JP2001335944A - System and method for plasma treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system and a method for plasma treatment, in which a substrate of relatively large area can be treated uniformly by means of stable plasma at such a high treatment speed as impossible to attain by the conventional process. SOLUTION: In this system or method for plasma treatment for forming a deposit film on a substrate to be subjected to film deposition treatment, a phase control means for controlling the phase of high-frequency power to be applied to a plurality of cathode electrodes is provided. Uniform plasma treatment is performed by controlling, by this phase control means, the phase of the high-frequency power propagated to each of the above plurality of cathode electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus and a plasma processing method, and is particularly useful for an electrophotographic photosensitive member device as a semiconductor device, an image input line sensor, an imaging device, a photovoltaic device, and the like. A plasma CVD apparatus and a film forming method capable of suitably forming a crystalline or non-single-crystalline functional deposition film, or 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. The present invention relates to a plasma processing apparatus and a plasma processing method such as a film method or an etching apparatus and a method for a semiconductor device.

[0002]

2. Description of the Related Art In recent years, in a process for manufacturing a semiconductor device or the like, a plasma CVD apparatus and a plasma CVD method have been industrially put to practical use. In particular, a plasma CVD apparatus using a high frequency of 13.56 MHz or a microwave of 2.45 GHz is widely used because a substrate material, a deposited film material, and the like can be processed regardless of a conductor or an insulator. As an example of a conventional high-frequency electrode for plasma generation and a plasma CVD method using the high-frequency electrode, a method using a parallel plate type apparatus will be described with reference to FIG. A high-frequency electrode 102 is arranged in the reaction vessel 100 via an insulating high-frequency electrode support. 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. An earth shield 101 is arranged around the high-frequency electrode 102 so that no discharge occurs between the side of the high-frequency electrode 102 and the reaction vessel 100. A high frequency power supply 105 is connected to the high frequency electrode 102 via a matching circuit 104 and a high frequency power supply line. On a counter electrode arranged in parallel with the high-frequency electrode 102, a flat plate-shaped substrate 103 for performing plasma CVD is arranged.
A desired temperature is maintained by a substrate temperature control means (not shown).

[0003] Plasma CVD using this apparatus
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.

[0004] In view of these problems, the frequency is 25 to 1
Studies have been made on a plasma CVD method using a high frequency of about 50 MHz. For example, Plasma Ch
emistry and Plasma Processes
sing, Vol 7, No3, (1987) p26
No. 7-273 (hereinafter referred to as “Document 1”) discloses that a raw material gas (silane gas) is decomposed with a high frequency power of 25 to 150 MHz using a parallel plate type glow discharge decomposition apparatus to obtain amorphous silicon (a- It describes that a Si) film is formed. Specifically, in Document 1, a-S is changed by changing the frequency in the range of 25 MHz to 150 MHz.
When an i-film is formed and 70 MHz is used, the film deposition rate is the highest at 2.1 nm / sec, which is about 5 to 8 times that in the case of the above-described plasma CVD method using 13.56 MHz. It is described that the formation rate is high, and that the defect density, optical band gap, and conductivity of the obtained a-Si film are not significantly affected by the excitation frequency.

The above conventional example is an example of a deposited film forming method using a plasma CVD apparatus suitable for processing a flat substrate, but is suitable for forming a deposited film on a plurality of cylindrical substrates. One example of a deposited film forming method using a plasma CVD apparatus is described in Japanese Patent Application Laid-Open No. 60-186849 (hereinafter referred to as “Document 2”). Reference 2 discloses a plasma CVD apparatus using a microwave energy source having a frequency of 2.45 GHz and radio frequency energy (high frequency power).
A plasma CVD apparatus using a source is disclosed. An RF plasma CVD apparatus using the high-frequency power source of Document 2 will be described with reference to the drawings. The plasma CVD apparatus shown in FIGS.
This is a plasma CVD apparatus based on the plasma CVD apparatus. 13A and 13B, reference numeral 100 denotes a reaction vessel. In the reaction vessel 100, six substrate holders 1 are provided.
12 are concentrically arranged at predetermined intervals. 103 is a cylindrical substrate for film formation arranged on each substrate holder 112. A heater 111 is provided inside each of the substrate holders 112 and the cylindrical substrate 103 is provided.
Can be heated from the inside.

Further, each base holder 112
It is connected to a shaft connected to a motor 108 and is rotatable. Reference numeral 102 denotes an antenna-type high-frequency electrode located at the center of the plasma generation region. The high-frequency electrode 102 is connected to the high-frequency power source 1 via a matching circuit 104.
05. The exhaust pipe communicates with an exhaust mechanism 106 having a vacuum pump. Reference numeral 107 denotes a source gas supply system including 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 apparatus
Is performed as follows. Exhaust mechanism 1 for reaction vessel 100
06, the gas supply means 10
From 7, a source gas is introduced into the reaction vessel 100 via a gas supply pipe and a gas discharge pipe, and is maintained at a predetermined pressure. At this point, high-frequency power is supplied from the high-frequency power supply 105 to the high-frequency electrode 102 via the matching circuit 104 to generate plasma between the high-frequency electrode and the cylindrical base 103. By doing so, the source gas is decomposed and excited by the plasma, and a deposited film is formed on the cylindrical substrate 103. Plasma CVD shown in FIGS. 13A and 13B
The use of the apparatus has the advantage that the source space can be used with high utilization efficiency since the discharge space is surrounded by the cylindrical base 103.

[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 increases, the effect of the standing wave on the high-frequency electrode becomes remarkable, and a two-dimensional complicated standing wave is generated particularly in the case of a flat electrode. For this reason, it is expected that it will be difficult to form a large-area film uniformly. Also,
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. There is a problem that it is reduced to about 1/3 to 1/5 of the case where a plasma CVD apparatus is used. 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 apparatus. This is because a deposited film is hardly formed at a position not in contact with the substrate.

Reference 2 does not mention the specific frequency of the high-frequency power. Using the plasma CVD apparatus shown in FIG. 13 by the present inventors, a general high-frequency power of 13.56 MHz and a source gas of SiH ₄ are used, and the deposition rate becomes high, but this may cause deterioration of the film quality such as polysilane. Several hundreds of powders that are likely to be generated
When the cylindrical substrate was rotated under mTorr pressure conditions to deposit an amorphous silicon film over the entire surface of the substrate, the substantial deposition rate was at most 0.5 nm / s.
For example, when an electrophotographic photosensitive member using an amorphous silicon film as a photosensitive layer is manufactured using the plasma CVD apparatus shown in FIG.
Since about 0 μm is required, at the above-mentioned deposition rate of about 0.5 nm / s, film deposition takes 16 hours or more, and the productivity is extremely poor. Also in this method, when the frequency of the high-frequency power is set to 30 MHz or more, the density of the plasma increases, and the deposition rate is improved. However, non-uniform plasma is easily formed due to the effect of the standing wave, and a uniform deposited film is formed on the substrate. There is a problem that it is extremely difficult to form. This point is easily understood from the result of a comparative example in which the method described in Reference 2 performed by the present inventors described below is performed.

[0010] Further, in any of the conventional methods of Documents 1 and 2, when the frequency of the high-frequency power is set to 30 MHz or more, the density of plasma increases, and the generation density of radicals in the plasma increases. However, since the reaction between radicals in the plasma also proceeds, the generation of polysilane which deteriorates the quality of the deposited film increases. In order to suppress the generation of polysilane in a situation where the radical generation density is high, it is effective to lower the pressure during film formation, but it becomes difficult to generate and maintain plasma. In particular, since there is a large difference in impedance before and after the plasma is generated, there is a problem that the discharge disappears due to a slight change in the state of the plasma with high-frequency power.

Accordingly, the present invention solves the above-mentioned problems in the prior art, and makes it possible to treat a substrate having a relatively large area with a uniform and stable plasma at a processing speed which cannot be achieved by a conventional plasma process. It is an object to provide a plasma processing apparatus and a plasma processing method.

[0012]

SUMMARY OF THE INVENTION The present invention provides a plasma processing apparatus and a plasma processing method configured as described in the following (1) to (40) in order to achieve the above object. (1) A reaction vessel that can be depressurized, and a plasma C
A source gas supply unit for supplying a VD source gas, a substrate holding unit disposed in the reaction vessel, and a plurality of cathode electrodes having a film formation processing substrate held by the substrate holding unit as a counter electrode. Dividing the plurality of cathode electrodes through a matching circuit and applying high-frequency power from a high-frequency power source to generate plasma between the plurality of cathode electrodes and the film-forming substrate, A plasma processing apparatus for forming a deposited film on a substrate, comprising: a phase control unit configured to control a phase of a high-frequency power applied to the plurality of cathode electrodes, wherein each of the plurality of cathode electrodes is controlled by the phase control unit. A plasma processing apparatus, comprising: forming a uniform plasma by controlling a phase of a transmitted high-frequency power; and performing plasma processing. (2) The phase control means grounds the opposite side of the high-frequency power supply point of the cathode electrode via a high-voltage variable capacitor (C1), and also connects the other high-frequency power supply point to the other side.
A high-voltage variable capacitor (C2) is provided after the matching circuit and after the power dividing point supplied from the high-frequency power supply and before the feeding point for each of the cathode electrodes, and the total amount of the capacitances of both capacitors (C1 + C2 = k) is (1) wherein the capacitance value of each of the capacitors (C1, C2) is controlled so as to be constant, and the phase of the high-frequency power applied to each of the cathode electrodes is controlled.
3. The plasma processing apparatus according to 1. (3) The phase control means has a configuration in which the capacitance value is controlled to be within a range of ± 30% of the total amount of the capacitances of the two capacitors (C1 + C2 = k). A) a plasma processing apparatus. (4) the phase control means includes: a reactance between the high-voltage variable capacitor (C1) and the grounded portion;
And (3) or (3), wherein the reactance to the grounding portion on the side opposite to the feeding point is adjusted by the distance of the line to the grounding portion or the capacitance of a capacitor. The plasma processing apparatus according to the item (1). (5) The phase control means is characterized in that the reactance between the high voltage variable capacitor (C2) and the cathode electrode is adjusted by the distance between the high voltage variable capacitor and the cathode electrode or the capacitance of the capacitor. The plasma processing apparatus according to the above (2) or (3). (6) The phase control means includes a high-voltage variable capacitor (C) at a cathode side of the tuned high-voltage variable capacitor in the matching circuit before a power dividing point supplied from the high-frequency power supply.
3) is installed and grounded via the high-voltage variable capacitor (C3), and after the high-voltage variable capacitor of the tune, between the power dividing point and the feeding point for each of the cathode electrodes (3). C4) is provided,
The capacitance value of each of the capacitors (C3, C4) is controlled so that the total amount (C3 + C4 = k) of both capacitors is constant, and the phase of the high-frequency power applied to each of the cathode electrodes is controlled. The plasma processing apparatus according to (1), wherein: (7) The phase control means has a configuration in which the capacitance value is controlled to be within a range of ± 30% of the total amount (C3 + C4 = k) of the capacitances of the two capacitors. The plasma processing apparatus according to the item (1). (8) The phase control means includes: a reactance between the high-voltage variable capacitor (C3) and the high-voltage variable capacitor (C4) and the grounded portion, and a reactance to the grounded portion on the side opposite to the feeding point. The plasma processing apparatus according to the above (6) or (7), wherein the plasma processing apparatus has a configuration in which the distance is adjusted by a distance of the line to the ground portion or a capacitance of a capacitor. (9) The plasma processing apparatus according to any one of (1) to (8), wherein high-frequency power is divided and applied from the same high-frequency power supply to the plurality of cathode electrodes. (10) The high frequency power supply has a frequency of 30 to 600 MHz.
The plasma processing apparatus according to any one of (1) to (9) above, wherein the plasma processing apparatus is a high-frequency power supply that oscillates a high frequency in a range of z. (11) The plasma processing apparatus according to any one of (1) to (10), wherein the surface of each of the cathode electrodes is covered with a dielectric. (12) The plasma processing apparatus according to any one of (1) to (11), wherein the cathode electrode is a cylindrical cathode electrode. (13) The plasma processing apparatus according to any one of (1) to (12), wherein the substrate to be processed is a cylindrical substrate. (14) The above-mentioned (1) to (1), wherein a plurality of the substrates to be processed are arranged on concentric circles.
(13) The plasma processing apparatus according to any of (13). (15) The reaction container according to any one of (1) to (14), wherein the reaction container is formed of a dielectric member, and the cathode electrode is disposed on the outside air side of the dielectric member. 3. The plasma processing apparatus according to 1. (16) The plasma processing apparatus according to any one of (1) to (15), wherein a deposited film is formed on a surface of the cylindrical substrate while rotating the cylindrical substrate. (17) The plurality of substrates to be processed are arranged on the same circumference, and the plurality of cathode electrodes are arranged on a concentric circle outside the plurality of substrates to be processed at equal distances between the substrates to be processed. The plasma processing apparatus according to any one of (1) to (16), wherein high-frequency power is divided and supplied to the plurality of cathode electrodes from the same power supply. (18) The plurality of substrates to be processed are arranged on the same circumference, and the plurality of cathode electrodes are arranged at equal distances between the substrates to be processed on concentric circles outside the plurality of substrates to be processed. The plurality of cathode electrodes are configured so that high-frequency power is divided and supplied from the same power supply, and the cathode electrodes supplied with power from another power supply are concentric with the circumference on which the plurality of cathode electrodes are arranged. The plasma processing apparatus according to any one of the above (1) to (16), wherein (19) The substrate according to any one of (1) to (11), wherein the substrate to be processed is a flat substrate, and the substrate to be processed and the plurality of cathode electrodes face each other. Plasma processing equipment. (20) The substrate to be processed is a sheet-like substrate that is sent out from a holding roll during film formation and wound up by a take-up roll, and one or more high-frequency electrodes are arranged in parallel to the sheet-like substrate. Generating plasma between the high-frequency electrode and the sheet-like substrate to form a deposited film on the sheet-like substrate;
The plasma processing apparatus according to any one of (11). (21) A reaction vessel that can be decompressed, a raw material gas supply means for supplying a raw material gas for plasma CVD into the reaction vessel, a substrate holding means disposed in the reaction container, and a substrate held by the substrate holding means A plurality of cathode electrodes having a film processing base as a counter electrode are divided into the plurality of cathode electrodes via a matching circuit, and high-frequency power is applied from a high-frequency power source to the plurality of cathode electrodes and the film-forming process. A plasma processing method for generating plasma between a substrate and forming a deposited film on the film-forming substrate, wherein the plasma is propagated to each of the plurality of cathode electrodes when applied to the plurality of cathode electrodes. A uniform plasma is generated by controlling the phase of the high-frequency power to form a deposited film on the substrate on which the film is to be formed. (22) In the phase control of the high-frequency power, the opposite side of the high-frequency power supply point of the cathode electrode is grounded via a high-voltage variable capacitor (C1), and the other high-frequency power supply point is also connected to the high-frequency power supply point after the matching circuit. And a high voltage variable capacitor (C2) is provided after the power dividing point supplied from the high frequency power supply and before the power supply point for each of the cathode electrodes, so that the total amount of the capacitances of both capacitors (C1 + C2 = k) is constant. The method according to (21), wherein the method is performed by controlling the capacitance value of each of the capacitors (C1, C2). (23) In the phase control of the high-frequency power, the capacitance value is a total amount (C1 + C2 =
The plasma processing method according to the above (22), wherein the control is performed so as to be within ± 30% of k). (24) In the phase control of the high-frequency power, the reactance between the high-voltage variable capacitor (C1) and the grounded ground portion and the reactance to the ground portion on the side opposite to the power supply point are changed to the ground portion. The plasma processing method according to the above (22) or (23), which is adjusted by a distance of a line or a capacitance of a capacitor. (25) In the phase control of the high frequency power, a reactance between the high voltage variable capacitor (C2) and the cathode electrode is adjusted by a distance between the high voltage variable capacitor and the cathode electrode or a capacitance of the capacitor. (22) or the plasma processing method according to the above (23). (26) The phase control of the high-frequency power is performed by installing a high-voltage variable capacitor (C3) on the cathode side of the tuned high-voltage variable capacitor in the matching circuit before the power dividing point supplied from the high-frequency power supply. Capacitor (C3)
And a high voltage variable capacitor (C4) after the high voltage variable capacitor of the tune and before the power dividing point and the power supply point for each cathode electrode.
So that the total amount (C3 + C4 = k) of both capacitors is constant.
The method according to (21), wherein the capacitance value is controlled to control the phase of the high-frequency power applied to each of the cathode electrodes. (27) In the phase control of the high-frequency power, the capacitance value is a total amount (C3 + C4 =
The plasma processing method according to the above (26), wherein the control is performed so as to be within ± 30% of k). (28) in the phase control of the high-frequency power, the reactance between the high-voltage variable capacitor (C3) and the high-voltage variable capacitor (C4) and the grounded part,
And (26) the reactance to the ground portion opposite to the feeding point is adjusted by the distance of the line to the ground portion or the capacitance of a capacitor.
Alternatively, the plasma processing method according to the above (27). (29) The plasma processing method according to any one of (21) to (28), wherein high-frequency power is divided and applied from the same high-frequency power supply to the plurality of cathode electrodes. (30) The frequency is 30 to 600M by the high frequency power supply.
The plasma processing method according to any one of the above (21) to (29), wherein a high frequency in a range of Hz is applied. (31) The plasma processing method according to any one of (21) to (30), wherein the surface of each of the cathode electrodes is covered with a dielectric. (32) The plasma processing method according to any one of (21) to (31), wherein the cathode electrode is a cylindrical cathode electrode. (33) The plasma processing method according to any one of (21) to (32), wherein the substrate to be processed is a cylindrical substrate. (34) The above (21) to (21) to (21) to (24), wherein a plurality of the substrates to be processed are arranged on concentric circles.
(32) The plasma processing method according to any of (32). (35) The reaction container according to any one of (21) to (34), wherein the reaction container is formed of a dielectric member, and the cathode electrode is disposed on the outside air side of the dielectric member. 4. The plasma processing method according to 1. (36) The method according to (2), wherein a deposited film is formed on the surface of the cylindrical substrate while rotating the cylindrical substrate.
The plasma processing method according to any one of 1) to (35). (37) The plurality of substrates to be processed are arranged on the same circumference, and the plurality of cathode electrodes are arranged on a concentric circle outside the plurality of substrates to be processed at equal distances between the substrates to be processed. The plasma processing method according to any one of the above (21) to (36), wherein high frequency power is divided and supplied from the same power supply to the plurality of cathode electrodes. (38) The plurality of substrates to be processed are arranged on the same circumference, and the plurality of cathode electrodes are arranged on a concentric circle outside the plurality of substrates to be processed at an equal distance from the substrates to be processed. The plurality of cathode electrodes are configured so that high-frequency power is divided and supplied from the same power supply, and the cathode electrodes supplied with power from another power supply are concentric with the circumference on which the plurality of cathode electrodes are arranged. The plasma processing method according to any one of the above (21) to (36), wherein the plasma processing method is disposed. (39) The substrate according to any one of the above (21) to (31), wherein the substrate to be processed is a flat substrate, and the substrate to be processed and the plurality of cathode electrodes face each other. Plasma treatment method. (40) The substrate to be processed is a sheet-like substrate which is sent out from a holding roll at the time of film formation and wound up by a take-up roll, and one or more high-frequency electrodes are arranged in parallel with the sheet-like substrate. The above (21) to (21) to (21), wherein plasma is generated between the high-frequency electrode and the sheet-like substrate to form a deposited film on the sheet-like substrate.
(31) The plasma processing method according to any of (31).

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an embodiment of the present invention,
By applying the above configuration, for example, 30 MHz or more,
By using a high frequency of 600 MHz or less and forming a deposited film while controlling the phase of the high frequency power transmitted to the cathode electrode in front of the cathode electrode, a large area homogeneous high frequency discharge is easily achieved, It becomes possible to perform plasma processing on the substrate uniformly and at high speed. This is based on the following findings of the present inventors.

That is, the present inventors use the conventional plasma CVD method and apparatus as described above, and set the discharge frequency to the conventional value for the purpose of improving the deposition rate of a good quality film and uniformity of the film thickness and film quality of the deposited film. Investigation was performed using higher frequency power of a higher frequency instead of 13.56 MHz. As a result, by increasing the frequency, it was possible to produce a good quality film at a higher deposition rate than before, but on the other hand, the following problems which did not become a problem at a discharge frequency of 13.56 MHz were obtained. Newly occurred. That is,
Increasing the discharge frequency causes the plasma to be ubiquitous, causing a non-uniform deposition rate, and as a result, poses a practical problem for relatively large-area workpieces such as electrophotographic photoreceptors. Such film thickness unevenness (for example, film thickness unevenness of ± 20% or more in the case of an electrophotographic photosensitive member) and film quality unevenness occurred. Such film thickness unevenness is caused when a crystalline or non-single crystalline functional deposition film used not only for an electrophotographic photoreceptor but also for an image input line sensor, an imaging device, a photovoltaic device and the like is formed. Is also a big problem. Also, in other plasma processes such as dry etching and sputtering, when the discharge frequency is increased, similar processing unevenness occurs, and this causes a serious problem in practical use.

The inventors of the present invention have found that when the frequency of the high-frequency power is set to 30 MHz or higher, discharge in a high vacuum region becomes possible. However, there is a problem in its stability. Experiments were conducted to elucidate the cause of the decrease in deposition rate, and as a result of intensive studies, the following findings were obtained. First, the present inventors have presumed that the stability of discharge in a high vacuum region is problematic because 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.

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. The plasma distribution such as plasma density, plasma potential, and electron temperature is disturbed, which adversely affects the film formation quality of plasma CVD.

In the above-described experiment, 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. it is conceivable that. 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. Further, at frequencies of 400 MHz 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. The present invention has been completed based on the above study results.

Hereinafter, the present embodiment will be described in more detail with reference to the drawings. First, a plasma CVD apparatus including the phase control circuit of the present invention will be described with reference to FIG. In FIG. 2, 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 (the electrode of FIG. 2 is the electrode of FIG. 1,
In this case, when the phase control function circuit is removed) Usually, the high-frequency electrode 102 itself is described by the series impedance of the skin resistance (R) and the inductance (L). The electrodes are
It is 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 holder 112
The upper substrate 103 has a capacitance (C) determined by its positional relationship and shape. The capacitance (C) between the high-frequency electrode 102 and the base 103 causes the high-frequency electrode 102
The high-frequency current flowing through the high-frequency electrode 10
The likelihood of plasma generation is greatly affected by the positional relationship between the substrate 2 and the base 103 and the shape thereof, and even a slight change in the positional relationship requires adjustment for optimization.

Further, 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. The capacitance is inversely proportional to the distance between the conductors when the area and the dielectric constant of the medium are the same, but the thickness of the ion sheath is considerably smaller than the distance between the high-frequency electrode and the base, and the capacitance is large. For this reason, the impedance between the high-frequency electrode and the substrate changes greatly before and after the plasma is generated, which makes it extremely difficult to adjust the matching circuit, and makes it difficult to generate the plasma. In addition, even if a slight change in plasma occurs, the impedance change is large and even if an automatic matching circuit or the like is used, matching cannot be made in time, and in the worst case, the plasma disappears. Regarding the uniformity of the plasma, the tip of the high-frequency electrode is an open end, and a strong standing wave is easily generated. Furthermore, when the impedance of the plasma is lower than the impedance of the high-frequency electrode and the base, when considered with a distributed constant circuit, a large amount of the high-frequency current flows on the high-frequency introduction side of the high-frequency electrode, so that the high-frequency current rapidly decreases toward the tip . Thus, a non-uniform plasma is likely to be formed due to these two factors.

On the other hand, the phase control circuit 11 to which the present invention is applied
The high frequency power generated by the high frequency power supply 105 is supplied to the high frequency electrode 102 via the matching circuit 104 and the phase control circuit 113 by configuring the plasma CVD apparatus using the high frequency electrode 102 (shown in FIG. Is done. The high-frequency electrode 102 has a simple rod-like antenna shape, and the opposite side of the feeding point is grounded, or a high-voltage capacitor is interposed between the grounded portion and the opposite side of the feeding point of the cathode electrode 102. Usually, the high-frequency electrode 102 itself is described by a series impedance of skin resistance and inductance. When the frequency is high, the impedance (jωL) due to the L component naturally increases.

However, through the phase control circuit 113 configured by applying the present invention described above, even if the shape of the substrate is changed, the possibility of generating plasma and the influence on stability are small and optimization is not performed. It will be easier. That is, when the plasma is generated, if the absolute value of the LC circuit of the circuit is made smaller than the absolute value of the series impedance of the plasma and the ion sheath, the high-frequency current has a large effect on the impedance of the LC circuit of the circuit even after the plasma is generated. The change in impedance before and after the occurrence of plasma is relatively small.
For this reason, the change in the matching condition is small with respect to the change in the plasma condition, and the plasma is stabilized. Further, by introducing and operating such a circuit for controlling the phase, the difference in the amount of high-frequency current on the high-frequency electrode 102 is reduced, and the uniformity of the plasma is improved. The impedance of the plasma varies depending on the conditions of the plasma, but the resistance, which is the real part, is often 50Ω or less, and the reactance, which is the imaginary part, varies depending on the discharge frequency and other conditions. On this occasion,
When a stable discharge does not occur, a uniform high-speed deposition film can be similarly obtained by using the phase control circuit 113 configured by applying the present invention.

Phase control circuit 1 constructed by applying the present invention
As described above, in the plasma CVD apparatus using No. 13, since uniform and stable plasma can be formed, it is possible to form a deposited film having extremely uniform film quality and thickness. The points will be described in more detail.
The plasma CVD apparatus shown in FIG. 2 is an example of the plasma CVD apparatus according to the present embodiment. In FIG. 2, reference numeral 100 denotes a reaction vessel. 6 in the reaction vessel 100
The substrate holders 112 are arranged concentrically at predetermined intervals. 103 is a cylindrical substrate for film formation arranged on each substrate holder 112. A heater 111 is provided inside each base holder 112 so that the cylindrical base 103 can be heated from the inside. Each of the base holders 112 is connected to a shaft connected to the motor 108, and is rotatable.

Reference numeral 102 denotes a high-frequency electrode for inputting high-frequency power, which is located at the center of the plasma generation region. High frequency power supply 1
05 denotes one of the matching circuit 104 and the phase adjustment circuit 113.
It is connected to one end of the high-frequency electrode 102 via the section. The high-frequency electrode 102 is covered with a dielectric cover 109, and the exhaust pipe is an exhaust mechanism 1 equipped with a vacuum pump.
06. The source gas supply system is a gas cylinder,
It has a mass flow controller, a valve and the like. The source gas supply system 107 is connected via a gas supply pipe 110 to a gas discharge pipe having a plurality of gas discharge holes.

Plasma CVD using this apparatus
Is performed as follows. Exhaust mechanism 1 for reaction vessel 100
06, the gas supply means 10
Source gas is introduced into the reaction vessel 100 from 7 via a gas supply pipe 110 and a gas discharge pipe, and is maintained at a predetermined pressure. At this point, high-frequency power is output from the high-frequency power supply 105 and supplied to the high-frequency electrode 102 via the matching circuit 104 and the phase control circuit 113 to generate plasma between the high-frequency electrode and the cylindrical base 103.

At this time, the opposite side of the high-frequency power supply point of the high-frequency power supply 105 is grounded via a high-voltage variable capacitor (C1), and the high-frequency power supply point is also supplied from the high-frequency power supply after the matching circuit. A high-voltage variable capacitor (C2) is provided after the divided power point and before the power supply point to the high-frequency power supply 105, and each capacitor (C2) is fixed so that the total amount (C1 + C2 = k) of these capacitors is constant. C1 and C2) are controlled, and the phase of the high-frequency power applied to the high-frequency power supply 105 is controlled. By controlling the phase of the high-frequency power transmitted to the high-frequency power supply 105 in this way, the variation in the amount of current on the surface of the high-frequency electrode 102 is made substantially uniform, whereby a uniform plasma is formed. It is decomposed and excited by the plasma, and a good deposited film is formed on the cylindrical substrate 102.

At this time, the configuration of the phase control circuit 113 is such that a high voltage variable capacitor (C3) is provided on the cathode side of the tuned high voltage variable capacitor in the matching circuit 104 before the power dividing point supplied from the high frequency power supply. And grounded via the high voltage variable capacitor (C3), and after the high voltage variable capacitor of the tune,
A high-voltage variable capacitor (C4) is provided between the power division point and a point before the power supply point for each of the cathode electrodes, and the respective capacitors (C3, C4) are controlled so that the total amount (C3 + C4 = k) of both capacitors is constant. Control the capacitance value of
A configuration for controlling the phase of the high-frequency power applied to the high-frequency electrode 102 may be adopted.

Here, the plasma CVD apparatus using the phase control circuit 113 performs control so that the capacitance value is within a range of ± 30% of the total amount of the capacitances of the two capacitors (C1 + C2 = k). Is preferable. Also, the reactance between the high-voltage variable capacitor (C1) and the grounded ground portion and the reactance to the ground portion opposite to the feeding point are determined by the distance of the line to the ground portion or the capacitance of the capacitor. It is preferable to adjust the volume according to the capacity. Also, the reactance between the high voltage variable capacitor (C2) and the cathode electrode is:
It is preferable to adjust the distance between the high-voltage variable capacitor and the cathode electrode or the capacitance of the capacitor. Also, the reactance between the high-voltage variable capacitor (C3) and the high-voltage variable capacitor (C4) and the grounded portion, and the reactance to the grounded portion on the side opposite to the feeding point are the values of the line to the grounded portion. distance,
Alternatively, it is preferable to adjust the capacitance by the capacitance of the capacitor.

When the plasma-generating high-frequency electrode is present in the reaction vessel 100, the surface is preferably covered with a dielectric. The dielectric material used for the dielectric cover 109 can be selected from any known materials.
A material having a small dielectric loss is preferable, and a material having a dielectric loss tangent of 0.01 or less is preferable, and 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. Further, the shape of the high-frequency electrode 102 is preferably a rod shape such as a columnar shape, a cylindrical shape, a polygonal column shape, or a long plate shape. In addition, the high frequency power supply 10
The frequency of 5 is preferably in the range of 30 to 600 MHz, more preferably 60 to 300 MHz.

As shown in FIGS. 3 and 4, a plurality of high-frequency electrodes 102 are provided around a cylindrical base 103.
May be arranged. By doing so, the entire peripheral surface of the cylindrical substrate can be exposed to plasma at all times during film formation, so that the deposition rate can be greatly increased and productivity can be greatly improved. Furthermore, by optimizing the number and arrangement of high-frequency electrodes, a uniform deposited film can be formed on the entire peripheral surface of the substrate without rotating the cylindrical substrate, and a rotating mechanism is not required. Can be simplified. It is needless to say that a more uniform deposited film can be formed by rotating the cylindrical substrate.

Further, as shown in FIG. 6, the apparatus may have a structure in which a plurality of high-frequency electrodes 102 are arranged in parallel with the flat substrate 103. This makes it possible to form a high-quality deposited film having a very uniform thickness and a uniform film quality on a large-area flat substrate at a high speed. Also,
As shown in FIG. 5, the apparatus configuration includes a single or a plurality of high-frequency electrodes 10 parallel to a sheet-like substrate 114 which is sent out from a holding roll during film formation and wound up by a winding roll.
2 may be arranged. This makes it possible to form a high-quality deposited film having a very uniform thickness and a uniform film quality on a large-sized sheet-like substrate at a high speed. Further, as shown in FIGS.
0 may be constituted by a dielectric member. This makes it possible to form a high-quality deposited film having a high gas utilization efficiency, a very uniform film thickness and a uniform film quality on a large-area flat substrate at a high speed.

When using the plasma CVD apparatus of the present invention, as a gas to be used, a known source gas that contributes to film formation is appropriately selected and used according to the type of a deposited film to be formed. For example, in the case of forming an a-Si based deposited film, silane, disilane, high disilane, or the like, or a mixed gas thereof is mentioned as a preferable source gas. When forming another deposited film, for example, germane,
A raw material gas such as methane and 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 100 together with the carrier gas. Hydrogen gas, carrier gas
And inert gases such as argon gas and 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; Silicon fluoride, disilicon hexafluoride,
A gaseous fluorine compound such as germanium tetrafluoride or a mixed gas thereof may be used.

A dopant gas can 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.
The substrate temperature at the time of forming the deposited film can be set as appropriate. However, when forming an amorphous silicon-based deposited film, it is preferably 60 ° C to 400 ° C, more preferably 100 ° C to 35 ° C.
Desirably, it is 0 ° C.

[0034]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited by these examples. [Example 1] Plasma CVD used in Example 1
FIGS. 3 and 4 show schematic views of the apparatus. (The cathode electrode of FIG. 1 is installed in FIG. 3) This apparatus includes a configuration (the high-frequency electrode structure shown in FIG. 1) to which the phase control means of the present invention is applied, and the power supply point of the cathode electrode On the other side, a variable high-voltage capacitor C1 is grounded via a variable high-voltage capacitor C1, and a variable high-voltage capacitor C2 is also provided after the matching circuit and before the cathode electrode power supply point, and C1 + C2 = k
(Constant) conditions are satisfied. FIG. 4 is a cross-sectional view when FIG. 3 is cut in a lateral direction from a central portion of the apparatus.

In this embodiment, the high-frequency power source (10
As 5), a power supply having a frequency of 13.56 MHz to 650 MHz was used. The high-frequency electrode 102 has a simple rod shape. In this embodiment, the diameter is 108 mm and the length is 35
An Al-made cylindrical deposition substrate having a thickness of 8 mm and a thickness of 5 mm was placed in the reaction vessel 100, and the substrate was deposited while rotating. The dielectric member 109 made of alumina ceramics is a cylindrical member having an inner diameter of about 180 mm and a length of 500 mm, a thickness of 5 mm at a thin portion, and a thickness of 10 mm at a portion in contact with an electrode.
Was used. As the high frequency electrode (102), six Al electrodes having a diameter of 30 mm and a length of 450 mm were used. For evaluation of film quality, a Corning # vapor-deposited with a comb-shaped electrode of 250 μm gap made of Cr for evaluation of electrical characteristics
A 7059 glass substrate was installed as an electrical property evaluation substrate over an axial length of 358 mm on the surface of a cylindrical deposition substrate, and a film was formed by the following procedure.

First, the inside of the reaction vessel 100 is evacuated by the exhaust mechanism 106.
Is operated to exhaust gas, and the inside of the reaction vessel 100 is 1 × 10 ⁻⁶ To.
The pressure was adjusted to about rr. Then, a current was supplied to the substrate heater 111 from a heating power supply (not shown), and the cylindrical substrate 103 was heated and held at a temperature of about 250 ° C. Then, a film was formed in the following procedure. That is, SiH ₄ gas was introduced into the reaction vessel 100 at a flow rate of 500 sccm from the raw material gas supply means 107 via a gas discharge pipe (Table 2), and the pressure in the reaction vessel was adjusted to about 10 mTorr.

In such a case, a high frequency power of 13.56 MHz to 650 MHz is generated by the high frequency power supply 105 at 1.5 kW, and the high frequency is divided into six by the matching circuit 104 and is uniformly divided by the LC circuit of the present invention. The high-frequency electrode 102 was supplied. Here, as the high-frequency power supply 105, a predetermined high-frequency power supply was used so that the above-mentioned frequency in the range of 13.56 MHz to 650 MHz was given. The matching circuit 104 was appropriately adjusted according to the frequency of the high-frequency power supply. Thus, an electric discharge was generated and plasma treatment was performed, so that an amorphous silicon film was formed on the cylindrical substrate 103 and the above-described substrate for evaluating electrical characteristics. The film quality and film quality distribution, the deposition rate distribution, and the deposition rate distribution of the amorphous silicon film formed as described above were evaluated by the following methods. The film quality and the film quality distribution are about 20 from the upper end to the lower end of the electrical characteristic evaluation substrate.
The evaluation was performed by measuring the light / dark conductivity ratio ((photoconductivity σp) / (dark conductivity σd) at 18 positions every mm. Here, the photoconductivity σp was 1 mW / cm ² . The evaluation is made based on the conductivity at the time of irradiation with a high intensity He-Ne laser (wavelength 632.8 nm).

According to the findings of the present inventors from the production of electrophotographic photosensitive members, optimization based on the conditions for obtaining a deposited film having a light / dark conductivity ratio of 10 ³ or more according to the above-described method was carried out. An image worthy of practical use is obtained in the electrophotographic photoreceptor produced in this manner. However, the high contrast of the recent image, the bright / dark conductivity ratio described above have become essential ones 10 ⁴ or more, further the near future 10 ⁵ or more light /
It is expected that a dark conductivity ratio will be required. From such a point of view, based on the results obtained in this example,
The value of the dark conductivity ratio was evaluated according to the following criteria. ：: The light / dark conductivity ratio is 10 ⁵ or more, which is a very excellent film property. ：: The light / dark conductivity ratio is 10 ⁴ or more, and the film has good film properties. Δ: The light / dark conductivity ratio is 10 ³ or more, and there is no practical problem. ×: The light / dark conductivity ratio is less than 10 ^3, which is not suitable for practical use.

The evaluation of the deposition rate and the distribution of the deposition rate was performed using a-
About 20 mm in the axial direction of the cylindrical substrate on which the Si film is formed, similarly to the above-described light / dark conductivity ratio measurement position.
Evaluation was made by measuring the film thickness at every 18 locations using an eddy current film thickness meter (manufactured by Kett Scientific Research Institute). The deposition rate was calculated based on the film thickness at 18 locations, and the average of the obtained values was defined as the average deposition rate. Evaluation of the deposition rate distribution was performed as follows. That is, with respect to the deposition rate distribution in the axial direction, the difference between the maximum value and the minimum value of the deposition rate at 18 locations in the axial direction is obtained, and the difference is divided by the average deposition rate at 18 locations to obtain the deposition rate distribution ｛(maximum value− (Minimum value) / average value｝, which was expressed as a percentage as the axial deposition rate distribution.

Table 1 shows the evaluation results of the light / dark conductivity ratio, average deposition rate, and deposition rate distribution of the formed sample. 13.
In the case of 56 MHz, the evaluation could not be performed because no discharge occurred at 10 mTorr. One formed by the high frequency power having a frequency of 30MHz, it light / dark conductivity ratio in all samples were good film properties in the range of ^{1 × 10 4 ~3 × 10 4} (○). The average deposition rate is 2.0 nm /
s and the deposition rate distribution was 3.2%. 60 MHz
Films formed by high-frequency power having a frequency of 300 MHz have a light / dark conductivity ratio of 1 × 10 in all samples.
^{It was 5 to} 5 × 10 ⁵ , which was very excellent film characteristics (◎) (Table 1). The average deposition rate was 4.0-7.8 nm / s, and the deposition rate distribution was 4-5%. 400MHz ~
In the sample using high-frequency power having a frequency of 600 MHz, the light / dark conductivity ratio was 5 × 10 ⁴ to 8 × 10 ⁴ , indicating good film characteristics (〇) (Table 1). The average deposition rate is 2.0-2.8 nm / s, and the deposition rate distribution is 6-7.
%Met. In the case of 650 MHz, the discharge occurred unstablely or disappeared, and the formation and evaluation of the deposited film could not be performed.

As described above, in this embodiment, 30 MH
Under the discharge frequency conditions of z to 600 MHz, an amorphous silicon film having a good light / dark conductivity ratio and an average deposition rate distribution was obtained, and an especially excellent amorphous silicon film was obtained at a frequency of 60 MHz to 300 MHz. Each film obtained by using the apparatus and the processing method in this embodiment was partially measured for the film quality of the a-Si film, and the film quality was found to be a practical value such as an electrophotographic photosensitive member device or an image input line sensor. Was tolerable enough. As described above, by setting the discharge frequency to the VHF band, the film forming rate is increased, the production efficiency is improved, and the deposited film can be formed into a deposited film that can withstand the electrophotographic photoreceptor sufficiently. .

Further, a variable vacuum high voltage capacitor (C3) is installed on the cathode side of the tune variable high voltage vacuum capacitor in the matching circuit before the power dividing point, and is electrically connected to the ground potential via the variable high voltage vacuum capacitor C3. A variable vacuum high-voltage capacitor (C4) is installed between the power split point and the cathode electrode power supply point, after the vacuum high-voltage variable capacitor of the tune, and C3
+ C4 = k (constant) by controlling the capacitance value of each capacitor and forming the deposited film while controlling the phase of the high-frequency power applied to the cathode. Almost similar results were obtained.

[0043]

[Table 1]

[0044]

[Table 2] [Embodiment 2] It has a plurality of substrates 103 shown in FIGS. 8 and 9, and has a plurality of cathode electrodes 102 which separately supply high-frequency power from the same power supply 105.
Reaction vessel 10 in which cathode electrode 102 is made of a dielectric
0, and a high frequency power supply 105 having a frequency of 100 MHz using a circuit shown in FIG. 1 in a plasma processing apparatus in which an earth shield 101 is installed around the cathode electrode. Plasma was generated depending on the conditions, and an a-Si film was deposited on the # 7059 substrate provided on the substrate to be processed in the same manner as in Example 1.

When the deposited film deposited using the above apparatus was evaluated using the evaluation method of Example 1, the average deposition rate was 3.5 nm / s and the distribution of the deposition rate was 5.7%. Also, as shown in Table 1, the film quality was 8 × 10 ^{4 to} 5
It was in the range of × 10 ⁵ , and a high-quality deposited film having good uniformity was formed. It was possible to form a deposited film having a sufficient film thickness and film quality to withstand the actual electrophotographic process. As described above, by supplying the high-frequency power propagated on the cathode electrode while controlling the phase, a deposition film with good uniformity can be formed.

Example 3 The reaction vessel 10 shown in FIG.
0 is made of a dielectric material, a plurality of cathode electrodes 102 are arranged around the reaction vessel 100, and high-frequency power is divided and supplied from the same power supply 105 after the matching circuit,
Further, an alumina cover is installed on the cathode electrode installed at the center position of the reaction vessel 100 from the separate power source 105 ', and the cathode electrode at the center position and the cathode electrodes installed around the center are shown in FIG. A phase control circuit is provided for each of the high-frequency power supplies 105 and 10
Plasma is generated by high-frequency power generated from 5 ′, and is provided concentrically in a reaction vessel and performs plasma processing on a substrate to be film-formed.
An electrophotographic photosensitive member made of aluminum was provided with a phase control circuit under the conditions shown in Table 3, and was mounted on six aluminum cylindrical substrates using the apparatus shown in FIG. 11 in which six cathode electrodes were arranged on the same circumference. ,
An electric field injection blocking layer, a photoconductive layer, and a surface layer were formed in this order.

As a result, the image defect / density and charging ability were evaluated as follows. (Charging ability) The photoreceptor for electrophotography was installed in the experimental device,
A high voltage of +6 kV is applied to the charger to perform corona charging, and the surface potential of the dark portion of the electrophotographic light-receiving member is measured by a surface electrometer. Normalization was performed by dividing the measured value by the film thickness, and the influence of the film thickness was removed. In addition, evaluation was performed for each of a thick position and a thin position. (Image Characteristics) The image was set on a Canon copier NP-6650, and an image was taken out. Each of the six electrophotographic photoconductors satisfies the characteristics as electrophotographic photoconductors formed on six Al-made cylindrical substrates, and all electrophotographic photoconductors showed excellent results.

[0048]

[Table 3] [Embodiment 4] Having a plurality of substrates to be processed shown in FIG.
In a plasma processing apparatus having a plurality of cathode electrodes for supplying high frequency power by dividing the same power source and a cathode electrode for supplying high frequency power from another power source, FIG.
0, using a high-frequency power supply 105 having a frequency of 100 MHz while controlling the phase in the same manner as in the second embodiment.
Plasma was generated under the conditions shown in Table 1 of Example 1, and an a-Si film was deposited on the # 7059 substrate provided on the substrate to be processed in the same manner as in Example 1. When the deposited film deposited using the above apparatus was evaluated using the evaluation method of Example 1,
The average deposition rate was 3.8 nm / s, and the deposition rate distribution was 6.6%. Also, the film quality was 4 × as in Example 2.
It was in the range of 10 ^{4 to} 2 × 10 ⁵ , and the uniformity was good and a high-quality deposited film could be formed. It was possible to form a deposited film having a sufficient film thickness and film quality to withstand the actual electrophotographic process. As described above, by supplying the high-frequency power propagated on the cathode electrode while controlling the phase, a deposition film with good uniformity can be formed.

[Embodiment 5] Similar to Embodiment 1, the phase control of FIG. 1 used in Embodiment 1 of the present invention in an apparatus in which the cathode electrode shown in FIG. 3 and FIG. # 705 placed on the substrate to be processed using the circuit 113
An a-Si film was deposited on 9 substrates. The cathode electrode is covered with an electrode cover made of an alumina member.
When the deposited film deposited using the above apparatus was evaluated using the evaluation method of Example 1, the average deposition rate was 2.7 nm / s.
And the deposition rate distribution was 5.5%. Further, as shown in Table 1, the film quality was in the range of 4 × 10 ⁴ to 2 × 10 ⁵ , and a highly uniform and high-quality deposited film could be formed. It was possible to form a deposited film having a sufficient film thickness and film quality to withstand the actual electrophotographic process. As described above, even when the cathode electrode is in the reaction vessel, a high uniformity of the deposited film can be formed by supplying the high-frequency power transmitted on the cathode electrode while controlling the phase thereof.

[Embodiment 6] An electrophotographic photoreceptor having the same phase control circuit 113 as in Embodiment 1 under the conditions shown in Table 3 and an apparatus shown in FIG. 4 in which six cathode electrodes are arranged on the same circumference. 6
An electric field injection blocking layer, a photoconductive layer, and a surface layer were formed in this order on a cylindrical substrate made of Al. As a result, the image defect / density and charging ability were evaluated as follows. (Charging ability) The photoreceptor for electrophotography was installed in the experimental device,
A high voltage of +6 kV is applied to the charger to perform corona charging, and the surface potential of the dark portion of the electrophotographic light-receiving member is measured by a surface electrometer. Normalization was performed by dividing the measured value by the film thickness, and the influence of the film thickness was removed. In addition, evaluation was performed for each of a thick position and a thin position. (Image characteristics) Installed in a Canon NP-6650 copier, output images, and evaluated with halftone images. Each of the six electrophotographic photoconductors satisfies the characteristics as electrophotographic photoconductors formed on six Al-made cylindrical substrates, and all electrophotographic photoconductors showed excellent results.

[Embodiment 7] A flat plate made of # 7059 glass having a length of 400 mm, a width of 400 mm, and a thickness of 1 mm in the parallel plate type shown in FIG. 6 and incorporating the phase control circuit 113 shown in FIG. The substrate was placed in a reaction vessel to form a film. In the cathode electrode of FIG. 6, 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 flat substrate under the film forming conditions shown in Table 1, and the deposition rate and the deposition rate distribution were evaluated by the following procedure. The film thickness was measured using the film thickness measuring device used in Example 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 6.4 nm / s.
The deposition rate distribution is obtained by calculating the difference between the maximum value and the minimum value of the deposition rate, dividing the difference by the average deposition rate, and calculating the deposition rate distribution as 10
Expressed as 0 fraction. The obtained deposition rate distribution was 6.2%, which was enough to withstand an electrophotographic photosensitive member device, an image input line sensor, and the like.

[Embodiment 8] Using the parallel-plate type phase-controllable apparatus shown in Embodiment 7, the stainless steel sheet-like substrate 114 of FIG. 5 was placed in a reaction vessel and wound up on a take-up roll. The membrane was made. Figure 1 shows the structure of the high-frequency electrode.
Were covered with a 5 mm-thick alumina ceramic dielectric cover, and three high-frequency electrodes were arranged in a reaction vessel. The frequency of the high frequency power supply is 1
An amorphous silicon film was formed on a sheet-like substrate under the film forming conditions shown in Table 3 using a 50 MHz frequency band, and had a length of 50 nm.
A 0-mm sheet-like substrate was cut out, and the deposition rate and the deposition velocity distribution were evaluated in the same procedure as in Example 7. The obtained average deposition rate was 4 nm / s, and the deposition rate distribution was 10%. By controlling the phase of the high-frequency power transmitted to the high-frequency electrode, the deposition rate was significantly increased as compared with the conventional example, and the uniformity was improved. And not only the productivity was improved, but also the uniformity was significantly improved. Further, even when the circuit shown in FIG. 10 was used, an amorphous silicon film having sufficient performance was deposited with good uniformity.

[0053]

As described above, according to the present invention,
A plasma processing apparatus and a plasma processing method capable of uniformly processing a substrate having a relatively large area with a stable plasma at a processing speed that cannot be achieved by a conventional plasma process can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a cathode electrode having a phase control circuit used in an embodiment of the present invention.

FIG. 2 is a schematic view showing an example of a plasma CVD apparatus having a cathode electrode with a cylindrical phase control circuit used in an embodiment of the present invention.

FIG. 3 is a schematic diagram showing an example of a plasma CVD apparatus having a plurality of film-forming substrates used in an example of the present invention and having a cathode electrode with a cylindrical phase control circuit.

FIG. 4 is a schematic view showing an example of a plasma CVD apparatus showing a cross section of FIG.

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

FIG. 6 is a view showing a configuration of a parallel plate type plasma CVD apparatus having a phase control mechanism used in an embodiment of the present invention.

FIG. 7 has a phase control mechanism used in the embodiment of the present invention,
FIG. 2 is a schematic view showing a cross section of a plasma CVD apparatus in which a cathode electrode is outside a reaction vessel.

FIG. 8 has a phase control mechanism used in the embodiment of the present invention,
FIG. 2 is a schematic diagram showing a vertical cross section of a plasma CVD apparatus in which a cathode electrode is outside a reaction vessel.

FIG. 9 includes a phase control circuit used in the embodiment of the present invention,
Plasma CVD with six cathodes outside the reactor
It is a schematic diagram which shows the cross section of an apparatus.

FIG. 10 is a diagram showing a configuration of a phase control circuit of another embodiment used in the embodiment of the present invention.

FIG. 11 is a schematic diagram showing an example of another embodiment of a plasma CVD apparatus having a plurality of film-forming substrates used in an example of the present invention and having a cathode electrode with a cylindrical phase control circuit.

FIG. 12 shows a conventional parallel plate type plasma CVD apparatus.

FIG. 13 is a schematic view showing a vertical and a horizontal section of a plasma CVD apparatus disclosed in Japanese Patent Application Laid-Open No. 60-186849.

[Explanation of symbols]

 100: Reaction vessel 101: Earth shield 102: Cathode electrode 103: Deposition substrate 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: Phase control circuit 114: Sheet-shaped substrate for film formation C1, C2, C3, C4: High-voltage variable condenser

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G075 AA29 AA30 AA42 AA61 BC04 BD14 CA02 CA05 CA13 CA15 CA25 CA62 CA65 DA02 DA18 EA01 EA05 EB01 EB41 EC06 EC21 ED01 EE04 EE36 FB02 FB04 FC10 FC15 4K030 AA02 GA16 FA30 FA01 JA03 JA16 JA18 JA19 JA20 KA04 KA15 KA18 KA24 KA39 KA41 LA17

Claims (40)

[Claims] 1. A reaction vessel capable of reducing pressure, a raw material gas supply means for supplying a raw material gas for plasma CVD into the reaction vessel, a substrate holding means disposed in the reaction container, and a substrate held by the substrate holding means. A plurality of cathode electrodes having a film-forming substrate as a counter electrode are provided. The plurality of cathode electrodes are divided through a matching circuit, and high-frequency power is applied from a high-frequency power supply to the plurality of cathode electrodes. What is claimed is: 1. A plasma processing apparatus for generating plasma between a film processing substrate and forming a deposited film on the film forming substrate, comprising: a phase control unit configured to control a phase of a high frequency power applied to the plurality of cathode electrodes. Wherein the phase control means controls the phase of the high-frequency power transmitted to each of the plurality of cathode electrodes to form uniform plasma and performs plasma processing. Equipment. 2. A high-voltage variable capacitor (C), comprising:
1), and the other high-frequency power supply point is also connected to the other high-frequency power supply point after the matching circuit and after the power division point supplied from the high-frequency power supply and before the power supply point for each of the cathode electrodes. (C2) is provided, and the capacitance values of the respective capacitors (C1, C2) are controlled so that the total amount (C1 + C2 = k) of the capacitances of the two capacitors is constant. 2. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus has a configuration for controlling the phase. 3. The phase control means according to claim 1, wherein said capacitance value is ± 30 of a total amount of the capacitances of said two capacitors (C1 + C2 = k).
3. The plasma processing apparatus according to claim 2, wherein the plasma processing apparatus is configured to perform control so as to be within the range of%. 4. The phase control means according to claim 1, wherein a reactance between the high-voltage variable capacitor (C1) and the grounded ground portion, and a reactance between the high-voltage variable capacitor (C1) and the ground portion on the side opposite to the power feeding point are adjusted to the ground portion. The plasma processing apparatus according to claim 2, wherein the plasma processing apparatus has a configuration in which the distance is adjusted by a distance of a line or a capacitance of a capacitor. 5. The phase control means has a structure in which the reactance between the high voltage variable capacitor (C2) and the cathode electrode is adjusted by the distance between the high voltage variable capacitor and the cathode electrode or the capacitance of the capacitor. The plasma processing apparatus according to claim 2 or 3, wherein: 6. The high-voltage variable capacitor (C3) is disposed on the cathode side of the tuned high-voltage variable capacitor in the matching circuit and before a power dividing point supplied from the high-frequency power supply. A high-voltage variable capacitor (C4) is provided between the power split point and the power supply point for each of the cathode electrodes, after being grounded via a capacitor (C3), and after the high-voltage variable capacitor of the tune, It is characterized in that the capacitance (C3, C4) is controlled so that the amount (C3 + C4 = k) is constant, and the phase of the high-frequency power applied to each cathode electrode is controlled. The plasma processing apparatus according to claim 1. 7. The phase control means according to claim 1, wherein said capacitance value is ± 30 of a total amount (C3 + C4 = k) of capacitances of said two capacitors.
The plasma processing apparatus according to claim 6, wherein the plasma processing apparatus has a configuration for controlling so as to be within the range of%. 8. The reactance between the high-voltage variable capacitor (C3) and the high-voltage variable capacitor (C4) and the grounded portion, and the reactance to the grounded portion on the side opposite to the feeding point. 8. The plasma processing apparatus according to claim 6, wherein the apparatus has a configuration in which the distance is adjusted by a distance of the line to the ground portion or a capacitance of a capacitor. 9. The plasma processing apparatus according to claim 1, wherein high-frequency power from the same high-frequency power source is divided and applied to said plurality of cathode electrodes. 10. The high frequency power supply has a frequency of 30 to 60.
The plasma processing apparatus according to any one of claims 1 to 9, wherein the plasma processing apparatus is a high-frequency power supply that oscillates a high frequency in a range of 0 MHz. 11. The plasma processing apparatus according to claim 1, wherein a surface of each of the cathode electrodes is covered with a dielectric. 12. The plasma processing apparatus according to claim 1, wherein said cathode electrode is a cylindrical cathode electrode. 13. The plasma processing apparatus according to claim 1, wherein the substrate to be processed is a cylindrical substrate. 14. The apparatus according to claim 1, wherein a plurality of said substrates to be processed are arranged on concentric circles.
14. The plasma processing apparatus according to any one of items 13 to 13. 15. The reaction vessel according to claim 1, wherein the reaction vessel is formed of a dielectric member, and the cathode electrode is disposed on the outside air side of the dielectric member. Item 6. The plasma processing apparatus according to Item 1. 16. The plasma processing apparatus according to claim 1, wherein a deposited film is formed on a surface of the cylindrical substrate while rotating the cylindrical substrate. 17. The plurality of substrates to be processed are arranged on the same circumference, and the plurality of cathode electrodes are disposed on a concentric circle outside the plurality of substrates to be processed at an equal distance from the substrates to be processed. 17. The plasma processing apparatus according to claim 1, wherein the plurality of cathode electrodes are arranged so that high-frequency power is divided and supplied from the same power supply to the plurality of cathode electrodes. 18. The plurality of substrates to be processed are arranged on the same circumference, and the plurality of cathode electrodes are arranged on a concentric circle outside the plurality of substrates to be processed at an equal distance from the substrates to be processed. The plurality of cathode electrodes are arranged so that high-frequency power is divided and supplied from the same power source to the plurality of cathode electrodes, and the cathode electrode supplied with power from another power source is formed around the circumference where the plurality of cathode electrodes are arranged. 17. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is concentrically arranged. 19. The substrate according to claim 1, wherein the substrate to be processed is a flat substrate, and the substrate to be processed is opposed to the plurality of cathode electrodes. Plasma processing equipment. 20. The substrate to be processed is 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. 2. The method according to claim 1, wherein a plasma is generated between the high-frequency electrode and the sheet-like substrate to form a deposited film on the sheet-like substrate.
12. The plasma processing apparatus according to any one of items 11 to 11. 21. A reaction vessel capable of reducing pressure, source gas supply means for supplying a source gas for plasma CVD into the reaction vessel,
A substrate holding means disposed in the reaction vessel; and a plurality of cathode electrodes having a film-forming target substrate held by the substrate holding means as a counter electrode, and a plurality of cathode electrodes connected to the plurality of cathode electrodes via a matching circuit. In a plasma processing method, a high frequency power is applied from a high frequency power source in a divided manner, a plasma is generated between the plurality of cathode electrodes and the film formation processing substrate, and a deposition film is formed on the film formation processing substrate. When applying to the plurality of cathode electrodes, a uniform plasma is generated by controlling the phase of the high-frequency power propagated to each of the plurality of cathode electrodes, and a deposited film is formed on the deposition target substrate. A plasma processing method characterized by forming. 22. The phase control of the high-frequency power, the opposite side of the high-frequency power supply point of the cathode electrode is grounded via a high-voltage variable capacitor (C1), and the matching is performed on the other high-frequency power supply point side. A high voltage variable capacitor (C2) is provided after the circuit and before the power supply point for each of the cathode electrodes after the power dividing point supplied from the high frequency power supply, and the total amount of the capacitances of both capacitors (C1 + C2 = k) is constant. 22. The plasma processing method according to claim 21, wherein the method is performed by controlling the capacitance value of each of the capacitors (C1, C2). 23. In the phase control of the high frequency power, the capacitance value is a sum of the capacitances of the two capacitors (C1 + C
23. The plasma processing method according to claim 22, wherein the control is performed so as to be within a range of ± 30% of 2 = k). 24. In the phase control of the high-frequency power, the reactance between the high-voltage variable capacitor (C1) and the grounded grounding part and the reactance to the grounding part opposite to the feeding point are different from the grounding part. 24. The plasma processing method according to claim 22, wherein the plasma processing method is adjusted by a distance of a line up to or a capacitance of a capacitor. 25. In the phase control of the high frequency power, the reactance between the high voltage variable capacitor (C2) and the cathode electrode is adjusted by the distance between the high voltage variable capacitor and the cathode electrode or the capacitance of the capacitor. The plasma processing method according to claim 22 or claim 23, characterized in that: 26. The phase control of the high-frequency power is performed by installing a high-voltage variable capacitor (C3) on a cathode side of a tuned high-voltage variable capacitor in the matching circuit before a power dividing point supplied from the high-frequency power supply. A high-voltage variable capacitor (C4) is provided between the power dividing point and the power supply point for each of the cathode electrodes, after being grounded via the high-voltage variable capacitor (C3), and after the high-voltage variable capacitor of the tune. By controlling the capacitance values of the respective capacitors (C3, C4) and controlling the phase of the high-frequency power applied to the respective cathode electrodes so that the total amount (C3 + C4 = k) becomes constant. The plasma processing method according to claim 21, wherein: 27. In the phase control of the high-frequency power, the capacitance value is a total amount (C3 + C
27. The plasma processing method according to claim 26, wherein the control is performed so as to be within a range of ± 30% of 4 = k). 28. In the phase control of the high-frequency power, the reactance between the high-voltage variable capacitor (C3) and the high-voltage variable capacitor (C4) and the grounded portion and the grounded portion on the side opposite to the feeding point. The reactance is adjusted by the distance of the line to the ground or the capacitance of a capacitor.
The plasma processing method according to claim 6 or 27. 29. The plasma processing method according to claim 21, wherein high-frequency power from the same high-frequency power source is divided and applied to said plurality of cathode electrodes. 30. A frequency of 30 to 6 by said high frequency power supply.
30. The plasma processing method according to claim 21, wherein a high frequency in a range of 00 MHz is applied. 31. The cathode electrode according to claim 21, wherein a surface of each of the cathode electrodes is covered with a dielectric.
The plasma processing method according to any one of the above items. 32. The plasma processing method according to claim 21, wherein the cathode electrode is a cylindrical cathode electrode. 33. The plasma processing method according to claim 21, wherein the substrate to be processed is a cylindrical substrate. 34. The apparatus according to claim 2, wherein a plurality of said substrates to be processed are arranged on concentric circles.
The plasma processing method according to any one of Items 1 to 33. 35. The reaction container according to claim 21, wherein the reaction vessel is formed of a dielectric member, and the cathode electrode is disposed on the outside air side of the dielectric member. Item 6. The plasma processing method according to item 1. 36. The plasma processing method according to claim 21, wherein a deposited film is formed on the surface of the cylindrical substrate while rotating the cylindrical substrate. 37. The plurality of substrates to be processed are arranged on the same circumference, and the plurality of cathode electrodes are disposed on a concentric circle outside the plurality of substrates to be processed at an equal distance from the substrates to be processed. The plasma processing method according to any one of claims 21 to 36, wherein the plasma processing method is arranged so that high-frequency power is divided and supplied from the same power supply to the plurality of cathode electrodes. 38. The plurality of substrates to be processed are arranged on the same circumference, and the plurality of cathode electrodes are arranged on a concentric circle outside the plurality of substrates to be processed at the same distance as between the substrates to be processed. The plurality of cathode electrodes are arranged so that high-frequency power is divided and supplied from the same power source to the plurality of cathode electrodes, and the cathode electrode supplied with power from another power source is formed around the circumference where the plurality of cathode electrodes are arranged. The plasma processing method according to any one of claims 21 to 36, wherein the plasma processing method is arranged concentrically. 39. The method according to claim 21, wherein the substrate to be processed is a flat substrate, and the substrate to be processed is opposed to the plurality of cathode electrodes. Plasma processing method. 40. The substrate to be processed is 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. 3. The method according to claim 2, further comprising: generating plasma between the high-frequency electrode and the sheet-like substrate to form a deposited film on the sheet-like substrate.
The plasma processing method according to any one of Items 1 to 31.