JP2908629B2 - Deposition film forming method using microwave plasma CVD method and roll-to-roll method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously producing a large-area functional deposition film by generating a uniform microwave plasma over a large area and decomposing and exciting a raw material gas by a reaction caused by the microwave plasma. To a method for forming the same.

More specifically, the present invention relates to a method for forming a large-area photovoltaic device using an amorphous semiconductor, and more particularly to a method for forming a stacked photovoltaic device, which comprises at least hydrogen-containing amorphous silicon-germanium (hereinafter, referred to as "amorphous silicon germanium"). The ratio of the above elements in each of an a-SiGe film and an amorphous silicon carbide (hereinafter abbreviated as a-Sic) film containing at least hydrogen is ideally controlled to improve the photovoltaic element. On how to do it.

[0003]

2. Description of the Related Art In recent years, the demand for electric power has rapidly increased worldwide, and the problem of environmental pollution has become more serious as electric power production has been activated to meet such demand.

[0004] In nuclear power generation, which is expected to be an alternative to thermal power generation and has already entered the practical use period, serious radioactive contamination damages the human body as represented by the accident at the Chernobyl nuclear power plant. As a result, nuclear power generation has been threatened in the future, and even some countries have actually set laws prohibiting the construction of new nuclear power plants.

In addition, the use of fossil fuels, such as coal and petroleum, continues to increase in order to meet the increasing demand for power even with thermal power generation, and the amount of carbon dioxide emitted increases accordingly. It raises the concentration of greenhouse gases such as carbon dioxide in the atmosphere, causing global warming, and the annual average temperature of the earth is steadily rising.
(International Energy Age
ncy) will reduce CO2 emissions by 2 by 2005
It is recommended to reduce it by 0%.

[0006] Under such a background, population growth in developing countries and accompanying increase in power demand are inevitable, and the power consumption per capita in advanced countries will be further promoted by the further promotion of electronics in lifestyles. With the increase in power supply, the issue of power supply has to be considered on a global scale.

[0007] Under such circumstances, the power generation method using solar cells utilizing sunlight does not cause the above-mentioned problems such as radioactive contamination and global warming. Energy sources are less unevenly distributed, and relatively high power generation efficiency can be obtained without the need for complicated and large-scale facilities. Attention has been paid to a clean power generation system that can be used without any problems, 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 must have a sufficiently high photoelectric conversion efficiency and excellent characteristic stability. It is basically required to be able to be mass-produced.

[0009] The power required in a typical home is about 3 kW per household. On the other hand, the energy of the sun is 1 KW / m ² at the peak, and if the photoelectric conversion efficiency of the solar cell is, for example, about 10%, the area of the solar cell is 3 to cover necessary power.
It is about 0 m ² . For example, in order to supply necessary electric power to 100,000 households, 3,000,000 m ²
A solar cell having such an area is required.

For this reason, a gaseous raw material gas such as silane, which is easily available, is used and is decomposed by glow discharge to form amorphous silicon (hereinafter referred to as "a") on a relatively inexpensive substrate such as glass or a metal sheet. -Si ")
Solar cells that can be manufactured by depositing a semiconductor thin film such as are attracting attention because they are rich in mass productivity and can be produced at low cost compared to solar cells manufactured using single crystal silicon, etc. Various proposals have been made on the basic layer configuration, the manufacturing method, and the like.

First, when looking at the conventional basic layer structure of such a photovoltaic element, the bandgap of the a-Si film is about 1.7 ev, which is not sufficiently large, so that the output voltage is low, and In particular, there is a problem that a sufficient photoelectric conversion efficiency cannot be obtained for a light source such as a fluorescent lamp having a large proportion of short-wavelength light. For this reason, application to consumer devices is also limited to devices with extremely low power consumption. Furthermore, the a-Si film deteriorates in photoelectric characteristics when continuously irradiated with strong light, that is, a so-called Staebler-Wr.
In many cases, it has a property called the onski effect. For these reasons, the above-described photovoltaic element is not practical for a power solar cell that is required to maintain stable characteristics for a long period of time.

In the design of a solar cell for power using a photovoltaic element, it is important to efficiently convert sunlight into light. It is important to have a layer structure that can perform photoelectric change in a wide wavelength range.

For example, when a photovoltaic element is formed from a semiconductor material having a small energy band gap, the wavelength range of light absorbed by the film spreads over a wide range from the short wavelength side to the long wavelength side. The amount of energy extracted by photoelectric conversion is determined by the energy band gap of the semiconductor material used, so that the long wavelength component effectively contributes to the photoelectric conversion, but the energy of the short wavelength light component is not effectively used for the photoelectric conversion. .

When the photovoltaic element is formed of a semiconductor material having a large energy band gap,
The wavelength component of sunlight absorbed by the film and contributing to photoelectric conversion is a short-wavelength light component having energy equal to or greater than the energy band gap of the semiconductor material used, and a long-wavelength light component does not lead to photoelectric conversion.

In any case, the maximum voltage taken out as a photovoltaic element, that is, the open-circuit voltage (Voc)
Is determined by the value of the energy band gap of the semiconductor material to be joined, and a semiconductor material having a large band gap is effective for obtaining a high Voc.

However, even if a photovoltaic element is formed using only one semiconductor material and an attempt is made to perform a desired photoelectric conversion as a solar cell, the photoelectric conversion efficiency is naturally limited.

In consideration of such circumstances, a plurality of photovoltaic elements are stacked using a plurality of semiconductor materials having different energy band gaps, and are formed of semiconductor materials having different energy band gaps. There has been proposed a method of improving the photoelectric conversion efficiency of sunlight by dividing a wavelength region for photoelectric conversion by a photovoltaic element.

The layer structure of the proposed solar cell has a so-called electrically serial structure in which a plurality of photovoltaic elements are stacked. If the characteristics of the individual photovoltaic elements are not good, a high photovoltaic element as a whole is required. Conversion efficiency cannot be obtained.

FIG. 16 is a schematic view showing an example of such a stacked solar cell.

In FIG. 16, reference numeral 1601 denotes a conductive substrate,
Reference numeral 602 denotes a lower photovoltaic element (hereinafter abbreviated as “bottom cell”), specifically, using a-SiGe as a material. Reference numerals 1602a to 1602c denote layers constituting the bottom cell, respectively, and include n-type a-Si and i-type a-SiG
e, p-type microcrystal (μC) -Si layer. Reference numeral 1603 denotes an upper photovoltaic element (hereinafter abbreviated as “top cell”), specifically using a-Si as a material. 1603
Reference numerals a to 1603c denote layers constituting the top cell, which are an n-type a-Si layer, an i-type a-Si layer, and a p-type μC-Si layer. Reference numeral 1604 denotes a transparent electrode, specifically, ITO,
It is made of a material such as IO. Reference numeral 1605 denotes a current collecting electrode. In FIG. 16, light enters from the top and the top cell a-S
Optical carriers are generated by being absorbed by the i-layer and the a-SiGe layer of the bottom cell, and photoelectric conversion is performed.

Meanwhile, photocarriers generated in the a-Si and a-SiGe films, specifically, electrons of a pair of electrons and holes have a high mobility and travel relatively easily through all layers to generate photovoltaics. While the hole can contribute to electric power, the mobility of the hole is small. For example, carriers generated in the a-SiGe layer cannot be completely run through the a-SiGe layer and are trapped in the film. As a result, there is a problem that the electromotive force cannot be effectively taken out. For such a situation, a-
In order to improve the quality of the SiGe film and, consequently, to improve the runnability of the holes, improvements using a hydrogen dilution method, a three-electrode method, etc. have been tried.
Some success is being achieved. However, as far as the a-SiGe film is concerned, it is still difficult to say that a material having sufficient hole traveling properties has been obtained despite the various efforts described above.

Therefore, a method recently proposed as a means for improving the traveling property of holes in the a-SiGe layer includes:
There is a method for continuously changing the optical band gap of the a-SiGe layer (hereinafter abbreviated as a graded band gap method). FIG. 17A shows the energy band of the a-SiGe film formed by the graded band gap method. A schematic diagram showing an example is shown.

In FIG. 17A, light enters from the left side. Reference numeral 1701 denotes an energy level of the conduction band (Ec), and reference numeral 1702 denotes an energy level of the valence band (Ev). In FIG. 17A, the band gap (Ec-E) is changed by continuously changing the contents of Si and Ge.
A large region and a small region of v) can be created.
As a result, a stronger internal electric field is created on the light incident side. The narrow bandgap portion is located closer to the p-layer side because light is incident from the p-layer side so that more carriers are generated on the p-layer side. Because it moves to the side.

In FIG. 17A, the hole can run through the a-SiGe film with the help of the strong internal electric field, but there is no energy change portion shown in FIG. 17B. In the conventional a-SiGe film, the holes cannot travel, but remain in the a-SiGe film and do not contribute to the electromotive force.

The graded band gap a-
It should be noted that when forming the SiGe layer, the Ge content is set to approximately 0% at the p-layer side interface and the n-layer side interface, and good energy matching with the p-layer and n-layer is obtained. Forming a bond. Forming a good junction increases the carrier injection efficiency and consequently the solar cell efficiency.

As described above, the a-Si top cell having the configuration shown in FIG.
At present, different studies are being conducted on a stacked type photovoltaic device having a SiGe bottom cell or a middle cell as a solar cell having good photovoltaic characteristics.

By the way, the research and development relating to the improvement of the layer structure or the band profile of the graded band gap as described above has been carried out in a conventional badge type production apparatus, that is, without moving the substrate in one film formation space. The continuous change of the composition at the time of film deposition, switching of each layer, and creation of a graded band gap has been realized by changing the composition of the film forming gas over time. Therefore, in the badge type, for example, graded band gap a-Si
It should be noted that at the interface between the Ge layer and the p-layer side and the n-layer side, the Ge content can be reduced relatively easily to 0 and a good junction can be formed.

Next, let us turn our attention to a method of mass-producing such photovoltaic elements.

As one of efficient mass production methods of photovoltaic elements, when an amorphous silicon solar cell is manufactured,
There has been proposed a method in which an independent film forming chamber for forming each semiconductor layer is provided, and each semiconductor layer is formed in the film forming chamber.

In the specification of US Pat. No. 4,400,409, Roll to Roll is disclosed.
ll) system is disclosed. According to this apparatus, a plurality of glow discharge regions are provided, and a sufficiently long flexible substrate having a desired width is arranged along a path through which the substrate sequentially passes through each of the glow discharge regions. It is stated that the element having a semiconductor junction can be continuously formed by continuously transporting the substrate in the longitudinal direction while depositing and forming a semiconductor layer of a conductivity type required in the discharge region.
In this specification, a gas gate is used to prevent a dopant gas used for forming each semiconductor layer from diffusing and mixing into another glow discharge region. Specifically, means for separating the respective glow discharge regions from each other by a slit-like separation passage and further forming a flow of a scavenging gas such as Ar, H ₂ or the like in the separation passage is employed. . From this, it can be said that this roll-to-roll system is suitable for mass production of semiconductor devices.

However, each of the semiconductor layers is formed by R
When performed by a plasma CVD method using F (radio frequency), there is naturally a limit in improving the film deposition rate while continuously maintaining the characteristics of a film formed continuously. That is, for example, even when a semiconductor layer having a thickness of at most 5000 ° is formed, it is necessary to always generate a predetermined plasma over a large area and to maintain the plasma uniformly. However, doing so requires considerable skill and it is difficult to generalize the various plasma control parameters involved.
Further, the decomposition efficiency and utilization efficiency of the film-forming raw material gas used are not high, which is one of the factors for raising the production cost.

On the other hand, a plasma process using microwaves has recently attracted attention. Since the microwave has a short frequency band, the energy density can be increased as compared with the case where the conventional RF is used, and is suitable for efficiently generating and sustaining the plasma.

For example, US Pat. Nos. 4,517,223 and 4,504,518 disclose depositing a thin film on a small area substrate in a microwave glow discharge plasma at low pressure. Although a method of forming the film is disclosed, according to the method, since the process is performed under a low pressure, polymerization of active species that causes deterioration of film characteristics is prevented, and a high-quality deposited film can be obtained. It is said that the generation of powder such as polysilane in plasma can be suppressed and the deposition rate can be dramatically improved. However, there is no specific disclosure for forming a uniform deposited film over a large area.

On the other hand, US Pat. No. 4,729,341 discloses that a photoconductive semiconductor thin film is deposited on a large-sized cylindrical substrate by a high power process using a pair of radiation type waveguide applicators. Although a low-pressure microwave plasma CVD method and apparatus to be formed are disclosed, the large-area substrate is limited to a cylindrical substrate, that is, a drum as a photoreceptor for electrophotography. No application to the substrate has been made.

In view of the above situation, the microwave plasma CVD method (hereinafter referred to as “μW
-CVD method) and a roll-to-roll production method are rationally combined to provide a mass production method with even higher throughput.

Next, a roll-to-roll μW plasma CVD method (hereinafter referred to as “R-Rμ
An example of producing an a-SiGe single-layer (single) cell solar cell using an a-SiGe layer as an i-layer (photoelectric conversion layer) using a "WCVD method" is briefly described. State.

The production apparatus using the R-R μW CVD method continuously feeds a band-shaped substrate for forming an a-SiGe film from a bobbin wound in a roll shape to form at least an n-type a-Si layer and an i-type a-SiGe layer, p-type a-S
A plurality of layers composed of layers including an i-layer and the like are formed in a deposition chamber, which is a separate reaction vessel, and a plurality of layers of a substrate are formed while maintaining a reduced pressure in each deposition space. Enables movement between chambers and prevents mutual diffusion and mixing of the raw material gas supplied to each deposition chamber, such as an n-type a-Si layer and a p-type a-Si layer. A connecting member (generally referred to as "gas gate" or simply "gate").

FIG. 15 shows an a-
It is a schematic diagram which shows the production apparatus of semiconductor elements, such as a SiGe solar cell, In FIG. 15, 1501 is a strip | belt-shaped base | substrate (only henceforth a base | substrate) which deposits an a-Si film | membrane, Usually, deformable electroconductive A member obtained by coating a base material, for example, a thin plate of stainless steel, aluminum or the like, or a non-conductive thin plate with a conductive thin film or the like is used. The base 1501 is wound around a circular bobbin 1511 and the delivery chamber 151
Installed within 0. The substrate 1501 delivered from the bobbin installed in the delivery chamber 1510 includes a gas gate (hereinafter simply referred to as “gate”) 1520 and an n-type a
-Si film formation chamber 1530, gate 1540, i-type a-Si
After passing through the Ge film forming chamber 1550, the gate 1560, the p-type a-Si film forming chamber 1570, and the gate 1580, the winding chamber 1
It is taken up by a take-up bobbin 1591 installed in 590.

Reference numerals 1530a, 1550a, and 1570a denote applicators composed of dielectric windows for radiating microwaves to the discharge space. The applicators do not pass through rectangular waveguides 1530b, 1550b, and 1570b that are respectively provided in a direction perpendicular to the dielectric windows. Electric power is applied from the illustrated microwave power supply, and a glow discharge is generated in a discharge space in each film forming chamber. 1
502a~1506a gas each serving as a raw material of the deposited film formation is filled, 1502a is SiH ₄ gas, 15
03a is GeH ₄ gas, 1504a is H ₂ gas, 150
5a is filled with PH ₃ gas, and 1506a is filled with B ₂ H ₆ gas.

Each gas is used as an on-off valve 1502b-15.
06b and decompressors 1502c to 1506c, and are guided to gas mixers 1530c, 1550c, and 1570c. Gas mixers 1530c to 1570c for desired flow rate,
The raw material gas having the mixing ratio is supplied to a gas introduction line 153.
The gas is ejected into each deposition chamber through 0d, 1550d, and 1570d. The gas introduced into the deposition chamber is
Exhaust devices 1510e, 1530e, 155 composed of mechanical booster pumps, rotary pumps, etc.
With 0e, 1570e, and 1590e, the air is exhausted while being adjusted to a desired pressure in each chamber, and is guided to an exhaust gas treatment device (not shown). Also, 1530f, 1
Reference numerals 550f and 1570f denote substrate heating heaters, respectively, to which power is supplied from power supplies 1530g, 1550g and 1570g, respectively.

Reference numerals 1541 and 1561 denote components for adjusting the opening cross-sectional area of the gate. The gas passage is narrowed to reduce mutual diffusion of gas between the respective film forming chambers. Further, a gas that does not adversely affect film formation, for example, a gas such as H ₂ or He, is supplied from the gas inlets 1542 and 1562 to the gate from the cylinder 1507 a to the pressure reducer 1507 b and the flow controller 15.
07c and 1507d to further suppress the mutual diffusion of the source gas in each film forming chamber.

The substrate 1501 delivered from the delivery chamber 1510 advances in each deposition chamber one after another, and an n-type a-Si film, an i-type a-SiGe film, and a p-type a-Si film are formed on the surface thereof. Finally, it enters the winding chamber 1590.

First, in the n-type a-Si film forming chamber 1530, the base 1501 is heated by the heater 1530f to a desired temperature. Further, gases such as SiH ₄ , H ₂ , PH _3, etc., which are raw materials for the n-type a-Si film, are mixed at optimal flow rates by the gas mixer 1530 c and introduced into the film forming chamber 1530. At the same time, microwave power is applied through the waveguide 1530b and the applicator 1530a, causing a glow discharge in the film formation space and causing n on the surface of the substrate 1501.
A mold a-Si film is formed.

Next, the substrate proceeds in the gate 1540, and i
It enters the mold a-SiGe film formation chamber 1550. Film forming chamber 155
In the case of 0, SiH ₄ set to the optimum flow rate as described above,
Optimum power is given to GeH ₄ and H ₂ gas, and the n-type a-
A desired i-type a-SiGe film is formed on the Si film. Similarly, the base 1501 is formed by a gate 1560 and a p-type a-Si
The bobbin 1 in the winding chamber 1590 via the film forming chamber 1570
591. In this manner, since the substrate is successively passed through the n-type, i-type, and p-type film forming chambers, an extremely high throughput can be obtained in the roll-to-roll type production apparatus.

As described above, the method of manufacturing an a-SiGe solar cell using the R-R μW CVD type deposited film forming apparatus has been described. In this example, a-SiGe had a single band gap.

When an attempt was made to realize a solar cell having an a-SiGe layer having the above-mentioned graded band gap with an R-R μW CVD type production apparatus, there were difficulties described below.

FIG. 18 shows an example of forming an i-layer, ie, an a-SiGe layer, when manufacturing a solar cell using an a-SiGe film having a graded band gap as a photovoltaic layer using the R-R μWCVD method. It is the schematic diagram which took out and showed the film space. The film formation space for depositing the p-type a-Si layer and the n-type a-Si layer is completely the same as in the above-mentioned case, and is omitted here. In FIG. 18, reference numeral 1801 denotes a band-shaped base. Reference numeral 1802 denotes a vacuum chamber for creating a reduced pressure state.
It is connected to an exhaust unit 1805 composed of a diffusion pump or the like. Reference numeral 1803 denotes a film formation space chamber,
Together with 1, the film forming space is formed.

1820 is a SiH ₄ gas line, 182
1 is a GeH ₄ gas line, and 1822 is an H ₂ gas line. Each gas is supplied to a gas mixer 1814a, 1814
b, 1814c and 1814d, and the gas mixed at a desired gas flow rate and ratio in the gas mixers 1814a to 1814d are respectively connected to gas pipes 1813a and 1813a.
13b, 1813c, and 1813d, and the gas outlets 1812a, 1812b, 1812c, and 1812d, respectively.
It is released to the film formation space.

1810a, 1810b, 1810c, 1
Reference numeral 810d denotes an applicator having a dielectric window for introducing microwaves into the film formation space, and a waveguide 1811a, 1811b, 1811 from a microwave power supply (not shown).
c, 1811 d, microwaves are applied, and microwave glow discharge plasma is excited in the film forming space, and
A desired a-SiGe layer is deposited on 801.

Here, the graded band cap a
-For depositing the SiGe layer, a gas mixer 1814a-
The mixing ratio of the SiH ₄ gas and the GeH ₄ gas mixed at 1814 d may be changed. Specifically, for example, in a gas mixer 1814a, SiH ₄ gas 100scc
m (GeH ₄ 0%) SiH ₄ gas 90scc in the gas mixer 1814b
m GeH ₄ gas 10 sccm (GeH ₄ 10%) SiH ₄ gas 50 sccc in the gas mixer 1814 c
m GeH ₄ gas 50 sccm (GeH ₄ 50%) SiH ₄ gas 100 sccc in a gas mixer 1814d
m (GeH ₄ 0%), a graded band gap a-Si having a maximum Ge ratio in the film in the vicinity of the gas outlet 1812c and thus having a minimal band gap.
A Ge layer is formed. FIG. 19 shows the band gap profile of the a-SiGe layer at this time.

In FIG. 19, Ec indicates the energy level of the conduction band, and Ev indicates the energy level of the valence band.
Ec 'indicates the energy level of the conduction band in the case of the a-Si single film, and Ev' indicates the energy level of the valence band at that time. That is, the a-SiG body made in this example
The e-film does not expand to the band gap of the a-Si film at both the p-layer side interface and the n-layer side interface, indicating that a considerable amount of Ge is contained. As a result, satisfactory energy matching cannot be obtained on both the p-layer side and the n-layer side, and the problem has arisen that the injection efficiency of photocarriers decreases and the solar cell efficiency decreases.

In order to avoid such a problem, the ratio of the GeH ₄ gas in the source gas is reduced, that is, a-SiGe
A method for reducing the Ge content in the steel is considered. However, in this method, the band gaps on the p-layer side and the n-layer side are widened, and a good junction with each layer can be formed, and the carrier injection efficiency increases. As a result, the amount of generated carrier itself was reduced, and as a result, excellent solar cell efficiency could not be obtained.

Further, as another method for avoiding the above-mentioned problem, there is a method of further extending the film forming space and providing a larger number of gas outlets. That is, in FIG. 18, the film forming chamber 1803 is further extended right and left, and a new gas outlet is provided at each of the extended left and right portions, and only the SiH ₄ gas flows from both gas outlets, so that This is a method of extending a region having a high Si content to the p-layer side and the n-layer side. But,
This method also requires a large number of gas lines, gas outlets, and gas mixers, and has the drawback that the cost for constructing the apparatus is significantly increased.

To summarize the problems described above, it is better to prepare a graded band gap a-SiGe film of any profile by changing the film composition freely using a badge type production apparatus. Is known, but R which changes the composition positionally, not temporally,
According to the -RμWCVD method, it is difficult to form such an ideal graded band gap a-SiGe film.

The above description is based on the a-S
Although the iGe film has been particularly described, such a problem is not limited to this example. That is, as an example, even if it is limited to the fabrication of a photovoltaic element, the material on the light incident side is a-
When continuously changing the composition of a high band-cap amorphous semiconductor compound such as SiC or a-SiN,
It is difficult to control the ideal composition at the aforementioned interface,
There is a problem that it is impossible to ideally control the composition including the doping agent in the vicinity of the interface by the roll-to-roll method.

[0056]

As described above, according to the present invention, an amorphous semiconductor compound such as a-SiGe, a-SiC, or the like, whose composition continuously changes using the R-R μW CVD method, or Including a film or the like in which the doping amount of a valence electron controlling agent to a semiconductor element continuously changes, for example, when manufacturing an element such as a photovoltaic element, by stacking with the end face of the element or a film of another kind. In some cases, it is intended to provide a method for producing a device having excellent characteristics by forming an ideal bonding surface by controlling the composition at the interface with another film as desired.

A further object of the present invention is to provide a method capable of producing a large number of photovoltaic elements having the above-mentioned good characteristics in a large area at low cost.

[0058]

[MEANS FOR SOLVING THE PROBLEMS] A first microphone according to the present invention.
Chromatic plasma CVD method and roll-to-roll method
The deposited film forming method used is such that the band-shaped substrate is formed on the side wall of the film forming space.
Do not move continuously in the longitudinal direction
Meanwhile, the film forming gas is supplied into the film forming space through the gas supply means.
And introduce microwave energy
Radiated into the film deposition space by means of a wave applicator.
Said strip-shaped substrate moving and generating microwave plasma
Microwave continuously forms a deposited film on the surface of the body to be deposited
Using plasma CVD method and roll-to-roll method
In the method of forming a deposited film, the moving direction of the
Out of a plurality of gas outlets
A first gas containing a first element from the first gas discharge port
Released into the film formation space and separated from the first gas discharge port
A second element not containing the first element from the second gas outlet;
Discharging a second gas containing silicon into the film forming space and depositing the second gas.
When forming a film, the first gas is discharged from the second gas outlet.
Gas emission unevenly distributed near the gas outlet
The inside of the film formation space is evacuated from the mouth, and
The concentration of the first element near the first gas discharge port is
Be higher than the concentration of the element near the second gas outlet.
With this, the first element and the second element
The composition ratio of the element is characterized and this <br/> to form a film that varies in thickness direction. Second microwave plasma according to the present invention
Deposited film using the CVD method and the roll-to-roll method
The forming method is such that the strip-shaped substrate is used as one of the side walls of the film forming space.
While moving continuously in the longitudinal direction,
Introducing a film-forming gas into the film space via a gas supply means
Microwave energy with microwave application
Radiated into the deposition space by the
Deposition surface of the strip-shaped substrate that generates and moves plasma
Microwave plasma CV that continuously forms a deposited film on it
Deposition film forming method using D method and roll-to-roll method
At a distance from each other along the moving direction of the band-shaped substrate
Outgassing out of a plurality of gas outlets provided
A first gas containing a first element is discharged from the mouth into the film formation space.
Out and, wherein the first gas discharge ports discharge the second gas spaced
A second element containing the second element without the first element from the outlet
Is discharged into the film forming space to form the deposited film.
Sometimes, the supply flow rate of the first gas is changed to the supply rate of the second gas.
The first gas in the film forming space with a flow rate less than the supply flow rate;
Let the pressure near the outlet be the pressure near the second gas outlet.
Near the first gas outlet in the film forming space.
The concentration of the first element in the second gas outlet
By increasing the concentration of the element in the vicinity,
The first element and the second element on the strip-shaped substrate;
It is characterized by forming a film whose composition ratio changes in the film thickness direction.
I do.

[0059]

For example, the graded band gap i-
Solar cell having three-layer structure having a-SiGe layer (paS
In the case where i / ia-SiGe / na-Si) is continuously formed in the shape of a strip-shaped substrate, the two banks according to the present invention described above are used.
By the Sekimaku forming method lever, in the vicinity second gas outlet
Since the concentration of the first element becomes very low,
The content of the first element in the deposited film to a very low value
Can be A first element concentration in the first gas;
The first element concentration near the second gas outlet
Composition ratio of the first element in the deposited film
Can be changed in a wide range. For example, a-S
The Ge content in the iGe layer was determined to be na-Si and pa-S.
It becomes possible to make it substantially zero at the interface with i. That is, the band gap near the interface between the p layer side and the n layer side is a-
Since it can be made as close as possible to that of the Si film, an ideal junction can be formed. As a result, a solar cell having excellent photovoltaic characteristics can be manufactured over a large area at low cost.

[0060]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described below in detail together with embodiments.

The present inventor has shown in FIG. 1 a discharge space for producing a graded band cap a-SiGe shown in FIG.
As a result of intensive studies using the Roll to Roll production apparatus of No. 5, the following facts were found.

In the discharge space shown in FIG. 18, 100% SiH ₄ gas is used as a film forming gas,
１８1812d to the same film formation space. Microwaves are applied only from the applicator 1810c to generate glow discharge, and no microwave power is applied to other applicators. In this state, a-S
An i film was deposited. The result of examining the film thickness distribution of the a-Si film deposited on the belt-like substrate in the longitudinal direction of the substrate is shown by a solid line 2001 in FIG.

In FIG. 20, 2011a, 2011
b, 2011c and 2011d denote gas discharge holes 1812a, 1812b, 1812c and 1812 in FIG.
Indicates the position corresponding to d. As shown in this figure, the thickness of the a-Si film has a distribution close to a Gaussian shape with the maximum value at the 2011c position where the microwave power is applied.

On the other hand, GeH ₄ gas was introduced from all gas outlets in exactly the same manner,
The result of examining the film thickness distribution of amorphous germanium (hereinafter abbreviated as "a-Ge") deposited by applying microwave power only from 10c is shown by a broken line 2002 in FIG.

From the above results, the distribution of the film deposition rate of a-Ge in the film formation space is narrower and sharper than the distribution distribution of the a-Si film deposition. You can see it has. This is presumably because the precursors for depositing the a-Si film and the a-Ge film have a certain diffusion distance. On the other hand, actually a graded band cap a-SiGe
When a layer is to be formed, 2011a and 20a in FIG.
At all positions 11c and 2011d, microwave power is applied from the applicator to cause microwave glow discharge to increase the film deposition rate of the a-Si film at that position. Since the deposition rate of a-Ge is finite even at the end of the space, it is clear that reducing the Ge content in the film is finite.

In other words, in the above experiment, a-
Unless a method for substantially reducing the deposition rate of the Ge film to 0 is devised, it is impossible to make the band gap near the interface between the p-layer and the n-layer of the a-SiGe film the same as that of the a-Si film. It is possible.

The present inventor has made intensive studies based on the above findings, and as a result, in the above experiment, a method in which the film thickness distribution of the a-Ge film was made to be steep, and the film forming speed was suddenly reduced to zero, That is, the actual graded band gap a
The inventors have found a method of the present invention for making the band gap near the interface between the p-layer and the n-layer in the -SiGe film as close as possible to that of the a-Si film.

Hereinafter, a specific example thereof will be described with reference to FIG.

FIG. 1 is a schematic view showing an example of an apparatus obtained by improving the conventional graded band gap a-SiGe film forming chamber shown in FIG. 18 according to the method of the present invention.

In FIG. 1, reference numeral 101 denotes a belt-like substrate.
Reference numeral 102 denotes a vacuum chamber for creating a reduced pressure state. The vacuum chamber 102 is connected to an exhaust unit 105 such as a diffusion pump through an exhaust port 104 provided at a lower portion. 103
Denotes a film forming chamber, which forms a film forming space together with the substrate 101.

Reference numeral 120 denotes a SiH ₄ gas line, 121 denotes a GeH ₄ gas line, and 122 denotes an H ₂ gas line. Each gas is supplied to a gas mixer 114a, 114b, 11
4c, 114d and a gas mixer 114a
The gas mixed at a desired gas flow rate and ratio at 114d to 114d are respectively gas pipes 113a, 113b, 113c, 1
13d, the gas outlets 112a, 112b,
It is discharged from 112c and 112d to the film formation space.

110a, 110b, 110c, 110d
Is an applicator having a dielectric window for introducing microwaves into the film formation space. Microwaves are supplied from a microwave power supply (not shown) through waveguides 111a, 111b, 111c, and 111d. Microwave glow discharge plasma is excited, and desired a-
A SiGe film is deposited.

Also, 115a, 115b, 115c, 11
Reference numeral 5d denotes a pressure gauge, which is a gas outlet 112a, 112, respectively.
It is installed so that the pressure near b, 112c, 112d can be checked.

Here, in order to deposit an a-SiGe layer having a graded band gap, as described above, SiH ₄ gas and GeH mixed with the gas mixers 114 a to 114 d are used.
_{What is} necessary is just to change the ratio of _four gases to each gas mixer.

The difference between the means embodying the method of the present invention and the conventional one, which is shown in the figure, lies in the arrangement of holes formed in the bottom of the film formation space 103. That is, when an a-SiGe film having the smallest band gap, that is, the highest Ge content is to be obtained in the vicinity of the gas emission port 112c, the exhaust port is provided in a concentrated manner at a position corresponding to the position. There is. FIG. 2 schematically shows the gas flow at this time.

In FIG. 2, reference numeral 201 denotes a vacuum vessel;
Reference numeral 203 denotes an exhaust unit including a diffusion pump or the like; 203, a chamber for forming a film forming space; 204a to 204d, gas discharge holes; 205, an exhaust hole provided at the bottom of the chamber 203;

In the configuration of FIG. 2 of the present invention, the pressure is 20
4a and 204d are high and 204b and 204c are low, and the gas flow has a flow toward the exhaust hole as shown by the arrow in the figure. By creating such a gas flow, for example, GeH ₄ gas flowing out into the film formation space from the gas release holes 204b and 204c, and a precursor before film deposition by being excited by microwave power of the GeH ₄ gas The components are obstructed by the flow of the gas released from the gas discharge ports 204a and 204d, so that such a precursor does not reach the end of the discharge space, and substantially G at that point.
The deposition rate of the e component is almost zero.

The above fact was confirmed by the following experiment.

In the discharge space shown in FIG. 1, 100% gas of GeH ₄ was used as a film forming gas.
An equivalent amount is released from 12d into the film formation space. Microwaves are applied only from the applicator 110c to generate glow discharge, and no microwave power is applied to other applicators. In this state, an a-Ge film was deposited on the band-shaped substrate that was stationary. The a-G deposited on the strip substrate in this manner
The result of examining the film thickness distribution of the e film along the longitudinal direction of the substrate is shown by the solid line in FIG.

In FIG. 3, 301a, 301b, 301
c and 301d are gas discharge holes 112a,
Positions corresponding to 112b, 112c, 112d are shown.
The point that the film thickness of the a-Ge film shows a distribution close to Gaussian with the maximum value at the position 301c is similar to the above-described experiment, but the distribution shape is sharper and The film deposition rate of the a-Ge film in the portion is 0.

The above facts indicate that according to the deposited film forming method of the present invention, the flow rates of the SiH ₄ gas and the GeH ₄ gas are appropriately adjusted from the gas discharge ports 112a to 112d and flowed.
When a microwave is introduced into all the applicators of 0d to perform film deposition, the content of Ge at the end of the film formation space is set to 0, and a film having the same band gap as that of a-Si can be produced. It is shown that.

Next, a graded band gap a-SiGe was actually deposited using the above-described apparatus based on the deposited film forming method of the present invention.

A-Si of graded band gap
To deposit a Ge layer, the mixing ratio of the SiH ₄ gas and the GeH ₄ gas mixed in the gas mixtures 114a to 114d may be changed. Specifically, for example, a SiH ₄ gas of 100 sccm is
(GeH ₄ 0%) gas mixer 114b in SiH ₄ gas 90 sccm GeH ₄ gas 10sccm (GeH ₄ 10%) gas mixer 114c in SiH ₄ gas 50 sccm GeH ₄ gas 50sccm (GeH ₄ 50%) gas mixer 114d At 100 sccm of SiH ₄ gas
(GeH ₄ 0%), a graded band gap a-SiG having a maximum Ge ratio in the film in the vicinity of the gas outlet 112 c and therefore having a minimum band gap value.
An e-layer is formed. FIG. 4 shows the band gap profile of the a-SiGe layer actually deposited under the above conditions.
Shown in

In FIG. 4, 401a to 401d correspond to the positions of the gas outlets 112a to 112d, respectively, Ec represents the energy level of the conduction band, and Ev represents the energy level of the valence band. Ec 'indicates the energy level of conduction electricity in the case of the a-Si single film, and Ev' indicates the energy level of the valence band at that time. That is, the a-SiGe film manufactured in this example has a
It can be seen that the a-Si film has been expanded to the band gap of the -Si film, and an almost complete a-Si film is formed on the end face.

As a result, good energy matching and junction are formed on both the p-layer side and the n-layer side, so that a photovoltaic element having good photocarrier injection efficiency and excellent solar cell efficiency can be formed. it can.

FIG. 5 shows the pressure distribution in the film formation space measured by the pressure gauges 115a to 115d. In FIG. 5, 501a to 501d are gas outlets 112a to 112d, respectively.
This corresponds to the position 12d.

As described above, the method of the present invention in which the pressure at the position where the Ge content becomes the maximum is minimized, the Ge content at the end of the film formation space is reduced, and both the p-layer side and the n-layer side are excellent. It was clarified that a perfect junction could be formed.

Although the method of forming a deposited film of the present invention has been invented using the apparatus shown in FIG. 1, the intention of the present invention is to concentrate on only a part of the bottom of the film forming chamber as shown in FIG. Any method other than the method of providing the exhaust port and controlling the gas flow may be a method of reducing the pressure at a location where the Ge content is high, and other means for that may be considered. . One such example is described below.

As the film forming apparatus, an apparatus of the type shown in FIG. 18 in which the exhaust ports in the lower part of the film forming space are uniformly arranged is used.
The pressure is controlled by the dilution gas flow rate. As a specific example, a gas mixer 1814a uses a SiH ₄ gas of 100 scc.
mH ₂ gas 500 sccm SiH ₄ gas 90 sccc in a gas mixer 1814b
m GeH ₄ gas 10 sccm H ₂ gas 150 sccm SiH ₄ gas 50 sccc in a gas mixer 1814 c
m GeH ₄ gas 50 sccm SiH ₄ gas 100 sccc in the gas mixer 1814d
By setting the mH ₂ gas to 500 sccm, the pressure at the end of the film formation space can be made higher than the pressure at the location where the Ge content is highest. Even in such a method, G in the film deposited at the end of the film formation space
The present inventors have confirmed that the content of e is extremely small, and the result will be described in detail in Examples, and is omitted here.

As described above, the graded band gap a−
Although the case of fabricating a SiGe film has been particularly described, the present invention is not limited to the above example, and forms a different kind of bandgap profile and controls the composition of various semiconductors and alloys. In addition, when controlling the doping profile of the valence electron controlling agent ideally when controlling the valence electrons of the semiconductor, the microwave plasma CVD
It is needless to say that the method and the roll-to-roll method can be applied to various applications of film deposition.

[0091] Such an example will be described below.

First, variations of band gap profiles in amorphous semiconductor materials and alloys thereof will be described.

Semiconductor materials constituting the i-type semiconductor layer suitably used in the photovoltaic device manufactured according to the present invention include a-Si: H, a-Si: F, and a-S
i: H: F, a-SiC: H, a-SiC: F, a-S
iC: H: F, a-SiGe: H, a-SiGe: F,
a-SiGe: H: F, poly-Si: H, poly
-Si: F, poly-Si: H: F and other so-called group IV and IV group alloy semiconductor materials, as well as II-VI and I
Group II-V so-called compound semiconductor materials and the like can be mentioned. Among them, a-SiGe: H, a-SiGe: F, a-
SiGe: H: F, a-SiC: H, a-SiC: F,
When a so-called group IV alloy semiconductor such as a-SiC: H: F is used for the i-type semiconductor layer, the characteristics are obtained by appropriately changing the forbidden band width (band gap: _Eg opt) from the light incident side. We have already mentioned that it can be improved.

FIGS. 6A to 6D show specific examples of various variations of band gap profiles.
The arrow (→) in the figure indicates the light incident side.

The band gap profile shown in FIG. 6A has a constant band gap from the light incident side. The band gap profile shown in FIG. 6B is of a type in which the band gap on the light incident side is narrow and the band gap gradually widens.
Factor: curve factor) is effective. FIG.
The band gap profile shown in (c) is of a type in which the band gap on the light incident side is wide and the band gap gradually narrows, and is effective in improving Voc: open-circuit voltage.

The bandgap profile shown in FIG. 6D is of the type described above in which the bandgap on the light incident side is wide, the bandgap narrows relatively sharply, and spreads again. By combining (b) and FIG. 6 (c), both effects can be obtained at the same time.
By forming an ideal joint surface, good characteristics can be obtained.

According to the method of the present invention, for example, a-Si:
Using H and a-SiGe: H, an i-type semiconductor layer having a band gap profile shown in FIG. 6D can be manufactured. Also, a-SiC: H ( _Eg opt = 2.
05EV) and a-Si: by using the _{H (E g opt = 1.72eV)} , can be manufactured i-type semiconductor layer having a band gap profile shown in FIG. 6 (c).

Further, the method and apparatus of the present invention
A semiconductor layer having a doping profile shown in (a) to (d) can be manufactured. The arrow (→) in the figure indicates the light incident side.

FIG. 7A is a profile of a non-doped i-type semiconductor layer. On the other hand, FIG. 7B shows a type in which the Fermi level on the light incident side is higher than the valence band, and the Fermi level gradually approaches the conduction band. It is effective for improving running performance. FIG. 7 (c) shows a type in which the Fermi level gradually approaches the valence band from the light incident side, and is similar to the case of FIG. 7 (b) when an n-type semiconductor layer is provided on the light incident side. Has the effect. FIG. 7D shows a type in which the Fermi level changes from the valence band to the conduction band almost continuously from the light incident side.

When forming a deposited film in which the Fermi level continuously changes as shown in FIGS. 7B to 7D, the method of the present invention employs, for example, in the case of FIG. Since high concentration doping is performed on the light incident side, the pressure should be low at a position in the film forming space corresponding to the deposition on the light incident side,
On the opposite side of the film-forming space, a high pressure is set so as to prevent the inflow of the dopant in order to form an i-type semiconductor. In the case of FIG. 7C, the pressure is symmetrical to that of FIG.
Similarly, in FIG. 7D, the Fermi level becomes an i-layer type in the middle of the film and the dopant concentration is the lowest, so that
The pressure at the position in the film formation space corresponding to the deposition of the i-layer film is assumed to be the highest.

By appropriately designing the band gap profile and the Fermi level profile, a photovoltaic element having high photoelectric conversion efficiency can be manufactured. In particular, these profiles are desirably applied to the i-type semiconductor layer of the tandem or triple photovoltaic element shown in FIG.

Hereinafter, such portions of the present invention will be described in more detail.

The method of the present invention is an apparatus for continuously forming a functional deposition film on a continuously moving strip member by a microwave plasma CVD method, wherein the strip member is continuously formed in the longitudinal direction. While moving, the apparatus has a film forming chamber capable of maintaining the inside thereof substantially in vacuum in combination with a discharge chamber forming a discharge space on the way, and has a microwave for generating microwave plasma in the film forming chamber. Wave applicator means, exhaust means for evacuating the film forming chamber, means for introducing a source gas for forming a deposited film into the film forming chamber, and temperature control means for heating and / or cooling the strip-shaped member And forming a deposition film whose composition is ideally controlled on the surface of the continuously moving belt-shaped member exposed to the microwave plasma. A continuous method for forming a deposited film to be.

In the present invention, the microwave energy is applied to the end face or the opposite end faces of the film forming space formed by using the film forming chamber and the belt-shaped member as side walls via at least one or more microwave applicator means. The light is radiated into the film forming space.

The microwave applicator means is disposed perpendicular to the end face so as to radiate the microwave energy in a direction parallel to the side wall.

In the method of the present invention, the microwave energy is radiated through a dielectric window provided at a tip portion of the microwave applicator means.

The airtightness between the microwave applicator means and the film forming space is maintained by the dielectric window.

In the method of the present invention, in order to uniformly generate and confine microwave plasma in the film formation space, microwave energy is radiated from one or both ends of both end surfaces of the film formation space. Try to confine microwave energy in space.

When the width of the belt-like member is relatively narrow,
Even when microwave energy is emitted from only one side, the uniformity of the microwave plasma generated in the film formation space is maintained, but the width of the band-shaped member exceeds, for example, one wavelength of the microwave. It is preferable to radiate microwave energy from both sides in order to maintain uniformity of microwave plasma.

In the case where the microwave energy is radiated from one microwave applicator means, the other microwave applicator means receives the microwave energy, and the received microwave energy is applied to the other microwave applicator means. Special care must be taken not to reach the microwave power supply connected to the microwave applicator means and to have any adverse effects such as damaging the microwave power supply or causing abnormalities in microwave oscillation. There is. Specifically, the microwave applicator is arranged so that the directions of electric fields of the microwaves traveling in the microwave applicator means are not parallel to each other.

In the method of the present invention, when microwave energy is emitted from only one of the two end faces of the film forming space, it is necessary to prevent leakage of the microwave energy from the other end face. The end face is sealed with a conductive member, or the hole diameter is preferably 以下 wavelength or less, more preferably １ ／ wavelength of the microwave wavelength used.
It is desirable to cover with a wire mesh having a wavelength equal to or less than the wavelength or a punching board.

Needless to say, the uniformity of the microwave plasma generated in the film formation space requires that microwave energy be sufficiently transmitted into the film formation space. It is desirable to have a similar structure.
For this purpose, the film forming chamber and the belt-like member are preferably made of a conductive material. However, the belt-like member may have at least one surface subjected to a conductive treatment.

The microwave permeable member is provided at a tip portion of the microwave applicator means, and separates a vacuum atmosphere in the film forming chamber from outside air in which the microwave applicator means is installed. Designed to withstand existing pressure differences. Specifically, the cross-sectional shape of the microwave in the traveling direction is preferably circular, square, elliptical flat plate, bell jar,
Desirably, it has a doublet shape and a conical shape.

The thickness of the microwave transmitting member in the direction in which the microwave travels is designed in consideration of the dielectric constant of the material to be used so that the reflection of the microwave is minimized. Preferably, for example, in the case of a flat plate, it is preferable that the wavelength is substantially equal to a half wavelength of the microwave. Further, the material is such that microwave energy radiated from the microwave applicator means can be transmitted into the film forming chamber with a minimum loss, and airtightness does not occur in the air flowing into the film forming chamber. Are preferred, specifically, quartz, alumina, silicon nitride, beryllia, magnesia, zirconia,
Glass such as boron nitride and silicon carbide, fine ceramics, and the like are included.

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 applicator means may be cooled air, water, or the like. The microwave-permeable member may be cooled by a cooling medium such as oil or freon, and cooled through a portion in contact with the microwave applicator means. By cooling the microwave permeable member to a sufficiently low temperature, even if microwave energy of relatively high power is introduced into the film forming chamber, the generated heat may cause the microwave permeable member to have cracks or the like. A high electron density plasma can be generated without causing destruction.

Further, in the method of the present invention, film deposition occurs on the portion where the microwave permeable member is in contact with the microwave plasma, as on the strip-shaped member. Therefore,
Although it depends on the type and characteristics of the film to be deposited, microwave energy to be radiated from the microwave applicator means is absorbed or reflected by the deposited film, and microwaves into the film forming chamber formed by the band-shaped member are absorbed. If the amount of energy radiation decreases and the amount of change increases significantly compared to immediately after the start of discharge, not only is it difficult to maintain the microwave plasma itself, but also the deposition rate of the deposited film decreases. And changes in characteristics and the like. In such a case, the initial state can be restored by removing the film deposited on the microwave transmitting member by dry etching, wet etching, a mechanical method, or the like. 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 permeable member is subjected to wet etching or It may be separated and reused by mechanical removal or the like, or may be replaced with a new one.

Further, a sheet made of a material having a microwave permeability substantially equal to that of the microwave permeable member is continuously fed along the surface of the microwave permeable member on the film forming chamber side. Thus, a method of attaching and forming a deposited film on the surface of the sheet and discharging the deposited film out of the microwave plasma region can also be adopted.

The microwave applicator means in the method of the present invention may be of the same standard as the microwave transmission waveguide, or may be of another standard. The microwave transmission mode in the microwave applicator means enables efficient transmission of microwave energy in the film forming chamber and stably generates, maintains, and controls microwave plasma. Therefore, it is desirable that the size, shape, and the like of the microwave applicator are designed to be a single mode. However, even when a plurality of modes are transmitted, they can be used by appropriately selecting microwave plasma generation conditions such as a source gas, pressure, and microwave power to be used. The transmission mode when it is designed to be single mode, for example, TE ₁₀ mode, TE ₁₁ mode, eH
₁ mode, TM ₁₁ mode, there may be mentioned a TM ₀₁ mode or the like, preferably TE ₁₀ mode, TE ₁₁ mode,
eH ₁ mode is selected. A waveguide capable of transmitting the above-mentioned transmission mode is connected to the microwave applicator means. Preferably, the transmission mode in the waveguide and the transmission mode in the microwave applicator means coincide with each other. Is desirable. The type of the waveguide is appropriately selected depending on the frequency band (band) and mode of the microwave used, and it is preferable that at least the cutoff frequency is smaller than the frequency used. Is JIS, EIAJ, IEC, J
In addition to rectangular waveguides, circular waveguides, elliptical waveguides, etc. of standards such as AN, the company's own standard for 2.45 GHz microwaves has a square cross section with an inner diameter of 96 mm and a height of 27 mm. And the like.

In the method of the present invention, since the microwave energy supplied from the microwave power supply is efficiently radiated into the film forming chamber through the microwave applicator means, the reflected wave caused by the so-called microwave applicator is used. Is relatively easy to avoid, and in a microwave circuit, a relatively stable discharge can be maintained without using a microwave matching circuit such as a three-stub tuner or an EH tuner. If a strong reflected wave is generated due to abnormal discharge or the like even after the start, it is desirable to provide the microwave matching circuit to protect the microwave power supply.

The microwave frequency supplied from the microwave power source used in the method of the present invention is preferably 2.45 GHz which is used for consumer use. Any material that is easily available can be used. Further, in order to obtain a stable discharge, it is desirable that the oscillation mode is so-called continuous oscillation. The ripple width thereof is preferably within 30%, more preferably within 10% in a used output region.

Next, a belt-like member used in the deposited film forming apparatus of the present invention will be described. As the material of the belt-shaped member suitably used in the method of the present invention, deformation, distortion is small at a temperature required at the time of forming a functional deposited film by a microwave plasma CVD method, the material has a desired strength, and It is preferable to have a property, specifically, a thin plate of a metal such as stainless steel, aluminum and its alloys, iron and its alloys, copper and its alloys and a composite thereof, and a metal of a different material on their surface. Thin film and / or SiO ₂ , Si ₃ N ₄ , Al
Insulating thin films such as ₂ O ₃ and AlN are sputtered, vapor-deposited,
Those that have been subjected to surface coating by plating or the like.
In addition, the surface of a heat-resistant resin sheet such as polyimide, polyamide, polyethylene terephthalate, epoxy, or a composite of these with glass fiber, carbon fiber, boron fiber, metal fiber, or the like, may be a simple metal or alloy, and a transparent conductive oxide. (TCO) plating, evaporation,
Examples include those subjected to a conductive treatment by a method such as sputtering and coating.

Of course, even if the belt-shaped member is made of an electrically conductive material such as a metal, the reflectance of long-wavelength light on the substrate surface can be improved or the constituent elements between the substrate material and the deposited film can be improved. A different kind of metal layer or the like may be provided on the side of the substrate on which the deposited film is formed, for the purpose of preventing mutual diffusion of the layers and forming an interference layer for preventing short circuit. When the band-shaped member is relatively transparent and a solar cell having a layer configuration in which light is incident from the side of the band-shaped member, a conductive thin film such as the transparent conductive oxide or a metal thin film is previously deposited. It is desirable to form it.

The surface of the belt-shaped member may be a so-called smooth surface or a fine uneven surface.
In the case of a minute uneven surface, the uneven shape is spherical, conical, pyramidal, or the like, and its maximum height (Rmax)
Is preferably 500 ° to 5000 °, the light reflection on the surface becomes irregular reflection, and the optical path length of the reflected light on the surface is increased.

The thickness of the belt-like member is desirably as thin as possible in consideration of cost, storage space, and the like, as long as it is within a range where the strength required at the time of transportation by the transportation means is exhibited. Specifically, preferably 0.0
1 mm to 5 mm, more preferably 0.02 mm to 2
mm, optimally 0.05 mm to 1 mm, but a relatively thin metal or the like makes it easier to obtain a desired strength even if the thickness is reduced.

Further, regarding the width dimension of the band-like member,
When the microwave applicator is used, it is preferable that the uniformity of the microwave plasma in the longitudinal direction is maintained and the curved shape is maintained, and specifically, preferably, 5 cm to 100 cm.
cm, more preferably 10 cm to 80 cm.

Further, the length of the belt-like member is not particularly limited, and may be a length that can be wound up in a roll shape. It may be what you did.

The gas supply means provided in the method of the present invention is constituted by a pipe-shaped gas introduction pipe, and one or more rows of gas discharge ports are opened on the side thereof.

As the material constituting the gas introduction tube, a material which is not damaged in microwave plasma is preferably used. Specifically, heat-resistant metals such as stainless steel, nickel, titanium, niobium, tantalum, tungsten, vanadium, molybdenum, and alumina,
Examples thereof include ceramics such as silicon nitride and quartz sprayed or the like, ceramics such as alumina, silicon nitride, and quartz, and ceramics and composites.

In the method of the present invention, the raw material gas for forming a deposited film discharged from the gas supply means is preferably discharged uniformly in the width direction of the belt-shaped member.

The gas supply means is arranged in parallel with the strip.

It is desirable that the number of the gas supply means used in the method of the present invention is at least equal to or greater than the number of component elements of the functional deposition film to be formed. By appropriately changing the composition of the deposition film forming source gas to be released, a functional deposition film whose composition is ideally controlled can be formed.

It is preferable that each of the gas supply means is disposed so as to be contained in the film forming space so that the discharged deposited film forming material gas is surely decomposed by excitation. Also, in order to give a desired composition distribution to the deposited film to be formed,
It is desirable to appropriately adjust the arrangement of the gas supply means.
Further, a rectifying plate or the like may be provided in the film forming space in order to adjust and control the flow path of the source gas for forming a deposited film in the film forming space.

In the method of the present invention, in order to control the plasma potential of the microwave plasma generated in the film forming chamber,
A bias voltage may be applied to the gas introduction pipe. The bias voltages applied to the plurality of gas introduction tubes may be equal to each other or may be different from each other. As the bias voltage, it is desirable to apply a DC, a pulsating current, and an AC voltage alone or by superimposing each of them.

To apply a bias voltage effectively,
It is desirable that the surfaces of both the gas introduction pipe and the belt-shaped member are conductive.

By controlling the plasma potential by applying a bias voltage, the stability, reproducibility and film characteristics of the plasma can be improved, and the occurrence of defects can be suppressed.

In the method of the present invention, a part or all of the deposited film forming raw material gas introduced into the columnar film forming chamber from the gas introduction pipe is decomposed to generate a deposited film forming precursor. In this case, a deposited film is formed, and the raw material gas of the final decomposition or the gas having a different composition due to the decomposition needs to be immediately exhausted to the outside of the film forming chamber. However, if the area of the exhaust hole is made unnecessarily large, microwave energy leaks from the exhaust hole, causing instability of plasma or adversely affecting other electronic devices, the human body, and the like. . Therefore, in the method of the present invention, it is preferable that the exhaust hole has a wavelength of preferably １ ／ or less, more preferably 以下 or less of the wavelength of the microwave used for preventing leakage of the microwave. .

In the method of the present invention, the film forming chamber and / or the isolation container are separated from a vacuum container having another film forming means in a vacuum atmosphere, and the belt-like member is continuously penetrated therethrough. A gas gate means is suitably used for the transfer. In the apparatus of the present invention, the film forming chamber and / or
Alternatively, since it is desirable that the pressure in the isolation container is maintained at a low level necessary for operation near the minimum value of the modified Paschen curve, the pressure in the film formation chamber and / or another vacuum container connected to the isolation container is Is often at least approximately equal to or higher than the pressure. Therefore, it is necessary for the gas gate means to have a capability of preventing the mutually used deposition film forming source gases from diffusing due to a pressure difference generated between the containers. Thus, the basic concept can employ the gas gating means disclosed in U.S. Pat. No. 4,438,723, but its capabilities need to be further improved. Specifically, it is necessary to be able to withstand a pressure difference of about 10 ⁶ times at the maximum, and an oil diffusion pump, a turbo molecular pump, a mechanical booster pump, or the like having a large exhaust capacity is preferably used as the exhaust pump. In addition, the cross-sectional shape of the gas gate is a slit shape or a shape similar thereto, and the dimensions thereof are calculated using a general conductance calculation formula, together with the overall length and the exhaust capacity of the exhaust pump to be used.
Designed. Further, it is preferable to use a gate gas in combination to enhance the separation ability. For example, Ar, He, Ne,
A rare gas such as Kr, Xe, or Rn, or a diluent gas for forming a deposited film such as H ₂ may be used. The gate gas flow rate and pressure are appropriately determined by the conductance of the entire gas gate and the capacity of the exhaust pump to be used, but if a point at which the pressure is maximized is set substantially at the center of the gas gate, the gate gas is vacuumed from the center of the gas gate to both sides. If a point where the pressure is minimized is set at a substantially central portion of the gas gate, the gate gas is exhausted from the central portion of the gas gate together with the raw material gas for forming a deposited film flowing from the containers on both sides. Therefore, in both cases, mutual gas diffusion between the containers on both sides can be minimized. In practice, the optimum conditions are determined by measuring the amount of gas diffused using a mass spectrometer or by analyzing the composition of the deposited film.

The functionally-deposited films of controlled composition formed by the method of the present invention include SiGe, SiC, Ge
So-called group IV alloy semiconductor thin film such as C, SiSn, GeSn, SnC, GaAs, GaP, GaSb, InP, InA
so-called III-V compound semiconductor thin film, ZnSe, Z
So-called I such as nS, ZnTe, CdS, CdSe, CdTe
I-VI compound semiconductor thin film, CuAlS ₂ , CuAl
Se ₂ , CuAlTe ₂ , CuInS ₂ , CuInSe
₂ , CuInTe ₂ , CuGaS ₂ , CuGaSe ₂ ,
CuGaTe, AgInSe _2, AgInTe ₂ Hitoshishoi I-III-VI compound semiconductor thin film, ZnSiP _2,
So-called II-IV-V compound semiconductor thin films such as ZnGeAs ₂ , CdSiAs ₂ , CdSnP ₂ , Cu ₂ O, TiO
₂ , In ₂ O ₃ , SnO ₂ , ZnO, CdO, Bi ₂ O
₃ , so-called oxide semiconductor thin films such as CdSnO ₄ and those containing a valence controlling element for controlling valence electrons in these semiconductors.

Further, there can be mentioned a material in which a valence electron controlling element is contained in a so-called group IV semiconductor thin film such as Si, Ge and C. Of course, amorphous semiconductors such as a-Si: H and a-Si: H: F may have different contents of hydrogen and / or fluorine.

By controlling the composition of the above-described semiconductor thin film, forbidden band width control, valence electron control, refractive index control,
Crystal control and the like are performed. A large-area thin-film semiconductor device having excellent electrical, optical, and mechanical properties can be manufactured by forming a functional deposition film having a controlled composition on the belt-like member.

That is, the electrical characteristics can be improved by increasing the mobility of carriers and preventing the recombination of carriers at the semiconductor interface by changing the forbidden band width and / or valence electron density of the deposited semiconductor layer. improves.

In addition, by continuously changing the refractive index to provide an optically non-reflective surface, the light transmittance into the semiconductor layer can be improved.

Furthermore, by changing the hydrogen content and the like, the structural change is applied to alleviate the stress, so that a deposited film having high adhesion to the substrate can be formed.

In the present invention, the raw material gas for forming a deposited film used for forming the above-mentioned functional deposited film is prepared by appropriately adjusting the mixing ratio thereof in accordance with the desired composition of the functional deposited film. Introduce into the space. Although a plurality of gas supply means are used for the introduction, the composition of the deposited film forming source gas introduced from each gas supply means may be different, or may be the same depending on the purpose. Further, if necessary, the composition may be continuously changed over time.

In the present invention, the compound containing a group IV element of the periodic table, which is preferably used for forming a film such as a group IV semiconductor or a group IV alloy semiconductor, includes Si atom, Ge
A compound containing an atom, a C atom, a Sn atom, and a Pb atom, specifically, SiH ₄ , Si ₂ H ₆ , Si ₃ H ₈ , S
silane compounds such as i ₃ H ₆ , Si ₄ H ₈ , Si ₅ H ₁₀ , SiF ₄ , (SiF ₂ ) ₅ , (SiF ₂ ) ₆ , (S
iF ₂ ) ₄ , Si ₂ F ₆ , Si ₃ F ₈ , SiHF ₃ , S
iH ₂ F ₂ , Si ₂ H ₂ F ₄ , Si ₂ H ₃ F ₃ , SiC
l ₄ , (SiCl ₂ ) ₅ , SiBr ₄ , (SiBr ₂ )
₅ , Si ₂ Cl ₆ , Si ₂ Br ₆ , SiHCl ₃ , Si
HBr _3, SiHl _3, Si halogenated silane compounds such as _{2 Cl 3 F 3, GeH 4} , Ge germane compounds such as _{2 H 6, GeF 4, (} GeF 2) 5, (GeF 2) 6,
(GeF ₂ ) ₄ , Ge ₂ F ₆ , Ge ₃ F ₈ , GeH
F ₃ , GeH ₂ F ₂ , Ge ₂ H ₂ F ₄ , Ge ₂ H
₃ F ₃ , GeCl ₄ , (GeCl ₂ ) ₅ , GeBr ₄ ,
(GeBr ₂ ) ₅ , Ge ₂ Cl ₆ , Ge ₂ Br ₆ , Ge
HCl ₃ , GeHBr ₃ , GeHl ₃ , Ge ₂ Cl ₃ F
₃ or other halogenated germanium compounds, CH ₄ , C ₂
Methane series hydrocarbon gas such as H ₆ , C ₃ H ₈ , C ₂ H ₄ ,
Ethylene series hydrocarbon gas such as C ₃ H ₆ , cyclic hydrocarbon gas such as C ₆ H ₆ , CF ₄ , (CF ₂ ) ₅ , (C
F ₂ ) ₆ , (CF ₂ ) ₄ , C ₂ F ₆ , C ₃ F ₈ , CHF
₃ , CH ₂ F ₂ , CCl ₄ , (CCl ₂ ) ₅ , CB
r ₄ , (CBr ₂ ) ₅ , C ₂ Cl ₆ , C ₂ Br ₆ , CH
Halogenated carbon compounds such as Cl ₃ , CHl ₃ and C ₂ Cl ₃ F ₃ , tin compounds such as SnH ₄ and Sn (CH ₃ ) ₄ ,
Lead compounds such as Pb (CH ₃ ) ₄ and Pb (C ₂ H ₅ ) ₆ can be mentioned. These compounds may be used alone or in combination of two or more.

In the present invention, so-called composition control is performed by appropriately mixing and using these compounds.

As the valence electron controlling agent used for controlling the valence electrons of the group IV semiconductor or the group IV alloy semiconductor formed in the present invention, as a p-type impurity, a group III element of the periodic table, for example, , B, Al, Ga, In, T
l and the like are listed as preferable ones. Examples of the n-type impurity include elements of Group V of the periodic table, such as N, P, As, and S.
b, Bi, etc. are mentioned as preferable ones.
B, Ga, P, Sb, etc. are optimal. The amount of the impurity to be doped is appropriately determined according to desired electrical and optical characteristics.

As such a raw material for introducing impurities, those which are in a gaseous state at normal temperature and normal pressure or which can be easily gasified at least under film forming conditions are employed. As the starting material for introducing such impurities, specifically, PH ₃ , P
₂ H ₄ , PF ₃ , PF ₅ , PCl ₃ , AsH ₃ , AsF
_{3, AsF 5, AsCl 3,} SbH 3, SbF 5, Bi
H ₃ , BF ₃ , BCl ₃ , BBr ₃ , B ₂ H ₆ , B ₄ H
_{10, B 5 H 9, B} 5 H 11, B 6 H 10, B 6 H 12, AlC
It can be mentioned the l ₃ and the like. The compounds containing the above impurity elements may be used alone or in combination of two or more.

In the present invention, the compound containing a Group II element of the periodic table used for forming a Group II-VI compound semiconductor is specifically Zn (CH ₃ ) ₂ , Zn
(C ₂ H ₅ ) ₂ , Zn (OCH ₃ ) ₂ , Zn (OC ₂ H
₅ ) ₂ , Cd (CH ₃ ) ₂ , Cd (C ₂ H ₅ ) ₂ , Cd
(C ₃ H ₇ ) ₂ , Cd (C ₄ H ₉ ) ₂ , Hg (CH ₃ )
_{2, Hg (C 2 H 5} ) 2, Hg (C 6 H 5) 2, Hg
(C = (C ₆ H ₅ )) _{2 and the} like. As the compound containing a Group VI element of the periodic table, specifically, NO,
N ₂ O, CO ₂ , CO, H ₂ S, SCl ₂ , S ₂ C
_{l 2, SOCl 2, SeH 2} , SeCl 2, Se 2 Br
₂ , Se (CH ₃ ) ₂ , Se (C ₂ H ₅ ) ₂ , Te
H ₂ , Te (CH ₃ ) ₂ , Te (C ₂ H ₅ ) _{2 and the} like.

Of course, these raw materials can be used alone or in combination of two or more.

As the valence electron controlling agent used for controlling the valence electrons of the II-VI compound semiconductor formed in the present invention, compounds containing elements of the I, III, IV and V groups of the periodic table are effective. Can be cited.

Specifically, compounds containing a Group I element include LiC ₃ H ₇ , Li (sec-C ₄ H ₉ ), Li ₂ S,
Li ₃ N and the like can be mentioned as preferable ones.

Compounds containing group III elements include BX ₃ , B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B
_{5 H 11, B 6 H 10} , B (CH 3) 3, B (C
_{2 H 5) 3, B 6} H 12, AlX 3, Al (CH 3) 2 C
1, Al (CH ₃ ) ₃ , Al (OCH ₃ ) ₃ , Al (C
H ₃ ) Cl ₂ , Al (C ₂ H ₅ ) ₃ , Al (OC
_{2 H 5) 3, Al (} CH 3) 3 Cl 3, Al (i-C 4
H ₉ ) ₃ , Al (i-C ₃ H ₇ ) ₃ , Al (C ₃ H ₇ )
₃ , Al (OC ₄ H ₉ ) ₃ , GaX ₃ , Ga (OC
H ₃ ) ₃ , Ga (OC ₂ H ₅ ) ₃ , Ga (OC ₃ H ₇ )
₃ , Ga (OC ₄ H ₉ ) ₃ , Ga (CH ₃ ) ₃ , Ga ₂
H ₆ , GaH (C ₂ H ₅ ) ₂ , Ga (OC ₂ H ₅ ) (C
_{2 H 5) 2, In (} CH 3) 3, In (C 3 H 7) 3,
Compounds containing In (C ₄ H ₉ ) ₃ and Group V elements include N
_{H 3, HN 3, N 2} H 5 N 3, N 2 H 4, NH 4 N 3,
PX ₃ , P (OCH ₃ ) ₃ , P (OC ₂ H ₅ ) ₃ , P
(C ₃ H ₇ ) ₃ , P (OC ₄ H ₉ ) ₃ , P (C
_{H 3) 3, P (C} 2 H 5) 3, P (C 3 H 7) 3, P
(C ₄ H ₉ ) ₃ , P (OCH ₃ ) ₃ , P (OC ₂ H ₅ )
₃ , P (OC ₃ H ₇ ) ₃ , P (OC ₄ H ₉ ) ₃ , P (S
CN) ₃ , P ₂ H ₄ , PH ₃ , AsH ₃ , AsX ₃ , A
s (OCH ₃ ) ₃ , As (OC ₂ H ₅ ) ₃ , As (OC
₃ H ₇ ) ₃ , As (OC ₄ H ₉ ) ₃ , As (C
_{H 3) 3, As (CH} 3) 3, As (C 2 H 5) 3, A
s (C ₆ H ₅ ) ₃ , SbX ₃ , Sb (OCH ₃ ) ₃ , S
b (OC ₂ H ₅ ) ₃ , Sb (OC ₃ H ₇ ) ₃ , Sb (O
C ₄ H ₉ ) ₃ , Sb (CH ₃ ) ₃ , Sb (C
₃ H ₇ ) ₃ and Sb (C ₄ H ₉ ) ₃ .

In the above, X represents a halogen (F, Cl,
Br, I).

Of course, these raw materials may be used alone or in combination of two or more.

Further, as the compound containing a group IV element, the compounds described above can be used.

The compound containing a Group III element of the periodic table, which is used for forming a Group III-V compound semiconductor in the present invention, is specifically BX ₃ (where X represents a halogen atom). , B ₂ H ₆ , B ₄ H ₁₀ , B
_{5 H 9, B 5 H 11} , B 6 H 10, B 6 H 12, AlX 3 ( where, X is a halogen _{atom.), Al (CH 3)} 2 C
1, Al (CH ₃ ) ₃ , Al (OCH ₃ ) ₃ , Al (C
H ₃ ) Cl ₂ , Al (C ₂ H ₅ ) ₃ , Al (OC
_{2 H 5) 3, Al (} CH 3) 3 Cl 3, Al (i-C 4
H ₉ ) ₃ , Al (i-C ₃ H ₇ ) ₃ , Al (C ₃ H ₇ )
₃ , Al (OC ₄ H ₉ ) ₃ , GaX ₃ (where X represents a halogen atom), Ga (OCH ₃ ) ₃ , Ga (CO
_{2 H 5) 3, Ga (} OC 3 H 7) 3, Ga (OC
₄ H ₉ ) ₃ , Ga (CH ₃ ) ₃ , Ga ₂ H ₆ , GaH
(C ₂ H ₅ ) ₂ , Ga (OC ₂ H ₅ ) (C ₂ H ₅ ) ₂ ,
In (CH ₃ ) ₃ , In (C ₃ H ₇ ) ₃ , In (C ₄ H
₉ ) ₃ etc. Examples of the compound containing a Group V element of the periodic table include NH ₃ , HN ₃ , and N ₂ H _5.
N ₃ , N ₂ H ₄ , NH ₄ N ₃ , PX ₃ (where X represents a halogen atom), P (OCH ₃ ) ₃ , P (OC ₂ H
₅ ) ₃ , P (C ₃ H ₇ ) ₃ , P (OC ₄ H ₉ ) ₃ , P
(CH ₃ ) ₃ , P (C ₂ H ₅ ) ₃ , P (C ₃ H ₇ ) ₃ ,
P (C ₄ H ₉ ) ₃ , P (OCH ₃ ) ₃ , P (OC
₂ H ₅ ) ₃ , P (OC ₃ H ₇ ) ₃ , P (OC
_{4 H 9) 3, P (} SCN) 3, P 2 H 4, PH 3, As
X ₃ (where X represents a halogen atom), AsH ₃ ,
As (OCH ₃ ) ₃ , As (OC ₂ H ₅ ) ₃ , As (O
C ₃ H ₇ ) ₃ , As (OC ₄ H ₉ ) ₃ , As (CH ₃ )
₃ , As (CH ₃ ) ₃ , As (C ₂ H ₅ ) ₃ , As (C
₆ H ₅ ) ₃ , SbX ₃ (where X represents a halogen atom), Sb (OCH ₃ ) ₃ , Sb (OC ₂ H ₅ ) ₃ ,
Sb (OC ₃ H ₇ ) ₃ , Sb (OC ₄ H ₉ ) ₃ , Sb
(CH ₃ ) ₃ , Sb (C ₃ H ₇ ) ₃ , Sb (C ₄ H ₉ )
_{3 and the} like. (However, X represents a halogen atom, specifically, at least one selected from F, Cl, Br, and I.) Of course, these raw materials are used alone or in combination of two or more. Can be.

As the valence atom controlling agent used for controlling the valence atom of the group III-V compound semiconductor formed in the present invention, a compound containing an element of group II, IV or VI of the periodic table, or the like is effective. It can be mentioned as.

Specifically, compounds containing a group II element include Zn (CH ₃ ) ₂ , Zn (C ₂ H ₅ ) ₂ , Zn
(OCH ₃ ) ₂ , Zn (OC ₂ H ₅ ) ₂ , Cd (C
_{H 3) 2, Cd (C} 2 H 5) 2, Cd (C 3 H 7) 2,
Cd (C ₄ H ₉ ) ₂ , Hg (CH ₃ ) ₂ , Hg (C ₂ H
₅ ) ₂ , Hg (C ₆ H ₅ ) ₂ , Hg ((C = (C
₆ H ₅ )) _{2 and the} like, and examples of the compound containing a Group VI element include NO, N ₂ O, CO ₂ , CO, H
₂ S, SCl ₂ , S ₂ Cl ₂ , SOCl ₂ , SeH ₂ ,
SeCl ₂ , Se ₂ Br ₂ , Se (CH ₃ ) ₂ , Se
(C ₂ H ₅ ) ₂ , TeH ₂ , Te (CH ₃ ) ₂ , Te
(C ₂ H ₅ ) _{2 and the} like.

Of course, these raw materials may be used alone or in combination of two or more.

Further, examples of the compound containing a group IV element include the compounds described above.

In the present invention, the starting compound described above is H
rare gases such as e, Ne, Ar, Kr, Xe, Rn, and H
₄ , may be introduced by mixing with a diluting gas such as HF or HCl. These diluent gases and the like may be independently introduced from gas supply means.

[0165]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.

(Example 1 and Comparative Example 1) The following experiments were conducted by using both the deposited film forming method of the present invention shown in FIG. 1 and the conventional deposited film forming method shown in FIG.

The specific working method, for example, the method of mixing and introducing the gas is as described above, and will be omitted here because it is redundant, and the characteristic items performed in the present embodiment will be described.

First, the method of forming a deposited film of the present invention shown in FIG. 1 and the conventional method of forming a deposited film shown in FIG. 18 are applied to an i-layer film forming chamber of a roll-to-roll type production apparatus shown in FIG. Imported as 1550. In other words, only the i-layer film forming chamber in the roll-to-roll type production apparatus shown in FIG. 15 was subjected to an experiment by exchanging the one using the deposited film forming method of the present invention with the one using the conventional deposited film forming method. is there.

The graded band gap aS
The gas mixer to the iGe layer deposition chamber further has a plurality of gas mixers therein for each gas outlet.

In this embodiment, the n-layer film forming chamber 1530
In addition, a film formation gas and a doping gas were not flowed into the p-layer film formation chamber 1570 at all, and no discharge was caused by microwave power. That is, in the present embodiment, one of the purposes is to grasp the single film characteristics of the film deposited in the i-layer film formation chamber. Secondly, in the present embodiment, the belt-like substrate is assumed to be fixed and immovable, and is positioned along the longitudinal direction of the substrate so as to face the deposition space at a position corresponding to the i-layer deposition chamber of the belt-like substrate. 7059 glass was installed. Examples of the method of fixing the glass to the band-shaped substrate include a method in which a hole is formed in the band-shaped substrate and the glass and fixing with a screw, or a method of fixing with a high melting point inorganic adhesive such as Aron ceramic or the like. Adopted the former.

That is, in the present embodiment, the film is not examined in a state where the films deposited at the respective locations from the inlet side end face to the outlet side end face of the i-layer chamber film forming chamber are laminated. The purpose is to separate and examine the characteristics of each part of the room.

Thirdly, in the conventional method for forming a deposited film shown in FIG. 18, a plurality of vacuum gauges are provided along the longitudinal direction of the film forming chamber similarly to the method for forming a deposited film of the present invention shown in FIG. The pressure in each part of the film forming chamber was monitored.

Under the above basic conditions, an a-SiGe film having a thickness of about 1 μm was formed under the film forming conditions shown in Table 1. The deposition conditions in the deposited film forming method of the present invention and the conventional deposited film forming method are exactly the same except for the pressure.

The positions a, a in the i-layer film forming chamber shown in Table 1
b, c, and d are vacuum gauges 115a to 115 in FIG.
d corresponds to the measurement position.

[0175]

[Table 1] About the obtained film, measurement of an optical band gap using a spectroscope and use of an X-ray microanalyzer were performed.
The composition of Si and Ge was analyzed. i-layer chamber
FIG. 8 shows the results of the above measurements performed at various locations in the longitudinal direction of the film forming chamber.

FIG. 8 (a) shows the optical band gap at each position. The solid line is the one by the deposited film forming method of the present invention, and the broken line is the one by the conventional deposited film forming method.
FIG. 8B shows the Ge content in the film at each position. The solid line indicates the deposited film forming method of the present invention, and the broken line indicates the conventional deposited film forming method.

As can be seen from FIGS. 8 (a) and 8 (b), in the conventional deposited film formation method, Ge is contained at the edge of the film formation space at about several percent, and accordingly, the optical band gap is about 1%. .65 eV, which is narrower than that of a-Si. Therefore, it has been found that the method of forming a deposited film of the present invention can ideally control the Ge content to produce a film having a desired bandgap profile.

(Examples and Comparative Example 2) The following experiments were carried out by both the deposited film forming method of the present invention shown in FIG. 1 and the conventional deposited film forming method shown in FIG.

The specific working method, for example, the method of mixing and introducing the gas is as described above, and is omitted here, and the characteristic items performed in this embodiment will be described. First, as in the first embodiment, the roll-to-roll system shown in FIG. 15 is used to form the deposition model forming method of the present invention shown in FIG. 1 and the conventional deposited film forming method shown in FIG. As an i-layer film forming chamber 1550.

Secondly, in the conventional deposition forming method shown in FIG. 18, a plurality of vacuum gauges are provided along the longitudinal direction of the deposition chamber in the same manner as in the deposited film forming method of the present invention shown in FIG. The pressure at each point in the chamber was monitored.

Third, in this embodiment, a single
An n-type a-Si layer, an i-type graded band gap a-SiGe layer, and a p-type a-Si layer, which constitute a cell solar cell, were stacked. Each layer thickness is 200 ° for an n-type a-Si layer,
i-type graded band gap a-SiGe layer
The thickness was 500 ° and the p-type a-Si layer was 120 °. Table 2 shows these film forming conditions.

[0182]

[Table 2] The film forming conditions in the deposited film forming method of the present invention and the conventional deposited film forming method are the same except for the pressure. The positions a, b, c and d in the i-layer type membrane chamber in Table 2 correspond to the positions measured by the pressure gauges 115a to 115d in FIG. 1, respectively.

In each of the deposited film forming method of the present invention and the conventional deposited film forming method, two samples were prepared, one of which was subjected to composition analysis, and one of which was further provided with a transparent electrode (I
TO) and a collecting electrode (lamination of Cr and Ag) to form a single solar cell. The composition analysis was performed by Auger electron spectroscopy, and the analysis was advanced from the p-layer side, and the profile of the Ge content in the depth direction up to the substrate was examined. FIG. 9 shows the result. In FIG. 9, the solid line is obtained by the deposited film forming method of the present invention, and the broken line is obtained by the conventional deposited film forming method. As can be seen from FIG. 9, in the conventional deposited film forming method, the vicinity of the interface on the p-layer side and the vicinity of the interface on the n-layer side contain about several% of Ge, whereas in the deposited film forming method of the present invention, It turns out that Ge is not included in the film, and ideal film composition control can be performed.

On the other hand, the solar cell characteristics of the cell in which the transparent electrode and the current collecting electrode were laminated were examined. Simulated sunlight of AM1.5 was used as the irradiation light, and the energy density was 1
00 mW / cm ² . The measurement area of each subcell is 0.5 cm ² . The results are as follows.

The conversion efficiency of the cell manufactured by using the conventional deposited film forming apparatus is 8.6%. The conversion efficiency of the cell manufactured by using the deposited film forming apparatus of this embodiment is 9.0% or more. It has been found that a cell whose composition is ideally controlled by using the deposited film forming apparatus described above has improved conversion efficiency as compared with a conventional cell.

(Example 3) 1812a to 1812 using an i-layer deposition chamber in which exhaust holes shown in FIG.
d. The method of forming a deposited film of the present invention was performed by changing the amount of gas introduced from the gas discharge port.

Also in this example, a plurality of pressure gauges were provided along the longitudinal direction of the film forming chamber and the pressure at the name of the film forming chamber was monitored in the same manner as in the deposited film forming method of the present invention shown in FIG.

In this example, the conditions for forming the n-type a-Si layer and the p-type a-Si layer are exactly the same as those in Table 2, and the thickness of each layer is set to 200 ° for the n-type a-Si layer and 200 μm for the i-type. Graded band gap a-SiGe of 2500 °, p-type a-
The Si layer was set to 100 °.

The experiment was performed using an i-layer chamber 1812a-181.
The experiment was performed four times while changing the amount of gas discharged from each gas discharge port of 2d, and the experiments are referred to as Experiments 1 to 4, respectively.

Table 3 shows the gas amount and the pressure at each position at that time.

[0191]

[Table 3] In Experiment 1, the flow rate of H ₂ discharged from each gas outlet was 1812.
a to 1812d are the same, and correspond to a conventional deposited film forming method. In Experiments 2 to 4, the flow rate of H ₂ gas discharged from the gas discharge ports 1812c was minimized, and the amount of H ₂ gas flowing out of the other gas discharge ports was gradually increased.
The pressure gradient becomes steeper as going from Experiments 2 to 4.

In each case, two samples were prepared. One sample was subjected to composition analysis, and one sample was further subjected to a transparent electrode (ITO) and a current collecting electrode (lamination of Cr and Ag) on the sample by vapor deposition. Were laminated to form a single solar cell.

The composition analysis was performed by Auger electron spectroscopy, and the analysis was performed from the p-layer side, and the profile of the Ge content in the depth direction up to the substrate was examined. The results for Experiments 1-4 are shown in FIG.

As shown in FIG. 10, the content near the edge of the film formation space decreased from Experiment 1 to Experiment 4 and
The e content has a steep slope.

On the other hand, the solar cell characteristics of a cell in which a transparent electrode and a current collecting electrode were laminated were examined. Simulated sunlight of AM1.5 was used as the irradiation light, and the energy density was 1
00 mW / cm ² . The measurement area of each sub-cell is 0.5 cm ² . Table 4 shows the measurement results for Experiments 1 to 4.

[0196]

[Table 4] As shown in Table 4, the conversion efficiency was improved from Experiments 1 to 3, which proved that the deposited film forming method of the present invention was excellent.

In Experiment 4, the conversion efficiency is lower than that in Experiment 3, but it is superior to Experiment 1, that is, the conventional deposition film forming method. The reason why the conversion efficiency was lower in Experiment 4 than in Experiment 3 is that the bandgap profile became too steep at the location where the Ge content was high, and conversely the bandgap profile at the edge of the film formation space became flat. It is considered that the traveling property of the carrier was lowered.

Example 4 Using the method of the present invention, a tandem solar cell in which the i-layer of the top cell was made of amorphous silicon was produced.

FIG. 11 is a schematic diagram of the apparatus used for the preparation. The production apparatus shown in FIG. 11 is basically the same as the production apparatus shown in FIG. 15 except that the number of film forming chambers is increased for a tandem solar cell. 11, reference numeral 1100 denotes a substrate delivery chamber, 1110 denotes an n-type a-Si layer film formation chamber for a bottom cell,
Reference numeral 1120 denotes an i-type graded band gap a-SiGe layer film forming chamber for a bottom cell, 1130 denotes a p-type a-Si layer film forming chamber for a bottom cell, and 1140 denotes an n-type a-Si layer for a top cell. Deposition chamber, 1150: i-type a-Si layer deposition chamber for top cell, 1160: p-type a-Si layer for top cell
Si film formation chambers, each of which has a gas mixer 11
The film forming gas mixed at a desired flow rate and flow rate ratio is introduced from 11, 1121,... 1161, and power is supplied from a microwave power supply (not shown) to form a desired film on the base 1102. Graded band gap a-SiG
The gas mixer for e-formation deposition also has a plurality of gas mixers for each gas outlet within 3. The raw material cylinder for the deposition gas is basically the same as that shown in FIG.
Reference numerals 1181 to 1187 denote gates that connect the respective rooms.

Each gate is provided with a purge gas ejection port, and a purge gas is supplied to each ejection port from a purge gas cylinder at a desired flow rate. The other portions related to the film formation and the steps for forming the a-Si film are the same as those shown in the related art, and thus the description thereof is omitted.

Further, in this embodiment, the i-type graded band gap a-
As the SiGe film forming chamber 1120, the deposited film forming means of FIG. 12 based on the deposited film forming method of the present invention was used.

FIG. 12 shows a substrate used in the roll-to-roll system, which is curved in an i-layer film forming chamber, and a film forming chamber is formed by the substrate itself.

With such a structure, a considerable portion of the film deposition surface is occupied by the substrate, and the utilization efficiency of the film forming gas is improved.

In the columnar discharge space having a circular cross section formed by such a curved substrate, an exhaust adjusting plate for adjusting the pressure of the present invention is provided concentrically to adjust the pressure.

In this example, the microwave has two applicators so as to face the end face of the columnar discharge space.

In FIG. 12, reference numeral 1201 denotes a band-shaped member having a width of 20 cm, which is made of SUS430BA, and which is curved like a column having a radius of 12 cm. 1202, 1203
Is a roller 1 for bending the belt-like member 1201 into a column shape.
Reference numeral 204 denotes a transfer ring, and reference numerals 1206a and 1206b denote temperature control mechanisms provided all around. 1207,1
Reference numeral 208 denotes a microwave introduction applicator, 1209 denotes a dielectric window, and 1211 and 1212 denote waveguides, which are connected to a microwave power supply (not shown). 1213a-12
13d is a gas introduction pipe, and 1214 is an exhaust port, which is connected to exhaust means such as a diffusion pump (not shown). 1215
Is an exhaust control plate for pressure control.

The pressure at an arbitrary position can be checked by a vacuum gauge (not shown). FIG. 13 schematically shows a gas flow having such a configuration.

In FIG. 13, reference numeral 1301 denotes a column-shaped curved base, 1302 denotes a roller, 1303 denotes an exhaust adjustment plate, and 1304 denotes a gas discharge port.

Using the apparatus shown in FIGS. 11 and 12, a tandem cell solar cell was manufactured by the method of forming a deposited film of the present invention. The layer structure of the cell is of the type shown in FIG.

The thickness of each layer is 200 ° for the bottom cell n-type a-Si layer, 2800 ° for the bottom cell i-type graded band gap i-type a-SiGe layer, and 120 ° for the bottom cell p-type a-Si layer. , Top cell n-type a-Si
180 ° layer, 2000 top cell i-type a-Si layer
Å, the top cell p-type a-Si layer was 100Å. Table 5 shows the film forming conditions. In the table, positions a, b, c, and d in the i-type a-SiGe layer and the i-type a-Si layer correspond respectively to the positions of the gas discharge ports counted from the approach direction of the belt-shaped substrate.

[0211]

[Table 5] A transparent electrode and a current collecting electrode were further laminated on the prepared cell, and the solar cell characteristics were examined. As irradiation light, AM1.5
Energy density is 100mW / c
It was m ^2. The measurement area is 0.5 cm ² . As a result, it was confirmed that the device had excellent characteristics with an in-hand conversion efficiency of 12.4%.

Example 5 An a-SiC film was deposited by the deposition film forming method of the present invention using the apparatus shown in FIG.

The specific working method, for example, the method of mixing and introducing gas, is as described above, and is redundant. Therefore, the description is omitted here, and the characteristic items performed in this embodiment are described.

First, the deposited film forming method of the present invention shown in FIG. 1 was taken in as the a-SiC film forming chamber 1550 of the roll-to-roll type production apparatus shown in FIG.

In this embodiment, the n-layer film forming chamber 1530
And a p-layer deposition chamber 1570 contains deposition gas and doping gas.
No gas was caused to flow, and no discharge was caused by microwave power. That is, in this embodiment, one of the purposes is to grasp the single-layer characteristics of the film deposited in the a-SiC film deposition chamber.

Second, in this embodiment, the belt-like substrate is
A-Si of the band-shaped substrate as fixed and immovable
The # 7059 glass was placed along the longitudinal direction of the substrate on the side of the film formation space corresponding to the C film formation chamber. Examples of the method of fixing the glass to the band-shaped substrate include a method in which a hole is formed in the band-shaped substrate and the glass and fixing with a screw, or a method of fixing with a high melting point inorganic adhesive such as Aron ceramic or the like. Adopted the former.

That is, in this embodiment, a-Si
The C film deposition chamber is not intended to examine the film in a state where the film is deposited at each location from the entrance end face to the exit end face of the deposition chamber. Is to be investigated separately.

In this embodiment, the cylinder 150 shown in FIG.
3a is converted to a C ₂ H ₂ gas cylinder instead of a GeH ₄ gas cylinder. Further, in this embodiment, a DC power supply was connected to all the gas outlets of the SiC layer film forming chamber, and a bias voltage of +60 V was applied.

Under the above basic conditions, an a-SiC film having a film pressure of about 1 μm was formed under the film forming conditions shown in Table 6. In Table 6, positions a,
b, c and d are gas outlets 112a to 112a in FIG.
It corresponds to the position of 12d.

[0220]

[Table 6] The C content of the obtained film was measured by an X-ray micro analyzer. FIG. 1 shows the results of the above measurements performed at various locations in the longitudinal direction of the i-layer chamber film forming chamber.
It is shown in FIG.

As can be seen from FIG. 14, the C content at the end of the film forming space was substantially 0, and the effect of the deposited film forming method of the present invention was confirmed.

[0222]

As described above, according to the present invention, the R-Rμ
The composition changes continuously by the WCVD method, for example, a-
When manufacturing an element such as a photovoltaic element, which includes an alloy film such as SiGe, a-SiC, or a film in which the doping amount of a valence electron controlling agent to a semiconductor element continuously changes, for example, In the case of lamination with an end face or another kind of film, composition control at an interface with another film can be realized as desired, and an ideal bonding surface can be formed to produce a device having good characteristics. It becomes possible.

Further, according to the present invention, for example, a photovoltaic element having good characteristics can be manufactured in a large area in a large amount at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an apparatus for realizing a deposited film forming method of the present invention.

FIG. 2 is a diagram schematically showing a gas flow in a deposited film forming apparatus employing the deposited film forming method of the present invention.

FIG. 3 is a diagram showing an example of a- fabricated using the deposited film forming method of the present invention.
7 is a graph showing a film thickness distribution of a Ge film.

FIG. 4 is a schematic diagram showing an energy band of a graded band-cap a-SiGe film manufactured by using the deposited film forming method of the present invention.

FIG. 5 is a graph showing a pressure in a film forming space when a deposited film is formed based on the deposited film forming method of the present invention.

FIG. 6 is a schematic view showing various variations when the band gap is continuously changed in the a-SiGe film.

FIG. 7 is a schematic view showing various variations when the content of a valence electron controlling agent is continuously changed in a semiconductor and the Fer level is continuously changed.

FIG. 8 (a) is a graph showing the position dependence of the optical band gap of a film deposited using the present invention and a conventional deposited film forming method. FIG. 8B is a graph showing the position dependence of the Ge content in films deposited using the present invention and the conventional deposited film forming method.

FIG. 9 is a graph showing the distribution in the depth direction of the Ge content in films deposited using the present invention and a conventional deposited film forming method.

FIG. 10 is a graph showing the distribution of the Ge content in the depth direction in a film manufactured by variously changing the pressure distribution in the film forming space in the deposited film forming method of the present invention.

FIG. 11 shows a-SiG using the deposited film forming method of the present invention.
FIG. 2 is a schematic diagram showing an example of an apparatus used when producing a stacked solar cell made of e and a-Si.

FIG. 12 shows a deposited film forming apparatus using the deposited film forming method of the present invention, in which a band-shaped substrate is curved to form a columnar film-forming space, and microwaves are applied from both end surfaces of the columnar film-forming space. FIG.

FIG. 13 is a view schematically showing a gas flow in the deposition film forming apparatus shown in FIG.

FIG. 14 shows a graded band gap a produced by the deposition film forming method of the present invention using the apparatus shown in FIG.
-Graph which shows the C content in the SiC film.

FIG. 15 is a schematic view showing a conventional roll-to-roll production apparatus.

FIG. 16 is a schematic view illustrating an example of a stacked solar cell.

FIG. 17 is an energy band diagram of an a-SiGe film. (A) In case of graded band gap method (b) In case of conventional method

FIG. 18 is a schematic view showing an arrangement of a conventional film formation space in a roll-to-roll production apparatus.

FIG. 19 shows a-S fabricated using a conventional deposited film forming method.
FIG. 3 is a schematic diagram showing an energy band of an iGe film.

FIG. 20 shows aS fabricated using a conventional deposited film forming method.
5 is a graph showing a film thickness distribution of an i film and an a-Ge film.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 Belt-like base 102 Vacuum chamber for creating a decompressed state 104 Exhaust port 105 Exhaust means 103 Film formation chamber 120 SiH ₄ gas line 121 GeH ₄ gas line 122 H ₂ gas line 114a, 114b, 114c, 114d Gas mixer 113a, 113b, 113c, 113d Gas pipe 112a, 112b, 112c, 112d Gas outlet 110a, 110b, 110c, 110d Microwave applicator having dielectric window 111a, 111b, 111c, 111d Waveguide 201 Vacuum chamber 222 Evacuation Means 203 Film formation chamber 204a to 204d Gas emission port 205 Exhaust port 206 Band-like substrate 1100 Delivery chamber 1102 Substrate 1110 Bottom cell n-type a-Si layer film formation chamber 1120 Bottom Cell i-type a-SiGe layer deposition chamber 1130 Bottom cell p-type a-Si layer deposition chamber 1140 Top cell n-type a-Si layer deposition chamber 1150 i-type a-Si layer for top cell Film forming chamber 1160 p-type a-Si layer film forming chamber for top cell 1111, 1121, 1161 Gas mixer 1190 SiH ₄ gas, GeH ₄ gas, H ₂ gas, B
₂ H ₆ gas, PH ₃ gas filled gas cylinders 1181 to 1187 Gate. 1201 belt-like member 1202, 1203 roller for bending belt-like member 1201 into a column shape 1204 transport ring 1206a, 1206b temperature control mechanism 1207, 1208 microwave applicator 1209 dielectric window 1211, 1212 waveguide 1213a to 1213d gas introduction pipe 1214 Exhaust port 1215 Exhaust control plate 1301 Column-shaped curved base 1302 Roller 1303 Exhaust control plate 1304 Gas outlet 1501 Strip base 1511, 1591 Bobbin around which base 1501 is wound 1510 Substrate delivery chamber 1530 n-type a-Si film formation chamber 1550 i-type a-SiGe film formation chamber 1570 p-type a-Si film formation chamber 1590 substrate winding room 1520, 1540, 1560, 1580 Gate 1530a, 1550a, 1570 Microwave applicators 1530b, 1550b, 1570b waveguide 1502a~1506a material gas cylinders 1502a SiH ₄ gas cylinder 1503a GeH ₄ gas cylinder 1504a H ₂ gas cylinder 1505a PH ₃ gas cylinder 1506a B ₂ H ₆ gas cylinder 1502b to 1506b Opening / closing valve of gas cylinder 1502c to 1506c Decompressor 1530c, 1550c, 1570c Gas mixer 1530d, 1550d, 1570d Gas introduction line 1510e, 1530e, 1550e, 1570e, 1
590e Exhaust pump 1530f, 1550f, 1570f Substrate heating heater 1530g, 1550g, 1570g Substrate heating heater power supply 1507a Gate purge gas cylinder 1507b Depressurizer 1507c, 1507d Gas flow controller 1601 Conductive substrate 1602 Lower photovoltaic Element (bottom cell) 1602 n-type a-Si, 1602bi i-type a-SiGe, 1602c p-type microcrystalline μC-Si layer 1603 top photovoltaic element 1603a n-type a-Si, 1603bi i-type a-Si, 1603c p-type microcrystalline μC-Si layer 1604 transparent electrode 1605 current collecting electrode 1801 belt-like substrate 1802 vacuum chamber 1803 deposition chamber 1804 exhaust port 1805 exhaust means 1820 SiH ₄ gas line 1821 GeH ₄ gas line Emissions 1822 H ₂ gas line 1814a~1814d gas mixer 1813a~1813d gas pipe 1812a~1812d gas outlet 1810a~1810d microwave applicator 1811a~1811d waveguide

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoshi Yoshiri, 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Shotaro Oka 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Non Corporation (72) Inventor Akira Sakai 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Corporation (56) References JP-A-3-30421 (JP, A)

Claims (12)

(57) [Claims] 1. A method for forming a film through a gas supply means into a film forming space while continuously moving the belt-shaped substrate in a longitudinal direction so as to become one of side walls of the film forming space. by radiating the microwave energy by the microwave applicator means into the film-forming space while introducing a gas to rise to the microwave plasma, the deposition of the band-like substrate to move
Microwave plasma C to form a continuous deposited film on the surface
In a method of forming a deposited film using a VD method and a roll-to-roll method, a method is provided in which the belt-shaped substrates are separated from each other along a moving direction of the band-shaped substrate.
Out of the plurality of gas outlets from the first gas outlet.
Discharging a first gas containing the element of
Forward from the second gas outlet spaced from the first gas outlet
The second gas which does not contain the first element but contains the second element
When the film is discharged into the film formation space to form the deposited film, the second gas discharge port is closer to the first gas discharge port than the second gas discharge port.
The film forming space from a gas outlet provided unevenly at a position
The inside of the film formation space is evacuated, and
The concentration of the first element in the vicinity of the second gas outlet
By making the concentration higher than the concentration of the nearby element, the first element and the second element
A method of forming a deposited film using a microwave plasma CVD method and a roll-to-roll method, wherein a film whose composition ratio changes in a film thickness direction is formed. 2. The surface to be deposited is below the concave portion of the box-shaped chamber.
While moving the strip-shaped substrate so as to face
A plurality of eccentrically located at the bottom of the chamber below the first gas outlet;
From the gas outlet provided in the chamber
2. The method according to claim 1 , wherein the gas is exhausted . 3. The film-forming space is formed by forming the strip-shaped substrate into a pillar shape.
While being bent and moved, the curved substrate
Inside the first gas, along the surface of the band-shaped substrate to be deposited.
An opening serving as the gas exhaust port is unevenly provided near the discharge port.
A curved exhaust adjustment plate is provided, and the component is
2. The method according to claim 1 , wherein the inside of the film space is evacuated by a microwave plasma CVD method and a roll-to-roll method. 4. The method according to claim 1 , wherein
The second gas outlets are respectively provided on both sides of the first gas outlet.
Placing and releasing said second gas from each second gas outlet
Microwave plasma CVD method according to any one of claims 1 to 3, characterized in that and roll-to-
A method for forming a deposited film using a roll method. 5. The first element is germanium.
And silicon as the second element.
At least one of hydrogen and halogen as a deposition film
Amorphous semiconductor film containing silicon, germanium and silicon
2. The microwave pump according to claim 1, wherein
Deposition using the plasma CVD method and the roll-to-roll method
A method for forming a laminated film. 6. The method according to claim 6, wherein carbon is used as the first element.
And silicon is used as the second element.
With at least one of hydrogen and halogen as a film
Form an amorphous semiconductor film containing carbon and silicon
The microwave plasma according to claim 1, wherein:
Deposition film type using CVD method and roll-to-roll method
Method. 7. The band-shaped substrate becomes one of side walls of a film forming space.
As described above, while continuously moving in the longitudinal direction,
Introducing a film-forming gas into the film-forming space via gas supply means
Microwave energy and microwave application
Radiated into the film forming space by
Of the moving band-shaped substrate by generating wave plasma
Microwave plasma C that continuously forms a deposited film on the surface
Deposition film formation using VD method and roll-to-roll method
In the law, Provided apart from each other along the moving direction of the band-shaped substrate.
Out of the plurality of gas outlets from the first gas outlet.
Discharging a first gas containing the element of
Forward from the second gas outlet spaced from the first gas outlet
The second gas which does not contain the first element but contains the second element
When the film is released into the film forming space to form the deposited film, The supply flow rate of the first gas is changed to the supply flow rate of the second gas
The first gas outlet in the film formation space with a smaller number
Pressure near the second gas outlet is lower than the pressure near the second gas outlet.
And in the film forming space, in the vicinity of the first gas discharge port.
Said first element Element concentration near the second gas outlet.
Higher than the concentration of the element in The first element and the second element on the strip-shaped substrate;
It is characterized by forming a film whose composition ratio changes in the film thickness direction.
Microwave plasma CVD method and roll-to-roll
A method for forming a deposited film using a rule method. 8. The surface to be deposited is lower on the concave portion of the box-shaped chamber.
While moving the strip-shaped substrate so as to face
A plurality of said gas outlets evenly arranged at the bottom of the chamber
Exhausting the inside of the chamber through an opening
Item 7. The microwave plasma CVD method and the roll according to Item 7,
A deposited film forming method using a two-roll method. 9. The method according to claim 9, wherein the direction of movement of the band-shaped substrate is
The second gas outlets are respectively provided on both sides of the first gas outlet.
Placing and releasing said second gas from each second gas outlet
9. The micro device according to claim 7, wherein
Using microwave plasma CVD method and roll-to-roll method
Deposited film formation method. 10. The method according to claim 1, wherein the first element is germanium.
Using silicon as the second element,
At least one of hydrogen and halogen as a deposited film
Semiconductor film containing silicon, germanium and silicon
The microwave according to claim 7, wherein the microwave is formed.
Using plasma CVD method and roll-to-roll method
A method for forming a deposited film. 11. The method according to claim 11, wherein carbon is used as the first element.
And silicon is used as the second element.
With at least one of hydrogen and halogen as a film
Form an amorphous semiconductor film containing carbon and silicon
The microwave plasma according to claim 7, wherein
Deposition film type using CVD method and roll-to-roll method
Method. 12. An N-type silicon film as the deposition film
I-type silicon gel sandwiched between P-type silicon film
When forming a manium film, the I-type silicon germanium
Germanium content at both ends in the film thickness direction
Claims characterized by being formed to be substantially zero
Item 7. The microwave plasma CVD method according to item 1 or 7,
A method for forming a deposited film using a rule-to-roll method.