JP6899731B2 - Manufacturing method of photoelectric conversion element - Google Patents

Description

The present invention relates to a method for manufacturing a photoelectric conversion element.

In Patent Document 1 below, a p-type amorphous silicon layer is formed on the entire surface of a substrate tray on which a semiconductor substrate is placed, and then a true amorphous silicon layer is formed on the upper surface of the substrate tray on which the p-type amorphous silicon layer is formed. The method is disclosed. By adopting such a manufacturing method, when the intrinsic amorphous silicon layer is subsequently formed on the semiconductor substrate placed on the substrate tray by using the substrate tray, the p-type amorphous silicon layer adhering to the substrate tray is formed. It is possible to prevent the added impurities from being mixed into the intrinsic amorphous silicon layer.

Japanese Unexamined Patent Publication No. 2010-34162

However, in the above-mentioned conventional manufacturing method, there is a problem that it is difficult to improve the manufacturing efficiency. That is, in the conventional manufacturing method, it is necessary to form an intrinsic amorphous silicon layer on the substrate tray each time another conductive semiconductor layer is formed using the substrate tray, which makes it difficult to improve the manufacturing efficiency. It had been done.

The present invention has been made in view of the above problems, and an object of the present invention is to improve manufacturing efficiency.

(1) In the method for manufacturing a photoelectric conversion element according to the present disclosure, the photoelectric conversion element has a first main surface and a second main surface, and has at least a first conductive semiconductor layer, a semiconductor substrate, and a second main surface. The conductive semiconductor layer is included in this order, and the manufacturing method is a manufacturing method using an in-line film forming apparatus, and is a first conductive semiconductor forming step, a second conductive film forming chamber passing step, and a first. The in-line type film forming apparatus includes a step of passing through a conductive type film forming chamber and a step of forming a second conductive type semiconductor layer, and the in-line type film forming apparatus includes a first transport closing path, a second transport closing path, a first conductive type film forming chamber, and A second conductive film-forming chamber is provided, the first transport closing path is a closing path for forming a film on the first main surface side of the photoelectric conversion element, and the second transport closing path is the second main of the photoelectric conversion element. It is a closed circuit for forming a film on the surface side, and in the first conductive type film forming chamber, a part of the first conveying closed path and a part of the second conveying closed path are arranged, and the second conductive type film forming chamber is arranged. Is arranged with the other part of the first transport closed circuit and the other part of the second transport closed circuit, and is connected in series with the first conductive type film forming chamber to form the first conductive type semiconductor layer. In the step, in the first conductive film forming chamber, the first conductive semiconductor layer is formed on the first main surface side of the semiconductor substrate arranged in the first transport closed path, and the second conductive type is manufactured. In the film chamber passing step, the semiconductor substrate arranged in the first transport closed path passes through the second conductive film forming chamber in a state where the first main surface side is not formed, and the first conductive film forming is formed. In the chamber passing step, the semiconductor substrate arranged in the second transport closed path passes through the first conductive film forming chamber in a state where the second main surface side is not formed, and the second conductive semiconductor layer is formed. In the step, in the second conductive film forming chamber, the second conductive semiconductor layer is formed on the second main surface side of the semiconductor substrate arranged in the second transport closed path.

(2) In the method for manufacturing a photoelectric conversion element in (1) above, after performing the first conductive type semiconductor layer forming step and the second conductive type film forming chamber passing step, the first transport closed circuit is reached. The arranged semiconductor substrate further includes a step of being transferred to the second transfer closed path so that the second main surface side is exposed, and after performing the step of being transferred to the second transfer closed path, the second transfer is performed. The manufacturing method may be such that the step of passing through the conductive film forming chamber and the step of forming the second conductive semiconductor layer are performed.

(3) In the method for manufacturing a photoelectric conversion element in (1) above, after performing the first conductive type film forming chamber passing step and the second conductive type semiconductor layer forming step, the second transport closed path is reached. The arranged semiconductor substrate further includes a step of being transferred to the first transfer closed path so that the first main surface side is exposed, and after performing the step of being transferred to the first transfer closed path, the first transfer is performed. The manufacturing method may be such that the 1-conducting semiconductor layer forming step and the 2nd conductive film-forming chamber passing step are performed.

(4) In the method for manufacturing the photoelectric conversion element in the above (1) to (3), the first conductive type semiconductor layer forming step and the first conductive type film forming chamber passing step are carried out within the same period. It may be a manufacturing method.

(5) In the method for manufacturing the photoelectric conversion element in the above (1) to (4), the second conductive film forming chamber passing step and the second conductive semiconductor layer forming step are performed within the same period. It may be a manufacturing method.

FIG. 1 is a schematic plan view showing the surface side (light receiving surface side) of the photoelectric conversion element according to the present embodiment. FIG. 2 is a schematic cross-sectional view showing a cross section of lines II-II in FIG. FIG. 3 is a schematic perspective view showing a substrate holder used in the method for manufacturing a photoelectric conversion element according to the present embodiment. FIG. 4 is a schematic top view showing a film forming apparatus used in the method for manufacturing a photoelectric conversion element according to the present embodiment. FIG. 5 is a schematic cross-sectional view showing a manufacturing process of the photoelectric conversion element according to the present embodiment. FIG. 6 is a schematic cross-sectional view showing a manufacturing process of the photoelectric conversion element according to the present embodiment. FIG. 7 is a schematic cross-sectional view showing a manufacturing process of the photoelectric conversion element according to the present embodiment. FIG. 8 is a schematic cross-sectional view showing a manufacturing process of the photoelectric conversion element according to the present embodiment. FIG. 9 is a schematic top view showing a film forming apparatus used in the method for manufacturing a photoelectric conversion element according to the present embodiment. FIG. 10 is a schematic top view showing another embodiment of the film forming apparatus used in the method for manufacturing a photoelectric conversion element according to the present embodiment.

The embodiments of the present disclosure will be described below with reference to the drawings.

[Photoelectric conversion element 100]
FIG. 1 is a schematic plan view showing the surface side (light receiving surface side) of the photoelectric conversion element 100 according to the present embodiment.

As shown in FIG. 1, the photoelectric conversion element 100 of the present embodiment has a photoelectric conversion unit 8 and a current collecting electrode 2 provided on the surface side of the photoelectric conversion unit 8. The current collecting electrode 2 includes two wide bus bar electrodes 2A substantially parallel to one side of the semiconductor substrate included in the photoelectric conversion unit 8, and a large number of narrow finger electrodes 2B substantially orthogonal to the bus bar electrode 2A. Including.

In the present embodiment, the current collecting electrode 2 is also provided on the back surface side of the photoelectric conversion unit 8, the current collecting electrode 2 on the front surface side has the first polarity, and the current collecting electrode 2 on the back surface side. Has a polarity opposite to that of the first polarity. In the present embodiment, the current collecting electrode 2 on the front surface side is a positive electrode, and the current collecting electrode 2 on the back surface side is a negative electrode.

FIG. 2 is a schematic cross-sectional view showing a cross section of line II-II in FIG.

As shown in FIG. 2, the photoelectric conversion element 100 in the present embodiment includes a semiconductor substrate 1 made of, for example, single crystal silicon or polycrystalline silicon. The first intrinsic semiconductor layer 5A is formed on the front surface side of the semiconductor substrate 1, and the second intrinsic semiconductor layer 5B is formed on the back surface side of the semiconductor substrate 1. A P-type semiconductor layer 3 is formed on the front surface side of the first intrinsic semiconductor layer 5A, and an N-type semiconductor layer 4 is formed on the back surface side of the second intrinsic semiconductor layer 5B. A first transparent conductive layer 6A is formed on the front surface side of the P-type semiconductor layer 3, and a second transparent conductive layer 6B is formed on the back surface side of the N-type semiconductor layer 4.

[Manufacturing method of photoelectric conversion element]
Hereinafter, a method for manufacturing the photoelectric conversion element 100 according to the present embodiment will be described with reference to the drawings.

FIG. 3 is a schematic perspective view showing a substrate holder 200 used in the method for manufacturing the photoelectric conversion element 100 according to the present embodiment.

As shown in FIG. 3, the substrate holder 200 includes a first holder 31, a second holder 32, and a holding portion 33 for holding the first holder 31 and the second holder 32. The first holder 31 and the second holder 32 each have a board mounting surface, and the surface of the first holder 31 opposite to the board mounting surface and the side of the second holder 32 opposite to the board mounting surface. It is arranged so as to face the surface of.

FIG. 4 is a schematic top view showing a film forming apparatus 300 used in the method for manufacturing the photoelectric conversion element 100 according to the present embodiment.

As shown in FIG. 4, the film-forming device 300 used in the present embodiment has a first film-forming chamber 61 for forming an intrinsic semiconductor layer and a second film-forming chamber 62 for forming a first conductive semiconductor layer. It has a third film forming chamber 63 for forming a film of the second conductive semiconductor layer. Each film forming chamber is connected in series, the film forming apparatus 300 constitutes an in-line plasma CVD (chemical vapor deposition) apparatus, and the substrate holder 200 carried into the first film forming chamber 61 is a third. It is sequentially conveyed in the direction of the film forming chamber 63 of the above.

Further, the film-forming device 300 in the present embodiment has a transport means 64 for returning the substrate holder 200 from the third film-forming chamber 63 to the first film-forming chamber 61, and the third film-forming device 300 is manufactured. The semiconductor substrate 1 that has undergone the film forming process in the film forming chamber 63 will undergo the film forming process in the first film forming chamber 61 again.

Here, in the film forming apparatus 300 of the present embodiment, the path through which the first holder 31 is conveyed is defined as the "first transport closed path", and the path through which the second holder 32 is conveyed is defined as the "second transport closed path". .. In the present embodiment, an example will be described in which the front surface side (light receiving surface side) of the photoelectric conversion element 100 is formed into a film in the first transport closing path, and the back surface side of the photoelectric conversion element 100 is formed into a film in the second transport closing path. .. In addition, a manufacturing method may be used in which the back surface side of the photoelectric conversion element 100 is formed into a film in the first transport closing path, and the front surface side of the photoelectric conversion element 100 is formed into a film in the second transport closing path.

The first film-forming chamber 61 includes a first cathode electrode 71 and a second cathode electrode 72 connected to a high-frequency power source, and a first anode electrode 51 in a grounded state, and the first film-forming chamber 61 is provided. A first cathode electrode 71 and a second cathode electrode 72 are arranged at both ends of the chamber 61, and a first anode electrode 51 is arranged between the first cathode electrode 71 and the second cathode electrode 72. The substrate holder 200 holding the first holder 31 and the second holder 32 is conveyed to the first film forming chamber 61 and electrically connected to the first anode electrode 51. The first holder 31 and the second holder 32 function as an anode together with the first anode electrode 51. The first film-forming position 81 is between the first cathode electrode 71 and the first anode electrode 51, and the second film-forming position 82 is between the second cathode electrode 72 and the first anode electrode 51. To do. When the first high-frequency power source 91 connected to the first cathode electrode 71 is turned on, a plasma discharge is generated between the first cathode electrode 71 and the first anode electrode 51. Further, when the second high frequency power supply 92 connected to the second cathode electrode 72 is turned on, a plasma discharge is generated between the second cathode electrode 72 and the first anode electrode 51.

In the present embodiment, a part of the first transport closing path described above is arranged at the first film forming position 81 in the first film forming chamber 61, and a part of the second transport closing path is the first film forming. It is arranged at the second film forming position 82 in the chamber 61. In the first transport closing path, the first holder 31 is transported into the first film forming position 81, and in the second transport closing path, the second holder 32 is transported into the second film forming position 82.

In the present embodiment, the first cathode electrode 71 and the second cathode electrode 72 are shower head electrodes, and have a gas introduction port to which a raw material gas or the like is supplied.

Further, in the present embodiment, the first anode electrode 51 has a built-in heater, and the temperatures of the first holder 31 and the second holder 32 arranged in the vicinity of the first anode electrode 51 at the time of film formation are obtained. Can be raised.

Therefore, the first film-forming chamber 61 in the present embodiment supplies a silicon-containing gas or the like as a raw material gas from the first cathode electrode 71 and the second cathode electrode 72, and also supplies the first anode electrode 51 with a silicon-containing gas or the like. The semiconductor substrate 1 mounted on the substrate holder 200 is heated by using the built-in heater, and the first high frequency power supply 91 and the second high frequency power supply 92 are turned on, so that the first cathode electrode 71 A plasma discharge is generated between the first anode electrode 51 and the second cathode electrode 72 and the first anode electrode 51 to ionize the raw material gas. The intrinsic semiconductor layer is formed by depositing the ionized raw material gas component on the front surface or the back surface of the semiconductor substrate 1.

The second film forming chamber 62 includes a third cathode electrode 73, a fourth cathode electrode 74, and a grounded second anode electrode 52, and the third cathode electrode 73 and the second anode. The third film-forming position 83 is located between the electrodes 52, and the fourth film-forming position 84 is located between the fourth cathode electrode 74 and the second anode electrode 52. The third cathode electrode 73 is connected to the third high frequency power supply 93, and the fourth cathode electrode 74 is connected to the fourth high frequency power supply 94. The configuration of the third cathode electrode 73, the fourth cathode electrode 74, the second anode electrode 52, the third high-frequency power supply 93, and the fourth high-frequency power supply 94 is basically the first film-forming chamber 61. Since the configuration is the same as that of the first cathode electrode 71, the second cathode electrode 72, the first anode electrode 51, the first high frequency power supply 91, and the second high frequency power supply 92, the description thereof will be omitted.

In the present embodiment, a part of the first transport closing path described above is arranged at the third film forming position 83 in the second film forming chamber 62, and a part of the second transport closing path is formed by the second film forming. It is arranged at the fourth film forming position 84 in the chamber 62. In the first transport closing path, the first holder 31 is transported into the third film forming position 83, and in the second transport closing path, the second holder 32 is transported into the fourth film forming position 84.

The third film forming chamber 63 includes a fifth cathode electrode 75, a sixth cathode electrode 76, and a grounded third anode electrode 53, and the fifth cathode electrode 75 and the third anode. The fifth film-forming position 85 is located between the electrodes 53, and the sixth film-forming position 86 is located between the sixth cathode electrode 76 and the third anode electrode 53. The fifth cathode electrode 75 is connected to the fifth high frequency power supply 95, and the sixth cathode electrode 76 is connected to the sixth high frequency power supply 96. The configuration of the fifth cathode electrode 75, the sixth cathode electrode 76, the third anode electrode 53, the fifth high frequency power supply 95, and the sixth high frequency power supply 96 is basically the first film forming chamber 61. Since the configuration is the same as that of the first cathode electrode 71, the second cathode electrode 72, the first anode electrode 51, the first high frequency power supply 91, and the second high frequency power supply 92, the description thereof will be omitted.

In the present embodiment, a part of the above-mentioned second transport closing path is arranged at the fifth film forming position 85 in the third film forming chamber 63, and a part of the second transport closing path is formed by the third film forming. It is arranged at the sixth film forming position 86 in the chamber 63. In the first transport closing path, the first holder 31 is transported into the fifth film forming position 85, and in the second transport closing path, the second holder 32 is transported into the sixth film forming position 86.

In the present embodiment, the configuration in which the film-forming device 300 has three film-forming chambers is given as an example, but another film-forming chamber may be interposed between the film-forming chambers. That is, the above-mentioned "each film forming chamber is connected in series" includes a configuration in which each film forming chamber is indirectly connected in series via another film forming chamber.

In the present embodiment, the first conductive semiconductor is a P-semiconductor, the second conductive semiconductor is an N-semiconductor, and the second film-forming chamber 62 forms a P-type semiconductor layer to form a third. A method in which the film chamber 63 forms an N-type semiconductor layer will be described as an example, but a method in which the first conductive type semiconductor is an N-type semiconductor and the second conductive type semiconductor is a P-type semiconductor may be used.

[Step of arranging the first semiconductor substrate at the first film forming position in the first film forming chamber]
First, a semiconductor substrate 1 in which an intrinsic semiconductor layer is not formed on either the front surface side or the back surface side is prepared. As the semiconductor substrate 1, for example, a single crystal silicon substrate, a polycrystalline silicon substrate, or the like can be used. When a single crystal silicon substrate is used as the semiconductor substrate 1, it contains impurities that supply electric charges to silicon in order to have conductivity. As a specific example, the single crystal silicon substrate contains an n-type containing an atom (for example, phosphorus) for introducing an electron into a silicon atom and an atom (for example, boron) for introducing a hole into a silicon atom. There is a p-type. When comparing holes and electrons, electrons with smaller effective mass and scattered cross section generally have higher mobilities. From the above viewpoint, it is desirable to use an n-type single crystal silicon substrate as the semiconductor substrate 1. As the semiconductor substrate 1, it is desirable to use a substrate having fine irregularities (textures) on its surface. This is because the light uptake efficiency can be improved by the fine unevenness.

The semiconductor substrate 1 is placed on the substrate mounting surface of the first holder 31 shown in FIG. At this time, the semiconductor substrate 1 is placed on the substrate mounting surface of the first holder 31 with the back surface of the semiconductor substrate 1 facing the first holder 31 side so that the front surface side of the semiconductor substrate 1 is exposed. That is, the semiconductor substrate 1 is arranged in the first transport closed circuit with its front surface side exposed.

Here, in the present embodiment, the semiconductor substrate 1 on which the desired thin film is not formed on either the front surface side or the back surface side is referred to as a "first semiconductor substrate".

The substrate holder 200 on which the first semiconductor substrate is placed on the first holder 31 is carried into the first film forming chamber 61. At this time, the first holder 31 and the second holder 32 are electrically connected to the first anode electrode 51, the first holder 31 is arranged at the first film forming position 81 described above, and the second holder 32. Is arranged at the second film forming position 82 described above.

[First intrinsic semiconductor layer film forming step]
When the first semiconductor substrate is arranged at the first film forming position 81, the door of the first film forming chamber 61 is closed, the inside of the first film forming chamber 61 is evacuated, and then the shower head electrode is used. A silicon-containing gas or the like as a raw material gas is supplied from a first cathode electrode 71. In the present embodiment, SiH ₄ gas and H ₂ gas are supplied to the first film forming position 81.

In the present embodiment, the semiconductor substrate 1 mounted on the first holder 31 is heated by using the heater built in the first anode electrode 51, and the first high frequency power supply 91 is turned on. , A plasma discharge is generated between the first cathode electrode 71 and the first anode electrode 51. By the occurrence of this plasma discharge, SiH ₄ gas and H ₂ gas, which are raw material gases, are ionized, and as shown in FIG. 5, a first intrinsic semiconductor layer is formed on the surface of the semiconductor substrate 1 which is the first semiconductor substrate. A true amorphous silicon layer is formed as 5A.

[First conductive semiconductor layer film forming step]
Next, a first conductive semiconductor layer is formed on the surface side of the semiconductor substrate 1 arranged in the first transport closed circuit. Specifically, after the first intrinsic semiconductor layer 5A is formed on the surface of the semiconductor substrate 1, the door of the first film forming chamber 61 is opened, and the substrate holder 200 is the first conductive type film forming chamber. It is moved into the second film forming chamber 62. In the second film-forming chamber 62, the first holder 31 and the second holder 32 are electrically connected to the second anode electrode 52, and the first holder 31 is arranged at the third film-forming position 83 described above. Then, the second holder 32 is arranged at the fourth film forming position 84 described above. After that, the door of the second film forming chamber 62 is closed, the inside of the second film forming chamber 62 is evacuated, and then the shower head electrode, the third cathode electrode 73, to the inside of the second film forming chamber 62. _{SiH 4} gas and H ₂ gas as a raw material gas _{and hydrogen-diluted B 2} H ₆ gas as a dopant-added gas are supplied to the third film forming position 83. Since the amount of dopant impurities added may be very small, a mixed gas diluted with _{SiH 4} or H _{2 in advance may be used.}

In the present embodiment, the semiconductor substrate 1 mounted on the first holder 31 is heated by using the heater built in the second anode electrode 52, and the third high frequency power supply 93 is turned on. , A plasma discharge is generated between the third cathode electrode 73 and the second anode electrode 52. As shown in FIG. 6, the P-type semiconductor layer 3 as the first conductive semiconductor layer is formed on the surface side of the first intrinsic semiconductor layer 5A by the occurrence of this plasma discharge.

As the P-type semiconductor layer 3, a P-type amorphous silicon layer or a P-type microcrystalline silicon layer is preferably used. When the P-type semiconductor layer 3 is formed _{, a gas containing different elements such as CH 4} , CO ₂ , NH ₃ , and GeH ₄ is added to alloy the silicon-based thin film to form the energy of the silicon-based thin film. You can also change the gap. Further, a small amount of impurities such as oxygen and carbon may be added in order to improve the light transmission. In that case, it can be formed by introducing a gas such as _{CO 2} or CH _{4 at the time of CVD film formation.}

[Third membrane-forming chamber passing step]
Next, the semiconductor substrate 1 arranged in the first transport closed path passes through the third film forming chamber 63, which is the second conductive type film forming chamber, in a state where the surface side thereof is not formed. Specifically, after the P-type semiconductor layer 3 is formed on the surface side of the first intrinsic semiconductor layer 5A, the door of the second film forming chamber 62 is opened, and the substrate holder 200 is placed in the third film forming chamber. Move within 63. In the third film-forming chamber 63, the first holder 31 and the second holder 32 are electrically connected to the third anode electrode 53, and the first holder 31 is located at the fifth film-forming position 85 described above. The second holder 32 is arranged at the sixth film forming position 86 described above.

In the present embodiment, the third film-forming chamber 63 is a film-forming chamber for forming the N-type semiconductor layer 4, and does not form the N-type semiconductor layer 4 on the surface side of the P-type semiconductor layer 3, so that the fifth film-forming chamber 63 is formed. The semiconductor substrate 1 placed on the first holder 31 arranged at the film forming position 85 of the above is passed through the third film forming chamber 63 without performing any film forming. That is, in the third film-forming chamber passing step, the fifth high-frequency power source 95 connected to the fifth cathode electrode 75 is turned off, and the semiconductor substrate 1 mounted on the first holder 31 is manufactured. The film is not formed. At that time, no gas may be supplied from the fifth cathode electrode 75, which is the shower head electrode.

[Transfer / reversal step]
When the substrate holder 200 passes through the third film forming chamber 63, the conveying means 64 described above performs a conveying step of conveying the substrate holder 200 into the first film forming chamber 61 again.

Here, as shown in FIG. 6, the first intrinsic semiconductor layer 5A and the P-type semiconductor layer 3 are film-formed on the surface side of the semiconductor substrate 1 that has passed through the third film-forming chamber 63. It has become.

The semiconductor substrate 1 in which a desired thin film is formed on the surface side in this way is referred to as a "second semiconductor substrate".

Next, the semiconductor substrate 1, which is a second semiconductor substrate mounted on the first holder 31 shown in FIG. 3 so that the front surface side is exposed, is inverted so that the back surface side thereof is exposed. 2 The reversing step of placing the holder 32 on the substrate mounting surface is performed.

By performing the transport / reversal step in this way, the semiconductor substrate 1 arranged in the first transport closed path is moved to the second transport closed path so that the back surface side thereof is exposed.

Further, in the present embodiment, the second semiconductor substrate is moved to the second holder 32 and becomes empty, and the substrate mounting surface of the first holder 31 is desired on either the front surface side or the back surface side. A new first semiconductor substrate on which a thin film is not formed is placed so that the surface side thereof is exposed.

That is, the first semiconductor substrate was arranged in the first transport closed circuit with its front surface side exposed, and the second semiconductor substrate was arranged in the second transport closed circuit with its back surface side exposed. It becomes a state.

It does not matter which of the transfer step and the reversal step is performed first. That is, the transfer step may be performed after the reversal step is performed at the outlet of the third film forming chamber 63. Alternatively, a method of performing an inversion step in the middle of the transfer step may be used.

[Step of arranging the second semiconductor substrate at the second film forming position of the first film forming chamber]
When the second semiconductor substrate is mounted on the substrate mounting surface of the second holder 32 and the first semiconductor substrate is mounted on the substrate mounting surface of the first holder 31, the substrate holder 200 is again placed in the first position. It is carried into the film forming chamber 61 of. In the first film-forming chamber 61, the first holder 31 and the second holder 32 are electrically connected to the first anode electrode 51, and the first holder 31 is located at the first film-forming position 81 described above. The second holder 32 is arranged at the second film forming position 82 described above.

Here, in the present embodiment, the step of arranging the second semiconductor substrate at the second film forming position 82 of the first film forming chamber 61 and the above-mentioned first semiconductor substrate being placed in the first film forming chamber 61 The step of arranging the film at the first film forming position 81 of the above is performed substantially at the same time.

[Second intrinsic semiconductor layer film forming step]
When the first semiconductor substrate is arranged at the first film forming position 81 and the second semiconductor substrate is arranged at the second film forming position 82, the door of the first film forming chamber 61 is closed and the first film forming chamber 61 is closed. The inside of the film forming chamber 61 of the above is put into a vacuum state. After that, a silicon-containing gas or the like as a raw material gas is supplied from the first cathode electrode 71, which is a shower head electrode, and the second cathode electrode 72. In the present embodiment, SiH ₄ gas and H ₂ gas are supplied to the first film forming position 81 and the second film forming position 82.

That is, a common raw material gas is supplied to the first film forming position 81 and the second film forming position 82. In the present disclosure, even if only the ratio of the supplied raw material gas is different, it is expressed as "a common raw material gas is supplied".

In the present embodiment, the first semiconductor substrate mounted on the first holder 31 and the second semiconductor substrate placed on the second holder 32 are used by using the heater built in the first anode electrode 51. To heat. Then, by turning on the first high-frequency power source 91 connected to the first cathode electrode 71, a plasma discharge is generated between the first cathode electrode 71 and the first anode electrode 51. Further, by turning on the second high frequency power supply 92 connected to the second cathode electrode 72, a plasma discharge is generated between the second cathode electrode 72 and the first anode electrode 51. By the occurrence of this plasma discharge, SiH ₄ gas and H ₂ gas, which are raw material gases, are ionized, and as shown in FIG. 5, the semiconductor substrate 1 which is the first semiconductor substrate mounted on the first holder 31 A semiconductor substrate 1 which is a second semiconductor substrate mounted on the second holder 32 is formed by forming an intrinsic amorphous silicon layer as the first intrinsic silicon layer 5A on the surface thereof, and as shown in FIG. An intrinsic amorphous silicon layer as the second intrinsic semiconductor layer 5B is formed on the back surface.

As described above, a common raw material gas is supplied to the first film forming position 81 and the second film forming position 82, and the first intrinsic semiconductor layer 5A and the second intrinsic semiconductor layer 5B are It has a common composition.

In the first film forming chamber 61 of the present embodiment, the first high frequency power supply 91 and the second high frequency power supply 92 may be configured by a common high frequency power supply.

The second intrinsic semiconductor layer film forming step and the first intrinsic semiconductor layer film forming step described above are performed within the same period. The "same period" means that the period from closing the door of the film forming chamber accommodating the first semiconductor substrate and the second semiconductor substrate to opening is the same, and the first one. This includes the case where the film formation on the semiconductor substrate and the film formation on the second semiconductor substrate are not performed exactly at the same time.

By such a manufacturing method, it is possible to separate the first transport closed circuit in which the first holder 31 is transported and the second transport closed circuit in which the second holder 32 is transported. As a result, the first conductive semiconductor layer (P-type semiconductor layer 3 in the present embodiment) is formed in the first transport closed circuit, and the second conductive semiconductor layer (N-type semiconductor layer 4 in the present embodiment) is formed. ) Is never formed. Similarly, in the second transport closed circuit, the second conductive type semiconductor layer is formed, and the first conductive type semiconductor layer is not formed. That is, it is not necessary to use the first holder 31 to which the impurities added to the first conductive semiconductor layer are attached for the film formation of the second conductive semiconductor layer, and the impurities added to the second conductive semiconductor layer are present. It is not necessary to use the attached second holder 32 for forming the first conductive semiconductor layer. Therefore, in order to prevent impurities added to the first conductive semiconductor layer from being mixed into the second conductive semiconductor layer, the surface of the first holder 31 is intrinsic after the formation of the first conductive semiconductor layer. There is no need to form a semiconductor layer. Similarly, in order to prevent impurities added to the second conductive semiconductor layer from being mixed into the first conductive semiconductor layer, the back surface of the second holder 32 is formed after the formation of the second conductive semiconductor layer. There is no need to form an intrinsic semiconductor layer. As a result, improvement in manufacturing efficiency can be realized.

Further, by such a manufacturing method, a film forming chamber for forming a first thin film (intrinsic semiconductor layer in the present embodiment) on the front surface side of the semiconductor substrate 1 and the first film forming chamber on the back surface side of the semiconductor substrate 1 are provided. Since it is not necessary to separately provide a film forming chamber for forming the second thin film formed by using the same raw material gas as the thin film of the above, it is possible to realize miniaturization of the in-line type manufacturing apparatus. ..

Further, since the second intrinsic semiconductor layer film forming step and the first intrinsic semiconductor layer film forming step described above can be carried out in the same period, it is possible to realize a highly productive in-line manufacturing process. it can.

Further, even when the film forming conditions of the first intrinsic semiconductor layer 5A formed on the front surface side of the semiconductor substrate 1 and the film forming conditions of the second intrinsic semiconductor layer 5B formed on the back surface side are different from each other. In the process of the present disclosure, the film forming conditions of the first film forming position 81 and the film forming conditions of the second film forming position 82 in the first film forming chamber 61 are kept constant. Therefore, it is possible to realize an in-line manufacturing process with high productivity and film forming quality. That is, in the process of the present disclosure, since the first holder 31 whose surface side of the semiconductor substrate 1 is exposed is always carried into the first film forming position 81, the first holder 31 connected to the first cathode electrode 71 is connected. The power condition of the high-frequency power source 91, the ratio and flow rate condition of the gas supplied to the first film-forming position 81, the temperature condition of the first film-forming position 81, the film-forming pressure condition, etc. It is possible to fix the semiconductor layer 5A under the conditions for forming a film. Further, since the second holder 32 whose back surface side of the semiconductor substrate 1 is exposed is always carried into the second film forming position 82, the power condition of the second high frequency power supply 92 connected to the second cathode electrode 72, In order to form the second intrinsic semiconductor layer 5B, the ratio and flow rate conditions of the gas supplied to the second film forming position 82, the temperature conditions of the second film forming position 82, the conditions of the film forming pressure, and the like are set. It is possible to fix it to the condition of.

[Second film-forming chamber passing step]
Next, the semiconductor substrate 1 arranged in the second transport closed path passes through the second film-forming chamber 62, which is the first conductive film-forming chamber, in a state where the back surface side thereof is not film-formed. Specifically, after the first intrinsic semiconductor layer 5A is formed on the surface of the first semiconductor substrate and the second intrinsic semiconductor layer 5B is formed on the back surface of the second semiconductor substrate, the first one is formed. The door of the film forming chamber 61 is opened, and the substrate holder 200 is moved into the second film forming chamber 62. In the second film forming chamber 62, the second anode electrode 52 is arranged between the first holder 31 and the second holder 32, and the first holder 31 is arranged at the above-mentioned third film forming position 83. , The second holder 32 is arranged at the fourth film forming position 84 described above. In the present embodiment, the step in which the first holder 31 is arranged at the third film forming position 83 and the step in which the second holder 32 is arranged at the fourth film forming position 84 are performed substantially at the same time. ..

In the present embodiment, the second film-forming chamber 62 is a film-forming chamber for forming the P-type semiconductor layer 3, and the P-type semiconductor layer 3 is not formed on the back surface side of the second intrinsic semiconductor layer 5B. The second semiconductor substrate placed on the second holder 32 arranged at the fourth film forming position 84 is passed through the second film forming chamber 62 without performing any film forming. That is, in this second film forming chamber passing step, the fourth high-frequency power supply 94 connected to the fourth cathode electrode 74 is turned off, and the second semiconductor substrate mounted on the second holder 32 is turned off. The film is not formed. At that time, no gas may be supplied from the fourth cathode electrode 74, which is the shower head electrode. When the fourth cathode electrode 74 and the third cathode electrode 73 are connected to a common gas cylinder, a solenoid valve is used to stop only the gas supply to the fourth cathode electrode 74 side. May be good.

The second film-forming chamber passing step can be performed in the same period as the above-mentioned first conductive semiconductor layer film-forming step. That is, the fourth high-frequency power source 94 connected to the fourth cathode electrode 74 is left in the off state, and at the fourth film forming position 84, the second semiconductor substrate mounted on the second holder 32 is placed. On the other hand, while not forming any film, the third high-frequency power source 93 connected to the third cathode electrode 73 is turned on, and various gases are discharged from the third cathode electrode 73, which is a shower head electrode. At the third film forming position 83, the P-type semiconductor layer 3 can be formed on the surface of the first intrinsic semiconductor layer 5A formed on the surface side of the first semiconductor substrate.

[Second conductive semiconductor layer film forming step]
Next, a second conductive semiconductor layer is formed on the back surface side of the semiconductor substrate 1 arranged in the second transport closed circuit. Specifically, when the substrate holder 200 passes through the second film forming chamber 62, the substrate holder 200 is moved into the third film forming chamber 63. In the third film-forming chamber 63, the third anode electrode 53 is arranged between the first holder 31 and the second holder 32, and the first holder 31 is arranged at the fifth film-forming position 85 described above. The second holder 32 is arranged at the sixth film forming position 86 described above. After that, the door of the third film forming chamber 63 is closed, the inside of the third film forming chamber 63 is evacuated, and then the sixth cathode electrode 76, which is the shower head electrode, is placed in the third film forming chamber 63. _{SiH 4} gas and H _{2 gas as a raw material gas and hydrogen-diluted PH 3} gas as a dopant-added gas are supplied to the sixth film forming position 86. Since the amount of dopant impurities added may be very small, a mixed gas diluted with _{SiH 4} or H _{2 in advance may be used.}

In the present embodiment, the heater built in the third anode electrode 53 is used to heat the second semiconductor substrate mounted on the second holder 32, and the sixth high-frequency power supply 96 is turned on. This causes a plasma discharge between the sixth cathode electrode 76 and the third anode electrode 53. As shown in FIG. 8, the occurrence of this plasma discharge causes the N-type semiconductor layer 4 as the second conductive semiconductor layer to be formed on the back surface side of the second intrinsic semiconductor layer 5B.

As the N-type semiconductor layer 4, an N-type amorphous silicon layer or an N-type microcrystalline silicon layer is preferably used. When the N-type semiconductor layer 4 is formed _{, a gas containing different elements such as CH 4} , CO ₂ , NH ₃ , and GeH ₄ is added to alloy the silicon-based thin film to form the energy of the silicon-based thin film. You can also change the gap. Further, a small amount of impurities such as oxygen and carbon may be added in order to improve the light transmission. In that case, it can be formed by introducing a gas such as _{CO 2} or CH _{4 at the time of CVD film formation.}

The second conductive semiconductor layer film forming step can be performed in the same period as the above-mentioned third film forming chamber passing step. Specifically, the fifth high-frequency power source 95 connected to the fifth cathode electrode 75 is left in the off state, and at the fifth film forming position 85, the first holder 31 is placed. The sixth high-frequency power source 96 connected to the sixth cathode electrode 76 was turned on while the semiconductor substrate was not formed with any film, and the sixth cathode electrode 76, which is the shower head electrode, was turned on. Various gases can be supplied, and at the sixth film forming position 86, the N-type semiconductor layer 4 can be formed on the back surface of the second intrinsic semiconductor layer 5B formed on the back surface side of the second semiconductor substrate. Is.

[Transparent conductive layer film forming step]
Then, using another film-forming device or the like, the first transparent conductive layer 6A shown in FIG. 2 is formed on the surface side of the P-type semiconductor layer 3, and the second transparent conductive layer 6B is formed on the N-type semiconductor layer 4. It is formed on the back side of.

The method for forming the first transparent conductive layer 6A and the second transparent conductive layer 6B is not particularly limited, but a physical vapor deposition method such as a sputtering method or a reaction between an organometallic compound and oxygen or water is used. A chemical vapor deposition (MOCVD) method or the like is preferable. In any of the film forming methods, energy generated by heat or plasma discharge can also be used.

As the constituent materials of the first transparent conductive layer 6A and the second transparent conductive layer 6B, transparent conductive metal oxides such as indium oxide, zinc oxide, tin oxide, titanium oxide, and composite oxides thereof are used. Further, it may be a transparent conductive material made of a non-metal such as graphene. Among the above-mentioned constituent materials, from the viewpoint of high conductivity and transparency, an indium-based composite oxide containing indium oxide as a main component can be used as the first transparent conductive layer 6A and the second transparent conductive layer 6B. preferable. Further, in order to secure reliability and higher conductivity, it is more preferable to add a dopant to the indium oxide and use it. Examples of impurities used as the dopant include Sn, W, Ce, Zn, As, Al, Si, S, Ti and the like.

As shown in FIG. 9, the film forming apparatus 300A includes a fourth film forming chamber 65 connected to the third film forming chamber 63 after the third film forming chamber 63, and the fourth film forming chamber 63 is included. The film-forming chamber 65 may be configured to include a seventh film-forming position 87 and an eighth film-forming position 88. The fourth film-forming chamber 65 has a seventh cathode electrode 77, an eighth cathode electrode 78, and a fourth anode electrode 54, and has the same configuration as the first film-forming chamber 61 and the like described above. Suppose that it has. In that case, at the seventh film forming position 87, the first transparent conductive layer 6A is formed on the front surface side of the P-type semiconductor layer 3, and at the eighth film forming position 88, the back surface side of the N-type semiconductor layer 4 is formed. It may be a method of forming the second transparent conductive layer 6B.

Specifically, as shown in FIG. 6, the semiconductor substrate 1 having the first intrinsic semiconductor layer 5A and the P-type semiconductor layer 3 formed on the surface side is carried into the fourth film forming chamber 65, and the semiconductor substrate 1 is carried into the fourth film forming chamber 65. In the fourth film forming chamber 65, the first transparent conductive layer 6A is formed on the surface side of the P-type semiconductor layer 3. After that, the semiconductor substrate 1 is carried back into the first film forming chamber 61 as the second semiconductor substrate through the above-mentioned transport step and inversion step. After that, the semiconductor substrate 1 has the second intrinsic semiconductor layer 5B and the N-type semiconductor layer 4 formed on the back surface side thereof, and then is carried into the fourth film forming chamber 65 again to form the N-type semiconductor layer 4. A second transparent conductive layer 6B is formed on the back surface side.

[Current collector electrode formation step]
After that, the current collecting electrode 2 including the bus bar electrode 2A and the finger electrode 2B is formed on the front surface side of the first transparent conductive layer 6A and the back surface side of the second transparent conductive layer 6B. The current collecting electrode 2 includes a base electrode formed on the front surface side of the first transparent conductive layer 6A and the back surface side of the second transparent conductive layer 6B, and a plating electrode formed on the base electrode. ..

The base electrode can be formed by, for example, an inkjet method, a screen printing method, a spray method, a roll coating method, or the like. The base electrode can be patterned into a predetermined shape, and the screen printing method is suitable from the viewpoint of productivity when forming the patterned base electrode. In the screen printing method, a method of printing a printing paste containing conductive fine particles using a screen plate having an opening pattern corresponding to the pattern shape of the current collecting electrode 2 is preferably used.

As the conductive particles contained in the base electrode, for example, silver, copper, aluminum, nickel, tin, bismuth, zinc, gallium, carbon and a mixture thereof can be used.

As the thermosetting resin contained in the base electrode, an epoxy resin, a phenol resin, an acrylic resin or the like can be used. By including the thermosetting resin in the base electrode, the base electrode can be cured in the heat curing step.

The base electrode may be composed of a plurality of layers. For example, by forming the base electrode to include a lower layer having a low contact resistance with respect to the first transparent conductive layer 6A and the second transparent conductive layer 6B, improvement of the curve factor of the photoelectric conversion element 100 can be expected.

The plating electrode is formed by depositing a metal starting from the base electrode by a plating method. As the metal to be deposited as the plating electrode, for example, copper, nickel, tin, aluminum, chromium, silver, etc. can be used, and any material that can be formed by a plating method may be used.

[Insulating film forming step]
Although not shown in FIG. 2, an insulating film is formed on the front surface of the first transparent conductive layer 6A and the back surface of the second transparent conductive layer 6B in a region where the current collecting electrode 2 is not formed. It doesn't matter. In the plating method for forming the plating electrode described above by forming the insulating film, the front surface of the first transparent conductive layer 6A and the back surface of the second transparent conductive layer 6B are chemically and electrically removed from the plating solution. It becomes possible to protect. That is, it is possible to prevent metal from being deposited on the surfaces of the first transparent conductive layer 6A and the second transparent conductive layer 6B.

In this insulating film forming step, for example, the film forming apparatus 300A shown in FIG. 9 further adds a fifth film forming chamber 66 connected to the fourth film forming chamber 65 after the fourth film forming chamber 65. Including, the fifth film forming chamber 66 can be performed in a configuration including the ninth film forming position 89 and the tenth film forming position 90. The fifth film-forming chamber 66 has a ninth cathode electrode 79, a tenth cathode electrode 80, and a fifth anode electrode 55, and has the same configuration as the first film-forming chamber 61 and the like described above. Suppose that it has. In that case, at the ninth film forming position 89, the first insulating film is formed on the surface side of the first transparent conductive layer 6A, and at the tenth film forming position 90, the second transparent conductive layer 6B A method of forming a second insulating film on the back surface side may be used.

Specifically, the semiconductor substrate 1 having the first intrinsic semiconductor layer 5A, the P-type semiconductor layer 3 and the first transparent conductive layer 6A formed on the surface side is carried into the fifth film forming chamber 66, and the semiconductor substrate 1 is carried into the fifth film forming chamber 66. In the fifth film forming chamber 66, a first insulating film is formed on the surface side of the first transparent conductive layer 6A. After that, the semiconductor substrate 1 is carried back into the first film forming chamber 61 as the second semiconductor substrate through the above-mentioned transport step and inversion step. After that, the semiconductor substrate 1 is formed with the second intrinsic semiconductor layer 5B, the N-type semiconductor layer 4, and the second transparent conductive layer 6B on the back surface side thereof, and then again in the fifth film forming chamber 66. It is carried in and a second insulating film is formed on the back surface side of the second transparent conductive layer 6B.

As the material constituting the insulating film, it is necessary to use a material that exhibits electrical insulation, and it is desirable that the material has chemical stability with respect to the plating solution. By using a material having high chemical stability to the plating solution, the insulating film is difficult to dissolve when the above-mentioned plating electrode is formed, and the surface of the first transparent conductive layer 6A and the second transparent conductive layer 6B It is possible to suppress the occurrence of damage to the back surface.

Further, as the material constituting the insulating film, it is preferable to use a material having a high adhesion strength with the first transparent conductive layer 6A and the second transparent conductive layer 6B. By increasing the adhesion strength with the first transparent conductive layer 6A and the second transparent conductive layer 6B, the insulating film is less likely to peel off when the above-mentioned plating electrode is formed, and the first transparent conductive layer 6A, It is possible to prevent metal from being deposited on the second transparent conductive layer 6B.

It is preferable to use a material having high light transmittance for the insulating film. If the light absorption by the insulating film is small, more light can be taken into the semiconductor substrate 1 side. For example, when the insulating film has sufficient transparency with a transmittance of 90% or more, the optical loss due to light absorption in the insulating film is small, and the step of removing the insulating film after forming the plating electrode is not required. It can be used as it is as a part of the photoelectric conversion element 100. Therefore, the manufacturing process of the photoelectric conversion element 100 can be simplified, and the productivity can be further improved. Further, when the insulating film is used as it is as a part of the photoelectric conversion element 100 without providing a step of removing the insulating film, the insulating film is made of a material having sufficient weather resistance and stability against heat and humidity. It is more desirable to use.

The material constituting the insulating film may be an inorganic insulating material or an organic insulating material. As the inorganic insulating material, for example, materials such as silicon oxide, silicon nitride, titanium oxide, aluminum oxide, and magnesium oxide can be used. As the organic insulating material, for example, materials such as polyester, ethylene vinyl acetate copolymer, acrylic, epoxy, and polyurethane can be used.

Among such inorganic materials, from the viewpoint of plating solution resistance and transparency, silicon oxide, silicon nitride, silicon oxide nitride, aluminum oxide, sialon (SiAlON), yttrium oxide, magnesium oxide, barium titanate, strontium oxide, etc. Barium titanate, tantalum oxide, magnesium fluoride, titanium oxide, strontium titanate and the like are preferably used. Among them, from the viewpoint of electrical characteristics and adhesion to the transparent electrode layer, silicon oxide, silicon nitride, silicon oxide, aluminum oxide, sialon (SiAlON), yttrium oxide, magnesium oxide, barium titanate, samarium oxide, etc. Barium titanate, tantalum oxide, magnesium fluoride and the like are preferable, and silicon oxide, silicon nitride and the like are particularly preferably used from the viewpoint of appropriately adjusting the refractive index. In addition, these inorganic materials are not limited to those having a stoichiometric composition, and may contain oxygen deficiency and the like.

When an inorganic insulating material such as silicon oxide or silicon nitride is used as the constituent material of the insulating film, a dry method such as a plasma CVD method or a sputtering method is preferably used as a method for forming the insulating film. When an organic insulating material is used as the constituent material of the insulating film, a wet method such as a spin coating method or a screen printing method is preferably used as a method for forming the insulating film. According to these methods, it is possible to form a film having a dense structure with few defects such as pinholes.

In the present embodiment, the insulating film is formed by the plasma CVD method from the viewpoint of forming a film having a more dense structure. By this method, a film having a highly dense structure can be formed not only when a thick insulating film having a thickness of about 200 nm but also a thin insulating film having a film thickness of about 30 to 100 nm is formed.

[Other Embodiments]
An example is shown in which the film forming apparatus 300 described with reference to FIG. 4 and the film forming apparatus 300A described with reference to FIG. 9 are provided with the conveying means 64 and perform the above-mentioned conveying step and the inversion step. Is not limited to this example. For example, the first semiconductor substrate is placed on the first holder 31, and in the first transport closure, the first intrinsic semiconductor layer film forming step, the first conductive semiconductor layer film forming step, and the third film forming chamber pass through. Through the steps, the semiconductor substrate 1 is stored as a second semiconductor substrate, and then the stored second semiconductor substrate is placed on the second holder 32, and in the second transport closing path, the second semiconductor substrate is placed. The method may be a method of performing the intrinsic semiconductor layer film forming step 2, the second film forming chamber passing step, and the second conductive semiconductor layer film forming step.

In the present embodiment, the first intrinsic semiconductor layer forming step for forming the first intrinsic semiconductor layer 5A on the surface side of the semiconductor substrate 1 and the first conductive type on the surface side of the first intrinsic semiconductor layer 5A. After passing through the first conductive semiconductor layer film forming step, the third film forming chamber passing step, and the transport / inversion step of forming the P-type semiconductor layer 3 as the semiconductor layer, a second is placed on the back surface side of the semiconductor substrate 1. A second intrinsic semiconductor layer film forming step for forming the intrinsic semiconductor layer 5B, a second film forming chamber passing step, and an N-type semiconductor layer as a second conductive semiconductor layer on the back surface side of the second intrinsic semiconductor layer 5B. Although an example in which the second conductive semiconductor layer film forming step for forming No. 4 is performed has been shown, the present disclosure is not limited to such a method. An example thereof will be described below with reference to FIGS. 4 and 9.

[Step of arranging the first semiconductor substrate at the second film forming position of the first film forming chamber]
First, the semiconductor substrate 1 on which the desired thin film is not formed on the front and back surfaces is placed on the substrate mounting surface of the second holder 32 so that the back surface side thereof is exposed. Then, the substrate holder 200 is carried into the first film forming chamber 61 shown in FIGS. 4 and 9, and the semiconductor substrate 1 is arranged at the second film forming position 82. That is, the semiconductor substrate 1 is arranged in the second transport closed circuit with its back surface exposed.

[Second intrinsic semiconductor layer film forming step]
Next, a second intrinsic semiconductor layer film forming step is performed in which the second intrinsic semiconductor layer 5B is formed on the back surface side of the semiconductor substrate 1. Specifically, after the inside of the first film forming chamber 61 is evacuated, a silicon-containing gas or the like as a raw material gas is supplied from the second cathode electrode 72 which is a shower head electrode, and the second high frequency power supply 92 Is turned on to generate a plasma discharge at the second film forming position 82. By the occurrence of this plasma discharge, the raw material gas is ionized, and the second intrinsic semiconductor layer 5B is formed on the back surface of the semiconductor substrate 1 which is the first semiconductor substrate.

[Second film-forming chamber passing step]
After that, the semiconductor substrate 1 arranged in the second transport closed path passes through the second film-forming chamber 62, which is the first conductive film-forming chamber, in a state where the back surface side thereof is not film-formed. Perform a passing step. Specifically, the substrate holder 200 is carried into the second film forming chamber 62, and the fourth high frequency power supply 94 is turned off at the fourth film forming position 84 in the second film forming chamber 62. As a result, the semiconductor substrate 1 is passed through without forming a film on the back surface side of the semiconductor substrate 1.

[Second conductive semiconductor layer film forming step]
Next, a second conductive semiconductor layer film forming step is performed in which the second conductive semiconductor layer is formed on the back surface side of the semiconductor substrate 1 arranged in the second transport closed path. Specifically, next, the substrate holder 200 is carried into the third film forming chamber 63, and the second conductive semiconductor layer is formed on the back surface side of the second intrinsic semiconductor layer 5B. Perform a layered film formation step. Specifically, after the semiconductor substrate 1 is arranged at the sixth film forming position 86 and the inside of the third film forming chamber 63 is evacuated, the raw material gas is transferred from the sixth cathode electrode 76, which is the shower head electrode. By supplying the silicon-containing gas, the dopant-added gas, and the like to turn on the sixth high-frequency power source 96, a plasma discharge is generated at the sixth film-forming position 86. By the occurrence of this plasma discharge, the raw material gas and the dopant-added gas are ionized, and a second conductive semiconductor layer is formed on the back surface side of the second intrinsic semiconductor layer 5B.

[Transfer / reversal step]
When the substrate holder 200 passes through the third film forming chamber 63, the conveying means 64 described above performs a conveying step of conveying the substrate holder 200 into the first film forming chamber 61 again.

Here, the second intrinsic semiconductor layer 5B and the N-type semiconductor layer 4 are film-formed on the back surface side of the semiconductor substrate 1 that has passed through the third film-forming chamber 63.

In this embodiment, the semiconductor substrate 1 in which a desired thin film is formed on the back surface side is referred to as a "second semiconductor substrate".

Then, the semiconductor substrate 1 mounted on the second holder 32 so that the back surface side is exposed is inverted so that the front surface side thereof is exposed and placed on the substrate mounting surface of the first holder 31. Take steps.

By performing the transport / reversal step in this way, the semiconductor substrate 1 arranged in the second transport closed path is moved to the first transport closed path so that the surface side thereof is exposed.

Further, in this embodiment, the second semiconductor substrate is moved to the first holder 31 and becomes empty, and the substrate mounting surface of the second holder 32 is desired on either the front surface side or the back surface side. A new first semiconductor substrate on which a thin film is not formed is placed so that the back surface side thereof is exposed.

That is, the first semiconductor substrate was arranged in the second transport closed circuit with its back surface side exposed, and the second semiconductor substrate was arranged in the first transport closed circuit with its front surface side exposed. It becomes a state.

It does not matter which of the transfer step and the reversal step is performed first. Further, a method of performing an inversion step in the middle of the transfer step may be used.

[Step of arranging the second semiconductor substrate at the first film forming position of the first film forming chamber]
When the second semiconductor substrate is mounted on the substrate mounting surface of the first holder 31 and the first semiconductor substrate is mounted on the substrate mounting surface of the second holder 32, the substrate holder 200 is again placed in the first position. It is carried into the film forming chamber 61 of. In the first film-forming chamber 61, the first anode electrode 51 is arranged between the first holder 31 and the second holder 32, and the first holder 31 is arranged at the first film-forming position 81 described above. , The second holder 32 is arranged at the second film forming position 82 described above.

[First intrinsic semiconductor layer film forming step]
When the first semiconductor substrate is arranged at the second film forming position 82 and the second semiconductor substrate is arranged at the first film forming position 81, the door of the first film forming chamber 61 is closed and the first film forming chamber 61 is closed. The inside of the film forming chamber 61 of the above is put into a vacuum state. After that, a silicon-containing gas or the like as a raw material gas is supplied from the first cathode electrode 71, which is a shower head electrode, and the second cathode electrode 72.

By turning on the first high-frequency power source 91 connected to the first cathode electrode 71, a plasma discharge is generated between the first cathode electrode 71 and the first anode electrode 51. Further, by turning on the second high frequency power supply 92 connected to the second cathode electrode 72, a plasma discharge is generated between the second cathode electrode 72 and the first anode electrode 51. By the occurrence of this plasma discharge, SiH4 gas and H2 gas, which are raw material gases, are ionized, and a first intrinsic semiconductor layer is formed on the surface of the semiconductor substrate 1 which is the second semiconductor substrate placed on the first holder 31. The intrinsic amorphous silicon layer as the second intrinsic silicon layer 5B is formed on the back surface of the semiconductor substrate 1 which is the first semiconductor substrate placed on the second holder 32, and the intrinsic amorphous as the second intrinsic semiconductor layer 5B is formed. A silicon layer is formed.

The first intrinsic semiconductor layer film forming step and the second intrinsic semiconductor layer film forming step described above are performed within the same period.

By such a method, a film forming chamber for forming a desired thin film (intrinsic semiconductor layer in the present embodiment) on the back surface side of the semiconductor substrate 1 and the desired thin film on the front surface side of the semiconductor substrate 1 are common. Since it is not necessary to separately provide a film forming chamber for forming a thin film formed by using the raw material gas, it is possible to realize miniaturization of the in-line type manufacturing apparatus.

Further, since the second intrinsic semiconductor layer film forming step and the first intrinsic semiconductor layer film forming step described above can be carried out in the same period, it is possible to realize a highly productive in-line manufacturing process. it can.

[First conductive semiconductor layer film forming step]
Next, a first conductive semiconductor layer is formed on the surface side of the semiconductor substrate 1 arranged in the first transport closed circuit. Specifically, after the first intrinsic semiconductor layer 5A is formed on the surface of the second semiconductor substrate, the substrate holder 200 is moved into the second film forming chamber 62 which is the first conductive type film forming chamber. Let me. In the second film-forming chamber 62, the second anode electrode 52 is arranged between the first holder 31 and the second holder 32, and the first holder 31 is arranged at the third film-forming position 83 described above. The second holder 32 is arranged at the fourth film forming position 84 described above. After that, the door of the second film forming chamber 62 is closed, the inside of the second film forming chamber 62 is evacuated, and then the third cathode electrode 73, which is the shower head electrode, is placed in the second film forming chamber 62. SiH4 gas and H2 gas as a raw material gas and hydrogen-diluted PH3 gas as a dopant-added gas are supplied to the third film forming position 83. Since the amount of dopant impurities added may be very small, a mixed gas diluted with SiH4 or H2 in advance may be used.

In the present embodiment, the heater built in the second anode electrode 52 is used to heat the second semiconductor substrate mounted on the first holder 31, and the third high-frequency power supply 93 is turned on. This causes a plasma discharge between the third cathode electrode 73 and the second anode electrode 52. Due to the occurrence of this plasma discharge, a P-type semiconductor layer 3 as a first conductive semiconductor layer is formed on the surface side of the first intrinsic semiconductor layer 5A.

The first conductive semiconductor layer film forming step can be performed in the same period as the above-mentioned second film forming chamber passing step. Specifically, the first semiconductor mounted on the second holder 32 at the fourth film forming position 84 with the fourth high-frequency power source 94 connected to the fourth cathode electrode 74 left in the off state. While the substrate is not formed with any film, the third high-frequency power source 93 connected to the third cathode electrode 73 is turned on, and various types are formed from the third cathode electrode 73, which is a shower head electrode. By supplying gas, at the third film forming position 83, it is possible to form the P-type semiconductor layer 3 on the surface of the first intrinsic semiconductor layer 5A formed on the surface side of the first semiconductor substrate. is there.

[Third membrane-forming chamber passing step]
Next, the semiconductor substrate 1 arranged in the first transport closed path passes through the third film forming chamber 63, which is the second conductive type film forming chamber, in a state where the surface side thereof is not formed. Specifically, when the P-type semiconductor layer 3 is formed on the surface side of the first intrinsic semiconductor layer 5A, the door of the second film forming chamber 62 is opened, and the substrate holder 200 is moved to the third film forming chamber. Move within 63. In the third film-forming chamber 63, the third anode electrode 53 is arranged between the first holder 31 and the second holder 32, and the first holder 31 is arranged at the fifth film-forming position 85 described above. , The second holder 32 is arranged at the sixth film forming position 86 described above.

In the present embodiment, the third film-forming chamber 63 is a film-forming chamber for forming the N-type semiconductor layer 4, and does not form the N-type semiconductor layer 4 on the surface side of the P-type semiconductor layer 3, so that the fifth film-forming chamber 63 is formed. The semiconductor substrate 1 placed on the first holder 31 arranged at the film forming position 85 of the above is passed through the third film forming chamber 63 without performing any film forming. That is, in the third film-forming chamber passing step, the fifth high-frequency power source 95 connected to the fifth cathode electrode 75 is turned off, and the semiconductor substrate 1 mounted on the first holder 31 is manufactured. The film is not formed. At that time, no gas may be supplied from the fifth cathode electrode 75, which is the shower head electrode. When the fifth cathode electrode 75 and the sixth cathode electrode 76 are connected to a common gas cylinder, a solenoid valve is used to stop only the gas supply to the fifth cathode electrode 75 side. May be good.

The third film-forming chamber passing step can be performed in the same period as the above-mentioned second conductive semiconductor layer film-forming step. That is, the fifth high-frequency power source 95 connected to the fifth cathode electrode 75 is left in the off state, and at the fifth film forming position 85, the second semiconductor substrate mounted on the first holder 31 is placed. On the other hand, while the state in which no film formation is performed, the sixth high-frequency power source 96 connected to the sixth cathode electrode 76 is turned on, and various gases are discharged from the sixth cathode electrode 76, which is the shower head electrode. At the sixth film forming position 86, the N-type semiconductor layer 4 can be formed on the back surface of the second intrinsic semiconductor layer 5B formed on the front surface side of the first semiconductor substrate.

After the third film forming chamber passing step, the transparent conductive layer film forming step and the current collecting electrode forming step described above may be performed with reference to FIG. 9.

In the present embodiment, a method of converting the first conductive semiconductor into a P-type semiconductor and the second conductive semiconductor into an N-type semiconductor has been described as an example, but the first conductive semiconductor is an N-type semiconductor and the second is a second. A method of using a conductive semiconductor as a P-semiconductor may be used.

In the manufacturing method described above in the present embodiment, the manufacturing method may be performed in which the front surface side and the back surface side of the semiconductor substrate 1 are all reversed. That is, for example, in the first film forming chamber 61, the second film forming chamber 62, and the third film forming chamber 63, the non-light receiving surface side (back surface side) of the first semiconductor substrate is formed to form a second film. It may be a manufacturing method of forming a film on the light receiving surface side (surface side) of the semiconductor substrate.

In the board holder 200 described with reference to FIG. 3, the first holder 31 and the second holder 32 are held by the holding portion 33, and the first holder 31 and the second holder 32 are integrated. However, the present disclosure is not limited to such examples. For example, as shown in FIG. 10, the first holder 31A and the second holder 32A are separately configured, and the first holder 31A serves as the first transport closing path, and the first film forming chamber 61 in the film forming apparatus 300B is used. After being transported through the first film-forming position 81, the third film-forming position 83 of the second film-forming chamber 62, and the fifth film-forming position 85 of the third film-forming chamber 63, the first transfer is performed. It may be a method of being conveyed to the first film forming chamber 61 again by the means 64A. Similarly, the second holder 32A serves as a second transport closing path, that is, the second film forming position 82 of the first film forming chamber 61 and the fourth film forming position of the second film forming chamber 62 in the film forming apparatus 300B. 84, after the sixth film forming position 86 of the third film forming chamber 63 is conveyed, it may be conveyed to the first film forming chamber 61 again by the second conveying means 64B.

In the example described with reference to FIG. 10, when the surface side of the semiconductor substrate 1 is first film-formed, the first transport means 64A is used to move the third film-forming chamber 63 to the first film-forming chamber 61. The semiconductor substrate 1 to be conveyed may be taken out from the first holder 31 and placed on the second holder 32 conveyed by the second conveying means 64B so that the back surface side thereof is exposed. When the back surface side of the semiconductor substrate 1 is first formed, the semiconductor substrate 1 transported from the third film forming chamber 63 to the first film forming chamber 61 by the second conveying means 64B is transferred. It may be taken out from the second holder 32 and placed on the first holder 31 conveyed by the first conveying means 64A so that the surface side thereof is exposed.

In this embodiment, an example of supplying various gases from the cathode electrode side in each film forming chamber has been described, but the anode electrode is a shower head electrode, and various gases are supplied into the film forming chamber from the anode electrode side. It may be a manufacturing method to supply.

In the examples shown in FIGS. 4 and 9 of this embodiment, two cathode electrodes connected to a high-frequency power source are arranged at both ends of each film forming chamber, and an anode electrode is placed between the two cathode electrodes. Although an example of arranging the electrodes is shown, an example may be obtained in which two anode electrodes are arranged at both ends of each film forming chamber and the cathode electrodes are arranged between the anode electrodes. In this case, the cathode electrode arranged in the center is connected to the high frequency power supply, and plasma discharge may occur between one anode electrode and the cathode electrode and between the other anode electrode and the cathode electrode. it can.

In the configuration example of the board holder 200 shown in FIG. 3 of the present embodiment, an example is shown in which the board mounting surface of the first holder 31 and the board mounting surface of the second holder 32 face in opposite directions. However, the substrate mounting surface of the first holder 31 and the substrate mounting surface of the second holder 32 may be arranged so as to face each other. In that case, the first holder 31 and the second holder 32 of the substrate holder 200 are separated from each other, and when the substrate holder 200 is carried into each film forming chamber, the first holder 31 and the second holder 32 are separated from each other. The electrodes arranged between the electrodes and the substrate mounting surfaces of the first holder 31 and the second holder 32 may be arranged with a certain distance.

Further, in the substrate holder 200, when the substrate mounting surface of the first holder 31 and the substrate mounting surface of the second holder 32 are arranged so as to face each other, the substrate is arranged inside the substrate holder 200. In order to facilitate the passage of gas to the mounting surface, a plurality of holes may be provided in the regions of the first holder 31 and the second holder 32 where the semiconductor substrate 1 is not mounted.

1 Semiconductor substrate, 2 current collecting electrode, 2A bus bar electrode, 2B finger electrode, 3P type semiconductor layer, 4N type semiconductor layer, 5A first intrinsic semiconductor layer, 5B second intrinsic semiconductor layer, 6A first transparent Conductive layer, 6B 2nd transparent conductive layer, 8 photoelectric conversion part, 31 1st holder, 31A 1st holder, 32 2nd holder, 32A 2nd holder, 33 holding part, 51 1st anode electrode, 52 2nd Anode electrode, 53 3rd anode electrode, 54 4th anode electrode, 55 5th anode electrode, 61 1st film forming chamber, 62 2nd film forming room, 63 3rd film forming room, 64 Transport means, 64A 1st transport means, 64B 2nd transport means, 65 4th film forming chamber, 66 5th film forming chamber, 71 1st cathode electrode, 72 2nd cathode electrode, 73 3rd , 74 4th cathode electrode, 75 5th cathode electrode, 76 6th cathode electrode, 77 7th cathode electrode, 78 8th cathode electrode, 79 9th cathode electrode, 80 10th Cathode electrode, 81 1st film forming position, 82 2nd film forming position, 83 3rd film forming position, 84 4th film forming position, 85 5th film forming position, 86 6th film forming position , 87 7th film forming position, 88 8th film forming position, 89 9th film forming position, 90 10th film forming position, 91 1st high frequency power supply, 92 2nd high frequency power supply, 93 3rd High frequency power supply, 94 4th high frequency power supply, 95 5th high frequency power supply, 96 6th high frequency power supply, 100 photoelectric conversion element, 200 substrate holder, 300 film forming device, 300A film forming device, 300B film forming device.

Claims (5)

It is a manufacturing method of photoelectric conversion element.
The photoelectric conversion element has a first main surface and a second main surface, and includes at least a first conductive semiconductor layer, a semiconductor substrate, and a second conductive semiconductor layer in this order.
The manufacturing method is a manufacturing method using an in-line film forming apparatus, and includes a first conductive semiconductor forming step, a second conductive film forming chamber passing step, and a first conductive film forming chamber passing step. Including a second conductive semiconductor layer forming step,
The in-line type film forming apparatus includes a first transport closing path, a second transport closing path, a first conductive type film forming chamber, and a second conductive type film forming chamber.
The first transport closed path is a closed path for forming a film on the first main surface side of the photoelectric conversion element.
The second transport closed path is a closed path for forming a film on the second main surface side of the photoelectric conversion element.
In the first conductive film forming chamber, a part of the first transport closing path and a part of the second transport closing path are arranged.
In the second conductive type film forming chamber, another part of the first conveying type closed circuit and another part of the second conveying type closing path are arranged and connected in series with the first conductive type film forming chamber.
In the first conductive semiconductor layer forming step, in the first conductive film forming chamber, the first conductive semiconductor layer is formed on the first main surface side of the semiconductor substrate arranged in the first transport closed path. And
In the second conductive film forming chamber passing step, the semiconductor substrate arranged in the first transport closed path passes through the second conductive film forming chamber in a state where the first main surface side is not formed.
In the step of passing through the first conductive film forming chamber, the semiconductor substrate arranged in the second transport closed path passes through the first conductive film forming chamber in a state where the second main surface side is not formed.
In the second conductive semiconductor layer forming step, in the second conductive film forming chamber, the second conductive semiconductor layer is formed on the second main surface side of the semiconductor substrate arranged in the second transport closed path. To do,
A method for manufacturing a photoelectric conversion element. After performing the first conductive type semiconductor layer forming step and the second conductive type film forming chamber passing step,
The semiconductor substrate arranged in the first transport closure further includes a step of being transferred to the second transport closure so that the second main surface side is exposed.
After performing the step of being transferred to the second transport closed circuit, the first conductive type film forming chamber passing step and the second conductive type semiconductor layer forming step are performed.
The method for manufacturing a photoelectric conversion element according to claim 1. After performing the first conductive type film forming chamber passing step and the second conductive type semiconductor layer forming step,
The semiconductor substrate arranged in the second transport closure further includes a step of being transferred to the first transport closure so that the first main surface side is exposed.
After performing the step of being transferred to the first transport closed circuit, the first conductive type semiconductor layer forming step and the second conductive type film forming chamber passing step are performed.
The method for manufacturing a photoelectric conversion element according to claim 1. The first conductive type semiconductor layer forming step and the first conductive type film forming chamber passing step are performed within the same period.
The method for manufacturing a photoelectric conversion element according to any one of claims 1 to 3. The second conductive film forming chamber passing step and the second conductive semiconductor layer forming step are performed within the same period.
The method for manufacturing a photoelectric conversion element according to any one of claims 1 to 4.

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