Patent Application
20110189384
The present invention relates to a thin-film solar cell manufacturing apparatus. Priority is claimed on Japanese Patent Application No. 2008-149933 filed on Jun. 6, 2008, the contents of which are incorporated herein by reference.
Most current solar cells are a single crystal Si type solar cell and a polycrystal Si type solar cell. However, due to material shortages of Si or the like, demand has recently been increasing for thin-film solar cells formed with a thin-film Si-layer in which manufacturing costs are low and the risk of material shortages is low. Moreover, in addition to conventional thin-film solar cell with only an a-Si (amorphous silicon) layer, a demand for tandem-type thin-film solar cells has recently been increasing, in which the conversion efficiency of the tandem-type thin-film solar cells is improved by laminating an a-Si-layer and a μc-Si (microcrystalline silicon) layer.
A plasma-CVD apparatus is often used for forming a thin-film Si-layer (semiconductor layer) for the thin-film solar cell. As such a plasma-CVD apparatus, for example a single-wafer-type PE-CVD (plasma CVD) apparatus, an in-line type PE-CVD apparatus, a batch-type PE-CVD apparatus, and the like exist.
Here, when the conversion efficiency of a thin-film solar cell is taken into consideration, the μc-Si layer of the tandem-type solar cell needs to be formed with a film thickness (about 1.5 μm) of approximately five times larger than that of the a-Si layer. Additionally, since the μc-Si layer needs to uniformly form a good microcrystalline layer, there is a limit on increasing a film formation rate. Accordingly, there is a need to increase the number of batch processing to improve productivity. That is, an apparatus which can realize higher throughput at a lower film formation rate is needed.
Additionally, a CVD apparatus which can form a high-quality thin film and can lower manufacturing costs or maintenance costs is proposed in Patent Literature 1. For example, the CVD apparatus of Patent Literature 1 includes a substrate (base) delivery-dispensing apparatus, a film forming chamber group which can store a plurality of substrates, a transfer chamber, and a chamber transfer apparatus. A shutter with airtightness is provided at an inlet and outlet port of a film forming room of a film forming chamber, and an inlet and outlet port of a storage chamber of the transfer chamber is always open. Also, when forming a Si-layer on a substrate, the transfer chamber is transferred to a position of the substrate delivery-dispensing apparatus by the chamber transfer apparatus, and a substrate carrier is transferred to the transfer chamber side. Additionally, the transfer chamber and the film forming chamber are joined together by the chamber transfer apparatus, the substrate carrier is transferred to the film forming chamber, and a Si layer is formed on the substrate.
Meanwhile, in the CVD apparatus of Patent Literature 1, in order to form a thin-film Si-layer on a substrate, the transfer chamber is joined to the film forming chamber, the shutter of the film forming chamber is opened after the inside of the transfer chamber is brought into a vacuum state, and the substrate carrier is transferred to the film forming chamber from the transfer chamber. Thereafter, the substrate is heated within the film forming chamber, and a thin-film Si-layer is formed on the substrate by a plasma CVD method. After the film forming of the thin-film Si-layer is ended, the substrate is cooled, and the substrate is conveyed to the other processing chambers. Accordingly, although Si-layers can be simultaneously formed on a plurality of substrates, in order to form a thin-film Si-layer on a substrate, a number of other steps are required besides the film forming step to the substrate. Additionally, in order to realize a high throughput, it is necessary to increase the installation number of CVD apparatuses. However, when the effects of the apparatuses on the installation area and the cost are taken into consideration, there is a limit on increasing the installation number of the CVD apparatuses.
Additionally, a heater is provided in the transfer chamber in the Patent Literature 1, and a substrate is heated to a predetermined temperature in advance before being moved to the film forming chamber. That is, a heater function is provided in both the transfer chamber and the film forming chamber. Thereby, there are a problems in that the apparatus becomes expensive, and the energy consumed when a film is formed becomes large.
The object of the present invention is to provide a thin-film solar cell manufacturing apparatus which can reduce consumption energy, and can realize high productivity, low manufacturing cost, and high throughput.
A thin-film solar cell manufacturing apparatus related to a first aspect of the present invention includes: a film forming chamber that is evacuated to a reduced pressure and forms a film on a substrate using a CVD method, a loading-ejecting chamber that is connected to the film forming chamber via a first opening-closing part and that is switchable between atmospheric pressure and reduced pressure, a first carrier that holds a pre-processed substrate, and a second carrier that holds a post-processed substrate; wherein the loading-ejecting chamber simultaneously stores the first carrier and the second carrier.
The loading-ejecting chamber may alternately store a plurality of the first carriers and a plurality of the second carriers.
The loading-ejecting chamber may simultaneously store the first carrier and a plurality of the second carriers in a state where the internal pressure of the loading-ejecting chamber is reduced.
At least one of a plurality of the first carriers and a plurality of the second carriers may be movable in a direction substantially perpendicular to a moving direction to the film forming chamber within the loading-ejecting chamber.
The first carrier and the second carrier may hold the substrate in a vertical posture where a surface to be film-formed of the substrate is parallel to a direction of gravitational force.
The first carrier and the second carrier may hold a plurality of the substrates so that the substrates are parallel to each other and face each other.
The loading-ejecting chamber may have a carrier transfer mechanism which collectively transfers a plurality of the second carriers to the loading-ejecting chamber from the film forming chamber.
The carrier transfer mechanism may collectively transfer a plurality of the first carriers to the film forming chamber from the loading-ejecting chamber.
The thin-film solar cell manufacturing apparatus may further include a plurality of process modules in which one film forming chamber is connected to one loading-ejecting chamber, and the plurality of process modules is arranged in parallel.
A plurality of the film forming chambers may be connected to one loading-ejecting chamber.
According to the above aspect, since the pre-processed substrate and the post-processed substrate can be simultaneously stored in the loading-ejecting chamber, the evacuation process of the loading-ejecting chamber can be reduced by half. Accordingly, productivity can be markedly improved. Additionally, when the post-processed substrate and the pre-processed substrate are simultaneously stored in the loading-ejecting chamber, the heat accumulated in the post-processed substrate is transferred to the pre-processed substrate, whereby heat exchange is performed. That is, a heating process which is usually performed after storing the pre-processed substrate in the film forming chamber, and a cooling process which is usually performed before carrying the post-processed substrate out of the loading-ejecting chamber can be omitted.
As a result, the heating process and the cooling process become unnecessary, productivity can be improved, and the conventional devices used for the heating process and the cooling process can be reduced. Therefore, space saving and lower cost can be simultaneously achieved.
According to the above aspect, the first carrier and the second carrier are adjacent to each other when being simultaneously stored in the loading-ejecting chamber. Therefore, the heat accumulated in the post-processed substrate held by the second carrier is efficiently transferred to the pre-processed substrate held by the first carrier, so that heat exchange can be performed reliably.
According to the above aspect, a conveyance passage along which a substrate is carried into and carried out of the loading-ejecting chamber can be fixed. Accordingly, the size of the apparatus itself can be kept down, and the installation space of the apparatus can be reduced.
According to the above aspect, the area required for a substrate to move within the apparatus can be reduced. Thus, the apparatus can be miniaturized, and a larger number of apparatuses can be arranged in the same installation area as in the conventional technique. Accordingly, the number of substrates on which films can be simultaneously formed can be increased, and productivity can be improved. Additionally, when a film is formed on a substrate in a state where the substrate is erected in the vertical direction, particles generated when forming a film can be kept from depositing on the film formation face of the substrate. Accordingly, a high-quality semiconductor layer can be formed on the substrate.
According to the above aspect, since films can be simultaneously formed on a plurality of substrates in one carrier, productivity can be further improved.
According to the above aspect, the number of substrates on which films can be simultaneously formed can be further increased by arranging a plurality of process modules in parallel. Therefore, even when a film is formed on a substrate at a low rate, high throughput can be realized. Additionally, the installation time (building time of a manufacturing line) of the apparatus when the manufacturing line is built in a factory or the like can be shortened by integrating the apparatus as the process module. Moreover, when maintenance of the film forming chamber is performed, it becomes unnecessary to stop the whole manufacturing line by performing maintenance for every process module. Accordingly, a decrease in production efficiency during maintenance can be suppressed to a minimum.
According to the above aspect, a substrate attached to a carrier can be moved within the loading-ejecting chamber. Therefore, different film forming materials can be supplied in the film forming chambers respectively, and a plurality of layers with different film forming materials can be more efficiently formed on a substrate.
According to the aspect of the present invention, since the pre-processed substrate and the psot-processed substrate can be simultaneously stored in the loading-ejecting chamber, the evacuation process of the loading-ejecting chamber can be reduced by half. Accordingly, productivity can be markedly improved. Additionally, in such a case, the post-processed substrate and the pre-process substrate are simultaneously stored in the loading-ejecting chamber in a state where the substrates face each other. Thereby, the heat accumulated in the post-processed substrate is transferred to the pre-processed substrate, whereby heat exchange is positively performed. That is, a heating process which is usually performed after the pre-processed substrate is stored in the film forming chamber, and a cooling process which is usually performed before the post-processed substrate is carried out of the loading-ejecting chamber can be omitted. As a result, the heating process and the cooling process become unnecessary, productivity can be improved, and the conventional devices used for the heating process and the cooling process can be reduced. Therefore, space saving and lower cost can be achieved simultaneously.
A thin-film solar cell manufacturing apparatus related to an embodiment of the present invention will be described below with reference to
<Thin-film Solar Cell>
The top cell 102 has a three-layer structure configured by laminating a p-layer 102p, an i-layer 102i, and an n-layer 102n in the top-bottom order in the drawing. The three-layer structure of the p-layer 102p, i-layer 102i, and n-layer 102n of the top cell 102 is formed from amorphous silicon. Additionally, the bottom cell 104 has a three-layer structure configured by laminating a p-layer 104p, an i-layer 104i, and an n-layer 104n in the top-bottom order in the drawing. The three-layer structure of the p-layer 104p, i-layer 104i, and n-layer 104n of the bottom cell 104 is made of microcrystalline silicon.
In the thin-film solar cell 100 configured in the above way, when an energy particle called a photon in sunlight strikes the i-layer, an electron and a hole are generated by a photovoltaic effect, the electron moves toward the n-layer and the hole moves toward the p-layer. Light energy can be converted into electrical energy by taking out the electron generated by the photovoltaic effect by the top electrode 101 and the back electrode 106.
Additionally, the intermediate electrode 103 is provided between the top cell 102 and the bottom cell 104, whereby a part of the light which passes through the top cell 102 and reaches the bottom cell 104 is reflected by the intermediate electrode 103 and incident on the top cell 102 again. Accordingly, the sensitivity characteristics of the cell are improved, and the power generation efficiency can be improved.
Additionally, the sunlight incident from the glass substrate W side passes through the respective layers, and is reflected by the back electrode 106. In order to improve the conversion efficiency of light energy, the thin-film solar cell 100 employs a texture structure which aims to achieve a prismatic effect which extends the optical path of the sunlight which incident on the top electrode 101, and the confinement effect of light.
<Thin-Film Solar Cell Manufacturing Apparatus>
As shown in
That is, the side plate portion 63 forms a part of a wall surface of the film forming chamber 11. An anode unit 90 and a cathode unit 68 which are arranged on both sides of the substrate W when forming a film are formed at a first surface 65 (surface which faces the inside of the film forming chamber 11) of the side plate portion 63. In the electrode unit 31 of the present embodiment, anode units 90 are respectively arranged on both sides of the cathode unit 68 so as to separate from each other so that films can be simultaneously formed on two substrates W by one electrode unit 31. Accordingly, substrates W are respectively on both sides of the cathode unit 68 so as to face each other in a state where the substrates are substantially parallel to the direction of gravitational force, and two anode units 90 are arranged outside the respective substrates W in the thickness direction in a state where the anode units face the substrates W, respectively. In addition, the anode unit 90 is constituted by a plate-shaped anode 67, and a heater H built in the anode unit 90.
Additionally, a drive device 71 for driving the anode units 90, and a matching box 72 for feeding electric power to the cathode intermediate member 76 of the cathode unit 68 when forming a film are attached to the second surface 69 of the side plate portion 63. Moreover, a connecting portion (not shown) for piping which supplies the film forming gas to the cathode unit 68 is formed at the side plate portion 63.
A heater H is built in each anode unit 90, and the heater H is a temperature control unit which controls the temperature of the substrate W. Additionally, the two anode units 90 and 90 are movable in directions (horizontal directions) in which the anode units approach to and separate from each other using the drive device 71 provided at the side plate portion 63, and the separation distance between the substrate W and the cathode unit 68 can be controlled. Specifically, when forming films on the substrates W, the two anode units 90 and 90 move toward the cathode unit 68, and abut the substrates W, and further move in directions in which the anode units approach the cathode unit 68, thereby adjusting the separation distance between the substrates W and the cathode unit 68 to a desired distance. Thereafter, film formation are performed, and after the end of film forming, the anode units 90 and 90 move in the directions in which the anode units separate from each other, so that the substrates W can be easily taken out from the electrode unit 31.
Moreover, each anode unit 90 is attached to the drive device 71 via a hinge (not shown), and can be turned (opened) until the surface 67A of the anode unit 90 (anode 67) on the side of the cathode unit 68 becomes substantially parallel to the first surface 65 of the side plate portion 63, in a state in which the electrode unit 31 is pulled out of the film forming chamber 11. That is, as shown by a dotted line in
The cathode unit 68 has a shower plate 75 (cathode), a cathode intermediate member 76, a discharge duct 79, and a floating capacitance member 82.
Shower plates 75 formed with a plurality of small holes (not shown) are arranged on the surfaces of the cathode unit 68 which face the anode units 90 (anodes 67), so that the film forming gas can be jetted toward the substrates W. Moreover, the shower plates 75 and 75 are cathodes (high-frequency electrodes) connected to the matching box 72. The cathode intermediate member 76 connected to the matching box 72 is provided between the two shower plates 75 and 75. That is, the shower plates 75 are arranged on both sides of the cathode intermediate member 76 in a state where the shower plates are electrically connected to the cathode intermediate member 76. The cathode intermediate member 76 and the shower plates (cathodes) 75 are formed from electrical conductors, and high frequency is applied to the shower plates (cathodes) 75 via the cathode intermediate member 76. For this reason, voltages of the same potential and phase for generating plasma are applied to the two shower plates 75 and 75.
The cathode intermediate member 76 is connected to the matching box 72 by a wiring which is not shown. A space portion 77 is formed between the cathode intermediate member 76 and each shower plate 75, and the film forming gas is supplied to the space portion 77 from a gas supply apparatus (not shown). The space portions 77 are separated from each other by the cathode intermediate member 76, and are individually formed so as to correspond to the shower plates 75 and 75 respectively, so that the gases discharged from the respective shower plates 75 and 75 are controlled independently. That is, the space portion 77 has a function as a gas supply passage. In this embodiment, the space portions 77 are separately formed so as to correspond to the shower plates 75 and 75, respectively. Thus, the cathode unit 68 has two-types of gas supply passages.
Additionally, a hollow discharge duct 79 is provided at a peripheral edge portion of the cathode unit 68 over its whole circumference. The discharge duct 79 is formed with a vacuuming port 80 for evacuating the film forming gas or reactive by-products (powder) in a film formation space 81. Specifically, the vacuuming port 80 is formed so as to face the film formation space 81 which is formed between the substrate W and the shower plate 75 when forming a film. A plurality of vacuuming ports 80 are formed along the peripheral edge portion of the cathode unit 68, and is configured so that evacuation can be made substantially equal over its whole circumference. Additionally, the discharge duct 79 has a surface which faces the inside of the film forming chamber 11 at the lower portion of the cathode unit 68, and the surface of the discharge duct which faces the inside of the film forming chamber 11 is formed with an opening (not shown) so that the evacuated film forming gas can be discharged into the film forming chamber 11. The gas discharged into the film forming chamber 11 is evacuated to the outside through the vacuuming pipe 29 provided at the lateral lower portion 28 of the film forming chamber 11. Additionally, the floating capacitance member 82 which has at least a dielectric body or laminating space (a dielectric body and/or laminating space) is provided between the discharge duct 79 and the cathode intermediate member 76. The discharge duct 79 is connected to an installation potential. The discharge duct 79 also functions as a shield frame for preventing abnormal electrical discharge from the cathode 75 and the cathode intermediate member 76.
Moreover, masks 78 are provided at the peripheral edge portion of the cathode unit 68 so as to cover the part from the peripheral portion of the discharge duct 79 to the peripheral portion of the shower plate 75 (cathode). The masks 78 covers a holding piece 59A (refer to
Since such an electrode unit 31 is provided, in one electrode unit 31, two gaps are formed between the anode units 90 and the cathode unit 68 into which substrates W are inserted. Accordingly, films can be simultaneously formed on two substrates W by one electrode unit 31.
Additionally, the substrate W is disposed between the anode unit 90 and the cathode unit 68, and the anode unit 90 (anode 67) abuts on the substrate W, and is movable in order to adjust the separation distance between the substrate W and the cathode unit 68. Accordingly, when a thin-film Si-layer is formed on the substrate W by the plasma CVD method, the gap between the substrate W and the cathode unit 68 should be set to about 5 mm to 15 mm However, the separation distance between the anode 67 and the cathode unit 68 can be adjusted before and after film formation by moving the anode 67. Accordingly, entrance and exit of the substrate W can be made easier. Additionally, when the substrate W enters and exits, it is possible to prevent the substrate W from being damaged by contacting with the anode 67 or the cathode unit 68. Moreover, by abutting (contacting) the anode 67 and the substrate W, the heat of the heater H can be effectively transferred to the substrate W when a film is formed while the substrate W is heated by the heater H. Accordingly, high-quality film forming can be performed.
Moreover, since the electrode unit 31 is configured to be attachable to and detachable from the film forming chamber 11, the periodical maintenance of removing the films deposited on the cathode unit 68 and anode units 90 of the electrode unit 31 can be easily performed. Additionally, if a spare electrode unit 31 is prepared, while the above electrode unit 31 is removed from the film forming chamber 11 for maintenance, the spare electrode unit 31 is attached instead, so that maintenance can be performed without stopping the manufacturing line. Accordingly, production efficiency can be improved. As a result, high throughput can be realized even when a semiconductor layer is formed on the substrate W at a low rate.
Referring back to
Additionally, the loading-ejecting chamber 13 is provided with a push-pull mechanism 38 (carrier transfer mechanism) for transferring the carrier 21 between the film forming chamber 11 and the loading-ejecting chamber 13 along the transfer rails 37. As shown in
Moreover, a transfer mechanism (not shown) for transferring the carrier 21 by a predetermined distance in a direction substantially orthogonal to a direction in which the transfer rails 37 are laid in plan view is provided within the loading-ejecting chamber 13 in order to simultaneously store the pre-processed substrate W1 and the post-processed substrate W2. A vacuuming pipe 42 for evacuating the inside of the loading-ejecting chamber 13 is connected to a lateral lower portion 41 of the loading-ejecting chamber 13, and a vacuum pump 43 is provided at the vacuuming pipe 42.
The substrate replacement robot 17 has a drive arm 45, and can suck the substrate W at the tip of the drive arm 45. Additionally, the drive arm 45 can be driven between the carrier 21 disposed at the substrate replacement chamber 15, and the substrate storage holder 19. That is, the drive arm 45 can remove the pre-processed substrates W1 from the substrate storage holder 19, and attach the pre-processed substrates W1 to the carrier 21 (first carrier) disposed at the substrate replacement chamber 15. Moreover, the drive arm 45 can remove the post-processed substrate W2 from the carrier (second carrier) 21 which has returned to the substrate replacement chamber 15, and can convey the post-processed substrate W2 to the substrate storage holder 19.
Each frame 51 has an opening 56, a peripheral edge portion 57, and a holding portion 59. The surface to be film-formed (front surface WO) of the substrate W is exposed to the opening 56 formed in the frame 51, and the holding portion 59 holds and fixes the substrate W from both sides at the peripheral edge portion 57 of the opening 56. A biasing force caused by a spring or the like acts on the holding portion 59 which holds the substrate W. Additionally, the holding portion 59 has holding pieces 59A and 59B which abut on the front surface WO which is the surfaces to be film-formed of the substrate W and the rear surface WU (back surface) (refer to
Also, in the thin-film solar cell manufacturing apparatus 10 of the present embodiment, four substrate film formation lines 16 each including the above-described film forming chamber 11, loading-ejecting chamber 13, and substrate replacement chamber 15 are arranged. Accordingly, films can be substantially simultaneously formed on twenty four substrates W.
<Manufacturing method of Thin-film Solar Cell>
Next, a method for forming a film on a substrate W using the thin-film solar cell manufacturing apparatus 10 of the present embodiment will be described. In addition, although drawings of one substrate film formation line 16 are used in this description, the other three substrate film formation lines 16 also form films on substrates according to almost the same flow.
As shown in
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Here, the operation of the push-pull mechanism 38 will be described. In addition, the operation when the carriers 21A located in the film forming chamber 11 are transferred into the loading-ejecting chamber 13 will be described here.
As shown in
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At this time, the holding piece 59A of the holding portion 59 of the carrier 21 which abuts on the front surface WO of the pre-processed substrate W1 is displaced along with the movement of the pre-processed substrates W1 (of the anode unit 90). In addition, when the anode unit 90 has moved toward the direction away from the cathode unit 68, the restoring force of the spring or the like acts on the holding piece 59A so that this holding piece is displaced toward the holding piece 59B. The pre-processed substrate W1 at this time is held by the anode 67 and the holding piece 59A.
As shown in
Here, as shown in
Additionally, since the movement of the pre-processed substrate W1 stops when the outer-edge portion of the substrate W abuts on the mask 78, the flow passage height of the gas flow passage R in a thickness direction, which is formed by the gap between the mask 78 and the shower plate 75 and between the mask 78 and the discharge duct 79, is set so that the gap between the pre-processed substrate W1 and the cathode unit 68 reaches a predetermined distance.
As another aspect, the distance between the substrate W and the shower plate 75 (cathode) can also be arbitrarily changed by the stroke of the drive mechanism 71 by attaching the mask to the discharge duct 79 via an elastic body. A case where the mask 78 and the substrate W abut on each other has been described above. However, the mask 78 and the substrate W may be arranged so as to leave a minute gap which limits the passage of the film forming gas.
In such a state, the film forming gas is jetted from the shower plate 75 of the cathode unit 68, and the matching box 72 is started to apply a voltage to the shower plate (cathode) 75 of the cathode unit 68, thereby generating plasma in the film formation space 81 to form a film on the front surface WO of the pre-processed substrate W1. At this time, the pre-processed substrate W1 is heated to a desired temperature by the heater H built in the anode 67.
Here, the anode unit 90 stops heating when the pre-processed substrate W1 reaches a desired temperature. However, plasma is generated within the film formation space 81 by applying a voltage to the cathode unit 68. Even if the heating of the anode unit 90 is stopped, there is a possibility that the temperature of the pre-processed substrate W1 may rise higher than a desired temperature due to the heat input from the plasma with the passage of time. In this case, the anode unit 90 can also be made to function as a radiator plate for cooling the pre-processed substrate W1 where the temperature has risen excessively. Accordingly, the temperature of the pre-processed substrate W1 is maintained at a desired temperature irrespective of the passage of the film formation processing time.
In addition, when a plurality of layers is formed through one film formation processing process, a film forming gas material to be supplied can be changed every predetermined time.
During film forming and after film forming, the gas or particles in the film formation space 81 are evacuated from the vacuuming ports 80 formed in the peripheral edge portion of the cathode unit 68. Along with this, the evacuated gas passes through the opening (opening formed in the surface of the discharge duct 79 which faces the inside of the film forming chamber 11 at the lower portion of the cathode unit 68) from the discharge duct 79 at the peripheral edge portion of the cathode unit 68 via the gas flow passage R, and flows to the outside from the vacuuming pipe 29 provided at the lateral lower portion 28 of the film forming chamber 11. In addition, the reactive by-products (powder) generated when forming a film can be collected and disposed of when being made to adhere to the inner wall surface of the discharge duct 79. Since the same processing as the above-described processing is performed in all the electrode units 31 within the film forming chamber 11, film forming can be simultaneously performed on six substrates.
When the film forming is ended, the two anode units 90 are moved in directions away from each other by the drive device 71, and the post-processed substrate W2 and the frames 51 (holding pieces 59A) are returned to their original positions (refer to
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According to the thin-film solar cell manufacturing apparatus 10 of the present embodiment, the carrier 21 (21A) holding the post-processed substrate W2 and the carrier 21 holding the pre-processed substrates W1 can be simultaneously stored in the loading-ejecting chamber 13. Therefore, the evacuation process can be reduced by half in a series of substrate film forming processes of the loading-ejecting chamber 13. That is, an evacuation process which is performed in the stage where a carrier holding a pre-processed substrate is stored in a conventional loading chamber, and an evacuation process which is performed before a carrier holding a post-processed substrate is stored in an ejecting chamber can be simultaneously performed. Accordingly, productivity can be markedly improved. Additionally, when the post-processed substrate W2 and the pre-processed substrate W1 are simultaneously stored in the loading-ejecting chamber 13, the heat accumulated in the post-processed substrate W2 is transferred to the pre-processed substrate W1, whereby heat exchange is positively performed. That is, a heating process which is usually performed after the pre-processed substrate W1 is stored in the film forming chamber 11, and a cooling process which is usually performed before the post-processed substrate W2 is carried out of the loading-ejecting chamber 13 can be omitted. As a result, the heating process and the cooling process become unnecessary, productivity can be improved, and the conventional devices used for the heating process and the cooling process can be reduced. Therefore, space saving and lower cost can be simultaneously achieved.
Additionally, in the loading-ejecting chamber 13, the carrier 21 on which the pre-processed substrates W1 are mounted and the carrier 21 (21A) on which the post-processed substrates W2 are mounted are alternately arranged in plan view. Accordingly, when the post-processed substrates W2 and the pre-processed substrates W1 are simultaneously stored in the loading-ejecting chamber 13, the heat accumulated in the post-processed substrate W2 is efficiently transferred to the pre-processed substrates W1, so that heat exchange can be performed reliably.
Additionally, in order to simultaneously store the carrier 21 holding the pre-processed substrates W1 and the carrier 21 (21A) holding the post-processed substrates W2 in the loading-ejecting chamber 13, the substrates W (carrier 21) is movable in a direction substantially perpendicular to a moving direction (direction along the transfer rails 37) to the film forming chamber 11 in plan view. By adopting such a configuration, the transfer rails 37 along which the substrate W enters and exits the loading-ejecting chamber 13 can be fixed. That is, one certain carrier 21 always moves between chambers along the same transfer rails 37. Accordingly, the size of the apparatus itself can be kept down, and the installation space of the apparatus can be reduced.
Additionally, in the present embodiment, transfer and film formation processing within the thin-film solar cell manufacturing apparatus 10 are performed in a state where the substrate W is erected in the vertical direction (state where the substrate W is arranged so that the surface to be film-formed thereof becomes parallel to the direction of gravitational force). As a result, the area required for a substrate W to move within the thin-film solar cell manufacturing apparatus 10 can be reduced to miniaturize the apparatus, and a larger number of apparatuses can be arranged in the same installation area as a conventional technique. Accordingly, the number of substrates W on which films are simultaneously formed can be increased, and productivity can be improved. Additionally, when a film is formed on a substrate W in a state where the substrate is erected in the vertical direction, particles generated when forming a film can be kept from depositing on the film formation face of the substrate W. Accordingly, a high-quality semiconductor layer can be formed on the substrate W.
Additionally, since the carrier 21 can hold a plurality of (two) substrates W, films can be simultaneously formed on a plurality of substrates W in one carrier 21, and productivity can be further improved. Moreover, since a plurality of carriers 21 can be simultaneously conveyed to the film forming chamber 11, the processing rate can be further raised.
Moreover, since a plurality of process modules 14 in which the film forming chamber 11 and the loading-ejecting chamber 13 are connected to is configured so as to be arranged in parallel, the number of substrates W on which films can be simultaneously formed can be further increased, and even when a semiconductor layer is formed on a substrate W at a low rate, high throughput can be realized. Additionally, the installation time (building time of a manufacturing line) of the apparatus when the manufacturing line is built in a factory or the like can be shortened by integrating the apparatus as the process module 14. Moreover, when maintenance of the film forming chamber 11 is performed, it becomes unnecessary to stop the whole manufacturing line by performing the maintenance for every process module 14. Accordingly, a decrease in production efficiency during maintenance can be suppressed to a minimum.
In addition, it should be understood that the technical scope of the present invention is not limited to the above-described embodiment, but that various modifications of the above-described embodiment may be made without departing from the scope of the invention. That is, the specific shapes and configurations as mentioned in the embodiment are merely examples, and can be appropriately changed.
For example, although the case where one loading-ejecting chamber is connected to one film forming chamber has been described in the present embodiment, as shown in
Additionally, the thin-film solar cell manufacturing apparatus may be arranged as shown in
Moreover, the thin-film solar cell manufacturing apparatus may be arranged as shown in
In the present embodiment, in the loading-ejecting chamber 13, the carrier holding the pre-processed substrates W1 and the carrier holding the post-processed substrates W2 are alternately arranged in plan view. However, these carriers may have arrangements other than the alternate arrangement.
According to the embodiment of the present invention, the heating process and the cooling process which are usually performed can be omitted. Therefore, productivity can be improved, and the conventional devices used for the heating process and the cooling process can be reduced. Therefore, space saving and lower cost can be simultaneously achieved.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-149933 | Jun 2008 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP09/60154 | 6/3/2009 | WO | 00 | 1/5/2011 |
