JP2010109089A - Conveyance device, and method of manufacturing film-formed substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent film quality and a yield from becoming worse by preventing a substrate on which a thin film is formed by using a CVD device from curving when mounted on a temperature-raised film forming plate. <P>SOLUTION: A method of mounting the substrate on the film forming plate used for a continuous parallel flat plate type CVD device includes heating a nearly center portion of the substrate before or after mounting the substrate on the film forming plate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transfer apparatus for mounting a substrate on a film formation plate used in a plasma chemical vapor deposition (hereinafter abbreviated as CVD) apparatus for forming a thin film and a method for manufacturing the film formation substrate.

  A CVD apparatus used in a conventional substrate manufacturing method includes a load lock chamber for carrying a substrate into a processing atmosphere, a film forming chamber for forming a film on the carried substrate by CVD, and forming a processed substrate. It consists of an unload lock chamber taken out from the chamber, and these are arranged in series.

  In the conventional substrate transfer path, a substrate to be processed is first transferred into a load lock chamber by a transfer mechanism, and then the substrate is transferred into a film formation chamber. The substrate is deposited on a deposition plate disposed opposite to the electrode plate in the deposition chamber. Here, the film formation chamber is heated by heat from a reaction during film formation or by heat in the film formation process. Then, the deposited substrate proceeds to the unload lock chamber and is carried out of the apparatus from the unload lock chamber.

Generally, in order to improve productivity, a film formation plate used for film formation is further used without being cooled while being heated after being unloaded from the unload lock chamber.
JP-A-10-340896 JP 2004-231999 A

  In the above-described substrate processing step, the film formation plate is unheated after being unloaded from the unload lock chamber and is used without being cooled, so when a new substrate is placed on the film formation plate. There is a problem that the substrate is easily warped due to the temperature difference.

  The present invention has been made in view of such problems, and can provide a substrate transport apparatus and a film formation that can reduce the warpage of the substrate and reduce the defects such as film quality and yield. An object is to provide a method for manufacturing a substrate.

  The substrate transport apparatus of the present invention includes a suction pad for placing a substrate on a film forming plate transported into a CVD apparatus, and means for heating a central region of the substrate.

  Further, the method for manufacturing a film formation substrate of the present invention includes a step of preparing a substrate, a film formation plate to be transferred into the CVD apparatus, and a transfer mechanism for transferring the substrate to the film formation plate, Heating the substrate by applying a high-temperature gas from the transport mechanism to the central region of the substrate, placing the substrate on the film formation plate by the transport mechanism, and placing the substrate A step of advancing the formed film forming plate into a CVD apparatus and forming a film on the substrate.

  In addition, the method for manufacturing a film formation substrate of the present invention includes a step of preparing a substrate, a film formation plate to be transferred into the CVD apparatus, and a transfer mechanism that includes a jig and transfers the substrate to the film formation plate. A step of pressing the jig having a temperature higher than that of the substrate against the central region of the substrate and heating the substrate; a step of placing the substrate on the film formation plate by the transport mechanism; and the substrate And a step of depositing the film on the substrate by advancing the film-forming plate on which is placed in a CVD apparatus.

  According to the present invention, since the temperature of the substrate to be processed can be brought close to the temperature of the film formation plate by the above-described configuration or process, the thermal stress applied to the substrate to be processed can be reduced. Warpage can be reduced. Therefore, the problem which arises in a board | substrate by curvature can also be eliminated.

  FIGS. 1A, 1B, and 1C are diagrams showing an embodiment of operations of the transfer device and the CVD device. The CVD apparatus is used, for example, in a film forming process of a silicon nitride thin film as an antireflection film of a solar cell element or a manufacturing process of a semiconductor element or a liquid crystal display device.

  The substrate 1 is supported by a transfer cart 2 including a film formation plate 17 and is carried into a CVD apparatus, and is formed into a film in the film formation chamber 4. The substrate 1 is unloaded from the unload lock chamber 5 of the CVD apparatus to the atmosphere side and then collected from the transfer cart 2. The transport cart 2 is transported in front of the load lock chamber 3 after being unloaded from the unload lock chamber 5 in order to increase the tact time, and a new substrate 1 is supplied. Such a transport cart 2 is in a heated state when transported in front of the load lock chamber 3.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

<Embodiment 1>
FIG. 2 is a perspective view showing an example of a transfer device for placing the substrate 1 on the film forming plate 17 of the transfer cart 2 arranged on the loader belt 15, and FIGS. It is process drawing which shows operation | movement.

  The transport device includes a drive shaft 29, a base arm 24, and a spray nozzle 27, and includes a suction movable portion 23 that is fixed to the drive shaft 29 by screwing or the like via an air cylinder.

  The base arm 24 of the suction movable portion 23 is made of a metal prism such as stainless steel or aluminum. A plurality of rubber suction pads 25 are attached to the base arm 24. The number of the rubber suction pads 25 is preferably three or more from the viewpoint of stability during movement after suction holding. The plurality of suction pads 25 have a role of placing the substrate 1 on the film forming plate 17 transported into the CVD apparatus, and are connected to the decompression hose 26, respectively. Is connected to decompression means such as a vacuum pump. In addition, an opening / closing means such as an electromagnetic valve is provided at an intermediate portion of the decompression hose 26. Further, a spray nozzle 27 is attached to a substantially central portion of the base arm 24. A gas supply hose 28 is connected to the spray nozzle 27, and the other end of the gas supply hose 28 is connected to a hot air generator such as air or nitrogen. In addition, an opening / closing means such as an electromagnetic valve is provided at a substantially middle portion of the gas supply hose 28. It is desirable that the decompression hose 26 and the gas supply hose 28 are spiral expandable and contractible hoses so as to follow the movement of the suction movable portion 23 in the vertical and horizontal directions.

  The drive shaft 29 is connected to a servo motor controlled by a sequencer or the like, and can move the suction movable unit 23 to a predetermined position.

  FIG. 4 is a plan view showing the configuration of the transport cart 2 on which the substrate 1 is placed. The transport cart 2 is configured to support the plurality of substrates 1 and travel on the transport member 6 after the plurality of substrates 1 are placed by the transport device. Such a transport cart 2 has a structure in which a film forming plate 17 is fitted into a metal frame 9 made of stainless steel or the like and fixed by a film forming plate fixing jig 20. The transport cart 2 is moved inside by the transport member 6 of the plasma CVD apparatus, and is fixed by a positioning jig 16 provided on the metal frame 19 at a predetermined position.

  FIG. 5 is a plan view of the film forming plate 17 shown in FIG. The film forming plate 17 includes substrate positioning pins 18 that can support the substrate 2. As a material of the film forming plate 17, carbon, aluminum, aluminum alloy, or the like can be used. In FIG. 5, the positioning pins 18 are implanted on the film forming plate 17 so that the distance between the positioning pins 18 is slightly larger than the size of the substrate 1 in order to prevent the substrates 1 from overlapping each other and falling from the film forming plate 17. It is installed. A portion of the film forming plate 17 surrounded by the positioning pins 18 serves as a substrate mounting portion 19.

  In this embodiment, the board | substrate 1 is mounted on the film-forming plate 17 of the conveyance cart 2 arrange | positioned on the loader belt 15 from a work table with the following procedure.

  First, when the plurality of substrates 1 are supplied onto the work table 22, the suction movable unit 23 is lowered until the substrate 1 and the suction pad 25 come into contact with each other by the air cylinder (FIG. 3A).

  Next, an electromagnetic valve connected to the suction pad 25 is opened to suck and hold the substrate 1 on the suction movable portion 23. At this time, an electromagnetic valve connected to the hot air generator is opened, and a gas (hot air) having a temperature higher than that of the substrate 1 is blown from the spray nozzle 27 so as to hit the substantially central portion (region A shown in FIG. Thereafter, the suction movable unit 23 is raised while the substrate 1 is sucked and held by the suction movable unit 23 (FIG. 3B).

  Thereafter, the suction movable portion 23 is moved in the horizontal direction on the substrate mounting portion 19 on the film forming plate 17 (FIG. 3C).

  Thereafter, the suction movable portion 23 is lowered until the substrate 1 and the film forming plate 17 come into contact with each other, the electromagnetic valve connected to the suction pad 25 is closed, and the substrate 1 is separated from the suction movable portion 23. Thereafter, the solenoid valve connected to the hot air generator is closed, and the hot air from the spray nozzle 27 is stopped (FIG. 3D). Thereafter, the suction movable unit 23 is raised, and the suction movable unit 23 is moved laterally on the work table 22.

  A plurality of substrates 1 can be placed on the film forming plate 17 by repeating the above operation.

  Thus, in the present embodiment, the temperature of the upper surface of the substrate 1 can be raised by blowing a gas having a temperature higher than that of the substrate 1 from the spray nozzle 27 to the upper surface side of the substrate 1. As a result, when the substrate 1 is placed on the film formation plate 17, the temperature of the lower surface of the substrate 1 rises due to the heated film formation plate 17, but the upper surface of the substrate 1 is also raised by hot air as described above. Since the temperature is high, the temperature difference between the upper surface and the lower surface of the substrate 1 is almost eliminated, and the substrate 1 warps in a concave shape on the film formation plate 17 (the end B of the substrate 1 shown in FIG. Floating) can be reduced. Further, by reducing the warpage of the substrate, the substrate 1 becomes difficult to move on the film formation plate 17 when the film formation plate 17 on which the substrate 1 is placed is transported into the CVD apparatus, and the overlap between the substrates 1 is reduced. This makes it easy to form a film uniformly. Furthermore, since the probability that the substrate 1 rides on the positioning pins 18 of the film formation plate 17 is reduced, film formation can be performed stably, and the film quality can be improved.

  As the hot air blown from the spray nozzle 27, clean air, nitrogen or the like can be used. From the viewpoint of cost, it is preferable to use air, and from the viewpoint of preventing oxidation of the substrate 1 by hot air, it is desirable to use nitrogen.

  The temperature of the hot air and the blowing pressure may be determined optimally in view of the temperature and warpage after the substrate 1 is placed on the film formation plate 17.

  Further, the blowing of hot air from the spray nozzle 27 is performed after the suction movable portion 23 is lowered until the substrate 1 and the film formation plate 17 come into contact with each other in order to eliminate the danger of the substrate from dropping from the suction movable portion 23 by the hot air. First, an electromagnetic valve connected to the hot air generator may be opened, and hot air may be blown from the spray nozzle 27 for a predetermined time so as to hit the substrate 1. Further, as described above, after the substrate 1 is sucked and held on the suction movable portion 23 on the work table 22, it continues until the substrate 1 is placed on the film forming plate 17 and separated from the suction movable portion 23. Then, hot air may be blown from the spray nozzle 27 so as to strike the substrate 1. In this case, the hot air hits the substrate 1 for a long time, and the suction movable portion 23 moves in the vertical and horizontal directions, so that the hot air uniformly hits the substrate 1 and the temperature difference on the substrate surface is reduced. Warpage of the substrate 1 after the substrate 1 is placed on the substrate is reduced. In particular, it is effective when a substrate 1 of about 150 mm or more used for a solar cell element or the like is used. Further, this method has an advantage that the tact time can be shortened because the temperature of the substrate 1 is raised during the movement of the suction movable portion 23.

  Further, as shown in FIG. 3D, after the suction movable portion 23 is lowered until the substrate 1 and the film formation plate 17 contact each other, the substrate 1 is pressed against the film formation plate 17 by the suction pad 25 for a predetermined time. It is desirable to maintain. As a result, the temperatures of the substrate 1 and the film forming plate 17 can be made substantially equal, the warpage of the substrate on the film forming plate 17 can be further reduced, and various problems occurring in the substrate can also be reduced. The time for pressing the substrate 1 against the film formation plate 17 with the suction pad 25 is preferably 3 seconds or more. By setting it to 3 seconds or more, the substrate 1 is hardly warped.

  Next, the CVD apparatus of this embodiment will be described. The CVD apparatus of the present embodiment is a parallel plate type plasma CVD apparatus, and a substrate 1 supported by a transfer cart 2 including a film formation plate 17 is carried in, and the inside of the substrate 1 is kept in a predetermined vacuum state while maintaining the temperature of the substrate 1. The load lock chamber 3, the film formation chamber 4 in which the substrate 1 from the load lock chamber 3 is carried in to form a film on the substrate 1, the substrate 1 from the film formation chamber 4 is carried in to cool the substrate 1, and the inside And an unload lock chamber 5 for returning the pressure to atmospheric pressure and carrying it out to the atmosphere side. The load lock chamber 3, the film formation chamber 4, and the unload lock chamber 5 are connected in a straight line via an openable / closable gate valve that can maintain airtightness. A similar gate valve is also provided on the atmosphere side of the load lock chamber 3 and the unload lock chamber 5.

  The film forming chamber 4 includes a pair of electrode plates arranged so as to face each other, a conveying member 6 for placing the substrate 1 placed between the electrode plates, and an RF power source for generating plasma between the electrode plates 8, a ground 11, a vacuum pump 10 as an evacuation system, a mass flow controller 9 for controlling the amount of gas sent into the film formation chamber to a predetermined amount, and a heater 12 for heating the substrate.

  The transfer member 6 is laid in the load lock chamber 3, the film formation chamber 4, and the unload lock chamber 5, and the transfer cart 2 is sequentially loaded with the load lock chamber 3, the film formation chamber 4, and the unload lock by the transfer member 6. It is conveyed in the chamber 5.

  The substrate 1 supported by the transfer cart 2 including the film formation plate 17 is carried into the load lock chamber 3 from the loader belt 15 in a state where the load lock chamber 3 and the film formation chamber 4 are blocked by a gate valve. Here, the load lock chamber 3 is evacuated from the atmospheric state to a vacuum state and is heated to a predetermined temperature by the heater 12. Next, the outside of the CVD apparatus and the load lock chamber 3 are blocked by a gate valve, and then the load lock chamber 3 and the film formation chamber 4 are opened to carry the substrate 1 into the film formation chamber 4. The substrate 1 carried into the film forming chamber 4 is placed on one electrode plate of the film forming chamber 4. In the film forming chamber 4, the vacuum pump 10 evacuates, RF power is applied between the electrodes from the RF power source 8, and plasma is generated between the electrode plate 7 and the transport cart 2 on the ground 11 side. A gas is introduced into the plasma space from the mass flow controller 9 to be excited to form a thin film such as a semiconductor film, an insulating film, or a conductive film on the surface of the substrate 1 placed on the film forming plate of the transport cart 2. . Here, at the time of film formation, heat is generated in the film formation chamber by reaction and is heated. If necessary, the substrate 1 is heated to form a film, and the film formation chamber is heated to about 350 to 450 degrees. After the film formation, the film forming chamber 4 and the load lock chamber 3 are blocked by a gate valve, and then the film forming chamber 4 and the unload lock chamber 5 are opened to carry the substrate 1 into the unload lock chamber 5. . Then, the unload lock chamber 5 was purged from the vacuum state to the atmospheric state with the gate valve shutting off the film forming chamber 4 and the unload lock chamber 5, and a film was deposited from the unload lock chamber 5. The substrate 1 is unloaded.

  The transfer cart 2 unloaded from the unload lock chamber 5 is heated to a predetermined temperature in the vicinity of 350 to 450 ° C. in the load lock chamber 3 and the film formation chamber 4 so that an optimum film quality can be formed at the time of film formation. In order to increase the cycle time, the substrate 1 placed on the substrate 1 is accommodated and quickly transferred to the front of the load lock chamber 3 without increasing the temperature.

  At this time, a substrate 2 supply mechanism is provided on the inlet side of the load lock chamber 3 so that a new substrate 1 before film formation is supplied onto the transfer cart 2 from the upper side of the transfer cart 2 or the unload lock chamber 5 is supplied. A substrate 1 recovery mechanism is provided on the outlet side of the substrate 1 to recover the deposited substrate 1. It is also possible to supply and collect at the entrance side at the same time.

  Furthermore, in order to shorten the tact time, a heater or the like may be embedded in the loader belt 15 on which the film formation plate 17 is placed, and the film formation plate 17 may be heated from the lower side at a predetermined temperature. By doing in this way, it can prevent that the temperature of the film-forming plate 17 falls while mounting the board | substrate 1. FIG.

  It is also possible to provide a tunnel-type heat insulation furnace or heating furnace between the time when the transport cart 2 comes out of the unload lock chamber 5 and returns to the front of the load lock chamber 3.

  Further, when a large number of substrates 1 are mounted on a single film-forming plate 17 using a large CVD apparatus, the substrate 1 is mounted by a plurality of suction movable parts 23 that operate separately. Tact time can be shortened. Further, as described above, a plurality of the suction movable parts 23 may be connected in the vertical or horizontal direction, and the substrates 1 may be placed one column at a time for each row direction or column direction of the film forming plate 17.

The substrate mounting method on the film formation plate 17 according to the present embodiment is a plasma CVD apparatus using monosilane gas or ammonia gas on the light receiving surface of a crystalline solar cell element using single crystal silicon or polycrystalline silicon as a substrate. This is particularly effective when silicon nitride (Si ₃ N ₄ ) is formed as an antireflection film. When a silicon nitride film is simultaneously formed by a large-sized CVD apparatus with about 10 to 100 silicon substrates, the deposited silicon nitride film is antireflective by raising the film formation temperature to around 400 to 600 ° C. It is known to work as a passivation film in addition to the film. For this reason, when the film is formed at such a high temperature, the takt time of the CVD apparatus can be remarkably shortened by raising the temperature of the film formation plate (conveying cart 2) and the substrate 1 in advance. In addition, it is possible to improve the film thickness, and to form a film with good and uniform film thickness and quality on all the substrates 1 of the film formation plate, and to reduce the variation in photoelectric conversion efficiency of the solar cell element. It becomes possible to improve the average value of the photoelectric conversion efficiency for each lot in the element manufacturing.

<Embodiment 2>
FIG. 6 is a perspective view showing another embodiment of the suction movable portion 23 of the transport apparatus, and FIGS. 7A and 7B are side views showing the operation thereof. In FIG. 6 and FIG. 7, the transfer device can contact the central region of the substrate 1 and has a heating jig 30 having a temperature higher than that of the substrate 1. The heating jig 30 is made of a metal such as stainless steel, and is attached to a substantially central portion of the suction movable portion 23 with a screw or the like. Inside, a temperature sensor such as a heater and a thermocouple is embedded, and the heating jig 30 is maintained at a predetermined temperature by an external temperature controller through wiring.

  The thickness of the heating jig 30 is a thickness at which the heating jig 30 comes into contact with the substrate 1 when the substrate 1 is sucked and held on the suction pad 25 of the suction movable unit 23. Further, it is desirable to insert a heat insulating material between the base arm 24 and the heating jig 30 so that the temperature of the base arm 24 of the adsorption movable part 23 does not rise too much.

  In the present embodiment, as shown in FIG. 7A, the suction movable unit 23 is lowered until the substrate 1 and the suction pad 25 come into contact with each other, the electromagnetic valve connected to the suction pad 25 is opened, and the substrate 1 is moved to the suction movable unit 23. Adsorb and hold on. At this time, since the heating jig 30 is in contact with the substrate 1, the temperature of the substrate 1 is raised by the heating jig 30.

  Thereafter, as shown in FIG. 7B, the suction movable unit 23 is raised while the substrate 1 is sucked and held on the suction movable unit 23. Next, the suction movable part 23 is moved in the lateral direction on the substrate mounting part 19 on the film forming plate 17. Thereafter, the suction movable portion 23 is lowered until the substrate 1 and the film forming plate 17 come into contact with each other, the electromagnetic valve connected to the suction pad 25 is closed, and the substrate 1 is separated from the suction movable portion 23. During this time, the substrate 1 is brought into contact with the heating jig 30 and heated up until the substrate 1 is separated from the suction movable portion 23. Thereafter, the suction movable unit 23 is raised, and the suction movable unit 23 is moved laterally on the work table 22. A plurality of substrates 1 can be placed on the film forming plate 17 by repeating the above operation.

  The heating jig 30 may be attached with a spring or the like, and may be in contact with the substrate with a certain pressure.

  Thus, the temperature of the substrate 1 can be easily raised by the heating jig 30 attached to the suction movable portion 23, and the concave warpage of the substrate 1 on the film forming plate 17 can be reduced.

It is the figure which showed one Embodiment of the operation | movement of a conveying apparatus and a CVD apparatus. It is a perspective view which shows an example of a board | substrate conveyance apparatus. (A)-(d) It is a side view which shows operation | movement of a board | substrate conveyance apparatus. It is a top view which shows an example of the structure of a conveyance cart. It is a top view which shows an example of the film-forming plate shown in FIG. It is a perspective view which shows another embodiment of an adsorption | suction movable part. (A) (b) It is a side view which shows operation | movement of another embodiment of an adsorption | suction movable part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Substrate 2; Transfer cart 3; Load lock chamber 4; Deposition chamber 5; Unload lock chamber 6; Transfer mechanism 17; Deposition plate 20; Deposition plate fixing jig 23;

Claims (9)

A suction pad for placing a substrate on a film-forming plate transported into the CVD apparatus;
Means for heating a central region of the substrate;
The board | substrate conveyance apparatus which has this. The transport apparatus according to claim 1, wherein the means for heating the central region of the substrate is a gas having a temperature higher than that of the substrate. The transport apparatus according to claim 2, wherein the gas is nitrogen. The transport apparatus according to claim 2, wherein the gas is air. The transport apparatus according to claim 1, wherein the means for heating the central region of the substrate is a jig that can contact the central region of the substrate and has a higher temperature than the substrate. Preparing a substrate, a deposition plate transported into the CVD apparatus, and a transport mechanism capable of ejecting gas and transporting the substrate to the deposition plate;
Moving the transport mechanism onto the substrate;
Applying a gas higher in temperature than the substrate to the central region of the substrate from the transport mechanism, and heating the substrate;
Placing the substrate on the deposition plate by the transport mechanism;
Advancing the film formation plate on which the substrate is placed into a CVD apparatus, and forming a film on the substrate;
The manufacturing method of the film-forming board | substrate which has this. Preparing a substrate, a film forming plate to be transferred into the CVD apparatus, and a transfer mechanism that includes a jig and transfers the substrate to the film forming plate;
Moving the transport mechanism onto the substrate;
Pressing the jig at a higher temperature than the substrate against the central region of the substrate, and heating the substrate;
Placing the substrate on the deposition plate by the transport mechanism;
Advancing the film formation plate on which the substrate is placed into a CVD apparatus, and forming a film on the substrate;
The manufacturing method of the film-forming board | substrate which has this. 8. The film formation plate is carried out of the CVD apparatus after the substrate is formed, the substrate is removed, and a new substrate is placed thereon. A manufacturing method of a film formation substrate. The method for manufacturing a film formation substrate according to claim 6, wherein the substrate placed on the film formation plate is pressed against the film formation plate by the transport mechanism for 3 seconds or more. .

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