JPH0454945B2 - - 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,
Must have a high signal-to-noise ratio [photocurrent (Ip)/dark current (Id)], have absorption spectral characteristics that match the spectral characteristics of the irradiated electromagnetic waves, have fast photoresponsiveness, and have the desired dark resistance value. At times, 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.
Particularly 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 these points, amorphous silicon (hereinafter referred to as a-Si) is a photoconductive material that has recently attracted attention. As a photographic image forming member, application to a photoelectric conversion reader is described in DE 2933411. However, conventional photoconductive members having photoconductive layers composed of a-Si have poor electrical, chemical, and photoconductive properties such as dark resistance, photosensitivity, and photoresponsiveness, as well as use environment characteristics. In terms of stability, stability over time, and durability, each property has been improved individually, but the reality is that there is still room for further improvement in terms of overall property improvement. be. For example, when applied to electrophotographic image forming members, when trying to achieve high photosensitivity and high dark resistance at the same time, in the past, it has often been observed that residual potential remains during use, and this type of photoconductive member When used repeatedly for a long period of time, fatigue accumulates due to repeated use, resulting in a so-called ghost phenomenon in which an afterimage occurs. In addition, when the photoconductive layer is composed of a-Si material, in order to improve its electrical and photoconductive properties, hydrogen atoms, halogen atoms such as fluorine atoms, chlorine atoms, etc., and electrically conductive type Boron atoms, phosphorus atoms, etc. are included for control purposes, and other atoms are included as constituent atoms in the photoconductive layer for the purpose of improving other properties. In some cases, problems may arise in the electrical or photoconductive properties or voltage resistance of the formed layer. That is, for example, the lifetime of photocarriers generated by light irradiation in the formed photoconductive layer is not sufficient, or the injection of charge from the support side is not sufficiently prevented in dark areas, etc. There were cases where this occurred. Therefore, while efforts are being made to improve the properties of the a-Si material itself, it is necessary to take measures to solve all of the above-mentioned problems 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 found that silicon atoms An amorphous material containing at least either a hydrogen atom (H) or a halogen atom (X), so-called hydrogenated amorphous silicon, halogenated amorphous silicon, or halogen-containing hydrogenated amorphous silicon [hereinafter referred to as "hydrogenated amorphous silicon"] ``a-Si(H,X)'' is used as a generic notation. The produced photoconductive member not only exhibits extremely excellent 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. The electrical, optical, and photoconductive properties of the present invention are almost unaffected by the usage environment, are always stable, are extremely resistant to light fatigue, do not deteriorate even after repeated use, are highly durable, and have excellent durability. The main objective is to provide a photoconductive member in which no or almost no potential is 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. An object of the present invention is to provide a photoconductive member having excellent electrophotographic properties. Still another object of the present invention is to provide a photoconductive member for electrophotography that can easily produce high-quality images with high density, clear halftones, and high resolution. 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 high voltage resistance. The photoconductive member of the present invention includes a support for the photoconductive member, a first amorphous layer having photoconductivity made of an amorphous material having silicon atoms as a matrix, and silicon atoms and carbon atoms. and a second amorphous layer made of an amorphous material consisting of, and the first amorphous layer occupies the entire layer area of the first amorphous layer. A first layer region containing oxygen atoms as atoms, and atoms belonging to Group 3 of the periodic table as constituent atoms, the distribution concentration of which is continuous in the layer thickness direction and is greater on the support side, on the upper surface side. is characterized in that it has a second layer region containing a distributed distribution with a relatively lowered portion compared to the support side. The photoconductive member of the present invention designed to have the above-mentioned layer structure can solve all of the above-mentioned problems, and has extremely excellent electrical, optical, photoconductive properties, and pressure resistance. and usage environment characteristics. In particular, when applied as an electrophotographic image forming member, there is no influence of residual potential on image formation, its electrical characteristics are stable, and it is highly sensitive and has high
It has a high signal-to-noise ratio, has excellent light fatigue resistance and repeated use characteristics, and can stably and repeatedly produce high-quality images with high density, clear halftones, and high resolution. Hereinafter, the photoconductive member of the present invention will be explained in detail with reference to the drawings. FIG. 1 is a schematic structural diagram schematically shown to explain the layer structure of the photoconductive member of the present invention. The photoconductive member 100 shown in FIG. 1 has a-Si (H,
A first amorphous layer I10 having photoconductivity consisting of
2 and a second amorphous layer 103, the first amorphous layer I102 includes a layer region O containing oxygen atoms as constituent atoms and atoms belonging to group 1 of the periodic table. The layer region O occupies the entire layer region of the first amorphous layer I102. The oxygen atoms contained in the layer region O are continuously and substantially uniformly distributed in the layer thickness direction, and
It is contained in the layer region O in a substantially uniform distribution state in a plane parallel to the interface between 01 and the first amorphous layer I102. The atoms belonging to the group of the periodic table contained in the layer region are continuous in the layer thickness direction of the first amorphous layer I102 and are located on the side opposite to the side where the support 101 is provided. side (second amorphous layer 103
the support 1 towards the free surface 104 side)
01 side (support 101 and first amorphous layer I102
It is contained in the layer region so that it is distributed in a larger amount on the interface side). In the present invention, atoms belonging to group of the periodic table contained in the layer region constituting the first amorphous layer I102 include B (boron), A (aluminum), Ga (gallium), In ( indium), T
(thallium), etc., and B and Ga are particularly preferably used. In the present invention, the distribution state of group atoms contained in the layer region is as described above in the layer thickness direction, and substantially in the plane parallel to the surface of the support 101. It is assumed that the distribution is uniform. In the present invention, the layer region O and the layer region constituting the first amorphous layer I102 are arranged so that the layer region O and the layer region share at least a part of the layer region in order to effectively achieve the object of the present invention. This is taken into consideration when forming the first amorphous layer I102. 2 to 10 show typical examples of the distribution state of group group atoms in the layer thickness direction contained in the layer region constituting the first amorphous layer I of the photoconductive member in the present invention. shown. In the examples shown in FIGS. 2 to 10, the layer region O containing oxygen atoms may be the same layer region as the layer region, or may include the layer region. Therefore, in the following explanation, the layer region O containing oxygen atoms will not be mentioned unless a particular explanation is required. 2 to 10, the horizontal axis represents the distribution concentration C of group atoms, and the vertical axis represents the layer region that constitutes the first amorphous layer I exhibiting photoconductivity and contains group atoms. Indicates the layer thickness, t _B indicates the position of the interface on the support side, and t _T indicates the position of the interface on the opposite side from the support side.
That is, the layer region containing group atoms is formed from the t _B side toward the t _T side. In the present invention, the layer region containing group atoms is a-Si(H,X) constituting the photoconductive member.
It may occupy the entire layer area of the first amorphous layer I exhibiting photoconductivity, or may occupy a part thereof. In the present invention, when the layer region occupies a part of the layer region of the first amorphous layer I, as shown in the example of FIG. It is preferable to provide it in the lower layer region of the quality layer I102. FIG. 2 shows a first typical example of the distribution state of group atoms contained in the first amorphous layer I in the layer thickness direction. In the example shown in FIG. 2, the distribution concentration of group atoms is from the interface position t _B to the position t ₁ where the surface where the layer region containing group atoms is formed contacts the surface of the layer region. C is contained in the layer region where group group atoms are formed while taking a constant value of C ₁ , and the distribution concentration C is from the position t ₁ to the interface position t _T from C ₂ .
has been gradually and continuously reduced until . At the interface position _tT , the distribution concentration C of group atoms is _C3 . In the example shown in FIG. 3, the distribution concentration C of the contained group atoms gradually and continuously decreases from the concentration _C4 from position _tB to position _tT , and at position _tT the concentration _{C5 decreases} . The distribution state is formed as follows. In the case of Fig. 4, the distribution concentration C of group atoms from position t _B to position t ₂ is a constant value of concentration C ₆ ,
It is gradually and continuously decreased between the position t ₂ and the position t _T , and is substantially zero at the position t _T. In the case of FIG. 5, the distribution concentration C of group atoms is gradually decreased from the concentration C ₈ from position t _B to position t _T , and becomes substantially zero at position t _T. There is. In the example shown in FIG. 6, the distribution concentration C of group atoms is the concentration C ₉ between position t _B and position t ₃ .
is a constant value, and the concentration is _C10 at position _tT . Between the positions t ₃ and t _T , the distribution concentration C is linearly decreased from the position t ₃ to the position t _T . In the example shown in FIG. 7, the distribution concentration C takes a constant value of concentration C ₁₁ from position t _B to position t ₄ ,
From position _t4 to position _tT , the distribution state is such that the concentration decreases linearly from _C12 to _C13 . In the example shown in FIG. 8, from position t _B to position t _T
Until , the distribution concentration C of group atoms is the concentration C ₁₄
It decreases in a linear manner as it approaches zero. In FIG. 9, from position t _B to position t ₅ , the distribution concentration C of group atoms decreases linearly from the concentration C ₁₅ to the concentration C ₁₆ , and from position t ₅ to position t _T
An example is shown in which the concentration C ₁₆ is set to a constant value. In the example shown in FIG. 10, the distribution concentration C of group atoms is the concentration C ₁₇ at position t _B ;
Until reaching position t ₆ , the concentration C ₁₇ is slowly decreased at first, and near the position t ₆ , it is rapidly decreased to the concentration C ₁₈ at position t ₆ . Between position t ₆ and position t ₇ , the distribution concentration C
is decreased rapidly at first, and then slowly and gradually decreased to a concentration C ₁₉ at position t ₇ , and between positions t ₇ and t ₈ , it decreases very slowly and gradually. At t ₈ the concentration C ₂₀ is reached. Between position _t8 and position _tT , the concentration is reduced from _C20 to substantially zero according to a curve shaped as shown in the figure. As described above with reference to FIGS. 2 to 10, some typical examples of the distribution state of group atoms contained in the layer region in the layer thickness direction, in the present invention, on the support side, Distribution concentration C of group atoms
On the upper surface _tT side of the layer region, the distribution concentration C is relatively low compared to the support side. It is provided in the first amorphous layer I. In the present invention, the layer region containing group atoms constituting the first amorphous layer I is a localized region containing group atoms at a relatively high concentration toward the support side, as described above. It is desirable to have region A. If the localized region A is explained using the symbols shown in FIGS. 2 to 10, it is preferable that the localized region A be provided within 5 μm from the interface position t _B. In the present invention, the localized region A is at the interface position.
It may be the entire layer region L _T up to 5μ thick from t _B , or it may be a part of the layer region L _T. Whether the localized region A is a part or all of the layer region L _T is determined as appropriate depending on the characteristics required of the first amorphous layer I to be formed. In the localized region A, the maximum value Cmax of the content distribution value (distribution concentration value) of group atoms is usually the distribution state of the group atoms contained therein in the layer thickness direction.
It is desirable that the layer be formed in such a manner that a distribution state of 50 atomic ppm or more, preferably 80 atomic ppm or more, optimally 100 atomic ppm or more can be obtained. That is, in the present invention, the layer region containing group atoms has the maximum distribution concentration within 5μ of the layer thickness from the support side (layer region of 5μ thickness from t _B ).
It is formed so that Cmax exists. In the present invention, the content of group atoms contained in the layer region containing group atoms may be determined as desired so as to effectively achieve the object of the present invention. , usually 0.01~5
×10 ⁴ atomic ppm, preferably 0.5 to 1 × 10 ⁴
atomic ppm, optimally 1-5×10 ³ atomic ppm
It is desirable that this is the case. The amount of oxygen atoms contained in the layer region O is appropriately determined depending on the characteristics required of the photoconductive member formed according to the purpose of the present invention, but is usually 0.001 to 30 atomic%, preferably 0.001 to 30 atomic%. 0.002～
It is desirable that the content be 20 atomic%, most preferably 0.003 to 10 atomic%. In the present invention, the first amorphous layer I composed of a-Si (H, It is done by a deposition method. For example, in order to form the first amorphous layer I composed of a-Si (H, Along with raw material gas for
A raw material gas for introducing hydrogen atoms (H) and/or for introducing halogen atoms (X) is introduced into a deposition chamber whose interior can be reduced in pressure to generate a glow discharge in the deposition chamber, and is placed in a predetermined position in advance. A layer made of a-Si(H,X) may be formed on the surface of a predetermined support. In addition, when forming by sputtering, hydrogen atoms (H ) or/and a gas for introducing halogen atoms (X) may be introduced into the deposition chamber for sputtering. In the present invention, the halogen atoms (X) contained in the first amorphous layer I as necessary include:
Specific examples include fluorine, chlorine, bromine, and iodine, with fluorine and chlorine being particularly preferred. As the raw material gas for supplying Si used in the present invention, silicon hydride (silanes) in a gaseous state or that can be gasified such as SiH ₄ , Si ₂ H ₆ , Si ₃ H ₈ , Si ₄ H ₁₀ is effective. Among them, SiH ₄ and Si ₂ H ₆ are particularly preferred in terms of ease of layer preparation work and good Si supply efficiency. Effective raw material gases for introducing halogen atoms used in the present invention include many halogen compounds, such as halogen gases, halides, interhalogen compounds, halogen-substituted silane derivatives, etc. Preferred examples include halogen compounds that can be converted into Further, a silicon compound containing a halogen atom, which is in a gaseous state or can be gasified and whose constituent elements are a silicon atom and a halogen atom, can also be mentioned as an effective compound in the present invention. Specifically, halogen compounds that can be suitably used in the present invention include fluorine, chlorine, bromine,
Iodine halogen gas, BrF, CF, CF ₃ ,
Examples include interhalogen compounds such as BrF ₅ , BrF ₃ , IF ₃ , IF ₇ , IC, 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 , SiC ₄ , and SiBr ₄ . I can do it. When forming the characteristic photoconductive member of the present invention by a glow discharge method using such a silicon compound containing a halogen atom, silicon hydride gas is used as a raw material gas capable of supplying Si. At least, the first amorphous layer I made of a-Si containing halogen atoms can be formed on a predetermined support. When forming the first amorphous layer I containing halogen atoms according to the glow discharge method, basically Si
Silicon halide gas, which is the raw material gas for supply, and
Gases such as Ar, Hz, He, etc. are introduced into the deposition chamber for forming the first amorphous layer I at a predetermined mixing ratio and gas flow rate, and a glow discharge is generated to remove these gases. By forming a plasma atmosphere,
Although the first amorphous layer I can be formed on a predetermined support, a predetermined amount of a silicon compound gas containing hydrogen atoms is also mixed with these gases in order to introduce hydrogen atoms. A layer may also be formed. Moreover, each gas may be used not only as a single species but also as a mixture of multiple species at a predetermined mixing ratio. To form the first amorphous layer I made of a-Si(H, This is sputtered in a predetermined gas plasma atmosphere, and 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. This can be done by heating and evaporating the flying evaporated material using a beam method (EB method) or the like and passing it through a predetermined gas plasma atmosphere. At this time, in order to introduce halogen atoms into the layer formed by either the sputtering method or the ion plating method, a gas of the above-mentioned halogen compound or a silicon compound containing the above-mentioned halogen atoms is introduced into the deposition chamber. It is sufficient to introduce the gas to form a plasma atmosphere of the gas. In addition, when introducing hydrogen atoms, a raw material gas for introducing hydrogen atoms, such as H ₂ or the above-mentioned silane gases, is introduced into a deposition chamber for sputtering to form a plasma atmosphere of the gas. Just do it. In the present invention, the above-mentioned halogen compounds or halogen-containing silicon compounds are effectively used as the raw material gas for introducing halogen atoms, but in addition, HF, HC,
Hydrogen halides such as HBr, HI, SiH ₂ F ₂ , SiH ₂
Halogen-substituted silicon hydrides such as I ₂ , SiH ₂ C ₂ , SiHC ₃ , SiH ₂ Br ₂ , SiHBr ₃ and other gaseous or gasifiable halides containing hydrogen atoms as one of their constituents are also effective. It can be mentioned as a starting material for forming the first amorphous layer I. In these halides containing hydrogen atoms, when forming the first amorphous layer I, hydrogen atoms, which are extremely effective in controlling electrical or photoelectric properties, are also introduced at the same time as halogen atoms are introduced into the layer. Therefore, in the present invention, it is used as a suitable raw material for introducing halogen atoms. In order to structurally introduce hydrogen atoms into the first amorphous layer I, in addition to the above, H ₂ , SiH ₄ , Si ₂ H ₆ ,
This can also be done by causing a discharge by causing a silicon hydride gas such as Si ₃ H ₈ or Si ₄ H ₁₀ to coexist with a silicon compound for supplying Si in the deposition chamber. For example, in the case of the reactive sputtering method, Si
Using a target, a gas for introducing halogen atoms and H ₂ gas, including inert gases such as He and Ar as necessary, are introduced into the deposition chamber to form a plasma atmosphere, and the Si target is sputtered. As a result, a first amorphous layer I made of a-Si(H,X) is formed on the substrate. Furthermore, a gas such as B ₂ H ₆ can also be introduced for doping with impurities. In the present invention, the amount of hydrogen atoms (H), the amount of halogen atoms (X), or the sum of the amounts of hydrogen atoms and halogen atoms contained in the first amorphous layer I of the photoconductive member to be formed is Normally 1 to 40 atomic%,
The preferred range is 5 to 30 atomic %. In order to control the amount of hydrogen atoms (H) and/or halogen atoms (X) contained in the first amorphous layer I, for example, the support temperature or/and the amount of hydrogen atoms (H) or halogen atoms The amount of the starting material used to contain (X) introduced into the deposition system, the discharge force, etc. may be controlled. In order to provide the layer region containing group atoms and the layer region O containing oxygen atoms in the first amorphous layer I, the first amorphous layer is formed by a glow discharge method, a reactive sputtering method, etc. In this case, a starting material for introducing group atoms and a starting material for introducing oxygen atoms are used together with the above-mentioned starting material for forming the first amorphous layer I, and the amounts thereof are determined in the layer to be formed. This is achieved by controlling and containing the When using the glow discharge method to form the layer region O containing oxygen atoms and the layer region containing group atoms constituting the first amorphous layer I, the raw materials for forming each layer region The starting material to become a gas is one selected as desired from among the starting materials for forming the first amorphous layer I described above, and a starting material for introducing oxygen atoms or/and group atom introduction. The starting materials for are added. Such starting materials for introducing oxygen atoms or starting materials for introducing group atoms include gaseous substances or gasified substances whose constituent atoms are at least oxygen atoms or group atoms. Most can be used. For example, if layer region O is to be formed, a raw material gas containing silicon atoms (Si), a raw material gas containing oxygen atoms (O), and hydrogen atoms (H) or / and a raw material gas whose constituent atoms are halogen atoms (X) at a desired mixing ratio, or a raw material gas whose constituent atoms are silicon atoms (Si), oxygen atoms (O), and hydrogen. A raw material gas containing atoms (H) as constituent atoms is also mixed at a desired mixing ratio, or
Alternatively, a raw material gas containing silicon atoms (Si) and silicon atoms (Si) and oxygen atoms (O)
and a raw material gas containing three hydrogen atoms (H) as constituent atoms can be used in combination. Alternatively, a raw material gas containing silicon atoms (Si) and hydrogen atoms (H) as constituent atoms may be mixed with a raw material gas containing oxygen atoms (O) as constituent atoms. Specifically, starting materials for introducing oxygen atoms include, for example, oxygen (O ₂ ), ozone (O ₃ ), nitric oxide (NO), nitrogen dioxide (NO ₂ ), and nitrogen monooxide (N ₂ O ), nitrogen sesquioxide (N ₂ O ₃ ), nitrogen tetroxide (N ₂ O ₄ ), nitrogen pentoxide (N ₂ O ₅ ), nitrogen trioxide (NO ₃ ), silicon atoms (Si) and oxygen atoms (O )
and a hydrogen atom (H) as constituent atoms, for example,
Examples include lower siloxanes such as disiloxane (H ₃ SiOSiH ₃ ) and trisiloxane (H ₃ SiOSiH ₂ OSiH ₃ ). When a layer region is formed using a glow discharge method, B ₂ H ₆ and B ₄ H ₁₀ are effectively used in the present invention as starting materials for introducing group group atoms. , B ₅ H ₉ , B ₅ H ₁₁ , B ₆ H ₁₀ ,
Boron hydride such as B ₆ H ₁₂ , B ₆ H ₁₄ , BF ₃ , BC ₃ ,
Examples include boron halides such as _BBr3 . In addition, AC ₃ , GaC ₃ , Ga(CH ₃ ) ₃ , InC ₃ ,
TC ₃ etc. can also be mentioned. The content of group atoms introduced into the layer region containing group atoms is determined by the gas flow rate of the starting material for introducing group atoms introduced into the deposition chamber, the gas flow rate ratio, the discharge power, the support temperature, It can be arbitrarily controlled by controlling the pressure in the deposition chamber, etc. To form the layer region O containing oxygen atoms by the sputtering method, a single crystal or polycrystalline Si wafer or a SiO ₂ wafer, or a Si and
The sputtering may be carried out by targeting wafers containing a mixture of SiO ₂ and sputtering them in various gas atmospheres. For example, if a Si wafer is used as a target, oxygen atoms and optionally hydrogen atoms or/
The raw material gas for introducing halogen atoms is diluted with a diluent gas as necessary and introduced into a deposition chamber for sputtering, and a gas plasma of these gases is formed to sputter the Si wafer. All you have to do is ring it. Alternatively, Si and SiO ₂ may be used as separate targets or by using a single mixed target of Si and SiO ₂ in an atmosphere of diluent gas as a sputtering gas or at least This is accomplished by sputtering in a gas atmosphere containing hydrogen atoms (H) and/or halogen atoms (X) as constituent atoms. As the raw material gas for introducing oxygen atoms, the raw material gas for introducing oxygen atoms among the raw material gases shown in the glow discharge example described above can be used as an effective gas also in the case of sputtering. In the present invention, the diluent gas used when forming the first amorphous layer I by a glow discharge method or the sputtering gas used when forming the first amorphous layer I by a sputtering method is a so-called rare gas. gas,
For example, He, Ne, Ar, etc. can be mentioned as suitable materials. The layer thickness of the first amorphous layer I is the layer thickness of the first amorphous layer I
In order to efficiently transport the photocarriers generated in
~100μ, preferably 1-80μ, optimally 2-50μ
It is desirable that this is done. In the photoconductive member 100 shown in FIG. 1, the second amorphous layer 105 formed on the first amorphous layer I102 has a free surface 106,
It is provided mainly to achieve the objectives of the present invention in terms of moisture resistance, continuous repeated usage characteristics, pressure resistance, usage environment characteristics, and durability. Further, in the present invention, the first amorphous layer I10
Since each of the amorphous materials forming the second amorphous layer 105 and the second amorphous layer 105 have a common constituent element of silicon atoms, chemical stability can be sufficiently ensured at the laminated interface. has been done. The second amorphous layer is formed of an amorphous material (a-Si _x C _1-x , where 0<X<1) composed of silicon atoms and carbon atoms. Second amorphous layer 1 composed of a-Si _x C _1-x
07 is formed by a sputtering method, an ion implantation method, an ion plating method, an electron beam method, or the like. These manufacturing methods depend on the manufacturing conditions, the level of capital investment,
They are selected and adopted as appropriate depending on factors such as the production scale and the desired characteristics of the photoconductive member to be produced, but it is relatively easy to control the production conditions to produce a photoconductive member with the desired properties. A sputtering method, an electron beam method, or an ion plating method is preferably employed because of the advantages that carbon atoms can be easily introduced into the amorphous layer to be formed together with silicon atoms. To form the second amorphous layer by the sputtering method, target a single-crystal or polycrystalline Si wafer and C wafer, or a wafer containing a mixture of Si and C. etc., by sputtering in various gas atmospheres. For example, when using Si wafers and C wafers as targets, He, Ne, Ar
A sputtering gas such as the above may be introduced into a sputtering deposition chamber to form a gas plasma, and the Si wafer and C wafer may be sputtered. Alternatively, by using a single target containing a mixture of Si and C, a gas for sputtering is introduced into the equipment system, and sputtering is performed in the gas atmosphere. will be accomplished. When using the electron beam method, single-crystal or polycrystalline high-purity silicon and high-purity graphite are placed in two evaporation boats, and each is independently co-deposited by an electron beam or simultaneously deposited. Silicon and graphite placed in a boat at a desired mixing ratio may be deposited using a single electron beam. The content ratio of silicon atoms and carbon atoms contained in the second amorphous layer is controlled in the former case by changing the acceleration voltage of the electron beam with respect to silicon and graphite, and in the latter case is controlled by determining the amount of silicon and graphite mixed in advance. When using the ion plating method, various gases are introduced into the evaporation tank, and a high-frequency electric field is applied to a coil placed around the tank to generate a glow. Si and C are then deposited using the electron beam method. It can be vapor-deposited. The second amorphous layer in the present invention is carefully formed to provide the desired properties. In other words, materials whose constituent atoms are Si and C can have structural forms ranging from crystalline to amorphous depending on the conditions for their creation, and electrical properties ranging from conductive to semiconductive to insulating. and exhibit properties ranging from photoconductive properties to non-photoconductive properties, so in the present invention, a-Si _x C _1-x having desired properties depending on the purpose is formed. The preparation conditions are strictly selected according to the desired results. For example, in order to provide a second amorphous layer with the main purpose of improving voltage resistance, a-Si _x C _1-x should be created as an amorphous material with remarkable electrically insulating behavior in the usage environment. be done. In addition, when a second amorphous layer is provided for the main purpose of improving the characteristics of continuous repeated use and the characteristics of the usage environment, the above-mentioned degree of electrical insulation is relaxed to a certain extent, and it resists the irradiated light to a certain extent. a-Si _x C _1-x is created as an amorphous material with a sensitivity of . When forming the second amorphous layer made of a-Si _x C _1-x on the surface of the first amorphous layer I, the temperature of the support during layer formation depends on the structure and characteristics of the layer to be formed. In the present invention, the temperature of the support during layer formation must be strictly controlled so that a-Si _x C _1-x having the desired properties can be formed as desired. Desirably controlled. In order to effectively achieve the purpose of the present invention, the temperature of the support when forming the second amorphous layer should be set in an appropriate range according to the method of forming the second amorphous layer. The formation of the second amorphous layer is carried out at a temperature selected, preferably between 20 and 300°C, optimally between 20 and 300°C.
A temperature of 250°C is desirable. Sputtering is used to form the second amorphous layer because it is relatively easy to finely control the composition ratio of the atoms that make up the layer and control the layer thickness compared to other methods. However, when forming the second amorphous layer using these layer forming methods, the discharge power during layer formation, as well as the support temperature mentioned above, is advantageous. Created a-Si _x
It can be cited as one of the important factors that influence the characteristics of C _1-x . The discharge power condition for effectively producing a-Si _x C _1-x having the characteristics for achieving the purpose of the present invention with good productivity is preferably 50W.
~250W, optimally 80W ~ 150W. In the present invention, the support temperature and discharge power for forming the second amorphous layer are preferably within the ranges described above, but these layer forming factors are independent of each other. The optimum values of each production factor are determined based on their mutual organic relationship so that a second amorphous layer consisting of a-Si _x C _1-x with the desired properties is formed, rather than being determined separately. It is desirable to be able to decide. The amount of carbon atoms contained in the second amorphous layer in the photoconductive member of the present invention is the same as the manufacturing conditions of the second amorphous layer, so that desired characteristics to achieve the object of the present invention can be obtained. This is an important factor in the formation of layers. The amount of carbon atoms contained in the second amorphous layer in the present invention is usually 1×10 ^-3 to 90 atomic%, based on the sum of silicon atoms and carbon atoms.
Suitably 1-80 atomic%, optimally 10-80 atomic%
A desirable value is 75 atomic%.
That is, if we represent x in a-Si _x C _1-x above, x
is usually 0.1 to 0.99999, preferably 0.2 to 0.99, optimally 0.25 to 0.9. The numerical range of the layer thickness of the second amorphous layer in the present invention is appropriately determined according to the desired purpose so as to effectively achieve the purpose of the present invention. Furthermore, the layer thickness of the second amorphous layer varies in each layer region in relation to the amount of carbon atoms contained in the layer and the layer thickness of the first amorphous layer I. It is necessary to appropriately determine the desired characteristics based on the organic relationship depending on the required characteristics. In addition, it is desirable to take into consideration economic efficiency, which takes into account productivity and mass production. The thickness of the second amorphous layer in the present invention is usually 0.003 to 30μ, preferably 0.004 to 20μ, and most preferably 0.005 to 10μ. The support used in the present invention may be electrically conductive or electrically insulating. Examples of the conductive support include NiCr, stainless steel, A,
Examples include metals such as Cr, Mo, Au, Nb, Ta, V, Ti, Pt, and 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. Ru. 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. For example, if it is glass, NiCr,
A, Cr, Mo, Au, Ir, Nb, Ta, V, Ti,
Conductivity can be imparted by providing a thin film made of Pt, Pd, In ₂ O ₃ , SnO ₂ , ITO (In ₂ O ₃ + SnO ₂ ), etc., or if it is a synthetic resin film such as polyester film, NiCr ,A,Ag,Pb,Zn,
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 may be any shape such as a cylinder, a belt, or a plate, and the shape is determined as desired.
If the photoconductive member 100 shown in the figure is used as an electrophotographic image forming member, it is preferably in the form of an endless belt or a cylinder in the case of 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, from the viewpoint of manufacturing and handling of the support, mechanical strength, etc.,
It is considered to be 10μ or more. Next, a method for manufacturing a photoconductive member of the present invention will be explained. FIG. 11 shows an example of a photoconductive member manufacturing apparatus. Gas cylinders 1102 to 1106 in the diagram include
The raw material gas for forming each layer region of the present invention is sealed, and as an example, 11
02 is SiH ₄ gas diluted with He (purity 99.999
%, hereinafter abbreviated as SiH ₄ /He. ) cylinder, 1103
B ₂ H ₆ gas (99.999% purity, diluted with He)
Hereinafter, it will be abbreviated as B ₂ H ₆ /He. ) cylinder, 1104 is Ar
Gas (99.99% purity) cylinder, 1105 is NO gas (99.999% purity), 1106 is diluted with He.
It is a SiF ₄ gas (purity 99.999%, hereinafter abbreviated as SiF ₄ /He) cylinder. In order to flow these gases into the reaction chamber 1101, valves 112 of gas cylinders 1102 to 1106 are used.
2-1126, confirm that the leak valve 1135 is closed, and also check that the inflow valve 1112-1126 is closed.
Step 1116: After confirming that the outflow valves 1117 to 1121 and the auxiliary valves 1132 and 1133 are open, first open the main valve 1134 to exhaust the reaction chamber 1101 and the gas piping. Next, when the reading on the vacuum gauge 1136 reaches approximately 5×10 ^-6 torr, the auxiliary valves 1132 and 1133 and the outflow valve 11
Close 17-1121. Next, to give _an example of forming a photoconductive member having _the layer structure _shown in FIG. 11
From 05, NO gas is supplied from valves 1122 and 112, respectively.
3,1125 open and outlet pressure gauge 1127,1
Adjust the pressure of 128 and 1130 to 1Kg/cm ² respectively,
Gradually open the inflow valves 1112, 1113, and 1115, respectively, and the mass flow controllers 1107,
1108 and 1110, respectively. Subsequently, the outflow valves 1117, 1118, 1120,
The auxiliary valve 1132 is gradually opened to allow each gas to flow into the reaction chamber 1101. At this time
The outflow valves 1117, 1118, and 1120 are adjusted so that the ratio of the SiH ₄ /He gas flow rate to the B ₂ H ₆ /He gas flow rate and NO gas flow rate becomes the desired value, and the pressure inside the reaction chamber is adjusted to the desired value. Vacuum gauge 11 to get the value
Adjust the opening of the main valve 1134 while checking the reading of 36. After confirming that the temperature of the base cylinder 1137 is set to a temperature in the range of 50 to 400°C by the heater 1138, the power source 1140 is set to the desired power to generate glow discharge in the reaction chamber 1101. and at the same time B ₂ H ₆ /He according to the pre-designed rate of change curve.
The distribution concentration of boron atoms contained in the formed layer in the layer thickness direction is controlled by gradually changing the gas flow rate manually or by using an externally driven motor or the like by operating the valve 1118. As described above, when the layer region (B, O) containing boron atoms and oxygen atoms is formed to the desired layer thickness, the outflow valve 1118 is closed, and the reaction chamber 110 is closed.
By continuing to form layers under the same conditions except for blocking the inflow of B ₂ H ₆ /He gas into layer 1, a layer region O containing no boron atoms but containing oxygen atoms was formed. is formed on the layer region (B, O) to a desired layer thickness. In this way, the first amorphous layer I having desired characteristics can be formed on the substrate. The layer region containing boron atoms becomes B ₂ at an appropriate point in the process of forming the first amorphous layer I.
By cutting off the flow of H ₆ /He gas into the reaction chamber 1101, a desired layer thickness can be formed.
The layer region may occupy the entire layer region of the first amorphous layer I or a portion thereof. For example, in the above example, the first amorphous layer I
During the formation process, the entire layer of the first amorphous layer I is formed by continuing the layer formation until the desired layer thickness without cutting off the flow of B ₂ H ₆ /He gas into the reaction chamber 1101. The region can be a layer region containing boron atoms and oxygen atoms. When containing halogen atoms in the first amorphous layer I, for example, SiF ₄ /He is added to the above gas,
Further, it is added and sent into the reaction chamber 1101. Depending on the selection of gas species during the formation of the amorphous layer,
The layer formation speed can be further increased. For example, if layer formation is performed using Si ₂ H ₆ gas instead of SiH ₄ gas, the productivity can be increased several times. To form the second amorphous layer on the first amorphous layer I, for example, the following procedure is performed. First, open shutter 1142. All gas supply valves are once closed, and the reaction chamber 1101 is
34 is fully opened to exhaust the air. A target in which a high purity silicon wafer 1142-1 and a high purity graphite wafer 1142-2 are placed in a desired area ratio is provided in advance on the electrode 1141 to which high voltage power is applied. Ar gas is supplied from the gas cylinder 1104 to the reaction chamber 110.
1, and the internal pressure of the reaction chamber 1101 is 0.05~
Adjust the main valve 1134 so that the pressure is 1 torr. The second amorphous layer can be formed on the first amorphous layer I by turning on the high voltage power supply 1140 and sputtering the target. The amount of carbon atoms contained in the second amorphous layer is determined by the sputter area ratio of the silicon wafer 1142-1 and the graphite wafer 1142-2, and the mixture of silicon powder and graphite powder when creating the target. It can be controlled as desired by adjusting the ratio as desired. Needless to say, all outflow valves for gases other than those required for forming each layer are closed, and
When forming each layer, the gas used to form the previous layer is released into the reaction chamber 1101 and through the outflow valves 1117 to 1.
121 to the inside of the reaction chamber 1101, the outflow valves 1117 to
1121, open the auxiliary valve 1132, and fully open the main valve 1134 to temporarily evacuate the system to a high vacuum, as necessary. Example 1 Using the manufacturing apparatus shown in FIG.
An image forming member having a concentration distribution of B and O as shown in FIG. 12 was prepared under the conditions shown in Table 1. The image forming member thus obtained was placed in a charging, exposing and developing device, corona charging was performed at 5KV for 0.2 seconds, and a light image was immediately irradiated. A tungsten lamp was used as the light source, and a light intensity of 1.0 ux·sec was irradiated using a transmission type test chart. Immediately thereafter, a good toner image was obtained on the surface of the member by cascading a charged developer (including toner and carrier) over the surface of the member. The toner image thus obtained was once cleaned with a rubber blade, and the above image forming and cleaning process was repeated again. No deterioration of the image was observed even after repeating the test over 150,000 times.

[Table] Example 2 By changing the flow rate of B ₂ H ₆ , the first
Image forming members having boron concentration distributions as shown in FIGS. 3 to 17 were prepared. Other conditions and evaluation methods were carried out in exactly the same manner as in Example 1, and the results shown in the table below were obtained.

[Table] ◎ High image quality with no image defects ○ Example with no image defects 3 Images were obtained in exactly the same manner as in Example 1 except that the flow rate of NO was changed and the content of oxygen in the amorphous layer I was changed. A formed member was prepared and evaluated in the same manner as in Example 1, and the results shown in the table below were obtained.

[Table] ◎ Very good
○ Good Example 4 Example 1 except that when forming the amorphous layer, the area ratio of the silicon wafer and graphite was changed to change the content ratio of silicon atoms and carbon atoms in the amorphous layer. An imaging member was prepared in exactly the same manner as described above. The image forming member thus obtained was subjected to the image forming, developing and cleaning steps as described in Example 1 about 50,000 times and then subjected to image evaluation, and the results shown in Table 4 were obtained.

[Table] ◎〓Very good ○〓Good △〓Sufficient for practical use ×〓Example 5 where some image defects occur Example 5 The same method as Example 1 was used except for changing the thickness of the amorphous layer. An imaging member was prepared.
The steps of image formation, development, and cleaning as described in Example 1 were repeated to obtain the following results.

[Table] Example 6 Layer formation was carried out in the same manner as in Example 1 except that the method for forming the amorphous layer I was changed as shown in the table below, and good results were obtained when evaluated.

【table】 [Brief explanation of drawings]

FIG. 1 is a schematic layer configuration diagram for explaining one layer configuration of a preferred embodiment of the photoconductive member of the present invention, and FIGS. 2 to 10 are a first amorphous layer I.
Explanatory diagram for explaining the distribution state of group atoms in a layer region containing group atoms constituting
FIG. 1 is a schematic explanatory diagram of the apparatus used in the present invention, and FIGS. 12 to 17 are explanatory diagrams for explaining the distribution state of contained atoms in the examples of the present invention, respectively. 100...Photoconductive member, 101...Support, 1
02...First amorphous layer I, 103...Second amorphous layer, 104...Free surface.

Claims (1)

[Scope of Claims] 1. A support for a photoconductive member, a first amorphous layer having photoconductivity made of an amorphous material having silicon atoms as a matrix, and silicon atoms and carbon atoms. and a second amorphous layer made of an amorphous material consisting of the first amorphous layer, the first amorphous layer occupies the entire layer area of the first amorphous layer, and the constituent atoms a first layer region containing oxygen atoms as constituent atoms; and atoms belonging to Group 3 of the periodic table as constituent atoms, the distribution concentration of which is continuous in the layer thickness direction and is greater on the support side, on the upper surface side. The second component is contained in a distribution state having a relatively lower portion than the support side.
A photoconductive member having a layer region of. 2. Claim 1, wherein the second layer area substantially occupies the entire layer area of the first amorphous layer.
The photoconductive member described in .