JPS6382421A - 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 IIIa element of the periodic table by glow discharge to form a positively 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 by decomposing a gas contg. 10<-6>-1mol% gas contg. a group IIIa element of the periodic table. The first region 6 contains a larger amount of the group IIIa element than the second region 7. The second region 7 contains 0.1-10,000ppm, preferably 0.1-1,000ppm group IIIa element, so the resulting sensitive body is positively 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 IIIa 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 from the substrate 1 side is hindered and light carriers 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 positively charged. be.

[Prior art and its problems]

In recent years, progress in electrophotographic photoreceptors has been remarkable, and with the development of copying machines and printers equipped with photoreceptors, various characteristics are required of the photoreceptors themselves. It is attracting attention because of its excellent properties such as hardness, abrasion resistance, non-pollution, and photosensitivity.

However, the amorphous silicon (hereinafter abbreviated as a-St) layer can only obtain a dark resistance value of about 109 Ω・cll unless it is doped with any impurity element, and when used in an electrophotographic photoreceptor, It is necessary to increase the charge retention ability by increasing the dark resistance value to 101 zΩ·cm 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. Further, even if boron or the like is added, a high resistance can be expected, but a sufficiently satisfactory dark resistance value cannot be obtained and is only about IQIIΩ·cm.

On the other hand, along with the development of doping agents as mentioned above, a-5i
A laminated photoreceptor has been proposed in which a photoconductive layer is laminated with another non-photoconductive layer.

For example, FIG. 2 shows this laminated photoreceptor, and the group 1rIi
A carrier injection blocking layer (2), an a-St photoconductive layer (3), and a surface protection layer (4) are sequentially laminated on (1).

According to this laminated photoreceptor, the carrier injection blocking layer (2)
The surface protection layer (4) protects the a-Si photoconductive layer (3) and improves moisture resistance, etc., but the layer(
The purpose of both 2) and (4) is to increase the dark resistance value of the photoreceptor to increase the charging ability, and for that purpose, it is not necessary to make the layer photoconductive.

As described above, the conventionally well-known a-3i 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, carrier injection prevention N(2
) and surface protection N (4) complement the defects of the a-Si photoconductive layer itself, and the a-5i 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-3iC) 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 10+3Ω·cn+ regardless of the presence or absence of a doping agent, and has also been found to be an electrophotographic photoreceptor that can be positively charged by selecting a doping agent. Ta.

Therefore, the present invention was completed based on the above findings, and its purpose is to provide a photoconductive a-S 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 in which all layers are made of photoconductive a-SiC.

Still another object of the present invention is to provide a method for producing an electrophotographic photoreceptor that can be positively 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 1
A-5iCli, which can be positively charged, is formed on a substrate by glow discharge decomposition of an a-SiC generation gas containing a gas containing a group IIIa element of the periodic table in an amount of 0-h to 1 mole χ. A method for manufacturing an electrophotographic photoreceptor is provided.

The present invention will be explained in detail below.

According to the production method of the present invention, CJ is produced by glow discharge decomposition method.
photoconductive a-Si onto the substrate from Z gas and Sl-containing gas.
CJi! When it is formed, a large dark resistance value can be obtained, and when it contains 10-'' to 1 mol% of a gas belonging to the Ha group of the periodic table, it is positively charged. Figure 1 shows its basic structure. It is a photoreceptor.

That is, according to FIG. 1, a photoconductive a-3iC layer (5) is formed on a conductive substrate (1) by a glow discharge decomposition method, and carbon and a periodic rule are formed over the thickness direction of this layer. Group IIIa elements (hereinafter abbreviated as Ina 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. practical a-5
The fact that it became an iC photoreceptor was an unexpected result.

Furthermore, when the present inventors charged this a-3iC photoreceptor to positive or negative polarity and compared the charging performance of the two, they found that the a-SiC layer (5) contained 0.1 to 10 of the 1ira group elements.
．． 000 ppm, preferably from 0.1 to 11000
It has also been found that doping within the pp range can advantageously enhance the charging ability with positive polarity.

In this way, group IIIa element doping left ≠ tite cow = 4
Although it is still a matter of speculation that a-SiCJi is more likely to be positively charged due to This is thought to be due to the fact that it has an excellent effect of preventing oxidation, and also has excellent charge mobility for positive charges.

In addition, the IIIa group elements include B, AI+Ga+I
Of these, P is preferred because it has excellent covalent bonding properties and can sensitively change semiconductor properties, and is also desirable because it has excellent charging ability and sensitivity.

In doping the IIIa group element as described above, the a-3iC generation gas is doped with 10-h to 1 mol χ
, preferably 10 -6 to 0.1 mol χ of the Ha group element gas, thereby making it possible to dope within the above-mentioned required range.

In addition, when doping with IIIa group elements, l1h
Hb, BPs, AI(CH3)s+Ga(CHris+I
n(CHs)s+ etc. are used, and BJi is particularly preferred.

Furthermore, in manufacturing the above-mentioned electrophotographic photoreceptor, the present inventors used CgHz gas and S based on the glow discharge decomposition method.
It has been found that by mixing i-containing gases at a predetermined ratio, an a-3iC layer can be formed at high speed and has photoconductivity.

That is, when introducing CtHt 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 1011 Ω·cs, 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.

As the Si-containing gas, 5iHe+5fJi, SiJ□
Sin,.

There are 5iC1+, 5iHC1s, etc., especially 5iHa
Since +5iJa+ itself has St bonded to -, H is easily incorporated into the film, reducing dangling bonds in the film, thereby improving photoconductivity, which is desirable.

In addition, when H is used as the element for terminating the dangling bond, the Ht gas may be blended in an amount not more than three times, preferably not more than twice, the total flow rate of the CJz gas and the SiH4 gas. 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, in producing the a-3iC 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 within the range of 0.05 to 0.5 W/cm. If it is less than 0.05 W/cm, the deposition rate will be low, and if it exceeds 0.5 W/c+++ The film quality deteriorates due to plasma damage and the carrier mobility decreases.Also, the gas pressure is 0.1 to 2.0.
Just set it in the range of Torr<, 0. If it is less than I Torr, the film formation rate will be low, and if it exceeds 2.0 Torr, the discharge will become unstable. Furthermore, the substrate temperature is
:The temperature is preferably about 30 to 80°C higher than that of the H film, and preferably in the range of 200 to 400°C.

If the substrate temperature is less than 200° C., networking of Si and C is inhibited, and if it exceeds 400° C., hydrogen desorption becomes significant and the dark resistivity decreases.

The a-SiC layer obtained by the manufacturing method of the present invention has photoconductivity because amorphous silicon and carbon are essential constituent elements, and the dangling bonds are terminated (H It is thought that photoconductivity occurs by containing carbon and halogen elements within the required range.The present inventors conducted experiments to confirm the presence or absence of photoconductivity by varying the content ratio of carbon. However, in the a-SiC layer (5), 1 to 90 atoms of carbon χ
, preferably within the range of 5 to 50 atoms χ, or the carbon content may be varied within this range over the layer thickness direction.

In addition, the content of H and halogen elements is 5 to 50 atoms χ,
Preferably, it is a giant to 40 atoms χ, optimally 1 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 the a-SiC layer 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.
50 atoms χ, preferably 1 to 30 atoms χ, and this halogen element includes F, C1, Br, 1. Although there are At and the like, F is particularly desirable because its large electronegativity increases the bonding between atoms, resulting in excellent thermal stability.

Further, the thickness of the photoconductive a-SiC (5) should be at least 5 cm or more, so that the surface potential is 200 nm or more.
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 conducted by the present inventors, the thickness is 5 to 100 V.
μI, preferably set within the range of 10 to 50μI.

When we determined the spectral sensitivity characteristics, dark decay curve, and light decay curve of this a-SiCjii, we found that the former has a spectral sensitivity peak (peak wavelength of about 670
nm), 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.

Thus, an electrophotographic photoreceptor is provided which can be put into practical use with just a photoconductive a-SiC layer having a single composition.

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

That is, in the manufacturing method of the present invention, the content ratio of carbon or group IIIa elements is varied in the layer thickness direction during film formation by glow discharge decomposition, thereby producing a plurality of layer regions, and The manufacturing methods of electrophotographic photoreceptors according to the following first to fourth aspects can be obtained in accordance with the numbers.

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.

According to the first aspect, a method for manufacturing an electrophotographic photoreceptor in which a photoconductive a-StC layer that can be positively charged is formed on a substrate by glow discharge decomposition of an a-3iC generation gas. In this method, the gas is composed of a gas containing C, lh, and Si, and the gas composition ratio thereof is set within the range of 0.01:1 to 3:1, and a gas containing a group IIIa element is contained, and the film is formed. Provided is a method for producing an electrophotographic photoreceptor characterized in that the content ratio thereof is reduced.

That is, according to this first aspect, at least the third group element is contained in the photoconductive a-SiCii of the single composition shown in FIG. 1, and the content ratio thereof is changed accordingly. This method generates an N9i region of 1 and a second layer region, and this aspect 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); It is important that the second layer region (7) contains more group IIIa elements than the second layer region (7).

The second layer region (7) has a group IIIa element content of 0.1
Within the range of 10.000 ppn+, preferably 0.1
It is appropriately determined within the range of 1°,000 ppm, and as a result, it is charged to a negative polarity and required electrophotographic properties such as surface potential and photosensitivity properties are obtained. And this N?
When the first layer region (6) containing a higher content of Group IIIa elements than the fI region is formed, the photoconductive a-3iC layer (5a)
The conductivity increases in the substrate side region of the a-SiC, which prevents carrier injection from the substrate side and
Photocarriers generated in all areas of the layer flow smoothly to the substrate,
As a result, it was found that as the surface potential increases, 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 -5i 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-3i electrophotographic photoreceptor, the layer thickness of the carrier injection blocking layer (2) is reduced to a layer thickness of the a-5t photoconductive layer (3).
), whereas according to the manufacturing method of the present invention, the layer thickness of the first layer region (6) is set to be 1 times or less than that of the second layer region (7). Even if the residual potential is present, the residual potential can be sufficiently reduced to improve the photosensitivity characteristics, and the preferred layer thickness ratio is preferably set to 1/2 or less, and optimally to 1/4 or less.

The carbon content of this photoconductive a-5iC 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 N Jii region, which further increases the surface potential and improves the photosensitivity characteristics. 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 layer region (6) may contain at least one of oxygen and nitrogen (by this, a-5iC
The adhesion of the layer (5a) to the substrate (1) is improved.

According to a second aspect, an electrophotographic photoreceptor is provided, in which a photoconductive a-SiC layer that can be charged to a positive polarity is formed on a substrate by glow discharge decomposition of an a-5iC generation gas. In the manufacturing method, the gas is composed of Czlb and Si-containing gas, and the gas composition ratio is set within the range of 0.01:1 to 3:1, and the CzHz content composition ratio is changed during film formation to produce the a- The 3iC layer includes at least a first region, a second N9N region, and a third region, the first layer region being closer to the substrate than the second N region, and the second layer region being closer to the third layer region. The third layer region contains more carbon than the second layer region, and when forming the second layer region, the a-SiC
The generation gas contains a group IIIa element-containing gas of 10-h to 1 mol χ, and a-3i when forming the first layer region.
Provided is a method for manufacturing an electrophotographic photoreceptor, characterized in that the proportion of the Group IIIa element-containing gas in the C-generating gas is larger than that during the formation of the second layer region.

That is, according to this second aspect, as shown in FIG. 1O,
A third layer region (8) is further formed on the second N region (7) shown in the first embodiment, and the carbon content of the third layer region (8) is accordingly increased. and the first N region (6), the second layer region (7) and the third layer region (8) are substantially integrated to form a photoconductive a. −
A SiC layer (5b) was formed.

When this third layer region (8) is formed, the a-3iC 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 photoconductive a-5iCJii (
It is formed to increase the resistance of the surface side of layer 5b), and is completely distinguishable from the conventionally known surface protective layer (4) described in FIG. Furthermore, according to a functionally separated photoconductor that is divided into a photocarrier generation layer and a carrier transport layer, the carrier transport layer has a high resistance of 1013 Ωcm or more, but this layer is required to have exceptionally high photoconductivity. Usually, the ratio of photoconductivity to dark conductivity is 1000.
On the other hand, the third layer region (8) has a photoconductivity that is 1000 times or more higher than that of the carrier transport layer. They can also be clearly distinguished.

The layer thickness of the third layer region (8) is not more than 1 times, preferably not more than 1/2 times, optimally 17 times, compared to the second layer region (7).
4 times or less is preferable, and this can be said to be desirable because the surface potential is significantly improved, the photosensitivity is excellent, and the residual potential is small.

According to the present invention, the carbon content distribution of photoconductive a-3iC [(5b) is as shown in FIGS. 11 to 16, where the horizontal axis indicates the layer thickness direction from the substrate to the surface of the photoreceptor, The vertical axis shows carbon content. Furthermore, on this horizontal axis, (6
) (7) Each range shown in (8) is the first N
area, a second layer area and a third layer area.

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. .

Third aspect According to the third aspect B, there is provided a method for manufacturing an electrophotographic photoreceptor in which photoconductive a-Sicm, which can be positively charged, is formed on a substrate by glow discharge decomposition of a-SiC generation gas. The gas is composed of C, H, and Si-containing gas, and the gas composition ratio is set within the range of 0.01:1 to 3:l, and the CzHz-containing composition ratio is changed during film formation. The a-5iC layer is provided with at least a first N'pM region, a second N region, a third N region, and a fourth layer region in order from the substrate side toward the photoreceptor surface, and a third layer The area is compared to the second layer boundary area.
The fourth Fl 8M region contains more carbon than the third layer region, and when the second N'pM region is formed, the a
-3iC generation gas from 10-h to 1 mol χ of IIIa
Group element-containing gas and the first N? When forming the iJi region, the ratio of the Group IIIa element-containing gas in the a-3iC generation gas is the second 1! ? Provided is a method for manufacturing an electrophotographic photoreceptor characterized in that the area iI is larger than when it is formed.

That is, according to the third aspect, as shown in FIG.
A fourth layer region (9) is further formed on the third IWTJ region (8) shown in the embodiment, and accordingly, the fourth layer region (9) is formed on the third N region (8). ), and the first layer region (6) to the fourth layer region (
9) is substantially integrated to form a photoconductive a-5iC layer (5C).
And so.

This fourth N region (9) contains more carbon than the third layer region (8) to have 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 N region, the second NeX region, the third N region, and the fourth 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.

Fourth Embodiment According to the embodiment shown in FIG. 4, a photoconductive a-SiC layer that can be positively charged and an a-SiC surface protective layer are sequentially formed by glow discharge decomposition of an a-SiC generation gas. In the method for manufacturing a photographic photoreceptor, the photoconductive a-SiC generating gas is composed of C2H4 and Si-containing gas, and the gas composition ratio is set within the range of 0.01:1 to 3:1. The a-5iC layer is provided with at least a first layer region, a second layer region, and a third layer region by changing the CtHz content composition ratio in the film, and the first layer region is higher than the second N region. On the substrate side, the second layer regions are arranged closer to the substrate than the third layer regions, and the third layer regions contain more carbon than the second region, and the second layer regions contain more carbon than the second layer regions, and At the time of formation, the a-SiC generation gas contains 10-6 to 1 mole of Group IIIa element-containing gas, and at the time of formation of the first N region, a-5iC
Provided is a method for manufacturing an electrophotographic photoreceptor, characterized in that the ratio of the Group IIIa element-containing gas in the generation gas is larger than when the second ONjI region is formed.

That is, according to this fourth aspect, as shown in FIG.
Further a on the third 1M area (8) shown in the second embodiment
-SiC surface retention 11Jl! (10), and this a-SiC surface protective layer (10) is a photoconductive a-SiC surface protective layer (10).
It is formed to overcoat and protect the surface of SiCjEJ (5b).

The a-SiC surface protection layer (10) is the same as the photoconductive a-SiC layer (5b) in that it is made of a-SiC, but it has a high carbon content to make it highly hard, thereby protecting the surface. bring about action.

This a-5iC 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-3.
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 N iJl area and the second M
region, the third layer region and the a-3iC surface protective layer.

According to the present invention, the a-SiC layer of a single composition and the a-5iC layer of the first to third aspects are both photoconductive a-SiC 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. For example, organic materials such as polyimide resin + a-SiC, S
ing, Sin, Al zO! + stc, S1
3Nm+ a-Si, a-3i:H, a-St:
F, a-SiC:)1. ;a-5iC:F and other inorganic materials 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), SiH4+Czlh+BJ, (Hz
Contains 0.2χ when diluted with gas), BtHi (contains 38ppm when diluted with Ih gas), Hl, and NO gas are sealed.
Hl is also used as a carrier gas. These gases correspond to the first. Second. Third. 4th. Fifth. Sixth regulating valve (17) (18) (19) (20) (21)
(22) is released by opening the mass flow controller (23) (24) (25) (2
6) (27) Controlled by (2B), the first and second
．． Third. 4th. 5th tank (11) (12) (13)
) (14) The gas from (15) is transferred to the first main pipe (29)
The NO gas from the 6th tank (16) is transferred to the 2nd main pipe (3
0). Note that (31) and (32) are stop valves. Gas flowing through the first main pipe (29) and the second main pipe (30) is sent into the reaction tube (33), and a capacitively coupled discharge electrode (34) is installed inside this reaction tube (33). The high frequency power applied to it ranges from 50 to 3%, and the frequency ranges from IMHz to 10MHz.
is appropriate. Inside the reaction tube (33), a cylindrical film-forming substrate (35) made of aluminum is placed in a sample holding position (36).
), this holding stand (36) is driven to rotate by a motor (37), and the substrate (35) is heated to about 200 degrees by a suitable heating means.
It is heated uniformly to a temperature of from 400°C to 400°C, preferably from about 200°C to 350°C. Furthermore, the inside of the reaction tube (33) is a-
3iC film is formed in a high vacuum state (discharge voltage 0.1 to 2
．． By requiring a rotary pump (0 Torr)
38) and a diffusion pump (39).

In the glow discharge decomposition device configured as above,
For example, an a-3iC film (containing B) is placed on the substrate (35).
1. Second. Third. Fifth regulating valve (
17) (1B) (19) Open (21) and release 5iHa+CzHt, BtHh Hz gas from each. The release amount is determined by the mass flow controller (23) (2
4) (25) Controlled by (27), Si! (a
The mixed gas of +CtHz+BzHh+Hz is sent to the first main pipe (2
9) into the reaction tube (33). 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 Kw.
, or in conjunction with the frequency being set to 1 to 10 MHz, glow discharge occurs, the gas decomposes, and an a-3iC film containing B is formed on the 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! )I! The conductivity was measured with respect to the gas mixture ratio.

That is, using the capacitively coupled glow discharge decomposition device shown in FIG.
sccm, H2 gas is released from the fifth tank (15) at a flow rate of 30Qsccn+, and the second tank (12)
C2H2 gas is released at a flow rate of 10~101005e, and a-S with a thickness of about 5 μm is produced based on the glow discharge decomposition method.
When an iC film was manufactured and its dark conductivity and photoconductivity were measured, the results shown in FIG. 26 were obtained. The manufacturing conditions are a substrate temperature of 300°C and a gas pressure of 0.45T.
orr, and the high frequency power was set to 150-.

According to Fig. 26, the horizontal axis shows the cJz gas flow! (sccm)
, the vertical axis represents conductivity [(Ω·cm)−′), the mark . is a plot of dark conductivity, the mark Q is a plot of photoconductivity, and a+b are respective characteristic curves.

As is clear from Fig. 26, the dark conductivity is 10-” (Ω・
cm)-' or more, with a maximum of 10-'' (Ω・cm)
−' or more was obtained. Furthermore, the photoconductivity was 1000 times or more as compared to the dark conductivity, which indicates that this a-SiC layer has photoconductivity that is sufficiently satisfactory for use in electrophotographic photoreceptors.

(Example 2) In this example, when BzHh gas (or Plh gas) was introduced based on (Example 1) and the dark conductivity and photoconductivity were measured, the results shown in Figure 27 were obtained. Ta.

In the figure, the horizontal axis is B for the total flow rate of 5 kHa and CzHz.
,H.

The pure amount (this is the absolute flow rate of B, H, calculated from the dilution ratio of Ht gas). Furthermore, az
A case where the uhN amount is replaced with PH, the pure amount, is also described as a reference example.

According to FIG. 27, the mark is a plot of dark conductivity,
The circle mark is a plot of photoconductivity, and c and d are respective characteristic curves.

As is clear from FIG. 27, the photoconductivity is more than 1000 times that of the dark conductivity, and P J? The a-5iC layer doped with 3B has satisfactory photoconductivity for use in electrophotographic photoreceptors.

(Example 3) In this example, (Example 1) medium CzHt gas flow rate is 105
The spectral sensitivity characteristics of a-5iCJiI obtained by setting CCII+ were measured, and the results were the spectral sensitivity curve ge 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 CJz gas flow rate is 1010
a-3iC layer (thickness 30 μm) obtained by setting 5c
The characteristics of surface potential, dark decay, and light decay were measured. This measurement was performed by positively charging with a +5.6KV corona charger, and by measuring the change in surface potential over time in the dark and the 650KV corona charger.
This figure follows the change in surface potential over time immediately after irradiation with nm monochromatic light.

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

As is clear from FIG. 29, the surface potential is as large as about +600V, and the dark decay is about 25χ 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-stc layer obtained in (Example 4) was heated to -5.6 KV.
When negatively charged with a corona charger, the surface potential was several tens of volts.

And a-5iC manufactured based on this (Example 4)
The layered photoreceptor was positively charged with a +5.6KV corona charger, and then exposed to image light to perform a magnetic brush phenomenon. As a result, a high-quality image with high image density and contrast was 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 device shown in FIG. 12), BJh gas from the third tank (13), and 1 from the fifth tank (15).
1□ gas and No gas were released from the sixth tank (16), respectively, and the first layer region and the second layer region were formed under the manufacturing conditions shown in Table 1.

The electrophotographic properties of the photoreceptor thus obtained were +5 in the dark.
．． Positively charged with a corona charger connected to a 6KV high voltage source, and then split into 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...+700v Photosensitivity...0.38c is erg-' Residual potential...25V (Example 6) In this example, the photoreceptor of the second embodiment was manufactured under the conditions shown in Table 2, As a result, the following electrophotographic properties were obtained.

Surface potential...+760v Photosensitivity...0.40 CIlterg-1 Residual potential...
-30V (Example 7) In this example, a photoreceptor of the third embodiment was manufactured under the conditions shown in Table 3, and the following electrophotographic characteristics were obtained.

Surface potential...+820■ Photosensitivity...0.42C1erg-1 Residual potential...35V In addition, the surface potential, dark decay, and light decay characteristics of this photoreceptor were measured in the same manner as in (Example 4). Then, 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, approximately +820 V, and the dark decay is approximately 8χ after 5 seconds, indicating excellent charge retention ability.

(Example 8) In this example, a photoreceptor of the fourth embodiment was manufactured under the conditions shown in Table 4, and the following electrophotographic characteristics were obtained.

Surface potential...+870■ Photosensitivity...0.42cl12erg-1 (Example 9) In this example, the film formation rate was measured under the following manufacturing conditions using the glow discharge decomposition apparatus shown in Figure 25. However, the results shown in FIG. 31 were obtained.

RF power...150W Gas pressure...0.45TOrr Substrate temperature...300℃ 5in4 gas flow rate...100scc+wUZ gas flow rate...300sec The ○ marks in Figure 31 are plots of measurement results. , and j is its characteristic curve.

As is clear from Fig. 31, as the content ratio of CJt gas increases, the film formation rate increases, and the rate of film formation increases by approximately 5.
The film formation rate was ~13μ/hour.

(Example 10) In this example, C
, H, and the hydrogen content in the film while changing the content ratio of the gases, the results shown in FIG. 32 were obtained.

In FIG. 32, marks O and * are plots showing the amount of H bonded to C and Si, respectively, and k and 1 are their characteristic curves, respectively.

As is clear from Fig. 32, as the content ratio of CtHz gas increases, the number of C-H bonds increases and the number of 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-SiC layer could be provided.

Further, 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-rich Ht 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 group A elements in the layer thickness direction, it is possible to improve the surface potential, enhance the photosensitivity characteristics, and significantly reduce the residual potential. can.

In particular, when the carbon content is varied in the layer thickness direction, the resistivity can be controlled and the required N region 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, a positive polarity electrophotographic photoreceptor that can be charged advantageously to positive polarity is provided.

Furthermore, when a conventional a-St photoreceptor is used for a long period of time, local discharge damage on the surface of the photoreceptor is likely to occur due to corona discharge, which causes spots on the image. However, according to the manufacturing method of the present invention, a
-St has a dielectric constant of ε=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 producing 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 special protective layer, and, for example, it is not necessary to provide a protective layer due to exposure to corona discharge or the resin component of the developer. When the surface of a photoconductor is deteriorated due to filming, etc., the initial characteristics of the photoconductor 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-St photoreceptor, the problem with the a-5i photoreceptor is that it is inferior in moisture resistance, which 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 the a-S i photoreceptor is used, 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-3T 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 the JW 6i area of the photoconductor of the second embodiment of the present invention. 11, 12, 13, 14, 15
16 and 16 are explanatory diagrams showing the carbon content of the second B-type photoconductor according to the present invention, respectively, and FIG. 17 is an explanatory diagram showing the i-area of the third embodiment photoconductor according to the present invention. , FIG. 18, FIG. 19, FIG. 20, and FIG. 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. 23 and 24 are explanatory diagrams showing the carbon content of the photoconductor of the fourth embodiment according to the present invention, and FIG. 25 is an explanatory diagram showing the layer area 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 the conductivity versus the flow rate ratio of CtH2 gas, and FIG. 27 is a diagram showing the conductivity with respect to the flow rate ratio of CtH2 gas
*A diagram showing the electrical conductivity for each gas flow rate ratio, 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 optical attenuation of the amorphous silicon carbide layer. , FIG. 30 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 versus Ctll and gas flow rate ratio, and FIG. 32 is a diagram showing C.
FIG. 3 is a diagram showing the bonding ratio of hydrogen atoms to the flow rate ratio of YoH□ gas. Process...Substrates 5.5a, 5b, 5c...Photoconductive amorphous silicon carbide layer 6...First layer region 7...Second layer region 8...Third and third layers Region 9...Fourth layer Region 10...Amorphous silicon carbide surface protective layer Patent applicant (663) Kyocera Corporation Takao Kawamura

Claims (3)

[Claims] (1) Consisting of at least acetylene and silicon-containing gas, the gas composition ratio is set within the range of 0.01:1 to 3:1, and 10^-^6 to 1 mol% Group IIIa of the periodic table A method for producing an electrophotographic photoreceptor, which comprises forming an amorphous silicon carbide layer that can be positively charged on a substrate by glow discharge decomposition of an amorphous silicon carbide generating gas containing an element-containing gas. (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 electrophotographic photoreceptor according to claim (1), wherein the amorphous silicon carbide layer contains 1 to 90 atomic % carbon and 5 to 50 atomic % hydrogen. Manufacturing method.