JP3017392B2 - Manufacturing method of photovoltaic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to laminating a non-single-crystal n-type layer (or p-type layer) containing silicon atoms, a non-single-crystal i-type layer and a non-single-crystal p-type layer (or n-type layer). Pi
The n structure, thickness formed by laminating at least one structure or
The present invention relates to a method for forming a photovoltaic element such as a solar cell and a sensor.

[0002]

2. Description of the Related Art Conventionally, defects existing in a semiconductor are closely related to generation and recombination of electric charges, and deteriorate the characteristics of the device. As a method of compensating for such a defect level, a hydrogen plasma treatment has been proposed. For example, US
P41113514 (JI Pankove et al., RCA
Sep. 12, 1978) describes a hydrogen plasma treatment of a completed semiconductor device. Also"
EFFECT OF PLASMA TREATMENT OF THE TCO ON a-Si SOLA
RCELL PERFORMANCE ", F. Demichelis et.al., Mat.Res.S
oc. Symp. Proc. Vol. 258, p9O5, 1992 discloses a method of performing a hydrogen plasma treatment on a transparent electrode deposited on a substrate and forming a solar cell having a pin structure thereon. Furthermore, "HYDR
OGEN-PLASMA REACTION FLUSHING F0R a-Si: H PIN SOL
AR CELL FABRlCATION ", YSTsuo et.al., Mat.Res.Soc.S
Proc. Vol. 149, p471, 1989, shows that in a solar cell having a pin structure, the surface of the p-layer is subjected to hydrogen plasma treatment before the deposition of the i-layer. In the conventional hydrogen plasma processing as described above, only hydrogen gas is introduced into the chamber and R
Hydrogen plasma treatment was performed by activating hydrogen gas with F power.

However, the hydrogen plasma spreads not only to act on the substrate to be processed, the unfinished device, and the completed device, but also throughout the chamber. Since hydrogen plasma is very active, impurities (for example, oxygen,
There is a problem that nitrogen, carbon, iron, chromium, nickel, aluminum, etc. are extracted.

In addition, hydrogen gas is more difficult to cause discharge than other gases, and plasma using only hydrogen gas cannot perform stable hydrogen plasma treatment because it is more difficult to maintain plasma than other gases. There is a problem.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems. That is, an object of the present invention is to provide a hydrogen plasma processing method that substantially prevents the incorporation of impurities adsorbed or contained on the chamber wall surface, and a method of performing a more stable hydrogen plasma processing. is there.

It is another object of the present invention to provide a method for forming a photovoltaic element in which the semiconductor layer does not substantially peel even when the photovoltaic element is placed at high temperature and high humidity. It is a further object of the present invention to provide a method for forming a photovoltaic element in which a pin semiconductor layer is not easily peeled off even when the substrate is bent when a pin structure is formed on a flexible substrate.

It is a further object of the present invention to provide a method for forming a photovoltaic element in which defect levels are unlikely to increase near the interface between a p-type layer and an i-type semiconductor layer due to long-time light irradiation. . Still further, an object of the present invention is to provide a photovoltaic element that suppresses deterioration in characteristics of the photovoltaic element such as separation of a substrate and a semiconductor layer and increase in series resistance when irradiated with light under high temperature and high humidity. It is to provide a forming method.

An object of the present invention is to provide an n-type layer (or p-type layer)
It is an object of the present invention to provide a photovoltaic element having improved initial efficiency by preventing diffusion of impurities from the semiconductor to the i-type layer. It is another object of the present invention to provide a photovoltaic element in which the characteristics are not significantly reduced when used at a high temperature.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that the above object can be achieved by a method of forming between a p / i buffer layer and an i-type layer. I found it. That is, the present invention provides a non-single-crystal n-type layer (or p-type layer) containing silicon atoms on a substrate,
Non-single-crystal i-type n / i buffer layer (or p / i buffer layer), non-single-crystal i-type layer, non-single-crystal i-type p / i buffer layer (or n / i buffer layer) and non-single crystal A pin structure formed by stacking p-type layers (or n-type layers)
In a method of manufacturing a photovoltaic device having at least one or more stacked layers, a silicon atom-containing gas is deposited in such a manner that substantially no silicon atom-containing gas is deposited near an interface where the p / i buffer layer and the i-type layer are in contact with each other. It is characterized in that plasma treatment is carried out with hydrogen gas contained.

Further, the present invention provides a method for manufacturing a semiconductor device, comprising the steps of:
Is plasma-treated with a hydrogen gas containing a silicon atom-containing gas to such an extent that it does not substantially deposit.
Still further, the present invention provides the above-mentioned n / i buffer layer and the n / i buffer layer.
The plasma processing is performed on the vicinity of the interface where the mold layer is in contact and the vicinity of the interface where the n / i buffer layer and the i-type layer are in contact with a hydrogen gas containing a silicon atom-containing gas to such an extent that substantially no deposition occurs.

Further, in the present invention, the silicon atom-containing gas may be SiH ₄ , Si ₂ H ₆ , SiF ₄ , SiFH ₃ , SiF _{2
H 2, SiF 3 H, SiC} l 2 H 2, SiCl 3 H, SiC
Of l _4, it is characterized in that at least one.
In addition, the present invention is characterized in that the content of the silicon atom-containing gas with respect to hydrogen gas is 0.1% or less.

[0012]

The above object can be attained by forming a photovoltaic device by forming a semiconductor layer by performing a hydrogen plasma treatment by adding a silicon-containing gas to a hydrogen gas so as not to substantially contribute to the deposition. it can. Although the detailed mechanism is not clear at present, the present inventors think as follows.

That is, when the hydrogen gas contains a silicon atom-containing gas to such an extent that it does not substantially contribute to the deposition, and the hydrogen plasma treatment is performed, the activated silicon atom-containing gas is adsorbed on the inner wall of the chamber. Acts on oxygen and water to produce stable silicon oxide and the like, which is more stable than adsorbed on the inner wall of the chamber in the form of oxygen or water. As a result, the silicon atom-containing gas is contained to such an extent that it does not substantially contribute to deposition, and when plasma processing is performed, the incorporation of impurities such as oxygen and water adsorbed on the chamber wall surface into the semiconductor is suppressed to a very low level. It is thought that things can be done.

In addition, when hydrogen plasma treatment is performed with a hydrogen gas containing a small amount of a silicon atom-containing gas, hydrogen atoms are prevented from deeply diffusing into the chamber wall surface on the chamber wall surface, and the chamber wall surface is prevented from being diffused. It is considered that a reaction such as taking out impurities that form a defect level by entering the semiconductor layer from the inside can be suppressed as much as possible.

Although hydrogen gas has a high ionization energy and it is difficult to stably maintain a plasma discharge for a long time, a small amount of a silicon atom-containing gas that can easily maintain a plasma discharge is added to the hydrogen gas as in the present invention. By things
It is believed that the maintenance of the plasma discharge of hydrogen gas is facilitated. By applying such a very stable hydrogen plasma discharge to a substrate or element, the uniformity and reproducibility of the hydrogen plasma treatment can be greatly improved. By improving the uniformity and reproducibility of such hydrogen plasma treatment, it is possible to prevent local peeling of semiconductor layers and increase in series resistance under high temperature, high humidity and light irradiation for a long time on substrates and elements that have been subjected to hydrogen plasma treatment. You can do it.

In the hydrogen plasma treatment of the present invention, a portion where the surface of the substrate has a textured structure and the textured structure is locally sharply developed is directed to a direction in which the surface is blunted to contain a silicon atom-containing gas. It works. As a result, even if a semiconductor layer is deposited on a substrate having a texture structure subjected to the hydrogen plasma treatment of the present invention, abnormal growth of the semiconductor layer does not substantially occur. Therefore, when a photovoltaic element having a pin structure is formed, the characteristic unevenness of the photovoltaic element is small, the adhesion between the substrate and the semiconductor layer is excellent,
Further, a photovoltaic element having excellent durability under high temperature and high humidity can be obtained.

When the hydrogen plasma treatment of the present invention is performed at the interface between the p / i buffer layer and the i-type layer, defects near the interface can be reduced, and the transfer of the charge excited by light can be facilitated. be able to. In particular, silicon atom-containing active species generated by plasma from silicon atom-containing gas to such an extent that they do not substantially deposit, collide with or replace silicon atoms on the surface subjected to the hydrogen plasma treatment, and the structural relaxation progresses, and the surface state is reduced. Is to be improved.

Further, the hydrogen plasma treatment of the present invention may be performed with n /
When the treatment is performed at the interface between the i-buffer layer and the i-type layer, the strain near the interface between the n / i buffer layer and the i-type layer can be reduced. As a result, it is possible to suppress an increase in localized levels due to light degradation when light irradiation is performed for a long time. In addition, the photo-excited charges also easily move to the n-type layer and the p-type layer.

Further, when the hydrogen plasma treatment of the present invention is performed at the interface between the n-type layer and the n / i buffer layer, diffusion of impurities from the n-type layer to the i-type layer can be prevented. Although the detailed mechanism is unknown, the present inventors think as follows. When the surface of the n-type layer or the n / i buffer layer is subjected to a hydrogen plasma treatment containing a small amount of the silicon atom-containing gas of the present invention, defects or structural distortion of the surface of the n-type layer or the n / i buffer layer are caused. It is believed that it can be reduced by diffusing active hydrogen plasma into the layer or diffusing silicon atoms contained in trace amounts into vacancies.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail. First, a method and an apparatus for forming a photovoltaic element of the present invention will be described in detail with reference to the drawings. (Hydrogen Plasma Treatment Conditions) FIGS. 1 to 3 show examples of a photovoltaic element of the present invention which has been subjected to hydrogen plasma treatment with a hydrogen gas containing a small amount of a silicon atom-containing gas.

FIG. 1 is a schematic explanatory view of a photovoltaic element having one pin structure. When the photovoltaic element emits light from the side opposite to the substrate, the substrate 190 (support 10
0, reflection layer 101, reflection enhancement layer 102), first n-type layer (or p-type layer) 103, first n / i buffer layer (or p / i buffer layer) 151, first i-type layer 1
04, first p / i buffer layer (or n / i buffer layer) 161, first p-type layer (or n-type layer) 10
5, a transparent electrode 112 and a current collecting electrode 113. When light is irradiated from the substrate side, 100 is a light-transmitting support, 101 is a transparent conductive layer, 102 is an antireflection layer, and 112 is a conductive layer also serving as a reflective layer.

FIG. 2 is a schematic illustration of a photovoltaic element having two pin structures. The photovoltaic element is mounted on a substrate 290.
(Support 200, reflection layer 201, reflection enhancement layer 202),
A first n-type layer (or p-type layer) 203, a first n / i buffer layer (or p / i buffer layer) 251,
Layer 204, the first p / i buffer layer (or n
/ I buffer layer) 261, first p-type layer (or n-type layer) 205, second n-type layer (or p-type layer) 206, second n / i buffer layer (or p / i buffer layer) )
252, second i-type layer 207, second p / i buffer layer (or n / i buffer layer) 262, second p-type layer (or n-type layer) 208, transparent electrode 212, current collecting electrode 2
13. When light is irradiated from the substrate side, 200 is a transparent support, 201 is a transparent conductive layer, 202 is an antireflection layer, and 212 is a conductive layer also serving as a reflective layer.

FIG. 3 is a schematic explanatory view of a photovoltaic element having three pin structures. The photovoltaic element is mounted on a substrate 390.
(Support 300, reflection layer 301, reflection enhancement layer 302),
A first n-type layer (or p-type layer) 303, a first n / i buffer layer (or p / i buffer layer) 351,
Layer 304, the first p / i buffer layer (or n
/ I buffer layer) 361, first p-type layer (or n-type layer) 305, second n-type layer (or p-type layer) 306, second n / i buffer layer (or p / i buffer layer) )
352, a second i-type layer 307, a second p / i buffer layer (or n / i buffer layer) 362, a second p-type layer (or n-type layer) 308, a third n-type layer (or p-type layer) 309, third n / i buffer layer (or p / i
Buffer layer) 353, third i-type layer 310, third p-type layer
/ I buffer layer (or n / i buffer layer) 36
3, third p-type layer (or n-type layer) 311, transparent electrode 3
12, a current collecting electrode 313. When light is irradiated from the substrate side, 300 is a light-transmitting support, 301 is a transparent conductive layer, 302 is an antireflection layer, 312
Is formed of a conductive layer also serving as a reflective layer.

In the present invention, it is effective that the plasma treatment with a hydrogen gas containing a gas containing a silicon atom to such an extent that it does not substantially deposit is performed near the interface between the p / i buffer layer and the i-type layer. In the present invention, the plasma treatment with a hydrogen gas containing a silicon atom-containing gas to such an extent that substantially no deposition occurs is performed in the vicinity of the interface between the substrate and the first n-type layer (or p-type layer), and furthermore, n / i Buffer layer and i-type layer and n /
It is more effective to perform it near the interface where the i-buffer layer and the n-type layer are in contact.

The hydrogen flow rate suitable for achieving the object of the present invention is appropriately optimized depending on the size of the processing chamber, but is preferably 1 to 2000 sccm. When the hydrogen flow rate is less than 1 sccm, the power for maintaining the plasma discharge increases, the damage to the base slope becomes severe, and impurities are easily taken in from the chamber wall. On the other hand, when the hydrogen flow rate is 2000 sc
cm, the residence time of the silicon-based active species and hydrogen active species in the plasma discharge in the chamber is shortened. The effect of the processing is less likely to appear.

In the hydrogen plasma processing method of the present invention,
The preferable addition amount of the silicon atom-containing gas added to the hydrogen gas is 0.001% to 0.1%.
The addition amount of silicon atom-containing gas to hydrogen gas is
If the amount is less than 0.001%, the effect of the present invention is not exhibited. If the amount is more than 0.1%, the deposition of silicon atoms increases, so that the original effect of the hydrogen plasma treatment is not exhibited.

The energy suitable for generating the hydrogen plasma of the present invention is an electromagnetic wave, especially RF (r
audio frequency), VHF (very
high frequency), MW (microrow)
ave) is a suitable energy. When the hydrogen plasma treatment of the present invention is performed by RF, a preferable frequency range is:
It is in the range of 1 MHz to 50 MHz. When the hydrogen plasma treatment of the present invention is performed with VHF, a preferable frequency range is from 51 MHz to 500 MHz. When the hydrogen plasma treatment of the present invention is performed by MW, a preferable frequency range is from 0.51 GHz to 10 GHz.

In order to effectively carry out the hydrogen plasma treatment of the present invention, the degree of vacuum is an important factor. Is largely dependent on When the hydrogen plasma treatment is performed in the RF frequency band, the degree of vacuum is preferably in the range of 0.05 Torr to 10 Torr. The preferred degree of vacuum when performing the hydrogen plasma treatment in the VHF frequency band is in the range of 0.0001 Torr to 1 Torr. The preferred degree of vacuum when performing hydrogen plasma processing in the MW frequency band is 0.0001 T
The range is from orr to 0.01 Torr.

In the hydrogen plasma processing of the present invention, the power density supplied into the chamber to generate hydrogen plasma is an important factor for effectively performing the hydrogen plasma processing of the present invention. Such power density depends on the frequency of the electromagnetic wave used. When using the RF frequency band, the power density is 0.01 to 1
W / cm ³ is a preferred range. When the VHF frequency band is used, a preferable range is 0.01 to 1 W / cm ³ . Particularly, in the case of the VHF frequency band, there is a feature that plasma discharge can be maintained in a wide pressure range. When performing hydrogen plasma processing at a high pressure, it is preferable to perform hydrogen plasma processing at a relatively low power density. On the other hand, when performing hydrogen plasma treatment at a low pressure,
It is preferable to carry out at a relatively high power density.
When the hydrogen plasma treatment of the present invention is performed using the MW frequency band, the preferable power density is 0.1 to 10 W / cm ³ . In performing the hydrogen plasma treatment of the present invention, there is a close relationship between the power density and the hydrogen plasma treatment time, and when the power density is high, it is preferable that the hydrogen plasma treatment time be relatively short. is there.

In the hydrogen plasma processing of the present invention, the substrate temperature during the hydrogen plasma processing is a very important factor for making the effects of the present invention effective. In the case of performing the hydrogen plasma treatment using the RF frequency band, the substrate temperature is preferably a relatively high temperature. 100 to 4
00 ° C. is a preferred temperature range. When the hydrogen plasma treatment of the present invention is performed using the VHF or MW frequency band, it is preferable that the substrate temperature be relatively low. In this case, 50 to 300 ° C. is a preferable temperature range. Further, the substrate temperature during the hydrogen plasma treatment of the present invention also depends closely on the power density supplied into the chamber, and when the supplied power density is relatively high, the substrate temperature is performed at a lower temperature. Is preferred.

When performing the hydrogen plasma treatment of the present invention, the above-described power density, gas flow rate, substrate temperature, pressure, etc.
It may be changed with respect to the processing time. Usually, a substrate has many defects and many impurities near the surface. Therefore, the hydrogen plasma treatment is preferably performed at a relatively high power density and a high pressure at the start of the treatment.

In the hydrogen plasma treatment of the present invention, the silicon atom-containing gas added to the hydrogen gas is Si
H ₄ , Si ₂ H ₆ , SiF ₄ , SiF ₃ H, SiF ₂ H ₂ , S
iF ₃ H, Si ₂ FH ₅ , SiCl ₄ , SiClH ₃ , Si
Silicon hydride compounds or silicon halide compounds such as Cl ₂ H ₂ and SlClH ₃ are suitable. These silicon atom-containing gases may be added alone to the hydrogen gas, or may be added in combination of two or more. In particular, the mixing ratio of the silicon atom-containing gas containing a halogen atom is preferably larger than that of the silicon atom-containing gas not containing a halogen atom.

(Forming Method and Apparatus) A method of forming a photovoltaic element of the present invention and a forming apparatus suitable for the method will be described. An example of the forming apparatus is shown in a schematic explanatory view of FIG. 4, a forming apparatus 400 includes a load chamber 401, transfer chambers 402, 403, and 404, an unload chamber 405, and gate valves 406, 407, 408, and 40.
9, substrate heating heaters 410, 411, 412, substrate transport rails 413, n-type layer (or p-type layer) deposition chamber 417, i-type layer deposition chamber 418, p-type layer (or n-type layer) deposition chamber 419 , Plasma forming cups 420, 421, power supplies 422, 423, 42
4. Microwave introduction window 425, waveguide 426, gas introduction pipes 429, 449, 469, valves 430, 431,
432, 433, 434, 441, 442, 443, 4
44, 450, 451, 452, 453, 454, 45
5, 461, 462, 463, 464, 465, 47
0, 471, 472, 473, 474, 481, 48
2, 483, 484, mass flow controller 43
6, 437, 438, 439, 456, 457, 45
8, 459, 460, 476, 477, 478, 47
9, a shutter 427, a bias rod 428, a substrate holder 490, an exhaust device (not shown), a microwave power source (not shown), a vacuum gauge (not shown), a control device (not shown), and the like.

A method for forming a photovoltaic element to which the hydrogen plasma processing method of the present invention is applied is performed as follows using a forming apparatus shown in FIG. All the chambers of the deposition apparatus 400 are pulled up to a vacuum of 10 ⁻⁶ Torr or less by a turbo molecular pump (not shown) connected to each chamber. When the hydrogen plasma treatment of the present invention is performed by RF, it is performed as follows. A base plate on which a reflective layer of silver or the like is deposited on a stainless steel support and a reflection-enhancing layer of zinc oxide or the like is further deposited is attached to a base holder 490. The substrate holder 4
90 is put into the load chamber 401. The door of the load chamber 401 is closed, and the load chamber 401 is raised to a predetermined degree of vacuum by a mechanical booster pump / rotary pump (MP / RP) (not shown). When the load chamber reaches a predetermined degree of vacuum, the MP / RP is switched to a turbo molecular pump to raise the degree of vacuum to 10 ^-6 Torr or less. Load chamber is 10 ^-6 Torr
When the degree of vacuum becomes as follows, the gate valve 406 is opened, the substrate holder 490 on the substrate transport rail 413 is moved to the transport chamber 402, and the gate valve 406 is opened.
Close. The substrate heating heater 410 of the transfer chamber 402 is raised so that the substrate holder 490 does not hit. The position of the substrate holder is determined so that the substrate comes directly under the heater. The substrate heating heater 410 is lowered, and the substrate is put into the n-type layer deposition chamber.

The substrate temperature was changed to a temperature suitable for deposition of the n-type layer, SiH for n-type layer deposition _4, Si ₂ H ₆ or the like Periodic Table V for silicon atom-containing gas and n-type layer deposition Group element containing gas with valve 443, mass flow controller 43
8. Introduce into the deposition chamber 417 via the valve 433. It is also preferable that the flow rate of the hydrogen gas is appropriately adjusted according to the n-type layer. In this way, the source gas for depositing the n-type layer is introduced into the deposition chamber 417, and the degree of opening and closing of the exhaust valve (not shown) is changed to make the inside of the deposition chamber 417 a desired degree of vacuum of 0.1 to 10 Torr. Then, the RF power is supplied from the RF power supply 422 to the plasma forming cup 420.
Power is applied to cause a plasma discharge and maintain the discharge for a desired time. In this manner, an n-type semiconductor layer is deposited on the substrate to a desired thickness.

After the deposition of the n-type layer is completed, supply of the source gas to the deposition chamber 417 is stopped, and the inside of the deposition chamber 417 is purged with hydrogen gas or helium gas.
After sufficient purging, supply of hydrogen gas or helium gas was stopped, and the inside of the deposition chamber was
Raise to 0 ^-6 Torr. The gate valve 407 is opened, the substrate holder 490 is moved to the transfer chamber 403, and the gate valve is closed. Heater 4 for substrate heating
Adjust the position of the substrate holder so that it can be heated in step 11. The substrate heating heater 411 is brought into contact with the substrate and heated to a predetermined temperature. At the same time, an inert gas such as a hydrogen gas or a helium gas is introduced into the deposition chamber 418. Further, it is preferable that the degree of vacuum at that time is the same as that at the time of depositing the n / i buffer layer.

When the substrate temperature reaches a desired temperature, the gas for heating the substrate is stopped, and the source gas for depositing the n / i buffer layer is supplied to the deposition chamber 418 from the gas supply device. For example, hydrogen gas, silane gas, germane gas,
The valves 462, 463, and 464 are opened, the flow rates are set to desired values by the mass flow controllers 457, 458, and 459. The valves 452, 453, 454, and 450 are opened, and the deposition chamber 418
To supply. At the same time, supply gas with a diffusion pump (not shown),
The deposition chamber 418 is evacuated to a desired pressure. When the degree of vacuum in the chamber 418 is stabilized at a desired degree of vacuum, desired power is introduced from a RF power supply (not shown) into a bias rod for applying a bias. And R
An n / i buffer layer is deposited by F plasma CVD.
Preferably, the n / i buffer layer is deposited at a lower deposition rate than the i-type layer deposited thereafter.

Next, the substrate is heated to a predetermined temperature for the i-type layer deposition. It is preferable to open the valve 461 and set a desired flow rate of an inert gas such as hydrogen gas or helium gas by a mass flow controller, and heat the substrate while opening the valves 451 and 450.
Further, it is preferable that the degree of vacuum at that time is the same as that for depositing the i-type layer.

When the substrate temperature reaches a desired temperature, the gas for heating the substrate is stopped, and the source gas for depositing the i-type layer is supplied to the deposition chamber 418 from the gas supply device. For example, hydrogen gas, silane gas, and germane gas are set to desired flow rates by opening valves 462, 463, and 464, respectively, and using mass flow controllers 457, 458, and 459.
The valves 452, 453, 454, and 450 are opened to supply the gas to the deposition chamber 418 via the gas introduction pipe 449.
At the same time, the supply gas is evacuated by a diffusion pump (not shown) so that the degree of vacuum in the deposition chamber 418 becomes a desired pressure. When the degree of vacuum in the chamber 418 is stabilized at a desired degree of vacuum, desired power is introduced from a micro power supply (not shown) into the deposition chamber 418 via the waveguide 426 and the microwave introduction window 425. Simultaneously with the introduction of the microwave energy, it is also preferable to introduce desired bias power into the deposition chamber 418 from an external DC, RF or VHF power supply 424 to the biasing bias bar, as shown in an enlarged view of the deposition chamber 418. Things. Thus, an i-type layer is deposited to a desired thickness. When the i-type layer has been deposited to a desired thickness, the application of microwave power and bias is stopped.

The hydrogen plasma treatment of the present invention on the i-type layer is performed as follows. A predetermined amount of hydrogen gas and a gas containing silicon atoms necessary for performing the hydrogen plasma treatment of the present invention are supplied to the deposition chamber 418 through valves 461 and 462, mass flow controllers 456 and 457, valves 451 and 452, and a valve 450.
To be introduced. The inside of the deposition chamber 418 is set to a desired degree of vacuum by changing the opening / closing degree of an exhaust valve (not shown). Chamber 41
When the degree of vacuum of 8 is stabilized, RF power is applied from the RF power supply 424 to the bias bar 428 to generate plasma. Thus, the hydrogen plasma treatment of the present invention is performed for a predetermined time.

Depending on the surface state of the substrate and the state of the inner wall of the chamber, the flow rate of the hydrogen gas, the flow rate of the silicon atom-containing gas, the RF power,
It is desirable to appropriately change the substrate temperature and the like. Preferred forms of these parameters include:
The first is to increase the hydrogen flow rate and decrease the hydrogen flow rate over time. As a form of a change in the flow rate of the silicon atom-containing gas, the flow rate of the silicon atom-containing gas is initially small and the flow rate of the silicon atom-containing gas is increased with time. A preferred form of change is that the RF power is initially high and then reduced over time.

When the plasma processing of the present invention is completed,
The source gas for hydrogen plasma processing supplied to the deposition chamber is stopped. If necessary, the deposition chamber 418
The inside is purged with an inert gas such as hydrogen gas or helium gas. Thereafter, a p / i buffer layer is deposited to a desired thickness in the same manner as the deposition of the n / i buffer layer.
Thereafter, if necessary, the inside of the deposition chamber 418 is purged with an inert gas such as a hydrogen gas or a helium gas. The evacuation is changed from the diffusion pump to the turbo molecular pump, and the degree of vacuum in the deposition chamber is reduced to 10 ⁻⁶ Torr or less. At the same time, the heater for heating the substrate is raised so that the substrate holder can be moved.

The gate valve 408 is opened, the substrate holder is moved from the transfer chamber 403 to the transfer chamber 404, and the gate valve 408 is closed. The substrate holder is moved directly below the substrate heating heater 412, and the substrate is heated by the base heating heater 412. It is more preferable that the substrate be heated by changing the exhaust gas from the turbo molecular pump to MP / RP and flowing an inert gas such as a hydrogen gas or a helium gas to a pressure at the time of deposition of the p-type layer during heating. is there. When the substrate temperature is stabilized at a desired substrate temperature, supply of a substrate heating gas such as a hydrogen gas or an inert gas for substrate heating is stopped, and a source gas for p-type layer deposition, for example, H ₂ ,
A gas containing a Group III element of the periodic table such as SiH ₄ and BF ₃ is opened through valves 482, 483, and 484, and valves 472, 473, and 474 are further opened through mass flow controllers 477, 478, and 479 to form a deposition chamber. 4
19 to a desired flow rate through a gas introduction pipe 469.
The exhaust valve is adjusted so that the internal pressure of the deposition chamber 419 reaches a desired degree of vacuum. When the internal pressure of the deposition chamber 419 is stabilized at a desired degree of vacuum, the RF power
F power is supplied to the plasma forming cup. The p-type layer is then deposited for the desired time.

After completion of the deposition, the supply of the RF power and the source gas is stopped, and the inside of the deposition chamber is sufficiently purged with an inert gas such as hydrogen gas or helium gas. After completion of the purging, the exhaust gas is changed from MP / RP to a turbo molecular pump for 1 minute.
Evacuate to a degree of vacuum of 0 ^-6 Torr or less. At the same time, the heater 412 for heating the substrate is raised, the gate valve 409 is opened, and the substrate holder 490 is moved to the unload chamber 4.
Move to 05. The gate valve 409 is closed, and when the temperature of the substrate holder becomes 100 ° C. or less, the door of the unload chamber is opened and taken out.

Thus, a pin semiconductor layer is formed on the substrate. The substrate on which the pin semiconductor layer is formed is set in a vacuum evaporator for depositing a transparent electrode, and a transparent electrode is formed on the semiconductor layer. Next, a photovoltaic element having a transparent electrode
The electrode is set in a vacuum evaporator for depositing a collector electrode, and the collector electrode is deposited to form a photovoltaic element. When the hydrogen plasma treatment of the present invention is performed by MW, it is performed as follows. The gate valve 407 is opened, the substrate holder 490 is moved to the transfer chamber 403, and the gate valve 407 is closed. The position of the substrate holder is determined so that the substrate comes directly under the heater 411. The substrate heating heater 411 is lowered, and the substrate is put into the i-type layer deposition chamber. The substrate temperature is raised to a desired substrate temperature by the substrate heater 411. The turbo molecular pump is switched to MP / RP, and hydrogen gas and silicon atom-containing gas necessary for performing the hydrogen plasma treatment of the present invention are supplied into the chamber by valves 461 and 46.
2. A predetermined flow rate is introduced into the deposition chamber 418 via the mass flow controllers 456 and 457, the valves 451 and 452, and the valve 450. The inside of the deposition chamber 418 is set to a desired degree of vacuum by changing the opening / closing degree of an exhaust valve (not shown). When the degree of vacuum in the chamber 418 becomes stable, M
MW power from the W power source is introduced into the deposition chamber 418 via the microwave introduction window 425 to generate plasma. Thus, the hydrogen plasma treatment of the present invention is performed for a predetermined time. Depending on the surface state of the substrate and the state of the inner wall of the chamber, it is desirable to appropriately change the flow rate of the hydrogen gas, the flow rate of the silicon atom-containing gas, the MW power, the substrate temperature, etc. during the hydrogen plasma treatment. . A preferred form of variation of these parameters is to initially increase the hydrogen flow and decrease the hydrogen flow over time. As a form of the change in the flow rate of the silicon atom-containing gas, the flow rate of the silicon atom-containing gas is initially small, and the flow rate of the silicon atom-containing gas is increased with time. A preferred form of change is that the MW power is initially high and then reduced over time. When performing the hydrogen plasma treatment of the present invention with VHF, it is preferable to perform the same treatment as with MW.

Further, it is also preferable to perform a hydrogen plasma treatment on the vicinity of the interface between the substrate and the n-type layer with a hydrogen gas containing a gas that does not substantially deposit silicon atom-containing gas. To perform the hydrogen plasma treatment near the interface between the substrate and the n-type layer, the substrate is transferred to the n-type layer deposition chamber or the i-type layer deposition chamber in the above-described procedure, and the substrate is maintained at a predetermined substrate temperature. In the above procedure, a predetermined flow rate of the silicon atom-containing gas and the hydrogen gas is introduced into the deposition chamber. The pressure is adjusted by the pressure adjusting valve so that the degree of vacuum is appropriate for the type of the introduced power such as RF, VHF and / or MW power. A plasma discharge is generated by introducing RF, VHF or / and MW power, and the hydrogen plasma treatment of the present invention is performed on the substrate for a predetermined time.

The vicinity of the interface between the n / i buffer layer and the i-type layer is also subjected to a hydrogen plasma treatment with a hydrogen gas containing a silicon atom-containing gas to such an extent that it does not contribute to the deposition. Is further improved, but the hydrogen plasma treatment of the present invention on the n / i buffer layer is performed as follows. The hydrogen gas and the silicon atom-containing gas necessary for performing the hydrogen plasma treatment of the present invention are placed in the chambers 461 and 46.
2. A predetermined flow rate is introduced into the deposition chamber 418 via the mass flow controllers 456 and 457, the valves 451 and 452, and the valve 450. The inside of the deposition chamber 418 is set to a desired degree of vacuum by changing the opening / closing degree of an exhaust valve (not shown). When the degree of vacuum in the chamber 418 becomes stable, R (not shown)
RF power is introduced from the F power supply to the bias rod 428 to generate plasma. Thus, the hydrogen plasma treatment of the present invention is performed for a predetermined time. Depending on the surface state of the substrate and the state of the inner wall of the chamber, the flow rate of the hydrogen gas, the flow rate of the silicon atom-containing gas,
It is desirable to appropriately change the F power, the substrate temperature, and the like. A preferred form of variation of these parameters is to initially increase the hydrogen flow and decrease the hydrogen flow over time. As a form of the change in the flow rate of the silicon atom-containing gas, the flow rate of the silicon atom-containing gas is initially small, and the flow rate of the silicon atom-containing gas is increased with time. A preferred form of change is that the RF power is initially high and then reduced over time.

In the above-described method for forming a photovoltaic element for performing a hydrogen plasma treatment according to the present invention, the gas cylinder may be replaced with a necessary gas cylinder as needed. In that case, it is preferable that the gas line be sufficiently heated and purged. A photovoltaic element in which a plurality of pin semiconductor layers are stacked can be formed by performing a desired number of depositions in the n-type layer deposition chamber, the i-type layer deposition chamber, and the p-type layer deposition chamber of the forming apparatus 400. Things.

Next, the components of the photovoltaic element will be described in detail. (Substrate) As a material of the support preferably used in the present invention, a material having little deformation and distortion at a temperature required for forming a deposited film, having a desired strength, and having conductivity is preferably used. A support that does not decrease the adhesion of the reflective layer or the reflection-enhancing layer to the support even when the hydrogen plasma treatment of the present invention is performed after depositing the reflection layer or the reflection-enhancing layer is preferable.

Specifically, thin films of metals such as stainless steel, aluminum and its alloys, iron and its alloys, copper and its alloys and their composites, and metal thin films of different materials and / or SiO _{2 on} their surfaces, Si ₃ N ₄ , Al ₂
O ₃ , AlN or other insulating thin film that has been subjected to surface coating by sputtering, vapor deposition, plating, etc., or a heat-resistant resin sheet such as polyimide, polyamide, polyethylene terephthalate, epoxy, or glass fiber, Carbon fiber, boron fiber, metal fiber, etc., the surface of which has been subjected to a conductive treatment by plating, vapor deposition, sputtering, coating, or the like with a simple metal or alloy, and a transparent conductive oxide on the surface. .

In addition, the thickness of the support may be set as much as possible in consideration of cost, storage space, and the like as long as the thickness is within a range where the curved shape formed during the movement of the support is strong enough to maintain the strength. Thinner is desirable. Specifically, it is preferably 0.01 mm to 5 mm, more preferably 0.02 mm
The thickness is desirably from 2 mm to 2 mm, optimally from 0.05 mm to 1 mm. However, when a thin film of metal or the like is used, a desired strength is easily obtained even if the thickness is relatively thin.

The width of the support is not particularly limited and is determined by the size of the vacuum vessel and the like. The length of the support is not particularly limited, and may be a length that can be wound into a roll, or may be a longer one that is made longer by welding or the like. Good. In the present invention, the support is heated and cooled in a short time. However, it is not preferable that the temperature distribution spreads in the longitudinal direction of the support. In order to follow the heating and cooling, it is preferable that the heat conduction is large in the thickness direction.

The heat conduction of the support is reduced in the moving direction with a small thickness.
To increase in the direction, the thickness should be reduced, and the support
Is uniform, (heat conduction) × (thickness) is preferably 1 ×
10 ^-1W / K or less, more preferably 0.5 × 10^-1W /
It is desirably K or less. (Reflective layer) Ag, Au, Pt,
Ni, Cr, Cu, Al, Ti, Zn, Mo, W, etc.
Metals or their alloys;
Vacuum deposition, electron beam deposition, sputtering, etc.
Form. In addition, the formed metal thin film serves as a photovoltaic element.
If the output must be considered so that it does not become a resistance component
The sheet resistance of the reflection layer is preferably 50Ω or less,
More preferably, the resistance is preferably 10Ω or less.
is there.

When the support is translucent and the photovoltaic element is irradiated with light from the translucent support, it is preferable to form a translucent conductive layer instead of the reflective layer. Things. As a light-transmitting conductive layer suitable for such a purpose, tin oxide, indium oxide, an alloy thereof, or the like is suitable. Further, it is preferable that these light-transmitting conductive layers be deposited to a thickness that satisfies antireflection conditions. The sheet resistance of these translucent conductive layers is preferably 50Ω or less, more preferably 10Ω.
It is desirable that:

(Reflection Increasing Layer) The reflection increasing layer comprises a semiconductor layer.
The reflected light from the passing substrate is efficiently absorbed in each semiconductor layer.
In order to collect light, the light reflectance must be 85% or more.
It is desirable, and furthermore, electrically, to the output of the photovoltaic element.
Sheet resistance is 100Ω or less so that it does not become a resistance component
It is desirable that Materials with these characteristics
Then, SnΟ _Two, In_TwoO_Three, ZnΟ, CdΟ, Cd_TwoSn
O_Four, ITO (In_TwoΟ_Three+ SnO_Two) And other metal oxides
No. The reflection-enhancing layer is formed by p in the photovoltaic element.
Good adhesion to each other, in contact with the mold layer or n-type layer
It is necessary to choose something new. The reflection enhancement layer is reflective
It is preferable to deposit to a layer thickness that meets the increasing conditions
It is. As a method for producing the reflection increasing layer, resistance heating evaporation
Method, electron beam heating evaporation method, sputtering method, spray method
Method can be used.
It is.

(I-type layer) In particular, in a photovoltaic element using a group IV or group IV alloy amorphous semiconductor material,
The i-type layer used for the in-junction is an important layer that generates and transports carriers with respect to irradiation light. For an i-type layer, only p
Type, only n-type layers can be used. The amorphous semiconductor material contains a hydrogen atom (H, D) or a halogen atom (X), and has an important function.

The hydrogen atoms (H, D) or the halogen atoms (X) contained in the i-type layer work to compensate for dangling bonds (dangling bonds) of the i-type layer, and the carrier in the i-type layer has a carrier. To improve the product of the mobility and the lifetime. Also p
It has a function of compensating the interface state of each interface of the type layer / i-type layer and the n-type layer / i-type layer, and has an effect of improving the photovoltaic power, the photocurrent and the photoresponsiveness of the photovoltaic element. It is. The number of hydrogen atoms and / or halogen atoms contained in the i-type layer is 1 to
40 at% is mentioned as the optimum content. In particular, p
A preferred distribution form is one in which a large amount of hydrogen atoms and / or halogen atoms are distributed on each interface side of the n-type layer / i-type layer and the n-type layer / i-type layer. The content of atoms and / or halogen atoms is preferably 1.1 to 2 times the content in the bulk as a preferred range. Further, it is preferable that the content of hydrogen atoms and / or halogen atoms is changed in accordance with the content of silicon atoms.

When the photovoltaic element of the present invention has a plurality of pin structures, it is preferable to stack the i-type layers in order from the light incident side so that the band gap becomes smaller. Amorphous silicon or amorphous silicon carbide is used for the i-type layer having a relatively wide band gap, and amorphous silicon germanium is used for the i-type semiconductor layer having a relatively narrow band gap. Amorphous silicon and amorphous silicon germanium can be divided into a-Si: H, a-Si: F, a
-Si: H: F, a-SiGe: H, a-SiGe:
F, a-SiGe: H: F, etc.

When amorphous silicon germanium is used for the i-type layer, it is preferable to change the germanium content in the thickness direction of the i-type layer. In particular, it is a preferable distribution form of germanium that the germanium content continuously decreases in the direction of the n-type layer and / or the p-type layer. The state of distribution of germanium atoms in the layer thickness is
This can be performed by changing the flow rate ratio of the germanium-containing gas contained in the source gas. Also, MW
As a method of changing the content of germanium atoms in the i-type layer by the plasma PCVD method, in addition to the method of changing the flow rate ratio of the germanium-containing gas, changing the flow rate of hydrogen gas which is a diluent gas of the source gas is used. Can be performed similarly. The germanium content in the deposited film (i-type layer) can be increased by increasing the hydrogen dilution amount.

The hydrogen plasma treatment of the present invention particularly improves the electrical connection between the so-called graded band gap layer in which germanium atoms are continuously changed as described above and the buffer layer in contact with the layer. It is. More specifically, for example, as a pin junction i-type semiconductor layer suitable for the photovoltaic device of the present invention, i-type hydrogenated amorphous silicon (a-Si: H) can be mentioned. The optical band gap (Eg) is 1.60 eV
８５1.85 eV, hydrogen atom content (CH) is 1.0
２５25.0%, AM1.5, 100 mW / cm ² , the photoelectric conductivity (σp) under simulated sunlight irradiation was 1.0 × 10 ⁻⁵ S
/ Cm or more, and the dark conductivity (σd) is 1.0 × 10 ⁻⁹ S /
cm or less, constant photocurrent method (CP
It is preferable that the inclination of the Urbach tail according to M) is 55 meV or less and the localized level density is 10 ¹⁷ / cm ³ or less.

The semiconductor material amorphous silicon germanium constituting the i-type semiconductor layer having a relatively narrow band gap of the photovoltaic device of the present invention has an optical band gap (Eg) of 1.20 eV as a characteristic. ~ 1.60e
V, the content of hydrogen atoms (CH) is 1.0 to 25%, the slope of the Urbach tail by the constant photocurrent method (CPM) is 55 meV or less, and the localized level density is 10 ¹⁷ cm ³ or less. Are preferred.

The i-type layer suitable for the present invention is preferably deposited under the following conditions. The amorphous semiconductor layer is preferably deposited by RF, VHF or MW plasma CVD. In the case of deposition by RF plasma CVD, the substrate temperature is 100 to 350 ° C., the degree of vacuum in the deposition chamber is 0.05 to 10 Torr, and the RF frequency is 1 to 50 MHz. Especially RF
Is suitably 13.56 MHz. The RF power supplied to the deposition chamber is 0.01 to 5 W / cm ²
Is a preferable range. The preferable range of the self-bias applied to the substrate by the RF power is 0 to 300.

When depositing by VHF plasma CVD, the substrate temperature is 100 to 450 ° C., the degree of vacuum in the deposition chamber is 0.0001 to 1 Torr, and the frequency of VHF is 6
0 to 500 MHz is a suitable range. Particularly, the frequency of VHF is suitably 100 MHz. The VHF power supplied into the deposition chamber is preferably in the range of 0.01 to 1 W / cm ³ . The preferable range of the self-bias applied to the substrate by the VHF power is 10 to 1000 V. In addition, the characteristics of the deposited amorphous film are improved by introducing DC or RF into the deposition chamber by overlapping with VHF or separately providing a bias rod. When introducing a DC bias using a bias bar,
It is preferred that the bias rod be positive. When the DC bias is introduced to the substrate side, it is preferable to introduce the DC bias so that the substrate side becomes a negative electrode. When introducing an RF bias, the RF
It is preferable to reduce the area of the electrode into which the gas is introduced.

In the case of deposition by the MW plasma CVD method, the substrate temperature is 100 to 450 ° C., the degree of vacuum in the deposition chamber is 0.0001 to 0.05 Torr, and the frequency of the MW is 501 MHz to 10 GHz. . In particular, the MW frequency is suitably 2.45 GHz. The MW power input into the deposition chamber is 0.01 to 1 W / c.
m ³ is a suitable range. MW power is optimally introduced into the deposition chamber via a waveguide. Further, in addition to the MW, a bias rod is separately provided to introduce DC or RF into the deposition chamber, thereby improving the characteristics of the deposited amorphous film. When a DC bias is introduced using a bias bar, it is preferred that the bias bar be positive. When the DC bias is introduced to the substrate side, it is preferable to introduce the DC bias so that the substrate side becomes a negative electrode. When introducing an RF bias, it is preferable to make the area of the electrode into which RF is introduced smaller than the substrate area.

For deposition of an i-type layer suitable for the plasma treatment of the present invention, a silane-based source gas such as SiH ₄ , Si ₂ H ₆ , SiF ₄ , or SiF ₂ H ₂ is suitable. In order to widen the band gap, it is preferable to add a gas containing carbon, nitrogen or oxygen. The carbon, nitrogen or oxygen containing gas is more preferably contained in the p-type layer than in the i-type layer.
It is preferable that a large amount be contained near the mold layer and / or the n-type layer. By doing so, the open-circuit voltage can be improved without alienating the traveling properties of the charges in the i-type layer. As the carbon-containing gas, C
_n H _{2n + 2} , C _n H _2n , C ₂ H _{2 and the} like are suitable. As the nitrogen-containing gas, N ₂ , NO, N ₂₀ , NO ₂ , NH _{3 and the} like are suitable. O ₂ , CO ₂ , O _3, etc. are suitable as the oxygen-containing gas. Further, a plurality of these gases may be introduced in combination. A suitable amount of the source gas for increasing the band gap is 0.1 to 50%.

Further, the characteristics of the i-type layer are improved by adding an element of Group III and / or Group V of the periodic table. As the Group III elements of the periodic table, B,
Al, Ga and the like are suitable. In particular, when B is added, it is preferable to use a gas such as B ₂ H ₆ or BF ₃ . In addition, as the Group V element of the periodic table,
N, P, As, etc. are suitable. Particularly when P is added, PH ₃ is mentioned as a suitable one. The suitable amount of the Group III and / or Group V element of the periodic table added to the i-type layer is 0.1 to 1000 ppm.

For the i-type layer, the n / i buffer layer and p
By providing the / i buffer layer, the characteristics of the photovoltaic element are improved. As the buffer layer,
A semiconductor layer similar to the i-type layer can be used.
It is preferable to deposit at a lower deposition rate than the mold layer. When an element of Group III or / and Group V of the periodic table is added to the buffer layer, a Group III element of the periodic table is added to the n / i buffer layer, and the p / i buffer layer is added to the p / i buffer layer. It is preferable to add a Group V element of the periodic table. By doing so, it is possible to further prevent deterioration in characteristics due to diffusion of impurities from the n-type layer and / or the p-type layer into the i-type layer.

(N-type layer, p-type layer) The p-type layer or the n-type layer is also an important layer that affects the characteristics of the photovoltaic device of the present invention. Examples of the amorphous material (denoted as a-) of the p-type layer or the n-type layer (it goes without saying that a microcrystalline material (denoted as μc-) are also included in the range of the amorphous material). a-Si: H, a-Si: HX, a-SiC: H,
a-SiC: HX, a-SiGe: H, a-SiGe
C: H, a-SiO: H, a-SiN: H, a-SiO
N: HX, a-SiOCN: HX, μc-Si: H, μ
c-SiC: H, μc-Si: HX, μc-SiC: H
X, μc-SiGe: H, μc-SiO: H, μc-S
iGeC: H, μc-SiN: H, μc-SiON: H
X, μc-SiOCN: HX, p-type valence electron control agent (Group III atom B, Al, Ga, In, TI in the periodic table)
And n-type valence electron controlling agents (Group V atoms P, As,
Sb, Bi) are added at a high concentration, and a polycrystalline material (denoted as poly-) is, for example, po
ly-Si: H, poly-Si: HX, poly-S
iC: H, poly-SiC: HX, poly-SiG
e: H, poly-Si, poly-SiC, poly
-SiGe, etc. with p-type valence electron controlling agent (Periodic Table III
Group atom B. Al, Ga, In, Tl) and a material to which an n-type valence electron controlling agent (atom P, As, Sb, Bi in the periodic table, group V atom) is added at a high concentration.

In particular, the p-type layer or the n-type layer on the light incident side includes:
A crystalline semiconductor layer with little light absorption or an amorphous semiconductor layer with a wide band gap is suitable. The optimum amount of addition of Group III atoms of the periodic table to the p-type layer and addition of Group V atoms of the periodic table to the n-type layer is 0.1 to 50 at%. Hydrogen atoms (H, D) or halogen atoms contained in the p-type layer or the n-type layer work to compensate for dangling bonds of the p-type layer or the n-type layer, and doping efficiency of the p-type layer or the n-type layer. Is to improve. A hydrogen atom or a halogen atom added to the p-type layer or the n-type layer is 0.1 to
40 at% is mentioned as the optimum amount. In particular, when the p-type layer or the n-type layer is crystalline, the optimum amount of hydrogen atoms or halogen atoms is 0.1 to 8 at%. And p
A preferred distribution form is one in which a large amount of hydrogen atoms and / or halogen atoms are distributed on each interface side of the n-type layer / i-type layer and the n-type layer / i-type layer. The content of atoms and / or halogen atoms is preferably 1.1 to 2 times the content in the bulk as a preferred range. By increasing the content of hydrogen atoms or halogen atoms in the vicinity of each interface between the p-type layer / i-type layer and the n-type layer / i-type layer, the defect level and mechanical strain near the interface are reduced. Accordingly, the photovoltaic power and the photocurrent of the photovoltaic device of the present invention can be increased.

The p-type layer and the n-type layer of the photovoltaic element preferably have an activation energy of 0.2 eV or less, and most preferably have an activation energy of 0.1 eV or less. The specific resistance is preferably 100 Ωcm or less, and most preferably 1 Ωcm or less. Further, the layer thickness of the p-type layer and the n-type layer is 1 to
50 nm is preferred, and 3 to 10 nm is optimal. Group IV and I suitable as the semiconductor layer of the photovoltaic device of the present invention
The most preferable manufacturing method for forming a group V alloy-based amorphous semiconductor layer is microwave plasma CVD (MWPCV).
D) method, and the next preferred manufacturing method is RF plasma CV.
D (RFPCVD) method.

In the microwave plasma CVD method, a material gas such as a source gas and a diluent gas is introduced into a deposition chamber,
While evacuating by a vacuum pump, the internal pressure of the deposition chamber is kept constant, microwaves oscillated by a microwave power supply are guided by a waveguide, and introduced into the deposition chamber through a dielectric window (alumina ceramics or the like). Is a method of generating a plasma of a material gas and decomposing the same to form a desired deposited film on a substrate disposed in a deposition chamber, and forms a deposited film applicable to a photovoltaic device under a wide range of deposition conditions. be able to.

The source gas suitable for depositing the group IV and group IV alloy-based amorphous semiconductor layer suitable for the photovoltaic device of the present invention includes a gasizable compound containing silicon atoms, a germanium atom. Containing gasifiable compounds,
Gasified compounds containing carbon atoms, compounds that can be gasified containing nitrogen atoms, compounds that can be gasified containing oxygen atoms, and the like, and mixtures of these compounds can be produced.

As the gaseous compound containing a silicon atom, a chain or cyclic silane compound is used. Specifically, for example, SiH ₄ , Si ₂ H ₆ , Si
_{F 4, SiFH 3, SiF 2} H 2, SiF 3 H, Si 3 H 8,
SiD ₄ , SiHD ₃ , SiH ₂ D ₂ , SiH ₃ D, SiF
D ₃ , SiF ₂ D ₂ , SiD ₃ H, Si ₂ D ₃ H ₃ , (Si
F ₂ ) ₅ , (SiF ₂ ) ₆ , (SiF ₂ ) ₄ , Si ₂ F ₆ , Si
_{3 F 8, Si 2 H 2} F 4, Si 2 H 3 F 3, SiCl 4, (Si
Cl ₂ ) ₅ , SiBr ₄ , (SiBr ₂ ) ₅ , Si ₂ Cl ₆ ,
SiHCl ₃ , SiH ₂ Br ₂ , SiH ₂ Cl ₂ , Si ₂ Cl
₃ which may or easily gasified gas conditions such as F ₃ and the like.

Specifically, a gas containing a germanium atom
The compound which can be converted to is GeH_Four, GeD_Four, GeF_Four,
GeFH_Three, GeF_TwoH_Two, GeF_ThreeH, GeHD_Three, Ge
H_TwoD _Two, GeH_ThreeD, Ge_TwoH₆, Ge_TwoD₆Etc.
You. Specifically, a gasizable compound containing a carbon atom and
Then CH_Four, CD_Four, C _nH_{2n + 2}(N is an integer), C_nH
_2n(N is an integer), C_TwoH_Two, C₆H₆, CO_Two, CO etc.
I can do it.

As the nitrogen-containing gas, N ₂ , NH ₃ , N
D ₃ , NO, NO ₂ and N ₂ O are mentioned. O ₂ , CO, CO ₂ , NO, NO ₂ , N ₂ O, CH
₃ CH ₂ OH, CH ₃ OH, etc. In addition, as a substance introduced into the p-type layer or the n-type layer for controlling valence electrons, there may be mentioned a Group III element and a Group V atom of the periodic table.

As a starting material for introducing a group III atom effectively, specifically, for introducing a boron 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,} B 6 H 14 hydride such as boron, BF _3, B
Examples thereof include halogenated boron such as Cl ₃ .
In addition, AlCl ₃ , GaCl ₃ , InCl ₃ , TIC
l ₃ and the like can also be mentioned. Particularly, B ₂ H ₆ and BF ₃ are effectively used as starting materials for introducing a group V atom, specifically, PH ₃ and P ₂ for introducing a phosphorus atom.
H ₄ phosphorus hydride, PH ₄ I, PF ₃ , PF ₅ , PCl ₃ , P
Phosphorus halides such as Cl ₅ , PBr ₃ , PBr ₅ , and PI ₃ can be used. In addition, AsH ₃ , AsF ₃ , AsCl ₃ , A
sBr ₃ , AsF ₅ , SbH ₃ , SbF ₃ , SbF ₅ , Sb
Cl ₃ , SbCl ₅ , BiH ₃ , BiCl ₃ , BiBr _{3 and the} like can also be mentioned. Particularly, PH ₃ and PF ₃ are suitable.

The compounds capable of being gasified are H ₂ , H
The gas may be appropriately diluted with a gas such as e, Ne, Ar, Xe, or Kr and introduced into the deposition chamber. In particular, microcrystalline semiconductors and a-Si
In the case of depositing a layer having a small light absorption such as C: H or a wide band gap, the source gas is diluted 2 to 100 times with hydrogen gas, and a relatively high microwave power or RF power is introduced. Is preferred.

(Transparent Electrode) The transparent electrode desirably has a light transmittance of 85% or more in order to efficiently absorb light from the sun, a white fluorescent lamp, or the like into each semiconductor layer.
Further, it is desirable that the sheet resistance is 100Ω or less so that the resistance of the output of the photovoltaic element does not become a resistance component. As a material having such properties, S
nO ₂ , In ₂ O ₃ , ZnO, CdO, Cd ₂ SnO ₄ , I
Metal oxides such as TO (In ₂ O ₃ + SnO ₂ );
Examples of the metal thin film include a metal such as u, Al, and Cu that is formed to be extremely thin and translucent. The transparent electrode is laminated on the p-type layer or the n-type layer half in the photovoltaic element,
When a photovoltaic element is formed on a light-transmitting support and light is irradiated from the light-transmitting support side, the light-emitting element is laminated on the support, so that one having good mutual adhesion is selected. It is necessary. Further, it is preferable that the transparent electrode is deposited to a thickness that meets the antireflection conditions. As a method for manufacturing the transparent electrode, a resistance heating evaporation method, an electron beam heating evaporation method, a sputtering method, a spray method, or the like can be used, and is appropriately selected as desired.

(Current Collecting Electrode) The current collecting electrode of the photovoltaic element which has been subjected to the hydrogen plasma treatment of the present invention may be formed by screen printing silver paste, or may be made of Cr, Ag, Au,
It may be formed by vacuum evaporation using a mask of Cu, Ni, ΜO, Al or the like. Alternatively, carbon or Ag powder may be attached to a metal wire such as Cu, Au, Ag, or Al together with a resin and attached to the surface of the photovoltaic element to form a current collecting electrode.

When a photovoltaic device having a desired output voltage and output current is manufactured using the photovoltaic device of the present invention, the photovoltaic devices of the present invention are connected in series or in parallel. A protective layer is formed on the front and back surfaces, and output output electrodes and the like are attached. When the photovoltaic elements of the present invention are connected in series, a diode for preventing backflow may be incorporated.

[0081]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for forming a photovoltaic element of the present invention will be described in detail for a solar cell made of a non-single-crystal silicon-based semiconductor material, but the present invention is not limited thereto. (Example 1) The solar cell of FIG. 1 was manufactured using the deposition apparatus shown in FIG. First, a substrate was manufactured. Thickness 0.5
mm, 50 × 50 mm ² stainless steel support (10 mm
0) was ultrasonically washed with acetone and isopropanol and dried with warm air.

At room temperature, a 0.3 μm thick Ag layer was
Light reflecting layer (101) and a layer thickness of 1.0 at 350 ° C.
A μm ZnO reflection enhancement layer (102) was formed, and the fabrication of the substrate was completed. Next, each semiconductor layer was formed on the reflection increasing layer using the deposition apparatus 400. The deposition device 400 is MW
Both PCVD and RFPCVD can be performed.

A raw material gas cylinder (not shown) is provided in the deposition apparatus.
It is connected through the inlet pipe. Raw gas cylinder Yes
The deviation is also purified to ultra-high purity,_FourGas bon
Ba, SiF_FourGas cylinder, CH_FourGas cylinder, GeH_FourMoth
Bomb, GeF_FourGas cylinder, Si_TwoH₆Gas cylinders,
PH_Three/ H_Two(Dilution: 1000 ppm) Gas cylinder, B
_TwoH₆/ H_Two(Dilution: 2000 ppm) Gas cylinder, H_Two
Gas cylinder, He gas cylinder, SiCl_TwoH_TwoGas bon
Bae, SiH_Four/ H_Two(Dilution: 1000 ppm)
Be connected.

Next, the substrate 490 on which the reflection layer 101 and the reflection enhancement layer 102 are formed is disposed on the substrate transfer rail 413 in the load chamber 401, and the inside of the load chamber 401 is pressurized by a vacuum exhaust pump (not shown). Is about 1
The chamber was evacuated to ^10-5 Torr. Next, the gate valve 406 was opened and transported into the transport chamber 402 and the deposition chamber 417, which were previously evacuated by a vacuum pump (not shown). The back surface of the substrate 490 was heated by being brought into close contact with a heater 410 for heating the substrate, and the inside of the deposition chamber 417 was evacuated by a vacuum exhaust pump (not shown) until the pressure became about 1 × 10 ⁻⁵ Torr.

The preparation for film formation was completed as described above.
Thereafter, an RF n-type layer 103 made of μc-Si was formed.
To form an RF n-type layer made of μc-Si, H_TwoMoth
Through the gas introduction pipe 429 into the deposition chamber 417.
And introduced, H_TwoSo that the gas flow rate is 180sccm
Open the valves 441, 431, and 430, and
It was adjusted with the Troller 436. Inside the deposition chamber 417
(Not shown) so that the pressure becomes 1.10 Torr.
It was adjusted with a reactance valve. When the temperature of the substrate 490 is 370
Set the substrate heating heater 410 to
When the plate temperature is stabilized, the SiH_FourGas, PH_Three/ H_Two
The gas is supplied to the deposition chamber 417 by the valves 443 and 43.
3, 444 and 434 are operated to pass through the gas introduction pipe 429.
Introduced. At this time, SiH _FourGas flow rate is 1.4scc
m, H_TwoGas flow rate 110sccm, PH_Three/ H_TwoGas flow
Mass flow control so that the volume is 200 sccm
438, 436, 439
Adjust the pressure in 417 to 1.10 Torr.
Was. The power of the RF power supply 422 is set to 0.04 W / cm^ThreeSet to
Then, RF power is introduced into the plasma forming cup 420,
Glow discharge is generated, and the formation of an RF n-type layer on the substrate is started.
When an RF n-type layer having a thickness of 20 nm is formed, R
F power is turned off, glow discharge is stopped, and the RF n-type layer 103 is turned off.
Finished the formation. SiH into the deposition chamber 417_Four
Gas, PH_Three/ H_TwoThe flow of H into the deposition chamber for 5 minutes.
_TwoAfter continuing the gas flow, H_TwoStop the inflow of
And 1 × 10^-FiveEvacuate to Torr
Was.

Next, an n / i buffer layer 151 made of a-Si was formed by RFPCVD. First, the transfer chamber 403 and the i-type layer deposition chamber 41 evacuated by a vacuum pump (not shown) in advance.
8, the gate valve 407 was opened, and the substrate 490 was transported. The back surface of the substrate 490 was heated by being brought into close contact with a heater 411 for heating the substrate, and the inside of the i-type layer deposition chamber 418 was evacuated by a vacuum exhaust pump (not shown) until the pressure reached about 1 × 10 ⁻⁵ Torr.

To form the n / i buffer layer 151
Heats the substrate so that the temperature of the substrate 490 becomes 360 ° C.
Heater 411 is set, and the base hill is sufficiently heated.
Filter valves 464, 454, 450, 463, 453
Open gradually, Si_TwoH₆Gas, H_TwoGas inlet pipe 4
49 into the i-type layer deposition chamber 418
Was. At this time, Si_TwoH₆Gas flow rate 3.5 sccm, H_Two
Each mass flow so that the gas flow rate is 80 sccm
The adjustment was performed by the controllers 459 and 458. i-type layer deposition
The pressure inside the chamber 418 will be 0.8 Torr
Thus, the opening of the conductance valve (not shown) was adjusted.
Next, a high frequency (hereinafter abbreviated as “RF”) power supply 424 is
0.06W / cm^ThreeSet to and apply to bias bar 428
To generate a glow discharge and open the shutter 427
Starts production of n / i buffer layer on RF n-type layer
Then, an n / i buffer layer having a thickness of 10 nm was prepared.
To stop the RF glow discharge and turn off the output of the RF power supply 424.
Thus, the production of the n / i buffer layer 151 was completed. valve
464 and 454 are closed and the i-type layer deposition chamber 418 is closed.
Si inside_TwoH₆Stop the inflow of gas and deposit the i-type layer for 2 minutes.
H into chamber 418 _TwoAfter continuing the gas flow, the valve
453 and 450 are closed and inside the i-type layer deposition chamber 418
And 1 × 10^-FiveEvacuate to Torr
Was.

Next, the MWi type layer 1 made of a-SiGe
04 was formed by the MWPCVD method. In order to manufacture the MWi-type layer, the substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 370 ° C., and when the substrate is sufficiently heated, the valves 461, 451, 450, 46
2, 452, 463 and 453 are gradually opened, and SiH ₄
Gas, GeH ₄ gas, and H ₂ gas were caused to flow into the i-type layer deposition chamber 418 through the gas introduction pipe 449.

At this time, the flow rate of the SiH ₄ gas is 38 scc.
m, GeH ₄ gas flow rate is 37 sccm, H ₂ gas flow rate is 1
Each mass flow controller 456, 457, 458 was adjusted to 30 sccm. The opening of the conductance valve (not shown) was adjusted so that the pressure in the i-type layer deposition chamber 418 became 5 mTorr. Next, the RF power source 424 was set at 0.70 W / cm ³ and applied to the bias bar 428. After that, the power of a MW power supply (not shown) is set to 0.30 W / cm ³ , MW power is introduced into the i-type layer deposition chamber 418 through the waveguide 426 and the microwave introduction window 425, and glow discharge is generated. By opening the shutter 427, the production of the MWi-type layer on the n / i buffer layer is started, and when the i-type layer having a thickness of 0.15 μm is produced, the MW glow discharge is stopped, and the output of the bias power supply 424 is turned off. The fabrication of the MWi layer 204 has been completed. The valves 451 and 452 are closed to stop the flow of the SiH ₄ gas and the GeH ₄ gas into the i-type layer deposition chamber 418, and the H ₂ gas is introduced into the i-type layer deposition chamber 418 for 2 minutes.
After continuing the gas flow, the valves 453 and 450 are closed,
1 × in the i-type layer deposition chamber 418 and the gas pipe
The chamber was evacuated to 10 ^-5 Torr.

Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed. In order to carry out the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention, SiH ₄ gas and H ₂ gas are introduced into the deposition chamber 418 through the gas introduction pipe 449 as silicon atom-containing gas, and the H ₂ gas flow rate is 10
The valves 463, 453, and 45 are set to be 00 sccm.
0 was opened and adjusted by the mass flow controller 458. The silicon atom-containing gas is supplied to the valve 461 such that the SiH ₄ gas amount becomes 0.01% with respect to the total H ₂ gas flow rate.
451 was opened and adjusted by the mass flow controller 456. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 418 became 0.8 Torr.
The substrate heater 411 is set so that the temperature of the substrate 490 becomes 300 ° C., and when the substrate temperature is stabilized,
The power of the RF power supply 424 is set to 0.05 W / cm ³ ,
RF power was applied to the bias bar 428. A glow discharge was generated in the deposition chamber 418, and a hydrogen plasma treatment containing a small amount of silane-based gas of the present invention was performed for 3 minutes. Thereafter, the RF power supply is turned off, the glow discharge is stopped, the flow of SiH ₄ gas into the deposition chamber 418 is stopped, and the flow of H ₂ gas into the deposition chamber 418 is continued for 3 minutes, and then the flow of H ₂ gas is also stopped. The inside of the deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, a p / i buffer layer 161 made of a-Si was formed by RFPCVD. To manufacture the p / i buffer layer 161, the temperature of the substrate 490 is set to 23.
The substrate heating heater 411 is set to be 0 ° C.
When the substrate is sufficiently heated, valves 464, 454,
450, 463 and 453 were gradually opened, and Si ₂ H ₆ gas and H ₂ gas were introduced into the i-type layer deposition chamber 418 through the gas introduction pipe 449. At this time, the mass flow controllers 459 and 458 were adjusted so that the flow rate of the Si ₂ H ₆ gas was 3 sccm and the flow rate of the H ₂ gas was 80 sccm.
Was adjusted. The pressure in the i-type layer deposition chamber 418 is
The opening of the conductance valve (not shown) was adjusted to 0.7 Torr. Next, the RF power supply 424 is set to 0.0
It is set to 7 W / cm ³ and applied to the bias bar 428 to generate a glow discharge. By opening the shutter 427, the formation of a p / i buffer layer on the MWi-type layer is started. When the buffer layer was prepared, R
The F glow discharge is stopped, the output of the RF power supply 424 is turned off, and p
The production of the / i buffer layer 161 was completed. Valve 46
4 and 454 are closed, the flow of Si ₂ H ₆ gas into the i-type layer deposition chamber 418 is stopped, and the flow of H ₂ gas into the i-type layer deposition chamber 418 is continued for 2 minutes.
3, 450 was closed, and the inside of the i-type layer deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, the RFp type layer 105 made of a-SiC
Was formed. In order to form the RF p-type layer 105 made of a-SiC, the gate valve 408 is opened into the transfer chamber 404 and the p-type layer deposition chamber 419 that have been evacuated in advance by a vacuum pump (not shown), and the substrate 490 is removed. Conveyed. The back surface of the substrate 490 is brought into close contact with the substrate heating heater 412 and heated, and the pressure in the p-type layer deposition chamber 419 is reduced to about 1 × by a vacuum exhaust pump (not shown).
The chamber was evacuated to 10 ^-5 Torr.

The temperature of the substrate 490 is set to 200 ° C.
Set the substrate heating heater 412 to keep the substrate temperature stable.
By the way, H_TwoGas, SiH_Four/ H_TwoGas, B_TwoH₆/ H_Two
Gas, CH_FourGas, valve in deposition chamber 419
481, 471, 470, 482, 472, 483, 4
73, 484, and 474 to operate the gas introduction pipe 469.
And introduced. At this time, H_TwoGas flow rate 80scm, S
iH_Four/ H_TwoGas flow rate 1sccm, B_TwoH₆/ H_TwoGas flow
Amount is 10sccm, CH_FourWhen the gas flow rate is 0.3sccm
Mass flow controllers 476, 477,
478, 479, and adjust the pressure in the deposition chamber 419.
Conductor (not shown) so that the force is 1.3 Torr
The opening of the valve was adjusted. The power of the RF power supply 423
0.09W / cm^ThreeAnd the plasma forming cup 4
RF power is introduced to 21 to generate glow discharge, and p /
Start forming an RFp-type layer on the i-buffer layer,
When the 0 nm RFp type layer is formed, the RF power is turned off.
To stop the glow discharge and finish forming the RFp type layer 105.
Was. Valves 472, 482, 473, 483, 474,
484 is closed and the Si is introduced into the p-type layer deposition chamber 419.
H_Four/ H_TwoGas, B_TwoH₆/ H _TwoGas, CH_FourStop gas flow
Into the p-type layer deposition chamber 419 for 3 minutes._Twogas
And then close valves 471, 481, and 470
H_TwoOf p-type layer deposition chamber 419
And 1 × 10^-FiveEvacuate to Torr
Was.

Next, the substrate 490 is transported by opening the gate valve 409 into the unload chamber 405 evacuated by a vacuum pump (not shown), and the leak valve (not shown) is opened to open the unload chamber 40.
5 leaked. Next, as the transparent conductive layer 112, ITO having a thickness of 70 nm was vacuum-deposited on the RFp-type layer 105 by a vacuum evaporation method.

Next, a mask having a comb-shaped hole is placed on the transparent conductive layer 112, and Cr (40 nm) / Ag (1000 n
m) / Combined current collector electrode 113 made of Cr (40 nm)
Was vacuum deposited by a vacuum deposition method. Thus, the production of the solar cell has been completed. This solar cell is called (SC Ex. 1),
Hydrogen plasma treatment conditions containing a trace amount of silane-based gas of the present invention,
RFn type layer, RFn / i buffer layer, MWi type layer, R
Table 1 shows the conditions for forming the Fp / i buffer layer and the RFp type layer.
(1), shown in 1 (2).

Comparative Example 1 A solar cell (SC ratio 1) was manufactured under the same conditions as in Example 1 except that the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was not performed. Nine solar cells (SC Ex. 1) and (SC ratio 1) were manufactured, each having 9 units, with initial photoelectric conversion efficiency (photovoltaic power / incident optical power), vibration deterioration, light deterioration, and high temperature and high humidity when bias voltage was applied. Vibration degradation and light degradation in the environment were measured.

The initial photoelectric conversion efficiency can be obtained by installing the manufactured solar cell under AM1.5 (100 mW / cm ² ) light irradiation and measuring the VI characteristics. As a result of the measurement, with respect to (SC ratio 1), the fill factor (FF) of initial photoelectric conversion efficiency and characteristic unevenness (the characteristic unevenness is preferably smaller) of (SC actual 1) are as follows. Vibration degradation was measured by placing a solar cell whose initial photoelectric conversion efficiency was measured in advance in a dark place with a humidity of 55% and a temperature of 26 ° C.
AM1.5 (100 mW / cm ² ) after adding for 0 hours
The measurement was performed based on the rate of decrease in photoelectric conversion efficiency under irradiation (photoelectric conversion efficiency after vibration degradation test / initial photoelectric conversion efficiency).

The photodegradation was measured by placing a solar cell, whose initial photoelectric conversion efficiency was measured in advance, in an environment of a humidity of 55% and a temperature of 26 ° C., and applying AM1.5 (100 mW / cm ² ) light for 500 hours. AM1.5 after irradiation (100 mW / cm ² )
The measurement was performed based on the rate of decrease in photoelectric conversion efficiency under irradiation (photoelectric conversion efficiency after light degradation test / initial photoelectric conversion efficiency). As a result of the measurement, the rate of decrease in photoelectric conversion efficiency after light deterioration (SC ratio 1) and the rate of decrease in photoelectric conversion efficiency after vibration deterioration with respect to (SC actual 1) were as follows.

[0099] Vibration degradation and light degradation in a high temperature and high humidity environment at the time of bias application were measured. Two solar cells whose initial photoelectric conversion efficiency was measured in advance were placed in a dark place at a humidity of 91% and a temperature of 85 ° C., and 0.7 V was applied as a forward bias voltage. The above-mentioned vibration was applied to one of the solar cells to measure the vibration deterioration, and the other solar cell was irradiated with AM1.5 light to measure the light deterioration. As a result of the measurement, (S
With respect to C Ex 1), the rate of decrease in photoelectric conversion efficiency after vibration deterioration of (SC ratio 1) and the rate of decrease in photoelectric conversion efficiency after light deterioration were as follows.

[0100] The state of delamination was observed using an optical microscope. In (SC Ex. 1), no delamination was observed, but in (SC ratio 1), delamination was slightly observed. As described above, the solar cell (SC Ex. 1) of the present invention has more fill factor and characteristic unevenness in the photoelectric conversion efficiency of the solar cell than the conventional solar cell (SC ratio 1).
It was found that the film had more excellent characteristics in light deterioration characteristics, adhesion, and durability.

Example 2 Using the deposition apparatus shown in FIG. 4, the tandem solar cell shown in FIG. 2 was manufactured. Reflection layer 201 and reflection enhancement layer 20 prepared by the same method as in Example 1.
2 is formed in the load chamber 40.
The load chamber 401 was evacuated by a vacuum evacuation pump (not shown) until the pressure reached about 1 × 10 ⁻⁵ Torr.

Next, the gate valve 406 was opened and transported into the transport chamber 402 and the deposition chamber 417, which were previously evacuated by a vacuum pump (not shown). The back surface of the substrate 490 was heated by being brought into close contact with a heater 410 for heating the substrate, and the inside of the deposition chamber 417 was evacuated by a vacuum exhaust pump (not shown) until the pressure became about 1 × 10 ⁻⁵ Torr.

Preparation for film formation was completed as described above.
Thereafter, an RF n-type layer 203 made of μc-Si was formed.
To form an RF n-type layer made of μc-Si, H_TwoMoth
Through the gas introduction pipe 429 into the deposition chamber 417.
And introduced, H_TwoSo that the gas flow rate is 300sccm
Open the valves 441, 431, and 430, and
It was adjusted with the Troller 436. Inside the deposition chamber 417
(Not shown) so that the pressure becomes 1.2 Torr.
Adjusted with a lance valve. The temperature of the substrate 490 is 380 ° C.
The heater 410 for the base slope heating is set so that
When the temperature stabilizes, the SiH _FourGas, PH_Three/ H_TwoMoth
Valves 443 and 433 in the deposition chamber 417.
Operate 444 and 434 to guide through gas introduction pipe 429.
Entered. At this time, SiH_FourGas flow rate of 1.7 sccm,
H_TwoGas flow rate 90 sccm, PH_Three/ H_TwoGas flow is 2
Mass flow controller 4 so that it becomes 00sccm
38, 436 and 439, the deposition chamber 417
The internal pressure was adjusted to be 1.2 Torr. RF
The power of the power supply 422 is 0.05 W / cm^ThreeSet to
RF power is introduced into the cup 420 for forming
To generate an RF n-type layer on the substrate,
When the RF n-type layer having a thickness of 20 nm is formed, the RF power supply is turned on.
Cut off the glow discharge to stop the formation of the RF n-type layer 203.
finished. SiH into the deposition chamber 417_FourGas, P
H_Three/ H_TwoThe flow of H into the deposition chamber for 4 minutes._TwoGas
After continuing to flow, H_TwoStop the inflow of
1 × 10 inside the piping^-FiveEvacuated to Torr.

Next, an n / i buffer layer 251 made of a-Si was formed by RFPCVD. First, the transfer chamber 403 and the i-type layer deposition chamber 41 evacuated by a vacuum pump (not shown) in advance.
8, the gate valve 407 was opened, and the substrate 490 was transported. The back surface of the substrate 490 was heated by being brought into close contact with a heater 411 for heating the substrate, and the inside of the i-type layer deposition chamber 418 was evacuated by a vacuum exhaust pump (not shown) until the pressure reached about 1 × 10 ⁻⁵ Torr.

To form the n / i buffer layer 251
Heats the substrate so that the temperature of the substrate 490 becomes 360 ° C.
Heater 411 is set and the board is sufficiently heated.
Filter valves 464, 454, 450, 463, 453
Open gradually, Si_TwoH₆Gas, H_TwoGas inlet pipe 4
49 into the i-type layer deposition chamber 418
Was. At this time, Si_TwoH₆Gas flow rate 3.5 sccm, H_Two
Each mass flow so that the gas flow rate is 85 sccm
The adjustment was performed by the controllers 459 and 458. i-type layer deposition
The pressure inside the chamber 418 will be 0.8 Torr
Thus, the opening of the conductance valve (not shown) was adjusted.
Next, the RF power supply 424 is set to 0.08 W / cm ^ThreeSet to
The glow discharge is applied to the bias rod 428 to generate a glow discharge.
By opening the shutter 427, the n / i barrier
Production of a buffer layer is started, and a 10 nm thick n / i buffer
When the fur layer was formed, the RF glow discharge was stopped.
The output of the F power supply 424 is turned off, and the n / i buffer layer 251 is turned off.
Finished. Close the valves 464 and 454,
Si into layer deposition chamber 418_TwoH₆Stop gas flow
Into the i-type layer deposition chamber 418 for 2 minutes._TwoGas
After continuing the flow, the valves 453 and 450 are closed, and the i-type layer
1 × 10 in the deposition chamber 418 and gas pipe^-Five
Evacuated to Torr.

Next, the MWi type layer 2 made of a-SiGe
04 was formed by the MWPCVD method. To manufacture the MWi-type layer, the substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 380 ° C., and when the substrate is sufficiently heated, the valves 461, 451, 450, 46
2, 452, 463 and 453 are gradually opened, and SiH ₄
Gas, GeH ₄ gas, and H ₂ gas were caused to flow into the i-type layer deposition chamber 418 through the gas introduction pipe 449.

At this time, the flow rate of the SiH ₄ gas is 45 scc.
m, GeH ₄ gas flow rate is 40 sccm, H ₂ gas flow rate is 1
Each mass flow controller 456, 457, 458 adjusted the flow rate to 50 sccm. The opening of the conductance valve (not shown) was adjusted so that the pressure in the i-type layer deposition chamber 418 became 5 mTorr. Next, the RF power source 424 was set at 0.6 W / cm ³ and applied to the bias bar 428. Thereafter, the power of a MW power supply (not shown) is set to 0.25 W / cm ³ , and MW power is introduced into the i-type layer deposition chamber 418 through the waveguide 426 and the window 425 for introducing microwaves to generate glow discharge. Then, the shutter 427 is opened to start the production of the MWi-type layer on the n / i buffer layer. When the i-type layer having a thickness of 0.15 μm is produced, the MW glow discharge is stopped, and the output of the bias power supply 424 is turned off. Then, the fabrication of the MWi type layer 204 was completed. The valves 451 and 452 are closed to stop the flow of the SiH ₄ gas and the GeH ₄ gas into the i-type layer deposition chamber 418, and H is introduced into the i-type layer deposition chamber 418 for 2 minutes.
After the continuous flow of the _two gases, the valves 453 and 450 were closed, and the inside of the i-type layer deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 2 (1)). In order to perform the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention, Si ₂ H ₆ gas and H ₂ gas are introduced into the deposition chamber 418 through the gas introduction pipe 449 as silicon atom-containing gas.
_{(2) The} valve 46 is adjusted so that the gas flow rate becomes 850 sccm.
3, 453 and 450 were opened and adjusted by the mass flow controller 458. The gas containing silicon atoms is Si ₂ H ₆
The valves 464 and 454 were opened and the mass flow controller 459 adjusted so that the gas amount became 0.005% with respect to the total H ₂ gas flow rate. The pressure inside the deposition chamber 418 was adjusted with a conductance valve (not shown) so as to be 0.012 Torr. The substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 285 ° C., and when the substrate temperature becomes stable, the power of a VHF power supply (not shown) is set to 0.
At a setting of 08 W / сm ³ , a voltage was applied to the bias rod 428 to generate a glow discharge in the deposition chamber 418, and a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed for 4 minutes. Thereafter, the VHF power supply is turned off, the glow discharge is stopped, the flow of Si ₂ H ₆ gas into the deposition chamber 418 is stopped,
After continuously flowing the H ₂ gas into the deposition chamber 418 for 4 minutes, the flow of the H ₂ gas is stopped, and the deposition chamber 418 is stopped.
The inside and the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, a p / i buffer layer 261 made of a-Si was formed by RFPCVD. To form the p / i buffer layer 261, the substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 250 ° C., and when the substrate is sufficiently heated, the valves 464 and 45 are formed.
4, 450, 463 and 453 are gradually opened, and Si ₂ H ₆
Gas and H ₂ gas were introduced into the i-type layer deposition chamber 418 through the gas introduction pipe 449. At this time, the mass flow controllers 459 and 45 were set so that the flow rate of the Si ₂ H ₆ gas was 3 sccm and the flow rate of the H ₂ gas was 70 sccm.
Adjusted at 8. The opening of the conductance valve (not shown) was adjusted so that the pressure in the i-type layer deposition chamber 418 became 0.7 Torr. Next, the RF power source 424 is set to 0.07 W / cm ³ , applied to the bias bar 428 to generate glow discharge, and the shutter 427 is opened to form the p / i buffer layer 261 on the MWi-type layer. Starting, when a 20 nm-thick p / i buffer layer was formed, the RF glow discharge was stopped, the output of the RF power supply 424 was turned off, and the formation of the p / i buffer layer 261 was completed.
The valves 464 and 454 are closed to stop the flow of the Si ₂ H ₆ gas into the i-type layer deposition chamber 418, and the H ₂ gas is continuously flown into the i-type layer deposition chamber 418 for 2 minutes.
The valves 453 and 450 are closed, and the i-type layer deposition chamber 4 is closed.
The inside of 18 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, the RFp type layer 205 made of a-SiC
In order to form the substrate, the gate valve 408 was opened and the substrate 490 was transferred into the transfer chamber 404 and the p-type layer deposition chamber 419 that were previously evacuated by a vacuum pump (not shown). The back surface of the substrate 490 was heated by being brought into close contact with a heater 412 for heating the substrate, and the inside of the p-type layer deposition chamber 419 was evacuated by a vacuum exhaust pump (not shown) until the pressure became about 1 × 10 ⁻⁵ Torr.

The temperature of the substrate 490 is set to 250 ° C.
Set the substrate heating heater 412 to keep the substrate temperature stable.
By the way, H_TwoGas, SiH_Four/ H_TwoGas, B_TwoH₆/ H_Two
Gas, CH_FourThe gas is introduced into the deposition chamber 419 by the valve 4.
81, 471, 470, 482, 472, 483, 47
Operate 3, 484, 474 through gas introduction pipe 469
Introduced. At this time, H_TwoGas flow rate 60scm, Si
H_Four/ H_TwoGas flow rate 2sccm, B_TwoH₆/ H_TwoGas flow
Is 10 sccm, CH_FourGas flow is 0.3sccm
Mass flow controllers 476, 477, 4
The pressure in the deposition chamber 419 is adjusted at 78 and 479.
Is a conductance (not shown) so as to be 1.8 Torr.
The opening of the valve was adjusted. The power of the RF power supply 423 is set to 0.
07W / cm^ThreeAnd the plasma forming cup 421
RF power is introduced into the p / i
The formation of an RFp type layer on the buffer layer is started, and the layer thickness is 10 n.
When the RFp type layer of m is formed, the RF power is turned off,
The glow discharge was stopped, and the formation of the RFp type layer 205 was completed.
Valves 472, 482, 473, 483, 474, 48
4 is closed and SiH is introduced into the p-type layer deposition chamber 419._Four
/ H_TwoGas, B_TwoH₆/ H _TwoGas, CH_FourStop gas flow
Into the p-type layer deposition chamber 419 for 3 minutes._Twogas
And then close valves 471, 481, and 470
H_TwoIs stopped, and the inside of the p-type layer deposition chamber 419 is stopped.
And 1 × 10^-FiveEvacuate to Torr
Was.

Next, an RF n-type layer 206 made of μc-Si
In order to form the substrate, the gate valves 408 and 407 were opened and the substrate 490 was transferred into the transfer chamber 402 and the deposition chamber 417 through the transfer chamber 403 evacuated by a vacuum pump (not shown) in advance. The back surface of the substrate 490 was heated by being brought into close contact with a heater 410 for heating the substrate, and the inside of the deposition chamber 417 was evacuated by a vacuum exhaust pump (not shown) until the pressure became about 1 × 10 ⁻⁵ Torr.

Form RF n-type layer made of μc-Si
H_TwoGas is introduced into the deposition chamber 417
429, introduced by H_TwoGas flow rate is 200sccm
Open the valves 441, 431 and 430 so that
It was adjusted by the flow controller 436. Sedimentary chan
Unnecessary so that the pressure in the bar 417 becomes 1.1 Torr
It was adjusted with the indicated conductance valve. Temperature of substrate 490
The substrate heating heater 410 is set to a temperature of 250 ° C.
When the substrate temperature is stabilized, _Fourgas,
PH_Three/ H_TwoThe gas is introduced into the deposition chamber 417 by the valve 44.
3, 433, 444, and 434 are operated to operate the gas introduction pipe 42.
9 introduced. At this time, SiH_FourGas flow is 2s
ccm, H_TwoGas flow rate 70 sccm, PH_Three/ H_Twogas
Mass flow control so that the flow rate is 250 sccm
438, 436, 439
The pressure inside -417 was adjusted to be 1.1 Torr.
Was. The power of the RF power supply 422 is set to 0.04 W / cm^ThreeSet to
Then, RF power is introduced into the plasma forming cup 420,
A glow discharge is generated to form an RFn-type layer on the RFp-type layer.
Started to form an RF n-type layer with a thickness of 10 nm.
Turn off the RF power at the filter to stop the glow discharge.
The formation of 206 was completed. S in the deposition chamber 417
iH_FourGas, PH_Three/ H_TwoStop the inflow of water for 2 minutes in the deposition chamber
H inside_TwoAfter continuing the gas flow, H_TwoStops inflow of water and accumulates
1 × 10 in the room and gas pipe^-FiveEvacuate to Torr
I noticed.

Next, an n / i buffer layer 252 made of a-SiC was formed by RFPCVD. First, the transfer chamber 403 and the i-type layer deposition chamber 41 evacuated by a vacuum pump (not shown) in advance.
8, the gate valve 407 was opened, and the substrate 490 was transported. The back surface of the substrate 490 was heated by being brought into close contact with a heater 411 for heating the substrate, and the inside of the i-type layer deposition chamber 418 was evacuated by a vacuum exhaust pump (not shown) until the pressure reached about 1 × 10 ⁻⁵ Torr.

To form the n / i buffer layer 252, the substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 250 ° C., and when the substrate is sufficiently heated, the valves 464, 454, 450 and 463 are formed. , 453,
465 and 455 were gradually opened, and Si ₂ H ₆ gas, H ₂ gas, and CH ₄ gas were caused to flow into the i-type layer deposition chamber 418 through the gas introduction pipe 449. At this time, the flow rate of the Si ₂ H ₆ gas was 0.4 sccm, and the flow rate of the H ₂ gas was 80 sccc.
The mass flow controllers 459, 458, and 460 adjusted the flow rates of m and CH ₄ gas to 0.2 sccm.

The pressure in the i-type layer deposition chamber 418 is
The opening of the conductance valve (not shown) was adjusted to 1.3 Torr. Next, the RF power supply 424 is set to 0.0
It is set to 6 W / cm ³ and applied to the bias rod 428 to generate a glow discharge. By opening the shutter 427, the production of an n / i buffer layer on the RF n-type layer is started. When the buffer layer was prepared, R
F glow discharge is stopped, the output of the RF power supply 424 is turned off, and n
The production of the / i buffer layer 252 was completed. Valve 46
4, 454, 465 and 455 are closed to stop the flow of the Si ₂ H ₆ gas and the CH ₄ gas into the i-type layer deposition chamber 418, and the H ₂ gas continues to flow into the i-type layer deposition chamber 418 for 2 minutes. After that, the valves 453 and 450 are closed, and the inside of the i-type layer
^The chamber was evacuated to ^-5 Torr.

Next, an RFi type layer 207 made of a-Si was formed by RFPCVD. To manufacture the RFi-type layer, the substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 200 ° C., and when the substrate is sufficiently heated, the valves 464, 454, 450, 463, and 453 are gradually opened. Then, Si ₂ H ₆ gas and H ₂ gas are introduced into the gas introduction pipe 4.
49, and flowed into the i-type layer deposition chamber 418. At this time, the mass flow controllers 459 and 458 adjusted the flow rates of the Si ₂ H ₆ gas to 3 sccm and the H ₂ gas to 60 sccm. The opening of the conductance valve (not shown) was adjusted so that the pressure in the i-type layer deposition chamber 418 became 0.5 Torr. Next, the RF power source 424 is set to 0.07 W / cm ³ and applied to the bias bar 428 to generate glow discharge. The shutter 427 is opened to open the n / i buffer layer 252.
The RFi-type layer was formed thereon. When the i-type layer having a thickness of 110 nm was formed, the RF glow discharge was stopped, the output of the RF power source 424 was turned off, and the preparation of the RFi-type layer 207 was completed. The valves 464 and 454 are closed to stop the flow of the Si ₂ H ₆ gas into the i-type layer deposition chamber 418, and the i.
After continuing to flow the H ₂ gas into the mold layer deposition chamber 418, the valves 453 and 450 were closed, and the inside of the i-type layer deposition chamber 418 and the gas pipe were evacuated to 1 × 10 ^-5 Torr.

Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 2 (2)). To do trace silane-based gas containing hydrogen plasma treatment of the present invention, as the silicon atom-containing gas is introduced through the SiH ₄ gas, the gas inlet pipe 449 and H ₂ gas into the deposition chamber 418, H ₂
The valve 46 is adjusted so that the gas flow rate becomes 1100 sccm.
3, 453 and 450 were opened and adjusted with a mass flow controller 458. The content of silicon atoms was adjusted by the mass flow controller 456 by opening the valves 461 and 451 so that the SiH ₄ gas amount became 0.003% with respect to the total H ₂ gas flow rate. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 418 became 0.7 Torr. The substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 200 ° C., and when the substrate temperature is stabilized, the power of the RF power supply 424 is reduced to 0.02 W /
cm ³ , and RF power was applied to the bias bar 428. Causing a glow discharge in the deposition chamber 418;
The hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed for 3 minutes. Then turn off the RF power to stop the glow discharge, to stop the flow of SiH ₄ gas into the deposition chamber 418 for three minutes, after which continued to flow推積chamber 418 in F H ₂ gas, the inflow of the H ₂ gas Then, the inside of the deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, ap / i buffer layer 262 made of a-SiC was formed by RFPCVD. To form the p / i buffer layer 262, the temperature of the substrate
The substrate heating heater 411 is set to be 00 ° C., and when the substrate is sufficiently heated, the valves 464 and 45 are set.
4, 450, 463, 453, 465, and 455 were gradually opened, and Si ₂ H ₆ gas, H ₂ gas, and CH ₄ gas were caused to flow into the i-type layer deposition chamber 418 through the gas introduction pipe 449. At this time, the flow rate of the Si ₂ H ₆ gas is 0.4 sccm,
H ₂ gas flow rate is 60 sccm, CH ₄ gas flow rate is 0.3 s
Each mass flow controller 4 so that it becomes ccm
Adjustment was made at 59, 458 and 460. The opening of the conductance valve (not shown) was adjusted so that the pressure in the i-type layer deposition chamber 418 became 1.2 Torr. Next, R
The F power source 424 was set to 0.06 W / cm ³ , applied to the bias bar 428 to generate a glow discharge, and opened the shutter 427 to start the production of the p / i buffer layer on the RFi-type layer. When a 15 nm thick p / i buffer layer was formed, the RF glow discharge was stopped and the RF power source 4 was turned off.
The output of 24 was turned off, and the production of the p / i buffer layer 262 was completed. The valves 464, 454, 465, and 455 are closed to stop the flow of Si ₂ H ₆ gas and CH ₄ gas into the i-type layer deposition chamber 418, and the H ₂ gas enters the i-type layer deposition chamber 418 for 2 minutes. After continuing to flow, valve 4
53 and 450 were closed, and the inside of the i-type layer deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, the RFp type layer 208 made of a-SiC
In order to form the substrate, the gate valve 408 was opened and the substrate 490 was transferred into the transfer chamber 404 and the p-type layer deposition chamber 419 that were previously evacuated by a vacuum pump (not shown). The back surface of the substrate 490 was heated by being brought into close contact with a heater 412 for heating the substrate, and the inside of the p-type layer deposition chamber 419 was evacuated by a vacuum exhaust pump (not shown) until the pressure became about 1 × 10 ⁻⁵ Torr.

The substrate heating heater 412 is set so that the temperature of the substrate 490 becomes 170 ° C. When the substrate temperature is stabilized, H ₂ gas, SiH ₄ / H ₂ gas, B ₂ H ₆ / H ₂
Gas and CH ₄ gas into the deposition chamber 419
81, 471, 470, 482, 472, 483, 47
3, 484 and 474 were operated to introduce gas through the gas introduction pipe 469. At this time, the flow rate of H ₂ gas is 60 scm,
The mass flow controllers 476, 477, and ₄ are set so that the H ₄ / H ₂ gas flow rate is ₂ sccm, the B ₂ H ₆ / H ₂ gas flow rate is 10 sccm, and the CH ₄ gas flow rate is 0.3 sccm.
At 78 and 479, the opening of a conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 419 was 1.7 Torr. The power of the RF power supply 423 is set to 0.
07 W / cm ³ and the plasma forming cup 421
To generate a glow discharge, start forming an RFp-type layer on the p / i buffer layer 262, and turn off the RF power supply when the RFp-type layer having a layer thickness of 10 nm is formed. Then, the formation of the RFp type layer 208 was completed. Valves 472, 482, 473, 483, 47
4 and 484 are closed to stop the flow of the SiH ₄ / H ₂ gas, the B ₂ H ₆ / H ₂ gas, and the CH ₄ gas into the p-type layer deposition chamber 419, and then into the p-type layer deposition chamber 419 for 2 minutes. H ₂
After the gas continues to flow, valves 471, 481, 470
Was closed to stop the inflow of H ₂ , and the inside of the p-type layer deposition chamber 9 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, the gate valve 409 is opened into the unload chamber 405 that has been evacuated by an unillustrated evacuation pump, and the substrate 490 is transported.
5 leaked. Next, as the transparent conductive layer 212, ITO with a thickness of 70 nm was vacuum-deposited on the RFp-type layer 208 by a vacuum deposition method.

Next, a mask having a comb-shaped hole was placed on the transparent conductive layer 212, and Cr (40 nm) / Ag (1000 n
m) / Cr (40 nm) comb-shaped current collecting electrode 213
Was vacuum deposited by a vacuum deposition method. Thus, the production of the solar cell has been completed. We call this solar cell (SC Ex. 2)
Hydrogen plasma treatment conditions containing a trace amount of silane-based gas of the present invention,
RF n-type layer, n / i buffer layer, MWi-type layer, p / i
The formation conditions of the buffer layer, RFi-type layer, and RFp-type layer are shown in Tables 2 (1) to 2 (3).

<Comparative Example 2> A solar cell (SC ratio 2) was manufactured under the same conditions as in Example 2 except that the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was not performed. Seven solar cells (SC actual 2) and (SC ratio 2) were each manufactured in a quantity of seven, and the initial photoelectric conversion efficiency (photovoltaic power / incident optical power), vibration degradation, light degradation, and high temperature and high humidity when bias voltage was applied Vibration degradation and light degradation in the environment were measured.

The initial photoelectric conversion efficiency can be obtained by installing the manufactured solar cell under AM1.5 (100 mW / cm ² ) light irradiation and measuring the VI characteristics. As a result of the measurement, the fill factor (FF) and characteristic unevenness of the initial photoelectric conversion efficiency of (SC Ex. 2) were as follows with respect to (SC ratio 2). Vibration degradation was measured by placing a solar cell whose initial photoelectric conversion efficiency was measured in advance in a dark place at a humidity of 52% and a temperature of 28 ° C.
AM1.5 (100 mW / cm ² ) after adding for 0 hours
The measurement was performed based on the rate of decrease in photoelectric conversion efficiency under irradiation (photoelectric conversion efficiency after vibration degradation test / initial photoelectric conversion efficiency).

For the measurement of photodegradation, a solar cell whose initial photoelectric conversion efficiency was measured in advance was placed in an environment of a humidity of 52% and a temperature of 28 ° C., and was irradiated with AM-1.5 (100 mW / cm ² ) light. After irradiation for 500 hours, AM1.5 (100 mW / cm
² ) The reduction rate of the photoelectric conversion efficiency under irradiation (photoelectric conversion efficiency after light degradation test / initial photoelectric conversion efficiency) was used. As a result of the measurement, the rate of decrease in photoelectric conversion efficiency after light deterioration (SC ratio 2) and the rate of decrease in photoelectric conversion efficiency after vibration deterioration with respect to (SC actual 2) were as follows.

[0127] Vibration degradation and light degradation in a high temperature and high humidity environment at the time of bias application were measured. Two solar cells whose initial photoelectric conversion efficiencies were measured in advance were placed in a dark place at a humidity of 90% and a temperature of 81 ° C., and 0.7 V was applied as a forward bias voltage. The above-mentioned vibration was applied to one of the solar cells to measure the vibration deterioration, and the other solar cell was irradiated with AM1.5 light to measure the light deterioration. As a result of the measurement, (S
With respect to C Ex 2), the reduction rate of the photoelectric conversion efficiency after vibration deterioration (SC ratio 2) and the reduction rate of the photoelectric conversion efficiency after light deterioration were as follows.

[0128] The state of delamination was observed using an optical microscope. In (SC Ex. 2), no delamination was observed, but in (SC ratio 2), delamination was slightly observed. As described above, the solar cell (SC Ex. 2) of the present invention has more fill factor and characteristic unevenness in the photoelectric conversion efficiency of the solar cell than the conventional solar cell (SC Ex. 2).
It was found that the film had more excellent characteristics in light deterioration characteristics, adhesion, and durability.

Example 3 Using the deposition apparatus shown in FIG. 4, the triple solar cell shown in FIG. 3 was manufactured. Reflection layer 301 and reflection enhancement layer 30 prepared by the same method as in Example 1.
2 is formed in the load chamber 40.
The load chamber 401 was evacuated by a vacuum evacuation pump (not shown) until the pressure reached about 1 × 10 ⁻⁵ Torr.

Next, the substrate was transported by opening the gate valve 406 into the transport chamber 402 and the deposition chamber 417, which were previously evacuated by a vacuum exhaust pump (not shown). The back surface of the substrate 490 was heated by being brought into close contact with a heater 410 for heating the substrate, and the inside of the deposition chamber 417 was evacuated by a vacuum exhaust pump (not shown) until the pressure became about 1 × 10 ⁻⁵ Torr.

After the preparation for film formation is completed as described above, Rc of μc-Si
An Fn type layer 303 was formed. Next, the gate valve 40 is put into the transfer chamber 403 and the deposition chamber 418 that have been evacuated by a vacuum pump (not shown) in advance.
6 was opened and transported. The back surface of the substrate 490 is brought into close contact with the substrate heating heater 411 and heated, and the deposition chamber 418 is heated.
The pressure is about 1 × 10 ^-5 by a vacuum pump (not shown).
The system was evacuated to Torr.

Next, a-Si was formed in the same manner as in Example 2.
N / i buffer layer 351 made of and MWi type layer 304 made of a-SiGe are formed by RFPCVD method and MWPCVD method.
Formed by the method. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 3 (1)). In order to carry out the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention, SiCl ₂ H ₂ / He (dilution ratio: 1) is used as a silicon atom-containing gas.
000 ppm) gas and H ₂ gas in a deposition chamber 418.
The gas is introduced through the gas introduction pipe 449 and the H ₂ gas flow rate 7
The valves 463, 453, and 45 are set to be 00 sccm.
0 was opened and adjusted by the mass flow controller 458. The silicon atom-containing gas was adjusted with a mass flow controller by opening a valve so that the amount of SiCl ₂ H ₂ gas was 0.04% of the total H ₂ gas flow rate. The pressure inside the deposition chamber 418 was adjusted with a conductance valve (not shown) so as to be 0.008 Torr. Substrate 490
So that the temperature of the substrate becomes 340 ° C.
1 is set, and when the substrate temperature is stabilized, M (not shown)
The power of the W power source was set to 0.12 W / cm ³ ,
MW power is introduced into the i-type layer deposition chamber 418 through the window 26 and the microwave introduction window 425 to generate glow discharge, and the shutter 427 is opened to perform the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention for 4 minutes. Was.
Thereafter, the MW power supply is turned off, the glow discharge is stopped, and SiCl ₂ H ₂ / He (dilution: 10) is introduced into the deposition chamber 418.
00Ppm) stopping the flow of gas, after the continued flow of 4 minutes deposition chamber 418 in F H ₂ gas, stopping the inflow of H ₂ gas, the deposition chamber 418 and the gas pipe 1x
The chamber was evacuated to 10 ^-5 Torr.

Next, aS was obtained in the same manner as in Example 2.
a p / i buffer layer 361 made of i, an RF p-type layer 305 made of a-SiC, an RF n-type layer 306 made of μc-Si, an n / i buffer layer 352 made of a-Si,
RF Wiring a MWi layer 307 made of a-SiGe
And the MWPCVD method. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 3).
(2)). In order to perform the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention, SiH
_{A 4} / H ₂ (dilution: 1000 ppm) gas and a H ₂ gas are introduced into the deposition chamber 418 through a gas introduction pipe 449, and the valves 463, 453, and 450 are opened so that the flow rate of the H ₂ gas becomes 900 sccm. Adjusted at 458. The gas containing silicon atoms is Si
The valve was opened and the mass flow controller was adjusted so that the H ₄ gas amount became 0.05% of the total H ₂ gas flow rate. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 418 became 0.8 Torr.
The substrate heater 411 is set so that the temperature of the substrate 490 becomes 300 ° C., and when the substrate temperature is stabilized,
The power of the RF power supply 424 is set to 0.03 W / cm ³ ,
RF power was applied to the bias bar 428 to generate a glow discharge in 418, and the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed for 3 minutes. Thereafter, the RF power supply is turned off to stop the glow discharge, and the S
After stopping the flow of iH ₄ / H ₂ (dilution: 1000 ppm) gas and continuing to flow the H ₂ gas into the deposition chamber 418 for 3 minutes, the flow of H ₂ gas was also stopped and the deposition chamber 4 was stopped.
The inside of 18 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, aS was obtained in the same manner as in Example 2.
p / i buffer layer 362 made of i, RFp type layer 308 made of a-SiC, RF n type layer 309 made of μc-Si, n / i buffer layer 35 made of a-SiC
3. RFP CVD of a-Si RFi layer 310
It was sequentially formed by the method. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 3 (3)). To perform the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention,
As a silicon atom-containing gas, SiH ₄ / H ₂ (dilution degree:
1000 ppm) gas and H ₂ gas
8 through a gas introduction pipe 449, and the valves 463, 453, and 453 are set so that the H ₂ gas flow rate is 800 sccm.
450 was opened and adjusted by the mass flow controller 458. Silicon atom-containing gas, SiH ₄ gas amount total H ₂
The valve was opened so that it became 0.04% with respect to the gas flow rate, and adjustment was performed with a mass flow controller. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 418 became 0.7 Torr. The substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 200 ° C. When the substrate temperature is stabilized, the power of the RF power supply 424 is set to 0.03 W / cm ³ , and the RF power is supplied to the bias rod 428. To generate a glow discharge in 418,
The hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed for 3 minutes. Thereafter, the RF power supply was turned off, the glow discharge was stopped, the flow of SiH ₄ / H ₂ (dilution: 1000 ppm) gas into the deposition chamber 418 was stopped, and the H ₂ gas continued to flow into the deposition chamber 418 for 3 minutes. Thereafter, the flow of H ₂ gas was stopped, and the inside of the deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, aS was obtained in the same manner as in Example 2.
A p / i buffer layer 363 made of iC and an RFp type layer 311 made of a-SiC were sequentially formed by RFPCVD. Next, the transparent conductive layer 3 is formed on the RFp type layer 311.
As No. 12, ITO having a layer thickness of 70 nm was vacuum deposited by a vacuum deposition method.

Next, a mask having a comb-shaped hole was placed on the transparent conductive layer 312, and Cr (40 nm) / Ag (1000 n
m) / Cr (40 nm) comb-shaped current collecting electrode 313
Was vacuum deposited by a vacuum deposition method. Thus, the production of the solar cell has been completed. This solar cell is called (SC Ex. 3),
Hydrogen plasma treatment conditions containing a trace amount of silane-based gas of the present invention,
RF n-type layer, n / i buffer layer, MWi-type layer, p / i
The formation conditions of the buffer layer, the RFi-type layer, and the RFp-type layer are shown in Tables 3 (1) to 3 (4).

<Comparative Example 3> A solar cell (SC ratio 3) was manufactured under the same conditions as in Example 3 except that the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was not performed. Six solar cells (SC Ex. 3) and (SC ratio 3) were manufactured in each of 6 pieces, and the initial photoelectric conversion efficiency (photovoltaic power / incident light power), vibration degradation, light degradation, and high temperature and high humidity environment when bias voltage was applied The measurement of vibration deterioration and light deterioration was performed.

The initial photoelectric conversion efficiency can be obtained by installing the manufactured solar cell under irradiation of AM1.5 (100 mW / cm ² ) light and measuring the VI characteristics. As a result of the measurement, the fill factor (FF) and the characteristic unevenness of the initial photoelectric conversion efficiency of (SC Ex. 3) with respect to (SC ratio 3) were as follows. Vibration degradation was measured by placing a solar cell whose initial photoelectric conversion efficiency was measured in advance in a dark place at a humidity of 53% and a temperature of 25 ° C., and applying a vibration having a vibration frequency of 60 Hz and an amplitude of 0.1 mm to 50%.
AM1.5 (100 mW / cm ² ) after adding for 0 hours
The measurement was performed based on the rate of decrease in photoelectric conversion efficiency under irradiation (photoelectric conversion efficiency after vibration degradation test / initial photoelectric conversion efficiency).

The photodegradation was measured by placing a solar cell, whose initial photoelectric conversion efficiency was measured in advance, in an environment with a humidity of 53% and a temperature of 25 ° C., and exposed to AM1.5 (100 mW / cm ² ) light for 500 hours. AM1.5 after irradiation (100 mW / cm ² )
The measurement was performed based on the rate of decrease in photoelectric conversion efficiency under irradiation (photoelectric conversion efficiency after light degradation test / initial photoelectric conversion efficiency). As a result of the measurement, the rate of decrease in photoelectric conversion efficiency after light deterioration (SC ratio 3) and the rate of decrease in photoelectric conversion efficiency after vibration deterioration with respect to (SC actual 3) were as follows.

[0140] Vibration degradation and light degradation in a high temperature and high humidity environment at the time of bias application were measured. Two solar cells whose initial photoelectric conversion efficiency was measured in advance were placed in a dark place at a humidity of 90% and a temperature of 82 ° C., and 0.7 V was applied as a forward bias voltage. The above-mentioned vibration was applied to one of the solar cells to measure the vibration deterioration, and the other solar cell was irradiated with AM1.5 light to measure the light deterioration.

As a result of the measurement, (S
The reduction rate of the photoelectric conversion efficiency after the vibration deterioration of the C ratio 3) and the reduction rate of the photoelectric conversion efficiency after the light deterioration were as follows. The state of delamination was observed using an optical microscope. In (SC Ex. 3), no delamination was observed, but in (SC ratio 3), delamination was slightly observed.

As described above, the solar cell (SC Ex. 3) of the present invention is more improved than the conventional solar cell (SC Comp. It was found that it had more excellent properties in durability. (Example 4) The hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 4 (1) using the deposition apparatus shown in FIG. The triple solar cell of FIG. 3 was produced. Table 4 (1) shows the conditions of the hydrogen plasma treatment containing a trace amount of silane-based gas, and Table 4 (2) shows the manufacturing conditions of the triple solar cell.

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 4 (3).
The hydrogen flow rate in the hydrogen plasma treatment with a trace amount of silane-based gas of the present invention is 1 to 20 in the fill factor, characteristic unevenness, light deterioration characteristic, adhesion, and durability in the photoelectric conversion efficiency of the solar cell.
00 sccm was found to be a suitable flow rate.

(Example 5) In the same manner as in Example 3, using the deposition apparatus shown in FIG. 4, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 5 (1). 3 was produced in the same manner as in FIG. Table 5 (1) shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 5 (2) shows the manufacturing conditions of the triple solar cell.

[0145] In the same manner as in Example 3, the fabricated triple type solar cell was evaluated. The results are shown in Table 5 (3).
Even if the input power of the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention is changed from the RF power supply of the fourth embodiment to the VHF power supply,
Fill factor, characteristic unevenness in photoelectric conversion efficiency of solar cell,
The hydrogen flow rate in light deterioration characteristics, adhesion, and durability is 1 to
2000 sccm was found to be a suitable flow rate.

(Example 6) In the same manner as in Example 3, using the deposition apparatus shown in FIG. 4, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 6 (1). 3 was produced in the same manner as in FIG. Table 6 (1) shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 6 (2) shows the manufacturing conditions of the triple solar cell.

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 6 (3).
The addition amount of the silane-based gas-containing gas added to the hydrogen gas in the trace amount silane-based gas-containing hydrogen plasma treatment of the present invention depends on the fill factor in the photoelectric conversion efficiency of the solar cell, uneven characteristics, light deterioration characteristics, adhesion, and durability. , It was found that 0.001% to 0.1% is a preferable range.

(Example 7) In the same manner as in Example 3, the deposition apparatus shown in FIG. 4 was used to perform the hydrogen plasma treatment containing a trace amount of silane-based gas three times under the conditions shown in Table 7 (1). 3 was produced in the same manner as in FIG. Table 7 (1) shows the hydrogen plasma treatment conditions containing the measured silane-based gas.
Table 7 (2) shows the conditions for manufacturing the triple type solar cell.

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 7 (3).
The addition amount of the silane-containing gas to be added to the hydrogen gas in the hydrogen plasma treatment with the trace amount of silane-based gas of the present invention can be determined by changing the input power from the RF power supply of the sixth embodiment to the VHF power supply. 0.001% in curve factor in efficiency, characteristic unevenness, light deterioration characteristic, adhesion and durability
Was found to be a preferred range.

Example 8 In the same manner as in Example 3, the deposition apparatus shown in FIG. 4 was used to perform the hydrogen plasma treatment containing a trace amount of silane-based gas three times under the conditions shown in Table 8 (1). 3 was produced in the same manner as in FIG. Table 8 (1) shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 8 (2) shows the conditions for manufacturing the triple solar cell.

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 8 (3).
The addition amount of the silane-based gas-containing gas to be added to the hydrogen gas in the trace amount silane-based gas-containing hydrogen plasma treatment of the present invention can be obtained by changing the input power from the RF power supply of the sixth embodiment to the MW power supply.
Fill factor, characteristic unevenness in photoelectric conversion efficiency of solar cell,
It was found that 0.001% to 0.1% is a preferable range in light deterioration characteristics, adhesion, and durability.

Example 9 In the same manner as in Example 3, using the deposition apparatus shown in FIG. 4, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 9 (1). 3 was produced in the same manner as in FIG. Table 9 (1) shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 9 (2) shows the manufacturing conditions of the triple solar cell.

As in Example 3, the fabricated triple solar cell was evaluated. The results are shown in Table 9 (3).
The pressure of the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention is, when an RF power supply is used as input power, a fill factor in photoelectric conversion efficiency of the solar cell, characteristic unevenness, light deterioration characteristic,
Adhesion and durability from 0.05 Torr to 10 To
rr was found to be in the preferred range.

Example 10 As in Example 3, using the deposition apparatus shown in FIG. 4, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 10 (1).
A triple solar cell of FIG. 3 was produced in the same manner as in Example 3. Table 1 shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 10 shows the manufacturing conditions of the triple solar cell at 0 (1).
This is shown in (2).

In the same manner as in Example 3, the fabricated triple type solar cell was evaluated. The results are shown in Table 10 (3). When a VHF power supply is used as the input power, the pressure of the hydrogen plasma treatment with a trace amount of silane-based gas of the present invention is 0. 0 in terms of a fill factor in photoelectric conversion efficiency of a solar cell, characteristic unevenness, light deterioration characteristics, adhesion, and durability. It has been found that 0001 Torr to 1 Torr is a preferable range.

(Example 11) In the same manner as in Example 3, using the deposition apparatus shown in FIG. 4, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 11 (1).
A triple solar cell of FIG. 3 was produced in the same manner as in Example 3. Table 1 shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 1 shows the manufacturing conditions of the triple solar cell in Table 1 (1).
This is shown in (2).

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 11 (3). The pressure of the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention is set to 0.1 in terms of the fill factor in the photoelectric conversion efficiency of the solar cell, characteristic unevenness, light deterioration characteristics, adhesion, and durability when a MW power supply is used as the input power. It has been found that 0001 Torr to 0.01 Torr is a preferable range.

(Example 12) As in Example 3, using the deposition apparatus shown in FIG. 4, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 12 (1).
A triple solar cell of FIG. 3 was produced in the same manner as in Example 3. Table 1 shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 12 shows the production conditions for the triple solar cell in Table 2 (1).
This is shown in (2).

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 12 (3). The input power density (power amount) of the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention is as follows: when an RF power source is used as the input power, the fill factor, the characteristic unevenness, the light degradation characteristic, and the adhesion in the photoelectric conversion efficiency of the solar cell. It was found to be 1.0 W / cm ³ from 0.01 W / cm ³ in the durability and the preferred range.

(Example 13) As in Example 3, using the deposition apparatus shown in FIG. 4, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 13 (1).
A triple solar cell of FIG. 3 was produced in the same manner as in Example 3. Table 1 shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 16 shows the manufacturing conditions of the triple type solar cell in 3 (1).
This is shown in (2).

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 13 (3). The input power density (power amount) of the hydrogen plasma treatment containing a trace amount of silane-based gas according to the present invention is as follows: when a VHF power supply is used as the input power, the fill factor, the characteristic unevenness, the light degradation characteristic, and the adhesiveness in the photoelectric conversion efficiency of the solar cell. It was found to be 1.0 W / cm ³ from 0.01 W / cm ³ in the durability and the preferred range.

(Example 14) As in Example 3, using the deposition apparatus shown in FIG. 4, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 14 (1).
A triple solar cell of FIG. 3 was produced in the same manner as in Example 3. Table 1 shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 14 shows the conditions for manufacturing the triple type solar cell.
This is shown in (2).

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 14 (3). The input power density (electric energy) of the hydrogen plasma treatment containing a trace amount of silane-based gas according to the present invention is as follows: when an MW power supply is used as the input power, the fill factor, the characteristic unevenness, the light degradation characteristic, and the adhesiveness in the photoelectric conversion efficiency of the solar cell. It was found that the durability was preferably 0.1 W / cm ³ to 10 W / cm ³ .

(Example 15) In the same manner as in Example 3, using the deposition apparatus shown in FIG. 4, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 15 (1).
A triple solar cell of FIG. 3 was produced in the same manner as in Example 3. Table 1 shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 15 shows the manufacturing conditions of the triple solar cell in Table 15 (1).
This is shown in (2).

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 15 (3). The substrate temperature of the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention is 100% in terms of a fill factor in photoelectric conversion efficiency of a solar cell, characteristic unevenness, light deterioration characteristic, adhesion, and durability when an RF power supply is used as input power. ℃ to 400 ℃
Was found to be a preferable range.

Example 16 In the same manner as in Example 3, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times using the deposition apparatus shown in FIG.
A triple solar cell of FIG. 3 was produced in the same manner as in Example 3. Table 1 shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 16 shows the manufacturing conditions of the triple solar cell in Table 6 (1).
This is shown in (2).

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 16 (3). When a VHF power supply is used as the input power, the substrate temperature of the hydrogen plasma treatment with a trace amount of silane-based gas according to the present invention is 50% in terms of a fill factor in photoelectric conversion efficiency of a solar cell, characteristic unevenness, light deterioration characteristics, adhesion, and durability. ℃ to 300 ℃
Was found to be a preferable range.

(Example 17) As in Example 3, using the deposition apparatus shown in FIG. 4, the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed three times under the conditions shown in Table 17 (1).
A triple solar cell of FIG. 3 was produced in the same manner as in Example 3. Table 1 shows the hydrogen plasma treatment conditions containing a trace amount of silane-based gas.
Table 17 shows the manufacturing conditions of the triple solar cell in Table 7 (1).
This is shown in (2).

In the same manner as in Example 3, the manufactured triple solar cell was evaluated. The results are shown in Table 17 (3). The substrate temperature of the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention is 50% in terms of a fill factor in photoelectric conversion efficiency of a solar cell, characteristic unevenness, light deterioration characteristic, adhesion, and durability when a MW power supply is used. C. to 300.degree. C. was found to be a preferred range.

Example 18 Using the deposition apparatus shown in FIG. 4, the triple solar cell shown in FIG. 3 was manufactured. Reflection layer 301 and reflection enhancement layer 3 prepared by the same method as in Example 1.
02 is formed on the load chamber 4
The load chamber 401 was evacuated by a vacuum exhaust pump (not shown) until the pressure became about 1 × 10 ⁻⁵ Torr.

Next, the substrate was transported by opening the gate valve 406 into the transport chamber 402 and the deposition chamber 417 evacuated by a vacuum pump (not shown) in advance. The back surface of the substrate 490 was heated by being brought into close contact with a heater 410 for heating the substrate, and the inside of the deposition chamber 417 was evacuated by a vacuum exhaust pump (not shown) until the pressure became about 1 × 10 ⁻⁵ Torr.

Next, hydrogen plasma treatment containing a trace amount of silane-based gas was performed under the conditions shown in Table 18 (1). In order to perform the hydrogen plasma treatment containing a trace amount of silane-based gas, a SiH ₄ / H ₂ (dilution: 1000 ppm) gas and a H ₂ gas as silicon atom-containing gas are introduced into the deposition chamber 417 by a gas introduction pipe 4.
The valves 441, 431, and 430 were opened so that the flow rate of the H ₂ gas became 900 sccm, and adjustment was performed using the mass flow controller 436. As for the silicon atom-containing gas, SiH ₄ is 0.04 to the total H ₂ gas flow rate.
%, The valves 442 and 432 were opened and adjusted by the mass flow controller 437. Deposition chamber 41
7 was adjusted with a conductance valve (not shown) such that the pressure in the chamber 7 became 0.9 Torr. When the temperature of the substrate 490 is 36
Set the substrate heating heater 410 to 0 ° C.
When the substrate temperature becomes stable, the power of the RF power supply 422 is set to 0.03 W / cm ³ , RF power is introduced, and a glow discharge is generated in the plasma forming cup 420 to cause the glow discharge.
Hydrogen plasma treatment containing a trace amount of silane-based gas was performed for one minute.
Thereafter, the RF power supply was turned off to stop glow discharge, and SiH ₄ / H ₂ (diluted degree: 1000 p) was introduced into the deposition chamber 417.
pm) Stop the gas flow and leave the deposition chamber 41 for 5 minutes.
After continued to flow H ₂ gas into the 7, stop the inflow of the H ₂ gas, the deposition chamber 417 and in the gas pipe 1 × 1
The chamber was evacuated to 0 ^-5 Torr.

After the preparation for film formation is completed as described above, Rc of μc-Si is formed in the same manner as in Example 2.
An Fn type layer 303 was formed. Next, hydrogen plasma treatment containing a trace amount of silane-based gas was performed under the conditions shown in Table 18 (2). In order to perform the hydrogen plasma treatment containing a trace amount of silane-based gas, a silicon atom-containing gas of SiH ₄ / H ₂ (dilution degree: 100
0 ppm) gas and H ₂ gas are introduced into the deposition chamber 417 through the gas introduction pipe 429, and the H ₂ gas flow rate is
The valves 441, 431, and 430 are set to 0 sccm.
Was opened and adjusted by the mass flow controller 436.
The gas containing silicon atoms was adjusted by the mass flow controller 437 by opening the valves 442 and 432 so that SiH ₄ became 0.03% of the total H ₂ gas flow rate. The pressure inside the deposition chamber 417 was adjusted with a conductance valve (not shown) so as to be 0.9 Torr. Substrate 490
Substrate heating heater 41 so that the temperature of
0, and when the substrate temperature becomes stable, the RF power supply 4
The power of No. 22 was set to 0.02 W / cm ³ , RF power was introduced, glow discharge was generated in the plasma forming cup 420, and hydrogen plasma treatment containing a trace amount of silane-based gas was performed for 3 minutes. Thereafter, the RF power supply was turned off, the glow discharge was stopped, the flow of SiH ₄ / H ₂ (dilution: 1000 ppm) gas into the deposition chamber 417 was stopped, and the H ₂ gas continued to flow into the deposition chamber 417 for 5 minutes. Thereafter, the flow of H ₂ gas was stopped, and the inside of the deposition chamber 417 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, the gate valve 407 was opened and transported into the transport chamber 403 and the deposition chamber 418, which were previously evacuated by a vacuum pump (not shown). The back surface of the substrate 490 was heated by being brought into close contact with a substrate heating heater 411, and the inside of the deposition chamber 418 was evacuated by a vacuum exhaust pump (not shown) until the pressure became about 1 × 10 ⁻⁵ Torr.

Next, a-Si was formed in the same manner as in Example 2.
An n / i buffer layer 351 made of C was formed by RFPCVD. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 18 (3)). In order to perform the hydrogen plasma treatment containing a trace amount of silane-based gas according to the present invention, SiH ₄ gas and H ₂ gas are introduced into the deposition chamber 418 through the gas introduction pipe 449 as silicon atom-containing gas, and the H ₂ gas flow rate is reduced to 950 sccm. The valves 463, 453, and 450 were opened and adjusted by the mass flow controller 458. The gas containing silicon atoms is Si
The valves 461 and 451 were opened and the mass flow controller 456 adjusted so that the H ₄ gas amount became 0.003% of the total H ₂ gas flow rate. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 418 became 0.7 Torr. The substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 350 ° C., and when the substrate temperature is stabilized, the power of the RF power source 424 is reduced to 0.02.
W / cm ³ was set, and RF power was applied to the bias bar 428. A glow discharge was generated in the deposition chamber 418, and a hydrogen plasma treatment containing a small amount of silane-based gas of the present invention was performed for 3 minutes. Thereafter, the RF power supply is turned off, the glow discharge is stopped, the flow of the SiH ₄ gas into the deposition chamber 418 is stopped, and the flow of the H ₂ gas into the deposition chamber 418 is continued for 3 minutes, and then the flow of the H ₂ gas is also stopped. The inside of the deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, aS was obtained in the same manner as in Example 2.
The MWi type layer 304 made of iGe was formed by the MWPCVD method. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 18 (4)). In order to carry out the hydrogen plasma treatment containing a trace amount of silane-based gas according to the present invention, SiH ₄ gas and H ₂ gas are introduced into the deposition chamber 418 through the gas introduction pipe 449 as silicon atom-containing gas.
_{2 The} valve 46 is adjusted so that the gas flow rate becomes 900 sccm.
3, 453 and 450 were opened and adjusted by the mass flow controller 458. The gas containing silicon atoms is SiH ₄
The valves 461 and 451 were opened and the mass flow controller 456 adjusted so that the gas amount became 0.003% with respect to the total H ₂ gas flow rate. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 418 became 0.7 Torr. The substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 330 ° C., and when the substrate temperature is stabilized, the power of the RF power supply 424 is reduced to 0.03 W.
/ Cm ³ , and RF power was applied to the bias bar 428. A glow discharge was generated in the deposition chamber 418, and a hydrogen plasma treatment containing a small amount of silane-based gas of the present invention was performed for 3 minutes. Thereafter, the RF power supply is turned off, the glow discharge is stopped, the flow of SiH ₄ gas into the deposition chamber 418 is stopped, and the flow of H ₂ gas into the deposition chamber 418 is continued for 3 minutes, and then the flow of H ₂ gas is also stopped. The inside of the deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, aS was obtained in the same manner as in Example 2.
A p / i buffer layer 361 made of iC, an RF p-type layer 305 made of a-SiC, and an RF n-type layer 306 made of μc-Si were sequentially formed. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 18 (5)).

In order to carry out the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention, the gas containing silicon
H ₄ / H ₂ (dilution: 1000 ppm) gas and H ₂ gas are introduced into the deposition chamber 417 through the gas introduction pipe 429, and the valves 441, 431, and 430 are opened so that the H ₂ gas flow rate becomes 1100 sccm, and mass flow is performed. It was adjusted by the controller 436. Silicon atom containing gas is
The valves 442 and 432 were opened and the mass flow controller 437 adjusted the SiH ₄ gas amount to 0.04% of the total H ₂ gas flow rate. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 417 became 0.6 Torr. The substrate heating heater 410 is set so that the temperature of the substrate 490 becomes 300 ° C., and when the substrate temperature is stabilized, the power of the RF power source 422 is reduced to 0.0.
The power was set to ³ W / cm ³ , RF power was introduced, a glow discharge was generated in the plasma forming cup 420, and the hydrogen plasma treatment with a trace amount of silane-based gas of the present invention was performed for 3 minutes. Thereafter, the RF power source was turned off to stop the glow discharge, and SiH ₄ / H ₂ (dilution degree: 100) was introduced into the deposition chamber 417.
0 ppm) stopping the flow of gas, 3 minutes, after which continued to flow deposition chamber 417 in F H ₂ gas, stopping the inflow of H ₂ gas, the deposition chamber 417 and the gas pipe 1x
The chamber was evacuated to 10 ^-5 Torr.

Next, a-Si was produced in the same manner as in Example 2.
An n / i buffer layer 352 made of C was formed by RFPCVD. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 18 (6)). In order to perform the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention, SiH ₄ gas and H ₂ gas are introduced into the deposition chamber 418 through the gas introduction pipe 449 as silicon atom-containing gas, and the H ₂ gas flow rate is reduced to 900 sccm. The valves 463, 453, and 450 were opened and adjusted by the mass flow controller 458. The gas containing silicon atoms is Si
The valves 461 and 451 were opened and the mass flow controller 456 adjusted so that the H ₄ gas amount became 0.003% of the total H ₂ gas flow rate. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 418 became 0.8 Torr. The substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 300 ° C., and when the substrate temperature is stabilized, the power of the RF power supply 424 is reduced to 0.02.
W / cm ³ was set, and RF power was applied to the bias bar 428. A glow discharge was generated in the deposition chamber 418, and a hydrogen plasma treatment containing a small amount of silane-based gas of the present invention was performed for 3 minutes. Then turn off the RF power to stop the glow discharge, to stop the flow of SiH ₄ gas in the deposition chamber 418 f, after continued to flow for 3 minutes deposition chamber 418 in F H ₂ gas, stopping the inflow of the H ₂ gas, The inside of the deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, aS was obtained in the same manner as in Example 2.
The MWi type layer 307 made of iGe was formed by the MWPCVD method. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 18 (7)). In order to carry out the hydrogen plasma treatment containing a trace amount of silane-based gas according to the present invention, SiH ₄ gas and H ₂ gas are introduced into the deposition chamber 418 through the gas introduction pipe 449 as silicon atom-containing gas.
_{2 The} valve 46 is adjusted so that the gas flow rate becomes 950 sccm.
3, 453 and 450 were opened and adjusted by the mass flow controller 458. The gas containing silicon atoms is SiH ₄
The valves 461 and 451 were opened and the mass flow controller 456 adjusted so that the gas amount became 0.004% with respect to the total H ₂ gas flow rate. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 418 became 0.7 Torr. The substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 330 ° C., and when the substrate temperature is stabilized, the power of the RF power supply 424 is reduced to 0.03 W.
/ Cm ³ , and RF power was applied to the bias bar 428. A glow discharge was generated in the deposition chamber 418, and a hydrogen plasma treatment containing a small amount of silane-based gas of the present invention was performed for 3 minutes. Thereafter, the RF power supply is turned off, the glow discharge is stopped, the flow of SiH ₄ gas into the deposition chamber 418 is stopped, and the flow of H ₂ gas into the deposition chamber 418 is continued for 3 minutes, and then the flow of H ₂ gas is also stopped. The inside of the deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, aS was obtained in the same manner as in Example 2.
A p / i buffer layer 362 made of iC, an RF p-type layer 308 made of a-SiC, and an RF n-type layer 309 made of μc-Si were sequentially formed. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 18 (8)). In order to perform the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention, SiH ₄ / H ₂ (diluted degree: 1000 ppm) gas and H ₂ gas are introduced into the deposition chamber 417 through the gas introduction pipe 429 as silicon atom-containing gas. Then, the valves 441 and 43 are adjusted so that the H ₂ gas flow rate becomes 650 sccm.
1, 430 were opened and adjusted by the mass flow controller 436. The mass flow controller 437 is opened by opening the valves 442 and 432 of the silicon atom-containing gas so that the SiH ₄ gas amount becomes 0.03% of the total H ₂ gas flow rate.
Was adjusted. The pressure in the deposition chamber 417 is 0.9 T
orr was adjusted by a conductance valve (not shown). The substrate heating heater 410 is set so that the temperature of the substrate 490 becomes 230 ° C. When the substrate temperature is stabilized, the power of the RF power supply 422 is set to 0.03 W / cm ³ , RF power is introduced, and plasma Forming cup 42
A glow discharge was generated within 0, and a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed for 2 minutes. Thereafter, the RF power is turned off to stop the glow discharge, and the deposition chamber 417 is turned off.
The flow of SiH ₄ / H ₂ (dilution: 1000 ppm) gas into the chamber was stopped, and the H ₂ gas was continuously flowed into the deposition chamber 417 for 3 minutes. Then, the flow of H ₂ gas was also stopped, and the inside of the deposition chamber 417 and the gas were stopped. The inside of the pipe was evacuated to 1 × 10 ⁻⁵ Torr.

Next, a-Si was formed in the same manner as in Example 2.
An n / i buffer layer 353 made of C was formed by RFPCVD. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 18 (9)). In order to perform the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention, SiH ₄ gas and H ₂ gas are introduced into the deposition chamber 418 through the gas introduction pipe 449 as silicon atom-containing gas, and the H ₂ gas flow rate is reduced to 900 sccm. The valves 463, 453, and 450 were opened and adjusted by the mass flow controller 458. The gas containing silicon atoms is Si
The valves 461 and 451 were opened and the mass flow controller 456 adjusted so that the H ₄ gas amount became 0.003% of the total H ₂ gas flow rate. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 418 became 0.7 Torr. The substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 230 ° C., and when the substrate temperature is stabilized, the power of the RF power supply 424 is reduced to 0.02.
W / cm ³ was set, and RF power was applied to the bias bar 428. A glow discharge was generated in the deposition chamber 418, and a hydrogen plasma treatment containing a small amount of silane-based gas of the present invention was performed for 3 minutes. Then turn off the RF power to stop the glow discharge, to stop the flow of SiH ₄ gas in the deposition chamber 418 f, after continued to flow for 3 minutes deposition chamber 418 in F H ₂ gas, stopping the inflow of the H ₂ gas, The inside of the deposition chamber 418 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, aS was obtained in the same manner as in Example 2.
An RFi-type layer 310 made of i was formed by an RFPCVD method. Next, a hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was performed (Table 18 (10)). In order to carry out the hydrogen plasma treatment containing a trace amount of silane-based gas according to the present invention, SiH ₄ gas and H ₂ gas are introduced into the deposition chamber 418 through the gas introduction pipe 449 as silicon atom-containing gas.
_{(2) The} valve 46 is adjusted so that the gas flow rate becomes 850 sccm.
3, 453 and 450 were opened and adjusted by the mass flow controller 458. The gas containing silicon atoms is SiH ₄
The valves 461 and 451 were opened and the mass flow controller 456 adjusted so that the gas amount became 0.003% with respect to the total H ₂ gas flow rate. The conductance valve (not shown) was adjusted so that the pressure in the deposition chamber 418 became 0.8 Torr. The substrate heating heater 411 is set so that the temperature of the substrate 490 becomes 200 ° C., and when the substrate temperature is stabilized, the power of the RF power supply 424 is reduced to 0.02 W.
/ Cm ³ , and RF power was applied to the bias bar 428. A glow discharge was generated in the deposition chamber 418, and a hydrogen plasma treatment containing a small amount of silane-based gas of the present invention was performed for 3 minutes. After that, the RF power source was turned off, the glow discharge was stopped, the flow of SiH ₄ into the deposition chamber 418 was stopped, the H ₂ gas was kept flowing into the deposition chamber 418 for 3 minutes, and then the flow of the H ₂ gas was stopped. Deposition chamber 4
The inside of 18 and the inside of the gas pipe were evacuated to 1 × 10 ⁻⁵ Torr.

Next, aS was obtained in the same manner as in Example 2.
A p / i buffer layer 363 made of iC and an RFp type layer 311 made of a-SiC were sequentially formed by RFPCVD. Next, the transparent conductive layer 3 is formed on the RFp type layer 311.
As No. 12, ITO having a layer thickness of 70 nm was vacuum deposited by a vacuum deposition method.

Next, a mask having a comb-shaped hole is placed on the transparent conductive layer 312, and Cr (40 nm) / Ag (1000 n
m) / Cr (40 nm) comb-shaped current collecting electrode 313
Was vacuum deposited by a vacuum deposition method. Thus, the production of the solar cell has been completed. This solar cell is referred to as (SC Ex. 18), and the hydrogen plasma treatment conditions including the trace amount of silane-based gas, RF n-type layer, n / i buffer layer, MWi-type layer, p-type
Tables 18 (1) to 18 (11) show the conditions for forming the / i buffer layer, RFi-type layer, and RFp-type layer.

<Comparative Example 18> A solar cell (SC ratio: 18) was manufactured under the same conditions as in Example 18 except that the hydrogen plasma treatment containing a trace amount of silane-based gas of the present invention was not performed. Eight solar cells (SC Ex. 18) and (SC ratio 18) were produced respectively, and the initial photoelectric conversion efficiency (photovoltaic power / incident optical power),
Vibration deterioration, light deterioration, and vibration deterioration and light deterioration in a high temperature and high humidity environment when a bias voltage was applied were measured.

The initial photoelectric conversion efficiency can be obtained by installing the produced solar cell under AM-1.5 (100 mW / cm ² ) light irradiation and measuring the VI characteristics. As a result of the measurement, the fill factor (FF) and the characteristic unevenness of the initial photoelectric conversion efficiency of (SC Ex. 18) with respect to (SC Comp. 18) were as follows. Vibration degradation was measured by installing a solar cell whose initial photoelectric conversion efficiency had been measured in advance in a dark place at a humidity of 54% and a temperature of 25 ° C., and applying a vibration having a vibration frequency of 60 Hz and an amplitude of 0.1 mm.
AM1.5 (100 mW / cm ² ) after adding for 0 hours
The measurement was performed based on the rate of decrease in photoelectric conversion efficiency under irradiation (photoelectric conversion efficiency after vibration degradation test / initial photoelectric conversion efficiency).

The photodegradation was measured by placing a solar cell, whose initial photoelectric conversion efficiency was measured in advance, in an environment of a humidity of 54% and a temperature of 25 ° C., and was exposed to AM-1.5 (100 mW / cm ² ) light. After irradiation for 500 hours, AM1.5 (100 mW / cm
² ) The reduction rate of the photoelectric conversion efficiency under irradiation (photoelectric conversion efficiency after light degradation test / initial photoelectric conversion efficiency) was used. As a result of the measurement, the rate of decrease in photoelectric conversion efficiency after light deterioration (SC ratio 18) and the rate of decrease in photoelectric conversion efficiency after vibration deterioration with respect to (SC actual 18) were as follows.

[0189] Vibration degradation and light degradation in a high temperature and high humidity environment at the time of bias application were measured. Two solar cells whose initial photoelectric conversion efficiency was measured in advance were placed in a dark place at a humidity of 90% and a temperature of 82 ° C., and 0.7 V was applied as a forward bias voltage. The above-mentioned vibration was applied to one of the solar cells to measure the vibration deterioration, and the other solar cell was irradiated with AM1.5 light to measure the light deterioration.

As a result of the measurement, (SC Ex. 18)
(SC ratio 18) Decrease rate of photoelectric conversion efficiency after vibration degradation,
The rate of decrease in photoelectric conversion efficiency after light degradation was as follows. The state of delamination was observed using an optical microscope. No delamination was observed in (SC Ex 18), but (SC ratio 18)
In, slight delamination was observed.

As described above, the solar cell of the present invention (SC Ex. 1)
8) was found to have better characteristics than conventional solar cells (SC ratio 18) in terms of the fill factor in photoelectric conversion efficiency of the solar cells, characteristic unevenness, light degradation characteristics, adhesion, and durability. In the above embodiment, the n-type layer is provided on the substrate,
n / i buffer layer, i-type layer, p / i buffer layer, p
Although the solar cell stacked in the order of the mold layer has been described, the solar cell stacked in the order of the p-type layer, the p / i buffer layer, the i-type layer, the n / i buffer layer, and the n-type layer on the substrate is also described.
A similar hydrogen plasma treatment was performed to produce a solar cell.

The same evaluation as in the above example was performed.
It has been confirmed that by performing the hydrogen plasma treatment between the p / i buffer layer and the i-type layer, the fill factor, characteristic unevenness, light deterioration characteristic, adhesion, durability, and the like of the photoelectric conversion efficiency of the solar cell are improved. . Furthermore, it was confirmed that the above characteristics were further improved by performing hydrogen plasma treatment on the substrate and the p-type layer, the n-type layer and the n / i buffer layer, and the n / i buffer layer and the i-type layer.

[0193]

[Table 1 (1)]

[0194]

[Table 1 (2)]

[0195]

[Table 2 (1)]

[0196]

[Table 2 (2)]

[0197]

[Table 2 (3)]

[0198]

[Table 3 (1)]

[0199]

[Table 3 (2)]

[0200]

[Table 3 (3)]

[0201]

[Table 3 (4)]

[0202]

[Table 4 (1)]

[0203]

[Table 4 (2)]

[0204]

[Table 4 (3)]

[0205]

[Table 5 (1)]

[0206]

[Table 5 (2)]

[0207]

[Table 5 (3)]

[0208]

[Table 6 (1)]

[0209]

[Table 6 (2)]

[0210]

[Table 6 (3)]

[0211]

[Table 7 (1)]

[0212]

[Table 7 (2)]

[0213]

[Table 7 (3)]

[0214]

[Table 8 (1)]

[0215]

[Table 8 (2)]

[0216]

[Table 8 (3)]

[0219]

[Table 9 (1)]

[0218]

[Table 9 (2)]

[0219]

[Table 9 (3)]

[0220]

[Table 10 (1)]

[0221]

[Table 10 (2)]

[0222]

[Table 10 (3)]

[0223]

[Table 11 (1)]

[0224]

[Table 11 (2)]

[0225]

[Table 11 (3)]

[0226]

[Table 12 (1)]

[0227]

[Table 12 (2)]

[0228]

[Table 12 (3)]

[0229]

[Table 13 (1)]

[0230]

[Table 13 (2)]

[0231]

[Table 13 (3)]

[0232]

[Table 14 (1)]

[0233]

[Table 14 (2)]

[0234]

[Table 14 (3)]

[0235]

[Table 15 (1)]

[0236]

[Table 15 (2)]

[0237]

[Table 15 (3)]

[0238]

[Table 16 (1)]

[0239]

[Table 16 (2)]

[0240]

[Table 16 (3)]

[0241]

[Table 17 (1)]

[0242]

[Table 17 (2)]

[0243]

[Table 17 (3)]

[0244]

[Table 18 (1)]

[0245]

[Table 18 (2)]

[0246]

[Table 18 (3)]

[0247]

[Table 18 (4)]

[0248]

[Table 18 (5)]

[0249]

[Table 18 (6)]

[0250]

[Table 18 (7)]

[0251]

[Table 18 (8)]

[0252]

[Table 18 (9)]

[0253]

[Table 18 (10)]

[0254]

[Table 18 (11)]

[0255]

According to the present invention, impurities (for example, oxygen, nitrogen, carbon, iron, chromium, etc.) which become defect levels when taken into a semiconductor layer adsorbed on or contained in a deposition chamber wall usually observed in a hydrogen plasma treatment. , Nickel, aluminum, etc.) can be solved. In addition, stable hydrogen plasma processing can be performed. As a result, 1) it is possible to provide a photovoltaic element having substantially no peeling of the semiconductor layer when the photovoltaic element is placed at high temperature and high humidity.

2) When a pin structure is formed on a flexible substrate, it is possible to provide a photovoltaic element in which a pin semiconductor layer is hardly peeled off even when the substrate is bent. 3) It is possible to provide a photovoltaic element in which an increase in defect levels near the interface between the substrate and the semiconductor layer is suppressed by long-time light irradiation. 4) Even when light is irradiated under high temperature and high humidity, it is possible to provide a photovoltaic element in which the substrate and the semiconductor layer do not peel off, and a decrease in characteristics such as an increase in series resistance is suppressed.

5) It is possible to provide a photovoltaic element having improved initial efficiency by preventing diffusion of impurities from the n-type layer (or p-type layer) to the i-type layer. 6) Even when used at a high temperature, it is possible to provide a photovoltaic element with less deterioration in characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a photovoltaic element to which a method for forming a photovoltaic element according to the present invention is applied.

FIG. 2 is a schematic explanatory view of another photovoltaic element to which the method for forming a photovoltaic element of the present invention is applied.

FIG. 3 is a schematic explanatory view of another photovoltaic element to which the method of forming a photovoltaic element according to the present invention is applied.

FIG. 4 is a schematic explanatory view of a photovoltaic element forming apparatus suitable for the photovoltaic element forming method of the present invention.

[Explanation of symbols]

100, 200, 300 Support, 101, 201, 301 Reflective layer (or transparent conductive layer), 102, 202, 302 Reflection increasing layer (or antireflective layer), 103, 203, 303 First n-type layer (or 104, 204, 304 First i-type layer, 105, 205, 305 First p-type layer (or n-type layer), 112, 212, 312 Transparent conductive layer (or conductive layer), 113 , 213, 313 collecting electrode, 151, 251, 351 first n / i buffer layer, 161, 261, 361 i th p / i buffer layer, 206, 306 second n-type layer (or p-type layer) ), 207,307 second i-type layer, 208,308 second p-type layer (or n-type layer), 252,352 second n / i buffer layer, 262,362 second p / i buffer layer 309 third n-type layer (or p-type layer), 311 third p-type layer (or n-type layer), 310 third i-type layer, 353 third n / i buffer layer, 363 third p / i buffer layer, 400 forming apparatus, 401 load chamber, 402, 403, 404 transfer chamber, 405 unload chamber, 406, 407, 408, 409 gate valve, 410, 411, 412 substrate heater, 413 Substrate transport rails, 417 n-type (or p-type) layer deposition chamber, 418 i-type layer deposition chamber, 419 p-type (or n-type layer) deposition chamber, 420,421 cup for plasma formation, 422,423, 424 power supply, 425 microwave introduction window, 426 waveguide, 427 shutter, 428 bias rod, 429, 4 9,469 gas inlet tube, 430,431,432,433,434,441,4
42,443,444,450,451,452,4
53,454,455,461,462,463,4
64,465,468,466,470,471,47
2,473,474,481,482,483,48
4 valves, 436, 437, 438, 439, 456, 457, 4
58, 459, 460, 467, 476, 477, 4
78,479 Mass flow controller, 490 Substrate holder.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-177372 (JP, A) JP-A-3-136380 (JP, A) JP-A-1-103829 (JP, A) JP-A-2- 177375 (JP, A) JP-A-2-177376 (JP, A) JP-A-58-64070 (JP, A) JP-A-3-200374 (JP, A) JP-A-2-177371 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 31/04-31/078 H01L 21/205

Claims (5)

(57) [Claims] 1. A non-single-crystal n-type layer (or p-type layer) containing silicon atoms, a non-single-crystal i-type n / i buffer layer (or p / i buffer layer), a non-single crystal i
Layer, non-single-crystal i-type p / i buffer layer (or n /
i-buffer layer) and non-single-crystal p-type layer (or n-type layer)
In a method of manufacturing a photovoltaic device in which at least one or more pin structures formed by stacking are stacked, the vicinity of the interface where the p / i buffer layer and the i-type layer are in contact with each other is substantially non-deposited. Made in the photovoltaic element, characterized in that a plasma treatment with hydrogen gas containing containing gas
Construction method . 2. A plasma process is performed on the vicinity of the interface between the substrate and the n-type layer (or the vicinity of the interface between the substrate and the p-type layer) with a hydrogen gas containing a gas containing silicon atoms to such an extent that substantially no deposition occurs. The method for manufacturing a photovoltaic device according to claim 1, wherein: 3. A silicon atom-containing gas that does not substantially deposit near the interface where the n / i buffer layer contacts the n-type layer and near the interface where the n / i buffer layer contacts the i-type layer. production of the photovoltaic device according to claim 2 in hydrogen gas containing, characterized in that a plasma treatment
Law . 4. The method according to claim 1, wherein the silicon atom-containing gas is Si gas.
H ₄ , Si ₂ H ₆ , SiF ₄ , SiFH ₃ , SiF ₂ H ₂ , S
_{iF 3 H, SiCl 2 H 2} , SiCl 3 H, of the SiCl _4, claim, characterized in that it comprises at least one 1
4. The method for producing a photovoltaic device according to any one of items 3 to 5. 5. The photovoltaic device according to claim 1, wherein the content of the silicon atom-containing gas with respect to hydrogen gas is 0.1% or less .
Construction method .