JPS6382418A - Production of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a sensitive body having high dark resistivity by decomposing a gas contg. C2H2 and Si in a prescribed ratio and a gas for forming amorphous silicon carbide (a-SiC) contg. a prescribed amount of a group Va element of the periodic table by glow discharge to form a negatively chargeable layer on a substrate. CONSTITUTION:A first layered region 6 and a second layered region 7 are successively formed on an electrically conductive substrate 1 in the form of an integrated photoconductive a-SiC layer 5a. In order to form the a-SiC layer 5a, a gas contg. C2H2 and Si in 0.01:1-3:1 ratio is used. The second region 7 contains 0-10,000ppm, preferably 0-1,000ppm group Va element, so the resulting sensitive body is negatively chargeable and required electrophotographic characteristics such as surface potential and photosensitivity are obtd. Since the first region 6 contg. a larger amount of the group Va element than the second region 7 is formed, the conductivity of the a-SiC layer 5a is increased in the substrate side region, the injection of carriers is hindered and light carriers generated in the layer 5a flow smoothly to the substrate 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing an electrophotographic photoreceptor comprising a photoconductive amorphous silicon carbide layer, and particularly relates to a method for manufacturing an electrophotographic photoreceptor that can be charged to a negative polarity. be.

[Prior art and its problems]

In recent years, progress in electrophotographic photoreceptors has been remarkable, and with the development of copying machines, printers, etc. equipped with photoreceptors, various characteristics are required of the photoreceptors themselves.

In response to this demand, amorphous silicon layers are attracting attention because they have excellent heat resistance, wear resistance, non-pollution properties, and photosensitivity characteristics.

However, the amorphous silicon (hereinafter abbreviated as a~Si) layer can only obtain a dark resistance value of about 109 Ωcm unless it is doped with any impurity element, and this is used in electrophotographic photoreceptors. In case 1012Ω・01
It is necessary to increase the charge retention ability by setting the dark resistance value to 1 or more. For this purpose, it is possible to increase the resistance by doping a small amount of elements such as oxygen or nitrogen, but on the other hand, there is a problem that the photoconductivity decreases.Additionally, even if boron is added, high resistance can be expected. However, a sufficiently satisfactory dark resistance value cannot be obtained, and is only about 1011 Ω·cm.

On the other hand, along with the development of doping agents as mentioned above, a-Si
A laminated photoreceptor has been proposed in which a photoconductive layer is laminated with another non-photoconductive layer.

For example, Figure 2 shows this laminated photoreceptor, with the substrate (1)
A carrier injection blocking layer (2), an a-Si photoconductive layer (3) and a surface protection layer (4) are sequentially laminated thereon.

According to this laminated photoreceptor, the carrier injection blocking layer (2)
is to prevent injection of carriers from the substrate (1), and surface protection N (4) is to protect the a-3i photoconductive layer (3) and improve moisture resistance. Layer (2
) and (4) are both intended to increase the dark resistance value of the photoreceptor to increase the charging ability, and for that purpose, it is not necessary to make these layers photoconductive.

As described above, the conventionally well-known a-Si electrophotographic photoreceptor has a major feature in that the photocarrier generation layer is formed of an a-Si photoconductive layer, and as a result, it has excellent heat resistance, durability, and photosensitivity characteristics. However, since the dark resistance value is insufficient, the dark resistance value is increased by using a doping agent or by forming a laminated type photoreceptor. That is, the carrier injection blocking layer (2
) and the surface protective layer (4) complement the defects of the a-3t photoconductive layer itself, and the a-3i photoconductive layer (3)
It can be said that it is a layer that can be practically distinguished.

[Purpose of the invention]

In view of the above circumstances, the present inventors conducted intensive research and found that amorphous silicon carbide (hereinafter abbreviated as a-SiC) obtained by glow discharge decomposition of a mixed gas containing acetylene and silicon-containing gas at a certain ratio. ) has photoconductivity and has a dark resistance value of easily 101'Ω·cm or more regardless of the presence or absence of a doping agent, and furthermore, can be an electrophotographic photoreceptor that can be charged to a negative polarity by selecting a doping agent. I found out.

Therefore, the present invention has been completed based on the above findings, and its purpose is to provide photoconductive a-3 having a large dark resistance value.
An object of the present invention is to provide a method for manufacturing an electrophotographic photoreceptor comprising an iC layer.

Another object of the present invention is to provide a method for manufacturing an electrophotographic photoreceptor that substantially eliminates the need for a surface protective layer and a carrier injection blocking layer and is composed of photoconductive a-3iC throughout the entire layer.

Still another object of the present invention is to provide a method for producing an electrophotographic photoreceptor that can be negatively charged.

Still another object of the present invention is to provide a method for manufacturing an electrophotographic photoreceptor that achieves high-speed film formation.

[Means for solving problems]

According to the present invention, the gas contains at least acetylene (CJz) and silicon (St), and the gas composition ratio is set within the range of 0.01:1 to 3:1, and 0.01:1 to 3:1.
a containing gas containing 1 to 1 mole χ of Group Va elements of the periodic table
- A method for manufacturing an electrophotographic photoreceptor is provided, which comprises forming an a-SiC layer that can be charged to a negative polarity on a substrate by glow discharge decomposition of a -SiC generating gas.

The present invention will be explained in detail below.

According to the production method of the present invention, Cz
Photoconductive a-3 on the substrate from Ht gas and St-containing gas
When an iC layer is formed, a large dark resistance value can be obtained, and when it contains 0 to 10.000 ppI of Group Va elements of the periodic table, it is negatively charged. Figure 1 shows its basic configuration. It is a photoreceptor.

That is, according to FIG. 1, a photoconductive a-SiC layer (5) is formed on a conductive substrate (1) by, for example, a glow discharge decomposition method, and carbon and periodic layers are formed over the thickness direction of this layer. Group Va elements (hereinafter abbreviated as Va group elements) are contained in the same content ratio. It was discovered that this resulted in a dark resistivity of 1013 cm Ω or higher, which was also 1000 times higher than the bright resistivity.As is clear from the examples described below based on this knowledge, a layer of this single composition is sufficient. It was an unexpected result that a practical a-SiC photoreceptor could be created.

Furthermore, when the present inventors charged this a-SiC photoreceptor to a positive polarity or a negative polarity and compared the charging performance of the two, the Va group element was added to the a-SiC layer (5) in an amount of 0 to 10,000.
It has also been found that doping in the range of pp+m, preferably in the range of 0 to 1000 ppn+, can advantageously increase the charging ability with negative polarity.

Although it is still a matter of speculation that doping or non-doping with Va group elements makes it easier to be negatively charged, it is clear that the a-SiC layer has a resistivity high enough to retain negative charges. This is believed to be due to the fact that it has excellent durability, is also effective in preventing injection of positive charges from the substrate, and has excellent charge mobility with respect to negative charges.

In addition, the Va group elements include N, P, As, Sb, and B.
Among them, P is preferable because it has excellent covalent bonding properties and can sensitively change semiconductor properties, or even if it is non-doped, stable properties can be obtained because the number of constituent elements in the film is reduced. Moreover, it is desirable in that it has excellent charging ability and sensitivity.

When doping the Va group element as described above, it is preferable that the a-5iC generation gas contains the Va group element in an amount of 0 to 1 mol χ, preferably O to 0.1 mol χ,
This makes it possible to dope within the above-mentioned required range. Furthermore, when doping with Va group elements, Hz, NHs, PHs, AsF, 5bHi, etc. are used.

The present inventors have found that when manufacturing the above-mentioned electrophotographic photoreceptor, it is preferable to mix CtHz gas and Si-containing gas at a predetermined ratio based on a glow discharge decomposition method.
It has been found that an a-5iC layer can be formed at high speed and has photoconductivity.

That is, when introducing C□H2 and Si-containing gas into the glow discharge region, the gas composition ratio is set to 0.01:1 to 3:
l, preferably within the range of 0.05:1 to 1:1, optimally within the range of 0.05:1 to 0.3:1, and from a ratio of 0.01:1 to If it is off, the dark resistivity will be less than IQIIΩcm, and the charge retention ability will be insufficient, making it impossible to obtain a large charged potential.3:
When the ratio deviates from 1, the number of dangling bonds in the film increases and the dark resistivity becomes less than IQIIΩ·cm.

SiH4,51 as the Si-containing gas! Ha+5IJ
There are s+5IFn+5iC1e, 5iHC1s, etc.
Among these, +5tH4+5IJi+ is desirable since St itself is bonded with H, so H is easily dissolved into the film, reducing dangling bonds in the film and improving photoconductivity. When H is used as an element for terminating dangling bonds, the H2 gas may be mixed at a rate of 3 times or less, preferably 2 times or less, of the total flow rate of C, H, gas, and 5tH4 gas, and deviates from this. This results in excessive hydrogen in the film, deteriorating the electrical characteristics required of the photoreceptor.

According to the manufacturing method of the present invention, when producing an a-SiC layer under the manufacturing conditions as described above, the high-frequency power for glow discharge, the gas pressure inside the reaction chamber, and the substrate temperature are set as follows. good.

In other words, the high frequency power should be set in the range of 0.05 to 0.5 W/co+". If it is less than 0.05 W/cm", the deposition rate will be low, and if it exceeds 0.5 W/cm". The film quality deteriorates due to plasma damage and carrier mobility decreases.In addition, the gas pressure is 0.1 to 2.0T.
Just set it in the range of orr < , 0. If it is less than ITorr, the film formation rate will be low; 2. If QTorr is exceeded, the discharge becomes unstable. Furthermore, the substrate temperature is a-Si:
The temperature should be about 30 to 80°C higher than the H film formation, preferably in the range of 200 to 400°C. If this substrate temperature is less than 200°C, networking of St and C will be inhibited. When the temperature exceeds 400°C, hydrogen desorption becomes significant and the dark resistivity decreases.

The reason why a-SiCN obtained by the production method of the present invention has photoconductivity is that amorphous silicon and carbon are essential constituent elements, and H and carbon are added to terminate the dangling bonds. It is believed that photoconductivity occurs when the halogen element is contained within the required range.The inventors conducted experiments to confirm the presence or absence of photoconductivity by varying the content ratio of carbon. , carbon may be contained in the a-SiC layer (5) in the range of 1 to 90 atoms χ, preferably 5 to 50 atoms χ, or the carbon content may be increased within this range in the layer thickness direction. You can change it.

In addition, the content of H and halogen elements is 5 to 50 atoms χ,
Preferably 5 to 40 atoms 2, optimally 10 to 30 atoms χ, and H is usually used. Since this H is easily incorporated into the terminal portion of the dangling bond, the localized level density in the band gap is reduced, thereby providing excellent semiconductor characteristics.

Furthermore, a part of this H may be replaced with a halogen element, whereby the localized level density of a-SiC@ can be lowered and the photoconductivity and heat resistance (temperature characteristics) can be improved. Its substitution ratio is 0.01 among all elements for dangling bond termination.
It is preferably between 1 and 50 atoms χ, preferably between 1 and 30 atoms χ. In addition, this halogen element includes F, C1, Br+It^, etc., but especially when F is used, the bond between atoms becomes larger due to its large electronegativity, which results in excellent thermal stability. desirable.

Further, the thickness of the photoconductive a-3iC (5) should be at least 5 μI, so that the surface potential can be increased by 20
On the other hand, the upper limit of the thickness of this layer (5) is appropriately selected within the range of image resolution and image blurring, and according to experiments by the present inventors, the thickness is 5 to 100 V.
μm1 is preferably set within the range of 10 to 50 μm.

When we determined the spectral sensitivity characteristics, dark decay curve, and light decay curve of this a-SiC layer, we found that the former has a spectral sensitivity peak (peak wavelength of approximately 600 nm) in the visible light region.
), and it has been found that this can be fully applied to tungsten lamps commonly used as light sources for copying machines. It was also found that the latter decay curve also had a high surface potential, excellent photosensitivity characteristics, and a small residual potential.

In this way, an electrophotographic photoreceptor is provided which can be put into practical use with just the photoconductive a-3iC layer having a single composition.

Next, based on the above results, the present inventors conducted further intensive research and discovered that the electrophotographic properties could be further improved by creating various layer regions within this single composition layer. Ta.

That is, in the manufacturing method of the present invention, the content ratio of carbon or Va group elements is varied in the layer thickness direction during film formation using the glow emission decomposition method, thereby generating a plurality of layer regions, and this Nem region The manufacturing methods of electrophotographic photoreceptors according to the following first to fourth aspects can be obtained depending on the number of the electrophotographic photoreceptors.

Hereinafter, the third embodiment of the method for manufacturing an electrophotographic photoreceptor according to the present invention will be described.
This will be explained with reference to Figures 24 to 24.

Presentation 1 According to the first aspect, a method for manufacturing an electrophotographic photoreceptor in which a photoconductive a-9iC layer that can be charged to a negative polarity is formed on a substrate by glow discharge decomposition of an a-SiC generation gas. The gas is composed of CJz and Si-containing gas, the gas composition ratio is set within the range of 0.01:1 to 3:1, and V
Provided is a method for manufacturing an electrophotographic photoreceptor, characterized in that a gas containing a group A element is contained and the content ratio thereof is reduced during film formation.

That is, according to the first aspect, at least the Va group element is contained in the photoconductive a-SiCN having a single composition shown in FIG. 1, and the content ratio thereof is changed accordingly. This method generates a first layer region and a second layer region, and this type B will be explained with reference to FIGS. 3 to 9.

In FIG. 3, a first layer region (
6) and a second layer region (7) are successively formed, both layer regions consisting of an integrated photoconductive a-3iC layer (5a); is the second N6N
It is important that the Va group element is contained in a larger amount than in region (7).

In the second 1ieff region (7), the content of Va group elements is 0 to 10. It is appropriately controlled within the range of OOOppm, preferably within the range of 0 to 1,000pp+m, whereby it is charged to a negative polarity and the required electrophotographic properties such as surface potential and photosensitivity properties are obtained. And this ILJ
The first N81 region (6
), the conductivity increases in the substrate side region of the photoconductive a-5iC layer (5a), which prevents carrier injection from the substrate side and prevents carrier injection from occurring in the entire region of the a-SiC layer. It was discovered that the photocarriers flow smoothly to the substrate, and as a result, the surface potential increases and the photosensitivity characteristics improve.

This first layer region (6) is photoconductive over its entire region, which makes it possible to avoid the conventional a shown in FIG.
It can be distinguished from the carrier injection blocking layer (2) of the -3t electrophotographic photoreceptor.

That is, the first layer region (6) improves the photosensitivity characteristics over the whole area due to the photoconductivity of the entire region. In particular, excellent photosensitivity characteristics can be obtained for relatively long wavelength light that easily reaches the first layer region (6), making it suitable for electrophotographic photoreceptors using semiconductor lasers as recording light sources. becomes.

Further, according to the conventional a-St electrophotographic photoreceptor, the layer thickness of the carrier injection blocking layer (2) is set to 3.
), whereas according to the manufacturing method of the present invention, the layer thickness of the first layer region (6) is set to 175 times or less than that of the second layer region (6).
'Even if it is less than 1 times the pH range (7), the residual potential can be sufficiently reduced and the photosensitivity characteristics can be improved.
The preferred layer thickness ratio is preferably set to 172 or less, most preferably 174 or less.

The carbon content of this photoconductive a-SiC layer (5a) is as shown in FIGS. It shows the content. Note that (6) on this horizontal axis.

Each range shown in (7) represents a first layer region and a second layer region.

That is, in FIG. 4, the carbon content ratio is constant throughout the entire layer, or in FIG. 5, the carbon content is reduced in the first layer region, whereas in FIGS. indicates that the first layer region contains more carbon than the second layer region, which causes the surface potential to be higher (
As a result, the photosensitivity characteristics are improved. Further, if the carbon content is gradually changed in the layer thickness direction as shown in FIGS. 7 to 9, the surface potential and photosensitivity will be further increased and the residual potential will be reduced.

Further, the first Njii region (6) may contain at least one of oxygen and nitrogen, thereby a-5
iCJ! The adhesion of (5a) to the substrate (1) is improved.

According to a second aspect of the invention, an electrophotographic photoreceptor is provided, in which a photoconductive a-5iC layer that can be charged to a negative polarity is formed on a substrate by glow discharge decomposition of an a-SiC generation gas. In the manufacturing method, the gas is composed of CzHt and Si-containing gas, and the gas composition ratio is set within the range of 0.01:1 to 3:1, and the CtHz-containing composition ratio is changed during film formation to produce the a- The SiC layer includes at least a first region, a second layer region, and a third region, the first layer region being closer to the substrate than the second layer region, and the second layer region being closer to the substrate than the second layer region.
The layer regions are arranged closer to the substrate than the third layer region, and the third layer region contains more carbon than the second layer region, and when forming the second layer region, the a- The SiC generation gas contains O to 1 mole χ of the Va group element-containing gas, and when the first layer region is formed, the proportion of the Va group element-containing gas in the a-SiC generation gas is smaller than that of the second layer region. Provided is a method for manufacturing an electrophotographic photoreceptor characterized in that it is larger than when it was formed.

That is, according to this second aspect, as shown in FIG.
A third layer region (8) is further formed on the second layer region (7) shown in the first embodiment, and the carbon content of the third layer region (8) is accordingly increased. 2 J! layer area 7), and the first layer area (6) and the second layer area (7).
and the third layer region (8) are substantially integrated to form a photoconductive a
-SiC layer (5b).

When this third layer region (8) is formed, the a-SiC layer (
It has been found that the dark resistance value on the surface side of 5b) increases, and the surface potential of the photoreceptor increases markedly.

This third layer region (8) is a photoconductive a-3iC layer (5b
) is formed to increase the resistance on the surface side of the shield, and can be completely distinguished from the conventional well-known surface protection 11 (4) described in FIG. In addition, according to a functionally separated photoreceptor that is divided into a photocarrier generation layer and a carrier transport layer, the carrier transport layer has a high resistance of 10'3Ω・Cl11 or more, but this layer has exceptionally high photoconductivity. Not required, typically a ratio of photoconductivity to dark conductivity of 10
In contrast, the third layer region (8) has a photoconductivity of less than 1000 times.
It has more than double the photoconductivity and can be sufficiently distinguished from the carrier transport layer.

The layer thickness of the third layer region (8) is not more than 1 times, preferably not more than 1 times, optimally not more than 1 times that of the second 101 region (7).
/4 times or less is good, and as a result, the surface potential is significantly improved, the photosensitivity is excellent, and the residual potential is small.
It can be said that it is desirable.

According to the present invention, the carbon content distribution of the photoconductive a-5iC layer (5b) is as shown in FIGS. 11 to 16, where the horizontal axis indicates the i-thickness direction from the substrate to the photoreceptor surface, The vertical axis shows carbon content. Furthermore, on this horizontal axis, (6
) (7) Each range shown in (8) represents a first layer region, a second layer region, and a third layer region.

Figures 12, 14, 15, and 16 show that the carbon content is gradually changed in the layer thickness direction, which improves the surface potential, provides excellent photosensitivity, and reduces residual potential. .

According to a third aspect, a method for manufacturing an electrophotographic photoreceptor in which a photoconductive a-5tC layer that can be charged to a negative polarity is formed on a substrate by glow discharge decomposition of an a-SiC generation gas. The gas is composed of CzHt and St-containing gas, and the gas composition ratio is set within the range of 0.01:1 to 3:1, and the CJz content composition ratio is changed during film formation to obtain the a- SiCl is provided with at least a first layer region, a second layer region, a third layer region, and a fourth layer region sequentially from the substrate side toward the photoreceptor surface, and the third layer region is provided with the second layer region. Compared to the layer boundary region, the fourth layer region contains more carbon than the third layer region. The method is characterized in that the Va group element-containing gas occupies a larger proportion of the a-3tC generation gas when forming the first layer region than when forming the second layer region. A method of making an electrophotographic photoreceptor is provided.

That is, according to the third aspect, as shown in FIG.
A fourth layer region (9) is further formed on the third layer region (8) shown in the embodiment, and accordingly, a fourth layer region (9) is formed.
) contains more carbon than the third layer region (8), and the first layer region (6) to the fourth layer region (9)
were substantially integrated to form a photoconductive a-3iC layer (5c).

This fourth layer region (9) contains more carbon than the third layer region (8) and has a high resistance, thereby increasing the charging ability and improving the surface potential. result,
A photoreceptor with high withstand voltage and long life can be obtained.

According to the manufacturing method of the present invention, the photoconductive a-SiC layer (5c)
The carbon content distribution of is as shown in FIGS. 18 to 21, where the horizontal axis indicates the layer thickness direction from the substrate to the photoreceptor surface,
The vertical axis shows carbon content. In addition, on this horizontal axis, the respective ranges shown in (6), (7), (8), and (9) represent the first layer region, second layer region, third layer region, and fourth layer region. There is.

In FIGS. 19 and 21, the carbon content is gradually changed in the layer thickness direction, thereby improving the surface potential and photosensitivity, and reducing the residual potential.

1 (According to the embodiment shown in Figure 4 of Tansaragi, a photoconductive a-SiC layer that can be charged to a negative polarity and an a-SiC surface protective layer are sequentially formed by glow discharge decomposition of the a-3iC generation gas. In the method for producing an electrophotographic photoreceptor, the photoconductive a-3iC generating gas is composed of a gas containing CgHg and St, and the gas composition ratio is set within the range of 0.01:1 to 3:1, The CtHz content composition ratio is changed during film formation so that the a-SiC layer has at least a first layer region, a second layer region, and a third layer region, and the first layer region is different from the second layer region. the second layer region is arranged closer to the substrate than the third layer region, the third layer region contains more carbon than the second region, and the second layer region When forming the area, the a-
The SiC generation gas contains O to 1 mol χ of the Va group element-containing gas, and when the first layer region is formed, the proportion of the Va group element-containing gas in the a-9iC generation gas is smaller than that of the second layer region. Provided is a method for manufacturing an electrophotographic photoreceptor characterized in that it is larger than when it was formed.

That is, according to this fourth aspect, as shown in FIG.
Further a on the third layer region (8) shown in the second embodiment
-SiC surface protection layer (10) is formed, and this a-SiC surface protection layer (10) is a photoconductive a-5
It is formed to overcoat and protect the surface of the t0 layer (5b).

The a-3iC surface protective layer (10) is the same as the photoconductive a-5iC layer (5b) in that it is made of a-3iC, but it has a higher carbon content to give it higher hardness, thereby protecting the surface. bring about action.

This a-3iC surface protective layer (10) can be made photoconductive or non-photoconductive by changing the composition ratio of its constituent elements; increasing the carbon content tends to make it non-photoconductive. With this, high hardness characteristics are obtained, and high hardness is A-5.
It becomes an iC surface protective layer.

According to the fourth aspect, the carbon content distribution is shown in FIGS.
As shown in FIG. 4, the horizontal axis indicates the layer thickness direction from the substrate to the surface of the photoreceptor, and the vertical axis indicates the carbon content. Furthermore, on this horizontal axis (6) (7) (8) (10)
The respective ranges shown in are the first layer region, the second layer region,
The third layer region and the a-3iC surface retaining flI layer are represented.

According to the present invention, the a-3iC layer of a single composition and the a-3iC layer of the first to third aspects are both photoconductive a-3iC layers.
The a-5iC layer is composed of a SiC layer, which provides sufficient practical electrophotographic properties, but a conventionally known surface protective layer may be formed on the surface of these a-5iC layers.

Various materials can be used for this layer as long as they themselves have high insulating properties, high corrosion resistance, and high hardness properties, such as organic materials such as polyimide resin + a -S I
CHS i OZ I S iOHA 1! 021
S t CI S s 3 N a 1 a -S
t1a-Ss:H, a-5t:F, a-3i
Inorganic materials such as C:H,;a-5iC:F can be used.

Next, a capacitively coupled glow discharge decomposition device used in an embodiment of the present invention will be explained with reference to FIG.

In the figure, 1st. Second. Third. 4th. Fifth. 6th tank (1
1) (12) (13) (14) (15) (1
6), SiH* and CJz, respectively.

PH5 (H* gas dilution contains 0.2χ), PH5 (Ht
With gas dilution 331) l11m containing), H! , NO gas is sealed, and H2 is also used as a carrier gas. These gases correspond to the first. Second. Third. Fourth
．． Fifth. Sixth regulating valve (17) (1B) (19) (2
0) (21) (22), and its flow rate is controlled by the mass flow controllers (23) (24).
)(25)(26)(27)(28), and the first. 2nd, 3rd. 4th. 5th tank (11) (
12) (13) (14) The gas from (15) is sent to the first main pipe (29), and the NO gas from the sixth tank (16) is sent to the second main pipe (30). Furthermore, (31) (32
) is a stop valve. The first main pipe (29) and the second main pipe (3
The gas flowing through 0) is sent into the reaction tube (33), and a capacitively coupled discharge electrode (34) is installed inside this reaction tube (33), and the high frequency power applied to it is 50 - is in %1 to 3, and the frequency is IMH
Inside the reaction tube (33), which is suitable for 2 to 10 MH2, a cylindrical film-forming substrate (35) made of aluminum is placed on a sample holder (36). 36) is rotatably driven by a motor (37), and the substrate (35) is heated uniformly to a temperature of about 200 to 400°C, preferably about 200 to 350°C, by an appropriate heating means. Ru. Furthermore, a reaction tube (3
3) is connected to a rotary pump (38) and a diffusion pump (39) because a high degree of vacuum (discharge voltage 0.1 to 2.0 Torr) is required during a-5iC film formation.

In the glow discharge decomposition device configured as above,
For example, an a-3iC film (containing P) is used as a substrate (35).
1. Second. Third. Open the 5th iPi control valves (17), (1B), (19), and (21) to release 5IH41CJz, I'1lff, and Hz gases from each. The amount of release is determined by the mass flow controller (23)
(24) (25) (27), 5i
The mixed gas of Ht+CJz+PHi+Ht is passed through the first main pipe (2
9) into the reaction tube (33). Then, the inside of the reaction tube (33) is in a vacuum state of about 0.1 to 2.0 Torr, the substrate temperature is 200 to 400°C, and the high frequency power of the capacitive discharge electrode (34) is 50% to 3%.
1 or the frequency is set to 1 to 10 MHz, a glow discharge occurs, the gas decomposes, and P
An a-SiC film containing is formed on a substrate at high speed.

〔Example〕

Next, embodiments of the present invention will be described in detail.

(Example 1) In this example, a photoconductive a-SiC layer is produced on an aluminum deposition substrate, and its C, H! The conductivity was measured with respect to the gas mixture ratio.

That is, using the capacitively coupled glow discharge decomposition chamber shown in FIG.
sccm, H2 gas was released from the fifth tank (15) at a flow rate of 300 seconds, and the C, Hz conductivity and photoconductivity were measured from the second tank (12).
The results shown in Figure 6 were obtained. As manufacturing conditions, the substrate temperature was set to 300° C., the gas pressure was set to 0.45 Torrs, and the high frequency power was set to 150 degrees.

According to FIG. 26, the horizontal axis shows C, H, + gas flow rates (see
m), the vertical axis represents the conductivity [(Ω・cm)-'),
- The mark is a plot of dark conductivity, the mark O is a plot of photoconductivity, and a and b are respective characteristic curves.

As is clear from Fig. 26, the dark conductivity is 10-” (Ω・
co+)-' or more, with a maximum of 10-'' (Ω・
CI+) was achieved up to Yudori. Further, the photoconductivity was 1000 times or more as compared to the dark conductivity, indicating that this a-5iC layer had photoconductivity sufficiently satisfactory for use in electrophotographic photoreceptors.

(Example 2) In this example, based on (Example 1), PH, gas (or B
When dark conductivity and photoconductivity were measured by introducing zHb gas), the results shown in FIG. 27 were obtained.

In the figure, the horizontal axis is the PH relative to the total flow rate of SiH4 and CJz.
3 pure amount (this is the absolute flow rate of PH3 calculated from the dilution ratio of H! gas). In addition, PH
! A case where the pure amount is replaced with the BgHb pure amount is also described as a reference example.

According to FIG. 27, the symbol ・ is the dark conductivity blower),
O marks are plots of photoconductivity, and c+d are respective characteristic curves.

As is clear from Fig. 27, the photoconductivity is more than 100 times the dark conductivity, and the a-
The SiC layer has satisfactory photoconductivity for use in electrophotographic photoreceptors.

(Example 3) In this example, (Example 1) medium C, O, gas flow rate is 101
The spectral sensitivity characteristics of a-3iCii obtained with the setting of 05e were measured, and the results were the spectral sensitivity curve e shown in FIG. Note that this figure shows the photoconductivity when irradiated with equal energy light at each wavelength.

As is clear from FIG. 28, photosensitivity is observed in the visible light region, and as a result, it can be satisfactorily used as a photoconductor for electrophotography.

(Example 4) In this example, (Example 1) medium czuz gas flow rate is 1Os.
A-SiC layer (thickness 30 μm
), the characteristics of surface potential, dark decay, and light decay were measured. This measurement was performed by negatively charging the surface with a -5,6KV corona charger, and measuring the time-dependent change in surface potential in the dark and the 65KV corona charger.
This figure follows the change in surface potential over time immediately after irradiation with 0 nm monochromatic light.

The results are shown in FIG. 29, where f and g are the dark decay curve and the light decay curve, respectively.

As is clear from FIG. 29, the surface potential is as large as about -530V, and the dark decay is about 30X after 5 seconds, indicating excellent charge retention ability. It can also be said that it has excellent photoconductivity and low residual potential.

In addition, the a-3iC layer obtained in (Example 4) was heated to +5.6KV.
When positively charged with a corona charger, the surface potential was several tens of volts.

And a-SiC manufactured based on this (Example 4)
Layered photoreceptor photoreceptor - Negatively charged with a 5.6KV corona charger, then exposed to image light to perform magnetic brush phenomenon.As a result, high image density, high contrast, and high quality images were obtained, and after 200,000 cycles. Even after repeated tests, no deterioration of the initial image was observed, and it was confirmed that the durability was good.

(Example 5) In this example, a photoreceptor of the first embodiment was manufactured.

That is, the aluminum drum for the substrate was installed in the reaction tube (33) of the capacitively coupled glow discharge decomposition apparatus shown in FIG. 25, and SiH was then supplied from the first tank (11).

C and Ht gases from the second tank (12) and the third tank (12).
PH and gas from tank (13), 5th tank (15)
+rz gas was released from the tank (16), and No gas was released from the sixth tank (16), and the first Ei? gas was released under the manufacturing conditions shown in Table 1.
An iW region and a second layer region were formed.

The electrophotographic properties of the photoreceptor thus obtained were -5 in the dark.
, charged to negative polarity with a corona charger connected to a high voltage source of 6KV, and then subjected to monochromatic light (650nm)
was irradiated onto the surface of the photoreceptor, and the following characteristics were obtained. Note that the residual potential is the value 5 seconds after the start of exposure.

Surface potential...-720v Photosensitivity...0.53cm"erg-'Residual potential...
30V (Example 6) In this example, a photoreceptor of the first embodiment was manufactured in the same manner as in (Example 4).

The manufacturing conditions were as shown in Table 2, and the electrophotographic properties were as follows.

Surface potential...-680V Photosensitivity...bow, 63cm"erg-' Residual potential...30V It was manufactured under the conditions shown in Table 3, and the following electrophotographic properties were obtained.

Surface potential...-720■ Photosensitivity...0.65cmI2erg-1 Residual potential...
-25V (Example 8) In this example, a photoreceptor of the third embodiment was manufactured under the conditions shown in Table 4, and the following electrophotographic characteristics were obtained.

Surface potential...-790v Photosensitivity...0.65CIII! erg-1 residual potential・
...30V In addition, when the surface potential, dark decay, and light decay characteristics of this photoreceptor were measured in the same manner as in (Example 4), the 30th
The results shown in the figure were obtained. In the figure, h and i are a dark decay curve and a light decay curve, respectively.

As is clear from FIG. 30, the surface potential is significantly large at approximately -790V, and the dark decay is approximately 24χ after 5 seconds, indicating excellent charge retention ability.

(Example 9) In this example, a photoreceptor of the fourth embodiment was manufactured under the conditions shown in Table 5, and the following electrophotographic characteristics were obtained.

Surface potential...-830■ Light sensitivity...0.63clI! erg-1 residual potential...
-40V (Example 10) In this example, the film formation rate was measured under the following manufacturing conditions using the glow discharge decomposition apparatus shown in FIG. 25, and the results shown in FIG. 31 were obtained.

11uk Raw RF power...150W Gas pressure...0.45Torr Substrate temperature...300℃ SiH, gas flow rate...1003cC11UZ gas flow rate...3003ccI11 The circle mark in Figure 31 is a plot of the measurement results. , j is its characteristic curve.

As is clear from Fig. 31, as the content ratio of CJz gas increases, the film formation rate increases, and the rate is approximately 5%.
The film formation rate was ~13 μI at 11 hours.

(Example 11) In this example, we tracked the hydrogen content in the film while changing the content ratio of CtHz gas under the same manufacturing conditions as in (Example 10), and the results shown in Figure 32 were obtained. .

In FIG. 32, the marks ◯ and * are plots showing the amount of H bonded to C and St, respectively, and k and l are their characteristic curves, respectively.

As is clear from Fig. 32, as the content ratio of CtHt gas increases, the number of C-H bonds increases and S-
It can be seen that H-bonds are reduced.

〔Effect of the invention〕

As described above, according to the method for manufacturing an electrophotographic photoreceptor of the present invention,
Since a-5iC, which has photoconductivity throughout the entire layer, has a high dark resistance value and excellent photosensitivity characteristics, it is possible to substantially eliminate the need for a surface protection layer and a carrier injection blocking layer. As a result, an electrophotographic photoreceptor consisting only of a photoconductive a-3iC layer could be provided.

Furthermore, according to the manufacturing method of the present invention, a significantly high film formation rate can be obtained by glow discharge decomposition using a combination of C, H, gas and St-containing gas, thereby improving manufacturing efficiency and manufacturing cost.

Furthermore, according to the manufacturing method of the present invention, by changing the content of carbon and Va group elements in the layer thickness direction, it is possible to improve the surface potential, enhance the photosensitivity characteristics, and significantly reduce the residual potential. .

In particular, when the carbon content is varied in the layer thickness direction, the resistivity can be controlled and a desired layer area can be obtained, and as a result, an electrophotographic photoreceptor with significantly higher performance can be provided.

Further, according to the manufacturing method of the present invention, there is provided an electrophotographic photoreceptor for negative polarity that can be charged advantageously to negative polarity.

Furthermore, when a conventional a-Si photoreceptor is used for a long period of time, local discharge damage on the photoreceptor surface is likely to occur due to corona discharge, and this causes spots to appear on the image. However, according to the manufacturing method of the present invention, a
-St has a dielectric constant of 8-12, while a-SiC
is about half that of ε・7, so it has excellent charging ability.As a result, the above-mentioned discharge breakdown does not occur even if the surface potential is increased, and as a result, high-quality and highly reliable electronic A photographic photoreceptor is provided.

Further, according to the method for manufacturing an electrophotographic photoreceptor of the present invention, since it has excellent charging ability and environmental resistance by itself, there is no need to provide a protective layer. When the surface of a photoreceptor is deteriorated due to filming, etc., the initial characteristics of the photoreceptor can be maintained without being limited in the amount of polishing even if the deteriorated surface is repeatedly polished and regenerated with an abrasive. This makes it possible to stably supply a good initial image over a long period of time.

Furthermore, when the electrophotographic photoreceptor obtained by the manufacturing method of the present invention is compared with a conventional a-Si photoreceptor, the problem with this a-Si photoreceptor is that it is inferior in moisture resistance and tends to cause image deletion. Furthermore, since the charging ability is poor, a ghost phenomenon occurs, but in order to solve this problem, a heater is used to heat the photoreceptor when using the a-Si photoreceptor, thereby preventing the occurrence of this phenomenon.

On the other hand, the electrophotographic photoreceptor according to the manufacturing method of the present invention has excellent moisture resistance and charging ability, and therefore has the advantage that it does not require the use of a heater as described above.

Furthermore, compared to the a-5i photoreceptor, the manufacturing method of the electrophotographic photoreceptor of the present invention allows a wide range of spectral sensitivity characteristics (peak 600 to 700 nm) to be obtained by simply changing the carbon content, and it is also possible to increase the photosensitivity itself. Furthermore, there is an advantage that sensitization on the long wavelength side is also possible by doping with an impurity element as necessary.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the layer structure of an electrophotographic photoreceptor according to the manufacturing method of the present invention, FIG. 2 is an explanatory diagram showing the layer structure of a conventional electrophotographic photoreceptor, and FIG. 4, 5, 6, and 7
8 and 9 are explanatory diagrams showing the carbon content of the photoconductor of the first embodiment according to the present invention, respectively, and FIG. 10 is an explanatory diagram showing the carbon content of the photoconductor of the second embodiment according to the present invention. Explanatory diagrams shown, Figures 11, 12, 13, 14, 15
16 and 16 are explanatory diagrams showing the carbon content of the photoconductor of the second embodiment according to the present invention, respectively, and FIG. 17 is an explanatory diagram showing the layer region of the photoconductor of the third embodiment according to the present invention, 18, 19, 20, and 21 are explanatory diagrams showing the carbon content of the photoreceptor of the third embodiment of the present invention, respectively, and FIG. 22 is an explanatory diagram showing the carbon content of the photoreceptor of the fourth embodiment of the present invention. FIGS. 23 and 24 are explanatory diagrams showing the layer regions of the photoconductor, FIGS. 23 and 24 are explanatory diagrams showing the carbon content of the photoconductor of the fourth embodiment of the present invention, and FIG. 25 is an explanatory diagram showing the carbon content of the photoconductor according to the fourth embodiment of the present invention. An explanatory diagram of a capacitively coupled glow discharge decomposition device, Fig. 26 is a diagram showing conductivity versus flow rate ratio of C2H2 gas, Fig. 27 is a diagram showing PH, gas and B, e.
) A diagram showing the conductivity for each flow rate ratio of 1 m gas, Figure 28 is a diagram showing the spectral sensitivity characteristics of the amorphous silicon carbide layer, and Figure 29 is a diagram showing the dark attenuation and light attenuation of the amorphous silicon carbide layer. Figure, 3rd
0 is a diagram showing the dark decay and optical attenuation of the amorphous silicon carbide layer of the third embodiment, FIG. 31 is a diagram showing the film formation rate with respect to the flow rate ratio of C, H, and gases, and FIG. 32 is a diagram showing C, FIG. 2 is a diagram showing the bonding ratio of hydrogen atoms to the flow rate ratio of lI□ gas. 1...Substrate 5.5a, 5b, 5c...Photoconductive amorphous silicon carbide layer 6...First N region 7...Second layer region 8...Third layer region 9...Fourth layer region 10...Amorphous silicon carbide surface protection! i
Layer patent applicant (663) Takao Kawamura, Kyocera Corporation

Claims (3)

[Claims] (1) In a method for manufacturing an electrophotographic photoreceptor in which a photoconductive amorphous silicon carbide layer that can be charged to a negative polarity is formed on a substrate by glow discharge decomposition of an amorphous silicon carbide generating gas, the gas is acetylene and a silicon-containing gas. The gas composition ratio is set within the range of 0.01:1 to 3:1, and a gas containing Group Va elements of the periodic table is contained, and this content ratio is reduced during film formation. Characteristic manufacturing method of electrophotographic photoreceptor. (2) The method for manufacturing an electrophotographic photoreceptor according to claim 1, wherein the amorphous silicon carbide layer contains 1 to 90 atomic percent carbon. (3) The method for manufacturing an electrophotographic photoreceptor according to item 3, wherein the amorphous silicon carbide layer contains 1 to 90 atomic % carbon and 5 to 50 atomic % hydrogen.