JP6754530B2 - Film formation equipment, film formation method, and solar cell manufacturing method - Google Patents

Description

The present invention relates to a technique of a film forming apparatus for forming a film on one side of a substrate in vacuum by sputtering, and particularly to a technique of forming a metal layer on one side of a substrate for a heterojunction type solar cell.

In recent years, solar cells have been put into practical use as a clean and safe energy source, and among them, heterojunction type solar cells are attracting attention.
The heterojunction type solar cell has advantages such as higher conversion efficiency than a single crystal silicon solar cell and the use of an amorphous silicon layer, so that the amount of silicon used can be reduced.

In recent years, as a heterojunction type solar cell, a so-called back contact structure having no electrode on the light receiving surface and having a back electrode on the back surface opposite to the light receiving surface has been proposed.
This back electrode is made of metal and is formed by forming a film by sputtering. However, when the metal layer is formed by sputtering, the temperature becomes considerably high, so that it is formed in order to avoid the influence on other films. It is necessary to cool the film (before and after).

However, when cooling the substrate on which the metal layer is formed, it is difficult to directly cool the metal layer and indirectly cool due to the low emissivity of the metal layer. There is also the problem that it is inefficient to do.
Further, even when the heterojunction type solar cell has an electrode layer made of metal on the light receiving surface, there is a similar problem.

Such a problem has become an important issue because it is necessary to repeatedly form a metal layer when the electrode layer is formed to be thick.
The above-mentioned problems occur not only when the metal layer is formed on the film-forming target substrate of the heterojunction solar cell, but also when the sputter film made of metal is formed on the film-forming target substrate. ..

Japanese Unexamined Patent Publication No. 2011-146528

The present invention has been made in consideration of such problems of the prior art, and an object of the present invention is to efficiently and reliably cool a metal layer when a metal layer is formed on a film-forming target substrate by sputtering. It is to provide the technology that can be done.

Another object of the present invention is a technique for manufacturing a heterojunction solar cell capable of efficiently and surely cooling when a back electrode or a front electrode made of metal is formed on a substrate to be filmed by sputtering. To provide.

The present invention made to achieve the above object is the first with respect to a vacuum chamber in which a single vacuum atmosphere is formed and a film-forming target substrate provided in the vacuum chamber and held in a substrate cage. A metal layer having a cooling region for cooling from the surface side and a sputter source for forming a metal layer on the second surface of the film-forming target substrate provided in the vacuum chamber and held in the substrate cage. The film-forming region and the transport path provided so as to form a series of annular projection shapes with respect to the vertical plane and passing through the metal layer film-forming region and the cooling region, and the substrate cage are horizontally arranged. The membrane cage transport mechanism is provided with a substrate cage transport mechanism that transports the substrate cage along the transport path in a state of being carried, and the substrate cage transport mechanism includes a first transport unit that transports the substrate cage in a predetermined direction along the transport path. The first transport unit, which transports the substrate cage in a direction opposite to the transport direction of the first transport unit along the transport path, and the substrate cage in a state where the substrate cage is maintained in a vertical relationship. It has a transport-folded portion that folds back and transports from the transport unit toward the second transport unit, and the first transport unit passes through one of the metal layer film forming region and the cooling region, and The second transporting unit is a film forming apparatus provided so as to pass through the other of the metal layer film forming region and the cooling region.
Further, the present invention comprises a vacuum chamber in which a single vacuum atmosphere is formed, and a transparent conductive oxide layer on the first surface of a substrate to be deposited, which is provided in the vacuum chamber and held in a substrate cage. Transparent conductivity on a first transparent conductive oxide layer film forming region having a sputter source for forming a film and a second surface of the film forming target substrate provided in the vacuum chamber and held in the substrate cage. A second transparent conductive oxide layer film forming region having a sputter source for forming an oxide layer, and a film forming target substrate provided in the vacuum chamber and held in the substrate cage. A metal having a cooling region for cooling from two surfaces and a sputter source for forming a metal layer on the first surface of the substrate to be deposited, which is provided in the vacuum chamber and is held by the substrate cage. The layer film forming region and the projected shape with respect to the vertical surface are formed so as to form a series of rings, and pass through the first and second transparent conductive oxide layer forming regions, the metal layer forming region, and the cooling region. The substrate cage transport mechanism includes a transport path provided so as to carry the substrate cage and a substrate cage transport mechanism that transports the substrate cage horizontally along the transport path. The substrate cage transport mechanism holds the substrate cage. A first transport unit that transports the substrate cage in a predetermined direction along the transport path, and a second transport unit that transports the substrate cage along the transport path in a direction opposite to the transport direction of the first transport unit. The substrate cage is provided with a transport folding portion that folds back and transports the substrate cage from the first transport portion toward the second transport portion while maintaining the vertical relationship, and the first transport portion is the said. It passes through one of the first and second transparent conductive oxide layer film forming regions, and the second transporting portion passes through the other of the first and second transparent conductive oxide layer film forming regions. As it passes, the first transport portion passes through one of the metal layer film forming region and the cooling region, and the second transport portion is the metal layer film forming region and the cooling region. It is a film forming apparatus provided so as to pass through the other of them.
Further, the present invention is a film forming apparatus, in which the substrate cage holding the film-forming target substrate after film formation is taken out from the substrate cage transport mechanism, and the taken-out substrate cage is taken out from the substrate cage transport mechanism. It is a film forming apparatus configured to be introduced into.
Further, the present invention is a film forming apparatus, and the substrate cage is a film forming apparatus configured to arrange and hold a plurality of film forming target substrates in a direction orthogonal to the transport direction.
Further, the present invention is a film forming method using any of the above-mentioned film forming devices, in which the substrate cage is cooled by one of the first and second conveying portions of the substrate cage conveying mechanism. A cooling step of transporting the substrate in a predetermined direction along the transport path so as to pass through the substrate and cooling from the first surface side of the film-forming target substrate held by the substrate cage, and the substrate cage transport mechanism. The substrate cage is conveyed to the substrate cage by the other of the first and second conveying portions along the transfer path in the direction opposite to the predetermined direction so as to pass through the metal layer film forming region. This is a film forming method including a metal layer forming step of forming a metal layer on the second surface of the held substrate to be formed by sputtering.
Further, the present invention is a film forming method using the film forming apparatus described above, wherein the substrate cage is formed into the first transparent conductive oxide layer by the first conveying portion of the substrate cage conveying mechanism. A step of transporting a first transparent conductive oxide layer by sputtering on the first surface of a substrate to be filmed, which is transported in a predetermined direction along the transport path so as to pass through a region and is held by the substrate cage. In the direction opposite to the predetermined direction along the transport path so that the substrate cage passes through the second transparent conductive oxide layer film forming region by the second transport portion of the substrate cage transport mechanism. A step of forming a second transparent conductive oxide layer by sputtering on the second surface of the substrate to be deposited, which is conveyed and held by the substrate cage, and the second transfer of the substrate cage transfer mechanism. The substrate carrier is conveyed by the unit in the direction opposite to the predetermined direction along the transfer path so as to pass through the cooling region, and the second surface with respect to the film-forming target substrate held by the substrate cage. The substrate cage is transported in the predetermined direction along the transport path so as to pass through the metal layer film forming region by the cooling step of cooling from the side and the first transport portion of the substrate cage transport mechanism. This is a film forming method including a metal layer film forming step of forming a metal layer on the first surface of the film forming target substrate held by the substrate cage by sputtering.
Further, the present invention is a film forming method, in which the substrate cage holding the film-forming target substrate after film formation is taken out from the substrate cage transport mechanism, and the taken-out substrate cage is taken out from the substrate cage transport mechanism. This is a film forming method having a step of performing the cooling step and the metal layer film forming step a plurality of times.
Further, the present invention is a method for manufacturing a solar cell using the film forming apparatus described above, wherein an amorphous silicon layer and an antireflection film having a texture structure are sequentially provided on the first surface of an n-type single crystal silicon substrate. At the same time, a film-forming target substrate in which an i-type amorphous silicon layer, a p-type amorphous silicon layer, and an n-type amorphous silicon layer are provided adjacent to each other on the second surface of the n-type single crystal silicon substrate is prepared. The substrate cage is transported in a predetermined direction along the transport path so as to pass through the cooling region by one of the first and second transport portions of the cage transport mechanism, and is held by the substrate cage. The substrate cage is layered with the metal by a cooling step of cooling the film-forming target substrate from the first surface side and the other of the first and second transport portions of the substrate cage transport mechanism. A metal layer for a back surface electrode is transported along the transport path so as to pass through the film region in a direction opposite to the predetermined direction, and is carried on the second surface of the film-forming target substrate held by the substrate cage by sputtering. This is a method for manufacturing a solar cell, which comprises a metal layer film forming step for forming a film.
Further, the present invention is a method for manufacturing a solar cell using the film forming apparatus described above, in which an i-type amorphous silicon layer and a p-type amorphous silicon layer are sequentially provided on the first surface of an n-type crystalline silicon substrate. At the same time, a film-forming target substrate in which an i-type amorphous silicon layer and an n-type amorphous silicon layer are sequentially provided on the second surface of the n-type crystalline silicon substrate is prepared, and the first transfer of the substrate cage transfer mechanism is performed. The substrate cage is conveyed in a predetermined direction along the transfer path so as to pass through the first transparent conductive oxide layer film forming region, and the film-forming target substrate held by the substrate cage is the first. The process of forming the first transparent conductive oxide layer on one surface by sputtering and the second transporting portion of the substrate cage transport mechanism allow the substrate cage to be formed into the second transparent conductive oxide layer film forming region. A second transparent conductive oxide layer is conveyed on the second surface of the film-forming target substrate held in the substrate cage in a direction opposite to the predetermined direction along the conveying path so as to pass through. The substrate cage is conveyed in the direction opposite to the predetermined direction along the transfer path so as to pass through the cooling region by the step of forming the substrate cage and the second transfer portion of the substrate cage transfer mechanism. The substrate cage is metal-layered by a cooling step of cooling the film-forming target substrate held by the substrate cage from the second surface side and the first transport portion of the substrate cage transport mechanism. A metal layer for a surface electrode is formed by sputtering on the first surface of the film-forming target substrate held in the substrate cage after being transported in the predetermined direction along the transport path so as to pass through the film region. This is a method for manufacturing a solar cell, which comprises a metal layer film forming step.

In the film forming apparatus according to the first invention, a first transport unit that transports the substrate cage in a predetermined direction along a transport path and a substrate cage are provided in a vacuum chamber in which a single vacuum atmosphere is formed. From the first transport section to the second transport section while maintaining the vertical relationship between the second transport section that transports the first transport section in the direction opposite to the transport direction of the first transport section along the transport path and the substrate cage. The substrate cage is provided with a transfer folding mechanism having a transfer folding section, and the first transport section passes through one of the metal layer film forming region and the cooling region, and the second transport section is It is provided so as to pass through the other of the metal layer film forming region and the cooling region.

In such a first invention, in the substrate cage transport mechanism, for example, the substrate cage is transported in a predetermined direction along the transport path so as to pass through the cooling region by the first transport unit, and is held by the substrate cage. Cooling is performed from the first surface side of the film-forming target substrate, and the substrate cage is passed through the metal layer film-forming region by, for example, the second transport section of the first transport section along the transport path. A metal layer can be formed by sputtering on the second surface of the substrate to be formed by being conveyed in the direction opposite to the conveying direction and held in the substrate cage.

As a result, in the first invention, when the film-forming target substrate is cooled first, the metal layer is formed by sputtering on the film-forming target substrate in a sufficiently cooled state. It is possible to reliably prevent the temperature rise of the film-forming target substrate at the time of film formation, and thereby suppress the influence on the films of other layers.

Further, when the film-forming target substrate in which the metal layer is formed by sputtering on the second surface of the film-forming target substrate is cooled, the metal layer is formed without cooling from the metal layer side having a low radiation coefficient. By cooling from the first surface side of the film-forming target substrate that has not been formed, the film-forming target substrate can be efficiently cooled and its temperature can be surely lowered. The influence of the layer on the film can be suppressed.

Further, when the metal layer is formed to be thick on the substrate to be formed, it is necessary to repeatedly form the metal layer. However, according to the first invention, every time the metal layer is formed. Since it can be cooled, it can be efficiently cooled and the temperature rise of the film-forming target substrate can be reliably prevented.

Further, in the film forming apparatus according to the second invention, the first conveying portion that conveys the substrate cage in a predetermined direction along the conveying path and the substrate holding in the vacuum chamber in which a single vacuum atmosphere is formed. A second transport unit that transports the vessel along the transport path in the direction opposite to the transport direction of the first transport unit, and a second transport unit from the first transport unit to the second transport unit while maintaining the vertical relationship of the substrate cage. A substrate cage having a substrate cage transport mechanism having a transport folded portion for folding and transporting the first transport portion passes through one of the first and second transparent conductive oxide layer film forming regions, and the first transport portion passes through one of the first and second transparent conductive oxide layer film forming regions. , The second transport section passes through the other of the first and second transparent conductive oxide layer film forming regions, and the first transport section passes through one of the metal layer film forming region and the cooling region. Moreover, the second conveying portion is provided so as to pass through the other of the metal layer film forming region and the cooling region.

In such a second invention, in the substrate cage transport mechanism, the substrate cage is passed through the first and second transparent conductive oxide layer film forming regions via the first transport section and the second transport section. The first and second transparent conductive oxide layers are formed by sputtering on both surfaces of the substrate to be deposited, which are conveyed in a predetermined direction and in opposite directions along the conveying path. After that , the substrate cage is transported in a predetermined direction along the transport path so as to pass through the cooling region by the second transport unit, and cooling is performed from the second surface side of the substrate to be filmed held by the substrate cage. In addition , the substrate cage is transported along the transport path in the direction opposite to the transport direction of the second transport portion so as to pass through the metal layer film forming region by the first transport portion, and is held by the substrate cage. A metal layer can be formed on the first surface of the film-forming target substrate by sputtering.

As a result, in the second invention, when the film-forming target substrate on which the first and second transparent conductive oxide layers are formed on both sides of the substrate is first cooled, it is in a sufficiently cooled state. By forming a metal layer on the film-forming target substrate by sputtering, it is possible to reliably prevent the temperature rise of the film-forming target substrate during film formation, thereby suppressing the influence on the films of other layers. be able to.

Further, when cooling is performed on the film-forming target substrate in which the first and second transparent conductive oxide layers are formed on both surfaces of the substrate and the metal layer is formed by sputtering on the first surface, the radiation coefficient is high. By cooling from the second surface side of the film-forming target substrate on which the metal layer is not formed without cooling from the low metal layer side, the film-forming target substrate is efficiently cooled and its temperature is ensured. As a result, the influence on the film of the other layer of the substrate to be formed can be suppressed.

Further, when the metal layer is formed to be thicker on the substrate to be formed, it is necessary to repeatedly form the metal layer. However, in the second invention as well as in the first invention, the metal layer is formed. Since cooling can be performed every time the film is formed, it is possible to efficiently cool the film and reliably prevent the temperature of the film-forming target substrate from rising.

On the other hand, in the above-mentioned first and second inventions, the transport path is formed so as to form a series of rings when projected onto the vertical surface, and the film forming step and the cooling step of the metal layer are performed. By performing this in different transport units, it is possible to form a metal layer on the film-forming target substrate by a compact pass-through type film-forming device while suppressing the influence on the film of another layer of the film-forming target substrate.

According to the first and second inventions, a heterojunction type capable of efficiently and reliably cooling when a back electrode or a front electrode made of metal is formed on a substrate to be filmed by sputtering. It is possible to provide a manufacturing technique for a solar cell.

On the other hand, in the first and second inventions, when a plurality of film-forming target substrates are arranged and held in a direction orthogonal to the transport direction, the substrate transport direction as in the prior art. Compared with the case where a substrate cage for holding a plurality of substrates side by side is transported to perform film formation, the length of the substrate cage and the excess space associated therewith can be reduced, so that the film forming apparatus can be saved. Space can be achieved.

Schematic configuration diagram showing the whole embodiment of the film forming apparatus according to the present invention. The plan view which shows the schematic structure of the substrate cage transport mechanism in this embodiment. Front view showing the main part of the board cage transport mechanism (A) to (c): The configuration of the substrate cage used in the present embodiment is shown. FIG. 4A is a plan view of a state in which the substrate is not held, and FIG. 4B is a substrate. 4 (c) is a cross-sectional view taken along the line AA of FIG. 4 (a). (A) (b): Shows the configuration of the transport folded-back portion of the substrate cage transport mechanism of the present embodiment, FIG. 5 (a) is a plan view, and FIG. 5 (b) is FIG. 5 (a). BB line sectional view Explanatory drawing of the operation of the film forming apparatus of this embodiment and the film forming method (No. 1) Explanatory drawing of the operation of the film forming apparatus and the film forming method (Part 2) Explanatory drawing of the operation of the film forming apparatus and the film forming method (No. 3) (A) (b): Operation explanatory view of the substrate cage transport mechanism of this embodiment (No. 1) (A) to (c): Operation explanatory view of the transfer folding portion of the substrate cage transfer mechanism. (A) (b): Operation explanatory view of the substrate cage transport mechanism (No. 2) (A) (b): Operation explanatory view of the substrate cage transport mechanism (No. 3) Explanatory drawing of the operation of the film forming apparatus and the film forming method (No. 4) Explanatory drawing of the operation of the film forming apparatus and the film forming method (No. 5) Explanatory drawing of the operation of the film forming apparatus and the film forming method (No. 6) (A) (b): Cross-sectional process diagram showing a method of forming a transparent conductive oxide layer in the present embodiment. Operational explanatory diagram when film formation is performed multiple times on a substrate (Part 1) Operational explanatory view when film formation is performed multiple times on a substrate (Part 2) Schematic configuration diagram showing the whole of other embodiments of the film forming apparatus according to the present invention. Explanatory drawing of the film forming method in the same embodiment (No. 1) Explanatory drawing of the film forming method in the same embodiment (Part 2) Explanatory drawing of the film forming method in the same embodiment (No. 3) Explanatory drawing of the film forming method in the same embodiment (No. 4) (A) to (d): Cross-sectional process chart showing a method of forming a transparent conductive oxide layer and a metal layer in the same embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing the entire embodiment of the film forming apparatus according to the present invention.
Further, FIG. 2 is a plan view showing a schematic configuration of the substrate cage transport mechanism according to the present embodiment, and FIG. 3 is a front view showing a main part of the substrate cage transport mechanism.

Further, FIGS. 4 (a) to 4 (c) show the configuration of the substrate cage used in the present embodiment, and FIG. 4 (a) shows the substrate to be film-formed (hereinafter referred to as "substrate"). A plan view of the state in which the substrate is not held, FIG. 4 (b) is a plan view of the state in which the substrate is held, and FIG. 4 (c) is a sectional view taken along line AA of FIG. 4 (a).
Furthermore, FIGS. 5 (a) and 5 (b) show a configuration of a transport folding back portion of the substrate cage transport mechanism of the present embodiment, FIG. 5 (a) is a plan view, and FIG. 5 (b) is a plan view. FIG. 5A is a cross-sectional view taken along the line BB of FIG. 5A.

As shown in FIG. 1, the film forming apparatus 1 of the present embodiment has a vacuum chamber 2 connected to a vacuum exhaust apparatus 1a to form a single vacuum atmosphere.
Inside the vacuum chamber 2, a substrate cage transport mechanism 3 for transporting the substrate cage 11, which will be described later, along a transport path is provided.

The substrate cage transport mechanism 3 is configured to continuously transport a plurality of substrate cages 11 that hold the substrate 50.
Here, the substrate cage transport mechanism 3 has a first and second circular drive wheels 31 and 32 having the same diameter, which are made of, for example, sprockets and the like, and the first and second drive wheels 31 and 32 have the same diameter. The drive wheels 31 and 32 of No. 2 are arranged at a predetermined distance in a state where their respective rotation axes are parallel to each other.

Then, a series of transport drive members 33 made of, for example, a chain or the like are bridged over the first and second drive wheels 31 and 32, thereby forming a series of annular transports with respect to the vertical plane as described below. A route is formed.
In the present embodiment, the first and second drive wheels 31 and 32 are configured to operate by transmitting a rotational driving force from a drive mechanism (not shown).

Then, the outbound side transport unit (third) that moves from the first drive wheel 31 toward the second drive wheel 32 and transports the substrate cage 11 to the upper portion of the transport drive member 33 that constitutes the transport path. 1) 33a is formed, and a folded-back portion 33b is formed by folding back the transporting direction of the substrate cage 11 and converting it in the opposite direction by the transporting drive member 33 in the peripheral portion of the second drive wheel 32. Further, a return path side transport portion (second transport portion) 33c that moves from the second drive wheel 32 toward the first drive wheel 31 is formed on the lower portion of the transport drive member 33.

Further, the substrate cage transport mechanism 3 includes a substrate cage introduction unit 30A for introducing the substrate cage 11, a transport folded-back portion 30B for folding and transporting the substrate cage 11, and a substrate holder for discharging the substrate cage 11. A vessel discharge unit 30C is provided.

On the other hand, a guide member 38 for preventing the substrate holder 11 to be conveyed from falling off is provided around the transfer drive member 33 of the substrate cage transfer mechanism 3.
The guide member 38 is formed in a series of rails, and as shown in FIG. 3, the first drive wheel 31 is formed from the substrate cage introduction portion 30A above the first drive wheel 31 via the transfer folding portion 30B. It is provided in parallel with the transport drive member 33 over the lower substrate cage discharge portion 30C.
The guide member 38 is not provided in the area on the board loading / unloading mechanism 6 side, which will be described later, with respect to the first drive wheel 31.

A cooling region 7 for cooling the substrate 50 held by the substrate cage 11 is provided above the substrate cage transport mechanism 3 in the vacuum chamber 2.
In the cooling region 7 of the present embodiment, a pair of cooling mechanisms 7a and 7b are arranged side by side between the first drive wheel 31 and the second drive wheel 32 above the outward transport portion 33a of the transport drive member 33. The substrate 50 is cooled from the first surface (front side surface in the present embodiment) side of the substrate 50 held by the substrate cage 11.

The cooling mechanisms 7a and 7b are those that cool by radiation in a non-contact state with the substrate 50, and for example, a cold plate, a cryogenic refrigerator, a water cooling block, or the like can be preferably used.
The first and second metal layer film forming regions 4 and 5 are located on the opposite sides of the cooling mechanisms 7a and 7b, that is, below the outward transport portion 33a with the outward transport portion 33a of the transport drive member 33 interposed therebetween. A shielding member 7c for shielding heat from the cooling mechanisms 7a and 7b is provided.

A pair of metal layer film forming regions 4 and 5 are provided in the vacuum chamber 2.
In the present embodiment, a first metal layer film forming region 4 having a sputtering source 4T and a second metal layer forming region having a sputtering source 5T are formed below the substrate cage transport mechanism 3 in the vacuum chamber 2. 5 and are provided.

The first and second metal layer film forming regions 4 and 5 of the present embodiment form a metal layer having a predetermined pattern on the second surface (back surface in the present embodiment) of the substrate 50. The first and second sputter sources 4T and 5T are arranged side by side between the first drive wheel 31 and the second drive wheel 32 below the return path side transport portion 33c of the transport drive member 33.
The first and second metal layer film forming regions 4 and 5 are provided with gas introduction mechanisms (not shown) for introducing a predetermined sputter gas, respectively.

The outbound transport portion 33a of the transport drive member 33 described above is configured to linearly pass through the cooling mechanisms 7a and 7b, and the return transport portion 33c is formed in the first and second metal layer film forming regions. It is configured to pass through 4 and 5 in a straight line.

Then, when the substrate cage 11 passes through the outward transport side transport portion 33a and the return route side transport portion 33c of these transport drive members 33 constituting the transport path, the substrate 50 held by the board cage 11 is transported in a horizontal state. It is supposed to be done.

To transfer and receive the substrate cage 11 to and from the substrate cage transfer mechanism 3 at a position in the vacuum chamber 2 near the substrate cage transfer mechanism 3, for example, 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 the drive rod 61 driven by the elevating mechanism 60, for example, in the vertical vertical direction.
In the present embodiment, the transfer robot 64 is provided on the support portion 62 of the board loading / unloading mechanism 6, and the board holder 11 is supported on the transfer robot 64 to move the board holder 11 in the vertical vertical direction. The transfer robot 64 is configured to transfer and receive the substrate cage 11 from and to the substrate cage transfer mechanism 3.

In this case, as will be described later, the board cage 11 is delivered from the board loading / unloading mechanism 6 to the board cage introduction portion 30A of the outbound side transport portion 33a of the board cage transport mechanism 3 (this position is referred to as “board cage delivery position”. (), And the board cage 11 is taken out from the board holder discharge part 30C of the return path side transport part 33c of the board holder transfer mechanism 3 (this position is referred to as "board cage take-out position"). Has been done.

For example, in the upper part of the vacuum chamber 2, a substrate loading / unloading chamber 2A for loading the substrate 50 into the vacuum chamber 2 and unloading the substrate 50 from the vacuum chamber 2 is provided.
The board loading / unloading chamber 2A is provided, for example, at a position above the support portion 62 of the board loading / unloading mechanism 6 described above via a communication port 2B. For example, the upper part of the board loading / unloading chamber 2A can be opened and closed. A lid 2a is provided.

Then, as will be described later, the substrate 50 carried into the substrate loading / unloading chamber 2A is handed over to the substrate cage 11 on the transfer robot 64 of the support portion 62 of the substrate loading / unloading mechanism 6 to be held, and after the film formation. The substrate 59 of the above is configured to be unloaded from the substrate cage 11 on the transfer robot 64 of the support portion 62 of the substrate loading / unloading mechanism 6 into 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 the substrate 50 is loaded / unloaded at the upper edge of the support portion 62 of the substrate loading / unloading mechanism 6. For example, 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 FIG. 2, the substrate cage transport mechanism 3 of the present embodiment is a pair provided in parallel in the vertical direction at predetermined intervals on a flat plate-shaped base frame 25 provided parallel to a horizontal plane. A frame structure 28 having a flat plate-shaped side frame 26 is provided, and each member described later is assembled to the frame structure 28 so as to be symmetrical with respect to, for example, a transport direction, and a substrate is formed as an integral unit. The cage transport mechanism 3 is configured.

The substrate cage transport mechanism 3 is detachably mounted in the vacuum chamber 2 described above by a mounting portion 17 provided on the frame structure 28.
The substrate cage transport mechanism 3 is provided with the first and second drive wheels 31 and 32 described above on the pair of side frames 26, respectively.

Here, the first drive wheel 31 has a drive shaft 31a that rotates about a rotation axis in a direction orthogonal to the transport direction, and rotates about the drive shaft 31a.
On the other hand, each of the second drive wheels 32 has drive shafts 35 that are rotationally driven about the same rotation axis orthogonal to the transport direction, and each drive shaft 35 has a second drive shaft 35 via a connecting member 34. They are connected to the drive wheels 32, respectively (see FIGS. 2 and 5 (a) and 5 (b)).

Then, the above-mentioned transport drive members 33 are bridged to the first and second drive wheels 31 and 32 provided on the pair of side frames 26, respectively, thereby forming a transport path for transporting the substrate cage 11. Has been done.

As described above, the substrate cage transport mechanism 3 of the present embodiment is placed on the outward path side transport portion (second transport portion) 33a located above each transport drive member 33 and below each transport drive member 33. The return path side transport section (first transport section) 33c, which is located, is configured to face each other and overlap in the vertical direction (see FIGS. 1 and 2).

A plurality of holding drive units 36 are provided on the pair of transport drive members 33 at predetermined intervals.
These holding drive units 36 are for holding the substrate cage 11 and driving the transfer, and are attached to the transfer drive member 33 so as to project outward from the transfer drive member 33. For example, a holding recess 37 having a J-hook shape (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) is provided, which is formed toward the downstream side in the transport direction.

Further, as shown in FIG. 2, at a position inside the pair of transport drive members 33, between the first and second drive wheels 31 and 32, a pair of substrate holders that support the substrate holder 11 to be transported are held. A vessel support mechanism 18 is provided.

The substrate cage support mechanism 18 is composed of, for example, a plurality of rotatable members such as rollers, and is provided in the vicinity of each of the transfer drive members 33.
In the present embodiment, as shown in FIGS. 2 and 3, the outward path side substrate cage support mechanism 18a is provided in the vicinity of the outward path side transport portion 33a of the transport drive member 33, and the transport drive member 33 is transported on the return path side. A return path side substrate cage support mechanism 18b is provided in the vicinity of the portion 33c, and is arranged so as to support both edges of the lower surface of the substrate cage 11 to be conveyed.

Here, the outward path side substrate cage support mechanism 18a is located at the position closest to the transfer folding portion 30B via the cooling region 7 (see FIG. 1) with the end provided in the substrate cage introduction portion 30A as the starting end. It is provided in a straight line so as to be the end portion.

On the other hand, the return path side substrate cage support mechanism 18b passes through the first and second film forming regions 4 and 5 (see FIG. 1) with the position on the second drive wheel 32 side of the transport folding back portion 30B as the starting end. The substrate cage discharge portion 30C is provided in a straight line so as to be the terminal portion.

The substrate cage 11 used in the present embodiment forms a film on the second surface (back side surface) of the substrate 50, and is formed of a tray-like structure having an opening.
As shown in FIGS. 4A to 4C, the substrate cage 11 has a plurality of, for example, rectangular shapes in a direction orthogonal to the longitudinal direction, that is, the transport direction thereof, for example, in the long frame-shaped main body portion 11a. A plurality of holding portions 13 for arranging and holding the substrates 50 in a row are provided.

Here, each holding portion 13 has, for example, a rectangular shape in which the front side surface of each substrate 50 is entirely exposed on the surface (upper surface) side of the main body portion 11a during transportation with the same size and shape as each substrate 50. On the back surface (lower surface) side of the main body 11a during transportation, for example, a rectangular opening 15 smaller than the size of the communication board 50 is provided with each of the openings 14. There is.

A mask 15a for forming a predetermined pattern at the time of film formation is provided at, for example, the lower part of the opening 15.
On the other hand, in the middle portion of the main body portion 11a of each holding portion 13, a mounting portion 16 formed of a rectangular frame-shaped recess on which each substrate 50 can be mounted is provided.
Each of these mounting portions 16 is configured such that the bottom surface of the recess is formed in a plane parallel to, for example, the front surface and the back surface of the main body portion 11a, and each substrate 50 is held horizontally during film formation.

In the substrate cage 11 of the present embodiment having such a configuration, in the film forming process of the plurality of substrates 50 held by the plurality of holding portions 13, the front surface surface, which is the first surface of each substrate 50, is entirely covered. On the back surface of each substrate 50, metal film formations that fly from the first and second sputter sources 4T and 5T when passing through the first and second film formation regions 4 and 5 are formed. The material reaches through the mask 15a.

On the other hand, support shafts 12 are provided at both ends of the main body 11a of the substrate cage 11 in the longitudinal direction and at one end in the width direction, that is, in the transport direction.
These support shafts 12 are formed in a circular cross-section centered on a rotation axis extending in the longitudinal direction of the main body 11a, and are formed in a truncated cone shape in which each base portion 12a is tapered toward both sides. The portion 12b is formed in a cylindrical shape having a diameter smaller than that of the base portion 12a.

Then, each tip portion 12b of the support shaft 12 of the substrate cage 11 is fitted into the holding recess 37 of the holding drive portion 36 of the transport drive member 33 described above, and is rotatably held around the support shaft 12. The dimensions of each part are specified in.

With such a configuration, when each tip portion 12b of the support shaft 12 of the substrate cage 11 is fitted into the holding recess 37 of the holding drive portion 36 of the transport driving member 33 and is held and transported, the holding drive portion 36 The substrate cage 11 is positioned in the support shaft 12 direction by abutting the holding recess 37 of the substrate holder 11 with the tapered support shaft 12 described above.

Further, in the present embodiment, in a state where each tip portion 12b of the support shaft 12 of the substrate cage 11 is fitted and supported in the holding recess 37 of the holding drive portion 36 of the transport drive member 33, the substrate cage 11 is supported. The dimensions of each member are determined so that a slight gap is formed between the tip portion 12b of the support shaft 12 and the guide member 38.

With such a configuration, when each tip portion 12b of the support shaft 12 of the substrate cage 11 is fitted into the holding recess 37 of the holding drive portion 36 of the transport driving member 33, is supported and transported, the guide member 38 and the guide member 38 The contact of the support shaft 12 of the substrate cage 11 with the tip end portion 12b prevents the substrate cage 11 from falling off from the transport path.

The transport folding back portion 30B of the substrate cage transport mechanism 3 of the present embodiment is configured as described below.
First, as shown in FIGS. 3 and 5 (a) and 5 (b), the substrate 50 is located adjacent to the second drive wheel 32 in the substrate cage transport mechanism 3 on the side of the first drive wheel 31. A posture control mechanism 20 is provided to support the substrate cage 11 and control its posture when the substrate holder 11 is folded back and conveyed.

The attitude control mechanism 20 has a drive shaft 21 extending in a direction orthogonal to the transport direction, and the drive shaft 21 is rotatably supported through a pair of side frames 26.
A pair of support arms 22 are attached to the drive shaft 21 at intervals smaller than the distance between the pair of substrate cage support mechanisms 18 (see FIG. 5A).
These support arms 22 are made of straight rod-shaped members, and support rollers 23 are provided at both ends thereof.

On the other hand, the drive shaft 21 of the support arm 22 is connected to the drive shaft 35 of the second drive wheel 32 by, for example, a belt-shaped power transmission member 24, whereby the second drive wheel 32 and the support arm 22 are connected to each other. As will be described later, it is configured to rotate in the same direction in synchronization with a predetermined relationship.

Hereinafter, the operation of the film forming apparatus 1 of the present embodiment and the film forming method using the film forming apparatus 1 will be described with reference to FIGS. 6 to 16. Further, in the present specification, a case where a back electrode layer made of metal of a heterojunction solar cell is formed will be described as an example.

Here, in order to facilitate understanding, a case where one substrate 50 is held in one substrate cage 11 to form a film will be described as an example.
Further, it is assumed that the substrate cage 11 is introduced into the substrate cage introduction unit 30A with the side of the substrate cage 11 provided with the support shaft 12 facing forward (see FIG. 9A).

In the present embodiment, first, as shown in FIG. 6, 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 to carry in the substrate with respect to the atmosphere inside the vacuum chamber 2. With the atmosphere in the carry-out chamber 2A isolated, the lid 2a of the board carry-in / carry-out chamber 2A is opened, and the board 50 is transferred to the board 50 on the transfer robot 64 of the support portion 62 of the board carry-in / carry-out mechanism 6 using a transfer robot (not shown). It is attached to the cage 11 and held.

Here, as shown in FIG. 16A, the substrate 50 has the amorphous silicon layer 52 and the amorphous silicon layer 52 on the first surface (front side surface) which is the surface opposite to the film formation side surface of the n-type single crystal silicon substrate 51. Antireflection films 53 having a texture structure are sequentially provided.

On the other hand, an i-type amorphous silicon layer 56 is provided on a second surface (back side surface) which is a film-forming side surface of the n-type single crystal silicon substrate 51, and a p-type amorphous silicon layer 56 is provided on the i-type amorphous silicon layer 56. A silicon layer 57a and an n-type amorphous silicon layer 57b are provided adjacent to each other.

Then, as shown in FIG. 7, after closing the lid 2a of the board loading / unloading chamber 2A, the support portion 62 of the board loading / unloading mechanism 6 is lowered to the board cage delivery position, and the height of the board cage 11 is raised. The height position of the transport drive member 33 is set to be the same as that of the forward side transport portion 33a.

Further, as shown in FIG. 8, the substrate cage 11 is arranged in the substrate cage introduction portion 30A of the substrate cage transport mechanism 3 by the transfer robot 64 provided in the support portion 62 of the substrate loading / unloading mechanism 6.
As a result, as shown in FIG. 9A, the lower surface 11b of the substrate cage 11 is supported by the outbound substrate cage support mechanism 18a.

Next, the first and second drive wheels 31 and 32 of the substrate cage transport mechanism 3 are operated, and the outward transport portion 33a of the transport drive member 33 is changed from the first drive wheel 31 to the second drive wheel 32. At the same time, the return path side transport portion 33c of the transport drive member 33 is moved from the second drive wheel 32 toward the first drive wheel 31.

As a result, as shown in FIG. 9B, the holding recess 37 of the holding drive unit 36 provided on the transport drive member 33 is fitted with the pair of support shafts 12 of the substrate cage 11, and the support shaft 12 is formed. It is held by the holding drive unit 36, and the substrate cage 11 is transported on the outward path side transport portion 33a of the transport drive member 33 toward the transport turn-back portion 30B near the second drive wheel 32.

Then, when passing through the cooling region 7, cooling is performed by radiation from above by the cooling mechanisms 7a and 7b from the first surface (front side surface) side of the substrate 50 held by the substrate cage 11 (see FIG. 1). ..
Specifically, the surface of the antireflection film 53 of the substrate 50 shown in FIG. 16A is cooled from above by the cooling mechanisms 7a and 7b.
As described above, in the present embodiment, since the first surface of the substrate 50 held by the substrate cage 11 is completely exposed, the entire substrate 50 is sufficiently cooled.

10 (a) to 10 (c) are explanatory views showing the operation of the transfer folding portion of the substrate cage transfer mechanism of the present embodiment.
In the present embodiment, as described above, the support shaft 12 of the substrate cage 11 is held by the holding drive unit 36 of the transport drive member 33, and the lower surface 11b of the substrate cage 11 is the outbound side substrate cage support mechanism. It is conveyed toward the transfer folding portion 30B while being supported by 18a (see FIGS. 9A and 9B).

Then, as shown in FIG. 10A, when the support shaft 12 of the substrate cage 11 reaches the upper part of the second drive wheel 32 of the transport folding back portion 30B, the rear end portion of the substrate cage 11 is on the outward path. The dimensions of the substrate cage 11, the arrangement position of the support shaft 12, and the dimensions of the outward path side substrate cage support mechanism 18a are set so as to deviate from the terminal portion 18c of the side substrate cage support mechanism 18a.

Here, the substrate cage 11 rotates about the support shaft 12 in a state where the tip portions 12b of the pair of support shafts 12 are held in the holding recesses 37 of the holding drive portion 36 of the transport drive member 33 as described above. Therefore, in the present embodiment, when the substrate cage 11 is separated from the terminal portion 18c of the outward path side substrate cage support mechanism 18a, one of the pair of support arms 22 of the attitude control mechanism 20 is enabled. A support roller 23 provided at the end supports the lower surface 11b on the rear end side with respect to the support shaft 12 of the substrate cage 11 to maintain a horizontal state.
As described above, the pair of support arms 22 of the attitude control mechanism 20 are configured to rotate in the same direction as the second drive wheels 32 in synchronization with the second drive wheels 32.

As shown in FIG. 10B, in the present embodiment, as the transport drive member 33 moves, the holding drive unit 36 moves from the outward transport side transport portion 33a to the return route side transport portion 33c via the turn-back portion 33b. Move towards.

At the time of this movement, the support shaft 12 of the substrate cage 11 moves in an arc shape around the second drive wheel 32 and descends. In this embodiment, at that time, a pair of supports of the attitude control mechanism 20 The attitude control mechanism 20 supports the lower surface 11b on the rear end side of the substrate cage 11 by the support roller 23 at one end of the arm 22 so that the posture of the substrate cage 11 is kept substantially horizontal. The dimensions and rotation angle of the support arm 22 are set.

Further, during this movement, the support shaft 12 of the substrate cage 11 supported by the holding recess 37 of the holding drive unit 36 is located below the holding recess 37 of the holding drive unit 36, so that gravity A force acting in the direction of detaching from the holding recess 37 of the holding drive unit 36 acts on the support shaft 12 of the substrate cage 11, but in the present embodiment, as described above, the support shaft 12 of the substrate cage 11 In a state where each of the tip portions 12b (see FIG. 4A) is fitted and held in the holding recess 37 of the holding drive portion 36 of the transport drive member 33, the tip portion 12b of the support shaft 12 of the substrate cage 11 and Since it is configured so that a slight gap is formed between the guide member 38 and the guide member 38, the tip portion 12b of the support shaft 12 of the substrate cage 11 has a slight gap with respect to the holding recess 37 of the holding drive portion 36. Is generated, and is supported by contacting with the inner portion of the guide member 38.
As a result, in the present embodiment, the substrate cage 11 does not fall off from the holding drive unit 36 of the transport driving member 33 when passing through the transport folding back portion 30B.

Further, as shown in FIG. 10C, when the support shaft 12 of the substrate cage 11 reaches the lower part of the second drive wheel 32 of the transport folding back portion 30B, the support shaft 12 of the substrate cage 11 is provided. The end on the opposite side to the side is the tip on the transport direction side, but in the present embodiment, at this point, the lower surface 11b of the tip of the substrate cage 11 is smoothly the return path side substrate cage support mechanism 18b. The dimensions and rotation angle of the support arm 22 of the posture control mechanism 20 are set so that the support roller 23 of the support arm 22 is separated from the lower surface 11b of the substrate cage 11.

At this point, the dimensions and rotation angle of the support arm 22 of the attitude control mechanism 20 are adjusted so that the support roller 23a at the other end of the support arm 22 supports the lower surface 11b of the subsequent substrate cage 11. It is set.
From the above, according to the present embodiment, it is possible to carry out the transfer without changing the vertical relationship of the substrate cage 11 when the transfer is performed via the transfer folding portion 30B.

After that, by continuing the operation of the first and second drive wheels 31 and 32 of the substrate cage transport mechanism 3, as shown in FIGS. 11A and 11B, the return path side substrate cage support mechanism 18b is provided. The supported substrate cage 11 is moved from the transport folding back portion 30B toward the substrate cage discharge portion 30C by the operation of the holding drive portion 36 of the return path side transport portion 33c of the transport drive member 33.

During this operation, when passing through the positions of the first and second film forming regions 4 and 5 with respect to the substrate 50 held by the substrate cage 11, the first and second and second positions located below the substrate cage 11 A film is formed by sputtering using the second sputtering sources 4T and 5T, respectively (see FIG. 1).

In this case, in the substrate cage transport mechanism 3 of the present embodiment, as described above, the vertical relationship of the substrate cage 11 does not change when the substrate cage 11 is transported via the transport folding back portion 30B, so that the substrate cage 11 is used. A film is formed on the second surface of the held substrate 50 opposite to the first surface.

As described above, in the present embodiment, the opening 15 on the second surface (back side surface) side of the substrate 50 held by the substrate cage 11 is provided with the mask 15a having a predetermined pattern. , A metal layer having a predetermined pattern is formed on the second surface of the substrate 50.

Specifically, back electrode layers 58a and 58b made of metal are formed on the surfaces of the p-type amorphous silicon layer 57a and the n-type amorphous silicon layer 57b of the substrate 50 shown in FIG. 16B by sputtering, respectively. The target substrate 59 after film formation is obtained.

After that, when the substrate cage 11 reaches the substrate cage discharge portion 30C and then the substrate cage 11 reaches the terminal portion of the guide member 38 of the substrate cage discharge portion 30C, as shown in FIG. 12A, Since the portion of the substrate cage 11 on the downstream (front) side in the transport direction protrudes from the terminal portion of the return path side substrate cage support mechanism 18b and the guide member 38, the support portion 62 of the substrate loading / unloading mechanism 6 is mounted on the substrate. It is arranged at the cage take-out position (see FIG. 13), and the lower surface 11b of the substrate cage 11 is supported by the mounting portion 65 constituting the transfer robot 64 of the substrate loading / unloading mechanism 6 described above.

Further, when the operation of the transport drive member 33 is continued, the holding drive unit 36 that moves together with the transport drive member 33 around the first drive wheel 31 moves from the support shaft 12 of the substrate cage 11 together with the arc-shaped transport drive member 33. Since they move upward apart from each other, as shown in FIG. 12B, the holding drive unit 36 of the transport drive member 33 and the support shaft 12 of the substrate cage 11 are disengaged, and the substrate cage 11 is disengaged. Stop at that position.

Therefore, using the transfer robot 64 of the board loading / unloading mechanism 6, as shown in FIG. 13, the board cage 11 is taken out from the board cage discharge section 30C to the board loading / unloading mechanism 6 side, and together with the transfer robot 64, on the support portion 62. Place in.

After that, as shown in FIG. 14, the support portion 62 of the substrate loading / unloading mechanism 6 is raised, and the seal member 63 on the support portion 62 is brought into close contact with the inner wall of the vacuum chamber 2 so that the substrate is exposed to the atmosphere inside the vacuum chamber 2. Isolate the atmosphere in the carry-in / carry-out room 2A.

Then, as shown in FIG. 15, the lid 2a of the substrate loading / unloading chamber 2A is opened, and the film-deposited substrate 59 is taken out from the substrate cage 11 into the atmosphere by using a transfer robot (not shown).
As a result, the basic cooling step and the film forming step in the present embodiment are completed.

By the way, in the above-described embodiment, the case where the film is formed once in the first and second film forming regions 4 and 5 on the substrate 50 has been described as an example, but the present invention has the first and the second. It is also possible to configure the film formation region 4 and 5 to pass through the film formation regions 4 and 5 a plurality of times to perform a plurality of film formations, and in that case, it is more effective.

In this case, for example, as shown in FIG. 17, the support portion 62 of the substrate loading / unloading mechanism 6 is arranged at the substrate cage take-out position, and the transfer robot 64 is used to hold the substrate 59 after the first film formation. The substrate cage 11 is taken out from the substrate cage discharge portion 30C to the substrate loading / unloading mechanism 6 side and arranged on the support portion 62 together with the transfer robot 64.

Then, as shown in FIG. 18, the support portion 62 of the substrate loading / unloading mechanism 6 is raised to the substrate cage delivery position, and the height of the substrate cage 11 is the same as the outbound side transport portion 33a of the transfer drive member 33. The substrate cage 11 is delivered to the substrate cage introduction portion 30A of the substrate cage transfer mechanism 3 by the transfer robot 64 on the support portion 62 of the substrate loading / unloading mechanism 6 and arranged so as to be in the vertical position.

Then, as described above, the substrate cage 11 is transported on the outward-passing transport portion 33a of the transport drive member 33 toward the transport folding portion 30B, and the first surface of the substrate 50 held by the substrate cage 11 (table). The side surface) is cooled for the second time from above by the cooling mechanisms 7a and 7b.

Then, with the substrate cage 11 maintained in a vertical relationship, the substrate cage 11 is folded back from the outward transport side transport portion 33a of the transport drive member 33 toward the return route side transport portion 33c via the transport turn-back portion 30B, and the first and second The second metal layer is formed by sputtering on the second surface (back side surface) of the substrate 59 after the first film formation held in the substrate cage 11 after passing through the metal layer film forming regions 4 and 5 of the above. I do.
Further, by repeating the above-mentioned operations and steps, it is possible to perform the cooling step and the film forming step three or more times on the substrate 59.

As described above, in the present embodiment, the outbound side transport portion 33a for transporting the substrate cage 11 in a predetermined direction along the transport path and the substrate in the vacuum tank 2 in which a single vacuum atmosphere is formed. The return path side transport section 33c that transports the cage 11 along the transport path in the direction opposite to the transport direction of the outward path side transport section 33a, and the board cage 11 from the outward path side transport section 33a to the return path side while maintaining the vertical relationship. A substrate cage transport mechanism 3 having a transport folding section 30B that folds back toward the transport section 33c is provided, the outward transport section 33a passes through the cooling region 7, and the return path side transport section 33c is the first. It is provided so as to pass through the first and second metal layer film forming regions 4 and 5.

In such an embodiment, in the substrate cage transport mechanism 3, the substrate cage 11 is transported in a predetermined direction along the transport path so as to pass through the cooling region 7 by the outbound side transport unit 33a, and the substrate cage is transported. While the substrate 50 is cooled from the first surface (front side surface) side of the substrate 50 held by 11, the substrate cage 11 is moved by the return path side transport portion 33c to the first and second metal layer film forming regions 4, A metal layer is transported along the transport path so as to pass through 5 in the direction opposite to the transport direction of the outward transport unit 33a, and is bonded onto the second surface (back side surface) of the substrate 50 held by the substrate cage 11. The film is formed.

As a result, in the present embodiment, by forming the metal layer on the substrate 50 in a sufficiently cooled state by sputtering, it is possible to reliably prevent the temperature rise of the substrate 50 at the time of film formation. As a result, the influence on the film of the other layer of the substrate 50 can be suppressed.

Further, when forming a thick metal layer on the substrate 50, it is necessary to repeatedly form the metal layer, but in the present embodiment, sputtering is performed on the second surface (back surface) of the substrate 50. By cooling the substrate 50 on which the metal layer is formed from the above, from the first surface (front side surface) side of the substrate 50 without cooling from the metal layer side having a low radiation rate, the substrate 50 is efficiently cooled. Cooling can be performed and the temperature can be surely lowered, whereby the influence on the film of the other layer of the substrate 50 can be suppressed.

Further, in the present embodiment, the transport path is formed so as to form a series of rings when projected onto the vertical surface, and while the cooling step is performed by the outward transport side transport portion 33a, the return side transport is performed. By forming a metal layer by sputtering in the portion 33c, the metal layer is formed on the substrate 50 by the compact pass-through type film forming apparatus 1 while suppressing the influence on the film of the other layer of the substrate 50. Can be done.

According to the present embodiment as described above, there is provided a technique for manufacturing a heterojunction type solar cell capable of efficiently and surely cooling when a back electrode made of metal is formed on a substrate 50 by sputtering. be able to.

Further, in the present embodiment, since the plurality of substrate cages 11 for arranging and holding the plurality of substrates 50 in the direction orthogonal to the transport direction are configured to be transported along the transport path. To reduce the length of the substrate cage and the excess space associated therewith, as compared with the case of transporting a substrate cage that holds a plurality of substrates side by side in the substrate transport direction as in the prior art. Therefore, space saving can be achieved.

FIG. 19 is a schematic configuration diagram showing the whole of other embodiments of the film forming apparatus according to the present invention. Hereinafter, the parts corresponding to the above embodiments are designated by the same reference numerals and detailed description thereof will be omitted. To do.

In the present embodiment, a first transparent conductive oxide layer film forming region 81 having a sputtering source 81T is provided in the upper part of the vacuum chamber 2 with the substrate cage transport mechanism 3 sandwiched therein, and sputtering is performed in the lower part of the vacuum chamber 2. A second transparent conductive oxide layer film forming region 82 having a source 82T is provided.
Gas introduction mechanisms (not shown) for introducing a predetermined sputter gas are provided in the first and second transparent conductive oxide layer film forming regions 81 and 82, respectively.

Here, the first transparent conductive oxide layer film-forming region 81 forms the first transparent conductive oxide layer 54A described later on the first surface (front side surface in the present embodiment) of the substrate 50A. The sputter source 81T is arranged between the first drive wheel 31 and the second drive wheel 32 above the outward transport portion 33a of the transport drive member 33.

On the other hand, the second transparent conductive oxide layer film forming region 82 forms the second transparent conductive oxide layer 58A described later on the second surface (back surface in the present embodiment) of the substrate 50A. A sputter source 82T is arranged between the first drive wheel 31 and the second drive wheel 32 below the return path side transport portion 33c of the transport drive member 33.
In the case of the present embodiment, the first and second transparent conductive oxide layer film forming regions 81 and 82 are provided in the vicinity of the second drive wheel 32, respectively.

Further, a metal layer film forming region 9 is provided on the upper part of the substrate cage transport mechanism 3 in the vacuum chamber 2.
The metal layer film forming region 9 of the present embodiment forms the metal layer 55A described later on the first surface (front side surface in the present embodiment) of the substrate 50A, and the first and first surfaces of the above embodiment. It has the same structure as the metal layer film forming regions 4 and 5 of 2.

Here, the metal layer film forming region 9 is located between the first drive wheel 31 and the second drive wheel 32, above the outbound side transfer portion 33a of the transfer drive member 33, and in the vicinity of the first drive wheel 31. A sputter source 9T is arranged in the above.

A cooling region 7 for cooling the substrate 50A held by the substrate cage 11A corresponding to the substrate cage 11 of the above embodiment is provided in the lower part of the substrate cage transport mechanism 3 in the vacuum chamber 2. There is.
In the cooling region 7 of the present embodiment, the cooling mechanism 7a is arranged below the return path side transport portion 33c of the transport drive member 33 between the first drive wheel 31 and the second drive wheel 32, and the substrate is held. It is configured to cool the second surface (the back surface in the present embodiment) opposite to the first surface forming the metal layer with respect to the substrate 50A held by the vessel 11A.

The first transparent conductive oxide layer film forming region 81 and the metal layer film forming are formed on the opposite side of the cooling mechanism 7a with the return path side transport portion 33c of the transport drive member 33, that is, above the return path side transport portion 33c. A shielding member 7c for shielding heat from the region 9 to the cooling mechanism 7a is provided.

Further, between the cooling mechanism 7a and the second transparent conductive oxide layer film forming region 82, a shielding member 7d for shielding heat from the second transparent conductive oxide layer film forming region 82 to the cooling mechanism 7a. Is provided.

When forming a film on the substrate 50A in the present embodiment having such a configuration, first, the substrate 50A introduced into the vacuum chamber 2 is held by the substrate cage 11A in the same manner as in the above embodiment. , The substrate cage 11A is arranged in the substrate cage introduction portion 30A of the substrate cage transport mechanism 3 (see, for example, FIGS. 6 to 8 of the above embodiment).

In the substrate 50A of the present embodiment, as shown in FIG. 24A, an i-type amorphous silicon layer 52A and a p-type amorphous silicon layer 53A are sequentially provided on the first surface of the n-type crystalline silicon substrate 51A. The i-type amorphous silicon layer 56A and the n-type amorphous silicon layer 57A are sequentially provided on the second surface of the n-type crystalline silicon substrate 51A.

Unlike the substrate cage 11 of the above embodiment, the substrate cage 11A used in the present embodiment is not provided with a mask so that the film can be completely formed on both surfaces of the substrate 50A. It is configured.

Also in the present embodiment, the substrate cage 11A arranged in the substrate cage introduction portion 30A of the substrate cage transport mechanism 3 is operated by operating the substrate cage transport mechanism 3 as shown in FIG. The substrate cage 11A is moved from the cage introduction portion 30A toward the transport folding portion 30B.

Then, when the substrate 50A held by the substrate cage 11A passes through the first transparent conductive oxide layer film forming region 81, the sputter source 81T located above the substrate cage 11A causes the substrate 50A to become the first. A film is formed on one surface (front side surface) by sputtering.
Specifically, as shown in FIG. 24 (b), the first transparent conductive oxide layer 54A is entirely formed on the surface of the p-type amorphous silicon layer 53A of the substrate 50A by sputtering.

After that, by continuing the operation of the substrate cage transport mechanism 3, the substrate cage 11A is reversed in the transport direction by the operation of the transport folding back portion 30B without changing its vertical relationship, as in the above embodiment. , The transfer drive member 33 is moved toward the substrate cage discharge section 30C via the return path side transport section 33c (see FIG. 21).

During this operation, when passing through the second transparent conductive oxide layer film forming region 82 with respect to the second surface (back side surface) of the substrate 50A held by the substrate cage 11A, it is below the substrate cage 11A. A film is formed by sputtering with a sputtering source 82T located at.

Specifically, as shown in FIG. 24 (c), a second transparent conductive oxide layer 58A is entirely formed on the surface of the n-type amorphous silicon layer 57A of the substrate 50A by sputtering.

Further, when passing through the cooling region 7, a predetermined cooling step is performed from the second surface (back side surface) side of the substrate 50A held by the substrate cage 11A.
After that, as shown in FIGS. 21 and 22, for example, the support portion 62 of the substrate loading / unloading mechanism 6 is arranged at the substrate cage take-out position, and the transfer robot 64 is used to use the first and second transparent conductive oxide layers 54A. , The substrate cage 11A holding the substrate 50A for which the film formation of 58A has been completed is taken out from the substrate cage discharge portion 30C to the substrate loading / unloading mechanism 6 side and arranged on the support portion 62 together with the transfer robot 64.

Then, as shown in FIG. 23, the support portion 62 of the substrate loading / unloading mechanism 6 is raised to the substrate cage delivery position, and the height of the substrate cage 11A is as high as the outward path side transport portion 33a of the transfer drive member 33. The substrate cage 11A is delivered to the substrate cage introduction portion 30A of the substrate cage transport mechanism 3 by the transfer robot 64 on the support portion 62 of the substrate loading / unloading mechanism 6 and arranged so as to be in the vertical position.

Further, by operating the substrate cage transport mechanism 3 as described above, the substrate cage 11A is transported again on the outward transport side transport portion 33a of the transport drive member 33 toward the transport turn-back portion 30B.
During this operation, the sputtering source 9T located above the substrate cage 11A when passing through the metal layer film forming region 9 on the first surface (front side surface) of the substrate 50A held by the substrate cage 11A. The film is formed by sputtering.

Specifically, as shown in FIG. 24D, the metal layer 55A is entirely formed on the surface of the first transparent conductive oxide layer 54A of the substrate 50A by sputtering.
By the above steps, the first transparent conductive oxide layer forming step, cooling step, and metal layer forming step in the present embodiment are completed, and the substrate 59A after film formation is obtained.

On the other hand, when the above-mentioned metal layer 55A is formed to be thicker, the above-mentioned first and second transparent conductive oxide layers 54A and 58A are not formed, and the above-mentioned metal layer forming step and cooling are performed. Repeat the process.

In order to prepare a linear electrode portion for a solar cell from the metal layer 55A formed on the first transparent conductive oxide layer 54A, the substrate 59A after the film formation is taken out from the vacuum chamber 2 and known. Processing such as etching may be performed.

As described above, in the present embodiment, the outbound side conveying portion 33a for conveying the substrate cage 11A in a predetermined direction along the conveying path and the substrate holding in the vacuum tank 2 in which a single vacuum atmosphere is formed. The return path side transport section 33c that transports the vessel 11A along the transport path in the direction opposite to the transport direction of the outward path side transport section 33a, and the board cage 11A are transported from the outward path side transport section 33a to the return path side while maintaining the vertical relationship. A substrate cage transport mechanism 3 having a transport-folding portion 30B that folds back and transports toward the portion 33c is provided, and the outward-passing transport portion 33a passes through the first transparent conductive oxide layer film-forming region 81 and is conveyed. The return path side transport section 33c passes through the second transparent conductive oxide layer film forming region 82, the outward path side transport section 33a passes through the metal layer film formation region 9, and the return path side transport section 33c is formed. It is provided so as to pass through the cooling region 7.

In such an embodiment, in the substrate cage transport mechanism 3, the substrate cage 11A is formed with the first and second transparent conductive oxide layers, for example, via the outward transport side transport portion 33a and the return route side transport portion 33c. The first and second transparent conductive oxide layers are conveyed in a predetermined direction and in opposite directions along a transfer path so as to pass through the regions 81 and 82, and are subjected to sputtering on both surfaces of the substrate 50A held by the substrate cage 11A. After that, the substrate cage 11A is conveyed in a predetermined direction along the conveying path so as to pass through the metal layer film forming region 9 by the outbound side conveying portion 33a, and the substrate held by the substrate cage 11A is conveyed. A metal layer is formed on the first surface (front side surface) of 50A by sputtering, and the substrate cage 11A is transported along the transport path along the transport path so as to pass through the cooling region 7 by the return path side transport unit 33c. The portion 33a can be conveyed in a direction opposite to the conveying direction, and cooling can be performed from the second surface (back side surface) side of the substrate 50A held by the substrate cage 11A.

As a result, in the present embodiment, the first and second transparent conductive oxide layers are formed on both surfaces of the substrate, and a metal layer is formed by sputtering on the substrate 50A in a state of being sufficiently cooled by the cooling step. By performing the above, it is possible to surely prevent the temperature rise of the substrate 50A at the time of film formation, and thereby it is possible to suppress the influence on the films of other layers.

Further, when cooling the substrate 59A in which the first and second transparent conductive oxide layers are formed on both surfaces of the substrate and the metal layer 55A is formed by sputtering on the first surface (front side surface), radiation is emitted. By cooling from the second surface (back side surface) side of the substrate 50A on which the metal layer is not formed without cooling from the metal layer side having a low rate, the substrate 50A is efficiently cooled and its temperature. Can be reliably reduced, whereby the influence of the substrate 50A on the film of the other layer can be suppressed.

Further, in the case of forming the metal layer 55A thickly on the substrate 59A, it is necessary to repeatedly form the metal layer, but also in the present embodiment, the metal layer 55A is similarly formed in the above embodiment. Since cooling can be performed every time the film is formed, it is possible to efficiently cool the substrate and reliably prevent the temperature of the substrate 50A from rising.

According to the present embodiment, there is provided a technique for manufacturing a heterojunction solar cell capable of efficiently and surely cooling when a surface electrode made of metal is formed on a substrate 50A by sputtering. be able to.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, in the above embodiment, as the substrate cage 11, a plurality of substrates 50 are arranged and held in a row in the longitudinal direction of the long frame-shaped main body portion 11a, but the present invention is not limited to this. For example, a plurality of substrates 50 may be arranged and held in a plurality of rows (two to three rows) in the longitudinal direction of the main body portion 11a.

Furthermore, in the above embodiment, the case where the metal layer for the electrode is formed on one side of the substrates 50 and 50A of the heterojunction type solar cell has been described as an example, but the present invention is not limited to this, and the substrate to be filmed is not limited to this. It can be applied when various metal sputtered films are formed on one side of the above.
However, the present invention is particularly effective when a metal layer for an electrode is formed on one side of a substrate to be formed into a heterojunction solar cell.

On the other hand, in the above-described embodiment, the upper portion of the transport drive member 33 is the outward transport portion 33a, which is the first transport portion, and the lower portion of the transport drive member 33 is the second transport portion. Although the return-side transport portion 33c, which is a portion, is used, the present invention is not limited to this, and the vertical relationship between them can be reversed.
Along with this, the vertical relationship between the metal layer forming region and the cooling region can be reversed.

Further, in the above embodiment, the front side surface of the film-forming target substrate is the first surface and the back side surface is the second surface, but the back side surface of the film-forming target substrate is the first surface and the front side surface is the second surface. It can also be.

1 ... Film formation device 2 ... Vacuum tank 3 ... Substrate cage transport mechanism 4 ... First metal layer film formation region 4T ... Sputter source 5 ... Second metal layer film formation region 5T ... Sputter source 6 ... Substrate loading / unloading mechanism 7 ... Cooling region 11 ... Board cage 30A ... Board cage introduction unit 30B ... Transfer folding unit 30C ... Board cage discharge unit 33 ... Transfer drive member 33a ... Outward route side transfer unit (first transport unit)
33b ... Folded portion 33c ... Return route side transport section (second transport section)
50 ... Substrate to be filmed 59 ... Substrate to be filmed

Claims (9)

A vacuum chamber in which a single vacuum atmosphere is formed,
A cooling region provided in the vacuum chamber to cool the film-forming target substrate held in the substrate cage from the first surface side, and
A metal layer film forming region having a sputtering source for forming a metal layer on the second surface of the film forming target substrate provided in the vacuum chamber and held in the substrate cage.
A transport path formed so that the projected shape with respect to the vertical plane is a series of rings and passed through the metal layer film forming region and the cooling region.
It is provided with a substrate cage transport mechanism that transports the substrate cage horizontally along the transport path.
The substrate cage transport mechanism transports a first transport unit that transports the substrate cage in a predetermined direction along the transport path, and a transport unit that transports the substrate cage along the transport path. A second transport section that transports in the direction opposite to the direction, and a transport folding section that folds back and transports the substrate cage from the first transport section toward the second transport section while maintaining the vertical relationship. Have,
The first transport unit passes through one of the metal layer film forming region and the cooling region, and the second transport portion passes through the other of the metal layer film forming region and the cooling region. A film forming apparatus provided so as to perform. A vacuum chamber in which a single vacuum atmosphere is formed,
A first transparent conductive oxide layer film forming region provided in the vacuum chamber and having a sputtering source for forming a transparent conductive oxide layer on the first surface of the substrate to be filmed held in a substrate cage. When,
A second transparent conductive oxide layer having a sputter source provided in the vacuum chamber and having a sputter source for forming a transparent conductive oxide layer on the second surface of the film-forming target substrate held in the substrate cage. Membrane area and
A cooling region provided in the vacuum chamber and held in the substrate cage to cool the film-forming target substrate from the second surface side.
A metal layer film forming region having a sputtering source for forming a metal layer on the first surface of the film forming target substrate provided in the vacuum chamber and held in the substrate cage.
The projected shape with respect to the vertical plane is formed so as to form a series of rings, and is provided so as to pass through the first and second transparent conductive oxide layer film forming regions, the metal layer film forming region, and the cooling region. Transport route and
It is provided with a substrate cage transport mechanism that transports the substrate cage horizontally along the transport path.
The substrate cage transport mechanism transports a first transport unit that transports the substrate cage in a predetermined direction along the transport path, and a transport unit that transports the substrate cage along the transport path. A second transport section that transports in the direction opposite to the direction, and a transport folding section that folds back and transports the substrate cage from the first transport section toward the second transport section while maintaining the vertical relationship. Have,
The first transport section passes through one of the first and second transparent conductive oxide layer film forming regions, and the second transport section is the first and second transparent conductive oxidation. While passing through the other of the material layer film formation regions
The first transport unit passes through one of the metal layer film forming region and the cooling region, and the second transport portion passes through the other of the metal layer film forming region and the cooling region. A film forming apparatus provided so as to perform. Claim 1 is configured such that the substrate cage holding the substrate to be film-formed after film formation is taken out from the substrate cage transport mechanism, and the taken-out substrate cage is introduced into the substrate cage transport mechanism. Or the film forming apparatus according to any one of 2. The film forming apparatus according to any one of claims 1 to 3, wherein the substrate cage is configured to arrange and hold a plurality of film forming target substrates in a direction orthogonal to the transport direction. A film forming method using the film forming apparatus according to any one of claims 1, 3 or 4.
The substrate cage is conveyed in a predetermined direction along the transfer path so as to pass through the cooling region by one of the first and second transfer portions of the substrate cage transfer mechanism, and is transferred to the substrate cage. A cooling step of cooling from the first surface side of the held substrate to be filmed, and
The substrate cage is transported by the other of the first and second transport portions of the substrate cage transport mechanism along the transport path in a direction opposite to the predetermined direction so as to pass through the metal layer film forming region. A film forming method comprising a metal layer film forming step of forming a metal layer on the second surface of the film forming target substrate held by the substrate cage by sputtering. A film deposition method using the film deposition apparatus of claim 2 Symbol placement,
The substrate cage is transported in a predetermined direction along the transport path so as to pass through the first transparent conductive oxide layer film forming region by the first transport portion of the substrate cage transport mechanism, and the substrate is held. A step of forming a first transparent conductive oxide layer by sputtering on the first surface of the film-forming target substrate held in the vessel, and
The substrate cage is conveyed in the direction opposite to the predetermined direction along the transfer path so as to pass through the second transparent conductive oxide layer film forming region by the second transfer portion of the substrate cage transfer mechanism. A step of forming a second transparent conductive oxide layer on the second surface of the film-forming target substrate held by the substrate cage by sputtering.
The substrate cage is conveyed by the second transfer portion of the substrate cage transfer mechanism along the transfer path in the direction opposite to the predetermined direction so as to pass through the cooling region, and is held by the substrate cage. A cooling step of cooling the film-forming target substrate from the second surface side,
The substrate cage is transported in the predetermined direction along the transport path so as to pass through the metal layer film forming region by the first transport portion of the substrate cage transport mechanism, and is held by the substrate cage. A film forming method including a metal layer film forming step of forming a metal layer on the first surface of the film forming target substrate by sputtering. The substrate cage holding the film-forming target substrate after film formation is taken out from the substrate cage transport mechanism, and the taken-out substrate cage is introduced into the substrate cage transport mechanism, and the cooling step and the metal layering are performed. 6 Symbol mounting film forming method according to claim comprising the step of performing a plurality of times the membrane process. A method for manufacturing a solar cell using the film forming apparatus according to any one of claims 1, 3 or 4.
An amorphous silicon layer and an antireflection film having a texture structure are sequentially provided on the first surface of the n-type single crystal silicon substrate, and the i-type amorphous silicon layer and p are placed on the second surface of the n-type single crystal silicon substrate. Prepare a substrate for film formation in which a type amorphous silicon layer and an n-type amorphous silicon layer are provided adjacent to each other.
The substrate cage is conveyed in a predetermined direction along the transfer path so as to pass through the cooling region by one of the first and second transfer portions of the substrate cage transfer mechanism, and is transferred to the substrate cage. A cooling step of cooling the held substrate to be filmed from the first surface side, and
The substrate cage is transported by the other of the first and second transport portions of the substrate cage transport mechanism along the transport path in a direction opposite to the predetermined direction so as to pass through the metal layer film forming region. A method for manufacturing a solar cell, which comprises a metal layer film forming step of forming a metal layer for a back surface electrode on a second surface of the film forming target substrate held by the substrate cage by sputtering. A method of manufacturing a solar cell using the film deposition apparatus of claim 2 Symbol placement,
An i-type amorphous silicon layer and a 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 and the n-type are provided on the second surface of the n-type crystalline silicon substrate. Prepare a substrate for film formation on which amorphous silicon layers are sequentially provided,
The substrate cage is transported in a predetermined direction along the transport path so as to pass through the first transparent conductive oxide layer film forming region by the first transport portion of the substrate cage transport mechanism, and the substrate is held. A step of forming a first transparent conductive oxide layer by sputtering on the first surface of the film-forming target substrate held in the vessel, and
The substrate cage is conveyed in the direction opposite to the predetermined direction along the transfer path so as to pass through the second transparent conductive oxide layer film forming region by the second transfer portion of the substrate cage transfer mechanism. A step of forming a second transparent conductive oxide layer on the second surface of the film-forming target substrate held by the substrate cage by sputtering.
The substrate cage is conveyed by the second transfer portion of the substrate cage transfer mechanism along the transfer path in the direction opposite to the predetermined direction so as to pass through the cooling region, and is held by the substrate cage. A cooling step of cooling the film-forming target substrate from the second surface side,
The substrate cage is transported in the predetermined direction along the transport path so as to pass through the metal layer film forming region by the first transport portion of the substrate cage transport mechanism, and is held by the substrate cage. A method for manufacturing a solar cell, which comprises a metal layer film forming step of forming a metal layer for a surface electrode on the first surface of the film forming target substrate by sputtering.

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