JP2001316826A - Method and device for forming deposition film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for forming a deposition film, by a plasma treatment which can discharge steadily and stably form a deposition film of high quality with extremely uniform thickness at high speed, on various shapes of large area base substances. SOLUTION: The method for forming a deposition film comprises generating plasma between a high frequency electrode and a film formed base substance of a counter electrode by applying high frequency electric power of 30 MHz or more and 600 MHz or less to the high frequency electrode, decomposing source gas introduced into a reaction vessel, and forming a sedimentary film on the base substance. The device comprises several high frequency electrodes, and divided high frequency electric power from the same power source is supplied to each of high frequency electrodes through a high-voltage capacitor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for forming a deposited film by plasma processing.
A plasma CVD apparatus capable of suitably forming a crystalline or non-single-crystalline functional deposited film useful for an electrophotographic photoreceptor device as a semiconductor device, an image input line sensor, an imaging device, a photovoltaic device, and the like; The present invention relates to a film forming method, a sputtering apparatus and a film forming method capable of suitably forming an insulating film, a metal wiring, or the like as a semiconductor device or an optical element, or a plasma processing method such as an etching apparatus and a method for a semiconductor device.

[0002]

2. Description of the Related Art There are various methods for plasma processing used in semiconductors and the like according to the respective applications. For example, various types of plasma, such as an oxide film, a nitride film, and an amorphous silicon-based semiconductor film formed by a plasma CVD method, a metal wiring film formed by a sputtering method, or a fine processing technique by etching. Devices and methods that utilize features are used. Further, in recent years, demands for improving film quality and processing capacity have been increasing, and various devices have been studied. In particular, a plasma process using high-frequency power is widely used because of its advantages such as discharge stability and application to insulating materials such as oxide films and nitride films.

Conventionally, the oscillation frequency of a high-frequency power supply for discharge used in a plasma process such as plasma CVD is 13.
56 MHz is common. FIG. 8 shows an example of such a conventional high frequency electrode for plasma generation and a plasma CVD method using the high frequency electrode. With reference to FIG. 8, a method using the above-described conventional parallel plate type apparatus will be described. In the figure, a high-frequency electrode 102 is arranged in a reaction vessel 100 via an insulating high-frequency electrode support 114. The high-frequency electrode 102 is a flat plate arranged in parallel with the counter electrode, and generates plasma by an electric field determined by the capacitance between the electrodes. When plasma is generated, a substantially conductive plasma and a sheath between the electrodes and the electrode and the reaction vessel wall, which mainly acts as a capacitor equivalently, are generated between the electrodes, resulting in a large impedance compared to before the plasma is generated. Are often different. High frequency electrode 10
Around the high-frequency electrode 102 and the reaction vessel 10
Ground shield 10 so that no discharge occurs between
1 is arranged. The high-frequency electrode 102 has a matching circuit 1
04 and a high-frequency power supply 105 are connected via a high-frequency power supply line. On the counter electrode 112 arranged in parallel with the high-frequency electrode 102, a flat-plate-shaped substrate 103 for performing plasma CVD is disposed, and the substrate 103 is maintained at a desired temperature by the substrate temperature control means 111. It is.

[0004] Plasma CVD using this method
Is performed as follows. After the reaction vessel 100 is evacuated to a high vacuum by the vacuum evacuation means 106, the reaction gas is introduced into the reaction vessel by the gas supply means 107 and maintained at a predetermined pressure. High-frequency power is supplied from the high-frequency power supply 105 to the high-frequency electrode 102 to generate plasma between the high-frequency electrode 102 and the counter electrode. By this method, the reaction gas is decomposed and excited by the plasma, and the film-forming substrate 103 is formed.
A deposited film is formed thereon. As high frequency power, 13.5
Generally, high-frequency power of 6 MHz is used. When the discharge frequency is 13.56 MHz, the discharge conditions are relatively easy to control, and the resulting film has the advantages of excellent film quality. However, there is a problem that the utilization efficiency of the film is low and the formation speed of the deposited film is relatively low. In view of these problems, studies have been made on a plasma CVD method using a high frequency of about 25 to 150 MHz.

In recent years, parallel plate type plasma C
Report on a plasma CVD method using a VD apparatus and a high frequency power supply of 13.56 MHz or more (Plasma Chem)
istry and Plasma Processessi
ng, Vol 7, No 3 (1987) p267-2
73 (hereinafter referred to as "Document 1"), and the a-Si film is formed by setting the discharge frequency higher than the conventional 13.56 MHz, that is, changing the frequency in the range of 25 MHz to 150 MHz. , 70 MHz, the film deposition rate is the highest at 2.1 nm / s, which is about 5 to 8 times that of the above-described plasma CVD method using 13.56 MHz high frequency power. It is described that the formation rate and the defect density, optical band gap and conductivity of the obtained a-Si film are not significantly affected by the excitation frequency. In addition, reports of increasing the discharge frequency have been reported for sputtering and the like, and have been widely studied in recent years. The conventional example of Document 1 is an example of a plasma CVD method suitable for processing a flat substrate, but an example of a plasma CVD method suitable for forming a deposited film on a plurality of cylindrical substrates is described below. JP-A-60-186849
(Hereinafter referred to as “Document 2”). This document 2 discloses a plasma CVD method using a microwave energy source of a frequency of 2.45 GHz and a plasma CVD method using a radio frequency energy (high frequency power) source.

The RF plasma CVD method using the high-frequency power source described in Document 2 will be described. The plasma CVD method is a plasma CVD apparatus based on the RF plasma CVD method described in Document 2. Six substrate holders are arranged concentrically at predetermined intervals in the reaction vessel. The cylindrical substrate is provided on a substrate holder. A heater is provided inside each substrate holder so that the cylindrical substrate can be heated from the inside. Each substrate holder is connected to a shaft connected to a motor so that it can rotate. The high-frequency electrode is located at the center of the plasma generation region. The high-frequency electrode is connected to a high-frequency power supply via a matching circuit. The exhaust pipe communicates with an exhaust mechanism provided with a vacuum pump. The source gas supply system includes a gas cylinder, a mass flow controller, a valve, and the like. The source gas supply system is connected to a gas discharge pipe having a plurality of gas discharge holes via a gas supply pipe.

[0007] Plasma CVD using this method
Is performed as follows. After the reaction vessel is evacuated to a high vacuum by an exhaust mechanism, a source gas is introduced into the reaction vessel from a gas supply means via a gas supply pipe and a gas discharge pipe, and is maintained at a predetermined pressure. In such a case, high-frequency power is supplied from the high-frequency power source to the high-frequency electrode via the matching circuit to generate plasma between the high-frequency electrode and the cylindrical substrate. By doing so, the source gas is decomposed and excited by the plasma, and a deposited film is formed on the cylindrical substrate. The use of the plasma CVD method has an advantage that the raw material gas can be used with high utilization efficiency since the discharge space is surrounded by the cylindrical substrate.

[0008]

However, the frequency of 25 to 15 in the parallel plate type apparatus described in the prior art document 1 is used.
The film formation by the high frequency power of 0 MHz is a laboratory scale, and there is no mention as to whether such an effect can be expected in the formation of a large-area film. In general, as the excitation frequency becomes higher, the effect of the standing wave on the high-frequency electrode becomes remarkable, and particularly, a two-dimensional complicated standing wave is generated in a flat electrode. For this reason, it is expected that it will be difficult to form a large-area film uniformly. Further, when a deposited film is formed on the entire surface of a cylindrical substrate described in Reference 2 of the related art, it is necessary to rotate the cylindrical substrate. However, there is a problem that it is reduced to about 1/3 to 1/5 of that in the case of using the plasma CVD method of the mold type. That is,
Since the discharge space is surrounded by the cylindrical substrate, a deposition film is formed at a position at which the cylindrical substrate faces the high-frequency electrode at a deposition rate similar to that of the parallel plate type plasma CVD method. This is because a deposited film is hardly formed at a position where no deposition is performed. Further, in Reference 2,
No specific frequency of the high frequency power is mentioned.

Therefore, the present invention solves the above-mentioned problems in the prior art, and enables a stable discharge, a very uniform film thickness, and a high-quality deposited film on a large-area substrate of various shapes. It is an object of the present invention to provide a deposited film forming method and a deposited film forming device by plasma processing that can be formed stably at a high speed.

[0010]

According to the present invention, in order to achieve the above object, a method and an apparatus for forming a deposited film by plasma processing are configured as described in the following (1) to (22). It is characterized by the following. (1) The method for forming a deposited film according to the present invention comprises the steps of:
A high-frequency power of 0 MHz or more and 600 MHz or less is applied to generate plasma between the film-forming substrate serving as a counter electrode, and the source gas introduced into the reaction vessel is decomposed to form a plasma on the film-forming substrate. A method for forming a deposited film, wherein the high-frequency electrode is composed of a plurality of high-frequency electrodes, and high-frequency power divided from the same power source is supplied to these high-frequency electrodes via a high-voltage capacitor to form a deposited film. It is characterized by doing. (2) The method for forming a deposited film according to the present invention includes forming the deposited film such that the surface area per one high-frequency electrode is equal to or smaller than the surface area per the substrate to be processed. Features. (3) In the method of forming a deposited film according to the present invention, the high-frequency electrode is
It is characterized in that the deposited film is formed by covering with a dielectric member. (4) The method of forming a deposited film according to the present invention is characterized in that a plurality of the substrates to be deposited are arranged to form a deposited film. (5) In the method for forming a deposited film according to the present invention, the reaction container is a cylindrical reaction container, and a plurality of cylindrical film-forming substrates to be disposed on a circumference are provided with a plurality of reaction containers. It is characterized in that rod-shaped high-frequency electrodes are arranged concentrically to form a deposited film. (6) The method for forming a deposited film according to the present invention is characterized in that a deposited film is formed on the surface of the cylindrical substrate to be processed while rotating the substrate. (7) In the method of forming a deposited film according to the present invention, the frequency of the high-frequency power applied to the high-frequency electrode is 60 MHz to 300 MHz.
It is characterized by being in the range of z. (8) The method of forming a deposited film according to the present invention is characterized in that the substrate is a flat substrate, and a single or a plurality of plate-like high-frequency electrodes are arranged in parallel with the flat substrate to form a deposited film. And (9) In the method of forming a deposited film according to the present invention, the substrate is a sheet-like substrate which is sent out from a holding roll during film formation and is wound up by a take-up roll. It is characterized in that electrodes are arranged and a deposited film is formed. (10) The method for forming a deposited film according to the present invention, wherein the deposited film is:
It is characterized by being silicon, germanium, carbon, or any alloy thereof. (11) The method for forming a deposited film according to the present invention is characterized in that the deposited film is for an electrophotographic photosensitive member. (12) The method for forming a deposited film of the present invention is characterized in that the deposited film is for a solar cell. (13) The method for forming a deposited film according to the present invention is characterized in that the deposited film is for a thin film transistor. (14) The apparatus for forming a deposited film according to the present invention includes a conductive high-frequency electrode for plasma generation arranged in a reaction vessel capable of reducing pressure,
A high frequency power of 30 MHz or more and 600 MHz or less is applied by a high frequency power source to generate plasma between the film forming substrate serving as a counter electrode and decompose the source gas introduced into the reaction vessel to form the film. A deposition film forming apparatus for forming a deposition film on a processing substrate, wherein the high-frequency electrode includes a plurality of high-frequency electrodes, and a high-frequency power is divided and supplied to the high-frequency electrodes from the same power supply; A high-voltage capacitor is provided between each power dividing point and the plurality of high-frequency electrodes. (15) The apparatus for forming a deposited film according to the present invention,
It is characterized in that the surface area per unit is equal to or smaller than the surface area per unit of the film forming substrate. (16) The deposited film forming apparatus of the present invention is characterized in that the high-frequency electrode is covered by a dielectric member. (17) The apparatus for forming a deposited film according to the present invention is characterized in that a plurality of the substrate to be film-formed can be arranged in the reaction vessel. (18) In the apparatus for forming a deposited film of the present invention, the reaction vessel
A cylindrical reaction vessel, wherein a plurality of rod-shaped high-frequency electrodes are concentrically arranged with respect to a plurality of cylindrical film-forming substrates to be disposed on the circumference. . (19) The deposited film forming apparatus according to the present invention is characterized in that the cylindrical substrate is rotatable. (20) In the deposited film forming apparatus of the present invention, the frequency of the high-frequency power applied to the high-frequency electrode by the high-frequency power source is 6
The frequency range is 0 MHz to 300 MHz. (21) In the apparatus for forming a deposited film of the present invention, the substrate to be film-formed is a flat substrate, and a single or a plurality of plate-like high-frequency electrodes are arranged in parallel to the flat substrate. It is characterized by. (22) In the deposited film forming apparatus of the present invention, the film-forming substrate is a sheet-like substrate which is sent out from a holding roll at the time of film-forming and wound up by a take-up roll. In which one or more high-frequency electrodes are arranged.

[0011]

Embodiments of the present invention will be described below. The present inventors set the frequency of the high-frequency power to 3
When the frequency is set to 0 MHz or more, discharge in a high vacuum region where a gas phase reaction does not easily occur becomes possible, and very excellent film characteristics can be obtained. The deposition rate is improved as compared with the case of 13.56 MHz. It has been found that there is a problem in the stability of discharge in a high vacuum region and that the distribution of film quality and deposition rate deteriorates. Therefore, the present inventors set the frequency of the high-frequency power to 30.
When the frequency is higher than MHz, discharge in a high vacuum region becomes possible, but there is still a problem in stability, and intensive studies were conducted to clarify the cause of uneven film quality deterioration and deposition rate reduction. The present invention has been completed based on the knowledge obtained through the experiment.

First, the present inventors have presumed that the problem of the stability of discharge in a high vacuum region is that the impedance change before and after discharge is too large. In a discharge in a high vacuum region, a voltage that causes and maintains a discharge is higher than that in a relatively simple low vacuum region. In the case of high-frequency discharge, glow discharge is usually constant power, and discharge is maintained by performing impedance conversion of constant power through a matching circuit in accordance with a discharge load. In this case, for example, in an extreme case, when an instantaneous arc discharge occurs, the impedance is instantaneously reduced, the discharge becomes a low voltage and a large current, the glow discharge cannot be maintained, and the discharge disappears. At this time, if the impedance change before and after the discharge is too large, the impedance conversion by the matching circuit will not be successful, and the discharge will continue to disappear.

Next, the present inventors have conducted intensive studies to elucidate the cause of the uneven distribution of the film quality when the frequency of the high-frequency power is set to 30 MHz or more. As a result, it was found that there was a strong correlation between the plasma potential distribution and the uneven distribution of the film quality. That is, when the plasma potential was measured along the axial direction of the cylindrical substrate by the Langmuir probe method, a decrease in the plasma potential was observed at a position corresponding to a position where the film quality was unevenly deteriorated. From these examination results, it was inferred that the deterioration of the film quality distribution and the deposition rate distribution was caused by the standing wave generated on the high-frequency electrode and the attenuation of the high-frequency power on the high-frequency electrode. In general, when plasma is generated by applying high-frequency power between a high-frequency electrode and a counter electrode, a non-negligible standing wave may be generated on the electrode due to the relationship between the frequency of the high-frequency power applied to the electrode and the size of the electrode. is there. That is, when the frequency of the high-frequency power is high or when the area of the high-frequency electrode is large, a standing wave is likely to be generated. Plasma distribution such as plasma density, plasma potential, and electron temperature of
This has an adverse effect on the film formation quality of VD. In the above-described experiment, it is considered that a reflected wave was generated on the high-frequency electrode at the tip of the high-frequency electrode, and a standing wave that affected the film quality and deposition rate was generated at a frequency of 30 MHz or more due to interference with the incident wave. . In particular, it is considered that the electric field was weakened at the position of the node of the standing wave, which caused the uneven distribution of the plasma potential and the film quality was unevenly deteriorated. In addition, as the frequency of the high-frequency power increases, the high-frequency power is more absorbed into the plasma, and the farther away from the point of supplying the high-frequency power to the high-frequency electrode, the higher the attenuation of the high-frequency power becomes, which adversely affects the deposition rate distribution. In addition, 400MH
At a frequency of z to 600 MHz, it is considered that the nodes of the standing wave occurred at a plurality of positions while the high-frequency power was attenuated from the feeding point. In addition, when power is divided and supplied from the same power source, unevenness occurs between the substrates unless power is supplied to each high-frequency electrode uniformly. The above-described configurations (1) to (22) of the present invention have been completed based on the above-described examination results.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. First, a deposition film forming method using plasma will be described. 6 and 7
Is a plasma CVD apparatus without a high-voltage capacitor for comparison with the plasma CVD apparatus according to the embodiment of the present invention.
FIG. 2 is a schematic cross-sectional configuration diagram of the device. 6 and 7, high-frequency power generated by a high-frequency power supply 105 is supplied to a high-frequency electrode 102 via a matching circuit 104. The high-frequency electrode 102 has a simple rod-like antenna shape. Usually, the high-frequency electrode 102 itself has a skin resistance (R).
And the series impedance of inductance (L). The base 103 facing the high-frequency electrode 102 is grounded at the end but has sufficient inductance, and is similarly described by the series impedance (R + jωL) of the skin resistance (R) and the inductance (L). When no plasma is generated, the high-frequency electrode 102 and the base 10
3 has a capacitance (C) determined by its positional relationship and shape. Since the high-frequency current flowing through the high-frequency electrode 102 is determined by the capacitance (C) between the high-frequency electrode 102 and the base 103, the high-frequency electrode 102 and the base 10
The easiness of plasma generation is greatly affected by the positional relationship and the shape of the plasma 3, and even a slight change in the positional relationship requires adjustment for optimization. On the other hand, once the plasma is generated, the plasma becomes a conductor having resistance, and the ion sheath between the high-frequency electrode 102 and the base 103 and the plasma becomes a capacitance. When the capacitance is the same as the area and the dielectric constant of the medium, the capacitance is inversely proportional to the distance between the conductors.
Is much thinner than that of the distance, and its capacitance is large. Therefore, the high-frequency electrode 102 and the base 10 before and after the plasma is generated
The change in impedance between the three is large, so that it is very difficult to adjust the matching circuit 105, and it is also difficult to generate plasma. In addition, even if a slight change in plasma is used, the impedance is largely changed, and matching cannot be made in time even if an automatic matching circuit is used. In the worst case, the plasma disappears.
Further, even if a discharge is generated, the film thickness and film quality of the films deposited on the plurality of substrates 103 vary greatly among the substrates, and stable production may not be performed. This is considered to be because the high frequency power is not evenly supplied to each high frequency electrode 102, and is presumed to be due to the difference in the impedance Z applied to each load.

On the other hand, as shown in FIGS. 1 to 4, in the configuration according to the present embodiment via a high-voltage capacitor after the high-frequency power dividing section and before the power supply point of the high-frequency electrode 102, the high-frequency power is divided. Therefore, the high frequency L component of the propagation path becomes large, so that the state of mismatch can be canceled by using the high voltage capacitor 113, so that a stable discharge can be formed, and a deposited film can be formed stably. Further, since the reflected wave of the high-frequency power from the tip of the cathode 102 can be controlled, the high-frequency power can be uniformly supplied to the high-frequency electrode 102.

In the embodiment of the present invention, any known dielectric material can be selected for the dielectric cover 109, but a material having a small dielectric loss is preferable.
Preferably, the dielectric loss tangent is 0.01 or less, more preferably 0.001 or less. For polymer dielectric materials, polytetrafluoroethylene, polytetrafluorochloride ethylene, polyfluoroethylene propylene, polyimide and the like are preferable, for glass materials, quartz glass and borosilicate glass are preferable, and for porcelain materials, boron nitride and nitride are preferable. A porcelain mainly containing one or more elemental oxides among elemental oxides such as silicon, aluminum nitride, aluminum oxide, magnesium oxide, and silicon oxide is preferable. In the embodiment of the present invention, the high-frequency electrode 1
The shape of 02 is preferably a rod shape such as a columnar shape, a cylindrical shape, a polygonal column shape, or a long plate shape. In the embodiment of the present invention, the frequency of the high frequency power supply 105 is preferably 3
It is desirable that the frequency range be 0 to 600 MHz, more preferably 60 to 300 MHz.

In the embodiment of the present invention, when using the plasma CVD method, as a gas to be used, a known source gas contributing to film formation is appropriately selected and used according to the type of deposited film to be formed. You. For example, a-Si
In the case of forming a system deposition film, silane, disilane, high disilane, or the like, or a mixed gas thereof is mentioned as a preferable source gas. In the case of forming another deposited film, for example, a raw material gas such as germane, methane, or ethylene, or a mixed gas thereof may be used. In any case, the source gas for film formation can be introduced into the reaction vessel together with the carrier gas. Examples of the carrier gas include a hydrogen gas and an inert gas such as an argon gas and a helium gas. It is also possible to use a gas for improving characteristics such as adjusting the band gap of the deposited film. Examples of such a gas include a gas containing a nitrogen atom such as nitrogen and ammonia; a gas containing an oxygen atom such as oxygen, nitric oxide and nitrous oxide; a hydrocarbon gas such as methane, ethane, ethylene, acetylene, and propane; A gaseous fluorine compound such as silicon fluoride, disilicon hexafluoride, and germanium tetrafluoride, or a mixed gas thereof may be used. A dopant gas may be used for doping the deposited film to be formed. Examples of such a doping gas include gaseous diborane, boron fluoride, phosphine, and phosphorus fluoride. In the embodiment of the present invention, the substrate temperature at the time of forming a deposited film can be set as appropriate. However, when an amorphous silicon-based deposited film is formed, the temperature is preferably from 60 ° C. to 400 ° C.
More preferably, the temperature is set to 100 ° C to 350 ° C. Further, the following means can be used in a parallel plate type apparatus and can be easily applied.

[0018]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited by these examples. [Embodiment 1] In Embodiment 1 of the present invention, the inside of the reaction vessel 100 is evacuated by the vacuum evacuation means 106 using the plasma CVD apparatus shown in FIG. After heating, a plurality of high-frequency electrodes 102 are provided in the reaction vessel 100, and a high-frequency power supply 105
The generated high-frequency power is supplied to the high-frequency electrode 102 via a matching circuit 104, and the source gas supply means 10
The source gas supplied from 7 was turned into plasma to form a deposited film on one substrate 103 to be processed.

The high-frequency electrode 102 is covered with a dielectric cover 109 made of alumina ceramics. The other film forming conditions are as shown in Table 1, and the amorphous film is formed on the cylindrical base 103 and the electric characteristic evaluation substrate. A silicon film was formed. After the power dividing point and before the high-frequency electrode feeding point,
A high-voltage condenser 113 is provided. Based on the above conditions, the film quality, film quality distribution, and deposition rate distribution of the amorphous silicon film deposited on the # 7059 glass substrate were evaluated. The film was formed under pressure conditions of 50 mTorr, 25 mTorr, and 5 mTorr.

In the case of a sample using high-frequency power having a frequency of 30 MHz, a film formed under a pressure condition of 50 mTorr has a light sensitivity of 8 × 10 ³ to 2 × in all samples.
It was in the range of 10 ⁴ , and there was no practical problem. The deposition rate distribution was 8%. Films formed under a pressure condition of 25 mTorr have a light sensitivity of 1 × 10 ^{4 to} 3 in all samples.
It was in the range of × 10 ⁴ and had good film properties. The deposition rate distribution was 8%. Further, discharge could not be generated under the pressure condition of 5 mTorr.

In the case of a sample using high-frequency power having a frequency of 60 MHz to 300 MHz, a film formed under a pressure condition of 50 mTorr has a light sensitivity of 1 in all samples.
It was in the range of × 10 ^{4 to} 3 × 10 ⁴ , indicating good film properties. The deposition rate distribution was 4-6%. 25mTorr
In all of the samples, the film formed under the above pressure conditions had a photosensitivity of 4 × 10 ⁴ to 8 × 10 ⁴ , indicating good film characteristics.
The deposition rate distribution was 4-6%. Films formed under a pressure condition of 5 mTorr have a light sensitivity of 1 in all samples.
× 10 ^{5 to} 5 × 10 ⁵ , which were very excellent film properties. The deposition rate distribution was 5%. As a result, a stable discharge can be generated even in a low pressure region by increasing the discharge frequency.

In the case of a sample using high-frequency power having a frequency of 400 MHz to 600 MHz, the film formed under a pressure condition of 50 mTorr has a light sensitivity in the range of 7 × 10 ³ to 1 × 10 ⁴ in all the samples, which is a practical problem. No film properties. The deposition rate distribution was 6-9%. 25
Films formed under mTorr pressure conditions had photosensitivity of 1 × 10 ^{4 to} 3 × 10 ⁴ in all samples, indicating good film characteristics. The deposition rate distribution was 6-9%. 5mTo
Films formed under the rr pressure condition had photosensitivity of 5 × 10 ⁴ to 8 × 10 ⁴ in all samples, and had good film characteristics. The deposition rate distribution was 6-8%. Also, under all conditions, unevenness in the distribution of film thickness between cylinders
Did not occur. That is, it means that a uniform plasma was generated in the discharge space.

[0023]

[Table 1] [Embodiment 2] Embodiment 2 of the present invention has a plurality of high-frequency electrodes and a plurality of film-forming substrates shown in FIGS. 2 and 3, and before a high-frequency power supply point after a power division point. Using an apparatus provided with a high-voltage capacitor 113, an amorphous silicon film was formed on the amorphous silicon film in the same manner as in Example 1 under the condition 2 in Table 1.
The deposition was performed under the condition of 5 mTorr. For comparison, an amorphous silicon film was deposited under the same conditions in the apparatus shown in FIG. 7 without the high-voltage capacitor 113. In the case of the apparatus having no high-voltage capacitor 113 shown in FIG. 7, the matching may not be performed, and the discharge may not be stable. In addition, even when the discharge is stable, when a deposited film is formed on a plurality of substrates to be processed, a large unevenness in film thickness occurs between the respective substrates to be processed. Had occurred. In this situation, it was considered that power was not uniformly supplied to the high-frequency electrode.

However, in the present embodiment in which the high-voltage capacitor 113 of FIGS. 2 and 3 is installed on each electrode after the power division point and before the power supply point of the high-frequency electrode 102, the L component can be canceled and the matching can be achieved. Was obtained stably, and as a result, a stable discharge was obtained, and the film thickness unevenness between the respective substrates to be processed was about 3%. This is considered that the power is divided equally between the high-frequency electrodes 102.

The amorphous silicon deposited according to this embodiment was a high quality deposited film having no practical problem. Also, a discharge experiment was performed using a high-frequency power supply 105 having a frequency of 100 MHz under the conditions of 5 mTorr in Table 1.
In this experimental example, the stability of discharge was confirmed by changing the reactance L between the main circuit and the load (high-frequency electrode) to 111.13 nH and changing the capacity of the high-voltage capacitor to be installed. Table 2 shows the results. From the results in Table 2, it is clear that by installing a capacitor having an appropriate capacitance between the matching circuit and the load, the L component is canceled and stable discharge is possible.

[0026]

[Table 2] Example 3 In Example 3, a deposited film was formed by the following method using the apparatus described in Example 2 described above. In the electrophotographic photoreceptor, six aluminum cylindrical substrates having a diameter of 108 mm, a length of 358 mm, and a thickness of 5 mm were placed in a reaction vessel under the film forming conditions shown in Table 3, and the discharge frequency was set to 100 MHz. The charge injection blocking layer, the photoconductive layer, and the surface protective layer were formed in this order under the conditions shown in (1). One of the six cylindrical substrates on which the amorphous silicon film is formed has an axial direction of about 2
A line is drawn every 0 mm, and the film thickness is measured using an eddy current film thickness meter at an intersection 180 when a line is drawn every 32 mm in the circumferential direction, and the deposition rate at each measurement point is calculated. The average of the values obtained was taken as the average deposition rate. The obtained average deposition rate was 4.0 nm / s, and the deposition rate was significantly higher than that of the apparatus described in the conventional example, and the productivity was improved. The deposition rate distribution in the axial direction is obtained by calculating the difference between the maximum value and the minimum value of the deposition rate at nine measurement points in one row in the axial direction, dividing the difference by the average deposition rate at 18 locations, and calculating the deposition rate per row. The distribution was determined. As a result, the film thickness unevenness in the axial direction was 4
%, And also about 7% in the circumferential direction.

Further, a deposited film is further formed under the same conditions,
The charging ability, image density, and image defects of the electrophotographic photosensitive member were evaluated. As a result, all of the electrophotographic photosensitive members showed extremely excellent results over the entire surface of the electrophotographic photosensitive member with respect to these evaluation items. Further, the film thickness distribution of the deposited film was measured to be about 10%, which was sufficient for practical use such as an electrophotographic photosensitive member device and an image input line sensor.

[0028]

[Table 3] [Embodiment 4] In the embodiment 4, using the apparatus of the present invention shown in FIG. 4, a 400 mm long, 400 mm wide and 1 mm thick #
A flat substrate made of 7059 glass was placed in a reaction vessel to form a film. As shown in FIG. 4, five high-frequency electrodes were arranged in the reaction vessel. An amorphous silicon film was formed on a flat substrate under the film forming conditions shown in Table 3 using a high-frequency power source having a frequency of 150 MHz, and the deposition rate and deposition rate distribution were evaluated in the following procedure. The film thickness was measured using the eddy current film thickness meter used in Experiment 1, the deposition rate at each measurement location was calculated, and the average of the obtained values was defined as the average deposition rate.
The average deposition rate obtained was 4.6 nm / s. The deposition rate distribution determines the difference between the maximum value and the minimum value of the deposition rate,
The difference was divided by the average deposition rate and expressed as a deposition rate distribution as a percentage. The obtained deposition rate distribution was 13%, which was enough to withstand the electrophotographic photoreceptor device and the line sensor for image input.

Example 5 In Example 5, using the parallel plate type apparatus shown in FIG. 4, the stainless steel sheet-like substrate of FIG. 5 was placed in a reaction vessel and wound on a winding roll. The membrane was made. As the high-frequency electrodes, three high-frequency electrodes were arranged in a reaction vessel. The frequency of the high frequency power supply is 150M
Hz, an amorphous silicon film was formed on the sheet-like substrate under the film forming conditions shown in Table 3, and the length was 500 mm.
Was cut out, and the deposition rate and the deposition rate distribution were evaluated in the same procedure as in Example 4. The obtained average deposition rate was 3.6 nm / s, and the deposition rate distribution was 16%. The deposition rate was much higher than in the conventional example, and not only the productivity was improved, but also the uniformity was significantly improved. .

[0030]

As described above, according to the present invention,
A high-quality deposited film having a very uniform thickness and uniform film quality can be formed on a large-area substrate having various shapes such as a cylindrical substrate, a flat substrate, and a sheet substrate at a high speed. In addition, stable discharge is possible, and even when a large number of substrates are produced at the same time, unevenness of each substrate hardly occurs.
Large area high quality deposited film can be efficiently produced,
In particular, large-area semiconductor devices having excellent electrophotographic characteristics can be stably mass-produced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of an apparatus in which a substrate to be processed and a plurality of cathode electrodes are present and a high-voltage capacitor is installed in a plasma CVD apparatus of the present invention.

FIG. 2 is a longitudinal sectional view showing an example of an apparatus in which a film-forming substrate and a high-frequency electrode are concentrically arranged and a high-voltage capacitor is installed in the plasma CVD apparatus used in Example 2 of the present invention. is there.

FIG. 3 shows an example of an apparatus in which a plurality of film-forming substrates and a plurality of high-frequency electrodes are arranged concentrically and a high-voltage capacitor is installed in the plasma CVD apparatus used in Example 2 of the present invention. FIG.

FIG. 4 shows a parallel plate type apparatus 1 in a plasma CVD apparatus provided with a high-voltage capacitor used in Example 4 of the present invention.
It is a schematic diagram which shows an example.

FIG. 5 is a schematic diagram of a roll-shaped substrate to be subjected to film formation used in Example 5 of the present invention.

FIG. 6 is a schematic cross-sectional configuration diagram of a plasma CVD apparatus with a high-voltage capacitor removed for comparison with the plasma CVD apparatus according to the embodiment of the present invention.

FIG. 7 is a schematic vertical cross-sectional configuration view of a plasma CVD apparatus with a high-voltage capacitor removed for comparison with the plasma CVD apparatus according to the embodiment of the present invention.

FIG. 8 is a schematic configuration diagram of a conventional plasma CVD apparatus.

[Explanation of symbols]

 100: Reaction vessel 101: Earth shield 102: Cathode electrode (electrode for high frequency) 103: Substrate to be processed 104: Matching circuit 105: High frequency power supply 106: Vacuum exhaust means 107: Gas supply means 108: Motor 109: Dielectric member 110: Source gas supply pipe 111: heater 112: substrate holder 113: high-pressure condenser 114: insulating member 115: sheet-like roll

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H068 DA00 EA24 4K030 BA09 BA27 BA29 CA12 CA14 CA17 FA03 GA05 GA14 JA18 KA05 KA15 KA46 5F045 AA08 AB02 AB04 AB05 AB07 AC01 AC19 AD06 AE15 AE17 AF08 AF10 CA13 CA15 CA16 DP10 DP22 DP25 D25D EH13 5F051 AA05 BA12 CA16 CA23

Claims (22)

[Claims] 1. A high-frequency electrode for generating conductive plasma, which is disposed in a reaction vessel capable of reducing pressure, has a frequency of 30 MHz to 600 M
A high-frequency power of less than or equal to Hz is applied to generate plasma between the film-forming substrate serving as a counter electrode, and the source gas introduced into the reaction vessel is decomposed and deposited on the film-forming substrate. A method for forming a deposited film, wherein the high-frequency electrode is composed of a plurality of high-frequency electrodes, and high-frequency power divided from the same power supply is supplied to these high-frequency electrodes via a high-voltage capacitor to form a deposited film. A method for forming a deposited film. 2. The method according to claim 1, wherein a surface area per one high-frequency electrode is equal to a surface area per one substrate to be processed.
The method according to claim 1, wherein the deposition film is formed with a surface area smaller than that of the deposition film. 3. The method according to claim 1, wherein the high-frequency electrode is covered with a dielectric member to form a deposited film. 4. The deposition film forming method according to claim 1, wherein a plurality of said deposition target substrates are arranged to form a deposition film. 5. The reaction vessel according to claim 1, wherein the reaction vessel is a cylindrical reaction vessel, and a plurality of rod-shaped high-frequency electrodes are concentrically arranged with respect to a plurality of cylindrical deposition target substrates arranged on a circumference. The method of forming a deposited film according to any one of claims 1 to 4, wherein the deposited film is formed in such a manner as to form a deposited film. 6. The deposition film forming method according to claim 5, wherein the deposition film is formed on the surface of the cylindrical film-forming substrate while rotating the substrate. 7. The method according to claim 1, wherein a frequency of the high-frequency power applied to the high-frequency electrode ranges from 60 MHz to 300 MHz. 8. The substrate according to claim 1, wherein the substrate is a flat substrate, and one or more high-frequency plate-like electrodes are arranged in parallel to the flat substrate to form a deposited film. Item 3. The method for forming a deposited film according to Item 2. 9. A sheet-like substrate which is sent out from a holding roll during film formation and wound up by a take-up roll, wherein one or more high-frequency electrodes are arranged in parallel with the sheet-like substrate. The method according to claim 1, wherein: 10. The method according to claim 1, wherein the deposited film is made of silicon, germanium, carbon, or an alloy thereof. 11. The method according to claim 1, wherein the deposited film is for an electrophotographic photosensitive member. 12. The method according to claim 1, wherein the deposited film is for a solar cell. 13. The method according to claim 1, wherein the deposited film is for a thin film transistor. 14. A high-frequency power source is connected to a conductive high-frequency electrode for generating plasma arranged in a reaction vessel capable of reducing pressure.
A high-frequency power of MHZ to 600 MHz is applied to generate plasma between the film-forming substrate serving as a counter electrode, and the source gas introduced into the reaction vessel is decomposed to form a plasma on the film-forming substrate. A high-frequency electrode comprising a plurality of high-frequency electrodes, wherein a high-frequency power is divided and supplied to the high-frequency electrodes from the same power supply; A deposited film forming apparatus, wherein a high-voltage capacitor is provided between a point and each of the plurality of high-frequency electrodes. 15. The surface area per one high-frequency electrode is as follows:
15. The deposited film forming apparatus according to claim 14, wherein the surface area is equal to or smaller than the surface area per one substrate to be film-formed. 16. An apparatus according to claim 14, wherein said high-frequency electrode is covered by a dielectric member. 17. The apparatus according to claim 1, wherein a plurality of said film formation processing substrates can be arranged in said reaction vessel.
The deposited film forming apparatus according to any one of claims 4 to 16. 18. The reaction vessel is a cylindrical reaction vessel, and a plurality of rod-shaped high-frequency electrodes are concentrically arranged with respect to a plurality of cylindrical deposition target substrates arranged on a circumference. The deposition film forming apparatus according to any one of claims 14 to 17, wherein the deposition film forming apparatus is arranged in a matrix. 19. The apparatus according to claim 18, wherein said cylindrical substrate is rotatable. 20. A high-frequency power applied to a high-frequency electrode by the high-frequency power source has a frequency of 60 MHz to 300 MHz.
20. The deposition film forming apparatus according to claim 14, wherein z is z. 21. A substrate according to claim 14, wherein said film-forming substrate is a flat substrate, and one or more plate-like high-frequency electrodes are arranged parallel to said flat substrate. Alternatively, the deposited film forming apparatus according to claim 15. 22. The substrate to be film-formed is a sheet-like substrate which is sent out from a holding roll during film formation and wound up by a take-up roll, and a single or a plurality of high-frequency electrodes are arranged in parallel with the sheet-like substrate. The deposited film forming apparatus according to claim 14 or 15, wherein are arranged.