JP2007063628A - Apparatus for forming deposition film and method for forming deposition film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for forming a deposition film which reduces an image defect and simultaneously enhances the uniformity of potential characteristics in an electrophotographic photoconductor, and enhances the stability of them as well. <P>SOLUTION: The apparatus for forming a deposition film has: a reaction vessel 201 which is composed by being sandwiched between a first cylindrical side wall 101 and a second cylindrical side wall 102 surrounding it; a substrate-holding member which is placed in the reaction vessel 201 and holds a substrate 205; a source-gas supply means 210; and a power supply system for supplying a high-frequency power into the reaction vessel. At least one part of the first cylindrical side wall 101 is made from a dielectric substance. On the central axis of the first cylindrical side wall, a first high-frequency electrode 202 is arranged in a state of being separated from the first cylindrical side wall. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a deposited film forming apparatus and a deposited film forming method using high-frequency power, which are used for forming a deposited film in a semiconductor device, an electrophotographic photosensitive member, an image input line sensor, a photographing device, a photovoltaic device, or the like. .

  Conventionally, as a method of forming a deposited film used for semiconductor devices, electrophotographic photosensitive members, image input line sensors, photographing devices, photovoltaic devices, other various electronic elements, and optical elements, vacuum deposition, sputtering, ion There are many known methods such as a plating method, a thermal CVD method, a photo CVD method, a plasma CVD method, etc., and an apparatus therefor is also put into practical use.

  In particular, 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 has been put into practical use, and various apparatuses for that purpose have been proposed. (See, for example, Patent Document 1). The plasma CVD method is suitable for forming a hydrogenated amorphous silicon (hereinafter referred to as “a-Si: H”) deposited film for electrophotography.

  FIG. 5 is a schematic view showing an example of an a-Si: H deposited film forming apparatus for electrophotography using high-frequency power in the VHF band. FIG. 5 (a) is a schematic sectional view, and FIG. FIG. 6 is a schematic cross-sectional view taken along a cutting line AA ′ in FIG.

  An exhaust port 209 is formed in the lower part of the reaction vessel 201, and the other end of the exhaust port 209 is connected to an exhaust device (not shown). Six cylindrical substrates 205 on which a deposited film is formed are disposed so as to surround the central portion of the reaction vessel 201, and the substrates 205 are parallel to each other. Each cylindrical substrate 205 is provided so as to be held by a rotating shaft 208 and heated by a heating element 207. By driving a motor (not shown), the rotation shaft 208 is rotated via a gear (not shown) so that the cylindrical base body 205 rotates around the shaft.

  The source gas is supplied from the source gas supply means 210 into the reaction vessel 201. The high frequency power is introduced into the reaction vessel 201 from the first high frequency electrode 202 via the matching box 212 from the high frequency power supply 211.

  Formation of a deposited film using such an apparatus is generally performed by the following procedure.

  First, the cylindrical substrate 205 is installed in the reaction vessel 201, and the inside of the reaction vessel 201 is exhausted through an exhaust port 209 by an exhaust device (not shown). Subsequently, the cylindrical base 205 is heated and controlled to a predetermined temperature by the heating element 207.

  When the cylindrical substrate 205 reaches a predetermined temperature, the source gas is introduced into the reaction vessel 201 through the source gas supply means 210. After confirming that the flow rate of the source gas is the set flow rate and that the pressure in the reaction vessel 201 is stable, the output of the high frequency power supply 211 is set to a predetermined value, and then the impedance of the matching circuit in the matching box 212 is set. Adjust. As a result, high-frequency power is efficiently supplied into the reaction vessel 201 via the first high-frequency electrode 202, glow discharge occurs in the reaction vessel 201, and the source gas is excited and dissociated and deposited on the cylindrical substrate 205. A film is formed.

  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 light-receiving layer having a desired multilayer structure is formed on the substrate 205. During the formation of the deposited film, the cylindrical substrate 205 is rotated at a predetermined speed by a motor (not shown) via the rotating shaft 208 so that a uniform deposited film is formed over the entire surface of the cylindrical substrate 205. It has become.

  FIG. 6 is a schematic diagram showing another example of an apparatus for forming a hydrogenated amorphous silicon deposited film for electrophotography using high-frequency power in the VHF band. FIG. 6A is a schematic cross-sectional view, and FIG. 6B is a schematic cross-sectional view taken along a cutting line A-A ′ in FIG.

  In the apparatus of FIG. 6, a plurality of second high-frequency electrodes 213 are arranged outside the reaction vessel 201, and high-frequency power is introduced into the reaction vessel 201 from the second high-frequency electrode 213 through the dielectric wall 203. It has come to be.

  The high-frequency power is supplied to the second high-frequency electrode 213 from the second high-frequency power source 214 via the second matching box 215. In addition, a high frequency shield 204 is provided so as to surround the second high frequency electrode 213, so that leakage of electric power to the outside is prevented.

  Formation of a deposited film using such an apparatus is performed while controlling the second high-frequency power source 214 and the second matching box 215 in parallel with the control of the high-frequency power source 211 and the matching box 212, respectively. Other operations can be performed in the same manner as in the case of using the apparatus of FIG.

  When the apparatus as shown in FIG. 6 is used, high-frequency power is supplied from both inside and outside the reaction vessel 201, so that the power density in the reaction vessel 201 can be adjusted more appropriately. As a result, the characteristics of the formed electrophotographic photoreceptor can be improved.

  By the way, when high-frequency power having a frequency in the VHF band is used as high-frequency power, power unevenness is relatively likely to occur. Therefore, in order to improve this, an apparatus for forming a hydrogenated amorphous silicon deposited film for electrophotography using high-frequency power of two different frequencies as shown in FIG. 7 has also been developed, and further when such an apparatus is used. The deposited film forming method is improved in various ways (see, for example, Patent Document 2).

  This will be described below with reference to FIG. 7A is a schematic cross-sectional view, and FIG. 7B is a schematic cross-sectional view taken along a cutting line A-A ′ in FIG. 7A.

  In the apparatus of FIG. 7, a superimposed high frequency power source 217 capable of outputting high frequency power having a frequency different from the high frequency power output from the high frequency power source 211 is provided. Similarly, a second superimposed high-frequency power source 216 capable of outputting high-frequency power having a frequency different from that of the high-frequency power output from the second high-frequency power source 214 is provided.

  The high frequency powers output from the high frequency power supply 211 and the superimposed high frequency power supply 217 are combined in the matching box 212 and then supplied to the first high frequency electrode 202. Similarly, the high-frequency powers output from the second high-frequency power source 214 and the second superimposed high-frequency power source 216 are combined in the matching box 215 and then supplied to the second high-frequency electrode 213.

  In the matching box 212, a matching circuit for performing matching adjustment of the high frequency power input from the high frequency power supply 211 and a matching circuit for performing matching adjustment of the high frequency power input from the superimposed high frequency power supply 217 are provided. Each can be adjusted independently. Similarly, a matching circuit for performing matching adjustment of high-frequency power input from the second high-frequency power source 214 and matching adjustment of high-frequency power input from the second superimposed high-frequency power source 216 are also performed in the matching box 215. And a matching circuit for performing the adjustment, each of which can be adjusted independently.

In order to form a deposited film using such an apparatus, high-frequency power is output from the superimposed high-frequency power source 217 simultaneously with the output of high-frequency power from the high-frequency power source 211, and the second high-frequency power source 214 is output. The high-frequency power is also output from the second superimposed high-frequency power source 216 in parallel with the output of the high-frequency power from. The matching adjustment is performed independently for the high-frequency power output from each of the high-frequency power source 211, the superimposed high-frequency power source 217, the second high-frequency power source 214, and the second superimposed high-frequency power source 216. Except for such high-frequency power output and matching adjustment, a deposited film can be formed in the same manner as in the case of using the apparatus shown in FIG.
Japanese Patent Application Laid-Open No. 11-092932 JP 2003-268557 A

  Even with the conventional apparatus and processing method as described above, it is possible to produce electrophotographic photoreceptors at a level where there is no practical problem at present. However, there is still room for improvement for higher image quality. In particular, the suppression of image defects and the improvement of the uniformity of potential characteristics are required to be promptly achieved in order to meet the recent demand for higher image quality.

  For example, when an electrophotographic photosensitive member is formed using the apparatus shown in FIG. 7, it is effective to increase the high frequency power as a means for further improving the uniformity of the potential characteristics. However, when the high-frequency power is increased, the film peeling of the deposited film deposited on the first high-frequency electrode 202 installed in the reaction vessel 201 becomes remarkable, which is accompanied by a decrease in the image defect level due to the structural defect. There is. Conversely, when the high frequency power is reduced to improve the image defect level, the uniformity of the potential characteristics may be deteriorated. For this reason, the realization of the deposited film forming apparatus and the deposited film forming method capable of simultaneously improving the uniformity of the image defect level and the potential characteristic remains as a problem.

  In the current electrophotographic photoreceptor formation, the high frequency power value at the time of forming the deposited film is set in consideration of the balance between the image defect level and the uniformity level of the potential characteristics. However, since the influence of the high frequency power on the image defect level and the uniformity level of the potential characteristic is high, the image defect level is deteriorated or the uniformity level of the potential characteristic is easily deteriorated due to the deviation or variation of the high frequency power. For this reason, from the viewpoint of improving the yield rate, it has been left as a problem to improve the stability of the image defect level and the uniformity level of the electrical characteristics.

  The present invention aims to solve the above problems. That is, an object of the present invention is to provide a deposited film forming apparatus and a deposited film forming method capable of simultaneously improving the image defect level and improving the uniformity of the potential characteristics and capable of improving the stability of these. .

  As a result of intensive studies to achieve the above object, the inventors of the present invention preferably have a high power density on the surface of the high-frequency electrode in order to improve the uniformity of the potential characteristics, while to improve the image defect level. It was found that it is preferable that the power density in the high-frequency power introduction portion that is in contact with the plasma is low. As a result of further investigation based on this knowledge, it is possible to improve the image defect level and make the potential characteristics uniform simultaneously by devising the configuration of the reaction vessel and the arrangement relationship between the reaction vessel and the high-frequency electrode. In addition, the inventors have found that the stability can be improved and have completed the present invention.

  That is, the present invention includes a reaction vessel that is configured between a first cylindrical side wall and a second cylindrical side wall that surrounds the first cylindrical side wall, and is disposed in the reaction vessel. A deposited film comprising: a substrate holding member for holding the substrate; a source gas supply means for supplying a source gas into the reaction vessel; and a power supply system for supplying high-frequency power into the reaction vessel. In the device, at least a part of the first cylindrical side wall is made of a dielectric, and a first high-frequency electrode is provided on the central axis of the first cylindrical side wall as the power supply system. It is characterized in that it is arranged apart from the cylindrical side wall.

  In the present invention, a substrate is disposed in a depressurizable reaction vessel formed between a first cylindrical side wall and a second cylindrical side wall surrounding the first cylindrical side wall, and the reaction vessel In the deposited film forming method of supplying a raw material gas into the reaction vessel and introducing high frequency power into the reaction vessel from a high frequency power introducing means to decompose the raw material gas to form a deposited film on the substrate, the high frequency power is A dielectric comprising at least a part of the first cylindrical side wall from a first high-frequency electrode surrounded by the first cylindrical side wall and spaced apart from the first cylindrical side wall It is characterized by being introduced into the reaction vessel through the body member.

  According to the present invention as described above, it is possible to simultaneously improve the uniformity of the image defect level and the potential characteristic, and to improve the stability thereof.

  When high-frequency power is introduced into the reaction vessel, power unevenness is generated on the high-frequency electrode according to the wavelength of the high-frequency power used. We found that the smaller the high-frequency power density, the easier it becomes. That is, it has been found that the uniformity of the deposited film formed tends to deteriorate as the high-frequency power density on the high-frequency electrode decreases. From this viewpoint, it is preferable that the surface area of the high-frequency electrode is as small as possible. When a cylindrical or columnar high-frequency electrode is used, the diameter is preferably as small as possible.

  On the other hand, the inventors of the present invention have further studied that the deposited film adhering to the reaction vessel wall surface is more likely to be peeled off at the high frequency power introducing portion, and further, the higher the power density at the surface of the high frequency power introducing portion is, the more the film is peeled off. Has been found to be prominent. That is, it has been found that the higher the power density on the surface of the high-frequency power introduction portion, the more likely the defects in the deposited film to be formed, and in the case of forming an electrophotographic photoreceptor, the image defects are likely to increase. The idea or design of reducing the surface area of the high-frequency electrode and reducing the film adhesion to the surface of the high-frequency electrode as much as possible for the purpose of improving the efficiency of utilization of the raw material gas has been a barrier to film peeling suppression and image defect suppression. I found out.

  Based on the knowledge so far, considering a method for simultaneously suppressing power unevenness and film peeling, for example, in the case of the apparatus having the configuration shown in FIG. 5, the first high-frequency electrode 202 is made of a conductive member. It is conceivable that the conductive member is composed of a configured part and a dielectric member covering the outside thereof, the diameter of the conductive member is reduced, and the diameter is increased by increasing the thickness of the dielectric member. This increases the power density on the surface of the conductive member, and also reduces the power density on the surface of the dielectric member serving as the power introduction part to the reaction vessel 201, thereby suppressing power unevenness and the deposited film being processed. It aims at coexistence of film peeling suppression.

  However, with such a configuration, in reality, the power loss when high-frequency power passes through the dielectric member increases, and the dielectric member heats up accompanying this power loss. As a result, it has been found that the dielectric member may be damaged or the deposited film attached to the surface of the dielectric member may be easily peeled off.

  As another configuration, the first high-frequency electrode 202 is composed of a portion made of a conductive member and a cylindrical dielectric member covering the outside thereof, and the diameter of the conductive member is made small so that the cylindrical dielectric member is formed. It is conceivable to increase the diameter of the body member and further reduce the thickness of the cylindrical dielectric member. However, in this case, it is actually understood that a discharge is likely to occur between the conductive member and the cylindrical dielectric member, and the loss of power in this discharge may adversely affect the deposited film characteristics. It was. Further, it has been found that the discharge generated between the conductive member and the cylindrical dielectric member is unstable and the discharge in the entire reaction vessel may be unstable.

  As a result of further investigation by the present inventors based on the further knowledge as described above, a part of the reaction vessel is divided into a first cylindrical side wall made of at least a part of a dielectric, And a second cylindrical side wall surrounding the cylindrical side wall, and the first high-frequency electrode is disposed on the central axis of the first cylindrical side wall and spaced apart from the first cylindrical side wall. It was found that such harmful effects are suppressed. As a result, the suppression of film peeling and the suppression of power non-uniformity can be achieved at the same time, and the stability can be improved. Simultaneously, the improvement of the image defect level and the improvement of the uniformity of the potential characteristics, which are the objects of the present invention. It has been found that this can be realized and the stability of these can be improved. In addition, as a specific structural example of the reaction vessel, the reaction vessel is configured by the first cylindrical side wall and the second cylindrical side wall, and an upper wall and a lower wall respectively disposed at upper and lower ends thereof. There may be.

  As described above, according to the present invention, a part of the reaction vessel is constituted by the first cylindrical side wall and the second cylindrical side wall surrounding the first cylindrical side wall, and the first high-frequency electrode is the first high-frequency electrode. By disposing on the central axis of the cylindrical side wall in a state of being separated from the first cylindrical side wall, film peeling and power unevenness during formation of the deposited film are suppressed, and as a result, the level of structural defect is improved. In addition, the uniformity of the potential characteristics can be improved at the same time, and the stability thereof can also be improved.

  The present invention will be described in detail below with reference to the drawings.

  FIG. 1 is an example of a schematic configuration diagram of a deposited film forming apparatus that can be used in the present invention.

  In FIG. 1, 101 is a first cylindrical side wall, 102 is a second cylindrical side wall, and is surrounded by the first cylindrical side wall 101, the second cylindrical side wall 102, and the upper and lower walls. The inside of the reaction vessel 201 can be depressurized. At least a part of the first cylindrical side wall 101 is made of a dielectric, and a first high-frequency electrode 202 is separated from the first cylindrical side wall 101 on the central axis of the first cylindrical side wall 101. Has been placed. High frequency power is introduced from the first high frequency electrode 202 into the reaction vessel 201 through the dielectric portion of the first cylindrical side wall 101.

  Note that the space surrounded by the first cylindrical side wall 101, that is, the space where the first high-frequency electrode 202 is installed is in an atmospheric state. Thus, since the space between the first high-frequency electrode 202 and the first cylindrical side wall 101 is in the atmospheric state, the occurrence of discharge between them is suppressed, and the first high-frequency electrode 202 and the first cylindrical side wall 101 are The adverse effect on the deposited film characteristics caused by the occurrence of discharge between the one cylindrical side wall 101 is suppressed. In addition, electromagnetic shields (not shown) are provided above and below the first cylindrical side wall 101 so that high frequency power radiated from the first high frequency electrode 202 does not leak outside the reaction vessel.

  The configuration other than the above is the same as that of the conventional apparatus shown in FIG. 5, and the deposited film formation using the apparatus shown in FIG. 1 is performed in the same manner as in the case of using the conventional apparatus shown in FIG. Can be done.

  In the present invention, first, by appropriately setting the surface area of the first high-frequency electrode 202 and the outer diameter of the first cylindrical side wall 101, the power density on the surface of the first high-frequency electrode 202 is increased, In addition, it is possible to reduce the power density on the outer peripheral surface of the first cylindrical side wall 101 serving as a power introduction part to the reaction vessel 201. In addition, by appropriately setting the thickness of the dielectric that forms at least a part of the first cylindrical side wall 101, it is possible to suppress power loss in the dielectric portion, thereby suppressing the temperature rise there. In addition, film peeling during processing can be suppressed.

  The material forming the first high-frequency electrode 202 is not particularly limited as long as it is a conductive material, and aluminum, nickel, titanium, silver, gold, SUS, or the like can be used. The first high-frequency electrode 202 does not need to be entirely made of such a conductive material. For example, the first high-frequency electrode 202 has a structure in which a conductive material is provided on the surface of a non-conductive material such as a resin or ceramic. Also good. Alternatively, the surface of the conductive material may be covered with a nonconductive material such as resin or ceramic. When the surface of the conductive material is covered with a non-conductive material, it is preferable to use a material with a small dielectric loss in order to suppress the loss of high-frequency power in the non-conductive material.

  In the present invention, it is necessary that at least a part of the first cylindrical side wall 101 is made of a dielectric material. Since the first cylindrical side wall 101 constitutes a part of the reaction vessel 201, the first cylindrical side wall 101 needs to be a decompression vessel wall capable of blocking the atmosphere. In addition, since the first cylindrical side wall 101 also serves as a high-frequency power introduction part into the reaction vessel, it is preferable that the first cylindrical side wall 101 be made of a material having a small dielectric loss and a small loss of high-frequency power there. Specifically, ceramic materials such as alumina, silicon oxide, boron nitride, silicon nitride, or carbon nitride are preferably used.

  When using high frequency power in the VHF band with a frequency of the high frequency power of 50 MHz or more and 250 MHz or less, a particularly remarkable effect can be obtained. In the high frequency power in the VHF band, the wavelength at the part in contact with the plasma is often about 10 cm to several meters, and is often the same as the device size and the substrate size. The effect on uniformity is likely to manifest. However, in this embodiment, the uniformity of the high frequency power density is improved while suppressing the exfoliation of the film, so that the uniformity of the processed property can be kept good even in the high frequency power in the VHF band. it can. For this reason, it becomes possible to simultaneously obtain high processing speed, high processing characteristics and suppression of structural defects, and uniformity of processing characteristics, which are characteristics when using high frequency power in the VHF band, In addition, the processing cost can be reduced.

  Next, it is preferable that the first cylindrical side wall 101 and the second cylindrical side wall 102 are arranged so that their central axes are the same. This is because the uniformity of the high frequency power in the reaction vessel 201 is improved, and as a result, the uniformity of the deposited film characteristics is improved.

  Furthermore, a plurality of base bodies 205 (in other words, base body holding members for holding them) may be arranged on a circumference having centers on the central axes of the first cylindrical side wall 101 and the second cylindrical side wall 102. It is more preferable in that the processing capability can be improved while maintaining the uniformity of the processing characteristics.

  In the present invention, in addition to the above-described configuration, at least a part of the second cylindrical side wall is made of a dielectric, and the second high-frequency electrode disposed outside the second cylindrical side wall can also be used in the reaction vessel. It is good also as a structure which introduces high frequency electric power into. This makes it possible to further improve the uniformity of the characteristics to be processed.

  This will be described below with reference to FIG. 2A and 2B are schematic views showing an example of an apparatus according to the present invention. FIG. 2A is a schematic cross-sectional view, and FIG. 2B is a schematic view taken along a cutting line AA ′ in FIG. It is sectional drawing.

  In the apparatus of FIG. 2, a plurality of second high-frequency electrodes 213 are arranged outside the reaction vessel 201, and the high-frequency power passes through the second cylindrical side wall 203 that is a dielectric wall that forms a part of the reaction vessel 201. It is configured to be able to penetrate and be introduced into the reaction vessel 201 also from the second high-frequency electrode 213.

  The high-frequency power is supplied to the second high-frequency electrode 213 from the second high-frequency power source 214 and the second superimposed high-frequency power source 216 via the second matching box 215. In addition, a high frequency shield 204 is provided so as to surround the second high frequency electrode 213, so that leakage of electric power to the outside is prevented.

  Such a second cylindrical side wall 203 is made of at least a part of a dielectric, and high-frequency power is also fed into the reaction vessel 201 from the second high-frequency electrode 213 disposed outside the second cylindrical side wall 203. In the case of the configuration to be introduced, the dielectric material in the first cylindrical side wall 101 and the dielectric material in the second cylindrical side wall 203 are made different materials as necessary, thereby obtaining the effect of the present invention more remarkably. There are cases where it is possible. This is because by changing the dielectric material, the dielectric constant changes accordingly, the introduction efficiency of the high frequency power introduced from the inside of the reaction vessel 201, and the introduction efficiency of the high frequency power introduced from the outside of the reaction vessel 201 It is inferred that this is because of the adjustment.

  In addition, although there is no restriction | limiting in particular as a shape of the high frequency electrode in this invention, It is more preferable that it is a cylindrical shape or a column shape from a viewpoint of a viewpoint of symmetry and a reduction of an unnecessary electrode surface area.

  Furthermore, it is preferable that the outer diameter of the first high-frequency electrode is 1/3 or less of the outer diameter of the first cylindrical side wall in order to obtain the effects of the present invention more remarkably. By setting such a dimensional ratio, it is presumed that a preferable condition is a balance between the power density on the surface of the high-frequency electrode and the power density on the surface of the dielectric member serving as the high-frequency power introduction part to the reaction vessel. .

  The outer diameter of the first cylindrical side wall is preferably 1/2 or more than the outer diameter of the cylindrical substrate. As the deposited film forming conditions, the most effective conditions for suppressing film peeling on the substrate are generally used from the viewpoint of film adhesion. When the outer diameter of the first cylindrical side wall is smaller than 1/2 of the outer diameter of the cylindrical substrate, the curvature of the first cylindrical side wall is too large with respect to the film peeling due to the curvature of the first cylindrical side wall. May be disadvantageous. Therefore, by setting the outer diameter of the first cylindrical side wall to be 1/2 or more of the outer diameter of the cylindrical base body, the occurrence of film peeling due to such a difference in curvature is suppressed, and a good deposited film can be formed. It becomes possible.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not restrict | limited at all by these.

[Example 1]
Using the deposited film forming apparatus shown in FIG. 1, on a cylindrical aluminum cylinder (base) 205 having a diameter of 80 mm and a length of 358 mm, the oscillation frequency of the high frequency power supply 211 is 100 MHz and the oscillation frequency of the superimposed high frequency power supply 217 is 55 MHz. A deposited film was formed under the conditions shown in 1. The deposited film was an amorphous silicon photoconductor (a-Si photoconductor) composed of a charge injection blocking layer, a photoconductive layer, and a surface layer, and was prepared by the following procedure.

  The first high-frequency electrode 202 was a SUS304 cylinder having a diameter of 30 mm and a length of 50 cm. The first cylindrical side wall 101 is an alumina cylinder having an outer diameter of 90 mm and a thickness of 5 mm, and the outer peripheral surface in contact with the plasma is blasted so that Rzjis (JIS B0601: '01) is Rzjis = 20 μm. Regarding the high-frequency power, the power from the high-frequency power source 211 and the power from the superimposed high-frequency power source 217 were set to the same value, and the sum of them was the value shown in Table 1.

  First, a cylindrical aluminum cylinder 205 was installed in the reaction vessel 201, and the inside of the reaction vessel 201 was exhausted through an exhaust port 209 by an exhaust device (not shown). Subsequently, the cylindrical aluminum cylinder 205 was rotated at a speed of 3 rpm by a motor (not shown) via the rotating shaft 208. Also, while supplying Ar into the reaction vessel 201 from the source gas supply means 210 at 500 ml / min (normal), the heating element 207 heats and controls the cylindrical aluminum cylinder 205 to 250 ° C., and maintains this state for 2 hours. did.

  Next, the supply of Ar is stopped, the inside of the reaction vessel 201 is exhausted through an exhaust port 209 by an exhaust device (not shown), and then the raw material used for forming the charge injection blocking layer shown in Table 1 through the raw material gas supply means 210 Gas was introduced. After confirming that the flow rate of the source gas has reached the set flow rate, the conductance of a pressure adjustment valve (not shown) provided between the exhaust port 209 and an exhaust device (not shown) is adjusted to adjust the pressure in the reaction vessel 201. The predetermined pressure was set. After confirming that the pressure has stabilized, the sum of the outputs of the high frequency power supply 211 and the superimposed high frequency power supply 217 is set to the value shown in Table 1, and the high frequency power is supplied to the first high frequency electrode 202 via the matching box 212. Supplied.

  The high frequency power radiated from the first high frequency electrode 202 passes through the first cylindrical side wall 101 and is introduced into the reaction vessel 201, and charge is injected onto the cylindrical aluminum cylinder 205 by exciting and dissociating the source gas. A blocking layer was formed. After the formation of the predetermined film thickness, the supply of the high frequency power was stopped, and then the supply of the source gas was stopped to finish the formation of the charge injection blocking layer. Thereafter, a photoconductive layer and a surface layer were sequentially formed by repeating the same operation a plurality of times.

[Comparative Example 1]
Using the deposited film forming apparatus shown in FIG. 3, on a cylindrical aluminum cylinder 205 having a diameter of 80 mm and a length of 358 mm, the oscillation frequency of the high-frequency power source 211 is 100 MHz, and the oscillation frequency of the superimposed high-frequency power source 217 is 55 MHz. A deposited film was formed under the conditions. The deposited film is an a-Si photoreceptor including a charge injection blocking layer, a photoconductive layer, and a surface layer, as in the first embodiment, and the formation procedure is the same as in the first embodiment.

  The deposited film forming apparatus shown in FIG. 3 has a configuration in which a superimposed high frequency power source 217 is added to the conventional deposited film forming apparatus shown in FIG. As in Example 1, the high-frequency power is the same as the power from the high-frequency power source 211 and the power from the superimposed high-frequency power source 217, and the sum of them is the value shown in Table 1.

  The first high-frequency electrode 202 was configured to cover the outside of a SUS304 cylinder having a diameter of 30 mm and a length of 50 cm with an alumina cylinder having an inner diameter of 33 mm and an outer diameter of 37 mm. Rzjis (JIS B0601: '01) was set to Rzjis = 20 μm by blasting the outer peripheral surface of the alumina cylinder.

  Thus, the a-Si photosensitive member produced in Example 1 and Comparative Example 1 was placed in a Canon copying machine iR6010 modified for this test, and the characteristics of the a-Si photosensitive member were evaluated. The evaluation items were “image density unevenness”, “optical memory”, “characteristic variation”, and “image defect”, and each item was evaluated by the following specific evaluation method.

  “Image density unevenness”: First, the main charger current is adjusted so that the dark portion potential at the developer position becomes a predetermined value, and then a white paper having a reflection density of 0.1 or less is used for the original, and the light at the developer position is determined. The image exposure light amount was adjusted so that the partial potential was a predetermined value. Next, an A3 size halftone original having a reflection density of 0.3 was placed on the original platen, and evaluation was made based on the difference between the highest value and the lowest value of the reflection density in the entire area on the copy image obtained when copying. The evaluation result was the average value of all the photoreceptors formed at the same time. Therefore, the smaller the value, the better. The image density was measured using an image densitometer: Macbeth RD914.

  “Optical memory”: After adjusting the current value of the main charger so that the dark portion potential at the developing device position becomes a predetermined value, the bright portion potential when a blank paper having a reflection density of 0.1 or less is used as a predetermined value. The image exposure light amount is adjusted so as to be a value. In this state, the test chart in which a black circle having a reflection density of 1.5 and a diameter of 10 mm is attached to an A3 size halftone original having a reflection density of 0.3 as shown in FIG. Place it on the platen as the leading edge and copy. In the obtained copy image, the difference between the reflection density of the black circle memory image observed on the halftone copy and the reflection density of the halftone portion adjacent to the black circle memory image was measured. In FIG. 4, 501 is an A3 size halftone original having a reflection density of 0.3, and 502 is a black circle having a reflection density of 1.5 and a diameter of 10 mm. The black circles 502 are arranged in two rows at intervals of 20 mm, and the rows are arranged at intervals of 20 mm. Such a measurement was performed over the entire region in the direction of the photoreceptor bus, and the maximum reflection density difference among them was used as the value of the optical memory. The evaluation result was the average value of all the photoreceptors formed at the same time. Therefore, the smaller the value, the better the optical memory. The image density was measured using an image densitometer: Macbeth RD914.

  “Characteristic variation”: The maximum value / minimum value is obtained from the optical memory values of all the photoconductors obtained in the process of evaluating “optical memory”, and then the value of ((maximum value) / (minimum value) −1) Was determined as the value of “characteristic variation”. Therefore, the smaller the numerical value, the smaller the characteristic variation and the better.

  “Image defect”: A3 size solid black document with a reflection density of 1.5 is 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 by copying are counted. Evaluated by number. Therefore, the smaller the value, the better. The image density was measured using an image densitometer: Macbeth RD914.

  The evaluation results are shown in Table 2. In Table 2, the evaluation result is based on the evaluation result of Comparative Example 1, and regarding “image density unevenness”, the maximum reflection density difference is improved to less than 1/4, ◎, 1/4 or more and 1/2 Better to less than less than ◎ to 〇, better to less than 1/2 to less than 3/4 ◯, better to 3/4 to less than 7/8 ○ to △, 7/8 to 9/8 Less than Δ was indicated by Δ, and 9/8 or more was indicated by ×.

  As for “optical memory”, those whose maximum reflection density difference is improved to less than ¼ are ◎, those which are improved to 1/4 or more and less than 1/2 are ◎ to ○, 1/2 or more and less than 3/4. The improvement was ◯, 3/4 or more and less than 7/8, ◯ to Δ, 7/8 or more and less than 9/8 was shown as Δ, and 9/8 or more was shown as ×.

  “Characteristic variation” is improved to less than 1/4, ◎, improved from 1/4 to less than 1/2, ◎ to ○, improved from 1/2 to less than 3/4. ◯ 3 to more than 7/8 improved, △ to Δ, 7/8 to less than 9/8, Δ, 9/8 or more ×.

  Regarding “image defects”, those in which the number of white spots having a diameter of 0.1 mm or more was improved to less than ¼, and those in which the number of white spots was improved to from ¼ to less than 1/2 were ◎ to 〇, 1 / Improved from 2 to less than 3/4, ◯, improved from 3/4 to less than 7/8, ◯ to Δ, 7/8 to less than 9/8, and 9/8 or more to ×. .

  From Table 2, it was confirmed that the a-Si photoreceptor produced in Example 1 was particularly excellent in “characteristic variation” and “image defect”, and the effects of the present invention were confirmed.

[Example 2]
The deposited film forming apparatus shown in FIG. 1 is modified so that 12 cylindrical aluminum cylinders 205 having a diameter of 30 mm and a length of 358 mm are installed on the same circumference, the oscillation frequency of the high-frequency power source 211 is 90 MHz, and the superimposed high-frequency power source 217. The oscillation frequency was set to 60 MHz. Then, an a-Si photoreceptor comprising a charge injection blocking layer, a first photoconductive layer, a second photoconductive layer, and a surface layer under the conditions shown in Table 3 was prepared in the same procedure as in Example 1.

  Note that the high-frequency power is the same as the power from the high-frequency power supply 211 and the power from the superimposed high-frequency power supply 217, and the sum of them is the value shown in Table 3. The first high-frequency electrode 202 was a SUS304 cylinder having a diameter of 30 mm and a length of 50 cm. The first cylindrical side wall 101 is an alumina cylinder having an outer diameter of 90 mm and a thickness of 5 mm, and the outer peripheral surface in contact with the plasma is blasted so that Rzjis (JIS B0601: '01) is Rzjis = 20 μm.

[Comparative Example 2]
The deposited film forming apparatus shown in FIG. 5 is modified so that 12 cylindrical aluminum cylinders 205 having a diameter of 30 mm and a length of 358 mm are installed on the same circumference, the oscillation frequency of the high frequency power supply 211 is 90 MHz, and the superimposed high frequency power supply 217 The oscillation frequency was set to 60 MHz. Then, an a-Si photoreceptor comprising a charge injection blocking layer, a first photoconductive layer, a second photoconductive layer, and a surface layer under the conditions shown in Table 3 was prepared in the same procedure as in Example 1.

  Note that the high-frequency power is the same as the power from the high-frequency power supply 211 and the power from the superimposed high-frequency power supply 217, and the sum of them is the value shown in Table 3. The first high-frequency electrode 202 is configured to cover the outside of a SUS304 cylinder having a diameter of 75 mm and a length of 50 cm with an alumina cylinder having an inner diameter of 80 mm and an outer diameter of 90 mm. Rzjis (JIS B0601: '01) was set to Rzjis = 20 μm by blasting the outer peripheral surface of the alumina cylinder.

  The a-Si photosensitive member produced in Example 2 and Comparative Example 2 was installed in a Canon copying machine GP55 modified for this test, and the characteristics of the a-Si photosensitive member were evaluated. The evaluation items were four items of “image density unevenness”, “optical memory”, “characteristic variation”, and “image defect”, and each item was evaluated by the same specific evaluation method as in Example 1. The evaluation results are shown in Table 4. In Table 4, the evaluation results are indicated by the same index as in the comparison between Example 1 and Comparative Example 1 with the evaluation result of Comparative Example 2 as a reference.

  From Table 4, it was confirmed that the a-Si photosensitive member produced in Example 2 was excellent especially in “image density unevenness”, “optical memory”, and “characteristic variation”. The effect was confirmed.

Example 3
Using the deposited film forming apparatus shown in FIG. 1, on a cylindrical aluminum cylinder 205 having a diameter of 80 mm and a length of 358 mm, the oscillation frequency of the high-frequency power source 211 is 150 MHz and the oscillation frequency of the superimposed high-frequency power source 217 is 60 MHz. Thus, an a-Si photosensitive member comprising a charge injection blocking layer, a first photoconductive layer, a second photoconductive layer, and a surface layer was prepared in the same procedure as in Example 1.

  The high-frequency power is the same as the power from the high-frequency power supply 211 and the power from the superimposed high-frequency power supply 217, and the sum of these values is the value shown in Table 5. In this example, the a-Si photosensitive member was manufactured under the four conditions shown in Table 6 with respect to the diameter of the first high-frequency electrode 202 and the outer diameter of the first cylindrical side wall 101. Note that the length of the first high-frequency electrode 202 was 50 cm and the thickness of the first cylindrical side wall 101 was 5 mm under any conditions. Rzjis (JIS B0601: '01) was set to Rzjis = 20 μm on the outer peripheral surface in contact with plasma of the first cylindrical side wall 101 by blasting.

[Comparative Example 3]
5 using the deposited film forming apparatus shown in FIG. 5 on a cylindrical aluminum cylinder 205 having a diameter of 80 mm and a length of 358 mm, the oscillation frequency of the high frequency power supply 211 is 150 MHz, and the oscillation frequency of the superimposed high frequency power supply 217 is 60 MHz. Thus, an a-Si photosensitive member comprising a charge injection blocking layer, a first photoconductive layer, a second photoconductive layer, and a surface layer was prepared in the same procedure as in Example 1.

  The high-frequency power is the same as the power from the high-frequency power supply 211 and the power from the superimposed high-frequency power supply 217, and the sum of these values is the value shown in Table 5. The first high-frequency electrode 202 was configured to cover the outside of a SUS304 cylinder having a diameter of 40 mm and a length of 50 cm with an alumina cylinder having an inner diameter of 45 mm and an outer diameter of 55 mm. Rzjis (JIS B0601: '01) was set to Rzjis = 20 μm by blasting the outer peripheral surface of the alumina cylinder.

  The a-Si photoreceptors prepared in Example 3 and Comparative Example 3 were installed in a Canon copier iR6010 modified for this test, and the characteristics of the a-Si photoreceptor were evaluated. The evaluation items were four items of “image density unevenness”, “optical memory”, “characteristic variation”, and “image defect”, and each item was evaluated by the same specific evaluation method as in Example 1. Table 7 shows the evaluation results. In Table 7, the evaluation results are indicated by the same index as in the comparison between Example 1 and Comparative Example 1 with the evaluation result of Comparative Example 3 as a reference.

  From Table 7, the a-Si photosensitive member produced in Example 3 showed good characteristics under any conditions, and the outer diameter of the first high-frequency electrode was 1/3 of the outer diameter of the first cylindrical side wall. It was confirmed that particularly remarkable effects can be obtained in the following cases (conditions 2 to 4). Moreover, it was confirmed that the further effect is acquired by reducing the surface area of a high frequency electrode (condition 4).

Example 4
The deposited film forming apparatus shown in FIG. 2 is used. On the cylindrical aluminum cylinder 205 having a diameter of 30 mm and a length of 358 mm, the oscillation frequency of the high-frequency power source 211 and the second high-frequency power source 214 is 120 MHz, the superimposed power source 217 and the second power source. An a-Si photosensitive member comprising a charge transport layer, a charge generation layer, and a surface layer was produced under the conditions shown in Table 8 with the oscillation frequency of the superimposed power source 216 being 70 MHz.

  The power from the high frequency power supply 211 was set to 2/3 times the power from the superimposed high frequency power supply 217, and the total of these powers was the value of the internal high frequency power in Table 8. The power from the second high-frequency power source 214 was set to 2/3 times the power from the second superimposed high-frequency power source 216, and the total of these powers was the value of the external high-frequency power in Table 8. Another specific manufacturing procedure is to control the second high-frequency power source 214, the second superimposed high-frequency power source 216, and the second matching box 215, respectively, and control the high-frequency power source 211, the superimposed high-frequency power source 217, and the matching box 212. The same procedure as in Example 1 was performed except that the processes were performed simultaneously.

  The first high-frequency electrode 202 was a SUS304 cylinder having a diameter of 20 mm and a length of 50 cm. The first cylindrical side wall 101 is an alumina cylinder having an outer diameter of 100 mm and a thickness of 5 mm, and the outer peripheral surface in contact with the plasma is blasted so that Rzjis (JIS B0601: '01) is Rzjis = 20 μm.

  The second high-frequency electrode 213 is an SUS304 cylinder having a diameter of 20 mm and a length of 50 cm, the second cylindrical side wall 203 is formed of an alumina cylinder having an outer diameter of 500 mm and a thickness of 12 mm, and the inner peripheral surface in contact with the plasma is blasted. By processing, Rz = 20 μm. The distance between the central axis of the second high-frequency electrode 213 and the outer peripheral surface of the second cylindrical side wall 203 was 30 mm.

[Comparative Example 4]
Using the deposited film forming apparatus shown in FIG. 7, on the cylindrical aluminum cylinder 205 having a diameter of 30 mm and a length of 358 mm, the oscillation frequencies of the high-frequency power supply 211 and the second high-frequency power supply 214 are both 120 MHz, the superimposed power supply 217 and the second power supply. An a-Si photosensitive member comprising a charge transport layer, a charge generation layer, and a surface layer was produced under the conditions shown in Table 8 with the oscillation frequency of the superimposed power source 216 being 70 MHz.

  The power from the high frequency power supply 211 was set to 2/3 times the power from the superimposed high frequency power supply 217, and the total of these powers was the value of the internal high frequency power in Table 8. The power from the second high-frequency power source 214 was set to 2/3 times the power from the second superimposed high-frequency power source 216, and the total of these powers was the value of the external high-frequency power in Table 8. Other specific production procedures were performed in the same manner as in Example 4.

  The first high-frequency electrode 202 was configured to cover the outside of a SUS304 cylinder having a diameter of 30 mm and a length of 50 cm with an alumina cylinder having an inner diameter of 35 mm and an outer diameter of 45 mm. Rzjis (JIS B0601: '01) was set to Rzjis = 20 μm by blasting the outer peripheral surface of the alumina cylinder.

  The second high-frequency electrode 213 is an SUS304 cylinder having a diameter of 20 mm and a length of 50 cm, the second cylindrical side wall 203 is formed of an alumina cylinder having an outer diameter of 500 mm and a thickness of 12 mm, and the inner peripheral surface in contact with the plasma is blasted. By processing, Rzjis (JIS B0601: '01) was set to Rzjis = 20 μm. The distance between the central axis of the second high-frequency electrode 213 and the outer peripheral surface of the second cylindrical side wall 203 was 30 mm.

  The a-Si photosensitive member produced in Example 4 and Comparative Example 4 was installed in a Canon copying machine GP55 modified for this test, and the characteristics of the photosensitive member were evaluated. The evaluation items were four items of “image density unevenness”, “optical memory”, “characteristic variation”, and “image defect”, and each item was evaluated by the same specific evaluation method as in Example 1. Table 9 shows the evaluation results. In Table 9, the evaluation results are indicated by the same index as in the comparison between Example 1 and Comparative Example 1, with the evaluation result of Comparative Example 4 as a reference.

  From Table 9, the a-Si photosensitive member produced in Example 4 showed good characteristics in all items, and the effect of the present invention was confirmed.

Example 5
A-Si comprising a charge transport layer, a charge generation layer, and a surface layer under the conditions shown in Table 8 in the same manner as in Example 4 except that the first cylindrical side wall 101 in Example 4 is a boron nitride cylinder. A photoconductor was prepared.

  The characteristics of the a-Si photosensitive member produced in Example 5 were evaluated in the same manner as in Example 4. Table 10 shows the evaluation results. In Table 10, the evaluation results are indicated by the same index as in the comparison between Example 1 and Comparative Example 1 with the evaluation result of Comparative Example 4 as a reference.

  From Table 10, the a-Si photoreceptor produced in Example 5 showed particularly good characteristics in all items, and the effects of the present invention were confirmed.

It is an example of the schematic block diagram of the deposited film formation apparatus by one Embodiment of this invention. It is an example of the schematic block diagram of the deposited film formation apparatus by other embodiment of this invention. It is an example of the schematic block diagram of the conventional deposited film formation apparatus comprised as a comparative example. It is the figure which showed typically the original document used for evaluation of optical memory. It is a figure which shows an example of the conventional deposited film formation apparatus. It is a figure which shows the other example of the conventional deposited film formation apparatus. It is a figure which shows the further another example of the conventional deposited film formation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 1st cylindrical side wall 102 2nd cylindrical side wall 202 1st high frequency power supply 205 Cylindrical base | substrate 210 Source gas supply means 211 High frequency power supply 212 Matching box

Claims (16)

A depressurizable reaction vessel configured between a first cylindrical side wall and a second cylindrical side wall surrounding the first cylindrical side wall;
A substrate holding member disposed in the reaction vessel and holding the substrate;
Source gas supply means for supplying source gas into the reaction vessel;
In a deposited film forming apparatus comprising: a power supply system for supplying high-frequency power into the reaction vessel;
At least a part of the first cylindrical side wall is made of a dielectric, and a first high-frequency electrode is formed on the central axis of the first cylindrical side wall as the first cylindrical shape as the power supply system. A deposited film forming apparatus, wherein the deposited film forming apparatus is disposed apart from a side wall.   2. The deposited film forming apparatus according to claim 1, wherein the frequency of the high-frequency power is 50 MHz or more and 250 MHz or less.   3. The deposited film forming apparatus according to claim 1, wherein the first cylindrical side wall and the second cylindrical side wall are disposed so as to have the same central axis, and the base body holding member includes: A deposited film forming apparatus, wherein a plurality of films are arranged on a circle having a center on a central axis.   4. The deposited film forming apparatus according to claim 1, further comprising a second high-frequency electrode disposed outside the second cylindrical side wall, and the second cylindrical shape. 5. At least a part of the side wall is made of a dielectric, and is configured so that high-frequency power can be introduced into the reaction vessel from a second high-frequency electrode.   5. The deposited film forming apparatus according to claim 4, wherein the dielectric material constituting at least part of the first cylindrical side wall and the dielectric constituting at least part of the second cylindrical side wall. A deposited film forming apparatus characterized in that the material is different.   6. The deposited film forming apparatus according to claim 1, wherein the first high-frequency electrode is cylindrical or columnar.   7. The deposited film forming apparatus according to claim 1, wherein an outer diameter of the first high-frequency electrode is 1/3 or less of an outer diameter of the first cylindrical side wall. A deposited film forming apparatus.   8. The deposited film forming apparatus according to claim 1, wherein the base body is cylindrical, and an outer diameter of the first cylindrical side wall is equal to or more than 1/2 of an outer diameter of the base body. A deposited film forming apparatus. A substrate is disposed in a depressurizable reaction vessel configured between a first cylindrical side wall and a second cylindrical side wall surrounding the first cylindrical side wall, and a source gas is supplied into the reaction vessel. In the deposited film forming method of introducing a high frequency power from the high frequency power introducing means into the reaction vessel to decompose the source gas to form a deposited film on the substrate,
The high-frequency power is at least part of the first cylindrical side wall from a first high-frequency electrode surrounded by the first cylindrical side wall and spaced apart from the first cylindrical side wall. A method for forming a deposited film, wherein the deposited dielectric material is introduced into the reaction vessel through the dielectric member.   The deposited film forming method according to claim 9, wherein the frequency of the high-frequency power is 50 MHz to 250 MHz.   The deposited film forming method according to claim 9 or 10, wherein the first cylindrical side wall and the second cylindrical side wall are arranged so as to have the same central axis and have a center on the central axis. A deposited film forming method, comprising forming deposited films on a plurality of the substrates arranged on a circumference.   12. The deposited film forming method according to claim 9, wherein high-frequency power is supplied from a second high-frequency electrode disposed outside the reaction vessel to at least a part of the second cylindrical side wall. A method for forming a deposited film, comprising: passing through a dielectric member constituting the material and introducing the dielectric member into the reaction vessel.   13. The deposited film forming method according to claim 12, wherein the dielectric member constituting at least part of the first cylindrical side wall and the dielectric member constituting at least part of the second cylindrical side wall. And a deposited film forming method, wherein:   14. The deposited film forming method according to claim 9, wherein high-frequency power is introduced into the reaction vessel from the cylindrical or columnar first high-frequency electrode. Method.   The deposited film forming method according to any one of claims 9 to 14, wherein the reaction vessel includes the first high-frequency electrode having an outer diameter of 1/3 or less of the outer diameter of the first cylindrical side wall. A method for forming a deposited film, wherein high-frequency power is introduced into the inside.   The deposited film forming method according to any one of claims 9 to 15, wherein the base is cylindrical, and an outer diameter of the first cylindrical side wall is 1/2 or more of an outer diameter of the base. A method for forming a deposited film.

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