JP6697118B2 - Film forming apparatus, film forming method, and solar cell manufacturing method - Google Patents

Description

  The present invention relates to a technique of a film forming apparatus that forms a film on both surfaces of a substrate in a vacuum, and particularly to a technique of forming a transparent conductive oxide film on both surfaces of a substrate of a heterojunction solar cell.

  In recent years, solar cells have been put to practical use as clean and safe energy sources, and among them, attention has been paid to heterojunction solar cells.

FIG. 19 is a sectional view showing a schematic configuration of a general heterojunction solar cell.
As shown in FIG. 19, this heterojunction solar cell 100 has an i-type amorphous silicon layer 102, a p-type amorphous silicon layer 103, and a p-type amorphous silicon layer 103 on one surface (sunlight side) of an n-type crystalline silicon substrate 101. A first transparent conductive oxide film 104 and an electrode layer 105 are sequentially formed, and an i-type amorphous silicon layer 106, an n-type amorphous silicon layer 107, and a second layer are formed on the other surface of the n-type crystalline silicon substrate 101. The transparent conductive oxide film 108 and the electrode layer 109 are sequentially formed.

  Heterojunction solar cells have a higher conversion efficiency and a lower silicon consumption than conventional crystalline solar cells because the power generation loss at the interface can be significantly reduced by passivating the silicon wafer to the amorphous silicon layer. There are advantages such as

  In addition, the heterojunction solar cell has an advantage that it can achieve high power generation efficiency because it can generate power on both sides with the n-type crystalline silicon substrate sandwiched therebetween.

  However, the heterojunction solar cell has a problem due to the presence of transparent conductive oxide films made of, for example, indium oxide on both sides of the n-type crystalline silicon substrate.

  That is, the transparent conductive oxide film on the light-receiving surface side is required to have a particularly low resistance value and a high light transmittance, and this high light transmittance is required not only in the visible light region but also in the near infrared region. High carrier mobilities are required to achieve.

  Conventionally, as a method for obtaining a high carrier mobility, it is known to use a sputtering gas containing hydrogen when forming a transparent conductive oxide film by a sputtering method.

  This contributes to increase the mobility of carriers by forming larger crystal grains and reducing the crystal grain boundaries that cause carrier trapping.

  In the process of obtaining high carrier mobility, annealing is performed on an amorphous film immediately after film formation by sputtering, and the transparent conductive oxide is crystallized while the grains are enlarged, resulting in high carrier mobility. Be done.

  In such a conventional technique, the amorphous film is annealed by using the heat history when the electrode of the crystalline silicon solar cell is formed by firing. However, the firing temperature and firing time of the electrode are It is difficult to form a high-quality and uniform transparent conductive oxide film because it depends on the component.

  Also, when the annealing temperature is low or the annealing time is insufficient, the original ability of the transparent conductive oxide film is not fully exerted, and as a result, the power generation efficiency of the crystalline silicon solar cell decreases. There was a problem that it would end up.

JP, 2011-146528, A

  The present invention has been made in view of the above problems of the conventional technique, and an object thereof is to provide a pass-type film forming apparatus using a plurality of substrate holders, for example, in a heterojunction solar cell. It is an object of the present invention to provide a technique for forming a high-quality and uniform transparent conductive oxide film on both surfaces of a substrate to be used.

The present invention, which has been made to achieve the above object, includes a vacuum chamber capable of transporting a substrate along a transport path, and a first chamber provided in the vacuum chamber for forming a film on a first surface of the substrate. A first film forming region having a sputtering source, and an amorphous state formed on the first surface of the substrate in the first film forming region on the downstream side in the transport direction. A first vacuum annealing treatment mechanism for performing a vacuum annealing treatment on the first sputtered film, and a second sputtering source provided in the vacuum chamber for forming a film on the second surface of the substrate. Second film formation region and a second sputter film in an amorphous state, which is provided on the downstream side in the transport direction of the second film formation region and is formed on the second surface of the substrate in the second film formation region. It has a second vacuum annealing processing mechanism for performing a vacuum annealing process on the a first vacuum annealing mechanism, between the second film formation region, the first vacuum annealing mechanism The film forming apparatus is provided with an annealing accelerating vacuum annealing mechanism that further performs a vacuum annealing process on the first sputtered film on the first surface of the substrate that has been vacuum annealed by .
The present invention relates to a vacuum chamber in which a single vacuum atmosphere is formed, and a first film forming region provided in the vacuum chamber and having a first sputtering source for forming a film on a first surface of a substrate. A second film formation region provided in the vacuum chamber and having a second sputtering source for forming a film on the second surface of the substrate, and a projection shape on the vertical plane formed in a series of annular shapes And has a transport path provided so as to pass through the first and second film forming regions and an opening through which the first and second surfaces of the substrate are exposed, and holds the substrate in a horizontal state. A substrate holder transport mechanism for transporting the substrate holder along the transport path, wherein the substrate holder transport mechanism is configured to pass the substrate holder through the first film formation region. A first transport unit that transports in the transport direction, and a second transport that transports the substrate holder in the second transport direction opposite to the first transport direction so as to pass through the second film formation region. And a transport fold back unit that folds and transports the substrate holder from the first transport unit toward the second transport unit while maintaining the vertical relationship of the substrate holder. A first vacuum annealing treatment mechanism is provided on the downstream side of the first film formation region in the transport direction for performing a vacuum annealing treatment on the amorphous first sputtered film formed on the first surface of the substrate. At the same time, a vacuum annealing process is performed on the second sputtered film in the amorphous state formed on the second surface of the substrate on the downstream side of the second film formation region of the second transfer section in the transfer direction. A second vacuum annealing treatment mechanism is provided , and further, a vacuum is applied by the first vacuum annealing treatment mechanism to the second conveyance direction side of the second conveyance section with respect to the first conveyance direction. The film forming apparatus is provided with an annealing accelerating vacuum annealing processing mechanism that further performs a vacuum annealing process on the first sputtered film on the first surface of the annealed substrate.
The present invention is a film forming method for forming a film by sputtering on both surfaces of a substrate while moving the substrate in a vacuum, and forming a first sputtered film in an amorphous state on the first surface of the substrate. A first film forming step, a first vacuum annealing step of performing a vacuum annealing process on the first sputtered film on the first surface of the substrate, and an amorphous state on the second surface of the substrate. a second film forming step of forming a second sputter film, and a second vacuum annealing step of performing vacuum annealing process on the second sputter film on the second surface of the substrate possess, After the first vacuum annealing process of performing the vacuum annealing process on the first sputtered film in the amorphous state on the first surface of the substrate, the second sputtered film in the amorphous state is formed on the second surface of the substrate. The film forming method includes an annealing promoting step of further performing a vacuum annealing process on the first sputtered film on the first surface of the substrate before the second film forming step of forming the sputtered film .
The present invention is a film forming method for forming a film by sputtering on both surfaces of a substrate while moving the substrate in a vacuum, and forming a first sputtered film in an amorphous state on the first surface of the substrate. A first film forming step, a first vacuum annealing step of performing a vacuum annealing process on the first sputtered film on the first surface of the substrate, and an amorphous state on the second surface of the substrate. A second film forming step of forming a second sputtered film; a second vacuum annealing step of performing a vacuum annealing process on the second sputtered film on the second surface of the substrate; A second sputtered film in an amorphous state is formed on the second surface of the substrate after the first vacuum annealing process of performing a vacuum annealing process on the first sputtered film in the amorphous state on the first surface. Before the second film forming step of forming, an annealing promoting step of further performing a vacuum annealing process on the first sputtered film on the first surface of the substrate , wherein the substrate is n-type crystalline silicon. An i-type amorphous silicon layer and a p-type amorphous silicon layer are sequentially provided on the first surface of the substrate, and an i-type amorphous silicon layer and an n-type amorphous silicon layer are provided on the second surface of the n-type crystalline silicon substrate. In the film forming method, the substrates are sequentially provided, the first sputtered film is a first transparent conductive oxide film, and the second sputtered film is a second transparent conductive oxide film.
The present invention is a film forming method using the above-described film forming apparatus, wherein the first holder of the substrate holder conveying mechanism allows the substrate holder to pass through the first film forming region. A first film forming step of forming a first sputtered film on the first surface of the substrate held by the substrate holder by sputtering, the first film being transported along the transport path in the first transport direction; The first carrier of the substrate holder carrying mechanism carries the substrate holder in the first carrying direction along the carrying path, with respect to the first sputtered film on the first surface of the substrate. A first vacuum annealing step of performing a vacuum annealing process by the first vacuum annealing process mechanism, and the transfer path in a state in which the substrate holder is maintained in a vertical relationship by a transfer folding portion of the substrate holder transfer mechanism. A step of folding the substrate holder from the first carrier portion toward the second carrier portion and carrying the substrate holder along the carrier path by a second carrier portion of the substrate holder carrier mechanism. With respect to the first sputtered film on the first surface of the substrate that has been transported in the second transport direction and has been vacuum-annealed by the first vacuum annealing processing mechanism, the annealing annealing vacuum annealing processing mechanism is used. Further, an annealing accelerating step of performing a vacuum annealing process, and a second transport unit of the substrate holder transport mechanism configured to move the substrate holder through the second film formation region so as to pass the second path along the second path. A second film forming step of forming a second sputtered film on the second surface of the substrate held by the substrate holder by sputtering, and a second step of the substrate holder conveying mechanism. The substrate holder is transported in the second transport direction along the transport path by the transport unit of the second vacuum annealing mechanism for the second sputtered film on the second surface of the substrate. And a second vacuum annealing treatment step in which the vacuum annealing treatment is performed .
The present invention is a method for manufacturing a solar cell using the film forming apparatus described above, wherein an i-type amorphous silicon layer and a p-type amorphous silicon layer are formed on the first surface of an n-type crystalline silicon substrate as the substrate. A substrate is provided in which the i-type amorphous silicon layer and the n-type amorphous silicon layer are sequentially provided on the second surface of the n-type crystalline silicon substrate, and the first transport of the substrate holder transport mechanism is performed. On the first surface of the substrate held by the substrate holder, the substrate holder being conveyed in the first conveying direction along the conveying path so as to pass through the first film formation region by a unit. A step of forming a first transparent conductive oxide film in an amorphous state by sputtering on the substrate holder, and a first carrier part of the substrate holder carrier mechanism for moving the substrate holder along the carrier path in the first carrier direction. A first vacuum annealing treatment step of carrying out vacuum annealing treatment to the first transparent conductive oxide film in the amorphous state on the first surface of the substrate by the first vacuum annealing treatment mechanism, A step of folding back and transporting the substrate holder along the transport path from the first transporting portion toward the second transporting portion in a state in which the transporting and folding portion of the substrate holder transporting mechanism maintains the vertical relationship. And the second holder of the substrate holder transfer mechanism transfers the substrate holder in the second transfer direction along the transfer path, and is vacuum annealed by the first vacuum annealing processing mechanism. An annealing promotion step of further performing a vacuum annealing treatment on the first sputtered film on the first surface of the substrate by the annealing promotion vacuum annealing treatment mechanism, and a second conveyance section of the substrate holder conveyance mechanism. The substrate holder is conveyed in the second conveyance direction along the conveyance path so as to pass through the second film formation region, and sputtering is performed on the second surface of the substrate held by the substrate holder. Forming a second transparent conductive oxide film in an amorphous state by means of: and carrying the substrate holder in the second carrying direction along the carrying path by the second carrying part of the substrate holder carrying mechanism. And a second vacuum annealing treatment step of subjecting the second transparent conductive oxide film in the amorphous state on the second surface of the substrate to the vacuum annealing treatment by the second vacuum annealing treatment mechanism. It is a manufacturing method of a battery .

  In the present invention, the first vacuum annealing treatment is performed on the first sputtered film (for example, the first transparent conductive oxide film) in an amorphous state formed on the first surface of the substrate in vacuum. Since the second vacuum annealing process is performed on the second sputtered film (for example, the second transparent conductive oxide film) in the amorphous state formed on the second surface of the substrate, The carrier mobility can be improved by enlarging the crystal grains of the first and second transparent conductive oxide films in a crystalline state, and thus, for example, it is possible to improve the mobility on both sides of the substrate used for the heterojunction solar cell. It is possible to form a transparent conductive oxide film of uniform quality, and since crystallization progresses faster in vacuum annealing than in atmospheric annealing, it is possible to improve the efficiency of film formation and annealing. it can.

In addition , after performing the first vacuum annealing treatment on the first sputtered film on the first surface of the substrate and before forming the second sputtered film in an amorphous state on the second surface of the substrate, the substrate by further performing vacuum annealing process on the first sputter film on the first surface of the can to facilitate the progress of some degree crystallization of the first sputter film in an amorphous state in which crystallization has progressed, this As a result, it is possible to improve the carrier mobility of the first sputtered film in the crystalline state on the first surface of the substrate. Transparent conductive oxide film can be formed.

Schematic configuration diagram showing the entire embodiment of a film forming apparatus according to the present invention (A) (b): It shows the basic configuration of the substrate holder transporting mechanism and the direction changing mechanism in the present embodiment. FIG. 2 (a) is a plan view and FIG. 2 (b) is a front view. 3A and 3B show the structure of the substrate holder used in the present embodiment. FIG. 3A is a plan view and FIG. 3B is a side view. The front view which shows the structure of the direction change mechanism in this Embodiment. (A)-(d): Sectional process drawings showing the method for forming the transparent conductive oxide film in the present embodiment. Explanatory diagram showing the operation of the film forming apparatus of the present embodiment (Part 1) Explanatory diagram showing the operation of the film forming apparatus of the present embodiment (Part 2) Explanatory diagram showing the operation of the film forming apparatus of the present embodiment (Part 3) (A) (b): Explanatory drawing which shows operation | movement of the board | substrate holder conveyance mechanism in this Embodiment (the 1). (A)-(c): Explanatory drawing which shows operation | movement of the board | substrate holder conveyance mechanism in this Embodiment, and a direction change mechanism (the 1). (A)-(c): Explanatory drawing which shows operation | movement of the board | substrate holder conveyance mechanism in this Embodiment, and a direction change mechanism (the 2). (A) (b): Explanatory drawing which shows operation | movement of the board | substrate holder conveyance mechanism in this Embodiment (the 3). Explanatory drawing (4) which shows operation | movement of the film-forming apparatus of this Embodiment. Explanatory drawing (5) which shows operation | movement of the film-forming apparatus of this Embodiment. Explanatory drawing (6) which shows operation | movement of the film-forming apparatus of this Embodiment. Front view showing the configuration of another example of the direction changing mechanism (A)-(c): Explanatory drawing which shows operation | movement of the other example of a board | substrate holder conveyance mechanism and a direction change mechanism (the 1). (A)-(c): Explanatory drawing which shows operation | movement of the other example of a board | substrate holder conveyance mechanism and a direction change mechanism (the 2). Sectional drawing which shows the schematic structure of a general heterojunction solar cell. (A) and (b): SEM photographs showing the surface and cross section of the indium oxide film of the example. (A) and (b): SEM photographs showing the surface and cross section of the indium oxide film of the comparative example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an entire embodiment of a film forming apparatus according to the present invention.

  2 (a) and 2 (b) show the basic structure of the substrate holder transporting mechanism and the direction changing mechanism in the present embodiment. FIG. 2 (a) is a plan view and FIG. 2 (b) is a front view. It is a figure.

  Further, FIGS. 3A and 3B show the structure of the substrate holder used in the present embodiment. FIG. 3A is a plan view and FIG. 3B is a side view.

  Furthermore, FIG. 4 is a front view showing the configuration of the direction changing mechanism in the present embodiment.

  As shown in FIG. 1, the film forming apparatus 1 of the present embodiment has a vacuum chamber 2 connected to a vacuum evacuation apparatus 1a having, for example, a turbo molecular pump, in which a single vacuum atmosphere is formed. ..

  Inside the vacuum chamber 2, a substrate holder transport mechanism 3 that transports a substrate holder 11 described later along a transport path is provided.

  The substrate holder transport mechanism 3 is configured to continuously transport the plurality of substrate holders 11 holding the substrate 10.

  Here, the substrate holder transport mechanism 3 includes, for example, circular first and second drive wheels 31 and 32 having the same diameter, which are operated by a rotational drive force transmitted from a drive mechanism (not shown), such as a sprocket. The first and second drive wheels 31 and 32 are arranged with a predetermined distance in a state where their respective rotation axes are parallel to each other.

  A series of transport drive members 33, such as chains, are bridged between the first and second drive wheels 31 and 32.

  Further, the structure in which the transport drive member 33 is bridged over the first and second drive wheels 31 and 32 is arranged in parallel at a predetermined distance (see FIG. 2A), and the pair of transports is carried. The drive member 33 forms a series of annular transport paths with respect to the vertical plane.

  In the present embodiment, the substrate holder 11 is moved to the upper part of the transfer driving member 33 constituting the transfer path from the first drive wheel 31 toward the second drive wheel 32 to transfer the substrate holder 11 to the first transfer wheel. An outward-side transport unit (first transport unit) 33a that transports in the direction P1 is formed, and the transport direction of the substrate holder 11 is folded back and opposite by the transport drive member 33 around the second drive wheel 32. A turn-back portion 33b that changes the direction is formed. Further, the substrate holder 11 is moved to the lower portion of the transport driving member 33 by moving from the second driving wheel 32 toward the first driving wheel 31. A return path side transport section (second transport section) 33c for transporting in the second transport direction P2 is formed.

  In the substrate holder transporting mechanism 3 of the present embodiment, a forward transporting section 33a located above each transport driving member 33 and a return transporting section 33c located below each transport driving member 33 face each other. However, they are configured to overlap in the vertical direction.

  In addition, the substrate holder transport mechanism 3 includes a substrate holder introducing section 30A for introducing the substrate holder 11, a transport folding section 30B for folding and transporting the substrate holder 11, and a substrate holder for discharging the substrate holder 11. A container discharge unit 30C is provided.

  Here, a direction changing mechanism 40, which will be described later, is provided in the vicinity of the transport folding section 30B.

  In the vacuum chamber 2, first and second film forming regions 4 and 5 are provided.

  In the present embodiment, in the vacuum chamber 2, the first film formation region 4 having the first sputtering source 4T is provided, for example, above the substrate holder transport mechanism 3, and the substrate holder transport mechanism 3 is A second film formation region 5 having a second sputtering source 5T is provided below.

  In the present embodiment, the forward path side transport part 33a of the above-described transport drive member 33 is configured to linearly pass through the first film formation region 4 in the horizontal direction, and the return path side transport part 33c is configured as described above. It is configured to pass through the second film forming region 5 linearly in the horizontal direction.

  Then, when the substrate holder 11 passes through the forward path side transport section 33a and the backward path side transport section 33c of the transport drive members 33 that form the transport path, the plurality of substrates 10 held by the substrate holder 11 (see FIG. 2). (See (a)) is conveyed in a horizontal state.

  As shown in FIG. 1, in the present embodiment, a first vacuum annealing processing mechanism 21 is provided in the vacuum chamber 2 in the vicinity of the first transport direction P1 side of the first film formation region 4. There is.

  Further, a second vacuum annealing treatment mechanism 22 is provided in the vacuum chamber 2 near the second transport direction P2 side of the second film formation region 5.

  As the first and second vacuum annealing treatment mechanisms 21 and 22, for example, a radiation (radiation) electrothermal type heater such as a sheath heater can be preferably used.

  Further, between the first and second film forming regions 4 and 5, for example, below the second drive wheel 32, a vacuum annealing treatment mechanism 23 for annealing promotion is provided.

  As the vacuum anneal processing mechanism 23 for accelerating the anneal, similarly to the first and second vacuum anneal processing mechanisms 21 and 22, for example, a radiation (radiation) electrothermal type heater such as a sheath heater can be preferably used.

  On the other hand, a cooling mechanism 25 is provided on the second transport direction P2 side of the annealing accelerating vacuum annealing mechanism 23 and near the first transport direction P1 side of the second film formation region 5.

  As the cooling mechanism 25, for example, radiation (radiation) of a structure in which copper having good thermal conductivity is cooled using a cooling medium or a plate in which cooling water is circulated through a metal plate through a pipe ) Method can be preferably used.

  For transferring and receiving the substrate holder 11 to and from the substrate holder transfer mechanism 3 at a position near the substrate holder transfer mechanism 3 in the vacuum chamber 2, for example, at a position adjacent to the first drive wheel 31. A substrate loading / unloading mechanism 6 is provided.

  The substrate loading / unloading mechanism 6 of the present embodiment has a support portion 62 provided at the tip (upper) end of a drive rod 61 that is driven by the elevating mechanism 60 in the vertical vertical direction, for example.

  In the present embodiment, the transfer robot 64 is provided on the support portion 62 of the substrate loading / unloading mechanism 6, and the substrate holder 11 is supported on the transfer robot 64 to move the substrate holder 11 in the vertical and vertical directions. The transfer robot 64 transfers and receives the substrate holder 11 to and from the substrate holder transfer mechanism 3.

  In this case, as will be described later, the substrate holder 11 is delivered from the substrate loading / unloading mechanism 6 to the substrate holder introducing portion 30A of the outward transport section 33a of the substrate holder transport mechanism 3 (this position is referred to as “substrate holder delivery position”). In addition, the substrate holder 11 is taken out from the substrate holder discharge part 30C of the backward path side carrier part 33c of the substrate holder carrier mechanism 3 (this position is referred to as a "substrate holder take-out position"). Has been done.

  A substrate loading / unloading chamber 2A for loading the substrate 10 into the vacuum chamber 2 and unloading the substrate 10 from the vacuum chamber 2 is provided, for example, in the upper part of the vacuum chamber 2.

  The substrate loading / unloading chamber 2A is provided, for example, at a position above the support portion 62 of the substrate loading / unloading mechanism 6 via the communication port 2B. For example, the substrate loading / unloading chamber 2A can be opened and closed at the upper portion of the substrate loading / unloading chamber 2A. A lid portion 2a is provided.

  Then, as will be described later, the pre-deposition substrate 10a loaded into the substrate loading / unloading chamber 2A is delivered to and held by the substrate holder 11 on the transfer robot 64 of the support portion 62 of the substrate loading / unloading mechanism 6, and The substrate 10b after film formation is carried out from the substrate holder 11 on the transfer robot 64 of the support portion 62 of the substrate loading / unloading mechanism 6 to the atmosphere outside the vacuum chamber 2, for example.

  In the case of the present embodiment, in order to isolate the atmosphere in the substrate loading / unloading chamber 2A and the vacuum chamber 2 when loading / unloading the substrate 10 to / from the upper edge of the support portion 62 of the substrate loading / unloading mechanism 6. A seal member 63 such as an O-ring is provided.

  In this case, the support portion 62 of the substrate loading / unloading mechanism 6 is raised toward the substrate loading / unloading chamber 2A side, and the seal member 63 on the support portion 62 is brought into close contact with the inner wall of the vacuum chamber 2 to close the communication port 2B. The atmosphere in the substrate loading / unloading chamber 2A is isolated from the atmosphere in the vacuum chamber 2.

  As shown in FIGS. 2 (a) and 2 (b), a plurality of first drive units 36 are provided at predetermined intervals in the pair of transfer drive members 33 of the substrate holder transfer mechanism 3 of the present embodiment. It is provided so as to project to the outside of the transport drive member 33.

  The first drive portion 36 is formed in, for example, a J-hook shape (a shape in which a groove is formed such that the height of the protrusion on the downstream side in the transport direction is lower than the height of the protrusion on the upstream side in the transport direction). The substrate holder 11 supported by the substrate holder support mechanism 18 described in (1) is brought into contact with the later-described first driven shaft 12 of the substrate holder 11 to drive the substrate holder 11 in the first or second transport direction P1, P2. Is configured to.

  Inside the pair of transport driving members 33, a pair of substrate holder support mechanisms 18 that support the substrate holder 11 to be transported are provided.

  The substrate holder support mechanism 18 is composed of a rotatable member such as a plurality of rollers, and is provided near the transport drive member 33.

  In the present embodiment, the forward path side substrate holder support mechanism 18a is provided near the forward path side transfer section 33a of the transfer drive member 33, and the return path side substrate is provided near the backward path side transfer section 33c of the transfer drive member 33. A holder support mechanism 18c is provided and arranged so as to support both edges of the lower surface of the substrate holder 11 being conveyed.

  The forward path side substrate holder support mechanism 18a is provided up to the vicinity of the entrance of the first direction change path 51 of the direction change mechanism 40 described later, and the backward path side substrate holder support mechanism 18c is the direction change mechanism described later. It is provided up to the vicinity of the outlet of the second direction changing path 52 of 40.

  The substrate holder 11 used in the present embodiment is for performing vacuum processing on both surfaces of the substrate 10, and is made of a tray-shaped member having an opening.

  As shown in FIGS. 2A and 3A, the substrate holder 11 according to the present embodiment is formed in, for example, a long rectangular flat plate shape, and its longitudinal direction, that is, the first and second conveyance directions. A plurality of holding portions 14 that hold, for example, a plurality of rectangular substrates 10 arranged in a line in a direction orthogonal to P1 and P2, respectively, are provided.

  Here, each holding portion 14 is provided with, for example, a rectangular opening in which both surfaces of each substrate 10 are exposed in the same size and shape as each substrate 10, and each substrate 10 is held by a holding member (not shown). Is configured to be held horizontally.

  In the present invention, although not particularly limited, from the viewpoint of reducing the installation area and improving the processing capacity, the substrate holder 11 has a direction orthogonal to the transport direction as in the present embodiment. In addition, it is preferable that the plurality of substrates 10 are arranged in a line and held respectively.

  However, from the viewpoint of improving the processing efficiency, it is possible to arrange the plurality of substrates 10 in a plurality of rows in a direction orthogonal to the transport direction.

  On the other hand, the first driven shafts 12 are provided at both ends of the substrate holder 11 in the longitudinal direction on the upstream side in the first transport direction P1, and on the downstream side in the first transport direction P1. A second driven shaft 13 is provided at each end.

  Each of the first and second driven shafts 12 and 13 is formed in a circular cross section around a rotation axis extending in a direction orthogonal to the transport direction, that is, the longitudinal direction of the substrate holder 11.

  In the present embodiment, the dimension of the second driven shaft 13 is determined such that the length of the second driven shaft 13 is longer than the length of the first driven shaft 12.

  Specifically, as shown in FIG. 2A, when the substrate holder 11 is arranged in the substrate holder transport mechanism 3, the first driven shafts 12 on both sides of the substrate holder 11 are mounted on the substrate holder 11. The second driven shaft 13 contacts the first drive unit 36 of the transport mechanism 3 and contacts the second drive unit 46 described later when the substrate holder 11 is arranged in the direction changing mechanism 40 described later. The dimensions of the first and second driven shafts 12 and 13 are determined so that

  A pair of direction changing mechanisms 40 having the same configuration is provided on the downstream side of the pair of transport driving members 33 in the first transport direction P1.

  In the case of the present embodiment, the pair of direction changing mechanisms 40 are arranged at positions outside the pair of transport driving members 33 with respect to the first and second transport directions P1 and P2, respectively.

  Further, the pair of direction changing mechanisms 40 are provided such that the upstream side portion in the first transport direction P1 slightly overlaps the downstream side portion in the first transport direction P1 of each transport driving member 33. ..

  As shown in FIG. 4, the direction changing mechanism 40 of the present embodiment has a first guide member 41, a second guide member 42, and a third guide member 43, and these first to third guides are provided. The members 41 to 43 are arranged in this order from the upstream side in the first transport direction P1.

  In the present embodiment, the first to third guide members 41 to 43 are arranged at positions near the outer sides of the pair of transport driving members 33, respectively, and further outside the first to third guide members 41 to 43. The transport driving members 45, which will be described later, are arranged at positions near each other.

  In addition, in FIG. 2B, a part of the direction changing mechanism 40 is omitted, and the positional relationship between the members in the transport direction is illustrated by ignoring the overlapping relationship of the members.

  As shown in FIGS. 2A and 4, the first to third guide members 41 to 43 are, for example, plate-shaped members, and are provided in the vertical direction.

  Here, the portion of the first guide member 41 on the first transport direction P1 side is formed into a curved surface shape that is convex toward the first transport direction P1 side, and the second guide member 42 has a second curved surface shape. The portion on the transport direction P2 side is formed into a curved surface shape that is concave toward the first transport direction P1 side.

  The first and second guide members 41 and 42 have curved surfaces in which a portion of the first guide member 41 on the first transport direction P1 side and a portion of the second guide member 42 on the second transport direction P2 side are equal. The portions are formed in a shape, and these portions are closely arranged so as to face each other with a gap slightly larger than the diameter of the first driven shaft 12 of the substrate holder 11. A first direction changing path 51 that guides the first driven shaft 12 of the substrate holder 11 by this gap is provided.

  Further, the portion of the second guide member 42 on the first transport direction P1 side is formed into a curved surface shape that is convex toward the first transport direction P1 side, and the second transport of the third guide member 43 is performed. The portion on the direction P2 side is formed in a curved surface shape that is concave toward the first transport direction P1 side.

  The second and third guide members 42, 43 have curved surfaces in which a portion of the second guide member 42 on the first transport direction P1 side and a portion of the third guide member 43 on the second transport direction P2 side are equal. They are formed in a shape, and these portions are closely arranged so as to face each other with a gap slightly larger than the diameter of the second driven shaft 13 of the substrate holder 11. A second direction changing path 52 for guiding the second driven shaft 13 of the substrate holder 11 is provided by this gap.

  And in this Embodiment, the 1st direction change path 51 and the 2nd direction change path 52 are formed in the equivalent curved surface shape.

  Further, the horizontal distance of each part of the first and second direction changing paths 51, 52 is equal to the distance between the first and second driven shafts 12, 13 of the substrate holder 11. The dimensions are defined as follows.

  Further, in the present embodiment, the upper opening of the first direction changing path 51 serves as the entrance of the first driven shaft 12 of the substrate holder 11, and the height position thereof is the forward path substrate. The substrate holder 11 supported by the holder support mechanism 18a is arranged at a position lower than the height of the second driven shaft 13 (see FIG. 2B).

  Further, the opening on the lower side of the first direction change path 51 serves as the discharge port of the first driven shaft 12 of the substrate holder 11, and the height position thereof is the return path side substrate holder support mechanism 18c. The substrate holder 11 is supported by the second driven shaft 13 and is positioned higher than the height of the second driven shaft 13 (see FIG. 2B).

  Further, with respect to the second direction change path 52, the opening on the upper side thereof serves as the entrance of the second driven shaft 13 of the substrate holder 11, and the height position thereof is the forward side substrate holder support. The substrate holder 11 supported by the mechanism 18a is configured to have a position equivalent to the height position of the second driven shaft 13 (see FIG. 2B).

  On the other hand, the opening on the lower side of the second direction change path 52 serves as the discharge port of the second driven shaft 13 of the substrate holder 11, and the height position thereof is the return path side substrate holder support mechanism 18c. The substrate holder 11 is supported by the second driven shaft 13 and is positioned at the same height as the driven shaft 13 (see FIG. 2B).

  The direction changing mechanism 40 of the present embodiment has, for example, a pair of sprockets and a transport driving member 45 composed of a chain spanned by the pair of sprockets. It is configured to have an annular shape.

  The transport drive member 45 is configured such that the radius of curvature of the folded portion is equal to the radius of curvature of the folded portion 33b of the transport drive member 33 of the substrate holder transport mechanism 3.

  Further, the transport driving member 45 is driven so that the upper portion thereof moves in the first transport direction P1 and the lower portion thereof moves in the second transport direction P2.

  The transport drive member 45 is provided with a plurality of second drive portions 46 at predetermined intervals so as to project to the outside of the transport drive member 45.

  The second drive unit 46 has a recess formed on the outer side of the transport drive member 45, and the edge of the recess contacts the second driven shaft 13 of the substrate holder 11 to cause the substrate holder to move. 11 is configured to be supported and driven along the second turning path 52.

  Further, in the second drive unit 46 of the present embodiment, as will be described later, when the positions of the entrance and the exit of the second direction change path 52 are reached, the end portion on the recess side is the second end. The path of the transport drive member 45 and the dimensions of the second drive section 46 are set so as to retract from the direction change path 52 (see FIG. 2B).

  In the present embodiment, as will be described later, the transport drive member 33 of the substrate holder transport mechanism 3 so that the second drive unit 46 operates in synchronization with the first drive unit 36 of the substrate holder transport mechanism 3. And the operation of the transport driving member 45 of the direction changing mechanism 40.

  Then, in the present embodiment, the first holder 36 of the substrate holder transfer mechanism 3 drives the substrate holder 11 in the first transfer direction P1 to move the first and second driven shafts 12 and 13. When the substrate holder 11 is inserted into the first and second direction changing paths 51 and 52, the first and second drive units 36 and 46 maintain the vertical relationship, and the first and second driven units 36 and 46 are operated. The first and second drive parts 36, 46, and the first and second drive parts 36, 46 are supported so that the drive shafts 12, 13 move and are smoothly discharged from the first and second direction changing paths 51, 52. The shapes and dimensions of the second direction changing paths 51 and 52 are set respectively.

  On the other hand, below the first guide member 41 and the second guide member 42, in the vicinity of the discharge port of the first direction changing path 51, the substrate holder 11 is moved from the direction changing mechanism 40 to the substrate holder supporting mechanism 18. A delivery member 47 is provided for smoothly delivering to the return path side substrate holder support mechanism 18c.

  The transfer member 47 is, for example, an elongated member that extends in the horizontal direction, and has a rotary shaft 48 provided at a position below the backward path side substrate holder support mechanism 18c at an end portion thereof on the second transport direction P2 side. Is configured to rotate in the vertical direction. The portion of the delivery member 47 on the first transport direction P1 side is biased upward by an elastic member (not shown), for example.

  The elastic member used in the present invention is not particularly limited, but from the viewpoint of surely preventing buckling without increasing the number of parts, a torsion coil spring is used rather than a coil spring (for example, a compression coil spring). Preferably.

  An upper part of the transfer member 47 is continuous with the first direction changing path 51 at a portion in the vicinity of the discharge port of the first direction changing path 51 on the second conveyance direction P2 side, and the substrate holder support mechanism. A curved transfer portion 47a is provided so as to be continuous with the return path side substrate holder supporting mechanism 18c (see FIG. 2B).

  Further, on the upper part of the transfer member 47, an inclined surface 47b that is inclined downward toward the first transport direction P1 is provided at a portion on the first transport direction P1 side. The inclined surface 47b is provided at a height position facing the discharge port of the second direction changing path 52.

  Hereinafter, an example of the operation of the film forming apparatus 1 of the present embodiment and the film forming method will be described with reference to FIGS.

  5A to 5D are cross-sectional process charts showing the method for forming the transparent conductive oxide film in the present embodiment.

  As shown in FIG. 5A, the substrate 10a before film formation used in the present embodiment has an i layer on the first surface (the upper surface which is the light receiving surface in the present embodiment) of the n-type crystalline silicon substrate 10A. Type amorphous silicon layer 10B and a first conductivity type (for example, p type) amorphous silicon layer 10D are sequentially provided, and the second surface of the n-type crystalline silicon substrate 10A (the lower surface which is the reflection surface side in the present embodiment). An i-type amorphous silicon layer 10C and a second conductivity type (for example, n-type) amorphous silicon layer 10E are sequentially provided thereon.

  In the present embodiment, first, the seal member 63 on the support portion 62 of the substrate loading / unloading mechanism 6 is brought into close contact with the inner wall of the vacuum chamber 2 so that the atmosphere in the substrate loading / unloading chamber 2A is changed relative to the atmosphere in the vacuum chamber 2. After venting to atmospheric pressure in the isolated state, as shown in FIG. 6, the lid portion 2a of the substrate loading / unloading chamber 2A is opened.

  After that, the substrate 10a before film formation is mounted and held on the substrate holder 11 on the transport robot 64 of the support portion 62 of the substrate loading / unloading mechanism 6 by using a transport robot (not shown).

  Then, after closing the lid portion 2a of the substrate loading / unloading chamber 2A and evacuating to a predetermined pressure, the supporting portion 62 of the substrate loading / unloading mechanism 6 is moved to the substrate holder delivery position described above, as shown in FIG. The substrate holder 11 is lowered so that the height of the substrate holder 11 is at the same height as the forward path transporting portion 33a of the transporting drive member 33.

  Further, as shown in FIG. 8, the substrate holder 11 is arranged in the substrate holder introduction part 30A of the substrate holder transport mechanism 3 by the transport robot 64 provided on the support portion 62 of the substrate loading / unloading mechanism 6.

  In this case, as shown in FIG. 9A, the first driven shaft 12 of the substrate holder 11 is positioned so as to be arranged in the groove portion of the first drive unit 36, and the forward substrate holder support is performed. It is placed on the mechanism 18a.

  In this state, as shown in FIG. 9B, the outward path side transport portion 33a of the transport driving member 33 of the substrate holder transport mechanism 3 is moved in the first transport direction P1.

  As a result, the first drive shaft 36 of the substrate holder 11 is driven in the first transport direction P1 by the first drive unit 36 on the forward path transport unit 33a of the transport drive member 33, and the substrate holder 11 moves. The sheet is conveyed on the outward-side conveyance section 33a of the conveyance driving member 33 toward the conveyance folding section 30B.

  In this operation, when passing through the first film formation region 4 with respect to the first surface (upper surface) of the substrate 10a before film formation held by the substrate holder 11, a position above the substrate holder 11 is set. A film is formed by sputtering with the first sputtering source 4T.

  Specifically, as shown in FIG. 5B, the surface of the p-type amorphous silicon layer 10D of the substrate 10a before film formation is, for example, an n-type first transparent conductive oxide film (first Sputtered film) 10f is formed on the entire surface. At this point, the first transparent conductive oxide film 10f is a film in an amorphous state.

  In the case of the present invention, the material of the first transparent conductive oxide film 10f is not particularly limited, but it is preferable to use an indium oxide-based material which is a low resistance and light transmissive material, and more preferably. Is a material in which at least one or more kinds of metal oxides such as titanium oxide, zirconium oxide, tungsten oxide, cerium oxide, gallium oxide, and silicon oxide are added to indium oxide in a trace amount.

  After this film formation, before the substrate holder 11 reaches the transport folding section 30B of the substrate holder transport mechanism 3, the first vacuum annealing treatment mechanism 21 (see FIG. 1) described above makes the first transparent state in the amorphous state. The conductive oxide film 10f is heated to perform the first vacuum annealing treatment.

  In this case, the heating condition is preferably set to 180 ° C. or higher and 220 ° C. or lower.

  10 (a) to 10 (c) and 11 (a) to 11 (c) are explanatory views showing the operation of the substrate holder transport mechanism and the direction changing mechanism in the present embodiment.

  In the present embodiment, after the above-described film forming process, by moving the first drive unit 36 of the substrate holder transport mechanism 3 in the first transport direction P1, as shown in FIG. The substrate holder 11 that has reached the transport folding section 30B of the substrate holder transport mechanism 3 is further moved in the first transport direction P1, and the second driven shaft 13 of the substrate holder 11 is moved to the second direction of the direction changing mechanism 40. It is arranged at the entrance of the turning path 52 of the.

  In this case, the operation of the transport driving member 45 is controlled so that the second driving unit 46 of the direction changing mechanism 40 is located below the second driven shaft 13 of the substrate holder 11.

  Then, the transport drive member 33 of the substrate holder transport mechanism 3 is driven to move the first drive section 36 in the first transport direction P1, and the transport drive member 45 of the direction changing mechanism 40 is driven to drive the second drive unit 45. The driving unit 46 of is moved in the first transport direction P1. In this case, the operations of the first drive unit 36 and the second drive unit 46 are controlled so as to be synchronized.

  As a result, as shown in FIG. 10B, the first and second driven shafts 12 and 13 of the substrate holder 11 are supported and driven by the first and second drive portions 36 and 46, respectively, And the second direction change paths 51 and 52, respectively, moving downward.

  In this process, the first driven shaft 12 of the substrate holder 11 does not come into contact with each other in the first direction changing path 51 at the same time, but the first guide member 41 and the second guide member 42 do not contact each other. The edge of the second driven member 13 does not contact the edge of the second guide member 42 and the edge of the third guide member 43 at the same time in the second turning path 52. Although in contact, the substrate holder 11 maintains the vertical relationship.

  Then, from the vicinity where the first and second driven shafts 12 and 13 have passed through the middle portions of the first and second direction changing paths 51 and 52, respectively, from the vicinity of the first and second driven shafts 12 and 13, The carrying direction is changed to the second carrying direction P2 opposite to the first carrying direction P1 while maintaining the vertical relationship of the substrate holder 11.

  In this process, the first driven shaft 12 of the substrate holder 11 does not come into contact with each other in the first direction changing path 51 at the same time, but the first guide member 41 and the second guide member 42 do not contact each other. The edge of the second driven member 13 does not contact the edge of the second guide member 42 and the edge of the third guide member 43 at the same time in the second turning path 52. Contact.

  Further, when the transport drive member 33 of the substrate holder transport mechanism 3 and the transport drive member 45 of the direction changing mechanism 40 are continuously driven, as shown in FIG. 10C, the first driven shaft of the substrate holder 11 is driven. 12 is arranged at a position above the transfer member 47 via the discharge port of the first direction changing path 51 and the transfer portion 47a of the transfer member 47, and the second driven shaft 13 of the substrate holder 11 is The substrate holder 11 is arranged at the position of the discharge port of the second direction changing path 52, and then the substrate holder 11 is attached to the return path side substrate holder supporting mechanism 18c of the substrate holder supporting mechanism 18 as shown in FIG. Delivered.

  At the time point shown in FIG. 10C, the second drive unit 46 of the direction changing mechanism 40 and the second driven shaft 13 of the substrate holder 11 are not in contact with each other, and the substrate holder 11 holds the substrate holder. The first drive unit 36 of the container transport mechanism 3 is driven by the contact between the first driven shaft 12 and the first driven shaft 12 to move in the second transport direction P2.

  Then, by further driving the transport driving member 33 of the substrate holder transport mechanism 3, the second driven shaft 13 of the substrate holder 11 is moved to the inclined surface 47 b of the delivery member 47 as shown in FIG. 11B. Upon contact, the transfer member 47 rotates downward about the rotation shaft 48, and as shown in FIG. 11C, the second driven shaft 13 of the substrate holder 11 passes above the transfer member 47. Substrate holder 11 moves in the second transport direction P2.

  The delivery member 47 returns to the original position by the urging force of the elastic member (not shown) after this process.

  After that, as shown in FIG. 12A, the backward path side transport unit 33c of the transport drive member 33 of the substrate holder transport mechanism 3 is moved in the second transport direction P2, and the first drive unit 36 is moved in the same direction. By driving, the substrate holder 11 is conveyed toward the substrate holder discharge unit 30C.

  In this case, since the temperature of the substrate 10a before film formation is lowered when passing through the direction changing mechanism 40, the substrate holder 11 is conveyed when the substrate holder 11 is conveyed toward the substrate holder discharge unit 30C. The second surface (lower surface) of the substrate 10a before film formation held by 11 is heated by the above-described annealing annealing vacuum annealing mechanism 23 (see FIG. 1), and the first transparent conductive oxide film in an amorphous state. 10f is further heated to perform vacuum annealing treatment.

  In this case, the heating condition is preferably set to 180 ° C. or higher and 220 ° C. or lower. Then, this annealing treatment promotes the progress of crystallization of the transparent conductive oxide film 10f. In addition, the time of the above-mentioned first vacuum annealing process and this annealing process for promoting annealing is about several minutes in total.

  Then, in order to prevent the substrate temperature from rising excessively, the cooling mechanism 25 (see FIG. 1) described above cools the substrate 10a as necessary.

  After that, when passing through the second film formation region 5 shown in FIG. 1, the substrate is held on the surface of the n-type amorphous silicon layer 10E on the second surface (lower surface) of the substrate 10a held by the substrate holder 11. For example, an n-type second transparent conductive oxide film (second sputtered film) 10g is entirely formed by sputtering by a second sputter source 5T located below the container 11 (see FIG. 5C). . At this point, the second transparent conductive oxide film 10g is an amorphous film.

  When forming the second transparent conductive oxide film 10g, a mask not shown is used so as not to short-circuit with the first transparent conductive oxide film 10f formed on the first surface of the substrate 10a. It is preferable to form the edge of the first transparent conductive oxide film 10f so as to be located slightly inward of the edge of the substrate 10a.

  In the case of the present invention, the material of the second transparent conductive oxide film 10g is not particularly limited, but similar to the above-mentioned first transparent conductive oxide film 10f, a low resistance and light transmissive material. It is preferable to use an indium oxide-based material, and more preferably, at least one metal oxide such as titanium oxide, zirconium oxide, tungsten oxide, cerium oxide, gallium oxide, or silicon oxide is added to indium oxide in a trace amount. It was done.

  In the present embodiment, when the second transparent conductive oxide film 10g in the amorphous state is formed by sputtering, the amorphous state in which the crystallization on the first surface of the substrate 10a has progressed to some extent by the heat of the plasma due to the discharge Crystallization of the first transparent conductive oxide film 10f further progresses and is almost completed. Then, as shown in FIG. 5C, this forms the first transparent conductive oxide film 10F in a crystalline state.

  Furthermore, in the present embodiment, after the above-described film formation, before the substrate holder 11 reaches the substrate holder discharge part 30C of the substrate holder transport mechanism 3, the above-mentioned second vacuum annealing treatment mechanism 22 (FIG. The second transparent conductive oxide film 10g in the amorphous state is heated according to (1) to perform a vacuum annealing process.

  In this case, the heating condition is preferably set to 180 ° C. or higher and 220 ° C. or lower.

  By this second annealing treatment, the second transparent conductive oxide film 10g in the amorphous state is crystallized to form the second transparent conductive oxide film 10G in the crystalline state. As a result, as shown in FIG. Then, the substrate 10b after film formation is obtained.

  Then, after the substrate holder 11 moving in the second transport direction P2 reaches the substrate holder discharge portion 30C, the backward path transport portion 33c of the transport driving member 33 is moved in the second transport direction P2, and When the drive unit 36 of the first drive unit 36 is driven in the same direction as the first drive unit 36 is inclined from the vertical direction with the movement of the backward path side transport unit 33c, as shown in FIG. The driving part 36 of the substrate and the first driven shaft 12 are disengaged from each other, and the substrate holder 11 loses its propulsive force. Therefore, the transfer robot 64 of the substrate loading / unloading mechanism 6 shown in FIG. Is moved in the second transport direction P2 to be separated from the first drive unit 36.

  Further, the transfer robot 64 of the substrate loading / unloading mechanism 6 is used to take out the substrate holder 11, and the substrate holder 11 is placed on the support portion 62 together with the transport robot 64, as shown in FIG.

  After that, as shown in FIG. 14, the support part 62 of the substrate loading / unloading mechanism 6 is raised, and the seal member 63 on the support part 62 is brought into close contact with the inner wall of the vacuum chamber 2 so that the substrate is exposed to the atmosphere in the vacuum chamber 2. Venting is performed up to atmospheric pressure in a state where the atmosphere in the carry-in / carry-out chamber 2A is isolated.

  Then, as shown in FIG. 15, the lid 2a of the substrate loading / unloading chamber 2A is opened, and the substrate 10b after film formation is taken out from the substrate holder 11 to the atmosphere by using a transfer robot (not shown).

  After that, by returning to the state shown in FIG. 6 and repeating the above-described operation, the above-described film formation and annealing treatment are performed on both surfaces of each of the plurality of substrates 10a before film formation.

  The surface electrode of the heterojunction solar cell may be formed by applying, for example, a silver paste by screen printing on the above-described first and second transparent conductive oxide films 10F and 10G in the crystalline state, and firing the paste. it can.

  In the present embodiment described above, the first vacuum is applied to the first transparent conductive oxide film 10f in the amorphous state formed on the first surface of the substrate 10a before film formation in vacuum. After performing the annealing process, the second vacuum annealing process is performed on the second transparent conductive oxide film 10g in the amorphous state formed on the second surface of the substrate 10a. The mobility of carriers can be improved by enlarging the crystal grains of the first and second transparent conductive oxide films 10F and 10G in the crystalline state of, thereby, for example, a substrate used for a heterojunction solar cell. High-quality and uniform transparent conductive oxide film can be formed on both sides, and vacuum anneal improves crystallization faster than anneal in air, improving the efficiency of film formation and anneal. Can be made.

  In this case, after performing the first vacuum annealing treatment on the first transparent conductive oxide film 10f on the first surface of the substrate 10a, the second amorphous state film is formed on the second surface of the substrate 10a. If the first transparent conductive oxide film 10f in the amorphous state on the first surface of the substrate 10a is further vacuum-annealed before forming the transparent conductive oxide film 10g, the first The crystallization of the transparent conductive oxide film 10f can be accelerated, which further improves the carrier mobility of the crystalline first transparent conductive oxide film 10F on the first surface of the substrate 10a. Therefore, for example, a high-quality and uniform transparent conductive oxide film can be formed on the light-receiving surface side of the substrate used for the heterojunction solar cell.

  FIG. 16 is a front view showing the configuration of another example of the direction changing mechanism.

  As shown in FIG. 16, the direction changing mechanism 40A of the present example has a delivery member 49 that replaces the delivery member 47 shown in FIG.

  The transfer member 49 is, for example, an elongated member extending in the transport direction, and is provided above the return path side substrate holder support mechanism 18c in the vicinity of the discharge port of the first direction changing path 51 of the direction changing mechanism 40A. A portion extending toward the second transport direction P2 side about the shaft 49a is configured to rotate and move in the vertical direction.

  The delivery member 49 has a lower portion 49b formed in a planar shape, and a lower end portion 49b of the delivery member 49 is formed such that a front end portion 49c thereof on the second transport direction P2 side is inclined upward.

  The delivery member 49 is configured such that a portion thereof on the second transport direction P2 side with respect to the rotation shaft 49a is inclined slightly downward with respect to the horizontal direction in a state where no external force acts.

  In this case, a portion of the delivery member 49 on the second conveyance direction P2 side is urged downward by an elastic member such as a torsion coil spring (not shown) to prevent the external force from acting on the second conveyance direction P2 side. The portion can be configured to be inclined slightly downward with respect to the horizontal direction, and the portion on the second conveyance direction P2 side with respect to the horizontal direction can be configured in a state where external force does not act due to the weight of the transfer member 49. It can also be configured to incline slightly downward.

  17A to 17C and FIGS. 18A to 18C are explanatory views showing the operation of the substrate holder transport mechanism and the direction changing mechanism in this example.

  Also in this example, by moving the first driving unit 36 of the substrate holder transport mechanism 3 in the first transport direction P1, as shown in FIG. 17A, the film formation process is completed and the substrate holder is completed. The substrate holder 11 that has reached the transport folding section 30B of the transport mechanism 3 is further moved in the first transport direction P1, and the second driven shaft 13 of the substrate holder 11 is redirected to the second direction of the redirecting mechanism 40A. It is arranged at the entrance of the path 52, and the operation of the transport drive member 45 is controlled so that the second drive portion 46 of the direction changing mechanism 40A is located below the second driven shaft 13 of the substrate holder 11. To do.

  Then, the first drive unit 36 and the second drive unit 46 are synchronously moved in the first transport direction P1, respectively, so that as shown in FIG. And driving the first and second driven shafts 12 and 13 by the first and second drive units 36 and 46, respectively, and moving the first and second direction change paths 51 and 52 downward. Thus, the substrate holder 11 is moved downward while maintaining the vertical relationship.

  Then, from the vicinity where the first and second driven shafts 12 and 13 have passed through the middle portions of the first and second direction changing paths 51 and 52, respectively, from the vicinity of the first and second driven shafts 12 and 13, The carrying direction is changed to the second carrying direction P2 opposite to the first carrying direction P1 while maintaining the vertical relationship of the substrate holder 11.

  Further, when the transport drive member 33 of the substrate holder transport mechanism 3 and the transport drive member 45 of the direction changing mechanism 40A continue to be driven, as shown in FIG. 17C, the first driven shaft of the substrate holder 11 is driven. 12 passes through the outlet of the first direction changing path 51 and the transfer member 49, and the second driven shaft 13 of the substrate holder 11 is arranged at the position of the outlet of the second direction changing path 52. After that, as shown in FIG. 18A, the substrate holder 11 is transferred to the return path side substrate holder supporting mechanism 18 c of the substrate holder supporting mechanism 18.

  17C, the second drive unit 46 of the direction changing mechanism 40A and the second driven shaft 13 of the substrate holder 11 are not in contact with each other, and the substrate holder 11 holds the substrate. The first drive unit 36 of the container transport mechanism 3 is driven by the contact between the first driven shaft 12 and the first driven shaft 12 to move in the second transport direction P2.

  Then, by further driving the transport drive member 33 of the substrate holder transport mechanism 3, as shown in FIG. 18B, the second driven shaft 13 of the substrate holder 11 is located below the transfer member 49. 18b, the transfer member 49 is rotated upward about the rotation shaft 49a, and the second driven shaft 13 of the substrate holder 11 is connected to the tip of the transfer member 49 as shown in FIG. 18C. The substrate holder 11 moves in the second transport direction P2 by passing below 49c.

  After this process, the transfer member 49 returns to the original position by the urging force of the elastic member (not shown) or its own weight.

  According to the direction changing mechanism 40A having the transfer member 49 of the present embodiment described above, the frictional force when the substrate holder 11 passes through the transfer member 49 is minimized.

  Note that the present invention is not limited to the above-described embodiment, and various changes can be made.

  For example, in the above-described embodiment, the film forming apparatus having the transfer path formed so that the projection shape on the vertical plane is a series of loops has been described as an example, but the present invention is not limited to this, and the linear transfer is performed. It can also be applied to a so-called in-line type film forming apparatus having a path.

  Further, in the above-described embodiment, the upper portion of the transport driving member 33 is the forward transport portion 33a which is the first transport portion, and the lower portion of the transport driving member 33 is the second transport portion. Although the return path side transport unit 33c, which is a unit, is used, the present invention is not limited to this, and the vertical relationship between them may be reversed.

  Further, in the above embodiment, the upper surface of the substrate is the first surface and the lower surface is the second surface, but the lower surface of the substrate may be the first surface and the upper surface may be the second surface.

  Furthermore, in the above-described embodiment, the case where the transparent conductive oxide film is formed on both surfaces of the substrate for the heterojunction solar cell has been described as an example, but the present invention is not limited to this, and both surfaces of various substrates are described. It can be applied when forming various films on top.

  However, the present invention is particularly effective when the transparent conductive oxide film is formed on both surfaces of the substrate for the heterojunction solar cell.

  Further, in the above embodiment, the substrate holder transport mechanism 3 and the direction changing mechanism 40 are composed of a pair of sprockets and a chain spanning the pair of sprockets. However, for example, a belt or a rail is used. It is also possible to use an annular transport drive mechanism.

  Further, the substrate holder supporting mechanism 18 may be configured by using a belt or rail instead of the roller.

  Furthermore, the present invention is not limited to the case where the substrate 10a before film formation is carried into the vacuum chamber 2 and the substrate 10b after film formation is carried out from the vacuum chamber 2 as in the above-described embodiment. The present invention can also be applied to the case where the substrate 10a of 1) is carried into the vacuum chamber 2 together with the substrate holder 11, and the substrate 10b after film formation is carried out together with the substrate holder 11 from the vacuum chamber 2.

  Examples of the present invention will be described below.

<Example>
A 110 nm-thick film of indium oxide (In ₂ O ₃ ) was formed on a glass substrate by sputtering.
When the sheet resistance value of this indium oxide film was measured, it was 42.9 Ω / □.

Then, the indium oxide film was annealed at a temperature of 200 ° C. for 5 minutes in vacuum using a sheath heater.
Further, the annealed indium oxide film is immersed in phosphorous nitric acid (phosphoric acid 73: nitric acid 3: acetic acid 7: water 17) at a temperature of 40 ° C. for 70 seconds to perform half etching, and then the surface and the cross section are observed by SEM. Was observed.
The results are shown in FIGS. 20 (a) and 20 (b).

  The sheet resistance of the indium oxide film after the half etching was measured and found to be 44.0 Ω / □.

<Comparative example>
The sheet resistance value of the indium oxide film formed by the same method as in the above example was measured and found to be 41.4 Ω / □.

Further, the indium oxide film was immersed in the phosphorous nitric acid acetic acid at 40 ° C. for 70 seconds for half etching, and then the surface and cross section were observed by SEM.
The results are shown in FIGS. 21 (a) and 21 (b).

  When the sheet resistance value of the indium oxide film after the half etching was measured, it was 1518 Ω / □.

<Evaluation>
As shown in FIGS. 20 (a) and 20 (b), the indium oxide film of the example subjected to the vacuum annealing treatment after the film formation has a uniform surface and the inside and is densely formed. The resistance value hardly increased.

  On the other hand, in the indium oxide film of the comparative example in which the vacuum annealing process was not performed after the film formation, as shown in FIGS. 21A and 21B, the surface was formed in an island shape and voids were formed inside. Many were seen.

  Furthermore, the sheet resistance value of the indium oxide film of the comparative example increased significantly (41.4 Ω / □ → 1518 Ω / □) after the half etching.

  From the above, it was found that by performing the vacuum annealing treatment of the present invention, it is possible to form a uniform and high quality sputtered film when it is discharged from the film forming apparatus.

DESCRIPTION OF SYMBOLS 1 ... Film-forming apparatus 2 ... Vacuum tank 3 ... Substrate holder conveyance mechanism 4 ... 1st film-forming area | region 4T ... 1st sputtering source 5 ... 2nd film-forming area | region 5T ... 2nd sputtering source 6 ... Substrate carry-in Unloading mechanism 10 ... Substrate 10a ... Substrate 10b before film formation ... Substrate 10A after film formation ... n-type crystalline silicon substrate 10B ... 10C ... i-type amorphous silicon layer 10D ... p-type amorphous silicon layer 10E ... n-type amorphous silicon layer 10f ... First transparent conductive oxide film in amorphous state (first sputtered film in amorphous state)
10F ... First transparent conductive oxide film in crystalline state (first sputtered film in crystalline state)
10 g ... second transparent conductive oxide film in amorphous state (second sputtered film in amorphous state)
10G ... Second transparent conductive oxide film in crystalline state (second sputtered film in crystalline state)
11 ... Substrate holder 12 ... 1st driven shaft 13 ... 2nd driven shaft 14 ... Holding part 18 ... Substrate holder support mechanism 21 ... 1st vacuum annealing processing mechanism 22 ... 2nd vacuum annealing processing mechanism 23 ... Vacuum annealing treatment mechanism for accelerating annealing 25 ... Cooling mechanism 30A ... Substrate holder introducing section 30B ... Conveyance folding section 30C ... Substrate holder discharging section 33 ... Conveyance driving member (conveyance path)
33a ... Forward side transport unit (first transport unit)
33b ... Fold-back section 33c ... Return path side transport section (second transport section)
40 ... Direction changing mechanism P1 ... 1st conveyance direction P2 ... 2nd conveyance direction

Claims (6)

A vacuum chamber that can transport substrates along the transport path,
A first film formation region which is provided in the vacuum chamber and has a first sputtering source for forming a film on the first surface of the substrate;
A vacuum annealing process is performed on the first sputtered film in the amorphous state, which is provided on the downstream side of the first film formation region in the transport direction and is formed on the first surface of the substrate in the first film formation region. A first vacuum annealing treatment mechanism to perform,
A second film formation region provided in the vacuum chamber and having a second sputtering source for forming a film on the second surface of the substrate;
A vacuum annealing process is performed on the second sputter film in an amorphous state, which is provided on the downstream side of the second film forming region in the transport direction and is formed on the second surface of the substrate in the second film forming region. second have a vacuum annealing treatment mechanism for performing,
Between the first vacuum annealing treatment mechanism and the second film formation region, a first sputtered film on the first surface of the substrate vacuum-annealed by the first vacuum annealing treatment mechanism is formed. On the other hand, a film forming apparatus provided with a vacuum annealing treatment mechanism for promoting annealing that further performs vacuum annealing treatment . A vacuum chamber in which a single vacuum atmosphere is formed,
A first film formation region provided in the vacuum chamber and having a first sputtering source for forming a film on the first surface of the substrate;
A second film formation region provided in the vacuum chamber and having a second sputtering source for forming a film on the second surface of the substrate;
A conveyance path that is formed so that the projection shape on the vertical plane is a series of annular shapes and that is provided so as to pass through the first and second film formation regions;
A substrate holder transport mechanism for transporting a substrate holder having an opening for exposing the first and second surfaces of the substrate and holding the substrate in a horizontal state along the transport path;
The substrate holder transport mechanism transports the substrate holder in the first transport direction so as to pass through the first film formation region, and the substrate holder transports the second holder. A second transport unit that transports in a second transport direction opposite to the first transport direction so as to pass through the film region, and the substrate holder from the first transport unit in a state where the substrate holder is maintained in a vertical relationship. A transporting and folding section for folding and transporting toward the second transporting section,
A vacuum annealing process is performed on the first sputtered film in the amorphous state formed on the first surface of the substrate, on the downstream side in the transport direction of the first film formation region of the first transport unit. With the vacuum annealing treatment mechanism of
A second annealing process is performed on the second sputter film in an amorphous state formed on the second surface of the substrate, on the downstream side of the second film formation region in the second conveyance region in the conveyance direction. vacuum annealing mechanism is provided,
Further, on the first transport direction side of the second transport portion in the second transport portion, on the first surface of the substrate that has been vacuum annealed by the first vacuum annealing mechanism. A film forming apparatus provided with a vacuum annealing treatment mechanism for promoting annealing, which further performs vacuum annealing treatment on the first sputtered film . A method of forming a film by sputtering on both surfaces of the substrate while moving the substrate in a vacuum,
A first film forming step of forming a first sputtered film in an amorphous state on the first surface of the substrate;
A first vacuum annealing treatment step of performing a vacuum annealing treatment on the first sputtered film on the first surface of the substrate;
A second film forming step of forming a second sputtered film in an amorphous state on the second surface of the substrate;
Have a second vacuum annealing step of performing vacuum annealing process on the second sputter film on the second side of the substrate,
After the first vacuum annealing process of performing the vacuum annealing process on the first sputtered film in the amorphous state on the first surface of the substrate, the second sputtered film in the amorphous state is formed on the second surface of the substrate. A film forming method comprising an annealing promoting step of further performing a vacuum annealing treatment on the first sputtered film on the first surface of the substrate before the second film forming step of forming the sputtered film . A method of forming a film by sputtering on both surfaces of the substrate while moving the substrate in a vacuum,
A first film forming step of forming a first sputtered film in an amorphous state on the first surface of the substrate;
A first vacuum annealing treatment step of performing a vacuum annealing treatment on the first sputtered film on the first surface of the substrate;
A second film forming step of forming a second sputtered film in an amorphous state on the second surface of the substrate;
A second vacuum annealing treatment step of performing a vacuum annealing treatment on the second sputtered film on the second surface of the substrate;
After the first vacuum annealing process of performing the vacuum annealing process on the first sputtered film in the amorphous state on the first surface of the substrate, the second sputtered film in the amorphous state is formed on the second surface of the substrate. Before the second film forming step of forming the sputtered film, an annealing promoting step of further performing a vacuum annealing process on the first sputtered film on the first surface of the substrate,
The i-type amorphous silicon layer and the p-type amorphous silicon layer are sequentially provided on the first surface of the n-type crystalline silicon substrate, and the i-type amorphous silicon layer is formed on the second surface of the n-type crystalline silicon substrate. A substrate on which a layer and an n-type amorphous silicon layer are sequentially provided,
Wherein the first sputter film is in the first transparent conductive oxide film, and said second sputter film and the second transparent conductive oxide film Der Ru film forming method. A film forming method using the film forming apparatus according to claim 2 ,
The first carrier of the substrate holder carrying mechanism carries the substrate holder in the first carrying direction along the carrying path so as to pass through the first film forming region, and the substrate holder A first film forming step of forming a first sputtered film by sputtering on the first surface of the substrate held at
The first carrier of the substrate holder carrying mechanism carries the substrate holder in the first carrying direction along the carrying path, with respect to the first sputtered film on the first surface of the substrate. A first vacuum annealing treatment step of performing a vacuum annealing treatment by the first vacuum annealing treatment mechanism,
A step of folding back and transporting the substrate holder along the transport path from the first transporting portion toward the second transporting portion in a state in which the transporting and folding portion of the substrate holder transporting mechanism maintains the vertical relationship. When,
The substrate that has been transported in the second transport direction along the transport path by the second transport section of the substrate holder transport mechanism in the second transport direction and has been vacuum annealed by the first vacuum annealing mechanism. An annealing promoting step of further performing a vacuum annealing process on the first sputtered film on the first surface by the annealing promoting vacuum annealing mechanism.
The second carrier of the substrate holder carrying mechanism carries the substrate holder in the second carrying direction along the carrying path so as to pass through the second film formation region, and the substrate holder. A second film forming step of forming a second sputtered film by sputtering on the second surface of the substrate held at
The second carrier of the substrate holder carrying mechanism carries the substrate holder in the second carrying direction along the carrying path, with respect to the second sputtered film on the second surface of the substrate. A second vacuum annealing treatment step of performing a vacuum annealing treatment by the second vacuum annealing treatment mechanism. A method for manufacturing a solar cell using the film forming apparatus according to claim 2 ,
As the substrate, an i-type amorphous silicon layer and a p-type amorphous silicon layer are sequentially provided on a first surface of an n-type crystalline silicon substrate, and an i-type amorphous silicon layer is provided on a second surface of the n-type crystalline silicon substrate. A substrate on which a layer and an n-type amorphous silicon layer are sequentially provided,
The first carrier of the substrate holder carrying mechanism carries the substrate holder in the first carrying direction along the carrying path so as to pass through the first film forming region, and the substrate holder Forming a first transparent conductive oxide film in an amorphous state on the first surface of the substrate held by sputtering by sputtering.
The first transport unit of the substrate holder transport mechanism transports the substrate holder in the first transport direction along the transport path, and the first transparent substrate in the amorphous state on the first surface of the substrate. A first vacuum annealing treatment step of performing a vacuum annealing treatment on the conductive oxide film by the first vacuum annealing treatment mechanism;
A step of folding back and transporting the substrate holder along the transport path from the first transporting portion toward the second transporting portion in a state in which the transporting and folding portion of the substrate holder transporting mechanism maintains the vertical relationship. When,
The substrate that has been transported in the second transport direction along the transport path by the second transport section of the substrate holder transport mechanism in the second transport direction and has been vacuum annealed by the first vacuum annealing mechanism. An annealing promoting step of further performing a vacuum annealing process on the first transparent conductive oxide film on the first surface of the first transparent conductive oxide film by the annealing promoting vacuum annealing process mechanism;
The second carrier of the substrate holder carrying mechanism carries the substrate holder in the second carrying direction along the carrying path so as to pass through the second film formation region, and the substrate holder. Forming a second transparent conductive oxide film in an amorphous state by sputtering on the second surface of the substrate held at
The second carrier of the substrate holder carrying mechanism carries the substrate holder in the second carrying direction along the carrying path, and the second transparent substrate in the amorphous state on the second surface of the substrate. A second method for producing a solar cell, comprising: performing a second vacuum annealing process on the conductive oxide film by the second vacuum annealing process mechanism.

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