JP4478376B2 - Vertical chemical vapor deposition apparatus and film forming method using the apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vertical chemical vapor deposition apparatus and a film forming method using the apparatus. Accompanying the recent trend toward larger and thinner substrates, the advantages of a vertical chemical vapor deposition apparatus capable of carrying and depositing a film while the substrate is substantially upright are being evaluated.
[0002]
[Prior art]
Conventionally, when a film is formed by a chemical vapor deposition method in a vacuum chamber, it is common to transfer or form a film on a substrate placed horizontally for convenience of handling.
[0003]
By the way, in recent years, the tendency for liquid crystal displays and solar cells to increase in size has become remarkable, and accordingly, practical development of 1 m class large substrates for film formation has been promoted. When such a large substrate is handled by the conventional horizontal method, various problems are encountered. For example, due to the increase in size and thickness of the substrate, the horizontally mounted substrate is likely to bend and warp due to its own weight, and it is difficult to perform precise film formation in terms of film thickness and flatness. In particular, if it is based on tray conveyance, the number of parts such as a conveyance carrier is large, and a film adheres to the tray portion, which causes generation of particles. Furthermore, the film forming apparatus structure becomes large corresponding to the substrate area, and it is necessary to secure a considerable occupation space.
[0004]
[Problems to be solved by the invention]
On the other hand, the vertical method is more unstable than the horizontal method. And handling the substrate in an unstable state, combined with the increase in the size of the substrate described above, causes a decrease in the yield of the film forming process.
[0005]
In view of the above problems, the present invention provides a chemical vapor deposition apparatus capable of reliably performing film formation by a chemical vapor deposition method with a compact and simple apparatus configuration corresponding to an increase in the size of a substrate, and a It is an object to provide a film forming method used.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a chemical vapor deposition apparatus of the present invention is a vertical chemical vapor deposition apparatus for forming a film on a substantially upright substrate in a vacuum chamber at a predetermined interval over the entire surface. A vertical transfer base plate with a plurality of airflow holes is placed in a tilted position with the substrate support surface of the plate as the top surface, and the lower edge of the substrate is supported along the substrate transfer direction at the lower end of the plate. A plurality of transport rollers for transporting the substrate were attached.
[0007]
This makes it possible to save space on the installation floor by using the apparatus as a vertical type, and also avoids problems such as bending of the substrate unlike horizontal conveyance. That is, the substrate can be transported by the transport roller on the transport base plate in the tilted posture in which the airflow is generated. Furthermore, the contact surface of the substrate is limited to the conveyance roller contact portion at the lower end portion, and particle generation as in tray conveyance can be suppressed.
[0008]
In order to achieve the tilt posture as described above, the transport base plate can be tilted about the axis of the lower end of the plate in the substrate transport direction. Thereby, it becomes possible to arbitrarily change the tilting posture of the transport base plate.
[0009]
Using this device, first, the carrier base plate is tilted around the axis line so that the substrate support surface of the vertical carrier base plate becomes the upper surface, and the air flow is performed in the direction of the substrate support surface of the carrier base plate through a plurality of air flow holes. The first step of loading the substrate onto the substrate support surface of the transfer base plate, and then, after stopping the air flow, tilting the transfer base plate around the axis while supporting the substrate, erecting the substrate, A film forming method of sequentially performing the second step of forming a film on the substrate becomes possible. Thereby, fixed film formation can be performed on the substrate conveyed while suppressing generation of particles. And this film-forming method can be used for a plasma chemical vapor deposition apparatus and a sputtering film-forming apparatus, for example.
[0010]
In this case, the air flow in the first step is adjusted so that the arrangement position is a small flow rate in the air flow hole below the upper air flow hole, so that the separation distance from the transfer base plate due to the air flow can be ensured, so that the substrate transfer Becomes smoother.
[0011]
Then, when upright conveying the base plate in the second step, a plurality of air flow holes, the first step, i.e., contrary to the time of conveyance, when sucking the substrate in the conveying base plate direction, upright substrate is attracted to the conveyor base plate Therefore, the above fixed film formation can be performed reliably.
[0012]
In addition, using such an apparatus, film formation is performed on a substrate that passes over the substrate support surface in a state in which airflow is performed by a plurality of airflow holes in the direction of the substrate support surface of the transport base plate in an inclined posture. Is possible. Thereby, it is possible to perform the pass film formation on the substrate being transferred, and realize a film formation process in which the tact time is shortened and the operation rate of the apparatus is improved as compared with the above-described fixed film formation. Such a film forming method does not require an airtight chamber, and can be used, for example, in a catalytic chemical vapor deposition method.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a top sectional view of a vertical catalytic chemical vapor deposition apparatus (Cat-CVD apparatus) configured in an in-line manner. This in-line CVD apparatus is configured by linearly arranging units of a preparation position 1, a preparation chamber 2, a first film formation chamber 3, a second film formation chamber 4, an extraction chamber 5, and an extraction position 6. Each unit is isolated by the gate valves 7a to 7e. On the other hand, when all the gate valves are opened, each unit communicates in a hollow shape in the connecting direction, and the transport substrate can be transported sequentially through the hollow space.
[0014]
One of the advantages of the vertical apparatus is that space can be saved as described above. In this apparatus, this advantage is further utilized to simultaneously apply to the pair of substrates 8a and 8b at symmetrical positions. It is comprised so that film-forming can be performed.
[0015]
In each unit of the present apparatus, cassettes 10a and 10b, which accommodate the substrates 8a and 8b, respectively, and are rotatable around the rotation shafts 9a and 9b, are disposed in the preparation position 1 so as to face each other. In addition, the first film formation chamber 3 is provided with transport base plates 11a and 11b having heaters therein for performing film formation by catalytic chemical vapor deposition, and substrates 8a and 8b mounted thereon. A plurality of catalyst wires 12a and 12b are connected in the vertical direction at a position opposite to each other. The second film forming chamber 4 has the same structure as the first film forming chamber 3, and includes transfer base plates 13a and 13b and catalyst wires 14a and 14b. In the take-out position 6, as in the preparation position 1, cassettes 16 a and 16 b that can be rotated around the rotation shafts 15 a and 15 b are arranged to face each other.
[0016]
Note that the transfer base plates 11a and 11b, the transfer base plates 13a and 13b, and the transfer base plate 17 in the preparation chamber 2 and the transfer base plate 18 in the take-out chamber 5 are different from those in the preparation position 1 and the extraction position 6 in vacuum. Must be used.
[0017]
Of course, in addition to the above, the operation of each unit is performed. 4) and a vacuum evacuation mechanism.
[0018]
When film formation by catalytic chemical vapor deposition is performed on the transfer substrate 8 using the inline vertical CVD apparatus configured as described above, the glass substrates 8a and 8b adjusted in a clean room not shown are used. After being stored in the cassettes 10a and 10b at the preparation position 1, only the substrates 8a and 8b on which film formation is performed are taken out from the cassettes 10a and 10b, respectively, and rotated about the rotation shafts 9a and 9b to be substantially upright. 8a and 8b are set in a vertical state, and are transferred to the transport base plate 10c as they are.
[0019]
In this way, the substrates 8a and 8b are transported to the transport base plate 17 in the preparation chamber 2 in the vertical state, the gate valve 7a is closed, and the interior of the preparation chamber 2 is evacuated to a predetermined pressure state. Then, the vertical substrates 8a and 8b are transferred into the first film forming chamber 3 which is kept in a predetermined vacuum state in advance. Further, the reaction gas introduced is reacted by heating by the heaters in the transport base plates 11a and 11b and the action of the catalyst wires 12a and 12b, and a thin film made of the reaction product is formed on the surfaces of the substrates 8a and 8b. Do the membrane.
[0020]
The substrates 8a and 8b on which the desired film formation has been completed are transferred into the second film formation chamber 4 in a vertical state by opening and closing the gate valve 7c, and this time, heating by the heaters in the transfer base plates 13a and 13b and catalyst lines are performed. By the action of 14a and 14b, the second film made of the reaction product is formed.
[0021]
Then, the substrates 8a and 8b are transferred to the take-out chamber 5 in a vertical state, and the vacuum state of the take-out chamber 5 which is closed by closing the gate valve 7d is gradually returned to atmospheric pressure, and the substrate 8a is passed through the gate valve 7e. , 8b are conveyed to the take-out position 6. At the take-out position 6, the carry-in substrates 8a and 8b, which are delivered from the transfer base plate 16c and are accommodated in the cassettes 16a and 16b in a vertical state, rotate the respective rotation shafts 15a and 15b, thereby the cassettes 16a and 16b. It becomes horizontal in the inside and prepares for subsequent removal.
[0022]
As described above, the substrates 8a and 8b are always transported and formed in a vertical state without a tray during the process from the preparation position 1 to the take-out position 6. As described above, handling the substrate in a vertical type is advantageous in terms of dealing with an increase in the size of the substrate and saving the space of the entire apparatus, but on the other hand, it is necessary to pay attention to the stability of the transport substrate.
[0023]
For this reason, the chemical vapor deposition apparatus of the present invention improves the stability of the transport substrate by the transport mechanism shown in FIG. That is, the transport mechanism of FIG. 2 is provided with airflow holes 20 a to 20 c at positions substantially above, below, and below the vertical transport base plate 11. Further, a series of air flow holes having such upper, middle, and lower positions are arranged at predetermined intervals in the substrate transport direction over the entire surface of the plate 11. In addition, the lower end portion of the transport base plate 11 is provided with a rotation mechanism 22 capable of rotating at a predetermined angle around the axis line 21 in the substrate transport direction, and further for transporting the substrate 8 supported by the transport base plate 11. Conveying rollers 23 that can be driven by a driving mechanism (not shown) are pivotally supported at a plurality of locations in the substrate conveying direction. A series of airflow holes 20 a to 20 c having upper, middle, and lower positions are respectively connected to an airflow line 24 that is continuous with the axis 21 in the transport base plate 11. As shown in FIG. 2, the airflow line 24 is led to the outside from the axis 21 of the rotating mechanism 22 and connected to the airflow gas introduction line 25 and a valve 28 connected to the adsorption pump 27. Connected to.
[0024]
In the transport mechanism described above, the airflow holes 20a to 20c and the rotation mechanism 22 improve the stability of the transport substrate 8 in the vertical state, which cannot be ensured only by the support by the transport roller 23. That is, when the substrate 8 is transported, the transport base plate 11 is tilted from the upright state by an angle θ by the rotation mechanism 22 and air flow is performed from the air flow holes 20 a to 20 c toward the support surface 11 s of the transport base plate 11. By doing so, the substrate 8 supported and transported by the transport roller 23 is leaned against the tilted transport base plate 11 with the buffer layer made of an air layer formed between the support surface 11s as a cushion. At the same time as the posture is increased and stability is increased, the airflow from the airflow holes 20a to 20c avoids sliding with the support surface 11s and is smoothly conveyed.
[0025]
At this time, it is desirable that the flow rate of the airflow from the airflow holes 20a to 20c is as large as the airflow hole at the upper position. This is because the gap between the substrate 8 and the transport base plate 11 at the time of transport increases as it moves upward, and a large force is required to separate the substrate 8 correspondingly.
[0026]
The airflow holes 20a to 20c are used for the operation of the exhaust mechanism of the airflow gas introduction line 25 and the adsorption pump 27 outside the apparatus in FIG. That is, the air flow gas introduction line 25 generates a differential pressure between the substrate 8 side of the transport base plate 11 and the opposite side, thereby obtaining an air flow. Furthermore, by operating the suction pump 27, the substrate 8 can be sucked on the transport base plate 11. This is useful, for example, when the substrate 8 is fixed to the transport base plate 11 during film formation.
[0027]
That is, when the in-line type CVD apparatus shown in FIG. 1 is operated, the transfer mechanism shown in FIG. 2 is used as the transfer base plates 11a, 11b, 13a, and 13b under vacuum such as the first film formation chamber 3 and the second film formation chamber 4. When transporting the substrates 8a and 8b, the air flow is circulated in the direction of the support surface 11s, and the substrates 8a and 8b are prepared for transport in a tilted state (tilt angle θ). In addition, the preparation position 1 and the extraction position 6 are provided with a transfer base plate 10c and 16c under atmospheric pressure having only a gas introduction mechanism. When the substrates 8a and 8b are transferred, the air flow is circulated in the direction of the support surface 11s and tilted. In this state (tilt angle θ), the substrate 8a and 8b are prepared for transport. In the preparation chamber 2 and the take-out chamber 5, the substrate 8 a is used in a tilted state (tilt angle θ) by using the transfer base plates 17, 18 having a vacuum specification equipped only with a gas introduction mechanism and circulating airflow in the direction of the support surface 11 s. , 8b in preparation.
[0028]
Then, at the time of film formation on the substrates 8a and 8b, the substrates 8a and 8b are sucked up through the airflow holes instead of the airflow so as to stand upright. Thus, by tilting the transport base plates 11 and 13, it becomes possible to cope with the situation (transport or film formation) of the substrate 8.
[0029]
FIG. 3 shows a first embodiment of a film forming method using the above transport mechanism. FIG. 3 is a schematic cross-sectional view of the first film forming chamber 3 in the in-line CVD apparatus of FIG. The transport base plate 11a side is tilted by the rotation mechanism 22a and airflow is generated from the airflow holes 20a to 20c toward the substrate 8a. In this state, the substrate 8a is supported and transported on the transport roller 23a. On the other hand, the conveyance base plate 11b side stands upright by the rotation mechanism 22b, and the substrate 8b is absorbed and exhausted from the air flow holes 30a to 30c and is adsorbed by the conveyance base plate 11b. Film formation by vapor phase growth is performed. The substrate 8b supported by the transfer base plate 11b stands upright, and the entire surface of the substrate 8b is located at the same distance from the catalyst wire 12b. In this way, film formation uniformity can be ensured.
[0030]
In the present embodiment, spring structures 31a and 31b are provided on the catalyst wires 12a and 12b in order to ensure the tension of the catalyst wire 12 connected in the vertical direction. In addition, a swing stage 35 that can be swung by an X-axis drive system 32, a Y-axis drive system 33, and a bellows 34 is provided so that a uniform film can be formed on the entire surface of the substrate 8 by a plurality of catalyst wires 12. Yes.
[0031]
In FIG. 3, the first mode of the present embodiment illustrates an apparatus configuration for catalytic chemical vapor deposition. However, this vertical structure is not limited to the above-described application. For example, a plasma CVD apparatus or sputtering is used. It can also be applied to devices.
[0032]
Next, FIG. 4 shows a second embodiment of the film forming method using the transport mechanism. Although the apparatus configuration is the same as that in FIG. 3, not only the substrate 8a in the transport state but also the substrate 8b in the film forming process is in a tilted state. The reason why the film forming process by catalytic chemical vapor deposition is performed while the substrate 8b is tilted without being upright is to perform the pass film forming on the substrate 8b, unlike the fixed film forming of the first aspect. In this embodiment, film formation is performed while air flow is performed on the substrate 8a side and the substrate 8 is moved. Therefore, the tact time during operation of the apparatus is shortened, and it is possible to realize the high operating rate maintenance inherent in the inline apparatus. Such a pass film formation method is particularly useful in the catalytic chemical vapor deposition method.
[0033]
Further, when a substrate is heated by providing a heater in the transfer base plate, the efficiency of heat input / output to / from the substrate is improved by the air layer (buffer layer) between the substrates due to airflow. Then, not only that, when fixed film formation by Rukoto to suck the substrate to transport the base plate, with respect to heat input into the substrate from the catalyst line, cooling efficiency of the substrate is improved.
[0034]
【The invention's effect】
As is apparent from the above description, the chemical vapor deposition apparatus of the present invention can ensure the stability of the substrate in the vertical state by the airflow hole and the rotation mechanism provided in the transfer base plate. It is possible to cope with the advantage, that is, increase in the size of the substrate and downsizing of the entire apparatus.
[0035]
In addition, since this chemical vapor deposition apparatus can be used for both fixed film formation and passing film formation, it is not limited to the chemical vapor deposition method and can respond to changes in the film formation method as necessary. .
[Brief description of the drawings]
FIG. 1 is a top sectional view of an inline Cat-CVD apparatus. FIG. 2 is a transport mechanism of a chemical vapor deposition apparatus of the present invention. FIG. 3 is a first embodiment of the present invention. Aspect [Explanation of symbols]
3 first film formation chamber,
4 Second film forming chambers 8a, 8b Substrate 11a, 11b, 13a, 13b, 17, 18
Conveyance base plate (under vacuum)
10c, 16c Transport base plate (specification under atmospheric pressure)
11s Substrate support surfaces 20a to 20c, 30a to 30c Air flow holes 21a and 21b Axes 22a and 22b Rotating mechanisms 23a and 23b Conveying rollers

Claims (9)

In a vertical chemical vapor deposition apparatus that forms a film on a substantially upright substrate, a plurality of air flow holes that can be switched between an air flow operation, a suction operation, and an operation stop are provided in the vacuum chamber at predetermined intervals. The vertical transfer base plate is disposed in a tilted posture in which the substrate support surface of the vertical transfer base plate is the upper surface, and the lower end edge of the substrate is aligned along the substrate transfer direction at the lower end of the vertical transfer base plate. A vertical chemical vapor deposition apparatus characterized in that a plurality of transport rollers for supporting and transporting a substrate are attached. 2. The vertical chemical vapor deposition according to claim 1, wherein the air flow holes are provided at predetermined positions in the substrate transfer direction at positions substantially above , below, and below the vertical transfer base plate. Equipment . Vertical chemical vapor deposition apparatus according to the vertical transport baseplate, to claim 1 or 2, characterized in that the tiltable about the axis of the substrate transfer direction of the vertical transport baseplate lower end. In a deposition method using a vertical chemical vapor deposition apparatus according to claim 3, first, tilting the vertical conveying base plate so that the substrate supporting surface of the vertical conveying the base plate is the upper surface in the axis line A first step of carrying the substrate onto the substrate support surface of the vertical transfer base plate in a state where the air flow operation is performed in the direction of the substrate support surface of the vertical transfer base plate by the plurality of air flow holes; Next, after the air flow operation is stopped, the vertical transfer base plate is tilted around the axis while supporting the substrate to erect the substrate, and a film is formed on the upright substrate. A film forming method comprising the steps of: The air flow in the first step is positioned when the vertical transfer base plate is upright in the second step, compared to the air flow hole whose upper position is when the vertical transfer base plate is upright in the second step. The film forming method according to claim 4, wherein the lower airflow hole has a smaller flow rate. When the vertical transfer base plate stands upright in the second step, the air flow hole is switched from operation stop to suction operation, and the substrate is sucked toward the vertical transfer base plate by the plurality of air flow holes. The film forming method according to claim 4 or 5. When forming the film in the second step, the air flow hole of the vertical transfer base plate is switched from operation stop to suction operation, and the substrate is sucked in the direction of the vertical transfer base plate by the plurality of air flow holes. The film-forming method as described in any one of Claim 4 to 6 . 4. The film forming method using the vertical chemical vapor deposition apparatus according to claim 1, wherein the plurality of airflow holes are formed in the tilted posture toward the substrate support surface of the vertical transfer base plate. 5. The film forming method is characterized in that film formation is performed on the substrate passing over the substrate support surface in an airflow state. The airflow, claims disposed position when the inclined posture as compared with the air flow hole as the upper, who arranged position during the tilting attitude of the air flow hole as the lower side, characterized in that a small flow rate Item 9. The film forming method according to Item 8 .

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