JP2013108148A - Deposited film forming method - Google Patents

Abstract

Disclosed is a method for forming a deposited film, which can stably produce a uniform deposited film at a low cost.
[Solution]
A reaction vessel, means for introducing a cleaning gas into the reaction vessel, means for exhausting the cleaning gas, a substrate holder for installing a substrate in the reaction vessel, and rotating the substrate holder An outer periphery of the substrate using a deposited film forming apparatus comprising a shaft for moving or reciprocating and a bearing for supporting the shaft, and at least one of the shaft and a sliding surface of the bearing is made of a solid lubricant. A deposition film forming method for forming a deposition film on a surface, wherein after the deposition film is formed on the outer peripheral surface of the substrate, a cleaning gas is introduced into the reaction vessel, and the shaft is rotated or moved. A cleaning process is performed while reciprocating, and a driving state of the rotational movement or the reciprocating movement is changed during the cleaning process.
[Selection] Figure 2

Description

  The present invention relates to a deposited film forming method.

  A semiconductor deposited film made of a non-single crystal material has been proposed. For example, amorphous silicon (hereinafter abbreviated as “a-Si”) compensated for at least one of hydrogen and halogen (for example, fluorine and chlorine) is used as the light receiving member. Such a light receiving member can be used as an element member in, for example, a semiconductor device, an electrophotographic photoreceptor device, an image input line sensor, an imaging device, a photovoltaic device, other various electronic elements, and optical elements.

Various methods for forming this kind of deposited film have also been proposed. For example, a vacuum deposition method, an ion plating method, a sputtering method, a thermal CVD method, a plasma CVD method, a photo CVD method, and the like. In particular, a plasma CVD method, that is, a method in which DC power or RF high frequency power is applied to a raw material gas to decompose the raw material gas and form a deposited film on the outer peripheral surface of the cylindrical substrate is an electrophotographic photosensitive member. In the formation method, etc., the practical application is currently progressing.
When forming a deposited film, it is required to make the film thickness and film characteristics uniform. For this purpose, it is effective to devise a method for supplying and exhausting the source gas, to rotate the substrate to be processed on which the deposited film is formed, or to adopt a method for making the plasma uniform when using the plasma CVD method. It is shown that.

On the other hand, as described above, when a deposited film is formed on the outer peripheral surface of a predetermined substrate, the deposited film or a powdery polymer (hereinafter referred to as polysilane) is formed on other components in the reaction vessel for forming the deposited film. May be deposited). For example, when a deposited film is formed by plasma CVD using glow discharge decomposition, a deposited film or polysilane is formed on the counter electrode or the inner wall of the reaction vessel, which is a portion other than the substrate inside the reaction vessel.
These deposited films or polysilane may be taken in as impurities in the deposited film formed at the time of the next deposited film formation. As a result, the characteristics of the obtained film may be deteriorated, or polysilane may adhere to the substrate and defects may be formed in the formed deposited film.
For this reason, it is possible to clean the inside of the reaction vessel after several deposition film formation cycles or after each deposition film formation cycle, and to remove the deposited film or polysilane deposited on portions other than the target deposited film formation site. Done.

As a cleaning method at that time, a so-called dry etching cleaning method has been proposed in which an element forming a deposited film or polysilane is reduced by a gas phase molecule and cleaned by a gas phase chemical reaction.
In the dry etching cleaning method (hereinafter simply referred to as “cleaning process”), a so-called cleaning gas such as ClF ₃ gas, CF ₄ gas, NF ₃ gas, and SF ₆ is introduced into the reaction vessel. Then, it is excited to be excited by energy such as plasma, heat, light, etc., reacted with a deposited film or polysilane, and these elements are converted into gas phase molecules, which are removed by an exhaust means and cleaned.
Patent Document 1 discloses a cleaning method using a cleaning gas containing at least one of ClF, ClF ₃ , and ClF ₅ .

Japanese Patent No. 2720966

In recent years, for example, as a result of improvements in an optical exposure device, a developing device, a transfer device, etc. in an electrophotographic apparatus in order to improve the image characteristics of the electrophotographic apparatus, the electrophotographic photosensitive member has more uniform characteristics than before. Improvement has come to be demanded. Therefore, when the cleaning process is performed as described above, the following problems may occur.
For example, the solid lubricant installed on the sliding surface of the support member of the rotating means is generally a material having excellent corrosion resistance and wear resistance. However, the usage conditions (location, environment) and cleaning process conditions In some cases, corrosion does not progress at all. Specifically, corrosion (oxidation) occurs due to the action of the cleaning gas on the surface of the solid lubricant, and as a result, the conduction state of the substrate through the solid lubricant may become unstable. In addition, wear may increase due to alteration due to corrosion, and smooth sliding may not be possible, resulting in reduced rotational accuracy. As a result, the uniformity of the deposited film may be reduced.
Furthermore, when used for a long time in such a situation, the solid lubricant may adhere to the mating surface and may be difficult to slide. As a result, the uniformity of the deposited film may be further reduced.

In view of the above problems in the case of using a cleaning gas, during actual use, after performing a certain number of cleaning processes, the deposited film forming apparatus is stopped and the solid lubricant is replaced. Has been made. However, according to this coping method, there is a problem that the operating rate of the apparatus is reduced and the cost is increased due to the replacement of parts.
As another countermeasure, there is a method of diluting to a very low concentration with a diluent gas when using a cleaning gas. However, in this case, there is a problem that the time required for cleaning increases and the manufacturing tact time increases. As a result, the manufacturing cost of the deposited film increases.

As described above, it solves the above-mentioned problems when using a cleaning gas, suppresses unevenness of the deposited film due to corrosion and friction received by the solid lubricant, and enables stable and inexpensive uniform deposition. A method of forming a film is desired.
An object of the present invention is to provide a deposited film forming method capable of stably producing a uniform deposited film at a low cost.

  The method for forming a deposited film according to the present invention includes a reaction vessel, a means for introducing a cleaning gas into the reaction vessel, a means for exhausting the cleaning gas, and a substrate inside the reaction vessel. And a shaft for rotating or reciprocating the substrate holder, and a bearing for supporting the shaft, and at least one of the shaft and the sliding surface of the bearing is a deposited film made of a solid lubricant. A deposition film forming method for forming a deposition film on the outer peripheral surface of the substrate using a forming apparatus, wherein after forming the deposition film on the outer peripheral surface of the substrate, a cleaning gas is introduced into the reaction vessel. The cleaning process is performed while rotating or reciprocating the shaft, and the driving state of the rotation or reciprocation is changed during the cleaning process.

  According to the present invention, it is possible to reduce corrosion caused by the cleaning gas of the solid lubricant and wear due to driving, and to form a stable and uniform deposited film. Further, since the frequency of maintenance of the manufacturing apparatus can be reduced without increasing the manufacturing tact time, the deposited film can be formed at a low cost.

It is a schematic diagram which shows an example of the manufacturing apparatus of an a-Si electrophotographic photoreceptor. It is a graph which shows the rotation speed during a cleaning process. It is a schematic diagram which shows an example of the layer structure of an a-Si electrophotographic photoreceptor.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
(Deposited film forming device)
FIG. 1 is a diagram schematically showing an example of a deposited film forming apparatus 100 for manufacturing an electrophotographic photosensitive member by an RF (Radio Frequency) -CVD (Chemical Vapor Deposition) method. The deposited film forming apparatus 100 is an apparatus that forms a deposited film on the cylindrical substrate 102 by plasma processing. The cylindrical cathode electrode 103, the insulator 104, the upper wall 105, the gate valve 106, and the bottom wall 107 form a reaction vessel 101 that can be depressurized.

  The cylindrical base 102 may be made of any material that meets the purpose of use. As a material of the cylindrical substrate 102, for example, copper, aluminum, nickel, cobalt, iron, chromium, molybdenum, titanium, or an alloy thereof can be used. Among these, aluminum is excellent in consideration of workability and manufacturing cost. In this case, it is preferable to use either an Al—Mg alloy or an Al—Mn alloy.

A heating heater 108 is provided inside the reaction vessel 101. Any heater may be used as long as it can be used in a vacuum. Specifically, heat-exchanging heaters such as sheathed heaters, plate heaters, ceramic heaters, and carbon heaters, heat radiation lamps such as halogen lamps and infrared lamps, and heat exchange using liquid or gas as a heat medium Means are listed as targets.
In addition, a raw material gas introduction pipe (raw material gas introduction unit) 109 for introducing a raw material gas into the reaction vessel 101 is provided inside the reaction vessel 101. The source gas introduction pipe 109 extends in parallel to the longitudinal direction of the cylindrical base 102 to be held. The source gas introduction pipe 109 is connected via a connection pipe 120 to a gas supply system including a mixing device 121 having a mass flow controller (not shown) for adjusting the flow rate of the source gas and a source gas inflow valve 122. ing.

  In the exhaust system provided in the deposited film forming apparatus 100, a vacuum pump unit (not shown) as exhaust means is connected to the exhaust port 124 of the bottom wall 107 through an exhaust pipe 123. An exhaust main valve 125 is provided in the exhaust pipe 123. In addition, a vacuum gauge 126 for measuring the internal pressure is attached to the reaction vessel 101. By using these, the inside of the reaction vessel 101 can be maintained at a predetermined pressure suitable for each step. As the vacuum pump unit, for example, a rotary pump or a mechanical booster pump can be used.

  A high-frequency power source (applying means) 111 is electrically connected to the cylindrical cathode electrode 103 via a matching box 110 having a matching circuit. The upper and lower sides of the cylindrical cathode electrode 103 are insulated from the upper wall 105 and the bottom wall 107 by an insulator 104 made of ceramics. The upper wall 105 is provided with a gate valve 106 that is an opening / closing portion that allows the inside and outside of the reaction vessel 101 to communicate with each other. A substrate holder 112 that holds the cylindrical substrate 102 is carried into and out of the reaction vessel 101 from here.・ Installed.

  A rotation holding mechanism 130 that rotatably holds one end side of the substrate holder 112 to which the cylindrical substrate 102 and the cap 113 are attached is provided below the reaction vessel 101. The rotation holding mechanism 130 includes a turntable 131 for rotating the base holder 112, a support column 132 that supports the turntable 131, and a bearing 133 made of a solid lubricant installed on the support column 132. The turntable 131 is rotated by a motor 134. The bearing 133 is fixed to the support column 132 and forms a sliding surface on the surface in contact with the turntable 131. Therefore, the cylindrical base 102 can be rotated around the support column 132 and the bearing 133 together with the turntable 131 while being mounted on the base holder 112. At this time, since the rotation holding mechanism 130 is entirely composed of a conductive member, the base holder 112 and the bottom wall 107 are electrically connected.

  In addition, a conductive rod-like body 140 is provided inside the reaction vessel 101 so as to penetrate the inside of the support 132 of the rotation holding mechanism 130 and the heater 108 for heating. The conductive rod 140 penetrates the bottom wall 107 and is connected to a moving device 141 installed at the lower part of the bottom wall 107. By this moving device 141, the conductive rod-shaped body 140 can be moved in the longitudinal direction of the substrate holder 112. The moving device 141 includes a bellows for keeping the reaction vessel 101 airtight and an air cylinder (both not shown) for allowing the conductive rod 140 to move. The moving device 141 is not particularly limited, and may be a driving method using a cylinder mechanism using air pressure, hydraulic pressure, or water pressure, or a driving method using a ball screw mechanism using an electric motor.

After the substrate holder 112 is placed on the turntable 131, the conductive rod-shaped body 140 rises through the hole 143 formed in the center of the upper surface 142 of the substrate holder 112.
The conductive rod-shaped body 140 has a conductive connecting body 144. When the conductive rod-shaped body 140 is raised, the connecting body 144 comes into contact with the upper surface 142 of the base holder 112, and the base holder 112 and the conductive stick-shaped body are connected. The body 140 is configured to conduct. Further, a first contact 145 is provided at the upper end of the conductive rod-shaped body 140.
As the conductive rod-shaped body 140 is raised, the first contact 145 comes into contact with the valve body 146 of the gate valve 106 of the base holder 112, and the gate valve 106 and the conductive rod-shaped body 140 are electrically connected. . The conductive rod 140 contracts when the substrate holder 112 is carried into and out of the reaction vessel 101, and expands and contracts so that the substrate holder 112 and the gate valve 106 are finally brought into contact with each other during installation. It may be possible.

  The connection body 144 of the conductive rod-shaped body 140 has a connection portion 148 including a bearing 149 made of a solid lubricant and a conductive second contact 147 that contacts the upper surface 142 of the base holder 112. The bearing 149 is fixed to the conductive rod-shaped body 140, and forms a sliding surface on the surface in contact with the connecting portion 148. When the substrate holder 112 is rotated, the conductive rod-shaped body 140 is stationary, and the connecting portion 148 is configured to rotate with the substrate holder 112 around the conductive rod-shaped body 145 and the bearing 149.

The second contact 147 of the connecting portion 144 and the first contact 145 at the upper end of the conductive rod 140 are not particularly limited as long as they are conductive materials. As the first contact 145 and the second contact 147, for example, copper, aluminum, gold, silver, platinum, lead, nickel, cobalt, iron, chromium, molybdenum, titanium, and stainless steel have good electrical conductivity. Therefore, it is preferable. Of these, stainless steel is most suitable from the viewpoint of dust generation and durability during repeated use. The configuration of the second contactor 147 and the first contactor 145 is not particularly limited as long as they are in contact with the upper surface 142 and the valve body 146, respectively. However, in order to prevent the base holder 112 and the valve body 146 from being pushed up at high temperatures and even when the base holder 112 rotates, it is desirable to have elasticity, and a leaf spring is preferable.
An example of a procedure for forming a deposited film using the deposited film forming apparatus 100 configured as described above will be described with reference to FIGS.

(Deposited film formation method)
First, the substrate holder 112 to which the cylindrical substrate 102 and the cap 113 are attached is loaded into the reaction vessel 101 and placed on the rotation holding mechanism 130, and then the valve body 146 of the gate valve 106 is closed. Subsequently, the conductive rod-shaped body 140 is raised, the second contact 147 of the connection body 144 of the conductive rod-shaped body 140 is the upper surface 142 of the base holder 112, and the first contact 145 of the conductive rod-shaped body 140 is the valve body. 146, respectively. Then, both longitudinal ends of the substrate holder 112 are electrically connected to the reaction vessel 101 and become conductive. At this time, since the upper end portion of the cap 113 is in contact with the substrate holder 112, both ends in the longitudinal direction of the cylindrical substrate 102 are electrically connected to the reaction vessel 101 through the substrate holder 112 and the cap 113 and become conductive. ing.

Thereafter, the cylindrical substrate 102 is heated inside the reaction vessel 101 evacuated by a vacuum pump unit (not shown) via a mixing device 121, a source gas inflow valve 122, a connection pipe 120 and a source gas introduction pipe 109. Necessary, for example, Ar or He gas is introduced. Then, the rotational frequency of the vacuum pump unit (not shown) is adjusted while checking the vacuum gauge 126 so that the inside of the reaction vessel 101 has a predetermined pressure. This adjustment can be performed, for example, by adjusting the rotation frequency of a mechanical booster pump of a vacuum pump unit (not shown).
Next, after reaching a predetermined pressure, the temperature of the cylindrical substrate 102 is set to a desired temperature of 200 [° C.] to 450 [° C.], more preferably 250 [° C.] to 350 [° C.] by the heater 108. Control.

  After the preparation for forming the deposited film is completed by the above procedure, the deposited film is formed on the outer peripheral surface of the cylindrical substrate 102. For this purpose, first, as the source gas for forming the deposited film, the main source gas, the dilution gas, and the characteristic improving gas are mixed and introduced through the mixing device 121 and adjusted so that the introduced gas has a desired flow rate. To do. At that time, the rotational frequency of the vacuum pump unit (not shown) is adjusted while checking the vacuum gauge 126 so that the pressure inside the reaction vessel 101 becomes a desired pressure of 13.3 [mPa] to 1330 [Pa]. To do.

As the main source gas used for forming the deposited film, amorphous silicon formation of silane (SiH ₄ ), disilane (Si ₂ H ₆ ), silicon tetrafluoride (SiF ₄ ), and disilicon hexafluoride (Si ₂ F ₆ ) is formed. Raw material gas or a mixed gas thereof can be used. As a dilution gas, hydrogen (H ₂ ), argon (Ar), or helium (He) can be used. Further, as the characteristic improving gas, those containing nitrogen atoms, those containing oxygen atoms, those containing carbon atoms, those containing fluorine atoms, or a mixed gas thereof may be used in combination. As those containing nitrogen atoms for use in this, nitrogen _(N 2), ammonia (NH ₃₎ can be mentioned. Oxygen (O ₂ ), nitrogen monoxide (NO), nitrogen dioxide (NO ₂ ), dinitrogen oxide (N ₂ O), carbon monoxide (CO), carbon dioxide (CO ₂ ) are included as oxygen atoms. Is mentioned. As those containing carbon atoms, methane _(CH 4), ethane _{(C 2 H} 6), ethylene _{(C 2 H} 4), acetylene _{(C 2 H} 2), include propane _(C 3 _{H 8).} Examples of those containing fluorine atoms include germanium tetrafluoride (GeF ₄ ) and nitrogen fluoride (NF ₃ ). Further, a characteristic improving gas such as diborane (B ₂ H ₆ ), boron fluoride (BF ₃ ), or phosphine (PH ₃ ) may be simultaneously introduced into the discharge space.

Next, after the pressure inside the reaction vessel 101 is stabilized, the high-frequency power source 111 is set to a desired power, and the high-frequency power is supplied to the cylindrical cathode electrode 103 via the matching box 110, thereby Causes a discharge. The supplied power can be set to a frequency of 13.56 [MHz], for example. By this discharge energy, the source gas for forming the deposited film introduced into the reaction vessel 101 is excited to generate excited species, that is, decomposed to form a deposited film on the outer peripheral surface of the cylindrical substrate 102. The
In order to form a uniform deposited film, the cylindrical substrate 102 is rotated at the same time as the deposited film is formed or from the stage of heating the cylindrical substrate 102. This rotation is set to a rotation speed of 0.5 [rpm] to 20 [rpm], for example, 10 [rpm]. By doing so, a uniform deposited film is formed in the circumferential direction of the cylindrical substrate 102.

As described above, a deposited film is formed on the outer peripheral surface of the cylindrical substrate 102.
After the deposited film is formed, the supply of the deposited film forming source gas, the high frequency power and the heater 108 is stopped, and the reaction vessel 101 is exhausted. Thereafter, the inside of the reaction vessel 101 and the source gas introduction pipe 109 is purged using a purge gas, for example, at least one of an inert gas such as Ar or He and N ₂ . After the purge process is completed, the substrate holder 112 with the cylindrical substrate 102 attached is carried out of the reaction vessel 101. At the time of carrying out, the electroconductive rod-shaped body 140 descends.

(Cleaning process)
Thereafter, the deposited film and polysilane deposited in the reaction vessel 101 are cleaned. As a procedure, first, instead of the cylindrical substrate 102, a substrate holder 112 equipped with a cleaning dummy substrate (not shown) having substantially the same shape is carried into the reaction vessel 101 and installed.
Thereafter, the conductive rod 140 is raised as described above. Then, the first contact 145 at the upper end of the conductive rod-shaped body 140 is brought into contact with the valve body 146 of the gate valve 106.

Next, the reaction vessel 101 is evacuated by a vacuum pump unit (not shown). Subsequently, a cleaning gas necessary for the cleaning process is introduced into the reaction vessel 101 through the mixing device 121 and the source gas introduction pipe 109. Then, the rotation frequency of the vacuum pump unit (not shown) is adjusted while checking the vacuum gauge 126 so that the pressure inside the reaction vessel 101 becomes a predetermined pressure.
Examples of the cleaning gas used in the cleaning process include CF ₄ , CF ₄ / O ₂ , SF ₆ , NF ₃ , and ClF ₃ (chlorine trifluoride). In this embodiment, the cleaning time is shortened. ClF ₃ which is effective from the surface is used. In the present embodiment, it is effective to use an inert gas for dilution in order to adjust the concentration of the cleaning gas. Examples of the inert gas include He, Ne, and Ar. Among them, it is preferable to use Ar.

  After the pressure inside the reaction vessel 101 is stabilized, the substrate holder 112 is rotated. That is, the turntable 131 and the connecting portion 148 are driven during the cleaning process. This rotation is set to a rotation speed of 0.5 [rpm] to 20 [rpm], for example, 10 [rpm]. Then, the high frequency power supply 111 is set to a desired power, and the high frequency power is supplied to the cylindrical cathode electrode 103 through the matching box 110, thereby generating a high frequency glow discharge. The supplied power can be set to a frequency of 13.56 [MHz], for example. With this discharge energy, the cleaning gas introduced into the reaction vessel 101 is decomposed, and the cleaning process inside the reaction vessel 101 is started.

Next, for example, after a predetermined time has elapsed, the rotation speed of the substrate holder 112 is set to a rotation speed of 2 [rpm], for example. By doing so, the driving states of the turntable 131 and the connecting portion 148 are changed during the cleaning process. The change in the number of rotations of the substrate holder 112 during the cleaning process at this time is shown in FIG.
2A to 2C are schematic diagrams showing the number of rotations of the substrate holder 112 during the cleaning process. In each case, the horizontal axis represents the elapsed time during the cleaning process, and the vertical axis represents the number of rotations of the substrate holder 112 during the cleaning process.
After that, for example, after a predetermined time has elapsed,
The supply of the raw material gas for cleaning and the high frequency power is stopped, and the reaction vessel 101 is exhausted. Thereafter, the inside of the reaction vessel 101 and the raw material gas introduction pipe 109 is purged using a purge gas, for example, at least one of an inert gas such as Ar and He and N2. After the purge process is completed, the substrate holder 112 on which a cleaning dummy substrate (not shown) is mounted is unloaded from the reaction vessel 101.

According to the deposited film forming method of the present embodiment configured as described above, first, during the cleaning process, the bearing 133 made of a solid lubricant, the turntable 131 serving as a shaft with respect to the bearing 149, and the connecting portion 148 are driven. Can be made. Thereby, it becomes possible to reduce the corrosion by the cleaning gas of the sliding surface portion of the solid lubricant.
This is because the solid lubricant is a self-lubricating material, and the bearings (bearing 133 and bearing 149) made of the solid lubricant and the shaft (the rotary table 131 and the connecting portion 148) contacting these always slide. A new sliding surface is formed. Therefore, it is possible to reduce corrosion due to the cleaning gas at the sliding surface portion of the solid lubricant.

On the contrary, when the cleaning process is performed without sliding the bearing and the shaft, the corrosion progresses at an accelerated speed as compared with the case where the sliding is performed. As a result, depending on the type of solid lubricant, or depending on the cleaning conditions and the number of treatments, the sliding surface of the solid lubricant and the surface of the sliding partner adhere to each other, making it difficult to slide and the conduction state to be unstable. There is a case.
Therefore, for example, if the formation of a new sliding surface is increased by increasing the number of revolutions, the corrosion is further reduced.

On the other hand, increasing the number of revolutions increases the mechanical wear of the solid lubricant. Therefore, even if the rotational speed is uniquely increased, corrosion due to the cleaning gas can be reduced, but the rotational accuracy may be reduced due to wear.
One factor that determines the rate of progress of corrosion by the cleaning gas of the solid lubricant is the operating temperature of the solid lubricant. In other words, the progress of corrosion is faster when the cleaning gas is contacted at a high temperature than when the cleaning gas is contacted at a low temperature.

In the cleaning process, first, the reaction vessel 101 to which a cleaning gas is supplied is mainly implemented. As a result, the cleaning of the reaction vessel 101 is completed first, and then the cleaning process in the vicinity of the exhaust pipe 123 and further the vacuum pump unit (not shown) is completed.
Further, when the cleaning gas chemically reacts with polysilane or the deposited film, thermal energy is transferred between the upper wall 105, the cylindrical cathode electrode 103, the turntable 131, and the exhaust pipe 123. Therefore, the temperature of the components of the reaction vessel 101 and the exhaust pipe 123 increases.

As described above, as the cleaning process proceeds, the temperature inside the reaction vessel 101 first increases, and then the temperature inside the reaction vessel 101 decreases when the cleaning process of the reaction vessel 101 ends. Therefore, the operating temperature of the solid lubricant varies during the cleaning process depending on the place where the solid lubricant is installed.
As a result, when the temperature of the solid lubricant is high, the rotational speed is increased to reduce corrosion, and when the temperature is low, the rotational speed is decreased to reduce wear. It is possible to reduce corrosion and wear optimally.
That is, as in this embodiment, the shaft is driven during the cleaning process, and further, the driving state of the shaft is changed during the cleaning process, thereby suppressing wear and cleaning gas on the sliding surface portion of the solid lubricant. Corrosion due to corrosion can be reduced.

In the present invention, the way of changing the driving state is not particularly limited, and an optimal change is made according to the situation.
For example, in the deposited film forming apparatus shown in FIG. 1, solid lubricants are installed at positions on the upper and lower ends of the reaction vessel 101 during the cleaning process. Therefore, as shown in FIG. 2A, first, the cleaning process is performed in a driving state with a high rotational speed (conditions for cleaning 1), and when the cleaning process inside the reaction vessel 101 is almost completed, the rotational speed is increased. The driving state may be changed to a low driving state (conditions for cleaning 2).

  Further, as described above, the driving state is appropriately determined depending on the position where the solid lubricant is installed, the position where the cleaning gas is introduced during the cleaning process, the amount of gas introduced, the dilution rate, or the input power. . For example, as shown in FIG. 2B, the rotational speed may be gradually decreased in each of cleaning 1 and cleaning 2 from the start of the cleaning process. Further, as shown in FIG. 2C, in cleaning 1, the number of rotations may be gradually increased in the initial stage of the cleaning process, and then the cleaning number may be gradually decreased in cleaning 2 after the cleaning process is performed at a constant number of rotations.

  As described above, the cleaning process is completed from the inside of the reaction vessel 101 in the order of the exhaust pipe 123 and the vicinity of the vacuum pump unit (not shown). Therefore, during the cleaning process inside the reaction vessel 101, that is, when the temperature of the solid lubricant is high, the cleaning process is performed in a driving state with a high rotational speed (conditions for cleaning 1). This is because the corrosion of the solid lubricant can be reduced. Then, after the cleaning process inside the reaction vessel 101 is almost completed, that is, when the temperature of the solid lubricant is low, the cleaning process is performed by changing to a driving state (condition of cleaning 2) with a low rotational speed. This is because wear of the solid lubricant can be reduced. By reducing the drive state at a predetermined time in this way, it is possible to improve the durability of the solid lubricant.

In the present invention, the timing for changing the driving state is not particularly limited, and an optimal change is made according to the situation.
For example, the timing for changing the driving state from cleaning 1 to cleaning 2 is before and after the end of the cleaning process inside the reaction vessel 101 in which the solid lubricant is used as described above. There is no particular limitation on how to determine the time. For example, a time for ending the cleaning process may be determined in advance, and the time may be used to change the driving state.

Also, it is possible to monitor the temperature of a part of the deposited film forming apparatus 100 and change the driving state based on the monitored value.
For example, a part of the inside of the reaction vessel 101 may be monitored by using a temperature measuring device such as a thermocouple, and the time when the monitored value exceeds a predetermined temperature may be set as the timing for changing the driving state. Further, when the monitor value exceeds the peak value, or after a predetermined time has elapsed after exceeding the peak value, the drive state may be changed.
Further, for example, the temperature of the external surface of the exhaust pipe 123 between the reaction vessel 101 and the exhaust device (not shown) may be monitored to determine the timing for changing the driving state as described above.

There is no restriction | limiting in particular as a solid lubricant used in this invention, What is necessary is just to select suitably according to deposited film formation conditions.
For example, a solid lubricant composed of WS ₂ , graphite, and BN has conductivity and heat resistance, and these are dispersed in a metal matrix material composed of a W-based alloy, a Cu-based alloy, and a Ni-based alloy, etc. Is mentioned.

The bearing and shaft in the present invention are not particularly limited as long as a solid lubricant is used on at least one sliding surface.
The axis in the present invention indicates a moving part, and there is no particular limitation on the form. For example, as described above, the rotary base 131 and the connection portion 148 for rotating the cylindrical base 102 may be rotated. In the present invention, the embodiment using both the turntable 131 and the connecting portion 148 as an axis has been described. However, as long as the base holder 112 can be rotated, either one of the axes may be used. For example, the form which reciprocates for moving components up and down or back and forth may be sufficient. As a form of reciprocating movement, a drive mechanism using a motor and a gear, an electromagnet, an air cylinder, or the like can be suitably used.

The bearing in the present invention is a component that supports the shaft by receiving a load in contact with the shaft that performs the rotational motion and the reciprocating motion as described above. The form of the bearing is not particularly limited, and a rolling bearing using the rolling motion of balls and “rollers” and a sliding bearing using a lubricating function are used.
In the present invention, driving means a state in which a rotational motion or a reciprocating motion is performed as described above.

  Hereinafter, the present invention will be described in more detail with reference to examples. In the following description, the same portions as those shown in the above-described embodiment will be described using the same reference numerals.

<Example 1>
The deposited film forming apparatus 100 shown in FIG. 1 is used to form a deposited film on the surface of the cylindrical substrate 102 made of aluminum having a diameter of 84 mm, a length of 381 mm, and a thickness of 3 mm under the conditions shown in Table 1. An a-Si electrophotographic photosensitive member having the layer structure shown in FIG. Reference numeral 301 denotes a cylindrical substrate, reference numeral 302 denotes a lower blocking layer (first layer), reference numeral 303 denotes a photoconductive layer (second layer), and reference numeral 304 denotes a surface layer (third layer).

  In this embodiment, the cleaning process was performed under the conditions shown in Table 2. First, a cleaning gas was introduced through the source gas introduction pipe 109 under the conditions of “Cleaning 1” in Table 2. During the cleaning 1, the turntable 131 and the connecting portion 148, which are rotating shafts, are driven, and the rotational speed of the cylindrical substrate 102 is set to 10 as shown in the “cleaning 1” column shown in Table 2. It was rotated at [rpm].

  During the cleaning process, a thermocouple was attached to the external surface of the exhaust pipe 123 on the reaction vessel 101 side connected to the exhaust main valve 125, and the temperature of the external surface of the exhaust pipe 123 was monitored. Then, when the temperature of the external surface of the exhaust pipe 123 exceeds a predetermined temperature (in this case, the temperature of 70 ° C.), it is determined that the cleaning process inside the reaction vessel 101 has ended, and the cleaning process conditions are shown in Table 2. Changed to “Cleaning 2”. That is, the drive state of the turntable 131 and the connection portion 148 that are the rotation shafts was changed from the rotation of 10 [rpm] to the rotation state of 2 [rpm]. The change of the rotation state is as shown in FIG. Thereafter, the cleaning process was performed until a predetermined cleaning process end time.

Further, in this embodiment, FW-430L manufactured by Fuji Dice Co., Ltd. including WS ₂ is used as the bearing 133 and the bearing 149, and nickel is processed into the turntable 131 and the connection portion 148 serving as a rotating shaft. I used something.
After replacing the bearing 133, the bearing 149, the turntable 131, and the connection portion 148 with new ones, the formation of the deposited film and the cleaning process were performed 30 times. Then, regarding the a-Si electrophotographic photosensitive member produced at the first time and the 30th time, evaluation of “axial charging unevenness” and “circumferential charging unevenness” was performed as follows.

(Evaluation of “axial charging unevenness” and “circumferential charging unevenness”)
For evaluation of charging unevenness of the a-Si electrophotographic photosensitive member, a copy machine (Canon copy machine iRC6880N) modified for surface potential measurement was used. When measuring the surface potential, the developing device was removed, and a potential probe (Model 344 manufactured by TREK) that can measure the surface potential at a predetermined position in the axial direction of the a-Si electrophotographic photosensitive member was attached instead of the developing device. .
The electrophotographic photosensitive member was charged with a process speed of 265 mm / sec, a pre-exposure (LED with a wavelength of 660 nm) light amount of 4 lx · s, and a current value of the main charger of 1000 μA.
At this time, the surface potential of the dark part of the electrophotographic photosensitive member was measured with a surface potential meter. Then, the center position of the electrophotographic photosensitive member was set to 0 position, and the potential of 8 points (± 4 cm, ± 8 cm, ± 12 cm, ± 16 cm) in total was measured at intervals of 4 cm on both sides in the axial direction.
Further, the potential at 36 points in the circumferential direction was measured for each 9 points.

"Axial charging unevenness"
At 9 points in the axial direction, an average value of the obtained potentials at 36 points in the circumferential direction was obtained. The potential difference between the maximum value and the minimum value of the average value at each position obtained was defined as axial charging unevenness.
"Circumferential charging unevenness"
At each nine points in the axial direction, the potential difference between the maximum value and the minimum value of the obtained 36 points in the circumferential direction was obtained. Among the nine points, the value having the largest potential difference was defined as circumferential charging unevenness.
The obtained results are shown in Table 3. All the evaluations were carried out by relative evaluation with the result of the a-Si electrophotographic photosensitive member produced in the first time obtained in Comparative Example 1 being 100.

<Example 2>
In this example, as in Example 1, an a-Si electrophotographic photosensitive member was produced. However, in this example, the cleaning process was performed as follows. First, a cleaning gas was introduced through the source gas introduction pipe 109 under the conditions of “cleaning 1” shown in Table 2. Then, over a predetermined time, the rotational speeds of the turntable 131 and the connecting portion 148 were linearly increased from 0 [rpm] (static state) at the start of the cleaning process to 10 [rpm]. In this embodiment, the predetermined time is a time when the temperature of the thermocouple attached to the surface of the heater for heating is from room temperature to 100 ° C. when the cleaning process is performed under the same conditions in advance. Thereafter, the rotational speed was constant at 10 [rpm], and the cleaning process was continued.

  Next, as in Example 1, the temperature of the thermocouple connected to the exhaust main valve 125 and attached to the outer surface of the exhaust pipe 123 on the reaction vessel 101 side exceeds a predetermined temperature (here, a temperature of 50 ° C.). At that time, the rotation speed was changed. The changing method was linearly changed from 10 [rpm] to 0 [rpm] (stationary state) until a predetermined cleaning processing end time. The relationship between the rotational speed and the elapsed time of the cleaning process is as shown in FIG. And the a-Si electrophotographic photoreceptor was produced like Example 1, and the same evaluation was performed.

<Example 3>
In this example, as in Example 1, an a-Si electrophotographic photosensitive member was produced. However, in this example, the cleaning process was performed as follows. First, a cleaning gas was introduced through the source gas introduction pipe 109 under the conditions of “cleaning 1” shown in Table 2. Then, at the start of the cleaning process, the turntable 131 and the connecting portion 148 which are rotating shafts were driven, and the cylindrical base body 102 was rotated at a rotational speed of 12 [rpm]. Then, the rotational speed was linearly changed until the end time of cleaning 1 determined in advance, and the rotational speed was set to 8 [rpm] at the end of cleaning 1. In the present embodiment, the predetermined end time of the cleaning 1 is the time during which the temperature of the thermocouple attached to the surface of the heater for heating is changed from room temperature to 110 ° C. when the cleaning process is performed under the same conditions in advance. It was. Next, the rotational speed was linearly changed from 8 [rpm] to 0 [rpm] (stationary state) until a predetermined cleaning processing time. The relationship between the rotation speed and the elapsed time of the cleaning process is as shown in FIG. And the a-Si electrophotographic photoreceptor was produced like Example 1, and the same evaluation was performed.

<Comparative Example 1>
In this comparative example, an a-Si electrophotographic photosensitive member was produced in the same manner as in Example 1. However, in this comparative example, the rotation speed of the cylindrical substrate 102 was stopped at 0 [rpm] during the cleaning process.
And the a-Si electrophotographic photoreceptor was produced like Example 1, and the same evaluation was performed.
<Comparative example 2>
In this comparative example, an a-Si electrophotographic photosensitive member was produced in the same manner as in Example 1. However, in this comparative example, the rotational speed of the cylindrical substrate 102 during the cleaning process was kept constant at 10 [rpm], and the drive was not changed during the cleaning process.
And the a-Si electrophotographic photoreceptor was produced like Example 1, and the same evaluation was performed.
<Comparative Example 3>
In this comparative example, an a-Si electrophotographic photosensitive member was produced in the same manner as in Example 1. However, in this comparative example, the rotational speed of the cylindrical substrate 102 during the cleaning process was kept constant at 2 [rpm], and the drive was not changed during the cleaning process.
And the a-Si electrophotographic photoreceptor was produced like Example 1, and the same evaluation was performed.

As can be seen from Table 3, according to the deposited film forming method of the present invention, it was found that uniformity of the electrical characteristics of the a-Si electrophotographic photoreceptor can be achieved.
About this reason, it estimates as follows.
After completion of the 30th cleaning process, the substrate holder 112 with the cylindrical substrate 102 and the cap 113 mounted thereon was placed inside the reaction vessel 101, and the pressure inside the reaction vessel 101 was changed to the atmospheric state in the state shown in FIG. Thereafter, the gate valve 106 was removed, and a check was made regarding the continuity between the surface of the cylindrical substrate 102 and the surface of the conductive rod 140. When the resistance between the surface of the cylindrical substrate 102 and the surface of the conductive rod 140 was measured with a tester by rotating the cylindrical substrate 102 at the same 10 [rpm] as that when the deposited film was formed, Example 1 Regarding Example 2, Example 3, and Comparative Example 2, it was stable during rotation. On the other hand, for Comparative Example 1, a fluctuation of several tens of Ω was observed during the rotation, and for Comparative Example 3, a fluctuation of several Ω was observed during the rotation. Thus, regarding Comparative Example 1 and Comparative Example 3, when the bearing 149 was replaced with a new one, it was stable during rotation as in Example 1 and Comparative Example 2.
From this, the reason why the resistance fluctuated in Comparative Example 1 and Comparative Example 3 is considered to be caused by the deterioration of the bearing 149 made of the solid lubricant.

Further, from Example 1, Example 2, Example 3, Comparative Example 2, and Comparative Example 3, the shaft 149 is driven during the cleaning process, so that the solid lubricant changes in quality on the sliding surface with the connection portion 148. It was found that the stability of conduction was improved. Furthermore, from Comparative Example 2 and Comparative Example 3, it was found that the higher the rotation speed, the better the conduction stability. Thus, by driving the shaft during the cleaning process, the non-uniform impedance in the vertical direction of the cylindrical substrate 102 is greatly reduced. Therefore, it has been found that the uniformity of plasma in the vertical direction is improved, and a uniform deposited film can be formed even after long-term use.
Further, when the cylindrical substrate 102 was rotated at 10 [rpm] in the same manner as described above and the runout during rotation was measured on the surface of the central portion of the cylindrical substrate 102 using a dial gauge, Example 1 Example 2 and Example 3, it was found that chatter and eccentricity were extremely small. On the other hand, in the comparative example 1, remarkable chatter was observed. When the periphery of the bearing 133 and the bearing 149 was observed, it was observed that there was a minute fixed object in which a part of the solid lubricant was altered on the sliding surface of the mating side as an axis. It turned out that it was not sliding.

  On the other hand, in Comparative Example 2 and Comparative Example 3, the amount of eccentricity was larger than in Example 1, Example 2, and Example 3, and occurrence of chatter in a short time was observed although it was irregular. When the bearing 133 and the bearing 149 were observed, it was found that the wear of the surface sliding with the counterpart as the shaft was progressing as compared with Example 1, Example 2, and Example 3. Therefore, it is considered that a gap is generated in the sliding surface portion between the bearing and the shaft, and the eccentricity amount is increased due to this, causing sudden chatter. The cause of the increased amount of wear compared to Example 1, Example 2, and Example 3 is estimated as follows.

When Example 1, Example 2, and Example 3 are compared with Comparative Example 3, in “Cleaning 1”, Example 1, Example 2, and Example 3 have higher rotational speeds. Therefore, the progress of corrosion due to the cleaning gas is reduced. However, since there are many rotation speeds, it becomes easy to advance about abrasion.
In “Cleaning 2”, there is no difference in the rotational speed. In “cleaning 2”, since the cleaning process (cleaning 1) inside the reaction container 101 has been completed, the temperature of the solid lubricant is lowered and corrosion is unlikely to proceed.
On the other hand, when comparing a corroded portion and a portion without corrosion, the amount of wear increases as the corrosion progresses even at the same rotational speed. This is because the amount of wear increases because the original smooth sliding cannot be achieved due to corrosion.
Therefore, Example 1, Example 2, and Example 3 suppress the increase in the amount of wear due to the influence of corrosion by suppressing the corrosion with “cleaning 1” in which corrosion easily proceeds. On the other hand, in Comparative Example 3, since the corrosion is not sufficiently suppressed by “Cleaning 1”, the rotational speed is lower than that of Example 1, Example 2, and Example 3, so that the mechanical wear condition is advantageous. The increase in wear due to corrosion becomes significant. Therefore, it is considered that the amount of wear is increased at the stage of cleaning 2 as compared with Example 1, Example 2, and Example 3.

Next, when Example 1, Example 2, and Example 3 are compared with Comparative Example 2, in “Cleaning 2”, Example 1, Example 2, and Example 3 rotate. Since the number is small, corrosion by the cleaning gas is likely to proceed, and since the number of rotations is small, it is difficult to proceed with respect to wear. However, in “cleaning 2”, since the cleaning process (cleaning 1) inside the reaction vessel 101 has been completed, the temperature of the solid lubricant is lowered, and corrosion is unlikely to proceed. Therefore, it is considered that the amount of wear is smaller in Examples 1, 2 and 3 where mechanical wear conditions are advantageous.
As described above, according to the present invention, when the temperature of the solid lubricant is high and the corrosion is likely to proceed, the corrosion is reduced by increasing the rotational speed. Further, when the temperature is low and corrosion is difficult to proceed, it is possible to reduce the wear by reducing the rotation speed, thereby making it possible to perform optimum corrosion and wear reduction.

As a result, according to the present invention, the shaft is driven during the cleaning process, and further, the driving state is changed during the cleaning process, thereby reducing the damage caused by the corrosion and friction of the cleaning gas of the solid lubricant. Can do. Thereby, a stable and uniform deposited film can be formed.
Therefore, even if the maintenance frequency is reduced, a stable and uniform deposited film can be formed, so that the deposited film can be formed at a low cost.

DESCRIPTION OF SYMBOLS 100 Deposited film formation apparatus 101 Reaction container 102 Cylindrical base | substrate 103 Cylindrical cathode electrode 104 Insulator 105 Upper wall 106 Gate valve 107 Bottom wall 108 Heating heater 109 Source gas introduction pipe 110 Matching box 111 High frequency power supply 112 Substrate holder 113 Cap 120 Connecting pipe 121 Mixing device 122 Source gas inflow valve 123 Exhaust pipe 124 Exhaust port 125 Exhaust main valve 126 Vacuum gauge 130 Rotation holding mechanism 131 Turntable (shaft)
132 support 133 bearing 134 motor 140 conductive rod 141 moving device 142 upper surface 143 hole 144 connection body 145 first contact 146 valve body 147 second contact 148 connection (shaft)
149 Bearing

Claims (2)

A reaction vessel, means for introducing a cleaning gas into the reaction vessel, means for exhausting the cleaning gas, a substrate holder for installing a substrate in the reaction vessel, and rotating the substrate holder An outer periphery of the substrate using a deposited film forming apparatus comprising a shaft for moving or reciprocating and a bearing for supporting the shaft, and at least one of the shaft and a sliding surface of the bearing is made of a solid lubricant. A deposited film forming method for forming a deposited film on a surface,
After forming a deposited film on the outer peripheral surface of the substrate, a cleaning gas is introduced into the reaction vessel, and a cleaning process is performed while rotating or reciprocating the shaft, and the rotation is performed during the cleaning process. A method for forming a deposited film, wherein the driving state of movement or reciprocation is changed. In the cleaning process, when the temperature of the solid lubricant is high by lowering the driving state when the temperature of the solid lubricant is lower than the driving state when the temperature of the solid lubricant is high 2. The deposited film forming method according to claim 1, which reduces corrosion of the solid lubricant and reduces wear of the solid lubricant when the temperature of the solid lubricant is low.

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