JP2011236489A - Film deposition apparatus and dust collection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film deposition apparatus reliably removing dusts on a substrate after film deposition treatment.SOLUTION: The film deposition apparatus (1) includes: a film deposition treatment chamber (12) which forms a thin film on the substrate (17) mounted on a tray (16); conveyance devices (14, 15) for conveying the tray (16) on which the substrate (17) subjected to the film deposition treatment is mounted; blowers (22A, 22B) which jet air toward a substrate mounting surface of the tray (16) during conveying movement and blow off dusts attached to the tray (16) and the substrate (17) mounted on the tray (16); and a nozzle (25) which sucks the blown off dusts together with air. The blowers (22A, 22B) include a jetting port which jets air obliquely to the conveyance direction downstream side and a jetting port which jets air obliquely to the conveyance direction upstream side, wherein a suction port which is arranged between the jetting ports and faces the substrate mounting surface is disposed on the nozzle (25).

Description

  The present invention relates to a film forming apparatus provided with a dust collecting apparatus and a dust collecting method in the film forming apparatus.

  One technique for forming a thin film is a CVD method (chemical vapor deposition method). For example, in a plasma CVD method using plasma, a material gas is introduced into a film formation chamber and decompressed by an exhaust pump, and plasma is generated by applying DC power, high frequency power, microwave power, etc., and a thin film is formed on a substrate. Form. During the film formation, a product film is generated not only on the substrate but also on the transfer tray on which the substrate is placed and the inner wall of the chamber. The amount of coating on the inner wall of the chamber increases each time the film forming process is repeated. When the coating amount on the inner wall of the chamber increases, peeling occurs due to film stress, and peeling also occurs due to temperature change.

  The peeled film falls on the substrate or the transfer tray. The amount of the coating film that peels off and falls tends to increase as the film forming operation time increases. In addition, the peeled film remaining on the transfer tray or in the chamber may be wound up when the inside of the chamber is purged to the atmosphere or in the substrate transfer process and fall on the substrate.

  Therefore, in the conventional CVD apparatus, the activated cleaning gas is introduced into the film forming chamber, and reaction products (film forming products, by-products, etc.) adhering to the material gas introduction line and the inner wall of the chamber are removed. (For example, refer to Patent Document 1). In addition, a method is also disclosed in which a charged dust collecting plate is conveyed into a film forming chamber before substrate processing, and dust remaining in the film forming chamber is adsorbed by an electrostatic force.

Japanese Patent Laid-Open No. 6-252066

  By the way, the above-described cleaning operation is performed in order to prevent the coating film from dropping onto the substrate, and does not remove the dust that has dropped onto the substrate. Therefore, the above-described cleaning operation is performed each time the film formation process is performed in order to suppress the fall of the film as much as possible. As a result, the time per film forming process becomes longer, leading to a decrease in production efficiency.

A film forming apparatus according to the invention of claim 1 includes a film forming chamber for forming a thin film on a substrate placed on a tray, a transfer device for carrying a tray on which a film-formed substrate is placed, A blower that blows air toward the substrate mounting surface of the tray that is being transported and blows off the dust on the tray and the substrate placed on the tray; and a nozzle that sucks the blown-off dust together with air; It is provided with.
According to a second aspect of the present invention, there is provided the film forming apparatus according to the first aspect, wherein the blower ejects air toward the downstream side in the transport direction so as to enter the substrate mounting surface obliquely. And a second jet port for jetting air toward the upstream side in the transport direction so as to be incident obliquely with respect to the substrate mounting surface, and the nozzle includes a first jet port and a second jet port It is characterized by comprising a suction port disposed between and facing the substrate mounting surface.
According to a third aspect of the present invention, in the film forming apparatus according to the second aspect, the ejection direction of each of the air ejected from the first and second ejection ports is ejected from the first and second ejection ports. The air is set to intersect on the tray side with respect to the surface of the substrate.
According to a fourth aspect of the present invention, in the film forming apparatus according to any one of the first to third aspects, the untreated substrate is carried into the film forming apparatus and the film-treated substrate is carried out from the film forming apparatus. A load / unload chamber and a return transfer chamber for transferring a film-formed substrate to the load / unload chamber are provided, and a blower and a nozzle are provided in the return transfer chamber.
According to a fifth aspect of the present invention, there is provided a dust collection method for a film forming apparatus, the step of stopping the film formation in the film forming processing chamber to lower the temperature of the film forming processing chamber, A step of supplying the film to the film forming chamber, a step of transferring the tray supplied to the film forming chamber by the transfer device, and a step of collecting dust on the tray while transferring the tray by the transfer device. It is characterized by that.
According to a sixth aspect of the present invention, in the dust collecting method according to the fifth aspect, in the dust collecting step, the dust on the tray is blown off by the air from the blower, and the blown off dust is sucked together with the air by the nozzle. Features.

  According to the present invention, it is possible to reliably remove dust on the substrate and the tray after film formation.

It is a figure which shows typically schematic structure of the film-forming apparatus provided with the dust collector by this invention. 3 is a plan view illustrating the configuration of the dust collector 2. FIG. It is a figure explaining the positional relationship of blower 22A, 22B and the suction nozzle 25. FIG. FIG. 6 is a schematic diagram illustrating a situation of dust collection work while the tray 16 moves below the suction nozzle 25. It is a figure which shows another example. It is a figure which shows the procedure of a film removal operation | work.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
-First embodiment-
FIG. 1 shows a first embodiment of a film forming apparatus according to the present invention, and is a schematic diagram showing a schematic configuration of a plasma CVD apparatus. The plasma CVD apparatus 1 includes a load / unload chamber 11, a film forming chamber 12, an elevating chamber 13, and a return transfer chamber 14. The film forming chamber 12 is provided with gate valves V1 and V2 for carrying the tray 16 in and out. The tray 16 on which the substrate 17 is placed is conveyed between the chambers by the conveyor 15. Although not shown, the loading / unloading chamber 11 and the lifting chamber 13 are provided with a lifting mechanism for lifting the tray.

  In the load / unload chamber 11, the unprocessed substrate 17 is supplied and the substrate 17 subjected to the film formation process is collected. For example, an unprocessed substrate 17 is placed on the tray 16 using a substrate supply / recovery device 18 such as a vacuum chuck or Bernoulli chuck, and the processed substrate 17 on the tray 16 is recovered. In addition, a groove is formed on the substrate mounting surface of the tray 16 so that the handling of the substrate 17 by the chuck described above is performed reliably, that is, the substrate 17 is easily pulled away from the surface of the tray 16. . Note that a heater for heating the substrate may be provided in the load / unload chamber 11 to preheat the unprocessed substrate 17.

  When the supply of the substrate 17 to the load / unload chamber 11 is completed, air purge is performed to return the film forming chamber 12 to the atmospheric pressure state, the gate valve V1 is opened, and the tray 16 is transferred to the film forming chamber 12. To do. Thereafter, after closing the gate valve V1 and evacuating, a material gas is introduced, and a desired thin film is formed on the substrate 17 by plasma CVD processing. Although the film forming apparatus of this embodiment forms a film by plasma CVD, there are various methods for generating plasma P, such as capacitively coupled plasma, inductively coupled plasma, and surface wave plasma. Plasma P is generated by those methods, and the material gas introduced into the film forming chamber 12 is decomposed and reacted using the plasma to form a thin film on the substrate 17.

  As described above, a film is formed on the inner wall of the film forming chamber 12 by the film forming process, and when the film forming process is repeated, the film on the inner wall may be peeled off and dropped onto the substrate 17 or the tray 16. . In addition, the film that has fallen into the film forming chamber 12 may rise and fall onto the substrate 17 due to a transfer process or an air purge when the film forming chamber 12 is returned to the atmospheric pressure state.

  When film formation on the substrate 17 is completed, an air purge is performed to return the film formation processing chamber 12 to the atmospheric pressure state, then the gate valve V2 is opened and closed, and the tray on which the film-formed substrate 17 is placed. 16 is conveyed to the lift chamber 13. The elevating chamber 13 is provided with an elevating mechanism for elevating the tray 16 and lowers the tray 16 to the transfer position to the return transfer chamber 14. When the position of the tray 16 becomes the transfer position, the tray 16 is transferred to the return transfer chamber 14 by the conveyor 15.

  The return conveyance chamber 14 is provided with a dust collector together with the conveyor 15. The blowers 22A and 22B and the suction nozzle 25 shown in FIG. 1 are a part of the components that constitute the dust collector. The detailed configuration of the dust collector will be described later. Air is blown in the direction of the transport tray 16 from the blowers 22 </ b> A and 22 </ b> B while the tray 16 is transported in the right direction in the figure by the conveyor 15. Dust (such as a peeled film) on the substrate 17 and the transport tray 16 is blown up by the blown air in the direction of the suction nozzle 25 and sucked by the suction nozzle 25 together with the air. In this way, the dust collection work of the dust falling on the substrate 17 and the tray 16 is automatically performed while the tray 16 is transported and moved.

  When the dust collection operation is completed, the tray 16 is returned to the load / unload chamber 11. The tray 16 conveyed to the load / unload chamber 11 is moved upward to the substrate supply / collection position by the lifting mechanism. When the tray 16 is raised to the carry-in / collection position, the substrate 17 that has been subjected to the film formation process is collected by the substrate supply / collection device 18.

  FIG. 2 is a diagram illustrating the configuration of the dust collector 2, and is a plan view of the return transfer chamber 14 as viewed from the film forming chamber 12 direction. As described above, the plurality of substrates 17 are placed on the tray 16. The dust collector 2 includes a gas supply device 20, a suction device 21, a pipe 23 and a manifold 24 in addition to the blowers 22 </ b> A and 22 </ b> B and the nozzle 25. Since the tray 16 on which the film-formed substrate 17 is placed is conveyed by the conveyor 15 shown in FIG. 1 in the right direction in the figure, the entire area of the tray 16 passes below the dust collector 2. .

  The blowers 22 </ b> A and 22 </ b> B are configured by a pipe having a gas ejection port, and air having a slightly higher pressure than the atmospheric pressure is supplied from the gas supply device 20 to the pipe. The suction nozzle 25 for sucking dust raised by the air from the blowers 22 </ b> A and 22 </ b> B has a T-shape when viewed from above, and a suction port 25 a is formed on the bottom surface portion facing the tray 16. As shown in FIG. 2, the plurality of suction nozzles 25 are juxtaposed in a direction perpendicular to the moving direction of the tray 16 without a gap. These suction nozzles 25 are attached to the manifold 24.

  A pipe 23 from the suction device 21 is connected to the manifold 24, and air in the manifold 24 is sucked by the suction device 21 through the pipe 23. A bellows-like flexible pipe is used for the pipe 23, and the gap between the suction nozzle 25 and the tray 16 can be accurately adjusted by adjusting the position of the manifold 24. The dust sucked by the suction nozzle 25 is carried to the suction device 21 together with air, and is collected in a dust box provided in the suction device 21.

  FIG. 3 is a view for explaining the positional relationship between the blowers 22 </ b> A and 22 </ b> B and the suction nozzle 25. A slit-like suction port 25 a having a width dimension W is formed on the bottom surface portion of the suction nozzle 25 so as to face the substrate mounting surface of the tray 16. The pair of blowers 22A and 22B are juxtaposed in the substrate transport direction, the blower 22A is disposed on the upstream side in the transport direction with respect to the suction port 25a, and the blower 22B is disposed on the downstream side in the transport direction. The position of the suction nozzle 25 is adjusted so that the suction port 25a is disposed at an intermediate position between the blowers 22A and 22B.

  In the blowers 22A and 22B, a plurality of air outlets 220 are arranged in parallel in the direction in which the blower pipe extends, that is, in the direction orthogonal to the tray conveying direction. The air outlet 220 of the blower 22 </ b> A is formed at a position that is inclined in the conveyance downstream direction by an angle θ with respect to the vertical downward direction, and is obliquely forward (at an angle θ with respect to the surface of the substrate 17 or the surface of the tray 16). Air is blown out in the conveyance downstream direction. On the other hand, the air jet 220 of the blower 22B is formed at a position tilted in the transport upstream direction by an angle θ with respect to the vertical downward direction, and obliquely rearward that forms an angle θ with respect to the surface of the substrate 17 or the surface of the tray 16. Air is blown out (in the upstream direction of conveyance).

  Reference numeral 101 denotes an intersection of straight lines indicating the jet direction of the air jetted from the blowers 22A and 22B. The angle θ is set so that the intersection point 101 is located on the lower side (tray side) than the surface of the substrate 17. That is, the vertical distance h2 between the lower end of the blower and the intersection 101 is set to be larger than the vertical distance h1 between the lower end of the blower and the substrate surface position 100. By setting in this way, the position where the straight line indicating the air ejection direction of the blower 22A and the substrate surface position 100 intersect is downstream of the intersection 101 and the straight line indicating the air ejection direction of the blower 22B and the substrate surface position. The position where 100 intersects is upstream of the intersection 101 in the transport direction.

  In FIG. 3, an arrow curve G schematically shows the flow of ejected air when the substrate 17 is present. The air jetted obliquely to the lower right from the jet port 220 of the blower 22 </ b> A flows in the right direction in the drawing along the substrate surface indicated by the substrate surface position 100. On the other hand, the air jetted obliquely to the lower left from the jet port 220 of the blower 22B flows in the left direction in the drawing along the substrate surface. The two air flows collide immediately below the suction port 25a of the suction nozzle 25 and flow upward from the substrate surface. Due to this air flow, dust and peeling pieces placed on the substrate surface and the tray surface are swung upward.

  As described above, since air is ejected from two directions so as to form the angle θ, it is possible to avoid the dust from being greatly deviated to the left and right from the position of the suction port 25a. On the other hand, since the suction nozzle 25 actively sucks air from the suction port 25a, the dust soared is sucked into the suction nozzle 25 together with air.

  Note that the hole diameter φ and angle θ of the ejection port 220, the width W of the suction port 25a, and the distances from the substrate surface to the lower ends of the suction nozzle 25 and the blowers 22A and 22B are optimum values by actually performing a dust collection test. To be determined.

(Description of dust collection operation)
FIG. 4 is a schematic diagram showing the state of dust collection work while the tray 16 moves below the suction nozzle 25. FIG. 4A shows a case where the intake nozzle 25 faces the tray 16. As described above, the air ejected from the blowers 22A, 22B collides with the tray surface and flows upward just below the suction port 25a. Therefore, the dust 30 on the tray 16 rises upward from the surface of the tray 16 and is sucked together with air into the suction nozzle 25 from the suction port 25a.

  FIG. 4B shows a state in which the tray 16 further moves rightward from the state of FIG. 4A, and a part of the substrate 17 enters below the suction nozzle 25. In this state, only the air ejected from the blower 22 </ b> A directly hits the surface of the substrate 17, and the air from the blower 22 </ b> B is blown onto the surface of the tray 16. For this reason, the substrate 17 is subjected to a force that is pressed against the tray 16 by the air ejected from the blower 22A. Thus, the substrate 17 is not lifted off the tray 16 and displaced.

  As described above, a groove or the like is formed on the substrate mounting surface of the tray 16 so that the substrate 17 can be easily separated from the tray 16 during substrate recovery. Therefore, as shown in FIGS. 4B and 4C, when air from the blowers 22A and 22B is blown onto the edge portion of the substrate 17, the air easily enters the gap between the tray 16 and the substrate 17, If the substrate 17 is a substrate that is not so large and has a very small thickness as a silicon wafer, the substrate 17 may be lifted. However, the arrangement as shown in FIG. 3 prevents the substrate 17 from being lifted by the pressing force of the air from the other blower.

  4C, the tray 16 further moves to the right from the state of FIG. 4B, and the opposite end of the substrate 17 is the suction nozzle 25 opposite to the case of FIG. 4A. The case of entering below is shown. In this case, it is only the air from the blower 22 </ b> B that the blown air directly hits the surface of the substrate 17, and the air from the blower 22 </ b> A is blown onto the surface of the tray 16. Therefore, the force that is pressed against the tray 16 by the air blown from the blower 22B acts on the substrate 17, and even if the air from the blower 22A is blown onto the end surface of the substrate, the substrate 17 does not float up.

  As described above, even when the air from the blowers 22A and 22B is blown to the end portions of the substrate, the effect of preventing the substrate from blowing up is that the position of the intersection point 101 is below the tray surface (tray side). Is obtained by setting the angle θ and the distance h1 to be

(Other examples)
FIG. 5 shows another example of the configuration shown in FIG. FIGS. 5A and 5B show a case where the intersection point 101 of the straight line indicating the direction of the jet gas is near the substrate surface. Even with such a setting, the function of collecting dust occurs, and the above-mentioned floating does not occur if the substrate has a large area and a relatively heavy weight.

  However, in the case of a light substrate such as a silicon wafer, the substrate 17 may be lifted by the air blown from the blower 22B at the substrate position as shown in FIG. Some may overlap each other. FIG. 5B shows a situation in which the left end of the substrate 17 passes below the suction port 25a. In this case as well, the substrate 17 may be lifted by the air from the blower 22A.

  FIG. 5C shows a configuration in which air is ejected obliquely from one blower 22 at an angle θ, and the suction nozzle 25 is arranged in the angle θ direction opposite to the blower 22. In the case of this configuration, dust is blown away in the direction of the suction nozzle 25 by the air from the blower 22, so that the blown dust is sucked by the suction nozzle 25. Also in this configuration, when the air from the blower 22 is blown to the edge of the moving substrate 17, the substrate 17 may be lifted and displaced.

  In the present embodiment, the dust collecting operation for removing dust and peeling pieces on the substrate 17 and the tray 16 described above is always performed while the film forming operation by the plasma CVD apparatus 1 is performed. As a result, it is possible to prevent dust (peeled film or the like) from remaining on the substrate 17 after film formation.

-Second embodiment-
By the way, the film adhering to the inner wall of the film forming chamber 12 increases as the number of film forming processes increases. As the amount of the coating film increases, the frequency of film peeling increases. For this reason, as a regular maintenance, it is common to manually perform a cleaning operation to remove the film adhering to the inner wall of the film forming chamber 12 or the peeling pieces dropped into the film forming chamber while the apparatus is stopped. It is. When performing this maintenance, if the dust on the substrate exceeds the reference amount, the production operation is stopped, and the inside of the chamber and the transfer tray are removed with a vacuum cleaner or the like.

  On the other hand, in the plasma CVD apparatus 1 of the present embodiment, by using the dust collector 2 described above, it is possible to automatically remove the film attached to the film formation chamber wall without human intervention. The film removal operation is performed according to the procedure shown in FIG.

  First, in step # 1, the film forming operation is stopped. That is, the film forming operation in the film forming chamber 12 is stopped and the supply of the substrate 17 is stopped. Although the film forming operation is stopped, the operations other than the film forming operation, that is, the driving of the load / unload chamber 11, the lift chamber 13, and the return transfer chamber 14 are continued. Dust collection work continues.

  In step # 2, the continuous conveyance operation of the tray 16 is started. In this operation, the film forming chamber 12 is returned to atmospheric pressure, and the gate valves V1 and V2 are maintained in the open state. Then, the plurality of trays 16 on which the substrate 17 is not placed are operated so as to continuously move from the next to the next through the gate valves V1 and V2 that are opened. .

  When the film forming operation in the film forming process chamber 12 is stopped in step # 1 described above, the temperature of the film forming process chamber 12 gradually decreases, so that the film attached to the wall surface is peeled off due to this temperature change. Fall. Due to the above-described step # 2, since the tray 16 is continuously moved in the film forming process chamber 12, the peeled film is dropped on the tray 16. The tray 16 on which the film that has been peeled and dropped is unloaded from the film forming chamber 12 by the conveyor 15 and is transferred to the return transfer chamber 14 via the lifting chamber 13.

  While the tray 16 transported to the return transport chamber 14 is moving in the return transport chamber 14, the release coating or dust that has dropped onto the tray 16 is removed by the dust collector 2. The tray 16 cleaned by the dust collector 2 is transferred again to the film forming chamber via the load / unload chamber 11. If such a film removal operation is performed for a predetermined time, the film removal operation is terminated in step # 3. Next, in step # 4, the film forming operation is restarted.

  As described above, the second embodiment is a dust collection method of the film forming apparatus, the step of stopping the film formation in the film forming process chamber 12 and lowering the temperature of the film forming process chamber 12; A step of supplying the tray 16 on which the substrate 17 is not placed to the film forming chamber 12; a step of transferring the tray 16 supplied to the film forming chamber 12 by the transfer device 15; And collecting dust on the tray 16 while being conveyed. As a result, the peeled film is received by the tray 16, the peeled film is collected by the dust collector 2, and the film attached to the inner wall of the film forming treatment chamber 12 can be removed without using human hands. . In the dust collection process, the dust on the tray 16 is blown off by the air from the blowers 22 </ b> A and 22 </ b> B, and the blown-off dust is sucked together with the air by the nozzle 25.

  Such an automatic cleaning mode is set in the plasma CVD apparatus 1, and when the operator instructs the automatic cleaning mode, the apparatus enters the automatic cleaning mode, and the film attached to the inner wall of the film forming chamber 12 automatically. Perform removal.

  Of course, in the above-described automatic cleaning, the peeled film that has dropped to a place other than the tray 16 cannot be collected, and the film cannot be removed sufficiently compared to the case where the film is removed manually. However, since the automatic cleaning described above can be performed without stopping the entire plasma CVD apparatus 1, it is possible to extend the interval of periodic cleaning maintenance performed manually by stopping the entire apparatus and reducing costs. Can be achieved.

  In addition, the above description is an example to the last, and this invention is not limited to the said embodiment at all unless the characteristic of this invention is impaired. For example, in the example shown in FIG. 2, a plurality of nozzles are arranged side by side, but one large nozzle may be provided, or 1 to 3 nozzles having the size shown in FIG. 2 may be provided according to the size of the tray. May be. In the above-described embodiment, the plasma CVD apparatus has been described as an example of the film forming apparatus. However, the present invention can be applied to a CVD apparatus that does not use plasma, or a film forming apparatus that uses sputtering.

  1: plasma CVD apparatus, 11: load / unload chamber, 12: film forming chamber, 13: lifting chamber, 14: return transfer chamber, 15: conveyor, 16: tray, 17: substrate, 18: substrate supply / recovery Device: 20: Gas supply device, 21: Suction device, 22, 22A, 22B: Blower, 23: Piping, 24: Manifold, 25: Suction nozzle, 25a: Suction port, 101: Intersection, 220: Air outlet

Claims (6)

A film formation chamber for forming a thin film on a substrate placed on a tray;
A transporting device for transporting the tray on which the film-formed substrate is placed;
Air is blown toward the substrate mounting surface of the tray that is transported and moved, and a blower that blows off dust on the tray and the substrate placed on the tray, and the blown-off dust are sucked together with air. A film forming apparatus comprising a nozzle. The film forming apparatus according to claim 1,
The blower is obliquely incident on the substrate placement surface, and a first jet outlet that ejects air toward the downstream side in the transport direction so as to be obliquely incident on the substrate placement surface. A second jet port for jetting air toward the upstream side in the transport direction,
The film forming apparatus, wherein the nozzle is provided between the first jet port and the second jet port, and includes a suction port facing the substrate mounting surface. The film forming apparatus according to claim 2,
The ejection direction of each air ejected from the first and second ejection ports is set so that the air ejected from the first and second ejection ports intersects on the tray side with respect to the surface of the substrate. A film forming apparatus characterized by being made. In the film-forming apparatus as described in any one of Claims 1-3,
A load / unload chamber for carrying an untreated substrate into a film forming apparatus and carrying out a film-formed substrate from the film forming apparatus;
A return transfer chamber for transferring the film-formed substrate to the load / unload chamber,
The film forming apparatus, wherein the blower and the nozzle are provided in the return transfer chamber. A dust collection method for a film forming apparatus,
Stopping film formation in the film formation chamber and lowering the temperature of the film formation chamber;
Supplying a tray on which the substrate is not placed to the film forming chamber;
A step of transporting the tray supplied to the film forming chamber by a transport device;
And collecting dust on the tray while transporting the tray by the transport device. The dust collection method according to claim 5,
In the dust collecting step, dust on the tray is blown off by air from a blower, and the dust blown off is sucked together with air by a nozzle.

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