Photoconductive member with doped and oxygen containing amorphous silicon layers

A photoconductive member comprises a support for a photoconductive member and an amorphous layer containing an amorphous material comprising silicon atom as a matrix and having photoconductivity, said amorphous layer comprising a first layer region containing oxygen atom as a constituent atom, the oxygen atom being distributed continuously in the direction of the layer thickness and enriched at the support side, and a second layer region containing an atom of the group III of the periodic table as a constituent atom, said first layer region being internally present at the support side in the amorphous layer, and the layer thickness T.sub.B of said second layer region and a layer thickness T resulted from subtracting T.sub.B from the layer thickness of the amorphous layer satisfying the relation, T.sub.B /T.ltoreq.1.

BACKGOUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a photoconductive member having sensitivity to 
electromagnetic waves such as light (herein used in a broad sense, 
including ultraviolet rays, visible light, infrared rays, X-rays and 
gamma-rays and the like). 
2. Description of the Prior Art 
Photoconductive materials constituting photoconductive layers for solid 
state image pick-up devices, electrophotographic image forming members in 
the field of image formation, or manuscript reading devices are required 
to have a high sensitivity, a high SN ratio (Photocurrent (Ip)/Dark 
Current (Id)), absorption spectral characterstics matching to the spectral 
characteristics of irradiating electromagnetic waves, a good response to 
light, a desired dark resistance value as well as no harm to human bodies 
during usage. Further, in a solid state image pick-up device, it is also 
required that the residual image should be easily treated within a 
predetermined time. In particular, in case of an image forming member for 
electrophotography to be assembled in an electrophotographic device to be 
used in an office as office apparatus, the aforesaid harmless 
characteristic is very important. 
From the standpoint as mentioned above, amorphous silicon (hereinafter 
referred to as "a-Si") has recently attracted attention as a 
photoconductive material. For example, German Laid-Open patent publication 
Nos. 2746967 and 2855718 disclose applications a-Si for use in image 
forming members for electrophotography, and German Laid-Open patent 
publication No. 2933411 discloses application of a-Si for use in a 
photoelectric converting reading device. 
However, under the present situation, although the photoconductive members 
having photoconductive layers constituted of a-Si of the prior art have 
been attempted to be improved with respect to individual characteristics, 
including various electrical, optical and photoconductive characteristics 
such as dark resistance value, photosensitivity and response to light, 
environmental characteristics in use, and further stability with lapse of 
time and durability, there exists room for further improvement in overall 
characteristics. 
For instance, when the a-Si photoconductor is applied to an image forming 
member for an electrophotographic device, residual potential is frequently 
observed to remain during use thereon if increases in both 
photosensitivity and dark resistance are contemplated. 
When such a photoconductive member is repeatedly used for a long time, 
there will be caused various inconveniences such as accumulation of 
fatigues by repeated uses or so-called ghost phenomenon wherein residual 
images are formed. 
Further, a-Si materials may contain as constituent atoms hydrogen atoms or 
halogen atoms such as fluorine atoms, chlorine atoms, etc. for improving 
their electrical, photoconductive characteristics, and boron atoms, 
phosphorus atoms, etc. for controlling the electroconductivity type, and 
further other atoms for improving other characteristics. Depending on the 
manner in which these constituent atoms are contained, there may sometimes 
be caused problems with respect to electrical, or photoconductive 
characteristics, or dielectric strength of the layer formed. 
For example, sometimes there are problems as shown below. Life of 
photocarriers produced in the formed photoconductive layer by irradiation 
is not sufficiently long in said layer. At the dark portions injected of 
electric charge from the support side can not be sufficiently prevented. 
Thus, it is required in designing a photoconductive material to make 
efforts to overcome all of such problems as mentioned above along with the 
improvement of a-Si materials per se. 
In view of the above points, the present invention contemplates the 
achievement obtained as a result of extensive studies made comprehensively 
from the standpoints of applicability and utility of a-Si as a 
photoconductive member for image forming members for electrophotography, 
solid state pick-up devices and reading devices etc. It has now been found 
that a photoconductive member having a photoconductive layer comprising 
a-Si, in particular, an amorphous material constituted of at least one of 
hydrogen atom (H) and halogen atom (X) in a matrix of silicon (hereinafter 
referred to comprehensively as a-Si (H, X)), (for example, so-called 
hydrogenated amorphous silicon, halogenated amorphous silicon or 
halogen-containing hydrogenated amorphous silicon), exhibits not only 
practically extremely good characteristics, but also surpasses 
conventional photoconductive members in substantially all aspects, 
provided that the photoconductive member is designed and constituted to 
have a specific layer structure as explained in the following. The 
photoconductive member has markedly excellent characteristics for 
electrophotography. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a photoconductive member 
having substantially constantly stable electrical, optical and 
photoconductive characteristics, suffering from substantially no influence 
from the use environment, and being markedly excellent in light fatigue 
resistance, excellent in durability and without causing any deterioration 
phenomenon after repeated uses and entirely or substantially free from 
residual potentials. 
Another object of the present invention is to provide a photoconductive 
member, which is sufficiently capable of bearing charges at the time of 
charging treatment for formation of electrostatic charges to an extent 
that a conventional electrophotographic method can be very effectively 
applied when it is provided for use as an image forming member for 
electrophotography. 
Still another object of the present invention is to provide a 
photoconductive member for electrophotography capable of providing easily 
a high quality image which is high in density, clear in half-tone and high 
in resolution. 
A further object of the present invention is to provide a photoconductive 
member having high photosensitivity, high SN ratio characteristic and high 
dielectric strength. 
According to the present invention, there is provided a photoconductive 
member which comprises a support for a photoconductive member and an 
amorphous layer containing an amorphous material comprising silicon atom 
as a matrix and having photoconductivity, said amorphous layer comprising 
a first layer region containing oxygen atom as a constituent atom, the 
oxygen atom being distributed continuously in the direction of the layer 
thickness and enriched at the support side, and a second layer region 
containing an atom of the group III of the periodic table as a constituent 
atom, said first layer region being internally present at the support side 
in the amorphous layer, and the layer thickness T.sub.B of said second 
layer region and a layer thickness T resulted from subtracting T.sub.B 
from the layer thickness of the amorphous layer satisfying the relation, 
T.sub.B /T.ltoreq.1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The photoconductive members of the present invention will be explained with 
reference to the drawings in the following. 
FIG. 1 shows a schematic layer constitution to be used for illustrating a 
layer constitution of a photoconductive member according to this 
invention. 
In FIG. 1, a photoconductive member 100 has a support 101 for a 
photoconductive member and an amorphous layer 102 comprising a-Si, 
preferably a-Si(H,X) and exhibiting photoconductivity overlying support 
101. Amorphous layer 102 has a layer structure which is constituted of a 
first layer region (O) 103 and a second layer region (III) 104, said first 
layer region (O) 103 contains oxygen atom as a constituent atom which is 
distributed continuously in the direction of the layer thickness and 
enriched at the side of support 101, and said second layer region (III) 
104 contains the group III atom as constituent atoms. 
In an example as shown in FIG. 1, the first layer region (O) 103 has such a 
layer structure as the first layer region (O) 103 per se constitutes a 
part of the second layer region (III) 104, and the first layer region (O) 
103 and the second layer region (III) 104 are present internally under the 
surface of amorphous layer 102. 
Oxygen atom which is presumably a factor to affect humidity resistance and 
corona ion resistance is not contained in the upper layer region 105 of an 
amorphous layer 102, but only in the first layer region (O) 103. Enhancing 
the dark resistance and enhancing the adhesion between a support 101 and 
an amorphous layer 102 are mainly contemplated by incorporating oxygen 
atoms in the first layer region (O) 103 while enhancing photosensitivity 
is mainly contemplated by incorporating no oxygen atom in the upper layer 
region 105. Oxygen atom contained in the first layer region (O) 103 is 
distributed continuously and nonuniformly in the direction of the layer 
thickness while oxygen atom is contained in the first layer region (O) 103 
and is substantially uniformly distributed in a plane parallel to the 
interface between support 101 and amorphous layer 102. 
As a group III atom contained in the second layer region (III) 104 of 
amorphous layer 102, there may be mentioned B (boron), Al (aluminium), Ga 
(gallium), In (indium), Tl (thallium) and the like, particularly 
preferably B and Ga. 
The distribution state of the group III atom contained in the second layer 
region (III) 104 is made substantially uniform both in the direction of 
the layer thickness and in a plane parallel to the surface of support 101. 
Since the layer thickness of the first layer region (O) 103 and that of the 
upper layer region 105 are one of the important factor to achieve the 
object of this invention, it is desirable to take a sufficient care for 
the design of a photoconductive member so that the intended 
characteristics may be sufficiently imparted to a photoconductive member 
to be formed. 
In the present invention, the upper limit of the layer thickness T.sub.B of 
the second layer region (III) 104 is preferably 50.mu., more preferably 
30.mu., and most preferably 10.mu.. 
Besides, the lower limit of the layer thickness T of the upper layer region 
105 is preferably 0.5.mu., more preferably 1.mu., and most preferably 
3.mu.. 
The lower limit of the layer thickness T.sub.B of the second layer region 
(III) 104 and the upper limit of the layer thickness T of the upper layer 
region 105 are preferably determined depending upon the organic relation 
between the characteristics required for the both layer regions and the 
characteristics required for the whole amorphous layer 102. 
In the present invention, the lower limit of the layer thickness T.sub.B 
and the upper limit of the layer thickness T are usually selected such 
that the relation T.sub.B /T.ltoreq.1 is satisfied. 
Moreover, in above selection of the values of the layer thicknesses T.sub.B 
and T, it is desirable that they preferably satisfies the relation T.sub.B 
/T.ltoreq.0.9; more preferably T.sub.B /T.ltoreq.0.8. 
In FIG. 1, the first layer region 103 is formed in the second layer region 
104 containing the group III atom, but the first layer region (O) and 
second layer region (III) may be in the same single region. 
Further, it can be also one of the preferable embodiments that the second 
layer region (III) is formed in the first layer region (O). 
The content of oxygen atom in the first layer region (O) may be properly 
selected depending on the characteristics required for the photoconductive 
member to be formed. It may be preferably 0.001-50 atomic %, more 
preferably 0.002-40 atomic % and most preferably 0.003-30 atomic %. 
When the layer thickness To of the first layer region (O) is sufficiently 
high or the ratio of To to the whole thickness of the amorphous layer is 
more than 2/5, the upper limit of oxygen atom in the first layer region 
(O) is preferably 30 atomic %, more preferably 20 atomic %, and most 
preferably 10 atomic %. 
In the present invention, the layer thickness of the amorphous layer is 
preferably 1-100.mu., more preferably 1-80.mu., and most preferably 
2-50.mu. from the standpoint of the characteristics required for the 
electrophotography as well as from the economical point of view. 
FIG. 2 through FIG. 10 show typical examples of the distribution state of 
oxygen atom in the direction of the layer thickness in the first layer 
region (O) containing oxygen atom of the amorphous layer in a 
photoconductive member according to the present invention. 
In the examples in FIG. 2 through FIG. 10, the layer region (III) 
containing the group III atom may be the same layer region as the layer 
region (O), may include the layer region (O), or may share a part with the 
layer region (O). Therefore, in the following description the layer region 
(III) containing thegroup III atom will not be referred to unless any 
particular explanation is necessary. 
In FIGS. 2 through 10, the abscissa indicates the content C of the oxygen 
atoms and the ordinate the layer thickness To of the layer region (O) 
containing the oxygen atoms constituting the amorphous layer exhibiting 
photoconductivity, t.sub.B showing the position of the interface on the 
support side and t.sub.T the position of the interface on the side 
opposite to the support side. That is, the layer region (O) containing the 
oxygen atoms is formed from the t.sub.B side toward the t.sub.T side. 
In the present invention, the first layer region (O) containing the oxygen 
atoms consists of a-Si, preferably a-Si(H,X) constituting the 
photoconductive member, and it may occupy a part of the region of the 
amorphous layer exhibiting photoconductivity. 
In the first layer region (O), it is preferred in an example shown in FIG. 
1 that said layer should be provided as the lower layer region of the 
amorphous layer 102 containing the interface on the side of the support 
101 in the amorphous layer 100. 
In FIG. 2, there is shown a first typical example of the distribution of 
the oxygen atoms in the layer thickness direction contained in the first 
layer region (O). 
According to the example as shown in FIG. 2, from the interface position 
t.sub.B between the first layer region (O) and a surface on which the 
first layer region (O) is formed to the other interface position t.sub.1, 
the oxygen atoms are contained in the layer region (O) formed with the 
concentration of the oxygen atoms taking a constant value of C.sub.1, and 
from the position t.sub.1 to the interface position t.sub.T, the 
concentration being gradually decreased from the concentration C.sub.2. At 
the interface position t.sub.T, the concentration C of the group III atoms 
is made C.sub.3. 
In the example as shown in FIG. 3, there is created a distribution such 
that the concentration C of the oxygen atoms is continuously gradually 
decreased from the position t.sub.B to the position t.sub.T from the 
concentration C.sub.4, until it becomes the concentration C.sub.5 at the 
position t.sub.T. 
In case of FIG. 4, the concentration C of the oxygen atoms is maintained at 
a constant value of C.sub.6 from the position t.sub.B to the position 
t.sub.2, gradually continuously decreased between the position t.sub.2 and 
the position t.sub.T, and at the position t.sub.T the concentration C is 
made substantially zero. 
In case of FIG. 5, the oxygen atoms are continuously gradually decreased in 
concentration from the concentration C.sub.8 from the position t.sub.B to 
the position t.sub.T at which the concentration is made substantially 
zero. 
In the example shown in FIG. 6, the concentration C of the oxygen atoms is 
maintained at a constant value of C.sub.9 from the position t.sub.B to 
t.sub.3 and is made C.sub.10 at the position t.sub.T. Between the position 
t.sub.3 and the position t.sub.T, the concentration C is decreased in a 
linear function from the position t.sub.3 to the position t.sub.T. 
In the example as shown in FIG. 7, the distribution is made such that a 
constant value of C.sub.11 is taken from the position t.sub.B to the 
position t.sub.4, and the concentration C is decreased in a linear 
function from the concentration C.sub.12 to the concentration C.sub.13 
from the position t.sub.4 to the position t.sub.T. 
In the example as shown in FIG. 8, the concentration C of the oxygen atoms 
is decreased from the position t.sub.B to the position t.sub.T in a linear 
function from the concentration C.sub.14 to zero. 
In FIG. 9, there is shown an example in which the concentration C of the 
oxygen atoms is decreased from the position t.sub.B to the position 
t.sub.5 in a linear function from the concentration C.sub.15 to the 
concentration C.sub.16, and maintained at a constant value of C.sub.16 
between the position t.sub.5 and the position t.sub.T. 
In the example as shown in FIG. 10, the concentration C of the oxygen atoms 
is the concentration C.sub.17 at the position t.sub.B, which is then 
initially gradually decreased to the position t.sub.6 and abruptly 
decreased near the position t.sub.6 to the concentration C.sub.18 at 
position t.sub.6. Between the position t.sub.6 and the position t.sub.7, 
the concentration is abruptly decreased at the beginning and then 
gradually decreased and becomes the concentration C.sub.19 at the position 
t.sub.7, and between the position t.sub.7 and the position t.sub.8, with a 
very gradual decrease, reaches the concentration C.sub.20 at t.sub.8. 
Between the position t.sub.8 and the position t.sub.T, the concentration 
is decreased from C.sub.20 along the curve as shown in the drawing to 
substantially zero. 
In the above, there are shown some typical examples of the distributions in 
the layer thickness direction of the oxygen atoms contained in the layer 
region (O) by referring to the FIG. 2 to FIG. 10. In the present 
invention, there is provided in the amorphous layer a first layer region 
(O), having a portion with higher value of the concentration C of the 
oxygen atoms on the support side, and having a portion with said 
concentration C which has been made relatively lower on the interface 
t.sub.T side, as compared with that on the suport side. 
In the present invention, it is desirable that the first layer region (O) 
constituting the amorphous layer has a localized region (A) containing the 
oxygen atoms at higher concentration on the support side as described 
above. Thus the adhesion between the support and the amorphous layer can 
be improved. 
The localized region (A) may preferably be provided at a position, in terms 
of the symbols shown in FIGS. 2 to 10, within 5.mu. from the interface 
position t.sub.B. 
In such a case as described above, the above localized region (A) may be 
made the whole layer region (L.sub.T) ranging from the interface position 
t.sub.B to the 5-micron thickness in some cases, or a part thereof in 
other cases. 
It may be suitably determined depending on the characteristics required for 
the amorphous layer formed, whether the localized region (A) should be 
made a part or whole of the layer region (L.sub.T). 
The localized region (A) may be desirably formed so that the oxygen atoms 
may be distributed in the layer thickness direction with the maximum 
distribution value of the oxygen atoms (concentration distribution value) 
C.sub.max being preferably 500 atomic ppm or more, more preferably 800 
atomic ppm or more, most preferably 1000 atomic ppm or more. 
That is, in the present invention, the first layer region (O) containing 
the oxygen atoms may be preferably formed so that the maximum value 
C.sub.max of the content distribution may exist at a depth within 5.mu. of 
layer thickness from the support side (layer region of 5 .mu. thickness 
from t.sub.B). 
In the present invention, the content of the group III atoms to be 
contained in the second layer region (III) may be suitably determined as 
desired to achieve the object of the present invention, but it is 
preferably in the range from 0.01 to 5.times.10.sup.4 atomic ppm, more 
preferably from 0.5 to 1.times.10.sup.4 atomic ppm, most preferably from 1 
to 5.times.10.sup.3 atomic ppm. 
The support to be used in the present invention may be either 
electroconductive or insulating. As the electroconductive support, there 
may be mentioned metals such as NiCr, stainless steel, Al, Cr, Mo, Au, Nb, 
Ta, V, Ti, Pt, Pd etc. or alloys thereof. 
As insulating supports, there may conventionally be used films or sheets of 
synchetic resins, including polyesters, polyethylene, polycarbonates, 
cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene 
chloride, polystyrene, polyamides, etc., glasses, ceramics, papers and so 
on. These insulating supports may preferably have at least one surface 
subjected to electroconductive treatment, and it is desirable to provide 
other layers on the side to which said electroconductive treatment has 
been applied. 
For example, electroconductive treatment of a glass can be effected by 
providing a thin film of NiCr, Al, Cr, Mo, Au, Ir, Nb, Ta, V, Ti, Pt, Pd, 
In.sub.2 O.sub.3, SnO.sub.2, ITO (In.sub.2 O.sub.3 +SnO.sub.2) thereon. 
Alternatively, a synthetic resin film such as polyester film can be 
subjected to the electroconductive treatment on its surface by vacuum 
vapor deposition, electron-beam deposition or sputtering of a metal such 
as NiCr, Al, Ag, Pb, Zn, Ni, Au, Cr, Mo, Ir, Nb, Ta, V, Ti, Pt, etc. or by 
laminating treatment with said metal, thereby imparting 
electroconductivity to the surface. The support may be shaped in any form 
such as cylinders, belts, plates or others, and its form may be determined 
as desired. For example, when the photoconductive member 100 in FIG. 1 is 
to be used as an image forming member for electrophotography, it may 
desirably be formed into an endless belt or a cylinder for use in 
continuous high speed copying. The support may have a thickness, which is 
conveniently determined so that a photoconductive member as desired may be 
formed. When the photoconductive member is required to have a flexibility, 
the support is made as thin as possible, so far as the function of a 
support can be exhibited. However, in such a case, the thickness is 
generally 10.mu. or more from the points of fabrication and handling of 
the support as well as its mechanical strength. 
In the present invention, formation of an amorphous layer comprising 
a-Si(H,X) may be conducted by the vacuum deposition method utilizing 
discharging phenomenon such as the glow discharge method, the sputtering 
method or the ion-plating method. For example, for the formation of an 
amorphous layer comprising a-Si(H,X) according to the glow discharge 
method, the basic procedure comprises introducing the starting gases for 
supplying hydrogen atoms (H) and/or halogen atoms (X) together with a 
starting gas capable of supplying silicon atoms (Si), into a deposition 
chamber which can be internally brought to a reduced pressure, wherein 
glow discharge is excited thereby to form a layer comprising a-Si(H,X) on 
the surface of a support placed at a predetermined position in said 
chamber. 
When it is formed according to the sputtering method, the starting gas for 
supplying hydrogen atoms (H) and/or halogen atoms (X) may be introduced 
into a deposition chamber for sputtering upon effecting sputtering with a 
target constituted of Si in an atmosphere of an inert gas such as Ar, He 
and the like or the gas mixture based on these gases. 
In the present invention, as the halogen atoms (X), which may be introduced 
into the amorphous layer if necessary, there may be mentioned fluorine, 
chlorine, bromine and iodine, particularly, fluorine and chlorine are 
preferred. 
The starting gas for supplying Si to be used in the present invention may 
include gaseous or gasifiable silicon hydrides (silanes) such as 
SiH.sub.4, Si.sub.2 H.sub.6, Si.sub.3 H.sub.8, Si.sub.4 H.sub.10 and the 
like. In particular, SiH.sub.4 and Si.sub.2 H.sub.6 are preferred with 
respect to easy handling during formation and efficiency for supplying Si. 
As the effective starting gas for incorporation of halogen atoms to be used 
in the present invention, there may be employed a number of halogen 
compounds including gaseous or gasifiable halogen compounds such as 
halogen gases, halides, interhalogen compounds, silane derivatives 
substituted by halogens and the like. 
Further, there may be also included gaseous or gasifiable silicon compounds 
containing halogen atoms, which comprises silicon atoms (Si) and halogen 
atoms (X) as constituents, as effective materials to be used in the 
present inventions. 
As the halogen compounds preferably used in the present invention, there 
may be included halogen gases such as fluorine, chlorine, bromine and 
iodine, and interhalogen compounds such as BrF, ClF, ClF.sub.3, BrF.sub.5, 
BrF.sub.3, IF.sub.2, IF.sub.7, ICl, IBr and the like. 
As silicon compounds containing halogen atoms, so called as silane 
derivatives substituted by halogen atoms, there may be included preferably 
silicon halides, e.g. specifically SiF.sub.4, Si.sub.2 F.sub.6, 
SiCl.sub.4, SiBr.sub.4 and the like. 
When the formation of a particular photoconductive member according to the 
present invention is carried out by the glow discharging method employing 
the above mentioned silicon compounds containing halogen atoms, it is 
possible to form an amorhpus layer constituted of a-Si containing halogen 
atoms on a support placed at a predetermined position without employing a 
silicon hydride gas as the starting gas capable of supplying Si. 
When an amorphous layer containing halogen atoms is formed on a 
predetermined support according to the glow discharging method, the basic 
procedure comprises introducing the silicon halides gases as starting 
gases capable of supplying Si together with a gas such as Ar, H.sub.2, He 
gases and the like at a predetermined mixing ratio and gas flow rate into 
a deposition chamber where an amorphous layer can be formed, and forming a 
plasma atmosphere of these gases by exciting a glow discharging, but it is 
also permitted to mix a predetermined amount of a gas of a silicon 
compound containing hydrogen atom with the abovementioned gases in order 
to supply hydrogen atoms for the formation of said layer. 
These gases may be used alone or in combination at a predetermined mixing 
ratio. 
The formation of an amorphous layer constituted of a-Si(H,X) according to 
the reactive sputtering method or ion plating method may be carried out as 
shown below. For example, when the sputtering method is employed, 
sputtering is effected with a target constituted of Si in an atmosphere of 
a predetermined gas plasma, and when the ion plating method is employed, 
the polycrystalline silicon or single crystalline silicon as the source 
for evaporation is placed in a vacuum evaporation boat, followed by 
causing the evaporation of said silicon source by means of a resistant 
heating method or electron beam method (EB method) and passing the flying 
evaporates through the atmosphere of the predetermined gas plasma. 
In the sputtering method or the ion plating method, introducing halogen 
atoms into the layer to be formed may be accomplished by introducing the 
halogen compound gas or a gas of the silicon compound containing a halogen 
atom into the depositing chamber followed by the formation of an 
atmosphere of plasma of said gas. 
Likewise, introducing hydrogen atoms may be accomplished by introducing, 
for example, H.sub.2 or the abovementioned silane gas and the like into 
the depositing chamber for sputtering followed by the formation of 
atmosphere of plasma of said gas. 
In the present invention, while the aforementioned halogen compounds or 
halogen containing silicon compounds may be employed as an effective 
starting gas for introducing halogen atoms, there may be also employed 
gasous or gasifiable halogen compounds having hydrogen atoms as one of the 
constituent elements for example, hydrogen halides such as HF, HCl, HBr, 
and HI, halo-substituted silicon hydrides such as SiH.sub.2 F.sub.2, 
SiH.sub.2 I.sub.2, SiH.sub.2 Cl.sub.2, SiHCl.sub.3, SiH.sub.2 Br.sub.2, 
SiHBr.sub.3 and the like as effective starting materials for forming the 
amorphous layer. 
These hydrogen-containing halogen compounds can introduce hydrogen atom as 
well as halogen atom into the amorphous layer upon forming said layer, and 
hydrogen atom is very effective for controlling the electrical or 
photoelectrical characteristics. Therefore, the hydrogen-containing 
halogen compounds are preferable starting materials for introducing 
halogen atom. 
Introducing the hydrogen atoms as constituent into an amorphous layer may 
be also achieved by coexisting H.sub.2 or a silicon halide gas such as 
SiH.sub.4, Si.sub.2 H.sub.6, Si.sub.3 H.sub.8, Si.sub.4 H.sub.10 and the 
like with a silicon compound for introducing Si into the depositing 
chamber and exciting discharging therein. 
For example, when the reactive sputtering method is employed, an amorphous 
layer comprising a-Si(H,X) may be formed on a support by introducing the 
gas for supplying halogen atoms and H.sub.2 gas and optionally inert gas 
such as He, Ar and the like into the depositing chamber, followed by 
forming the plasma atmosphere and by sputtering with the Si target. 
There may be permitted to introduce a gas such as B.sub.2 H.sub.6 and the 
like which can also serve for doping with impurity. 
In the present invention, the amount of hydrogen atom (H) or halogen atom 
(X) or the sum amount (H+X) of hydrogen atom and halogen atom to be 
contained in an amorphous layer of the photoconductive member to be formed 
may be preferably 1-40 atomic %, more preferably 5-30 atomic %. 
Controlling the amount of hydrogen atom (H) and/or halogen atom (X) to be 
contained in an amorphous layer may be effected by controlling e.g. the 
support temperature and/or the amount of the starting materials for 
supplying hydrogen atoms (H) or halogen atoms (X) to be introduced into 
the depositing device system, the discharging power, and the like. 
Forming the seocnd layer region (III) containing the group III atoms and 
the first layer region (O) containing oxygen atoms in an amorphous layer 
may be accomplished by employing the starting materials for supplying the 
group III atoms and oxygen atoms, respectively, together with the 
aforementioned starting materials for forming an amorphous layer while 
controlling the amount of said materials to be introduced into the layer 
to be formed when said amorphous layer is formed by glow discharging 
method or reactive sputtering method. 
When the glow discharging method is employed for the formation of the first 
layer region (O) containing oxygen atoms and the second layer region (III) 
containing the group III atoms in the amorphous layer, as the starting 
material used for the starting gas for forming each layer region, there 
may be used a starting material desirably selected from the above 
mentioned materials for forming the amorphous layer and a starting 
material for introducing oxygen atom and/or that for introducing the group 
III atom. 
As those starting materials for supplying oxygen atoms or the group III 
atoms, it is possible to use most of the gases which are selected from the 
gaseous substances or gasified gasifiable substances containing at least 
oxygen atom or group III atom. 
For example, for producing a layer region (O), there may be used a mixture 
of a starting gas containing silicon atom (Si) as a constituent atom, a 
starting gas containing oxygen atom (O) as a constituent atom and, if 
desired, a starting gas containing hydrogen atom (H) and/or halogen atom 
(X) as constituent atoms at a desired mixing ratio; there may be used a 
mixture of a starting gas containing silicon atom (Si) as a constituent 
atom and a starting gas containing oxygen atom (O) and hydrogen atom (H) 
as constituent atom at a desired mixing ratio; or there may be used a 
mixture of a starting gas containing silicon atom (Si) as a constituent 
atom and a starting gas containing silicon atom (Si), oxygen atom (O) and 
hydrogen atom (H) as constituent atoms. 
In addition, a mixture of a starting gas having silicon atom (Si) and 
hydrogen atom (H) as constituents atoms and a starting gas having oxygen 
atom (O) as a constituent atom may be also acceptable. 
As the starting materials for introducing oxygen atoms, there may be 
mentioned specifically, for example, oxygen (O.sub.2), ozone (O.sub.3), 
nitrogen monooxide (NO), nitrogen dioxide (NO.sub.2), dinitrogen monooxide 
(N.sub.2 O), dinitrogen trioxide (N.sub.2 O.sub.3), dinitrogen tetraoxide 
(N.sub.2 O.sub.4), dinitrogen pentoxide (N.sub.2 O.sub.5) and nitrogen 
trioxide (NO.sub.3) as well as lower siloxanes comprising silicon atom 
(Si), oxygen atom (O) and hydrogen atom (H) as constituent atoms such as 
disiloxane (H.sub.3 SiOSiH.sub.3) and trisiloxane (H.sub.3 SiOSiH.sub.2 
OSiH.sub.3) and the like. 
When the layer region (III) is formed by a glow discharging method, as 
effective starting materials for the introduction of the group III atoms, 
there may be mentioned boron hydrides such as B.sub.2 H.sub.6, B.sub.4 
H.sub.10, B.sub.5 H.sub.9, B.sub.5 H.sub.11, B.sub.6 H.sub.10, B.sub.6 
H.sub.12, B.sub.6 H.sub.14 and the like, boron halides such as BF.sub.3, 
BCl.sub.3, BBr.sub.3 and the like for the introduction of boron atoms. In 
addition, there may also be included AlCl.sub.3, GaCl.sub.3, 
Ga(CH.sub.3).sub.3, InCl.sub.3 and the TlCl.sub.3 and the like. 
The contents of the group III atoms to be introduced into the layer region 
(III) may be controlled freely by controlling the gas flow rate, the gas 
flow rate ratio of the starting materials for introducing the group (III) 
atoms, the discharging power, the support temperature and the pressure in 
the depositing chamber and others. 
For the formation of the layer region (O) containing oxygen atoms by 
sputtering method, single crystalline or polycristalline Si wafer, or 
SiO.sub.2 wafer, or a wafer containing both Si and SiO.sub.2 may be used 
as a target in an atmosphere of various gases to effect sputtering. 
For example, when a Si wafer is employed as a target, a starting gas for 
the introduction of oxygen atoms and optionally hydrogen atoms and/or 
halogen atoms which may be, if desired, diluted with a dilution gas are 
introduced into the depositing chamber for sputtering and the gas plasma 
of the gases is produced to effect sputtering with the Si wafer target. 
Alternatively, Si and SiO.sub.2 are used as separate targets, or a sheet of 
target composed of Si and SiO.sub.2 is used, and the sputtering may be 
effected in an atmosphere of a diluting gas or a gas atmosphere where the 
gas contains at least hydrogen atom (H) and/or halogen atom (X) as 
constituent atoms. 
As a starting gas for introducing oxygen atom, the starting gas for 
introducing oxygen atom as mentioned in the glow discharging method above 
may be also used for sputtering as an effective gas. 
In the present invention, as diluting gases for the formation of an 
amorphous layer according to the glow discharging method, or gases for the 
formation of an amorphous layer according to the sputtering method, there 
may be employed so-called rare gases such as He, Ne, Ar, and the like. 
FIG. 11 shows a schematical diagram to be used for illustrating another 
preferable embodiment of the layer constitution according to the present 
invention. 
In FIG. 11, a photoconductive member 1100 has a support 1101 for a 
photoconductive member and a first amorphous layer (I) 1102 overlying 
support 1101, comprising a-Si(H,X) and exhibting photoconductivity, and a 
second amorphous layer (II) 1106 comprising an amorphous material 
(hereinafter referred to as "a-SiC(H,X)") which contains silicon atom, 
carbon atom and optionally at least any one of hydrogen atom (H) and 
halogen atom (X). 
Photoconductive member 1100 as shown in FIG. 11 has a similar layer 
constitution to the photoconductive member as shown already in FIG. 1 
except that the second amorphous layer (II) 1106 is mounted on the first 
amorphous layer (I) 1102. 
That is, the first amorphous layer (I) 1102 has a layer constitution that 
the first layer region (O) 1103 contains oxygen atom as a constituent atom 
continuously distributed in the direction of the layer thickness and 
higher concentrated toward the side of said support 1101 and the second 
layer region (III) 1104 contains the group III atom as a constituent atom. 
The second amorphous layer (II) 1106 is provided primarily for the purpose 
of accomplishing the objects of the present invention with respect to 
humidity resistance, continuous repeated use characteristics, dielectric 
strength, enrivonmental characteristics in use and durability. 
In the photoconductive member 1100 as shown in FIG. 11, since each of the 
amorphous materials forming the first amorphous layer (I) 1102 and the 
second amorphous layer (II) 1106 have the common constitutent of silicon 
atom, chemical and electric stabilities are sufficiently ensured at the 
laminated interface. 
As a-SiC(H,X) constituting the second amorphous layer (II), there may be 
mentioned an amorphous material constituted of silicon atoms and carbon 
atoms (a-Si.sub.a C.sub.1-a, where 0&lt;a&lt;1), an amorphous material 
constituted of silicon atoms, carbon atoms and hydrogen atoms [a-(Si.sub.b 
C.sub.1-b).sub.c H.sub.1-c, where O&lt;a, b&lt;1] and an amorphous material 
constituted of silicon atoms, carbon atoms, halogen atoms (X) and, if 
desired, hydrogen atoms [a-(Si.sub.d C.sub.1-d).sub.e (X,H).sub.1-e, where 
O&lt;d, e&lt;1] as effective materials. 
Formation of the second amorphous layer (II) constituted of a-SiC(H,X) may 
be performed according to the glow discharge method, the sputtering 
method, the ion implantation method, the ion plating method, the electron 
beam method, etc. These preparation methods may be suitably selected 
depending on various factors such as the preparation conditions, the 
degree of the load for capital investment for installations, the 
production scale, the desirable characteristics required for the 
photoconductive member to be prepared, etc. For the advantages of 
relatively easy control of the preparation conditions for preparing 
photoconductive members having desired characteristics and easy 
introduction of silicon atoms and carbon atoms, optionally together with 
hydrogen atoms or halogen atoms, into the second amorphous layer (II) to 
be prepared, there may preferably be employed the glow discharge method or 
the sputtering method. 
Further, in the present invention, the second amorphous layer (II) may be 
formed by the glow discharge method and the sputtering method in 
combination in the same device system. 
For formation of the second amorphous layer (II) according to the glow 
discharge method, starting gases for formation of a-SiC(H,X), optionally 
mixed at a predetermined mixing ratio with diluting gas, may be introduced 
into a deposition chamber for vacuum deposition in which a support is 
placed, and the gas introduced is made into a gas plasma by excitation of 
glow discharging, thereby depositing a-SiC(H,X) on the first amorphous 
layer (I) which has already been formed on the aforesaid support. 
As the starting gases for formation of a-SiC(H,X) to be used in the present 
invention, it is possible to use most of gaseous substances or gasified 
gasifiable substances containing at least one of Si, C, H and X as 
constituent atoms. 
In case when a starting gas having Si as constitutent atoms as one of Si, 
C, H and X is employed, there may be employed, for example, a mixture of a 
starting gas containing Si as constituent atom, a starting gas containing 
C as constituent atom and a starting gas containing H or X as constituent 
atom at a desired mixing ratio, or alternatively a mixture of a starting 
gas containing Si as constituent atoms with a starting gas containing C 
and H or X also at a desired mixing ratio, or u a mixture of a starting 
gas containing Si as constituent atoms with a gas containing three atoms 
of Si, C and H or of Si, C and X as constituent atoms. 
Alternatively, it is also possible to use a mixture of a starting gas 
containing Si and H or X as constituent atoms with a starting gas 
containing C as constituent atom. 
In the present invention, the starting gases effectively used for formation 
of the second amorphous layer (II) may include silicon hydride gases 
containing Si and H as constituent atoms such as silanes (e.g. SiH.sub.4, 
Si.sub.2 H.sub.6, Si.sub.3 H.sub.8, Si.sub.4 H.sub.10, etc.), compounds 
containing C and H as constituent atoms such as saturated hydrocarbons 
having 1 to 5 carbon atoms, ethylenic hydrocarbons having 2 to 5 carbon 
atoms and acetylenic hydrocarbons haivng 2 to 4 carbon atoms. 
More specifically, there may be included, as saturated hydrocarbons, 
methane (CH.sub.4), ethane (C.sub.2 H.sub.6), propane (C.sub.3 H.sub.8), 
n-butane (n-C.sub.4 H.sub.10), pentane (C.sub.5 H.sub.12); as ethylenic 
hydrocarbons, ethylene (C.sub.2 H.sub.4), propylene (C.sub.3 H.sub.6), 
butene-1 (C.sub.4 H.sub.8), butene-2 (C.sub.4 H.sub.8), isobutylene 
(C.sub.4 H.sub.8), pentene (C.sub.5 H.sub.10); as acetylenic hydrocarbons, 
acetylene (C.sub.2 H.sub.2), methyl acetylene (C.sub.3 H.sub.4), butyne 
(C.sub.4 H.sub.6); and the like. 
As the starting gas containing Si, C and H as constituent atoms, there may 
be mentioned alkyl silanes such as Si(CH.sub.3).sub.4, Si(C.sub.2 
H.sub.5).sub.4 and the like. In addition to these starting gases, it is 
also possible as a matter of course to use H.sub.2 as effective starting 
gas for introduction of H.sub.2. 
In the present invention, preferable halogen atoms (X) to be contained in 
the second amorphous layer (II) are F, Cl, Br and I. Particularly, F and 
Cl are preferred. 
Incorporation of hydrogen atoms into the second amorphous layer (II) is 
convenient from aspect of production cost, because a part of starting gas 
species can be made common in forming continuous layers together with the 
first amorphous layer (I). 
In the present invention, as the starting gas which can be used effectively 
for introduction of halogen atoms (X) in formation of the second amorphous 
layer (II), there may be mentioned gaseous substances under conditions of 
normal temperature and normal pressure or readily gasifiable substances. 
Such starting gases for introduction of halogen atoms (X) may include 
single halogen substances, hydrogen halides, interhalogen compounds, 
silicon halides, halo-substituted silicon hydrides and the like. 
More specifically, there may be mentioned, as single halogen substances, 
halogenic gases such as of fluorine, chlorine, bromine and iodine; as 
hydrogen halides, HF, HI, HCl, and HBr; as interhalogen compounds, BrF, 
ClF, ClF.sub.3, ClF.sub.5, BrF , BrF.sub.3, IF.sub.7, IF.sub.5, ICl, IBr; 
as silicon halides, SiF.sub.4, Si.sub.2 F.sub.6, SiCl.sub.4, SiCl.sub.3 
Br, SiCl.sub.2 Br.sub.2, SiClBr.sub.2, SiCl.sub.3 I, SiBr.sub.4 ; as 
halo-substituted silicon hydrides, SiH.sub.2 F.sub.2, SiH.sub.2 Cl.sub.2, 
SiHCl.sub.3, SiH.sub.3 Cl, SiH.sub.3 Br, SiH.sub.2 Br.sub.2, SiHBr.sub.3 
and the like. 
In addition to these materials, there may also be employed halo-substituted 
paraffinic hydrocarbons such as CCl.sub.4, CHF.sub.3, CH.sub.2 F.sub.2, 
CH.sub.3 F, CH.sub.3 Cl, CH.sub.3 Br, CH.sub.3 I, C.sub.2 H.sub.5 Cl and 
the like, fluorinated sulfur compounds such as SF.sub.4, SF.sub.6 and the 
like, halo-containing alkyl silanes such as SiCl(CH.sub.3).sub.3, 
SiCl.sub.2 (CH.sub.3).sub.2, SiCl.sub.3 CH.sub.3 and the like, as 
effective materials. 
For formation of the second amorphous layer (II) according to the 
sputtering method, a single crystalline or polycrystalline Si wafer or C 
wafer or a wafer containing Si and C mixed therein is used as target and 
subjected to sputtering in an atmosphere of various gases. 
For example, when Si wafer is used as target, a starting gas for 
introducing at least C, which may be diulted with a diluting gas, if 
desired, is introduced into a deposition chamber for sputtering to form a 
gas plasma therein and effect sputtering with said Si wafer. 
Alternatively, Si and C as separate targets or one sheet target of a 
mixture of Si and C can be used and sputtering is effected in a gas 
atmosphere containing, if necessary, at least hydrogen atoms or halogen 
atoms. 
As the starting gas for introduction of C or for introduction of H or X, 
there may be employed those as mentioned in the glow discharge as 
described above as effective gases also in case of the sputtering method. 
In the present invention, as the diluting gas to be used in forming the 
second amorphous layer (II) by the glow discharge method or the sputtering 
method, there may be preferably employed so called rare gases such as He, 
Ne, Ar and the like. 
The second amorphous layer (II) in the present invention should be 
carefully formed so that the required characterictics may be given exactly 
as desired. 
That is, a substance containing as constituent atoms Si, C and, if 
necessary, H and/or X can take various forms from crystalline to 
amorphous, electrical properties from conductive through semi-conductive 
to insulating, and photoconductive properties from photoconductive to 
non-photoconductive depending on the preparation conditions. Therefore, in 
the present invention, the preparation conditions are strictly selected as 
desired so that there may be formed a-SiC(H,X) having desired 
characteristics depending on the purpose. 
For example, when the second amorphous layer (II) is to be provided 
primarily for the purpose of improvement of dielectric strength, 
a-SiC(H,X) is prepared as an amorphous material having marked electric 
insulating behaviours under the usage conditions. 
Alternatively, when the primary purpose for provision of the second 
amorphous layer (II) is improvement of continuous repeated use 
characteristics or environmental characteristics in use, the degree of the 
above electric insulating property may be alleviated to some extent and 
a-SiC(H,X) may be prepared as an amorphous material having sensitivity to 
some extent to the light irradiated. 
In forming the second amorphous layer (II) comprising a-SiC(H,X) on the 
surface of the first amorphous layer (I), the support temperature during 
layer formation is an important factor having influences on the structure 
and the characteristics of the layer to be formed, and it is desired in 
the present invention to control severely the support temperature during 
layer formation so that a-SiC(H,X) having intended characteristics may be 
prepared as desired. 
As the support temperature in forming the second amorphous layer (II) for 
accomplishing effectively the objects of the present invention, there may 
be selected suitably the optimum temperature range in conformity with the 
method for forming the second amorphous layer (II) in carrying out 
formation of the second amorphous layer (II). 
When the second amorphous layer (II) is to be formed of a-Si.sub.a 
C.sub.1-a, the support temperature may preferably be 20.degree. to 
300.degree. C., more preferably 20.degree. to 250.degree. C. 
When the second amorphous layer (II) is to be formed of a-(Si.sub.b 
C.sub.1-b).sub.1-c or a-(Si.sub.d C.sub.1-d).sub.e (X,H).sub.1-e, the 
support temperature may preferably be 50.degree. to 350.degree. C., more 
preferably 100.degree. to 250.degree. C. 
For formation of the second amorphous layer (II), the glow discharge method 
or the sputtering method may be advantageously adopted, because sever 
control of the composition ratio of atoms constituting the layer or 
control of layer thickness can be conducted with relative case as compared 
with other methods. In case when the second amorphous layer (II) is to be 
formed according to these layer formation methods, the discharging power 
and the gas pressure during layer formation are important factors 
influencing the characteristics of a-SiC(H,X) to be prepared, similaarly 
as the aforesaid support temperature. 
The discharging power condition for prepoaring effective a-Si.sub.a 
C.sub.1-a having characteristics for acomplilshing the objects of the 
present invention with good productivity may preferably be 50 W to 250 W, 
most preferably 80 W to 150 W. 
The discharging power condition, in case of a-(Si.sub.b C.sub.1-b).sub.c 
H.sub.1-c and a-(Si.sub.d C.sub.1-d).sub.e (X,H).sub.1-e, may preferably 
be 10 to 300 W, more preferably 20 to 200 W. 
The gas pressure in a deposition chamber may preferably be about 0.01 to 5 
Torr, more preferably about 0.01 to 1 Torr, more preferably about 0.1 to 
0.5 Torr. 
In the present invention, the above numerical ranges may be mentioned as 
preferable numerical ranges for the support temperature and discharging 
power, for preparation of the second amorphous layer (II). However, these 
factors for layer formation should not be determined separately 
independently of each other, but it is desirable that the optimum values 
of respective layer forming factors should be determined based on mutual 
organic relationship so that a second amorphous layer (II) comprising 
a-SiC(H,X) having desired characteristics may be formed. 
The contents of carbon atoms and hydrogen atoms in the second amorphous 
layer (II) in the photoconductive member of the present invention are 
another important factor for obtaining the desired characteristics to 
accomplish the objects of the present invention, similarly as the 
conditions for preparation of the second amorphous layer (II). 
The content of carbon atoms contained in the second amorphuos layer (II) in 
the present invention, when it is constituted of a-Si.sub.a C.sub.1-a, may 
be generally 1.times.10.sup.-3 to 90 atomic %, preferably 1 to 80 atomic 
%, most preferably 10 to 75 atomic %. That is, in terms of the aforesaid 
representation a in the formula a-Si.sub.a C.sub.1-a, a may be generally 
0.1 to 0.99999, preferably 0.2 to 0.99, most preferably 0.25 to 0.9. 
When the second amorphous layer (II) is constituted of a-(Si.sub.b 
C.sub.1-b).sub.c H.sub.1-c, the content of carbon atoms contained in said 
layer (II) may be generally 1.times.10.sup.-3 to 90 atomic %, preferably 1 
to 90 atomic %, most preferably 10 to 80 atomic %. The content of hydrogen 
atoms may be generally 1 to 40 atomic %, preferably 2 to 35 atomic %, most 
preferably 5 to 30 atomic %. A photoconductive member formed to have a 
hydrogen atom content with these ranges is sufficiently applicable as an 
excellent one in practical applications. That is, in terms of the 
representation by a-(Si.sub.b C.sub.1-b).sub.c H.sub.1-c, b may be 
generally 0.1 to 0.99999, preferably 0.1 to 0.99, most preferably 0.15 to 
0.9, and c generally 0.6 to 0.99, preferably 0.65 to 0.98, most preferably 
0.7 to 0.95. 
When the second amorphous layer (II) is constituted of a-(Si.sub.d 
C.sub.1-d).sub.e (X,H).sub.1-e, the content of carbon atoms contained in 
said layer (II) may be generally 1.times.10.sup.-3 to 90 atomic %, 
preferably 1 to 90 atomic %, most preferably 10 to 80 atomic %. The 
content of halogen atoms may be generally 1 to 20 atomic %, preferably 1 
to 18 atomic %, most preferably 2 to 15 atomic %. A photoconductive member 
formed to have a halogen atom content with these ranges is sufficiently 
applicable as an excellent one in practical applications. The content of 
hydrogen atoms to be optionally contained may be generally up to 19 atomic 
%, preferably up to 13 atomic %. That is, in terms of the representation 
by a-(Si.sub.d C.sub.1-d).sub.e (X,H).sub.1-e, e may be generally 0.1 to 
0.99999, preferably 0.1 to 0.99, most preferably 0.15 to 0.9, and e 
generally 0.8 to 0.99, preferably 0.82 to 0.99, most preferably 0.85 to 
0.98. 
The range of the numerical value of layer thickness of the second amorphous 
layer (II) in the present invention is one of important factors for 
accomplishing effectively the objects of the present invention. 
It is desirable that the range of the numerical value of layer thickness of 
the second amorphous layer (II) is suitably determined depending on the 
intended purpose so as to effectively accomplish the objects of the 
present invention. 
The layer thickness of the second amorphous layer (II) is required to be 
determined as desired suitably with due considerations about the 
relationships with the contents of carbon atoms, hydrogen atoms or halogen 
atoms, the layer thickness of the first amorphous layer (I), as well as 
other organic relationships with the characteristics required for 
respective layer regions. In addition, it is also desirable to have 
considerations from economical point of view such as productivity or 
capability of mass production. 
The second amorphous layer (II) in the present invention is desired to have 
a layer thickness generally of 0.003 to 30.mu., preferably 0.004 to 
20.mu., most preferably 0.005 to 10.mu.. 
An outline of the preparation method for the formation of a photosensitive 
member according to a glow discharging decomposition will be explained in 
the following. 
FIG. 12 illustrates an apparatus capable of producing the photoconductive 
member by a glow discharging decomposition method. 
In the gas bombs 1202-1206, there are hermetically contained starting gases 
for the formation of respective layers of the present invention. For 
example, 1202 is a bomb containing SiH.sub.4 gas duluted with He (purity: 
99.999%, hereinafter abbreviated as SiH.sub.4 /He), 1203 is a bomb 
containing B.sub.2 H.sub.6 gas diluted with He (purity: 99.999%, 
hereinafter abbreviated as B.sub.2 H.sub.6 /He), 1204 is a bomb containing 
Si.sub.2 H.sub.6 gas diluted with He (purity: 99.99%, hereinafter 
abbreviated as Si.sub.2 H.sub.6 /He), 1205 is a bomb containing NO gas 
(purity: 99.999%), and 1206 is a bomb containing SiF.sub.4 gas diluted 
with He (purity: 99.999%) (hereinafter abbreviated as SiF.sub.4 /He) 
For allowing these gases to flow into the reaction chamber 1201, on 
conformation of the valves 1222-1226 of the gas bombs 1202-1206 and the 
leak valve 1235 to be closed, and the inflow valves 1212-1216, the outflow 
valves 1217-1221 and the auxiliary valve 1232, 1233 to be opened, the main 
valve 1234 is first opened to evacuate the reaction chamber 1201 and the 
gas pipelines. As the next step, when the reading on the vacuum indicator 
1236 becomes about 5.times.10.sup.-6 Torr, the auxiliary valves 1232 and 
1233, and outflow valves 1217-1221 are closed. 
Next, an example of forming a photoconductive member having an amorphous 
layer having such a structure as shown in FIG. 1 overlying the 
cylinderlike substrate 1237 will be described below. 
SiH.sub.4 /He gas from bomb 1202, B.sub.2 H.sub.6 /He gas from bomb 1203 
and NO gas from bomb 1205 are permitted to flow into mass-flow controllers 
1207, 1208 and 1210 by opening valves 1222, 1223 and 1225 to control 
outlet pressure gauges 1227, 1228 and 1230 to 1 kg/cm.sup.2 amd opening 
gradually inflow valves 1212, 1213 and 1215, respectively. Then, outflow 
valves 1217, 1218 and 1220 and auxiliary valve 1232 are gradually opened 
to permit the respective gases to flow into reaction chamber 1201. Outflow 
valves 1217, 1218 and 1220 are controlled so that the flow rate ratio of 
SiH.sub.4 /He gas:B.sub.2 H.sub.6 /He gas: NO gas may have a desired 
value, and opening degree of main valve 1234 is also controlled watching 
the reading of vacuum indicator 1236 so that the pressure in the reaction 
chamber 1201 may reach a desired value. Then after confirming that the 
temperature of the substrate cylinder 1237 has reached to 
50.degree.-400.degree. C. by a heater 1238, a power source 1240 is set at 
a desired output to cause glow discharging in the reaction chamber 1201, 
simultaneously the opening degree of the valve 1220 is gradually adjusted 
to regulate the NO gas flowing rate by means of hand operation or outer 
driving motor or the like according to the indication from the predesigned 
relation curves so as to control the distirbution concentration in the 
direction of the thickness of oxygen atoms to be contained in the layer to 
be formed. 
After the formation of the layer region (B, O) has been completed so that 
said region (B, O) may contain boron atoms and oxygen atoms in the layer 
as desired thickness according to the above procedure, the subsequent 
layer formation may be further advanced under the same conditions as the 
foregoing except that the introduction of B.sub.2 H.sub.6 /He gas and NO 
gas into the reaction chamber 1201 is stopped by closing the outflow 
valves 1218 and 1220 and thereby a layer region containing neither oxygen 
atoms nor boron atoms and having a desired layer thickness is formed on 
the layer region (B, O). According to the above procedure, an amorphous 
layer having desired characteristics is formed on the substrate 1237. 
The layer region (III) contaiing boron atoms may be formed in a desired 
thickness by intercepting the inflow of B.sub.2 H.sub.6 /He gas into the 
reaction chamber 1201 at a proper time during the forming step for the 
amorphous layer. It is possible to form a layer structure that the layer 
region (III) occupies the whole layer region of the layer region (O) or a 
part thereof. 
In above embodiment, for example, after the layer region (B, O) has been 
formed in a desired thickness, the subsequent layer formation is advanced 
further under the same conditions as the foregoing except that the 
introduction of NO gas into the reaction chamber 1201 is stopped by 
closing wholly the outflow valve 1220 and thereby there can be formed, as 
a part of the amorphous layer, a layer region containing boron atom, but 
not oxygen atom on the layer region (B, O). 
On the other hand, the formation of a layer region containing no boron 
atoms, but oxygen atoms, can be effected, for example, by using NO gas and 
SiH.sub.4 /He gas. 
In the case of introducing halogen atoms into an amorphous layer, for 
example, SiF.sub.4 /He is further added to the abovementioned gas and then 
introduced into reaction chamber 1201. 
All the outflow valves other than those for gases necessary for formation 
of respective layers are, of course, closed, and during formation of 
respective layers, in order to avoid remaining of the gas used in the 
precedent layer in the reaction chamber 1201 and pipelines from the 
outflow valves 1217-1221 to the reaction chamber 1201, there may be 
conducted the procedure comprising once evacuating to a high vacuum the 
system by closing the outflow valves 1217-1221 and opening the auxiliary 
valve 1232 and 1233 with full opening of the main valve 1234, if 
necessary. 
During formation of the layer, the substrate 1237 may be rotated at a 
constant speed by means of a motor 1239 in order to effect a uniform layer 
formation. 
The production apparatus of FIG. 13 is an alternative example of an 
apparatus. 
In gas bombs 1302-1306, there are hermicically contained starting gases for 
producing respective layer regions of the present invention. For example, 
bomb 1302 contains SiH.sub.4 /He gas, bomb 1303 contains B.sub.2 H.sub.6 
/He gas, bomb 1304 contains Ar gas (purity: 99.99%), bomb 1305 contains NO 
gas (purity: 99.999%), and bomb 1306 contains SiF.sub.4 /He gas. 
For allowing these gases to flow into the reaction chamber 1301, on 
confirmation of the valves 1322-1326 of the gas bombs 1302-1306 and the 
leak valve 1335 to be closed, and the inflow valves 1312-1316, the outflow 
valves 1317-1321 and the auxiliary valve 1332 to be opened, the main valve 
1334 is first opened to evacuate the reaction chamber 1301 and the gas 
pipelines. As the next step, when the reading on the vacuum indicator 1336 
becomes about 5.times.10.sup.-6 Torr, the auxiliary valves 1332, and 
outflow valves 1317-1321 are closed. 
As the next, an example of forming a photoconductive member having such a 
layer constitution as shown in FIG. 11 overlying a substrate 1337 will be 
described below. 
SiH.sub.4 /He gas from bomb 1302, B.sub.2 H.sub.6 /He gas from bomb 1303 
and NO gas from bomb 1305 are permitted to flow into mass-flow controllers 
1307, 1308 and 1310 by opening valves 1322, 1323 and 1325 to control 
outlet pressure gauges 1327, 1328 and 1330 to 1 kg/cm.sup.2 and opening 
gradually inflow valves 1312, 1313 and 1315, respectively. Then outflow 
valves 1317, 1318 and 1320 and auxiliary valve 1332 are gradually opened 
to permit the respective gases to flow into reaction chamber 1301. Outflow 
valves 317, 1318 and 1320 are controlled so that the flow rate ratio of 
SiH.sub.4 /He gas: B.sub.2 H.sub.6 /He gas: NO gas may have a desired 
value, and opening degree of main valve 1334 is also controlled watching 
the reading of vacuum indicator 1336 so that the pressure in the reaction 
chamber 1301 may reach a desired value. Then after confirming that the 
temperature of the substrate 1337 has reached to 50.degree.-400.degree. C. 
by a heater 1338, a power source 1340 is set at a desired output to cause 
glow discharging in the reaction chamber 1301, simultaneously the opening 
degree of the valve 1320 is gradually adjusted to regulate the NO gas 
flowing rate by means of hand operation or outer driving motor and the 
like according to the indication from the predesigned relation curves to 
control the distribution concentration in the direction of the thickness 
of oxygen atoms to be contained in the layer to be formed. 
When the formation of the layer region (B, O) containing boron atom and 
oxygen atom has been completed according to the above procedure, the layer 
formation may be further advanced under the same conditions as the 
foregoing except that the introduction of B.sub.2 H.sub.6 /He gas and NO 
gas into the reaction chamber 1301 is intercepted by closing the outflow 
valves 1318 and 1320, and thereby, there is formed a layer region 
containing neither oxygen atom nor boron atom and having a desired layer 
thickness on the layer region (B, O). According to above procedure, the 
first amorphous layer (I) having desired characteristics can be formed on 
the substrate 1337. 
The layer region (III) containing boron atoms may be formed in a desired 
thickness by intercepting the inflow of B.sub.2 H.sub.6 /He gas into the 
reaction chamber 1301 at a proper time during forming the first amorphous 
layer (I), and it is possible to form the layer region (III) occupying a 
part or the whole region of the layer region (O). 
In the above embodiment, for example, when the layer region (B, O) has been 
formed in a desired thickness, the layer formation is advanced further 
under the same conditions as the foregoing except that the introduction of 
NO gas into the reaction chamber 1301 is stopped by closing wholly the 
outflow valve 1320, and thereby a layer region containing boron atom, but 
not oxygen atom as a part of the first amorphous layer (I) on the layer 
region (B, O). 
On the other hand, a layer region containing no boron atom, but oxygen 
atom, may be produced by using, for example, NO gas together with 
SiH.sub.4 /He gas. 
For producing a first amorphous layer (I) containing halogen atom, for 
example, SiF.sub.4 /He in addition to the above gases is introduced into 
the reaction chamber 1301. 
A second amorphous layer (II) may be formed on the first amorphous layer 
(I) as shown below. 
Shutter 1342 is opened, and all gas feeding valves are once closed and 
reaction chamber 1301 is evacuated by fully opening main valve 1334. High 
purity silicon wafer 1342-1 and high purity graphite wafer 1342-2 are 
placed as targets on an electrode 1341 to which a high voltage power is 
applied, at a desired area ratio. From bomb 1304, Ar gas is introduced 
into reaction chamber 1301, and main valve 1334 is controlled so that the 
inner pressure of the reaction chamber 1301 may become 0.05-1 Torr. The 
high voltage power source 1340 is switched on to effect sputtering with 
the above targets. As a result, the second amorphous layer (II) is formed 
on the first amorphous layer (I). 
The amount of carbon atoms contained in the second amorphous layer (II) may 
be controlled as required by means of adjusting the sputtering area ratio 
of silicon wafer 1342-1 to graphite wafer 1342-2 or the mixing ratio of 
silicon powder to graphite powder when a target is formed in accordance 
with a desire. 
All the outflow valves other than those for gases necessary for formation 
of respective layers are, of course, closed, and during formation of 
respective layers, in order to avoid remaining of the gases used in the 
precedent layer in the reaction chamber 1301 and pipelines from the 
outflow valves 1317-1321 to the reaction chamber 1301, there may be 
conducted the procedure comprising once evacuating to a high vacuum the 
system by closing the outflow valves 1317-1321 and opening the auxiliary 
valve 1332 with full opening of the main valve 1334, if necessary. 
A photoconductive member which is designed as described above specifically 
can solve all the problems cited in the foregoing and may exhibit markedly 
excellent electrical, optical and photoconductive characteristics, 
dielectric strength and environmental characteristics in use. 
In particular, when it is used as an image forming member for 
electrophotography, the image forming member is entirely free from 
residual potentials for image forming, constantly stable in electrical 
characteristics, high in photosensitivity, high in SN ratio, markedly 
excellent in light fatigue resistance and excellent in characteristics for 
repeated uses, and can repeatedly produce images of high quality, high 
density, clear half-tone, and high resolution. 
EXAMPLE 1 
By using the apparatus in FIG. 12, an image forming member having a first 
layer having the concentration distribution of oxygen as shown in FIG. 14 
was produced under the conditions of Table 1A. 
The resulting image forming member was set in a charging-exposing 
experimental device, and subjected to corona charging at .sym. 5 KV for 
0.2 sec. followed immediately by imagewise exposure at 1.5 lux.sec. 
through a transparent test chart with a tungsten lamp as a light source. 
Immediately thereafter, the surface of the member was subjected to 
cascading of a .crclbar. charged developer (including toner and carrier) 
to produce good toner images on the surface of the member. 
The resulting toner images on the surface of the member was transferred to 
an image receiving paper by corona charging at .sym. 5.0 KV. The images 
thus transferred were of excellent resolution, good tone reproducibility, 
high sharpness and high density. 
EXAMPLE 2 
By means of the preparation apparatus as shown in FIG. 12, an image forming 
member having such a concentration distribution of oxygen in the first and 
second layers as shown in FIG. 15 was formed under the conditions in Table 
2A. The other conditions were the same as those in Example 1. 
By using the resulting image forming member and repeating the procedure of 
Example 1, images were formed on an image receiving paper by transferring. 
The images are of sharp image quality. 
EXAMPLE 3 
By means of the preparation apparatus as shown in FIG. 12, an image forming 
member having such a concentration distribution of oxygen in the first 
layer as shown in FIG. 16 was formed under the conditions in Table 3A. The 
other conditions were the same as those in Example 1. 
By using the resulting image forming member and employing the procedure and 
conditions of Example 1, images were formed on an image receiving paper by 
transferring. The resulting images were very sharp and clear. 
EXAMPLE 4 
According to the entirely same procedure as that in Example 1 except for 
modifying the content of boron atoms in the first layer by varying the 
flow rate ratio of B.sub.2 H.sub.6 to SiH.sub.4 upon forming the first 
layer, image forming members were formed. Evaluation of the quality of 
each of the transferred images for respective image forming members thus 
obtained was performed as in Example 1. The results are shown in Table 4A. 
EXAMPLE 5 
According to the same procedure as that in Example 1 except for fixing the 
whole layer thickness to be formed on the image forming member to 10.mu. 
and modifying relatively the ratio of the layer thickness of the first 
layer to the second layer, image forming members were formed. Evaluation 
was effected as in Example 1. The results are shown in Table 5A. 
EXAMPLE 6 
By repeating the procedures of Example 1 except that the first and the 
second layers were produced under the conditions in Table 6A, a layer 
formation was effected. Image evaluation was conducted as in Example 1. 
Good result was obtained. 
EXAMPLE 7 
By using the apparatus in FIG. 13, an image forming member having a first 
and a second layers having the concentration distribution of oxygen as 
shown in FIG. 14 was produced under the conditions of Table 1B. 
The resulting image forming member was set in a charging-exposing 
experimental device, and subjected to corona charging at .sym. 5 KV for 
0.2 sec. followed immediately by imagewise exposure at 1.5 lux.sec. 
through a transparent test chart with a tungsten lamp as a light source. 
Immediately thereafter, the surface of the member was subjected to 
cascading of a .crclbar. charged developer (including toner and carrier) 
to produce good toner images on the surface of the member. 
The resulting toner images on the surface of the member was transferred to 
an image receiving paper by corona charging at .sym. 5.0 KV. The images 
thus transferred were of excellent resolution, good tone reproducibility, 
high sharpness and high density. 
EXAMPLE 8 
By means of the preparation apparatus as shown in FIG. 13, an image forming 
member having such a concentration distribution of oxygen in the first and 
the second layers as shown in FIG. 15 was formed under the conditions as 
indicated in Table 2B. The other conditions were the same as those in 
Example 7. 
The resulting image forming member was subjected to the image forming 
procedure under the conditions as in Example 7 to produce images on an 
image receiving paper by transferring. The resulting images were very 
clear and sharp. 
EXAMPLE 9 
By means of the preparation apparatus as shown in FIG. 13, an image forming 
member having such a concentration distribution of oxygen in the first 
layer as shown in FIG. 16 was formed under the conditions as indicated in 
Table 3B. The other conditions were the same as those in Example 7. 
By using the resulting image forming member under the conditions of and 
following the procedure of Example 7, very sharp and clear images were 
formed on an image receiving paper. 
EXAMPLE 10 
According to the same procedure as that in Example 9 except for modifying 
the content ratio of silicon atoms to carbon atoms in an amorphous layer 
(II) by varying the area ratio of silicon wafer to graphite wafer at the 
formation of said amorphous layer (II), an image forming member was 
formed. 
The resulting image forming member was subjected to image formation, 
development and cleaning steps as in Example 7 about 50,000 times, and 
image evaluation was effected. The results are shown in Table 4B. 
EXAMPLE 11 
According to the entirely same procedure as that in Example 7 except for 
modifying the layer thickness of an amorphous layer (II), the image 
forming members were formed. 
By repeating the image forming, developing and cleaning steps as in Example 
7, there were obtained the results as shown in Table 5B. 
EXAMPLE 12 
According to the same procedure as that in Example 7 except for modidying 
the layer forming conditions for the first and the second layers as shown 
in Table 6B, layer formation was effected. Image evaluation as in Example 
7 gave good results. 
EXAMPLE 13 
By using the apparatus in FIG. 13, an image forming member having a first 
and a second layers having the concentration distribution of oxygen as 
shown in FIG. 14 was produced under the conditions of Table 1C. 
The resulting image forming member was set in a charging-exposing 
experimental device, and subjected to corona charging at .sym. 5 KV for 
0.2 sec. followed immediately by imagewise exposure at 1.5 lux.sec. 
through a transparent test chart with a tungsten lamp as a light source. 
Immediately thereafter, the surface of the member was subjected to 
cascading of a .crclbar. charged developer (including toner and carrier) 
to produce good toner images on the surface of the member. 
The resulting toner images on the surface of the member was transferred to 
an image receiving paper by corona charging at .sym. 5.0 KV. The images 
thus transferred were of excellent resolution, good tone reproducibility, 
high sharpness and high density. 
EXAMPLE 14 
By means of the preparation apparatus as shown in FIG. 13, an image forming 
member having such a concentration distribution of oxygen in the first and 
the second layers as shown in FIG. 15 was formed under the conditions as 
indicated in Table 2C. 
By using the resulting image forming member under the conditions of and 
following the procedure of Example 13, very sharp and clear images were 
formed on an image receiving paper. 
EXAMPLE 15 
By means of the preparation apparatus as shown in FIG. 13 an image forming 
member having such a concentration distribution of oxygen in the first 
layer as shown in FIG. 16 was formed under the conditions as indicated in 
Table 3C. The other conditions were the same as those in Example 13. 
By using the resulting image forming member under the conditions of and 
following the procedure of Example 13, very sharp and clear images were 
formed on an image receiving paper. 
EXAMPLE 16 
According to the entirely same procedure as that in Example 13 except for 
modifying the content ratio of silicon atoms to carbon atoms in an 
amorphous layer (II) by varying the gas flow rate ratio of SiH.sub.4 gas 
to C.sub.2 H.sub.4 gas at the formation of said amorphous layer (II), 
image forming members were formed. 
The resulting photosensitive drum was subjected to the steps up to 
transferring as in Example 13 about 50,000 times. The image evaluation 
results are shown in Table 4C. 
EXAMPLE 17 
By repeating the procedure of Example 13 except for modifying the layer 
thicknesses of an amorphous layer (II) as in Table 5C, the layer formation 
was effected. Evaluation results are shown in Table 5C. 
EXAMPLE 18 
By repeating the procedure of Example 13 except for modifying the forming 
conditions for the first and the second layers as shown in Table 6C, the 
layer formation was effected. Evaluation of the image was effected as in 
Example 13. The results were satisfactory. 
EXAMPLE 19 
By using the apparatus in FIG. 13, an image forming member having a first 
and a second layers having the concentration distribution of oxygen as 
shown in FIG. 14 was produced under the conditions of Table 1D. 
The resulting image forming member was set in a charging-exposing 
experimental device, and subjected to corona charging at .sym. 5 KV for 
0.2 sec. followed immediately by imagewise exposure at 1.5 lux.sec. 
through a transparent test chart with a tungsten lamp as a light source. 
Immediately thereafter, the surface of the member was subjected to 
cascading of a .crclbar. charged developer (including toner and carrier) 
to produce good toner images on the surface of the member. 
The resulting toner images on the surface of the member was transferred to 
an image receiving paper by corona charging at .sym. 5.0 KV. The images 
thus transferred were of excellent resolution, good tone reproducibility, 
high sharpness and high density. 
EXAMPLE 20 
By means of the preparation apparatus in FIG. 13, an image forming member 
having such a concentration distribution of oxygen in the first and the 
second layers as shown in FIG. 15 was formed under the conditions as 
indicated in Table 2D. The other conditions were as those in Example 19. 
Images were formed on an image receiving paper under the same conditions 
and by the same procedure as in Example 19 with the resulting image 
forming member. The resulting images were of very clear and sharp image 
quality. 
EXAMPLE 21 
By means of the preparation apparatus as shown in FIG. 13, an image forming 
member having such a concentration distribution of oxygen in the first 
layer as shown in FIG. 16 was formed under the conditions as indicated in 
Table 3D. The other conditions were the same as those in Example 19. 
By using the resulting image forming member and following the conditions 
and procedure of Example 19, images were formed on an image receiving 
paper by transferring. Very clear and sharp images were produced. 
EXAMPLE 22 
According to the entirely same procedure as that in Example 19 except for 
modifying the content ratio of silicon atoms to carbon atoms in an 
amorphous layer (II) by varying the gas flow rate ratio, SiH.sub.4 gas : 
SiF.sub.4 gas : C.sub.2 H.sub.4 gas at the formation of said amorphous 
layers (II), the image forming member was formed. 
The resulting image forming member was subjected to the steps of image 
formation, development and cleaning as shown in Example 19 about 50,000 
times, and image evaluation was effected. The results are shown in Table 
4D. 
EXAMPLE 23 
According to the entirely same procedure as that in Example 19 except for 
modifying the layer thickness of the amorphous layer (II), an image 
forming member was formed. 
The steps of image forming, developing and cleaning as described in Example 
19 were repeated. The results are shown in Table 5D. 
EXAMPLE 24 
According to the similar procedure as that in Example 19 except for 
modifying the forming conditions for the first and the second layers as 
shown in Table 6D, the layer formation was effected. Image quality 
evaluation was effected as in Example 19. The result was satisfactory. 
TABLE 1A 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) 
Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
First layer 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 1 .times. 10.sup.-1 .about.0 
0.18 15 0.6 
NO B.sub.2 H.sub.6 /SiH.sub.4 = 4 .times. 10.sup.-3 
B.sub.2 H.sub.6 /He = 10.sup.-3 
Second layer 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
__________________________________________________________________________ 
Al support temperature: 250.degree. C. 
Discharge frequency: 13.56 MHz 
Inner pressure upon reaction: 0.5 Torr 
TABLE 2A 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) 
Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
First layer 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 
0.18 15 0.8 
NO 3 .times. 10.sup.-2 .about.2 .times. 10.sup.-2 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /SiH.sub.4 = 2 .times. 10.sup.-3 
Second layer 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 2 .times. 10.sup.-2 .about.0 
0.18 15 0.7 
NO 
Third layer 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
__________________________________________________________________________ 
TABLE 3A 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) 
Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
First layer 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 1.2 .times. 10.sup.-1 .about.0 
0.18 15 1.0 
NO B.sub.2 H.sub.6 /SiH.sub.4 = 1.5 .times. 10.sup.-3 
B.sub.2 H.sub.6 /He = 10.sup.-3 
Second layer 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
__________________________________________________________________________ 
TABLE 4A 
______________________________________ 
Sample No. 
401A 402A 403A 404A 405A 
______________________________________ 
B/Si 5 .times. 10.sup.-4 
1 .times. 10.sup.-3 
3 .times. 10.sup.-3 
6 .times. 10.sup.-3 
1 .times. 10.sup.-2 
(Content 
ratio) 
Image .circle. .circleincircle. 
.circleincircle. 
.circleincircle. 
.circle. 
quality 
evaluation 
______________________________________ 
.circleincircle. Very good 
.circle. Good 
TABLE 5A 
______________________________________ 
Sample No. 
501A 502A 503A 504A 505A 506A 
______________________________________ 
Thickness of 
1/200 1/50 1/20 1/5 1/2 1/1 
first layer/ 
Thickness of 
second layer 
Image quality 
.circle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circle. 
evaluation 
______________________________________ 
.circleincircle. Very good 
.circle. Good 
TABLE 6A 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
First layer 
SiH.sub.4 /He = 0.5 
SiH.sub.4 + 
NO/SiH.sub.4 /SiF.sub.4 = 
0.18 15 0.6 
SiF.sub.4 /He = 0.5 
SiF.sub.4 = 200 
1 .times. 10.sup.-1 10.5/0.05.about. 
NO 0/0.5/0.5 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /(SiH.sub.4 + 
SiF.sub.4) = 4 .times. 10.sup.-3 
Second layer 
SiH.sub.4 /He = 0.5 
SiH.sub.4 + 
SiH.sub.4 /SiF.sub.4 = 1 
0.18 15 20 
SiF.sub.4 /He = 0.5 
SiF.sub.4 = 200 
__________________________________________________________________________ 
TABLE 1B 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) 
Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 1 .times. 10.sup.-1 .about.0 
0.18 15 0.6 
layer layer 
NO B.sub.2 H.sub.6 /SiH.sub.4 = 4 
.times. 10.sup.-3 
(I) B.sub.2 H.sub.6 /He = 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
layer 
Amorphous Ar 200 Area ratio 0.3 2 0.3 
layer (II) Si wafer:Graphite = 
1.5:8.5 
__________________________________________________________________________ 
Al support temperature: 250.degree. C. 
Discharge frequency: 13.56 MHz 
Inner pressure upon reaction: 0.5 Torr 
TABLE 2B 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) 
Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 
0.18 15 0.8 
layer layer 
NO 3 .times. 10.sup.-2 .about.2 .times. 10.sup.-2 
(I) B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /SiH.sub.4 = 2 .times. 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 2 .times. 10.sup.-2 .about.0 
0.18 15 20 
layer 
NO 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
layer 
Amorphous Ar 200 Area ratio 0.3 1.5 0.3 
layer (II) Si wafer:Graphite = 
1.5:9.5 
__________________________________________________________________________ 
TABLE 3B 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) 
Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 1.2 .times. 10.sup.-1 .about.0 
0.18 15 1.0 
layer layer 
NO B.sub.2 H.sub.6 /SiH.sub.4 = 1.5 .times. 
10.sup.-3 
(I) B.sub.2 H.sub.6 /He = 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
layer 
Amorphous Ar 200 Area ratio 0.3 3 1.0 
layer (II) Si wafer:graphite 
6:4 
__________________________________________________________________________ 
TABLE 4B 
______________________________________ 
Sample 
No. 401B 402B 403B 404B 405B 406B 407B 
______________________________________ 
Si:C 9:1 6.5:3.5 4:6 2:8 1:9 0.5:9.5 0.2:9.8 
Target 
(Area 
ratio) 
Si:C 9.7:0.3 8.8:1.2 7.3:2.7 
4.8:5.2 
3:7 2:8 0.8:9.2 
(Content 
ratio) 
Image .DELTA. .circle. 
.circleincircle. 
.circleincircle. 
.circle. 
.DELTA. .times. 
quality 
eval- 
uation 
______________________________________ 
.circleincircle. Very good 
.circle. Good 
.DELTA. Sufficiently practically usable 
.times. Liable to form defective images 
TABLE 5B 
______________________________________ 
Thickness of 
amorphous 
Sample layer (II) 
No. (.mu.) Result 
______________________________________ 
501B 0.001 Liable to form defective 
images 
502B 0.02 Sometimes defective 
images are formed when 
repeated 20,000 times 
503B 0.05 Stable when repeated 
50,000 times or more 
504B 0.3 Stable when repeated 
100,000 times or more 
______________________________________ 
TABLE 6B 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 + 
NO/SiH.sub.4 /SiF.sub.4 = 
0.18 15 0.6 
layer layer 
SiF.sub.4 /He = 0.5 
SiF.sub.4 = 200 
1 .times. 10.sup.-1 /0.5/0.5.about. 
(I) NO 0/0.5/0.5 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /(SiH.sub.4 + 
SiF.sub.4) = 4 .times. 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 + 
SiH.sub.4 /SiF.sub.4 = 1 
0.18 15 20 
layer 
SiF.sub.4 /He = 0.5 
SiF.sub.4 = 200 
__________________________________________________________________________ 
TABLE 1C 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) 
Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 1 .times. 10.sup.-1 .about.0 
0.18 15 0.6 
layer (I) 
layer 
NO B.sub.2 H.sub.6 /SiH.sub.4 = 4 .times. 10.sup.-3 
B.sub.2 H.sub.6 /He = 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
layer 
Amorphous SiH.sub.4 /He = 0.5 
SiH.sub.4 = 50 
SiH.sub.4 :C.sub.2 H.sub.4 = 
0.18 6 0.5 
layer (II) 
C.sub.2 H.sub.4 
3:7 
__________________________________________________________________________ 
Al support temperature: 250.degree. C. 
Discharge frequency: 13.56 MHz 
Inner pressure upon reation: 0.5 Torr 
TABLE 2C 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) 
Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 
0.18 15 0.8 
layer (I) 
layer 
NO 3 .times. 10.sup.-2 .about.2 .times. 10.sup.-2 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /SiH.sub.4 = 2 .times. 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 2 .times. 10.sup.-2 .about.0 
0.18 15 2.0 
layer 
NO 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
layer 
Amorphous SiH.sub.4 /He = 1 
SiH.sub.4 = 15 
SiH.sub.4 :C.sub.2 H.sub.4 = 
0.18 15 0.3 
layer (II) 
C.sub.2 H.sub.4 
0.9:9.6 
__________________________________________________________________________ 
TABLE 3C 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) 
Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 1.2 .times. 10.sup.-1 .about.0 
0.18 15 1.0 
layer (I) 
layer 
NO B.sub.2 H.sub.6 /SiH.sub.4 = 1.5 .times. 
10.sup.-3 
B.sub.2 H.sub.6 /He = 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
layer 
Amorphous SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 :C.sub.2 H.sub.4 = 
0.18 8 1.5 
layer (II) 
C.sub.2 H.sub.4 
5:5 
__________________________________________________________________________ 
TABLE 4C 
__________________________________________________________________________ 
Sample No. 
401C 
402C 
403C 
404C 
405C 
406C 
407C 408C 
__________________________________________________________________________ 
SiH.sub.4 :C.sub.2 H.sub.4 
9:1 
6:4 
4:6 2:8 
1:9 
0.5:9.5 
0.35:9.65 
0.2:9.8 
(Flow rate 
ratio) 
Si:C 9:1 
7:3 
5.5:4.5 
4:6 
3:7 
2:8 1.2:8.8 
0.8:9.2 
(Content 
ratio) 
Image quality 
.DELTA. 
.circle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circle. 
.DELTA. 
.times. 
evaluation 
__________________________________________________________________________ 
.circleincircle. Very good 
.DELTA. Sufficiently practically usable 
.circle. Good 
.times. Somewhat defect images are formed. 
TABLE 5C 
______________________________________ 
Thickness of 
amorphous 
Sample layer (II) 
No. (.mu.) Result 
______________________________________ 
501C 0.001 Liable to form defective 
images 
502C 0.02 No defective image 
formed when repeated 
20,000 times 
503C 0.05 No defective image 
formed when repeated 
50,000 times 
504C 2 Stable when repeated 
200,000 times or more 
______________________________________ 
TABLE 6C 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 
NO/SiH.sub.4 /SiF.sub.4 = 
0.18 15 0.6 
layer (I) 
layer 
SiF.sub.4 /He = 0.5 
200 1 .times. 10.sup.-1 /0.5/0.5.about. 
NO 0/0.5/0.5 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /(SiH.sub.4 + SiF.sub.4) = 
4 .times. 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 
SiH.sub.4 /SiF.sub.4 = 1 
0.18 15 20 
layer 
SiF.sub.4 /He = 0.5 
200 
__________________________________________________________________________ 
TABLE 1D 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 1 .times. 10.sup.-1 .about.0 
0.18 15 0.6 
layer (I) 
layer 
NO B.sub.2 H.sub.6 /SiH.sub.4 = 4 .times. 
10.sup.-3 
B.sub.2 H.sub.6 /He = 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
layer 
Amorphous SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
0.18 6 0.5 
layer (II) 
SiF.sub.4 He = 0.5 
50 1.5:1.5:7 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
Al support temperature: 250.degree. C. 
Discharge frequency: 13.56 MHz 
Inner pressure upon reaction: 0.5 Torr 
TABLE 2D 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 
0.18 15 0.8 
layer (I) 
layer 
NO 3 .times. 10.sup.-2 .about.2 .times. 10.sup.-2 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /SiH.sub.4 = 2 .times. 
10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 2 .times. 10.sup.-2 .about.0 
0.18 15 2.0 
layer 
NO 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
layer 
Amorphous SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 
SiH.sub.4 :SiF.sub. 4 :C.sub.2 H.sub.4 
0.18 1.5 0.3 
layer (II) 
SiF.sub.4 /He = 0.5 
15 0.3:0.1:9.6 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
NO/SiH.sub.4 = 1.2 .times. 10.sup.-1 .about.0 
0.18 15 1.0 
layer (I) 
layer 
NO B.sub.2 H.sub.6 /SiH.sub.4 = 1.5 .times. 
10.sup.-3 
B.sub.2 H.sub.6 /He = 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 
layer 
Amorphous SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
0.18 10 1.5 
layer (II) 
SiF.sub.4 /He = 0.5 
150 3:3:4 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 4D 
__________________________________________________________________________ 
Sample No. 
401D 
402D 403D 
404D 
405D 406D 407D 408D 
__________________________________________________________________________ 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
5:4:1 
3:3.5:3.5 
2:2:6 
1:1:8 
0.6:0.4:9 
0.2:0.3:9.5 
0.2:0.15:9.65 
0.1:0.1:9.8 
Si:C 9:1 
7:3 5.5:4.5 
4:6 
3:7 2:8 1.2:8.8 
0.8:9.2 
(Content ratio) 
Image quality 
.DELTA. 
.circle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circle. 
.DELTA. 
.times. 
evaluation 
__________________________________________________________________________ 
.circleincircle. Very good 
.DELTA. Sufficiently practically usable 
.circle. Good 
.times. Somewhat defective images are formed. 
TABLE 5D 
______________________________________ 
Thickness of 
amorphous 
Sample layer (II) 
No. (.mu.) Result 
______________________________________ 
501D 0.001 Liable to form defective 
images 
502D 0.02 No defective image 
formed when repeated 
20,000 times 
503D 0.05 Stable when repeated 
50,000 times or more 
504D 1 Stable when repeated 
200,000 times or more 
______________________________________ 
TABLE 6D 
__________________________________________________________________________ 
Layer 
Discharge 
formation 
Layer 
Layer Flow rate power rate thickness 
constitution 
Gas employed 
(SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
__________________________________________________________________________ 
Amorphous 
First 
SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 
NO/SiH.sub.4 /SiF.sub.4 = 
0.18 15 0.6 
layer (I) 
layer 
SiF.sub.4 /He = 0.5 
200 1 .times. 10.sup.-1 /0.5/0.5.about. 
NO 0/0.5/0.5 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /(SiH.sub.4 + SiF.sub.4) = 
4 .times. 10.sup.-3 
Second 
SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 
SiH.sub.4 /SiF.sub.4 = 1 
0.18 15 20 
layer 
SiF.sub.4 /He = 0.5 
200 
__________________________________________________________________________