JP2003249454A - Plasma treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve plasma treatment characteristics, to improve reproducibility in the plasma treatment characteristics, and to reduce plasma treatment costs in a method for analyzing a feed gas introduced into a reaction chamber by high-frequency power that is outputted from a high-frequency power supply and is introduced into the reaction chamber via a matching box and an electrode to treat an object to be treated that is installed in the reaction container. <P>SOLUTION: In a plasma-treating apparatus, a feed gas introduced into a reaction container is analyzed by high-frequency power that is outputted from a high-frequency power supply and is introduced into the reaction chamber via a matching box and an electrode, and an object to be treated that is installed in the reaction container is treated. A matching circuit 101 of the matching box comprises a matching variable capacitor 102, a tuning variable capacitor 103, and a coil 104. At an impedance/phase control section 109, impedance in the tuning variable capacitor 103 and the matching variable capacitor 102 is adjusted within a preset variable range in advance. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to deposited film formation or etching in semiconductor devices, electrophotographic photoconductors, image input line sensors, photographing devices, photovoltaic devices, or plasma after deposition film formation. The present invention relates to a plasma processing method using high frequency power used for cleaning the inside of a processing apparatus.

[0002]

2. Description of the Related Art Conventionally, a vacuum vapor deposition method has been used as a deposited film forming method used for manufacturing semiconductor devices, electrophotographic photoconductors, image input line sensors, photographing devices, photovoltaic devices, various other electronic elements, and optical elements. ,
Sputtering method, ion plating method, thermal CVD
A large number of (Chemical Vapor Deposition) methods, photo CVD methods, plasma CVD methods and the like are known, and apparatuses therefor are put to practical use.

Among them, the plasma CVD method, that is, the method of decomposing a raw material gas by direct current or high frequency or microwave glow discharge to form a thin deposited film on a substrate is preferable as hydrogenated amorphous silicon for electrophotography. The formation of a deposited film (hereinafter, referred to as “a-Si: H”) and the like have been greatly put into practical use, and various devices have been proposed for that purpose.

Further, in recent years, among the plasma CVD methods, VHF plasma C using high frequency power in the VHF band is used.
The VD (hereinafter abbreviated as “VHF-PCVD”) method has attracted attention, and the development of various deposited film formation using this method is being actively promoted. This is because the VHF-PCVD method has a high film deposition rate and a high quality deposited film can be obtained, and thus it is expected that cost reduction and high quality of the product can be achieved at the same time. For example, JP-A-6-2877
No. 60 discloses an apparatus and a method which can be used for forming an amorphous silicon (a-Si) -based electrophotographic light-receiving member. Further, the development of a plasma processing apparatus as shown in FIG. 4 which is capable of forming a plurality of electrophotographic light-receiving members at the same time and has an extremely high productivity is under way.

FIG. 4 (a) is a schematic sectional view of a conventional plasma processing apparatus, and FIG. 4 (b) is a schematic sectional view taken along the section line AA 'of FIG. 4 (a). An exhaust pipe 411 is provided on the side surface of the reaction vessel 401.
Are integrally formed, and the other end of the exhaust pipe 411 is connected to an exhaust device (not shown). Six cylindrical substrates 4 on which deposited films are formed so as to surround the center of the reaction vessel 401.
05 are arranged in parallel with each other. Each cylindrical substrate 405 is held by a rotating shaft 408 and heated by a heating element 407. Motor 4
When driving 09, the rotary shaft 40 is driven through the reduction gear 410.
8 rotates, and the cylindrical substrate 405 rotates about its central axis in the generatrix direction (the central axis along the longitudinal direction of the cylindrical substrate).

A raw material gas is supplied from a raw material gas supply means 412 to a film forming space 406 surrounded by six cylindrical substrates 405. In the film formation space 406, high frequency power V
The HF power passes through a matching box (hereinafter referred to as a matching box) 404 from a high frequency power supply 403 and a cathode electrode 402.
Supplied by. At this time, the cylindrical substrate 405 maintained at the ground potential through the rotary shaft 408 acts as an anode electrode.

The deposition film formation using such an apparatus can be performed by the following procedure.

First, a cylindrical substrate 40 is placed in a reaction vessel 401.
5 is installed, and the inside of the reaction vessel 401 is exhausted through an exhaust pipe 411 by an exhaust device (not shown). Then, the heating element 40
7, the cylindrical substrate 405 is controlled while being heated to a predetermined temperature of about 200 ° C. to 300 ° C.

When the cylindrical substrate 405 reaches a predetermined temperature, the raw material gas is introduced into the reaction vessel 401 via the raw material gas supply means 412. After confirming that the flow rate of the raw material gas has reached the set flow rate and the pressure inside the reaction vessel 401 has stabilized, the output of the high frequency power supply 403 is set to a predetermined value. Then, the impedance of the matching circuit in the matching box (matching box) 404 and the output impedance of the high frequency power source 403 are matched with the matching box (matching box) 404.
Adjust so that the inlet impedance is the same. As a result, VHF power that is high frequency power is efficiently supplied into the reaction vessel 401 via the high frequency electrode 402,
Glow discharge occurs in the film formation space 406 surrounded by the cylindrical substrate 405, the source gas is excited and dissociated, and the cylindrical substrate 405.
A deposited film is formed on top.

After the desired film thickness is formed, VHF
The supply of electric power is stopped, and then the supply of raw material gas is stopped to complete the formation of the deposited film. By repeating the same operation a plurality of times, a desired light-receiving layer having a multilayer structure is formed.

During formation of the deposited film, the cylindrical substrate 405 is rotated at a predetermined speed by the motor 409 via the rotary shaft 408 to form the deposited film over the entire circumference of the surface of the cylindrical substrate.

In forming such a deposited film, the impedance of the matching circuit in the matching box (matching box) 404 is manually or automatically adjusted. When automatically performed, the configuration inside the matching box (matching box) 404 includes a system including a matching circuit 501 and a control system 500 as shown in FIG. 5, for example. The matching circuit 501 includes a matching variable capacitor 502, a tuning variable capacitor 503, and a coil 504.
At the entrance of 1, the high frequency current is detected by the current detection element 505, and the high frequency voltage is detected by the voltage detection element 506. Current detection element 505, voltage detection element 506
The respective outputs of 1 are input to the phase difference detector 507 and the impedance detector 508 in the control system 500. The phase difference detector 507 detects the phase of the impedance at the entrance of the matching circuit 501 and outputs a voltage according to the phase of the impedance to the tuning control circuit 509. The tuning control circuit 509 compares the voltage input from the phase difference detector 507 with the reference voltage, and outputs the voltage corresponding to the difference to the motor 51 that drives the tuning variable capacitor 503.
Supply to 0. As a result, the tuning variable capacitor 503 is adjusted by the motor 510 so that the impedance phase satisfies the predetermined matching target condition, for example, the phase becomes zero. On the other hand, the impedance detector 5
At 08, the absolute value of the impedance at the entrance of the matching circuit 501 is detected, and the voltage according to the absolute value of the impedance is output to the matching control circuit 511. The matching control circuit 511 compares the voltage input from the impedance detector 508 with the reference voltage, and supplies a voltage corresponding to the difference to the motor 512 that drives the matching variable capacitor 502. As a result, the matching variable capacitor 502 is adjusted by the motor 512 so that the absolute value of the impedance satisfies a predetermined matching target condition, for example, the absolute value of the impedance becomes 50Ω. With such a configuration, impedance adjustment is automatically performed, and high frequency power is efficiently supplied into the reaction vessel 501.

By such a plasma processing method and apparatus, a good deposited film can be formed. However, the market demand level for products using such plasma treatment is increasing day by day, and in order to meet this demand, higher quality plasma treatment methods are required.

For example, in the case of an electrophotographic apparatus, there is a strong demand for higher copy speed, higher image quality and lower price.
In order to realize these, it is indispensable to improve the characteristics of the photoconductor, specifically, the charging ability and the sensitivity, and to reduce the production cost of the photoconductor. Further, in digital electrophotographic devices and color electrophotographic devices, which have been remarkably popularized in recent years, not only text originals but also photographs, pictures, design images, etc. are frequently copied, so that unevenness in image density and light There is an increasing demand for reduction of memory than ever before.

[0015]

In order to achieve such improvement of plasma processing characteristics and reduction of plasma processing cost, a technique for stably generating, maintaining and reproducibly producing plasma having desired characteristics. Is important. For example,
In the plasma processing using the conventional plasma processing apparatus as shown in FIG. 4, the impedance of the matching box is generally automatically adjusted from the viewpoint of labor saving. However, in the conventional impedance adjusting method as described above, when the load impedance is temporarily changed due to abnormal discharge such as sparking, proper control is not always performed.

The abnormal discharge itself is temporary in many cases, and since the location where it is generated often occurs at a location that does not adversely affect the object to be processed, it may not directly affect the plasma processing. However, in the conventional impedance adjustment method, when an abnormal discharge occurs, the impedance of the matching box is adjusted so as to match the load impedance in that abnormal state, and the impedance is set to be significantly different from the normal matching condition. It may happen. As a result, after the abnormal discharge has subsided,
There is a case where the impedance cannot be immediately returned to the normal impedance, which may cause deterioration of the plasma processing characteristic itself or stability of the plasma processing characteristic. Further, when the abnormal discharge is generated, the impedance of the matching box is largely changed, which may promote the abnormal discharge and prevent the normal plasma state from being restored. As described above, the conventional impedance adjustment method has not always sufficiently dealt with a sudden change in the load impedance caused by an abnormal discharge or the like.

As a technique relating to impedance adjustment, for example, in Japanese Patent Laid-Open No. 09-260096, a plasma is ignited by searching for an impedance matching point at which the plasma ignites on the basis of a preset impedance, and then, A technique for automatically searching for an impedance matching point that stabilizes plasma discharge based on the matching point as a reference after automatically shifting to a preset impedance matching point that forms a stable plasma discharge is disclosed. It is said that the plasma can be reliably ignited even if the load impedance differs for each plasma treatment.

According to this technique, the trouble at the time of plasma generation, for example, the problem that the plasma is not ignited for a long time is solved, but the above-mentioned problems after the electric discharge is generated, for example, the abnormal discharge. The issue when it arises remains unresolved.

Further, Japanese Laid-Open Patent Publication No. 11-087097 discloses a technique relating to an impedance matching and power control system. Regarding impedance matching, the impedance of each element in the matching circuit is fixed to a preset value. The impedance adjustment is performed by changing the frequency of the high frequency power. According to such a technique, impedance adjustment can be dealt with by an electrical process of changing the frequency of the high frequency power, so that impedance adjustment can be performed quickly.
However, in the case of this technique, according to the study by the present inventors, if an abnormal discharge occurs during plasma processing and the load impedance suddenly changes, matching is immediately performed according to the impedance, This may promote abnormal discharge. Further, in the case of impedance matching by changing the frequency of such high frequency power,
The frequency is different for each processing lot, and as a result,
The plasma processing characteristics may vary. This is likely to occur when the frequency of the high frequency power is sensitive to the uniformity of plasma processing characteristics, such as in the VHF band.

In Japanese Patent Laid-Open No. 08-096992, impedance adjustment is performed at the beginning of each step of plasma processing, and impedance adjustment is not performed thereafter at that step, and impedance adjustment is performed again at the next step. A technique for performing the operation and then maintaining the same state is disclosed, and specific timings for impedance adjustment include a short adjustment time in the initial stage of each step and a time when reflection is abnormally increased. It is said that this technique eliminates inadequate impedance adjustment that tends to occur when high-frequency power is supplied from a plurality of electrodes, and avoids destabilization of plasma.
When this technique is used, the impedance is not adjusted even if an abnormal discharge occurs, so that the abnormal discharge is not promoted. However, with this technique,
It does not follow changes in impedance during plasma processing over time.For example, impedance changes due to changes in load impedance at the beginning of plasma processing or due to differences in impedance between the initial processing and the end of processing during long-time plasma processing. Matching will occur. As a result, there may be cases where sufficient plasma processing characteristics cannot be obtained due to this mismatch. Further, since the degree of the mismatch differs depending on the state of the reaction container, the plasma processing characteristics may differ for each plasma processing lot.

As described above, various efforts have been made so far with respect to impedance matching, but a matching method that can appropriately cope with a sudden change in load impedance due to abnormal discharge during plasma processing is used. Was not proposed until.

The present invention is intended to solve the above problems. That is, the high-frequency power output from the high-frequency power source is introduced into the reaction vessel through the matching device and the electrode to decompose the raw material gas introduced into the reaction vessel, and the object to be treated placed in the reaction vessel In the plasma processing method of performing the processing described above, the impedance adjustment by the matching device is properly and stably achieved, and as a result, the plasma processing characteristics, the reproducibility of the plasma processing characteristics, and the plasma processing cost can be reduced. It is to provide a possible plasma processing method.

[0023]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that in the impedance adjustment by a matching device, the impedance of each variable circuit element of the matching circuit is within a predetermined range. Within (hereinafter referred to as "impedance variable range"), to adjust to meet a predetermined matching target condition, and further change the impedance variable range as the plasma processing progresses, It has been found that it is effective in achieving the above object.

That is, according to the present invention, the high-frequency power output from the high-frequency power source is introduced into the reaction vessel through the matching device and the electrodes to decompose the raw material gas introduced into the reaction vessel and In the plasma processing method for processing an object to be processed, the impedance adjustment by the matching device is performed within a predetermined impedance variable range, and the impedance variable range is changed as the plasma processing progresses. It is characterized by

According to the present invention as described above, the impedance adjustment by the matching device is appropriately and stably achieved, and as a result, the plasma processing characteristics are improved, the reproducibility of the plasma processing characteristics is improved, and further the plasma processing cost is reduced. It is possible to reduce.

The present invention as described above will be described in detail below.

In the present invention, since the impedance adjustment by the matching device is performed within a predetermined impedance variable range, even if a large change in the load impedance occurs due to abnormal discharge or the like, the impedance adjustment of the matching circuit is performed by a predetermined impedance variable. Since it is only done within the range, it does not largely deviate from the impedance at the time of normality, and it suppresses problems such as promoting abnormal discharge and having a long time until the impedance returns to an appropriate value after the abnormal discharge is stopped. It will be possible. The present invention is further characterized in that such an impedance variable range is changed as the plasma processing progresses. This is to deal with the fact that the state inside the reaction vessel, for example, the state of the wall surface, differs between the initial stage of plasma processing and after the plasma processing has progressed to some extent, and as a result, the load impedance changes as the plasma processing progresses. When impedance adjustment is performed within the same impedance variable range during plasma processing, the impedance variable range must be set wide in order to handle changes in the load impedance as the plasma processing progresses. As a result, the impedance adjustment may not be properly and stably achieved. Therefore, the present invention is characterized in that the impedance adjustment by the matching device is performed within a preset impedance variable range, and the impedance variable range is changed as the plasma processing progresses. The stability can be further improved, the plasma processing characteristics can be improved, the reproducibility of the plasma processing characteristics can be improved, and the plasma processing cost can be reduced.

In the present invention as described above, it is more effective to change the impedance variable range substantially continuously when changing the impedance variable range as the plasma processing progresses. When changing the impedance variable range discontinuously, if the impedance of the matching circuit before the change is near the boundary of the variable range, the impedance of the matching circuit also changes substantially discontinuously due to the change of the impedance variable range. As a result, the matching state becomes discontinuous, and the effect of the present invention may not be maximized. Such a situation is likely to occur in a plasma treatment in which a plurality of treatments under different conditions are continuously performed. Therefore,
In particular, when the condition changes between a plurality of processes are abrupt, it becomes more effective to change the impedance variable range substantially continuously.

Further, in the present invention, it is judged that the matching has been achieved, and the condition serving as a reference for stopping the impedance adjustment,
That is, it is more effective to set the matching target condition in advance and, if necessary, change the matching target condition as the plasma processing progresses. The matching target condition is generally set by the absolute value of the impedance at the entrance of the matching circuit, the phase of the impedance, the power reflectivity, and a combination of these, etc. Judge and stop the impedance adjustment of the matching circuit. However, if the setting range is too narrow, the detection value during plasma processing cannot be adjusted within the setting range in some cases, and it may be difficult to constantly adjust the impedance of the matching circuit and maintain stable plasma. Occurs. On the other hand, on the contrary, if the setting range is too wide, impedance adjustment may be stopped even if the matching is not sufficient, and the power supply efficiency may be reduced or desired plasma characteristics may not be obtained. is there. Further, since the impedance variation between plasma processing lots also becomes large, the reproducibility of plasma processing characteristics may become insufficient.

Therefore, it is important to set the matching target condition to an appropriate value in order to stably generate the plasma having the desired characteristics with good reproducibility. In the actual plasma processing, as described above, the state in the reaction vessel changes as the plasma processing progresses, so the appropriate matching target condition also changes as the plasma processing progresses. Conventionally, even if the appropriate matching target condition changes with the progress of the plasma processing in this manner, it is not changed to the appropriate condition, and all the appropriate matching target conditions throughout the plasma processing are included. As described above, the matching target condition is set broadly, and this may be an obstacle to improving the reproducibility of the plasma processing characteristics. Therefore, if necessary, the matching target condition is also changed as the plasma processing progresses, so that such an obstacle can be eliminated, and further improvement in reproducibility of plasma processing characteristics can be achieved.

Further, it is more effective to change the matching target condition with the progress of the plasma processing substantially continuously like the change of the impedance variable range. When the matching target condition is changed discontinuously, if the matching state before the change is near the boundary of the matching target condition, the matching state may change discontinuously due to the change of the matching target condition. The effect of the present invention may not be maximized. Such a situation is likely to occur when a plurality of plasma treatments under different conditions are continuously performed. Therefore, it is more effective to change the matching target condition substantially continuously, especially when the condition change between a plurality of processes is rapid.

In the present invention, automatic control of impedance adjustment may be performed both before and after starting the plasma processing, or only after starting the plasma processing. When performing automatic control both before and after plasma processing, the load impedance may change significantly before and after plasma generation.Therefore, set the variable impedance range of the matching circuit before and after plasma generation. It is preferable to change. on the other hand,
When automatic control is started after plasma processing is started, plasma may be generated by manually adjusting impedance, or the impedance of each element in the matching circuit suitable for plasma generation may be checked and plasma generation may be performed. The impedance of each element in the matching circuit may be preset to that value before the plasma is generated by gradually increasing the output of the high frequency power source. In this case, the impedance of each element in the optimal matching circuit at the time of plasma generation differs to some extent depending on the state of the reaction vessel between plasma processing lots, but by starting automatic control immediately after plasma generation, there is no substantial adverse effect. Does not happen. The generation of plasma may be performed by a conventionally known method such as visual confirmation, detection using a light receiver, detection by fluctuation of pressure in the reaction container, and detection by change of load impedance.

The present invention as described above exhibits a remarkable effect when the frequency of the high frequency power used for the plasma processing is 50 MHz or more and 250 MHz or less. It is presumed that this is because the plasma is likely to be nonuniform in this frequency band, and when the impedance adjustment of the matching circuit is not appropriate, the influence thereof is likely to adversely affect the plasma uniformity. Although the mechanism has not been clarified at this stage, when abnormal discharge occurs in this frequency band, it is easy to promote abnormal discharge if the impedance of the matching circuit is inappropriate. By using the present invention in the plasma treatment using electric power, it is possible to effectively suppress the promotion of such abnormal discharge,
The effect of the present invention is remarkably obtained.

The present invention as described above can also obtain a particularly remarkable effect when the object to be processed is moving or rotating at least during the plasma processing.
When the object to be processed moves or rotates during the plasma processing, the load impedance often changes accompanying it. For example, when performing plasma processing while rotating a cylindrical substrate, the relative positional relationship of the substrates in the reaction container often changes subtly due to eccentricity during rotation. When the relative position of the base body changes in this way, abnormal discharge is likely to occur, and the load impedance also fluctuates with the change in the position. Even if such an abnormal discharge occurs in the present invention, the matching circuit impedance is limited to the vicinity of a proper value, so that problems such as the deviation of the matching circuit impedance from the proper value or the promotion of abnormal discharge are avoided. It becomes possible to maintain a stable plasma.

Further, according to the present invention, a particularly large effect can be obtained when the plasma treatment is for forming an electrophotographic photosensitive member.
It is presumed that the reason is probably due to the following two factors. First, in the case of forming an electrophotographic photosensitive member, a deposited film having a film thickness of several tens of μm is generally formed, so that the time required for plasma processing is long. Therefore, sudden changes in the load impedance often occur during plasma processing due to abnormal discharge and the like, and it is considered that the effect of the present invention that suppresses the adverse effect on the plasma processing due to this change appears prominently.
Further, since the time required for plasma processing is long, the load impedance changes greatly during the plasma processing with time, and the effect of the present invention is that the impedance matching is appropriately performed against such time change. In the case of formation, it is considered to appear clearly. The second factor is that a plurality of plasma treatments under different conditions such as gas species, pressure, and high-frequency power are continuously performed in the electrophotographic photosensitive member formation. Note that the term continuous here does not necessarily mean only a case where the plasma processing conditions are continuously changed in a state where plasma is generated, but the processing conditions are changed after the discharge is temporarily stopped when the processing conditions are changed. It also refers to a case where the plasma is changed and plasma is generated again. It has been confirmed that, when a plurality of plasma treatments with different conditions are continuously performed, a proper impedance variable range or a proper matching target condition is different for each condition. It is considered that by setting an appropriate impedance variable range or an appropriate matching target condition, an appropriate impedance adjustment is performed throughout the series of plasma processes, and a good plasma process is performed.

The present invention which achieves such effects will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing an outline of the configuration in a matching box (matching box) that can be used in the present invention and its control system. Matching device is matching circuit 101
And a control system 100. The matching circuit 101 includes a matching variable capacitor 102, a tuning variable capacitor 103 and a coil 104,
Further, at the entrance of the matching circuit 101, the current detection element 1
The high frequency current is detected by 05, and the voltage detection element 106
The high frequency voltage is detected by. Current detection element 105,
Each output of the voltage detection element 106 is input to the phase difference detector 107 and the impedance detector 108 in the control system 100. The phase difference detector 107 detects the phase of the impedance at the entrance of the matching circuit 101, and outputs a voltage corresponding to the phase of the impedance to the impedance / phase control unit 10.
Output to 9. The impedance / phase control unit 109 controls the impedance of the tuning variable capacitor 103 within a predetermined variable range based on the voltage input from the phase difference detector 107. Specifically, the voltage input from the phase difference detector 107 is compared with the reference voltage,
The voltage according to the difference is set to the tuning variable capacitor 10
3 is supplied to the motor 110 that drives the motor 3. At this time, when the impedance of the tuning variable capacitor 103 reaches the maximum value or the minimum value of the predetermined variable range, the impedance / phase control unit 109 stops the supply of the voltage to the motor 110 at that time. Further, when the impedance of the tuning variable capacitor 103 has already reached the maximum value of the variable range set in advance, the impedance / phase control unit 109 shifts the impedance of the tuning variable capacitor 103 to the motor 110 in the direction of decreasing the impedance. Although the voltage is supplied, the voltage is not supplied in the direction of increasing the impedance of the tuning variable capacitor 103. Similarly, the impedance / phase control unit 109 has already set the tuning variable capacitor 10
When the impedance of 3 is the minimum value of the predetermined variable range, the tuning variable capacitor 1
Motor 1 in the direction of increasing the impedance of 03
Although the voltage is supplied to 10, the voltage is not supplied in the direction of reducing the impedance of the tuning variable capacitor 103. In this way, the impedance of the tuning variable capacitor 103 is controlled within a predetermined variable range so that the phase of the impedance at the entrance of the matching circuit 101 is within the predetermined range, and the matching target condition is adjusted within the predetermined variable range. If is not satisfied, the impedance adjustment of the tuning variable capacitor 103 is stopped in the state where the phase is closest to the matching target condition.

On the other hand, the impedance detector 108 detects the absolute value of the impedance at the entrance of the matching circuit 101 and outputs a voltage according to the absolute value of the impedance to the impedance / phase control unit 109. In the impedance / phase control unit 109, the impedance detector 108
The input voltage is compared with the reference voltage, and the voltage corresponding to the difference is supplied to the motor 112 that drives the matching variable capacitor 102. At this time, the impedance / phase control unit 109 stops the supply of the voltage to the motor 112 when the impedance of the matching variable capacitor 102 reaches the maximum value or the minimum value of the predetermined variable range. Further, when the impedance of the matching variable capacitor 102 has already reached the maximum value of the variable range set in advance, the impedance / phase control unit 109 sends the impedance to the motor 112 in the direction of decreasing the impedance of the matching variable capacitor 102. Although the voltage is supplied, the voltage is not supplied in the direction of increasing the impedance of the matching variable capacitor 102. Similarly,
If the impedance of the matching variable capacitor 102 is already at the minimum value of the predetermined variable range, the impedance / phase control unit 109 supplies a voltage to the motor 112 in the direction of increasing the impedance of the matching variable capacitor 102. However, the voltage is not supplied in the direction of reducing the impedance of the matching variable capacitor 102. In this way, the impedance of the matching variable capacitor 102 is controlled within a predetermined variable range so that the absolute value of the impedance at the entrance of the matching circuit 101 falls within the predetermined range, and the matching target within the predetermined variable range is controlled. If the condition is not satisfied, the impedance adjustment of the matching variable capacitor 102 is stopped in a state where the impedance is closest to the matching target condition.

With such control, impedance adjustment is performed within a predetermined impedance variable range by automatic control. As a method of detecting the impedance of the tuning variable capacitor 103 and the matching variable capacitor 102, for example, a method of detecting the amount of movement of the variable capacitor or a mechanism that drives the variable capacitor, or a stepping motor is used as a motor for driving the variable capacitor. A conventionally known method such as a method of detecting based on the drive signal may be used. Further, it is not always necessary to always detect the impedances of the tuning variable capacitor 103 and the matching variable capacitor 102, and signals are output when the impedances of the tuning variable capacitor 103 and the matching variable capacitor 102 reach the maximum value or the minimum value of the variable range. Impedance / phase control unit 1
09 may be output.

In the present invention, the "impedance variable range" does not refer to the impedance variable range that is structurally limited by the variable width of the impedance variable element that forms the matching circuit, but the impedance variable range is set separately. To do.

By setting the impedance variable range separately from the variable width of the impedance variable element in this way, the impedance variable range can be accurately set to a desired range, and the setting can be easily changed. As a result, it is possible to improve the discharge stability during the vacuum processing, and it is possible to change the setting of the impedance variable range during the vacuum processing.

The plasma processing using the matching box having the structure shown in FIG. 1 is performed by using, for example, the plasma processing apparatus shown in FIG.
The electrophotographic photosensitive member including the surface layer can be formed as follows.

First, prior to the formation of the electrophotographic photoreceptor,
The impedance of the matching variable capacitor 102 and the impedance of the tuning variable capacitor 103 with which the plasma is stably maintained are preliminarily included, including variations among lots, for each condition of the charge injection blocking layer, the photoconductive layer, and the surface layer. It is checked in advance by an experiment, and based on the result, the impedance variable range of the matching variable capacitor 102 of each layer and the tuning variable capacitor 103
Determine the impedance variable range of. The variable impedance range is determined by, for example, setting the variable range of the impedance of the matching variable capacitor 102 and the variable impedance of the tuning variable capacitor 103 in the preliminary experiment to the variable range, or changing the variable range of about twice the variable range of the impedance. In order to keep the plasma stable in the actual plasma processing, such as setting the range, plasma formation conditions,
It is appropriately determined according to the configuration of the device used.

According to the studies by the present inventors, it is preferable to set the impedance variable range within a range of about twice the impedance variation range obtained by the preliminary experiment in order to maintain stable plasma. For example, according to preliminary experiments, the impedance of the variable capacitor is 200 pF ~
When the variation range of the impedance is 300 pF, that is, when the impedance variation range is 100 pF, it is preferable to set the impedance variable range of the variable capacitor to 200 pF, which is twice the variation range. In this example, the variable capacitor It is preferable that the variable impedance range is within the range of 150 pF to 350 pF.

The impedance variable range of the matching variable capacitor 102 and the variable impedance range of the tuning variable capacitor 103 in each of the charge injection blocking layer, the photoconductive layer, and the surface layer, which are determined in this way, are preset in the impedance / phase control unit 109. The impedance variable range of the matching variable capacitor 102 and the variable impedance range of the tuning variable capacitor 103 which are referred to may be changed according to the timing of switching layers, or at the timing of switching layers. Data may be externally sent to the impedance / phase control unit 109, or the impedance variable range may be changed by another method.

The variable impedance range of each layer does not necessarily have to be set to one, and a plurality of variable ranges may be set. In this case, the setting is changed to the next variable impedance range at a predetermined point in the middle of the layer. On the contrary,
It is not always necessary to set different impedance variable ranges for each layer, and for example, the same impedance variable range may be used for the charge injection blocking layer and the photoconductive layer,
The same variable impedance range may be used for the photoconductive layer and the surface layer, or the same variable impedance range may be used in the initial stage of the blocking layer and the photoconductive layer, and the variable impedance range may be changed in the middle of the photoconductive layer. Although good, the impedance variable range is changed at least at a temporary point during a series of plasma treatments.

The timing of changing the impedance variable range may be appropriately determined, but the effect of the present invention is remarkable when the impedance variable range is changed at the time when the load impedance changes significantly as the plasma processing progresses. It is preferable to obtain

After determining the variable impedance range in this way, in the plasma processing apparatus shown in FIG. 4, the cylindrical substrate 405 is installed in the reaction vessel 401, and the reaction vessel 401 is passed through the exhaust pipe 411 by an exhaust device (not shown). Exhaust the inside. Subsequently, the cylindrical substrate 405 is rotated at a predetermined speed by the motor 409 via the rotating shaft 408,
Further, the cylindrical base 405 is heated to 200 ° C. by the heating element 407.
Control is performed while heating to a predetermined temperature of about 300 ° C.

When the cylindrical substrate 405 reaches a predetermined temperature, the raw material gas used for forming the charge injection blocking layer is introduced into the reaction vessel 401 through the raw material gas supply means 412. After confirming that the flow rate of the raw material gas has reached the set flow rate and the pressure inside the reaction vessel 401 has stabilized, the output of the high frequency power supply 403 is set to a predetermined value. Then, in order that the output voltage from the phase detector 107 and the output voltage from the impedance detector 108 shown in FIG. 1 approach the reference voltage,
Alternatively, while looking at the power meter, the impedances of the matching variable capacitor 102 and the tuning variable capacitor 103 are adjusted so that the power reflectance decreases.
Further, although it is not always necessary to set the variable range for the impedances of the matching variable capacitor 102 and the tuning variable capacitor 103, setting the variable impedance range shortens the adjustment time and suppresses the variation in plasma processing characteristics between lots. It is preferable in terms. Further, the impedance of the matching variable capacitor 102 and the tuning variable capacitor 103 at the time of starting impedance adjustment is preset to a value at which discharge is most likely to occur, and impedance adjustment is started with that value as the starting point. It is preferable in terms of shortening and suppressing variation in plasma processing characteristics between lots.

By such impedance adjustment,
The high frequency power is efficiently supplied into the reaction vessel 401 via the cathode electrode (high frequency electrode) 402, and the cylindrical substrate 4
Plasma is generated in the film formation space 406 surrounded by 05.
If plasma is generated, the impedance variable range of the matching variable capacitor 102 and the tuning variable capacitor 103 is set to the value at the time of starting the charge injection blocking layer, and impedance adjustment is performed. At this time, it is preferable that the impedance variable range of the matching variable capacitor 102 and the tuning variable capacitor 103 is set to an impedance variable range that includes the impedance values of the matching variable capacitor 102 and the tuning variable capacitor 103 when plasma occurs.

In addition, the impedances of the appropriate matching variable capacitor 102 and the tuning variable capacitor 103 may differ greatly before and after the occurrence of plasma. In such a case, the variable range of the impedances of the matching variable capacitor 102 and the tuning variable capacitor 103 at the start of forming the charge injection blocking layer must be set wide, and therefore the variable range is continuously set during the formation of the charge injection blocking layer. It is preferable that the variable impedance range is gradually narrowed by gradually changing the value in a stepwise manner.

When the formation of the charge injection blocking layer is completed in this way, the photoconductive layer is subsequently formed. When stopping the discharge between the charge injection blocking layer and the photoconductive layer, the high-frequency power supply is stopped after the charge injection blocking layer having a desired thickness is formed, and then the supply of the source gas is stopped. Thus, the formation of the charge injection blocking layer is completed. Next, the photoconductive layer is formed by the same procedure as when the formation of the charge injection blocking layer is started. At this time, the plasma processing conditions, the variable impedance range, and if necessary, the matching target conditions are changed to the conditions for forming the photoconductive layer.

On the other hand, in the case of continuously forming the charge injection blocking layer and the photoconductive layer without cutting off the discharge, the plasma treatment conditions such as the flow rate of the raw material gas, the high frequency power and the pressure are continuously and
Or, it is changed stepwise to set the photoconductive layer forming conditions. There is no particular limitation on how to change the plasma processing conditions, and it may be appropriately determined while checking the plasma processing characteristics. Further, the change of the impedance variable range when changing to the charge injection blocking layer and the photoconductive layer can be performed, for example, by changing the impedance variable range when the charge injection blocking layer is formed, the impedance variable range when the processing condition is changed, and the photoconductive layer formation. The impedance variable range at the time may be set to different values, or the impedance variable range at the time of forming the charge injection blocking layer may be set until the processing conditions are changed, and the light may be changed when the photoconductive layer is formed. The impedance variable range for forming the conductive layer may be set, or the impedance variable range may be set to the impedance variable range for forming the photoconductive layer when the formation of the charge injection blocking layer is completed, and the processing condition is being changed. Also, the photoconductive layer may be formed within the same variable impedance range. Then, for example, when setting the variable impedance range when forming the charge injection blocking layer, the variable impedance range during changing the processing condition, and the variable impedance range when forming the photoconductive layer to different values, change the processing condition. Set multiple impedance variable ranges inside,
The impedance variable range may be changed even while the processing condition is being changed. How to change the variable impedance range depends on the desired plasma processing characteristics, plasma processing conditions, configuration of the plasma processing apparatus, etc. However, in any case, the variable impedance range is changed at least at a temporary point during the series of plasma treatments.

After the formation of the photoconductive layer is completed in this way, the surface layer is continuously formed. The procedure for transitioning from the photoconductive layer formation to the surface layer formation may be performed in the same manner as the procedure for transitioning from the charge injection blocking layer formation to the photoconductive layer formation.

When the formation of the surface layer is completed in this way, the output of the high frequency power is stopped, the supply of the raw material gas is stopped, and the formation of the electrophotographic photosensitive member is completed.

The variable impedance range can be changed by
Both the variable impedance range of the matching variable capacitor 102 and the variable impedance range of the tuning variable capacitor 103 may be changed, or either one of them may be changed.

[0056]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited thereto.

(Example 1) Using the plasma processing apparatus shown in FIG. 4 and the matching box (matching box) having the configuration shown in FIG.
Hz, a cylindrical substrate 405, which is an aluminum cylinder having a diameter of 80 mm and a length of 358 mm, and under the conditions shown in Table 1, a-S consisting of a charge injection blocking layer, a photoconductive layer, and a surface layer.
A total of 60 i-type photoreceptors were manufactured in 10 lots. In Table 1, the high frequency power indicates the effective power obtained by subtracting the reflected power from the incident power. Cathode electrode (high frequency electrode) 4
Reference numeral 02 denotes a SUS column having a diameter of 20 mm, and the outside thereof is covered with an alumina pipe having an inner diameter of 21 mm and an outer diameter of 24 mm. Alumina pipe is blasted to have a surface roughness of 20μ at Rz with a standard length of 2.5 mm.
m. The cylindrical substrates 405 are arranged at equal intervals on the same circumference.
The book is arranged.

The matching variable capacitor 102 used is variable in the range of 50 pF or more and 1000 pF or less, and the tuning variable capacitor 103 used in the range of 5 pF or more and 250 pF or less. The output of the high-frequency power source 403 is 50Ω, and the characteristic impedance is 50Ω between the output and the matching box (matching box) 404.
It is connected by a coaxial cable.

With such a device, first, the variable impedance range of the matching variable capacitor 102 and the tuning variable capacitor 103 was determined by the following procedure.

First, the cylindrical substrate 405 is attached to the reaction vessel 401.
It was installed on the inner rotating shaft 408. Then, the inside of the reaction vessel 401 was exhausted through an exhaust pipe 411 by an exhaust device (not shown). Then, the cylindrical substrate 40 is rotated through the rotary shaft 408.
5 is rotated at a speed of 10 rpm by a motor (not shown), and further 500 ml / min (normal) of argon (A) is fed into the reaction vessel 401 by the raw material gas supply means 412.
r) While supplying the gas, the cylindrical substrate 405 was heated by the heating element 407 while being controlled to 250 ° C., and the state was maintained for 2 hours.

Then, the supply of Ar gas is stopped, the reaction vessel 401 is evacuated through the exhaust pipe 411 by an exhaust device (not shown), and then the raw material gas supply means 412 is used.
The raw material gas used for forming the charge injection blocking layer shown in 1 was introduced. After confirming that the flow rate of the raw material gas was the set flow rate and the pressure inside the reaction vessel 401 was stable, the output of the high frequency power source 403 was set to 20 under the charge injection blocking layer conditions shown in Table 1.
It was set to the value of%. In this state, the capacitance of the matching variable capacitor 102 in the matching box (matching box) 404 was adjusted so that the difference between the output voltage from the impedance detector 108 and the reference voltage became smaller. The reference voltage was set to the output voltage value from the impedance detector 108 when the impedance viewed from the high frequency power input point of the matching box (matching box) 404 to the load side was 50Ω. Matching box (matching box) 404 simultaneously and in parallel
The capacitance of the tuning variable capacitor 103 therein is adjusted so that the difference between the output voltage from the phase detector 107 and the reference voltage becomes smaller. The reference voltage is set to the output voltage value from the phase detector 107 when the phase difference between the incident power to the load side and the reflected power at the high frequency power input point of the matching box (matching box) 404 is 0 degree.

In this way, the matching variable capacitor 10
2 and the capacitance of the tuning variable capacitor 103 are adjusted so that the difference between the output voltage from the impedance detector 108 and the reference voltage and the difference between the output voltage from the phase detector 107 and the reference voltage are minimized. High frequency power supply 40
Electric discharge was generated by increasing the output of No. 3 to the value of the condition of the charge injection blocking layer shown in Table 1, and the capacitance of each variable capacitor when the electric discharge was generated was examined. Subsequently, a charge injection blocking layer was formed. When the formation of the charge injection blocking layer is started, the capacitances of the matching variable capacitor 102 and the tuning variable capacitor 103 are changed to the absolute value of the impedance at the input point of the matching box (matching box) 404 and the phase difference between the incident voltage and the reflected voltage. Was adjusted to be the minimum. This adjustment was performed at intervals of 2 minutes during the formation of the charge injection blocking layer, and the variation range of the capacitance of the matching variable capacitor 102 and the tuning variable capacitor 103 during the formation of the charge injection blocking layer was examined.

When the formation of the charge injection blocking layer is completed, the output of the high frequency power is stopped, and the plasma processing conditions such as gas species, gas flow rate and pressure are set to the photoconductive layer forming conditions shown in Table 1, and the charge injection is performed. Similar to the case of forming the blocking layer, the variation range of the capacitance of the matching variable capacitor 102 and the tuning variable capacitor 103 at the time of occurrence of discharge, and the variation range of the capacitance of the matching variable capacitor 102 and the tuning variable capacitor 103 during the formation of the photoconductive layer were examined.

Similarly, regarding the surface layer, the capacitances of the matching variable capacitor 102 and the tuning variable capacitor 103 when a discharge occurs, the matching variable capacitor 102 and the tuning variable capacitor 1 during the surface layer formation.
The variation range of 03 capacity was investigated.

Such an experiment was conducted 10 times, and the matching variable capacitor 102 and the tuning variable capacitor 10 when the charge injection blocking layer, the photoconductive layer, and the surface layer generated when discharge occurred.
The variation range of the capacitance of No. 3 and the variation range of the capacitance of the matching variable capacitor 102 and the tuning variable capacitor 103 during formation of each layer were examined.

The results are shown in Table 2. Based on this result, the capacitance variable range of the matching variable capacitor 102 and the tuning variable capacitor 103 at the time of occurrence of discharge of the charge injection blocking layer, the photoconductive layer, and the surface layer and at the time of forming each layer is shown in Table 2. The width of the capacity variable range, which is the center of the capacity fluctuation, was determined to satisfy the two conditions of being twice the capacity fluctuation width in Table 2, that is, as shown in Table 3.

[0067]

[Table 1]

[0068]

[Table 2]

[0069]

[Table 3]

After determining the variable capacitance range of the matching variable capacitor 102 and the tuning variable capacitor 103 in this manner, 10 lots of electrophotographic photosensitive members were manufactured under the conditions shown in Table 1 as follows.

First, the cylindrical substrate 405 is attached to the reaction vessel 401.
It was installed on the inner rotating shaft 408. Then, the inside of the reaction vessel 401 was exhausted through an exhaust pipe 411 by an exhaust device (not shown). Then, the cylindrical substrate 40 is rotated through the rotary shaft 408.
5 is rotated at a speed of 10 rpm by a motor (not shown), and 500 ml / min (normal) Ar gas is supplied into the reaction vessel 401 from the raw material gas supply means 412 while the cylindrical base 405 is heated by the heating element 407.
While controlling the temperature to 50 ° C, heat it up to 2
Maintained for hours.

Then, the supply of Ar gas is stopped, the reaction vessel 401 is evacuated through the exhaust pipe 411 by an exhaust device (not shown), and then the raw material gas supply means 412 is used to generate the gas in Table 1.
The raw material gas used for forming the charge injection blocking layer shown in 1 was introduced. After confirming that the flow rate of the raw material gas was the set flow rate and the pressure inside the reaction vessel 401 was stable, the output of the high frequency power source 403 was set to 20 under the charge injection blocking layer conditions shown in Table 1.
It was set to the value of%. In this state, the matching capacitor 102 and the tuning capacitor 10 within the range shown in Table 3
The capacity adjustment of 3 is started. Specifically, the matching circuit 101
At the entrance of, the high-frequency current was detected by the current detection element 105 and the high-frequency voltage was detected by the voltage detection element 106. The outputs of the current detection element 105 and the voltage detection element 106 were input to the phase difference detector 107 and the impedance detector 108 in the control system 100. The phase difference detector 107 detects the impedance phase at the entrance of the matching circuit 101, and outputs a voltage corresponding to the impedance phase to the impedance / phase control unit 109. The impedance / phase control unit 109 controls the impedance of the tuning variable capacitor 103 based on the voltage input from the phase difference detector 107 within a predetermined variable range at the time of starting the charge injection blocking layer discharge shown in Table 3 . That is, the voltage input from the phase difference detector 107 is compared with the reference voltage, the voltage corresponding to the difference is supplied to the motor 110 driving the tuning variable capacitor 103, and the voltage input from the phase difference detector 107 is compared with the reference voltage. The adjustment was made so that the difference between the reference voltages became smaller. At this time, if the impedance of the tuning variable capacitor 103 reaches the maximum value or the minimum value of the variable range at the time of starting the charge injection blocking layer discharge shown in Table 3, the voltage supply to the motor 110 is stopped at that time. The capacity variable range in Table 3 was not exceeded.
The reference voltage was set to the output voltage value from the phase detector 107 when the phase difference between the incident voltage on the load side and the reflected voltage at the high frequency power input point of the matching box 304 was 0 degree.

On the other hand, the impedance detector 108 detects the absolute value of the impedance at the entrance of the matching circuit 101, and outputs the voltage according to the absolute value of the impedance to the impedance / phase control unit 109. The impedance / phase control unit 109 controls the impedance of the matching variable capacitor 102 within a predetermined variable range at the time of starting the charge injection blocking layer discharge shown in Table 3 based on the voltage input from the impedance detector 108.
That is, the voltage input from the impedance detector 108 is compared with the reference voltage, the voltage corresponding to the difference is supplied to the motor 112 driving the matching variable capacitor 102, and the voltage input from the impedance detector 108 is compared with the reference voltage. The difference was adjusted so that At this time, the impedance of the matching variable capacitor 102 is shown in Table 3.
When the maximum or minimum value of the variable range shown in is reached,
At that point, the supply of voltage to the motor 112 was stopped so that the capacity variable range in Table 3 would not be exceeded. The reference voltage was set to the output voltage value from the impedance detector 108 when the impedance viewed from the high frequency power input point of the matching box (matching box) 404 to the load side was 50Ω.

In this way, the matching variable capacitor 10
2 while adjusting the impedance of the tuning variable capacitor 103 and the output of the high frequency power supply 403.
By raising the value to the value of the charge injection blocking layer shown in (4), discharge was generated and the formation of the charge injection blocking layer was started. When the formation of the charge injection blocking layer is started, the matching variable capacitor 1
02 and the variable capacitance range of the tuning variable capacitor 103 was changed to the range shown in Table 3 when the charge injection blocking layer was formed. The impedance / phase control unit 109 controls the capacitance of the tuning variable capacitor 103 within the changed capacitance variable range. Then, when the capacitance of the tuning variable capacitor 103 becomes the maximum value or the minimum value of the variable range, or when the difference between the voltage input from the phase detector 107 and the reference voltage becomes the matching target condition or less, the motor The control method is such that the supply of voltage to 110 is stopped. The reference voltage is a matching box (matching box) 4
The output voltage value from the phase detector 107 when the phase difference between the incident voltage on the load side and the reflected voltage at the high frequency power input point of No. 04 was 0 degree was set. The matching target condition is the phase detector 1
The difference between the voltage input from 07 and the reference voltage is 5 of the reference voltage.
% Or less.

Simultaneously and in parallel, the impedance / phase control unit 109 caused the capacitance of the matching variable capacitor 102 to be adjusted within the changed capacitance variable range. Then, when the capacity of the matching variable capacitor 102 becomes the maximum value or the minimum value of the variable range, or when the difference between the voltage input from the impedance detector 108 and the reference voltage becomes the matching target condition or less, the motor The control method is to stop the supply of voltage to 112. The reference voltage was set to the output voltage value from the impedance detector 108 when the impedance on the load side at the high frequency power input point of the matching box (matching box) 404 was 50Ω. The matching target condition is set such that the difference between the voltage input from the impedance detector 108 and the reference voltage is 5% or less of the reference voltage.

In this way, after the formation of the charge injection blocking layer is completed, the output of the high frequency power is stopped, and the plasma treatment conditions such as gas species, gas flow rate and pressure are shown in Table 1 for the photoconductive layer forming conditions. And changing the capacitance variable range of the matching variable capacitor 102 and the tuning variable capacitor 103 to the range at the time of starting discharge of the photoconductive layer in Table 3, and then discharging in the same manner as when forming the charge injection blocking layer. Then, the photoconductive layer was formed.

After the formation of the photoconductive layer is completed, the output of the high frequency power is stopped, the plasma treatment conditions such as gas species, gas flow rate and pressure are set to the surface layer formation conditions shown in Table 1, and matching is performed. After changing the capacitance variable range of the variable capacitor 102 and the tuning variable capacitor 103 to the range at the surface layer discharge start time in Table 3, discharge is generated in the same manner as when the charge injection blocking layer is formed to form the surface layer. went.

In this way, a total of 60 electrophotographic photoconductors consisting of the charge injection blocking layer, the photoconductive layer and the surface layer were manufactured in 10 lots. A stable electrophotographic photosensitive member was formed in each lot.

(Comparative Example 1) In the same manner as in Example 1 except that the variable capacitance ranges of the matching variable capacitor 102 and the tuning variable capacitor 103 are not set in Example 1, the charge injection blocking layer under the conditions shown in Table 3, A total of 60 electrophotographic photoconductors consisting of a photoconductive layer and a surface layer were manufactured in 10 lots. As a result, in the three lots, the capacities of the matching variable capacitor 102 and the tuning variable capacitor 103 were temporarily deviated from the stable point during the formation of the electrophotographic photoreceptor, and the discharge became unstable.

The amorphous silicon (a-Si) photoconductors thus prepared in Example 1 and Comparative Example 1 were installed in a Canon copying machine NP-6750 modified for this test. The characteristics were evaluated. The evaluation items are
The four items of "image density unevenness", "optical memory", "characteristic variation", and "image defect" were evaluated, and each item was evaluated by the following specific evaluation methods.

Image density unevenness First, the current of the main charger is adjusted so that the dark portion potential at the developing device position becomes a constant value, and then a predetermined blank paper having a reflection density of 0.1 or less is used as the original document and the developing device is used. The image exposure light amount was adjusted so that the light portion potential at the position had a predetermined value. Then, a Canon halftone chart (part number: FY9-9042) was placed on a document table and evaluated by the difference between the maximum value and the minimum 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 photoconductors. Therefore, the smaller the value, the better.

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 light portion potential when a predetermined blank sheet is used as an original becomes a predetermined value. Image exposure light amount is adjusted as follows. In this state, Canon Ghost Test Chart (part number: FY9-904
A black circle having a reflection density of 1.1 and a diameter of 5 mm is affixed to 0) on the platen, and a halftone chart made by Canon is superimposed on it, and it is recognized on the halftone copy. It was performed by measuring the difference between the reflection density of a black circle having a diameter of 5 mm and the reflection density of a halftone portion of the ghost chart. The optical memory measurement was performed over the entire area of the photoconductor in the generatrix direction (the entire area along the longitudinal direction of the photoconductor), and the maximum reflection density difference therein was evaluated. The evaluation result was the average value of all the photoconductors. Therefore, the smaller the value, the better.

Characteristic variation: The maximum and minimum values of the evaluation results of all the photoconductors in the above "optical memory" evaluation were obtained, and then the value of (maximum value) / (minimum value) was obtained. Therefore,
The smaller the numerical value, the smaller the characteristic variation and the better.

Image defect: Count white spots with a diameter of 0.1 mm or more in the same area of a copy image obtained when a Canon halftone chart (part number: FY9-9042) is placed on a document table and copied. , Evaluated by the number.
Therefore, the smaller the value, the better.

Table 4 shows the evaluation results. In Table 4, the evaluation results are based on the evaluation results of Comparative Example 1, and regarding the image density unevenness, the maximum reflection density difference improved to less than 1/4 is ⊚, and 1/4 to less than 1/2. ◎ to ◯ for improved products, ◯ for improved to 1/2 or more and less than 3/4,
The improvement up to 3/4 or more is indicated by ◯ to Δ, the equivalent is indicated by Δ, and the deterioration is indicated by ×. As for "characteristic variation", improvement of 40% or more is excellent, and improvement of 20% or more and less than 40% is good, 10%.
Improvement of less than 20% is △, improvement of less than 10% or 1
Deterioration of less than 0% is shown by ▲, and deterioration of 10% or more is shown by x.
Regarding optical memory, those with a maximum reflection density difference improved to less than 1/4 are improved, and those with a maximum reflection density difference improved from 1/4 to less than 1/2 are improved to O, and 1/2 to less than 3/4 improved. ◯ to Δ indicates improvement up to 3/4 or more, Δ indicates equivalent, and X indicates deterioration. Regarding image defects, the number of white spots with a diameter of 0.1 mm or more improved to less than 1/4 is ◎, 1 /
∘ to ∘ for improvement of 4 or more and less than 1/2, ∘ for improvement of 1/2 or more and less than 3/4, ∘ to △ for improvement of 3/4 or more, Δ for equivalent, and worse Is indicated by x.

The electrophotographic photosensitive member produced in Example 1 gave good results in all evaluation items, confirming the effects of the present invention. Further, the electrophotographic image formed using the electrophotographic photosensitive member produced in Example 1 was extremely good without image deletion.

[0087]

[Table 4]

(Example 2) Using the deposited film forming apparatus, the matching box (matching box) and the control system used in Example 1, under the conditions shown in Table 1, the charge injection blocking layer and the photoconductive layer were prepared by the following procedure. The matching target conditions at the time of forming each layer of the layer and the surface layer were determined.

First, formation of the charge injection blocking layer was started by the same procedure as in determining the variable impedance range in Example 1. When the formation of the charge injection blocking layer is started,
The power reflectance is 1 while observing the incident power and reflected power at the high frequency power input point of the matching box (matching box) 404.
The capacitances of the matching variable capacitor 102 and the tuning variable capacitor 103 are changed within the range of 0% or less, and the maximum value of the difference between the voltage output from the phase detector 107 and the phase reference voltage and the impedance detector 108 are output. The maximum value of the difference between the voltage and the impedance reference voltage was investigated. The power reflectance is the ratio of reflected power to incident power. Further, the phase reference voltage is set to the output voltage value from the phase detector 107 when the phase difference between the incident voltage on the load side and the reflected voltage at the high frequency power input point of the matching box (matching box) 404 is 0 degree. The impedance reference voltage was set to the output voltage value from the impedance detector 108 when the impedance viewed from the high frequency power input point of the matching box (matching box) 404 to the load side was 50Ω.

The maximum value of the difference between the voltage output from the phase detector 107 and the phase reference voltage and the maximum value of the difference between the voltage output from the impedance detector 108 and the impedance reference voltage are measured. It was performed at intervals of 2 minutes during formation of the charge injection blocking layer, and the following phase matching target conditions and impedance matching target conditions were determined using the maximum values thereof.

Phase matching target condition (%) = {(maximum value of difference between output voltage of phase detector 107 and phase reference voltage) / (phase reference voltage)} × 100 Impedance matching target condition (%) = {(impedance The maximum value of the difference between the output voltage of the detector 108 and the impedance reference voltage) / (impedance reference voltage)} × 100 In the same manner, the matching target conditions for the photoconductive layer formation and the surface layer formation were determined. As a result, the matching target conditions of each layer are as shown in Table 5.

[0092]

[Table 5]

After the target alignment conditions at the time of forming each layer were determined in this manner, the electrophotographic photosensitive layer comprising the charge injection blocking layer, the photoconductive layer and the surface layer was formed under the conditions shown in Table 1 in the same manner as in Example 1. A total of 60 lots of 10 lots were prepared. However, in this example, the matching target conditions were set to the values shown in Table 5 for each of the charge injection blocking layer, the photoconductive layer, and the surface layer.
That is, the alignment target condition was changed during the formation of the electrophotographic photosensitive member.

In each of the lots, a stable electrophotographic photosensitive member was formed.

(Comparative Example 2) A charge injection blocking layer, a photoconductive layer,
In any of the surface layers, charge injection was performed under the conditions shown in Table 1 in the same manner as in Comparative Example 1 except that both the phase matching target condition and the impedance matching target condition were 2%, which is the same as the photoconductive layer condition of Example 2. A total of 60 lots of electrophotographic photoconductors including the blocking layer, the photoconductive layer and the surface layer were prepared.

As a result, in all lots, the capacitances of the matching variable capacitor 102 and the tuning variable capacitor 103 constantly fluctuated during the formation of the surface layer, and it was not possible to form a stable electrophotographic photosensitive member.

The a-Si photoconductors thus prepared in Example 2 and Comparative Example 2 were installed in a Canon copier NP-6750 modified for this test, and the photoconductor characteristics were evaluated. It was The four evaluation items were “image density unevenness”, “optical memory”, “characteristic variation”, and “image defect”, and each item was evaluated by the same evaluation method as in Example 1.

Table 6 shows the evaluation results. In Table 6, the evaluation results are based on the evaluation results of Comparative Example 1, and regarding the image density unevenness, the maximum reflection density difference improved to less than 1/4 is ⊚, and 1/4 to less than 1/2. ◎-○ for improved products, ◯ for improved to 1/2 or more and less than 3/4,
The improvement up to 3/4 or more is indicated by ◯ to Δ, the equivalent is indicated by Δ, and the deterioration is indicated by ×. As for "characteristic variation", improvement of 40% or more is excellent, and improvement of 20% or more and less than 40% is good, 10%.
Improvement of less than 20% is △, improvement of less than 10% or 1
Deterioration of less than 0% is shown by ▲, and deterioration of 10% or more is shown by x.
Regarding optical memory, those with a maximum reflection density difference improved to less than 1/4 are improved, and those with a maximum reflection density difference improved from 1/4 to less than 1/2 are improved to O, and 1/2 to less than 3/4 improved. ◯ to Δ indicates improvement up to 3/4 or more, Δ indicates equivalent, and X indicates deterioration. Regarding image defects, the number of white spots with a diameter of 0.1 mm or more improved to less than 1/4 is ◎, 1 /
∘ to ∘ for improvement of 4 or more and less than 1/2, ∘ for improvement of 1/2 or more and less than 3/4, ∘ to △ for improvement of 3/4 or more, Δ for equivalent, and worse Is indicated by x.

The electrophotographic photosensitive member produced in Example 2 provided good results in all evaluation items, confirming the effects of the present invention. Further, even better characteristics were obtained as compared with the electrophotographic photosensitive member produced in Example 1. From the comparison with Comparative Example 2, the effect of Example 2 is not simply caused by narrowing the matching target condition as compared with Example 1, but the impedance variable range is changed as the plasma processing progresses, and the matching target is changed. It was confirmed that the conditions were also changed as the plasma treatment proceeded.

[0100]

[Table 6]

Example 3 Using the deposited film forming apparatus shown in FIG. 2, an a-Si type photosensitive member was formed under the conditions shown in Table 7.
2, FIG. 2A is a schematic cross-sectional view of a deposited film forming apparatus according to a third embodiment of the present invention, and FIG. 2B is a schematic cross-sectional view taken along the section line AA ′ of FIG. 2A. is there. An exhaust port 209 is formed at the bottom of the reaction vessel 201, and the other end of the exhaust port 209 is connected to an exhaust device (not shown). Reaction vessel 201
Diameter 3 where the deposited film is formed so as to surround the center of the
12 cylindrical aluminum cylinders 205, each having 0 mm and a length of 358 mm, which are cylindrical aluminum cylinders, are placed on a holder 206 so as to be parallel to each other. Each cylindrical substrate 205 is held by a rotating shaft 208 and heated by a heating element 207. The rotation shaft 208 is rotated by driving a motor (not shown), and the cylindrical substrate 205 rotates about its center axis in the generatrix direction (center axis along the longitudinal direction of the cylindrical substrate). The cylindrical substrate 205 is maintained at the ground potential via the rotating shaft 208.

A raw material gas is supplied to the reaction vessel 201 from a raw material gas supply means 210. Raw material gas supply means 21
No. 0 is an alumina pipe having an inner diameter of 10 mm and an outer diameter of 13 mm, the end portion of which is sealed, and a raw material gas can be supplied from a gas outlet of 1.2 mm in diameter provided on the pipe. I was there. The surface of the source gas supply means 210 is
By blasting, the surface roughness was set to 20 μm in Rz with a reference length of 2.5 mm.

Six rod-shaped high-frequency electrodes 202 are installed in parallel with each other on the outside of a cylindrical dielectric wall 203 made of alumina, which constitutes a part of the reaction vessel 201, and a high-frequency power shield 204 is further provided outside thereof. Is a cylindrical dielectric wall 20
It is provided so as to surround 3 in a cylindrical shape.

The frequency of the high frequency power source 211 is 60 MHz, and the high frequency power output from the high frequency power source 211 is passed through the matching box (matching box) 212 to the high frequency electrode 2.
02. The output impedance of the high frequency power supply 211 is 50Ω, and the characteristic impedance 50 between the high frequency power supply 211 and the matching box (matching box) 212.
It is connected with an Ω coaxial cable. High frequency electrode 202
Is a SUS column having a diameter of 20 mm. Further, the cylindrical dielectric wall 2 made of alumina, which constitutes a part of the reaction vessel 201.
The inner surface of 03 has a surface roughness of 2.5 m due to blasting.
Rz with m as a reference length was set to 20 μm. Further, the specific configuration of the matching box (matching box) 212 is the configuration shown in FIG.
A variable capacitor in the range of pF or more and 1000 pF or less is used, and the tuning variable capacitor 103 is 5 pF or more,
A variable type was used within the range of 250 pF or less.

Using such a device, first, the variable impedance range was determined by the same procedure as in Example 1 under the conditions shown in Table 7. Next, the matching target conditions were determined under the conditions shown in Table 7 by the same procedure as in Example 2. After the charge transport layer was formed, the discharge was not stopped, the gas flow rate was continuously changed for 5 minutes, and then the electric power was changed for 5 minutes to form the charge generation layer as the next layer. After the charge generation layer was formed, the discharge was not stopped and the gas flow rate, power, and pressure were continuously changed for 15 minutes to form the next layer, the surface layer. In this way, the variable impedance range and the matching target condition are determined as shown in Table 8.

[0106]

[Table 7]

[0107]

[Table 8]

Five lots of electrophotographic photoconductors were produced under the conditions shown in Table 7 by the following procedure using the variable impedance range and the matching target conditions.

First, the cylindrical substrate 205, which is a cylindrical aluminum cylinder held by the substrate holder 206, was set on the rotating shaft 208 in the reaction vessel 201. Then, the inside of the reaction vessel 201 was exhausted through an exhaust pipe 209 by an exhaust device (not shown). Then, the cylindrical substrate 205 is rotated by a motor (not shown) at 10 rpm through the rotary shaft 208.
At a rate of 500 ml / min (normal) in the reaction vessel 201 from the source gas supply means 210.
While the Ar gas was being supplied, the cylindrical substrate 205 was heated by the heating element 207 while being controlled at 250 ° C., and this state was maintained for 2 hours.

Then, the supply of Ar gas is stopped, the reaction vessel 201 is evacuated through the exhaust pipe 208 by an exhaust device (not shown), and then the raw material gas supply means 210 is used.
The raw material gas used for forming the charge transport layer shown in 1 was introduced.
The flow rate of the raw material gas becomes the set flow rate, and the reaction vessel 20
After confirming that the pressure inside 1 is stable,
The output of No. 1 was set to a value of 20% of the charge transport layer conditions shown in Table 7. In this state, the capacitance adjustment of the matching capacitor 102 and the tuning capacitor 103 is started within the range shown in Table 7. The specific control method is the same as that in the first embodiment.

In this way, the matching variable capacitor 10
2 while adjusting the impedance of the tuning variable capacitor 103 and the output of the high frequency power supply 211.
By raising the value to the value of the charge transport layer conditions shown in, a discharge was generated and the formation of the charge transport layer was started. When the formation of the charge transport layer is started, the capacitance variable ranges of the matching variable capacitor 102 and the tuning variable capacitor 103 are changed to the ranges shown in Table 8 at the time of forming the charge transport layer, and the phase matching target condition and impedance are adjusted. Matching target conditions were set to those of the charge transport layer in Table 8. The specific method of adjusting the impedance during formation of the charge transport layer was the same as in Example 1.

In this way, after the formation of the charge transport layer is completed, the discharge is not stopped and the gas flow rate is continuously changed for 5 minutes, and then the electric power is changed for 5 minutes, so that the next layer is formed. The conditions for forming a charge generation layer were changed. During this time, the variable capacitance range of the matching variable capacitor 102 and the tuning variable capacitor 103, the phase matching target condition, and the impedance matching target condition are continuously changed, and at the start of the charge generation layer formation, the respective set values are as shown in Table 8. Each setting value of was set. After that, an electrophotographic photosensitive member was formed by changing the capacitance variable ranges of the matching variable capacitor 102 and the tuning variable capacitor 103, the phase matching target conditions, and the impedance matching target conditions in the same manner for the charge generation layer and the surface layer. After the charge generation layer is formed, the discharge is not stopped and the gas flow rate, power, pressure, and
A variable capacitance range of the matching variable capacitor 102 and the tuning variable capacitor 103, a phase matching target condition,
Change the impedance matching target condition in 15 minutes,
The next layer, the surface layer, was formed.

In this way, a total of 120 electrophotographic photoconductors consisting of the charge transport layer, the charge generation layer and the surface layer were prepared in 10 lots. A stable electrophotographic photosensitive member was formed in each lot.

Comparative Example 3 In Example 3, the variable capacitance range of the matching variable capacitor 102 and the tuning variable capacitor 103 is not set, and the phase matching target condition and the impedance matching target condition are fixed at 5% for each layer. Except for the above, in the same manner as in Example 3, 10 lots of electrophotographic photoreceptors including a charge transport layer, a charge generation layer, and a surface layer were prepared under the conditions shown in Table 7 for a total of 120 pieces. As a result, in the three lots, the capacities of the matching variable capacitor 102 and the tuning variable capacitor 103 were temporarily deviated from the stable point during the formation of the electrophotographic photoreceptor, and the discharge became unstable.

The a-Si type photoconductors thus produced in Example 3 and Comparative Example 3 were installed in the Canon copying machine NP-6030 modified for the test, and the characteristics of the photoconductors were evaluated. I did. The four evaluation items were "image density unevenness", "optical memory", "characteristic variation", and "image defect". Each item was evaluated by the following specific evaluation methods.

Table 9 shows the evaluation results. In Table 9, the evaluation results are based on the evaluation results of Comparative Example 3, and regarding the image density unevenness, the maximum reflection density difference improved to less than 1/4 is ⊚, and 1/4 to less than 1/2. ◎ to ◯ for improved products, ◯ for improved to 1/2 or more and less than 3/4,
The improvement up to 3/4 or more is indicated by ◯ to Δ, the equivalent is indicated by Δ, and the deterioration is indicated by ×. As for "characteristic variation", improvement of 40% or more is excellent, and improvement of 20% or more and less than 40% is good, 10%.
Improvement of less than 20% is △, improvement of less than 10% or 1
Deterioration of less than 0% is shown by ▲, and deterioration of 10% or more is shown by x.
Regarding optical memory, those with a maximum reflection density difference improved to less than 1/4 are improved, and those with a maximum reflection density difference improved from 1/4 to less than 1/2 are improved to O, and 1/2 to less than 3/4 improved. ◯ to Δ indicates improvement up to 3/4 or more, Δ indicates equivalent, and X indicates deterioration. As for image defects, the number of white spots with a diameter of 0.1 mm or more is improved to less than 1/4.
∘ to ∘ for improvement of 4 or more and less than 1/2, ∘ for improvement of 1/2 or more and less than 3/4, ∘ to △ for improvement of 3/4 or more, Δ for equivalent, and worse Is indicated by x.

The electrophotographic photosensitive member produced in Example 3 gave good results in all evaluation items, and the effect of the present invention was confirmed.

[0118]

[Table 9]

Example 4 An electrophotographic photosensitive member was first formed under the conditions shown in Table 10 using the plasma processing apparatus for forming an electrophotographic photosensitive member shown in FIG. After taking out the photoconductor from the reaction container, a dummy substrate was set in the reaction container, and the inside of the reaction container was cleaned under the conditions shown in Table 12. The structure of the plasma processing apparatus shown in FIG. 3 for forming an electrophotographic photosensitive member is as follows.

In the reaction vessel 301, a cylindrical substrate 302,
A substrate support 303 including a heater for heating a substrate, a source gas introducing pipe 306 are installed, and a matching box 312 connected to an RF power source 313 capable of outputting a high frequency power of 13.56 MHz is provided in a reaction vessel 301. Is connected to the cathode electrode 304 which constitutes a part of the.
The cathode electrode 304 is insulated from the ground potential by the insulator 305, is maintained at the ground potential through the base support 303, and is connected to the cylindrical base 302 which also serves as the anode electrode by RF.
Voltage can be applied. The configuration inside the matching box (matching box) 312 is the configuration shown in FIG. 1, and the matching variable capacitor 102 has a capacitance of 50 pF to 1000 p.
A variable capacitor in the range of F was used, and a variable variable tuning capacitor 103 used in the range of 5 pF to 250 pF was used.

The reaction container 301 is connected to an exhaust device (not shown) via an exhaust valve 308.
By opening 8, the inside of the reaction vessel 301 is evacuated and the pressure can be reduced. Further, reference numeral 309 in FIG. 3 denotes a leak valve. When the leak valve 309 is opened, a leak gas such as air, nitrogen gas, Ar gas, or He gas is introduced into the reaction container 301, and the reaction container is in a depressurized state. The inside of 301 can be opened to the atmosphere. In this example, He was used as the leak gas.

The supply of the raw material gas into the reaction container 301 is supplied through the raw material gas introduction pipe 306 connected to the raw material gas pipe 310, and the pressure in the reaction container can be detected by the vacuum gauge 307.

Using this apparatus, first, the proper impedance variable range of the matching variable capacitor 102 and the tuning variable capacitor 103 was determined by the following procedure.

First, the cylindrical substrate 30 is placed in the reaction vessel 301.
2 is installed and the exhaust valve 308 is opened to exhaust the inside of the reaction container 301 by an exhaust device (not shown). Then, the reaction gas is fed into the reaction vessel 301 through the source gas introduction pipe 306.
Supply 0 ml / min (normal) Ar gas,
The opening of the exhaust valve 308 is adjusted so that the pressure in the reaction container 501 is 85 Pa, and the cylindrical substrate 302 is heated to 260 by the substrate heating heater built in the substrate support 303.
Heating was performed while controlling the temperature to be 0 ° C., and the state was maintained for 1 hour and 30 minutes.

Next, after the supply of Ar gas is stopped and the reaction vessel 301 is evacuated by an exhaust device (not shown), the raw material gas shown in Table 10 used for forming the charge injection blocking layer is fed through the raw material gas introducing pipe 306. Was introduced. After confirming that the flow rate of the raw material gas was the set flow rate and the pressure inside the reaction vessel 301 was stable, the output of the RF power source 303 was set to the value of 20% of the charge injection blocking layer shown in Table 10. In this state, the capacitance of the matching variable capacitor 102 in the matching box (matching box) 312 is adjusted so that the difference between the output voltage from the impedance detector 108 and the reference voltage becomes smaller. The reference voltage is an impedance control device 10 when the impedance viewed from the high frequency power input point of the matching box (matching box) 312 to the load side is 50Ω.
The output voltage value from 8 was set. Simultaneously and in parallel, the capacitance of the tuning variable capacitor 103 in the matching box (matching box) 312 was adjusted so that the difference between the output voltage from the phase detector 107 and the reference voltage became smaller. The reference voltage was set to the output voltage value from the phase detector 107 when the phase difference between the incident power to the load side and the reflected power at the high frequency power input point of the matching box (matching box) 312 was 0 degree.

As described above, the matching variable capacitor 10
2 and the capacitance of the tuning variable capacitor 103 are adjusted so that the difference between the output voltage from the impedance detector 108 and the reference voltage and the difference between the output voltage from the phase detector 107 and the reference voltage are minimized. RF power supply 313
Discharge was caused by increasing the output of the above to the value of the charge injection blocking layer shown in Table 10, and the capacity of each variable capacitor when the discharge occurred was examined. Subsequently, a charge injection blocking layer was formed. When the formation of the charge injection blocking layer is started,
Again, the capacitances of the matching variable capacitor 102 and the tuning variable capacitor 103 were adjusted so that the absolute value of the impedance at the input point of the matching box (matching box) 312 and the phase difference between the incident voltage and the reflected voltage were minimized. This adjustment was continuously performed during the formation of the charge injection blocking layer, and the variation range of the capacitance of the matching variable capacitor 102 and the tuning variable capacitor 103 during the formation of the charge injection blocking layer was examined.

When the formation of the charge injection blocking layer is completed, the output of the high frequency power is stopped, and the plasma processing conditions such as gas species, gas flow rate and pressure are set to the photoconductive layer forming conditions shown in Table 10, and the charge injection is performed. Similar to the case of forming the blocking layer, the variation range of the capacitance of the matching variable capacitor 102 and the tuning variable capacitor 103 at the time of occurrence of discharge, and the variation range of the capacitance of the matching variable capacitor 102 and the tuning variable capacitor 103 during the formation of the photoconductive layer were examined.

Similarly, regarding the surface layer, the capacitances of the matching variable capacitor 102 and the tuning variable capacitor 103 when a discharge occurs, the matching variable capacitor 102 and the tuning variable capacitor 1 during the formation of the surface layer.
The variation range of 03 capacity was investigated.

Such an experiment was carried out 5 times, and the matching variable capacitor 102 and the tuning variable capacitor 103 at the time of occurrence of discharge of the charge injection blocking layer, the photoconductive layer and the surface layer
The variation range of the capacitance, the variation range of the matching variable capacitor 102 and the tuning variable capacitor 103 during the formation of each layer, and on the basis of this result, when the discharge of the charge injection blocking layer, the photoconductive layer, and the surface layer occurs, and The capacitance variable ranges of the matching variable capacitor 102 and the tuning variable capacitor 103 when forming each layer were determined in the same manner as in Example 1.

Next, the phase matching target condition and the impedance matching target condition were determined in the same manner as in the second embodiment. At this time, the operation procedure of the plasma processing apparatus for forming the electrophotographic photosensitive member can be performed in the same manner as when the capacitance variable range of the matching variable capacitor 102 and the tuning variable capacitor 103 is examined.

Matching variable capacitor 102 and tuning variable capacitor 103 thus determined
Table 11 shows the capacitance variable range, the target phase matching condition, and the target impedance matching condition.

In this way, after the capacitance variable range of the matching variable capacitor 102 and the tuning variable capacitor 103, the phase matching target condition, and the impedance matching target condition are determined, a-S is set under the conditions shown in Table 10 and Table 11.
An i-type photoreceptor was formed. After the formation of the a-Si-based photoreceptor, the inside of the reaction vessel 301 is sufficiently purged with He, and then the leak valve 30 is closed with the exhaust valve 308 closed.
9 was opened, and He was introduced into the reaction container 301 to open the reaction container 301 to the atmosphere. Then, the reaction vessel 301
Cylindrical substrate with deposited film formed from inside, ie, a-Si
The system photoreceptor was taken out and a dummy cylinder was installed instead.

Then, after the exhaust valve 308 is opened to exhaust the inside of the reaction container 301 by an exhaust device (not shown), the cleaning gas shown in Table 12 is supplied into the reaction container 301 through the source gas introduction pipe 306. The pressure inside the reaction vessel 301 was adjusted by adjusting the opening degree of the exhaust valve 308.

After the pressure adjustment, the capacitance variable ranges of the matching variable capacitor 102 and the tuning variable capacitor 103, the phase matching target conditions, and the impedance matching target conditions were determined in the same manner as when forming the photoconductor. The determined conditions were as shown in Table 13.

In this way, after the conditions for forming the a-Si photosensitive member and the cleaning conditions in the reaction container are determined, the a-Si photosensitive member is formed using the respective conditions, and the inside of the reaction container is thereafter determined. Five cycles of cleaning were performed.

[0136]

[Table 10]

[0137]

[Table 11]

[0138]

[Table 12]

[0139]

[Table 13]

COMPARATIVE EXAMPLE 4 Example 4 is different from Example 4 except that the variable capacitance range of the matching variable capacitor 102 and the tuning variable capacitor 103 is not set, and the phase matching target condition and the impedance matching target condition are always 6%. In the same manner as in No. 4, an a-Si based photoreceptor was formed under the conditions shown in Table 10. The phase matching target condition and the impedance matching target condition are 4%, which are the same as the PCL conditions of the fourth embodiment.
In such a case, the matching variable capacitor 102 and the tuning variable capacitor 103 constantly change their capacitances when the surface layer is formed.

Next, the matching variable capacitor 102
And the point that the variable capacity range of the tuning variable capacitor 103 is not set, the phase matching target condition is 5% from the cleaning start to the end, and the impedance matching target condition is 4% from the cleaning start to the end. Then, the inside of the reaction container was cleaned.

In this way, the formation of the a-Si type photosensitive member and the subsequent cleaning of the inside of the reaction container were performed for 5 cycles.

In this way, the a-Si type photoconductors prepared in Example 4 and Comparative Example 4 were installed in the Canon copying machine NP-6750 modified for this test, and the photoconductor characteristics were evaluated. Was done. The four evaluation items were “image density unevenness”, “optical memory”, “characteristic variation”, and “image defect”, and each item was evaluated by the same evaluation method as in Example 1.

The evaluation results are shown in Table 14. In Table 14, the evaluation results are based on the evaluation results of Comparative Example 4, and regarding the image density unevenness, the maximum reflection density difference improved to less than 1/4 is ⊚, and 1/4 to less than 1/2. The improved ones are indicated by ∘ to ∘, the ones improved from 1/2 to less than 3/4 are indicated by ∘, the improvement up to 3/4 or more is indicated by ∘ to Δ, the equivalent is indicated by Δ, and the deterioration is indicated by x. In addition, the “characteristic variation” is 40
% Improvement is ◎, 20% or more and less than 40% is good,
The improvement of 10% or more and less than 20% is shown by Δ, the improvement of less than 10% or the deterioration of less than 10% is shown by ▲, and the deterioration of 10% or more is shown by X. Regarding optical memory, those with a maximum reflection density difference improved to less than 1/4 are improved, and those with a maximum reflection density difference improved from 1/4 to less than 1/2 are improved to O, and 1/2 to less than 3/4 improved. ◯ to Δ indicates improvement up to 3/4 or more, Δ indicates equivalent, and X indicates deterioration. For image defects, diameter 0.
⊚ when the number of white spots of 1 mm or more was improved to less than 1/4, and ⊚ to ◯ when the number of white spots was improved from 1/4 to less than 1/2.
Those that were improved to ½ or more and less than 3/4 were indicated by ◯, improvements up to 3/4 or more were indicated by ◯ to Δ, equivalents were indicated by Δ, and deterioration was indicated by x.

The electrophotographic photosensitive member produced in Example 4 gave good results in all evaluation items, confirming the effects of the present invention.

Further, in Example 4, after cleaning the inside of the reaction vessel, the inside of the reaction vessel was cleanly cleaned without residue in any cycle, but in Comparative Example 4, the inside of the reaction vessel was cleaned in 2 cycles out of 5 cycles. Polysilane partially remained, and it was necessary to perform cleaning again.

[0147]

[Table 14]

[0148]

As described above, according to the present invention, the raw material gas introduced into the reaction vessel is decomposed by the high frequency power output from the high frequency power source and introduced into the reaction vessel through the matching device and the electrode. In the plasma processing method and the plasma processing apparatus for processing the object to be processed installed in the reaction container, impedance adjustment during plasma processing by the matching device is controlled within a predetermined impedance variable range, and By changing the impedance variable range with the progress of plasma processing, impedance matching by the matching device is properly and stably achieved,
As a result, it is possible to improve the plasma processing characteristics, improve the reproducibility of the plasma processing characteristics, and reduce the plasma processing cost.

Furthermore, when the variable impedance range is changed with the progress of the plasma processing, the impedance matching state is not discontinuous by changing the impedance changing range substantially continuously. It is more effective when is sudden.

Further, the impedance adjustment by the matching device is performed by automatic control. At this time, the automatic control is made to meet the predetermined matching target condition by adjusting the impedance of the matching device, and the plasma processing is performed. By changing the matching target condition with progress,
Further improvement in reproducibility of plasma processing characteristics can be achieved.

Also in this case, the impedance matching state does not become discontinuous by changing the matching target conditions substantially continuously with the progress of the plasma processing, and in particular, the condition change between a plurality of processes is not changed. More effective in a sudden case.

Further, when the frequency of the high frequency power is 50 MHz or more and 250 MHz or less, promotion of abnormal discharge can be effectively suppressed while maintaining a high vacuum processing speed, and the effect of the present invention is remarkably obtained.

Further, when the object to be processed moves or rotates at least during the plasma processing, problems that the matching circuit impedance largely deviates from an appropriate value and abnormal discharge is promoted are avoided.
It becomes possible to maintain a stable plasma.

When the plasma treatment of the present invention is used for forming an electrophotographic photoreceptor in which a long time is required for the plasma treatment and a plurality of plasma treatments under different conditions are continuously performed, a particularly large effect is obtained. be able to.

Furthermore, when the plasma treatment of the present invention is performed under a plurality of treatment conditions, optimum impedance matching is performed under each condition, so that a particularly large effect can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a configuration in a matching box (matching box) that can be used in a plasma processing method of the present invention.

FIG. 2 is a VHF plasma CV using frequencies in the VHF band.
It is a typical block diagram which showed an example of the manufacturing apparatus (plasma processing apparatus) of the photoreceptor member for electrophotography by D method.

FIG. 3 is a schematic configuration diagram showing an example of a manufacturing apparatus (plasma processing apparatus) of a photoreceptive member for electrophotography by a plasma CVD method using an RF band frequency.

FIG. 4 is a VHF plasma CV using frequencies in the VHF band.
It is a typical block diagram which showed an example of the manufacturing apparatus (plasma processing apparatus) of the photoreceptor member for electrophotography by D method.

FIG. 5 is a diagram showing an outline of an example of a configuration in a matching box (matching box) used in a conventional plasma processing apparatus.

[Explanation of symbols]

100 control system 101 matching circuit 102 Matching variable capacitor 103 Tuning variable capacitor 104 coils 105 Current detection element 106 Voltage detection element 107 Phase detector 108 Impedance detector 109 Impedance / phase control unit 110, 112 motor 201 reaction vessel 202 high frequency electrode 203 cylindrical dielectric wall 204 high frequency power shield 205 cylindrical substrate 206 holder 207 heating element 208 rotation axis 209 exhaust port 210 Source Gas Supply Means 211 high frequency power supply 212 Matching Box (Matching Box) 301 reaction vessel 302 cylindrical substrate 303 substrate support 304 cathode 305 insulator 306 Raw material gas introduction pipe 307 vacuum gauge 308 Exhaust valve 309 leak valve 310 Raw material gas piping 312 Matching device (matching box) 313 RF power supply 401 reaction vessel 402 Cathode electrode (high frequency electrode) 403 High frequency power supply 404 Matching device (matching box) 405 cylindrical substrate 406 Deposition space 407 heating element 408 rotation axis 409 motor 411 exhaust pipe 412 Source gas supply means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Makoto Aoki             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Tomohito Ozawa             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Nobufumi Tsuchida             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F term (reference) 2H068 DA23 EA25 EA30 EA36                 4K030 FA03 HA11 JA00 JA18 KA30                       KA41 LA11 LA16 LA17                 5F004 AA01 BA06 BB13 BD04 CA02                       CA03 CA04 DA00 DA23                 5F045 AA08 AB04 AC01 AC19 AD06                       AE15 AE17 AF10 BB02 BB08                       BB16 CA16 DA52 DA65 EF08                       EH04 EH15 EH19

Claims (10)

[Claims] 1. A high-frequency power output from a high-frequency power source is introduced into a reaction vessel through a matching unit and electrodes to decompose the raw material gas introduced into the reaction vessel, and the reaction vessel is installed in the reaction vessel. In a plasma processing method for processing a processed object, the impedance adjustment during plasma processing by the matching device is controlled within a predetermined impedance variable range,
A plasma processing method, characterized in that the variable impedance range is changed as the plasma processing progresses. 2. The impedance variable range is changed substantially continuously as the plasma processing progresses.
The plasma processing method described. 3. The plasma processing method according to claim 1, wherein impedance adjustment by a matching device is performed by automatic control. 4. The automatic control is adapted to meet a predetermined matching target condition by adjusting the impedance of the matching device, and the matching target condition is changed as the plasma processing progresses. The plasma processing method described in 1. 5. The plasma processing method according to claim 4, wherein the matching target condition is changed substantially continuously as the plasma processing progresses. 6. The high frequency power has a frequency of 50 MHz or more and 250 MH.
The plasma processing method according to claim 1, wherein the plasma processing method is z or less. 7. The plasma processing method according to claim 1, wherein the plasma processing continuously performs a plurality of processing under different conditions. 8. The object to be processed moves or rotates at least during a period during plasma processing.
The plasma processing method according to any one of 1. 9. The plasma processing method according to claim 1, wherein the plasma processing is performed to form a photoconductor for electrophotography. 10. The plasma processing comprises a plurality of processing conditions, and the variable range of the preset impedance is different between at least two processing conditions of the plurality of processing conditions. The processing method according to claim 1.