pipe side and the plasma density in the discharge space is lowered, so that electrical characteristics such as charging ability and residual potential are obtained. Has become worse.

As described above, from the results of Examples 1 and 2, the individual opening area of the opening of the portion 119b where the opening diameter of the plasma leakage preventing means 118 is large is more than 80 mm ² and 140 mm ² or less is a suitable range for the present invention.

Using the apparatus shown in FIG. 1, high-frequency power having two oscillation frequencies of 105 MHz (f1) and 60 MHz (f2) is supplied to the electrode 104 on a cylindrical aluminum cylinder having a diameter of 80 mm and a length of 358 mm. In addition, an electrophotographic photoreceptor was produced under the conditions shown in Table 1. In the present embodiment, the plasma leakage prevention means 118 is formed of the punching metal shown in FIG. 3A and has a portion 119b having a large opening diameter from the wall surface of the reaction vessel 103 to the gas introduction means 102, and the individual openings of the openings. The area of the 119b part was 90 mm ² and the aperture ratio was 50%, and the individual opening area of the opening part of the 119a part was changed to the values shown in Table 4. At this time, the aperture ratio of the portion 119a was also set to 50%.

  The surface of the plasma leakage prevention means was blasted.

  Evaluation similar to Example 1 was implemented with respect to the produced electrophotographic photoreceptor. The results are shown in Table 4 together with the results of Comparative Example 1.

表４の結果から明らかなように、プラズマ漏れ防止手段１１８の中央部１１９ａの開口部の個々の開口面積を０. ８ｍｍ²以上８０ｍｍ²以下とすることで良好な結果が得られた。

As is clear from the results in Table 4, good results were obtained by setting the individual opening area of the opening of the central portion 119a of the plasma leakage preventing means 118 to be 0.8 mm ² or more and 80 mm ² or less.

If the individual opening area of the central portion 19a of the plasma leakage prevention means 118 is smaller than 0.8 mm ² , clogging due to the film deposited on the plasma leakage prevention means 118 occurs during the film formation, and the inside of the reactor Since the pressure of the gas became unstable and abnormal discharge such as sparks occurred, the deposited film sometimes peeled off during the deposition. Therefore, it is not necessarily practical when the opening area of each of the central portions 19a is smaller than 0.8 mm ² . In addition, if the individual opening area of the opening exceeds 80 mm ² , the plasma in the reaction vessel leaks to the exhaust pipe side and the plasma density in the discharge space is reduced, so that electric characteristics such as charging ability and residual potential are reduced. It got worse.

From the above results, the individual opening area of the opening of the central portion 119a of the plasma leakage preventing means 118 is in a range suitable for the present invention from 0.8 mm ^{2 to} 80 mm ² .

Using the apparatus shown in FIG. 1, high-frequency power having two oscillation frequencies of 105 MHz (f1) and 60 MHz (f2) is supplied to the electrode 104 on a cylindrical aluminum cylinder having a diameter of 80 mm and a length of 358 mm. In addition, an electrophotographic photoreceptor was produced under the conditions shown in Table 1. In the present embodiment, the plasma leakage prevention means 118 has a portion 119b having a large opening diameter in the shape made of the punching metal shown in FIG. 3A from the reaction vessel 103 wall surface to the gas introduction means 102, and each of the openings. 119a portion opening area 50 mm ^2, 119b unit and 90 mm ^2, was varied aperture ratio at the same rate both.

  The surface of the plasma leakage prevention means was blasted.

  Evaluation similar to Example 1 was implemented with respect to the produced electrophotographic photoreceptor. The results are shown in Table 5 together with the results of Comparative Example 1.

表５の結果から明らかなように、プラズマ漏れ防止手段全体の面積に対する開口部全体の比率、即ち、開口率が２０％以上８０％以下の範囲であることが好ましいことが分かった。又、開口率が２０％よりも小さいと、コンダクタンスの低下が大きく、それに伴って排気能力は大幅に低下し、反応容器内の圧力を所望の値に維持できず、良好な膜質を得られないこともあった。

As is clear from the results in Table 5, it was found that the ratio of the entire opening to the area of the entire plasma leakage preventing means, that is, the opening ratio is preferably in the range of 20% to 80%. On the other hand, if the aperture ratio is less than 20%, the decrease in conductance is large, and the exhaust capacity is greatly reduced accordingly, the pressure in the reaction vessel cannot be maintained at a desired value, and good film quality cannot be obtained. There was also.

  On the other hand, if the aperture ratio is larger than 80%, the plasma in the reaction vessel leaks to the exhaust pipe side, and the plasma density in the discharge space is reduced, so that electrical characteristics such as charging ability and residual potential are reduced. There was also.

  For the above reasons, it is preferable to set the aperture ratio of the plasma leakage preventing means in the range of 20 to 80%.

Using the apparatus shown in FIG. 1, high-frequency power having two oscillation frequencies of 105 MHz (f1) and 60 MHz (f2) is supplied to the electrode 104 on a cylindrical aluminum cylinder having a diameter of 80 mm and a length of 358 mm. In addition, an electrophotographic photoreceptor was produced under the conditions shown in Table 1. In the present embodiment, the plasma leakage prevention means 118 is formed of the punching metal shown in FIG. 3A and has a portion 119b having a large opening diameter from the wall surface of the reaction vessel 103 to the gas introduction means 102, and the individual openings of the openings. 119a unit area is 40 mm ^2, 119b unit and 85 mm ^2, the aperture ratio was 55% both.

  The surface of the plasma leakage prevention means was blasted.

  Evaluation similar to Example 1 was implemented with respect to the produced electrophotographic photoreceptor.

  The results are shown in Table 6.

表６から明らかなように、全ての項目について良好な結果が得られた。

As is clear from Table 6, good results were obtained for all items.

A high frequency power having two types of oscillation frequencies of 105 MHz (f1) and 60 MHz (f2) is supplied to the electrode 104 by using the apparatus having the configuration shown in FIG. 1, on a cylindrical aluminum cylinder having a diameter of 80 mm and a length of 358 mm. In addition, an electrophotographic photoreceptor was produced under the conditions shown in Table 7. In the present embodiment, the plasma leakage preventing means 118 is formed of a punching metal shown in FIG. 3A, and a portion 119b having a large opening diameter is formed from the wall surface of the reaction vessel 103 to the gas introducing means 102, and individual openings of the openings are formed. 119a unit area is 30 mm ^2, 119b unit and 100 mm ^2, the aperture ratio was 60% both.

  The surface of the plasma leakage prevention means was blasted.

  The same evaluation as in Example 1 was performed on the produced electrophotographic photoreceptor, and good results were obtained as in Example 5.

Using the apparatus having the configuration shown in FIG. 2, high-frequency power having two types of oscillation frequencies of 105 MHz (f1) and 60 MHz (f2) is supplied to the electrode 204, on a cylindrical aluminum cylinder having a diameter of 80 mm and a length of 358 mm. In addition, an electrophotographic photoreceptor was produced under the conditions shown in Table 8. In the present embodiment, the plasma leakage preventing means 218 has a square lattice shape as shown in FIG. 3C and a portion 219b having a large opening diameter from the wall surface of the reaction vessel 203 to the gas introducing means 202, and the individual openings of the openings. 219a unit area is 60 mm ^2, 219b unit and 105 mm ^2, the aperture ratio was 45% both.

  The surface of the plasma leakage prevention means was nickel sprayed.

  The same evaluation as in Example 1 was performed on the six electrophotographic photoreceptors produced, and good results were obtained as in Example 5.

Using the apparatus having the configuration shown in FIG. 2, high-frequency power having two types of oscillation frequencies of 105 MHz (f1) and 60 MHz (f2) is supplied to the electrode 204, on a cylindrical aluminum cylinder having a diameter of 80 mm and a length of 358 mm. In addition, an electrophotographic photoreceptor was produced under the conditions shown in Table 8. In the present embodiment, the plasma leakage prevention means 218 has a square lattice shape as shown in FIG. 3C with a large opening 219b from the wall surface of the reaction vessel 203 to the gas introduction means 202, and each opening area of the opening. The 219a part was 50 mm ² , the 219b part was 95 mm ² , and the aperture ratio was 55% for the 219a part and 65% for the 219b part. At this time, the aperture ratio of the entire plasma leakage preventing means 218 was 60%.

  The surface of the plasma leakage prevention means was nickel sprayed.

  The same evaluation as in Example 1 was performed on the six electrophotographic photoreceptors produced, and good results were obtained as in Example 5.

  The present invention is useful as a vacuum processing apparatus using plasma, particularly as an apparatus suitable for forming a deposited film by a plasma CVD method.

It is a schematic diagram which shows an example of the plasma processing apparatus which concerns on this invention, (a) is the longitudinal cross-sectional view, (b) shows the cross-sectional view, respectively. It is a schematic diagram which shows an example of the plasma processing apparatus of this invention, (a) shows the longitudinal cross-sectional view, (b) shows the cross-sectional view, respectively. It is the schematic which shows an example of a plasma leak prevention means. It is a schematic diagram which shows an example of the conventional deposited film formation apparatus, (a) is the longitudinal cross-sectional view, (b) shows the cross-sectional view, respectively. It is the schematic for demonstrating the layer structure of the electrophotographic photoreceptor.

Explanation of symbols

100, 200, 400 Vacuum processing apparatus 101, 201, 401 Cylindrical substrate 102, 202, 402 Gas introduction pipe 103, 203, 403 Reaction vessel 104, 204, 404 High frequency electrode 105, 205, 405 High frequency power supply system 106, 206 , 406 Base support 107, 207, 407 Exhaust pipe 108, 208, 408 First high frequency power source 109, 209, 409 First matching box 110, 210, 410 Rotating shaft 111, 211, 411 Motor 112, 212, 412 Reduction gear 113, 213, 413 Power branch 114, 214, 414 Shield 115, 215, 415 Second high frequency power supply 116, 216, 416 Second matching box 117, 217, 417 Bottom surface 118, 218 Plasma leakage prevention means 119, 219a Plasma leak prevention means opening (first region on the reaction vessel central side)
119b, 219b Plasma leak prevention means opening (near second region on side surface of reaction vessel)
501 substrate 502 charge injection blocking layer 503 photoconductive layer 504 surface layer 505 charge transport layer 506 charge generation layer

Claims (7)

A reaction vessel capable of at least depressurization; means for housing a cylindrical substrate in the reaction vessel; gas introduction means for introducing gas into the reaction vessel; and high-frequency power for generating plasma in the reaction vessel. In a plasma processing apparatus comprising high-frequency power supply means for supplying and exhaust means for exhausting the gas in the reaction vessel through the exhaust port of the reaction vessel,
The opening diameter is larger in the second region on the side surface of the reaction vessel than the first region on the side of the central portion of the reaction vessel, and has a plurality of openings that allow the gas in the reaction vessel to flow. A plasma processing apparatus, wherein plasma leakage prevention means is provided between the surface having the exhaust port and the cylindrical base so as to cover the entire surface having the exhaust port.
2. The plasma processing apparatus according to claim 1, wherein the second region of the plasma leakage preventing means is between the side surface of the reaction vessel and the gas introducing means.
3. The plasma processing apparatus according to claim 1, wherein the opening area of each opening portion of the first region of the plasma leakage preventing means is 0.8 mm 2 or more and 80 mm 2 or less.
The plasma processing apparatus according to any one of claims 1 to 3, wherein an individual opening area of the opening in the second region of the plasma leakage preventing means is more than 80 mm2 and not more than 140 mm2.
The plasma processing apparatus according to claim 1, wherein the plasma leakage prevention means is made of a punching metal or a metal mesh.
6. The plasma processing apparatus according to claim 1, wherein the high-frequency power supply means is means for simultaneously supplying at least two different high-frequency frequencies to the same high-frequency electrode.
7. The plasma processing apparatus according to claim 1, wherein a deposited film made of a non-single crystal material containing at least silicon having a function as an electrophotographic photoreceptor is formed on the cylindrical substrate. .

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