JP3297487B2 - Photovoltaic element, method for forming the same, and apparatus for forming the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laminated film, a method for forming the same, and a continuous forming apparatus therefor. The present invention relates to a laminated film of a non-single-crystal semiconductor, a method for forming the same, and a continuous forming apparatus therefor.

[0002]

2. Description of the Related Art In recent years, the problem of environmental pollution has become serious.
No problems such as radioactive contamination due to nuclear power generation and global warming due to thermal power generation. In addition, sunlight is falling all over the earth, so there is little uneven distribution of energy sources.Furthermore, relatively high power generation efficiency can be obtained without the need for complicated large-scale facilities. On the other hand, it has attracted attention as a clean power generation method that can respond without causing earth destruction, and various R & Ds have been made for practical use.

By the way, in order to establish a power generation system using a solar cell to satisfy the power demand, the solar cell used has a sufficiently high photoelectric conversion efficiency and excellent characteristic stability. It is basically required to be capable of mass production.

[0004] In general, a solar cell having an output of about 3 kW per household is required to cover all the power required in a general home, and the photoelectric conversion efficiency of the solar cell is, for example, about 10%. If so, the area of the solar cell for obtaining the required output is about 30 m ² . For example, in order to supply necessary power to 100,000 households, a large area solar cell such as 3,000,000 m ² is required.

For this reason, a gaseous raw material gas such as silane, which is easily available, is used and decomposed by glow discharge to form a semiconductor thin film such as amorphous silicon on a relatively inexpensive substrate such as glass or a metal sheet. Solar cells that can be manufactured by depositing are attracting attention because of their high mass productivity and the possibility of being manufactured at a lower cost than solar cells manufactured using single-crystal silicon or the like. Various proposals have been made for the device.

[0006] US Pat. No. 4,400,409 discloses a roll-to-roll system.
A continuous plasma CVD apparatus employing the ll) method is disclosed. According to this apparatus, a plurality of glow discharge regions are provided, and a sufficiently long flexible band-shaped substrate having a desired width is arranged along a path in which the substrate sequentially passes through each of the glow discharge regions. By continuously transporting the substrate in its longitudinal direction while depositing and forming a conductive type semiconductor layer required in a glow discharge region, it is possible to continuously form a large-area element having a semiconductor junction. It is possible. From this, it can be said that this roll-to-roll method is suitable for mass production of large-area semiconductor devices.

On the other hand, a plasma process using microwaves has recently been receiving attention.

Since microwaves have a high frequency, the energy density can be increased as compared with the case where a radio frequency of a conventional radio frequency is used, and is suitable for efficiently generating and maintaining plasma.

For example, Japanese Patent Application Laid-Open No. Hei 3-30419 discloses a roll-type roll using microwave plasma CVD.
Although a two-roll method and apparatus for forming a deposited film are disclosed, generation of a deposited film is possible even under low pressure by generating plasma by using microwaves, and an activity that causes deterioration of the film properties of the deposited film is achieved. Not only can high-quality deposited films be obtained by preventing the kind of polymerization, but also suppress the generation of powder such as polysilane in plasma, and
It is said that the film formation speed can be dramatically improved.

[0010] In this specification, in order to continuously form a photovoltaic element having a pin structure by a roll-to-roll method,
The i-type semiconductor layer is n, p by microwave plasma CVD.
An apparatus having a configuration in which a mold semiconductor layer is formed by a high-frequency plasma CVD method is disclosed.

In a photovoltaic element made of a non-single-crystal semiconductor, a pin or nip layer structure is generally adopted. In such a layer structure, an i-type semiconductor layer is fixed to absorb incident light. Is required, but n,
The p-type semiconductor layer requires only a very thin film thickness of about 1/10 of the i-type semiconductor layer. Therefore, in the roll-to-roll method, even when an i-type semiconductor layer having a required film thickness is formed by a microwave plasma CVD method having a high film formation rate, the n-type and p-type semiconductor layers are compared in the film formation rate. It can be formed by a very slow high-frequency plasma CVD method.

[0012] Also, considerable skill is required to form a very thin semiconductor layer with good reproducibility by a microwave plasma CVD method having an extremely high film forming rate, and a high-frequency plasma CVD method having a relatively low film forming rate is required. However, a very thin semiconductor layer can be more easily formed with good reproducibility.

When a microwave plasma CVD method with a high film forming rate is employed for forming an i-type semiconductor layer in a roll-to-roll method, a high-frequency plasma CVD method is used.
The transfer speed of the belt-like substrate can be considerably increased as compared with the case where the method is adopted. When the transfer speed of the band-shaped substrate is increased, the time required for film formation is constant in forming the n-type and p-type semiconductor layers. They need to be lengthened in proportion. However, even with the high-frequency plasma CVD method, there is a limit in forming a thin and uniform non-single-crystal semiconductor layer over a large area in a long deposition chamber with good reproducibility, and it is inevitably too thin or too thick than a predetermined thickness. Variations in film thickness and unevenness in characteristics such as conductivity are likely to occur.

In particular, the p-type or n-type impurity-doped layer disposed on the light incident side of the i-type semiconductor layer prevents a decrease in the amount of light incident on the i-type semiconductor layer due to absorption of light by the impurity-doped layer. Therefore, it is necessary to make the film thickness as small as possible. However, it is difficult to form a thin and uniform impurity-doped layer over a large area in a long deposition chamber by a conventional high-frequency plasma CVD method. This has caused variations and unevenness in the characteristics of the element.

In a photovoltaic element such as a solar cell, the unit modules of the photovoltaic element are often connected in series or in parallel to form a unit to obtain a desired current and voltage. It is required that characteristics such as output voltage and output current between unit modules have little variation and unevenness.At the stage of forming a unit module, uniformity of the characteristics of the semiconductor laminated film, which is the largest determining factor of the characteristics, is required. You. Also, in order to simplify the module assembling process, it is necessary to be able to form a semiconductor laminated film having excellent characteristics over a large area. This will result in significant savings. In this regard, in a conventional apparatus for continuously forming a semiconductor laminated film in which a conventional i-type semiconductor layer is formed by a microwave CVD method and n and p-type semiconductor layers are formed by a high-frequency plasma CVD method, a photovoltaic element is formed. However, there is a problem that the characteristics of the semiconductor laminated film tend to vary or become uneven.

As another method for forming the n-type and p-type amorphous semiconductor layers, an ion implantation method is conventionally known.
According to the ion implantation method, the thickness of the n-type and p-type non-single-crystal semiconductor layers can be controlled by controlling the intensity of implanting the impurity ions by the acceleration voltage. In general, the system consists of a system for generating ions, a system for extracting ions in the form of a beam, and a system for scanning a beam. It is not suitable for manufacturing a power element with good productivity and low cost, and has not been adopted as a means for forming an impurity-doped layer.

On the other hand, as a method of forming a very shallow junction required for a super LSI or the like, plasma doping in which impurities are introduced by plasma of an impurity gas without using the above-described ion implantation method has recently attracted attention. LSI
Process Data Handbook (Science Forum)
1990).

Also, in the 1988 35th Applied Physics Alliance Lecture Meeting Preliminary Proceedings 30p-M-6, an amorphous silicon film was formed by plasma doping in which an i-type amorphous silicon film was exposed to high-frequency plasma of an impurity gas. It is disclosed that impurity doping is possible.

However, application of such plasma doping to the formation of an impurity-doped layer of a photovoltaic element such as a solar cell has not been disclosed, and an i-type semiconductor layer is formed by microwave plasma CVD. In the formation of a photovoltaic device, it has been completely unknown how a good photovoltaic device can be formed by performing plasma doping.

Incidentally, the amorphous silicon solar cell has a characteristic deterioration phenomenon (Staebller-Wronski effect) due to light irradiation which is not provided in the crystalline solar cell.
Along with achieving cost reductions based on high-efficiency technology and large-area production technology, it has become an important issue for practical use in power applications.

With respect to elucidation of the mechanism of light degradation and measures to suppress it, from the viewpoint of semiconductor materials such as reduction of impurities,
Numerous studies have been carried out on devices such as the adoption of a tandem-type element structure, and on characteristics recovery processing such as heat annealing. Among them, the adoption of a tandem-type element structure is based on the i-type semiconductor layer. Has attracted attention in recent years because it is possible to reduce the film thickness and suppress light degradation, and to increase the efficiency by stacking solar cells having different band gaps.

Among the tandem-type device structures, the three-layer tandem type can utilize a wider wavelength range of the incident light spectrum, obtain a higher photoelectric conversion efficiency, and have a higher output voltage than the two-layer tandem type. It is excellent in that it can be obtained. However, a three-layered tendam-type element is composed of a large number of layers of nine or more layers, and there has been a problem how to form a semiconductor laminated film having this multilayer structure with good reproducibility, at high speed and continuously.

[0023]

As described above, in the conventional apparatus for continuously forming a semiconductor laminated film by the roll-to-roll method described above, a microwave capable of forming an i-type layer having a required film thickness at a high speed. When formed by the plasma CVD method, there is a problem that the characteristics of the formed photovoltaic element are likely to vary or become uneven. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to provide a photovoltaic device having a semiconductor laminate film for a photovoltaic device having excellent characteristics without large-area variations or unevenness in characteristics, a method for forming the same, and a high-speed and continuous method. An object of the present invention is to provide a device which can be formed in a uniform manner.

Another object of the present invention is to suppress light degradation,
An object of the present invention is to provide a three-layer tandem-type semiconductor laminated film for a photovoltaic element capable of obtaining high photoelectric conversion efficiency and a high output voltage, and to provide an apparatus which can be formed with high reproducibility and at high speed and continuously.

[0025]

According to the present invention, there is provided a photovoltaic element, a method for forming the same, and an apparatus for forming the same, comprising: a first semiconductor having a first conductivity type; a first i-type semiconductor formed by microwave plasma; A second i-type semiconductor formed by high-frequency plasma, a second semiconductor having a conductivity type opposite to the first semiconductor , a third semiconductor having a first conductivity type, and a third i-type semiconductor formed by microwave plasma. Semiconductors,
A fourth i-type semiconductor formed by high-frequency plasma, a fourth semiconductor having a conductivity type opposite to the first semiconductor , a fifth semiconductor having the first conductivity type, and a fifth i-type semiconductor formed by microwave plasma And a sixth i-type semiconductor formed by high-frequency plasma and a sixth semiconductor having a conductivity type opposite to that of the first semiconductor in this order, and the second semiconductor, the fourth semiconductor, and the sixth semiconductor are formed by plasma. A photovoltaic element characterized by being formed by doping, and a photovoltaic element forming method for forming a stacked film of a silicon-based non-single-crystal semiconductor on a substrate, wherein n is formed by high-frequency plasma CVD. Forming a (or p) type semiconductor layer, and microwave plasma CVD
Forming an i-type semiconductor layer by a method, forming an i-type semiconductor layer by a high-frequency plasma CVD method, forming a p (or n) -type semiconductor layer by plasma doping, and n by a high-frequency plasma CVD method. A step of forming an (or p) type semiconductor layer, a step of forming an i-type semiconductor layer by microwave plasma CVD, a step of forming an i-type semiconductor layer by high frequency plasma CVD, and p (or forming an n) type semiconductor layer;
(Or p) type semiconductor layer forming step, i-type semiconductor layer forming step by microwave plasma CVD method, i-type semiconductor layer forming step by high frequency plasma CVD method, and p ( Or a step of forming an n-type semiconductor in this order to form a stacked film of a silicon-based non-single-crystal semiconductor, and a method of forming a silicon-based non-single-crystal semiconductor. In a photovoltaic element forming apparatus for continuously forming a non-single-crystal semiconductor laminated film, at least an unwinding chamber for a strip-shaped substrate, an n (or p) type semiconductor layer film forming chamber by a high-frequency plasma CVD method, and a microwave. I-type semiconductor layer deposition chamber by plasma CVD, i-type semiconductor layer deposition chamber by high-frequency plasma CVD, and p (or n) type semiconductor layer deposition by plasma doping An n (or p) type semiconductor layer deposition chamber by high frequency plasma CVD, an i type semiconductor layer deposition chamber by microwave plasma CVD, an i type semiconductor layer deposition chamber by high frequency plasma CVD, and plasma P (or n) type semiconductor layer deposition chamber by doping, n (or p) type semiconductor layer deposition chamber by high frequency plasma CVD, i-type semiconductor layer deposition chamber by microwave plasma CVD, high frequency plasma An i-type semiconductor layer deposition chamber by CVD, a p (or n) type semiconductor layer deposition chamber by plasma doping, and a winding chamber for a strip-shaped substrate
A silicon-based non-single crystal is disposed on the strip-shaped substrate which is arranged in this order along the direction in which the strip-shaped substrate is moved, and is connected to each other via a gas gate, and continuously moves through the film forming chambers. The semiconductor laminated film is formed continuously.

Further, in the apparatus for continuously forming a semiconductor laminated film of the present invention, an n (or p) type layer deposition chamber desirably disposed via a gas gate by the high-frequency plasma CVD method, and an i-type layer deposition chamber formed by the microwave CVD method. A high-frequency plasma CV at at least one position between the
An i-type layer film forming chamber by the method D is arranged via a gas gate.

In the apparatus for continuously forming a semiconductor laminated film according to the present invention, an i-type layer film forming chamber is preferably disposed via a gas gate by the high frequency plasma CVD method, and a p (or n) layer is formed by the plasma doping. A hydrogen plasma processing chamber is further disposed at at least one position between the chamber and the chamber via a gas gate.

Further, in the apparatus for continuously forming a semiconductor laminated film according to the present invention, preferably, the unwinding chamber of the strip-shaped member disposed via a gas gate;
A glow discharge cleaning chamber is further arranged between the n (or p) type layer deposition chamber by the method D via a gas gate.

In addition, in the apparatus for continuously forming a semiconductor laminated film of the present invention, the discharge frequency in the p (or n) type layer deposition chamber by the plasma doping is preferably 5 kHz to 500 kHz.

[0030]

The present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic explanatory view showing a basic example of an apparatus for continuously forming a semiconductor laminated film according to the present invention. In FIG. 1, an apparatus for continuously forming a semiconductor laminated film according to the present invention basically includes an unwinding chamber 101 for a strip-shaped substrate, a high-frequency plasma CV
An n (or p) type semiconductor layer deposition chamber 102A by the D method,
Microwave plasma CVD with three film forming chambers inside
Semiconductor layer film forming chamber 103A by the plasma method, i type semiconductor layer film forming chamber 104A by the high frequency plasma CVD method, p (or n) type semiconductor layer film forming chamber 10 by the plasma doping
5A, n (or p) type semiconductor layer deposition chamber 102B by high frequency plasma CVD, i type semiconductor layer deposition chamber 103B by microwave plasma CVD having three deposition chambers inside, and high frequency plasma CVD i-type semiconductor layer deposition chamber 104B, p (or n) -type semiconductor layer deposition chamber 105B by plasma doping, high-frequency plasma CVD
(Or p) -type semiconductor layer film forming chamber 102C by a plasma method, i-type semiconductor layer film forming chamber 103C by a microwave plasma CVD method having one film forming chamber inside, and high-frequency plasma C
I-type semiconductor layer deposition chamber 104C by VD method, p (or n) type semiconductor layer deposition chamber 105 by plasma doping
C, a winding chamber 106 for a band-shaped substrate,
Each of the chambers is connected by a gas gate 107.

In the apparatus of the present invention, the strip-shaped substrate 108 is unwound from the bobbin 109 in the unwinding chamber 101 for the strip-shaped substrate, and is connected by a gas gate until it is wound up on the bobbin 110 in the winding chamber 106 for the strip-shaped substrate. It is moved while passing through 12 film forming chambers, while ni
A stacked film of a non-single-crystal semiconductor having a pnipnip or pinpinpin structure is formed.

The present invention has been completed and further studied based on the following findings obtained as a result of earnest studies by the inventors.

The inventors have conventionally used the roll-to-roll type apparatus shown in FIG.
B, 104C is not used, and an i-type semiconductor layer is used as a device having a conventionally known structure by microwave plasma CVD.
An n, p-type semiconductor layer is formed by a high-frequency plasma CVD method, and a nipnip made of an amorphous silicon-based semiconductor is formed.
A three-layer tandem photovoltaic element having a nip or pinpinpin structure has been formed.

In this conventional apparatus, the i-type semiconductor layer film forming chambers 103A, 103A,
The film formation speed in 3B and 103C was extremely high at about 8 nm / sec or more, and high-speed film formation of a semiconductor laminated film for a two-layer tandem photovoltaic device was possible. And since the high-speed film formation has become possible, the transfer speed of the band-shaped substrate can be increased, and even if the transfer speed of the band-shaped substrate is increased to about 100 cm / min, the i-type semiconductor layer film formation chamber 103B By providing three deposition chambers each having a length of about 20 cm per
A 00 nm i-type semiconductor layer could be formed.

The impurity doped layer on the light incident side of the i-type semiconductor layer of the photovoltaic element includes a silicon-based material having a wide band gap, such as amorphous silicon carbide, to prevent light absorption in the layer. Microcrystalline silicon having a low absorptivity for short-wave light is generally used. However, the present inventors used microcrystalline silicon, which has a conductivity approximately three orders of magnitude higher than that of amorphous silicon, for the impurity-doped layer on the light incident side. .

In the case where a high-conductivity microcrystalline silicon layer doped with an impurity is formed at a high speed by a high-frequency plasma CVD method, the following problems arise.

That is, if the deposition rate is increased by increasing the flow rate of the raw material gas containing silicon atoms, the ratio of the high frequency power to the raw material gas flow rate decreases, and a microcrystalline film cannot be formed. There is a problem that the film becomes amorphous and the electrical conductivity sharply decreases, and the device characteristics deteriorate.

On the other hand, when the deposition rate is increased by increasing the high-frequency power, the distribution of the deposition rate and the conductivity in the deposition region becomes large, and a very thin layer can be formed uniformly over the entire deposition region. In addition, a large amount of high-frequency power is required for microcrystallization, so that an extremely large power source is required, it is difficult to uniformly supply power, and abnormal discharge is liable to occur.

For the above reasons, the high-frequency plasma CV
There is a limit in forming a very thin layer of high-conductivity microcrystalline silicon at a high speed by the method D. In order to uniformly form a very thin layer of about 10 nm, the layer is formed at a thickness of about 10 nm / min or less. It was necessary to form at a speed.

Therefore, in the conventional roll-to-roll type apparatus, when the i-type semiconductor layer is formed by the microwave plasma CVD method, the impurity doped layer on the light incident side of the i-type semiconductor layer is formed by the high frequency plasma CVD method. To form the film, a considerably long film forming chamber was required in the moving direction of the belt-like substrate.

Such a long film forming chamber 105A, 105
In B and 105C, it was extremely difficult to form an extremely thin impurity-doped layer of about 10 nm with good quality and uniformity. However, the present inventors found that the flow rate of the introduced silicon source gas was improved in order to find better film formation conditions. To change
The correspondence with the characteristics of the formed photovoltaic element was being investigated.
At this time, the present inventors made the deposition chambers 105A, 105B,
Although the flow rate of SiH ₄ of the silicon source gas flowing through 5C was reduced to zero finally, it was found that a photovoltaic element was still formed. That is, the impurity-doped layer is formed on the i-type semiconductor layer also by the plasma of the gas not containing the source gas of silicon atoms,
It has been found that a three-layer tandem photovoltaic element having a nip or pinpinpin structure is formed.

This is a phenomenon which cannot be expected from the conventional idea of forming an impurity-doped layer by depositing a silicon film doped with an impurity.

The distribution of the silicon element and the impurity element in the film thickness direction of the formed photovoltaic element was analyzed by secondary ion mass spectrometry (SIMS). The surface of the i-type semiconductor layer was plasma-treated without flowing SiH _4. Exposure to i
It was confirmed that a high-concentration impurity-doped layer having a very small thickness of about 10 nm was formed on the mold semiconductor layer.

Similarly, secondary ion mass spectrometry (SI
The MS), the variation due to the film thickness of the location of the impurity-doped layer on the i-type semiconductor layer formed photovoltaic devices, have been analyzed unevenness found the following if no shed SiH _4, having a predetermined thickness It was confirmed that the uniformity of the thickness of the impurity-doped layer was higher than when SiH ₄ was flowed in such an amount that the film was deposited.

As described above, the silicon source gas Si
The reason why the impurity doped layer was formed without flowing H ₄ was not that a silicon non-single-crystal semiconductor containing impurities was deposited, but that an impurity doping gas such as B ₂ H ₆ or PH ₃ was ionized by plasma. This is considered to be due to the fact that so-called plasma doping was performed by being implanted into an extremely thin region near the surface of the i-type semiconductor layer by the energy of the plasma.

Next, the inventors, when performing plasma doping on the i-type semiconductor layer of such a photovoltaic element, change the discharge frequency from 1 kHz to 1 while keeping the discharge power constant.
The frequency was changed to 3.56 MHz, and the relationship between the discharge frequency during plasma doping and the characteristics of the formed photovoltaic element was examined.

As a result, there is a relationship shown in FIG. 3 between the discharge frequency f of the plasma doping and the formed open circuit voltage Voc of the photovoltaic element, and when the discharge frequency is about 5 kHz or less and about 500 kHz or more, Shows that the open-circuit voltage of the formed photovoltaic element is reduced, and that a high-quality photovoltaic element with a high open-circuit voltage can be formed over a large area without variation or unevenness in a low frequency range of about 5 kHz to about 500 kHz. I found it.

Further, in the apparatus shown in FIG. 1, the inventors used the film forming chambers 104A, 104B and 104C to form an i-type semiconductor layer by microwave plasma CVD on an i-type semiconductor layer by microwave plasma CVD. Very thin about 3
When the film was laminated to a thickness of 0 nm or less and plasma doping was performed thereon, the open voltage of the photovoltaic element was lower than when plasma doping was performed directly on the i-type semiconductor layer by microwave plasma CVD. It has been found that characteristics such as fill factor are improved. In general, when the thickness of the i-type semiconductor layer of a photovoltaic device made of amorphous silicon is slightly increased within a practical range, the short-circuit current slightly increases, but the open-circuit voltage and the fill factor do not improve. It is considered that the change found by the present inventors is not due to a change in the thickness of the i-type semiconductor layer.

Based on the above findings, the present invention has realized an apparatus capable of forming a high-quality photovoltaic element at high speed without variation or unevenness over a large area.

That is, in a conventional roll-to-roll type continuous semiconductor film forming apparatus for forming an n-type semiconductor layer by a microwave plasma CVD method and an n-type and p-type semiconductor layer by a high frequency plasma CVD method, The problem that it is difficult to form an impurity-doped layer over a large-sized semiconductor layer thinly and uniformly over a large area, and that the resulting photovoltaic element tends to have characteristic variations and unevenness, is characterized by microwave plasma CVD.
The problem is solved by forming an impurity-doped layer by plasma doping after further laminating an i-type semiconductor layer by a high-frequency plasma CVD method on the i-type semiconductor layer by the high-temperature plasma CVD method. The power element can be formed at high speed and continuously without variation and unevenness over a large area.

Hereinafter, each of the film forming chambers constituting the apparatus of the present invention and the strip-shaped substrate used will be described.

I-type layer by microwave plasma CVD
Deposition chamber In the apparatus of the present invention, the i-type layer deposition chamber formed by microwave plasma CVD is a substantially intrinsic silicon-based non-single-crystal semiconductor layer formed on a continuously moving strip substrate by microwave plasma CVD. Refers to a film forming chamber for continuously forming a film.

In the apparatus of the present invention, the i-type layer film forming chamber formed by the microwave plasma CVD method is adapted to cope with a higher moving speed of the belt-like substrate without increasing the size of one film forming chamber to a certain size or more. In order to form one layer under a plurality of film formation conditions, a plurality of layers may be connected and provided.

In the apparatus of the present invention, it is necessary to supply microwave power for forming plasma to the film forming chamber by the microwave plasma CVD method. Kaihei 3-3041
9, a microwave introduction window made of a microwave transmitting member, a microwave leaky waveguide as disclosed in JP-A-3-30420,
Means such as a microwave radiating antenna disclosed in Japanese Patent Application No. 30421 and a means in which these are combined with a magnetic field forming apparatus to achieve ECR conditions can be cited.

Hereinafter, a case where a microwave introduction window made of a microwave permeable member is used as microwave power input means will be described in detail.

The microwave permeable member is provided at the tip of the microwave introduction window, and separates the vacuum atmosphere in the film forming chamber from the outside air in which the microwave introduction window is installed.
The structure is designed to withstand the pressure difference existing between the inside and outside. Specifically, it is desirable that the cross-sectional shape of the microwave in the traveling direction is preferably circular, square, elliptical, flat, bell jar, doublet, or conical.

The thickness of the microwave transmitting member in the direction in which the microwave travels should be designed in consideration of the dielectric constant of the material to be used so that the reflection of the microwave here is minimized. Desirably, for example, in the case of a flat plate shape, it is preferable to make the wavelength substantially equal to a half wavelength of the microwave. Further, the material is such that microwave energy radiated from the microwave introduction window can be transmitted into the film formation chamber with a minimum loss, and the airtightness does not cause air to flow into the film formation chamber. Are preferable, and specific examples thereof include glass such as quartz, alumina, silicon nitride, beryllia, magnesia, zirconia, boron nitride, and silicon carbide, and fine ceramics.

Further, it is preferable that the microwave permeable member is uniformly cooled in order to prevent heat deterioration (crack, destruction) or the like due to heating by microwave energy and / or plasma energy.

As a specific cooling means, a cooling air flow blown toward the atmosphere-side surface of the microwave permeable member may be used, or the microwave introduction window itself may be cooled air, water, or oil. Alternatively, the microwave permeable member may be cooled by a cooling medium such as Freon and the like, and may be cooled via a portion in contact with the microwave introduction window. By cooling the microwave permeable member to a sufficiently low temperature, even if a relatively high power of microwave power is introduced into the deposition chamber, the generated heat may cause the microwave permeable member to break, such as cracks. Without this, a high electron density plasma can be generated.

Further, film deposition occurs on the portion where the microwave permeable member is in contact with the microwave plasma, as on the belt-like substrate. Therefore, depending on the type and characteristics of the film to be deposited, the microwave power to be radiated from the microwave introduction window is absorbed or reflected by the deposited film, and the microwave into the film forming chamber formed by the band-shaped member is absorbed. When the amount of energy input decreases and the amount of change increases significantly compared to immediately after the start of discharge, not only the maintenance of the microwave plasma itself becomes difficult, but also the deposition rate of the deposited film to be formed decreases. It may cause a decrease or a change in characteristics.
In such a case, the initial state can be restored by removing the film deposited on the microwave transmitting member by a mechanical method such as dry etching, wet etching, or blast. In particular, dry etching is preferably used as a method for removing the deposited film while maintaining the vacuum state.

Further, while keeping the vacuum state in the film forming chamber together with the microwave applicator means, the film is taken out of the film forming chamber by a so-called load lock method, and the film deposited on the microwave transmitting member is wet-etched or mechanically removed. , And may be reused or replaced with a new one.

Further, by continuously feeding a sheet made of a material having a microwave permeability substantially equivalent to that of the microwave permeable member along the surface of the microwave permeable member on the film forming chamber side, It is also possible to employ a technique of depositing and forming a deposited film on the surface of the sheet and discharging the deposited film out of the microwave plasma region.

Further, as disclosed in Japanese Patent Application Laid-Open No. 3-110798, a metal or a microwave reflecting member for vertically dividing a microwave electric field into fine pieces is provided on the side of the microwave permeable member in the film forming chamber. The microwave power is placed in the deposition chamber, but it is difficult to generate plasma in the divided part.As a result, the distance between the plasma in the deposition chamber and the microwave introduction window is increased, The film may be prevented from adhering to the introduction window.

The microwave introduction window has a structure in which microwave power supplied from a microwave power supply is supplied into the film formation chamber, and the source gas for forming a deposited film introduced into the film formation chamber is turned into plasma and maintained. It has.

Specifically, it is preferable to use a microwave transmission waveguide in which a microwave permeable member is attached to a tip portion of the microwave transmission waveguide in a state capable of maintaining airtightness. The microwave introduction window may be of the same standard as the microwave transmission waveguide, or may be of another standard.
In addition, the microwave transmission mode in the microwave introduction window enables efficient transmission of microwave power in the film formation chamber and stably generates and generates microwave plasma.
For maintenance and control, it is desirable that the size, shape, and the like of the microwave introduction window be designed to be a single mode. However, even when a plurality of modes are transmitted, it can be used by appropriately selecting microwave plasma generation conditions such as a source gas, pressure, and microwave power to be used. As a transmission mode when designed to be a single mode, for example, TE ₁₀ mode,
TE ₁₁ mode, eH ₁ mode, TM ₁₁ mode, TM
₀₁ mode and the like.
₁₀ mode, TE ₁₁ and eH ₁ mode are selected. A waveguide capable of transmitting the above-mentioned transmission mode is connected to the microwave introduction window, and preferably, the transmission mode in the waveguide and the transmission mode in the microwave applicator means are made to coincide with each other. desirable. The type of the waveguide is appropriately selected depending on the frequency band (band) and mode of the microwave to be used, and at least the cutoff frequency is preferably smaller than the frequency to be used. JIS, EIAJ, IEC, JA
In addition to rectangular waveguides, circular waveguides, elliptical waveguides, and the like of standards such as N, for microwaves of 2.45 GHz, those having a square cross section with an inner diameter of 96 mm and a height of 27 mm, and the like are given. be able to.

Since the microwave power supplied from the microwave power supply is efficiently supplied to the film forming chamber through the microwave introduction window, it is easy to avoid the problem related to the reflected wave caused by the so-called microwave introduction window. In a microwave circuit, it is possible to maintain a relatively stable discharge without using a microwave matching circuit such as a three-stub tuner or an EH tuner. When a strong reflected wave is generated, it is desirable to provide the microwave matching circuit for protecting the microwave power supply.

In the apparatus of the present invention, the means for applying microwave power to the film formation chamber by the above-mentioned plasma CVD method using microwaves may be applied in the direction in which microwaves are applied if plasma is formed in the film formation chamber. The direction perpendicular to the semiconductor layer forming surface of the band-shaped substrate, parallel to the semiconductor layer forming surface of the band-shaped substrate, the direction perpendicular to the moving direction, and parallel to the semiconductor layer forming surface of the band-shaped substrate. It may be placed in any direction, such as a direction parallel to the direction, and may be placed in several directions at the same time, but is preferably placed in a direction parallel to the semiconductor layer forming surface of the strip-shaped substrate and perpendicular to the moving direction. I do.

Further, the above-mentioned microwave is applied to the plasma CV.
The number of means for supplying microwave power to the film formation chamber by the method D may be any number as long as the plasma is formed in the film formation chamber. However, if the plasma formation space is large, a plurality of means should be provided. Is preferred. When the microwave power is applied in a direction parallel to the semiconductor layer forming surface of the band-shaped substrate and perpendicular to the moving direction, when the width of the band-shaped substrate is relatively narrow, the microwave is applied from one side of the band-shaped substrate. Almost uniform plasma can be formed on the strip-shaped substrate only by introducing the same, but when the width of the strip-shaped substrate is wide, it is preferable to introduce microwaves from both sides of the strip-shaped substrate.

When a plurality of microwave input means are provided, a microwave power can be supplied to the microwave input means by providing a power source and supplying the microwave power from a small number of power sources. May be divided by a power divider and supplied to each of them.

Microwave plasma CVD of the apparatus of the present invention
When a plurality of microwave injection means are disposed so as to face each other in a film forming chamber by the method, the microwave power radiated from one of the microwave injection means is received by the other microwave injection means. The received microwave power reaches the microwave power supply connected to the other microwave input means, and damages the microwave power supply or causes an abnormality in microwave oscillation. Must be arranged so as not to exert

More specifically, the microwave input means is provided so that the electric field directions of the microwaves traveling in the microwave input means are not parallel to each other. That is, the waveguides are arranged such that the long side or the plane including the long axis connected to the microwave input means is not parallel to each other.

Further, in the apparatus of the present invention, it is necessary to pass through and pass through the strip-shaped substrate in order to continuously form a semiconductor layer in the film-forming chamber where the microwave plasma CVD method is performed. The shape of the substrate may be a planar shape as disclosed in U.S. Pat. No. 4,566,403, or a ohm as disclosed in Japanese Patent Application Laid-Open No. 3-30419.
Mold shape and the like can be given.

In the apparatus of the present invention, in the film forming chamber by the microwave plasma CVD method, the raw material gas for forming the deposited film is singly or plurally placed at the tip portion provided in the film forming chamber through which the band-shaped substrate passes. The gas is discharged into the film formation chamber from the gas introduction pipe having the gas discharge holes described above, and is turned into plasma by the supplied microwave power, thereby forming a microwave plasma region. As the material constituting the gas introduction tube, a material that is not damaged in the microwave plasma is preferably used. Specific examples include heat-resistant metals such as stainless steel, Ni, Ti and W, and those obtained by spraying ceramics such as alumina and silicon nitride on these metals.

The introduction of the raw material gas may be performed from any position in the film forming chamber. However, the width direction of the band-shaped substrate is controlled so that the plasma formed on the band-shaped substrate is uniform at least in the width direction of the band-shaped substrate. It is desirable to be introduced from a plurality of locations.

In the apparatus of the present invention, a vacuum pump is used as a means for evacuating the film forming chamber by microwave plasma CVD to a pressure suitable for forming a semiconductor layer. In microwave plasma CVD, plasma can be maintained at a lower pressure than in high-frequency plasma CVD, and a high-quality deposited film can be formed at high speed by lowering the pressure during deposition film formation. , High frequency plasma CVD
It is desirable to evacuate with a vacuum pump capable of obtaining a higher vacuum than in a film forming chamber formed by a method. Specific examples of a vacuum pump suitable for obtaining such a high vacuum include a turbo molecular pump, an oil diffusion pump, a cryopump and a pump in which a rotary pump, a mechanical booster pump, and the like are combined with these pumps, and the like. Preferably, a pump in which a rotary pump and a mechanical booster pump are combined with a turbo molecular pump or an oil diffusion pump is used.

An exhaust pipe (exhaust port) for exhausting the film formation chamber by the microwave plasma CVD method exhausts a large amount of source gas and a decomposition gas of the source gas. In order to evacuate the gas in each plasma space without interdiffusion when forming the plasma, to form a flow of the source gas in a plurality of directions in the film forming chamber, A plurality of exhaust means may be provided for different purposes, for example.

Further, microwave power supplied into the film formation chamber leaks from the plasma formation space of the film formation chamber to the outside in an exhaust pipe (exhaust port) for exhausting the film formation chamber by the microwave plasma CVD method. , So as not to make the plasma unstable or put noise into external electronic devices,
It is desirable to provide a metal mesh or a metal plate with a small hole with a high aperture ratio that does not allow microwaves to pass through, while allowing gas to pass while preventing microwave leakage.

In the apparatus of the present invention, a band-shaped substrate on which a semiconductor layer is formed while moving in the film forming chamber is placed at a temperature suitable for forming a semiconductor film. It is desirable to provide a temperature control means for controlling the temperature.

At low pressures suitable for microwave plasma CVD, the substrate cooling effect due to gas convection and the like is small. Therefore, the strip-shaped substrate is heated by being exposed to high-density plasma generated by microwaves in the process of forming the semiconductor layer. And may be heated to a desired temperature or higher. Therefore, it is preferable that the band-shaped substrate is heated to a temperature suitable for forming a semiconductor layer before entering the plasma formation space, and a temperature control means is provided so that a constant temperature is maintained in the plasma formation space. For example, when the microwave power to be applied is large, a heater for heating a strip-shaped substrate having a reduced temperature through a gas gate in front of the plasma formation space is provided in the plasma formation space. Cooling means for keeping the substrate at a constant temperature is provided.

Since a semiconductor layer is formed on the surface of the belt-like substrate in the film forming chamber, it is preferable to control the temperature during film formation from the back side.

Further, since the belt-like substrate is continuously moving in the film forming chamber, it is preferable to use a heater means such as a lamp heater capable of heating in a non-contact manner to heat the belt-like substrate. As a temperature measuring means for controlling the temperature of the moving surface, a moving surface thermometer using a thermocouple capable of measuring the temperature of the moving surface and having a small heat capacity and a high response speed, or a radiation thermometer capable of non-contact measurement is used. Is preferred.

FIG. 4 is a schematic sectional view showing a preferred example of a film forming chamber by the microwave plasma CVD method in the apparatus of the present invention.

Discharge chamber unit In FIG. 4, the band-shaped substrate 401 enters the vacuum vessel 402 through the gas gate 403, moves from left to right in the figure,
Exit to gas gate 404.

A box-shaped film-forming chamber unit 405 is detachably provided inside the vacuum vessel 402, and the inside of the film-forming chamber unit 405 is perforated with partition plates 421, 422, 423,
By forming plasma inside the film formation chambers 406, 407, and 408 partitioned by 424, a silicon-based non-single-crystal semiconductor is formed on the surface (lower surface) of the belt-shaped substrate 401 moving above the film formation chamber.

The reason why a plurality of film forming chambers for forming the i-type layer are provided is that the film properties such as the band gap change in the film thickness direction by changing the film forming conditions in each film forming chamber. This is for forming an i-layer, for example, 406, 407, 4
1.7 eV, 1.6 eV, 1.5 in three deposition chambers 08
If a deposited film having a band gap of eV is formed,
1.7 eV in the film thickness direction is applied to the continuously moving strip-shaped substrate.
An i-type layer changed to 1.6 eV and 1.5 eV can be formed. In addition, by changing the film forming speed in each film forming chamber, or by moving the positions of the perforated partition plates 422 and 423 that partition between the movable film forming chambers in the moving direction of the band-shaped substrate, It is possible to change the film thickness of the deposited film formed in the film forming chamber and change the characteristic profile in the film thickness direction.

Furthermore, it is also possible to change the characteristic profile in the film thickness direction by changing the aperture ratio of the perforated partition plates 422 and 423. By reducing the aperture ratio of the partition plate, the intermixing of the source gases in each of the film forming chambers is suppressed, and the composition of the source gas changes discontinuously depending on the film forming chambers. Can be changed discontinuously in the film thickness direction. In addition, by increasing the aperture ratio of the partition plate, the source gases of the respective film forming chambers are mixed with each other near the partition plate, and the composition of the source gas in the film forming chamber is continuously changed. The characteristics of the film can be changed continuously in the film thickness direction.

Several holes are formed in the bottom wall of each of the film forming chambers 406, 407, and 408, and source gas introduction pipes 409, 410, and 411 connected to a source gas supply system (not shown).
Pressure measuring tubes 412, 413, 414 connected to a pressure gauge
And bias electrodes 415, 416, and 417 connected to a bias power supply (not shown) by a coaxial structure, to introduce a source gas into each film forming chamber, measure a pressure, and supply a DC or high frequency bias power. Done.

The microwave introduction windows 418, 419, 420 connected to the microwave power supply (not shown) are disposed on the side wall surfaces of the respective film forming chambers in contact with the side walls of the film forming chamber unit.
Are provided, and microwave power is supplied to each film forming chamber.

The source gas introduction pipes 409, 410, 4
11 is provided with a plurality of nozzles in the width direction of the strip substrate,
The source gas can be introduced almost uniformly in the width direction of the strip-shaped substrate, and the bias electrodes 415, 416, 417
Is provided with a connection portion in the coaxial structure portion in the vacuum vessel, and is elongated in the width direction of the band-shaped substrate in front of the center of the microwave introduction window inside the film formation chamber, and is a T-shaped member made of a metal such as SUS or Ni. The electrode part and the conductor part connected to the current introduction terminal on the wall surface of the vacuum vessel can be separated.

Each of the film forming chambers has a metal perforated partition plate 4.
21, 422, 423, and 424, the gas in each of the film forming chambers is exhausted to the outside of the film forming chamber unit 405 through a small hole formed on almost the entire surface of each perforated partition plate. Is exhausted to the outside of the vacuum vessel 402 from exhaust pipes 425 and 426 connected to a high vacuum pump (not shown) via a gate valve together with the gate gas flowing from the vacuum chamber 402. The vacuum vessel 402 is provided with a roughing exhaust pipe 427 connected to another low vacuum pump of the exhaust pipes 425 and 426.

The metal perforated partition plates 421, 422, 4
The holes 23 and 424 are so small that the microwaves introduced into the respective film forming chambers do not pass therethrough, and are large enough to allow gas to sufficiently pass therethrough. A powder receiving plate 428 is provided on the outside,
Even if silicon powder or a film generated in the film forming chamber comes out of the film forming chamber through the hole of the perforated partition plate, it is trapped here and does not fall into the exhaust pipes 425 and 426.

Further, plasma leak guards 429 are provided at the entrance, exit, and both ends in the width direction of the band-shaped substrate 401 of the film forming chamber unit 405 to prevent plasma in the film forming chamber from leaking to the outside. The film formation chamber 40 of the plasma leak guard 429 provided at the entrance and the exit of the belt-shaped substrate 401 is provided.
By adjusting the length of the portion provided on the upper portion of each of the film forming chambers 406 and 408 in the moving direction of the band-shaped substrate,
The thickness of the semiconductor film formed in Step 8 can be adjusted.

The film forming chamber unit 405 is mounted on the film forming chamber temperature controller 430 so as to control the temperature by heating and cooling. The film formation chamber unit 405 can be heated and baked before the film formation by the film formation chamber temperature control device 430, and the temperature of the wall surface of the film formation chamber due to plasma can be changed by cooling or heating during the film formation. Can be suppressed and controlled.

FIG. 5 is a schematic view of the film forming chamber unit of FIG. 4 as viewed obliquely from above.

In FIG. 5, the strip-shaped substrate and a part of the wall of the film forming chamber unit are cut out to make it easy to see the internal structure, and the microwave introduction window is slightly displaced from the original position. 529 is 401 to 42 in FIG.
9, corresponding to the same one.

As can be seen from FIGS. 4 and 5, when the film-forming chamber unit does not pass through the belt-like substrate, the upper lid 431 of the vacuum vessel is closed.
Open and remove the electrode part in the film formation chamber of the bias electrode, it can be removed upward from the vacuum vessel.When a large amount of silicon film adheres to the inner wall, remove it from the vacuum vessel and remove it from the vacuum vessel by chemical treatment such as etching, blasting, etc. It can be easily cleaned by physical means.

(Microwave introduction window) In the film formation chamber by the microwave plasma CVD method shown in FIGS. 4 and 5, a microwave introduction window for supplying microwaves to the film formation chamber is not shown in FIG. This is a means for efficiently introducing microwave power supplied from the microwave power source through the waveguide through the isolator, power monitor, matching device, and the like into each film forming chamber.

2.4 provided by rectangular waveguide 550
The continuous microwave power of 5 GHz is converted from a rectangular TE ₁₀ mode to a circular T by a mode converter 551 having a cavity resonance structure.
Is converted into E ₁₁ mode, half of the microwave wavelength and 1 /
Disks 552 and 553 of alumina ceramics having a thickness of 4
Through a microwave introduction window 518, 519, 520 on which the pressure is reduced.

Of the two stacked alumina ceramic disks, a disk 5 having a half wavelength thickness on the mode converter side
At 52, the airtightness of the film forming chamber is maintained, its surroundings are water-cooled, and the air is forcedly cooled from the atmosphere side by a vortex cooler (registered trademark). Also, a disk 55 having a thickness of 1/2 wavelength
A small cylindrical disc made of alumina ceramics (not shown) is attached to two places on the atmosphere side surface of No. 2 to perform matching for increasing the efficiency of supplying microwave power to the film forming chamber. A silicon film is deposited on the surface of the disk 553 having a thickness of 1/4 wavelength on the film forming chamber side, but when a large amount of film adheres, only the disk having the thickness of 1/4 wavelength is removed and an etching process is performed. , And can be easily cleaned by blasting or the like.

(Temperature Control Mechanism of Strip-shaped Substrate) In the film forming chamber by the microwave plasma CVD method shown in FIG. 4, the vacuum vessel 402 can be opened and closed on the upper (back) side of the strip-shaped substrate 401 in the vacuum vessel 402. The lamp heater 432 and the substrate temperature controller 433,
34, 435 are disposed, and the surface of the band-shaped substrate 401 is measured while measuring the temperature with thermocouples 436, 437, 438, and 439 for measuring the surface temperature of a thin plate having a small heat capacity and a large contact area in surface contact with the back surface of the band-shaped substrate. From the back side to a predetermined temperature.

The temperature of the band-shaped substrate 401 is controlled by the gas gate 403.
Is reduced when passing through the discharge chamber, but is heated to a predetermined temperature suitable for film formation by the lamp heater 432 disposed in front of the discharge chamber 406 before the band-shaped substrate reaches the discharge chamber 406, The temperature is controlled by the substrate temperature controllers 433, 434, and 435 disposed on the substrates 406, 407, and 408 so that the temperature becomes constant during the formation of the deposited film.

The lamp heater 432 has a structure in which a plurality of rod-shaped infrared lamps having a length sufficient to uniformly heat the width of the band-shaped substrate are arranged in a direction perpendicular to the moving direction of the band-shaped substrate. 440 is provided to collect the radiated light from the lamp on the strip-shaped substrate side to increase the heating efficiency and to prevent the lid 431 of the vacuum vessel from being heated. Further, a wiring cover (not shown) is provided on the electric wiring for supplying electric power to the lamp heater 432,
Even if the plasma leaks from the discharge chamber unit 405 and hits the electric wiring, a spark, a leakage, etc. are not generated.

Temperature control devices 433, 434 on the discharge chamber
Reference numeral 435 is for controlling the temperature of the band-shaped substrate during film formation. The band-shaped substrate 401 heated to a predetermined temperature by the lamp heater 432 is cooled by a source gas introduced into the film formation chamber or heated by high-energy plasma. Thus, the temperature of the strip-shaped substrate during film formation is maintained and controlled at a predetermined temperature.

(Supporting mechanism for belt-like substrate) In the film forming chamber by the microwave plasma CVD method shown in FIG.
Support rollers 441 for rotatably supporting the rear surface of the band-shaped substrate are provided at several places on the upper surface (rear surface) side of the band-shaped substrate 401 in 2, and supported from the rear surface so that the band-shaped substrate 401 is linearly stretched in the vacuum container 402. are doing.

A permanent magnet (not shown), which has a high Curie point and generates a magnetic force that does not affect the plasma, is provided inside the support roller 441, and a belt-like substrate made of a magnetic material such as ferrite stainless steel. Is used, the support roller 441 and the belt-shaped substrate are brought into close contact with each other.

The surface of the support roller 441 is formed of a conductive material such as stainless steel and is electrically grounded, and the conductive strip substrate 401 is electrically grounded.

In the present invention, a film forming chamber formed by a high-frequency plasma CVD method is a film forming chamber formed by a high-frequency plasma CVD method.
A film formation chamber for continuously forming a silicon-based non-single-crystal semiconductor by the method D.

In the present invention, the film forming chamber formed by the high-frequency plasma CVD method is basically used for forming an impurity-doped layer on a strip substrate and an i-type layer to be laminated on the i-type layer formed by the microwave plasma CVD method. Preferably, an i-type layer is further formed by a high-frequency plasma CVD method between the film forming chamber for the impurity doped layer on the strip-shaped substrate and the film forming chamber for the i-type layer by the microwave plasma CVD method. It is arranged as a membrane chamber.

In the formation of the photovoltaic element, when the i-type layer is formed by the microwave plasma CVD method, the plasma formed by the microwave plasma CVD method has high energy. At the start of the formation, the impurity-doped layer under the i-type layer may be slightly sputter-etched.

When the impurity-doped layer is sputter-etched during the formation of the i-type layer, the i-type layer is doped with impurities,
The characteristics of the photovoltaic element formed by changing the characteristics of the i-type layer vary. In order to prevent sputter etching of the impurity-doped layer by such microwave plasma, high-frequency plasma CVD is performed between the impurity-doped layer on the belt-shaped substrate and the i-type layer by microwave plasma CVD.
A film forming chamber for forming an i-type layer with low-energy plasma by a plasma method is further arranged, and an i-type layer is formed thinly on the impurity-doped layer by a high-frequency plasma CVD method, and the impurity-doped layer is directly exposed to microwave plasma. It is desirable not to do so.

Further, in the apparatus of the present invention, the film forming chamber formed by the high-frequency plasma CVD method may be used to cope with a higher moving speed of the band-shaped substrate without increasing the size of one film forming chamber to a certain size or more. In order to form a layer under a plurality of film formation conditions, a plurality of layers may be connected and provided.

In the apparatus of the present invention, high-frequency plasma CV
Examples of a method of supplying high-frequency power to the film forming chamber by the method D include a capacitive coupling method using a discharge electrode and an inductive coupling method using a high-frequency coil. Preferably, a capacitive coupling method using a parallel plate electrode is used. A method is used.

In the apparatus of the present invention, the high-frequency plasma C
In a film formation chamber formed by the VD method, a temperature control means for controlling a band-shaped substrate on which a semiconductor layer is formed on the surface thereof at a temperature suitable for forming a semiconductor film while moving in the film formation chamber may be provided. desirable.

In order to keep the temperature of the band-shaped substrate constant during the formation of the semiconductor film, the band-shaped substrate is heated to a temperature suitable for forming a semiconductor layer before entering the plasma formation space. It is preferable to provide a temperature control means so that the temperature is maintained.

Since a semiconductor layer is formed on the front surface of the belt-like substrate in the film formation chamber, it is preferable to control the temperature during film formation from the back side.

Further, since the belt-like substrate moves continuously in the film forming chamber, it is preferable to use a heater means such as a lamp heater capable of heating in a non-contact manner to heat the belt-like substrate. For temperature measurement, use a moving surface thermometer that uses a thermocouple that can measure the temperature of the moving surface and has a small heat capacity and a fast response speed, or a temperature measuring device such as a radiation thermometer that can perform non-contact measurement. preferable.

FIG. 6 is a schematic sectional view showing a preferred example of a film forming chamber by the high frequency plasma CVD method in the apparatus of the present invention.

(Discharge Chamber) In FIG.
Enters the vacuum vessel 602 from the gas gate 603, moves from left to right in the drawing, and exits to the gas gate 604.

A discharge chamber 605 is provided inside the vacuum vessel 602, and high-frequency power is supplied from a high-frequency power supply (not shown) between the electrically grounded strip-shaped substrate 601 and the discharge electrode 606 to discharge the discharge chamber 605. Plasma is formed in 605, and a silicon-based non-single-crystal semiconductor is formed on the lower surface (front surface) of the belt-shaped substrate. The discharge chamber 605 is provided with a source gas introduction pipe 607 connected to a source gas supply system (not shown) and an exhaust pipe 608 connected to an exhaust device (not shown), so that a gas flow parallel to the moving direction of the strip-shaped substrate is provided. Form.

A block heater 609 is provided in the inflow path of the source gas to preheat the source gas before plasma decomposition and heat the discharge chamber 605, to promote the decomposition of the source gas near the blow-out portion and to improve the inner wall of the discharge chamber 605. To reduce the amount of polysilane powder adhering to the surface. A discharge chamber outside exhaust port 610 is provided in the exhaust gas discharge path, and a gas outside the discharge chamber 605 (a gate gas flowing from a gas gate, a vacuum vessel 602).
Gas discharged from the inner wall, etc.) is discharged to the exhaust pipe 608 without passing through the discharge chamber 605 to prevent impurities from being mixed into the deposited film.

The band-shaped substrate 6 above the discharge chamber 605
Plasma leak guards 611 are provided at the inlet, outlet and both ends in the width direction of the discharge chamber 01 to prevent the plasma inside the discharge chamber 605 from leaking to the outside.

(Temperature Control Mechanism of Strip-shaped Substrate) In the film forming chamber by the high-frequency plasma CVD method shown in FIG. 6, the vacuum vessel 602 can be opened and closed on the upper (back) side of the strip-shaped substrate 601 in the vacuum vessel 602. Lamp heaters 613 and 614 are provided fixed to the lid 612, and the band-shaped substrate 601 is heated from the back surface to a predetermined temperature while monitoring the temperature by thermocouples 615 and 616 that are in surface contact with the back surface of the band-shaped substrate. Although the temperature of the band-shaped substrate 601 decreases when passing through the gas gate 603, the temperature of the band-shaped substrate 601 is reduced to a predetermined temperature suitable for film formation until the band-shaped substrate reaches the discharge chamber 605 by the lamp heater 613 provided in front of the discharge chamber 605. And the temperature is maintained by a lamp heater 614 provided above the discharge chamber 605 so that the temperature becomes constant during the formation of the deposited film.

The lamp heaters 613 and 614 have a structure in which a plurality of rod-shaped infrared lamps having a length sufficient to uniformly heat the width of the band-shaped substrate are arranged in a direction perpendicular to the moving direction of the band-shaped substrate. In front of the discharge chamber 6
The interval is adjusted so that it becomes coarser as you go behind 05. Further, the lamp heaters 613 and 614 are provided with a reflector 617 having a double structure. The reflector 617 collects radiation light from the lamp on a strip-shaped substrate to increase heating efficiency and prevent the lid 612 of the vacuum vessel from being heated. I have. further,
A wiring cover (not shown) is provided on the electric wiring for supplying electric power to the lamp heaters 613 and 614.
Even if plasma leaks from 05, sparks from electrical wiring,
Electric leakage is prevented.

(Supporting mechanism for belt-like substrate) In the film forming chamber by the high-frequency plasma CVD method shown in FIG.
In the vicinity of the entrance and exit of the vacuum vessel 605 in the inside 02, a support roller 618 for rotatably supporting the back surface of the band-shaped substrate is provided,
A band-shaped substrate 601 is stretched linearly in a vacuum vessel 602,
It is supported from the back surface so that the distance from the discharge electrode 606 is kept constant.

A permanent magnet (not shown) that has a high Curie point and generates a magnetic force that does not affect the plasma is disposed inside the support roller 618, and a belt-like substrate made of a magnetic material such as ferrite stainless steel. Is used, the support roller 618 and the belt-shaped substrate 601 are brought into close contact with each other.

The surface of the support roller 618 is formed of a conductive material such as stainless steel and is electrically grounded, and the conductive strip substrate 601 is electrically grounded.

A film forming chamber by plasma doping In the apparatus of the present invention, a film forming chamber by plasma doping means that the surface of an i-type layer on a continuously moving strip-shaped substrate is exposed to a glow discharge plasma of a gas containing an impurity element.
A film formation chamber (discharge treatment chamber) for continuously forming an impurity doping layer by plasma doping.

In the present invention, the gas containing the impurity element during the plasma doping includes B ₂ H ₆ , B
In addition to a gas containing impurity elements such as F ₃ and PH ₃ , hydrogen and a diluent gas such as He, etc.
A gas containing Si atoms such as iH ₄ , Si ₂ H ₆ , and SiF ₄ may be contained in an amount small enough to form a semiconductor layer having a desired thickness by deposition.

The plasma doping of the present invention is desirably performed at a frequency of 5 kHz to 500 kHz, and the structure of a film forming chamber formed by plasma doping may be substantially the same as that of the high frequency plasma CVD method shown in FIG. However, the power supply connected to the discharge electrode is 5 kHz to 500 k.
It is desirable to use a low frequency power supply of Hz.

Further, in the present invention, the film formation chamber may be used to cope with a higher moving speed of the band-shaped substrate without increasing the size of one film formation chamber to a certain size or more. A plurality may be provided in order to form under conditions.

In the apparatus of the present invention, in the film formation chamber formed by plasma doping, the band-shaped substrate on which the semiconductor layer is formed while moving in the film formation chamber is controlled to a temperature suitable for the formation of the semiconductor layer. Alternatively, it is preferable to provide a temperature controller for heating and baking the inside of the film formation chamber.

Since a semiconductor layer is formed on the surface of the belt-like substrate in the film forming chamber, it is preferable to control the temperature during film formation on the back side.

Further, since the belt-like substrate is continuously moving in the film-forming chamber, when heating the belt-like substrate, it is preferable to use non-contact heating means such as a lamp heater capable of heating without radiation. To measure the temperature of the belt-like substrate, use a temperature measuring means such as a moving surface thermometer using a thermocouple capable of measuring the temperature of the moving surface and having a small heat capacity and a high response speed, or a radiation thermometer capable of non-contact measurement. Is preferred.

Glow Discharge Cleaning Chamber In the present invention, the glow discharge cleaning chamber is such that a continuously moving strip-shaped substrate is exposed to a glow discharge plasma of an inert gas such as Ar or He or a hydrogen gas, and adheres to the strip-shaped substrate. A discharge chamber that continuously removes adsorbed gas, moisture, and the like.

The removal of deposits such as adsorbed gas on the inner wall of a vacuum vessel and the surface of a substrate by plasma of an inert gas or hydrogen gas is generally known as discharge cleaning, and is described in Vacuum Technology Handbook (Toru Kanmochi, edited by Nikkan Kogyo Shimbun) 1990 issued).

In the roll-to-roll system, a long strip-shaped substrate is generally wound and stored in a winding chamber in a winding chamber, and is continuously supplied to a semiconductor film forming chamber. Pinpinpi by roll-to-roll method
In the formation of a photovoltaic device having an n or nipnipnip structure, the unwound strip-shaped substrate is first supplied to a deposition chamber for an impurity-doped layer, and the surface thereof is exposed to plasma.

Further, since the strip-shaped substrate is wound into a coil and placed in a vacuum container, even if the substrate is evacuated to a vacuum, the adsorbed gas and moisture adhering to the surface are not easily removed. There is a possibility that adsorbed gas, moisture, and the like that have adhered before being charged into the vacuum vessel may remain on the surface of the strip-shaped substrate.

Therefore, during the first film formation of the impurity-doped layer, the plasma may release the adsorbed gas or moisture remaining on the surface of the belt-like substrate, and may be mixed into the semiconductor film to be formed as impurities that deteriorate the characteristics of the film. .

In the roll-to-roll type semiconductor laminated film forming apparatus, the glow discharge cleaning chamber of the present invention is provided with the roll-to-roll substrate before the unwound strip-shaped substrate is supplied to the first film formation chamber. -The discharge cleaning is performed continuously by a roll method, whereby the contamination of the semiconductor film with impurities is prevented, and a high-quality semiconductor film with a small amount of impurities can be formed.

In the present invention, a plurality of cleaning chambers are provided in order to cope with a higher moving speed of the belt-shaped substrate without increasing the size of one cleaning chamber to a certain size or to perform cleaning under a plurality of cleaning conditions. You may connect and provide.

The structure may be the same as that of the high-frequency plasma CVD method shown in FIG. 6 or the structure of the microwave plasma CVD method shown in FIG. 4, for example. In terms of simplicity, it is preferable to use a high-frequency plasma CVD method as shown in FIG.

Hydrogen Plasma Processing Chamber In the present invention, the term “hydrogen plasma processing chamber” means that the surface of an i-type layer on a continuously moving strip-shaped substrate is exposed to glow discharge plasma of hydrogen gas, and the surface of a semiconductor is continuously subjected to hydrogen plasma processing. Refers to the discharge chamber to be performed.

It is known that an amorphous silicon-based film can be improved in quality by performing a hydrogen plasma treatment after film formation, and the proceedings of the 1991 Annual Conference of the Japan Society of Applied Physics, 10p-PF-5 and 10p-PF. -12,
Proceedings of the 1992 Applied Physics-related Lectures 28p
-ZV-9 and the like.

When the present inventors formed the photovoltaic element,
When the hydrogen plasma treatment was performed on the surface of the i-type layer after the formation of the i-type layer and before the formation of the impurity-doped layer, the open-circuit voltage of the photovoltaic device to be produced was improved as compared with the case where the hydrogen plasma treatment was not performed. It is confirmed that the hydrogen plasma treatment is performed after the formation of the i-type layer and before the formation of the impurity-doped layer.
It was confirmed that it was effective for forming a high-quality photovoltaic element.

In the hydrogen plasma processing chamber of the present invention, the hydrogen plasma processing can be continuously performed by a roll-to-roll method.

In the present invention, the processing chamber is used in order to cope with a higher moving speed of the strip-shaped substrate without increasing the size of one processing chamber to a certain size or more, or to perform processing under a plurality of processing conditions. A plurality of them may be connected.

The structure may be the same as the film forming chamber by the high frequency plasma CVD method shown in FIG. 6 as an example, or the film forming chamber by the microwave plasma CVD method as an example in FIG. In terms of simplicity, it is preferable to use a high-frequency plasma CVD method as shown in FIG.

[0149] The unwind chamber of the belt-like substrate in the unwinding chamber present invention of the strip substrate, houses a belt-like substrate before the film formation refers to a vacuum container for feeding the strip substrate continuously into the deposition chamber.

FIG. 7A is a schematic cross-sectional view showing an example of a chamber for unwinding a belt-like substrate in the apparatus of the present invention.

In FIG. 7A, a band-shaped substrate 701A is wound in a coil shape on a bobbin 703A in a vacuum container 702A, and is pulled by a winding mechanism of a band-shaped substrate winding chamber to be wound from the bobbin 703A. The film is formed into a flat surface with the film forming surface (surface) down by a roller 704A, and is moved and supplied to a film forming chamber (not shown) connected by a gas gate 705A. The bobbin 703A has a band-shaped substrate 70
A tension adjusting mechanism (not shown) for applying a constant tension to 1A is connected to apply tension to the band-shaped substrate 701A to prevent the slack from occurring. The film take-up bobbin 706A is connected to a take-up mechanism (not shown), and polyethylene, polyethylene terephthalate, and polyimide wound together with the band-shaped substrate to prevent the front and rear surfaces of the band-shaped substrate from rubbing and being damaged. , A thin and soft protective film 7 made of a resin sheet such as polyamide, non-woven fabric, paper, or a thin material obtained by evaporating a metal such as Al.
07A is wound in accordance with the unwinding of the belt-shaped substrate. Further, a steering mechanism (not shown) is provided on the roller 704A, and the roller 704A is provided from outside the vacuum container 702A.
A, the direction of the rotation axis of A is slightly changed to slightly change the traveling direction of the band-shaped substrate, and even if the position of the band-shaped substrate wound on the bobbin 703A in the width direction is uneven, the gas gate 7
At 05A, the strip-shaped substrate can always be supplied to a fixed position in the width direction.

The inside of the vacuum vessel 702A is exhausted by an exhaust pipe 708A connected to a vacuum exhaust device (not shown).

[0153] The take-up chamber for the belt-like substrate in the winding chamber present invention of the strip substrate, a belt-like substrate after the semiconductor multilayer film deposited continuously withdrawn from the film forming chamber refers to a vacuum container for storing.

FIG. 7B is a schematic sectional view showing an example of the unwinding chamber for the belt-like substrate in the apparatus of the present invention.

The winding chamber for the strip-shaped substrate and the unwinding chamber for the strip-shaped substrate may have almost the same device configuration, but the directions of rotation of the bobbins, rollers and the like are reversed.

In FIG. 7B, the band-shaped substrate 701B after the formation of the semiconductor laminated film is moved from the gas gate 705B to the vacuum vessel 7A.
02B, and is wound around a bobbin 703B connected to a rotation mechanism (not shown) via a roller 704B.

The film winding bobbin 706B
Is a resin sheet of polyethylene, polyethylene terephthalate, polyimide, polyamide, etc., a nonwoven fabric, paper, or a metal such as Al to be wound together with the band-shaped substrate in order to prevent the front and back surfaces of the band-shaped substrate from being rubbed and damaged. Is supplied to the bobbin 703B. Further, a steering mechanism (not shown) is provided for the roller 704B, and the direction of the rotation axis of the roller 704B is slightly changed from the outside of the vacuum container 702B to slightly change the traveling direction of the belt-like substrate, and the roller 704B enters from the gas gate 705B. Even if the positions of the band-shaped substrates in the width direction are irregular, the band-shaped substrate 701B can always be wound around the bobbin 703B at a fixed position in the width direction.

The exhaust pipe 708B is connected to the vacuum vessel 702B
Is evacuated, and is connected to an unillustrated evacuation device.

Hereinafter, the steering mechanism will be described in more detail with reference to the drawings.

In the winding chamber for the band-shaped substrate, a lateral displacement detecting mechanism and a steering mechanism for correcting the lateral displacement are provided inside the vacuum vessel in order to prevent the band-shaped substrate from being displaced in the direction perpendicular to the moving direction during the movement. Have.

FIG. 8 is a schematic diagram for explaining the lateral displacement detecting mechanism and the steering mechanism. In order to facilitate understanding, a part of the belt-like substrate is shown broken.

In FIG. 8, the moving direction of the belt-like substrate 801 is bent upward by the rollers 804. Further, the roller 804 is connected to the rotating mechanism 80 via a bearing 806.
3 and is rotatable about an axis orthogonal to the rotation axis of the roller 804, thereby constituting a steering mechanism.
The rotation mechanism 803 has a rotation shaft extending outside the vacuum vessel and is connected to a servomotor having a speed reduction mechanism (not shown) so that the rotation angle can be controlled from the outside.

Referring to FIG. 8, a description will be given of a steering mechanism when the belt-shaped substrate 801 is shifted to the left in the moving direction 805. First, before starting the movement of the belt-like substrate, the tension applied to the left and right of the roller 804 is the same, and the belt-like substrate 8
The positions of the winding bobbin, the rotating mechanism 803, and the bearing 806 are adjusted so that 01 is wound around the winding bobbin. The position is set such that the lateral displacement amount of the lateral displacement detection mechanism 802 = 0 and the rotation angle of the rotation mechanism = 0. Next, the band-shaped substrate 80
1 is started to shift to the left side, the horizontal shift detecting mechanism 802 detects the amount of horizontal shift of the strip-shaped substrate 801 in the left direction. Further, the right side of the roller 804 moves in the moving direction with respect to the moving direction 805 of the belt-like substrate in accordance with the amount of the lateral displacement.
The rotation mechanism 803 is rotated by a small angle so that the left side moves in the reverse direction of the movement. In response to this rotation, the tension applied to the belt-like substrate increases on the right side of the roller 804 and decreases on the left side. As a result, the belt-like substrate 801 is
If the rotation angle is set to 0 when the amount of lateral displacement finally becomes 0, the belt-shaped substrate is restored to the original position. When the belt-shaped substrate is shifted to the right side, the roller 804 is rotated in the reverse direction, and the belt-shaped substrate is returned to the left side to restore the original position. The above operation is automatically performed by a feedback mechanism (not shown) that connects the steering mechanism and the lateral displacement detecting mechanism. The position of the belt-shaped substrate is always controlled within a certain range in the width direction, and the winding bobbin is moved in the width direction. Is wound up in a state where are aligned.

Gas Gate In the present invention, a gas gate connects adjacent film forming chambers by a slit-shaped separation passage, and further introduces a gas such as Ar, He, H ₂ or the like into the separation passage, and heads toward the film formation chamber. This means means for connecting a film-forming chamber for separating a source gas by moving a strip-shaped substrate between adjacent film-forming chambers by forming a gas flow.

FIGS. 4, 6, and 7 are schematic cross-sectional views showing examples of various film forming chambers and gas gates connecting them in the present invention. The gas gates shown in FIGS. All have the same structure.

In FIG. 4, the gas gate 403 has a slit-shaped separation passage 442 for passing the band-shaped substrate 401 and separating the source gas. Above and below the strip substrate substantially at the center of the separation passage 442, gate gas introduction pipes 443 and 444 having a plurality of gas inlets in the width direction of the strip substrate and connected to a gate gas supply system (not shown) are connected. A gate gas for separating source gas is introduced from above and below the belt-shaped substrate 401. In the separation passage 442, the band-shaped substrate 40
1 is rotatably supported on its back surface by a plurality of support rollers 445 such that its surface does not come into contact with the lower wall surface of the separation passage 442 and maintains a constant slight interval.

A permanent magnet (not shown), which has a high Curie point and generates a magnetic force that does not affect the plasma, is provided inside the support roller 445, and a belt-like substrate made of a magnetic material such as ferrite stainless steel. Is used, the support roller 445 and the belt-shaped substrate 401 are brought into close contact with each other.

The slit-shaped separation passage 442 is provided so that the surface of the band-shaped substrate on which the semiconductor film is formed is not damaged by contact with the lower surface of the inner wall of the separation passage due to undulation or vibration when the band-shaped substrate moves. In order to prevent mixing of the source gas between the film forming chambers to be connected, it is preferable that the width is narrow in the thickness direction of the band-shaped substrate and narrow in the direction of movement of the band-shaped substrate. It is better to be longer in the direction of movement. Therefore, the inner size of the slit-shaped separation passage 442 in the width direction of the band-shaped substrate is slightly larger than the width of the band-shaped substrate and is almost constant everywhere. The smaller the pressure difference is, the smaller the allowable mixing amount of the impurity gas is, and the narrower it is. For example, an i-type layer film formation chamber formed by a microwave CVD method has a low internal pressure and an allowable mixed amount of an impurity gas is small. In the gas gate connecting between the two, the inner dimension of the separation passage in the thickness direction of the strip-shaped substrate is narrowed to such an extent that the strip-shaped substrate can finally pass, and is set in the range of about 0.3 to 3 mm. On the other hand, the unwinding chamber and the winding chamber of the strip-shaped substrate with almost no pressure difference and the high-frequency plasma CVD
In the gas gate connected to the film forming chamber in the method, the inner dimension of the separation passage in the thickness direction of the strip-shaped substrate is relatively wide so that the strip-shaped substrate can be easily moved, and is in a range of about 1 mm to 5 mm. Is set to

[0169] As the material of the belt-like substrate suitably used in the apparatus of the belt-like substrate present invention, variations in temperature required during semiconductor layer formation, less distortion, has the desired strength, also has conductivity Preferably, specifically, stainless steel, aluminum and its alloys, iron and its alloys, metal thin plates such as copper and its alloys and composites thereof,
And metal thin films of different materials and / or S
An insulating thin film made of iO ₂ , Si ₃ N ₄ , Al ₂ O ₃ , AlN, etc., which has been subjected to a surface coating treatment by a sputtering method, a vapor deposition method, a plating method, or the like. Also, polyimide, polyamide,
Heat-resistant resin sheets such as polyethylene terephthalate and epoxy, or composites of these with glass fibers, carbon fibers, boron fibers, metal fibers, etc., on the surface of a simple metal or alloy, and a transparent conductive oxide (TC
O) or the like, which is subjected to a conductive treatment by a method such as plating, vapor deposition, sputtering, or coating.

Even if the strip-shaped substrate is made of a conductive material such as metal, the reflectance of long-wave light reaching the substrate can be improved, the mutual diffusion between the substrate material and the semiconductor layer can be prevented and the adhesion can be improved. A different kind of metal layer may be provided on the semiconductor layer forming side surface for the purpose of smoothing the surface.

In the case where the light reflecting layer is provided, a metal such as Ag, Al, Cu, or AlSi having a high reflectance from visible light to near infrared is suitable for such a metal layer.

Further, on these metal layers, a transparent conductive layer may be further provided for the purpose of preventing diffusion of metal from the metal layer to the semiconductor layer, improving light reflectance, and the like.

As such a transparent conductive layer, ZnO, S
Transparent conductive oxides such as nO ₂ , In ₂ O ₃ , and ITO are mentioned as the most suitable ones.

The surface of the belt-shaped substrate may be a so-called smooth surface or a fine uneven surface. In the case of a minute uneven surface, the surface roughness is within a range that does not cause a defect due to unevenness in the formed semiconductor layer and that increases the optical path length of incident light due to a so-called light confinement effect. Is preferred.

The thickness of the belt-like substrate is desirably as thin as possible in consideration of cost, storage pace, and the like, as long as it is within a range in which the planar shape is maintained during moving and transporting. Specifically, the thickness is preferably 0.01 mm to 5 mm, more preferably 0.02 mm to 2 mm, and most preferably 0.05 mm to 1 mm.

Further, regarding the width dimension of the band-like member,
It is preferable that the uniformity of the plasma formed in each deposition chamber be maintained and that the size be suitable for modularization of the photovoltaic element to be formed, specifically 5 cm to 100 cm, more preferably It is desirable to be 10 cm to 80 cm.

Further, the length of the belt-like substrate is not particularly limited, and may be a length that can be wound up in a roll shape. The longer one is made longer by welding or the like. It may be something.

It is desirable that the above-mentioned strip-shaped substrate is put into the apparatus of the present invention in a form wound around a cylindrical bobbin in a coil shape with a diameter within a range that does not cause plastic deformation.

Hereinafter, examples of the apparatus of the present invention constituted by the above-described respective film forming chambers will be described with reference to the drawings, but the present invention is not limited to these examples of the apparatus.

Apparatus Example 1 FIG. 1 is a schematic explanatory view showing a basic example of an apparatus for continuously forming a semiconductor laminated film according to the present invention. In FIG. 1, an apparatus for continuously forming a semiconductor film according to the present invention includes an unwinding chamber 10 for a strip-shaped substrate.
1. n (or p) type layer deposition chamber 102A by high frequency plasma CVD, i by microwave plasma CVD
Mold layer deposition chamber 103A, i by high frequency plasma CVD
Mold layer forming chamber 104A, p (or n) layer film forming chamber 105A by plasma doping, n (or p) layer film forming chamber 102B by high-frequency plasma CVD, i-type layer film forming by microwave plasma CVD A chamber 103B, an i-type layer deposition chamber 104B by high frequency plasma CVD, and a p (or n) type layer deposition chamber 105 by plasma doping
B, n (or p) type layer deposition chamber 102C by high frequency plasma CVD, i by microwave plasma CVD
Mold layer forming chamber 103C, i by high frequency plasma CVD method
Mold layer film forming chamber 104C, p (or n) type layer film forming chamber 105C by plasma doping, strip substrate winding 10
6.

A series of film forming chambers are arranged in a shape of a convex curve in the direction of gravity, such as a hanging curve or an arc, along the shape of the band-shaped substrate that hangs down by its own weight. In addition to maintaining a constant shape during film formation and reducing the stress applied to the band-shaped substrate and the semiconductor film formed thereon when the band-shaped substrate moves, the deformation of the substrate and the occurrence of film defects due to the stress Has been suppressed.

In the apparatus shown in FIG. 1, the band-shaped substrate 108 is unwound from the bobbin 109 of the band-shaped substrate unwinding chamber 101 and is connected by the gas gate 107 until it is wound on the bobbin 110 of the band-shaped substrate winding chamber 106. The film is moved while passing through the 12 film forming chambers, and a laminated film of a non-single-crystal semiconductor having a nipnipnip or pinpinpin structure is continuously formed on the surface thereof.

The band-shaped substrate 108 supplied from the band-shaped substrate unwinding chamber 101 is passed through a gas gate, and (1) first, an n (or p) type layer forming chamber 1 by a high-frequency plasma CVD method.
02A, an n (or p) type silicon-based non-single-crystal semiconductor layer is formed on the surface by high-frequency plasma CVD, and (2) an i-type layer forming chamber 103A by microwave plasma CVD is next entered. Microwave plasma CV
An i-type silicon-based non-single-crystal semiconductor layer is further formed and laminated by the method D. (3) Next, high-frequency plasma CVD
Into the i-type layer forming chamber 104A by a plasma method, and further form and stack an i-type silicon-based non-single-crystal semiconductor layer by a high frequency plasma CVD method, and (4) forming a p (or n) type layer by plasma doping Entering the chamber 105A, a p (or n) type silicon-based non-single-crystal semiconductor layer is formed on the surface of the i-type layer by plasma doping,
(5) Next, the n-type or p-type layer forming chamber 102B by the high-frequency plasma CVD method is entered, and the high-frequency plasma CVD is performed.
An n (or p) type silicon-based non-single-crystal semiconductor layer is further formed and laminated by the method (6).
An i-type silicon-based non-single-crystal semiconductor layer is further formed and laminated by microwave plasma CVD. (7) Next, an i-type layer forming chamber 104B by high-frequency plasma CVD is used.
, A layer of an i-type silicon-based non-single-crystal semiconductor is further formed and laminated by a high-frequency plasma CVD method,
(8) Next, a p (or n) type layer forming chamber 105B is formed by plasma doping, and a p (or n) type silicon-based non-single-crystal semiconductor layer is formed on the surface of the i-type layer by plasma doping. 9) Next, high frequency plasma CV
Enter the n (or p) type layer forming chamber 102C by the D method,
An n (or p) type silicon-based non-single-crystal semiconductor layer is further formed and laminated by a high-frequency plasma CVD method,
(10) Next, enter the i-type layer forming chamber 103C by the microwave plasma CVD method, and further form and laminate an i-type silicon-based non-single-crystal semiconductor layer by the microwave plasma CVD method. After entering the i-type layer forming chamber 104C by the plasma CVD method, the high-frequency plasma C
An i-type silicon-based non-single-crystal semiconductor layer is further formed and laminated by the VD method. (12) Next, a p (or n) -type layer formation chamber 105C is formed by plasma doping, and the surface of the i-type layer is formed by plasma doping. Then, a layer of a p (or n) type silicon-based non-single-crystal semiconductor is formed, and finally collected in the winding chamber 106 of the belt-shaped substrate.

Apparatus Example 2 FIG. 2 is a schematic explanatory view showing another example of an apparatus for continuously forming a semiconductor laminated film according to the present invention.

In FIG. 2, an apparatus for continuously forming a semiconductor film according to the present invention comprises a strip-shaped substrate unwinding chamber 201, a glow discharge cleaning chamber 211, an n (or p) type layer forming chamber 202A by high frequency plasma CVD, a high frequency I-type layer deposition chamber 212A by plasma CVD, i-type layer deposition chamber 203A by microwave plasma CVD, i-type layer deposition chamber 204A by high-frequency plasma CVD, hydrogen plasma processing chamber 21
3A, p (or n) type layer deposition chamber 205A by plasma doping, n (or p) type layer deposition chamber 202B by high frequency plasma CVD, i-type layer deposition chamber 212B by high frequency plasma CVD, microwave plasma CVD
Layer forming chamber 203B by high-frequency method, high-frequency plasma CVD
I-type layer deposition chamber 204B, hydrogen plasma processing chamber 2
13B, p (or n) -type layer deposition chamber 205B by plasma doping, n (or p) -type layer deposition chamber 202C by high-frequency plasma CVD, i-type layer deposition chamber 212C by high-frequency plasma CVD, microwave plasma CV
I-type layer deposition chamber 203C by method D, high-frequency plasma CV
It comprises an i-type layer deposition chamber 204C by the method D, a hydrogen plasma processing chamber 213C, a p (or n) type layer deposition chamber 205C by plasma doping, and a strip substrate winding chamber 206.

Note that the series of film forming chambers are arranged in a shape of a convex curve in the direction of gravity, such as a hanging curve or an arc, along the shape of the band-shaped substrate that hangs down by its own weight. In addition to maintaining a constant shape during film formation and reducing the stress applied to the band-shaped substrate and the semiconductor film formed thereon when the band-shaped substrate moves, the deformation of the substrate and the occurrence of film defects due to the stress Has been suppressed.

In the apparatus shown in FIG. 2, the band-shaped substrate 208 is unwound from the bobbin 209 in the band-shaped substrate unwinding chamber 201 and is connected to the gas gate 207 until it is wound on the bobbin 210 in the band-shaped substrate winding chamber 206. Moved while passing through the seven film forming chambers,
A laminated film of a non-single-crystal semiconductor having a nipnip or pinpinpin structure is formed continuously.

The band-shaped substrate 208 supplied from the band-shaped substrate unwinding chamber 201 passes through a gas gate, (1) first enters a glow discharge cleaning chamber 211, and the surface thereof is glow discharge-cleaned, and (2) next is high-frequency plasma CVD. Into the n (or p) type layer forming chamber 202A by the high frequency plasma C
An n (or p) type silicon-based non-single-crystal semiconductor layer is formed on the surface by the VD method. (3) Next, the i-type layer forming chamber 212A is formed by the high frequency plasma CVD method, and the i-type layer is formed by the high frequency plasma CVD method. (4) Next, an i-type silicon-based non-single-crystal semiconductor layer is formed by microwave plasma CVD. Further forming and laminating a semiconductor layer,
(5) Next, enter the i-type layer forming chamber 204A by the high-frequency plasma CVD method, further form and stack the i-type silicon-based non-single-crystal semiconductor layer by the high-frequency plasma CVD method, and (6) hydrogen plasma treatment Enter room 213A and enter i
A hydrogen plasma treatment is performed on the surface of the mold layer, and (7) a p (or n)
5A, a p (or n) type silicon-based non-single-crystal semiconductor layer is formed on the surface of the i-type layer by plasma doping, and (8) n is then formed by high-frequency plasma CVD.
(Or p) type layer forming chamber 202B, and an n (or p) type silicon-based non-single-crystal semiconductor layer is formed on the surface by high-frequency plasma CVD, and (9) i-type by high-frequency plasma CVD After entering the layer forming chamber 212B, an i-type silicon-based non-single-crystal semiconductor layer is further formed and laminated by high frequency plasma CVD, and (10) the i-type layer forming chamber 203B by microwave plasma CVD is next formed.
And further form and laminate an i-type silicon-based non-single-crystal semiconductor layer by microwave plasma CVD,
(11) Next, the i-type layer forming chamber 204B by the high frequency plasma CVD method is entered, and i is formed by the high frequency plasma CVD method.
(12) Next, a hydrogen plasma treatment is performed on the surface of the i-type layer by entering the hydrogen plasma treatment chamber 213B, (1).
3) Next, enter the p (or n) type layer forming chamber 205B by plasma doping, and perform i by plasma doping.
A p (or n) type silicon-based non-single-crystal semiconductor layer is formed on the surface of the mold layer.
Enter the n (or p) type layer forming chamber 202C by the D method,
An n (or p) type silicon-based non-single-crystal semiconductor layer is formed on the surface by high-frequency plasma CVD, and (1)
5) Next, the i-type layer forming chamber 2 by the high frequency plasma CVD method
In step 12C, an i-type silicon-based non-single-crystal semiconductor layer is further formed and laminated by a high-frequency plasma CVD method.
Into the mold layer forming chamber 203C, microwave plasma CVD
An i-type silicon-based non-single-crystal semiconductor layer is further formed and laminated by a method, and (17) high-frequency plasma CVD
Into the i-type layer forming chamber 204C by the high frequency plasma CVD method, further form and laminate an i-type silicon-based non-single-crystal semiconductor layer, and then (18) enter the hydrogen plasma processing chamber 213C to obtain the i-type layer. Hydrogen plasma treatment is performed on the surface of
(Or n) -type layer formation chamber 205C, a p (or n) -type silicon-based non-single-crystal semiconductor layer is formed on the surface of the i-type layer by plasma doping, and finally, a winding chamber for a belt-like substrate. Collected at 206.

Apparatus Example 3 An apparatus example according to the present invention in which the glow discharge cleaning chamber 211 shown in FIG. 2 and the gas gate connecting it are removed can be mentioned.

In this case, the other parts are the same as those of the apparatus example 2 except that the strip-shaped substrate is not cleaned by glow discharge.

Apparatus Example 4 i-type layer forming chamber 21 by high frequency plasma CVD in FIG.
An apparatus without the 2A and / or 212B and / or 212C and the gas gate connecting it can be cited as an example of the apparatus of the present invention.

In this case, the structure is the same as that of the device example 2 except that the i-type layer is not formed on at least one n (or p) type layer by the high frequency plasma CVD method.

Apparatus Example 5 The hydrogen plasma processing chamber 213A and / or 21 shown in FIG.
An apparatus example of the present invention in which 3B and / or 213C and a gas gate connecting the 3B and / or 213C are removed can be mentioned.

In this case, the device is the same as the device example 2 except that the surface of the i-type layer is not subjected to the hydrogen plasma treatment before the formation of at least one p (or n) -type layer.

Apparatus Example 6 The glow discharge cleaning chamber 211 shown in FIG.
I-type layer forming chamber 212A and / or 212 by method D
A device in which B and / or 212C and a gas gate connecting it are removed can be given as an example of the device of the present invention.

In this case, the belt-like substrate is not cleaned by glow discharge, and the i-type layer is not formed on at least one n (or p) type layer by the high-frequency plasma CVD method. .

Apparatus Example 7 Glow discharge cleaning chamber 211 shown in FIG. 2 and hydrogen plasma processing chambers 213A and / or 213B and / or 213
A device obtained by removing C and a gas gate connecting it can be cited as an example of the apparatus of the present invention.

In this case, the belt-like substrate is not cleaned by glow discharge, and the surface of the i-type layer is not subjected to the hydrogen plasma treatment before the formation of at least one p (or n) layer.

Apparatus Example 8 i-type layer forming chamber 21 by high frequency plasma CVD in FIG.
2A and / or 212B and / or 212C
And the hydrogen plasma processing chamber 213A and / or 213
B and / or 213C and the gas gate that connects them are removed, and examples of the apparatus of the present invention can be given.

In this case, the i-type layer is not formed on at least one n (or p) type layer by the high frequency plasma CVD method, and the surface of the i-type layer is formed before the formation of at least one p (or n) type layer. Just not being hydrogen plasma treated,
Others are the same as the device example 2.

Hereinafter, an example of a method for continuously forming a semiconductor laminated film for a photovoltaic element using the apparatus of the present invention will be described with reference to FIG.
This will be described using an apparatus having the configuration shown in FIG.

Step of Loading a Strip Substrate To form a semiconductor laminated film using the apparatus of the present invention shown in FIG. 1, first, a strip substrate is loaded into the apparatus and set at a predetermined position.

In order to load a belt-like substrate into the apparatus of the present invention,
First, the bobbin 109 in which the band-shaped substrate 108 is wound in a coil shape is put into the band-shaped substrate unwinding chamber 101, the tip of which is unwound, and the film forming chambers 102 </ b> A to 102 </ b> A to
After passing through 105C, the belt-like substrate is stretched to the empty bobbin 110 of the take-up chamber 106, and the tip is fixed.

A bobbin 10 around which a belt-like substrate before film formation is wound
9, a protective film for preventing the surface of the band-shaped substrate from being damaged may be rolled up together with the band-shaped substrate 108. When such a protective film is rolled-up, the front end of this protective film is connected to the unwinding chamber 101 of the band-shaped substrate. To the bobbin for winding the protective film inside.

Similarly, a bobbin 110 for winding a belt-like substrate
A protective film for preventing the surface of the band-shaped substrate from being damaged may be wound together with the band-shaped substrate 108. When such a protective film is wound-in, the protective film is used for unwinding the protective film in the winding chamber 106 of the band-shaped substrate. The band is unwound from the bobbin, and the tip is overlaid on the band-shaped substrate 108 and fixed to an empty bobbin 110 for winding the band-shaped substrate.

After fixing the strip-shaped substrate and the film to each bobbin, the axis of the bobbin for winding is fixed and stopped, and a torque for generating tension is applied to the bobbin for unwinding.
The belt-like substrate and the protective film are stretched without loosening.

Preheating, baking process After the loading and setting of the belt-like substrate, the belt-like substrate is stretched and kept in a stationary state, the lids of the respective film forming chambers are closed, and the inside of the apparatus is a vacuum pump such as a rotary pump or a mechanical booster pump. To exhaust. At this time, the vacuum was connected to the strip-shaped substrate unwinding chamber 101 and the take-up chamber 106, and the vacuum pump was connected to the film-forming chambers 102A to 105C.
Is exhausted through the gas gate 107, and the belt-shaped substrate unwinding chamber 101 and the winding chamber 106 are discharged from the film forming chambers 102A to 102A.
The flow of the adsorbed gas into 105C and the impurity-doped layer deposition chambers 102A and 105C from the i-type semiconductor layer deposition chamber 103A
It is desirable to prevent the adsorbed gas from flowing into 104A, 104C and 103C.

After each of the film forming chambers is evacuated to about 10 Pa, each of the film forming chambers is further evacuated to 1 Pa or less by a vacuum pump connected to each of the film forming chambers.

When the internal pressure of each film forming chamber becomes 1 Pa or less,
The evacuation of the film forming chambers 102A to 105C is stopped, and H ₂ , He,
Gases such as Ar, Ne, Kr, and Xe are supplied to the film forming chambers 104A and 104A.
The gas is introduced into the chambers 03B, 104B, and 103C to form a gas flow from the film forming chamber to the unwinding chamber 101 and the winding chamber 106 for the belt-like substrate, and the pressure in each of the chambers 101 to 106 is set to about several Pa.

When the pressure in each of the film forming chambers is stabilized, each of the film forming chambers is heated by a lamp heater, a substrate temperature control device, a film forming room temperature control device, and a block heater in each of the film forming chambers. Then, the band-shaped substrate is preheated to 100 to 500 ° C. and baked.

Step of Forming Semiconductor Layer After preheating and baking of each film forming chamber, the axis of the winding bobbin 110 of the band-shaped substrate winding chamber 106 is rotated, and the band-shaped substrate 108 is unwound from the unwinding chamber 101 to the film forming chamber 102A. , 1
03A, 104A, 105A, 102B, 103B, 1
04B, 105B, 102C, 103C, 104C, 1
After passing through 05C, it is continuously moved to the winding chamber 106 at a constant speed. The transfer speed of the belt-like substrate is preferably 1 to
100 mm / sec, more preferably 5 to 50 mm / sec.

While moving the belt-like substrate, the
2A to 105C lamp heater, substrate temperature controller, film forming chamber controller, block heater,
The temperature of the strip-shaped substrate and the temperature of the wall surface of each deposition chamber in the deposition film formation space of each deposition chamber are controlled to predetermined temperatures.

When the temperature of the strip-shaped substrate is stabilized, the introduction of gases such as H ₂ , He, Ar, Ne, Kr, and Xe from the film forming chamber is stopped, and each of the film forming chambers 102A to 105C is connected to each of the film forming chambers. A gas such as H ₂ , He, Ar, Ne, Kr, and Xe for separating source gases is introduced into each gas gate 107 from a gas cylinder via a mass flow controller.

When the gas flow rate becomes stable, the i-type semiconductor layer film forming chambers 103A, 103A,
The exhaust of 3B and 103C is switched from a low vacuum pump such as a rotary pump and a mechanical booster pump to a high vacuum pump such as a turbo molecular pump and an oil diffusion pump.

Next, a predetermined flow rate of a source gas for forming a semiconductor layer is introduced into each of the film forming chambers 102A to 105C from a gas cylinder via a mass flow controller.

When the flow rate of the source gas in each film forming chamber is stabilized,
The evacuation capacity of each of the film forming chambers is adjusted by an exhaust amount adjusting valve or the like provided in an exhaust pipe, and each of the film forming chambers is set to a predetermined pressure.

The preferred internal pressure of each chamber when the raw material gas is introduced is the film forming chamber 10 by microwave plasma CVD.
3 is 0.1 to 10 Pa, and others are 10 to 1000 Pa. Note that in order to prevent entry of impurity gas, the internal pressure of the i-type semiconductor layer deposition chamber 104A is set to the p-type semiconductor layer deposition chamber 1A.
From the internal pressure of 05A, the internal pressure of the n-type semiconductor film forming chamber 102A is higher than the internal pressure of the belt-shaped substrate unwinding chamber 101, and the internal pressure of the p-type layer film forming chamber 105C is higher than the internal pressure of the belt-shaped substrate winding chamber 106. It is desirable to set a little higher.

When the pressure in each film forming chamber is stabilized, each film forming chamber 1
Discharge power such as microwave power, high-frequency power, low-frequency power, and DC power is supplied to each of 02A to 105C.
The source gas in each of the film forming chambers is ionized by the application of the discharge power to form plasma.

As described above, the plasma is simultaneously formed in each of the film forming chambers 102A to 105C while moving the band-shaped substrate at a constant speed. A layer is formed,
A semiconductor laminated film having a nipnipnip (or pinpinpin) structure is continuously formed.

At this time, the conditions for forming each semiconductor layer in each of the film forming chambers 102A to 105C are as follows.

(Film formation conditions in film formation chambers 102A, 102B and 102C) Film formation chambers 102A, 102B and 102C
In the above, an n (or p) type silicon-based non-single-crystal semiconductor layer is formed by a high-frequency plasma CVD method.

The source gas introduced into the film forming chamber includes:
It contains a gasifiable compound containing at least Si atoms. As a gasizable compound containing a Si atom, S
iH ₄ , Si ₂ H ₆ , SiF ₄ , SiFH ₃ , SiF ₂
H ₂ , SiF ₃ H, Si ₃ H ₈ , SiD ₄ , SiH
D ₃ , SiH ₂ D ₂ , SiH ₃ D, Si ₂ D ₃ H _{3 and the} like. Further, the source gas may contain a gasizable compound containing Ge atoms for the purpose of narrowing the optical band gap.

Specifically, gaseous compounds containing Ge atoms include GeH ₄ , GeD ₄ , GeF ₄ and Ge
FH ₃ , GeF ₂ H ₂ , GeF ₃ H, GeHD ₃ , Ge
H ₂ D ₂ , GeH ₃ D and the like can be mentioned. Furthermore, C, for the purpose of expanding the optical band gap,
It may contain a gasifiable compound containing atoms such as O and N.

Specifically, gasification containing a C atom can be performed.
CH as compound₄, CD₄, C_nH_{2n + 2}(N is integer
Number), C_nH_2n(N is an integer), C₂H₂, C₆H₆,
CO ₂, CO and the like.

Examples of gasizable compounds containing O atoms include O ₂ , CO, CO ₂ , NO, NO ₂ , N ₂ O, and CH.
₃ CH ₂ OH, CH ₃ OH and the like.

Examples of gasizable compounds containing N atoms include N ₂ , NH ₃ , ND ₃ , NO, NO ₂ , and N ₂ O.

Further, in order to control the conduction type of the formed non-single-crystal semiconductor layer to n (or p) valence electrons in the source gas, an atom belonging to Group V (or Group III) of the periodic table is used. Contains gasifiable compounds.

Examples of the substance effectively used as a starting material for introducing group V atoms include phosphorus hydrides such as PH ₃ and P ₂ H ₄ , PH ₄ I and PF for introducing P atoms. ₃ ,
PF ₅ , PCl ₃ , PCl ₅ , PBr ₃ , PBr ₅ , P
And halogenated phosphorus such as I _3. In addition, AsH ₃ , AsF ₃ , AsCl ₃ , AsBr ₃ , A
_{sF 5, SbF 3, SbF 5} , SbCl 3, SbC
₁₅ , BiH ₃ , BiCl ₃ , BiBr _{3 and the} like can also be mentioned. Particularly, PH ₃ , PF ₃ , and AsH ₃ are suitable.

Examples of the material effectively used as a starting material for introducing a group III atom include B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , and B ₅ H _{11 for} introducing a B atom. , B ₆
H ₁₂ , borohydride such as B ₆ H ₁₄ , BF ₃ , BCl
_And boron halide such as ₃ . In addition, AlCl ₃ , GaCl ₃ , InCl _{3 and the} like can also be mentioned. Particularly, B ₂ H ₅ and BF ₃ are suitable.

The source gases include H ₂ , D ₂ , He, and N.
It may contain a diluent gas such as e, Ar, Xe, or Kr.

The discharge power supplied to the film forming chamber is for forming high-frequency plasma, and includes at least high-frequency power. The high-frequency power to be supplied is appropriately determined according to the flow rate of the source gas introduced into the film formation chamber, but is preferably in the range of 0.001 to 1 W / cm ³ with respect to the plasma formation space, and fluctuations such as ripples are suppressed. It is desirable that the continuous oscillation wave is small and stable. As the frequency of the high frequency power,
The range of 1 M to 500 MHz is preferable, and 13.56 MH
The industrial frequency of z is preferably used, and preferably has little frequency fluctuation.

DC power may be supplied together with high-frequency power. A voltage of 10 to 200 V is applied to the high-frequency discharge electrode or an electrode provided separately from the discharge electrode so that the electrode side becomes positive so that abnormal discharge such as spark does not occur. It is preferable to charge within the range.

[0233] Such high-frequency power is supplied to the film forming chamber 102, and preferably DC power is supplied simultaneously.
In 2, the source gas is ionized and decomposed to form an n (or p) type silicon-based non-single-crystal semiconductor layer on the strip-shaped substrate.

Note that the semiconductor layer formed under such film formation conditions is a non-single-crystal silicon-based material from amorphous (including so-called microcrystal) to polycrystalline.

(Film Forming Conditions in Film Forming Rooms 103A, 103B, 103C) Film forming chambers 103A, 103B, 103C
, An i-type silicon-based non-single-crystal semiconductor layer is formed by a microwave plasma CVD method.

As the source gas introduced into the film forming chamber,
It contains a gasifiable compound containing at least Si atoms. As a gasizable compound containing a Si atom, S
iH ₄ , Si ₂ H ₆ , SiF ₄ , SiFH ₃ , SiF ₂
H ₂ , SiF ₃ H, Si ₂ H ₆ , SiD ₄ , SiH
D ₃ , SiH ₂ D ₂ , SiH ₃ D, Si ₂ D ₃ H _{3 and the} like. Further, the source gas may contain a gasizable compound containing Ge atoms for the purpose of narrowing the optical band gap. Specific examples of the gasizable compound containing a Ge atom include GeH ₄ , GeD ₄ , and Ge.
F ₄ , GeFH ₃ , GeF ₂ H ₂ , GeF ₃ H, GeH
D ₃ , GeH ₂ D ₂ , GeH ₃ D and the like. Furthermore, the source gas may contain a gasizable compound containing atoms such as C, O, and N for the purpose of widening the optical band gap.

Specific examples of the gasizable compound containing a C atom include CH ₄ , CD ₄ , C _n H _{2n + 2} (n is an integer), C _n H _2n (n is an integer), C ₂ H ₂ , and C ₆ H ₆ ,
CO ₂ , CO and the like can be mentioned.

The gasizable compounds containing O atoms include O ₂ , CO, CO ₂ , NO, NO ₂ , N ₂ O, CH
₃ CH ₂ OH, CH ₃ OH and the like.

Examples of the gasizable compound containing an N atom include N ₂ , NH ₃ , ND ₃ , NO, NO ₂ , N ₂ O and the like.

The semiconductor layer formed in the film formation chamber may contain a trace amount of impurities for controlling valence electrons if it is substantially intrinsic. It may also include gasifiable compounds containing Group or Group III atoms.

Examples of the substance effectively used as a starting material for introducing group V atoms include phosphorus hydrides such as PH ₃ and P ₂ H ₄ , PH ₄ I and PF for introducing P atoms. ₃ ,
PF ₅ , PCl ₃ , PCl ₅ , PBr ₃ , PBr ₅ , P
And halogenated phosphorus such as I _3. In addition, AsH ₃ , AsF ₃ , AsCl ₃ , AsBr ₃ , A
_{sF 5, SbF 3, SbF 5} , SbCl 3, SbC
₁₅ , BiH ₃ , BiCl ₃ , BiBr _{3 and the} like can also be mentioned. Particularly, PH ₃ , PF ₃ , and AsH ₃ are suitable.

Examples of the material effectively used as a starting material for introducing a group III atom include B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , and B ₅ H for introducing a B atom. ₁₁ , B
_{6 H 12, B 6} H _14, etc. _borohydride, BF 3, BC
mention may be made of the boron halide of l ₃ and the like. In addition, AlCl ₃ , GaCl ₃ , InCl _{3 and the} like can also be mentioned. Particularly, B ₂ H ₆ and BF ₃ are suitable.

The source gas is H ₂ , D ₂ , He, N
It may contain a diluent gas such as e, Ar, Xe, or Kr.

The discharge power supplied to the film formation chamber is for ionizing the raw material gas to form microwave plasma, and includes at least microwave power. The applied microwave power is appropriately determined according to the flow rate of the source gas introduced into the film formation chamber, but is preferably in the range of 0.01 to 1 W / cm ³ with respect to the plasma formation space, and the fluctuation of ripples and the like. It is desirable that the continuous oscillation wave has a small number of stable oscillations. The frequency of the microwave power is 500M to 10M
The range of GHz is preferable, and the industrial frequency of 2.45 GHz is suitably used, and it is preferable that the frequency has little fluctuation.

Further, the i-type layer film forming chambers 103A and 103B by the microwave plasma CVD method of the apparatus of the present invention are used.
It is desirable that high-frequency power or DC power be supplied to 103C together with microwave power by providing a bias electrode in the microwave plasma formation space.

When high-frequency power is applied, the power is preferably in the range of 0.02 to 2 W / cm ³ , and the frequency is preferably in the range of 1 to 500 MHz, and 13.56.
An industrial frequency of MHz is preferably used. When DC power is applied, it is preferable to apply a voltage of 10 to 300 V in a direction in which abnormal discharge such as spark does not occur in a direction in which the bias electrode side becomes positive.

[0247] Such microwave power is supplied to the film forming chamber, preferably high frequency or DC power is supplied simultaneously, and the source gas is ionized and decomposed in the film forming chamber to form an i-type silicon-based material on the belt-shaped substrate. A non-single-crystal semiconductor layer is formed.

Note that the semiconductor layer formed under such film formation conditions is a non-single-crystal material of a silicon-based material ranging from amorphous (including so-called microcrystal) to polycrystal.

(Deposition Conditions in Deposition Rooms 104A, 104B, 104C) Deposition Rooms 104A, 104B, 104C
, An i-type silicon-based non-single-crystal semiconductor layer is formed by a high-frequency plasma CVD method.

As the source gas introduced into the film forming chamber,
It contains a gasifiable compound containing at least Si atoms. As a gasizable compound containing a Si atom, S
iH ₄ , Si ₂ H ₆ , SiF ₄ , SiFH ₃ , SiF ₂
H ₂ , SiF ₃ H, Si ₃ H ₈ , SiD ₄ , SiH
D ₃ , SiH ₂ D ₂ , SiH ₃ D, Si ₂ D ₃ H _{3 and the} like. Further, the source gas may contain a gasizable compound containing Ge atoms for the purpose of narrowing the optical band gap.

Specific examples of the gasizable compound containing a Ge atom include GeH ₄ , GeD ₄ , GeF ₄ and GeF.
H ₃ , GeF ₂ H ₂ , GeF ₃ H, GeHD ₃ , GeH
₂ D _2, GeH ₃ D, and the like. Furthermore, C, O, and C are added to the source gas for the purpose of widening the optical band gap.
It may contain a gasizable compound containing an atom such as N.

Specific examples of the gasizable compound containing a C atom include CH ₄ , CD ₄ , C _n H _{2n + 2} (n is an integer), C _n H _2n (n is an integer), C ₂ H ₂ , and C ₆ H ₆ ,
CO ₂ , CO and the like can be mentioned.

The gasizable compounds containing O atoms include O ₂ , CO, CO ₂ , NO, NO ₂ , N ₂ O, CH
₃ CH, CH ₃ CH ₂ OH, CH ₃ OH and the like.

Examples of the gasizable compound containing an N atom include N ₂ , NH ₃ , ND ₃ , NO, NO ₂ , N ₂ O and the like.

The semiconductor layer formed in the film formation chamber may contain a trace amount of impurities for controlling valence electrons if it is substantially intrinsic. It may also include gasifiable compounds containing Group or Group III atoms.

Examples of the substance effectively used as a starting material for introducing group V atoms include phosphorus hydrides such as PH ₃ and P ₂ H ₄ , PH ₄ I, and PF for introducing P atoms. ₃ ,
PF ₅ , PCl ₃ , PCl ₅ , PBr ₃ , PBr ₅ , P
And halogenated phosphorus such as I _3. In addition, AsH ₃ , AsF ₃ , AsCl ₃ , AsBr ₃ , A
_{sF 5, SbF 3, SbF 5} , SbCl 3, SbC
l ₅ , BiH ₃ , BiCl ₃ , BiBr _{3 and the} like can also be mentioned. Particularly, PH ₃ , PF ₃ , and AsH ₃ are suitable.

Examples of the material effectively used as a starting material for introducing a group III atom include B ₂ H ₆ , B ₄ H ₁₀ , B ₆ H ₉ , and B ₅ H for introducing a B atom. ₁₁ , B
_{6 H 12, B 6} H _14, etc. _borohydride, BF 3, BC
mention may be made of the boron halide of l ₃ and the like. In addition, AlCl ₃ , GaCl ₃ , InCl _{3 and the} like can also be mentioned. Particularly, B ₂ H ₆ and BF ₃ are suitable.

The source gas is H ₂ , D ₂ , He, N
It may contain a diluent gas such as e, Ar, Xe, or Kr.

The discharge power supplied to the film formation chamber is used to ionize the source gas to form high-frequency plasma, and includes at least high-frequency power. The high-frequency power to be supplied is appropriately determined according to the flow rate of the source gas introduced into the film formation chamber.
/ Cm ³ , and a stable continuous wave with little fluctuation such as ripple. The frequency of the high-frequency power is preferably in the range of 1 M to 500 MHz, an industrial frequency of 13.56 MHz is suitably used, and it is preferable that the frequency has little fluctuation.

DC power may be supplied together with high-frequency power, and a voltage of 10 to 200 V is applied to the high-frequency discharge electrode or an electrode provided separately from the discharge electrode so that the electrode side becomes positive so that abnormal discharge such as spark does not occur. It is preferable to charge within the range.

[0261] Such high frequency power is supplied to the film forming chamber,
Preferably, a DC power is supplied at the same time to ionize and decompose the raw material gas in the film formation chamber to form an i-type silicon-based non-single-crystal semiconductor layer on the belt-like substrate.

Note that the semiconductor layer formed under such film formation conditions is a non-single-crystal material of a silicon-based material ranging from amorphous (including so-called microcrystal) to polycrystal.

(Film Forming Conditions in Film Forming Rooms 105A, 105B, 105C) Film forming chambers 105A, 105B, 105C
In the case of p (or n) by plasma doping
A silicon-based non-single-crystal semiconductor layer is formed.

As the source gas introduced into the film forming chamber,
In order to make the vicinity of the surface of the i-type non-single-crystal semiconductor layer into the p (or n) type by plasma doping, the periodic table II
Includes gasifiable compounds containing Group I (or Group V) atoms.

As a starting material effectively used for introducing a group III atom, specifically, for introducing a B atom, B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B ₅ H ₁₁ , B
_{6 H 12, B 6} H _14, etc. _borohydride, BF 3, BC
mention may be made of the boron halide of l ₃ and the like. In addition, AlCl ₃ , GaCl ₃ , InCl _{3 and the} like can also be mentioned. Particularly, B ₂ H ₆ and BF ₃ are suitable.

Examples of the substance effectively used as a starting material for introducing group V atoms include phosphorus hydrides such as PH ₃ and P ₂ H ₄ , PH ₄ I and PF for introducing P atoms. ₃ ,
PF ₅ , PCl ₃ , PCl ₅ , PBr ₃ , PBr ₅ , P
And halogenated phosphorus such as I _3. In addition, AsH ₃ , AsF ₃ , AsCl ₃ , AsBr ₃ , A
_{sF 5, SbF 3, SbF 5} , SbCl 3, SbC
l ₅ , BiH ₃ , BiCl ₃ , BiBr _{3 and the} like can also be mentioned. Particularly, PH ₃ , PF ₃ , and AsH ₃ are suitable.

The source gas is H ₂ , D ₂ , He, N
It may contain a diluent gas such as e, Ar, Xe, or Kr.

Further, the source gas contains a sufficiently small amount of Si to form an impurity-doped layer having a desired thickness by deposition.
A gas containing atoms and a gas containing atoms such as C, O, and N may be included.

The gas containing Si atom includes SiH ₄ , Si ₂ H ₆ , SiF ₄ and SiFH.
₃ , SiF ₂ H ₂ , SiF ₃ H, Si ₃ H ₈ , Si
D ₄ , SiHD ₃ , SiH ₂ D ₂ , SiH ₃ D, Si ₂
D ₃ H _{3 and the} like. Examples of the gas containing a C atom include CH ₄ , CD ₄ , C _n H _{2n + 2} (n is an integer), C _n H _2n (n is an integer), C ₂ H ₂ , C ₆ H ₆ ,
CO ₂ , CO, etc. are gases containing O atoms, such as O ₂ , CO, CO ₂ , NO, NO ₂ , N ₂ O, CH ₃ C
Examples of the gas containing H atoms such as H ₂ OH and CH ₃ OH containing N atoms include N ₂ , NH ₃ , ND ₃ , NO, NO ₂ , and N ₂ O.

The discharge power supplied to the film formation chamber is for low-frequency, high-frequency, microwave, etc. ionization of the source gas to form a glow discharge plasma, preferably a low frequency of 5 kHz to 500 kHz. Power.

The input power is preferably in the range of 0.01 to 1 W / cm ³ with respect to the volume of the plasma forming space, and is preferably a stable continuous wave with little fluctuation such as ripple. DC power may be supplied together with the discharge power, and a voltage of 10 to 200 V is applied to the discharge electrode or an electrode provided separately from the discharge electrode in a direction in which the electrode side becomes positive within a range where abnormal discharge such as spark does not occur. Is preferred.

[0272] Such discharge power is supplied to the film forming chamber, preferably DC power is supplied simultaneously, and the source gas is ionized and decomposed in the film forming chamber to form p (or n) on the strip-shaped substrate.
A silicon-based non-single-crystal semiconductor layer is formed.

Note that the semiconductor layer formed under such film formation conditions is a non-single-crystal material of a silicon-based material ranging from amorphous (including so-called microcrystal) to polycrystal.

While continuously moving the band-shaped substrate in each of the film forming chambers 102A to 105C, the above-described formation of the semiconductor layer is continued for a certain period of time. Forming and winding chamber 10
6 is continuously wound on the winding bobbin 110.

Step of taking out strip-like substrate [0275] When a strip-like substrate having a semiconductor laminated film formed on the surface thereof is formed to a predetermined length and wound on a bobbin of a winding chamber, discharge power is supplied to each of the film-forming chambers 102A to 105C. Then, the supply of the source gas, the movement and heating of the belt-shaped substrate are stopped, and the supply of the gate gas to each gas gate is also stopped. Each room 101-10
The inside of the chamber 6 is once evacuated by a vacuum pump connected to each chamber, and the evacuation of the film forming chambers 103A, 103B, 103C is switched from a high vacuum pump to a low vacuum pump. Next, the source gas supply system in which the source gas is supplied into each of the film forming chambers 102A to 105C and into each of the film forming chambers is sufficiently purged with an inert gas such as He or Ar.

When the purging of each film forming chamber and the source gas supply system for supplying the source gas to each film forming chamber is completed, each chamber 101
-106 is stopped, and H is introduced into each of the chambers 101-106.
e, an inert gas such as Ar is charged to a pressure slightly lower than the atmospheric pressure to cool each chamber and the strip-shaped substrate.

When each chamber and the strip-shaped substrate are cooled to near room temperature, a gas such as dry N ₂ , Ar, He is introduced into the apparatus to bring the apparatus to atmospheric pressure, and the driving force and torque applied to each bobbin are reduced. The bobbin 110 around which the band-shaped substrate is wound is taken out from the band-shaped substrate winding room 106 while leaving the portion from the band-shaped substrate winding room 101 to the winding room 106.

In addition, in the apparatus of the present invention, when the strip substrate is put into the apparatus or taken out of the apparatus,
The insides of the unwinding chamber 101 and the winding chamber 106 of the belt-shaped substrate are exposed to the atmosphere.
When air flows into A to 105A, an impurity gas such as water vapor or oxygen is adsorbed on the wall surface of the film formation chamber, which may affect characteristics of a semiconductor film to be formed. Therefore, a suitable so-called load lock structure may be provided by providing appropriate air inflow prevention means between the unwinding chamber 101 of the band-shaped substrate and the film forming chamber 102A and between the winding chamber 106 of the band-shaped substrate and the film forming chamber 105C. . In this case, the air inflow prevention means includes a vacuum sealing means for keeping the inside of the film forming chambers 102A to 105C in a reduced pressure state, and an inert gas such as He which does not affect the film formation in the film forming chambers 102A to 105C. Gas such as high-purity nitrogen or the like and pressurizing it to a pressure higher than the atmospheric pressure to form a clean gas flow into the unwinding chamber 101 and the winding chamber 106 to prevent air from flowing into the atmosphere. Means and the like.

However, when the sealing structure is provided, the film forming chambers 102A to 105C are kept in vacuum,
Since it is extremely difficult to penetrate the band-shaped substrate into the inside of 2A to 105C, the band-shaped substrate 108 is
An O-ring, a gasket, a helicflex, a magnetic fluid, or the like designed to hold a vacuum with a band-shaped substrate interposed therebetween was used as a seal structure so that a vacuum-sealed state could be maintained while penetrating the 105C. It is desirable to have a mechanical sealing structure.

The means for preventing inflow of air into the atmosphere are provided by the i-type layer deposition chambers 103A, 103B, 103B by microwave CVD.
03C may be provided. Since the high-speed film formation is performed in the i-type layer film formation chamber by the microwave plasma CVD method, a larger amount of semiconductor film adheres to the inside than in the other film formation chambers.
If semiconductor film formation is continued with a large amount of film adhered, the microwave transmittance of the microwave introduction window decreases and the input power decreases, and defects occur when the peeled film pieces adhere to the semiconductor film. Or film forming chambers 103A, 103B, 10B
It is necessary to periodically clean the inside of 3C. At that time, in order to prevent the air from flowing into the other film formation chambers to influence the other film formation chambers, it is effective to provide the above air flow prevention means. It is desirable to provide an air inflow prevention means between them.

Through the above series of steps, a semiconductor laminated film can be continuously formed on a belt-like substrate by the apparatus of the present invention.

[0282]

EXAMPLES Hereinafter, the present invention will be described with reference to specific examples using an apparatus for continuously forming a semiconductor laminated film, but the present invention is not limited to these examples.

Example 1 Using the apparatus for continuously forming a semiconductor laminated film of the present invention shown in Example 1, an i-type semiconductor layer was formed on a substrate by using amorphous silicon germanium, amorphous silicon germanium, and amorphous silicon, respectively. The three nip-structured photovoltaic elements composed of are sequentially stacked, and a stacked film of a silicon-based non-single-crystal semiconductor having a nipnipnip structure is formed continuously.

[0284] In the film forming chambers 103A and 103B, the i-type semiconductor layer is formed in three chambers having different concentrations of the source gas containing germanium atoms in the source gas.
The germanium content of the i-type semiconductor layer continuously formed in the film forming chambers 103A and 103B was made to vary slightly in the film thickness direction.

First, a stainless steel plate made of SUS430BA (width 12 cm × length 200 m × thickness 0.15 m)
m) 500 nm Ag by sputtering
A layer-shaped substrate having a fine uneven surface, on which a layer and a ZnO transparent conductive layer of about 2 μm are formed and laminated, is wound around a bobbin 109 and set in an unwinding chamber 101 of the strip-shaped substrate. Film forming chamber 1 through 107
02A to 105C, and the winding chamber 1 for the band-shaped substrate.
06, and tension was applied so as not to loosen.

In the winding chamber 106 for the belt-like substrate, a sufficiently dried protective film made of aramid paper (Nomex (trade name) manufactured by DuPont, width 12 cm × length 200 m ×
Set the wound bobbin of thickness 0.5mm),
The protective film was wound along with the belt-like substrate.

After setting the band-shaped substrate, each of the chambers 101 to 101
06 is evacuated once with a pump combining a rotary pump and a mechanical booster pump (not shown), and He gas is introduced while continuously evacuating to heat each film forming chamber to about 350 ° C. in a He atmosphere of about 200 Pa. I baked.

After heating and baking, each of the chambers 101-106
Is evacuated once, and then the film forming chambers 101 and 102A,
104A, 105A, 102B, 104B, 105B,
102C, 104C, 105C and 106 are pumps combining a rotary pump and a mechanical booster pump connected to the respective film forming chambers.
Each of the gas gates 107 is supplied with 500 sccm of H ₂ as a gate gas while exhausting 03B and 103C with two oil diffusion pumps (HS-16 manufactured by Varian) connected to the respective film forming chambers. A predetermined flow rate of each raw material gas was introduced into 105C. And each room 101
The internal pressures of the unwinding chamber 101 and the winding chamber 106 of the belt-like substrate are adjusted to 125 Pa by adjusting the opening of the throttle valve provided in the exhaust pipes of the first to sixth exhaust pipes.
103A, 104A, 105A, 102B, 103B,
104B, 105B, 102C, 103C, 104C,
The internal pressure of 105C is 130 Pa, about 1 Pa, 13
5Pa, 130Pa, 130Pa, about 1Pa, 135P
a, 130Pa, 130Pa, 1Pa, 135Pa, 1
It was set to 30 Pa.

When the pressure in each chamber is stabilized, the take-up bobbin 110 in the take-up chamber 106 for the band-like substrate is rotated to continuously move the band-like substrate 108 in the direction from the film formation chamber 102A to 105C at a constant speed of 100 cm / min. Was moved. The temperature was controlled by a temperature controller (not shown) provided in each of the film forming chambers 102A to 105C so that the moving belt-like substrate had a predetermined temperature in the film forming space of each film forming chamber.

When the temperature of the belt-shaped substrate is stabilized, the film forming chambers 102A, 104A, 102B, 104B, 102
13.56 MHz high frequency power from the parallel plate electrodes C and 104C is supplied to the film forming chambers provided inside the film forming chambers 103A, 103B and 103C by microwave introduction windows provided on one side wall of each film forming chamber. And a microwave power of 2.45 GHz, and a low frequency power of 75 kHz from a parallel plate electrode were applied to the film forming chambers 105A and 105B from a power supply (not shown) via a matching device.

Further, the film forming chambers 103A, 103B, 103
13.56 MH from a rod-shaped bias electrode disposed parallel to the belt-like substrate in front of the microwave introduction window into the film forming chamber inside C.
The high frequency power of z was supplied from a power supply (not shown) via a matching device.

In the film forming chambers 103A and 103B, three film forming chambers are used for forming an i-type semiconductor layer, and in the film forming chamber 103C, one film forming chamber is used for forming an i-type semiconductor layer. A film forming chamber was used. Also, 103A, 10
Although the length of each of the film forming chambers inside 3B and 103C in the moving direction of the strip-shaped substrate was about 20 cm, a shielding plate of a fixed length (also used as a plasma leak guard) was provided between the strip-shaped substrate surface and the plasma. The length of the formation region of the semiconductor layer with respect to the moving direction of the belt-like substrate was adjusted by the provision.

When the discharge power is applied, each of the film forming chambers 102A-
The source gas in 105C was turned into plasma, and a semiconductor film was formed on the surface of the continuously moving strip-shaped substrate in each film forming chamber, and a semiconductor laminated film having a nipnipnip structure was continuously formed on the surface of the strip-shaped substrate.

[0294] Table 1 shows the film forming conditions in the film forming chambers 102A to 105A for forming the first photovoltaic element, and Table 2 shows the film forming chamber 102 for forming the second photovoltaic element.
The film forming conditions in B to 105B are shown in Table 3 in the film forming chambers 102C to 105C for forming the third photovoltaic element.
Are shown below.

[0295] After the transfer of the belt-like substrate is started, 1
The substrate was moved for 80 minutes, during which a semiconductor laminated film was formed continuously for 170 minutes.

After forming the semiconductor laminated film for about 170 m, the supply of discharge power, the introduction of the source gas, and the heating of the strip-shaped substrate and the film forming chamber are stopped, and the purging of the film forming chamber is performed. After sufficiently cooling the substrate and the inside of the apparatus, the apparatus was opened, and the band-shaped substrate wound around the bobbin 110 was taken out of the apparatus from the band-shaped substrate winding chamber 106.

Further, the strip-shaped substrate taken out was continuously processed by a continuous modularization apparatus, and a 70 nm transparent electrode was formed as a transparent electrode on the semiconductor laminated film formed by the apparatus of the present invention.
An ITO (In ₂ O ₃ + SnO ₂ ) thin film is formed, a thin Ag electrode is formed at a constant interval as a current collecting electrode, and the band gap is changed by performing modularization such as serialization of unit elements. A 35 cm × 35 cm solar cell module constituted by a three-layer tandem solar cell in which photovoltaic elements were stacked was continuously produced.

FIG. 9 is a schematic diagram showing the layer structure of the manufactured solar cell.
Shown in

With respect to the manufactured solar cell module,
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was determined by forming the i-type semiconductor layer only by the microwave plasma CVD method and using the n-type semiconductor layer. A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured by using a conventional roll-to-roll type apparatus in which a semiconductor layer and a p-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .2
0 was a good value. In addition, the variation in photoelectric conversion efficiency between modules, which was ± 5% when manufactured using a conventional apparatus, was reduced to within ± 2%.

Comparative Example 1-1 Apparatus of the present invention shown in Apparatus Example 1
Film forming chambers 104A, 104B for i-type semiconductor layer by D method,
Except for 104C, p-type semiconductor layer deposition chambers 105A, 105A,
5B and 105C were each changed to a film forming chamber by a high-frequency plasma CVD method using a conventionally known apparatus,
Nipn in the same manner as in Example 1 except that the formation of the i-type semiconductor layer by the high-frequency plasma CVD method was stopped and the p-type semiconductor layer was formed by the high-frequency plasma CVD method.
A solar cell module was manufactured by continuously forming a laminated film of a silicon-based non-single-crystal semiconductor having an ipnip structure. 4th
Film forming chamber 102A for forming the first photovoltaic element in the table
Table 5 shows the film forming conditions in the film forming chambers 102B to 105B for forming the second photovoltaic element in Table 5, and Table 6 shows the film forming conditions in the third table. The film forming conditions in the film forming chambers 102C to 105C are shown.

Regarding the manufactured solar cell module,
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was the average value of the photoelectric conversion efficiency of the solar cell module manufactured in Example 1. The relative value as 1.20 was as low as 1.00. In addition, the variation in photoelectric conversion efficiency between the modules was as large as ± 5%.

Comparative Example 1-2 Each of the p-type semiconductor layer deposition chambers 105A and 105B of the apparatus of the present invention shown in the apparatus example 1 was subjected to a high-frequency plasma CV.
A laminated film of a silicon-based non-single-crystal semiconductor having a nipnipnip structure in the same manner as in Example 1 except that a p-type semiconductor layer is formed by a high-frequency plasma CVD method using an apparatus changed to a film forming chamber by the method D. Is formed continuously,
A solar cell module was manufactured.

Table 7 shows the film forming conditions in the film forming chambers 102A to 105A for forming the first photovoltaic element, and Table 8 shows the film forming chamber 102 for forming the second photovoltaic element.
Table 9 shows the film forming conditions for forming the third photovoltaic element in Tables B to 105B.
Are shown below.

Regarding the manufactured solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was the average value of the photoelectric conversion efficiency of the solar cell module manufactured in Example 1. The relative value as 1.20 was as low as 1.05. In addition, the variation in photoelectric conversion efficiency between the modules was as large as ± 5%.

Example 2 Example 1 was repeated except that the i-type semiconductor layer formed in the film forming chamber 103B was changed to amorphous silicon using the apparatus for continuously forming a semiconductor laminated film of the present invention shown in Example 1 of the present invention. In the same manner as described above, three nip-structure photovoltaic elements in which the i-type semiconductor layer is made of amorphous silicon germanium, amorphous silicon, and amorphous silicon are sequentially stacked on the substrate, respectively.
A laminated film of a silicon-based non-single-crystal semiconductor having a nipnip structure was continuously formed. And further modularization,
35cm × composed of three-layer tandem solar cell
A 35 cm solar cell module was produced continuously.

The film forming conditions in the film forming chambers 102A to 105A for forming the first photovoltaic element and the third
Film forming chambers 102C to 102C for forming the th photovoltaic element
The film forming conditions at 5C are the same as those in Example 1 in Tables 1 and 3
As shown in the table, only the film forming conditions in the film forming chambers 102B to 105B for forming the second photovoltaic element are in the 10th.
Changed as shown in the table.

FIG. 9 is a schematic view showing the layer structure of the manufactured solar cell.
Shown in

Regarding the manufactured solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was determined by forming the i-type semiconductor layer only by the microwave plasma CVD method and using the n-type semiconductor layer. A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured by using a conventional roll-to-roll type apparatus in which a semiconductor layer and a p-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .1
A good value of 5 was shown. In addition, the variation in photoelectric conversion efficiency between modules, which was ± 5% when manufactured using a conventional apparatus, was reduced to within ± 2%.

Comparative Example 2-1 Apparatus of the present invention shown in Apparatus Example 1
Film forming chambers 104A, 104B for i-type semiconductor layer by D method,
Except for 104C, p-type semiconductor layer deposition chambers 105A, 105A,
Using an apparatus having a conventionally known structure in which 5B and 105C are changed to a film forming chamber using a high-frequency plasma CVD method, the formation of the i-type semiconductor layer by the high-frequency plasma CVD method is stopped, and the p-type semiconductor layer is formed by the high-frequency plasma CVD method. Nipnipni in the same manner as in the second embodiment, except that
A stacked film of a p-type silicon-based non-single-crystal semiconductor was continuously formed to produce a solar cell module.

The film forming conditions in the film forming chambers 102A to 105A for forming the first photovoltaic element and the film forming conditions in the film forming chambers 102C to 105C for forming the third photovoltaic element are comparative examples. As shown in Tables 4 and 6, similarly to 1-1, only the film forming conditions in the film forming chambers 102B to 105B for forming the second photovoltaic element were changed as shown in Table 11.

[0311] Regarding the manufactured solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was the average value of the photoelectric conversion efficiency of the solar cell module manufactured in Example 2. The relative value was 1.15, which was as low as 1.00. In addition, the variation in photoelectric conversion efficiency between the modules was as large as ± 5%.

Comparative Example 2-2 P-type semiconductor layer deposition chambers 105A, 105B and 105C of the apparatus for continuously forming a semiconductor laminated film of the present invention shown in Example 1 of the present invention.
Nip was formed in the same manner as in Example 2 except that the p-type semiconductor layer was formed by a high-frequency plasma CVD method using an apparatus in which a film forming chamber was changed to a high-frequency plasma CVD method.
A laminated film of a silicon-based non-single-crystal semiconductor having a nipnip structure was continuously formed to produce a solar cell module.

The film forming conditions in the film forming chambers 102A to 105A for forming the first photovoltaic element and the film forming conditions in the film forming chambers 102C to 105C for forming the third photovoltaic element are compared. Tables 7 and 9 as in Example 1-2
As shown in the table, only the film forming conditions in the film forming chambers 102B to 105B for forming the second photovoltaic element are the first.
Changes were made as shown in Table 2.

With respect to the manufactured solar cell module,
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was the average value of the photoelectric conversion efficiency of the solar cell module manufactured in Example 2. The relative value was 1.15, which was as low as 1.03. In addition, the variation in photoelectric conversion efficiency between the modules was as large as ± 5%.

Example 3 The i-type semiconductor layer formed in the film forming chamber 103C was changed to amorphous silicon carbide by using the apparatus for continuously forming a semiconductor laminated film of the present invention shown in the apparatus example 1, and two layers were formed. Except that the film was formed in the film chamber, i
Three nip-structure photovoltaic elements, each of which is composed of amorphous silicon germanium, amorphous silicon germanium, and amorphous silicon carbide, are sequentially stacked, and
A stacked film of a silicon-based non-single-crystal semiconductor having a pnipnip structure was continuously formed. And further modularization, 35c composed of three-layer tandem solar cells
A solar cell module of mx 35 cm was continuously produced.

Note that the film forming conditions in the film forming chambers 102A to 105A for forming the first photovoltaic element and the second
Film forming chambers 102B to 102 for forming the th photovoltaic element
The film forming conditions in 5B are as shown in Tables 1 and 2 as in Example 1. Only the film forming conditions in the film forming chambers 102C to 105C for forming the third photovoltaic element are shown in Table 13. Was changed as shown.

FIG. 9 is a schematic diagram showing the layer structure of the manufactured solar cell.
Shown in

About the manufactured solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was determined by forming the i-type semiconductor layer only by the microwave plasma CVD method and using the n-type semiconductor layer. A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured by using a conventional roll-to-roll type apparatus in which a semiconductor layer and a p-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .2
0 was a good value. In addition, the variation in photoelectric conversion efficiency between modules, which was ± 5% when manufactured using a conventional apparatus, was reduced to within ± 2%.

Example 4 The i-type semiconductor layer formed in the film forming chamber 103C was changed to amorphous silicon carbide by using the apparatus for continuously forming a semiconductor laminated film of the present invention shown in the apparatus example 1, and two layers were formed. The same procedure as in Example 2 was carried out except that the film was formed in the film chamber.
Three ni layers each of which is composed of amorphous silicon germanium, amorphous silicon, and amorphous silicon carbide.
The p-type photovoltaic elements are sequentially stacked, and nipnipni
A stacked film of a p-type silicon-based non-single-crystal semiconductor was continuously formed. Then, further modularization was performed, and a 35 cm × 35 cm solar cell module constituted by a three-layer tandem type solar cell was continuously produced.

The film forming conditions in the film forming chambers 102A to 105A for forming the first photovoltaic element and the second
Film forming chambers 102B to 102 for forming the th photovoltaic element
The film forming conditions in 5B are as shown in Tables 1 and 10 as in Example 2, and only the film forming conditions in the film forming chambers 102C to 105C for forming the third photovoltaic element are shown in Table 13. Was changed as shown.

FIG. 9 is a schematic view showing the layer structure of the manufactured solar cell.
Shown in

About the manufactured solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was determined by forming the i-type semiconductor layer only by the microwave plasma CVD method and using the n-type semiconductor layer. A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured by using a conventional roll-to-roll type apparatus in which a semiconductor layer and a p-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .2
0 was a good value. In addition, the variation in photoelectric conversion efficiency between modules, which was ± 5% when manufactured using a conventional apparatus, was reduced to within ± 2%.

Example 5 The discharge frequency of the p-type semiconductor layer deposition chambers 105A, 105B, and 105C by plasma doping was increased to 75 k using the apparatus for continuously forming a semiconductor laminated film of the present invention described in Example 1 of the apparatus.
A laminated film of a silicon-based non-single-crystal semiconductor having a nipnipnip structure was continuously formed in the same manner as in Example 1 except that the frequency was changed from 400 Hz to 400 kHz. Then, the module is further modularized, and is constituted by a three-layer tandem solar cell in which photovoltaic elements having different band gaps are stacked.
A cm × 35 cm solar cell module was produced continuously.

FIG. 9 is a schematic view showing the layer structure of the manufactured solar cell.
Shown in

About the manufactured solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was determined by forming the i-type semiconductor layer only by the microwave plasma CVD method and using the n-type semiconductor layer. A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured by using a conventional roll-to-roll type apparatus in which a semiconductor layer and a p-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .2
0 was a good value. In addition, the variation in photoelectric conversion efficiency between modules, which was ± 5% when manufactured using a conventional apparatus, was reduced to within ± 2%.

Example 6 Using the apparatus for continuously forming a semiconductor multilayer film of the present invention shown in the apparatus example 1, SiH ₄ was contained in the source gas introduced into the film forming chambers 105A, 105B and 105C for p-type semiconductor layers by plasma doping. A laminated film of a silicon-based non-single-crystal semiconductor having a nipnipnip structure is continuously formed in the same manner as in Example 1 except that 3 sccm, which is a gas small enough to form a semiconductor layer of about 10 nm by deposition, is added. did. Then, further modularization was performed, and a 35 cm × 35 cm solar cell module constituted by a three-layer tandem type solar cell in which photovoltaic elements having different band gaps were stacked was continuously produced.

FIG. 9 is a schematic view showing the layer structure of the manufactured solar cell.
Shown in

About the produced solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was determined by forming the i-type semiconductor layer only by the microwave plasma CVD method and using the n-type semiconductor layer. A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured by using a conventional roll-to-roll type apparatus in which a semiconductor layer and a p-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .1
A good value of 8 was obtained. In addition, the variation in photoelectric conversion efficiency between modules, which was ± 5% when manufactured using a conventional apparatus, was reduced to within ± 2%.

Comparative Example 6 In the source gas introduced into the film formation chamber for the p-type semiconductor layer of the apparatus of the present invention shown in the apparatus example 1, SiH ₄ gas was sufficient to form a semiconductor layer of about 10 nm by deposition. Quantity of 30sc
cm and the p-type semiconductor layer is formed by low-frequency plasma CVD.
A solar cell module was manufactured by continuously forming a laminated film of a silicon-based non-single-crystal semiconductor having a nipnipnip structure in the same manner as in Example 6, except that the solar cell module was formed by the method.

About the manufactured solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was determined by forming the i-type semiconductor layer only by the microwave plasma CVD method and using the n-type semiconductor layer. When the average value of the photoelectric conversion efficiency of a solar cell module manufactured using a conventional roll-to-roll type apparatus in which a semiconductor layer and a p-type semiconductor layer are formed by a high-frequency plasma CVD method is 0, a relative comparison is 0. .
It was as low as 85. The variation in photoelectric conversion efficiency between modules was as large as ± 6%.

Example 7 The p-type semiconductor layer was formed in the film forming chambers 102A, 102B, and 102C, and the n-type semiconductor layer was formed in the film forming chambers 105A, 105B, and 105C by using the apparatus for continuously forming a semiconductor laminated film of the present invention shown in the apparatus example 1. Nip was formed in the same manner as in Example 1 except that the conductivity type of the semiconductor layer to be formed was changed in the opposite manner so that the semiconductor layer was formed.
A laminated film of a silicon-based non-single-crystal semiconductor having a nipnip structure was continuously formed. And further modularization,
35 cm × 35 c composed of a three-layer tandem solar cell in which photovoltaic elements with different band gaps are stacked
m solar cell modules were continuously produced.

[0332] Table 14 shows film forming conditions in the film forming chambers 102A to 105A for forming the first photovoltaic element.
Table 15 shows the film formation chamber 1 for forming the second photovoltaic element.
Table 16 shows the film forming conditions in the film forming chambers 102C to 102C for forming the third photovoltaic element in Table 16B.
The film forming conditions at 05C are shown.

FIG. 1 is a schematic view showing the layer structure of the manufactured solar cell.
0 is shown.

About the produced solar cell module, A
The characteristics were evaluated under simulated sunlight irradiation of M1.5 (100 mW / cm ² ). The average value of the photoelectric conversion efficiencies was as follows: the i-type semiconductor layer was formed only by the microwave plasma CVD method, and the p-type A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured using a conventional roll-to-roll type apparatus in which a semiconductor layer and an n-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .2
0 was a good value. In addition, the variation in the photoelectric conversion efficiency between modules, which was ± 5% when manufactured using the conventional apparatus, was reduced to within ± 2%.

Example 8 The apparatus for continuously forming a semiconductor laminated film of the present invention shown in Example 1 was used, and an Ag layer and a Z layer were formed on SUS430BA as a band-shaped substrate.
Example 1 except that the surface was changed from SUS430BA whose surface was sufficiently cleaned and degreased from the sputtered nO layer.
Similarly to the above, a laminated film of a silicon-based non-single-crystal semiconductor having a nipnipnip structure was continuously formed. Then, further modularization was performed, and a 35 cm × 35 cm solar cell module constituted by a three-layer tandem type solar cell in which photovoltaic elements having different band gaps were stacked was continuously produced.

FIG. 9 is a schematic diagram showing the layer structure of the manufactured solar cell.
Shown in

About the produced solar cell module, A
When the characteristics were evaluated under simulated sunlight irradiation of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiencies was as follows: SUS430BA was used as the band-shaped substrate, and the i-type semiconductor layer was subjected to microwave plasma CVD. And the average value of the photoelectric conversion efficiency of a solar cell module manufactured using a conventional roll-to-roll type apparatus in which an n-type semiconductor layer and a p-type semiconductor layer are formed by high-frequency plasma CVD. A good value of 1.20 was obtained with a relative value of 00. In addition, when fabricated using a conventional apparatus, ±
The variation in photoelectric conversion efficiency between modules, which was 5%, is ±
It decreased within 2%.

Example 9 Using the apparatus for continuously forming a semiconductor laminated film of the present invention shown in Example 2 of the present invention, the surface of a strip-shaped substrate was subjected to glow discharge cleaning, and high-frequency plasma was formed before forming an i-type semiconductor layer by microwave plasma CVD. An i-type semiconductor layer is formed by the CVD method,
In the same manner as in Example 1 except that the surface of the i-type semiconductor layer was subjected to hydrogen plasma treatment before the formation of the type semiconductor layer, an i-type semiconductor layer was formed on the substrate by amorphous silicon germanium and amorphous silicon, respectively. Three photovoltaic elements having a nip structure composed of silicon germanium and amorphous silicon were sequentially laminated, and a laminated film of a silicon-based non-single-crystal semiconductor having a nipnipnip structure was continuously formed. Then, further modularization is performed, and 35c constituted by a three-layer tandem solar cell in which photovoltaic elements having different band gaps are stacked.
A solar cell module of mx 35 cm was continuously produced.

The glow discharge cleaning was performed using He high frequency plasma, and the hydrogen plasma processing was performed using low frequency plasma.

Table 17 shows the film forming conditions and surface treatment conditions in the film forming chambers 211 to 205A for forming the first photovoltaic element, and Table 18 shows the conditions for forming the second photovoltaic element. Table 19 shows the film formation conditions and surface treatment conditions in the film chambers 202B to 205B, and Table 19 shows the film formation conditions and surface treatment conditions in the film formation chambers 202C to 205C for forming the third photovoltaic element.

FIG. 1 is a schematic view showing the layer structure of the manufactured solar cell.
It is shown in FIG.

About the manufactured solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was determined by forming the i-type semiconductor layer only by the microwave plasma CVD method and using the n-type semiconductor layer. A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured by using a conventional roll-to-roll type apparatus in which a semiconductor layer and a p-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .2
A good value of 2 was shown. In addition, the variation in photoelectric conversion efficiency between modules, which was ± 5% when manufactured using a conventional apparatus, was reduced to within ± 1.5%.

Example 10 The surface of a belt-shaped substrate was subjected to glow discharge cleaning using the apparatus for continuously forming a semiconductor laminated film of the present invention shown in Example 2 of the present invention, and high-frequency plasma was formed before forming an i-type semiconductor layer by microwave plasma CVD. An i-type semiconductor layer is formed by the CVD method,
In the same manner as in Example 4 except that the surface of the i-type semiconductor layer was subjected to hydrogen plasma treatment before the formation of the type semiconductor layer, an i-type semiconductor layer was formed on the substrate by amorphous silicon germanium and amorphous silicon, respectively. Three photovoltaic elements having a nip structure composed of silicon and amorphous silicon carbide are sequentially stacked, and n
A stacked film of a silicon-based non-single-crystal semiconductor having an ipnipnip structure was continuously formed. Then, further modularization is performed, and 35 cm × 35 constituted by a three-layer tandem solar cell in which photovoltaic elements having different band gaps are stacked.
cm of solar cell modules were continuously produced.

The glow discharge cleaning was performed with He high-frequency plasma, and the hydrogen plasma treatment was performed with low-frequency plasma.

Table 17 shows the film forming conditions and surface treatment conditions in the film forming chambers 211 to 205A for forming the first photovoltaic element, and Table 20 shows the conditions for forming the second photovoltaic element. Table 21 shows the film formation conditions and surface treatment conditions in the film chambers 202B to 205B, and Table 21 shows the film formation conditions and surface treatment conditions in the film formation chambers 202C to 205C for forming the third photovoltaic element.

FIG. 1 is a schematic view showing the layer structure of the manufactured solar cell.
It is shown in FIG.

About the produced solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was determined by forming the i-type semiconductor layer only by the microwave plasma CVD method and using the n-type semiconductor layer. A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured by using a conventional roll-to-roll type apparatus in which a semiconductor layer and a p-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .2
A good value of 2 was shown. In addition, the variation in photoelectric conversion efficiency between modules, which was ± 5% when manufactured using a conventional apparatus, was reduced to within ± 1.5%.

Example 11 The surface of a strip-shaped substrate was subjected to glow discharge cleaning using the apparatus for continuously forming a semiconductor laminated film of the present invention shown in Example 2 of the present invention, and high-frequency plasma was formed before forming an i-type semiconductor layer by microwave plasma CVD. An i-type semiconductor layer is formed by a CVD method,
In the same manner as in Example 7 except that the surface of the i-type semiconductor layer was subjected to the hydrogen plasma treatment before the formation of the type semiconductor layer, a laminated film of a silicon-based non-single-crystal semiconductor having a pinpinpin structure was continuously formed. . Then, further modularization was performed, and a solar cell module constituted by a three-layer tandem type solar cell in which photovoltaic elements having different band gaps were stacked was continuously manufactured.

The glow discharge cleaning was performed using He high-frequency plasma, and the hydrogen plasma processing was performed using low-frequency plasma.

Table 22 shows the film forming conditions and surface treatment conditions in the film forming chambers 211 to 205A for forming the first photovoltaic element, and Table 23 shows the conditions for forming the second photovoltaic element. Table 24 shows the film forming conditions and surface treatment conditions in the film chambers 202B to 205B in which the third photovoltaic element is formed.

FIG. 1 is a schematic view showing the layer structure of the manufactured solar cell.
It is shown in FIG.

About the produced solar cell module, A
The characteristics were evaluated under simulated sunlight irradiation of M1.5 (100 mW / cm ² ). The average value of the photoelectric conversion efficiencies was as follows: the i-type semiconductor layer was formed only by the microwave plasma CVD method, and the p-type A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured using a conventional roll-to-roll type apparatus in which a semiconductor layer and an n-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .2
A good value of 2 was shown. In addition, the variation in photoelectric conversion efficiency between modules, which was ± 5% when manufactured using a conventional apparatus, was reduced to within ± 1.5%.

Example 12 A nipnip structure was formed in substantially the same manner as in Example 9 except that the apparatus for continuously forming a semiconductor laminated film of the present invention having the structure shown in Example 2 was used and a wide band-like substrate having a width of 36 cm was used. Continuously forming a laminated film of a silicon-based non-single-crystal semiconductor of
35cm × 35c composed of three-layer tandem solar cells in which solar cells with different band gaps are stacked
m solar cell modules were continuously produced.

In the apparatus used in the present invention, only the dimension in the width direction of the strip-shaped substrate was three times that of the apparatus used in Examples 1 to 11. Deposition chamber 20 by microwave plasma CVD
3, 3, 1 in 3A, 203B, 203C respectively
In each of the film forming chambers, microwave input means are disposed on both sides of the strip-shaped substrate so as to face each other.
In the film forming chamber 203B, and four in the film forming chamber 203B.
Microwave power was applied to C from a total of two microwave input means.

The directions of the electric fields of the microwave injection means arranged opposite to each other were perpendicular to each other.

Table 25 shows the film forming conditions and surface treatment conditions in the film forming chambers 211 to 205A for forming the first photovoltaic element, and Table 26 shows the conditions for forming the second photovoltaic element. Table 27 shows the film formation conditions and surface treatment conditions in the film chambers 202B to 205B, and Table 27 shows the film formation conditions and surface treatment conditions in the film formation chambers 202C to 205C for forming the third photovoltaic element.

FIG. 1 is a schematic view showing the layer structure of the manufactured solar cell.
It is shown in FIG.

About the manufactured solar cell module, A
When the characteristics were evaluated under irradiation of simulated sunlight of M1.5 (100 mW / cm ² ), the average value of the photoelectric conversion efficiency was determined by forming the i-type semiconductor layer only by the microwave plasma CVD method and using the n-type semiconductor layer. A relative value of 1 when the average value of the photoelectric conversion efficiency of a solar cell module manufactured by using a conventional roll-to-roll type apparatus in which a semiconductor layer and a p-type semiconductor layer are formed by a high-frequency plasma CVD method is 1.00. .2
A good value of 3 was obtained. In addition, the variation in the photoelectric conversion efficiency between modules, which was ± 6% when manufactured using the conventional apparatus, has been reduced to within ± 2.0%, and the quality for photovoltaic elements of high quality over a large area has been reduced. It was confirmed that the semiconductor laminated film was formed with good uniformity.

[0359]

[Table 1]

[0360]

[Table 2]

[0361]

[Table 3]

[0362]

[Table 4]

[0363]

[Table 5]

[0364]

[Table 6]

[0365]

[Table 7]

[0366]

[Table 8]

[0367]

[Table 9]

[0368]

[Table 10]

[0369]

[Table 11]

[0370]

[Table 12]

[0371]

[Table 13]

[0372]

[Table 14]

[0373]

[Table 15]

[0374]

[Table 16]

[0375]

[Table 17]

[0376]

[Table 18]

[0377]

[Table 19]

[0378]

[Table 20]

[0379]

[Table 21]

[0380]

[Table 22]

[0381]

[Table 23]

[0382]

[Table 24]

[0383]

[Table 25]

[0384]

[Table 26]

[0385]

[Table 27]

[0386]

According to the present invention, an i-type semiconductor layer formed by a high-frequency plasma CVD method is laminated on an i-type semiconductor layer formed by a microwave plasma CVD method in a roll-to-roll method, and then plasma doping is performed. By forming the impurity-doped layer, a high-quality semiconductor laminated film for a photovoltaic element can be formed over a large area at high speed and continuously without variation or unevenness in characteristics.

Furthermore, according to the present invention, it is possible to form a three-layer tandem type semiconductor laminated film for a photovoltaic element of high photovoltaic efficiency at a high speed and continuously over a large area with little light degradation. it can.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of an apparatus for continuously forming a semiconductor laminated film according to the present invention.

FIG. 2 is a schematic cross-sectional view showing another example of the apparatus for continuously forming a semiconductor laminated film of the present invention.

FIG. 3 is a diagram showing a relationship between a discharge frequency f in plasma doping and an open voltage Voc of a formed photovoltaic element.

FIG. 4 shows a microwave plasma CV in the apparatus of the present invention.
FIG. 3 is a schematic cross-sectional view illustrating an example of a film forming chamber by a method D.

FIG. 5 is a schematic diagram showing an example of a film forming chamber unit.

FIG. 6 is a schematic cross-sectional view showing an example of a film forming chamber by a high-frequency plasma CVD method in the apparatus of the present invention.

FIG. 7A is a schematic cross-sectional view showing an example of a band-shaped substrate unwinding chamber in the apparatus of the present invention, and FIG. 7B is a schematic cross-sectional view showing an example of a band-shaped substrate winding chamber.

FIG. 8 is a schematic diagram illustrating an example of a steering mechanism.

FIG. 9 is a schematic sectional view showing an example of the photovoltaic device of the present invention.

FIG. 10 is a schematic sectional view showing an example of another photovoltaic element of the present invention.

FIG. 11 is a schematic sectional view showing an example of still another photovoltaic element of the present invention.

FIG. 12 is a schematic sectional view showing an example of another photovoltaic element of the present invention.

[Explanation of symbols]

101, 201, 702A Unwinding chamber 102A, 102B, 102C, 202A, 202B,
202C A film forming chamber 103A, 103B, 103C, 203A, 203B for an n (or p) type semiconductor layer by a high frequency plasma CVD method.
203C i-type semiconductor layer deposition chamber by microwave plasma CVD method 104A, 104B, 104C, 204A, 204B,
204C i-type semiconductor layer deposition chamber by high frequency plasma CVD method 105A, 105B, 105C, 205A, 205B,
205C Plasma deposition doping chamber for p (or n) type semiconductor layer 106, 206, 702B Strip substrate winding chamber 107, 207, 403, 4044, 603, 604,
705A, 705B gas gates 108, 208, 401, 501, 601, 701A,
701B, 801 Strip substrate 109, 209, 703A Strip substrate unwinding bobbin 110, 210, 703B Strip substrate unwinding bobbin 706A Protective film winding bobbin 706B Protective film unwind bobbin 211 Glow discharge cleaning chamber 212A, 212B, 212C, High frequency plasma CV
I-type layer film formation chamber 213A, 213B, 212C by D method Hydrogen plasma treatment chamber 402, 602 vacuum vessel 405, 505 discharge chamber unit 406, 407, 408, 506, 507, 508 film formation chamber 409, 410, 411, 511,607 Source gas introduction pipes 412,413,414,514 Pressure measurement pipes 415,416,417,515,516,517 Bias electrodes 418,419,420,518,519,520 Microwave introduction windows 421,422,423 , 424, 521, 522, 5
23, 524 Perforated partition plate 425, 426, 608, 708A, 708B Exhaust pipe 427 Rough exhaust pipe 428, 528 Powder receiving plate 429, 529, 611 Plasma leak guard 430 Deposition chamber temperature control device 431, 612 Cover 432 , 613, 614 Lamp heaters 433, 434, 435 Substrate temperature controllers 436, 437, 438, 439, 615, 616 Thermocouples 440, 617 Reflectors 441, 445, 618 Support rollers 442 Separation passages 443, 444 Gate gas inlet tube 550 Rectangular Waveguide 551 Mode converter 552, 553 Alumina ceramic disk 605 Discharge chamber 606 Discharge electrode 609 Block heater 610 Discharge chamber external exhaust port 704A, 704B, 804 Roller 707A, 707B Protective film 80 2 Lateral displacement detecting mechanism 803 Rotating mechanism 805 Moving direction of belt-like substrate 806 Bearings 901, 1001, 1101, 1201 Substrates 902A, 902B, 902C, 1102A, 1102
B, 1102C n-type semiconductor layers 903A, 903B, 1003A, 1003B, 100 by high frequency plasma CVD
3C, 1103A, 1103B, 1103C, 1203
A, 1203B i by microwave plasma CVD
Type semiconductor layers 904A, 904B, 904C, 1004A, 1004
B, 1004C, 1104A, 1104B, 1104
C, 1108A, 1108B, 1108C, 1204
A, 1204B, 1204C, 1208A, 1208
B, 1208C, i-type semiconductor layer 905A, 905B, 905C, 1105A, 1105 by high frequency plasma CVD
B, 1105C P-type semiconductor layers 906, 1006, 1106, 1206 by plasma doping Transparent conductive films 907, 1007, 1107, 1207 Current collecting electrodes 1009A, 1009B, 1009C, 1209A, 1
209B, 1209C p by high frequency plasma CVD
Type semiconductor layers 1010A, 1010B, 1010C, 1210A, 1
210B, 1210C n-type semiconductor layer by plasma doping

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shotaro Okabe 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Naoshi Yoshiri 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Non Co., Ltd. (72) Inventor Atsushi Hono 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hideo Tamura 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masahiro Kanai 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-3-124676 (JP, A) JP-A-1-290267 (JP, A) JP-A-59-52833 (JP, A) JP-A-4-32268 (JP, A) JP-A-3-273614 (JP, A) JP-A-60-140816 (JP, A)

Claims (7)

(57) [Claims] A first semiconductor having a first conductivity type; a first i-type semiconductor formed by microwave plasma;
A second i-type semiconductor formed by high-frequency plasma, a second semiconductor having a conductivity type opposite to the first semiconductor , a third semiconductor having a first conductivity type, and a third i-type semiconductor formed by microwave plasma A fourth i-type semiconductor formed by high-frequency plasma, a fourth semiconductor having a conductivity type opposite to the first semiconductor , a fifth semiconductor having the first conductivity type, and a fifth i-th semiconductor formed by microwave plasma. -type semiconductor, and the 6i type semiconductor formed by high-frequency plasma, and the first semiconductor and a sixth semiconductor having a conductivity type opposite to that order, the second semiconductor and the fourth semiconductor and said sixth semiconductor Is formed by plasma doping. 2. A method for forming a photovoltaic element for forming a laminated film of a silicon-based non-single-crystal semiconductor on a substrate, comprising the steps of: forming an n (or p) type semiconductor layer by high-frequency plasma CVD; A step of forming an i-type semiconductor layer by a CVD method; a step of forming an i-type semiconductor layer by a high-frequency plasma CVD method; a step of forming a p (or n) -type semiconductor layer by plasma doping; a step of forming an n (or p) type semiconductor layer, a step of forming an i-type semiconductor layer by microwave plasma CVD, a step of forming an i-type semiconductor layer by high frequency plasma CVD, and p ( Or forming an n) type semiconductor layer, and forming an n (or p) type semiconductor layer by high frequency plasma CVD. Forming, forming an i-type semiconductor layer by microwave plasma CVD, forming an i-type semiconductor layer by high-frequency plasma CVD, and forming a p (or n) semiconductor by plasma doping. Are performed in this order to form a stacked film of a silicon-based non-single-crystal semiconductor. 3. A photovoltaic element forming apparatus for continuously forming a laminated film of a silicon-based non-single-crystal semiconductor on a strip-shaped substrate, wherein at least a winding chamber of the strip-shaped substrate and n (or p) by high-frequency plasma CVD are used. ) Type semiconductor layer deposition chamber, i-type semiconductor layer deposition chamber by microwave plasma CVD, i-type semiconductor layer deposition chamber by high frequency plasma CVD, p (or n) type semiconductor layer deposition by plasma doping A film chamber, an n (or p) type semiconductor layer deposition chamber by high frequency plasma CVD, an i type semiconductor layer deposition chamber by microwave plasma CVD, and an i type semiconductor layer deposition chamber by high frequency plasma CVD. A p (or n) type semiconductor layer deposition chamber by plasma doping; an n (or p) type semiconductor layer deposition chamber by high frequency plasma CVD; An i-type semiconductor layer deposition chamber by plasma CVD, an i-type semiconductor layer deposition chamber by high-frequency plasma CVD, a p (or n) type semiconductor layer deposition chamber by plasma doping, and a strip substrate winding chamber. Are arranged in this order along the direction in which the strip-shaped substrate is moved, and are connected to each other via a gas gate, so that the photovoltaic power is generated on the strip-shaped substrate that continuously moves through the film-forming chambers. An apparatus for forming a photovoltaic element, wherein a stacked film of a silicon-based non-single-crystal semiconductor for an element is continuously formed. 4. At least one between an n (or p) type semiconductor layer film forming chamber formed by the high frequency plasma CVD method and the i type semiconductor layer film forming chamber formed by the microwave CVD method disposed via the gas gate. 4. The photovoltaic element forming apparatus according to claim 3, wherein an i-type semiconductor layer film forming chamber formed by a high-frequency plasma CVD method is further disposed at a location via a gas gate. 5. At least one location between an i-type semiconductor layer deposition chamber by the high-frequency plasma CVD method and a p (or n) type semiconductor layer deposition chamber by the plasma doping disposed via the gas gate. 5. The hydrogen plasma processing chamber is disposed via a gas gate.
3. The photovoltaic element forming apparatus according to claim 1. 6. A glow discharge cleaning chamber is further provided between the unwinding chamber of the strip-shaped member disposed via the gas gate and the n (or p) type semiconductor layer deposition chamber by the high frequency plasma CVD method. The photovoltaic element forming device according to claim 3, wherein the photovoltaic device forming device is arranged via a member. 7. A discharge frequency of 5 kHz in a p (or n) type semiconductor layer deposition chamber by said plasma doping.
7. The photovoltaic element forming apparatus according to claim 3, wherein the frequency is from 500 kHz to 500 kHz.