JPH05166733A - Method and apparatus for forming non-single crystal silicon film - Google Patents

Abstract

PURPOSE:To enable formation of a high-quality non-single crystal silicon film with photodeterioration suppressed, damage due to ions during film formation reduced, and characteristics stabilized. CONSTITUTION:A first step to deposit a non-single crystal silicon film on a substrate 101 by high frequency plasma CVD method in a reaction chamber 100 and a second step to expose the deposited film to atomized hydrogen are conducted alternately. The atomized hydrogen used in the second step is generated by an A microwave plasma generator 150 so as to be introduced into the reaction chamber 100 via a ground metal mesh 105, or supplied into a B reaction chamber so as to be generated by such dc discharge that a positive bias is applied to an anode electrode 103.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming a non-single crystal silicon film, and more particularly to depositing and growing a large area hydrogenated non-single crystal silicon film on a substrate.
The present invention relates to a method and an apparatus for forming a non-single crystal silicon film.

[0002]

2. Description of the Related Art In recent years, a semiconductor device using a non-single crystal silicon film such as hydrogenated amorphous silicon has been actively developed. The non-single-crystal silicon film is a silicon film which is not single crystal, that is, amorphous, microcrystalline, or polycrystalline. The non-single-crystal silicon film here includes a film made of a non-single-crystal silicon alloy in which carbon is added to silicon or germanium. In addition, this non-single crystal silicon film generally contains hydrogen, and is a so-called hydrogenated non-single crystal silicon film.

For example, an amorphous silicon film, unlike monocrystalline silicon, can be formed on a low temperature substrate or a glass substrate, can easily be made large in area, has a larger light absorption than crystalline silicon, and has isotropic characteristics. Since it has the characteristics such as, the field of application different from that of single crystal silicon has been developed. The main devices that use non-single-crystal silicon films are large-area, low-production-cost solar cells, lightweight and small solid-state imaging devices for facsimiles, line sensors, area sensors, and liquid crystal display drives. There are thin film transistors (TFTs), TFT arrays, TFT matrices, electrophotographic photoconductors, etc. used for switching photosensors, and the development of these is energetically advanced. Although there is an example in which a non-single-crystal silicon film is used for a single optical sensor, the center of a non-single-crystal silicon device is a large-area device as described above, which also makes the best use of its characteristics.

As a method of forming such a non-single-crystal silicon film, conventionally, for example, in the case of hydrogenated amorphous silicon, an RF (high frequency) plasma CVD method (so-called GD method) using SiH ₄ or Si ₂ H ₆ as a film forming gas is used. ), A microwave plasma CVD method, or a reactive sputtering method of sputtering a Si target in Ar plasma in the presence of hydrogen gas. Experimentally, in addition to this, photo CVD method, ECR (electron cyclotron resonance)
Examples using a CVD method, a vacuum deposition method of Si in the presence of hydrogen atoms, and the like have also been reported. There is also an example of film formation by a thermal CVD method using Si ₂ H ₆ or the like. Most of the hydrogenated amorphous silicon films obtained by these methods contain 10% or more of hydrogen.
It should be noted that all of the amorphous silicon showing properties that can be used in various electronic devices contain hydrogen of a certain amount or more.

Among the various methods described above, the most popular method for forming a hydrogenated amorphous silicon film is the plasma CVD method. In most cases, this method uses SiH ₄ or Si ₂ H ₆ as a film-forming gas, and dilutes it with hydrogen gas as needed.
Alternatively, it is a method in which plasma is generated at a high frequency (microwave) of 2.45 GH, the film forming gas is decomposed by the plasma to generate reactive active species, and a hydrogenated amorphous silicon film is deposited on the substrate. The film forming gas, PH _3,
By mixing a doping gas such as B ₂ H ₆ or BF ₃ , an n-type or n ⁺ -type or p-type or p ⁺ -type amorphous silicon film can be formed. Electronic devices are made.

However, when the above-mentioned non-single-crystal silicon film is used in a photoelectric conversion device such as an image sensor or a solar cell, photodegradation (so-called Stabler-Wronsk) which greatly affects deterioration of the characteristics of these devices.
It is known that there is a (i effect) phenomenon. As a cause for this, it is considered that dangling bonds and weak bonds between Si existing in the non-single crystal silicon film are broken by light irradiation, and thus the photoelectric conversion efficiency is lowered.
The degree of photodegradation varies depending on the difference in the conditions under which the non-single crystal silicon film is formed (substrate temperature, film formation pressure, source gas concentration, high frequency or microwave power). It is known that the excess hydrogen in the film causes photodegradation.

Therefore, recently, as a method of preventing this photodegradation, a method of forming a non-single-crystal silicon film by repeating film formation and hydrogen plasma treatment of the surface has been proposed (for example, the Japan Society of Applied Physics Association Lecture Meeting). Proceedings Spring 1990 31
a-2D-8, 31a-2D-11, Proceedings, Autumn 1988, 5p-2F-1, "Applied Physics", Vol. 59, No. 12, pp. 43-45). This is a method also called "chemical annealing", for example,
In the case of forming an amorphous silicon film by using an apparatus having a microwave plasma generator attached to an ordinary high-frequency plasma CVD apparatus, SiH ₄ gas is decomposed by ordinary high-frequency power to deposit the film, On the other hand, a large amount of atomic hydrogen generated by decomposing hydrogen gas with microwave power is transported toward the film being deposited. In this case, the deposition of the film and the transport of atomic hydrogen are alternately repeated. Specifically, when the above-mentioned apparatus is used, high frequency, microwave and hydrogen gas are constantly supplied, and only SiH ₄ which is a film forming gas is intermittently supplied. Further, when SiH ₄ is not supplied, the supply of high frequency is also stopped in order to prevent damage by ions in the high frequency plasma. By doing so, the atomic hydrogen abstracts the excess hydrogen in the deposited film, and at the same time, the structure of the film is relaxed. As a result, a dense film structure is formed, and the light caused by the excess hydrogen is removed. It is said that deterioration is suppressed.

Here, by exposing atomic hydrogen to the non-single crystal silicon film being deposited, the excess hydrogen is extracted and the structural relaxation of the deposited film is carried out.
The mechanism will be described. When exposed to atomic hydrogen,
It is not always clear at present what kind of phenomenon is occurring on the surface of the non-single crystal silicon film being deposited, but two models are currently considered. First, in the first model, the active atomic hydrogen coming to the deposition surface is
While diffusing on the deposition surface and the deposited film, it attacks excessive Si—H bonds on the film surface and in the film, and abstracts hydrogen from this bond. The dangling bonds generated at this time are re-bonded to each other, so that the structure of the entire film is relaxed while the excess hydrogen is extracted. On the other hand, in the second model, the active atomic hydrogen coming to the film surface is
Only the surface of the film diffuses and moves, and reacts with the hydrogen of the Si-H bond on the surface to extract this hydrogen. The dangling bonds generated on the surface by this diffuse from the surface through the film. This diffusion proceeds along with the inter-site movement of hydrogen atoms in the film, so the hydrogen in the film is moving toward the surface, and the hydrogen in the film is always supplied to the surface. Become. The hydrogen that has diffused is subsequently extracted by a surface reaction, and the structure of the entire film is relaxed while the excess hydrogen is extracted.

[0009]

When attempting to prevent photodegradation by using the above-described chemical annealing method, plasma is generally used to generate atomic hydrogen, so that it is mixed with atomic hydrogen. There is a problem that ions damage the non-single-crystal silicon film being deposited, which hinders the quality of the non-single-crystal silicon film to be formed, and the characteristics of the manufactured device become unstable. There is a point. Such instability of characteristics is particularly serious in the case of a large-area device, which causes a decrease in yield and an increase in manufacturing cost.

An object of the present invention is to form non-single-crystal silicon which is capable of forming a high-quality non-single-crystal silicon film in which photodegradation is suppressed, damage by ions during film formation is small, and characteristics are stable. It is to provide a method and a forming apparatus used for carrying out the forming method.

[0011]

A method of forming a non-single-crystal silicon film according to a first aspect of the present invention comprises a first step of depositing a non-single-crystal silicon film on a substrate, and a step of forming the non-single-crystal silicon film by the first step. In a method for forming a non-single-crystal silicon film, which comprises alternately repeating a second step of exposing the surface of the non-single-crystal silicon film to atomic hydrogen, the substrate is provided in a film forming container, and the first step is Atomic hydrogen used in the second step, which is performed by a high frequency plasma CVD method, is generated by a microwave plasma generating means connected to the film forming container,
The generated atomic hydrogen is introduced into the space in which the high-frequency plasma by the high-frequency plasma CVD method is to be formed in the film forming container through a grounded conductive net.

In the method for forming a non-single-crystal silicon film of the second invention, the first step of holding the substrate in a film forming container and depositing the non-single-crystal silicon film on the substrate, and the first step. In the method of forming a non-single-crystal silicon film, wherein the second step of exposing the surface of the non-single-crystal silicon film formed by the step to atomic hydrogen is alternately repeated, the substrate side is provided during the execution of the second step. A direct current discharge is generated in the film forming container such that a positive bias voltage is applied to, and atomic hydrogen generated by the direct current discharge is used in the second step. ..

A non-single-crystal silicon film forming apparatus according to a third aspect of the present invention comprises a film-forming container which can be evacuated, a high-frequency plasma means for generating high-frequency plasma in the film-forming container, a microwave source, and the film-forming container. On a substrate held in the film forming container, which has a diffusion port provided inside and a microwave plasma generation unit that is connected to the diffusion port and generates microwave plasma by a microwave from the microwave source. A non-single crystal silicon film forming apparatus for depositing and growing a non-single crystal silicon film on a substrate, wherein the diffusion port is opened toward a space where the high frequency plasma means generates high frequency plasma, and the film forming container A conductive net, which is grounded with respect to, is provided to cover the opening of the diffusion port.

A non-single-crystal silicon film forming apparatus according to a fourth aspect of the present invention comprises a film-forming container that can be evacuated, a support electrode that is provided in the film-forming container and can hold a substrate, and a support electrode that faces the support electrode. A counter electrode provided in the film forming container, a first gas introducing unit for introducing hydrogen gas into the film forming container, and a second gas for introducing a film forming gas into the film forming container. Introducing means, a high frequency power source for applying high frequency power between the supporting electrode and the counter electrode, a direct current power source for applying a positive bias voltage to the supporting electrode, the high frequency power source and the second electrode. The first time zone in which the gas introduction means operates and the DC power source does not operate, and the second time zone in which the DC power source operates and the high frequency power source and the second gas introduction means do not operate alternately. As it appears in the high frequency power source and the direct current And a control means for controlling the source and the second gas introducing means.

[0015]

In the method of forming a non-single-crystal silicon film of the first invention and the apparatus of forming a non-single-crystal silicon film of the third invention, atomic hydrogen is generated by the microwave plasma generating means, and the atomic hydrogen is generated. Since the ions are introduced into the film forming container through the conductive mesh, the ions existing in the plasma in the microwave plasma generating means and unavoidably contained in the atomic hydrogen from the microwave plasma generating means. Will be blocked by this conductive net, and the non-single-crystal silicon film being deposited can be prevented from being damaged by ions. In this case, during the execution of the second step, that is, when the film being deposited is exposed to atomic hydrogen, a film-forming gas (for example, SiH ₄ or Si ₂ H ₆ ) as a raw material is transferred to the film-forming container. It is desirable to stop not only the introduction but also the introduction of high frequency power. By doing so, it is possible to reduce the plasma damage of the deposited film due to the high frequency plasma. When T _D is the time when the first step is performed and T _A is the time when the second step is performed,
Since the non-single-crystal silicon film is formed only in the first step, the change over time in the film formation rate is as shown in FIG.

According to the non-single crystal silicon film forming method of the second invention and the non-single crystal silicon film forming apparatus of the fourth invention,
During the execution of the second step, that is, during the second time period, a DC voltage is applied to cause a positive bias on the substrate side to cause a DC discharge, so that a potential gradient that makes the substrate positive is formed. become. In direct current discharge, atomic hydrogen is generated mainly in the positive column, and this atomic hydrogen reaches the deposited film on the substrate. As the type of DC discharge, a normal glow discharge exhibiting a constant voltage characteristic is preferable, and the applied voltage and the load resistance are adjusted to increase the electron density in the positive column and increase the amount of atomic hydrogen generated. Good to do. Also, most of the ions in the plasma generated by the DC discharge are positive ions, so
Ions reaching the substrate side are only low-energy diffusion components, and damage to the substrate and the deposited film on the substrate due to ions when exposed to atomic hydrogen is reduced. This makes it possible to supply a sufficient amount of atomic hydrogen to the deposited film while reducing the amount of ions that enter the deposited film.

In the present invention, if the thickness of the film deposited during one repetition of the first step and the second step is thin, the amorphous structure cannot be kept stable and hydrogen is extracted by atomic hydrogen. This promotes microcrystallization and polycrystallization. On the other hand, if the deposited thickness is large during one repetition, it is difficult to extract hydrogen from the deposited film, and it becomes difficult to proceed with structural relaxation. Therefore, by changing the duration of each of the first step and the second step and the amount of atomic hydrogen supplied to the film surface, various non-single-crystal films including an amorphous silicon film or a microcrystalline silicon film can be obtained. A silicon film will be formed.

[0018]

Embodiments of the present invention will now be described with reference to the drawings.

[First Embodiment] First, as a first embodiment of the present invention, a microwave plasma generator is provided separately from the film forming container, and a conductive net grounded from the microwave plasma generator is provided. A case where atomic hydrogen is introduced into the film forming container through the above will be described. FIG. 1 is a schematic cross-sectional view showing the structure of a non-single crystal silicon film forming apparatus of this embodiment.

Reaction chamber 1 which is a film-forming container that can be evacuated
An exhaust pump 109 is connected to 00 through an exhaust pipe 108, and one ends of two gas introduction pipes 110 and 111 are connected to the exhaust pump 109. In the reaction chamber 100, a cathode electrode 102 and an anode electrode 103 are provided so as to face each other, and both electrodes 102,
The space sandwiched by 103 becomes a high frequency plasma space 119. The cathode electrode 102 is the matching box 10.
The other end is connected to one end of a high-frequency power source 107 whose other end is grounded. The frequency of the high frequency power source 107 is, for example, 13.56 MHz. On the other hand, the anode electrode 10
3 is grounded and can hold the substrate 101 which is the target of film formation. A heater 104 for heating the substrate 101 is embedded inside the anode electrode 103.

An air actuated valve 117, a valve 120, a mass flow controller 121, and a valve 122 are sequentially provided on one gas introduction pipe 110 from the reaction chamber 100 side, and a gas cylinder (not shown) is connected to the terminal side valve 122. It is like this. This one gas introduction pipe 1
Reference numeral 10 is for introducing a film-forming gas such as SiH ₄ or Si ₂ H ₆ into the reaction chamber 100. Also,
One of the gas introduction pipes 110 branches on the side of the mass flow controller 121 of the air actuated valve 117, and the branch side pipe (branch pipe 114) passes through the air actuated valve 116 and the exhaust pump 1
It is connected to 15. These two air operated valves 11
6, 117 are alternately opened, and the film-forming gas supplied to the gas introduction pipe 110 on one side through the valve 122 on the terminal side is alternately branched.
The gas is exhausted either directly through the exhaust pipe or by being supplied to the reaction chamber 100 and exhausted through the exhaust pipe 108. In this case, the operation of the air actuated valves 116 and 117 prevents the mass flow controller 121 from malfunctioning and the gas during film formation from staying.

A microwave plasma generator 150 is provided in the middle of the other gas introduction pipe 111. This microwave plasma generator 150 includes the other gas introduction pipe 1
11 includes a plasma generation chamber 151 provided in a portion penetrating the microwave plasma generator 150 and a waveguide 152 having one end connected to the plasma generation chamber 151.
The other end of the waveguide 152 is connected to a microwave source 153 having a frequency of 2.45 MHz, for example. The other end of the other gas introduction pipe 111 is branched into a plurality of branch pipes 130, and a valve 131, a mass flow controller 132, and a valve 133 are connected in series for each branch pipe 130. Each valve 133 on the terminal side is connected to a gas cylinder (not shown). The other gas introduction pipe 111 is provided with a non-film forming gas, that is, H ₂ gas or Ar.
A gas and a doping gas for doping impurities are introduced into the reaction chamber 100. Also,
At the connection point between the other gas introducing pipe 111 and the reaction chamber 100, the other gas introducing pipe 111 has an opening at its tip to serve as a diffusion port, and the diffusion port is attached so as to face the high-frequency plasma 119. ing. And
A metal mesh 105 is provided so as to cover the diffusion port, and the metal mesh 105 is grounded to the reaction chamber 100. As a result, the ions diffused from the microwave plasma generator 150 are captured by the metal mesh 105, and these ions are collected in the reaction chamber 1.
It will not invade 00.

Next, regarding the operation of this embodiment, p
An example in which a ⁺ in ⁺ type photovoltaic element is manufactured will be described. As shown in FIG. 2, this photovoltaic element includes a lower electrode 172, an n ⁺ type semiconductor layer 173, an i type semiconductor layer 174, ap ⁺ type semiconductor layer 175, a transparent upper electrode 1 on a substrate 171.
76 and a mesh-shaped collector electrode 177 are sequentially laminated. Each of the semiconductor layers 173 to 175 is made of amorphous silicon, and in particular, the i-type semiconductor layer 174, which has a significant effect on photoelectric conversion characteristics, is formed based on this embodiment.

First, the surface is mirror-polished to 0.05 μm R _max.
5 cm square stainless steel (SUS304)
The substrate 171 made of metal is attached to a sputtering device (not shown), the inside of the sputtering device is evacuated to 10 ^-7 Torr or less, and then Ar gas is introduced to generate a DC plasma discharge with an electric power of 200 W with an internal pressure of 5 mTorr. Sputtering was performed with an Ag target to deposit about 5000 Å Ag. Then, the target was changed to ZnO, DC plasma discharge was caused to occur under the same conditions of internal pressure and power, and sputtering was performed to deposit ZnO with a thickness of about 5000Å on Ag. Through the above steps, the lower electrode 172 is formed on the substrate 171.
Has been formed.

Then, the substrate 171 was taken out from the sputtering apparatus, attached to the anode electrode 103 of the reaction chamber 100 of this embodiment, and the exhaust chamber 109 exhausted the reaction chamber 100 sufficiently. It is confirmed that the degree of vacuum in the reaction chamber 100 is 10 ⁻⁶ Torr or less by an ion gauge (not shown), and the heater 104 heats the substrate.
The substrate temperature was stabilized at 250 ° C. Next, the valves 120 and 122 of the one gas introduction pipe 110 are opened, the flow rate is controlled by the mass flow controller 121, and the air operated valve 117
SiH ₄ gas 30s from SiH ₄ gas cylinder (not shown) via the
ccm was introduced into the reaction chamber 100. Similarly, from the other gas introduction pipe 111, H ₂ gas 30 sccc
m and 10 sccm of PH ₃ gas diluted to 5% with H ₂ gas were introduced into the reaction chamber 100. Reaction chamber 10
After adjusting the pressure in 0 to 0.5 Torr, 10 W of high-frequency power from the high-frequency power source 107 was introduced into the reaction chamber 100 through the matching box 106, high-frequency plasma discharge was performed for 3 minutes, and the thickness of amorphous silicon was increased. An n ⁺ type semiconductor layer 173 having a thickness of 400 Å was deposited.

After that, the high-frequency power supply and the gas supply are stopped, the reaction chamber 100 is evacuated to a vacuum degree of 10 ^-6 Torr, the SiH ₄ gas 30 sccm is supplied from one gas introduction pipe 110, and the other gas is supplied. 30 sccm of H ₂ gas was introduced into the reaction chamber 100 through the introduction pipe 111. In this state, the pressure of the reaction chamber 100 is set to 0.1 Torr.
After adjusting to r, high-frequency power of 10 W from the high-frequency power supply 107 is supplied to the reaction chamber 100 to generate SiH ₄ plasma discharge, while microwaves are supplied from the microwave source 153 to the microwave plasma generator 150, H ₂ plasma was generated in the plasma generation chamber 151, and atomic hydrogen was generated and supplied to the reaction chamber 100. At this time, if high frequency power is supplied for 30 seconds to deposit the i-type amorphous silicon film,
The high frequency power is stopped, the open / closed states of the air operated valves 116 and 117 are reversed, and the SiH ₄ gas is transferred to the reaction chamber 100.
This state was maintained for 40 seconds. At this time, since the supply of atomic hydrogen from the other gas introduction pipe 111 is continuing, the amorphous silicon film deposited on the substrate is exposed to atomic hydrogen. Since the grounded metal mesh 105 is provided at the connection between the other gas introduction pipe 111 and the reaction chamber 100, the ions diffused from the plasma generation chamber 151 do not enter the reaction chamber 100. Therefore, the ions do not enter the deposited film. After that, the supply of SiH ₄ gas and the input of high-frequency power were restarted, the amorphous silicon film was deposited again for 30 seconds, and thereafter, the step of supplying and stopping SiH ₄ gas in this way was performed for a total of 200 cycles. .. As a result, on the n ⁺ -type semiconductor layer 173, i having a thickness of 6000 Å
The type semiconductor layer 174 was deposited.

Next, after turning on the high frequency power and the microwave power and stopping the gas supply and exhausting the reaction chamber 100 to 10 ^-6 Torr, the substrate temperature is lowered to 200 ° C. to stabilize the substrate temperature. It was Then, 1 sccm of SiH ₄ gas is supplied from one gas introduction pipe 110 to the reaction chamber 10.
H ₂ gas 3 introduced from the other gas introduction pipe 111.
B ₂ H ₆ gas 1 diluted to 5% with 00 sccm and H ₂ gas
0 sccm was introduced into the reaction chamber 100. After adjusting the pressure in the reaction chamber 100 to 0.1 Torr, a high frequency power of 50 W is supplied from the high frequency power source 107 to the reaction chamber 100 to generate plasma discharge, and film formation is performed for 15 minutes to form a p ⁺ film having a thickness of 100 Å. The type semiconductor layer 175 was deposited.

Subsequently, the substrate is taken out of the reaction chamber 100, mounted on a resistance heating type vacuum vapor deposition apparatus (not shown), the inside of the vacuum vapor deposition apparatus is evacuated to 10 ^-7 Torr or less, and the substrate temperature is kept at 160 ° C. After that, O ₂ gas is introduced to adjust the internal pressure to 0.5 mTorr, and an alloy of In and Sn is vapor-deposited by resistance heating to form a transparent conductive film (ITO) which also has an antireflection effect.
A film) was deposited to a thickness of 700 Å to form an upper electrode 176. After completion of the vapor deposition, the substrate was taken out and separated into cells of 1 cm × 1 cm by a dry etching device (not shown), and a collector electrode 177 made of Al was formed by another vapor deposition device to complete the photovoltaic element.

On the other hand, an i-type semiconductor layer was formed by a conventional method, that is, a method in which SiH ₄ gas was supplied and high-frequency power was continuously supplied to form a comparative photovoltaic element. At this time, the gas flow rate, pressure, high-frequency power, thickness of the i-type semiconductor layer, and the like were the same as those in the photovoltaic element according to the present embodiment described above.

Next, the characteristics of each photovoltaic element obtained as described above were evaluated. First, the photovoltaic element according to the present example and the comparative photovoltaic element were irradiated with pseudo sunlight having an AM value of 1.5 and an intensity of 100 mW / cm ² from a solar simulator, and a voltage-current curve was obtained. The initial photoelectric conversion efficiency η (0) of each photovoltaic element was measured by determining. Next, the optimum load was calculated from the open circuit voltage V _oc and the short circuit current I _sc evaluated from the voltage-current curve, and the load resistance of this optimum load was connected to each photovoltaic element.

In this state, each photovoltaic element was continuously irradiated with the same pseudo-sunlight as above for 500 hours, and the subsequent light conversion efficiency η (500) was obtained in the same manner as described above. From η (0) and η (500) thus obtained, {1-η (500) /
Deterioration rate is obtained from η (0)}, and when compared with that of this example with η (0) and the degradation rate of 1 for comparison, respectively, η (0) in this example is 1.5, and deterioration is The rate was 0.1, the initial photoelectric conversion efficiency was increased, and the deterioration rate was low. In particular, it was found that the deterioration rate was remarkably small. Further, there were one in which only the i-type semiconductor layer was deposited on the silicon wafer by the method of this example, and the other in which only the i-type semiconductor layer was deposited by the conventional method. Was prepared, and the hydrogen concentration in the i-type semiconductor layer of these samples was measured from the infrared absorption spectrum. as a result,
In the present example, it was 3 atom%, whereas in the conventional method, it was 9 atom%.

Next, the basic characteristics of the amorphous silicon film formed in this example were examined. 50 mm x 5
An amorphous silicon film was formed on a No. 7059 glass plate manufactured by Corning Co., Ltd. having a size of 0 mm by the method of the present embodiment described above. The gas flow rate, pressure, high-frequency power, etc. were the same as above, and the step of depositing the amorphous silicon film and the step of exposing it to atomic hydrogen were repeated 300 cycles to form an amorphous silicon film with a thickness of about 9000 Å. On the surface of this film, a comb-shaped aluminum electrode having a gap width of 250 μm was vapor-deposited, and the photoconductivity was measured. As a result, it was 10 ⁻⁴ to 10 ⁻⁵ S / cm, which was larger than that of the conventional film. It was judged that it was a good quality film. In addition, photodegradation was also greatly reduced. Further, when Raman spectrum was measured, a peak near 520 cm ^-1 did not appear, and 480c
Only the peak around m ^-1 was observed. From this, it was found that this film maintained an amorphous structure.

[Second Embodiment] Next, a second embodiment of the present invention will be described. In this embodiment, a direct current discharge having a positive side on the substrate side is generated in the film forming container, and the atomic hydrogen generated at that time is used to extract hydrogen in the deposited film. Further, at the time of film formation, capacitive coupling high-frequency glow discharge is generated. FIG. 3 is a schematic cross-sectional view showing the configuration of the non-single crystal silicon film forming apparatus of this embodiment.

Reaction chamber 2 which is a film-forming container that can be evacuated
00, an exhaust pump 209 is connected via an exhaust pipe 208, and further the first and second gas introduction pipes 210, 2 are connected.
One end of each of 11 is connected. Reaction chamber 2
00, a cathode electrode 202 which is a counter electrode and an anode electrode 203 which is a support electrode are provided so as to face each other. The cathode electrode 202 is a high frequency power supply 2 whose other end is grounded via a matching box 206.
It is connected to one end of 07. Matching box 20
6 is for capacitive coupling. The frequency of the high frequency power source 207 is, for example, 13.56 MHz. Further, the cathode electrode 202 is connected to the negative electrode of the DC power supply 218 via the high frequency blocking coil 216 and the load resistor 217. The positive electrode of the DC power supply 218 is grounded.
On the other hand, the anode electrode 203 is grounded by a ground wire 205 and can hold the substrate 201 which is a target for film formation. A heater 204 for heating the substrate 201 is embedded inside the anode electrode 203.

A valve 220, a mass flow controller 221, and a valve 222 are sequentially provided from the reaction chamber 200 side to the first gas introduction pipe 210, and a gas cylinder (not shown) is connected to the terminal valve 222. There is. The first gas introduction pipe 210 is for introducing H ₂ gas or a doping gas for doping impurities into the reaction chamber 200.

A three-way valve 213 is attached in the middle of the second gas introduction pipe 211, and a branch side of the three-way valve 213 is provided with
One end of the exhaust pipe 214 is connected, and the exhaust pump 215 is connected to the other end of the exhaust pipe 214. The other end of the second gas introduction pipe 211 is branched into a plurality of branch pipes 230, and a valve 231, a mass flow controller 232, and a valve 233 are connected in series for each branch pipe 230. Each of the valves 233 on the end side is connected to a gas cylinder (not shown). The second gas introduction pipe 211 is for introducing a film-forming gas such as SiH ₄ gas or Si ₂ H ₆ gas into the reaction chamber 200. By switching the three-way valve 213, it is possible to supply or stop the supply of the film-forming gas into the reaction chamber 200.

Further, the high frequency power source 207 and the DC power source 21
8. A computer (not shown) for controlling the three-way valve 213 is provided. This computer is the first time zone (T
_{During D} ), the high frequency power supply 207 is operated, the three-way valve 213 is opened in the direction of flowing the film-forming gas into the reaction chamber 200, and the DC power supply 218 is not operated, and the second time zone ( During the period T _A ), the DC power supply 218 is operated and the three-way valve 213 discharges the film-forming gas to the exhaust pump 21.
The high-frequency power source 207 is opened so that the high-frequency power source 207 does not operate. The first time zone (T _D ) and the second time zone (T _A ) alternate with each other. One cycle of the first time period (T _D ) and the second time period (T _A ) is referred to as one cycle. By doing so, the operating states of the high frequency power supply 207 and the direct current power supply 218 are as shown in FIG.

By doing so, in the first time period (T _D ), the first step, that is, the deposition of the hydrogenated amorphous silicon film is performed by the high frequency plasma CVD method. On the other hand, the second time period (T _A)
Then, the high-frequency discharge is stopped, and the second step, that is, the step of exposing the deposited film to the atomic hydrogen, is performed by using the atomic hydrogen generated by the DC discharge. In addition,
Since the direct-current discharge is such that the substrate side is positive, ions are less likely to enter the substrate or the deposited film on the substrate.
In this embodiment, since capacitive coupling high-frequency plasma discharge is used, a capacitor (not shown) connected to the high-frequency power source 207 is provided on the cathode electrode 202 side of the matching box 206. The direct current voltage from the power source 218 is not applied to the high frequency power source 207.

Here, the effect of the exposure to atomic hydrogen according to the present embodiment will be described with respect to the difference from the conventional example. The conventional example referred to here is one in which high frequency discharge is continuously performed and the first step and the second step are switched only by turning on / off the supply of the film-forming gas. The film forming conditions of the film according to the present embodiment used in the following description are typical. That is, the gas flow rate is SiH ₄ gas 30 sccm,
The H ₂ gas was 30 sccm, the substrate temperature was 300 ° C., and the film forming pressure was 0.5 Torr. Film formation and exposure to atomic hydrogen were repeated by switching the three-way valve 213, turning on / off direct current discharge, and turning on / off high frequency discharge. The power of the high frequency discharge was 10 mW / cm ^2, and the applied voltage during DC discharge was 10 mW / cm ^2.
00V, the power density of DC discharge is 100 mW / cm ²
And

FIG. 5 shows the emission spectra of the discharge in this example (A) and the conventional example (B), which is considered to be proportional to the density of atomic hydrogen during the discharge, and the Hα ray (wavelength 486 nm).
In terms of the intensity, the direct current discharge of this example is about one digit larger than the high-frequency discharge of the conventional example, and it is considered that the density of atomic hydrogen is also increased by about one digit. .. Further, it was found from ESR (electron spin resonance) measurement that the number of defects in the film was smaller in the case of direct current discharge than in the case of high frequency discharge. This is considered to be due to the small number of ions incident on the substrate side in DC discharge, particularly in DC discharge in which the substrate side is positive.

FIG. 6 (A) is a diagram showing the outline of the potential distribution in the plasma in the DC discharge, and FIG. 6 (B) is a diagram showing the outline of the potential distribution in the plasma in the high frequency discharge.
In an actual high-frequency plasma, there is a change in the electric field depending on the frequency, which accelerates the ions as well, and there is a considerable probability of electric field drift even to the anode electrode, which is slightly negatively biased with respect to the plasma on average. Ions will rush in. On the other hand, in DC discharge, the substrate is grounded and a negative bias is applied to the opposite electrode (this is the same as setting the substrate side to a positive bias).
Therefore, the anode electrode becomes a positive bias with respect to the plasma, the majority of ions in the plasma drift to the electrode on the opposite side of the substrate, and only the ions that diffuse from the plasma enter the substrate. Is. Since the DC bias voltage is sufficiently applied, the electron density in the plasma increases correspondingly, and the atomic hydrogen produced by decomposition by the electrons can also increase.

The film thickness of the amorphous silicon deposited during the first time period (T _D ) is preferably 2 atomic layers or more, and practically 10 Å or more. This is because if the deposited layer is one atomic layer, the amorphous structure cannot be stably maintained, and exposure to atomic hydrogen will promote crystallization. The cause is
A sudden structural change due to excessive abstraction of hydrogen by atomic hydrogen is considered. That is, if the deposited layer is thin and hydrogen is extracted too much, structural relaxation will occur extremely and crystallization will proceed. To prevent excessive structural relaxation and promote relaxation with good controllability, it is necessary to deposit a layer of 10Å or more.

FIG. 7 shows the relationship between the length of the second time zone (T _A ) and the hydrogen concentration in the film. In the figure, A is due to the direct current discharge of this embodiment and the thickness of the deposited film in each cycle is 50Å, and B is due to the high frequency discharge of the conventional example and the thickness of the deposited film in each cycle is In the case of 50Å, C is the same as in B according to the conventional example, and the film thickness of the deposited film in each cycle is 100Å. It is understood that when the film thickness in each cycle is 100 Å or more, the structural relaxation does not proceed no matter how much the atomic hydrogen is exposed. Further, it can be seen that the effect of reducing the hydrogen concentration in the film is increased by the direct current discharge. Therefore, the first
It can be seen that the film thickness deposited during the time period (T _D ) is preferably 10 Å or more and 100 Å or less, and more preferably 50 Å or less.

FIG. 8 shows the relationship between the film thickness L of the deposited film and the hydrogen concentration in the film in the first time zone (T _D ). In the figure, A is due to the DC discharge of this embodiment,
B is due to the high frequency discharge of the conventional example. It can be seen that the atomic hydrogen is increased by the direct current discharge, and the hydrogen abstraction effect equivalent to that in the conventional case occurs with the film thickness L thicker than that in the conventional case. From FIGS. 7 and 8, by controlling the exposure time to the atomic hydrogen {that is, the second time zone (T _A )} or the deposition time {that is, the first time zone (T _D )}, It can be seen that the hydrogen concentration can be controlled.

FIG. 9 shows the relationship between the hydrogen concentration and the optical band gap E _gopt in the film deposited according to this example. Although the hydrogen concentration in the film depends on the atomic hydrogen concentration in the plasma, the optical band gap E
_{Since gopt} is uniquely dependent on the hydrogen concentration in the film as shown in the figure, it can be seen that the optical band gap E _gopt can also be controlled by controlling the hydrogen concentration in the film as described above. ..

The film forming conditions of this embodiment described above are H ₂
And a system using SiH ₄ are used, but a system in which a gas such as Ar is introduced is used to improve the ionization degree of H ₂ by utilizing the Penning effect of the mixed gas, and eventually increase the concentration of atomic hydrogen. That is also more effective.

Next, regarding the operation of this embodiment, p
An example of creating a ⁺ in ⁺ type solar cell will be described. As shown in FIG. 10, this solar cell has a lower electrode 272, an n ⁺ type layer 273, an i type layer 274, and a lower electrode 272 on a glass substrate 271.
The p ⁺ type layer 275 and the transparent upper electrode 276 are sequentially laminated. n ⁺ type layer 273, i type layer 274, p ⁺
Each of the mold layers 275 is made of hydrogenated amorphous silicon, and in particular, the i-type layer 274 having a significant effect on photoelectric conversion characteristics is formed based on the above-described present embodiment.

After forming the lower electrode 272 on the glass substrate 271 using a metal film such as Al, the reaction chamber 2
00 attached to the anode electrode 203, and the exhaust pump 20
The inside of the reaction chamber 200 is evacuated by 9 and the vacuum degree is adjusted to 10
^-6 Torr. SiH ₄ gas 30 sccm, H ₂ gas 30
sc cm, PH ₃ gas 100s diluted to 1% with H ₂ gas
ccm is introduced into the reaction chamber 200 and the pressure is set to 1.0 T
The substrate temperature was set to orr, the substrate temperature was set to 300 ° C., and the state was maintained for 1 hour. After that, a high frequency power of 50 mW / cm ² was applied and discharged for 7 minutes, and a thickness of 400 Å n ⁺
A mold layer 273 was deposited. After stopping the supply of each gas, the reaction chamber 200 was evacuated to 10 ⁻⁶ Torr or less.

Next, based on this embodiment, the i-type layer 274 is formed.
Was deposited. Open the valves 220 and 222 to release H ₂ gas 30
sccm was introduced into the reaction chamber 200. The three-way valve 21 is used to allow the film-forming gas to flow into the reaction chamber 200.
After setting 3, set valves 231 and 233 and open SiH ₄
Gas of 30 sccm is introduced into the other gas introduction pipe 211,
The substrate temperature was kept at 300 ° C. and kept for 1 hour. Next, by switching the three-way valve 213, turning on / off the high frequency discharge, and turning on / off the direct current discharge, the first step of film formation and the second step
And the step of exposing to atomic hydrogen were repeated. At this time, as described above, the timing of stopping the high-frequency discharge and the timing of starting the DC discharge were synchronized with the timing of exposure to atomic hydrogen, and in the DC discharge, the substrate side became the anode. High frequency discharge power is 10m
And W / cm ^2, the applied voltage at the time of DC discharge was set to 1000V, the power density of the direct current discharge was 100 mW / cm ^2.
At this time, the load resistance 217 was 50 kΩ. Under this condition, the density of atomic hydrogen is higher than that of high frequency discharge.
The emission intensity level increased by about one digit. The film formation time, that is, the first time period (T _D ) was set to 20 seconds. By this,
The film thickness deposited during one cycle is 20Å. Further, the exposure time to atomic hydrogen, that is, the second time period (T _A ) is 20 seconds, and the first and second time periods (T _D , T _A ) are 300 cycles under the control of a computer (not shown). I repeated. As a result, the total thickness of the i-type layer 274 is 60.
It became 00Å.

Then, p⁺A mold layer 275 was deposited. reaction
10 in the chamber 200^-6Exhaust below Torr, substrate temperature
To 250 degrees, then SiH_FourGas 1 sccm, H₂gas
300 sccm, H₂B diluted to 1% with gas₂H₆gas
Flowing 1 sccm in the reaction chamber 200,
Held for hours. After that, high frequency power 50mW / cm ²
And plasma discharge for 8 minutes, p⁺Mold layer 27
Formed 5. Finally, by electron beam heating evaporation method,
As the upper electrode 276, ITO (In₂O₃+ SnO ₂)
And a transparent conductive film having a thickness of 700 Å was formed.

The p ⁺ in ⁺ type solar cell produced in this manner had a higher photosensitivity and less photodegradation than the conventional one formed by continuous high frequency plasma CVD method. FIG. 11 shows a solar cell according to this embodiment.
3A and 3B show the photo-deterioration characteristics of both (A) and the conventional one (B). The conventional one is -1/3 with respect to the light irradiation time t.
Although it deteriorates according to the power law, it can be seen that the degree of deterioration is considerably suppressed in the film according to this example. This is because the hydrogen is favorably extracted from the i-type layer by atomic hydrogen, and the adverse effect of ion irradiation can be reduced. Therefore, the weak bond in the film is maintained while maintaining the amorphous structure. It is believed that this is due to the effect of successfully reducing the number of defects and the number of defects in the film. Moreover, by using direct current discharge, it is possible to generate atomic hydrogen at a concentration that was difficult to achieve with high-frequency plasma alone, and to control ions, and obtain similar effects with a thicker film and shorter exposure time than before. As a result, the device can be produced in a short process time, and the cost can be reduced.

Although the case of hydrogenated amorphous silicon has been described in the present embodiment, the method and apparatus of this embodiment are applicable to other hydrogenated amorphous silicon alloys (a-
It is clear that it is also effective when forming a film such as SiC: H and a-SiGe: H.

[Third Embodiment] Next, a third embodiment of the present invention will be described. In the above-described second embodiment, the anode electrode is grounded and the DC voltage is applied so that the cathode electrode has a negative bias. However, in this embodiment,
A third electrode different from the anode electrode and the cathode electrode is provided in the reaction chamber, and a negative bias voltage is applied to the third electrode. FIG. 12 is a schematic sectional view showing the structure of a non-single crystal silicon film forming apparatus according to the third embodiment.

The difference from the forming apparatus according to the second embodiment shown in FIG. 3 is that the cathode electrodes 2 arranged in parallel with each other.
02 and the anode electrode 203, a mesh electrode 219 made of metal is provided in the middle of the mesh electrode 2 so as to be parallel to the electrodes 202 and 203.
19 is connected to the negative electrode of the DC power supply 218. Along with this, the cathode electrode 202 is not connected to the negative electrode of the DC power supply. When exposing the deposited film to atomic hydrogen, a high negative bias voltage is applied to the mesh electrode 219. As a result, direct current discharge occurs between the mesh electrode 219 and the anode electrode 203. At the time of this DC discharge, since the substrate side is grounded and a negative bias is applied to the mesh electrode 219, most of the ions in the plasma drift to the electrode (cathode electrode 202) on the side opposite to the substrate, and the substrate Only a small number of ions that diffuse from the plasma are incident on. On the other hand, since the DC bias voltage is sufficiently applied, the discharge current becomes sufficient, the electron density in the plasma increases accordingly, and the atomic hydrogen decomposed and produced by the electrons can also increase. In this embodiment, the DC discharge and the high frequency discharge have different discharge regions, but the outline of the potential distribution in each discharge is the same as in the case of the second embodiment described above, except that the discharge regions are different. Is.

In order to prevent the ions generated in the plasma from entering the substrate, a bias power source (not shown) is connected to the mesh electrode 129 so that the mesh electrode 219 is biased slightly negative during high frequency discharge. May be. That is, during high-frequency discharge, the anode electrode 203 is, on average, slightly negatively biased with respect to the plasma, and ions enter the anode electrode 203 due to the electric field drift. May be controlled to prevent the ions from entering the anode electrode 203.

Also in this embodiment, as in the second embodiment, the high frequency power source 2 is operated by a computer (not shown).
07, the DC power supply 218, and the three-way valve 213 are controlled.

Next, regarding the operation of this embodiment, p
An example of creating a ⁺ in ⁺ type solar cell will be described. This solar cell has the same structure as the solar cell in the second embodiment described above with reference to FIG. However, the i-type layer 274, which has a significant effect on the photoelectric conversion characteristics, is formed based on the above-described present embodiment.

After forming the lower electrode 272 on the glass substrate 271 by using a metal film such as Al, an n ⁺ type layer 273 having a thickness of 400 Å was deposited as in the second embodiment. After stopping the supply of each gas, the inside of the reaction chamber 200 is changed to 10
Exhausted below ^-6 Torr.

Next, an i-type layer 274 was deposited according to this embodiment. Open the valves 220 and 222 and H ₂ gas 30s
ccm was introduced into the reaction chamber 200. After the three-way valve 213 is set so that the film forming gas flows into the reaction chamber 200, the valves 231 and 233 are opened and the SiH ₄ gas 3
0 sccm was introduced into the other gas introducing pipe 211, the substrate temperature was kept at 300 ° C., and the temperature was kept for 1 hour. Next, the three-way valve 2
The film formation as the first step and the exposure to atomic hydrogen as the second step were repeated by switching 13 and turning on / off the high frequency discharge and turning on / off the direct current discharge. At this time,
As described above, the timing of stopping the high frequency discharge and the timing of starting the DC discharge are synchronized with the timing of exposure to atomic hydrogen, and in the DC discharge, the mesh electrode 21 is used.
Negative bias was applied to 9. The power of the high frequency discharge was 10 mW / cm ^2, and the bias voltage of the mesh electrode 219 was 0 V during the high frequency discharge. The bias potential of the mesh electrode 210 during the high frequency discharge can be appropriately changed according to the optimum conditions.
The applied voltage during DC discharge was 1000 V, and the power density during DC discharge was 100 mW / cm ² . The load resistance 217 at this time was 50 kΩ. Under this condition, the density of atomic hydrogen increased by about one digit at the emission intensity level as compared with the case of high frequency discharge. The film formation time, that is, the first time period (T _D ) was set to 20 seconds. As a result, the film thickness deposited during one cycle was 20Å. Further, the exposure time to atomic hydrogen, that is, the second time period (T _A ) is 20 seconds, and the first and second time periods (T _D , T _A ) are 300 cycles under the control of a computer (not shown). I repeated. As a result, the total film thickness of the i-type layer 274 was 6000Å. Then, a p ⁺ type layer 275 and an upper electrode 276 were deposited and formed in the same manner as in the second embodiment described above, and a p ⁺ in ⁺ type solar cell was completed.

The p ⁺ in ⁺ type solar cell thus produced has a larger photosensitivity than the conventional continuous high frequency plasma CVD method, as in the case of the second embodiment. In addition, the light deterioration was small.

In this example, a film in which ions in the high-frequency discharge during film formation were better controlled by a mesh electrode was obtained, and this mesh electrode was used during exposure to atomic hydrogen. By applying a DC bias, plasma with a high electron density can be created, and a higher concentration of atomic hydrogen can be obtained. Furthermore, ions are less likely to enter the substrate during DC discharge, and the adverse effects of ions can be suppressed. As a result, the characteristics of the formed non-single-crystal silicon film itself are improved, and it is possible to obtain the same effect with a thicker film thickness and shorter exposure time than before, and as a result, it is possible to fabricate a device in a short process time. Therefore, the cost can be reduced.

Although the case of hydrogenated amorphous silicon has been described in the present embodiment, the method and apparatus of this embodiment can be applied to other hydrogenated amorphous silicon alloys (a-
It is clear that it is also effective when forming a film such as SiC: H and a-SiGe: H.

[0063]

As described above, according to the present invention, atomic hydrogen is generated by the microwave plasma generating means, and the atomic hydrogen is introduced into the film forming container through the conductive mesh, or , By applying a DC voltage so that the substrate side becomes a positive bias and causing a DC discharge,
In the process of exposure to atomic hydrogen, the ions in the plasma do not enter the non-single crystal silicon film being deposited, photodeterioration is suppressed, damage by ions during film formation is small, and the characteristics are stable and high. The effect is that a high quality non-single crystal silicon film can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the configuration of a non-single crystal silicon film forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing the configuration of a photovoltaic element created in the first embodiment.

FIG. 3 is a schematic cross-sectional view showing the configuration of a non-single crystal silicon film forming apparatus according to a second embodiment of the present invention.

FIG. 4 is a characteristic diagram showing operating states of a high frequency power supply and a DC power supply in the second embodiment.

FIG. 5 is a characteristic diagram showing an emission spectrum of discharge.

FIG. 6A is a characteristic diagram showing an outline of a potential distribution in plasma in a DC discharge, and FIG. 6B is a characteristic diagram showing an outline of a potential distribution in plasma in a high frequency discharge.

FIG. 7 is a characteristic diagram showing the relationship between the length of the second time period and the hydrogen concentration in the film.

FIG. 8 is a characteristic diagram showing the relationship between the film thickness L of the deposited film and the hydrogen concentration in the film in the first time zone.

FIG. 9: Hydrogen concentration in deposited film and optical band gap E
It is a characteristic view which shows the relationship with _gopt .

FIG. 10 is a schematic cross-sectional view showing the configurations of solar cells prepared in the second and third examples.

FIG. 11 is a characteristic diagram showing light deterioration characteristics.

FIG. 12 is a schematic cross-sectional view showing the configuration of a non-single crystal silicon film forming apparatus according to a third embodiment of the present invention.

FIG. 13 is a characteristic diagram showing a change over time in the film formation rate.

[Explanation of symbols]

 100,200 Reaction chamber 101,201 Substrate 102,202 Cathode electrode 103,203 Anode electrode 105 Metal mesh 106,206 Matching box 107,207 High frequency power supply 109,115,209,215 Exhaust pump 110 One gas inlet pipe 111 Other gas inlet pipe 116,117 Air operated valve 120,122,131,133,220,222,231,233 Valve 121,132,221,232 Plasma generator 150 Microwave mass flow controller 150 153 microwave source 210 first gas introduction pipe 211 second gas introduction pipe 213 three-way valve 216 coil 217 load resistance 218 DC power supply 219 mesh electrode

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H01L 29/784 31/04

Claims (9)

[Claims] 1. A first step of depositing a non-single-crystal silicon film on a substrate, and a second step of exposing the surface of the non-single-crystal silicon film formed by the first step to atomic hydrogen. In a method for forming a non-single-crystal silicon film, which is repeatedly performed alternately, the substrate is provided in a film forming container, the first step is performed by a high frequency plasma CVD method, and the atomic state used in the second step is used. Hydrogen is generated by a microwave plasma generating means connected to the film forming container, and the generated atomic hydrogen is transferred to the high frequency plasma CVD method in the film forming container through a grounded conductive net. The method for forming a non-single-crystal silicon film according to claim 1, wherein the high-frequency plasma is introduced into a space to be formed. 2. The method for forming a non-single-crystal silicon film according to claim 1, wherein high-frequency power for generating high-frequency plasma is not introduced into the film forming container during the second step. 3. A first step of holding a substrate in a film forming container and depositing a non-single crystal silicon film on the substrate, and the first step.
In the method for forming a non-single-crystal silicon film, wherein the second step of exposing the surface of the non-single-crystal silicon film formed by the step to the atomic hydrogen is alternately repeated. A direct current discharge is generated in the film forming container so that a positive bias voltage is applied to the side, and atomic hydrogen generated by the direct current discharge is used in the second step. Method for manufacturing non-single crystal silicon film. 4. An electrode not involved in the first step is provided in the film forming container, and a positive bias voltage is applied to the substrate side between the electrode and the substrate during the second step. The method for forming a non-single-crystal silicon film according to claim 3, wherein a DC voltage is applied in this manner. 5. Hydrogen gas is constantly supplied into the film forming container,
The first step is performed by a high-frequency plasma CVD method that proceeds by supplying a film-forming gas into the film-forming container, the DC discharge is stopped during the execution of the first step, and the second step is performed. 5. The method for forming a non-single-crystal silicon film according to claim 3, wherein the high-frequency discharge for the high-frequency plasma CVD method and the supply of the film-forming gas are stopped during execution. 6. An evacuable film forming container, a high frequency plasma means for generating a high frequency plasma in the film forming container, a microwave source, and a diffusion port provided in the film forming container.
A non-single-crystal silicon film is deposited and grown on a substrate held in the film forming container, the microwave plasma generating unit being connected to the diffusion port and generating a microwave plasma by a microwave from the microwave source. In the apparatus for forming a non-single-crystal silicon film, the diffusion port has an opening toward a space where the high-frequency plasma means generates high-frequency plasma, and the conductive port is grounded with respect to the film forming container. An apparatus for forming a non-single crystal silicon film, wherein a net is provided so as to cover the opening of the diffusion hole. 7. The non-single unit according to claim 6, wherein a means for introducing a film-forming gas is provided in the film-forming container, and a means for introducing a non-film-forming gas is provided to the microwave plasma generating means. Crystal silicon film forming equipment. 8. The apparatus for forming a non-single-crystal silicon film according to claim 7, wherein the non-film forming gas is hydrogen gas. 9. An evacuable film forming container, a support electrode provided in the film forming container and capable of holding a substrate, a counter electrode facing the support electrode and provided in the film forming container, A first gas introducing unit that introduces hydrogen gas into the film forming container; a second gas introducing unit that introduces a film forming gas into the film forming container; and the supporting electrode and the counter electrode. A high-frequency power source for applying high-frequency power between them, a direct-current power source for applying a positive bias voltage to the support electrode, the high-frequency power source and the second gas introducing means, and the direct-current power source operates The high frequency power supply and the direct current power supply are arranged so that the first time zone not operating and the second time zone in which the direct current power source operates and the high frequency power source and the second gas introducing unit do not operate alternately appear. Controlling the second gas introducing means Forming apparatus of the non-single-crystal silicon film and a control unit.