JP2004083997A - Vertical type chemical vapor deposition system and deposition method using this system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemical vapor growth system which can surely perform deposition by a chemical vapor deposition process with compact and simple system configuration in correspondence to upsizing of a substrate and a deposition method using the same. <P>SOLUTION: The vertical type chemical vapor growth system which performs deposition to the substrate 8 in an approximately upright state is constituted by mounting the inside of a first deposition chamber 3 with a plurality of conveyance rollers 23 which are provided with vertical type conveyance base plates 11 disposed with air flow apertures 20a, 20b and 20c at prescribed intervals over the entire surface rotationally movably around axes 21 in the substrate conveyance direction at the bottom ends of the conveyance base plates and perform substrate conveyance by supporting the bottom end edge of the substrate 8 along the substrate conveyance direction at the top and bottom ends of the conveyance base plates. The base plates 11 are inclined around the axes in such a manner that the substrate supporting surfaces 11s of the base plates 11 come to top surfaces. In addition, the substrate 8 is carried onto the surface 11s in the state of performing air flow toward the surfaces 11s of the base plates 11 by the apertures 20a, 20b and 20c. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vertical chemical vapor deposition apparatus and a film forming method using the apparatus. With the recent trend toward larger and thinner substrates, the advantage of a vertical chemical vapor deposition apparatus capable of carrying and forming a film while the substrate is substantially upright has been evaluated.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, when a film is formed by a chemical vapor deposition method in a vacuum chamber, it is common to carry or form a film on a horizontally placed substrate for convenience in handling.
[0003]
By the way, in recent years, the tendency for liquid crystal displays and solar cells to become large has become remarkable, and with this, practical development of 1 m class large substrates for film formation has been promoted. If such a large substrate is handled by a conventional horizontal method, various problems will be encountered. For example, as a substrate becomes larger and thinner, a substrate placed horizontally tends to be bent or warped 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 performed by tray conveyance, the number of components such as a conveyance carrier is large, and a film adheres to the tray portion, which contributes to generation of particles. Further, the structure of the film forming apparatus becomes large corresponding to the substrate area, and it is necessary to secure a considerable occupied space.
[0004]
[Problems to be solved by the invention]
On the other hand, the vertical type is more concerned about the stability of the transfer substrate than the horizontal type. Handling an unstable substrate, together with the above-described increase in the size of the substrate, causes a reduction 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 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 that forms a film on a substantially upright substrate, in a vacuum chamber, at predetermined intervals over the entire surface. A vertical transfer base plate provided with a plurality of airflow holes is arranged in a tilted posture in which the substrate support surface of the plate is the upper surface, and supports the lower edge of the substrate along the substrate transfer direction at the lower end of the plate. A plurality of transport rollers for transporting the substrate were mounted.
[0007]
This makes it possible to save space on the installation floor by using the apparatus as a vertical type, and to avoid 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 inclined position where the air flow is generated. Furthermore, the contact surface of the substrate is limited to the contact portion of the transport roller at the lower end thereof, and it is possible to suppress the generation of particles as in tray transport.
[0008]
In order to achieve the above-described tilting posture, the transport base plate can be tilted around the axis of the lower end of the plate in the substrate transport direction. This makes it 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 so that the substrate support surface of the vertical carrier base plate is on the upper surface, and airflow is performed in the direction of the substrate support surface of the carrier base plate by a plurality of airflow holes. A first step of loading the substrate onto the substrate support surface of the transport base plate, and then, after stopping the airflow, tilting the transport base plate around the axis while supporting the substrate to erect the substrate, A film forming method in which the second step of forming a film on a substrate is sequentially performed becomes possible. This makes it possible to perform fixed film formation on the transported substrate while suppressing generation of particles. This film forming method can be used, for example, in a plasma chemical vapor deposition apparatus or a sputter film forming apparatus.
[0010]
In this case, when the airflow in the first step is adjusted so that the disposition position is small at the airflow hole below the upper airflow hole, the distance from the conveyance base plate due to the airflow can be ensured, so that the substrate conveyance Will be smoother.
[0011]
Then, when the transfer base plate is upright in the second step, the substrate is sucked in the direction of the transfer base plate by the plurality of airflow holes in the first step, that is, contrary to the transfer, and the upright substrate is sucked by the transfer base plate. Since it is held, the above-described fixed film formation can be reliably performed.
[0012]
In addition, using such an apparatus, film formation is performed on a substrate passing over the substrate support surface in a state where airflow is performed through a plurality of airflow holes in the direction of the substrate support surface of the transfer base plate in a tilted posture. Is possible. As a result, it is possible to perform the pass-through film formation on the substrate being transported, so that the tact time is shortened as compared with the above-described fixed film formation, and a film formation process in which the operation rate of the apparatus is improved is realized. Such a film forming method can be used for, for example, a catalytic chemical vapor deposition method that does not require an airtight chamber.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a top sectional view of an in-line vertical catalytic chemical vapor deposition apparatus (Cat-CVD apparatus). This in-line CVD apparatus is configured such that units of a charging position 1, a charging chamber 2, a first film forming chamber 3, a second film forming chamber 4, an extracting chamber 5, and an extracting position 6 are linearly arranged. While each unit is isolated by the gate valves 7a to 7e, when all the gate valves are opened, each unit communicates in a hollow shape in the connecting direction, and the transfer substrate can be sequentially transferred through the hollow space.
[0014]
One of the advantages of the vertical device is that space can be saved as described above. In this device, this advantage is further utilized to simultaneously apply a pair of substrates 8a and 8b at symmetric positions. It is configured so that film formation 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 arranged in the loading position 1 so as to face each other. In addition, the first film forming chamber 3 is provided with transfer base plates 11a and 11b having heaters therein for performing film formation by the catalytic chemical vapor deposition method, and the substrates 8a and 8b mounted on these are provided. A plurality of catalyst wires 12a, 12b are provided in a position facing the vertical direction and connected in the vertical direction. The second film forming chamber 4 has the same structure as the first film forming chamber 3, and includes transport base plates 13a and 13b and catalyst wires 14a and 14b. At the unloading position 6, similarly to the charging position 1, the cassettes 16a and 16b rotatable around the rotating shafts 15a and 15b are arranged to face each other.
[0016]
The transfer base plates 11a and 11b, the transfer base plates 13a and 13b, and the transfer base plate 17 of the loading chamber 2 and the transfer base plate 18 of the unloading chamber 5 are different from those in the loading position 1 and the unloading position 6 in that they are designed under vacuum. Need to be used.
[0017]
Of course, in addition to the above, each unit operates, so a pump unit (not shown), a power panel, an operation panel, a heating power panel, a water supply / drain panel, a reaction gas introduction mechanism (the first film forming chamber 3, the second film forming chamber, etc.) 4) and a vacuum exhaust mechanism.
[0018]
When a film is formed on the transfer substrate 8 by the catalytic chemical vapor deposition method using the in-line 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 loading position 1, only the substrates 8a and 8b on which films are to be formed 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 directly delivered to the transport base plate 10c.
[0019]
In this manner, the substrates 8a and 8b are transported to the transport base plate 17 in the charging chamber 2 in the vertical state, the gate valve 7a is closed, and the charging chamber 2 is evacuated to a predetermined pressure state. Then, the substrates 8a and 8b in the vertical state are transported into the first film forming chamber 3 which is kept in a predetermined vacuum state in advance. Further, the reaction gas introduced is caused to react by heating by heaters in the transport base plates 11a and 11b and by the action of the catalyst wires 12a and 12b to form a thin film made of the reaction product on the surfaces of the substrates 8a and 8b. Perform 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. 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, a second film made of the reaction product is formed.
[0021]
Then, the substrates 8a and 8b are transported to the extraction chamber 5 in a vertical state, and the vacuum state of the extraction chamber 5 which is closed by closing the gate valve 7d is gradually returned to the atmospheric pressure, and the substrates 8a and 8b are closed via the gate valve 7e. , 8b to the take-out position 6. At the unloading position 6, the carry-in substrates 8a, 8b delivered from the transport base plate 16c and stored in the cassettes 16a, 16b in a vertical state rotate the respective rotating shafts 15a, 15b, thereby rotating the cassettes 16a, 16b. Inside, ready for subsequent removal.
[0022]
As described above, the substrates 8a and 8b are transported and formed while maintaining the vertical state without a tray during the process from the loading position 1 to the unloading position 6. As described above, handling a substrate in a vertical type is advantageous in terms of responding to an increase in the size of the substrate and saving space in the entire apparatus, but it is necessary to pay attention to the stability of the transfer substrate.
[0023]
Therefore, in the chemical vapor deposition apparatus of the present invention, the stability of the transfer substrate is improved by the transfer mechanism shown in FIG. That is, the transport mechanism shown in FIG. 2 has airflow holes 20a to 20c provided at substantially upper, middle, and lower positions of the vertical transport base plate 11. Further, a series of airflow holes having such upper, middle, and lower positions are provided at predetermined intervals in the substrate transport direction over the entire surface of the plate 11. The lower end of the transport base plate 11 is provided with a rotation mechanism 22 that can rotate at a predetermined angle around an axis 21 in the substrate transport direction, and further for transporting the substrate 8 supported by the transport base plate 11. A transport roller 23 that can be driven by a drive mechanism (not shown) is provided at a plurality of locations in the substrate transport direction so as to be pivotally supported. A series of airflow holes 20a to 20c formed at upper, middle, and lower positions are connected to airflow lines 24 connected to the axis 21 in the transport base plate 11, respectively. As shown in FIG. 2, the air flow line 24 is guided from the axis 21 of the rotation mechanism 22 to the outside of the atmosphere, and is connected to a valve 26 connected to an air flow gas introduction line 25 and a valve 28 connected to an adsorption pump 27. Connected to.
[0024]
In the transport mechanism described above, the air flow holes 20a to 20c and the rotation mechanism 22 improve the stability of the transport substrate 8 in the vertical state, which cannot be secured only by the support of the transport roller 23. That is, when the substrate 8 is transferred, the transfer base plate 11 is tilted by the angle θ from the upright state by the rotating mechanism 22, and the air flows from the airflow holes 20 a to 20 c in the direction of the support surface 11 s of the transfer base plate 11. In this way, the substrate 8 supported and transported by the transport rollers 23 is leaned against the inclined transport base plate 11 using the buffer layer formed of the air layer formed between the substrate 8 and the support surface 11s as a cushion. At the same time, the posture is increased, and the stability is increased. At the same time, the air flow from the air flow holes 20a to 20c avoids the sliding with the support surface 11s, and the air 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 larger as the airflow hole is located at a higher position. This is because the gap between the substrate 8 and the transport base plate 11 at the time of transport becomes larger upward, and accordingly, a large force is required to separate the substrate 8.
[0026]
The air flow holes 20a to 20c are used for operating the air flow gas introduction line 25 and the exhaust mechanism of the suction pump 27 outside the apparatus in FIG. That is, a differential pressure is generated between the substrate 8 side of the transfer base plate 11 and the opposite side thereof by the airflow gas introduction line 25, whereby an airflow is obtained. Further, by operating the suction pump 27, the substrate 8 can be sucked to the transfer base plate 11 on the contrary. This is useful, for example, when fixing the substrate 8 to the transport base plate 11 during film formation.
[0027]
That is, when the in-line type CVD apparatus of FIG. 1 is operated, the transfer mechanism of FIG. 2 is used as the transfer base plates 11a, 11b, 13a, and 13b of a vacuum specification such as the first film formation chamber 3 and the second film formation chamber 4. At the time of transporting the substrates 8a and 8b, respectively, the airflow is circulated in the direction of the support surface 11s to prepare for the transport of the substrates 8a and 8b in a tilted state (tilt angle θ). Further, the loading position 1 and the unloading position 6 are provided with transport base plates 10c and 16c under atmospheric pressure having only a gas introduction mechanism, and when transporting the substrates 8a and 8b, circulate the airflow in the direction of the support surface 11s and tilt. In this state (inclination angle θ), the substrate 8a, 8b is prepared for conveyance. In the loading chamber 2 and the unloading chamber 5, the air flow is circulated in the direction of the support surface 11s using the transfer base plates 17 and 18 provided with only the gas introduction mechanism and under vacuum, and the substrate 8a is tilted (tilt angle θ). , 8b.
[0028]
Then, at the time of film formation on the substrates 8a and 8b, the substrates 8a and 8b are vacuum-adsorbed and erect, instead of airflow. By tilting the transfer base plates 11 and 13 in this manner, it is possible to cope with the situation of the substrate 8 (transfer or film formation).
[0029]
FIG. 3 shows a first embodiment of a film forming method using the above-described transport mechanism. FIG. 3 is a schematic sectional view of the first film forming chamber 3 in the in-line type CVD apparatus of FIG. The transport base plate 11a is tilted by the rotating mechanism 22a, and an airflow is generated from the airflow holes 20a to 20c in the direction of the substrate 8a. In this state, the substrate 8a is supported on the transport rollers 23a and transported. On the other hand, the transport base plate 11b is erected by the rotation mechanism 22b, and the substrate 8b is exhausted and absorbed from the airflow holes 30a to 30c and is adsorbed to the transport base plate 11b. A film is formed by vapor phase growth. The substrate 8b supported by the transport base plate 11b stands upright, and the entire surface of the substrate 8b is positioned at the same distance as the catalyst wire 12b. Thus, uniformity of film formation can be secured.
[0030]
In the present embodiment, spring structures 31a and 31b are provided on the catalyst wires 12a and 12b in order to secure the tension of the catalyst wires 12 connected in the vertical direction. In addition, an X-axis drive system 32, a Y-axis drive system 33, and a swing stage 35 that can swing with a bellows 34 are provided so that uniform film formation can be performed on the entire surface of the substrate 8 by the plurality of catalyst wires 12. I have.
[0031]
In FIG. 3, the first embodiment of the present invention illustrates an apparatus configuration for catalytic chemical vapor deposition, but this vertical structure is not limited to the above-mentioned application. It is also applicable to devices and the like.
[0032]
Next, a second embodiment of the film forming method using the above-described transport mechanism is shown in FIG. The configuration of the apparatus is the same as that of FIG. 3, but not only the substrate 8a in the transport state but also the substrate 8b in the film forming process is tilted. The reason why the film formation step by catalytic chemical vapor deposition is performed while the substrate 8b is not upright and in an inclined state is to perform the pass-through film formation on the substrate 8b, unlike the fixed film formation of the first embodiment. In this embodiment, the film is formed while moving the substrate 8 by performing an air flow on the substrate 8a side. Therefore, the takt time during operation of the apparatus is shortened, and it is possible to maintain the high operation rate inherent in the in-line apparatus. Such a pass-through film forming method is particularly useful in catalytic chemical vapor deposition.
[0033]
Further, in the case where 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 an air layer (buffer layer) between the substrates due to airflow. In addition, by vacuum-adsorbing the substrate at the time of fixed film formation, the cooling efficiency of the substrate is improved with respect to heat input from the catalyst wire to the substrate.
[0034]
【The invention's effect】
As is clear from the above description, the chemical vapor deposition apparatus of the present invention can secure the stability of the substrate in the vertical state by the airflow holes and the rotation mechanism provided in the transfer base plate, so that the original Advantages, that is, it is possible to cope with an increase in the size of the substrate and a reduction in the size of the entire apparatus.
[0035]
Further, since this chemical vapor deposition apparatus can be used for both fixed film formation and pass-through 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 cross-sectional view of an in-line 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. FIG. Aspect [Explanation of symbols]
3 First film forming chamber,
4 Second film forming chambers 8a, 8b Substrates 11a, 11b, 13a, 13b, 17, 18
Transfer base plate (under vacuum)
10c, 16c Transport base plate (atmospheric pressure specification)
11s Substrate support surfaces 20a to 20c, 30a to 30c Airflow holes 21a, 21b Axis lines 22a, 22b Rotary mechanisms 23a, 23b Transport rollers

Claims (6)

In a vertical chemical vapor deposition apparatus for forming a film on a substrate in a substantially upright state, a vertical transfer base plate having a plurality of airflow holes arranged at predetermined intervals over the entire surface in a vacuum chamber is provided with the vertical transfer base plate. Vertically characterized in that the substrate supporting surface is arranged in an inclined position with the upper surface thereof, and a plurality of transport rollers for transporting the substrate while supporting the lower edge of the substrate along the substrate transport direction at the lower end of the plate are attached. Type chemical vapor deposition equipment. The vertical chemical vapor deposition apparatus according to claim 1, wherein the transfer base plate can be tilted around an axis in a substrate transfer direction at a lower end portion of the plate. 3. A film forming method using the vertical chemical vapor deposition apparatus according to claim 2, wherein the transport base plate is first tilted around the axis so that a substrate supporting surface of the vertical transport base plate is an upper surface. A first step of loading the substrate onto the substrate support surface of the transport base plate while airflow is being performed in the direction of the substrate support surface of the transport base plate by the plurality of airflow holes, and then, after stopping the air flow, A second step of tilting the transport base plate around the axis while supporting the substrate to erect the substrate, and forming a film on the substrate in the upright state. 4. The method according to claim 3, wherein the airflow in the first step has a small flow rate in an airflow hole provided at a position below the upper airflow hole. 5. 5. The film forming method according to claim 3, wherein the substrate is sucked in the direction of the transfer base plate by the plurality of airflow holes when the transfer base plate is erected in the second step. 3. The film formation method using the vertical chemical vapor deposition apparatus according to claim 1, wherein the airflow is performed by the plurality of airflow holes in a direction of the substrate supporting surface of the transfer base plate in the inclined posture. 4. A film forming method, wherein a film is formed on a substrate passing over a substrate supporting surface.

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