Photoconductive member

A photoconductive member is provided, which comprises a support for photoconductive member and a light receiving layer with a layer constitution, comprising a first layer region containing at least germanium atoms of which at least a portion is crystallized, a second region comprising an amorphous material containing at least silicon atoms and germanium atoms, a third layer region comprising an amorphous material containing at least silicon atoms and exhibiting photoconductivity, and a fourth layer region comprising an amorphous material containing silicon atoms and carbon atoms, provided successively in the order mentioned from the said support side.

BACKGROUND 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]. 
2. Description of the Prior Arts 
Photoconductive materials, which constitute image forming members for 
electrophotography in solid state image pick-up devices or in the field of 
image formation, or photoconductive layers in manuscript reading devices, 
are required to have a high sensitivity, a high SN ratio [Photocurrent 
(I.sub.p)/Dark current (I.sub.d)], spectral characteristics matching to 
those of electromagnetic waves to be irradiated, a rapid 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 easily be 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 of a-Si for use in image forming members 
for electrophotography, and German Laid-Open Patent Publication No. 
2933411 an application of a-Si for use in a photoconverting reading 
device. 
However, under the present situation, while the photoconductive members 
having photoconductive layers constituted of a-Si have been attempted to 
be improved in various aspects individually including electrical, optical 
and photoconductive characteristics such as dark resistance value, 
photosensitivity and response to light, etc., and environmental 
characteristics during use such as humidity resistance, and further 
stability with lapse of time and durability, there remains room for 
further improvement of overall characteristics. 
For instance, when applied in an image forming member for 
electrophotography, residual potential is frequently observed to remain 
during use thereof if improvements to higher photosensitivity and higher 
dark resistance are scheduled to be effected at the same time. 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 has a relatively smaller coefficient of absorption in the 
wavelength region longer than the longer wavelength region as compared 
with the shorter wavelength region of the visible light region and, in 
matching to the semiconductor laser practically applied at present time, 
when using a conventionally used halogen lamp or fluorescent lamp, there 
remains room for improvement in that the light on the longer wavelength 
side cannot effectively used. 
As another disadvantage, if the light irradiated cannot sufficiently be 
absorbed but the amount of light reaching the support is increased, when 
the support itself has a high reflectance against the light transmitted 
through the photoconductive layer, interference by multiple reflection 
occurs in the photoconductive layer, which may become a cause for 
generation of "unfocused" image. 
This effect is greater as the irradiated spot is made smaller for the 
purpose of enhancing resolution, posing a great problem particularly when 
using a semiconductor laser as the light source. 
On the other hand, it is also proposed to provide a light receiving layer 
constituted of an amorphous material containing at least germanium atoms 
on a support in consideration of matching to a semiconductor laser. In 
this case, however, problems may sometimes be ensued with respect to 
adhesion between the support and the above light receiving layer, and 
diffusion of impurities from the support to the light receiving layer. 
Alternatively, in the case of constituting a photoconductive layer of a-Si 
material, other atoms such as hydrogen atoms or halogen atoms such as 
fluorine atoms, chlorine atoms, etc. are contained in the photoconductive 
layer for improving their electrical, photoconductive characteristics; 
boron atoms, phosphorus atoms, etc. for controlling the 
electroconductivity; and other atoms for improving other characteristics 
as constituent atoms, respectively. Depending on the manner in which these 
constituent atoms are contained, there may sometimes be caused problems 
with respect to electrical, photoconductive characteristics or dielectric 
strength. 
For example, when used as an image forming member for electrophotography, 
the life of the photocarriers generated by light irradiation in the 
photoconductive layer formed is insufficient, or at the dark portion, the 
charges injected from the support side cannot sufficiently be impeded, or 
there occurs image defects commonly called as "white dropout" on the 
images transferred on a transfer paper which may be considered to be due 
to the local discharge destroying phenomenon, or so called image defects 
commonly called as "white streaks", which may be considered to be caused 
by, for example, scraping with a blade employed for cleaning. Also, when 
used in a highly humid atmosphere or immediately after being left to stand 
in a highly humid atmosphere for a long time, so called "unfocused" image 
was frequently observed. 
Thus, it is required in designing of a photoconductive material to make 
efforts to solve all of the 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 image pick-up devices, reading devices, etc. It has now been 
found that a photoconductive member having a photoconductive layer 
comprising an amorphous layer exhibiting photoconductivity, which is 
constituted of a-Si, particularly so called hydrogenated amorphous 
silicon, halogenated amorphous silicon or halogen-containing hydrogenated 
amorphous silicon which is an amorphous material containing at least one 
of hydrogen atom (H) and halogen atom (X) in a matrix of silicon atoms 
[hereinafter referred to comprehensively as a-Si(H,X)], said 
photoconductive member being prepared by designing so as to have a 
specific structure, is found to exhibit not only practically extremely 
excellent characteristics but also surpass the photoconductive members of 
the prior art in substantially all respects, especially markedly excellent 
characteristics as a photoconductive member for electrophotography. The 
present invention is based on such finding. 
SUMMARY OF THE INVENTION 
A primary object of the present invention is to provide a photoconductive 
member having electrical, optical and photoconductive characteristics 
which are substantially constantly stable with virtually no dependence on 
the environments under use, which member is markedly excellent in 
photosensitivity characteristics in longer wavelength range, light fatigue 
resistance and also excellent in humidity resistance and durability 
without causing deterioration phenomenon when used repeatedly, exhibiting 
no or substantially no residual potential observed. 
Another object of the present invention is to provide a photoconductive 
member which is high in photosensitivity in all visible light regions, 
particularly excellent in matching to a semiconductor laser and rapid in 
light response. 
Another object of the present invention is to provide a photoconductive 
member having a sufficient ability to retain charges during charging 
treatment for formation of electrostatic images, when applied as a member 
for formation of an electrophotographic image and having excellent 
electrophotographic characteristics, for which ordinary 
electrophotographic methods can very effectively be applied. 
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 halftone and high 
in resolution. 
Further, still another object of the present invention is to provide a 
photoconductive member having a high photosensitivity, and a high SN ratio 
characteristic. 
According to one aspect of the present invention, there is provided a 
photoconductive member, comprising a support for photoconductive member 
and a light receiving layer with a layer constitution, comprising a first 
layer region containing at least germanium atoms of which at least a 
portion is crystallized, a second region comprising an amorphous material 
containing at least silicon atoms and germanium atoms, a third layer 
region comprising an amorphous material containing at least silicon atoms 
and exhibiting photoconductivity, and a fourth layer region comprising an 
amorphous material containing silicon atoms and carbon atoms provided 
successively in the order mentioned from the said support side. 
According to another aspect of the present invention, there is provided a 
photoconductive member, comprising a support for photoconductive member 
and a light receiving layer with a layer constitution, comprising a first 
layer region containing at least germanium atoms of which at least a 
portion is crystallized, a second region comprising an amorphous material 
containing at least silicon atoms and germanium atoms, a third layer 
region comprising an amorphous material containing at least silicon atoms 
and exhibiting photoconductivity, and a fourth layer region comprising an 
amorphous material containing silicon atoms and carbon atoms provided 
successively in the order mentioned from the said support side, the 
germanium atoms in at least said second layer region being distributed 
unevenly in the layer thickness direction. 
According to still another aspect of the present invention, there is 
provided a photoconductive member, comprising a support for 
photoconductive member and a light receiving layer with a layer 
constitution, comprising a first layer region containing at least 
germanium atoms of which at least a portion is crystallized, a second 
region comprising an amorphous material containing at least silicon atoms 
and germanium atoms, a third layer region comprising an amorphous material 
containing at least silicon atoms and exhibiting photoconductivity, and a 
fourth layer region comprising an amorphous material containing silicon 
atoms and carbon atoms provided successively in the order mentioned from 
the said support side, either one of said first layer region and second 
layer region containing a substance which controls conductivity.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, the photoconductive member of the present 
invention is to be described in detail. 
FIG. 1 shows a schematic sectional view for illustration of a first 
embodiment of the photoconductive member of this invention. 
The photoconductive member 100 as shown in FIG. 1 has a support 101 for 
photoconductive member and a light receiving layer 102 provided on the 
support, said light receiving layer 102 having a free surface 105 on the 
end surface. 
The light receiving layer 102 has a layer constitution comprising, 
successively laminated from the support side 101, a first layer region (C) 
106 constituted of a material comprising a matrix of germanium atoms or a 
matrix of germanium atoms and silicon atoms, optionally containing 
hydrogen atoms or halogen atoms, of which at least a portion is 
crystallized (hereinafter written as ".mu.c-Ge(Si,H,X)", a second layer 
region (G) 103 constituted of a-Si(H,X) containing germanium atoms 
(hereinafter abbreviated as "a-SiGe(H,X)", a third layer region (S) 104 
constituted of a-Si, preferably a-Si(H,X), having photoconductivity and a 
fourth layer region (M) 107 constituted of an amorphous material 
containing silicon atoms and carbon atoms, optionally together with 
hydrogen atoms or/and halogen atoms (hereinafter abbreviated as 
a-(Si.sub.1-x C.sub.x).sub.Y (H,X).sub.1-y. 
When the first layer region (C) is constituted of a material comprising a 
matrix of germanium atoms and silicon atoms, the germanium atoms and the 
silicon atoms may be contained so that they are continuous in said first 
layer region (C) in the layer thickness direction and the direction within 
the plane parallel to the surface of the support and distributed evenly, 
or distributed unevenly in the layer thickness direction. 
The germanium atoms contained in the second layer region (G) 103 may be 
contained in said second layer region (G) 103 so that they are continuous 
in said second layer region (C) in the layer thickness direction and the 
direction within the plane parallel to the surface of the support and 
distributed evenly, or distributed unevenly in the layer thickness 
direction. 
In the case where the distribution of germanium atoms contained in the 
second layer region (G) 103 is uneven in the layer thickness direction, it 
is desirable that the germanium atoms contained in the layer region (G) 
103 should be continuous in the layer thickness direction and distributed 
to be more enriched on the side of the aforesaid support side 101 relative 
to the opposite to the side where the aforesaid support is provided (the 
side of the surface 105 of the light receiving layer 102). 
On the other hand, in the case where the first layer region (C) 106 is 
constituted of a material comprising a matrix containing also silicon 
atoms in addition to germanium atoms and the germanium atoms is 
distributed unevenly in the layer thickness direction, it is desirable 
that the germanium atoms contained in the first layer region (C) 106 
should be contained with an uneven distribution so as to be more enriched 
on the side of the support 101 similarly as in the case of the second 
layer region (G) 103. Further, in such a case, in the first layer region 
(C) 106 and the second layer region (G) 103, the distribution of germanium 
atoms should preferably be such that they are continuously and evenly 
distributed in the plane in the direction parallel to the surface of the 
support 101, and continuously and more enriched toward the side of the 
support 101 throughout the first layer region (C) 106 and the second layer 
region (G) 103. 
Within the first layer region (C) 106, due to smaller coefficient of 
diffusion of impurities than in the second layer region (G) 103 and the 
third layer region (S), it is possible to prevent diffusion of impurities 
from the support 101 to the second layer region (G) 103. 
In the present invention, no germanium atom is contained in the third layer 
region (S) provided on the second layer region (G), and by forming an 
amorphous layer to such a structure, there can be obtained a 
photosensitive member which is excellent in photosensitivity to the light 
with wavelengths over all the region from short wavelength to relatively 
longer wavelength. 
In the case where the germanium atoms are distributed in the first layer 
region (C) in such a state that the germanium atoms are continuously 
distributed throughout the entire layer region, when using a light source 
such as semiconductor laser, the light on the longer wavelength side which 
cannot substantially be absorbed by the second layer region (G) can be 
substantially completely absorbed in the first layer region (C), whereby 
the interference by reflection from the support surface can be prevented. 
On the other hand, in the case where the germanium atoms in the first layer 
region (C) and in the second layer region (G) are distributed in a state 
such that the germanium atoms are continuously distributed, with a change 
of the distribution concentration C in the layer thickness of germanium 
atoms being reduced from the support side toward the third layer region 
(S), affinity between the first layer region (C) and the second layer 
region (G) is excellent, and by making the distribution concentration C of 
germanium atoms extremely greater at the end of the support side, the 
light on the longer wavelength side which cannot substantially be absorbed 
by the third layer region (S) can be substantially completely absorbed in 
the second layer region (G), whereby the interference by reflection from 
the support surface can be prevented. 
In the photoconductive member of the present invention, since each of the 
materials constituting the second layer region (G) and the third layer 
region (S) contains common constituent elements of silicon atoms, chemical 
stability can sufficiently be ensured at the laminated interface. 
In the present invention, the content of germanium atoms contained in the 
first layer region (C) can be determined as desired so that the objects of 
the present invention can be accomplished effectively, but generally 1 to 
1.times.10.sup.6 atomic ppm, preferably 100 to 1.times.10.sup.6 atomic 
ppm, most preferably 500 to 1.times.10.sup.6 atomic ppm. 
In the present invention, the content of germanium atoms contained in the 
second layer region (G) may be determined as desired so that the objects 
of the present invention may effectively be accomplished, but preferably 1 
to 9.5.times.10.sup.5 atomic ppm, more preferably 100 to 8.times.10.sup.5 
atomic ppm, most preferably 500 to 7.times.10.sup.5 atomic ppm. 
FIGS. 2 through 10 show typical examples of nonuniform distribution in the 
direction of layer thickness of germanium atoms contained in the second 
layer region (G). 
In FIGS. 2 through 10, the axis of abscissa indicates the content C of 
germanium atoms and the axis of ordinate the layer thirckness of the 
second layer region (G), t.sub.B showing the position of the end surface 
of the second layer region (G) on the support side and t.sub.T the 
position of the end surface of the second layer region (G) on the side 
opposite to the support side. That is, layer formation of the second layer 
region (G) containing germanium proceeds from the t.sub.B side toward the 
t.sub.T side. 
In FIG. 2, there is shown a first typical embodiment of the depth profile 
of germanium atoms in the layer thickness direction contained in the 
second layer region (G). 
t.sub.B shows the interface position between the first layer region (C) and 
the second layer region (G), and t.sub.T shows the interface position 
between the second layer region (G) and the third layer region (S). 
From t.sub.B to the position t.sub.1, while the concentration of germanium 
atoms taking a constant value of C.sub.1, which concentration is gradually 
decreased continuously from the position t.sub.1 to the interface position 
t.sub.T. At the interface position t.sub.T, the concentration of germanium 
atoms is made C.sub.3. 
In the embodiment shown in FIG. 3, the concentration C of germanium atoms 
contained is decreased gradually and continuously 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 the case of FIG. 4, the concentration C of germanium atoms is made 
constant as C.sub.6 from t.sub.B to the position t.sub.2, gradually 
decreased from the position t.sub.2 to the position t.sub.T, and the 
concentration C is made substantially zero at the position t.sub.T 
("substantially zero" herein means the content less than the detectable 
limit). 
In case of FIG. 5, germanium atoms are decreased gradually and continuously 
from the position t.sub.B to the position t.sub.T from the concentration 
C.sub.8, until it is made substantially zero at the position t.sub.T. 
In the embodiment shown in FIG. 6, the concentration C of germanium atoms 
is constantly C.sub.9 between the position t.sub.B and the position 
t.sub.3, and it 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 is decreased 
as a first order function from the position t.sub.3 to the position 
t.sub.T. 
In the embodiment shown in FIG. 7, there is formed a depth profile such 
that the concentration C takes a constant value of C.sub.11 from the 
position t.sub.B to the position t.sub.4, and is decreased as a first 
order 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 embodiment shown in FIG. 8, the concentration C of germanium atoms 
is decreased as a first order function from the concentration C.sub.14 to 
zero from the position t.sub.B to the position t.sub.T. 
In FIG. 9, there is shown an embodiment, where the concentration C of 
germanium atoms is decreased as a first order function from the 
concentration C.sub.15 to C.sub.16 from the position t.sub.B to t.sub.T 
and made constantly at the concentration C.sub.16 between the position 
t.sub.5 and t.sub.T. 
In the embodiment shown in FIG. 10, the concentration C of germanium atoms 
is at the concentration C.sub.17 at the position t.sub.B, which 
concentration C.sub.17 is initially decreased gradually and abruptly near 
the position t.sub.6, until it is made the concentration C.sub.18 at the 
position t.sub.6. 
Between the position t.sub.6 and the position t.sub.7, the concentration is 
initially decreased abruptly and thereafter gradually, until it is made 
the concentration C.sub.19 at the position t.sub.7. Between the position 
t.sub.7 and the position t.sub.8, the concentration is decreased very 
gradually to the concentration C.sub.20 at the position t.sub.8. Between 
the position t.sub.8 and the position t.sub.T, the concentration is 
decreased along the curve having a shape as shown in the Figure from the 
concentration C.sub.20 to substantially zero. 
As described above about some typical examples of depth profiles of 
germanium atoms contained in the second layer region (G) in the direction 
of the layer thickness by referring to FIGS. 2 through 10, in the present 
invention, the second layer region (G) is provided desirably in a depth 
profile so as to have a portion enriched in concentration C of germanium 
atoms on the support side and a portion on the interface t.sub.T side 
depleted in concentration C of germanium atoms to considerably lower than 
that of the support side. 
Having described above about the nonuniform distribution of germanium atoms 
contained in the second layer region (G), the same explanation is 
applicable also in the case where germanium atoms are contained in the 
first layer region (C) and the second layer region (G) unevenly in the 
layer thickness direction. That is, in the explanation in FIGS. 2 to 10, 
the layer thickness (t.sub.B t.sub.T) was made the thickness of the second 
layer region (G), but when germanium atoms are contained in the first 
layer region (C) and the second layer region (G) unevenly in the layer 
thickness direction, the layer thickness (t.sub.B t.sub.T) is explained as 
the sum of the layer thicknesses of the two layer regions. In each Figure, 
the interface position t.sub.s may be selected at any desired position 
from t.sub.B to t.sub.T. 
The second layer region (G) constituting the light receiving layer of the 
photoconductive member in the present invention, when the first layer 
region (C) contains no silicon atom, should desirably have a localized 
region (A) containing germanium atoms at a relatively high concentration 
preferably on the support side. 
The localized region (A), may be desirably provided in the second layer 
region (G) within a depth of 5.mu. from the interface position t.sub.s 
between the first layer region (C) and the second layer region (G). 
In the present invention, the above localized region (A) may be made to be 
identical with the whole layer region (L.sub.T) up to the depth of 5.mu. 
thickness, or alternatively a part of the layer region (L.sub.T). 
It may suitably be determined depending on the characteristics required for 
the light receiving layer to be formed, whether the localized region (A) 
is made a part or whole of the layer region (L.sub.T). 
The localized region (A) may preferably be formed according to such a layer 
formation that the maximum C.sub.max of the concentrations of germanium 
atoms in a distribution in the layer thickness direction may preferably be 
1000 atomic ppm or more, more preferably 5000 atomic ppm or more, most 
preferably 1.times.10.sup.4 atomic ppm or more. 
That is, according to the present invention, the light receiving layer 
containing germanium atoms is formed so that the maximum value C.sub.max 
of the depth profile may exist within the second layer region (G) 
thickness of 5.mu. from the support side (the layer region within 5.mu. 
thickness from t.sub.s). 
In the present invention, when the first layer region (C) contains silicon 
atoms, the same idea as described above may be applicable by taking the 
layer thickness (t.sub.B t.sub.T) in FIGS. 2 to 10 as the sum of the layer 
thicknesses of the first layer region (C) and the second layer region (G) 
and the standard for the position where the localized region (A) exists as 
t.sub.B (in this case, the end face of the first layer region on the 
support side). 
In the present invention, sufficient care should be paid in designing of 
the photoconductive member to the layer thicknesses of the first layer 
region (G) and the second layer region (G), which are one of important 
factors to accomplish effectively the objects of the present invention, so 
that desired characteristics may sufficiently given to the photoconductive 
member formed. 
In the present invention, the layer thickness T.sub.c of the first layer 
region (C) should preferably be 30 .ANG. to 50.mu., more preferably 100 
.ANG. to 30.mu., most preferably 500 .ANG. to 20.mu.. 
On the other hand, the layer thickness T.sub.B of the second layer region 
(G) should preferably be 30 .ANG. to 50.mu., more preferably 40 .ANG. to 
40.mu., most preferably 50 .ANG. to 30.mu.. 
Further, the layer thickness T of the third layer region (S) should 
preferably be 0.5 to 90.mu., more preferably 1 to 80.mu., most preferably 
2 to 50.mu.. 
The sum of the layer thickness T.sub.B of the second layer region (G) and 
the thickness T of the third layer region (S), namely (T.sub.B +T) is 
determined suitably as desired during layer design of the photoconductive 
member, based on the relationships mutually between the characteristics 
required for the both layer regions and the characteristics required for 
the light receiving layer as a whole. 
In the photoconductive member, the numerical range of the above (T.sub.B 
+T) may preferably be 1 to 100.mu., more preferably 1 to 80.mu., most 
preferably 2 to 50.mu.. 
In more preferable embodiments of the present invention, it is desirable to 
select suitably appropriate numerical values for the above layer 
thicknesses T.sub.B and T, while satisfying preferably the relation of 
T.sub.B /T.ltoreq.1. 
In selection of the numerical values of the layer thickness T.sub.B and the 
layer thickness T in the above-mentioned case, the values of the layer 
thickness T.sub.B and the layer thickness T should desirably be 
determined, while satisfying more preferably the relation of T.sub.B 
/T.ltoreq.0.9, most preferably the relation of T.sub.B /T.ltoreq.0.8. 
In the present invention, when the content of the germanium atoms in the 
second layer region (G) is 1.times.10.sup.5 atomic ppm or more, the layer 
thickness T.sub.B of the second layer region (G) is desired to be made 
considerably thin, preferably 30.mu. or less, more preferably 25.mu. or 
less, most preferably 20.mu. or less. 
Also, in the photoconductive member 100, a substance (D) for controlling 
the conductive characteristics should preferably be incorporated at least 
in either the first layer region (C) 106 or the second layer region (G) 
103, to impart desired conductive characterictics especially to the second 
layer region (G). 
In the present invention, the substance (D) for controlling the conductive 
characteristics to be contained in the first layer region (C) 106 or the 
second layer region (G) 103 may be contained evenly within the whole of 
the first layer region (C) 106 or the second layer region (G) 103, or 
alternatively locally in a part of the first layer region (C) 106 or the 
second layer region layer (G) 103. 
When the substance (D) for controlling the conductive characteristics is 
particularly incorporated locally in a part of the second layer region (G) 
in the present invention, the layer region (PN) containing the aforesaid 
substance (D) may desirably be provided as the end layer region of the 
second layer region (G). In particular, when the aforesaid layer region 
(PN) is provided as the end layer region on the support side of the second 
layer region (G), injection of charges of a specific polarity from the 
support into the light receiving layer can effectively be inhibited by 
selecting suitably the kind and the content of the aforesaid substance (D) 
to be contained in said layer region (PN). 
In the photoconductive member of the present invention, the substance (D) 
capable of controlling the conductive characteristics may be incorporated 
in the second layer region (G) constituting a part of the light receiving 
layer either evenly throughout the whole region or locally in the 
direction of layer thickness. Further, alternatively, the aforesaid 
substance (D) may also be incorporated in the third layer region (S) 
disposed on the second layer region (G). 
When the aforesaid substance (D) is to be incorporated in the third layer 
region (S), the kind and the content of the substance (D) to be 
incorporated in the third layer region (S) as well as its mode of 
incorporation may be determined suitably depending on the kind and the 
content of the substance (D) incorporated in the second layer region (G) 
as well as its mode of incorporation. 
When the aforesaid substance (D) is to be incorporated in the third layer 
region (S), it is preferred that the aforesaid substance (D) should be 
incorporated within the layer region containing at least the contact 
interface with the second layer region (G). 
The aforesaid substance (D) may be contained evenly throughout the whole 
layer region of the third layer region (S) or alternatively uniformly in a 
part of the layer region. 
When the substance (D) for controlling the conductive characteristics is to 
be incorporated in both of the second layer region (G) and the third layer 
region (S), it is preferred that the layer region containing the aforesaid 
substance (D) in the second layer region (G) and the layer region 
containing the aforesaid substance (D) in the third layer region (S) may 
be contacted with each other. 
Also, when the aforesaid substance (D) is contained in the first layer 
region (C), the second layer region (G) and the third layer region (S), 
said substance (D) may be either the same or different in the first layer 
region (C), the second layer region (G) and the third layer region (S), 
and their contents may also be the same or different in respective layer 
regions. 
However, it is preferred that the content in the second layer region should 
be made sufficiently greater when the same kind of the aforesaid substance 
(D) is employed in respective three layer regions, or that different kinds 
of substance (D) with different electrical characteristics should be 
incorporated in desired respective layer regions. 
In the present invention, by incorporating the substance (D) for 
controlling the conductive characteristics in at least the second layer 
region (G) constituting the light receiving layer, the conductive 
characteristics of the layer region containing said substance (D) [either 
a part or whole of the second layer region (G)] can freely be controlled 
as desired. As such a substance (D), there may be mentioned so called 
impurities in the field of semiconductors. In the present invention, there 
may be included p-type impurities giving p-type conductive characteristics 
and n-type impurities giving n-type conductive characteristics to 
a-SiGe(H,X). 
More specifically, there may be mentioned as p-type impurities atoms 
belonging to the group III of the periodic table (Group III atoms), such 
as B (boron), Al (aluminum), Ga (gallium), In (indium), Tl (thallium), 
etc., particularly preferably B and Ga. 
As n-type impurities, there may be included the atoms belonging to the 
group V of the periodic table, such as P (phosphorus), As (arsenic), Sb 
(antimony), Bi (bismuth), etc., particularly preferably P and As. 
In the present invention, the content of the substance for controlling the 
conductive characteristics in the layer region (PN) may be suitably be 
selected depending on the conductive characteristics required for said 
layer region (PN), or when said layer region (PN) is provided in direct 
contact with the support, depending on the organic relation such as the 
relation with the characteristics at the contacted interface with the 
support. 
The content of the substance for controlling the conductive characteristics 
may be suitably selected also in consideration of other layer regions 
provided in direct contact with said layer region (PN) and the 
relationship with the characteristics at the contacted interface with said 
other layer regions. 
In the present invention, the content of the substance (D) for controlling 
the conductive characteristics in the layer region (PN) may be preferably 
0.01 to 5.times.10.sup.4 atomic ppm, more preferably 0.5 to 
1.times.10.sup.4 atomic ppm, most preferably 1 to 5.times.10.sup.3 atomic 
ppm. 
In the present invention, by making the content of the substance (D) for 
controlling the conductive characteristics in the layer region (PN) 
preferably 30 atomic ppm or more, more preferably 50 atomic ppm or more, 
most preferably 100 atomic ppm or more, in case, for example, when said 
substance (D) to be incorporated is a p-type impurity, at least injection 
of electrons from the support side through the second layer region (G) 
into the third layer region (S) layer can be effectively inhibited when 
the free surface of the light receiving layer is subjected to the charging 
treatment at .sym. polarity, or in the case when the aforesaid substance 
(D) to be incorporated is an n-type impurity, at least injection of 
positive holes from the support side through the second layer region (G) 
into the third layer region (S) can be effectively inhibited when the free 
surface of the light-receiving layer is subjected to the charging 
treatment at .crclbar. polarity. 
In the above cases, as described previously, the layer region (Z) excluding 
the aforesaid layer region (PN) may contain a substance for controlling 
the conductive characteristics with a conduction type of a polarity 
different from that of the substance (D) for controlling the 
characteristics contained in the layer region (PN), or a substance for 
controlling the conductive characteristics with a conduction type of the 
same polarity in an amount by far smaller than the practical amount to be 
contained in the layer region (PN). 
In such a case, the content of the substance for controlling the conductive 
characteristics to be contained in the aforesaid layer region (Z), which 
may suitably be determined as desired depending on the polarity and the 
content of the aforesaid substance contained in the aforesaid substance, 
may be preferably 0.001 to 1000 atomic ppm, more preferably 0.05 to 500 
atomic ppm, most preferably 0.1 to 200 atomic ppm. 
In the present invention, when the same kind of the substance (D) for 
controlling the conductive characteristics is contained in the layer 
region (PN) and the layer region (Z), the content in the layer region (Z) 
may preferably be 30 atomic ppm or less. 
In the present invention, by providing in the light receiving layer a layer 
region containing a substance for controlling the conductive 
characteristics having a conduction type of one polarity and a layer 
region containing a substance for controlling the conductive 
characteristics having a conduction type of the other polarity in direct 
contact with each other, there can also be provided a so called depletion 
layer at said contacted region. 
In short, for example, a depletion layer can be provided in the amorphous 
layer by providing a layer region containing the aforesaid p-type impurity 
and a layer region containing the aforesaid n-type impurity so as to be 
directly contacted with each other thereby to form a so called p-n 
junction. 
In the present invention, formation of the first layer region (C) 
constituted of .mu.c-Ge(Si,H,X) may be conducted according to a vacuum 
deposition method or a vapor deposition method utilizing discharging 
phenomenon, such as glow discharge method, sputtering method or 
ion-plating method. For example, for formation of the first layer region 
(C) constituted of .mu.c-Ge(Si,H,X) according to the glow discharge 
method, the basic procedure comprises introducing a starting gas for Ge 
supply capable of supplying germanium atoms (Ge) optionally together with 
a starting gas for Si capable of supplying silicon atoms (Si) and a 
starting gas for introduction of hydrogen atoms (H) and/or halogen atoms 
(X) into the deposition chamber which can be internally brought to a 
reduced pressure, and forming a plasma atmosphere of these gases by 
exciting glow discharge in said deposition chamber, thereby forming a 
layer consisting of .mu.c-Ge(Si,H,X) on the surface of a support set at a 
predetermined position. Alternatively, for formation according to the 
sputtering method, a starting gas for supplying Ge which may be diluted 
with a diluting gas such as He, Ar, etc. optionally together with a gas 
for introduction of hydrogen atoms (H) and/or halogen atoms (X) may be 
introduced into the deposition chamber for sputtering when sputtering one 
sheet of target constituted of Ge or two sheets of target of a constituted 
of Si and constituted of Ge, or a target of a mixture of Si and Ge in an 
atmosphere of an inert gas such as Ar, He or a gas mixture based on these 
gases. 
In the case of the ion plating method, the layer can be formed in the same 
manner as in the case of sputtering except that, for example, a 
polycrystalline silicon or a single crystalline silicon and a 
polycrystalline germanium or a single crystalline germanium are each 
placed in a vapor deposition boat as the vaporizing source, and the 
vaporizing source is heated by the resistance heating method or the 
electron beam method (EB method) to be vaporized thereby permitting the 
flying vaporized product to pass through a desired gas plasma atmosphere. 
For the purpose of crystallizing at least a part of the layer, it is 
necessary to raise the support temperature higher by 50.degree. C. to 
200.degree. C. than the support temperature during preparation of the 
second layer region (G). 
Formation of the second layer region (G) constituted of a-SiGe(H,X) may be 
conducted according to the vacuum deposition method utilizing discharging 
phenomenon, such as glow discharge method, sputtering method or 
ion-plating method. For example, for formation of the second layer region 
(G) constituted of a-SiGe(H,X) according to the glow discharge method, the 
basic procedure comprises introducing a starting gas for Si capable of 
supplying silicon atoms (Si) and a starting gas for Ge capable of 
supplying germanium atoms (Ge) optionally together with a starting gas for 
introduction of hydrogen atoms (H) and/or halogen atoms (X) into the 
deposition chamber which can be internally brought to a reduced pressure, 
and forming a plasma atmosphere of these gases by exciting glow discharge 
in said deposition chamber, thereby forming a layer consisting of 
a-Si(H,X) on the surface of a support set at a predetermined position. 
Alternatively, for formation according to the sputtering method, a 
starting gas for supplying Ge and Si which may be diluted with a diluting 
gas such as He, Ar, etc. optionally together with a gas for introduction 
of hydrogen atoms (H) and/or halogen atoms (X) may be introduced into the 
deposition chamber for sputtering when sputtering two sheets of target 
constituted of Si and constituted of Ge, or a target of a mixture of Si 
and Ge in an atmosphere of an inert gas such as Ar, He or a gas mixture 
based on these gases. 
In the case of the ion plating method, the layer can be formed in the same 
manner as in the case of sputtering except that, for example, a 
polycrystalline silicon or a single crystalline silicon and a 
polycrystalline germanium or a single crystalline germanium are each 
placed in a vapor deposition boat as the vaporizing source, and the 
vaporizing source is heated by the resistance heating method or the 
electron beam method (EB method) to be vaporized thereby permitting the 
flying vaporized product to pass through a desired gas plasma atmosphere. 
Formation of the third layer region (S) constituted of a-Si(H,X) may be 
performed following the same method and the conditions as in formation of 
the second layer region (G) by use of the starting materials (I) for 
forming the second layer region (G) as described above from which the 
starting gas for Ge is removed [starting materials (II) for formation of 
the third layer region (S)]. 
That is, in the present invention, formation of the third layer region (S) 
constituted of a-Si(H,X) may be conducted according to the vacuum 
deposition method utilizing discharging phenomenon, such as glow discharge 
method, sputtering method or ion-plating method. For example, for 
formation of the third layer region (S) constituted of a-Si(H,X) according 
to the glow discharge method, the basic procedure comprises introducing a 
starting gas for Si capable of supplying silicon atoms (Si) optionally 
together with a starting gas for introduction of hydrogen atoms (H) and/or 
halogen atoms (X) into the deposition chamber which can be internally 
brought to a reduced pressure, and forming a plasma atmosphere of these 
gases by exciting glow discharge in said deposition chamber, thereby 
forming a layer consisting of a-Si(H,X) on the surface of a support set at 
a predetermined position. Alternatively, for formation according to the 
sputtering method, a gas for introduction of hydrogen atoms (H) and/or 
halogen atoms (X) may be introduced into the deposition chamber for 
sputtering when sputtering a target constituted of Si in an atmosphere of 
an inert gas such as Ar, He or a gas mixture based on these gases. 
In the present invention, no germanium atom is contained in the third layer 
region (S) provided on the second layer region (G), and by forming a 
light-receiving layer to such a structure, there can be obtained a 
photosensitive member which is excellent in photosensitivity to the light 
with wavelengths over all the region from short wavelength to relatively 
longer wavelength. 
Also, since the germanium atoms are distributed in the first layer region 
(C) in such a state that the germanium atoms are continuously distributed 
throughout the entire layer region, when using a light source such as 
semiconductor laser, the light on the longer wavelength side which cannot 
substantially be absorbed by the third layer region (S) can be 
substantially completely absorbed in the first layer region (G), whereby 
the interference by reflection from the support surface can be prevented. 
Also, in the photoconductive member of the present invention, since each of 
the materials constituting the second layer region (G) and the third layer 
region (S) contains common constituent elements of germanium atoms, 
chemical stability can sufficiently be ensured at the laminated interface. 
The starting gas for supplying Si to be used in the present invention may 
include gaseous or gasifiable hydrogenated silicons (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 
others as effective materials. In particular, SiH.sub.4 and Si.sub.2 
H.sub.6 are preferred with respect to easy handling during layer formation 
and efficiency for supplying Si. 
As the substance which can be a starting gas for supplying Ge, there may be 
included gaseous or gasifiable hydrogenated germanium such as GeH.sub.4, 
Ge.sub.2 H.sub.6, Ge.sub.3 H.sub.8, Ge.sub.4 H.sub.10, Ge.sub.5 H.sub.12, 
Ge.sub.6 H.sub.14, Ge.sub.7 H.sub.16, Ge.sub.8 H.sub.18, Ge.sub.9 H.sub.20 
and the like. Particularly, from the standpoint of easiness in handling 
during layer forming working and good Ge supplying efficiency, GeH.sub.4, 
Ge.sub.2 H.sub.6 and Ge.sub.3 H.sub.8 are preferred. 
Effective starting gases for introduction of halogen atoms to be used in 
the present invention may include a large number of halogenic compounds, 
as examplified preferably by halogenic gases, halides, interhalogen 
compounds, or gaseous or gasifiable halogenic compounds such as silane 
derivatives substituted with halogens. 
Further, there may also be included gaseous or gasifiable silicon compounds 
containing halogen atoms constituted of silicon atoms and halogen atoms as 
constituent elements as effective ones in the present invention. 
Typical examples of halogen compounds preferably used in the present 
invention may include halogen gases such as of fluorine, chlorine, bromine 
or iodine, interhalogen compounds such as BrF, ClF, ClF.sub.3, BrF.sub.5, 
BrF.sub.3, IF.sub.3, IF.sub.7, ICl, IBr, etc. 
As the silicon compounds containing halogen atoms, namely so called silane 
derivatives substituted with halogens, there may preferably be employed 
silicon halides such as SiF.sub.4, Si.sub.2 F.sub.6, SiCl.sub.4, 
SiBr.sub.4 and the like. 
When forming the characteristic photoconductive member of the present 
invention by employment of a silicon compound containing halogen atoms 
according to the glow discharge method, without using a hydrogenated 
silicon gas as the starging material capable of supplying Si together with 
the starting material for supplying Ge, the first layer region (C) and the 
second layer region (G) can be formed on a desired support. 
In the case of preparing the first layer region (C) and the second layer 
region (G) containing halogen atoms, the basic procedure comprises 
introducing, for example, a halogenated silicon as the starting gas for 
supplying Si and a hydrogenated germanium as the starting gas for 
supplying Ge mixed with a gas such as Ar, H.sub.2, He, etc. at a desired 
ratio a flow rate into the deposition chamber for forming the first layer 
region (C) and the second layer region (G) and exciting glow discharge 
therein to form a plasma atmosphere of these gases, thereby forming the 
first layer region (C) and the second layer region (G) on the desired 
support. In order to control the ratio of hydrogen atoms introduced more 
easily, hydrogen gas or a gas of a silicon compound containing hydrogen 
atom may also be mixed at a desired amount in the starting gas for layer 
formation. 
The respective gases may be used not only as a single species but also as a 
mixture of plural species at predetermined mixing ratios. 
For formation of the first layer region (C) comprising .mu.c-Ge(Si,H,X) and 
the second layer region (G) comprising a-SiGe(H,X) according to the 
reactive sputtering method or the ion plating method, for example, in the 
case of the sputtering method, one sheet of a target comprising Ge or two 
sheets of targets comprising Si and Ge, respectively, or a target 
comprising Si and Ge may be used and subjected to sputtering in a desired 
gas plasma atmosphere. In the case of the ion plating method, for example, 
a polycrystalline silicon or a single crystalline silicon and a 
polycrystalline germanium or a single crystalline germanium are placed in 
vapor deposition boats as evaporating sources, respectively, and the 
evaporating sources are heated by resistance heating method or electron 
beam method (EB method), thereby permitting the flying vaporized products 
to pass through a desired gas plasma atmosphere. 
For incorporation of halogen atoms in the layer formed in the case of 
either the sputtering method or the ion plating method, a halogenic 
compound as mentioned above or a silicon compound containing halogen atoms 
may be introduced into a deposition chamber, followed by formation of a 
plasma atmosphere of said gas. 
For incorporation of hydrogen atoms, a starting gas for introduction of 
hydrogen atoms, for example, H.sub.2 or a silane or/and a hydrogenated 
germanium, etc. may be introduced into the deposition chamber for 
sputtering, followed by formation of a plasma atmosphere of said gases. 
In the present invention, as the starting gases effectively employed for 
introduction of halogen atoms, the halogen compounds or the 
halo-containing silicon compounds may be used as effective ones. 
Otherwise, there may also be employed gaseous or gasifiable substances, 
including halides containing hydrogen as one of the constituents, for 
example, hydrogen halides such as HF, HCl, HBr and HI, halo-substituted 
hydrogenated silicon 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, etc., 
and hydrogenated germanium halides such as GeHF.sub.3, GeH.sub.2 F.sub.2, 
GeH.sub.3 F, GeHCl.sub.3, GeH.sub.2 Cl.sub.2, GeH.sub.3 Cl, GeHBr.sub.3, 
GeH.sub.2 Br.sub.2, GeH.sub.3 Br, GeHI.sub.3, GeH.sub.2 I.sub.2, GeH.sub.3 
I, etc., or germanium halides such as GeF.sub.4, GeCl.sub.4, GeBr.sub.4, 
GeI.sub.4, GeF.sub.2, GeCl.sub.2, GeBr.sub.2, GeI.sub.2, etc., as the 
effective starting materials for formation of the first layer region (C) 
and the second layer region (G). 
Among these substances, halides containing a hydrogen atom or atoms can be 
used as a preferable starting material for introduction of halogen atoms, 
because hydrogen atoms very effective controlling electrical and 
photoelectric characteristics can be incorporated into the layers at the 
same time during formation of the first layer region (C) and the second 
layer region (G). 
Hydrogen atoms can be introduced structurally into the first layer region 
(C) and the second layer region (G), otherwise as described above, also by 
permitting H.sub.2 or a hydrogenated silicon such as SiH.sub.4, Si.sub.2 
H.sub.6, Si.sub.3 H.sub.8, Si.sub.4 H.sub.10, etc. and germanium or a 
germanium compound for supplying Ge, or a hydrogenated germanium such as 
GeH.sub.4, Ge.sub.2 H.sub.6, Ge.sub.3 H.sub.8, Ge.sub.4 H.sub.10, Ge.sub.5 
H.sub.12, Ge.sub.6 H.sub.14, Ge.sub.7 H.sub.16, Ge.sub.8 H.sub.18, 
Ge.sub.9 H.sub.20 and silicon or a silicon compound to coexist in the 
deposition chamber, and exciting discharging therein. 
According to a preferred embodiment of the present invention, the amount of 
hydrogen atoms (H) or halogen atoms (X) or the sum (H+X) of hydrogen atoms 
(H) and halogen atoms (X) to be contained in the first layer region (C), 
when containing at least one of hydrogen atoms or halogen atoms, is 
desired to be in the range generally from 0.0001 to 40 atomic %, 
preferably from 0.005 to 30 atomic %, most preferably 0.01 to 25 atomic %. 
For controlling the amount of hydrogen atoms (H) or/and halogen atoms (X) 
to be contained in the first layer region (C), for example, the support 
temperature, the amount of the starting material introduced into the 
deposition device system to be used for incorporation of hydrogen atoms 
(H) or halogen atoms (X), discharging power and others may be controlled. 
According to a preferred embodiment of the present invention, the amount of 
hydrogen atoms (H) or halogen atoms (X) or the sum (H+X) of hydrogen atoms 
(H) and halogen atoms (X) to be contained in the second layer region (G) 
is desired to be in the range generally from 0.01 to 40 atomic %, 
preferably from 0.05 to 30 atomic %, most preferably 0.1 to 25 atomic %. 
For controlling the amount of hydrogen atoms (H) or/and halogen atoms (X) 
to be contained in the second layer region (G), for example, the support 
temperature, the amount of the starting material introduced into the 
deposition device system to be used for incorporation of hydrogen atoms 
(H) or halogen atoms (X), discharging power and others may be controlled. 
In the present invention, the amount of hydrogen atoms (H) or halogen atoms 
(X) or the sum (H+X) of hydrogen atoms (H) and halogen atoms (X) to be 
contained in the third layer region (S) is desired to be in the range 
generally from 1 to 40 atomic %, preferably from 5 to 30 atomic %, most 
preferably 5 to 25 atomic %. 
The fourth layer region (M) in the present invention is constituted of an 
amorphous material comprising silicon atoms (Si), carbon atoms (C) and 
optionally hydrogen atoms (H) or/and halogen atoms (X) [hereinafter 
written as "a-(Si.sub.x C.sub.1-x).sub.y (H,X).sub.1-y ", where 0&lt;x&lt;1, and 
0&lt;y&lt;1]. 
Formation of the fourth layer region (M) constituted of a-(Si.sub.x 
C.sub.1-x).sub.y (H,X).sub.1-y may be performed according to the glow 
discharge method, the sputtering 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 fourth layer region (M) to be 
prepared, there may preferably be employed the glow discharge method or 
the sputtering method. 
Further, in the present invention, the fourth layer region (M) may be 
formed by using the glow discharge method and the sputtering method in 
combination in the same device system. 
For formation of the fourth layer region (M) according to the glow 
discharge method, starting gases for formation of a-(Si.sub.x 
C.sub.1-x).sub.y (H,X).sub.1-y, 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-(Si.sub.x C.sub.1-x).sub.y (H,X).sub.1-y on the third layer 
region (S) which has already been formed on the aforesaid substrate. 
As the starting gases for formation of a-(Si.sub.x C.sub.1-x).sub.y 
(H,X).sub.1-y 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 silicon atoms (Si), carbon atoms (C), hydrogen atoms (H) and 
halogen atoms (X) as constituent atoms. 
In the case when a starting gas having Si as constituent 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 atoms, and optionally a starting gas 
containing H as constituent atom and/or a starting gas containing X as 
constituent atom, if desired, 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 as constituent atoms also at a desired 
mixing ratio, or a mixture of a starting gas containing Si as constituent 
atom with a gas containing three kind of atoms of Si, C and H or of Si, C 
and X as constituent atoms at a desired mixing ratio. 
Alternatively, it is also possible to use a mixture of a starting gas 
containing Si and H as constituent atoms with a starting gas containing C 
as constituent atom, or a mixture of a starting gas containing Si and X as 
the constituent atoms with a starting gas containing C as constituent 
atom. 
In the present invention, preferable halogen atoms (X) to be contained in 
the fourth layer region (M) are F, Cl, Br and I, particularly preferably F 
and Cl. 
In the present invention, the compounds which can be effectively used as 
starting gases for formation of the fourth layer region (M) may include 
substances which are gaseous or can be readily gasified under normal 
temperature and normal pressure. 
In the present invention, the compound which can be effectively used as the 
starting gases for formation of the fourth layer region (M) may include 
hydrogenated silicon 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 4 carbon atoms, ethylenic hydrocarbons 
having 2 to 4 carbon atoms and acetylenic hydrocarbons having 2 to 4 
carbon atoms; single halogen substances; hydrogen halides; interhalogen 
compounds; silicon halides; halo-substituted hydrogenated silicon; and 
hydrogenated silicon. 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); as single halogen 
substances, halogenic gases such as of fluorine, chlorine, bromine and 
iodine; as hydrogen halides, HF, HI, HCl, HBr; as interhalogen compounds, 
BrF, ClF, ClF.sub.3, ClF.sub.5, BrF.sub.5, 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.3, SiCl.sub.3 I, 
SiBr.sub.4, as halo-substituted hydrogenated silicon, SiH.sub.2 F.sub.2, 
SiH.sub.2 Cl.sub.2, SiHCl.sub.3, SiH.sub.3 Cl, SiH.sub.2 Br.sub.2, 
SiHBr.sub.3, etc.; as hydrogenated silicon, silanes such as SiH.sub.4, 
Si.sub.2 H.sub.6, Si.sub.3 H.sub.8, Si.sub.4 H.sub.10, etc.; and so on. 
In addition to these materials, there may also be employed halo-substituted 
paraffinic hydrocarbons such as CF.sub.4, CCl.sub.4, CBr.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; alkyl silanes such as Si(CH.sub.3).sub.4, 
Si(C.sub.2 H.sub.5).sub.4, etc.; 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. 
These materials for forming the fourth layer region (M) may be selected and 
employed as desired during formation of the fourth layer region (M) so 
that silicon atoms, carbon atoms and optionally halogen atoms and/or 
hydrogen atoms may be contained at a desired composition ratio in the 
fourth layer region (M) to be formed. 
For example, Si(CH.sub.3).sub.4 capable of incorporating easily silicon 
atoms, carbon atoms and hydrogen atoms and forming a layer with desired 
characteristics together with a material for incorporation of halogen 
atoms such as SiHCl.sub.3, SiH.sub.2 Cl.sub.2, SiCl.sub.4 or SiH.sub.3 Cl, 
may be introduced at a certain mixing ratio under gaseous state into a 
device for formation of the fourth layer region (M), wherein glow 
discharging is excited thereby to form the fourth layer region (M) 
comprising a-(Si.sub.x C.sub.1-x).sub.y (Cl+H).sub.1-y. 
For formation of the fourth layer region (M) according to the sputtering 
method, a single crystalline or polycrystalline Si wafer and/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 containing, if desired, 
halogen atoms or/and hydrogen atoms as constituent atoms. 
For example, when Si wafer is used as an target, a starting gas for 
introducing C and H or/and X, which may be diluted with a diluting gas, if 
desired, is introduced into a deposition chamber for sputter to form a gas 
plasma therein and effect sputtering of 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, hydrogen atoms or/and halogen atoms 
As the starting gas for introduction of C, H and X, there may be employed 
the materials for formation of the fourth layer region (M) as mentioned in 
the glow discharge as described above as effective gases also in case of 
sputtering. 
In the present invention, as the diluting gas to be used in forming the 
fourth layer region (M) by the glow discharge method or the sputtering 
method, there may preferably employed so called rare gases such as He, Ne, 
Ar and the like. 
The fourth layer region (M) should be carefully formed so that the required 
characteristics may be given exactly as desired. 
More specifically, a substance containing as constituent atoms Si, C and, 
if necessary, H or/and 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-(Si.sub.x C.sub.1-x).sub.y 
(H,X).sub.1-y having desired characteristics depending on the purpose. For 
example, when the fourth layer region (M) is to be provided primarily for 
the purpose of improvement of dielectric strength, a-(Si.sub.x 
C.sub.1-x).sub.y (H,X).sub.1-y is prepared as an amorphous material having 
marked electric insulating behavior under the usage conditions. 
Alternatively, when the primary purpose for provision of the fourth layer 
region (M) is improvement of continuous repeated use characteristics or 
environmental use characteristics, the degree of the above electric 
insulating property may be alleviated to some extent and a-(Si.sub.x 
C.sub.1-x).sub.y (H,X).sub.1-y may be prepared as an amorphous material 
having sensitivity to some extent to the light irradiated. 
In forming the fourth layer region (M) comprising a-(Si.sub.x 
C.sub.1-x).sub.y (H,X).sub.1-y on the surface of the third layer region 
(S), 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-(Si.sub.x 
C.sub.1-x).sub.y (H,X).sub.1-y having intended characteristics may be 
prepared as desired. 
For accomplishing effectively the objects in the present invention, there 
may be selected suitably the optimum temperature range in conformity with 
the method for forming the fourth layer region (M) in carrying out 
formation of the fourth layer region (M). Preferably, however, the support 
temperature may be 20.degree. to 400.degree. C., more preferably 
50.degree. to 350.degree. C., most preferably 100.degree. to 300.degree. 
C. For formation of the fourth layer region (M), the glow discharge method 
or the sputtering method may be advantageously adopted, because severe 
control of the composition ratio of atoms constituting the layer or 
control of layer thickness can be conducted with relative ease as compared 
with other methods. In the case when the fourth layer region (M) is to be 
formed according to these layer forming methods, the discharging power 
during layer formation is one of important factors influencing the 
characteristics of a-(Si.sub.x C.sub.1-x).sub.y (H,X).sub.1-y to be 
prepared, similarly as the aforesaid support temperature. 
The discharging power condition for preparing effectively a-(Si.sub.x 
C.sub.1-x).sub.y (H,X).sub.1-y having characteristics for accomplishing 
the objects of the present invention with good productivity may preferably 
be 10 to 300 W, more preferably 20 to 250 W, most preferably 50 to 200 W. 
The gas pressure in the deposition chamber may preferably be 0.01 to 1 
Torr, more preferably 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, discharging 
power, etc. for preparation of the fourth layer region (M). However, these 
factors for layer formation should not 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 
relationships so that the fourth layer region (M) comprising a-(Si.sub.x 
C.sub.1-x).sub.y (H,X).sub.1-y having desired characteristics may be 
formed. 
The content of carbon atoms in the fourth layer region (M) in the 
photoconductive member of the present invention is the another important 
factor for obtaining the desired characteristics to accomplish the objects 
of the present invention, similarly as the conditions for preparation of 
the fourth layer region (M). 
The content of carbon atoms in the fourth layer region (M) in the present 
invention should desirably be determined depending on the amorphous 
material constituting the fourth layer region and its characteristics. 
More specifically, the amorphous material represented by the above formula 
a-(Si.sub.x C.sub.1-x).sub.y (H,X).sub.1-y may be classified broadly into 
an amorphous material constituted of silicon atoms and carbon atoms 
(hereinafter written as "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 (hereinafter written as "a-(Si.sub.b C.sub.1-b).sub.c H.sub.1-c ", 
where 0&lt;b&lt;1, 0&lt;c&lt;1) and an amorphous material constituted of silicon 
atoms, carbon atoms and halogen atoms and optionally hydrogen atoms 
(hereinafter written as "a-(Si.sub.c C.sub.1-c).sub.e (H,X).sub.1-e ", 
where 0&lt;d&lt;1, 0&lt;e&lt;1). 
In the present invention, the content of carbon atoms contained in the 
fourth layer region (M), when it is constituted of a-Si.sub.a C.sub.1-a, 
may be preferably 1.times.10.sup.-3 atomic %, more 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 
preferably 0.1 to 0.99999, more preferably 0.2 to 0.99, most preferably 
0.25 to 0.9. 
In the present invention, when the fourth layer region (M) is constituted 
of a-(Si.sub.b C.sub.1-b).sub.c H.sub.1-c, the content of carbon atoms 
contained in the fourth layer region (M) may be preferably 
1.times.10.sup.-3 to 90 atomic %, more preferably 1 to 90 atomic %, most 
preferably 10 to 80 atomic %. The content of hydrogen atoms may be 
preferably 1 to 40 atomic %, more preferably 2 to 35 atomic %, most 
preferably 5 to 30 atomic %. A photoconductive member formed to have a 
hydrogen atom content within 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 preferably 0.1 to 0.99999, preferably 0.1 to 0.99, 
most preferably 0.15 to 0.9, and c preferably 0.6 to 0.99, preferably 
0.65 to 0.98, most preferably 0.7 to 0.95. 
When the fourth layer region (M) is constituted of a-(Si.sub.d 
C.sub.1-d).sub.e (H,X).sub.1-e, the content of carbon atoms contained in 
the fourth layer region (M) may be preferably 1.times.10.sup.-3 to 90 
atomic %, more preferably 1 to 90 atomic %, most preferably 10 to 80 
atomic %. The content of halogen atoms may be preferably 1 to 20 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 preferably 19 atomic % or less, more preferably 13 atomic % or less. 
That is, in terms of the representation by a-(Si.sub.d C.sub.1-d).sub.e 
(H,X).sub.1-e, d may be preferably 0.1 to 0.99999, preferably 0.1 to 0.99, 
most preferably 0.15 to 0.9, and e preferably 0.8 to 0.99, more preferably 
0.82 to 0.99, most preferably 0.85 to 0.98. 
The range of the numerical value of layer thickness of the fourth layer 
region (M) is one of important factors for accomplishing effectively the 
objects of the present invention. 
It should desirably be determined depending on the intended purpose so as 
to effectively accomplish the objects of the present invention. 
The layer thickness of the fourth layer region (M) is required to be 
determined as desired suitably with due considerations about the 
relationships with the contents of carbon atoms, the layer thickness of 
the third layer region (S), as well as other organic relationships with 
the characteristics required for respective layers. 
In addition, it is also desirable to have considerations from economical 
point of view such as productivity or capability of bulk production. 
The fourth layer region (M) in the present invention is desired to have a 
layer thickness preferably of 0.003 to 30.mu., more preferably 0.004 to 
20.mu., most preferably 0.005 to 10.mu.. 
The support to be used in the present invention may be either 
electroconductive or insulating. As the electroconductive material, 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 
synthetic resins, including polyester, polyethylene, polycarbonate, 
cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene 
chloride, polystyrene, polyamide, etc., glasses, ceramics, papers and so 
on. These insulating supports should preferably have at least one surface 
subjected to electroconductive treatment, and it is desirable to provide 
other layers on the side at 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 
preferably 10.mu. or more from the points of fabrication and handling of 
the support as well as its mechanical strength. 
FIG. 11 shows an example of the device for producing a photoconductive 
member. 
In the gas bombs 1102-1106 in the Figure, there are hermetically contained 
starting gases for formation of the photoconductive member of the present 
invention. For example, 1102 is a bomb containing SiH.sub.4 gas diluted 
with He (purity: 99.999%, hereinafter abbreviated as "SiH.sub.4 /He"), 
1103 is a bomb containing GeH.sub.4 gas diluted with He (purity: 99.999%, 
hereinafter abbreviated as "GeH.sub.4 /He"), 1104 is a bomb containing 
SiF.sub.4 gas bomb diluted with He (purity: 99.99%, hereinafter 
abbreviated as SiF.sub.4 /He), 1105 is a He gas bomb (purity: 99.999%) and 
1106 is a H.sub.2 gas bomb (purity: 99.999%). 
For allowing these gases to flow into the reaction chamber 1101, on 
confirmation of the valves 1122-1126 of the gas bombs 1102-1106 and the 
leak valve 1135 to be closed, and the inflow valves 1112-1116, the outflow 
valves 1117-1121 and the auxiliary valves 1132 and 1133 to be opened, the 
main valve 1134 is first opened to evacuate the reaction chamber 1101 and 
the gas pipelines. As the next step, when the reading on the vacuum 
indicator 1136 becomes 5.times.10.sup.-6 Torr, the auxiliary valves 1132 
and 1133 and the outflow valves 1117-1121 are closed. 
Then, referring to one example of forming a first layer region (C) on the 
cylindrical substrate 1137, SiH.sub.4 /He gas from the gas bomb 1102, 
GeH.sub.4 /He gas from the gas bomb 1103 are permitted to flow into the 
mass-flow controllers 1107, 1108, respectively, by controlling the 
pressures at the outlet pressure gauges 1127, 1128 to 1 Kg/cm.sup.2, 
respectively, by opening the valves 1122, 1123 and opening gradually 
inflow valves 1112, 1113. Subsequently, the outflow valves 1117, 1118 and 
the auxiliary valves 1132 are gradually opened to permit respective gases 
to flow into the reaction chamber 1101. The outflow valves 1117, 1118 are 
controlled so that the flow rate ratio of the respective gases may have a 
desired value and opening of the main valve 1134 is also controlled while 
watching the reading on the vacuum indicator 1136 so that the pressure in 
the reaction chamber may reach a desired value. And, after confirming that 
the temperature of the substrate 1137 is set at a temperature in the range 
of from about 400.degree. to 600.degree. C. by the heater 1138, the power 
source 1140 is set at a desired power to excite glow discharge in the 
reaction chamber 1101, while at the same time performing the operation to 
change gradually the opening of the valve 1118 manually or by means of an 
externally driven motor to change the flow rate of GeH.sub.4 /He gas 
according to the change ratio curve previously designed, whereby the depth 
profile of the germanium atoms contained in the layer formed are 
controlled. 
As described above, glow discharging can be maintained for a desired period 
of time to form a first layer region (C) on the substrate 1137 to a 
desired thickness. At the stage, when the first layer region has been 
formed to a desired thickness, all the outflow valves are closed. 
Referring next to one example of forming a second layer region (G) on the 
first layer region (C), SiH.sub.4 /He gas from the gas bomb 1102, 
GeH.sub.4 /He gas from the gas bomb 1103 are permitted to flow into the 
mass-flow controllers 1107, 1108, respectively, by controlling the 
pressures at the outlet pressure gauges 1127, 1128 to 1 Kg/cm.sup.2, 
respectively, by opening the valves 1122, 1123 and opening gradually 
inflow valves 1112, 1113. Subsequently, the outflow valves 1117, 1118 and 
the auxiliary valves 1132 are gradually opened to permit respective gases 
to flow into the reaction chamber 1101. The outflow valves 1117, 1118 are 
controlled so that the flow rate ratio of the respective gases may have a 
desired value and opening of the main valve 1134 is also controlled while 
watching the reading on the vacuum indicator 1136 so that the pressure in 
the reaction chamber may reach a desired value. And, after confirming that 
the temperature of the substrate 1137 is set at a temperature in the range 
of from about 50.degree. to 400.degree. C. by the heater 1138, the power 
source 1140 is set at a desired power to excite glow discharge in the 
reaction chamber 1101, while at the same time performing the operation to 
change gradually the opening of the valve 1118 manually or by means of an 
externally driven motor to change the flow rate of GeH.sub.4 /He gas 
according to the change ratio curve previously designed, whereby the depth 
profile of the germanium atoms contained in the layer formed are 
controlled. 
As described above, glow discharging can be maintained for a desired period 
of time to form a second layer region (G) on the first layer region (C) to 
a desired thickness. At the stage, when the second layer region (G) has 
been formed to a desired thickness, all the outflow valves are closed, and 
the discharging conditions are changed, if desired, following otherwise 
the same conditions and the same procedure, glow dischage can be 
maintained for a desired period of time, whereby a third layer region (S) 
containing substantially no germanium atom can be formed on the second 
layer region (G). 
For incorporation of a substance controlling the conductivity in any 
desired layer region constituting the light receiving layer, a gas such as 
B.sub.2 H.sub.6, PH.sub.3, etc. may be added into the gas to be introduced 
into the deposition chamber 1101 during layer formation. 
For formation of a fourth layer region (M) on the third layer region (S) 
formed to a desired thickness as described above, the gas line not used is 
changed to be used for CH.sub.4 gas during deposition of the fourth layer 
region (M) and, according to the same valve operation as in formation of 
the third layer region (M), for example, diluting each of SiH.sub.4 gas 
and C.sub.2 H.sub.4 gas with He, if desired, and following the desired 
conditions, glow discharging may be excited thereby forming the fourth 
layer (M) on the third layer (S). 
For incorporation of halogen atoms into the fourth layer region (M), for 
example, SiF.sub.4 gas and C.sub.2 H.sub.4 gas, optionally together with 
SiH.sub.4, may be used and, following the same procedure as described 
above, the fourth layer region (M) can be formed with halogen atoms 
contained therein. 
The outflow valves other than those for the gases necessary for formation 
of respective layers are of course all closed, and for avoiding remaining 
of gases used in the preceding layer in the reaction chamber 1101 and in 
the pipelines from the inflow valves 1117 to 1121 to the reaction chamber 
1101, the operation to close and outflow valves 1117 to 1121, with opening 
of the auxiliary valves 1132, 1133 and full opening of the main valve 
1132, thereby evacuating once the system to high vacuum, may be conducted 
if desired. 
The content of the carbon atoms in the fourth layer region may be 
controlled by, for example, in the case of glow discharging, changing the 
flow rate ratio of SiH.sub.4 gas to C.sub.2 H.sub.4 gas to be introduced 
into the reaction chamber 1101, or in the case of sputtering by changing 
the area ratio of silicon wafer to graphite wafer when forming the target, 
or changing the mixing ratio of the silicon powder to the graphite powder 
before molding into a target as desired. The content of the halogen atoms 
(X) in the fourth layer region (M) can be controlled by controlling the 
flow rate of the starting gas for introduction of halogen atoms, for 
example, SiF.sub.4 gas, when introduced into the reaction chamber 1101. 
It is also desirable to set the substrate 1137 on rotation at a constant 
speed during layer formation in order to uniformize layer formation. 
The present invention is further illustrated by referring to the following 
Examples. 
EXAMPLE 1 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations on a 
cylindrical aluminum substrate under the conditions shown in Table 1. 
The image forming member thus obtained was set in a charging-exposure 
testing device and subjected to corona charging at .crclbar.5.0 KV for 0.3 
sec., followed immediately by irradiation of a light image. The light 
image was irradiated by means of a tungsten lamp light source at a dose of 
2 lux.multidot.sec through a transmission type test chart. 
Immediately thereafter, .sym. chargeable developer (containing toner and 
carrier) was cascaded on the surface of the image forming member to give a 
good toner image of the surface of the image forming member. When the 
toner image was transferred onto a transfer paper by corona charging of 
.crclbar.5.0 KV, a clear image of high density with excellent resolution 
and good gradation reproducibility was obtained. 
EXAMPLE 2 
By means of the device shown in FIG. 11, layer formations were conducted in 
the same manner as in Example 1 except for changing the conditions to 
those shown in Table 2 to prepare an image forming member for 
electrophotography. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 1 except for reversing the charged polarity and 
the charging polarity of the developer, respectively, whereby a very clear 
image quality could be obtained. 
EXAMPLE 3 
By means of the device shown in FIG. 11, layer formations were conducted in 
the same manner as in Example 1 except for changing the conditions to 
those shown in Table 3 to prepare an image forming member for 
electrophotography. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 1, whereby a very clear image quality could be 
obtained. 
EXAMPLE 4 
Example 1 was repeated except that the contents of germanium atoms 
contained in the first layer were varied by varying the gas flow rate 
ratio of GeH.sub.4 /He gas to SiH.sub.4 /He gas as shown in Table 4 to 
prepare image forming members for electrophotography, respectively. 
For the image forming members thus obtained, images were formed on transfer 
papers under the same conditions and according to the same procedure as in 
Example 1 to obtain the results as shown in Table 4. 
EXAMPLE 5 
Example 1 was repeated except for changing the layer thickness of the first 
layer as shown in Table 5 to prepare respective image forming members for 
electrophotography. 
For the image forming members thus obtained, images were formed on transfer 
papers under the same conditions and according to the same procedure as in 
Example 1 to obtain the results as shown in Table 5. 
EXAMPLE 6 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations on a 
cylindrical aluminum substrate under the conditions shown in Table 6. 
The image forming member thus obtained was set in a charging-exposure 
testing device and subjected to corona charging at .crclbar.5.0 KV for 0.3 
sec., followed immediately by irradiation of a light image. The light 
image was irradiated by means of a tungsten lamp light source at a dose of 
2 lux.multidot.sec through a transmission type test chart. 
Immediately thereafter, .sym. chargeable developer (containing toner and 
carrier) was cascaded on the surface of the image forming member to give a 
good toner image of the surface of the image forming member. When the 
toner image was transferred onto a transfer paper by corona charging of 
.crclbar.5.0 KV, a clear image of high density with excellent resolution 
and good gradation reproducibility was obtained. 
EXAMPLE 7 
The image forming member for electrophotography prepared under the same 
conditions as in Example 1 was subjected to image formation under the same 
image forming conditions except for using a GaAs type semiconductor laser 
(10 mW) of 810 nm in place of the tungsten lamp as the light source, and 
image evaluation of the toner transfer image was conducted. As a result, a 
clear image of high quality could be obtained which was excellent in 
resolution and good in gradation reproducibility. 
EXAMPLE 8 
Image forming members for electrophotography were prepared following the 
same conditions and the procedures as in Examples 1 to 6, except for 
changing the preparation conditions for the fourth layer region (M) as 
shown in Table 7, respectively (72 samples with Sample No. 12-201 to 
12-208, 12-301 to 12-308, . . . 12-1001 to 12-1008). 
Each of the thus prepared image forming members was individually set in a 
copying device and subjected to corona charging at .crclbar.5 KV for 0.2 
sec., followed by irradiation of light image. As the light source, a 
tungsten lamp was employed and the dose was controlled to 1.0 
lux.multidot.sec. The latent image was developed with a .sym. chargeable 
developer (containing toner and carrier) and transferred onto a plain 
paper. 
The transferred images were found to be very good. The toner remaining on 
the image forming member for electrophotography without transfer was 
cleaned by a rubber blade. When such steps were repeated for 100,000 times 
or more, no deterioration of image could be seen in every case. 
The overall evaluations of the respective transferred images and evaluation 
of durability after repeated successive copying are shown in Table 8. 
EXAMPLE 9 
Various image forming members were prepared according to the same method as 
in Example 1, respectively, except for varying the content ratio of 
silicon atoms to carbon atoms in the fourth layer region (M) by varying 
the target area ratio of silicon wafer to graphite during formation of the 
fourth layer region (M). For each of the image forming members thus 
obtained, the steps of image formation, developing and cleaning as in 
Example 1 were repeated for about 50,000 times, and thereafter image 
evaluations were conducted to obtain the results as shown in Table 9. 
EXAMPLE 10 
Various image forming members were prepared according to the same method as 
in Example 1, respectively, except for varying the content ratio of 
silicon atoms to carbon atoms in the fourth layer region (M) by varying 
the flow rate ratio of SiH.sub.4 gas to C.sub.2 H.sub.4 gas during 
formation of the fourth layer region (M). For each of the image forming 
members thus obtained, the steps up to transfer were repeated for about 
50,000 times according to the methods as described in Example 1, and 
thereafter image evaluations were conducted to obtain the results as shown 
in Table 10. 
EXAMPLE 11 
Various image forming members were prepared according to the same method as 
in Example 1, respectively, except for varying the content ratio of 
silicon atoms to carbon atoms in the fourth layer region (M) by varying 
the flow rate ratio of SiH.sub.4 gas, SiF.sub.4 gas and C.sub.2 H.sub.4 
gas during formation of the fourth layer region (M). For each of the image 
forming members thus obtained, the steps of image formation, developing 
and cleaning as described in Example 1 were repeated for about 50,000 
times, and thereafter image evaluations were conducted to obtain the 
results as shown in Table 11. 
EXAMPLE 12 
Respective image forming members were repeated in the same manner as in 
Example 1 except for changing the layer thickness of the fourth layer 
region (M), and the steps of image formation, developing and cleaning as 
described in Example 1 were repeated to obtain the results as shown in 
Table 12. 
The common layer forming conditions in the above Examples 1 to 12 of the 
present invention are shown below: 
Discharging frequency: 13.56 MHz 
Inner pressure in reaction chamber during reaction: 0.3 Torr 
EXAMPLE 13 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations on a 
cylindrical aluminum substrate under the conditions shown in Table 13, 
while varying the gas flow rate ratio of GeH.sub.4 /He gas to SiH.sub.4 
/He gas according to the change ratio curve shown in FIG. 12 with lapse of 
time for layer formation. 
The image forming member thus obtained was set in a charging-exposure 
testing device and subjected to corona charging at .crclbar.5.0 KV for 0.3 
sec., followed immediately by irradiation of a light image. The light 
image was irradiated by means of a tungsten lamp light source at a dose of 
2 lux.multidot.sec through a transmission type test chart. 
Immediately thereafter, .sym. chargeable developer (containing toner and 
carrier) was cascaded on the surface of the image forming member to give a 
good toner image of the surface of the image forming member. When the 
toner image was transferred onto a transfer paper by corona charging of 
.crclbar.5.0 KV, a clear image of high density with excellent resolution 
and good gradation reproducibility was obtained. 
EXAMPLE 14 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations under the 
conditions shown in Table 14, while varying the gas flow rate ratio of 
GeH.sub.4 /He gas to SiH.sub.4 /He gas according to the change ratio curve 
shown in FIG. 13 with lapse of time for layer formation, following 
otherwise the same conditions as in Example 13. 
For the image forming member thus obtained, an image was formed or a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby a very clear image quality could be 
obtained. 
EXAMPLE 15 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations under the 
conditions shown in Table 15, while varying the gas flow rate ratio of 
GeH.sub.4 /He gas to SiH.sub.4 /He gas according to the change ratio curve 
shown in FIG. 14 with lapse of time for layer formation, following 
otherwise the same conditions as in Example 13. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby a very clear image quality could be 
obtained. 
EXAMPLE 16 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations under the 
conditions shown in Table 16, while varying the gas flow rate ratio of 
GeH.sub.4 /He gas to SiH.sub.4 /He gas according to the change ratio curve 
shown in FIG. 15 with lapse of time for layer formation, following 
otherwise the same conditions as in Example 13. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby a very clear image quality could be 
obtained. 
EXAMPLE 17 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations under the 
conditions shown in Table 17, while varying the gas flow rate ratio of 
GeH.sub.4 /He gas to SiH.sub.4 /He gas according to the change ratio curve 
shown in FIG. 16 with lapse of time for layer formation, following 
otherwise the same conditions as in Example 13. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby a very clear image quality could be 
obtained. 
EXAMPLE 18 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations under the 
conditions shown in Table 18, while varying the gas flow rate ratio of 
GeH.sub.4 /He gas to SiH.sub.4 /He gas according to the change ratio curve 
shown in FIG. 17 with lapse of time for layer formation, following 
otherwise the same conditions as in Example 13. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby a very clear image quality could be 
obtained. 
EXAMPLE 19 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations under the 
conditions shown in Table 19, while varying the gas flow rate ratio of 
GeH.sub.4 /He gas to SiH.sub.4 /He gas according to the change ratio curve 
shown in FIG. 18 with lapse of time for layer formation, following 
otherwise the same conditions as in Example 13. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby a very clear image quality could be 
obtained. 
EXAMPLE 20 
The procedure of Example 13 was repeated except for using Si.sub.2 H.sub.6 
/He gas in place of SiH.sub.4 /He gas and changing the conditions to those 
shown in Table 20 to prepare an image forming member for 
electrophotography. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby a very clear image quality could be 
obtained. 
EXAMPLE 21 
The procedure of Example 13 was repeated except for using SiF.sub.4 /He gas 
in place of SiH.sub.4 /He gas and changing the conditions to those shown 
in Table 21 to prepare an image forming member for electrophotography. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby a very clear image quality could be 
obtained. 
EXAMPLE 22 
The procedure of Example 13 was repeated except for using (SiH.sub.4 /He 
gas+SiF.sub.4 /He gas) in place of SiH.sub.4 /He gas and changing the 
conditions to those shown in Table 22 to prepare an image forming member 
for electrophotography. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby a very clear image quality could be 
obtained. 
EXAMPLE 23 
In Examples 13 to 22, the conditions for preparation of the third layer 
were changed to those as shown in Table 23, following otherwise the same 
conditions in the respective Examples to prepare respective image forming 
members for electrophotography. 
For the image forming members thus obtained, images were formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby the results as shown in Table 23A were 
obtained. 
EXAMPLE 24 
In Examples 13 to 22, the conditions for preparation of the third layer 
were changed to those as shown in Table 24, following otherwise the same 
conditions in the respective Examples to prepare respective image forming 
members for electrophotography. 
For the image forming members thus obtained, images were formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 13, whereby the results as shown in Table 24A were 
obtained. 
EXAMPLE 25 
The image forming member for electrophotography prepared under the same 
conditions as in Example 13 was subjected to image formation under the 
same image forming conditions as in Example 13 except for using a GaAs 
type semiconductor laser (10 mW) of 810 nm in place of the tungsten lamp 
as the light source, and image evaluation of the toner transfer image was 
conducted. As a result, a clear image of high quality could be obtained 
which was excellent in resolution and good in gradation reproducibility. 
EXAMPLE 26 
Except for following the conditions for producing the fourth layer region 
(M) in Table 25, image forming members for electrophotography were 
prepared following the same conditions and the procedures as in Examples 
14 to 22, except for changing the preparation conditions as shown in Table 
25, respectively (72 samples with Sample No. 25-201 to 25-208, 25-301 to 
25-308, . . . , 25-1001 to 25-1009). 
Each of the thus prepared image forming members thus prepared was 
individually set in a copying device and subjected to corona charging at 
.crclbar.5 KV for 0.2 sec., followed by irradiation of light image. As the 
light source, a tungsten lamp was employed and the dose was controlled to 
1.0 lux.multidot.sec. The latent image was developed with a .sym. 
chargeable developer (containing toner and carrier) and transferred onto a 
plain paper. 
The transferred images were found to be very good. The toner remaining on 
the image forming member for electrophotography without transfer was 
cleaned by a rubber blade. When such steps were repeated for 100,000 times 
or more, no deterioration of image could been seen in every case. 
The overall evaluations of the respective transferred images and evaluation 
of durability after repeated successive copying are shown in Table 26. 
EXAMPLE 27 
Various image forming members were prepared according to the same method as 
in Example 13, respectively, except for varying the content ratio of 
silicon atoms to carbon atoms in the fourth layer region (M) by varying 
the target area ratio of silicon wafer to graphite during formation of the 
fourth layer region (M). For each of the image forming members thus 
obtained, the steps of image formation, developing and cleaning as in 
Example 13 were repeated for about 50,000 times, and thereafter image 
evaluations were conducted to obtain the results as shown in Table 27. 
EXAMPLE 28 
Various image forming members were prepared according to the same method as 
in Example 13, respectively, except for varying the content ratio of 
silicon atoms to carbon atoms in the fourth layer region (M) by varying 
the flow rate ratio of SiH.sub.4 gas to C.sub.2 H.sub.4 gas during 
formation of the fourth layer region (M). For each of the image forming 
members thus obtained, the steps up to transfer were repeated for about 
50,000 times according to the methods as described in Example 13, and 
thereafter image evaluations were conducted to obtain the results as shown 
in Table 28. 
EXAMPLE 29 
Various image forming members were prepared according to the same method as 
in Example 13, respectively, except for varying the content ratio of 
silicon atoms to carbon atoms in the fourth layer region (M) by varying 
the flow rate ratio of SiH.sub.4 gas, SiF.sub.4 gas and C.sub.2 H.sub.4 
gas during formation of the fourth layer region (M). For each of the image 
forming members thus obtained, the steps of image formation, developing 
and cleaning as described in Example 13 were repeated for about 50,000 
times, and thereafter image evaluations were conducted to obtain the 
results as shown in Table 29. 
EXAMPLE 30 
Respective image forming members were repeated in the same manner as in 
Example 13 except for changing the layer thickness of the fourth layer 
region (M), and the steps of image formation, developing and cleaning as 
described in Example 13 were repeated to obtain the results as shown in 
Table 30. 
The common layer forming conditions in the above Examples 13 to 30 of the 
present invention are shown below: 
Discharging frequency: 13.56 MHz 
Inner pressure in reaction chamber during reaction: 0.3 Torr 
EXAMPLE 31 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations on a 
cylindrical aluminum substrate under the conditions shown in Table 31. 
The image forming member thus obtained was set in a charging-exposure 
testing device and subjected to corona charging at .sym.5.0 KV for 0.3 
sec., followed immediately by irradiation of a light image. The light 
image was irradiated by means of a tungsten lamp light source at a dose of 
2 lux.multidot.sec through a transmission type test chart. 
Immediately thereafter, .crclbar. chargeable developer (containing toner 
and carrier) was cascaded on the surface of the image forming member to 
give a good toner image of the surface of the image forming member. When 
the toner image was transferred onto a transfer paper by corona charging 
of .sym.5.0 KV, a clear image of high density with excellent resolution 
and good gradation reproducibility was obtained. 
EXAMPLE 32 
By means of the device shown in FIG. 11, layer formations were conducted in 
the same manner as in Example 31 except for changing the conditions to 
those shown in Table 32 to prepare an image forming member for 
electrophotography. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 31 except for reversing the charging polarity and 
the chargeable polarity of the developer, respectively, whereby a very 
clear image quality could be obtained. 
EXAMPLE 33 
By means of the device shown in FIG. 11, layer formations were conducted in 
the same manner as in Example 31 except for changing the conditions to 
those shown in Table 33 to prepare an image forming member for 
electrophotography. 
For the image forming member thus obtained, an image was formed on a 
transfer paper under the same conditions and according to the same 
procedure as in Example 31, whereby a very clear image quality could be 
obtained. 
EXAMPLE 34 
The procedure of Example 31 was repeated except that the contents of 
germanium atoms contained in the first layer were varied by varying the 
gas flow rage ratio of GeH.sub.4 /He gas to SiH.sub.4 /He gas as shown in 
Table 34 to prepare image forming members for electrophotography, 
respectively. 
For the image forming members thus obtained, images were formed on transfer 
papers under the same conditions and according to the same procedure as in 
Example 31 to obtain the results as shown in Table 34. 
EXAMPLE 35 
The procedure of Example 31 was repeated except for changing the layer 
thickness of the first layer as shown in Table 35 to prepare respective 
image forming members for electrophotography. 
For the image forming members thus obtained, images were formed on transfer 
papers under the same conditions and according to the same procedure as in 
Example 31 to obtain the results as shown in Table 35. 
EXAMPLE 36 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations on a 
cylindrical aluminum substrate under the conditions shown in Table 36. 
The image forming member thus obtained was set in a charging-exposure 
testing device and subjected to corona charging at .sym.5.0 KV for 0.3 
sec., followed immediately by irradiation of a light image. The light 
image was irradiated by means of a tungsten lamp light source at a dose of 
2 lux.multidot.sec through a transmission type test chart. 
Immediately thereafter, .crclbar. chargeable developer (containing toner 
and carrier) was cascaded on the surface of the image forming member to 
give a good toner image of the surface of the image forming member. When 
the toner image was transferred onto a transfer paper by corona charging 
of .sym.5.0 KV, a clear image of high density with excellent resolution 
and good gradation reproducibility was obtained. 
EXAMPLE 37 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations on a 
cylindrical aluminum substrate under the conditions shown in Table 37. 
The image forming member thus obtained was set in a charging-exposure 
testing device and subjected to corona charging at .crclbar.5.0 KV for 0.3 
sec., followed immediately by irradiation of a light image. The light 
image was irradiated by means of a tungsten lamp light source at a dose of 
2 lux.multidot.sec through a transmission type test chart. 
Immediately thereafter, .sym. chargeable developer (containing toner and 
carrier) was cascaded on the surface of the image forming member to give a 
good toner image of the surface of the image forming member. When the 
toner image was transferred onto a transfer paper by corona charging of 
.crclbar.5.0 KV, a clear image of high density with excellent resolution 
and good gradation reproducibility was obtained. 
EXAMPLE 38 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared by carrying out layer formations on a 
cylindrical aluminum substrate under the conditions shown in Table 38. 
The image forming member thus obtained was set in a charging-exposure 
testing device and subjected to corona charging at .crclbar.5.0 KV for 0.3 
sec., followed immediately by irradiation of a light image. The light 
image was irradiated by means of a tungsten lamp light source at a dose of 
2 lux.multidot.sec through a transmission type test chart. 
Immediately thereafter, .sym. chargeable developer (containing toner and 
carrier) was cascaded on the surface of the image forming member to give a 
good toner image of the surface of the image forming member. When the 
toner image was transferred onto a transfer paper by corona charging of 
.crclbar.5.0 KV, a clear image of high density with excellent resolution 
and good gradation reproducibility was obtained. 
EXAMPLE 39 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared in the same manner as in Example 31, 
except for changing the conditions as shown in Table 39. 
When image formation was conducted by use of the image forming member thus 
obtained under the same conditions and according to the same procedure as 
in Example 31, a very clear image quality could be obtained. 
EXAMPLE 40 
By means of the device shown in FIG. 11, an image forming member for 
electrophotography was prepared in the same manner as in Example 31, 
except for changing the conditions as shown in Table 40. 
When image formation was conducted by use of the image forming member thus 
obtained under the same conditions and according to the same procedure as 
in Example 31 and the developed image was transferred onto a transfer 
paper, a very clear image quality could be obtained. 
EXAMPLE 41 
The image forming member for electrophotography prepared under the same 
conditions as in Example 31 was subjected to image formation under the 
same image forming conditions as in Example 31 except for using a GaAs 
type semiconductor laser (10 mW) of 810 nm in place of the tungsten lamp 
as the light source, and image evaluation of the toner transfer image was 
conducted. As a result, a clear image of high quality could be obtained 
which was excellent in resolution and good in gradation reproducibility. 
EXAMPLE 42 
Image forming members for electrophotography were prepared following the 
same conditions and the procedures as in Examples 31 to 39, except for 
changing the preparation conditions for the fourth layer region (M) as 
shown in Table 41, respectively (72 samples with sample No. 42-201 to 
42-208, 42-301 to 42-308, . . . , 42-1001 to 42-1008). 
Each of the image forming members thus prepared was individually set in a 
copying device and subjected to corona charging at .crclbar.5 KV for 0.2 
sec., followed by irradiation of light image. As the light source, a 
tungsten lamp was employed and the dose was controlled to 1.0 lux sec. The 
latent image was developed with a .sym. chargeable developer (containing 
toner and carrier) and transferred onto a plain paper. 
The transferred images were found to be very good. The toner remaining on 
the image forming member for electrophotography without transfer was 
cleaned by a rubber blade. When such steps were repeated for 100,000 times 
or more, no deterioration of image could be seen in every case. 
The overall evaluations of the respective transferred images and evaluation 
of durability after repeated successive copying are shown in Table 42. 
EXAMPLE 43 
Various image forming members were prepared according to the same method as 
in Example 31, respectively, except for varying the content ratio of 
silicon atoms to carbon atoms in the fourth layer region (M) by varying 
the target area ratio of silicon wafer to graphite during formation of the 
fourth layer region (M). For each of the image forming members thus 
obtained, the steps of image formation, developing and cleaning as in 
Example 31 were repeated for about 50,000 times, and thereafter image 
evaluations were conducted to obtain the results as shown in Table 43. 
EXAMPLE 44 
Various image forming members were prepared according to the same method as 
in Example 31, respectively, except for varying the content ratio of 
silicon atoms to carbon atoms in the fourth layer region (M) by varying 
the flow rate ratio of SiH.sub.4 gas to C.sub.2 H.sub.4 gas during 
formation of the fourth layer region (M). For each of the image forming 
members thus obtained, the steps up to transfer were repeated for about 
50,000 times according to the methods as described in Example 31, and 
thereafter image evaluations were conducted to obtain the results as shown 
in Table 44. 
EXAMPLE 45 
Various image forming members were prepared according to the same method as 
in Example 31, respectively, except for varying the content ratio of 
silicon atoms to carbon atoms in the fourth layer region (M) by varying 
the flow rate ratio of SiH.sub.4 gas, SiF.sub.4 gas and C.sub.2 H.sub.4 
gas during formation of the fourth layer region (M). For each of the image 
forming members thus obtained, the steps of image formation, developing 
and cleaning as described in Example 31 were repeated for about 50,000 
times, and thereafter image evaluations were conducted to obtain the 
results as shown in Table 45. 
EXAMPLE 46 
Respective image forming members were repeated in the same manner as in 
Example 31 except for changing the layer thickness of the fourth layer 
region (M), and the steps of image formation, developing and cleaning as 
described in Example 31 were repeated to obtain the results as shown in 
Table 46. 
The common layer forming conditions in the above Examples 31 to 46 of the 
present invention are shown below: 
Discharging frequency: 13.56 MHz 
Inner pressure in reaction chamber during reaction: 0.3 Torr 
TABLE 1 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
GeH.sub.4 /He = 0.05 
GeH.sub.4 = 10 0.2 3 0.1 450 
layer 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1 
0.18 5 3 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 15 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 2 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
GeH.sub.4 /He = 0.05 
GeH.sub.4 = 10 0.2 3 0.1 450 
layer 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 0.1 
0.18 5 20 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 5 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 3 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Fow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 10 
GeH.sub.4 /SiH.sub.4 = 3 
0.2 3 0.2 450 
layer 
GeH.sub.4 /He = 0.05 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 0.4 
0.18 5 2 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 250 
layer 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /SiH.sub.4 = 2 .times. 10.sup.-5 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 4 
______________________________________ 
Sample No. 
401 402 403 404 405 406 407 408 
______________________________________ 
Ge content 
1 3 5 10 40 60 90 100 
(atomic %) 
Evaluation 
.DELTA. 
o o o .circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
______________________________________ 
.circleincircle.: Excellent 
o: Good 
.DELTA.: Practically satisfactory 
TABLE 5 
______________________________________ 
Sample No. 501 502 503 504 505 506 507 
______________________________________ 
Layer 0.01 0.05 0.1 0.5 1 2 5 
thickness (.mu.) 
Evaluation .DELTA. 
.DELTA. 
.circleincircle. 
.circleincircle. 
o .DELTA. 
.DELTA. 
______________________________________ 
.circleincircle.: Excellent 
o: Good 
.DELTA.: Practically satisfactory 
TABLE 6 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
GeH.sub.4 /He = 0.05 
GeH.sub.4 = 10 0.2 
3 0.1 500 
layer 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1 
0.18 
5 2 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 
15 20 250 
layer 
PH.sub.3 /He = 10.sup.-3 
PH.sub.3 /SiH.sub.4 = 1/10.sup. -7 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 
10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 7 
__________________________________________________________________________ 
Discharging 
Layer 
gases Flow rate Flow rate ratio or 
power thickness 
Condition 
employed 
(SCCM) area ratio (W/cm.sup.2) 
(.mu.) 
__________________________________________________________________________ 
12-1 Ar 200 Si wafer:graphite= :5:8.5 
0.3 0.5 
12-2 Ar 200 Si wafer:graphite= 0.5:9.5 
0.3 0.3 
12-3 Ar 200 Si wafer:graphite = 6:4 
0.3 1.0 
12-4 SiH.sub.4 /He = 1 
SiH.sub.4 = 15 
SiH.sub.4 :C.sub.2 H.sub.4 = 0.4:9.6 
0.18 0.3 
C.sub.2 H.sub.4 
12-5 SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 :C.sub.2 H.sub.4 = 5:5 
0.18 1.5 
C.sub.2 H.sub.4 
12-6 SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 150 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
0.18 0.5 
SiF.sub.4 /He = 0.5 
C.sub.2 H.sub.4 
12-7 SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 15 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
= 0.3:0.1:9.6 0.18 0.3 
SiF.sub.4 /He = 0.5 
C.sub.2 H.sub.4 
12-8 SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 150 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
0.183:4 
1.5 
SiF.sub.4 /He = 0.5 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 8 
__________________________________________________________________________ 
Conditions for 
preparation of 
the fourth layer 
region (M) 
Sample No./Evaluation 
__________________________________________________________________________ 
12-1 12-201 
12-301 
12-401 
12-501 
12-601 
12-701 
12-801 
12-901 
12-1001 
o o o o o o o o o o o o o o o o o o 
12-2 12-202 
12-302 
12-402 
12-502 
12-602 
12-702 
12-802 
12-902 
12-1002 
o o o o o o o o o o o o o o o o o o 
12-3 12-203 
12-303 
12-403 
12-503 
12-603 
12-703 
12-803 
12-903 
12-1003 
o o o o o o o o o o o o o o o o o o 
12-4 12-204 
12-304 
12-404 
12-504 
12-604 
12-704 
12-804 
12-904 
12-1004 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
7 
12-5 12-205 
12-305 
12-405 
12-505 
12-605 
12-705 
12-805 
12-905 
12-1005 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
. 
12-6 12-206 
12-306 
12-406 
12-506 
12-606 
12-706 
12-806 
12-906 
12-1006 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
12-7 12-207 
12-307 
12-407 
12-507 
12-607 
12-707 
12-807 
12-907 
12-1007 
o o o o o o o o o o o o o o o o o o 
12-8 12-208 
12-308 
12-408 
12-508 
12-608 
12-708 
12-808 
12-908 
12-1008 
o o o o o o o o o o o o o o o o o o 
__________________________________________________________________________ 
Sample No. 
Evaluation of 
Evaluation of . . . -overall image durability 
quality 
Evaluation standards: 
.circleincircle. . . . Excellent 
.circle. . . . Good 
TABLE 9 
__________________________________________________________________________ 
Sample No. 
1301 
1302 
1303 
1304 
1305 
1306 
1307 
__________________________________________________________________________ 
Si:C target 
9:1 6.5:3.5 
4:6 2:8 1:9 
0.5:9.5 
0.2:9.8 
(area ratio) 
Si:C (content ratio) 
9.7:0.3 
8.8:1.2 
7.3:2.7 
4.8:5.2 
3:7 
2:8 0.8:9.2 
Image quality 
.DELTA. 
o .circleincircle. 
.circleincircle. 
o .DELTA. 
x 
evaluation 
__________________________________________________________________________ 
.circleincircle.: Very good 
o: Good 
.DELTA.: Practically satisfactory 
x: Image defect formed 
TABLE 10 
__________________________________________________________________________ 
Sample No. 
1401 
1402 
1403 
1404 
1405 
1406 
1407 
1408 
__________________________________________________________________________ 
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 (content ratio) 
9:1 
7:3 
5.5:4.5 
4:6 
3:7 
2:8 1.2:8.8 
0.8:9.2 
Image quality 
.DELTA. 
o .circleincircle. 
.circleincircle. 
.circleincircle. 
o .DELTA. 
x 
evaluation 
__________________________________________________________________________ 
.circleincircle.: Very good 
o: Good 
.DELTA.: Practically satisfactory 
x: Image defect formed 
TABLE 11 
__________________________________________________________________________ 
Sample No. 
1501 
1502 1503 
1054 
1505 1506 1507 1508 
__________________________________________________________________________ 
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 
(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. 
o .circleincircle. 
.circleincircle. 
.circleincircle. 
o .DELTA. 
x 
evaluation 
__________________________________________________________________________ 
.circleincircle.: Very good 
o: Good 
.DELTA.: Practically satisfactory 
x: Image defect formed 
TABLE 12 
______________________________________ 
Thickness (.mu.) 
of the fourth 
Sample layer region 
No. (M) Results 
______________________________________ 
1601 0.001 Image defect liable to be 
formed 
1602 0.02 No image defect formed 
after repetition for 
20,000 times 
1603 0.05 Stable for 50,000 times 
repetition 
1604 1 Stable for 200,000 times 
repetition 
______________________________________ 
TABLE 13 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
SiH.sub.4 /GeH.sub.4 = 1 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1 .about. 0 
0.18 5 9.9 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 10 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 14 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1/10 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1/10 .about. 0 
0.18 5 7.9 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 10 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 15 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 4/10 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 
0.18 5 1.9 250 
layer 
GeH.sub.4 /He = 0.05 
4/10 .about. 2/1000 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 16 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 3/10 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 3/10 .about. 0 
0.18 5 1.9 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 15 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 17 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 8/10 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 8/10 .about. 0 
0.18 5 0.7 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 18 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1 .about. 0 
0.18 5 7.9 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 15 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 19 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1/10 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1/10 .about. 0 
0.18 5 8 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 10 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 20 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
Si.sub.2 H.sub.6 /He = 0.05 
Si.sub.2 H.sub.6 + GeH.sub.4 = 50 
GeH.sub.4 /Si.sub.2 H.sub.6 = 1 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
Second 
Si.sub.2 H.sub.6 /He = 0.05 
Si.sub.2 H.sub.6 + GeH.sub.4 = 50 
GeH.sub.4 /Si.sub.2 H.sub.6 = 1 .about. 0 
0.18 5 10 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 10 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 21 
__________________________________________________________________________ 
Dis- Layer 
Layer 
Substrate 
Layer charging 
formation 
thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiF.sub.4 /He = 0.05 
SiF.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiF.sub.4 = 1 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
Second 
SiF.sub.4 /He = 0.05 
SiF.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiF.sub.4 = 1.about.0 
0.18 5 10 250 
layer 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 10 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 22 
__________________________________________________________________________ 
Dis- Layer 
Layer 
Substrate 
Layer charging 
formation 
thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + SiF.sub.4 + 
GeH.sub.4 /(SiH.sub.4 + SiF.sub.4) 
0.18 5 0.1 450 
layer 
SiF.sub.4 /He = 0.05 
GeH.sub.4 = 50 
GeH.sub.4 /He = 0.05 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + SiF.sub.4 + 
GeH.sub.4 /(SiH.sub.4 + SiF.sub.4) 
0.18about.0 
5 10 450 
layer 
SiF.sub.4 /He = 0.05 
GeH.sub.4 = 50 
GeH.sub.4 /He = 0.05 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 10 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 23 
__________________________________________________________________________ 
Layer Gases Flow rate Discharging 
Layer formation 
constitution 
employed (SCCM) 
Flow rate ratio 
power (w/cm.sup.2) 
speed (.ANG./sec) 
__________________________________________________________________________ 
Third SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
B.sub.2 H.sub.6 /SiH.sub.4 = 2/10.sup.-5 
0.18 15 
layer B.sub.2 H.sub.6 /He = 10.sup.-3 
__________________________________________________________________________ 
TABLE 23A 
__________________________________________________________________________ 
Sample No. 
1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 
__________________________________________________________________________ 
Second 
Example 
Example 
Example 
Example 
Example 
Example 
Example 
Example 
Example 
Example 
layer 13 14 15 16 17 18 19 20 21 22 
Layer 10 10 20 15 20 15 10 10 10 10 
thickness 
of the third 
layer (.mu.) 
Evaluation 
o o .circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
o o o o 
__________________________________________________________________________ 
.circleincircle.: Excellent 
o: Good 
TABLE 24 
__________________________________________________________________________ 
Layer Gases Flow rate Discharging 
Layer formation 
constitution 
employed (SCCM) 
Flow rate ratio 
power (W/cm.sup.2) 
speed (.ANG./sec) 
__________________________________________________________________________ 
Third SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
PH.sub.3 /SiH.sub.4 = 1 .times. 10.sup.-7 
0.18 15 
layer PH.sub.3 /He = 10.sup.-3 
__________________________________________________________________________ 
TABLE 24A 
__________________________________________________________________________ 
Sample No. 
1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 
__________________________________________________________________________ 
Second 
Example 
Example 
Example 
Example 
Example 
Example 
Example 
Example 
Example 
Example 
layer 13 14 15 16 17 18 19 20 21 22 
Layer 10 10 20 15 20 15 10 10 10 10 
thickness 
of the third 
layer (.mu.) 
Evaluation 
o o .circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
o o o o 
__________________________________________________________________________ 
.circleincircle.: Excellent 
o: Good 
TABLE 25 
__________________________________________________________________________ 
Discharging 
Layer 
gases Flow rate Flow rate ratio or 
power thickness 
Condition 
employed 
(SCCM) area ratio 
(W/cm.sup.2) 
(.mu.) 
__________________________________________________________________________ 
25-1 Ar 200 Si wafer:graphite = 
0.3 0.5 
1.5:8.5 
25-2 Ar 200 Si wafer:graphite = 
0.3 0.3 
0.5:9.5 
25-3 Ar 200 Si wafer:graphite = 
0.3 1.0 
6:4 
25-4 SiH.sub.4 /He = 1 
SiH.sub.4 = 15 
SiH.sub.4 :C.sub.2 H.sub.4 = 0.4:9.6 
0.18 0.3 
C.sub.2 H.sub.4 
25-5 SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 :C.sub.2 H.sub.4 = 5:5 
0.18 1.5 
C.sub.2 H.sub.4 
25-6 SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 150 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
0.18 0.5 
SiF.sub.4 /He = 0.5 
1.5:1.5:7 
C.sub.2 H.sub.4 
25-7 SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 15 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
0.18 0.3 
SiF.sub.4 /He = 0.5 
0.3:0.1:9.6 
C.sub.2 H.sub.4 
25-8 SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 150 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.2 
0.18 1.5 
SiF.sub.4 /He = 0.5 
3:3:4 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 26 
__________________________________________________________________________ 
Conditions for 
preparation of 
the fourth 
layer region 
(M) Sample No./Evaluation 
__________________________________________________________________________ 
25-1 25-201 
25-301 
25-401 
25-501 
25-601 
25-701 
25-801 
25-901 
25-1001 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
25-2 25-202 
25-302 
25-402 
25-502 
25-602 
25-702 
25-802 
25-902 
25-1002 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
25-3 25-203 
25-303 
25-403 
25-503 
25-603 
25-703 
25-803 
25-903 
25-1003 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
25-4 25-204 
25-304 
25-404 
25-504 
25-604 
25-704 
25-804 
25-904 
25-1004 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
25-5 25-205 
25-305 
25-405 
25-505 
25-605 
25-705 
25-805 
25-905 
25-1005 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
25-6 25-206 
25-306 
25-406 
25-506 
25-606 
25-706 
25-806 
25-906 
25-1006 
.circleincircle. 502 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
.circleincircle. .circleincircle. 
25-7 25-207 
25-307 
25-407 
25-507 
25-607 
25-707 
25-807 
25-907 
25-1007 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
25-8 25-208 
25-308 
25-408 
25-508 
25-608 
25-708 
25-808 
25-908 
25-1008 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
o o 
__________________________________________________________________________ 
Sample No. 
Evaluation of Evaluation of 
overall image durability 
quality 
Evaluation standards: 
.circleincircle. . . . Excellent 
o . . . Good 
TABLE 27 
__________________________________________________________________________ 
Sample No. 
1901 
1902 1903 
1904 1905 
1906 1907 
__________________________________________________________________________ 
Si:C target 
9:1 6.5:3.5 
4:6 2:8 1:9 0.5:9.5 
0.2:9.8 
(area ratio) 
Si:C (content ratio) 
9.7:0.3 
8.8:1.2 
7.3:2.7 
4.8:5.2 
3:7 2:8 0.8:9.2 
Image quality 
.DELTA. 
o .circleincircle. 
.circleincircle. 
o .DELTA. 
x 
evaluation 
__________________________________________________________________________ 
.circleincircle.: Very good 
o: Good 
.DELTA.: Practically satisfactory 
x: Image defect formed 
TABLE 28 
__________________________________________________________________________ 
Sample No. 
2001 
2002 
2003 
2004 
2005 
2006 
2007 2008 
__________________________________________________________________________ 
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 (content ratio) 
9:1 
7:3 
5.5:4.5 
4:6 
3:7 
2:8 1.2:8.8 
0.8:9.2 
Image quality 
.DELTA. 
o .circleincircle. 
.circleincircle. 
.circleincircle. 
o .DELTA. 
x 
evaluation 
__________________________________________________________________________ 
.circleincircle.: Very good 
o: Good 
.DELTA.: Practically satisfactory 
x: Image defect formed 
TABLE 29 
__________________________________________________________________________ 
Sample No. 
2101 
2102 2103 
2104 
2105 2106 2107 2108 
__________________________________________________________________________ 
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 
(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. 
x 
evaluation 
__________________________________________________________________________ 
.circleincircle. : Very good 
.circle. : Good 
.DELTA.: Practically satisfactory 
x: Image defect formed 
TABLE 30 
______________________________________ 
Thickness (.mu.) 
of the fourth 
Sample layer region 
No. (M) Results 
______________________________________ 
2201 0.001 Image defect liable to be 
formed 
2202 0.02 No image defect formed 
after repetition for 
20,000 times 
2203 0.05 Stable for 50,000 times 
repetition 
2204 1 Stable for 200,000 times 
repetition 
______________________________________ 
TABLE 31 
__________________________________________________________________________ 
Layer 
Dis- forma- 
Layer 
Sub- 
Layer charging 
tion thick- 
strate 
consti- 
Gases Flow rate power 
speed 
ness 
temper- 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
ature 
__________________________________________________________________________ 
First 
GeH.sub.4 /He = 0.05 
GeH.sub.4 = 10 0.2 3 0.1 450 
layer 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 3/10 
0.18 5 1 250 
layer 
GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
3 .times. 10.sup.-3 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 250 
layer 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 32 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 5/10 
0.2 8 0.2 450 
layer 
GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
3 .times. 10.sup.-3 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1/10 
0.18 5 1 250 
layer 
GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
B.sub.2 H.sub.6 /He = 10.sup.-3 
3 .times. 10.sup.-3 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1/10 
0.18 5 19 250 
layer 
GeH.sub.4 /He = 0.05 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 5 250 
layer 
Fifth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 33 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 5/10 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
B.sub.2 H.sub.6 /He = 10.sup.-3 
5 .times. 10.sup.-3 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 3/10 
0.18 5 2 250 
layer 
GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
B.sub.2 H.sub.6 /He = 10.sup. -3 
5 .times. 10.sup.-3 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
B.sub.2 H.sub.6 /SiH.sub.4 = 2 .times. 10.sup.-4 
0.18 15 20 250 
layer 
B.sub.2 H.sub.6 /He = 10.sup.-3 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 34 
__________________________________________________________________________ 
Sample No. 
3401 
3402 
3403 
3404 
3405 
3406 
3407 
3408 
3409 
3410 
3411 
__________________________________________________________________________ 
GeH.sub.4 /SiH.sub.4 
5/100 
1/10 
2/10 
4/10 
5/10 
7/10 
8/10 
1/1 
10/1 
100/1 
GeH.sub.4 
Flow rate ratio 100% 
Ge content 
4.3 8.4 
15.4 
26.7 
32.3 
38.9 
42 47.6 
70.4 
98.1 
100% 
(atomic %) 
Evaluation 
.circle. 
.circle. 
.circle. 
.circle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
__________________________________________________________________________ 
.circleincircle. : Excellent 
.circle. : Good 
TABLE 35 
______________________________________ 
Sample No. 
3501 3502 3503 3504 3505 3506 3507 3508 
______________________________________ 
Layer 30.ANG. 
500.ANG. 
0.1.mu. 
0.3.mu. 
0.8.mu. 
3.mu. 
4.mu. 
5.mu. 
thickness 
Evaluation 
.DELTA. 
.circle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circle. 
.circle. 
.DELTA. 
______________________________________ 
.circleincircle. : Excellent 
.circle. : Good 
.DELTA.: Practically satisfactory 
TABLE 36 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 10/1 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
B.sub.2 H.sub.6 /He = 10.sup.-3 
5 .times. 10.sup.-3 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 5/10 
0.18 5 2 250 
layer 
GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
B.sub.2 H.sub.6 /He = 10.sup.-3 
5 .times. 10.sup.-3 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
PH.sub.3 /SiH.sub.4 = 9 .times. 10.sup.-5 
0.18 15 20 250 
layer 
PH.sub.3 /He = 10.sup.-1 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 37 
__________________________________________________________________________ 
Layer Sub- 
Dis- forma- 
Layer 
strate 
Layer charging 
tion thick- 
temper- 
consti- 
Gases Flow rate power 
speed 
ness 
ature 
tution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 10/1 
0.18 5 0.1 450 
layer 
GeH.sub.4 /He = 0.05 
PH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 
PH.sub.3 /He = 10.sup.-3 
8 .times. 10.sup.-4 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 5/10 
0.18 5 15 250 
layer 
GeH.sub.4 /He = 0.05 
PH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 
PH.sub.3 /He = 10.sup.-3 
8 .times. 10.sup. -4 
Third 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
B.sub.2 H.sub.6 /SiH.sub.4 = 1 .times. 10.sup.-4 
0.18 15 5 250 
layer 
B.sub.2 H.sub.6 /He = 10.sup.-3 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 3/7 
0.18 10 0.5 250 
layer 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 38 
__________________________________________________________________________ 
Layer 
Discharging 
formation 
Layer 
Subtrate 
Layer Gases Flow rate power speed thickness 
temperature 
constitution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First layer 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 10/1 
0.18 5 0.3 450 
GeH.sub.4 /He = 0.05 
PH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 
PH.sub.3 /He = 10.sup.-3 
9 .times. 10.sup.-4 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 3/10 
0.18 5 1 250 
layer GeH.sub.4 /He = 0.05 
PH.sub.3 /(GeH.sub.4 + SiH.sub.4) = 
PH.sub.3 /He = 10.sup.-3 
9 .times. 10.sup. -4 
Third layer 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 
B.sub.2 H.sub.6 /SiH.sub.4 = 9 
.times. 10.sup.-4 
0.18 15 15 250 
B.sub.2 H.sub.6 /He = 10.sup.-3 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 39 
__________________________________________________________________________ 
Layer 
Discharging 
formation 
Layer 
Substrate 
Layer Gases Flow rate power speed 
thickness 
temperature 
constitution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 10/1 
0.18 7 1 450 
layer GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
9 .times. 10.sup.-4 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 1/10 
0.18 5 15 250 
layer GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
9 .times. 10.sup.-4 
Third SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 5 250 
layer B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /SiH.sub.4 = 9 .times. 
10.sup.-4 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 40 
__________________________________________________________________________ 
Layer 
Discharging 
formation 
Layer 
Substrate 
Layer Gases Flow rate power speed 
thickness 
temperature 
constitution 
employed (SCCM) Flow rate ratio 
(W/cm.sup.2) 
(.ANG./sec) 
(.mu.) 
(.degree.C.) 
__________________________________________________________________________ 
First SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 100/1 
0.18 7 0.1 450 
layer GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
2 .times. 10.sup.-4 
Second 
SiH.sub.4 /He = 0.05 
SiH.sub.4 + GeH.sub.4 = 50 
GeH.sub.4 /SiH.sub.4 = 3/10 
0.18 5 2 250 
layer GeH.sub.4 /He = 0.05 
B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /(GeH.sub.4 + SiH.sub.4) = 
2 .times. 10.sup.-4 
Third SiH.sub.4 /He = 0.5 
SiH.sub.4 = 200 0.18 15 20 250 
layer B.sub.2 H.sub.6 /He = 10.sup.-3 
B.sub.2 H.sub.6 /SiH.sub.4 = 2 .times. 
10.sup.-4 
Fourth 
SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 /C.sub.2 H.sub.4 = 1/9 
0.18 10 0.5 250 
layer C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 41 
__________________________________________________________________________ 
Discharging 
Layer 
gases Flow rate Flow rate ratio or 
power thickness 
Condition 
employed 
(SCCM) area ratio 
(W/cm.sup.2) 
(.mu.) 
__________________________________________________________________________ 
42-1 Ar 200 Si wafer:graphite = 
0.3 0.5 
1.5:8.5 
42-2 Ar 200 Si wafer:graphite = 
0.3 0.3 
0.5:9.5 
42-3 Ar 200 Si wafer:graphite = 
0.3 1.0 
6:4 
42-4 SiH.sub.4 /He = 1 
SiH.sub.4 = 15 
SiH.sub.4 :C.sub.2 H.sub.4 = 0.4:9.6 
0.18 0.3 
C.sub.2 H.sub.4 
42-5 SiH.sub.4 /He = 0.5 
SiH.sub.4 = 100 
SiH.sub.4 :C.sub.2 H.sub.4 = 5:5 
0.18 1.5 
C.sub.2 H.sub.4 
42-6 SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 150 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
0.18 0.5 
SiF.sub.4 /He = 0.5 
1.5:1.5:7 
C.sub.2 H.sub.4 
42-7 SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 15 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
0.18 0.3 
SiF.sub.4 /He = 0.5 
0.3:0.1:9.6 
C.sub.2 H.sub.4 
42-8 SiH.sub.4 /He = 0.5 
SiH.sub.4 + SiF.sub.4 = 150 
SiH.sub.4 :SiF.sub.4 :C.sub.2 H.sub.4 
0.18 1.5 
SiF.sub.4 /He = 0.5 
3:3:4 
C.sub.2 H.sub.4 
__________________________________________________________________________ 
TABLE 42 
__________________________________________________________________________ 
Conditions for 
preparation of 
the fourth 
layer region 
(M) Sample No./Evaluation 
__________________________________________________________________________ 
42-1 42-201 
42-301 
42-401 
42-501 
42-601 
42-701 
42-801 
42-901 
42-1001 
o o o o o o o o o o o o o o o o o o 
42-2 42-202 
42-302 
42-402 
42-502 
42-602 
42-702 
42-802 
42-902 
42-1002 
o o o o o o o o o o o o o o o o o o 
42-3 42-203 
42-303 
42-403 
42-503 
42-603 
42-703 
42-803 
42-903 
42-1003 
o o o o o o o o o o o o o o o o o o 
42-4 42-204 
42-304 
42-404 
42-504 
42-604 
42-704 
42-804 
42-904 
42-1004 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
42-5 42-205 
42-305 
42-405 
42-505 
42-605 
42-705 
42-805 
42-905 
42-1005 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
42-6 42-206 
42-306 
42-406 
42-506 
42-606 
42-706 
42-806 
42-906 
42-1006 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
.circleincircle. 
42-7 42-207 
42-307 
42-407 
42-507 
42-607 
42-707 
42-807 
42-907 
42-1007 
o o o o o o o o o o o o o o o o o o 
42-8 42-208 
42-308 
42-408 
42-508 
42-608 
42-708 
42-808 
42-908 
42-1008 
o o o o o o o o o o o o o o o o o o 
__________________________________________________________________________ 
Sample No. 
Evaluation of 
Evaluation of 
overall image 
durability 
quality 
__________________________________________________________________________ 
Evaluation standards: 
.circleincircle. Excellent 
o Good 
TABLE 43 
__________________________________________________________________________ 
Sample No. 4301 
4302 
4303 
4304 
4305 
4306 
4307 
__________________________________________________________________________ 
Si:C target (area ratio) 
9:1 6.5:3.5 
4:6 2:8 1:9 
0.5:9.5 
0.2:9.8 
Si:C (content ratio) 
9.7:0.3 
8.8:1.2 
7.3:2.7 
4.8:5.2 
3:7 
2:8 0.8:9.2 
Image quality evaluation 
.DELTA. 
o .circleincircle. 
.circleincircle. 
o .DELTA. 
x 
__________________________________________________________________________ 
.circleincircle.: Very good 
o: Good 
.DELTA.: Practically satisfactory 
x: Image defect formed 
TABLE 44 
__________________________________________________________________________ 
Sample No. 
4401 
4402 
4403 
4404 
4405 
4406 
4407 4408 
__________________________________________________________________________ 
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 (content ratio) 
9:1 
7:3 
5.5:4.5 
4:6 
3:7 
2:8 1.2:8.8 
0.8:9.2 
Image quality 
.DELTA. 
o .circleincircle. 
.circleincircle. 
.circleincircle. 
o .DELTA. 
x 
evaluation 
__________________________________________________________________________ 
.circleincircle.: Very good 
o: Good 
.DELTA.: Practically satisfactory 
x: Image defect formed 
TABLE 45 
__________________________________________________________________________ 
Sample No. 
4501 
4502 4503 
4504 
4505 4506 4507 4508 
__________________________________________________________________________ 
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 
(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. 
o .circleincircle. 
.circleincircle. 
.circleincircle. 
o .DELTA. 
x 
evaluation 
__________________________________________________________________________ 
.circleincircle.: Very good 
o: Good 
.DELTA.: Practically satisfactory 
x: Image defect formed 
TABLE 46 
______________________________________ 
Thickness (.mu.) 
of the fourth 
Sample layer region 
No. (M) Results 
______________________________________ 
4601 0.001 Image defect liable to be 
formed 
4602 0.02 No image defect formed 
after repetition for 
20,000 times 
4603 0.05 Stable for 50,000 times 
repetition 
4604 1 Stable for 200,000 times 
repetition 
______________________________________