JP2006070299A - Deposited film forming method - Google Patents

Abstract

An object of the present invention is to provide a method for forming a deposited film having excellent productivity while improving deposited film characteristics by efficiently reducing dust.
A method for forming a deposited film comprising the following steps:
(1) A step of placing a substrate to be processed from a gate valve at a charging stage in a reaction vessel that can be decompressed;
(2) separating the reaction vessel from the input stage, moving the reaction container to the processing stage, and performing a deposited film forming process on the substrate to be processed;
(3) A step of removing the substrate to be processed from the reaction vessel through the gate valve in a reduced pressure state,
(4) a step of performing dry etching using a cleaning gas in the reaction vessel at the processing stage;
(5) separating the reaction vessel from the processing stage and moving it to the reaction vessel maintenance stage;
(6) A step of performing maintenance of at least the gate valve at the reaction vessel maintenance stage.
[Selection] Figure 1

Description

  The present invention relates to a method for forming a deposited film of a semiconductor device, an electrophotographic photoreceptor, an image input line sensor, a photographing device, a photovoltaic device, and the like.

  When installing the substrate to be processed in the reaction vessel, or when performing processing such as formation of a deposited film or etching on the substrate to be processed in the reaction vessel, the cleanliness of the atmosphere in the reaction vessel is the product quality, May have a significant impact on performance. For example, in the formation of a deposited film, the quality of the deposited film is deteriorated by the abnormal growth of the deposited film with dust attached to the processing surface of the substrate serving as a nucleus. Further, in the etching process, it may be impossible to etch an appropriate portion due to dust adhering to the processing surface of the substrate. Therefore, when the substrate to be processed is installed in the reaction vessel, and when the substrate to be processed is further subjected to processing such as formation of a deposited film or etching, it is common to remove unnecessary substances such as dust in the reaction vessel. Has been done.

  A processing method comprising a cleaning means for removing dust or unnecessary component substances existing in the reaction vessel from the reaction vessel by circulating the atmosphere in the reaction vessel through a removal filter or supplying a clean gas. It is disclosed (for example, see Patent Document 1).

  In addition, a pipe for introducing clean gas into the vacuum chamber and a dust exhaust pipe that opens to the vacuum chamber and is provided separately from the main exhaust system and exhausts dust are provided. A processing method is disclosed in which a part can be sprayed onto the surface of a workpiece (for example, see Patent Document 2).

  On the other hand, the configuration of the vacuum processing apparatus in which the reaction vessel and the exhaust device can be separated greatly increases the flexibility in production, and can improve the production efficiency and reduce the production cost (for example, see Patent Document 3).

JP 09-264575 A Japanese Patent Publication No. 05-073826 JP-A-10-168576

  By the above conventional method, dust in the reaction container can be efficiently removed outside the reaction container, and a product with improved quality can be produced.

  However, for example, in amorphous silicon photoconductors for electrophotographic apparatuses, as a result of improvements in the charging system, optical exposure system, developing system, etc. in the electrophotographic apparatus as the electrophotographic apparatus is digitized at high speed and full color is achieved. Also in the photoreceptor, improvement in image characteristics more than before has been demanded. As a result, there has been a demand for reduction of white spot-like and black-spot-like image defects, commonly referred to as “pochi”, in particular, reduction of “pochi” of a minute size that has not been a problem in the past. Most of the “pochi” is caused by “spherical protrusions” which are abnormal growth of the deposited film using dust adhering to the substrate as a nucleus. For this reason, it is required to further reduce the number of dust adhering to the substrate.

  Furthermore, in the configuration of the vacuum processing apparatus in which the reaction vessel and the exhaust device can be separated, since the treated substrate is carried out in a general atmosphere, the probability that dust will adhere to the processing apparatus will be greatly improved. There is a need for more efficient dust removal methods than ever before.

  Therefore, it has been desired to realize an early treatment method that can further prevent dust from adhering to the substrate and at the same time further improve production efficiency.

  Accordingly, the present invention aims to solve the above problems. That is, an object of the present invention is to provide a deposited film forming method having excellent productivity while improving the deposited film characteristics by efficiently reducing dust.

In order to achieve the above-described object, the method for forming a deposited film of the present invention includes (1) a substrate to be processed from a gate valve provided at a substrate carry-in / out port of the reaction vessel in a reaction vessel capable of being depressurized. Installing the process,
(2) separating the reaction vessel from the input stage, moving the reaction container to the processing stage, and performing a deposited film forming process on the substrate to be processed;
(3) A step of taking out the substrate to be processed from the reaction vessel from the gate valve in a reduced pressure state after the deposited film forming process is completed;
(4) Thereafter, in the processing stage, a step of performing dry etching using a cleaning gas on the reaction vessel,
(5) separating the reaction vessel from the processing stage and moving it to the reaction vessel maintenance stage;
(6) a step of performing maintenance of at least the gate valve provided at the substrate carry-in / out port at the reaction vessel maintenance stage;
It is characterized by having.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view of an example of a processing apparatus for processing an object to be processed by the deposited film forming method of the present invention.

  The processing apparatus of FIG. 1 includes a substrate loading stage, a processing stage, and a reaction vessel maintenance stage. Reference numeral 100 denotes a movable processing vessel section, which includes a reaction vessel 120, an exhaust gate valve 123, a substrate carry-in / out entrance gate valve 124, a pedestal 121, casters 122 as movable means, and an exhaust pipe 125.

  The movable unit 122 may be any unit that can move the movable processing container unit 100, and caster movement, belt movement, magnetic floating movement, air floating movement, and the like can be used. desirable.

  Reference numerals 150 and 250 denote exhaust means, and an exhaust pipe 101, a main exhaust valve 102, an internal pressure measuring device 103, a connection means 104, a slow exhaust valve 105, and a slow exhaust line 106 are connected to the exhaust means 150.

  An exhaust pipe 201, a main exhaust valve 202, an internal pressure measuring device 203, a connection mechanism 204, a pre-exhaust valve 252, and a pre-exhaust line 251 are connected to the exhaust means 250.

  The movable processing container unit 100 can be connected to the exhaust means 150 and 250 via the connection mechanisms 104 and 204.

  Reference numeral 250 denotes a gas supply and flow rate control means. The gas supply and flow rate control means 260 preferably includes a plurality of gas cylinders, regulators, valves, mass flow controllers and the like necessary for vacuum processing, and supplies a desired gas at a desired flow rate and mixing ratio. Any configuration is possible if possible. More preferably, it is desirable to include a purge gas cylinder and a purge line, which makes it possible to operate the gas safely. The raw material gas necessary for the processing is supplied from the gas supply and flow rate control means 260 into the reaction vessel 120 via the flow rate variable valve 261 and the connection mechanism 204.

  Further, it is desirable to provide a gas connection mechanism between the movable processing container 100 and the variable flow rate valve 261, and the gas connection mechanism is incorporated in the connection mechanism 204.

  The connection mechanisms 104 and 204 preferably have a flange structure for maintaining a vacuum, and any of an O-ring seal, a metal seal, and the like may be used as a vacuum seal. As a method for fixing the connection mechanisms 104 and 204 and the exhaust gate valve 123, any method using a bolt, a coupler, a clamp, or the like may be used, but it is more preferable that the connection mechanism 104 or 204 can be easily attached and detached.

  Reference numeral 400 denotes a substrate unloading container for unloading the processed substrate from the reaction container 120, and includes a unloading container 401 and a gate valve 402. Reference numeral 500 denotes a dummy loading container for loading a dummy substrate into the reaction container 120, which includes a loading container 501 and a gate valve 502.

  110 is a clean room, and a wall 111 of the clean room 110 is provided with a door 111 that can be opened and closed.

  112 is a clean booth for the input stage.

  The reaction vessel maintenance stage includes a normal atmosphere area 600 and a clean booth area 601. A differential pressure is provided between the clean booth 601 and the normal atmosphere area 600, and the clean booth 601 is set to a positive pressure.

  The deposited film forming method of the present invention using the processing apparatus shown in FIG. 1 can be performed roughly as follows.

  First, the movable processing container 100 is moved to the connection mechanism 104 of the substrate loading stage, and the exhaust gate valve 123 and the connection mechanism 104 are connected. Next, the substrate carry-in / out entrance gate valve 124 is opened, and the door 111 provided on the wall surface of the clean room 110 and capable of opening and closing the wall surface is opened. At this time, a differential pressure is provided in the clean room 110, the clean booth 112, and other areas, and the positive pressure is set in the order of the clean room 110> the clean booth 112> the other areas. Next, the substrate carry-in / out gate valve 124 is opened.

  A substrate (not shown) to be processed is installed in the reaction vessel 100 through the door 111 that can be opened and closed. After installation, when the substrate carrying-in / out gate valve 124 is closed and the inside of the reaction vessel 100 can be decompressed, the slow exhaust valve 105 is opened, and the slow exhaust line 106 is used to start decompressing the reaction vessel 100.

  When the internal pressure measuring device 103 reaches a predetermined value, the slow exhaust valve 105 is closed, the main exhaust valve 102 is opened, and the inside of the reaction vessel 100 is further decompressed. When the internal pressure measuring device 103 reaches a predetermined value, the main exhaust valve 102 and the exhaust gate valve 123 are closed, the space between the main exhaust valve 102 and the exhaust gate valve 123 is returned to the atmospheric pressure, and the movable processing container 100 is connected to the connection mechanism 104. Disconnect from.

  Next, the movable processing container unit 100 is manually transported to the processing stage by an operator, and the connection mechanism 204 of the processing stage and the exhaust gate valve 123 are connected. When the pre-exhaust valve 252 is opened, the pressure between the exhaust gate valve 123 and the main exhaust valve 202 is reduced, and when the internal pressure measuring device 203 reaches a predetermined value, the pre-exhaust valve 252 is closed, and the main exhaust valve 202 and the exhaust gate valve are closed. 123 is opened. Thereafter, the gas supply and flow rate control means 260 is driven to introduce a desired processing source gas into the processing container 120, and a predetermined deposited film forming process is performed.

Next, the reaction container 100 is purged, and when the reaction container 100 is sufficiently purged, the gate valve 402 of the substrate carrying-out container 400 and the substrate carrying-in / out gate valve 124 of the movable processing container unit 100 are connected. . The pressure between the gate valve for loading and unloading the substrate 124 and the gate valve 402 is reduced by an exhaust means (not shown). At this time, the inside of the unloading container 401 is
Reduce pressure. When an internal pressure measuring device (not shown) reaches a predetermined value, the substrate carry-in / out gate valve 124 and the gate valve 402 are opened. The processed substrate is moved from the reaction container 100 into the unloading container 401 by a substrate unloading mechanism (not shown) in the unloading container 401. The gate valve 402 and the substrate carry-in / out gate valve 124 are closed, the space between the gate valve 402 and the substrate carry-in / out gate valve 124 is returned to the atmospheric pressure, and the substrate carry-out container 400 is disconnected from the movable processing container 100.

Next, the gate valve 502 of the dummy loading container 500 and the substrate loading / unloading gate valve 124 of the movable processing container unit 100 are connected. The space between the gate valve 124 for loading / unloading the substrate and the gate valve 502 is reduced by an exhaust means (not shown). At this time, the inside of the carry-in container 501 is
Reduce pressure. When an internal pressure measuring instrument (not shown) reaches a predetermined value, the substrate carry-in / out gate valve 124 and the gate valve 502 are opened. A dummy substrate is placed in the reaction vessel 100 by a dummy carry-out mechanism (not shown) in the carry-in vessel 501. When a dummy unloading mechanism (not shown) returns into the loading container 501, the gate valve 502 and the substrate loading / unloading gate valve 124 are closed, and the space between the gate valve 502 and the substrate loading / unloading gate valve 124 is returned to the atmospheric pressure. The dummy carry-in container 500 is separated from the movable processing container 100.

  Thereafter, the gas supply and flow rate control means 260 is driven, a desired cleaning gas is introduced into the reaction vessel 120, and a predetermined dry etching process is performed.

  After the dry etching is completed, the inside of the reaction vessel 120 is sufficiently purged, the movable treatment vessel portion 100 is moved from the treatment stage to the normal atmosphere area 600 of the reaction vessel maintenance stage, the reaction vessel 120 is cooled as necessary, and leakage occurs. A valve (not shown) is opened, the reaction vessel 120 is returned to atmospheric pressure, and the dummy substrate is taken out.

  Next, maintenance of the substrate carry-in / out gate valve 124 is performed at the reaction vessel maintenance stage. After the maintenance of the substrate carry-in / out gate valve 124 is completed, the movable processing container portion 100 is again conveyed to the substrate loading stage, and the next process is performed.

  Next, FIG. 2 shows an example of maintenance of the gate valve in the plasma processing method of the present invention.

  FIG. 2A shows a state in which the dry reaction is finished and the working reaction vessel 100 is moved to the normal atmosphere area 600 of the reaction vessel maintenance stage as described above. Here, 124A represents a gate valve for carrying in / out a substrate that has already been cleaned.

  Maintenance of the gate valve can be generally performed as follows.

  First, the substrate carry-in / out gate valve 124 attached to the working reaction vessel 100 is removed in the normal atmosphere area 600. The removed substrate carry-in / out gate valve 124 is temporarily stored in the normal atmosphere area 600 (FIG. 2B). Next, the working reaction vessel 100 is moved to the clean booth area 601. Then, another substrate carrying-in / out gate valve 124A that has already been cleaned and stored in the clean booth area 601 is attached to the working reaction vessel 100 (FIG. 2C).

  On the other hand, the removed base carry-in / out gate valve 124 stored in the normal atmosphere area 600 is once disassembled and accommodates the valve plate, the valve seat, the sealing surface, the sealing material, the cylinder rod, and the like. Wipe and clean the existing gate chamber. Further, air blow is performed on each part to remove dust existing on the surface of each part. At this time, it is not essential to use wiping and air blow together, and either one may be used. The air blow may be blown individually using a blow device such as an air gun, or may be installed in a private room such as an air shower room and air blow may be performed for a predetermined time.

  At this time, the cleanliness of each component is a cleanliness of class 3 or higher according to ISO cleanliness standards.

  Thereafter, the parts are assembled in the clean booth area 601 and stored as a cleaned substrate carry-in / out gate valve for the active reaction vessel that is then moved to the reaction vessel maintenance stage.

  Next, FIG. 3 shows another example of the maintenance of the gate valve in the plasma processing method of the present invention.

  In FIG. 3, reference numeral 124 denotes the above-mentioned substrate carry-in / out gate valve. Reference numeral 301 is an air cylinder, 302 is a cylinder rod, and 303 is a base connected to the cylinder rod 302. 304 is a valve plate, 305 is a sealing material, and an O-ring. Reference numeral 306 denotes an opening on the reaction vessel 120 side. Reference numeral 307 denotes a spring connecting the base 303 and the valve plate 304, and reference numeral 308 denotes a roller. Reference numeral 309 denotes a gate chamber that houses the components of the gate valve 124. Reference numeral 310 denotes a blow nozzle, and the blowout port 311 faces the operating part side.

  The maintenance of the gate valve 124 can be generally performed as follows.

  First, the substrate carry-in / out gate valve 124 is opened, and the blow nozzle 310 is installed as shown in FIG. Next, clean air is blown from the outlet 311 toward the operating portion of the gate valve 124.

  At this time, it is necessary to spray at least the reaction vessel 120 side of the valve plate 304 (the lower side in FIG. 3). Further, the blowout port 311 may be moved up and down, left and right, for example, or the blowout may be blown intermittently rather than continuously. Doing so is more effective and more preferable for removing dust. Moreover, the blowing pressure of clean air is implemented by 0.02 MPa-0.6 MPa, for example. If the discharge pressure is less than 0.02 MPa, it takes time to clean the operating part of the gate valve 124. On the other hand, when the blowing pressure is larger than 0.6 MPa, turbulent flow is generated in the vicinity of the gate valve 124, and dust may not be discharged well.

  As for the spraying time, a dust counter (not shown) is installed in the vicinity of the valve plate 304, and when the measured value is ISO cleanliness standard and cleanliness of class 3 or higher is obtained, spraying is stopped. The dust counter does not need to be performed every time, but may measure once, determine the time for the measured value to reach a predetermined value, and then manage at the determined time.

  Furthermore, in addition to the cleanliness of the gate valve 124 described above, the reaction vessel 120 may be cleaned. To clean the reaction vessel 120, the components in the reaction vessel 120 are replaced with cleaned components in the same manner as the gate valve 124, or clean air is reacted in the same manner as in the gate valve 124. The method of blowing in the container 120 is mentioned. This is more preferable from the viewpoint of reducing dust.

  In addition, by preparing a plurality of movable processing container parts 100, cleaning of the gate valve as described above is performed while another movable processing container part 100 is performing the deposited film forming process. Downtime can be prevented, which is more preferable.

  As described above, spraying clean air toward the working part of the gate valve, replacing parts in the reaction vessel 120, and blowing clean air into the reaction vessel 120 are performed in a clean atmosphere such as a clean booth. Is done.

  Conventionally, the substrate to be processed before the formation of the deposited film is strictly cleaned and installed in the reaction vessel in a dust-controlled environment such as a clean room so as to prevent dust from adhering to the substrate to be processed as much as possible. I did it. Although the substrate to be processed is transported into the reaction vessel in such a clean state, dust may adhere to it and adversely affect the characteristics after the deposited film is formed.

  As a result of extensive studies by the present inventors regarding the adhesion of dust, it has been found that the gate valve attached to the reaction vessel is one factor of dust generation.

  Since the gate valve is provided with a mechanically driven mechanism, vibration is generated by driving. Also, depending on the type of gate valve, there may be a portion that physically rubs.

  Therefore, it is considered as a component in which dust is relatively easily generated.

  When the gate valve is driven to install the substrate to be processed in the reaction vessel, even if dust is generated, there is no influence unless the substrate to be processed is present in the vicinity of the gate valve.

  However, after the substrate to be treated is installed in the reaction vessel, it is necessary to drive the gate valve in order to reduce the pressure of the reaction vessel or to maintain the reduced pressure state. At this time, when dust is generated from the gate valve, the substrate to be processed is present directly under the gate valve, so that it is directly affected by the dust. In particular, it becomes remarkable when the gate valve is driven at a low vacuum pressure. That is, for example, in the case of pressure, the generated dust floats in the space. As a result, the number of particles per unit time increases in a certain space. Conversely, when performed at a high vacuum pressure, the generated dust is considered to fall in a short time without floating too much.

In the present invention, after the deposited film is formed, the substrate to be processed is taken out from the reaction vessel under reduced pressure. When the deposited film is formed on the substrate to be processed, the deposited film is formed not only on the substrate to be processed but also in the reaction vessel, the reaction vessel side of the valve plate of the gate valve, or the like. At this time, when the reaction vessel is returned to atmospheric pressure and the substrate to be treated is taken out, for example, a deposited film on the valve plate of the gate valve is taken as an example.
(1) Moisture is adsorbed on the deposited film, the stress in the deposited film changes, and the deposited film is easily peeled off from the valve plate surface.
(2) When cooled and taken out, the deposited film is easily peeled off from the valve plate surface due to the difference in thermal expansion coefficient between the deposited film and the valve plate.

  As a result, film peeling may occur at the time of removal, and the inside of the gate chamber may be contaminated.

  According to the deposited film forming method of the present invention, after the deposited film is formed, the substrate to be processed is taken out from the reaction vessel in a reduced pressure state, so that the film peeling due to the above (1) and (2) can be suppressed. It is effective for preventing dust contamination inside. As a result, the gate valve described later can be cleaned effectively and in a short time.

  Furthermore, according to the deposited film forming method of the present invention, after carrying out dry etching, the reaction vessel is separated from the film forming stage, and the gate valve is cleaned.

  This is because the film peeling due to the above (1) is suppressed by removing the deposited film once deposited on the substrate other than the substrate to be processed by dry etching. Furthermore, after dry etching is performed, the following effects can be obtained by separating the reaction vessel from the film formation stage.

  As described above, the deposited film is deposited not only on the substrate to be processed, but also on the inner surfaces of the connection mechanism 204 and the exhaust pipe 201 of the film forming stage as well as in the reaction vessel. When the mobile reaction vessel 100 is separated from the film formation stage after the deposition film forming process is completed without dry etching, the deposited films on the inner surfaces of the connection mechanism 204 and the exhaust pipe 201 are accumulated, and the film may easily peel off. . When the mobile reaction vessel 100 is separated, the entire film forming stage is contaminated. In addition, when the mobile reaction vessel 100 is connected and film peeling occurs during the deposition film forming process, if a film piece of a certain size is scattered in the plasma, the plasma is disturbed, and the deposited film characteristics May be affected. Further, it may be necessary to stop the deposition stage to some extent in order to remove the accumulated deposited film.

  According to the deposited film forming method of the present invention, after dry etching is performed, the reaction vessel is separated from the deposition stage, thereby suppressing accumulation of deposited films on the inner surfaces of the connection mechanism 204 and the exhaust pipe 201 as described above. Therefore, the deposited film processing can be carried out stably. Furthermore, since the operation of removing the deposited film accumulated on the inner surfaces of the connection mechanism 204 and the exhaust pipe 201 is substantially unnecessary, the operating rate of the apparatus is also improved.

  Furthermore, according to the deposited film forming method of the present invention, the gate valve is cleaned for each deposited film forming process.

As described above, the deposited film is removed by dry etching. But,
(3) Depending on the configuration of the reaction container, the deposited film may not be completely removed.
(4) Although the deposited film is removed, an etching residue may be generated depending on the apparatus configuration or the quality of the deposited film.

  The etching residue means a substance newly generated by the reaction between the etching gas and the deposited film, not the unetched film residue as in (3).

  In (3) and (4), the existence ratio varies depending on the deposited film and the gas type of dry etching. However, when both are present in the gate valve, it can become dust by driving the gate valve. is there.

  According to the deposited film forming method of the present invention, since the gate valve is cleaned for each deposited film forming process, the generation of dust can always be greatly reduced regardless of the type of the deposited film and the dry etching conditions. .

  Furthermore, the present invention separates the reaction vessel and the exhaust device to form a deposited film. Therefore, by preparing a plurality of reaction vessels, even if the gate valve is cleaned for each deposited film forming process, the The deposited film forming process can be performed at the operating rate.

As described above, (1) the step of installing the substrate to be processed from the gate valve provided at the substrate loading / unloading port of the reaction vessel at the charging stage in the depressurized reaction vessel of the present invention,
(2) separating the reaction vessel from the input stage, moving the reaction container to the processing stage, and performing a deposited film forming process on the substrate to be processed;
(3) A step of taking out the substrate to be processed from the reaction vessel from the gate valve in a reduced pressure state after the deposited film forming process is completed;
(4) Thereafter, in the processing stage, a step of performing dry etching using a cleaning gas on the reaction vessel,
(5) separating the reaction vessel from the processing stage and moving it to the reaction vessel maintenance stage;
(6) a step of performing maintenance of at least the gate valve provided at the substrate carry-in / out port at the reaction vessel maintenance stage;
By the deposited film forming method having the above, the adhesion of dust on the substrate is greatly reduced, and at the same time, the production efficiency is improved.

  The means for forming a deposited film in the present invention is not particularly limited, and examples thereof include a plasma CVD method, a thermal CVD method, a sputtering method, and an ion plating method.

The dry etching method in the present invention is not particularly limited and may be appropriately selected according to the type of the deposited film. Examples of the cleaning gas include CF ₄ , CF ₄ / O ₂ , SF ₆ , and ClF ₃ (chlorine trifluoride).

  Further, in the present embodiment, it is effective to adjust the concentration by using an inert gas for dilution in order to adjust the concentration of the cleaning gas. As the introduced inert gas, for example, He, Ne, Ar are mentioned.

  Further, at the time of dry etching, for example, high frequency power may be input into the reaction vessel to form plasma.

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

  In the deposited film forming method of the present invention as described above using the apparatus shown in FIG. 4 as the working reaction vessel 100 using the deposited film forming apparatus shown in FIG. 1, the diameter is 80 mm and the length is made of aluminum. An amorphous silicon electrophotographic photosensitive member having a layer structure shown in FIG. 5 was formed on a cylindrical substrate 412 having a thickness of 358 mm and a thickness of 3 mm under the conditions shown in Table 1. In FIG. 5, reference numeral 501 denotes a cylindrical substrate, reference numeral 502 denotes a lower blocking layer (first layer), reference numeral 503 denotes a first photoconductive layer (second layer), and reference numeral 504 denotes a surface layer (third layer). ) Respectively.

FIG. 4 shows an RF (Radio Frequency) -CVD (Chemical) using a high frequency of 13.56 [MHz] band.
1 is a longitudinal sectional view schematically showing an example of a deposited film forming apparatus 100 for producing an electrophotographic photoreceptor by a Vapor Deposition method.

  The deposited film forming apparatus 100 includes a cylindrical reaction vessel 120 for forming a deposited film on the cylindrical substrate 412 by plasma processing, a heater 413 for heating the cylindrical substrate 412, and the inside of the cylindrical reaction vessel 120. A substrate holder 417 for holding a cylindrical substrate 412 disposed in the chamber, and a source gas introduction pipe 414 for introducing a source gas into the cylindrical reaction vessel 120.

  The cylindrical substrate 412 only needs to have a material corresponding to the purpose of use. As the material of the cylindrical substrate 412, for example, copper, aluminum, gold, silver, platinum, lead, nickel, cobalt, iron, chromium, molybdenum, titanium, stainless steel, and the like are preferable because of their good electrical conductivity. However, aluminum is optimal in consideration of workability and manufacturing cost. Moreover, as aluminum which forms the cylindrical base | substrate 412, it is preferable to use either an Al-Mg type alloy or an A-Mn type alloy, for example.

  The heating heater 413 is provided inside the base holder 417. The heating heater 413 may be a heating element that can be used in a vacuum. Specifically, an electric resistance heating element such as a sheath heater, a plate heater, a ceramic heater, or a carbon heater, a halogen lamp, an infrared lamp, etc. Examples of the heat radiation lamp heating element such as a heat radiation lamp and the like, and a heating element by heat exchange means using a liquid, gas, or the like as a heat medium, are examples. As the surface material of the heater 413, metals such as stainless steel, nickel, aluminum, and copper, ceramics, heat resistant polymer resins, and the like can be used.

  A high frequency power source 416 is electrically connected to the cylindrical reaction vessel 120 via a high frequency matching box 415. These are connected to the cylindrical reaction container 120 when the working reaction container 100 moves to the film forming stage.

  The cylindrical reaction vessel 120 is insulated from the lower plate 418 of the cylindrical reaction vessel 120 serving as the ground plane and the substrate carry-in / out gate valve 124 by an insulator 419 made of ceramics. Further, the whole is covered with a metal shield wall 411 having a ground potential.

  Further, a rotation support mechanism 420 that rotatably supports a substrate holder 417 that holds the cylindrical substrate 412 is provided at the lower portion of the cylindrical reaction vessel 120. The rotation support mechanism 420 includes a turntable 421 on which a base holder 417 is placed, a support shaft 422 that supports the turntable, and a motor 423 for rotating the turntable 421.

  The cylindrical base body 412 is mounted on the base body holder 417 and rotated around the axis of the support shaft 422 together with the turntable 421.

  A procedure of a method for forming a deposited film using the deposited film forming apparatus 100 configured as described above will be described below.

  In the deposited film forming apparatus 100 transported to the processing stage, the connection mechanism 204 of the processing stage and the exhaust gate valve 123 are connected. The pre-exhaust valve 252 is opened, the pressure between the exhaust gate valve 123 and the main exhaust valve 202 is reduced, and when the internal pressure measuring device 203 reaches a predetermined value, the pre-exhaust valve 252 is closed, the main exhaust valve 202, and the exhaust gate Open the valve 123.

  Subsequently, a raw material gas, for example, a gas such as Ar or He, required for heating the cylindrical substrate 412 is introduced into the cylindrical reaction vessel 120 via the gas supply and flow rate control means 260 and the raw material gas introduction pipe 414, and the exhaust means. Using 250, the inside of the cylindrical reaction vessel 120 is adjusted to a predetermined pressure while looking at the internal pressure measuring device 203. In this example, the conditions shown in Table 1 were used.

  Next, after a predetermined pressure is reached, the temperature of the cylindrical substrate 412 is about 200 [° C.] to 450 [° C.], more preferably about 250 [° C.] to 350 [° C.] by the heater 413 for heating. Control to temperature. In this embodiment, the temperature is 260 [° C.].

  After the preparation for forming the deposited film is completed by the above procedure, a photoconductive layer is formed on the cylindrical substrate 412.

  That is, the raw material gas for heating and the raw material gas for forming the deposited film are mixed and introduced via the gas supply and flow rate control means 260 and adjusted so that the raw material gas has the flow rate shown in Table 1. At that time, the rotational frequency of a mechanical booster pump (not shown) of the exhaust means 250 is adjusted while checking the internal pressure measuring device 203 so that the inside of the cylindrical reaction vessel 120 becomes the pressure shown in Table 1.

  After the pressure in the cylindrical reaction vessel 120 is stabilized, the high frequency power source 416 is set to a desired power, for example, about 10 [MHz] to 45 [MHz]. In this embodiment, the frequency is 13.56 [MHz]. A high frequency glow discharge is generated by supplying high frequency power to the cylindrical reaction vessel 120 via the high frequency matching box 415 using the RF power source.

  By this discharge energy, the raw material gas introduced into the cylindrical reaction vessel 120 is decomposed, and a deposited film mainly containing desired silicon atoms is formed on the cylindrical substrate 412.

  In order to form a uniform deposited film, the cylindrical substrate 412 is rotated at the same time as the deposited film is formed or at the stage where the cylindrical substrate 412 is heated. The motor 423 is rotated and rotated at a rotational speed of about 1 [rpm] to 10 [rpm], in this embodiment, 1 [rpm]. By doing so, a uniform deposited film is formed in the circumferential direction of the cylindrical substrate 412.

  When a multi-layered electrophotographic photosensitive member is manufactured as shown in Table 1, the rotational frequency of the mechanical booster pump is adjusted as needed so that the value of the internal pressure measuring device 203 becomes the value shown in Table 1 for each layer. .

  In this way, a deposited film is formed on the outer peripheral surface of the cylindrical substrate 412.

Next, after the deposited film is formed, the supply of the source gas and the high frequency power is stopped, and the inside of the cylindrical reaction vessel 120 is exhausted. Thereafter, the inside of the cylindrical reaction vessel 120 and the source gas introduction pipe 414 is purged gas, for example, inert gas such as Ar and N 2.
The purge process is performed using at least one of the above. In this example, N2 was used. After the purge process is completed, the processed cylindrical substrate 412 is taken out from the cylindrical reaction vessel 120 in the reduced pressure state using the substrate carrying-out vessel 400 as described above, and then the cylindrical reaction is carried out using the dummy carrying-in vessel 500. A dummy (not shown) was installed in the container 120.

  Thereafter, the deposited by-product such as polysilane is subjected to a cleaning process.

The inside of the cylindrical reaction vessel 120 is exhausted by the exhaust means 250. Subsequently, the raw material gas required for the cleaning process through the gas supply and flow rate control means 260 and the raw material gas introduction pipe 414 in the cylindrical reaction vessel 120. In this embodiment, as shown in Table 1, the mixture of Ar and ClF ₃ Gas and the like are introduced, and the exhaust means 250 is used to adjust the inside of the cylindrical reaction vessel 120 to the pressure shown in Table 1 while looking at the internal pressure measuring device 203.

  After the pressure in the cylindrical reaction vessel 120 is stabilized, the high-frequency power source 416 is set to the power shown in Table 1, for example, about 10 [MHz] to 45 [MHz]. In this embodiment, the frequency is 13.56 [MHz]. The high frequency glow discharge is generated by supplying high frequency power to the cylindrical reaction vessel 120 via the high frequency matching box 415 using the RF power source of FIG. With this discharge energy, the cleaning source gas introduced into the cylindrical reaction vessel 120 is decomposed, and the inside of the cylindrical reaction vessel 120 is cleaned.

Next, the supply of high frequency power is stopped after the cleaning process, and the inside of the cylindrical reaction vessel 120 is evacuated. Thereafter, the inside of the cylindrical reaction vessel 120 and the raw material gas introduction pipe 414 is purged using a purge gas, for example, at least one of an inert gas such as Ar and N ₂ . In this example, N ₂ was used. After completion of the purge process, the working reaction container 100 was separated from the film forming stage as described above.

  In the present embodiment, the maintenance of the gate valve was performed by replacing the gate valve with a cleaned one as described above.

As described above, 10 lots of electrophotographic photoreceptors were continuously produced, and the “number of spherical protrusions” was evaluated on the produced electrophotographic photoreceptor as follows.
`` Number of spherical protrusions ''
The surface of the produced electrophotographic photosensitive member was observed with an optical microscope, and the number of spherical protrusions of 15 μm or more per 10 cm ² was examined. A smaller value indicates fewer image defects and better image quality.

  Relative evaluation was performed on the result of Comparative Example 1 below with respect to the “number of spherical protrusions”.

  The results are shown in Table 2.

  In Table 2, the value obtained in the first lot of Comparative Example 1 is set to 100.

  As in Example 1, an amorphous silicon electrophotographic photosensitive member having a layer structure shown in FIG. 5 was formed on a cylindrical substrate 412 made of aluminum having a diameter of 80 mm, a length of 358 mm, and a thickness of 3 mm under the conditions shown in Table 1. went.

  However, in this example, the maintenance of the gate valve was performed by a method of blowing clean air on the operation part of the gate valve.

  Except for this, an electrophotographic photosensitive member was produced in the same manner as in Example 1, and the same evaluation as in Example 1 was performed.

  The obtained results are shown in Table 2.

  As in Example 1, an amorphous silicon electrophotographic photosensitive member having a layer structure shown in FIG. 5 was formed on a cylindrical substrate 412 made of aluminum having a diameter of 80 mm, a length of 358 mm, and a thickness of 3 mm under the conditions shown in Table 1. went.

However, in this example, the cylindrical reaction vessel 120
Of these, the gas introduction pipe 413 was also cleaned. To clean the gas introduction pipe 413, the gas introduction pipe 413 was once removed from the cylindrical reaction vessel 120, the surface was washed with alcohol, and then the surface and the inner face of the gas introduction pipe 413 were each blown with clean air for 1 minute.

  Except for this, an electrophotographic photosensitive member was produced in the same manner as in Example 1, and the same evaluation as in Example 1 was performed.

The obtained results are shown in Table 2.
<Comparative Example 1>
Similarly to Example 1, an amorphous silicon electrophotographic photosensitive member having a layer structure shown in FIG. 3 was formed on a cylindrical substrate 412 made of aluminum having a diameter of 80 mm, a length of 358 mm, and a thickness of 3 mm under the conditions shown in Table 1. went.

  However, in this comparative example, the gate valve was not maintained, and was produced continuously.

  Except for this, an electrophotographic photosensitive member was produced in the same manner as in Example 1, and the same evaluation as in Example 1 was performed.

  The obtained results are shown in Table 2.

  As is apparent from Table 2, according to the deposited film forming method of the present invention, dust adhering to the surface of the substrate to be processed can be greatly reduced, and a high-quality deposited film can be stably formed. It turned out that. Further, it has been found that it is more effective to clean the parts in the reaction vessel simultaneously with the cleaning of the gate valve.

  As in Example 2, an amorphous silicon electrophotographic photosensitive member having a layer structure shown in FIG. 5 was formed on a cylindrical substrate 412 made of aluminum having a diameter of 80 mm, a length of 358 mm, and a thickness of 3 mm under the conditions shown in Table 1. went.

  In this example, the maintenance of the gate valve was performed by a method of blowing clean air to the operation part of the gate valve as described in Example 2.

  Then, an electrophotographic photosensitive member was produced in the same manner as in Example 2, and the same evaluation as in Example 2 was performed with respect to the “number of spherical protrusions”.

Further, the “cleaning time” was evaluated as follows.
"Cleaning time"
During maintenance of the gate valve, a dust counter (not shown) is installed in the vicinity of the valve plate 304, and after clean air is blown, the measured value is an ISO cleanliness standard and a cleanliness of class 3 or higher is obtained. Time was measured.

  Regarding “the number of spherical protrusions”, as in Example 2, the results of Comparative Example 1 were subjected to relative evaluation. That is, the value obtained in the first lot of Comparative Example 1 is set to 100.

  With respect to “cleaning time”, relative evaluation was performed on the results of Comparative Example 2 below. That is, the value obtained in the first lot of Comparative Example 2 is set to 100.

The results are shown in Table 3.
<Comparative example 2>
As in Example 2, an amorphous silicon electrophotographic photosensitive member having the layer structure shown in FIG. 3 was formed on a cylindrical substrate 412 made of aluminum having a diameter of 80 mm, a length of 358 mm, and a thickness of 3 mm under the conditions shown in Table 1. went.

  However, in this comparative example, the cylindrical substrate 412 having been subjected to the deposited film formation is returned to the atmospheric pressure of the reaction vessel 120, the substrate carrying-in / out gate valve 124 is opened and taken out, and then a dummy is placed in the reaction vessel 120. did. Then, the substrate carry-in / out gate valve 124 was closed, and the pre-exhaust valve 252 and the main exhaust valve 202 were used to reduce the pressure in the reaction vessel 120 to perform dry etching.

  Except for this, an electrophotographic photoreceptor was prepared in the same manner as in Example 2, and the same evaluation as in Example 2 was performed.

  The obtained results are shown in Table 3.

表３から明らかなように、本発明の堆積膜形成方法によれば、短い清浄化時間で、被処理基体表面に付着する塵埃を大幅に低減することができ、安定して高品位の堆積膜を形成することが可能であることが分った。

As is apparent from Table 3, according to the deposited film forming method of the present invention, the dust adhering to the surface of the substrate to be processed can be greatly reduced in a short cleaning time, and the deposited film can be stably high quality. It was found that it is possible to form

  As in Example 1, an amorphous silicon electrophotographic photosensitive member having a layer structure shown in FIG. 5 was formed on a cylindrical substrate 412 made of aluminum having a diameter of 80 mm, a length of 358 mm, and a thickness of 3 mm under the conditions shown in Table 1. went.

Then, an electrophotographic photosensitive member was prepared in the same manner as in Example 1, and “charging ability” was evaluated as follows with respect to “charging ability”.
The process speed is 265 mm / sec, the pre-exposure (LED with a wavelength of 680 nm) light amount of 4 lx · s, and the current value of the charger is set constant. The surface potential at the middle position of the electrophotographic photosensitive member is measured by using a surface potential meter (TREK Model 344) set at the charger position. The value obtained at this time is defined as charging ability.

  Relative evaluation was performed on the results of Comparative Example 3 below with respect to “charging ability”. The results are shown in Table 4.

In Table 4, the value obtained in the first lot of Comparative Example 3 is set to 100.
<Comparative Example 3>
Similarly to Example 5, an amorphous silicon electrophotographic photosensitive member having a layer structure shown in FIG. 3 was formed on a cylindrical substrate 412 made of aluminum having a diameter of 80 mm, a length of 358 mm, and a thickness of 3 mm under the conditions shown in Table 1. went.

  However, in this comparative example, after the dummy is installed in the reaction vessel 120, the exhaust gate valve 123 and the main exhaust valve 202 are closed, and the space between the exhaust gate valve 123 and the main exhaust valve 202 is returned to the atmospheric pressure, thereby moving the movable reaction vessel. 100 was disconnected from the connection mechanism 104. Then, the movable reaction vessel 100 was connected to another exhaust means, and dry etching was performed there. That is, the deposited film forming process and the dry etching process were performed at different locations.

  Except this, an electrophotographic photosensitive member was produced in the same manner as in Example 5, and the same evaluation as in Example 5 was performed.

  Table 4 shows the obtained results.

  As is apparent from Table 4, it was found that according to the deposited film forming method of the present invention, it is possible to stably form a high-quality deposited film.

  A decrease in charging ability was observed in the fifth lot of Comparative Example 3. At this time, discharge disturbance was observed in the latter half of the photoconductive layer formation. After detaching the movable reaction vessel 100 from the connection mechanism 104, when the connection mechanism 204 and the inner surface of the exhaust pipe 101 are observed, film peeling is observed on the inner wall, and a large amount of film pieces are present away from the film peeling portion. It was confirmed that it was scattered. It is considered that this film peeling disturbed the discharge, and as a result, the charging ability was lowered.

  Furthermore, since the film on the inner surface of the connection mechanism 204 and the exhaust pipe 101 is removed, the film forming stage cannot be temporarily used.

It is sectional drawing which shows typically an example of the deposited film formation apparatus which concerns on the deposited film formation method of this invention. It is sectional drawing which shows typically an example of the cleaning of the gate valve of the deposited film formation method of this invention. It is sectional drawing which shows typically an example of the cleaning of the gate valve of the deposited film formation method of this invention. It is sectional drawing which shows typically an example of the deposited film formation apparatus which concerns on the deposited film formation method of this invention. It is a schematic diagram showing an example of a layer structure of an amorphous silicon electrophotographic photoreceptor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Movable reaction container part 101,201 Exhaust piping 102,202 Main exhaust valve 105 Slow exhaust valve 106 Slow exhaust line 110 Clean room 111 Door 112,601 Clean booth 120 Reaction container 123 Exhaust gate valve 124,124A Substrate carrying-in / out gate valve 150, 250 Exhaust means 412 Cylindrical substrate 413 Heater 414 Gas introduction tube 415 High frequency matching box 416 High frequency power source 417 Substrate holder 418 Lower plate 419 Insulator 420 Rotating mechanism 400 Substrate unloading container 500 Dummy loading container 600 Normal atmosphere area 601 Clean booth area

Claims (3)

(1) A step of installing a substrate to be processed from a gate valve provided at a substrate carry-in / out port of the reaction vessel at a charging stage in a depressurizable reaction vessel;
(2) separating the reaction vessel from the input stage, moving the reaction container to the processing stage, and performing a deposited film forming process on the substrate to be processed;
(3) A step of taking out the substrate to be processed from the reaction vessel from the gate valve in a reduced pressure state after the deposited film forming process is completed;
(4) Thereafter, in the processing stage, a step of performing dry etching using a cleaning gas on the reaction vessel,
(5) separating the reaction vessel from the processing stage and moving it to the reaction vessel maintenance stage;
(6) a step of performing maintenance of at least the gate valve provided at the substrate carry-in / out port at the reaction vessel maintenance stage;
A method for forming a deposited film, comprising:   The deposited film forming method according to claim 1, wherein the maintenance of the gate valve is replaced with a cleaned gate valve.   The deposited film forming method according to claim 1, wherein the maintenance of the gate valve is performed by blowing a gas to an operation part of the gate valve.

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