JPH0931659A - Deposited film forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deposited film forming device capable of decreasing the unequal film thickness in an axial direction without increasing image defects and executing film formation of relatively large areas for a short production time at a high treating speed and low cost with good reproducibility of characteristics without unequal densities, unequal sensitivity and rough feel of the images in film formation by high-frequency electric power of 20 to 450MHz. SOLUTION: This device has a vacuum reaction vessel having a discharge means and gaseous raw material supplying means, is installed with cylindrical substrates or the cylindrical substrates 102 mounted with auxiliary substrates rotatable by a revolving shaft 105 within the discharge space of this vessel and forms the deposited films on the substrates by impressing the high-frequency electric power of 20 to 450MHz thereon. The one electrode of this device is commonly used as the revolving shaft 105 and the other end is grounded via a capacitor without contact with the end constituted by arranging a dielectric substance and grounding electrode 106 successively from the cylindrical substrate or the auxiliary substrate side.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a functional deposited film of crystalline or non-single crystalline which is useful for a photoconductor device for electrophotography as a semiconductor device, a line sensor for image input, an imaging device, a photovoltaic device and the like. Plasma CVD apparatus capable of favorably forming a film, a sputtering apparatus capable of suitably forming an insulating film as an optical element, a metal wiring, etc., or a deposition film forming apparatus by plasma treatment such as an etching apparatus for a semiconductor device In more detail, regarding a plasma processing apparatus for processing a substrate using plasma as an excitation source, particularly, a plasma processing apparatus having a frequency of 20 MHz or more, 45
The present invention relates to a plasma processing apparatus that can suitably use a high frequency of 0 MHz or less.

2. Description of the Related Art There are various methods for a plasma processing apparatus used for a semiconductor or the like according to each application. For example, in film formation, an oxide film and a nitride film are formed using a plasma CVD device or a plasma CVD method, an amorphous silicon semiconductor film, a metal wiring film using a sputtering device or a sputtering method, an etching device and a method are used. A variety of devices and methods are used that take advantage of their features such as microfabrication technology. Further, in recent years, there has been a strong demand for improvement in film quality and processing capacity, and various devices have been studied. Particularly, a plasma process using high-frequency power has a high discharge stability and can be used for forming an insulating material such as an oxide film and a nitride film. Conventionally, 13.56 MHz is generally used as the oscillation frequency of the discharge high frequency power source used in plasma processes such as plasma CVD.
FIG. 6 shows an example of a plasma CVD apparatus that is generally used for forming the conventional deposited film. The plasma CVD apparatus shown in FIG. 6 is a film forming apparatus suitable for forming an amorphous silicon film (hereinafter referred to as “a-Si film”) on a cylindrical electrophotographic photosensitive member substrate. Hereinafter, a method for forming an a-Si film using this apparatus will be described. A cathode electrode 601 and a cylindrical substrate 602 as a counter electrode are arranged in a deposition chamber 600 capable of reducing the pressure. An auxiliary substrate 603 is attached to the cylindrical substrate 602 and forms a part of the electrode. The cylindrical substrate 602 is heated from the inside by a substrate heater 604 inside. The high frequency power source 610 is connected to the cathode electrode 60 via the matching circuit 609.
One is connected to one. Reference numeral 611 is an exhaust port, and 607 is a source gas introduction port. A cylindrical substrate is installed in the deposition chamber 600, and the deposition chamber 600 is temporarily exhausted through an exhaust port 611 by an exhaust device (not shown). After that, a raw material gas introduction port (not shown) is opened, an inert gas is introduced, and the flow rate and the exhaust speed are adjusted so as to have a predetermined pressure. While the cylindrical substrate is rotated in the circumferential direction by the drive motor 608, the heater 604 for heating the substrate is energized, and the cylindrical substrate is heated to 100 to 400 ° C.
Heat to the desired temperature of. After that, the raw material gas inlet 60
A raw material gas for film formation, for example, a raw material gas such as silane gas, disilane gas, methane gas, and ethane gas is supplied via
In addition, after introducing a doping gas such as diborane gas or phosphine gas with a mixing panel (not shown),
The evacuation speed is adjusted so as to maintain the pressure of several tens of mTorr to several Torr. 13.56 from high frequency power supply 610
A high frequency power of MHz is supplied to one portion of the cathode electrode 601 through the matching circuit 609 to generate plasma discharge between the cathode electrode 601 and the cylindrical substrate 602 to decompose the raw material gas. Deposit a Si film. During this period, the cylindrical substrate is heated by the substrate heater 604 to 10
The temperature is maintained at about 0 to 400 ° C., and the cylindrical substrate also rotates in the circumferential direction. When depositing an a-Si film on a cylindrical substrate for a copying machine according to the above procedure, even in the coaxial film forming apparatus shown in FIG. It is desirable to form the film while rotating the film. Further, in a device as shown in FIG. 7 in which a plurality of cylindrical substrates are installed concentrically and an electrode is installed inside the cylindrical substrates to generate a discharge, a film is deposited on the entire circumference of the substrate. Rotation is indispensable for the purpose. In the figure,
A deposition chamber 700 has a vacuum airtight structure.
Then, it is connected to an exhaust device (not shown) via an exhaust port 711. 701 is a cathode electrode, and a matching unit 709
It is connected to the high frequency power source 710 via. Reference numeral 707 is a source gas introduction port, which is connected to a gas supply source (not shown). A cylindrical substrate 702 is installed in the deposition chamber 700. The cylindrical base 702 has an auxiliary base 70.
3 is attached and forms part of the electrode. The substrate heating heater 704 is a rotary shaft 70 arranged on a concentric circle.
5 is installed. The rotating shaft 705 can be rotated by a base driving motor 708. Hereinafter, the film forming method is the same as in the case of using FIG. at the same time,
Generally, in a plasma CVD apparatus, it is necessary to maintain the temperature of the substrate during film formation at 100 to 400 ° C. Therefore, a heater for heating the substrate is essential. The heater has a large capacity of 0.5 to 5 kW because it is necessary to heat the substrate in a vacuum in which heat is hard to be transmitted, and it is difficult to supply power to the heater so that the heater is built in the rotary shaft. Therefore, the heater for heating the substrate is generally fixed in the deposition chamber in order to simplify the structure of the apparatus, reduce costs, and facilitate maintenance. For this reason, the rotating shaft is installed so as to pass through the inside of the heater for heating the substrate, and the rotating shaft supports the upper portion of the cylindrical substrate to enable heating and rotation of the cylindrical substrate. The deposition rate for obtaining an a-Si film satisfying the performance of the electrophotographic photoreceptor by this film formation method is, for example, about 0.5 to 6 μm per hour, and the deposition rate is further increased. In some cases, the characteristics as a photoconductor cannot be obtained. Further, generally, when an a-Si film is used as an electrophotographic photoreceptor, a film thickness of at least 20 to 30 μm is required to obtain charging ability, and it takes a long time to manufacture the electrophotographic photoreceptor. I needed it.
For this reason, there has been a strong demand for a technique for shortening the manufacturing time without deteriorating the characteristics as a photoreceptor. By the way, in recent years, there is a report of a plasma CVD method using a parallel plate type plasma CVD apparatus and a high frequency power source of 20 MHz or more (Pla.
sma Chemistry and Plasma
Processing, vol. 7, No. 3, (19
87) p267-273), the discharge frequency is set to 13.
It has been shown that a higher frequency than 56 MHz can improve the deposition rate without deteriorating the performance of the deposited film, and is attracting attention. Further, reports of increasing the discharge frequency have been made by sputtering and the like, and its superiority has been widely studied in recent years. Therefore, in order to improve the deposition rate, the discharge frequency was changed to a high frequency power having a frequency higher than the conventional 13.56 MHz, and the film forming procedure was performed in the same manner as the conventional method. I confirmed that I can do it.

However, it has been found that the following problems may newly occur, which are not a problem at the discharge frequency of 13.56 MHz in the above-mentioned conventional example. In the case where the substrate heating heater is fixed in the deposition chamber and the rotation axis passes through the deposition chamber, the cylindrical substrate comes into contact with the rotation axis and is connected to the ground from one location. 20MHz-450MHz with this configuration
When the film formation is performed using the electric power of the high frequency, 13.
The bad influence that the film thickness distribution occurs which is not a problem at a low frequency such as 56 MHz has come to occur. In other words, this is a phenomenon in which the film thickness on the grounded side becomes thicker and the film thickness on the opposite side becomes thinner. This causes a change in the film quality of the deposited film in the longitudinal direction, and in the electrophotographic photosensitive member, adverse effects such as density unevenness, sensitivity unevenness, and image roughness are likely to occur. Also, if the side opposite to the side grounded by the rotating shaft is forcibly grounded by rubbing something such as a ground electrode, this time, for example, due to dust generated by rubbing between metals, an electron In the case of a photographic photosensitive member, the image defect is extremely deteriorated and cannot be put to practical use. Furthermore, since the plasma state is different and unstable on the side opposite to the side where the ground is taken, there is a problem in reproducibility of characteristics. As described above, it is difficult to take the ground of the cylindrical substrate from above and below in the film formation by the high frequency power having a high frequency of 20 MHz or more. Therefore, the film thickness unevenness and the film quality unevenness occur in the axial direction of the substrate. However, for example, when it is applied to an electrophotographic photoreceptor, image unevenness such as density unevenness, sensitivity unevenness, and roughness may occur, and image defects may worsen, and there is a problem in reproducibility of characteristics. . The above-mentioned problems are caused even when forming a functional deposited film of a crystalline or non-single crystalline useful for an image input line sensor, an image pickup device, a photovoltaic device, etc. by smoothing out only the electrophotographic photoreceptor. It becomes a big problem. Also, in other plasma processes such as dry etching and sputtering, the same problem occurs when the discharge frequency is raised, and if it is left as it is, it becomes a serious problem in practical use. Therefore, the present invention solves the above-mentioned problems and enables film thickness unevenness in the axial direction to be reduced without increasing image defects in film formation by high frequency power, in particular, high frequency power of 20 MHz to 450 MHz. Provided is a deposition film forming apparatus that has no unevenness in sensitivity and image roughness, good reproducibility of characteristics, and can form a relatively large area film at a high processing speed in a short manufacturing time and at low cost. The purpose is to do.

In order to achieve the above-mentioned object, the present invention uses one of the end portions of the cylindrical substrate rotatably arranged in the reaction container in the generatrix direction by the rotation axis of the substrate. The above-mentioned film thickness is obtained by grounding, and the other end is grounded through a non-contact capacitor with the end formed by sequentially arranging a dielectric and a ground electrode from the side of the cylindrical substrate or the auxiliary substrate. This is to prevent the harmful effects of the occurrence of distribution. That is, the present invention comprises a vacuum-tight reaction container having an exhaust means and a raw material gas supply means, and a cylindrical substrate or an auxiliary substrate which also serves as one electrode rotatable by a rotating shaft in the discharge space of the reaction container. In a deposited film forming apparatus, in which a mounted cylindrical substrate is installed, and a high frequency power of 20 MHz to 450 MHz is applied between the one electrode and a cathode electrode provided separately to form a deposited film on the cylindrical substrate. , One end of the cylindrical base in the generatrix direction is grounded by contact with the rotating shaft, and the other end is provided with a dielectric and a ground electrode in order from the side of the cylindrical base or the auxiliary base. It is characterized in that it is grounded via a capacitor that is not in contact with the constructed end portion. The present invention has the configuration of 20 MHz to 450 MHz.
Good results can be achieved even at frequencies higher than the conventional 13.56 MHz of MHz. In the present invention, the capacitor may be disposed at the entire outer circumference, a part of the outer circumference, the entire inner circumference, or a part of the inner circumference of the cylindrical base body or the auxiliary base body. When the cylindrical substrate is arranged vertically in the discharge space of the reaction vessel, the earth is held and grounded by the rotating shaft at the upper part of the cylindrical substrate in the generatrix direction, and the lower part by the capacitor. This can be done by grounding, or by holding the lower part in the generatrix direction of the cylindrical substrate by the rotating shaft and grounding it, and the upper part by the capacitor. Further, in the present invention, a plurality of the cylindrical substrates may be concentrically arranged in the discharge space of the reaction vessel, and in that case, the cathode electrode is installed inside the space surrounded by the cylindrical substrates. To do. In the present invention, the dielectric is at least one of alumina ceramics, Teflon, quartz glass, and borosilicate glass, or at least one elemental oxide of elemental oxides of aluminum oxide, magnesium oxide, and silicon oxide. Can be used as a main component. In the present invention, the capacitance C (Farad) of the capacitor is 0.1 (4π ² f ² L) ⁻ when the frequency of the high frequency power is f (Hertz) and the inductance of the rotating shaft is L (Henry). It is preferable to satisfy ¹ ≦ C ≦ 10 (4π ² f ² L) ⁻¹ . Furthermore,
It is more preferable to satisfy 0.5 (4π ² f ² L) ⁻¹ ≦ C ≦ 5 (4π ² f ² L) ⁻¹ .

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, as described above, one end of the cylindrical substrate rotatably arranged in the reaction vessel in the generatrix direction is grounded by the rotating shaft of the substrate, and The other end is grounded via a capacitor that is not in contact with the other end to prevent the above-mentioned harmful effect of the film thickness distribution. This will be explained further. As described above, the conventional method for grounding a long substrate such as a cylindrical substrate for a copying machine from a single place as in the conventional case is described in 13.
There was no problem when the film was formed at a low frequency such as 56 MHz. However, 20MHz-450MH
When a film is formed by using a high frequency power of z, the effect of the impedance of the substrate itself cannot be ignored. For this reason, there arises an adverse effect that the plasma state is different between the grounded side and the grounded side in the longitudinal direction of the substrate and the film thickness distribution is generated. On the other hand, the impedance to the ground is low on the side where the ground wire is taken, so the plasma density is high, the deposition rate is high, and the film thickness is thick, but on the other side, some self-bias occurs due to the impedance of the cylindrical substrate itself. Therefore, the plasma density is reduced and the film thickness is also reduced. Further, the quality of the deposited film in the longitudinal direction also naturally changes because the plasma density and the deposition rate change, which causes density unevenness, image roughness, and sensitivity unevenness in the electrophotographic photosensitive member.
Further, there is a problem in reproducibility of characteristics. As a most fundamental solution to this problem, the present inventor prepared for the generation of dust and rubbed the cylindrical substrate on the side opposite to the side supported by the rotary shaft with a grounded brush electrode to ground it. An experiment was conducted in which the ground state of the cylindrical substrate was dropped to make it appear symmetrical. However, surprisingly, in this experiment, on the contrary, the side grounded by the rotating shaft was thin, and the ground electrode side was thick. The reason for this is that the side that is grounded by the rotating shaft is certainly grounded, but when viewed from a high frequency, it is grounded via a long path called the rotating shaft, so the impedance of this path is the brush It is considered that since the impedance is much higher than the impedance on the side grounded via the electrode, the plasma state is different and the film thickness distribution occurs. Therefore, the method of rubbing the side opposite to the side supported by the rotating shaft with the grounded brush-like electrode is not effective in terms of not only generating dust but also reducing the film thickness distribution and improving the reproducibility of characteristics. It has been found. Based on the above results, in order to eliminate dust generation, to eliminate axial unevenness of the cylindrical substrate, and to improve the reproducibility of the characteristics, the cylindrical substrate should be in non-contact with a certain level of high frequency resistance. It has been concluded that it is necessary to bring it down to earth. Then, a capacitor was considered as a structure having such a function. At that time, the first conceivable consideration is, for example, in the case of a cylindrical substrate whose upper portion is supported by a rotating shaft, an earth electrode grounded to the deposition chamber near the lower side of the cylindrical substrate,
It may be installed so as not to hinder the rotation of the substrate. That is, in this way, the cylindrical base and the ground electrode grounded form a kind of capacitor. In a conventional plasma CVD apparatus using a low frequency, the capacitor thus formed has a too small capacity to allow current to flow, but when a high frequency such as 20 to 450 MHz is used as in the present invention, it is Even low-capacity capacitors can pass sufficient current and can be grounded. After that, as a result of further diligent examination,
As a means of improving the stability of the reproducibility of characteristics by improving the change in the capacity of the capacitor formed between the earth electrode and the cylindrical substrate due to the flow of plasma between the earth electrode and the cylindrical substrate, It was considered to install a dielectric between the end of the cylindrical substrate on the side opposite to the grounded side and the ground electrode. By doing so, in a capacitor of the same capacity, the space between the end of the cylindrical substrate on the side opposite to the side grounded by the rotating shaft and the ground electrode becomes smaller than in the case where there is no dielectric, so that the flow of plasma does not occur. An experiment was conducted with the belief that the reproducibility of the characteristics would be reduced and the characteristics would be stable. as a result,
It was found that a better deposited film was obtained and the reproducibility of the characteristics was also better than when using the conventional deposited film forming apparatus. Then, it was found that the deposition rate was improved as compared with the case where the film was formed by the conventional deposited film forming apparatus using the high frequency power of 20 to 450 MHz. The reason for this is not clear, but it is considered that the impedance of the entire cylindrical substrate is lowered by taking the ground from the upper and lower portions, and the high frequency power can be applied more efficiently. As described above, one end of the cylindrical base body in the generatrix direction is grounded by the rotating shaft that rotates the cylindrical base body, and the other end is installed in order from the cylindrical base body without being in contact with the cylindrical base body. The effect of the present invention can be obtained for the first time by forming a capacitor between the dielectric and the ground electrode to perform non-contact grounding. In order to form the C coupling directly with the cylindrical substrate, the dielectric and the ground electrode may be provided in order from the cylindrical substrate without being in contact with the outside or inside of the cylindrical substrate. When the auxiliary substrate is attached to the upper and lower sides of the cylindrical substrate to form a film, the dielectric body and the ground electrode are provided in order from the cylindrical substrate without contacting the outside or the inside of the auxiliary substrate. Good. The dielectric and the ground electrode, which are sequentially installed from the cylindrical substrate, may be provided over the entire circumference of the cylindrical substrate or the auxiliary substrate in the circumferential direction, or may be provided only in a part of the circumferential direction. In a deposited film forming apparatus for forming a film by a high frequency power of a certain frequency f (Hz), the inductance of the rotating shaft is L (H).
If so, the capacity C (F) of the C coupling of the present invention is obtained by the following equation. C = (4π ² f ² L) ^{−1 It} is difficult to calculate the inductance of the rotating shaft when the shape is complicated, but the effect of the present invention is sufficiently obtained by using a value roughly approximated as a cylindrical rod. You don't have to pay much attention because you can get it. Further, it is of course possible to actually obtain the value by using an LCR meter or the like. Also, it is not necessary to strictly realize the value of C obtained from the calculation,
The effect of the present invention can be improved to a practically satisfactory level by designing it so as to fall within the range of 10 times to 10 times. In order to specifically design the C coupling from the value of C obtained from the above equation, a dielectric and an earth electrode installed so as to satisfy C = ε1ε2S / {ε1d2 + ε2 (d1 + d3)} may be attached. Here, ε1 is the dielectric constant between the cylindrical substrate and the dielectric and between the dielectric and the ground electrode, ε2 is the dielectric constant of the dielectric, d1 is the distance between the cylindrical substrate and the dielectric, and d2 is the width of the dielectric. d3 is the distance between the dielectric and the ground electrode, and S is the overlapping area of the dielectric, the ground electrode and the cylindrical substrate. Strictly speaking, the value of ε1 varies depending on the type and pressure of the source gas introduced into the deposition chamber, but the effect of the present invention can be sufficiently obtained even if the dielectric constant in vacuum is roughly used. In addition, in each of the deposited film forming apparatuses of the present invention, the cylindrical substrate can be rotated, but the effect of the present invention is not necessarily obtained without rotating the cylindrical substrate, and it is not a stationary state. The effect of the present invention can be obtained even when the film formation is performed by. Further, the effect of the present case can be obtained even if it is not rotatable as long as the mechanism for holding the cylindrical base body is a mechanism for holding the upper part or the lower part of the cylindrical base body similar to the present case. Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows an example of an apparatus for carrying out the method of the present invention, which is suitable for forming a deposited film on a cylindrical substrate such as an electrophotographic photoreceptor. In FIG. 1, 100 is a deposition chamber for forming a deposited film, which is connected to an exhaust device (not shown) through an exhaust port 111. Reference numeral 107 is a raw material gas inlet for introducing the raw material gas into the deposition chamber, and introduces the raw material gas into the deposition chamber from a gas supply system (not shown). Reference numeral 102 denotes a cylindrical base body, which is set on the auxiliary base body 103,
It is attached to 5. The rotation shaft 105 is rotatably attached to the deposition chamber. The cylindrical base body 102 and the auxiliary base body 103 are connected at their upper parts to the ground by a rotary shaft 105. Reference numeral 104 denotes a substrate heating heater for heating the cylindrical substrate to a predetermined temperature, which is fixed in the deposition chamber. Further, the cylindrical substrate 102 is rotated by the drive motor 108 via the rotating shaft 105, and the film thickness in the circumferential direction is made uniform. Reference numeral 110 is a high frequency power source that generates a high frequency of 20 MHz to 450 MHz, and the high frequency output is 10
It is wired so as to be applied to the cathode electrode 101 via the matching circuit of No. 9. As shown in the figure, the cathode electrode 101 may of course also serve as the inner wall of the deposition chamber 100. Reference numerals 106 and 112 respectively denote the ground electrode and the dielectric according to the present invention, and the ground electrode 106 and the dielectric 11 are provided in close proximity to each other so as not to contact the auxiliary substrate 103.
2. The auxiliary substrate 103 is installed in this order, and the capacitors are formed in the regions where they overlap each other. The capacitance of this capacitor is the height of the ground electrode 106 and the dielectric 112, the dielectric 112, the ground electrode 106 and the auxiliary substrate 1.
It can be arbitrarily set by changing the respective distances of 03. In this device configuration, the upper part of the cylindrical substrate 102 is installed in the deposition chamber via the rotating shaft 105, but at a high frequency such as 20 MHz to 450 MHz, the inductance of the rotating shaft cannot be ignored, and therefore, there is some resistance before it falls to the ground. have. The ground electrode 1 should have the same resistance as the resistance due to this inductance.
The capacitance of the capacitor formed between 06 and the auxiliary substrate 103 is adjusted. Specifically, the configuration may be set so that the value of C calculated by C = (4π ² f ² L) ⁻¹ is obtained. FIG. 2 schematically shows another example of the apparatus for carrying out the method of the present invention, which is suitable for forming a deposited film on a cylindrical substrate such as an electrophotographic photoreceptor.
In this apparatus, the cylindrical substrate 202 and the auxiliary substrate 203 are supported so as to be suspended from the upper part of the deposition chamber. The ground electrode 206 and the dielectric 212 are installed inside the auxiliary substrate in this device. Other components are the same as those in FIG. FIG. 3 schematically shows another example of the apparatus for carrying out the method of the present invention. In this apparatus, the substrate heater 304 is attached to the upper part of the deposition chamber, and the cylindrical substrate 302 is attached to the lower part of the deposition chamber.
It is installed so that it can be put on 05. In this example, since the auxiliary substrate is not used and the ground electrode 306 is provided outside the cylindrical substrate 302, the film thickness distribution becomes uneven.
It is installed inside the cylindrical substrate 302. Other components are the same as those in FIG. FIG. 4 shows the dielectric 41 of the present invention.
2, another example of the shapes of the ground electrode 406 and the auxiliary base 403 is schematically shown. A capacitor is formed by protruding the brim to the dielectric 412, the ground electrode 406 and the auxiliary base 403 in this way. But of course it's good. FIG. 5 schematically shows still another example of the present invention. The capacitor portion for taking the ground at the lower part of the cylindrical substrate 502 is the same as that in FIG. 1, but in this example, six cylindrical substrates are arranged in a concentric pattern, and the cathode electrode 501 is installed in the center of the cylindrical substrate. A discharge is generated in the space surrounded by 502. Ground electrode 106,
As a material used for 206, 306, 406, and 506, any material having high heat resistance and high conductivity can be used. Further, the material used for the purpose of minimizing the inductance of the ground electrodes 106, 206, 306, 406, 506 itself is preferably one having a small magnetic permeability. In addition, since the high frequency conducts only the outermost surface of the conductor by the skin effect, it is preferable that the surface area is as large as possible. Generally, a flat plate shape is used. Concrete earth electrode 1
As materials for 06, 206, 306, 406, and 506, copper, aluminum, gold, silver, and platinum are preferable because they have high conductivity and low magnetic permeability. Lead, nickel, cobalt, iron, chromium, molybdenum, titanium and stainless steel are also suitable because they are resistant to heat. Alternatively, a composite material of two or more of these materials is also preferable. Dielectrics 112, 212,
Materials used for 312, 412, 512 are mainly composed of alumina ceramics, Teflon, quartz glass, borosilicate glass, or one or more elemental oxides among aluminum oxide, magnesium oxide and silicon oxide elemental oxides. There is no particular limitation as long as it is an insulating material that is resistant to heat, such as a material that does. High frequency power supply 110, 210, 31 used
0, 410, 510 have oscillation frequencies from 20 MHz to 4
Anything can be used if it is 50 MHz. or,
The output is 10 W to 5000 W or more, and any output can be suitably used as long as it can generate electric power suitable for the device. Furthermore, the effect of the present invention can be obtained regardless of the output fluctuation rate of the high frequency power supply. Matching devices 1009, 209, 309, 409, 50 used
9 can be suitably used in any configuration as long as it can match the high frequency power supply and the load. or,
As a method for obtaining matching, those that are automatically adjusted are suitable for avoiding complexity during manufacturing, but even those that are manually adjusted have no effect on the effect of the present invention.
It is also desirable because it is cheap. There is no problem with the position where the matching device is arranged as long as the matching device can be installed in a range where the matching can be obtained. However, it is better to arrange the matching device so that the inductance of the wiring between the matching device and the cathode is as small as possible. This is desirable because matching can be achieved under conditions. Cathode electrodes 101, 201, 301,
Materials of 401 and 501 are copper, aluminum,
Gold, silver, platinum, lead, nickel, cobalt, iron, chromium,
Molybdenum, titanium, stainless steel, etc. have good thermal conductivity,
It is preferable because it has good electric conductivity. 2 of these materials
A composite material of at least one kind is also preferably used. In addition, the shape is preferably a cylindrical shape for ease of processing, but an elliptical shape or a polygonal shape may be used if necessary. Cathode electrode 10
1, 201, 301, 401, 501 may be provided with a cooling means as needed. As a concrete cooling means,
Cooling with water, air, liquid nitrogen, Peltier element, etc. is used as necessary. The cylindrical substrate 102 of the present invention,
202, 302, 402, 502 and the auxiliary substrate 103,
The materials 203, 303, 403, and 503 may be made of any material according to the purpose of use. As the material, copper, aluminum, gold, silver, platinum, lead, nickel, cobalt, iron, chromium, molybdenum, titanium, and stainless steel are preferable because they have good electric conductivity. Further, two or more composite materials among these materials are also desirable for improving heat resistance. Further, it is desirable to use an insulating material such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, glass, ceramics, or paper coated with a conductive material because the cost can be reduced. An example of the method of forming a deposited film of the present invention in the apparatus shown in FIG. 1 is performed as follows. In addition, this procedure is shown in FIGS.
The same can be applied to the above device. First, for example, the cylindrical substrate 102 whose surface is mirror-finished by using a lathe is attached to the auxiliary substrate 103, and is attached to the rotating shaft 105 so as to include the substrate heating heater 104 in the deposition chamber 100. Next, the raw material gas introduction valve (not shown) is closed, and the deposition chamber is temporarily evacuated by the exhaust device (not shown) through the exhaust port 111, and then the raw material gas introduction valve (not shown) is opened to heat the inert gas for heating. As an example, argon is introduced into the deposition chamber through the raw material gas inlet 107, and the exhaust speed of the exhaust device and the flow rate of the heating gas are adjusted so that the deposition chamber has a desired pressure. After that, while the cylindrical substrate 102 is rotated by the driving motor 108, a temperature controller (not shown) is operated to heat the cylindrical substrate 102 by the substrate heating heater 104. When the cylindrical substrate 102 is heated to a desired temperature, a raw material gas introduction valve (not shown) is closed to stop the gas flow into the deposition chamber. To form a deposited film, a raw material gas introduction valve (not shown) is opened, and a predetermined raw material gas such as silane gas, disilane gas, methane gas, ethane gas, or a doping gas such as diborane gas or phosphine gas is supplied from the raw material gas inlet 107. After mixing with a mixing panel (not shown), the mixture is introduced into the deposition chamber 100, and the mixture is fed from several mTorr to several Torr
Adjust the pumping speed to maintain that pressure. After the pressure has stabilized, turn on the high frequency power supply 110 and set the frequency to 20M.
Power of Hz to 450 MHz is supplied to cause glow discharge. At this time, the matching circuit 109 is adjusted so as to minimize the reflected wave. The value obtained by subtracting the reflected power from the high frequency incident power is adjusted to a desired value, and when the desired film thickness is formed, the glow discharge is stopped and the source gas deposition chamber 1
00 is stopped, the inside of the deposition chamber is once raised to a high vacuum, and then the layer formation is completed. During this period, it is desirable to perform film formation while rotating the cylindrical substrate in order to equalize the film thickness in the circumferential direction. When stacking deposited films having various functions, the above operation is repeated. Specific examples for demonstrating the effects of the present invention will be described below, but the present invention is not limited to the specific examples.

The present invention will be described below with reference to examples, but the present invention is not limited thereto. Example 1 In the deposited film forming apparatus shown in FIG. 1, a high frequency power source 110 having an oscillation frequency of 105 MHz was installed, an a-Si film was formed on a cylindrical base member 102 made of aluminum, and a photoconductor for electrophotography was produced. did. When the rotation axis of the deposited film forming apparatus was approximated to a cylinder, the inductance L was calculated to be 0.15 μH. Then C = (4
When C was calculated by applying it to π ² f ² L) ⁻¹ , it was 15.3 pF in this example. Therefore, the size and interval were set by using alumina ceramics as the dielectric 112 and aluminum as the ground electrode 106 so that the capacitor composed of the auxiliary substrate 103, the dielectric 112, and the ground electrode 106 would have this value in vacuum. In this embodiment,
The ground electrode 106 and the dielectric 112 were cylindrical and were installed over the entire circumference of the auxiliary base 103 in the circumferential direction. As film forming conditions, the film forming was performed according to the manufacturing conditions shown in Table 1. (Comparative Example 1) In the conventional deposited film forming apparatus shown in FIG. 6, a high frequency power source 610 with an oscillation frequency of 105 MHz was installed, and an a-Si film was formed on an aluminum cylindrical substrate 602. Was produced. As film forming conditions, the film forming was performed according to the manufacturing conditions shown in Table 1 as in Example 1. (Comparative Example 2) The lower part of the auxiliary substrate 603 was forcibly grounded by rubbing it with a metal brush grounded in the conventional deposited film forming apparatus shown in FIG. In this comparative example, a high frequency power source 610 with an oscillation frequency of 105 MHz is installed,
An a-Si film was formed on the aluminum-made cylindrical substrate 602 to prepare an electrophotographic photoreceptor. As film forming conditions,
Similar to Example 1, the film formation was performed according to the manufacturing conditions shown in Table 1. The electrophotographic photoconductors produced in Example 1 and Comparative Examples 1 and 2 were evaluated by the following methods. Film thickness distribution and deposition rate evaluation The film thickness at 16 axial positions of each photoconductor was measured with an eddy current film thickness meter (made by Kett Scientific Research Institute), and the difference between the maximum film thickness and the minimum film thickness was averaged. The ratio of the film thickness distribution was defined by dividing by the film thickness of, and classified into the following ranks. ◎ Very good ○ Good △ No practical problems × Practical problems At the same time, the deposition rate was obtained by dividing the total film thickness by the film formation time, and evaluated. The evaluation standard of the deposition rate was based on the apparatus of Comparative Example 1 and ranked as follows. ◎ 20% or more faster than Comparative Example 1 10 to 20% faster than Comparative Example 1 Same as Comparative Example 1 × Slower than Comparative Example 1 Electrophotographic characteristics Electrophotographic apparatus (Canon NP) for each photoconductor
6060 was modified for experiments), and the electrophotographic characteristics such as initial charging ability and residual potential were evaluated as follows. Electrification unevenness ..... An electrophotographic photoreceptor was installed in the experimental device, and a high voltage of +6 kV was applied to the charger to perform corona charging.
The surface potential of the dark portion of the electrophotographic photosensitive member is measured at the developing position with a surface potential meter. Five points are measured in the axial direction of the electrophotographic photoreceptor, and the potential unevenness at this time is evaluated. Sensitivity unevenness: Charges the electrophotographic photosensitive member to a constant dark surface potential. And immediately using a filter 550n
A halogen lamp light excluding light in a wavelength range of m or less is irradiated, and the light amount is adjusted so that the surface potential of the bright portion of the electrophotographic photosensitive member becomes a predetermined value. At this time, the necessary light amount is converted from the lighting voltage of the halogen lamp light source. According to this procedure, 5-point sensitivity is measured in the axial direction of the electrophotographic photosensitive member, and the sensitivity unevenness at this time is evaluated. For each, ◎ Very good ○ Good △ Practical no problem × Practical problem rustling of the image ... Copy the halftone chart, observe the obtained halftone image in detail, compare with the limit sample, and evaluate. . ◎ No rustiness is observed at all, and it is very good. ○ Some rustiness is slightly observed, but it is good. Canon full black chart (part number: F
Y9-9073) was placed on the platen and copied, and white spots having a diameter of 0.2 mm or more were evaluated within the same area of the copy image obtained. The evaluation categories are as follows. ◎ Very good ○ Good △ There are white spots, but there is no practical problem at the conventional level. × Many white spots exist, and there are practical problems. The reproducibility of the characteristics was measured 10 times for the charging unevenness of the electrophotographic characteristics, and the reproducibility at that time was compared with the case of the electrophotographic photosensitive member prepared in Comparative Example 1. ◎ Very good compared to Comparative Example 1 ○ Comparison Better than Example 1 Δ Equivalent to Comparative Example 1 × Worse than Comparative Example 1 was used for evaluation. Table 2 summarizes the above results. The electrophotographic photosensitive member according to the deposited film forming apparatus of the present invention has no unevenness and has excellent reproducibility of characteristics and is very excellent, but the conventional deposited film forming apparatus does not improve the unevenness. Further, even if the lower part of the auxiliary substrate is grounded forcibly by a metal brush, the unevenness is not improved, and the white spot level is deteriorated, which makes it unusable for practical use. It should be noted that the deposition rate is improved in Example 1 as compared with Comparative Example 1. The reason for this is not clear, but it is considered that the impedance of the entire cylindrical substrate is lowered by taking the ground from the upper and lower portions, and the high frequency power can be applied more efficiently. From the above examples, it was found that the deposited film forming apparatus of the present invention can improve the reproducibility of unevenness and characteristics without aggravating image defects, and can also improve the deposition rate.

[Table 1]

[Table 2] [Embodiment 2] As a material of the dielectric body 112 in Embodiment 1, Teflon, quartz glass, Teflon borosilicate glass, aluminum oxide, magnesium oxide, silicon oxide,
Aluminum oxide and magnesium oxide in a molar ratio of 1: 1
Including aluminum oxide and silicon oxide in a molar ratio of 1:
1 containing, 1: 1 containing magnesium oxide and silicon oxide in a molar ratio, and 1: 1: 1 containing aluminum oxide, silicon oxide and magnesium oxide in a molar ratio, respectively, and the auxiliary substrate 103 and the dielectric in vacuum. Under the same conditions as in Example 1, except that the size and the interval were set so that the capacitor composed of the body 112 and the earth electrode 106 had a capacitance of 15.3 pF, a
A -Si film was formed to prepare a photoconductor for electrophotography. The electrophotographic photosensitive member produced in Example 2 was evaluated for film thickness unevenness, deposition rate, charging unevenness, charging unevenness, uneven sensitivity, white spots, white spots, and reproducibility of characteristics in the same procedure as in Example 1, and the results are shown in Example 1. Similarly good results have been obtained. based on the above results,
It was found that a good deposited film can be obtained by using the deposited film forming apparatus of the present invention even if the dielectric is changed. [Embodiment 3] In the deposited film forming apparatus shown in FIG. 5, a high frequency power source 510 with an oscillation frequency of 105 MHz is installed, an a-Si film is formed on an aluminum cylindrical substrate 501, and an electrophotographic photoreceptor is produced. did. When the rotation axis of the deposited film forming apparatus was approximated to a cylinder, the inductance L was calculated to be 0.15 μH. Then C = (4
When C was calculated by applying it to π ² f ² L) ⁻¹ , it was 15.3 pF in this example. Therefore, the size and interval were set by using alumina ceramic as the dielectric 512 and aluminum as the ground electrode 506 so that the capacitor constituted by the auxiliary substrate 503, the dielectric 512, and the ground electrode 506 would have this value in vacuum. In this embodiment,
The ground electrode 506 and the dielectric 512 were cylindrical and were installed over the entire circumference of the auxiliary base 503 in the circumferential direction. As film forming conditions, the film forming was performed according to the manufacturing conditions shown in Table 1. (Comparative Example 3) In the conventional deposited film forming apparatus shown in FIG. 7, a high frequency power source 710 having an oscillation frequency of 105 MHz was installed, an a-Si film was formed on an aluminum cylindrical substrate 702, and an electrophotographic photosensitive member was formed. Was produced. As film forming conditions, the film forming was performed according to the manufacturing conditions shown in Table 1. The electrophotographic photoconductors produced in Example 3 and Comparative Example 3 are the same as those in Example 1.
In the same procedure as above, the film thickness unevenness, deposition rate, charging unevenness, sensitivity unevenness, rough spots, white spots, and reproducibility of characteristics were evaluated. The results are shown in Table 3. In the deposited film forming apparatus of the present invention, the image defects are not deteriorated, the film thickness, the characteristic unevenness, the reproducibility of the characteristics are improved, and the deposition rate is also improved.

[Table 3] [Embodiment 4] In the deposited film forming apparatus shown in FIG. 2, a high frequency power source 210 having an oscillation frequency of 60 MHz is installed, and an a-Si film is formed on an aluminum cylindrical substrate 202.
An electrophotographic photoreceptor was produced. When the inductance L was calculated by calculation by approximating the rotation axis of this deposited film forming apparatus to a cylinder, it was 0.07 μH. Then C = (4π ²
When C was calculated by applying it to f ² L) ⁻¹ , it was 100 pF in this example. In this embodiment, the values of the capacitors of the present invention are 0.1C, C, 5C and 10C (C = 100p).
The effect of the present invention was investigated by changing to F). In this embodiment, alumina ceramics is used as the dielectric 112 and aluminum is used as the grounding electrode 106 so that the capacitor constituted by the auxiliary substrate 503, the dielectric 512, and the grounding electrode 506 has the above values in vacuum. The interval was set. In this embodiment, the ground electrode 506 and the dielectric 512 are cylindrical and are installed over the entire circumference of the auxiliary base 503 in the circumferential direction. As film forming conditions, the film forming was performed according to the manufacturing conditions shown in Table 1. (Comparative Example 4) The a-Si was formed on the aluminum-made cylindrical substrate 202 under the same conditions as in Example 4 except that the values of the capacitor of the present invention were changed to 0.05C and 15C (C = 100pF). A film was formed and an electrophotographic photoreceptor was produced. The electrophotographic photoreceptors prepared in Example 4 and Comparative Example 4 were evaluated for film thickness unevenness, deposition rate, charging unevenness, sensitivity unevenness, roughness, white spots, and characteristic reproducibility in the same procedure as in Example 1. The results are shown in Table 4. The effect of the present invention is obtained when the value of the capacitor of the present invention is 0.1C to 10C, but it becomes clear that the effect diminishes when the value deviates from 0.05C to 15C. Also, the deposition rate is improved when the capacitance of the capacitor is 0.1 C or more.

[Table 4] [Example 5] An a-Si film was formed on a cylindrical substrate 402 made of aluminum in the deposited film forming apparatus shown in Fig. 4 to prepare an electrophotographic photoreceptor. Inductance L is calculated by approximating the rotation axis of the present deposited film forming apparatus to a cylinder, and the value of the capacitor of the present invention is calculated to use alumina ceramics as the dielectric 412 and aluminum as the ground electrode 406, and the size and interval are respectively set. It was set. In this embodiment, the ground electrode 406 and the dielectric 412 are used.
Has a disk shape and is installed over the entire circumference of the auxiliary base 403 in the circumferential direction. In this embodiment, the frequency of the high frequency power source 410 is set to 2
The film formation was performed according to the manufacturing conditions shown in Table 5 as 0 MHz, 50 MHz, 300 MHz, and 450 MHz. (Comparative Example 5) In the deposited film forming apparatus shown in FIG.
A -Si film was formed to prepare a photoconductor for electrophotography. However, in this comparative example, the frequency of the high frequency power source 410 is set to 13.5.
It was set to 6 MHz and 500 MHz. However, frequency 13.5
At 6 MHz, the internal pressures of the charge transport layer, charge generation layer, and surface protection layer were 200 mTorr, 300 mTorr, and 3 mTorr, respectively.
It was set to 50 mTorr. The electrophotographic photosensitive members produced in Example 5 and Comparative Example 5 were evaluated for unevenness in film thickness, deposition rate, uneven charging, uneven sensitivity, rustiness, white spots, and reproducibility of characteristics in the same procedure as in Example 1. . Table 6 shows the results. When the frequency of the high frequency power source is 20 MHz to 450 MHz, the effect of the present invention is obtained, and the film formation time can be shortened, but at 13.56 MHz, the film formation time cannot be shortened, and when it becomes 500 MHz, the axial direction is further increased. It can be seen that another unevenness occurs and the effect of the present invention cannot be obtained. [Embodiment 6] The oscillation frequency of 105 MH in the deposited film forming apparatus shown in FIG.
A high frequency power source 510 of z was installed, and an a-Si film was formed on a cylindrical substrate 502 made of aluminum to prepare an electrophotographic photoreceptor. When the rotation axis of the present deposited film forming apparatus was approximated to a cylinder and the inductance L was calculated, a value of 0.
It was 2 μH. Then, when C was calculated by applying C = (4π ² f ² L) ⁻¹ , it was 11.5 pF in this example. Therefore, in a vacuum, the auxiliary substrate 503 and the dielectric 51
2. Alumina ceramic was used as the dielectric 112 and aluminum was used as the ground electrode 106 to set the size and interval so that the capacitor constituted by the ground electrode 506 had the above value. In this embodiment, the ground electrode 506 and the dielectric 512 are cylindrical, and the auxiliary base 5
It was installed so as to face only half of the circumference of No. 03. As film forming conditions, film forming was performed according to the manufacturing conditions shown in Table 5. The photoconductor prepared in Example 6 was evaluated for film thickness unevenness, deposition rate, charge unevenness, sensitivity unevenness, roughness, white spots, and reproducibility of characteristics in the same manner as in Example 1. Good results similar to those of Example 1 were obtained.
Further, the obtained photoreceptor is used as a copying machine NP-6650 manufactured by Canon.
When the image was placed on the plate, the halftone image had no unevenness and a uniform image was obtained. Further, when a character original was copied, a clear image with high black density was obtained. Also, when copying a photographic original, a clear image faithful to the original could be obtained. [Embodiment 7] In the deposited film forming apparatus shown in FIG. 3, a high frequency power source 310 having an oscillation frequency of 60 MHz was installed, and an a-Si film was formed on an aluminum cylindrical substrate 302.
An electrophotographic photoreceptor was produced. In this embodiment, aluminum is used as the ground electrode 306 and alumina ceramics is used as the dielectric 312, and a cylindrical substrate having a shape facing only 1/6 of the circumferential direction is installed. Ground electrode 306,
The size and spacing of the dielectrics 312 were set by approximating the rotation axis of the present deposited film forming apparatus to a cylinder and calculating the inductance L by calculation to find the value of the capacitor of the present invention. As film forming conditions, film forming was performed according to the manufacturing conditions shown in Table 5. The photoreceptor prepared in Example 7 was evaluated for unevenness in film thickness, deposition rate, uneven charging, uneven sensitivity, roughness, white spots, and reproducibility of characteristics in the same manner as in Example 1. Good results similar to those of Example 1 were obtained.
Further, the obtained photoreceptor is used as a copying machine NP-6650 manufactured by Canon.
When the image was placed on the plate, the halftone image had no unevenness and a uniform image was obtained. Further, when a character original was copied, a clear image with high black density was obtained. Further, even in copying a photo original, a clear image that was faithful to the original could be obtained.

[Table 5]

[Table 6]

As described above, according to the present invention, one end of the cylindrical substrate rotatably arranged in the reaction vessel in the generatrix direction is grounded by the rotating shaft of the substrate and the other end is grounded. By grounding the part via a capacitor that is not in contact with the part, it is possible to eliminate the occurrence of film thickness distribution during film formation at a high frequency. Especially, 20 MHz to 450
In film formation by high frequency power of MHz, it is possible to reduce film thickness unevenness in the axial direction without increasing image defects. It is possible to realize an apparatus for forming a deposited film capable of forming a relatively large area film at a high processing speed, and in particular, it is possible to manufacture a low-cost electrophotographic photoreceptor in a short time.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a deposited film forming apparatus of the present invention used for forming a film on a single cylindrical substrate.

FIG. 2 is a schematic diagram showing an example of a deposited film forming apparatus of the present invention used for forming a film on a single cylindrical substrate.

FIG. 3 is a schematic view showing an example of the deposited film forming apparatus of the present invention used for forming a film on a single cylindrical substrate.

FIG. 4 is a schematic view showing an example of the deposited film forming apparatus of the present invention used for forming a film on a single cylindrical substrate.

FIG. 5 is a schematic view showing an example of a deposited film forming apparatus of the present invention used for forming a plurality of cylindrical substrates.

FIG. 6 is a schematic view showing an example of a conventional deposited film forming apparatus other than the present invention.

FIG. 7 is a schematic view showing an example of a deposited film forming apparatus other than the present invention, which is used for forming a plurality of cylindrical substrates.

[Explanation of symbols]

100, 200, 300, 400, 500, 600, 7
00 ... Deposition chamber 101, 201, 301, 401, 501, 601, 7
01 ... Cathode electrodes 102, 202, 302, 402, 502, 602, 7
02 ... Cylindrical substrate 103, 203, 403, 503, 603, 703 ... Auxiliary substrate 104, 204, 304, 404, 504, 604, 7
04 ... Heater for heating substrate 105, 205, 305, 405, 505, 605, 7
05 ... Rotating shaft 106, 206, 306, 406, 506 ... Ground electrode 107, 207, 307, 407, 507, 607, 7
07 ... Raw material gas inlets 108, 208, 308, 408, 508, 608, 7
08 ... Base driving motor 109, 209, 309, 409, 509, 609, 7
09 ... Matching device 110, 210, 310, 410, 510, 610, 7
10 ... High-frequency power source 111, 211, 311, 411, 511, 611, 7
11 ... Exhaust port 112, 212, 312, 412, 512, ... Derivative

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] August 21, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Detailed description of the invention

[Correction method] Change

[Correction contents]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a functional deposited film of crystalline or non-single crystalline which is useful for a photoconductor device for electrophotography as a semiconductor device, a line sensor for image input, an imaging device, a photovoltaic device and the like. Plasma CVD apparatus capable of favorably forming a film, a sputtering apparatus capable of suitably forming an insulating film as an optical element, a metal wiring, etc., or a deposition film forming apparatus by plasma treatment such as an etching apparatus for a semiconductor device In more detail, regarding a plasma processing apparatus for processing a substrate using plasma as an excitation source, particularly, a plasma processing apparatus having a frequency of 20 MHz or more, 45
The present invention relates to a plasma processing apparatus that can suitably use a high frequency of 0 MHz or less.

[0002]

2. Description of the Related Art There are various methods for a plasma processing apparatus used for a semiconductor or the like according to each application. For example, in film formation, an oxide film and a nitride film are formed using a plasma CVD device or a plasma CVD method, an amorphous silicon semiconductor film, a metal wiring film using a sputtering device or a sputtering method, an etching device and a method are used. A variety of devices and methods are used that take advantage of their features such as microfabrication technology. Further, in recent years, there has been a strong demand for improvement in film quality and processing capacity, and various devices have been studied. Particularly, a plasma process using high-frequency power has a high discharge stability and can be used for forming an insulating material such as an oxide film and a nitride film. Conventionally, 13.56 MHz is generally used as the oscillation frequency of the discharge high frequency power source used in plasma processes such as plasma CVD.
FIG. 6 shows an example of a plasma CVD apparatus that is generally used for forming the conventional deposited film. The plasma CVD apparatus shown in FIG. 6 is a film forming apparatus suitable for forming an amorphous silicon film (hereinafter referred to as “a-Si film”) on a cylindrical electrophotographic photosensitive member substrate.

A method of forming an a-Si film using this apparatus will be described below. A cathode electrode 601 and a cylindrical substrate 602 as a counter electrode are arranged in a deposition chamber 600 capable of reducing the pressure. An auxiliary substrate 603 is attached to the cylindrical substrate 602 and forms a part of the electrode. The cylindrical substrate 602 is heated from the inside by a substrate heater 604 inside. The high frequency power source 610 is connected to the cathode electrode 601 at one place via a matching circuit 609. 61
Reference numeral 1 is an exhaust port, and 607 is a raw material gas introduction port. Deposition chamber 6
A cylindrical substrate is installed in the chamber 00, and the deposition chamber 600 is temporarily exhausted through an exhaust port 611 by an exhaust device (not shown). After that, open the raw material gas inlet (not shown) and introduce an inert gas,
The flow rate and pumping speed are adjusted so that the pressure becomes a predetermined pressure.
The drive motor 608 rotates the cylindrical substrate in the circumferential direction and energizes the heater 604 for heating the substrate to heat the cylindrical substrate to a desired temperature of 100 to 400 ° C. After that, the raw material gas for film formation is supplied through the raw material gas inlet 607.
For example, a material gas such as silane gas, disilane gas, methane gas, and ethane gas, and a doping gas such as diborane gas and phosphine gas are introduced after being mixed with a mixing panel (not shown), and the mixture is introduced from several 10 mTorr to several Tor.
Adjust pumping speed to maintain r pressure. A high-frequency power of 13.56 MHz is supplied from a high-frequency power source 610 via a matching circuit 609 to one portion of the cathode electrode 601 to generate plasma discharge between the cathode electrode 601 and the cylindrical substrate 602 to decompose the raw material gas, thereby forming a cylinder. An a-Si film is deposited on the substrate 602. During this period, the cylindrical substrate is maintained at about 100 to 400 ° C. by the substrate heater 604, and the cylindrical substrate is also rotating in the circumferential direction.

According to the above procedure, a-
When depositing a Si film, it is desirable to rotate the cylindrical substrate while rotating it in the circumferential direction in order to improve the circumferential uniformity even in the coaxial film forming apparatus shown in FIG. Further, in a device as shown in FIG. 7 in which a plurality of cylindrical substrates are installed concentrically and an electrode is installed inside the cylindrical substrates to generate a discharge, a film is deposited on the entire circumference of the substrate. Rotation is indispensable for the purpose. In the figure, 700 is a deposition chamber having a vacuum airtight structure. Then, it is connected to an exhaust device (not shown) via an exhaust port 711.
A cathode electrode 701 is connected to a high frequency power source 710 via a matching unit 709. Reference numeral 707 is a source gas introduction port, which is connected to a gas supply source (not shown). A cylindrical substrate 702 is installed in the deposition chamber 700.
An auxiliary substrate 703 is attached to the cylindrical substrate 702 and forms a part of the electrode. The substrate heating heater 704 is installed on a rotating shaft 705 arranged concentrically. The rotating shaft 705 can be rotated by a base driving motor 708. Hereinafter, the film forming method is the same as in the case of using FIG. At the same time, generally, in a plasma CVD apparatus, the substrate temperature during film formation is 100 to
Since it is necessary to maintain the temperature at 400 ° C, a heater for heating the substrate is essential. The capacity of this heater is 0.5 to 0.5 because it is necessary to heat the substrate in a vacuum where heat is difficult to transfer.
It is difficult to supply power and it is difficult to incorporate the substrate into the rotating shaft that rotates the substrate as large as 5 kW. Therefore, the heater for heating the substrate is generally fixed in the deposition chamber in order to simplify the structure of the apparatus, reduce costs, and facilitate maintenance. For this reason, the rotating shaft is installed so as to pass through the inside of the heater for heating the substrate, and the rotating shaft supports the upper portion of the cylindrical substrate to enable heating and rotation of the cylindrical substrate.

The deposition rate for obtaining an a-Si film satisfying the performance of the electrophotographic photoreceptor by this film-forming method is, for example, 1.
The deposition rate is about 0.5 to 6 μm per hour, and if the deposition rate is further increased, the characteristics of the photoconductor may not be obtained. Further, generally, when an a-Si film is used as an electrophotographic photoreceptor, a film thickness of at least 20 to 30 μm is required to obtain charging ability, and it takes a long time to manufacture the electrophotographic photoreceptor. I needed it. For this reason, there has been a strong demand for a technique for shortening the manufacturing time without deteriorating the characteristics as a photoreceptor. By the way, in recent years, there has been a report of a plasma CVD method using a parallel plate type plasma CVD apparatus and a high frequency power source of 20 MHz or more (Plas.
ma Chemistry and Plasma P
processing, vol. 7, No. 3, (198
7) p267-273), the discharge frequency of the conventional 13.5
It has been noted that setting the frequency higher than 6 MHz may improve the deposition rate without deteriorating the performance of the deposited film, and is drawing attention. Further, reports of increasing the discharge frequency have been made by sputtering and the like, and its superiority has been widely studied in recent years. Therefore, in order to improve the deposition rate, the discharge frequency was changed to a high frequency power having a frequency higher than the conventional 13.56 MHz, and the film forming procedure was performed in the same manner as the conventional method. I confirmed that I can do it.

[0006]

However, it has been found that the following problems may newly occur, which are not a problem at the discharge frequency of 13.56 MHz in the above-mentioned conventional example. In the case where the substrate heating heater is fixed in the deposition chamber and the rotation axis passes through the deposition chamber, the cylindrical substrate comes into contact with the rotation axis and is connected to the ground from one location. 20MHz-450MHz with this configuration
When the film formation is performed using the electric power of the high frequency, 13.
The bad influence that the film thickness distribution occurs which is not a problem at a low frequency such as 56 MHz has come to occur. In other words, this is a phenomenon in which the film thickness on the grounded side becomes thicker and the film thickness on the opposite side becomes thinner. This causes a change in the film quality of the deposited film in the longitudinal direction, and in the electrophotographic photosensitive member, adverse effects such as density unevenness, sensitivity unevenness, and image roughness are likely to occur. Also, if the side opposite to the side grounded by the rotating shaft is forcibly grounded by rubbing something such as a ground electrode, this time, for example, due to dust generated by rubbing between metals, an electron In the case of a photographic photosensitive member, the image defect is extremely deteriorated and cannot be put to practical use. Furthermore, since the plasma state is different and unstable on the side opposite to the side where the ground is taken, there is a problem in reproducibility of characteristics. As described above, it is difficult to take the ground of the cylindrical substrate from above and below in the film formation by the high frequency power having a high frequency of 20 MHz or more. Therefore, the film thickness unevenness and the film quality unevenness occur in the axial direction of the substrate. However, for example, when it is applied to an electrophotographic photoreceptor, image unevenness such as density unevenness, sensitivity unevenness, and roughness may occur, and image defects may worsen, and there is a problem in reproducibility of characteristics. . The above-mentioned problems are caused even when forming a functional deposited film of a crystalline or non-single crystalline useful for an image input line sensor, an image pickup device, a photovoltaic device, etc. by smoothing out only the electrophotographic photoreceptor. It becomes a big problem. Also, in other plasma processes such as dry etching and sputtering, the same problem occurs when the discharge frequency is raised, and if it is left as it is, it becomes a serious problem in practical use.

Therefore, the present invention solves the above-mentioned problems and makes it possible to reduce the film thickness unevenness in the axial direction without increasing image defects in film formation by high frequency power, particularly high frequency power of 20 MHz to 450 MHz. Forming a deposited film that does not have density unevenness, sensitivity unevenness, image roughness, good reproducibility of characteristics, and can form a relatively large area film at a high processing speed in a short manufacturing time and at low cost. The purpose is to provide a device.

[0008]

In order to achieve the above-mentioned object, the present invention uses one of the end portions of the cylindrical substrate rotatably arranged in the reaction container in the generatrix direction by the rotation axis of the substrate. The above-mentioned film thickness is obtained by grounding, and the other end is grounded through a non-contact capacitor with the end formed by sequentially arranging a dielectric and a ground electrode from the side of the cylindrical substrate or the auxiliary substrate. This is to prevent the harmful effects of the occurrence of distribution. That is, the present invention comprises a vacuum-tight reaction container having an exhaust means and a raw material gas supply means, and a cylindrical substrate or an auxiliary substrate which also serves as one electrode rotatable by a rotating shaft in the discharge space of the reaction container. In a deposited film forming apparatus, in which a mounted cylindrical substrate is installed, and a high frequency power of 20 MHz to 450 MHz is applied between the one electrode and a cathode electrode provided separately to form a deposited film on the cylindrical substrate. , One end of the cylindrical base in the generatrix direction is grounded by contact with the rotating shaft, and the other end is provided with a dielectric and a ground electrode in order from the side of the cylindrical base or the auxiliary base. It is characterized in that it is grounded via a capacitor that is not in contact with the constructed end portion. The present invention has the configuration of 20 MHz to 450 MHz.
Good results can be achieved even at frequencies higher than the conventional 13.56 MHz of MHz. In the present invention, the capacitor may be disposed at the entire outer circumference, a part of the outer circumference, the entire inner circumference, or a part of the inner circumference of the cylindrical base body or the auxiliary base body. When the cylindrical substrate is arranged vertically in the discharge space of the reaction vessel, the earth is held and grounded by the rotating shaft at the upper part of the cylindrical substrate in the generatrix direction, and the lower part by the capacitor. This can be done by grounding, or by holding the lower part in the generatrix direction of the cylindrical substrate by the rotating shaft and grounding it, and the upper part by the capacitor. Further, in the present invention, a plurality of the cylindrical substrates may be concentrically arranged in the discharge space of the reaction vessel, and in that case, the cathode electrode is installed inside the space surrounded by the cylindrical substrates. To do. In the present invention, the dielectric is at least one of alumina ceramics, Teflon, quartz glass, and borosilicate glass, or at least one elemental oxide of elemental oxides of aluminum oxide, magnesium oxide, and silicon oxide. Can be used as a main component. In the present invention, the capacitance C (Farad) of the capacitor is 0.1 (4π ² f ² L) ⁻ when the frequency of the high frequency power is f (Hertz) and the inductance of the rotating shaft is L (Henry). It is preferable to satisfy ¹ ≦ C ≦ 10 (4π ² f ² L) ⁻¹ . Furthermore,
It is more preferable to satisfy 0.5 (4π ² f ² L) ⁻¹ ≦ C ≦ 5 (4π ² f ² L) ⁻¹ .

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, as described above, one end of the cylindrical substrate rotatably arranged in the reaction vessel in the generatrix direction is grounded by the rotating shaft of the substrate, and The other end is grounded via a capacitor that is not in contact with the other end to prevent the above-mentioned harmful effect of the film thickness distribution. This will be explained further. As described above, the conventional method for grounding a long substrate such as a cylindrical substrate for a copying machine from a single place as in the conventional case is described in 13.
There was no problem when the film was formed at a low frequency such as 56 MHz. However, 20MHz-450MH
When a film is formed by using a high frequency power of z, the effect of the impedance of the substrate itself cannot be ignored. For this reason, there arises an adverse effect that the plasma state is different between the grounded side and the grounded side in the longitudinal direction of the substrate and the film thickness distribution is generated. On the other hand, the impedance to the ground is low on the side where the ground wire is taken, so the plasma density is high, the deposition rate is high, and the film thickness is thick, but on the other side, some self-bias occurs due to the impedance of the cylindrical substrate itself. Therefore, the plasma density is reduced and the film thickness is also reduced. Further, the quality of the deposited film in the longitudinal direction also naturally changes because the plasma density and the deposition rate change, which causes density unevenness, image roughness, and sensitivity unevenness in the electrophotographic photosensitive member.
Further, there is a problem in reproducibility of characteristics.

As a most fundamental solution to this problem, the inventor of the present invention prepares for the generation of dust and rubs the cylindrical substrate on the side opposite to the side supported by the rotary shaft with a grounded brush electrode. Then, an experiment was conducted in which the state of the ground of the cylindrical substrate was made to be apparently symmetric. However, surprisingly, in this experiment, on the contrary, the side grounded by the rotating shaft was thin, and the ground electrode side was thick. The reason for this is that the side that is grounded by the rotating shaft is certainly grounded, but when viewed from a high frequency, it is grounded via a long path called the rotating shaft, so the impedance of this path is the brush It is considered that since the impedance is much higher than the impedance on the side grounded via the electrode, the plasma state is different and the film thickness distribution occurs. Therefore, the method of rubbing the side opposite to the side supported by the rotating shaft with the grounded brush-like electrode is not effective in terms of not only generating dust but also reducing the film thickness distribution and improving the reproducibility of characteristics. It has been found. Based on the above results, in order to eliminate dust generation, to eliminate axial unevenness of the cylindrical substrate, and to improve the reproducibility of the characteristics, the cylindrical substrate should be in non-contact with a certain level of high frequency resistance. It has been concluded that it is necessary to bring it down to earth. Then, a capacitor was considered as a structure having such a function. that time,
In the first case, for example, in the case of a cylindrical substrate whose upper part is supported by a rotating shaft, an earth electrode grounded to the deposition chamber is installed near the lower side of the cylindrical substrate so as not to hinder the rotation of the substrate. There are things to do. That is, in this way, the cylindrical base and the ground electrode grounded form a kind of capacitor. Plasma CVD using conventional low frequency
In the device, the capacitor thus formed has a too small capacity to allow current to flow.
When a high frequency such as 0 to 450 MHz is used, even such a low-capacity capacitor can sufficiently flow current and can be grounded.

As a result of further earnest studies, it was improved that the capacitance of the capacitor formed between the ground electrode and the cylindrical substrate due to the flow of plasma between the ground electrode and the cylindrical substrate was improved. As a means for stabilizing the reproducibility, it was considered to install a dielectric between the end of the cylindrical substrate on the side opposite to the side grounded by the rotating shaft and the ground electrode. By doing so, in a capacitor of the same capacity, the space between the end of the cylindrical substrate on the side opposite to the side grounded by the rotating shaft and the ground electrode becomes smaller than in the case where there is no dielectric, so that the flow of plasma does not occur. An experiment was conducted with the belief that the reproducibility of the characteristics would be reduced and the characteristics would be stable. As a result, it was found that a better deposited film was obtained and the reproducibility of the characteristics was better than in the case of using the conventional deposited film forming apparatus. And
It has been found that the deposition rate is improved as compared with the case where the film is formed by the conventional deposited film forming apparatus using the high frequency power of 20 to 450 MHz. The reason for this is not clear, but it is considered that the impedance of the entire cylindrical substrate is lowered by taking the ground from the upper and lower portions, and the high frequency power can be applied more efficiently. As described above, one end of the cylindrical base body in the generatrix direction is grounded by the rotating shaft that rotates the cylindrical base body, and the other end is installed in order from the cylindrical base body without being in contact with the cylindrical base body. The effect of the present invention can be obtained for the first time by forming a capacitor between the dielectric and the ground electrode to perform non-contact grounding.

In order to form the C coupling directly with the cylindrical substrate, the dielectric and the ground electrode may be provided in order from the cylindrical substrate without contacting the outside or the inside of the cylindrical substrate. When the auxiliary substrate is attached to the upper and lower sides of the cylindrical substrate to form a film, the dielectric body and the ground electrode are provided in order from the cylindrical substrate without contacting the outside or the inside of the auxiliary substrate. Good. The dielectric and the ground electrode, which are sequentially installed from the cylindrical substrate, may be provided over the entire circumference of the cylindrical substrate or the auxiliary substrate in the circumferential direction, or may be provided only in a part of the circumferential direction.

In a deposited film forming apparatus for forming a film by high frequency power of a certain frequency f (Hz), if the inductance of the rotating shaft is L (H), the capacity C (F) of the C coupling of the present invention is Can be obtained with. C = (4π ² f ² L) ^{−1 It} is difficult to calculate the inductance of the rotating shaft when the shape is complicated, but the effect of the present invention is sufficiently obtained by using a value roughly approximated as a cylindrical rod. You don't have to pay much attention because you can get it. Further, it is of course possible to actually obtain the value by using an LCR meter or the like. Also, it is not necessary to strictly realize the value of C obtained from the calculation,
The effect of the present invention can be improved to a practically satisfactory level by designing it so as to fall within the range of 10 times to 10 times. In order to specifically design the C coupling from the value of C obtained from the above equation, a dielectric and an earth electrode installed so as to satisfy C = ε1ε2S / {ε1d2 + ε2 (d1 + d3)} may be attached. Here, ε1 is the dielectric constant between the cylindrical substrate and the dielectric and between the dielectric and the ground electrode, ε2 is the dielectric constant of the dielectric, d1 is the distance between the cylindrical substrate and the dielectric, and d2 is the width of the dielectric. d3 is the distance between the dielectric and the ground electrode, and S is the overlapping area of the dielectric, the ground electrode and the cylindrical substrate. Strictly speaking, the value of ε1 varies depending on the type and pressure of the source gas introduced into the deposition chamber, but the effect of the present invention can be sufficiently obtained even if the dielectric constant in vacuum is roughly used. In addition, in each of the deposited film forming apparatuses of the present invention, the cylindrical substrate can be rotated, but the effect of the present invention is not necessarily obtained without rotating the cylindrical substrate, and it is not a stationary state. The effect of the present invention can be obtained even when the film formation is performed by. Further, the effect of the present case can be obtained even if it is not rotatable as long as the mechanism for holding the cylindrical base body is a mechanism for holding the upper part or the lower part of the cylindrical base body similar to the present case.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 schematically shows an example of an apparatus for carrying out the method of the present invention, which is suitable for forming a deposited film on a cylindrical substrate such as an electrophotographic photoreceptor. In FIG. 1, 100 is a deposition chamber for forming a deposited film, which is connected to an exhaust device (not shown) through an exhaust port 111. Reference numeral 107 is a raw material gas inlet for introducing the raw material gas into the deposition chamber, and introduces the raw material gas into the deposition chamber from a gas supply system (not shown). Reference numeral 102 denotes a cylindrical substrate, which is set on the auxiliary substrate 103 and attached to the rotating shaft 105. The rotation shaft 105 is rotatably attached to the deposition chamber. The cylindrical base body 102 and the auxiliary base body 103 are connected at their upper parts to the ground by a rotary shaft 105. 104
Is a substrate heating heater for heating the cylindrical substrate to a predetermined temperature, and is fixed in the deposition chamber. In addition, the cylindrical substrate 102 is driven by the drive motor 1 via the rotary shaft 105.
It is rotated by 08 to make the film thickness in the circumferential direction uniform. 1
Reference numeral 10 is a high frequency power source that generates a high frequency of 20 MHz to 450 MHz, and the high frequency output is wired so as to be applied to the cathode electrode 101 via a matching circuit 109. As shown in FIG.
Of course, it may be a double inner wall.

Reference numerals 106 and 112 respectively denote a ground electrode and a dielectric according to the present invention, and the auxiliary substrate 1
The earth electrode 106, the dielectric 112, and the auxiliary substrate 103 are placed in this order in close proximity so as not to contact 03, and a capacitor is formed in a region where they overlap each other. The capacitance of this capacitor can be arbitrarily set by changing the heights of the ground electrode 106 and the dielectric 112 and the distances between the dielectric 112, the ground electrode 106 and the auxiliary substrate 103. In this device configuration, the upper part of the cylindrical substrate 102 is installed in the deposition chamber via the rotating shaft 105, but since the rotating shaft inductance cannot be ignored at a high frequency of 20 MHz to 450 MHz,
It has some resistance before it falls to the ground. The capacitance of the capacitor formed between the ground electrode 106 and the auxiliary substrate 103 is adjusted so as to have the same resistance as that of the inductance. Specifically, the configuration may be set so that the value of C calculated by C = (4π ² f ² L) ⁻¹ is obtained.

FIG. 2 schematically shows another example of the apparatus for carrying out the method of the present invention, which is suitable for forming a deposited film on a cylindrical substrate such as an electrophotographic photoreceptor. Is. In this device, the cylindrical substrate 202 and the auxiliary substrate 203
Are supported so as to be suspended from the upper part of the deposition chamber. The ground electrode 206 and the dielectric 212 are installed inside the auxiliary substrate in this device. Other components are the same as those in FIG. FIG. 3 schematically shows another example of the apparatus for carrying out the method of the present invention. In this apparatus, the substrate heater 304 is mounted on the upper part of the deposition chamber, and the cylindrical substrate 302 is mounted on the rotary shaft 305 mounted on the lower part of the deposition chamber. In this example, since the auxiliary substrate is not used and the ground electrode 306 is provided outside the cylindrical substrate 302, the film thickness distribution becomes uneven. Other components are the same as those in FIG. FIG. 4 schematically shows another example of the shapes of the dielectric 412, the ground electrode 406 and the auxiliary base 403 of the present invention. It is of course possible to form a capacitor by taking out.

FIG. 5 schematically shows still another example of the present invention. The capacitor portion for taking the ground at the lower part of the cylindrical substrate 502 is the same as that in FIG. 1, but in this example, six cylindrical substrates are arranged in a concentric pattern, and the cathode electrode 501 is installed in the center of the cylindrical substrate. A discharge is generated in the space surrounded by 502.

Ground electrodes 106, 206, 306, 40
As the material used for Nos. 6 and 506, any material having high heat resistance and high conductivity can be used. Also, the ground electrodes 106, 20
The material used for the purpose of minimizing the inductance of 6, 306, 406, and 506 itself is preferably one having a small magnetic permeability. In addition, since the high frequency conducts only the outermost surface of the conductor by the skin effect, it is preferable that the surface area is as large as possible. Generally, a flat plate shape is used. Specific earth electrodes 106, 206, 30
As a material for 6,406 and 506, copper, aluminum, gold, silver, and platinum are preferable because they have high conductivity and small magnetic permeability. Lead, nickel, cobalt, iron, chromium, molybdenum, titanium and stainless steel are also suitable because they are resistant to heat. Alternatively, a composite material of two or more of these materials is also preferable. Dielectrics 112, 212, 312, 412, 5
Examples of the material used for 12 include alumina ceramics, Teflon, quartz glass, borosilicate glass, or those containing aluminum oxide, magnesium oxide, or elemental oxide of silicon oxide as the main component. There is no particular limitation as long as it is an insulating material that is resistant to heat. High frequency power supply 110, 210, 310, 410, 510 used
Any can be used as long as the oscillation frequency is 20 MHz to 450 MHz. Also, the output is from 5W to 5
Any output can be suitably used as long as it can generate electric power suitable for the apparatus up to 000 W or more. Furthermore, the effect of the present invention can be obtained regardless of the output fluctuation rate of the high frequency power supply.

Matching units 1009, 209, 30 used
As for 9, 409 and 509, any structure can be suitably used as long as it can match the load with the high frequency power supply. Further, as a method for obtaining the matching, an automatically adjusted method is suitable for avoiding complexity during manufacturing, but even a manually adjusted method has no influence on the effect of the present invention. It is desirable because the cost is low. or,
Regarding the position where the matching device is placed, there is no problem wherever it is installed within the range where matching can be achieved, but it is better to place it so that the inductance of the wiring between the matching device and the cathode is as small as possible under wide load conditions. It is desirable because it enables matching. Cathode electrode 101,
As the material of 201, 301, 401, 501, copper, aluminum, gold, silver, platinum, lead, nickel, cobalt, iron, chromium, molybdenum, titanium, stainless steel, etc. are preferable because they have good thermal conductivity and electrical conductivity. Is. Two or more composite materials among these materials are also suitably used. In addition, the shape is preferably a cylindrical shape for ease of processing, but an elliptical shape or a polygonal shape may be used if necessary.
Cathode electrodes 101, 201, 301, 401, 501
May be provided with a cooling means if necessary. As specific cooling means, cooling with water, air, liquid nitrogen, a Peltier element, or the like is used as necessary. The cylindrical substrates 102, 202, 302, 402, 502 and the auxiliary substrates 103, 203, 303, 403, 503 of the present invention may be made of any material having a material suitable for the purpose of use. As the material, copper, aluminum, gold, silver, platinum, lead, nickel, cobalt, iron, chromium, molybdenum, titanium, and stainless steel are preferable because they have good electric conductivity. Further, two or more composite materials among these materials are also desirable for improving heat resistance. Further, it is desirable to use an insulating material such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, glass, ceramics, or paper coated with a conductive material because the cost can be reduced.

An example of the method of forming a deposited film of the present invention in the apparatus shown in FIG. 1 is performed as follows. Incidentally, this procedure can be similarly applied to the apparatus shown in FIGS. First, for example, the cylindrical substrate 102 whose surface is mirror-finished by using a lathe is attached to the auxiliary substrate 103, and is attached to the rotating shaft 105 so as to include the substrate heating heater 104 in the deposition chamber 100. Next, the raw material gas introduction valve (not shown) is closed, and the deposition chamber is temporarily evacuated by the exhaust device (not shown) through the exhaust port 111, and then the raw material gas introduction valve (not shown) is opened to heat the inert gas for heating. As an example, argon is introduced into the deposition chamber through the raw material gas inlet 107, and the exhaust speed of the exhaust device and the flow rate of the heating gas are adjusted so that the deposition chamber has a desired pressure. After that, while the cylindrical substrate 102 is rotated by the driving motor 108, a temperature controller (not shown) is operated to heat the cylindrical substrate 102 by the substrate heating heater 104. When the cylindrical substrate 102 is heated to a desired temperature, a raw material gas introduction valve (not shown) is closed to stop the gas flow into the deposition chamber. To form the deposited film, a raw material gas introduction valve (not shown) is opened and a predetermined raw material gas is introduced from the raw material gas introduction port 107.
For example, a material gas such as silane gas, disilane gas, methane gas, and ethane gas, and a doping gas such as diborane gas and phosphine gas are mixed with a mixing panel (not shown), and then introduced into the deposition chamber 100 for several mTo.
The evacuation speed is adjusted so as to maintain the pressure at rr to several Torr. After the pressure is stabilized, the high frequency power supply 110 is turned on to supply power with a frequency of 20 MHz to 450 MHz to cause glow discharge. At this time, the matching circuit 109
Is adjusted so that the reflected wave is minimized. The value obtained by subtracting the reflected power from the high frequency incident power is adjusted to a desired value, the glow discharge is stopped when the desired film thickness is formed, the flow of the source gas into the deposition chamber 100 is stopped, and the inside of the deposition chamber is once brought to a high vacuum. The formation of layers is completed after pulling up. During this period, it is desirable to perform film formation while rotating the cylindrical substrate in order to equalize the film thickness in the circumferential direction. When stacking deposited films having various functions, the above operation is repeated.

Specific examples for demonstrating the effects of the present invention will be described below, but the present invention is not limited to the specific examples.

[0022]

The present invention will be described below with reference to examples, but the present invention is not limited thereto. Example 1 In the deposited film forming apparatus shown in FIG. 1, a high frequency power source 110 having an oscillation frequency of 105 MHz was installed, an a-Si film was formed on a cylindrical base member 102 made of aluminum, and a photoconductor for electrophotography was produced. did. When the rotation axis of the deposited film forming apparatus was approximated to a cylinder, the inductance L was calculated to be 0.15 μH. Then C = (4
When C was calculated by applying it to π ² f ² L) ⁻¹ , it was 15.3 pF in this example. Therefore, the size and interval were set by using alumina ceramics as the dielectric 112 and aluminum as the ground electrode 106 so that the capacitor composed of the auxiliary substrate 103, the dielectric 112, and the ground electrode 106 would have this value in vacuum. In this embodiment,
The ground electrode 106 and the dielectric 112 were cylindrical and were installed over the entire circumference of the auxiliary base 103 in the circumferential direction. As film forming conditions, the film forming was performed according to the manufacturing conditions shown in Table 1.

Comparative Example 1 In the conventional deposited film forming apparatus shown in FIG. 6, a high frequency power source 6 with an oscillation frequency of 105 MHz is used.
10 was installed, an a-Si film was formed on a cylindrical substrate 602 made of aluminum, and a photoconductor for electrophotography was produced. As film forming conditions, the film forming was performed according to the manufacturing conditions shown in Table 1 as in Example 1.

Comparative Example 2 In the conventional deposited film forming apparatus shown in FIG. 6, the lower part of the auxiliary substrate 603 was forcibly grounded by rubbing it with a metal brush grounded to ground.
In this comparative example, a high frequency power supply 61 with an oscillation frequency of 105 MHz is used.
0 is installed on the cylindrical base 602 made of aluminum.
-Si film was formed to prepare a photoconductor for electrophotography. As film forming conditions, the film forming was performed according to the manufacturing conditions shown in Table 1 as in Example 1.

The electrophotographic photoconductors produced in Example 1 and Comparative Examples 1 and 2 were evaluated by the following methods. Film thickness distribution and deposition rate evaluation The film thickness at 16 axial positions of each photoconductor was measured with an eddy current film thickness meter (made by Kett Scientific Research Institute), and the difference between the maximum film thickness and the minimum film thickness was averaged. The ratio of the film thickness distribution was defined by dividing by the film thickness of, and classified into the following ranks. ◎ Very good ○ Good △ No practical problems × Practical problems At the same time, the deposition rate was obtained by dividing the total film thickness by the film formation time, and evaluated. The evaluation standard of the deposition rate was based on the apparatus of Comparative Example 1 and ranked as follows. ◎ 20% or more faster than Comparative Example 1 10 to 20% faster than Comparative Example 1 Same as Comparative Example 1 × Slower than Comparative Example 1 Electrophotographic characteristics Electrophotographic apparatus (Canon NP) for each photoconductor
6060 was modified for experiments), and the electrophotographic characteristics such as initial charging ability and residual potential were evaluated as follows. Electrification unevenness ..... An electrophotographic photoreceptor was installed in the experimental device, and a high voltage of +6 kV was applied to the charger to perform corona charging.
The surface potential of the dark portion of the electrophotographic photosensitive member is measured at the developing position with a surface potential meter. Five points are measured in the axial direction of the electrophotographic photoreceptor, and the potential unevenness at this time is evaluated. Sensitivity unevenness: Charges the electrophotographic photosensitive member to a constant dark surface potential. And immediately using a filter 550n
A halogen lamp light excluding light in a wavelength range of m or less is irradiated, and the light amount is adjusted so that the surface potential of the bright portion of the electrophotographic photosensitive member becomes a predetermined value. At this time, the necessary light amount is converted from the lighting voltage of the halogen lamp light source. According to this procedure, 5-point sensitivity is measured in the axial direction of the electrophotographic photosensitive member, and the sensitivity unevenness at this time is evaluated. For each, ◎ Very good ○ Good △ Practical no problem × Practical problem rustling of the image ... Copy the halftone chart, observe the obtained halftone image in detail, compare with the limit sample, and evaluate. . ◎ No rustiness is observed at all, and it is very good. ○ Some rustiness is slightly observed, but it is good. Canon full black chart (part number: F
Y9-9073) was placed on the platen and copied, and white spots having a diameter of 0.2 mm or more were evaluated within the same area of the copy image obtained. The evaluation categories are as follows. ◎ Very good ○ Good △ There are white spots, but there is no practical problem at the conventional level. × Many white spots exist, and there are practical problems. The reproducibility of the characteristics was measured 10 times for the charging unevenness of the electrophotographic characteristics, and the reproducibility at that time was compared with the case of the electrophotographic photosensitive member prepared in Comparative Example 1. ◎ Very good compared to Comparative Example 1 ○ Comparison Better than Example 1 Δ Equivalent to Comparative Example 1 × Worse than Comparative Example 1 was used for evaluation. Table 2 summarizes the above results. The electrophotographic photosensitive member according to the deposited film forming apparatus of the present invention has no unevenness and has excellent reproducibility of characteristics and is very excellent, but the conventional deposited film forming apparatus does not improve the unevenness. Further, even if the lower part of the auxiliary substrate is grounded forcibly by a metal brush, the unevenness is not improved, and the white spot level is deteriorated, which makes it unusable for practical use. It should be noted that the deposition rate is improved in Example 1 as compared with Comparative Example 1. The reason for this is not clear, but it is considered that the impedance of the entire cylindrical substrate is lowered by taking the ground from the upper and lower portions, and the high frequency power can be applied more efficiently. From the above examples, it was found that the deposited film forming apparatus of the present invention can improve the reproducibility of unevenness and characteristics without aggravating image defects, and can also improve the deposition rate.

[0026]

[Table 1]

[0027]

[Table 2] [Embodiment 2] As a material of the dielectric body 112 in Embodiment 1, Teflon, quartz glass, Teflon borosilicate glass, aluminum oxide, magnesium oxide, silicon oxide,
Aluminum oxide and magnesium oxide in a molar ratio of 1: 1
Including aluminum oxide and silicon oxide in a molar ratio of 1:
1 containing, 1: 1 containing magnesium oxide and silicon oxide in a molar ratio, and 1: 1: 1 containing aluminum oxide, silicon oxide and magnesium oxide in a molar ratio, respectively, and the auxiliary substrate 103 and the dielectric in vacuum. Under the same conditions as in Example 1, except that the size and the interval were set so that the capacitor composed of the body 112 and the earth electrode 106 had a capacitance of 15.3 pF, a
A -Si film was formed to prepare a photoconductor for electrophotography. The electrophotographic photosensitive member produced in Example 2 was evaluated for film thickness unevenness, deposition rate, charging unevenness, charging unevenness, uneven sensitivity, white spots, white spots, and reproducibility of characteristics in the same procedure as in Example 1, and the results are shown in Example 1. Similarly good results have been obtained. based on the above results,
It was found that a good deposited film can be obtained by using the deposited film forming apparatus of the present invention even if the dielectric is changed.

[Embodiment 3] In the deposited film forming apparatus shown in FIG. 5, a high frequency power source 510 with an oscillation frequency of 105 MHz is installed, and an a-S is mounted on an aluminum cylindrical substrate 501.
An i film was formed to prepare a photoconductor for electrophotography. When the rotation axis of the deposited film forming apparatus was approximated to a cylinder, the inductance L was calculated to be 0.15 μH. Then, when C was calculated by applying C = (4π ² f ² L) ⁻¹ , it was 15.3 pF in this example. Therefore, the dielectric 512 is adjusted so that the capacitor composed of the auxiliary substrate 503, the dielectric 512, and the ground electrode 506 has this value in vacuum.
The size and interval were set by using alumina ceramics as the above and aluminum as the ground electrode 506. In this embodiment, the ground electrode 506 and the dielectric 512 are cylindrical and are installed over the entire circumference of the auxiliary base 503 in the circumferential direction.
As film forming conditions, the film forming was performed according to the manufacturing conditions shown in Table 1.

(Comparative Example 3) In the conventional deposited film forming apparatus shown in FIG. 7, a high frequency power source 7 with an oscillation frequency of 105 MHz was used.
10 was installed, an a-Si film was formed on a cylindrical substrate 702 made of aluminum, and a photoconductor for electrophotography was produced. As film forming conditions, the film forming was performed according to the manufacturing conditions shown in Table 1. The electrophotographic photoreceptors produced in Example 3 and Comparative Example 3 were evaluated for unevenness in film thickness, deposition rate, uneven charging, uneven sensitivity, rustiness, white spots, and reproducibility of characteristics in the same procedure as in Example 1. The results are shown in Table 3. In the deposited film forming apparatus of the present invention, the image defects are not deteriorated, the film thickness, the characteristic unevenness, the reproducibility of the characteristics are improved, and the deposition rate is also improved.

[0030]

[Table 3] [Embodiment 4] In the deposited film forming apparatus shown in FIG. 2, a high frequency power source 210 having an oscillation frequency of 60 MHz is installed, and an a-Si film is formed on an aluminum cylindrical substrate 202.
An electrophotographic photoreceptor was produced. When the inductance L was calculated by calculation by approximating the rotation axis of this deposited film forming apparatus to a cylinder, it was 0.07 μH. Then C = (4π ²
When C was calculated by applying it to f ² L) ⁻¹ , it was 100 pF in this example. In this embodiment, the values of the capacitors of the present invention are 0.1C, C, 5C and 10C (C = 100p).
The effect of the present invention was investigated by changing to F). In this embodiment, alumina ceramics is used as the dielectric 112 and aluminum is used as the grounding electrode 106 so that the capacitor constituted by the auxiliary substrate 503, the dielectric 512, and the grounding electrode 506 has the above values in vacuum. The interval was set. In this embodiment, the ground electrode 506 and the dielectric 512 are cylindrical and are installed over the entire circumference of the auxiliary base 503 in the circumferential direction.

As film forming conditions, film forming was performed according to the manufacturing conditions shown in Table 1.

(Comparative Example 4) In Example 4, the value of the capacitor of the present invention was 0.05C, 15C (C = 100 pF).
An a-Si film was formed on a cylindrical substrate 202 made of aluminum under the same conditions as in Example 4 except that the above was used to prepare an electrophotographic photoreceptor. The electrophotographic photoreceptors prepared in Example 4 and Comparative Example 4 were evaluated for film thickness unevenness, deposition rate, charging unevenness, sensitivity unevenness, roughness, white spots, and characteristic reproducibility in the same procedure as in Example 1. The results are shown in Table 4. The effect of the present invention is obtained when the value of the capacitor of the present invention is 0.1C to 10C, but it becomes clear that the effect diminishes when the value deviates from 0.05C to 15C. Also, the deposition rate is improved when the capacitance of the capacitor is 0.1 C or more.

[0033]

[Table 4] [Example 5] An a-Si film was formed on a cylindrical substrate 402 made of aluminum in the deposited film forming apparatus shown in Fig. 4 to prepare an electrophotographic photoreceptor. Inductance L is calculated by approximating the rotation axis of the present deposited film forming apparatus to a cylinder, and the value of the capacitor of the present invention is calculated to use alumina ceramics as the dielectric 412 and aluminum as the ground electrode 406, and the size and interval are respectively set. It was set. In this embodiment, the ground electrode 406 and the dielectric 412 are used.
Has a disk shape and is installed over the entire circumference of the auxiliary base 403 in the circumferential direction. In this embodiment, the frequency of the high frequency power source 410 is set to 2
The film formation was performed according to the manufacturing conditions shown in Table 5 as 0 MHz, 50 MHz, 300 MHz, and 450 MHz.

Comparative Example 5 In the deposited film forming apparatus shown in FIG. 4, an a-Si film was formed on an aluminum cylindrical substrate 402 in the same manner as in Example 5 to prepare an electrophotographic photoreceptor. However, in this comparative example, the frequency of the high frequency power supply 410 was 13.56 MHz and 500 MHz. However, at a frequency of 13.56 MHz, the internal pressures of the charge transport layer, charge generation layer, and surface protection layer were 200 mTorr and 300 mT, respectively.
orr and 350 mTorr. Example 5, Comparative Example 5
The electrophotographic photosensitive member prepared in 1. was evaluated for unevenness in film thickness, deposition rate, uneven charging, uneven sensitivity, rough spots, white spots, and reproducibility of characteristics in the same procedure as in Example 1. Table 6 shows the results. The frequency of the high-frequency power source is 20 MHz to 450
At MHz, the effect of the present invention is obtained, and the film formation time can be shortened, but at 13.56 MHz, the film formation time cannot be shortened, and at 500 MHz, another unevenness occurs in the axial direction. It can be seen that the effect of the present invention cannot be obtained.

[Embodiment 6] In a deposited film forming apparatus capable of simultaneously forming a plurality of cylindrical substrates shown in FIG. 5, a high frequency power source 510 with an oscillation frequency of 105 MHz is installed, and a cylindrical aluminum substrate 502 is provided with a- A Si film was formed to produce a photoconductor for electrophotography. When the rotation axis of the present deposited film forming apparatus was approximated to a cylinder, the inductance L was calculated to be 0.2 μH. Therefore, C = (4π ² f ²
L) ^-1 was applied to calculate C, and in this embodiment, it was 1
It became 1.5 pF. Therefore, in the vacuum, the auxiliary substrate 503
The size and the interval were set by using alumina ceramics as the dielectric 112 and aluminum as the grounding electrode 106 so that the capacitor constituted by the dielectric 512 and the grounding electrode 506 had the above values. In this embodiment, the ground electrode 506 and the dielectric 512 are cylindrical,
The auxiliary base 503 was installed so as to face only a half circumference of the auxiliary base 503. As film forming conditions, film forming was performed according to the manufacturing conditions shown in Table 5. The photoconductor prepared in Example 6 was evaluated for film thickness unevenness, deposition rate, charge unevenness, sensitivity unevenness, roughness, white spots, and reproducibility of characteristics in the same manner as in Example 1. Good results similar to those of Example 1 were obtained. The obtained photoconductor is used as a Canon copier NP.
When it was placed at -6650 and an image was output, a uniform image was obtained without unevenness in the halftone image. Further, when a character original was copied, a clear image with high black density was obtained. Also, when copying a photographic original, a clear image faithful to the original could be obtained.

[Embodiment 7] In the deposited film forming apparatus shown in FIG. 3, a high frequency power source 310 with an oscillation frequency of 60 MHz is installed, and an a-Si is formed on an aluminum cylindrical substrate 302.
A film was formed and an electrophotographic photoreceptor was produced. In this embodiment, the earth electrode 306 is made of aluminum, the dielectric 31
Alumina ceramics was used as 2, and a cylindrical substrate having a shape facing only 1/6 of the circumferential direction was installed. The sizes and intervals of the ground electrode 306 and the dielectric 312 were set by calculating the inductance L by calculating the value of the capacitor of the present invention by approximating the rotation axis of the present deposited film forming apparatus to a cylinder. As film forming conditions, film forming was performed according to the manufacturing conditions shown in Table 5. The photoreceptor prepared in Example 7 was evaluated for unevenness in film thickness, deposition rate, uneven charging, uneven sensitivity, roughness, white spots, and reproducibility of characteristics in the same manner as in Example 1. Good results similar to those of Example 1 were obtained. The obtained photoconductor is used as a Canon copier NP.
When it was placed at -6650 and an image was output, a uniform image was obtained without unevenness in the halftone image. Further, when a character original was copied, a clear image with high black density was obtained. Further, even in copying a photo original, a clear image that was faithful to the original could be obtained.

[0037]

[Table 5]

[0038]

[Table 6]

[0039]

As described above, according to the present invention, one end of the cylindrical substrate rotatably arranged in the reaction vessel in the generatrix direction is grounded by the rotating shaft of the substrate and the other end is grounded. By grounding the part via a capacitor that is not in contact with the part, it is possible to eliminate the occurrence of film thickness distribution during film formation at a high frequency. Especially, 20 MHz to 450
In film formation by high frequency power of MHz, it is possible to reduce film thickness unevenness in the axial direction without increasing image defects. It is possible to realize an apparatus for forming a deposited film capable of forming a relatively large area film at a high processing speed, and in particular, it is possible to manufacture a low-cost electrophotographic photoreceptor in a short time.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H01L 21/203 H01L 21/203 S 21/205 21/205 21/285 21/285 Z 21/3065 21/31 C 21/31 9216-2G H05H 1/46 A H05H 1/46 H01L 21/302 B

Claims (10)

[Claims] 1. A cylindrical base body or an auxiliary base body, which comprises a vacuum-tight reaction container having an exhaust means and a raw material gas supply means, and which serves as one electrode rotatable by a rotary shaft in a discharge space of the reaction container. The attached cylindrical substrate is installed, and 20 is provided between the one electrode and the cathode electrode provided separately.
In a deposited film forming apparatus for applying a high frequency power of MHz to 450 MHz to form a deposited film on the cylindrical substrate,
One end of the cylindrical base in the generatrix direction is grounded by contact with the rotating shaft, and the other end is arranged with a dielectric and a ground electrode in order from the side of the cylindrical base or the auxiliary base. The deposited film forming apparatus is characterized in that it is grounded via a capacitor that is not in contact with the end portion. 2. The deposited film forming apparatus according to claim 1, wherein the capacitor is provided on the entire outer circumference or a part of the outer circumference of the cylindrical substrate or the auxiliary substrate. 3. The deposited film forming apparatus according to claim 1, wherein the capacitor is provided on the entire inner circumference or a part of the inner circumference of the cylindrical substrate or the auxiliary substrate. 4. The cylindrical substrate is vertically arranged in a discharge space of the reaction vessel, an upper portion of the cylindrical substrate in a generatrix direction is held and grounded by the rotating shaft, and a lower portion is grounded by the capacitor. The deposited film forming apparatus according to any one of claims 1 to 3, characterized in that. 5. The cylindrical substrate is vertically arranged in a discharge space of the reaction vessel, a lower portion of the cylindrical substrate in a generatrix direction is held and grounded by the rotating shaft, and an upper portion is grounded by the capacitor. The deposited film forming apparatus according to any one of claims 1 to 4, characterized in that. 6. The cylindrical substrate has a plurality of cylindrical substrates arranged concentrically in a discharge space of the reaction vessel, and a cathode electrode is installed inside a space surrounded by the cylindrical substrates. The deposited film forming apparatus according to any one of claims 1 to 5, characterized in that: 7. The dielectric is alumina ceramics,
The deposited film forming apparatus according to claim 1, comprising at least one of Teflon, quartz glass, and borosilicate glass. 8. The dielectric according to claim 1, wherein the main component is at least one of element oxides of aluminum oxide, magnesium oxide, and silicon oxide. Deposited film forming device. 9. The capacitance C (farad) of the capacitor
When the frequency of the high frequency power is f (hertz) and the inductance of the rotating shaft is L (henry), 0.1 (4π ² f ² L) ⁻¹ ≦ C ≦ 10 (4π ² f ² L) ⁻ a deposited film forming apparatus according to any one of claims 1 to 8, characterized in that satisfies ^1. 10. The capacitance C (Farad) of the capacitor is 0.5 (4π ² f ² L) ⁻ when the frequency of the high frequency power is f (Hertz) and the inductance of the rotary shaft is L (Henry). 9. The deposited film forming apparatus according to claim ^{1, wherein 1} ≦ C ≦ 5 (4π ² f ² L) ⁻¹ is satisfied.