JP3475752B2 - Thin film manufacturing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a method of manufacturing a thin film element having a plurality of layers on a flexible substrate such as a thin film photoelectric conversion element, and is provided with a film forming chamber for independently forming each constituent layer. The present invention relates to a stepping roll type thin film manufacturing apparatus having a plurality of steps.

[0002]

2. Description of the Related Art For example, amorphous silicon (hereinafter a-
(Hereinafter referred to as Si) as a main material, a thin film photoelectric conversion element including a multilayer thin film including a photoelectric conversion layer is formed on a flexible substrate made of a long polymer material or a metal such as stainless steel. The method of cutting and individualizing is excellent in mass productivity.

As a method for depositing a plurality of layers on a long flexible substrate, a roll-to-roll method in which a film is continuously moved in each deposition chamber, and a method in which the deposition is stopped in each deposition chamber rear,
There is a stepping roll method in which the substrate portion after the film formation is sent out of the film formation chamber. For example, in the stepping roll method of forming a film by plasma enhanced chemical vapor deposition (hereinafter referred to as CVD), the film forming chamber is opened-the substrate is moved by one frame, the film forming chamber is sealed, the raw material gas is introduced, the pressure is controlled, the discharge is started, and the discharge is ended. -The operation of stopping the raw material gas-gassing-opening the film forming chamber is repeated.

FIG. 6 is a side sectional view of a stepping roll film forming type thin film manufacturing apparatus having a plurality of film forming chambers in a common vacuum chamber. The substrate 1 is formed in several film forming chambers 80 while being unwound from the core 82 and wound on the core 83. The common chamber 81 accommodates a plurality of film forming chambers 80 inside. This apparatus can be used for manufacturing a thin film photoelectric conversion element, and sputtering film formation or plasma CVD film formation is performed in the film formation chamber. The film forming apparatus adopting the stepping roll method is superior to the ordinary roll-to-roll film forming in the following points.

(1) There is no interdiffusion of gas with the adjacent film forming chamber. (2) The device is compact. A conventional technique relating to a stepping roll type film forming apparatus is disclosed in Japanese Patent Laid-Open No. 6-29134.
No. 9, JP-A-7-6953, JP-A 7-22
No. 1025, Japanese Patent Application Laid-Open No. 8-250431, Japanese Patent Application Laid-Open No. 8-293491, and Japanese Patent Application Laid-Open No. 9-63970.

Japanese Unexamined Patent Publication No. 6-291349 discloses a stepping roll type film forming apparatus and a method of manufacturing a thin film photoelectric conversion element using this apparatus. In a method of manufacturing a thin film photoelectric conversion element in which a plurality of thin films having different properties are laminated on a strip-shaped flexible substrate to form a photoelectric conversion element, a plurality of film formation chambers arranged in one common vacuum chamber are provided. The flexible substrate is passed through, and the film is formed on the surface of the substrate in a stopped state in a predetermined vacuum atmosphere in a film forming chamber where the entrance and exit of the substrate are sealed to the substrate by a wall through a sealing material. It is disclosed that the operation of transporting the substrate separated from the wall of the film chamber to the next film forming position is repeated. And it is effective that the substrate surface is within the vertical plane.

Further, a voltage is applied between the electrode contacting the substrate and the electrode facing the film forming surface of the substrate in the film forming chamber to form a film, and the electrode contacting the substrate at the time of transferring the substrate is removed from the substrate. It is effective to separate. It is said that it is effective that the substrate used is a resin film having a conductive film deposited on one surface, a metal film, or a metal film having a conductive film deposited via an insulating film on one surface. .

Further, in a thin-film photoelectric conversion element manufacturing apparatus in which a plurality of thin films having different properties are laminated on a strip-shaped flexible substrate to form a photoelectric conversion layer, the common vacuum chamber is arranged near both ends in the longitudinal direction. And a plurality of film formation chambers through which a flexible substrate that can be wound from one roll to the unrolled roll is provided in the common vacuum chamber. The entrance / exit is separated by a wall that adheres to the substrate via a sealing material, and the sealing material on the wall of the film forming chamber can be retracted to a position away from the substrate, and the common vacuum chamber and each film forming chamber are separated into separate exhaust systems. Connected. Then, it is effective to provide each film forming chamber with an electrode that is in contact with the substrate and can be retracted to a position apart from the substrate, and an opposing electrode of the electrode. It is also effective that the shafts of both rolls and the electrode surfaces of both electrodes are vertical.

In Japanese Patent Laid-Open No. 7-6953, a high frequency electrode is applied to one of two flat plate electrodes facing each other in parallel, and the other is installed to generate a plasma in a film forming chamber space between the two electrodes to generate a reaction gas. In a plasma CVD method in which a thin film is decomposed to deposit a thin film on a substrate, the reaction space is surrounded by parallel plate electrodes and side walls, and the common chamber space side of the high frequency electrode is 1 × 10 ^−3.
The vacuum chamber is placed in a vacuum below Torr, or the space inside the common chamber of the high frequency electrode is brought into contact with the atmosphere. By this plasma CVD method, it is possible to prevent discharge on the back surface of the high frequency electrode, obtain uniform discharge, and improve the film quality.
In addition, if multiple film forming chambers that contain the discharge are placed in one vacuum chamber and sent out in the vacuum chamber to sequentially form films on the flexible substrate that is being wound, a buffer vacuum like a roll-to-roll system is created. It is disclosed that it is not necessary to provide a chamber, the size and weight of the entire apparatus can be reduced, and the manufacturing cost can be significantly reduced.

Japanese Unexamined Patent Publication No. 7-221025 discloses that a flexible substrate being conveyed is stopped between the opening sides of two portions of the film forming chamber each having a box-shaped wall, and the substrate is formed in the film forming chamber. The film-forming space sandwiched between the opening-side end faces of the wall bodies of both parts and surrounded by one part of the film-forming chamber and the substrate is evacuated from the exhaust port communicating with the space, and the electrode in the space and the film-forming are formed. In a thin film photoelectric conversion element manufacturing apparatus for applying a voltage between an electrode in a space surrounded by the other part of the chamber and the substrate, a space surrounded by each part of the film formation chamber and the substrate A ventilation pipe that communicates with the pipe, the ventilation passage being a flexible pipe, and the flexible substrate on the opening side of the wall of both portions of the film formation chamber It is opened to the outside of the film formation chamber and airtightly isolated from the outside of the film formation chamber. It is intended.

With this manufacturing apparatus, it is possible to prevent gas accumulation in the space on the side where the exhaust port is not provided, and to realize a clean film formation in which fresh source gas is always supplied. Also,
It is disclosed that even if a plurality of types of semiconductor layers are formed in the same film formation chamber, film formation with little influence of residual gas can be realized.
In Japanese Patent Laid-Open No. 8-250431, a flexible substrate is brought into close contact with an end surface around an opening of a wall of a box-shaped film forming chamber, and a film forming space surrounded by the wall and the substrate is evacuated. In a method of manufacturing a thin film photoelectric conversion element in which a voltage is applied to an electrode housed in a substrate to form a thin film on a substrate, the outer periphery of the film deposition surface of the substrate is radially slid on the end face around the opening of the film deposition chamber wall. Let
Further, the film is formed after the wrinkles of the substrate are extended by pressing the substrate toward the electrode side by the pressing body located on the side opposite to the electrode, and in particular, the electrode housed in the film forming space as the pressing body. It is said that it is effective to use the counter electrode.

Further, it has an opening which surrounds the film-forming space and which opposes the opening of the box-shaped wall of the film-forming chamber in which the electrode to which a voltage is applied is accommodated, and can be driven in the direction of the wall of the film-forming chamber. The end face of the second box-shaped wall body is provided with an elastic lip-shaped body which is inclined outward with respect to the surface of the flexible substrate that is in close contact with the wall body of the film forming chamber,
Since the counter electrode housed in the second wall body can be driven to the inside of the opening surface of the wall of the film formation chamber while pressing the substrate with the surface thereof, the wrinkle of the flexible substrate is extended. It is disclosed that if a film is formed, the film formation pattern does not shift and a film having a uniform film thickness can be formed.

Japanese Unexamined Patent Publication No. 8-293491 discloses a first electrode between two rows of flexible substrates which are conveyed in parallel, and a second electrode which faces the first electrode and is outside each substrate. A thin film photoelectric device that is arranged and forms a thin film on one surface of each substrate by generating a discharge by applying a voltage between the first and second electrodes in a film formation space formed between the first electrode and each substrate. In the conversion element manufacturing apparatus, each substrate is provided with one first electrode, and the back surface of the first electrode parallel to the substrate surface is connected by an insulator. Each first electrode has an opening on the back surface thereof, and a through hole communicating with the opening is formed in an insulator connecting the back surfaces of both the first electrodes, and a vacuum exhaust port is opened on the inner surface of the through hole. There is. A sealing material that can be in close contact with the substrate is attached to the end surface of the first electrode.

Further, a voltage applying electrode and a ground electrode are arranged on both sides of the conveyed flexible substrate, and a discharge is generated by applying a voltage to the voltage applying electrode in a film forming space formed between the voltage applying electrode and the substrate. In the apparatus for manufacturing a thin film photoelectric conversion element in which a thin film is formed on one surface of a substrate by performing the above, the voltage application electrode is flat and is hermetically coupled to a conductive frame body having an end face capable of hermetically contacting the substrate. A conductive shield that surrounds the back and side surfaces of the voltage application electrode is conductively coupled to the conductive frame and grounded. Further, the voltage application electrode inside the substrate and the ground electrode outside the substrate are arranged to face each other with two rows of flexible substrates being conveyed in parallel, and both voltage application electrodes penetrate the shield body. It is connected by an insulator. Each voltage applying electrode has an opening, a through hole communicating with the opening is opened in an insulator connecting the both voltage applying electrodes, and a vacuum exhaust port is opened on the inner surface of the through hole. By using such a device for manufacturing a thin film photoelectric conversion element, a film is formed on two rows of flexible substrates that are conveyed in parallel by applying a voltage between the first and second electrodes provided for each. , It becomes possible to control both film forming conditions independently, it is possible to reduce the difference in film forming between the substrates, and the two first electrodes are connected through an insulator to connect the two substrates. Disclosed is a method for preventing an increase in the size of a thin-film photoelectric conversion device manufacturing apparatus, which is disposed between the substrates and allows the end faces of the substrates to hermetically contact each other to form a film-forming space.

Further, by shielding the shield body surrounding the back and side surfaces of the electrode to which a high voltage is applied, and a conductive frame body which is insulated and coupled to the substrate side and forms a film formation space between the shield body and the substrate. Arrangement of a plurality of film formation chambers for sequentially forming films on one row of flexible substrates in the substrate conveyance direction, and direction of substrate conveyance of a plurality of film formation chambers for parallel film formation on a plurality of rows of flexible substrates On the other hand, it is disclosed that the arrangement in the lateral direction can be performed by narrowing the distance between the film forming chambers, and therefore, the manufacturing apparatus of the thin film photoelectric conversion element in which a plurality of thin films need to be stacked can be downsized. .

In Japanese Unexamined Patent Publication No. 9-63970, an end face around the opening of a box-shaped film forming chamber wall of a flexible substrate is closely attached via a sealing member having elasticity, and is surrounded by the wall and the substrate. Disclosed is a thin film element manufacturing apparatus for forming a thin film on a substrate by applying a voltage to an electrode housed in this space and applying a voltage to the electrode. There is. Since the fluororesin has less adhesiveness to the surface of the flexible substrate made of a polymer material or a metal than fluororubber or the like, the adhesive which prevents the substrate transportation does not occur.

Similarly, the flexible substrate is brought into close contact with the end face around the opening of the wall of the box-shaped film-forming chamber via a sealing member having elasticity, and the film-forming chamber surrounded by the wall and the substrate is vacuumed. West,
In a thin-film element manufacturing apparatus for applying a voltage to an electrode housed in this space to form a thin film on a substrate, the flexible substrate of the seal member is in contact with the substrate more than the elastic base material. It is also disclosed that it is covered with a surface film made of a material having a low adhesive force to.

Furthermore, the flexible substrate is brought into close contact with the end face around the opening of the wall of the box-shaped film-forming chamber through a sealing member having elasticity, and the film-forming chamber surrounded by the wall and the substrate is evacuated. ,
In a method of manufacturing a thin film element in which a voltage is applied to an electrode housed in this space to form a thin film on a substrate, a thin film is formed, and after releasing the pressure for closely adhering the end face of the film forming chamber wall to the substrate, It is disclosed that the substrate is pressed from one surface side to the other surface side, and thereby the substrate adhered to the seal member is removed.

FIG. 7 is a sectional view of a film forming chamber of a conventional stepping roll type thin film manufacturing apparatus.
(B) is at the time of sealing. A box-shaped lower film forming chamber wall 21 and an upper film forming chamber wall 22 face each other above and below the flexible substrate 1 that is intermittently conveyed. A high voltage electrode 31 connected to the power source 4 is provided in the lower film forming chamber, and a heater 33 is provided in the upper film forming chamber.
A ground electrode 32 having a built-in electrode is provided.

During film formation (FIG. 7B), the upper film forming chamber wall 22 descends, and the ground electrode 32 holds the substrate 1 and is attached to the end surface of the lower film forming chamber wall 21 on the opening side. The sealing material 5 is contacted. As a result, the lower film forming chamber wall 21 and the substrate 1 form an airtightly sealed film forming space 6 communicating with the exhaust pipe 61, and by applying a high frequency voltage to the high voltage electrode 31, plasma is formed in the film forming space 6 And the raw material gas introduced from an introduction pipe (not shown) is decomposed to form a film on the substrate 1. In the figure, the outside of the film forming chamber is a common vacuum chamber.

FIG. 8 is a cross-sectional view of the seal portion of the lower and upper film forming chambers of the conventional thin film manufacturing apparatus. Two strip-shaped end plates 23, 24 are provided on the end surface of the lower film forming chamber wall 21.
Further, two strip-shaped end plates 2 are provided on the end surface of the upper film forming chamber wall 22.
Nos. 5 and 26 are respectively screwed, and the sealing material 5 is held in the dovetail groove formed therebetween so as not to fall off.
At the time of film formation, the substrate 1 is sandwiched between the surfaces of the end plates 23 and 24 on the lower film forming chamber side and the sealing material 5 therebetween and the surfaces of the end plates 25 and 26 on the upper film forming chamber side and the sealing material 5 therebetween. As a result, the spaces inside the upper and lower film forming chambers are maintained in vacuum.

As another example, JP-A-8-2504
There is also a method shown in 31. FIG. 9 is a cross-sectional view perpendicular to the transport direction of the flexible substrate, showing the opening of the film forming chamber of the conventional thin film manufacturing apparatus for forming a film by plasma CVD.
The flexible substrate 1 is conveyed in the direction perpendicular to the paper surface. The lower film forming chamber that houses the high-voltage electrode 31 is composed of the wall body 21 and the top plate 27 having an opening, and is connected to the vacuum exhaust pipe 61. The upper film forming chamber containing the ground electrode 32 containing a heater (not shown) is composed of the wall body 22 and the housing 28, and the support tube 34 of the ground electrode 32 is fitted in the housing 28 so as to be vertically movable. . A moving plate 29 is attached to the end of the housing 28. The moving plate 29 is guided by the vertical drive guide 30 and is vertically driven by the actuator 41 as indicated by an arrow 51. The vertical drive guide 30 and the actuator 41 are fixed to the mount 42 and are mounted on the upper flange 36 on the film forming chamber chamber 35. The support tube 34 has a cylindrical shape, and the inner cavity communicates with the vacuum exhaust pipe 63 at the upper end and communicates with the inner space of the upper film forming chamber through the through hole 37 at the lower end. The vacuum exhaust pipe 61 and the vacuum exhaust pipe 63 are connected by a flexible pipe 64. On the other hand, the support tube 34 of the ground electrode can be moved in the housing 28 via the moving plate 29, whereby the ground electrode 32 is driven in the vertical direction as shown by the arrow 52. A wrinkle-extending structure is formed between the lower end of the wall 22 of the upper film forming chamber and the top plate 27 of the lower film forming chamber.

FIG. 10 is an enlarged cross-sectional view of the seal portion of the film forming chamber of the conventional thin film manufacturing apparatus (FIG. 9). (A) shows the film forming chamber opened and (b) shows the film forming chamber closed. is there. Top plate 2
As in FIG. 9, the sealing material 5 is held between the end plates 23 and 24 on the portion of the No. 7 close to the opening 45. On the other hand, on the end face of the upper film forming chamber wall 22, the base of the lip (lips) 7 made of rubber should be inserted into the recess of the square L-shaped packing 71, and should be sandwiched between it and the lip retainer 72. Is held by. The L-shaped packing 71 and the lip retainer 72 are fixed to the end surface of the wall body 22 with screws, so that the lip 7 can be easily attached and detached. Lip 7
Is divided into four for each side of the rectangular wall body 22.

When the film forming chamber is opened, the lip 7 has the flexible substrate 1
The surface of the L-shaped packing 71 is inclined 45 to 60 degrees outward, and projects downward about 5 mm from the lower end of the L-shaped packing 71. The edge of the lip retainer 72 is chamfered at 30 degrees, for example. When the upper film forming chamber wall 22 begins to descend in the direction of the arrow 51, the tip of the lip 7 contacts the substrate shown by the chain line, and further pushes the substrate 1 onto the surfaces of the end plates 23 and 24 on the top plate 27. To reach. When the upper film forming chamber wall 22 descends in the direction of arrow 53 as it is, the tip of the lip 7 is deformed by sliding in the direction of arrow 54 parallel to the surfaces of the end plates 23 and 24. Since the edge of the lip retainer 72 is chamfered, the deformed end of the lip 7 can escape to this chamfer.

At this time, the tip of the lip 7 and the cross sections 23, 2
4 generates friction between the substrate 1 and the substrate 1, and
Since it is pulled outward in the direction of,
Wrinkles extend on the surfaces of Nos. 3 and 24 in a radial direction from the center to the outside. Then, as the descent continues, L
The mold packing 71 presses the lower substrate 1 against the sealing material 5 and the end plates 23 and 24, so that the space surrounded by the film forming space 6 below the substrate 1 and the wall 22 above the substrate 1 is formed. Vacuum seal. Then, the ground electrode 32
Down in the direction of arrow 55 to force the substrate 1 to move to arrow 5
The wrinkle is further extended by pulling in the direction of 6.
At this time, the pushing depth d of the ground electrode 32 into the substrate is 2.
It is effective that it is 0 to 2.5 mm.

In the above example, the upper film forming chamber can also be evacuated, but it can also be implemented in a thin film photoelectric conversion element manufacturing apparatus in which only the lower film forming chamber accommodating the high voltage electrode is evacuated. .

[0027]

In the example of FIG. 9 or 10, since the ground electrode 32 has the substrate heater 33 built therein, the wall 22 around the heater and the L-type packing 7 are provided.
1, the lip 7, the lip retainer 72, the end plates 23 and 24, the top plate 27, and the sealing material 5 are heated. Since the sealing material is usually made of fluororubber, the L-type packing 71, the lip 7, the lip retainer 72, and the sealing material 5 are heated to increase the viscosity. Therefore, after the film formation is completed, or when the upper film formation chamber is raised after the film formation chamber is sealed and the flexible substrate is conveyed and frame-fed, in the example of FIG.
The sealing material 5, in the example of FIG. 10, the sealing material 5, or
There was a problem that the flexible substrate could not be transported due to adhesion to either one of the L-type packings 71.

In order to solve this problem, a fluorocarbon rubber is used as a seal member that comes into contact with a flexible substrate on the outer periphery of the film forming chamber to hermetically seal a vacuum, and a material having a low adhesive property, such as Teflon (DuPont). (Registered trademark name), Daiflon (registered trademark name of Daikin Industries, Ltd.), or a material that reduces the adhesiveness to fluororubber, for example, a metal film such as Ag, Al, Ti, Cu, Cr, Alternatively, metal oxides such as ZnO, ITO, and SnO ₂ , or fluorine compounds such as Teflon (registered trademark of DuPont), Daiflon (registered trademark of Daikin Industries, Ltd.), silicon compounds, nitriding It has been considered to coat the surface with boron or the like. Further, in order not to increase the tackiness of the seal member itself, it has been considered that the circumference of the seal member is cooled to keep the seal member at 100 ° C. or lower, preferably 50 ° C. or lower, and the stickiness of the seal member is not enhanced.

However, when the seal portion is cooled, the temperature of the heater near the seal portion is lowered, and it is difficult to make the temperature of the substrate on which the thin film is formed uniform throughout the film formation region. Even when the seal portion is coated with various materials, the film quality of the film formed by degassing deteriorates when the temperature rises above the heat resistant temperature of the seal material itself.

In the unlikely event that the flexible substrate adheres to the seal member, a method for removing the sticking of the flexible substrate is to project the drivable pressing member in the upper film forming chamber before transporting the seal member to the seal member. There is a method of peeling off the adhered flexible substrate, but this method is a mechanical means, so there is a possibility that the flexible substrate may be scratched or the formed thin film or thin film photoelectric conversion element may be damaged. was there.

FIG. 11 is a cross-sectional view of a film forming chamber of a conventional thin film manufacturing apparatus for simultaneously forming films on two substrates. (A) shows the film forming chamber open, and (b) shows the film forming chamber closed. Is. High voltage electrode 2
21 and the ground electrode 222 containing the heater 223, the frame body 254 having the same potential as that of the ground electrode 222 is insulated by the insulator 253. For example, quartz is used as the insulator 253 and the high voltage electrode 221 and the quartz are used. , A frame 254 serving as a ground electrode
The sealing material 252 is used to keep the quartz airtight.
Alternatively, since the sealing material can also play a role as an insulating material, a sealing material having a thickness that can provide a necessary space has been used. Further, the two high voltage electrodes 221 are isolated by the insulating block 209 so that the two substrates can be independently formed. And the insulating block 2
09 is connected to the exhaust member 208 having a ground potential.

In the thin film manufacturing apparatus of this structure, both sides of the film forming chamber are surrounded by the ground electrode 222 having a built-in heater, the side walls are surrounded by a vacuum, and the lower part or the upper part fixed in the common chamber is closed. Since the heat is only released and escapes, the inside of the film forming chamber is sufficiently heated. For example, if the heater temperature is 250 ° C, the temperature inside the deposition chamber will be about 150 ° C to 20 ° C.
It rose to about 0 ℃. Therefore, when the temperature inside the film forming chamber rises or falls, when quartz is used as the insulator, the frame body 254 serving as a ground electrode or the high voltage electrode 2 is used.
21. In addition, due to the thermal expansion and thermal contraction of the members (SUS, aluminum) that constitute the film forming chamber, a force may be applied to the quartz and the quartz may be damaged. In this case, gas leaks from the film forming chamber to the common chamber, and the pressure at which stable discharge is possible cannot be maintained in the film forming chamber, or the pressure in the common chamber increases.
Discharge occurs between the high voltage electrode and the ground electrode outside the deposition chamber,
It was not possible to stably discharge in the film forming chamber.

Further, the insulator 253 is the high voltage electrode 221.
Since the laminated structure is sandwiched between the frame body 254 having the same potential as that of the ground electrode 222 and the ground electrode 222, the high voltage electrode 221 or the ground electrode is used to replace the damaged insulator 253. The frame 254 had to be disassembled, which required a great deal of labor and time. Further, as another problem, in order to convey the flexible substrate, tension is applied in the substrate conveying direction. Since the transport distance becomes long, the number of rolls supporting the flexible substrate must be increased, and the mechanical loss on the roll axis increases, resulting in a weak tension on the flexible substrate and wrinkling of the substrate. Was occurring.

Further, a large amount of gas was released from the sealing material, and the film quality was deteriorated. Further, when a thick sealing material was used as the insulating material, more degassing occurred and the film quality further deteriorated.
An object of the present invention is to provide a film forming chamber having a seal portion which is less likely to adhere to a substrate even when the film forming chamber is at high temperature, is less likely to be outgassed, is less susceptible to distortion of the film forming chamber wall, and is easy to replace. An object is to provide a thin film manufacturing apparatus having the above.

[0035]

In order to achieve the above object, a transport system for transporting a flexible substrate and a thin film is formed on the flexible substrate in one common vacuum chamber. And a plurality of film forming chambers each having a means, each film forming chamber including two film forming unit chambers having an opening having a flexible substrate as a boundary, and each opening being provided with a seal portion. In the thin film manufacturing apparatus in which the sealing parts are aligned with each other with the substrate sandwiched and the film forming chamber and the common vacuum chamber are airtight, the sealing part is made of a metal or ceramic inorganic material, and Of the chambers, the movable film forming chamber and the heater for heating the substrate have an integrated structure.

Of the film forming chambers, the movable film forming chamber and the heater for heating the substrate may have an integrated structure. The width of the portion of the seal portion that contacts the substrate is preferably 10 mm or more. The heater may be larger than the film formation area on the flexible substrate.

The pressure of the seal portion is 1 × 10 ⁴ Pa or more 5 ×
It should be 10 ⁵ Pa or less.

Further, in one common vacuum chamber, there are provided a transfer system for transferring the flexible substrate and one or a plurality of film forming chambers provided with means for forming a thin film on the flexible substrate. However, each film forming chamber is composed of two film forming unit chambers having an opening with a flexible substrate as a boundary, each opening is provided with a seal, and each seal is aligned with the substrate sandwiched therebetween. A thin film manufacturing apparatus in which a film forming chamber and a common vacuum chamber are airtight, and one film forming unit chamber includes a high-voltage electrode and a seal portion around its periphery, A flexible insulating sheet is used as an insulator between the high-voltage electrode and the portion that effectively becomes the ground potential.

The portion that effectively becomes the ground potential is preferably an exhaust member of the film forming chamber. The portion that is effectively at the ground potential is preferably the frame body at the peripheral portion of the ground electrode in the film forming chamber.
The insulating sheet is preferably fixed by a band-shaped fixing jig. The insulating sheet is preferably made of polyimide resin or aramid resin.

The thickness of the insulating sheet is preferably 10 μm to 500 μm. A substrate tension adjusting device is provided between the film forming chambers. According to the present invention, the material of the seal portion, which is in contact with the flexible substrate and the substrate on the outer periphery of the film forming chamber space and hermetically seals the vacuum, is a metal or a ceramic inorganic material, so that the adhesiveness to the substrate is small and the seal portion It is possible to prevent sticking to the substrate. Further, by using an inorganic substance such as metal or ceramic for the seal portion, degassing is reduced as compared with, for example, using a fluorine-based rubber or coating it.

The width of the seal portion that contacts the flexible substrate is 10 mm
With the above, the airtightness is improved and the common chamber pressure is 3 × 10 ^-2 Pa.
It can be kept below, and stable discharge can be obtained in the film forming chamber. The pressure of the seal part on the substrate should be 1 × 10 ⁴ Pa or more 5 × 10 ⁵ P
If it is set to a or less, the flexible substrate will not be broken even if a metal or ceramic inorganic material with low elasticity is used as the sealing material, and the common chamber pressure can be maintained at 3 × 10 ^-2 Pa or less. A stable discharge can be obtained in the film chamber.

When the film forming chamber space is formed with the flexible substrate sandwiched, the surface of the film forming chamber on one side which is operated can be moved relative to the seal surface, so that the seal surface can be brought into contact with the seal surface accurately and can be commonly used. Gas leakage to the chamber can be reduced. Since the seal part that makes the vacuum tight by contacting the flexible substrate and the substrate on the outer periphery of the film forming chamber space is made of a metal or ceramic inorganic substance, eliminating the cooling of the seal part, the heater temperature of the part near the seal part The temperature of the substrate for forming the thin film can be made uniform over the entire film formation region, and the uniformity of the film quality can be improved.

The high-voltage electrode and the ground electrode have a film-forming chamber structure insulated from each other by an insulator. By using a flexible insulating sheet for the insulator, the high-voltage electrode and the ground electrode can be insulated. By using a polyimide-based or aramid-based polymer film as the flexible insulating sheet substrate, a high-quality film with less degassing, that is, a high-quality photoelectric conversion element can be formed.

Replacing the insulator is facilitated by fixing the insulator from the side surfaces of the high voltage electrode and the ground electrode instead of sandwiching them. Since the surface of the flexible insulating sheet other than the sealing surface is roughened, film peeling is less likely to occur.

[0045]

Embodiment 1 FIG. 1 is an enlarged cross-sectional view of a sealing portion of a film forming chamber of a thin film manufacturing apparatus according to the present invention, in which (a) is an open state and (b) is a closed state. . The entire film forming chamber is the same as that shown in FIG. 1 and corresponds to the conventional seal portion FIG. Band-shaped end plates 171 and 123, which also serve as seal portions provided in the upper film forming chamber wall 22 and the lower film forming chamber wall 27, respectively, and a lip retainer 172.
Is made of Al material. In this embodiment, the band-shaped end plates 171 and 123 also serving as the seal portion, and the lip retainer 17
Although Al is used for 2, any other inorganic material such as a metal or a ceramic with less outgassing may be used. Lip 7
Is a fluorinated rubber. As the flexible substrate, a polyimide substrate having a thickness of 50 μm, on which electrode layers of a multilayer film containing metal or metal oxide were formed, was used. When the width W of the portion of the strip-shaped ring end plates 171 and 123, which also functions as the seal portions provided in the upper film forming chamber wall 22 and the lower film forming chamber wall 27, that contacts the flexible substrate is set to 10 mm or more, it is airtight. (Sealability) was secured.

Further, when the film forming chamber space is formed with the flexible substrate sandwiched, the movable film forming chamber wall on one side is bent so that it can be brought into proper contact with the sealing surface, and is shared with the film forming chamber. Secured the chamber seal. As a result, it was possible to reduce gas leakage to the common chamber when the film forming chamber space was filled with the film forming gas. The pressure in the film forming chamber is 3 × 10 ^-1 to 5 × 10 ² P, respectively.
When kept in the range of a, the pressure in the common chamber could be kept below 3 × 10 ^-2 Pa, and stable discharge could be performed in the film forming chamber.

When the thickness of the flexible substrate was changed, the thickness
Below 25 μm, gas leaked from the film formation chamber to the common chamber so much that the pressure in the common chamber could not be kept below 3 × 10 ^-2 Pa. Moreover, when the flexible metal foil substrate was used, the common chamber pressure could not be kept below 3 × 10 ^-2 Pa. When the pressure sandwiching the flexible substrate was 5 × 10 ⁵ Pa or more, the flexible substrate was scratched and sometimes ruptured. Also, 1 × 10 ⁴ Pa
In the following cases, the common chamber pressure could not be kept below 3 × 10 ^-2 Pa and stable discharge could not be performed in the film forming chamber.

FIG. 2 is a graph showing the dependence of the photoelectric conversion efficiency of the photoelectric conversion element formed by the thin film manufacturing apparatus according to the present invention on the heater temperature during film formation. Curve a is an element in which the intrinsic semiconductor layer is formed in the film forming chamber of the metallic seal portion according to the present invention, and curve b is an element in which the intrinsic semiconductor layer is formed in the film forming chamber of the conventional fluorine rubber seal portion. Is a characteristic of. When the fluorine rubber is used as the seal, raising the heater temperature raises the temperature of the seal, which increases degassing of impurities.
Degassing hardly increases when a metal product is used. For this reason, when the seal part is made of metal, degassing from the seal part is less even if the heater temperature is increased to form a film, compared to the case of fluorine rubber, so the film quality of the intrinsic semiconductor layer is good and the conversion efficiency is high. There was little decrease. Example 2 In the film forming chamber of Example 1 (FIG. 1), a metal (stainless steel) foil was used as the material of the lip 7. In the case of metal foil, the pressure per contact area with the substrate is higher than that of fluororubber, but the frictional force with the substrate is small, so the peripheral area of the lip 7 should be bent in an arc shape to increase the contact area. The frictional force was increased to improve the wrinkle extension by the lip 7. Example 3 FIG. 3 shows a sealing part of a film forming chamber of another example according to the present invention, in which (a) is an opened state and (b) is a sealed state. Example 2
The upper film forming chamber wall 22 (FIG. 1) and the high-voltage electrode 32 having the conventional heater 33 are integrated. In this embodiment, the seal members 171, 123 and the lip retainer 172 are made of Al, and the lip 7 of the metal foil is attached. Further, in order to ensure the sealing between the film forming chamber and the common chamber, when forming the film forming chamber space with the flexible substrate sandwiched, the surface of the film forming chamber on one side to be operated is opposed to the sealing surface. It is movable so that it can make contact with the sealing surface accurately.

In the case of this structure, since the seal portion is made entirely of metal and softening and degassing do not occur, a cooling mechanism for the seal portion is not necessary, the heater temperature in the portion near the seal portion does not decrease, and a thin film is formed. Since the substrate temperature to be applied can be made uniform over the entire film formation region and peeling of the film adhered to the wall of the film forming chamber can be suppressed, deterioration of the film quality due to peeling flakes does not occur,
It was also possible to improve the uniformity of film quality. Example 4 In this example, the upper film forming chamber wall 22 and the band-shaped end plate 171 in Example 3 (FIG. 3) were made of the same material, and were further integrated. Therefore, the temperature of the seal portion and its vicinity can be raised to near the substrate temperature, the temperature uniformity of the substrate can be improved, and the variation in the characteristics within the substrate is reduced. Example 5: FIG. 4 is an enlarged cross-sectional view of a seal portion of a film forming chamber of a film forming apparatus for simultaneously forming films on two substrates. (A) is a structure according to the present invention and (b) is a conventional structure. is there. This drawing is a schematic view of the seal portion having the structure shown in FIG. 11 for the sake of simplicity.
Conventionally, quartz is used as the insulator 253 and fluorine rubber is used as the sealing material 252, or thick fluorine rubber that serves as both the sealing material and the insulator is used. However, as the temperature rises, in the photoelectric conversion element, the gas serving as an impurity is degassed, which causes the deterioration of the film quality. In this embodiment, a 50 μm-thick seamless (endless) polyimide sheet is used as the insulating sheet 201 for insulating the frame body 254 having the same potential as the high-voltage electrode 221 and the ground electrode 222. Similarly, the exhaust member 208 and the high-voltage electrode 2
21 is also connected by the insulating sheet 201. Insulation sheet 2
No. 01 high-voltage electrode 221 and a frame 25 serving as a ground electrode
Unlike the conventional sandwich structure, the fixing to the insulating sheet 201 is performed by fixing the fixing jig 260 from the side with screws.
Was sandwiched between each electrode. Even with such a sealing method, the pressure in the common chamber could be maintained at 3 × 10 ^-2 Pa or less, and stable discharge and uniform film formation could be performed.

Not limited to the polyimide sheet, an aramid resin or the like can be used as long as it is a material having excellent heat resistance and high-frequency insulation properties. Also, because it is necessary to fit each electrode and the seal surface shape without gaps,
It was found that these insulating sheets should have a thickness of 10 to 500 μm. Since a film is also formed on the insulating sheet, film peeling can be suppressed by roughening the parts other than the seal part by, for example, sandblasting, and as a result, a film with few defects such as pinholes can be formed. I was able to.

Further, the flexible insulating sheet 201 can be similarly used for the seal between the high voltage electrode 221 and the exhaust block 209 on the back surface thereof. The film produced by the apparatus adopting such a sealing method was of high quality without being affected by degassing from the vacuum sealing material. Example 6 In a film forming chamber having a structure combining Example 3 and Example 5,
Fluorine-based rubber does not exist in the portion exposed to the film forming atmosphere, and is made of metal except for the substrate for film formation and the flexible insulating sheet for sealing the common chamber and the film forming chamber. In the film forming chamber having such a structure, it is not necessary to cool the seal portion. Therefore, there is no low-temperature portion in the film forming chamber, and it is difficult to form a flake-like film that causes pinholes.

Further, since the flexible insulating sheet is flexible between the high voltage electrode and the ground electrode, there is no influence of thermal strain due to thermal expansion or thermal contraction of the film forming chamber. Further, the device structure is simple and the cost can be kept low. Example 7 FIG. 5 is a side sectional view of a stepping roll film forming type thin film manufacturing apparatus having a tension adjusting device according to the present invention. In order to convey the flexible substrate, tension is applied in the substrate conveying direction. Since the transport distance becomes long, the number of rolls supporting the flexible substrate must be increased, and the tension loss at the roll axis increases, resulting in a weak tension on the flexible substrate and wrinkling of the substrate. Etc. are likely to occur. In this embodiment, the tension adjusting device T is arranged between the film forming chambers of the flexible substrate. The tension adjusting device T includes a driving roll R1 and a slack adjusting roll R2. The driving roll R1 pulls and conveys the substrate, and the slack adjusting roll R2 applies a pulling force to the extent that wrinkles do not occur. In this way, the tension of the substrate was maintained at about 100 N / width, wrinkles did not occur, and characteristic defects due to deformation of the substrate due to excessive tension did not occur.

When a pin / pin two-layer tandem amorphous silicon solar cell having the film forming chamber of this example was manufactured by a stepping roll type thin film manufacturing apparatus, it was found that compared with the one manufactured by the conventional structure thin film manufacturing apparatus, The photoelectric conversion efficiency was high and the photodegradation rate was low. Further, it was particularly effective to use the film forming chamber structure of Example 6 as the film forming chamber for forming the i layer.

[0054]

According to the present invention, one or a plurality of transport systems for transporting a flexible substrate and a means for forming a thin film on the flexible substrate are provided in one common vacuum chamber. Film forming chambers, each film forming chamber is composed of two film forming unit chambers having an opening with a flexible substrate as a boundary, and each opening is provided with a seal unit. In a thin-film manufacturing apparatus in which the substrate is sandwiched and the film forming chamber and the common vacuum chamber are airtight, a metal or ceramic inorganic material is used as the seal portion, so fluorine-based rubber that is often degassed may be used. , There is no degassing compared to the one coated on it,
Further, the airtightness between each film forming chamber and the common chamber is improved, and it becomes possible to form a high quality film, and the photoelectric conversion efficiency of the photoelectric conversion element is improved. Further, it is possible to prevent the flexible substrate from sticking to the seal portion. As a result, the trouble of transporting the flexible substrate was eliminated.

The high-voltage electrode and the ground electrode have a film-forming chamber structure in which they are insulated by an insulating material. By using a flexible insulating substrate for the insulating material, the manufacturing cost of the device is reduced.

Further, replacement is facilitated by fixing the insulator from the side surfaces of the high-voltage electrode and the ground electrode instead of sandwiching them between them.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a seal portion of a film forming chamber of a thin film manufacturing apparatus according to the present invention, where (a) is open and (b) is sealed.

FIG. 2 is a graph showing the heater temperature dependence of the photoelectric conversion efficiency of the photoelectric conversion element formed by the thin film manufacturing apparatus according to the present invention during film formation.

FIG. 3 is an enlarged cross-sectional view of a seal portion of a film forming chamber of another embodiment according to the present invention, (a) being opened and (b) being sealed.

4A and 4B are enlarged cross-sectional views of a seal portion of a film forming chamber of a film forming apparatus for forming a film on two substrates at the same time, where FIG. 4A is a structure according to the present invention and FIG.

FIG. 5 is a side sectional view of a stepping roll film forming type thin film manufacturing apparatus having a tension adjusting device according to the present invention.

FIG. 6 is a side sectional view of a stepping roll film forming type thin film manufacturing apparatus having a plurality of film forming chambers in a common vacuum chamber.

FIG. 7 is a cross-sectional view of a film forming chamber of a conventional stepping roll type thin film manufacturing apparatus, in which (a) is opened and (b) is sealed.

FIG. 8 is a cross-sectional view of a seal portion of a lower portion and an upper portion of a film forming chamber of a conventional thin film manufacturing apparatus.

FIG. 9 is a cross-sectional view perpendicular to the transport direction of the flexible substrate, showing the opening of the film forming chamber of the conventional thin film manufacturing apparatus for forming a film by plasma CVD.

FIG. 10 is an enlarged cross-sectional view of a seal portion of a film forming chamber of a conventional thin film manufacturing apparatus (FIG. 9), in which (a) shows the film forming chamber opened.
(B) When the film forming chamber is sealed

FIG. 11 is a cross-sectional view of a film forming chamber of a conventional thin film manufacturing apparatus that simultaneously forms a film on two substrates, FIG.
(B) is when the film formation chamber is sealed

[Explanation of symbols]

1 Flexible substrate 21 Lower film forming chamber wall 22 Upper film forming chamber wall 27 Top Plate 28 housing 29 Moving plate 43 Moving plate 30 Vertical drive guide 31 High voltage electrode 32 ground electrode 36 Common vacuum chamber wall 41 actuator 44 actuator 6 Film forming space 61 Vacuum exhaust pipe 64 flexible piping 7 lip 71 L type packing 72 Lip holder 80 Film forming chamber 81 common room 82 core 83 core 123 Strip end plate 171 strip end plate 173 Lip holder 201 Insulating flexible substrate 205 film deposition chamber 206 plasma 208 Exhaust member 209 Exhaust block 210 common room 221 High voltage electrode 222 Ground electrode 223 heater 252 sealing material 253 insulator 254 frame 255 sealing material 258 screw 260 fixing jig 272 Vacuum exhaust port T tension adjusting device R1 drive roll R2 slack adjustment roll

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/205

Claims (9)

(57) [Claims] 1. A common vacuum chamber comprises a transfer system for transferring a flexible substrate and one or a plurality of film forming chambers equipped with means for forming a thin film on the flexible substrate. However, each film forming chamber is composed of two film forming unit chambers having an opening with a flexible substrate as a boundary, each opening is provided with a seal, and each seal is aligned with the substrate sandwiched therebetween. Te in a thin film manufacturing apparatus is airtight between the deposition chamber and the common vacuum chamber, the sealing portion together with made of an inorganic material of metal or ceramic, before
Among the film forming chambers, a movable film forming chamber and a heater for heating the substrate.
The thin film manufacturing apparatus is characterized in that it has an integrated structure . 2. The thin film manufacturing apparatus according to claim 1, wherein the movable film forming unit chamber and the seal unit are made of the same material and are integrated. 3. A common vacuum chamber is provided with a transfer system for transferring a flexible substrate and one or a plurality of film forming chambers provided with means for forming a thin film on the flexible substrate. However, each film forming chamber is composed of two film forming unit chambers having an opening with a flexible substrate as a boundary, each opening is provided with a seal, and each seal is aligned with the substrate sandwiched therebetween. In the thin film manufacturing apparatus in which the film forming chamber and the common vacuum chamber are hermetically sealed, and one film forming unit chamber includes a high voltage electrode and a seal part at the periphery thereof, A thin film manufacturing apparatus characterized in that a flexible insulating sheet is used as an insulator between the high voltage electrode of the film chamber and a portion that is effectively at ground potential. 4. The thin film manufacturing apparatus according to claim 3, wherein the portion that is effectively at the ground potential is an exhaust member of the film forming chamber. 5. The thin film manufacturing apparatus according to claim 3, wherein the portion that is effectively at the ground potential is a frame body at the peripheral portion of the ground electrode in the film forming chamber. 6. The thin film manufacturing apparatus according to claim 3, wherein the flexible insulating sheet is fixed by a belt-shaped fixing jig. 7. The insulating sheet is made of a polyimide resin or an aramid resin.
The thin film manufacturing apparatus according to. 8. The thin film manufacturing apparatus according to claim 7, wherein the insulating sheet has a thickness of 10 μm to 500 μm. 9. The thin film manufacturing apparatus according to claim 1, further comprising a substrate tension adjusting device provided between the film forming chambers.