JP3490278B2 - Photoelectric conversion device and manufacturing method thereof - 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 manufacturing a photoelectric conversion device represented by a solar cell or an image input sensor and a photoelectric conversion device.

[0002]

2. Description of the Related Art An amorphous silicon film can be formed in a large area at a low temperature of 400 ° C. or less and has a thickness necessary for absorbing light as a photoelectric conversion layer, as compared with a crystalline silicon material. It is characterized in that about 1 μm is sufficient. Therefore, it has been proposed that silicon resources can be saved and manufacturing energy can be reduced, and it has been attracting attention as a low cost material.

Conventionally, a photoelectric conversion layer of a solar cell, an image sensor, a photosensor or the like generally uses a diode type structure having a pin junction in order to improve photoelectric conversion efficiency and photoresponsiveness. It was Here, although it is possible to form all of the p-type and n-type semiconductor films and the substantially intrinsic i-type semiconductor film with an amorphous silicon film, in order to obtain good photoelectric conversion characteristics, It has been known that good photoelectric conversion characteristics can be obtained by using a microcrystalline silicon material for p-type and n-type semiconductor films.

The reason for this is that, in the element having this structure, the p-type and n-type semiconductor films have high light transmittance because the i-type amorphous silicon film is responsible for light absorption and generation of electric charges accompanying it. This is because a material having high conductivity is required in order to obtain desirable and good contact with the electrode. In response to such requirements, the microcrystalline silicon film is a material having a property of having a low light absorption property and a high electrical conductivity and is a suitable material.

The amorphous silicon film is formed by a chemical deposition method (plasma CVD) using glow discharge plasma under reduced pressure.
Method). The plasma CVD method includes a reaction chamber, an evacuation unit for keeping the reaction chamber under reduced pressure, a gas introduction unit for introducing a source gas, a unit for generating glow discharge plasma in the reaction chamber, and a unit for holding and heating a substrate. A plasma CVD apparatus composed of and is used. Silane (SiH ₄ ) gas is usually used as the source gas, but disilane (Si ₂ H ₆ ) gas can also be used, and the source gas is diluted with hydrogen gas (H ₂ ) before use. I also got it.

On the other hand, the microcrystalline silicon film is used as a source gas,
A mixed gas of SiH ₄ gas and H ₂ gas is used.
It was possible to obtain by forming a film in a state in which the dilution ratio of H ₂ gas with respect to ₄ gas was increased. It has been known that a microcrystalline silicon film to which a p-type or n-type conductivity determining impurity element is not added exhibits n-type conductivity by itself. Usually, in order to further increase the electric conductivity, in order to control the p-type or n-type conductivity, an impurity gas containing p-type and n-type conductivity determining elements is simultaneously added to the source gas at the time of film formation. It is made by.

In the field of semiconductors, the p-type conductivity determining element is an element typified by boron (B), aluminum (Al), gallium (Ga), and indium (In) in Group IIIb of the periodic table. As the n-type conductivity determining element, elements represented by phosphorus (P), arsenic (As) and antimony (Sb) in the Vb group of the periodic table are known. In a normal plasma CVD method, an impurity gas typified by B ₂ H ₆ or PH ₃ is mixed with the raw material gas to form a film. The amount of the impurity gas mixed at this time is SiH
₄ to 0.1% to 5%, 10% at most
It was the following concentration.

As described above, since the microcrystalline silicon film and the amorphous silicon film have a low process temperature, the materials applicable to the substrate of the photoelectric conversion device include the glass material and the organic resin material as the substrate. It was also possible to do.

[0009]

A basic process of a photoelectric conversion device such as a solar cell or an image sensor manufactured on a substrate is to form a first electrode on the substrate and then to form a first electrode on the first electrode. A photoelectric conversion layer composed of a pin junction is formed in close contact, and a second electrode is further stacked to manufacture. At the time of manufacturing a pin junction, in order to improve the characteristics of the junction interface, film formation is usually performed without breaking the vacuum.

At this time, if the impurity gas is added to the source gas in order to form a p-type or n-type semiconductor film,
It has been known that a small amount of impurity gas and its reaction product remain and adhere to the reaction chamber and the discharge electrode which is a part of the glow discharge plasma generating means. Here, when a substantially intrinsic i-type amorphous silicon film is formed continuously without adding an impurity gas in the same reaction chamber, the residual impurities are released and newly taken into the film. There was a problem that it was lost.
Since the substantially intrinsic i-type amorphous silicon film is manufactured so that the defect density in the film is about 1 × 10 ¹⁶ / cm ³ or less, even if it is several tens of ppm to several hundred pp.
Even if the impurity element is taken in at a concentration of m, there is a problem that the order of impurities is formed and the characteristics of the film are changed.

In order to solve such a problem, plasma CV
There has been devised a multi-chamber separation type CVD apparatus in which a plurality of reaction chambers are provided in the apparatus D, and each reaction chamber is separated by a gate valve between the reaction chamber and another reaction chamber. Therefore, according to the conventional technique, it is necessary to provide at least three independent reaction chambers for forming at least p-type, i-type, and n-type semiconductor films in order to form a pin junction.

As a result, the plasma CVD apparatus is provided with a gas introduction means for introducing SiH ₄ , H ₂ , B ₂ H ₆ , PH _{3 and the} like, an exhaust means, a glow discharge plasma generation means, etc. corresponding to each reaction chamber. It was necessary, and it became a complicated and large-scale structure. Therefore, a great deal of labor is required also from the aspect of maintenance of the device.

From the viewpoint of the process, each time a conductive semiconductor film is formed, the substrate is moved from the reaction chamber to the other reaction chamber, the reaction gas is introduced, and the reaction gas is exhausted. And the process must be repeated, and this process must be sequentially repeated. Therefore, there is a limit to shortening the time for forming the photoelectric conversion layer.
Even if the actual film formation time is shortened by using the technique of high-speed film formation, the time required to transfer the substrate and to introduce and exhaust the gas has been a problem that cannot be ignored.

Further, in the technical field of conventional solar cells, there is a method of continuously changing the p-type impurity concentration at the p / i interface of the photoelectric conversion layer to form the continuity of the interface and improve the bondability. Known from the past. In the prior art,
In the film forming step, it was necessary to precisely control the gas containing a small amount of p-type impurity element by using a computer or the like.

[0015]

As a means for solving the above problems, the present invention provides a step of forming an amorphous semiconductor layer and a microcrystalline semiconductor layer, and a step of adding impurities to the microcrystalline semiconductor layer to obtain a conductive type. Disclosed is a method of forming a photoelectric conversion layer separately from the step of controlling the.

According to the first aspect of the present invention, in the process of producing a photoelectric conversion layer, in order to improve the productivity, the first type electrode is produced without adding a p-type or n-type conductivity type determining impurity element from the first electrode side. The step of forming a microcrystalline semiconductor film, the step of forming a substantially intrinsic amorphous semiconductor film, and the second microcrystal manufactured without adding a p-type or n-type conductivity determining impurity element A step of forming a semiconductor film, and thereafter, a step of injecting a p-type conductivity determining impurity element into the second microcrystalline semiconductor film and applying heat treatment, to form a photoelectric conversion layer. It is characterized by having. At this time, the p-type impurity element may be injected into the second microcrystalline silicon film and the vicinity of the interface between the second microcrystalline silicon film and the substantially intrinsic amorphous silicon film.

Further, according to the present invention, in the process of manufacturing the photoelectric conversion layer, in order to improve the productivity, the photoelectric conversion layer is formed from the first electrode side.
a step of forming a first microcrystalline semiconductor film which is manufactured without adding a p-type or n-type conductivity determining impurity element; a step of forming a substantially intrinsic amorphous semiconductor film; a step of forming a second microcrystalline semiconductor film which is manufactured without adding an n-type conductivity determining impurity element, and after forming a second electrode, a second electrode is formed from the surface of the second electrode. The photoelectric conversion layer is formed by the steps of injecting a p-type conductivity determining impurity element into the second microcrystalline semiconductor film and applying heat treatment. At this time, the p-type impurity element may be injected into the second microcrystalline silicon film and the vicinity of the interface between the second microcrystalline silicon film and the substantially intrinsic amorphous silicon film.

Further, according to the present invention, in order to prevent the contamination of the impurity gas by the plasma CVD method, the first and second microcrystals produced without adding the p-type or n-type conductivity determining impurity element. The first microcrystalline semiconductor film and a second p-type conductivity type determining impurity element are implanted into the semiconductor film.
By the step of applying heat treatment to the microcrystalline semiconductor film of
A photoelectric conversion layer is manufactured by obtaining a microcrystalline semiconductor film having p-type and n-type conductivity.

In the present invention, the most preferable embodiment is that a microcrystalline silicon film is applied to the microcrystalline semiconductor film and an amorphous silicon film is applied to the amorphous semiconductor film. Further, as the amorphous semiconductor film, an amorphous silicon carbide film, an amorphous silicon germanium film, or an amorphous silicon tin film can be applied.

As a method of implanting the p-type conductivity determining impurity element from the surface of the second electrode, an ion doping method is one example of a desirable embodiment of the present invention.

[Operation] According to the present invention, it is not necessary to add a p-type or n-type conductivity type determining impurity element to the conventional process of forming p-type and n-type microcrystalline semiconductor films. Becomes This means that it is not necessary to consider contamination by the impurities in the step of forming the p-type and n-type microcrystalline semiconductor films and the substantially intrinsic i-type amorphous semiconductor film, and for example, the same It is also possible to continuously form films in the film forming chamber.

Specifically, the p-type and n-type microcrystalline silicon films and the substantially intrinsic amorphous silicon film are SiH ₄
Since it is produced only from gas or Si ₂ H ₆ gas and H ₂ gas, it is possible to form a film by the same glow discharge plasma generation means provided in the same reaction chamber. further,
It is also possible to continuously form the p-type and n-type microcrystalline silicon films and the substantially intrinsic amorphous silicon film while maintaining the glow discharge plasma.

Further, according to this embodiment, it is necessary to introduce an impurity gas in the step of forming an i-type amorphous semiconductor film which is substantially intrinsic to the p-type and n-type microcrystalline semiconductor films. In addition, since the influence of impurity contamination in the plasma CVD apparatus is reduced, the number of reaction chambers is substantially one, and the configuration of the plasma CVD apparatus can be simplified.

Therefore, according to the present invention, the step of forming the first microcrystalline semiconductor film, the step of forming the substantially intrinsic amorphous semiconductor film, and the second microcrystalline semiconductor film are formed. A step of implanting a P-type determining impurity element into the second microcrystalline semiconductor film, and a step of applying heat treatment to the amorphous semiconductor film substantially intrinsic to the first and second microcrystalline semiconductor films. ,
And a microcrystalline semiconductor film exhibiting p-type and n-type conductivity,
It is possible to obtain a substantially intrinsic amorphous semiconductor film, and p
An in-junction can be formed. Therefore, it is not necessary to use the n-type impurity element which is the conventional technique.

In a preferred embodiment of the present invention, the first
Since the second microcrystalline silicon film and the substantially intrinsic amorphous silicon film can be produced from SiH ₄ gas and H ₂ gas, gas switching is not always necessary when producing each film. You don't have to. Therefore, the time required for moving the substrate from the reaction chamber to the reaction chamber and for introducing and exhausting the gas, which is required in the conventional process, becomes unnecessary, and the process throughput can be improved.

According to the present invention, the p-type and n-type microcrystalline silicon films and the substantially intrinsic amorphous silicon film are provided in each reaction chamber of a plasma CVD apparatus having a plurality of reaction chambers. It is possible to fabricate them at the same time or individually, and it is possible to improve the process capacity.

Further, by implanting the p-type conductivity determining impurity element from the surface of the second microcrystalline semiconductor film by using the ion doping method, the concentration distribution of the p-type impurity in the film thickness direction can be easily controlled. can do.

Further, the present invention can be applied to a photoelectric conversion device using an organic resin substrate selected from polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyimide and aramid.

[0029]

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

Example 1 An example of an embodiment according to the present invention will be described according to the steps of the solar cell shown in FIG. In this embodiment, an organic resin film is used for the substrate 101. Preferred organic resin film materials for producing this example include polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyimide, and aramid. Here, polyethylene naphthalate (PEN) having a thickness of 80 μm was used. .

A first electrode is formed on the surface of the substrate 101. The first electrode 102 was formed by a known method typified by a vacuum evaporation method or a sputtering method. First electrode 10
Materials used for 2 are Al, Ag, Ti, Cr, Ni, P
It may be formed of a light-reflective metal electrode selected from t. About 100 nm to 300 nm is sufficient as the necessary film thickness, but even if the thickness is out of this range,
It has nothing to do with the components of the present invention. Here, the first electrode was formed by forming Al to a thickness of 150 nm by the sputtering method and further forming Ti on the surface of the Al to a thickness of 20 nm by the sputtering method. (Fig. 1 (a))

Next, a step of forming a microcrystalline silicon film and an amorphous silicon film to be a photoelectric conversion layer on the surface of the first electrode 102 was performed. The first microcrystalline silicon film 103 without adding a p-type or n-type conductivity determining impurity element
Then, the substantially intrinsic amorphous silicon film 104 and the second microcrystalline silicon film 105a were formed by a plasma CVD method without adding a p-type or n-type conductivity determining impurity element. (Fig. 1 (b))

FIG. 2 is a conceptual diagram of the single-wafer plasma CVD apparatus used in this embodiment. The plasma CVD apparatus may have a configuration according to a conventional technique, and includes a substrate transfer chamber 201, a substrate loading / unloading chamber 202, and a plurality of reaction chambers 203a, 203b, and 203c, each of which has a plasma generating means 204. Is provided. Although not shown, each reaction chamber is provided with an evacuation unit for keeping the reaction chamber under reduced pressure and a unit for holding and heating the substrate.

According to this embodiment, the first and second microcrystalline silicon layers and the substantially intrinsic amorphous silicon layer are:
Since it is sufficient to supply two kinds of SiH ₄ gas and H ₂ gas,
It was possible to fabricate using the same discharge means in the same reaction chamber. Therefore, when the conventional single-wafer plasma CVD apparatus shown in FIG. 2 is used, the same film formation can be performed in each of the plurality of reaction chambers.

Although not used in this embodiment, an in-line type plasma C having a structure in which a substrate loading / unloading chamber and one or a plurality of reaction chambers are connected in series is used.
A VD device may be used.

In this step, the first microcrystalline silicon film 103 and the second microcrystalline silicon film 105a, which are formed without adding the p-type or n-type conductivity determining impurity element, are formed under the same conditions. . Specifically, the SiH ₄ flow rate is 2 sccm,
Film formation was carried out by maintaining the pressure at 133 Pa with an H ₂ flow rate of 200 sccm and applying an RF (13.56 MHz) RF power of 120 mW / cm ² . At this time, the substrate temperature is 160 ° C
Kept at. The film forming conditions for the microcrystalline silicon film are basically known techniques, and are not limited to the above film forming conditions.

The range of applicable film forming conditions is Si
_{H 4: H 2 = 1:} 30~100, pressure 5~266Pa, R
F power density 10 to 250 mW / cm ² , substrate temperature 80 to
It is 300 ° C. The deposited film thickness is the first microcrystalline silicon film 1
03 is 10 to 80 nm, the second microcrystalline silicon film 105
A may be formed in a range of 5 to 50 nm. In this embodiment, the first microcrystalline silicon film 103 has a thickness of 30 nm and the second microcrystalline silicon film 105a has a thickness of 25 nm.

Substantially intrinsic amorphous silicon film 104
Is a SiH ₄ flow rate of 40 sccm and a H ₂ flow rate of 360 sccm
As the pressure, the pressure was maintained at 133 Pa, and RF (13.56 MHz) power of 48 mW / cm ² was applied to form a film. At this time, the substrate temperature was kept at 160 ° C. The film forming conditions for the amorphous silicon film are basically known techniques and are not limited to the above film forming conditions.

The range of applicable film forming conditions is Si
The ratio of H ₂ gas to H ₄ gas may be selected in the range of 0% to 95%, the pressure is 5 to 266 Pa, the RF power density is 5 to 100 mW / cm ² , and the substrate temperature is 80 to 350 ° C. The deposited film thickness is preferably in the range of 100 to 2000 nm, and in this example, the film was formed to a thickness of 1000 nm.

Further, instead of the substantially intrinsic amorphous silicon film, in addition to SiH ₄ gas at the time of film formation, carbon (C), germanium (Ge), tin (Sn) hydride and fluoride are added. It is also possible to introduce a gas containing chloride to form an amorphous silicon carbide film, an amorphous silicon germanium film, or an amorphous silicon tin film.

A p-type conductivity determining impurity is introduced into the second microcrystalline silicon film 105a, and the p-type microcrystalline silicon film 1 is formed.
The step of forming 05b was performed. Impurities capable of controlling p-type valence electrons are added to the microcrystalline silicon film by adding elements of Group IIIb of the periodic table such as boron (B), aluminum (Al), gallium (Ga), and indium (In). Good. The ion doping method is to gasify a gas such as a hydride, a chloride, or a fluoride of the impurity element, ionize the generated impurity element, and apply an electric field in a direction of accelerating the substrate to apply the electric field to the substrate. It is a method of injecting.
In this example, B ₂ H ₆ gas was used. Dose amount is 2.0
It may be carried out in the range of × 10 ^{13 to} 5.0 × 10 ¹⁵ / cm ² ,
Here, it is set to 1.0 × 10 ¹⁴ / cm ² . (Fig. 1 (c))

In the ion doping method, depending on the acceleration voltage,
The implanted element has a concentration distribution in the depth direction, and it is necessary to adjust this value appropriately. In the case of a solar cell, the optimum conditions differ depending on the thickness of the p-type layer, but the acceleration voltage is 5
It was set within the range of 25 keV. In this embodiment, 15 keV
And Dose amount 1.0 × 10 ¹⁴ / cm ² , acceleration voltage 10
When B is injected under the condition of keV, B injected into the film
Can be investigated by secondary ion mass spectrometry, and a concentration of 5 × 10 ¹⁹ / cm ³ was obtained at the peak position.

Further, the accelerating voltage is increased, and the p-type impurity element is implanted into the second microcrystalline silicon film and the region of the substantially intrinsic amorphous silicon film which is in contact with the second microcrystalline silicon film. You may. In the technical field of solar cells, p /
By continuously changing the p-type impurity concentration at the i interface,
A method for improving the bonding property at the interface is a conventionally known technique. In the prior art, in the film forming process, it was necessary to precisely control the gas containing a small amount of p-type impurity element by using a computer or the like, but according to the present embodiment, in the process of the plasma doping method. Since only the accelerating voltage has to be controlled, the impurity concentration at this interface can be controlled more precisely in the film thickness direction.

Since the implanted B element does not act as a p-type impurity element as it is, an activation process by heat treatment is required. The heat treatment process is performed in the atmosphere,
It may be carried out in a nitrogen atmosphere or a hydrogen atmosphere, and the temperature may be in the range of 150 to 450 ° C, preferably 200 to 400 ° C. Here, using a clean oven, at 2
Heat treatment was performed for an hour. (Fig. 1 (d))

The change in conductivity due to the heat treatment of the microcrystalline silicon film was confirmed in advance by experiments. The result is shown in FIG. The electric conductivity of a microcrystalline silicon film produced from SiH ₄ gas and H ₂ gas is about 5 × 10 −4 S as an initial value.
/ Cm, the result of this example shows that the conductivity is 5 × 10 ⁻³ S / cm when p-type impurities are injected and heat treatment is applied.
To 5 × 10 ¹ S / cm.

The data in FIG. 3 shows that the amount is 1 × 10 ¹⁴ / cm ^2.
As a result, the conductivity increased to 1.2 × 10 ^-2 S / cm by heat treatment at 150 ° C, and increased to 1.5 × 10 ^-1 S / cm at heat treatment at 200 ° C. I was able to do it. Further, when a similar heat treatment is applied to the microcrystalline silicon film into which no impurity element is injected, the conductivity becomes 5
It was confirmed that the increase was in the range of × 10 ⁻³ S / cm to 5 × 10 ⁻² S / cm. It was confirmed that the microcrystalline silicon film into which no impurity element was injected had n-type conductivity.

Through the above steps, the photoelectric conversion layer including the first n-type microcrystalline silicon film, the substantially intrinsic amorphous silicon film, and the second p-type microcrystalline silicon film is formed. I was able to do it.

Further, a step of integration processing was carried out in which the photoelectric conversion layer and the electrode were divided on the same substrate surface and connected in series. The integration process is performed by a known technique, and includes a step of forming holes in the photoelectric conversion layer and the electrodes by a laser scribing method and a step of forming an insulating resin by a screen printing method. The matters relating to the design of the integrated processing are in accordance with known examples and will not be described in detail here.

The first openings 107a and 107b are openings for insulation separation formed in the photoelectric conversion layer and the first electrode, and the openings are a plurality of unit cells on the same substrate surface. Is for forming. Second openings 108a, 10
Reference numeral 8b is an opening provided adjacent to each of the first openings 107a and 107b for connecting the adjacent first electrode and second electrode. The formation of the openings was performed by a laser scribing method. (Fig. 1 (e))

After forming the first opening and the second opening,
The insulating resin was printed by the screen printing method. As the insulating resin, the first insulating resin regions 109a and 109b and the second insulating resin regions 111a and 111b were formed. The first insulating resin regions 109a and 109b are formed on the first openings 107a and 107b and in a form of filling the openings, and the second insulating resin regions 111a and 111b are formed in the second openings 108a. , 108b adjacent to each other. As the insulating resin, a commercially available one may be used, but an acrylic resin or a urethane resin is preferable, and it is desirable that the insulating resin can be baked at about 200 ° C. Although there is no particular limitation on the thickness of the insulating resin, it is formed here to a thickness of 20 μm. (Fig. 1 (f))

The second electrode 106 is composed of the second microcrystalline silicon film 105b and the first insulating resin regions 109a and 1a.
09b and the second insulating resin regions 111a and 111b. The second electrode 106 is a transparent electrode,
A known method represented by a vacuum vapor deposition method or a sputtering method may be used. Specifically, SnO ₂ , ZnO, an ITO film or the like may be used. Here, the ITO film is formed by a sputtering method.
It was formed to a thickness of nm. (Fig. 1 (g))

The third openings 112a and 112b for dividing the second electrode 106 into the respective unit cells are
It was formed by laser scribing on the second insulating resin region adjacent to the second opening. (Fig. 1 (h))

Since the second electrode 106 has a relatively high resistivity, the auxiliary electrode 113 has a more desirable structure. The auxiliary electrodes 113a and 113b are the second electrodes 1
06, and the second openings 108a, 108
It is formed so as to cover b. The auxiliary electrode is formed of a highly conductive metal material, and here, silver (Ag) was formed in a comb shape by a screen printing method. (Fig. 1 (h))

Through the above steps, a plurality of unit cells 11
A solar cell in which 0a, 110b, and 110c were connected in series could be manufactured. The method for manufacturing a solar cell described in this embodiment includes a step of forming a first electrode, a step of forming a first microcrystalline silicon film, a step of forming a substantially intrinsic amorphous silicon film, Second step of forming a microcrystalline silicon film, step of injecting a P-type determining impurity element into the second microcrystalline silicon film, amorphous silicon film substantially intrinsic to the first and second microcrystalline silicon films A step of applying heat treatment to
If a step of patterning the first or second electrode by a known method and arranging the second electrode at a predetermined position on the surface of the substrate is added, a series connection structure of solar cells or It can be applied to the production of image sensors and photosensors.

Example 2 An example of an embodiment according to the present invention will be described according to the steps of the solar cell shown in FIG. In this embodiment, an organic resin film substrate is used as the substrate 401. Desirable organic resin film material for producing the solar cell of the present embodiment, polyethylene terephthalate,
Polyethylene naphthalate, polyether sulfone,
There are polyimide and aramid, but here the thickness is 100μ.
m polyethylene naphthalate (PEN) was used.

A first electrode was formed on the surface of the substrate 401. The first electrode 402 was formed by a known method typified by a vacuum evaporation method or a sputtering method. First electrode 40
Materials used for 2 are Al, Ag, Ti, Cr, Ni, P
It may be formed of a light-reflective metal electrode selected from t. About 100 nm to 300 nm is sufficient as the necessary film thickness, but even if the thickness is out of this range,
It has nothing to do with the components of the present invention. Here, a first electrode was formed by forming Al to a thickness of 150 nm by a sputtering method and further forming a Ti film on the surface of the Al by a sputtering method to a thickness of 20 nm. (Fig. 4 (a))

Then, it is brought into close contact with the first electrode 402,
The photoelectric conversion layer was formed. From the first electrode side, the photoelectric conversion layer includes a first microcrystalline silicon film 403, a substantially intrinsic amorphous silicon film 404, and a second microcrystalline silicon film 405.
It was manufactured by the plasma CVD method in the order of a. First and second
The microcrystalline silicon film of was formed from SiH ₄ and H ₂ without adding a p-type or n-type conductivity determining impurity element.
(Fig. 4 (b))

FIG. 2 is a conceptual view of the single wafer type plasma CVD apparatus used in this embodiment. The plasma CVD apparatus may have a configuration according to a conventional technique, and includes a substrate transfer chamber 201, a substrate loading / unloading chamber 202, and a plurality of reaction chambers 203a, 203b, and 203c, each of which has a plasma generating means 204. Is provided. Although not shown, each reaction chamber is provided with an evacuation unit for keeping the reaction chamber under reduced pressure and a unit for holding and heating the substrate.

According to this embodiment, the first and second microcrystalline silicon layers and the substantially intrinsic amorphous silicon layer are:
Since it is sufficient to supply two kinds of SiH ₄ gas and H ₂ gas,
It was possible to fabricate using the same discharge means in the same reaction chamber. Therefore, when the conventional single-wafer plasma CVD apparatus shown in FIG. 2 is used, the same film formation can be performed in each of the plurality of reaction chambers.

Although not used in this embodiment, an in-line type plasma C having a structure in which a substrate loading / unloading chamber and one or a plurality of reaction chambers are connected in series is used.
A VD device may be used.

In this step, the first microcrystalline silicon film 403 and the second microcrystalline silicon film 405a which are formed without adding the p-type or n-type conductivity determining impurity element are formed under the same conditions. . Specifically, the SiH ₄ flow rate is 2 sccm,
Film formation was carried out by maintaining the pressure at 133 Pa with an H ₂ flow rate of 200 sccm and applying an RF (13.56 MHz) RF power of 120 mW / cm ² . At this time, the substrate temperature is 160 ° C
Kept at.

Prior to the film formation, the chamber was sufficiently evacuated until the degree of vacuum in the reaction chamber became 5 × 10 ^-6 Torr or less. The film forming conditions for the microcrystalline silicon film are basically known techniques, and are not limited to the above film forming conditions. The applicable film forming condition range is S
_{iH 4: H 2 = 1:} 30~100, pressure 5～266Pa,
RF power density 10 to 250 mW / cm ² , substrate temperature 80
~ 300 ° C. The deposited film thickness of the first microcrystalline silicon film 403 is 10 to 80 nm, and that of the second microcrystalline silicon film 40.
5a may be formed in the range of 5 to 50 nm. In this embodiment, the first microcrystalline silicon film 403 is 30 nm,
The second microcrystalline silicon film 405a has a thickness of 25 nm.

A substantially intrinsic amorphous silicon film 404
Is a SiH ₄ flow rate of 40 sccm and a H ₂ flow rate of 360 sccm
As the pressure, the pressure was maintained at 133 Pa, and RF (13.56 MHz) power of 48 mW / cm ² was applied to form a film. At this time, the substrate temperature was kept at 160 ° C. The film forming conditions for the amorphous silicon film are basically known techniques and are not limited to the above film forming conditions. As a range of applicable film forming conditions, the ratio of H ₂ gas to SiH ₄ gas may be selected in the range of 0% to 95%, the pressure is 5 to 266 Pa, and the RF power density is 5 to 100 m.
W / cm ² and substrate temperature 80 to 350 ° C. The deposited film thickness is preferably in the range of 100 to 2000 nm,
In this embodiment, the film is formed to a thickness of 1000 nm.

Further, instead of the substantially intrinsic amorphous silicon film, in addition to SiH ₄ gas at the time of film formation, carbon (C), germanium (Ge), hydride of tin (Sn), fluoride It is also possible to introduce a gas containing chloride to form an amorphous silicon carbide film, an amorphous silicon germanium film, or an amorphous silicon tin film.

After the above steps, an integration processing step was performed in which the photoelectric conversion layer and the electrodes were each divided within the same substrate surface and connected in series. The integration process is performed by a known technique, and includes a step of forming holes in the photoelectric conversion layer and the electrodes by a laser scribing method and a step of forming an insulating resin by a screen printing method. The matters relating to the design of the integrated processing are in accordance with known examples and will not be described in detail here.

The first openings 407a and 407b are openings for insulation separation formed in the photoelectric conversion layer and the first electrode, and the openings are a plurality of unit cells on the same substrate surface. Is for forming. Second openings 408a, 40
Reference numeral 8b is an opening that is provided adjacent to each of the first openings 407a and 407b and that connects the adjacent first electrode and second electrode. The formation of the openings was performed by a laser scribing method. (Fig. 4 (c))

After forming the first opening and the second opening,
The insulating resin was printed by the screen printing method. The insulating resin has first insulating resin regions 409a and 409b and second insulating resin regions 411a and 411b. First
Of the insulating resin regions 409a and 409b of the first opening 4
07a and 407b and formed to fill the opening,
The second insulating resin regions 411a and 411b are provided adjacent to the second openings 408a and 408b. As the insulating resin, a commercially available one may be used, but an acrylic resin or a urethane resin is preferable, and it is desirable that the insulating resin can be baked at about 200 ° C. Although there is no particular limitation on the thickness of the insulating resin, it is formed here to a thickness of 20 μm.
(Fig. 4 (d))

The second electrode 406 is composed of the second microcrystalline silicon film 405b and the first insulating resin regions 409a, 4 and 4.
09b and the second insulating resin regions 411a and 411b. The second electrode 406 is a transparent electrode,
A known method represented by a vacuum vapor deposition method or a sputtering method may be used. Specifically, SnO ₂ , ZnO, an ITO film or the like may be used. Here, the ITO film is formed by a sputtering method.
It was formed to a thickness of nm. (Fig. 4 (e))

The third openings 412a and 412b for dividing the second electrode 406 into the respective unit cells are
It was formed by laser scribing on the second insulating resin region adjacent to the second opening. (Fig. 4 (f))

Since the second electrode 406 has a relatively high resistivity, it is more desirable to form the auxiliary electrode 413. The auxiliary electrodes 413a and 413b are the second electrodes 4
06, and the second openings 408a, 408
It is formed so as to cover b. The auxiliary electrode is formed of a highly conductive metal material, and here, silver (Ag) was formed in a comb shape by a screen printing method. (Fig. 4 (f))

After the above steps, the second microcrystalline silicon film 40 is formed on the surface of the second electrode by ion doping.
A step of introducing a p-type conductivity determining impurity into 5a to form a p-type microcrystalline silicon film 405b was performed. Impurities capable of controlling p-type valence electrons in the microcrystalline silicon film are
Boron (B), Aluminum (Al), Gallium (G
Elements of Group IIIb of the periodic table such as a) and indium (In) may be added. The plasma doping method is a method in which a gas such as a hydride, a chloride, or a fluoride of the impurity element is plasmatized, the generated impurity element is ionized, and an electric field is applied to the substrate in a direction of accelerating the substrate, It is a method of injecting.

In this example, B ₂ H ₆ gas was used. The dose amount may be in the range of 2.0 × 10 ^{13 to} 5.0 × 10 ¹⁵ / cm ² , and here it is set to 1.0 × 10 ¹⁴ / cm ² .
(Fig. 4 (g))

In the plasma doping method, the implantation element has a concentration distribution in the depth direction depending on the acceleration voltage, and it is necessary to properly adjust this value. In the case of a solar cell, the optimum conditions differ depending on the thickness of the p-type layer, but the acceleration voltage is set within the range of 5 to 25 keV. 15k in this embodiment
It was set to eV. When B was implanted under the conditions of a dose amount of 1.0 × 10 ¹⁴ / cm ² and an acceleration voltage of 10 keV, the concentration of B implanted in the film was examined by secondary ion mass spectrometry.
A concentration of 5 × 10 ¹⁹ / cm ³ was obtained at the peak position.

Further, the acceleration voltage is increased, and the p-type impurity element is implanted into the second microcrystalline silicon film and the substantially intrinsic amorphous silicon film region in contact with the second microcrystalline silicon film. You may. In the technical field of solar cells, p /
By continuously changing the p-type impurity concentration at the i interface,
A method for improving the bonding property at the interface is a conventionally known technique. In the prior art, in the film forming process, it was necessary to precisely control the gas containing a small amount of p-type impurity element by using a computer or the like, but according to the present embodiment, in the process of the plasma doping method. Since only the accelerating voltage has to be controlled, the impurity concentration at this interface can be controlled more precisely in the film thickness direction.

Since the implanted B element does not act as a p-type impurity element as it is, an activation process by heat treatment is required. The heat treatment process is performed in the atmosphere,
It may be carried out in a nitrogen atmosphere or a hydrogen atmosphere, and the temperature may be in the range of 150 to 450 ° C, preferably 200 to 400 ° C. Here, heat treatment was performed for 2 hours at 200 ° C. in an air atmosphere using a clean oven. (Fig. 4 (h))

The change in conductivity due to the heat treatment of the microcrystalline silicon film was confirmed in advance by experiments. The result is shown in FIG. The electric conductivity of a microcrystalline silicon film produced from SiH ₄ gas and H ₂ gas is about 5 × 10 ⁻⁴ S as an initial value.
/ Cm, the result of this example shows that the conductivity is 5 × 10 ⁻³ S / cm when p-type impurities are injected and heat treatment is applied.
To 5 × 10 ¹ S / cm.

The data in FIG. 3 shows that the amount is 1 × 10 ¹⁴ / cm ^2.
As a result, the conductivity increases to 1.2 × 10 ^-2 S / cm by heat treatment at 150 ° C. and increases to 1.5 × 10 ^-1 S / cm by heat treatment at 200 ° C. I was able to. Further, when a similar heat treatment is applied to the microcrystalline silicon film into which no impurity element is injected, the conductivity becomes 5
It was confirmed that the increase was in the range of × 10 ⁻³ S / cm to 5 × 10 ⁻² S / cm. It was confirmed that the microcrystalline silicon film into which no impurity element was injected had n-type conductivity.

Since the microcrystalline silicon film produced without adding the p-type and n-type conductivity type determining impurity elements exhibits n-type conductivity, the first n-type microcrystalline silicon is obtained by the above steps. A photoelectric conversion layer including the film, the substantially intrinsic amorphous silicon film, and the second p-type microcrystalline silicon film was formed, and a solar cell could be manufactured.

Through the above steps, a plurality of unit cells 41
A solar cell in which 0a, 410b, 410c were connected in series could be manufactured. The method for manufacturing a solar cell described in this embodiment includes a step of forming a first electrode, a step of forming a first microcrystalline silicon film, a step of forming a substantially intrinsic amorphous silicon film, Second step of forming a microcrystalline silicon film, step of injecting a P-type determining impurity element into the second microcrystalline silicon film, amorphous silicon film substantially intrinsic to the first and second microcrystalline silicon films A step of applying heat treatment to
If a step of patterning the first or second electrode by a known method and arranging the second electrode at a predetermined position on the surface of the substrate is added, a series connection structure of solar cells or It can be applied to the production of image sensors and photosensors.

Example 3 Another example of the embodiment according to the present invention will be described according to the steps of the solar cell shown in FIG. The substrate 401 is an organic resin material, and has a thickness of 8 here.
A 0 μm polyethylene naphthalate (PEN) substrate was used. In addition, materials such as polyethylene terephthalate, polyether sulfone, polyimide, and aramid can be applied.

A first electrode is formed on the surface of the substrate 401. The first electrode 402 was formed by a known method typified by a vacuum evaporation method or a sputtering method. First electrode 40
Materials used for 2 are Al, Ag, Ti, Cr, Ni, P
It may be formed of a light-reflective metal electrode selected from t. About 100 nm to 300 nm is sufficient as the necessary film thickness, but even if the thickness is out of this range,
It has nothing to do with the components of the present invention. Here, Ti is formed to a thickness of 200 nm by a sputtering method.
(Fig. 4 (a))

Then, a step of forming a microcrystalline silicon layer and an amorphous silicon layer to be a photoelectric conversion layer on the surface of the first electrode 402 was performed. The first microcrystalline silicon film 403 without adding a p-type or n-type conductivity determining impurity element
Then, the substantially intrinsic amorphous silicon film 404 and the second microcrystalline silicon film 405a were formed by a plasma CVD method without adding a p-type or n-type conductivity determining impurity element. (Fig. 4 (b))

FIG. 2 is a conceptual diagram of the single wafer type plasma CVD apparatus used in this embodiment. The plasma CVD apparatus may have a configuration according to a conventional technique, and includes a substrate transfer chamber 201, a substrate loading / unloading chamber 202, and a plurality of reaction chambers 203a, 203b, and 203c, each of which has a plasma generating means 204. Is provided. Although not shown, each reaction chamber is provided with a substrate heating means, and the structure of the exhaust means and the like is in accordance with the conventional technique.

According to this embodiment, the first and second microcrystalline silicon layers and the substantially intrinsic amorphous silicon layer are
Since it is sufficient to supply two kinds of SiH ₄ gas and H ₂ gas,
It was possible to fabricate using the same discharge means in the same reaction chamber. Therefore, when the conventional single-wafer plasma CVD apparatus shown in FIG. 2 is used, the same film formation can be performed in each of the plurality of reaction chambers.

Although not used in this embodiment, an in-line type plasma C having a structure in which a substrate loading / unloading chamber and one or a plurality of reaction chambers are connected in series is used.
A VD device may be used.

According to this embodiment, the first microcrystalline silicon film 403 and the substantially intrinsic amorphous silicon film 404 are used.
And the second microcrystalline silicon film 405a have the same SiH
_{Since 4} gases and H ₂ gas can be produced in the same reaction chamber, continuous film formation can be performed by simply changing the conditions during film formation. Specifically, the mixing ratio of the gases, the discharge power and the reaction gas pressure may be adjusted.

In this step, the first microcrystalline silicon film 403 and the second microcrystalline silicon film 405a which are formed without adding the p-type or n-type conductivity determining impurity element are formed under the same conditions. Specifically, the SiH ₄ flow rate is ₄ sccm,
Film formation was carried out by keeping the pressure at 133 Pa with an H ₂ flow rate of 400 sccm and applying an RF (13.56 MHz) power of 120 mW / cm ² . At this time, the substrate temperature is 160 ° C
Kept at. The film forming conditions for the microcrystalline silicon film are basically known techniques, and are not limited to the above film forming conditions. Applicable film forming conditions are as follows: SiH ₄ : H ₂ = 1: 30 to 100, pressure 5 to 266
Pa, RF power density 10 to 250 mW / cm ² , and substrate temperature 80 to 300 ° C.

The thickness of the first microcrystalline silicon film 403 is
The deposition time was determined based on the deposition rate obtained in advance, and here, the thickness was set to 30 nm. Then, a substantially intrinsic amorphous silicon film 404 was formed without stopping the supply of the reaction gas of SiH ₄ gas and H ₂ gas and the glow discharge. Specifically, the SiH ₄ gas flow rate was increased from 4 sccm to 40 sccm, the H ₂ gas flow rate was decreased from 400 sccm to 360 sccm, and the RF power density was changed from 120 mW / cm ² to 48 m.
It was changed to W / cm ² . Here, the gas flow rate and the amount of change over time in the RF power density are design issues, and are not described here. At this time, the substrate temperature is 160 ° C and the pressure is 1
It was kept at 33 Pa.

Regarding the film forming conditions of the amorphous silicon film,
This is basically a known technique and is not limited to the above film forming conditions. As a range of applicable film forming conditions, the ratio of H ₂ gas to SiH ₄ gas is 0% to 9%.
It may be selected within the range of 5%, pressure 5 to 266 Pa, R
F power density 5 to 100 mW / cm ² , substrate temperature 80 to 3
It is 50 ° C.

The thickness of the substantially intrinsic amorphous silicon film 404 is also determined by the deposition time based on the deposition rate, and is set to 1000 nm here. And SiH
The second microcrystalline silicon film 405a was continuously formed without stopping the supply of the reaction gas of ₄ gas and H ₂ gas and the glow discharge.

Specifically, the SiH ₄ gas flow rate is 40 sc
cm to 4 sccm and the H ₂ gas flow rate is 360
RF from increasing from sccm to 400sccm
The power density was varied from 4 mW / cm ² to 120 mW / cm ^2. At this time, the substrate temperature is 160 ° C and the pressure is 133P.
kept at a. The second microcrystalline silicon film 405a has a thickness of 25n.
It was set to be m.

Further, instead of the substantially intrinsic amorphous silicon film in the above process, in addition to SiH ₄ gas at the time of film formation, carbon (C), germanium (Ge), tin (Sn) hydride are added. It is also possible to form a non-crystalline silicon carbide film, a non-crystalline silicon germanium film, or a non-crystalline silicon tin film by introducing a gas containing a fluoride, a chloride.

By taking the steps shown in the present embodiment, the junction in which the structure is continuously changed from the microcrystalline silicon film to the amorphous silicon film and from the amorphous silicon film to the microcrystalline silicon film Could be formed.

After the above steps, a step of integration processing was performed in which the photoelectric conversion layer and the electrode were divided in the same substrate surface and connected in series. The integration process is performed by a known technique, and includes a step of forming holes in the photoelectric conversion layer and the electrodes by a laser scribing method and a step of forming an insulating resin by a screen printing method. The matters relating to the design of the integrated processing are in accordance with known examples and will not be described in detail here.

The first openings 407a and 407b are openings for insulation separation formed in the photoelectric conversion layer and the first electrode, and a plurality of unit cells are formed on the same substrate surface by the openings. Is formed. The second openings 408a and 408b are provided adjacent to the first openings 407a and 407b, respectively.
It is an opening for connecting the first electrode and the second electrode which are adjacent to each other. The above was performed by the laser scribing method. (Fig. 4 (c))

After forming the first opening and the second opening,
The insulating resin was printed by the screen printing method. As the insulating resin, the first insulating resin regions 409a and 409b and the second insulating resin regions 411a and 411b were formed. The first insulating resin regions 409a and 409b are formed on the first openings 407a and 407b and in a form of filling the openings, and the second insulating resin regions 411a and 411b are formed into the second openings 408a. , 408b, respectively. As the insulating resin, a commercially available one may be used, but an acrylic resin or a urethane resin is preferable, and it is desirable that the insulating resin can be baked at about 200 ° C. Although there is no particular limitation on the thickness of the insulating resin, it is formed here to a thickness of 20 μm. (Fig. 4 (d))

The second electrode 106 is composed of the second microcrystalline silicon film 105b and the first insulating resin regions 109a and 1a.
09b and the second insulating resin regions 111a and 111b. The second electrode 106 is a transparent electrode,
A known method represented by a vacuum vapor deposition method or a sputtering method may be used. Specifically, SnO ₂ , ZnO, an ITO film or the like may be used. Here, the ITO film is formed by a sputtering method.
It was formed to a thickness of nm. (Fig. 4 (e))

Third holes 411a and 411b for separating the second electrode 406 into unit cells are formed adjacent to the second holes on the second insulating resin region by laser scribing. . (Fig. 4 (f))

Since the second electrode 406 has a relatively high resistivity, forming the auxiliary electrodes 413a and 413b provides a more desirable structure. The auxiliary electrode is provided in close contact with the second electrode 406 and is formed so as to cover the second openings 408a and 408b. The auxiliary electrode is formed of a highly conductive metal material, and here, silver (Ag) was formed in a comb shape by a screen printing method. (Fig. 4 (f))

After the above steps, the second microcrystalline silicon film 40 is formed on the surface of the second electrode by ion doping.
A step of introducing a p-type conductivity determining impurity into 5a to form a p-type microcrystalline silicon film 405b was performed. Impurities capable of controlling p-type valence electrons in the microcrystalline silicon film are
Boron (B), Aluminum (Al), Gallium (G
Elements of Group IIIb of the periodic table such as a) and indium (In) may be added. The plasma doping method is a method in which a gas such as a hydride, a chloride, or a fluoride of the impurity element is plasmatized, the generated impurity element is ionized, and an electric field is applied to the substrate in a direction of accelerating the substrate, It is a method of injecting. In this example, B ₂ H ₆ gas was used. The dose amount may be in the range of 2.0 × 10 ^{13 to} 5.0 × 10 ¹⁵ / cm ² , and here it is set to 1.0 × 10 ¹⁴ / cm ² . (Fig. 4 (g))

In the plasma doping method, the implantation element has a concentration distribution in the depth direction depending on the acceleration voltage, and it is necessary to adjust this value appropriately. In the case of a solar cell, the optimum conditions differ depending on the thickness of the p-type layer, but the acceleration voltage is set within the range of 5 to 25 keV. 10k in this embodiment
It was set to eV. When B was implanted under the conditions of a dose amount of 1.0 × 10 ¹⁴ / cm ² and an acceleration voltage of 10 keV, the concentration of B implanted in the film was examined by secondary ion mass spectrometry.
A concentration of 5 × 10 ¹⁹ / cm ³ was obtained at the peak position.

According to the result of the experiment, B injected into the film
The amount was changed in proportion to the dose amount, and when the dose amount was 1.0 × 10 ¹⁵ / cm ² , a concentration of 5 × 10 ²⁰ / cm ³ was obtained.

Further, the accelerating voltage is increased, and the p-type is formed in the second microcrystalline silicon film and the region of the substantially intrinsic amorphous silicon film which is in contact with the continuously changed second microcrystalline silicon film. An impurity element may be injected. In the technical field of solar cells, a method of continuously changing the p-type impurity concentration at the p / i interface to improve the bondability at the interface is a conventionally known technique. In the prior art, it was necessary to precisely control the gas containing a small amount of p-type impurity element in the film forming step by using a computer or the like. However, according to this example, in the plasma doping step, Since only the accelerating voltage needs to be controlled, it becomes easier to control the impurity concentration in this interface in the film thickness direction.

Since the implanted B element does not act as a p-type impurity element as it is, a step of activation by heat treatment is required. The heat treatment process is performed in the atmosphere,
It may be carried out in a nitrogen atmosphere or a hydrogen atmosphere, and the temperature may be in the range of 150 to 450 ° C, preferably 200 to 400 ° C. Here, heat treatment was performed for 2 hours at 200 ° C. in an air atmosphere using a clean oven. (Fig. 4 (h))

The change in conductivity due to the heat treatment of the microcrystalline silicon film was confirmed in advance by experiments. The result is shown in FIG. The electric conductivity of the microcrystalline silicon film produced from SiH ₄ gas and H 2 gas is about 5 × 10 ⁻⁴ S as an initial value.
/ Cm, the result of this example shows that the conductivity is 5 × 10 ⁻³ S / cm when p-type impurities are injected and heat treatment is applied.
To 5 × 10 ¹ S / cm.

The data in FIG. 3 shows that the amount is 1 × 10 ¹⁴ / cm ^2.
As a result, the conductivity increased to 1.2 × 10 ^-2 S / cm by heat treatment at 150 ° C, and increased to 1.5 × 10 ^-1 S / cm at heat treatment at 200 ° C. I was able to do it. Further, when a similar heat treatment is applied to the microcrystalline silicon film into which no impurity element is injected, the conductivity becomes 5
It was confirmed that the increase was in the range of × 10 ⁻³ S / cm to 5 × 10 ⁻² S / cm. It was confirmed that the microcrystalline silicon film into which no impurity element was injected had n-type conductivity.

Since the microcrystalline silicon film produced without adding the p-type and n-type conductivity type determining impurity elements exhibits n-type conductivity, the first n-type microcrystalline silicon is subjected to the above steps. A photoelectric conversion layer including the film, the substantially intrinsic amorphous silicon film, and the second p-type microcrystalline silicon film was formed, and a solar cell could be manufactured.

Through the above steps, a plurality of unit cells 41
A solar cell in which 0a, 410b, 410c were connected in series could be manufactured. The method for manufacturing a solar cell described in this embodiment includes a step of forming a first electrode, a step of forming a first microcrystalline silicon film, a step of forming a substantially intrinsic amorphous silicon film, Second step of forming a microcrystalline silicon film, step of injecting a P-type determining impurity element into the second microcrystalline silicon film, amorphous silicon film substantially intrinsic to the first and second microcrystalline silicon films A step of applying heat treatment to
If a step of patterning the first or second electrode by a known method and arranging the second electrode at a predetermined position on the surface of the substrate is added, a series connection structure of solar cells or It can be applied to the production of image sensors and photosensors.

[0109]

According to the present invention, in the step of forming a p-type and n-type microcrystalline silicon film and a substantially intrinsic i-type amorphous silicon film, p-type and n-type impurities are used. It is not necessary to consider contamination, and for example, it is possible to continuously form films in the same film forming chamber. Specifically, the p-type and n-type microcrystalline silicon films and the substantially intrinsic amorphous silicon film can be produced only from SiH ₄ gas or Si ₂ H ₆ gas and H ₂ gas. Therefore, the film can be formed by the same glow discharge plasma generation means provided in the same reaction chamber. This makes it possible to simplify the structure of the plasma CVD apparatus. Furthermore, p-type and n
It is also possible to continuously manufacture the mold type microcrystalline silicon film and the substantially intrinsic amorphous silicon film while maintaining the glow discharge plasma.

Therefore, according to the present invention, the step of forming the first electrode, the step of forming the first microcrystalline silicon film, the step of forming the substantially intrinsic amorphous silicon film, The step of forming the second microcrystalline silicon film, the step of injecting the P-type determining impurity element into the second microcrystalline silicon film, and the substantially intrinsic amorphous substance with the first and second microcrystalline silicon films. Depending on the process of applying heat treatment to the silicon film, p
A microcrystalline silicon film exhibiting n-type and n-type conductivity and a substantially intrinsic amorphous silicon film can be obtained.
A bond can be formed. Therefore, it is not necessary to use the n-type impurity element which is the conventional technique.

Since the first and second microcrystalline silicon films and the substantially intrinsic amorphous silicon film can be produced from SiH ₄ gas and H ₂ gas, the respective films are produced. Sometimes it is not necessary to switch gases. Therefore, the time required for moving the substrate from the reaction chamber to the reaction chamber and for introducing and exhausting the gas, which is required in the conventional process, becomes unnecessary, and the process throughput can be improved.

According to the present invention, the p-type and n-type microcrystalline silicon films and the substantially intrinsic amorphous silicon film are provided in each reaction chamber of a plasma CVD apparatus having a plurality of reaction chambers. It is possible to fabricate them at the same time or individually, and it is possible to improve the process capacity.

Further, by implanting the p-type conductivity determining impurity element from the surface of the second microcrystalline semiconductor film by using the ion doping method, the acceleration voltage at the time of implantation is controlled to control the p-type impurity film. The concentration distribution in the thickness direction can be easily controlled.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a method for manufacturing a photoelectric conversion device of the present invention.

FIG. 2 is a schematic diagram showing the configuration of a plasma CVD apparatus applied to manufacture the photoelectric conversion device of the present invention.

FIG. 3 shows changes in conductivity of a microcrystalline silicon film having p-type conductivity and n-type conductivity obtained according to the present invention with heat treatment temperature.

FIG. 4 is a schematic view showing an example of a method for manufacturing a photoelectric conversion device of the present invention.

[Explanation of symbols]

101 ... Substrate 102 ... First electrode 103 ... First microcrystalline silicon film (n-type) 104 ... Substantially intrinsic non-silicon Amorphous silicon film (i-type) 105a ... Second microcrystalline silicon film (before activation) 105b ... Second microcrystalline silicon film (after activation p)
Type) 106 ... Second electrodes 107a, 107b ... First openings 108a, 108b ... Second openings 109a, 109b ... First insulating resin region 110a , 110b, 110c ... Unit cells 111a, 111b ... Second insulating resin regions 112a, 112b ... Third holes 112a, 112b ... Auxiliary electrode 201 Transfer chamber 202 ... Substrate loading / unloading chambers 203a, 203b, 203c ... Reaction chamber 204 ...・ ・ ・ Glow discharge plasma generating means 205 ・ ・ ・ Reaction gas supply means 401 ・ ・ ・ ・ Substrate 402 ・ ・ ・ ・ First electrode 403 ・ ・ ・1. Microcrystalline silicon film (n-type) 404 The intrinsic amorphous silicon film (i-type) 405a · · · · second microcrystalline silicon film (prior to activation) 405 b · · · · second microcrystalline silicon film (after activation p
Type) 406 ... Second electrodes 407a, 407b ... First openings 408a, 408b ... Second openings 409a, 409b ... First insulating resin region 410a , 410b, 410c ... Unit cells 411a, 411b ... Second insulating resin regions 412a, 412b ... Third holes 412a, 412b.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-177376 (JP, A) JP-A-2-377 (JP, A) JP-A-57-67020 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01L 31/04 H01L 31/10

Claims (29)

(57) [Claims] 1. A method for manufacturing a photoelectric conversion device in which one or a plurality of unit cells formed by stacking a first electrode, a photoelectric conversion layer, and a second electrode on an organic resin substrate are connected. , the photoelectric conversion layer is in close contact with the first electrode, forming a first microcrystalline semiconductor film without the addition of n-type and p-type conductivity determining impurity element, a substantially intrinsic A step of forming an amorphous semiconductor film; a step of forming a second microcrystalline semiconductor film without adding n-type and p-type conductivity type determining impurity elements; implanting a second microcrystalline semiconductor film, at least, the a first microcrystalline semiconductor film, wherein the second microcrystalline semiconductor film, in addition to heat treatment, a first n-type microcrystalline A step of obtaining a semiconductor film and a second p-type microcrystalline semiconductor film. Method for manufacturing a photoelectric conversion device according to claim. 2. A method for manufacturing a photoelectric conversion device, in which one or a plurality of unit cells formed by stacking a first electrode, a photoelectric conversion layer, and a second electrode on an organic resin substrate are connected. , the photoelectric conversion layer is in close contact with the first electrode, forming a first microcrystalline semiconductor film without the addition of n-type and p-type conductivity determining impurity element, a substantially intrinsic A step of forming an amorphous semiconductor film; a step of forming a second microcrystalline semiconductor film without adding n-type and p-type conductivity type determining impurity elements; a second microcrystalline semiconductor film, the second microcrystalline semiconductor film and the substantially intrinsic ago
Serial implanting in the vicinity of the interface between the amorphous semiconductor film, at least, the a first microcrystalline semiconductor film, in addition to heat treatment and the second microcrystalline semiconductor film, a first n-type And a step of obtaining the second p-type microcrystalline semiconductor film of (1), and a method for manufacturing a photoelectric conversion device. 3. The method according to claim 1, wherein the first and second microcrystalline semiconductor films are substantially intrinsic.
A method for manufacturing a photoelectric conversion device, wherein the same glow discharge plasma generation means provided in the same reaction chamber is used in the step of forming the amorphous semiconductor film. 4. The method according to claim 1, wherein the first and second microcrystalline semiconductor films are substantially intrinsic.
The step of forming the amorphous semiconductor film is continuously performed by the same glow discharge plasma generating means provided in the same reaction chamber while maintaining glow discharge plasma. Method for manufacturing conversion device. 5. The method according to claim 1, wherein the first and second microcrystalline semiconductor films are substantially intrinsic.
Wherein the amorphous semiconductor film formed by plasma CVD apparatus, the plasma CVD apparatus has a plurality of reaction chambers, said first and second microcrystalline semiconductor film, a substantially intrinsic
The method for manufacturing a photoelectric conversion device, wherein the amorphous semiconductor film is formed in different reaction chambers. 6. The method for manufacturing a photoelectric conversion device according to claim 5, wherein the plasma CVD device includes at least one substrate loading / unloading chamber and a transfer chamber. 7. The method according to any one of claims 1 to 6,
In the step of injecting the p-type conductivity determining impurity element to said second microcrystalline semiconductor film, the second electrode and the p-type conductivity determining impurity element is in close to the microcrystalline semiconductor film of the second A method for manufacturing a photoelectric conversion device, characterized in that the photoelectric conversion device is injected from the surface. 8. The claim 1, the step of injecting the p-type conductivity determining impurity element to said second microcrystalline semiconductor film, and characterized in that the ion doping Method for manufacturing photoelectric conversion device. 9. The P-type conductivity determining impurity element according to claim 8, wherein B, Al, Ga,
A method for manufacturing a photoelectric conversion device, which is an element selected from In. 10. The dose amount of the p-type conductivity determining impurity element according to claim 8 or 9,
A method for producing a photoelectric conversion device, characterized in that it is in the range of × 10 ¹³ / cm ² or more and 5.0 × 10 ¹⁵ / cm ² or less. 11. The any one of claims 1 to 10, in that the temperature of the heat treatment of the first microcrystalline semiconductor film and the second microcrystalline semiconductor film is a 0.99 ° C. to 450 ° C. A method for manufacturing a characteristic photoelectric conversion device. 12. The any one of claims 1 to 11, wherein the first and second microcrystalline semiconductor film, a microcrystalline silicon film, is substantially intrinsic said amorphous semiconductor film, A method for manufacturing a photoelectric conversion device, which is an amorphous silicon film. 13. The any one of claims 1 to 12, wherein the first and second microcrystalline semiconductor film, a microcrystalline silicon film, is substantially intrinsic said amorphous semiconductor film, A method for manufacturing a photoelectric conversion device, which is an amorphous semiconductor film having a plurality of kinds of elements selected from carbon, silicon, germanium, and tin as constituent elements. 14. The light-transmissive electrode according to claim 1, wherein the second electrode is made of one or more materials selected from In ₂ O ₃ , SnO ₂ , and ZnO. A method for manufacturing a photoelectric conversion device, which is characterized by the following. 15. The organic resin substrate according to claim 1, wherein the organic resin substrate is an organic resin substrate selected from polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyimide and aramid. And a method for manufacturing a photoelectric conversion device. 16. A method for manufacturing a solar cell, characterized by using the manufacturing method according to any one of claims 1 to 15. 17. A method of manufacturing an image sensor, characterized in that the method of manufacturing according to any one of claims 1 to 15 is used. 18. A method for manufacturing a photosensor, characterized by using the manufacturing method according to any one of claims 1 to 15. 19. A photoelectric conversion device configured by connecting one or a plurality of unit cells formed by stacking a first electrode, a photoelectric conversion layer, and a second electrode on an organic resin substrate. , the photoelectric conversion layer, a first microcrystalline semiconductor film, wherein the closely n-type and p-type conductivity determining impurity element provided on the first electrode is not added, substantially intrinsic non A photoelectric conversion device comprising: a crystalline semiconductor film; and a second microcrystalline semiconductor film to which a p-type conductivity type determining impurity element is added without adding an n-type conductivity type determining impurity element . 20. The method of claim 19, wherein the first and second microcrystalline semiconductor film, a microcrystalline silicon film, substantially intrinsic said amorphous semiconductor film is an amorphous silicon film A photoelectric conversion device characterized in that. 21. The method of claim 19, wherein the first and second microcrystalline semiconductor film, a microcrystalline silicon film, substantially intrinsic said amorphous semiconductor film, amorphous silicon carbide film , Or an amorphous silicon germanium film or an amorphous silicon tin film. 22. The p-type conductivity determining impurity element according to claim 19, wherein B, Al, Ga,
A photoelectric conversion device, which is an element selected from In. 23. The method of claim 22, wherein the p-type conductivity determining impurity element is, 1.0 × 10 ¹⁹ / cm ³ or more in the second microcrystalline semiconductor film, 1.0 × 10
^A photoelectric conversion device characterized by being contained at a concentration of ²¹ / cm ³ or less. 24. A any one of claims 19 to 23, the first microcrystalline semiconductor film, oxygen, 1.0 × 10 ¹⁸
/ Cm ³ or more and 2.0 × 10 ²¹ / cm ³ or less, the photoelectric conversion device characterized by being contained. 25. Any one of claims 19 to 24, the electric conductivity of the first microcrystalline semiconductor, 5.0 × 10
^-3 S / cm ³ or more and 5.0 × 10 ^-2 S / cm ³ or less, the electrical conductivity of the second microcrystalline semiconductor, 5.0 × 10
^-3 S / cm ³ or more and 5.0 × 10 ¹ S / cm ³ or less, a photoelectric conversion device. 26. The organic resin substrate according to claim 19, wherein the organic resin substrate is an organic resin substrate selected from polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyimide and aramid. And a photoelectric conversion device. 27. A solar cell using the photoelectric conversion device according to any one of claims 19 to 26. 28. An image sensor using the photoelectric conversion device according to any one of claims 19 to 26. 29. A photosensor using the photoelectric conversion device according to any one of claims 19 to 26.