JPH0211142B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to light (here, light in a broad sense, including ultraviolet rays, visible rays, infrared rays, X-rays, γ-rays, etc.)
It relates to photoconductive members sensitive to electromagnetic waves such as. As a photoconductive material for forming a photoconductive layer in a solid-state imaging device, an electrophotographic image forming member in the image forming field, or a document reading device, it is highly sensitive,
It has a high signal-to-noise ratio [photocurrent (Ip)/(Id)], has absorption spectrum characteristics that match the spectrum characteristics of the irradiated electromagnetic waves, has fast photoresponsiveness, has the desired dark resistance value, and when used. Solid-state imaging devices are required to have characteristics such as being non-polluting to the human body and being able to easily process afterimages within a predetermined time. Especially,
In the case of an electrophotographic image forming member incorporated into an electrophotographic apparatus used in an office as a business machine, the above-mentioned non-polluting property during use is an important point. Based on this perspective, amorphous silicon (hereinafter referred to as a-
Si), for example, the German publication No.
No. 2746967 and No. 2855718 disclose applications to electrophotographic image forming members, and German Publication No.
No. 2933411 describes the application to a photoelectric conversion/reading device. However, the conventional photoconductive member having a photoconductive layer composed of a-Si has low dark resistance value, photosensitivity,
Further improvements require comprehensive improvements in electrical, optical, and photoconductive properties such as photoresponsivity, use environment properties such as moisture resistance, and stability over time. The reality is that there are issues that need to be addressed. For example, when applied to an electrophotographic image forming member, when trying to achieve high photosensitivity and high dark resistance at the same time, it has often been observed in the past that residual potential remains during use, and this type of photoconductive When a member is used repeatedly for a long period of time, fatigue due to repeated use may accumulate, resulting in a number of disadvantages such as a so-called ghost phenomenon in which an afterimage occurs. Furthermore, for example, according to many experiments conducted by the present inventors, a-Si as a material constituting the photoconductive layer of an electrophotographic image forming member can be used with conventional inorganic photoconductive materials such as Se, CdS, and ZnO. Although it has many advantages compared to organic photoconductive materials such as PVCz and TNF, it has a single-layer photoconductive layer made of a-Si that has properties suitable for use in conventional solar cells. Even if the photoconductive layer of the photographic image forming member is subjected to charging treatment for electrostatic image formation, dark decay is extremely fast, and preferably electrophotography is difficult to apply; In addition, it has been found that there are many issues that need to be resolved, such as the above-mentioned tendency being remarkable in a humid atmosphere, and in some cases, it may be impossible to hold the charged charge until the time of occurrence. ing. Furthermore, when forming a photoconductive layer with an a-Si material, hydrogen atoms, halogen atoms such as fluorine atoms and chlorine atoms, and electrically conductive type Boron atoms, phosphorus atoms, etc. are contained in the photoconductive layer as constituent atoms for the purpose of controlling In some cases, problems may arise with the electrical and photoconductive properties of the formed layer. In particular, at the interface between adjacent layers, dangling bonds are likely to be formed due to the manufacturing process, and complex bending of energy bands is likely to occur, depending on the content and distribution of atoms contained therein. For this reason, the various changes in charge behavior and structural stability issues are especially important, and control of these areas holds the key to success or failure in order for the photoconductive member to perform its intended function. There are quite a few. Furthermore, when an a-Si photoconductive member is made by a generally known method, for example, photocarriers generated in the formed photoconductive layer due to light irradiation may not have a sufficient lifespan in the layer. If sufficient image density cannot be obtained based on the image density, or if the image exposure amount is large, the image tends to become blurred and or even,
Problems often occur due to insufficient prevention of charge injection from the support side. Therefore,
While efforts are being made to improve the properties of the a-Si material itself, it is necessary to take measures to obtain the desired electrical and optical properties as described above when designing photoconductive members. The present invention has been made in view of the above points, and includes a
-As a result of intensive research and study on Si from the viewpoint of its applicability as a photoconductive member used in electrophotographic image forming members, solid-state imaging devices, reading devices, etc., we have found that a-Si, In particular, silicon atoms are used as the base material, hydrogen atoms (H) and halogen atoms (X)
Amorphous materials containing at least one of the above, i.e., so-called hydrogenated a-Si, halogenated a-Si, or halogen-containing hydrogenated a-Si
(Hereinafter, these will be collectively referred to as a-Si (H, The photoconductive member not only exhibits extremely superior properties in practical use, but also surpasses conventional photoconductive members in every respect;
This is based on the discovery that it has particularly excellent properties as a photoconductive member for electrophotography. An object of the present invention is to provide a photoconductive member for electrophotography that can easily obtain high-quality images with high density, clear halftones, and high resolution, and without image defects or image deletion. purpose. Another object of the present invention is to provide an all-environment type product whose electrical, optical, and photoconductive properties are almost unaffected by the usage environment and are always stable, and which has excellent light fatigue resistance and does not deteriorate even after repeated use. It is an object of the present invention to provide a photoconductive member that does not cause any phenomenon, has excellent durability, and has no or almost no residual potential observed. Another object of the present invention is that when applied as an electrophotographic image forming member, it has sufficient charge retention ability during charging processing for electrostatic image formation, and ordinary electrophotographic methods can be applied extremely effectively. It is an object of the present invention to provide a photoconductive member having excellent electrophotographic properties that can be used. Yet another object of the present invention is high photosensitivity,
Another object of the present invention is to provide a photoconductive member having high signal-to-noise ratio characteristics and good electrical contact between laminated layers. That is, the photoconductive member of the present invention includes a support, a photoconductive first layer provided on the support and made of an amorphous material containing silicon atoms as a matrix, and the first photoconductive layer. A photoconductive member for electrophotography, comprising: a second layer having a thickness of 0.003 to 30 μm and made of an amorphous material containing silicon atoms and carbon atoms as essential components; The first layer contains at least one kind of atom selected from Group 3 of the periodic table and a nitrogen atom, and the nitrogen atom is added to the second layer from a portion above the center of the layer in the thickness direction of the layer. It has a concentration distribution such that the concentration of nitrogen atoms increases toward Regarding the table group atoms, 80 to 1×10 ⁵ atomic ppm is added to the end surface of the layer on the side where the support is provided or in the vicinity thereof in the thickness direction of the layer.
It is characterized by having a concentration distribution having a maximum concentration of . The photoconductive member of the present invention, in which the photoconductive layer has the above-described layer structure, can solve all of the problems described above, and has extremely excellent electrical properties.
Indicates optical, photoconductive properties and usage environment characteristics. In particular, when applied as an image forming member for electrophotography, it has excellent charge retention ability during charging processing, has no influence of residual potential on image formation, has stable electrical properties, and has high sensitivity. It has a high signal-to-noise ratio, can obtain high-quality visible images with high image density, clear halftones, and high resolution, and has excellent light fatigue resistance and repeated use characteristics. Excellent for repeated use under humid atmosphere. Hereinafter, the photoconductive member of the present invention will be explained in detail with reference to the drawings. FIG. 1 is a diagram schematically showing a layer structure for explaining an embodiment of the structure of a photoconductive member of the present invention. Figures 2a to 2d are diagrams schematically showing the concentration distribution of nitrogen atoms and periodic table group atoms in the first layer of the photoconductive member of the present invention. The photoconductive member 100 of the present invention, as shown in FIG.
A photoconductive first layer 102 containing -Si, preferably a-Si (H, A second layer 103 containing as an essential component is formed and configured. The photoconductive member 100 of the present invention includes a-Si
An amorphous layer 102 containing (H, X) as main components and having photoconductivity is formed. The nitrogen atoms doped (contained) in the first layer have a nearly uniform concentration distribution state in the direction parallel to the support surface, but in the layer thickness direction, the concentration distribution state is almost uniform in the layer as shown in FIGS. 2a to 2t. (The vertical axis shows the distance from the support, and the horizontal axis shows the atomic concentration.) It has a distribution. Note that the concentration of nitrogen atoms from the center of the layer toward the surface on which the support is provided may have a constant concentration distribution as represented in FIG. 2a, or It may have a concentration distribution in which the nitrogen atom concentration increases, as typified by FIG. 2b. On the other hand, regarding the atoms of group of the periodic table doped in the first layer, the concentration distribution is almost uniform in the direction parallel to the support surface in the layer, similar to the nitrogen atom concentration; Regarding the layer thickness direction, the above-mentioned support is The maximum concentration is at or near the end face of the body. Note that the concentration distribution of atoms of Group Group of the periodic table from the central part of the layer toward the second layer is such that the concentration distribution increases as the nitrogen atom concentration increases, as typified by Figure 2a. It is preferable to have. In addition, the portion having the maximum nitrogen atom concentration or the portion having the maximum periodic table group atom concentration within the layer is shown in Figures 2d and 2i, respectively.
As shown in the figure, it may have a certain length in the layer thickness direction, or it may be just one point. Concerning the mode of increase, it is more preferable that it is continuous, but there is no problem even if it changes stepwise.The type of density distribution to be provided depends on the function required of the image forming member and the photoconductive member. The characteristics are selected appropriately depending on the manufacturing equipment. The photoconductive member of the present invention having the first layer formed in such a manner that the concentration of nitrogen atoms and atoms of group 3 of the periodic table has the above-mentioned atomic concentration relative to the layer thickness is suitable for use in electrophotography. When used as a photoreceptor, it produces high-quality visible images with clear halftones, clear halftones, and high resolution even when the image density is high and the image exposure amount is high. This is due to the effect of increasing the resistance of the first layer having photoconductivity due to nitrogen atom doping and the high concentration of nitrogen atoms near the layer interface between the first layer and the second layer. It is presumed that this is based on the fact that an extremely good charge-accepting ability is achieved by widening the energy band of the part, and on the effect of preventing charge injection from the support side by doping with atoms of group group of the periodic table. That is,
If a layer bonding interface exists in the upper part of the first layer,
It is understood that the excess carriers generated here move wherever an electric field is applied, causing the effect of canceling out the charge in dark areas, resulting in image blurring, but with the wide cap described above, Even if complex bending of energy bands occurs at the layer bonding interface, the activation energy for carrier generation becomes large and carriers are not easily generated. The reason why it is more preferable to have a concentration distribution in which the group atoms of the periodic table increase from the central part of the layer to the second layer in accordance with the increase in the nitrogen atom concentration is as follows.
As the concentration of nitrogen atoms increases toward the surface, the number of nitrogen atoms doped as donors also increases. In order to compensate for this, the number of atoms of Group Group of the periodic table is also increased. The concentration of nitrogen atoms doped in the first layer is
The concentration is preferably 0.1 in the most part where it is maximum, that is, in the vicinity of the layer junction interface with the second layer.
~50 atomic%, more preferably 1-57 atomic%,
The optimum concentration is 5 to 57 atomic %, and the concentration is preferably 0.005 to 35 atomic % in the lowest part, that is, in the central part of the layer or its vicinity.
More preferably 0.01-30atomic%, optimally 0.5
~25 atomic%. The maximum content concentration and the minimum content concentration of nitrogen atoms are determined within the above numerical range as appropriate according to the content concentration of Group Group atoms of the Periodic Table, respectively. In order to more effectively achieve the object of the present invention, it is desirable to increase the concentration of each of them. In addition, the maximum content concentration is preferably compared to the minimum content concentration.
It is desirable that the ratio be 1.05 times or more, more preferably 1.1 times or more, and optimally 1.15 times or more. In addition, the content of Group Group atoms of the periodic table is usually 80 to 1×10 ⁵ atomic ppm in the part where the concentration is maximum, that is, in the end face of the layer on the side where the support is provided or in the vicinity thereof. , preferably 100~
5×10 ⁴ atomic ppm, optimally 150 to 1×
10 ⁴ atomic ppm, while in the very small part, i.e. the central part of the first layer, it is usually 1 to 4 atomic ppm.
1000 atomic ppm, preferably 5-700 atomic
ppm, preferably 10 to 500 atomic ppm. The above maximum content concentration and minimum content concentration are determined within the above numerical ranges according to the nitrogen atom content concentration, but it is best to increase each content concentration according to the nitrogen atom content concentration. This is desirable for achieving the purpose of the invention more effectively. Further, it is desirable that the maximum content concentration is preferably twice or more, more preferably three times or more, as compared to the minimum content concentration. In the present invention, specific examples of the halogen atom (X) that may be contained in the first layer include fluorine, chlorine, bromine, iodine, etc., and chlorine, especially fluorine, is particularly preferred. It can be mentioned as. Examples of the periodic table group atoms doped into the first layer include boron, aluminum, gallium, indium, and thallium, with boron being particularly preferred. The support used in the present invention may be electrically conductive or electrically insulating. Examples of the conductive support include NiCr, stainless steel, Al,
Examples include metals such as Cr, Mo, Au, Nb, Ta, V, Ti, Pt, Pd, and alloys thereof. As the electrically insulating support, films or sheets of synthetic resins such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, glass, ceramic, paper, etc. are usually used. . Preferably, at least one surface of these electrically insulating supports is conductively treated, and another layer is preferably provided on the conductively treated surface side. That is, for example, if it is glass, its surface may contain NiCr, Al, Cr, Mo, Au, Ir, Nd, Ta,
V, Ti, Pt, In ₂ O ₃ , SnO ₂ , ITO (In ₂ O ₃ + SnO ₂ )
Conductivity can be imparted by providing a thin film consisting of NiCr, Al, Ag, Pb, Zn, etc., or if it is a synthetic resin film such as polyester film.
Ni, Au, Cr, Mo, Ir, Nb, Ta, V, Ti, Pt
Conductivity is imparted to the surface by providing a thin film of a metal such as by vacuum evaporation, electron beam evaporation, sputtering, etc., or by laminating the surface with the metal. The shape of the support is determined depending on the need, but for example, the photoconductive member 1 shown in FIG.
If 00 is used as an electrophotographic image forming member, it is preferably in the form of an endless belt or a cylinder for continuous high-speed copying. The thickness of the support is determined appropriately so that a desired photoconductive member is formed, but if flexibility is required as a photoconductive member, the support can sufficiently function as a support. It is made as thin as possible within this range. However, in such cases, in terms of manufacturing and handling of the support, as well as mechanical strength, it is usually
It is considered to be 10 μm or more. In the present invention, in order to form the first layer composed of a-Si (H, Applicable. For example, by glow discharge method, a-Si(H,X)
In order to form the first layer composed of, basically, together with a raw material gas for supplying Si that can supply silicon atoms (Si), a raw material gas for introducing hydrogen atoms (H) and/or
Alternatively, depending on the raw material gas for introducing halogen atoms (X) and the constituent atomic composition of the formation region, the raw material gas for introducing nitrogen atoms (N) and the raw material gas for introducing atoms of group 3 of the periodic table may be optionally mixed with Ar, A plasma atmosphere of these gases is created by introducing a predetermined mixing ratio and gas flow rate together with an inert gas such as He into a deposition chamber that can reduce the pressure inside the chamber to generate a glow discharge in the deposition chamber. By forming a layer of a-Si (H, In addition, when forming the first layer by the sputtering method, for example, in an atmosphere of an inert gas such as Ar or He, or a mixed gas based on these gases.
When sputtering a target composed of Si, a gas for introducing hydrogen atoms (H) and/or halogen atoms (X) and a raw material gas and period for introducing nitrogen atoms (N) are used depending on the atomic composition of the forming region. It is sufficient to introduce a raw material gas for introducing atoms of the Table of Groups into a deposition chamber for sputtering. The raw material gas for supplying Si used to form the first layer includes SiH ₄ , Si ₂ H ₆ , Si ₃ H ₈ ,
Gaseous silicon hydrides (silanes) such as Si ₄ H ₁₀ , which are in a gaseous state or can be gasified, can be effectively used, especially in terms of ease of handling in layer creation work, good Si supply efficiency, etc. Preferred examples include SiH ₄ and Si ₂ H ₆ . In the present invention, in order to introduce hydrogen atoms into the first layer, H ₂ or the above-mentioned SiH ₄ , Si ₂ H ₆ ,
This is carried out by supplying a silicon hydride gas such as Si ₃ H ₈ or Si ₄ H ₁₀ into a deposition chamber to generate an electric discharge. In the present invention, many halides are effective as the raw material gas for introducing halogen atoms that can be used to form the first layer, such as halogen gas, halides, interhalogen compounds,
Preferred examples include gaseous or gasifiable halogen compounds such as halogen-substituted silane derivatives. Furthermore, a gaseous state or gasifiable compound containing a silicon atom and a halogen atom,
Silicon compounds containing halogen atoms can also be mentioned as effective. Specifically, halogen compounds that can be suitably used to form the first layer in the present invention include halogen gases such as fluorine, chlorine, bromine, and iodine; BrF, ClF, ClF ₃ , BrF ₃ , _BrF5 , _IF3 , _IF7 ,
Examples include interhalogen compounds such as ICl and IBr. Preferred examples of silicon compounds containing halogen atoms, so-called silane derivatives substituted with halogen atoms, include silicon halides such as SiF ₄ , Si ₂ F ₆ , SiCl ₄ , and SiBr ₄ . can. As the raw material gas for introducing halogen atoms into the first layer, the above-mentioned halogen compounds or halogen-containing silicon compounds are effectively used, but in addition, HF, HCl,
Hydrogen halides such as HBr and HI, SiH ₂ F ₂ ,
Halogen-substituted silicon hydrides such as SiH ₂ I ₂ , SiH ₂ Cl ₂ , SiHCl ₃ , SiH ₂ Br ₂ , SiHBr ₃ , etc., and halides that have a hydrogen atom as one of their constituents in a gaseous state or can be gasified. Mention may be made as starting materials for forming the first layer. These halides containing hydrogen atoms are
When forming a layer, halogen atoms can be introduced at the same time as hydrogen atoms, which are extremely effective components for controlling electrical or photoelectric properties, so halogen atoms are suitable in the present invention. Used as raw material for introduction. In the present invention, the raw material gas for supplying nitrogen atoms used to form the first layer includes gases containing N as a constituent atom, such as nitrogen (N ₂ ), ammonia (NH ₃ ), hydrazine (H ₂ NNH ₂ ), gaseous or gasifiable nitrogen such as hydrogen azide (HN ₃ ), ammonium azide (NH ₄ N ₃ ), and nitrogen compounds such as nitrides and azides. In addition, nitrogen trifluoride (F ₃ N),
Examples include halogenated nitrogen compounds such as nitrogen tetrafluoride (F ₄ N ₂ ). In the present invention, the raw material gases for supplying atoms of group of the periodic table used to form the first layer include B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B ₅ H ₁₁ , B _{6H10 ,}
Examples include GaCl ₃ , AlCl ₃ , BF ₃ , BCl ₃ , BBr ₃ and BI ₃ . To form the first layer of a-Si (H, In the case of the ion plating method, polycrystalline silicon or single crystal silicon is housed in a deposition boat as an evaporation source, and this silicon evaporation source is heated using a resistance heating method or an electron beam method (EB method). This can be carried out by heating and evaporating the flying evaporated material using a method such as the method (method), etc., and passing the flying evaporated material through a predetermined gas plasma atmosphere. At this time, in both the sputtering method and the ion plating method, hydrogen atoms (H) and/or
Alternatively, depending on the gas for introducing halogen atoms (X), the raw material gas for introducing nitrogen atoms (N), and the raw material gas for introducing atoms of group 3 in the periodic table, depending on the atomic composition of the formation region, He , Ar, and other inert gases may be introduced into the sputtering or ion plating chamber to form a plasma atmosphere of the gases. To control the amount of hydrogen atoms, halogen atoms, nitrogen atoms, and atoms of Group Group of the Periodic Table contained in the first layer, for example, hydrogen atoms (H), halogen atoms (X)
One or more of the following may be controlled: the amount of the starting material used to contain nitrogen atoms (N) and atoms of group group of the periodic table introduced into the deposition system, the support temperature, and the discharge power. In the present invention, the diluting gas used when forming the first layer by a glow discharge method or a sputtering method is a so-called rare gas, such as He, Ne,
Preferred examples include Ar. Photoconductive first layer 102 in the present invention
The second layer 103 formed thereon has a free surface and is provided mainly to achieve the objectives of the present invention in terms of moisture resistance, continuous repeated use characteristics, electrical pressure resistance, use environment characteristics, and durability. It will be done. The photoconductive first layer and the second photoconductive layer in the present invention
Since each of the layers has a common constituent atom of silicon atoms, sufficient chemical stability is ensured at the laminated interface. The second layer 103 in the present invention is made of an amorphous material (hereinafter referred to as a-(Si _x C _1-x ) _y (H, X) written as _1-y ,
However, 0<x, y<1). The second composed of a-(Si _x C _1-x ) _y (H, X) _1-y
The layer is formed by a glow discharge method, a sputtering method, an ion implantation method, an ion plating method, an electron beam method, or the like. These manufacturing methods are selected and adopted as appropriate depending on factors such as manufacturing conditions, amount of equipment capital investment, manufacturing scale, and desired characteristics of the photoconductive member to be manufactured. Glow discharge has the advantages of being relatively easy to control the conditions for manufacturing photoconductive members, and of being able to easily introduce carbon atoms and halogen atoms together with silicon atoms into the second layer. A sputtering method or a sputtering method is preferably employed. Further, the second layer may be formed by using a glow discharge method and a sputtering method in the same apparatus system. To form the second layer by the glow discharge method, the raw material gas for forming a-(Si _x C _1-x ) _y ( _H , and introduced into a deposition chamber for vacuum deposition in which a support on which a photoconductive first layer is formed is installed;
The introduced gas is turned into gas plasma by causing a glow discharge, and a-(Si _x C _1-x ) _y (H, X) ₁ is deposited on the photoconductive first layer on the support.
_-y may be deposited. In the present invention, a-(Si _x C _1-x ) _y (H, X) _1-y
As raw material gas for formation, silicon atoms (Si),
Carbon atom (C), hydrogen atom (H) and halogen atom (X)
Most gaseous substances containing at least one of the following as constituent atoms or gasified substances that can be gasified can be used. When using a raw material gas containing Si as one of Si, C, H, and X, for example, Si
A raw material gas containing C as a constituent atom, a raw material gas containing C as a constituent atom, and a raw material gas containing H as a constituent atom and/or a raw material gas containing X as a constituent atom as necessary are mixed at a desired mixing ratio. Alternatively, a raw material gas containing Si as a constituent atom and a raw material gas containing C and H as constituent atoms and/or a raw material gas containing C and X as constituent atoms are mixed at a desired mixing ratio. Alternatively, a raw material gas containing Si as a constituent atom and a raw material gas containing Si, C and H as constituent atoms, or a raw material gas containing Si, C and X as constituent atoms. Examples include mixing and using them at a desired mixing ratio. Alternatively, a raw material gas containing Si and H as constituent atoms and a raw material gas containing C as constituent atoms may be mixed together, or a raw material gas containing Si and X as constituent atoms may be used. , C may be used in combination with a raw material gas having C as a constituent atom. In the present invention, preferred halogen atoms (X) that may be contained in the second layer include F,
Cl, Br, and I, with F and Cl being particularly desirable. In the present invention, gases effectively used as raw material gases for forming the second layer include SiH ₄ , Si ₂ H ₆ , Si ₃ H ₈ , and Si ₄ H ₁₀ whose constituent atoms are Si and H. Silicon hydride gas such as; C and H as constituent atoms, for example, saturated hydrocarbons having 1 to 4 carbon atoms, 2 carbon atoms
~4 ethylene hydrocarbons, acetylene hydrocarbons having 2 to 4 carbon atoms; simple halogens; hydrogen halides; interhalogen compounds; silicon halides;
Examples include halogen-substituted silicon hydride. Specifically, saturated hydrocarbons include methane,
Ethane, propane, n-butane, pentane; ethylene hydrocarbons include ethylene, propylene, butene-1, butene-2, i-butylene, pentene; acetylene hydrocarbons include acetylene, methylacetylene, butyne; halogens As simple substances, halogen gases include fluorine, chlorine, bromine, and iodine; as hydrogen halides, HF, HI,
HClHBr; Interhalogen compounds include ClF,
_ClF3 , _ClF5 , BrF, _BrF3 , _BrF5 , _IF5 , _IF7 ,
ICl, IBr; silicon halides include SiF ₄ ,
_Si2F6 , _{SiCl4 , SiCl3Br} , _SiCl2Br2 , _{SiClBr3 ,}
SiCl ₃ I, SiBr ₄ ; Examples of halogen-substituted silicon hydride include SiH ₂ F ₂ , SiH ₂ Cl ₂ , SiHCl ₃ , SiH ₃ Cl,
Examples include SiH ₃ Br, SiH ₂ Br ₂ and SiHBr ₃ . In addition to these, CF ₄ , CCl ₄ , CBr ₄ , CHF ₃ ,
_CH2F2 , _CH3F , _CH3Cl , _CH3Br , _{CH3I ,}
Halogen-substituted paraffinic hydrocarbons such as C ₂ H ₅ Cl,
Fluorinated sulfur compounds such as SF ₄ and SF ₆ ; Si(CH ₃ ) ₄ ,
Alkyl silicides such as Si(C ₂ H ₅ ) ₄ ; SiCl(CH ₃ ) ₃ ,
Silane derivatives such as halogen-containing alkyl silicides such as SiCl ₂ (CH ₃ ) ₂ and SiCl ₃ CH ₃ can also be mentioned as effective. These second layer-forming materials are
When forming the second layer, silicon atoms, carbon atoms, and optionally halogen atoms and/or hydrogen atoms are selected as desired so that the layer contains silicon atoms, carbon atoms, and optionally halogen atoms and/or hydrogen atoms in a predetermined composition ratio. used. For example, Si(CH ₃ ) ₄ can easily contain silicon atoms, carbon atoms, and hydrogen atoms and can form a layer with desired characteristics, and SiHCl ₃ and SiH ₂ can contain halogen atoms. Cl ₂ , SiCl ₄ or
Add SiH ₃ Cl, etc. to a predetermined mixing ratio in a gas state.
a-(Si _x C _{1-x ) y} (H,
A second layer consisting of: In order to form the second layer by the sputtering method, a monocrystalline or polycrystalline Si wafer and/or a C wafer or a wafer containing a mixture of Si and C is targeted, and these are necessary. Depending on the situation, sputtering may be performed in various gas atmospheres containing halogen atoms and/or hydrogen atoms as constituent elements. For example, if a Si wafer is used as a target, the raw material gas for introducing C, H and/or X is diluted with diluent gas as necessary.
The Si wafer may be sputtered by introducing the gas into a deposition chamber for sputtering and forming a gas plasma of these gases. Alternatively, by using a target other than Si and C, or by using a single target containing a mixture of Si and C, a gas atmosphere containing hydrogen atoms and/or halogen atoms can be created as necessary. This is done by sputtering inside.
As a material serving as a raw material gas for introducing C, H, and X, the material for forming the second layer shown in the glow discharge example described above can also be used as an effective material in the sputtering method. In the present invention, the diluent gas used when forming the second layer by a glow discharge method or a sputtering method is a so-called rare gas such as He, Ne,
Ar and the like can be mentioned as suitable examples. The second layer in the present invention is carefully formed to provide the desired properties. In other words, substances containing Si, C, and optionally H and/or semiconducting,
It shows properties ranging from insulating properties and properties ranging from photoconductive properties to non-photoconductive properties, so
In the present invention, the preparation conditions can be selected as desired so that a-(Si _x C _1-x ) _y (H,X) _1-y having desired characteristics depending on the purpose is formed. done strictly. For example, when providing the second layer with the main purpose of improving electrical breakdown voltage, a-(Si _x
C _{1-x ) y} (H, In addition, when a second layer is provided with the main purpose of improving the characteristics of continuous repeated use and the characteristics of the usage environment, the degree of electrical insulation described above is relaxed to a certain extent, and the layer has a certain degree of sensitivity to the irradiated light. As an amorphous material, a-(Si _x C _1-x ) _y (H, X) _1-y
is created. On the surface of the first layer a-(Si _x C _1-x ) _y (H,X) ₁
When forming the _second layer consisting of a-(Si _x C _1-x ) _y
It is desirable that the temperature of the support during layer formation be strictly controlled so that (H,X) _1-y can be formed as desired. In the present invention, the formation of the second layer is carried out by appropriately selecting the optimum range according to the method of forming the second layer in order to effectively achieve the desired purpose. ~400℃, more preferably 50~
The temperature is desirably 350°C, most preferably 100-300°C. Adoption of glow discharge method or sputtering method is advantageous because delicate control of the composition ratio of atoms forming the second layer is relatively easy compared to other methods. However, when forming the second layer using these layer forming methods, the discharge power during layer formation is created in the same manner as the support temperature described above.a-(Si _x C _1-x ) _y (H,X) can be cited as one of the important factors that influence the properties of _1-y . Discharge _power conditions for effectively producing a-(Si _x C _1-x ) _y (H, It is desirable that the power is preferably 10 to 300W, more preferably 20 to 250W, and optimally 50 to 200W. The gas pressure in the deposition chamber is preferably 0.01~
It is desirable to set it to 1 Torr, preferably about 0.1 to 0.5 Torr. In the present invention, the values in the above-mentioned ranges are mentioned as the preferable numerical ranges of the support temperature and discharge power for creating the second layer, but these layer creation factors can be determined independently and separately. , but the desired characteristics a-(Si _x C _1-x ) _y (H,X) _1-y
Preferably, the optimum value of each layer-forming factor is determined based on mutual organic relationships such that a second layer consisting of is formed. The amount of carbon atoms contained in the second layer in the photoconductive member of the present invention is:
Similar to the conditions for forming the second layer, this is one of the important factors for forming the second layer that provides the desired properties that achieve the object of the present invention. The amount of carbon atoms contained in the second layer in the present invention is appropriately determined as desired depending on the characteristics of the amorphous material constituting the second layer. That is, the general formula a-(Si _x C _1-x ) _y (H, X) _1-y
The amorphous material represented by can be broadly classified as an amorphous material composed of silicon atoms and carbon atoms (hereinafter referred to as
It is written as a-Si _a C _1-a . However, 0<a<1), an amorphous material composed of silicon atoms, carbon atoms, and hydrogen atoms (hereinafter referred to as a-(Si _b C _1-b ) _c H _1-c.However ,
0<b, c<1), an amorphous material composed of silicon atoms, carbon atoms, halogen atoms, and optionally hydrogen atoms (hereinafter a-(Si _d C _1-d ) _e (H, X) _1-e
It is written as However, it is classified as 0<d, e<1). In the present invention, when the second layer is composed of a-Si _a C _1-a , the amount of carbon atoms contained in the second layer is preferably 1×10 ^-3 to 90 atomic%, or more. Suitably 1-80 atomic%, optimally 10-80 atomic%
A desirable value is 75 atomic%.
That is, if we use the representation of a in the previous a-Si _a C _1-a , a
is preferably 0.1 to 0.99999, more preferably 0.2 to
0.99, optimally 0.25-0.9. On the other hand, in the present invention, the second layer is a-(Si _b
When composed of C _1-b ) _c H _1-c , the amount of carbon atoms contained in the second layer is preferably from 1×10 ⁻³ to
90 atomic%, more preferably 1~
A desirable value is 90 atomic%.
The content of hydrogen atoms is preferably 1-
40 atomic%, more preferably 2 to 35 atomic%,
The optimum value is 5 to 30 atomic%.
Photoconductive members formed with hydrogen contents within these ranges are well suited for practical applications. That is, if expressed as a-(Si _b C _1-b ) _c H _1-c above, b is preferably 0.1 to 0.99999, more preferably
0.1-0.99, optimally 0.15-0.9, preferably c
0.6-0.99, more preferably 0.65-0.98, optimally 0.7
~0.95 is desirable. When the second layer is composed of a-(Si _d C _1-d ) _e (H,X) _1-e , the content of carbon atoms contained in the second layer is as follows: Preferably 1×10 ^-3 ~
It is desirable that the content be 90 atomic %, more preferably 1 to 90 atomic %, most preferably 10 to 80 atomic %. The content of halogen atoms is preferably 1 to 20 atomic%, more preferably 1 to 20 atomic%.
The halogen atom content is preferably 18 atomic %, most preferably 2 to 15 atomic %, and photoconductive members prepared when the halogen atom content is within this range can be sufficiently applied in practice. The content of hydrogen atoms contained as necessary is preferably
It is desirable that the content be 19 atomic % or less, more preferably 13 atomic % or less. That is, d of the previous a-(Si _d C _1-d ) _e (H, X) _1-e ,
If expressed as e, d is preferably from 0.1 to
More suitable than 0.99999 is 0.1~0.99, optimally 0.15~
0.9, e is preferably 0.8 to 0.99, more preferably
It is desirable that it be between 0.82 and 0.99, most preferably between 0.85 and 0.98. The numerical range of the layer thickness of the second layer in the present invention is:
In order to effectively achieve the object of the present invention, it can be determined as desired depending on the intended purpose. In addition, the thickness of the second layer is determined according to the characteristics required for each layer, including the amount of carbon atoms contained in the second layer and the relationship with the thickness of the first layer. It needs to be appropriately determined according to the organic relationship and desired. In addition, it is desirable to take into account the economical aspects of productivity and mass production. The thickness of the second layer in the present invention is preferably 0.003 to 30 μm, more preferably 0.004 to 20 μm.
m, preferably 0.005 to 10 μm. The amount of carbon atoms contained in the second layer can be controlled by, for example, adjusting the flow rate of a gas introduced into the deposition chamber when using a glow discharge method, or by adjusting the flow rate of a gas for introducing carbon atoms into the deposition chamber, or when using a sputtering method. When forming a layer, the sputtering area ratio of the silicon wafer and the graphite wafer is changed when forming the target, or the mixing ratio of the silicon powder and the graphite powder is changed when forming the target. , can be controlled as desired. The amount of halogen atoms contained in the second layer can be controlled by adjusting the flow rate of a raw material gas for introducing halogen atoms introduced into the deposition chamber. Next, an example of a method for manufacturing a photoconductive member produced by a glow discharge decomposition method will be described. FIG. 3 shows an apparatus for manufacturing photoconductive members using the glow discharge decomposition method. Gas cylinders 1102 to 1106 in the diagram include
The raw material gas for forming the amorphous layer of the photoconductive member of the present invention is sealed, for example, 1102 is a cylinder of SiH ₄ gas (purity 99.99%), and 1103 is a cylinder of SiH 4 gas diluted with H ₂ . _B2H6 gas ₍ purity
99.99%, hereinafter abbreviated as B ₂ H ₆ /H ₂ gas) cylinder, 1
104 is NH ₃ gas (99.99% purity) cylinder, 11
05 is CH ₄ gas (99.99% purity) cylinder, 110
6 is a SiF ₄ gas (purity 99.99%) cylinder. Although not shown in the drawings, it is possible to add other desired gas types as needed. In order to flow these gases into the reaction chamber 1101, each valve 1 of the gas cylinders 1102 to 1106 is opened.
122 to 1126 and leak valve 1135 are closed, and inlet valve 1
112-1116, outflow valve 1117-112
1 and auxiliary valves 1132 and 1133 are open, first open the main valve 1134.
is opened to exhaust the reaction chamber 1101 and gas piping. Next, the reading on vacuum gauge 1136 is approximately 5×10 ^-6 torr.
When the temperature reaches 100, the auxiliary valves 1132, 1133 and the outflow valves 1117 to 1121 are closed. Next, SiH ₄ gas from gas cylinder 1102, B ₂ H ₆ /H ₂ gas from gas cylinder 1103, and gas cylinder 11.
NH ₃ gas from 04, from gas cylinder 1105
Inject CH ₄ gas and SiF ₄ gas from gas cylinder 1106 by opening valves 1122 to 1126 to adjust the pressure of outlet pressure gauges 1127 to 1131 to 1 Kg/cm ² , gradually opening inflow valves 1112 to 1116, and supplying SiF 4 gas to the mass flow controller. 1107 to 1111. Subsequently, the outflow valve 1117~
1121 and auxiliary valves 1132 and 1133 are gradually opened to allow the respective gases to flow into the reaction chamber 1101. At this time, the outflow valves 1117 to 1121
Also, while checking the reading on the vacuum gauge 1136, adjust the opening of the main valve 1134 so that the pressure inside the reaction chamber reaches the desired value. Then, the temperature of the gas cylinder 1137 is increased by the heating heater 1138.
After confirming that the temperature is set at 50 to 400° C., the power source 1140 is set to the desired power to generate glow discharge in the reaction chamber 1101. At the same time, in order to obtain the nitrogen atom and boron atom content curves designed in advance, the flow rates of NH ₃ gas and B ₂ H ₆ /H ₂ gas are changed appropriately, and the changing plasma state is corrected accordingly.
The first layer is formed by controlling the discharge power, substrate temperature, etc. as necessary. Further, during layer formation, the base cylinder 1137 is rotated at a constant speed by a motor 1139 in order to ensure uniform layer formation. Next, close all gas operation system valves used.
The reaction chamber 1101 is once evacuated to high vacuum. When the reading on the vacuum gauge 1136 reaches approximately 5×10 ^-6 torr, repeat the same operation as above to remove SiH ₄ ,
Open the operation system valves such as CH ₄ and He if necessary,
The flow rate of each raw material gas is controlled to a desired value, and a glow discharge is generated in the same manner as in the case of the first layer to form the second layer. When halogen atoms are contained in the second layer, the SiF ₄ operating valve may be simultaneously opened to generate glow discharge. Examples will be described below. Example 1 Using the photoconductive member manufacturing apparatus shown in FIG.
A first layer and a second layer having photoconductivity were formed on an Al cylinder according to the manufacturing conditions shown in Table 1 by the glow discharge decomposition method detailed above.
A part of the obtained drum-shaped photoconductive member was cut out, and the concentration of boron atoms and nitrogen atoms in the layer thickness direction was determined using a secondary ion mass spectrometer.
The concentration distribution results shown in FIG. 4 were obtained. In addition, the remaining part of the drum-shaped photoconductive member was set in an electrophotographic device, and the charging corona voltage was +6KV, and the image exposure was 0.8.
A latent image was formed at ~1.5 lux·sec, and subsequent development, transfer, and fixing processes were performed using well-known methods, and the image was evaluated. Image evaluation was performed by printing images equivalent to a total of 150,000 sheets using A4 size paper under normal conditions, and performing image printing equivalent to an additional 150,000 sheets in a high temperature and high humidity environment. [Density] [Resolution] [Tone reproducibility] of each image for each sample
Evaluations were made based on the quality of image defects, etc., and extremely good evaluations were obtained for all of the above items, regardless of environmental conditions or number of durable sheets. In particular, [concentration]
There is something noteworthy about the item, and it was confirmed that extremely high concentration can be obtained. This is also supported by the results of potential measurements; for example, when compared with a product without nitrogen atoms, it is 2 to 2.5
It was found that the acceptance potential was improved by about twice as much, indicating that the synergistic effect of increasing the resistance by doping the first layer with nitrogen atoms and preventing charge injection by changing the content of boron atoms was sufficiently effective. It was inferred. This improvement in charge acceptance ability is not limited to just image density, but also allows for a wide range of latitudes under corona conditions.
This has the great advantage of expanding the selection range of image quality. Another item worth mentioning is resolution, and this series of tests revealed that extremely clear images can be maintained under any environmental conditions. This seems to be the effect of having a nitrogen atomic concentration distribution as shown in Figure 4, where the maximum portion is near the bonding interface between the first layer and the second layer, and the nitrogen atomic concentration distribution that does not have such a nitrogen atomic concentration distribution The difference was obvious. Example 2 A drum-shaped photoconductive member was produced in the same manner as in Example 1 except that the concentration distribution form of nitrogen atoms and boron atoms was changed. Details of the manufacturing conditions are shown in Table 1. Regarding this drum-shaped photoconductive member, the constituent atomic concentration analysis and image evaluation were carried out in exactly the same manner as in Example 1. As a result, the nitrogen atom and boron atom concentration distribution results shown in FIG. 5 were obtained. In addition, good results almost equivalent to those of Example 1 were obtained regarding image evaluation. Comparative Example 1 and Examples 3 to 5 The concentration distribution forms of nitrogen atoms and boron atoms are shown in Figure 6 (Comparative Example 1) and Figures 7 to 9 (Examples 3 to 9).
A drum-shaped photoconductive member was produced in the same manner as in Example 1, except for the changes described in 5). The same image evaluation as in Example 1 was performed on these drum-shaped photoconductive members. As a result, for the drum-shaped photoconductive member of Comparative Example 1, the image was good under normal conditions, but under high temperature and high humidity conditions, it was found that
Image blurring occurred after the 10,000th print. On the other hand, with respect to the drum-shaped photoconductive members of Examples 3 to 5, very excellent contrast images were obtained, and no image deletion occurred even under high temperature and high humidity conditions. Example 6 For the first layer, Examples 1, 2, and
JP 57-52178 and JP 57-52179 were formed on a drum-shaped photoconductive member formed according to the same conditions and procedures as 3.
The second layer was formed using the sputtering method disclosed in detail in Table 3-1 under the conditions shown in Table 3-1, and the Examples except that the conditions were changed to those shown in Table 3-2. 15 types of samples (sample No. 6-1) in which a second layer was formed on the same drum-shaped photoconductive member as described above by the same glow discharge method as in No. 1.
-1 to 6-1-8, 6-2-1 to 6-2-8, 6
A total of 24 samples (3-1 to 6-3-8) were created. Each of the electrophotographic image forming members obtained in this way was individually installed in a copying machine, and
Corona charging was performed for 0.2 seconds and a light image was irradiated. The light source uses a tungsten lamp, and the light intensity is 1.0lux.
sec. The latent image was developed with a positively charged developer (including toner and carrier) and transferred to regular paper. The transferred image was extremely good. Toner remaining on the electrophotographic imaging member without being transferred was cleaned with a rubber blade. Even after repeating this process over 100,000 times, no image deterioration was observed in any case. Table 4 shows the results of the overall image quality evaluation of the transferred image of each sample and the evaluation of durability through repeated and continuous use. Example 7 When forming the second layer by sputtering method, the target area ratio of silicon wafer and graphite was changed, and the content ratio of silicon atoms and carbon atoms in the second layer was changed.
Each of the imaging members was made in exactly the same manner as in Example 1. For each of the image forming members thus obtained, the same image forming process as in Example 1 was carried out.
After repeating the development and cleaning steps 100,000 times, image evaluation was performed, and the results shown in Table 5 were obtained. Example 8 Same as Example 1 except that when forming the second layer, the flow rate ratio of SiH ₄ gas and C ₂ H ₄ gas was changed to change the content ratio of silicon atoms and carbon atoms in the second layer. Each of the imaging members was made in exactly the same manner. For each of the image forming members thus obtained, the same image forming, developing, and cleaning steps as in Example 1 were repeated 100,000 times, and then image evaluation was performed, and the results shown in Table 6 were obtained. . Example 9 When forming the second layer, SiH ₄ gas, SiF ₄ gas,
Each of the image forming members was created in exactly the same manner as in Example 1, except that the content ratio of silicon atoms and carbon atoms in the second layer was changed by changing the flow rate ratio of C ₂ H ₄ gas. did. For each of the imaging members thus obtained, similar to Example 1,
After repeating the steps of image formation, development, and cleaning 100,000 times, image evaluation was performed, and the results shown in Table 7 were obtained.

【table】

【table】

【table】

【table】

【table】

【table】

[Table] ◎: Very good ○: Good △: Practically sufficient. ×: Image defects occur.

[Table] ◎: Very good ○: Good △: Practically sufficient. ×: Image defects occur.

[Table] ◎: Very good ○: Good △: Sufficient for practical use
×: Image defects occur.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing a layer structure for explaining an embodiment of the structure of a photoconductive member of the present invention. Figures 2a to 2t are diagrams schematically showing the concentration distribution of nitrogen atoms and periodic table group atoms in the first layer of the photoconductive member of the present invention. Third
The figure shows an apparatus for manufacturing a photoconductive member using a glow discharge decomposition method. Figures 4, 5, 7-9 are
FIG. 3 is a diagram showing the analysis results of the constituent atomic concentration distribution of a photoconductive member in an example of the present invention. FIG. 6 is a diagram showing the analysis results of the constituent atomic concentration distribution of a photoconductive member of a comparative example. 100: Photoconductive member, 101: Support, 10
2: first layer, 103: second layer, 1101: reaction chamber, 1102-1106: gas cylinder, 110
7-1111: Mass flow controller, 1112
~1116: Inflow valve, 1117~1121:
Outflow valve, 1122-1126: Valve, 11
27-1131: Pressure regulator, 1132: Auxiliary valve, 1133: Auxiliary valve, 1134: Main valve, 1135: Leak valve, 1136: Vacuum gauge, 1137: Base cylinder, 1138: Heater, 1139: Motor, 1140: High frequency Power supply (matching box).

Claims (1)

[Claims] 1 a support, a photoconductive first layer provided on this support and made of an amorphous material with silicon atoms as a matrix, and a photoconductive first layer provided on this first layer and made of an amorphous material with silicon atoms as a matrix; and a layer thickness of 0.003 to 30 μm composed of an amorphous material containing carbon atoms as an essential component.
and a second layer of the electrophotographic photoconductive member, wherein the first layer contains at least one kind of atom selected from Group Group of the Periodic Table and a nitrogen atom, and the nitrogen atom contains: The layer has a concentration distribution such that its concentration of atoms increases from a portion above the center of the layer toward the second layer in the layer thickness direction, and the nitrogen atoms are present in the portion where the concentration is maximum. 0.1~57 atomic%, 0.005~ in the smallest part
35 atomic% of the periodic table group atoms are contained, and 80% of the periodic table group atoms are contained on or near the end surface on the side where the support is provided in the thickness direction of the layer.
A photoconductive member for electrophotography, characterized in that it has a concentration distribution having a maximum concentration of ~1×10 ⁵ atomic ppm.