JP2010077500A - Method for forming deposited film and method for manufacturing amorphous silicone photoreceptor - Google Patents

Abstract

The present invention provides a method capable of stably forming a functional deposited film having a large area in the film thickness direction. In particular, a method for producing a high-quality electrophotographic photoreceptor excellent in charging characteristics at low cost with high productivity is provided.
In a deposition film forming method, a substrate is placed in a vacuum-tight reaction vessel, a source gas containing silicon atoms is decomposed by high-frequency power, and a deposited film is formed on the substrate. A gas containing chlorine trifluoride is supplied into an exhaust pipe connecting the reaction vessel and the exhaust means.
[Selection] Figure 1

Description

  The present invention relates to a deposited film forming method for forming an amorphous silicon (hereinafter also referred to as “a-Si”) deposited film on a substrate by glow discharge plasma CVD (Chemical Vapor Deposition), and an electrophotography using the a-Si film. The present invention relates to a method for producing a photoreceptor (amorphous silicon photoreceptor).

Several semiconductor devices using a non-single crystalline deposited film containing silicon (silicon) atoms represented by a-Si as a main component have been proposed. Among them, the electrophotographic photosensitive member makes the most of the characteristics of the a-Si film that are high performance, high durability, and non-polluting.
Some of such non-single crystalline deposited films have been put into practical use. As a method for forming a deposited film, there are a number of conventional methods such as sputtering, thermal CVD for decomposing source gas by heat, photo-CVD for decomposing source gas by light, and plasma CVD for decomposing source gas by plasma. It has been known.

  Among them, the plasma CVD method is currently in practical use as a method for forming an a-Si deposited film for electrophotography, and various manufacturing apparatuses have been proposed. Specifically, the raw material gas is decomposed by glow discharge such as direct current or high frequency (RF, VHF) or microwave, and a thin deposited film is formed on a conductive substrate such as aluminum. For example, photoconductivity in which a surface protective layer made of a non-photoconductive amorphous material is provided on a photoconductive layer mainly made of silicon atoms and made of an amorphous material containing at least one of a hydrogen atom and a halogen atom. Members are known. This surface protective layer is composed of a non-photoconductive amorphous material containing hydrogen atoms based on silicon atoms and carbon atoms.

In the conventional plasma CVD method, a raw material gas is introduced into a reaction vessel made of a material such as a metal or a quartz tube, and then high frequency power energy is applied to decompose the raw material gas in the reaction vessel. A deposited film is formed on the substrate. At this time, a method of exhausting exhaust gas remaining in the reaction vessel through an exhaust pipe connected to an exhaust means such as a vacuum pump is generally performed.
A method of forming a deposited film such as a-Si by such a conventional technique is performed as follows, for example.

FIG. 5 is a diagram schematically showing an example of a deposited film forming apparatus for RF plasma CVD using a 13.56 MHz high-frequency power source, which is used for producing an electrophotographic photosensitive member.
This apparatus is roughly divided into a reaction apparatus 5100, a gas supply apparatus 5200, and an exhaust apparatus (not shown) for exhausting the inside of the reaction apparatus 5100.
The reaction vessel 5101 includes a high-frequency electrode 5111 insulated from the upper lid 5110 and the bottom plate 5126 by an insulating member 5121. A cylindrical base 5112 connected to the ground, a heater 5113 for heating the cylindrical base, and a source gas introduction pipe 5114 are installed in the reaction vessel 5101, and a high-frequency power source 5120 is connected via a high-frequency matching box 5115. .
The gas supply device 5200 includes gas cylinders 5221 to 5226, cylinder header valves 5231 to 5236, inflow valves 5241 to 5246, outflow valves 5251 to 5256, and mass flow controllers 5211 to 5216. Each gas cylinder is connected to a gas introduction pipe 5114 in the reaction vessel 5101 via an auxiliary valve 5210.
The cylindrical substrate 5112 is installed on the substrate holder 5123, and a cap holder 5125 is installed on the cylindrical substrate 5112. The base holder 5123 and the cap holder 5125 are made of conductive members, and the cylindrical base 5112 made of a conductive material is connected to the ground via the base holder 5123.

Hereinafter, a procedure for forming a deposited film using FIG. 5 will be briefly described.
A cylindrical substrate 5112 is installed in the reaction vessel 5101. First, the inside of the reaction vessel 5101 is evacuated by an unillustrated evacuation unit. Next, the temperature of the cylindrical substrate 5112 is controlled to a desired temperature of 20 ° C. to 500 ° C. by the cylindrical substrate heating heater 5113 while flowing an inert gas for heating.
When the cylindrical substrate 5112 is heated to a desired temperature, the introduction of the inert gas is gradually stopped. At the same time, the source gas for film formation, for _{example, SiH 4, Si 2 H 6} , CH 4, C 2 material gas such as _{H 6} also, optionally _B 2 _H 6, the doping gas such as PH _3, etc. Are gradually introduced into the reaction vessel 5101 from the gas supply device 5200. At this time, it adjusts so that each source gas may become predetermined | prescribed flow volume with the mass flow controller connected to the gas line to be used among the mass flow controllers 5211-5216. At that time, the opening of the main valve 5118 or the exhaust speed of the exhaust device (not shown) is monitored while monitoring the vacuum gauge 5119 so that the inside of the reaction vessel 5101 is maintained at a desired pressure of 0.1 Pa to several hundred Pa. adjust.

After completing the film formation preparation by the above procedure, formation of the deposited film on the cylindrical substrate 5112 is started. First, after confirming that the pressure in the reaction vessel 5101 is stable, the high frequency power source 5120 is set to a desired power, and the high frequency power is supplied to the discharge electrode 5111 to cause a high frequency glow discharge. At this time, the matching box 5115 is adjusted so that the reflected wave is minimized, and the output of the high frequency power source 5120 is adjusted so that the value obtained by subtracting the reflected power from the high frequency incident power becomes a desired value. Each source gas introduced into the reaction vessel 5101 is decomposed by the discharge energy of the high-frequency glow discharge, and is deposited on the surface of the cylindrical substrate 5112 to form a predetermined deposited film. During film formation, the cylindrical substrate 5112 may be rotated at a predetermined speed by a driving device (not shown).
After the deposition film having a desired thickness is formed, the supply of high-frequency power is stopped, the flow of each source gas into the reaction vessel 5101 is stopped, the inside of the reaction vessel 5101 is once evacuated, and the film formation process is completed. By repeatedly performing such a film forming process, an electrophotographic photosensitive member is formed.

With this technology, an electrophotographic photoreceptor having improved electrical characteristics, optical characteristics, and photoconductivity characteristics can be produced, and image quality can be improved by forming an image using this electrophotographic photoreceptor. Is possible.
In these methods, all of the introduced raw material gas is decomposed and consumed in the reaction chamber, and is not formed as a deposited film on a desired substrate. In particular, in the manufacturing method using the RF plasma CVD method, a by-product called polysilane is formed in the reaction vessel simultaneously with the formation of the deposited film. This polysilane may accumulate not only in the reaction vessel but also in the exhaust pipe. This polysilane may contaminate the deposited film in the film forming process, and it is necessary to remove the polysilane in the reaction vessel after the deposited film is formed. However, it takes a long time to remove the polysilane generated in the exhaust pipe, which is a factor that increases the cost due to a decrease in the production cycle.

Some proposals regarding the removal of such by-products in the exhaust pipe have also been made.
Patent Document 1 discloses that a trap is provided between the processing chamber and the exhaust pipe, and a refractory metal filament is installed in the trap. Specifically, by heating the refractory metal filament, a chemical reaction occurs in the unreacted gas and by-products exhausted from the processing chamber, and these are sufficiently decomposed to form a hard film on the inner wall of the trap 101. It is disclosed to adhere and deposit as.
Further, Patent Document 2 discloses a processing apparatus that supplies chlorine trifluoride gas directly to an exhaust system while heating the chlorine trifluoride gas flowing through a gas pipe connected in the middle of the exhaust system. A cleaning method is disclosed.
JP 2000-306841 A Japanese Patent No. 02773078

In general, when a functional deposition film is formed using plasma CVD, it is important that uniform and stable plasma is generated in the space in the reaction vessel. In particular, in the case of a member using a functional deposited film having a large area such as an electrophotographic photosensitive member, the uniformity and stability of such plasma greatly affect the uniformity of characteristics.
With the above-described conventional deposited film forming apparatus, it is possible to obtain a photoreceptor having practical characteristics to some extent. In particular, among the film formation methods by the plasma CVD method, the RF plasma CVD method using the RF band as the high-frequency power can easily obtain a film having good characteristics. Therefore, an electrophotographic photosensitive member using an a-Si film (amorphous). Widely used in the manufacture of silicon photoconductors).

However, in recent years, the specs of electrophotographic apparatuses required in the market have become stricter year by year, and competition for price and running cost has intensified as well as higher image quality, higher speed, higher durability, and higher functionality. . Along with this, electrophotographic photoreceptors (amorphous silicon photoreceptors) using an a-Si film are becoming more demanding in terms of cost in addition to the improvement in electrical characteristics as in the prior art.
However, an electrophotographic photosensitive member (amorphous silicon photosensitive member) using an a-Si film has to have a certain film thickness in order to obtain sufficient charging ability because of the high dielectric constant of a-Si. In some cases, a deposited film having a thickness of 30 μm to 100 μm must be formed. Therefore, in the manufacturing method using the plasma CVD method, the film formation time requires a long time, and the production cost tends to increase.
In the manufacturing method using the RF plasma CVD method, as described above, a by-product called polysilane is formed in the reaction vessel and the exhaust pipe simultaneously with the formation of the deposited film. When the photoconductor is thickened to obtain sufficient charging performance, the amount of polysilane also increases, and it may be difficult to obtain stable film formation conditions due to the influence of polysilane accumulated in the reaction vessel and exhaust pipe. . In some cases, the exhaust pipe is blocked during the formation of the deposited film, which may cause a problem in stable deposited film formation.

とはならず、増加させた膜厚分の帯電特性が得られない（増加させた膜厚分だけ帯電特性が増加しない）という課題に直面した。
また、前述したように、ポリシランを除去するための成膜後の後処理工程にも長時間を要し、製造効率を低下させ、生産コストを上昇させる要因となっている。
本発明の目的は、上述した従来の諸問題を解決し、帯電特性の優れた感光体を歩留まりよく安定して製造し得る堆積膜形成方法を提供することにある。 The present inventors have studied to increase the thickness of the photoconductive layer of the above-described electrophotographic photosensitive member in order to obtain excellent charging characteristics. However, the charging of a photosensitive member having a photoconductive layer thickness of 30 μm was performed. The relationship between the characteristic Vd (30) and the charging characteristic Vd (50) obtained with a photoconductor having a photoconductive layer thickness of 50 μm is as follows:

However, it was faced with the problem that the charging characteristics for the increased film thickness could not be obtained (the charging characteristics did not increase for the increased film thickness).
In addition, as described above, a post-treatment process after film formation for removing polysilane also takes a long time, which is a factor that decreases manufacturing efficiency and increases production cost.
An object of the present invention is to provide a deposited film forming method capable of solving the above-described conventional problems and stably producing a photoconductor excellent in charging characteristics with a high yield.

The present invention relates to a deposition film forming method in which a substrate is placed in a vacuum-tight reaction vessel, a source gas containing silicon atoms is decomposed by high-frequency power, and a deposited film is formed on the substrate. A gas containing chlorine trifluoride (ClF ₃ ) is supplied into an exhaust pipe connecting the reaction vessel and the exhaust means.

In the deposited film forming method of the present invention, during the deposited film forming process, a gas containing chlorine trifluoride is supplied into the exhaust pipe connecting the vacuum-tight reaction vessel and the exhaust means, thereby forming the deposited film. The amount of polysilane generated in the exhaust pipe inside is suppressed. As a result, it is possible to provide a method for producing a high-quality electrophotographic photoreceptor excellent in charging characteristics, in which a deposited film is always formed in a stable state even during long-time film formation. “During the deposited film forming process” means that after the substrate is placed in the reaction vessel, the deposited film is formed on the substrate, and the substrate on which the deposited film is formed is taken out from the reaction vessel. For example, from the start of the first deposited film formation to the end of the first deposited film formation, from the start of the second deposited film formation to the end of the second deposited film formation, and after the completion of the first deposited film formation, This includes even before the start of deposited film formation.
Furthermore, by supplying a gas containing chlorine trifluoride into the exhaust pipe during the deposited film forming process, the post-processing time after film formation can be greatly shortened, and an electrophotographic photoreceptor having good characteristics can be obtained. It is possible to provide a method for manufacturing at low cost with high productivity.

The present invention has been repeatedly studied in order to obtain an electrophotographic photosensitive member having excellent charging characteristics. The present invention will be described.
The inventors of the present invention have studied to increase the film thickness of the above-described electrophotographic photosensitive member in order to obtain excellent charging characteristics. However, as described in the above problem, the charging characteristics are increased by the increased film thickness. Did not improve.
In order to investigate this cause, a thermocouple was installed in the exhaust pipe and the temperature of the exhaust pipe was measured. As a result, it was confirmed that the temperature of the exhaust pipe near the reaction vessel increased from the latter half of the film forming process.
From this result, the present inventors estimated that the amount of polysilane accumulated in the exhaust pipe increased in the latter half of the film forming process, and the pressure in the exhaust pipe increased. As a result, it was considered that the plasma would circulate from the reaction vessel into the exhaust pipe and the plasma would easily concentrate on the exhaust pipe near the reaction vessel. It was speculated that this would impair the stability of the plasma in the reaction vessel and the characteristics of the deposited film in the latter half of the film formation process. Accordingly, the present inventors have arrived at the present invention as a result of considering how to suppress the generation of polysilane in the exhaust pipe during the film forming process.

Hereinafter, embodiments of a deposited film forming apparatus of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a schematic diagram of one embodiment of the deposited film forming apparatus of the present invention.
The method for forming a deposited film of the present invention will be described in detail with reference to FIG.
This apparatus is roughly divided into a reaction apparatus 1100, a raw material gas supply apparatus 1200, and an exhaust apparatus (not shown) for exhausting the inside of the reaction apparatus 1100. The reaction apparatus 1100 includes a high-frequency electrode 1111 insulated from an upper lid 1110 and a bottom plate 1126 by an insulating member 1121. In the reaction vessel 1101, a cylindrical base 1112 connected to the ground, a heater 1113 for heating the cylindrical base, and a source gas introduction pipe 1114 are installed. Further, a high frequency power source 1120 is connected via a high frequency matching box 1115.

The gas supply device 1200 includes the following.
Source gas cylinders 1221 to 1224 such as SiH ₄ , H ₂ , CH ₄ , NO, and B ₂ H ₆ and etching gases such as ClF ₃ (chlorine trifluoride) and N ₂ and dilution gas cylinders 1225 to 1226.
Furthermore, cylinder header valves 1231 to 1236, inflow valves 1241 to 1246, outflow valves 1251 to 1256, and mass flow controllers 1211 to 1216.
Each source gas cylinder 1221 to 1224 is connected to a gas introduction pipe 1114 in the reaction vessel 1101 through an auxiliary valve 1210.
The etching gas and dilution gas cylinders 1225 to 1226 are connected to a gas introduction pipe 1114 in the reaction vessel 1101 through an auxiliary valve 1230. Furthermore, as a configuration for carrying out the present invention, the exhaust pipe 1122 is also connected via an auxiliary valve 1220.

The cylindrical substrate 1112 is installed on the substrate holder 1123, and a cap holder 1125 is installed on the cylindrical substrate 1112. The base holder 1123 and the cap holder 1125 are made of conductive members, and the cylindrical base 1112 made of a conductive material is connected to the ground via the base holder 1123.
A cylindrical substrate 1112 is installed in the reaction vessel 1101. First, the inside of the reaction vessel 1101 is evacuated by an exhaust means (not shown). Next, the temperature of the cylindrical substrate 1112 is controlled to a desired temperature of 20 ° C. to 500 ° C. by the cylindrical substrate heating heater 1113.
Subsequently, it is confirmed that the gas cylinder header valves 1231 to 1234 and the reaction vessel leak valve 1117 are closed in order to allow the source gas to flow into the reaction apparatus 1100. Further, it is confirmed that the inflow valves 1241 to 1244, the outflow valves 1251 to 1254, and the auxiliary valve 1210 are opened, and the main valve 1118 is opened to exhaust the reactor 1100 and the gas supply pipe 1116.

Thereafter, when the value of the vacuum gauge 1119 reaches 0.7 Pa, the auxiliary valve 1210, the outflow valves 1251-1254, and the inflow valves 1241-1244 are closed. Thereafter, each gas is introduced from the gas cylinders 1221 to 1224 by opening the header valves 1231 to 1234, and each gas pressure is adjusted to a predetermined pressure by the pressure regulators 1261 to 1264. Next, the inflow valves 1241 to 1244 and the outflow valves 1251 to 1254 are gradually opened to introduce each gas into the mass flow controllers 1211 to 1214.
In this way, each source gas is introduced into the reaction vessel 1101 from the gas introduction pipe 1114 through the auxiliary valve 1210 at a predetermined flow rate.

In the present invention, the etching gas and the dilution gas are introduced into the exhaust pipe 1122 simultaneously with the introduction of the above-described source gas into the reaction vessel 1101 or during the film forming process.
As a procedure, it is confirmed that the header valves 1235 to 1236 of the chlorine trifluoride gas cylinder 1225 and the dilution gas cylinder 1226 and the leak valve 1117 of the reaction vessel are closed. Further, it is confirmed that the inflow valves 1245 to 1246, the outflow valves 1255 to 1256, and the auxiliary valve 1220 are opened, and the main valve 1118 is opened to exhaust the gas supply pipe 1227.

Thereafter, when the value of the vacuum gauge 1124 reaches 0.7 Pa, the auxiliary valve 1220, the outflow valves 1255 to 1256, and the inflow valves 1245 to 1246 are closed. Thereafter, each gas is introduced from the gas cylinders 1225 to 1226 by opening the header valves 1235 to 1236, and each gas pressure is adjusted to a predetermined pressure by the pressure regulators 1265 to 1266. Next, the inflow valves 1245 to 1246 and the outflow valves 1251 to 1256 are gradually opened to introduce each gas into the mass flow controllers 1215 to 1216.
In this way, chlorine trifluoride gas and dilution gas are introduced into the exhaust pipe 1122 through the auxiliary valve 1220 at a predetermined flow rate.

After completing the film formation preparation by the above procedure, a charge injection blocking layer is first formed on the cylindrical substrate 1112.
First, when the cylindrical substrate 1112 reaches a desired temperature, necessary ones of the source gas outflow valves 1251 to 1254 and the auxiliary valve 1210 are gradually opened. Next, a desired source gas is introduced into the reaction apparatus 1100 from the gas cylinders 1221 to 1224 through the gas introduction pipe 1114.
Further, the chlorine trifluoride gas and dilution gas outflow valves 1255 to 1256 and the auxiliary valve 1220 are gradually opened, and a desired flow rate is adjusted from each gas cylinder 1225 to 1226 by each mass flow controller 1215 to 1216 and introduced into the exhaust pipe 1122. To do.
Next, each source gas is adjusted to have a desired flow rate by each mass flow controller 1211 to 1214 of the source gas. At that time, the opening of the main valve 1118 and the throttle valve 1127 are adjusted while looking at the vacuum gauge 1119 so that the inside of the reaction apparatus 1100 has a desired pressure of 133 Pa or less. When the internal pressure is stabilized, the high-frequency power source 1120 is set to a desired power and, for example, high-frequency power of 13.56 MHz is supplied to the high-frequency electrode 1111 via the high-frequency matching box 1115 to cause a high-frequency glow discharge. Each material gas introduced into the reaction apparatus 1100 is decomposed by this discharge energy, and a charge injection blocking layer containing a desired silicon atom as a main component is deposited on the cylindrical substrate 1112.

After the charge injection blocking layer having a desired film thickness is formed, the source gas is switched to a material gas necessary for forming the photoconductive layer. Then, after the photoconductive layer having a desired thickness is formed, the supply of high-frequency power is stopped, the outflow valves 1251 to 1254 are closed, the inflow of each raw material gas into the reaction apparatus 1100 is stopped, and the photoconductive layer is formed. Finish.
When the surface layer is formed on the photoconductive layer, basically, the above operation may be repeated. After the source gas in the reactor 1100 is exhausted, the source gas required for the surface layer is switched to the inside of the reactor 1100. Shed. After adjusting to a predetermined internal pressure, a surface layer having a desired film thickness may be formed by the same operation as the previous layer.

Introducing chlorine trifluoride and a dilution gas into the exhaust pipe 1122 through the auxiliary valve 1220 during the film forming step suppresses the amount of polysilane produced in the exhaust pipe 1122. This prevents polysilane from accumulating in the exhaust pipe even during long-time film formation, and does not cause pressure fluctuations due to clogging of the exhaust pipe or increase in pressure in the exhaust pipe. The deposited film is formed in a stable state.
Furthermore, in the polysilane removal treatment step after the film formation step, the treatment time is greatly shortened, so that the production efficiency of the electrophotographic photosensitive member is increased and the production cost is reduced.

In the present invention, the etching gas introduced into the exhaust pipe 1122 during the film forming process may be either chlorine trifluoride or a mixed gas of a dilution gas such as chlorine trifluoride and an inert gas. Further, the flow rate of chlorine trifluoride and the flow rate of the dilution gas can be arbitrarily set depending on the exhaust capacity and the like, but if the flow rate of chlorine trifluoride and the concentration with respect to the dilution gas are too small, it is difficult to obtain the effect of the present invention. Conversely, if it is too large, the deposited film characteristics may be affected by the influence of contamination on the deposited film due to diffusion of chlorine trifluoride gas into the reaction vessel.
In the present invention, the etch gas introduced into the exhaust pipe 1122 is preferably introduced before the deposited film forming step, but may be introduced in the middle of the deposited film forming step.
In the present invention, the pressure relationship between the pressure in the exhaust pipe and the pressure in the reaction vessel during the film forming process is important.
In the present invention, the pressure in the vicinity of introducing the etching gas in the exhaust pipe is preferably 40% or more and 80% or less of the pressure in the reaction vessel. If the value exceeds 80%, the etching gas diffuses to the reaction vessel side, which may affect the deposited film. If it is less than 40%, the effect of suppressing the amount of polysilane in the exhaust pipe will be low. In the present invention, the pressure in the vicinity of introducing the etching gas is defined as a pressure measured at a location within about 10 cm from the introduction port for introducing the etching gas in the exhaust pipe.

The etching gas introduction method to the exhaust pipe in the present invention may be introduced into the exhaust pipe in a mixed state of chlorine trifluoride and dilution gas as shown in FIG. 1, but each is separately provided as shown in FIG. May be introduced. At this time, it is preferable to introduce the dilution gas from the upstream side (reaction vessel side) of the chlorine trifluoride gas supply location. In the example shown in FIG. 2, it is preferable to introduce the dilution gas from the gas supply pipe 1227a and introduce the chlorine trifluoride gas from the gas supply pipe 1227b. This is because the diluting gas can prevent diffusion of chlorine trifluoride gas into the reaction vessel and further suppress the influence on the deposited film.
The diluent gas used in the present invention may be any inert gas, but is preferably a mixed gas containing helium, argon, nitrogen, or any one thereof. It is also effective in the present invention to use hydrogen gas as the dilution gas.

The deposited film forming method of the present invention is particularly effective for forming a deposited film using a source gas for supplying Si, and is particularly effective as a method for producing an electrophotographic photosensitive member.
The deposited film forming method of the present invention can be applied to the formation of an amorphous silicon film as an example.
The amorphous silicon film can be formed by introducing a source gas for supplying Si, a source gas for supplying H and / or a source gas for supplying halogen into the reaction vessel, and causing glow discharge.
Examples of the raw material gas for supplying Si used in the present invention include silicon hydrides (silanes) or fluorides in a gas state such as SiH ₄ , Si ₂ H ₆ , SiF ₄ , Si ₂ F ₆ or the like which can be gasified. It is mentioned that silicon is effectively used. In particular, SiH ₄ and Si ₂ H ₆ are preferable in terms of easy handling at the time of production, good Si supply efficiency, and the like.
Further, a desired amount of a gas of a silicon compound containing H ₂ and / or He or a hydrogen atom may be mixed to form a layer.

The amorphous silicon film may contain atoms that control conductivity. Atoms that control conductivity include atoms belonging to Group 13 of the periodic table that give p-type conductivity, such as boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), and the like. In particular, B, Al, and Ga are preferable. Examples of periodic group 15 atoms that give n-type conductivity include P (phosphorus), As (arsenic), Sb (antimony), Bi (bismuth), etc., with P and As being particularly preferred.
Specific examples of such source materials for introducing Group 13 atoms include B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B ₅ H ₁₁ , B ₆ H ₁₀ , B ₆ H ₁₂ , and B _6. Examples thereof include boron hydrides such as H ₁₄ and boron halides such as BF ₃ , BCl ₃ , and BBr ₃ . In addition, AlCl ₃ , GaCl ₃ , Ga (CH ₃ ) ₃ , InCl ₃ , TlCl _{3 and the} like can also be mentioned.
As raw materials for introducing Group 15 atoms, phosphorus hydrides such as PH ₃ and P ₂ H ₄ , PH ₄ I, PF ₃ , PF ₅ , PCl ₃ , PCl ₅ , and PBr ₃ are effectively used. , Phosphorous halides such as PBr ₅ and PI ₃ . In addition, AsH ₃ , AsF ₃ , AsCl ₃ , AsBr ₃ , AsF ₅ , SbH ₃ , SbF ₃ , SbF ₅ , SbCl ₃ , SbCl ₅ , BiH ₃ , BiCl ₃ , BiBr _3, etc. are also used for introducing Group 15 atoms. It can be mentioned as an effective starting material.
These source materials for introducing atoms for controlling conductivity may be used by diluting with a gas such as H ₂ , He, Ar, Ne or the like, if necessary.
The content of atoms for controlling the conductivity contained in the photoconductive layer is preferably 1 × 10 ⁻² to 1 × 10 ⁴ atomic ppm, more preferably 5 × 10 ^{−2 to} 5 × 10 ³ atomic ppm, Optimally, it is desirable to be 1 × 10 ⁻¹ to 1 × 10 ³ atomic ppm.

  In the present invention, 1 to 450 MHz is preferably used as the frequency range of the high-frequency power source 1120. Of these, the RF band represented by 13.56 MHz or the VHF band of 50 to 250 MHz is particularly preferable. Any output can be suitably used as long as it can generate power suitable for the apparatus and the prescription. Furthermore, the effect of the present invention can be obtained regardless of the value of the output fluctuation rate of the high-frequency power source.

By using the present invention, various a-Si electrophotographic light-receiving members (amorphous silicon photoreceptors) shown in FIGS. 4A to 4D can be formed.
The electrophotographic photosensitive member 400 shown in FIG. 4A has a configuration in which a photoconductive layer 402 having amorphous silicon containing hydrogen atoms or halogen atoms as a constituent element and having photoconductivity is provided on a substrate 401. It has become.
An electrophotographic photosensitive member 400 shown in FIG. 4B has a configuration in which an amorphous silicon-based or amorphous carbon-based surface layer 403 is provided on the electrophotographic photosensitive member shown in FIG.
An electrophotographic photoreceptor 400 shown in FIG. 4C has a configuration in which an amorphous silicon-based lower blocking layer 404, a photoconductive layer 402, and a surface layer 403 are provided on a substrate 401. Similarly to FIG. 4B, the photoconductive layer 402 is made of a-Si containing hydrogen atoms or halogen atoms as constituent elements and has photoconductivity, and the surface layer 403 is an amorphous silicon-based or amorphous carbon-based layer. .
The electrophotographic photosensitive member 400 shown in FIG. 4D also has a configuration in which a photoconductive layer 402 and a surface layer 403 are provided on a substrate 401. The photoconductive layer 402 includes a charge generation layer 405 and a charge transport layer 406 made of a-Si containing hydrogen atoms or halogen atoms as constituent elements, and the surface layer 403 is an amorphous silicon-based or amorphous carbon-based layer. .

Examples of the present invention and effects thereof will be specifically described below. The technical scope of the present invention is not limited to the following examples.
Example 1
Using the deposited film forming apparatus for forming an electrophotographic photosensitive member shown in FIG. 1, an electrophotographic photosensitive member was prepared according to the procedure described above.
A cylindrical aluminum substrate 1112 is set on the substrate holder 1123, and the cylindrical substrate 1112 is heated to 280 ° C. by a cylindrical substrate heating heater 1113, and then the film thickness of the photoconductive layer under the film formation conditions shown in Table 1 Produced an electrophotographic photosensitive member having a thickness of 30 μm or 50 μm.
At this time, in this embodiment, chlorine trifluoride gas was allowed to flow through the exhaust pipe 1122 at 50 ml / min (normal) during the electrophotographic photosensitive member manufacturing process.
(Example 2)
Similarly to Example 1, an electrophotographic photosensitive member having a photoconductive layer thickness of 30 μm or 50 μm as in the procedure shown in Example 1 under the conditions shown in Table 1 using the deposited film forming apparatus shown in FIG. It was created. In this example, a mixed gas of chlorine trifluoride (50%) / argon (50%) 100 ml / min (normal) was supplied to the exhaust pipe 1122 during the electrophotographic photosensitive member manufacturing process.
(Example 3)
Similarly to Example 1, an electrophotographic photosensitive member having a photoconductive layer thickness of 30 μm or 50 μm as in the procedure shown in Example 1 under the conditions shown in Table 1 using the deposited film forming apparatus shown in FIG. It was created. In this example, a chlorine trifluoride (50%) / helium (50%) mixed gas of 100 ml / min (normal) was supplied to the exhaust pipe 1122 during the electrophotographic photosensitive member manufacturing process.
Example 4
Similarly to Example 1, an electrophotographic photosensitive member having a photoconductive layer thickness of 30 μm or 50 μm as in the procedure shown in Example 1 under the conditions shown in Table 1 using the deposited film forming apparatus shown in FIG. It was created. In this example, a chlorine trifluoride (50%) / nitrogen (50%) mixed gas of 100 ml / min (normal) was supplied to the exhaust pipe 1122 during the electrophotographic photoreceptor manufacturing process.

(Comparative Example 1)
An electrophotographic photosensitive member was prepared according to the procedure described above using the conventional deposited film forming apparatus for forming a film of the electrophotographic photosensitive member shown in FIG.
Also in this comparative example, after heating the cylindrical aluminum substrate 5112 to 280 ° C. in the same manner as in Example 1, an electrophotographic photosensitive member having a photoconductive layer thickness of 30 μm or 50 μm was prepared under the conditions shown in Table 1. did.
The photoreceptors prepared in Examples 1 to 4 and Comparative Example 1 were evaluated as follows.

(Charge characteristic ratio)
For this test, the electrophotographic photosensitive member produced in this example and the comparative example is installed in a potential evaluation machine obtained by modifying the Canon copying machine iRC5870. A constant current (1000 μA) is passed through the main charger of the electrophotographic apparatus, and the surface potential in the dark portion is measured by a potential sensor of a surface potentiometer (TREK Model 344) set at the position of the developer. In the measurement, 11 points were measured at positions of 25.4 mm intervals in the direction of the photoreceptor bus, and the average value was defined as the charging ability. Therefore, the larger the value, the better the charging ability.
Based on the charging ability thus obtained, the charging characteristic ratio is obtained. As represented by the following formula, the charging characteristic ratio was defined as a ratio of charging ability per film thickness of the photoconductive layer of the photoconductive layer 30 μm or 50 μm prepared in each example and comparative example.

The values obtained by the above formulas were ranked as follows and compared with the electrophotographic photoreceptors prepared in Examples and Comparative Examples. The results are shown in Table 2.
◎… 98% or more ○ ～ ◎… 95% or more and less than 98% ○… 90% or more and less than 95% △ to ○… 85% or more and less than 90% △… 80% or more and less than 85% ×… less than 80%

(Uniformity of charging ability)
Similar to the above charging ability measurement, 11 points were measured at positions of 25.4 mm intervals in the direction of the photoreceptor bus, the average value was obtained, and the difference between the maximum value and the minimum value was
A: Within 5% B: Within 5% to 10% B: Within 10% to 20% X: Judged as 20% or more.
The above evaluation results are shown in Table 3.

As shown in Table 2, it can be seen that the electrophotographic photosensitive member produced in the examples according to the present invention has a larger increase rate of charging characteristics than the comparative example when the photoconductive layer is made thick.
As shown in Table 3, the electrophotographic photosensitive member produced in the examples according to the present invention has a very good chargeability uniformity at any film thickness.
In the comparative example not using the present invention, good results are obtained when the film thickness of the photoconductive layer is 30 μm, but when the film thickness is 50 μm, the unevenness of the charging ability bus line direction becomes large.

(Example 5)
After producing an electrophotographic photoreceptor having a photoconductive layer of 50 μm under the conditions of Examples 1 to 4, a dry etching process was performed to remove polysilane in the reaction vessel.
The procedure of the dry etching process was performed as follows.
After the electrophotographic photosensitive member is produced, the electrophotographic photosensitive member is taken out, and a dummy cylinder 1112 (anode electrode) for dry etching is installed instead, and the reaction vessel 1101 is evacuated. After exhausting the reaction vessel 1101 sufficiently, an etching gas is introduced into the reaction vessel 1101 and adjusted to a predetermined pressure, and then high frequency power is applied to the discharge electrode 1111 to generate plasma. At this time, it is assumed that the etching gas flows into the reaction vessel 1101 through the auxiliary valve 1230 and does not flow to the exhaust pipe 1122 side. Table 4 shows the dry etching conditions.

(Comparative Example 2)
After producing an electrophotographic photoreceptor having a photoconductive layer of 50 μm under the conditions of Comparative Example 1, a dry etching process was performed in the same manner as in Example 5 in order to remove polysilane in the reaction vessel.
The procedure of the dry etching process is the same as the procedure shown in the fifth embodiment. After the electrophotographic photosensitive member is prepared, the electrophotographic photosensitive member is taken out, and a dummy cylinder 5112 (anode electrode) for dry etching is installed instead. 5101 is exhausted. After the reaction vessel 5101 is sufficiently evacuated, an etching gas is introduced into the reaction vessel 5101 and adjusted to a predetermined pressure, and then high frequency power is applied to the discharge electrode 5111 to generate plasma. The dry etching conditions are as shown in Table 4 as in Example 5.

In Example 5 and Comparative Example 2, during the dry etching process, the state of polysilane in the reaction vessel and in the exhaust pipe was confirmed every hour, and the polysilane processing rate (remaining amount) was determined as follows.
◎… No polysilane remains.
○… Slightly polysilane remains.
Δ: Some polysilane remains.
×… There is considerable polysilane remaining.
Table 5 shows the state of polysilane in each reaction vessel and exhaust pipe observed every hour during the dry etching process.

  As shown in Table 5, after being created under the conditions of Examples 1 to 4, the polysilane in the reaction vessel and the exhaust pipe may be removed in a shorter time than after being created under the conditions of Comparative Example 1. I understand.

(Example 6)
In the same manner as in Example 2, an electrophotographic photosensitive member was produced in the same manner as in Example 1 under the conditions shown in Table 1 using the deposited film forming apparatus shown in FIG. In this example, a chlorine trifluoride (50%) / argon (50%) mixed gas of 100 ml / min (normal) was supplied to the exhaust pipe 1122 during the electrophotographic photosensitive member manufacturing process.
In the present embodiment, the throttle valve 1127 and the exhaust capacity were adjusted, and the pressure in the exhaust pipe 1122 was changed. The pressure in the exhaust pipe 1122 was measured with a pressure gauge 1124.
As shown in Table 6, the conditions of the pressure ratio in the reaction vessel and the exhaust pipe 1122 were changed, and the electrophotographic photosensitive member produced under each condition was evaluated in the same manner as in Example 1, and the results are shown in Table 6. It was shown to.

  As shown in Table 6, the electrophotographic photosensitive member prepared with the pressure in the exhaust pipe in the range of 40% to 80% of the pressure in the reaction vessel has very good charging characteristics and uniform charging ability in any range. Is obtained.

(Example 7)
In this example, an electrophotographic photosensitive member was produced using the deposited film forming apparatus for forming an electrophotographic photosensitive member shown in FIG.
Similarly to Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 under the conditions shown in Table 1. In this example, a chlorine trifluoride gas cylinder was installed in the gas cylinder 1225, and a hydrogen gas cylinder was installed in the gas cylinder 1226, and each flowed 50 ml / min (normal) through the valves during the film formation process.
The electrophotographic photoreceptor thus prepared was evaluated in the same manner as in Example 1, and the results are shown in Table 7.

  As shown in Table 7, the electrophotographic photosensitive member produced in Example 7 has a very excellent charging characteristic ratio. In addition, the electrophotographic photosensitive member produced in Example 7 has a very good chargeability uniformity at any film thickness.

(Example 8)
In this example, an electrophotographic photosensitive member was produced using the deposited film forming apparatus for forming an electrophotographic photosensitive member shown in FIG.
Similarly to Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 under the conditions shown in Table 1. In this example, a chlorine trifluoride gas cylinder was installed in the gas cylinder 1225 and an argon gas cylinder was installed in the gas cylinder 1226, and each flowed 50 ml / min (normal) during the film forming process.
In the present example, even when an argon gas cylinder was installed in the gas cylinder 1226, good results were obtained as in Example 7.

Example 9
In this example, an electrophotographic photosensitive member was produced using the deposited film forming apparatus for forming an electrophotographic photosensitive member shown in FIG.
Similarly to Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 under the conditions shown in Table 1. In this example, a chlorine trifluoride gas cylinder was installed in the gas cylinder 1225 and a helium gas cylinder was installed in the gas cylinder 1226, and each flowed 50 ml / min (normal) during the film forming process.
In the present example, even when a helium gas cylinder was installed in the gas cylinder 1226, good results were obtained as in Example 7.

(Example 10)
In this example, an electrophotographic photosensitive member was produced using the deposited film forming apparatus for forming an electrophotographic photosensitive member shown in FIG.
Similarly to Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 under the conditions shown in Table 1. In this example, a chlorine trifluoride gas cylinder was installed in the gas cylinder 1225 and a nitrogen gas cylinder was installed in the gas cylinder 1226, and each flowed 50 ml / min (normal) during the film forming process.
In the present example, even when a nitrogen gas cylinder was installed in the gas cylinder 1226, as in Example 7, good results were obtained.

(Example 11)
In this example, an electrophotographic photosensitive member was prepared using the deposited film forming apparatus for forming an electrophotographic photosensitive member shown in FIG.
The apparatus of FIG. 3A is provided with a trap 1300 for collecting by-products in the exhaust pipe, and chlorine trifluoride gas can be introduced into the trap 1300 via valves 1257 and 1258 and a mass flow controller 1217. . In this example, 50 ml / min (normal) of chlorine trifluoride gas was introduced into the trap 1300 during the electrophotographic photoreceptor manufacturing process.

Example 12
In this embodiment, as shown in FIG. 3B, an electrode 1302 connected to a high frequency power supply 1303 is installed in the trap 1300, and a high frequency can be applied to the trap 1300.
In this example, in addition to the conditions of Example 11, a high frequency of 200 W was applied to the trap 1300 during the electrophotographic photosensitive member manufacturing process.
After 50 cycles of the electrophotographic photoreceptor manufacturing process (including dry etching of the reaction vessel after manufacture) in Examples 11 and 12, the degree of contamination of the exhaust pump oil was examined.
For comparison, the steps in Comparative Example 1 and Example 1 were similarly performed 50 times, and the oil contamination was similarly examined.
In addition, evaluation of the oil stain was performed according to the degree of stain as follows, and the results are shown in Table 8.
◎… Beautiful.
○… A little dirty.
Δ: Dirty.
×… It is quite dirty.

It can be seen that the degree of contamination of the exhaust pump oil is improved by providing a trap in the exhaust pipe and flowing chlorine trifluoride through the trap. Further, the effect is improved by applying a high frequency to the trap.
As a result, the effect of increasing the maintenance frequency of the exhaust pump and improving the productivity is recognized.

1 is a schematic sectional view of a deposited film forming apparatus to which the present invention can be applied. The schematic sectional drawing of another deposited film formation apparatus which can apply this invention. (A) is a schematic sectional drawing of another deposited film formation apparatus which can apply this invention, (b) is an expanded schematic sectional drawing of a trap. (A)-(d) is a typical enlarged view which shows the various examples of the layer structure of the electrophotographic photoreceptor formed based on this invention. The schematic sectional drawing of the conventional deposited film formation apparatus which implements a comparative example.

Explanation of symbols

1100, 5100 Reactor 1101, 5101 Reaction vessel 1110, 5110 Upper lid 1111, 5111 High frequency electrode 1112, 5112 Cylindrical substrate 1113, 5113 Substrate heating heater 1114, 5114 Gas introduction pipe 1115, 5115 High frequency matching box 1116, 5116 Gas supply piping 1117, 5117 Leak valve 1118, 5118 Main valve 1119, 5119 Vacuum gauge
1124, 5124 Vacuum gauge 1120, 5120 High frequency power source 1121, 5121 Insulating member 1122, 5122 Exhaust piping 1123, 5123 Base holder 1125, 5125 Cap holder 1126, 5126 Bottom plate 1127 Throttle valve 1200, 5200 Gas supply device 1210, 1220 Auxiliary valve 1211- 1217 Mass flow controller 1221 to 1226 Cylinder 1231 to 1236 Header valve 1241 to 1247 Inflow valve 1251 to 1257 Outflow valve 1261 to 1266 Pressure regulator 1300 Trap 1301 Insulating member 1302 Electrode 1303 High frequency power supply 400 Electrophotographic photosensitive member 401 Base 402 Photoconductive layer 403 Surface layer 404 Lower blocking layer 405 Charge generation layer 406 Charge transport layer 5210 Complement Auxiliary valve 5211-5216 Mass flow controller 5221-5226 Cylinder 5231-5236 Header valve 5241-5246 Inflow valve 5251-5256 Outflow valve 5261-5266 Pressure regulator

Claims (7)

In a deposition film forming method in which a base is placed in a vacuum-tight reaction vessel, a source gas containing silicon atoms is decomposed by high-frequency power, and a deposited film is formed on the base.
A method for forming a deposited film comprising supplying a gas containing chlorine trifluoride into an exhaust pipe connecting the reaction vessel and the exhaust means during the deposited film forming step.   2. The deposited film forming method according to claim 1, wherein the pressure in the exhaust pipe is set to 40% to 80% of the pressure in the reaction vessel.   3. The deposited film forming method according to claim 1, wherein hydrogen or an inert gas is supplied to an upstream side (reaction vessel side) of a supply point of the gas containing chlorine trifluoride in the exhaust pipe.   4. The deposited film forming method according to claim 3, wherein the inert gas is a mixed gas containing any one or any of helium, argon, and nitrogen.   The deposited film forming method according to claim 1, wherein a trap for collecting by-products is provided in the exhaust pipe, and the chlorine trifluoride is supplied into the trap.   6. The deposited film forming method according to claim 5, wherein high frequency power is applied to the trap. A method for producing an amorphous silicon photoreceptor, wherein the deposited film forming method according to claim 1 is used.

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