JP2006253517A - Reduced-pressure dryer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reduced-pressure dryer in which the components of thin film, e.g. photoresist, can be prevented from adhering to an exhaust pump. <P>SOLUTION: The reduced-pressure dryer comprises a chamber 10 covering the circumference of a substrate W, an exhaust pump 50, a first opening/closing valve 41, a second opening/closing valve 42, and a third opening/closing valve 43. After photoresist formed on the major surface of the substrate W is vacuum dried by opening the first opening/closing valve 41 and evacuating the chamber 10, the first opening/closing valve 41 is closed and evacuation of the chamber 10 is stopped. Subsequently, inert gas is supplied to the exhaust pump 50 by opening the second opening/closing valve 42, and inert gas is supplied into the chamber 10 by opening the third opening/closing valve 43. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vacuum drying apparatus.

  For example, Patent Document 1 discloses a vacuum drying apparatus for drying a thin film such as a photoresist applied to a substrate such as a semiconductor wafer, a glass substrate for a liquid crystal display panel, or a mask substrate for a semiconductor manufacturing apparatus under reduced pressure. In the reduced-pressure drying apparatus described in Patent Document 1, the inside of the chamber into which the substrate is loaded is depressurized by an exhaust pump such as a dry pump, thereby promoting the evaporation of the solvent, which is the center of the components of the resist solution. I try to dry it quickly. When the photoresist is dried using such a reduced pressure drying apparatus, it is possible to prevent the influence of external factors such as wind and heat, and to dry the photoresist evenly.

Further, when such a vacuum drying apparatus is used, a phenomenon called bumping may occur immediately after the vacuum drying process is started. This is a phenomenon that occurs when the solvent component in the photoresist applied to the substrate surface suddenly evaporates and suddenly boils. When such bumping occurs, a phenomenon called small bubbles is formed on the surface of the photoresist called defoaming, and the substrate cannot be used. For this reason, in the initial stage of the vacuum drying process, exhausting is performed at a lower speed than in the chamber to prevent the occurrence of defoaming, and then the interior of the chamber is exhausted strongly to achieve rapid and uniform drying over the entire surface of the substrate. Like to do.
JP-A-7-283108

  Among photoresists constituting a thin film, for example, a resist containing an acrylic resin such as a resist for a color filter (Color Filter) or a resist for an organic film (Organic Resist) has a property of being easily solidified due to a change with time. Therefore, when such a color filter resist or a resist containing an acrylic resin is used as the photoresist, there arises a problem that the resist is fixed in the exhaust pump.

  That is, when performing the vacuum drying process, a large amount of inert gas or the like existing in the chamber passes through the exhaust pump at the initial stage of the exhaust process. On the other hand, in the middle of the exhaust process, vaporization of the solvent component in the photoresist is started. At this time, since there is almost no inert gas or the like in the chamber, a high-concentration solvent component contained in the gas passes through the pump.

  At this time, a dry pump is generally used as the exhaust pump. This dry pump is a screw-type pump, and has a configuration in which gas is compressed and moved while being compressed by rotating a rotor in a casing. When such a high-concentration solvent component enters the exhaust pump, the solvent component of the photoresist adheres to the rotor portion of the pump when the gas is compressed. And when the solvent component adhering to a rotor accumulates, it will interfere with the exhaust operation of an exhaust pump.

  In such a dry pump, a small amount of purge gas is allowed to flow in the pump in order to maintain the rotor and casing in a non-contact state with a slight gap. For this reason, it is possible to prevent the solvent component from sticking by increasing the flow rate of the purge gas. However, when such a configuration is adopted, the exhaust performance of the exhaust pump is reduced and the vacuum in the chamber is reached. The problem is that the degree decreases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vacuum drying apparatus capable of preventing thin film components such as a photoresist from adhering to an exhaust pump.

  According to a first aspect of the present invention, there is provided a vacuum drying apparatus for drying a thin film formed on a main surface of a substrate under reduced pressure, a chamber covering the periphery of the substrate, an exhaust pump for exhausting an atmosphere in the chamber, and the exhaust pump And a first on-off valve disposed between the chamber and the first on-off valve is opened to evacuate the chamber to dry the thin film formed on the main surface of the substrate under reduced pressure, After the first on-off valve is closed and exhaust of the chamber is stopped, an inert gas is supplied into a pipe line connecting the first on-off valve and the exhaust pump.

  According to a second aspect of the present invention, there is provided a vacuum drying apparatus for drying a thin film formed on a main surface of a substrate under reduced pressure, a chamber covering the periphery of the substrate, an exhaust pump for exhausting an atmosphere in the chamber, and the exhaust pump And a first on-off valve disposed between the chamber and the chamber, and a second pipe for connecting the first on-off valve and the exhaust pump to introduce an inert gas into the pipe. The on-off valve, a third on-off valve for supplying an inert gas into the chamber, and the thin film formed on the main surface of the substrate by depressurizing the inside of the chamber by opening the first on-off valve After drying, the first on-off valve is closed and the exhaust of the chamber is stopped, then the second on-off valve is opened and an inert gas is connected to the pipe connecting the first on-off valve and the exhaust pump. And the third opening and closing The open, characterized in that a control means for supplying an inert gas into the chamber.

  According to a third aspect of the present invention, in the second aspect of the present invention, the control unit opens the second on-off valve and the third on-off valve at the same time.

  According to a fourth aspect of the present invention, there is provided a vacuum drying apparatus for drying a thin film formed on a main surface of a substrate under reduced pressure, a chamber that covers the periphery of the substrate, an exhaust pump that exhausts an atmosphere in the chamber, and the exhaust pump And a first open / close valve disposed between the chamber and the chamber, an inert gas supply means for supplying an inert gas to the exhaust pump, and the interior of the chamber reaches a predetermined degree of vacuum by exhausting the exhaust pump. And a control means for closing the first on-off valve and controlling the inert gas supply means to increase the flow rate of the inert gas supplied to the exhaust pump.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the thin film is a resist for a color filter or a resist containing an acrylic resin.

  According to a sixth aspect of the present invention, in the first aspect of the present invention, the exhaust pump is a dry pump.

  According to the first, second, and fourth aspects of the invention, the inert gas is supplied into the pipe connecting the first on-off valve and the exhaust pump after drying under reduced pressure. By supplying an inert gas to the exhaust pump, it is possible to prevent thin film components such as a photoresist from adhering to the exhaust pump.

  According to invention of Claim 3, since the 2nd on-off valve and the 3rd on-off valve are open | released simultaneously, the structure for controlling an apparatus can be simplified.

  According to the fourth aspect of the present invention, it is possible to prevent the color filter resist or the resist component containing the acrylic resin from being easily solidified from adhering to the exhaust pump.

  According to the fifth aspect of the present invention, it is possible to prevent sticking to a dry pump that tends to cause solidification when the gas is compressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a vacuum drying apparatus according to the present invention.

  In this vacuum drying apparatus, a chamber 10 including a lid portion 11, a packing 12, and a base portion 13, a support pin 15 erected on the base portion 13 in the chamber 10, and a plurality of lifting pins 21 are erected. And a support plate 22. A substrate W coated with a resist containing an acrylic resin such as a color filter resist or organic film resist as a thin film on its main surface is supported in a horizontal posture with its main surface facing upward in the chamber 10. It is supported by the pin 15 or the lift pin 21.

  The support plate 22 is connected to the lifting mechanism 25 via a support bar 24. The lift pins 21 can move up and down between the transfer position of the substrate W for transferring the substrate W to and from the transfer arm (not shown) and the drying position shown in FIG. ing.

  An exhaust port 31 is formed in the base portion 13 of the chamber 10. The exhaust port 31 is connected to the exhaust pump 50 via a conduit 53, a first on-off valve 41, and a conduit 51. The exhaust pump 50 is composed of a screw-type dry pump that moves and exhausts gas while compressing it by rotating a rotor. The exhaust pump 50 is provided with a pipe 54 for supplying purge gas. A small amount of nitrogen gas is constantly purged into the exhaust pump 50 via the pipe line 54.

  Further, the exhaust pump 50 is connected to a gas-liquid separation unit 56 through a pipe line 55. The gas discharged from the exhaust pump 50 is exhausted to the atmosphere or an exhaust area after the liquid component is removed by the gas-liquid separator 56.

  A second on-off valve 42 is connected to a pipe line 51 connecting the first on-off valve 41 and the exhaust pump 54 via a pipe line 52. The second on-off valve 42 is for supplying nitrogen gas to the exhaust pump 50 via the pipelines 51 and 52, and is connected to a nitrogen gas supply source (not shown).

  In some cases, a resist for color filter or a resist containing an acrylic resin is fixed in the pipe 51, but the resist fixed in the pipe 51 is purged and removed by nitrogen gas. Is preferably connected to the pipe line 51 as close as possible to the first on-off valve 41.

  A nitrogen gas inlet 32 is formed in the base 13 of the chamber 10. A third on-off valve 43 is connected to the nitrogen gas introduction hole 32 via a pipe line 57. The third on-off valve 43 is for supplying nitrogen gas into the chamber 10 via the conduit 57, and is connected to a nitrogen gas supply source (not shown).

  FIG. 2 is a block diagram showing the main electrical configuration of the vacuum drying apparatus according to the present invention.

  The vacuum drying apparatus includes a control unit 60 including a ROM 61 that stores an operation program necessary for controlling the apparatus, a RAM 62 that temporarily stores data and the like during control, and a CPU 63 that executes a logical operation. The control unit 60 is connected to the first on-off valve 41, the second on-off valve 42, and the third on-off valve 43 described above via an interface 64. The control unit 60 is also connected to other driving mechanisms 65 including the above-described lifting mechanism 25 and a driving mechanism for opening and closing the lid portion 11 of the chamber 10.

  Next, a drying operation for drying the thin film formed on the main surface of the substrate by the reduced pressure drying apparatus will be described. 3 and 4 are flowcharts showing a drying operation by the reduced pressure drying apparatus according to the present invention.

  When drying the thin film formed on the main surface of the substrate W, first, the first, second, and third on-off valves 41, 42, and 43 are closed. In this state, the lid portion 11 in the chamber 10 is raised by an elevator mechanism (not shown) to open the chamber 10 (step S11). Next, a transfer arm (not shown) that supports the substrate W enters the chamber 10 (step S12).

  Next, by driving the lifting mechanism 25, the lifting pins 21 are raised together with the support plate 22 to the delivery position of the substrate W (step S13). As a result, the substrate W supported by the transport arm is supported by the lift pins 21. Then, the transfer arm exits from the chamber 10 (step S14).

  Next, the lift pin 21 is lowered together with the support plate 22 to the dry position by driving the lift mechanism 25 (step S15). As a result, the substrate W whose lower surface is supported by the lift pins 21 is transferred to the support pins 15. Then, the lid portion 11 in the chamber 10 is lowered by an elevator mechanism (not shown) to close the chamber 10 (step S16).

  In this state, the first on-off valve 41 is opened, and a small amount of exhaust is performed by the action of the exhaust pump 50 (step S17). Thus, when vacuum drying is performed with a small amount of exhaust, appropriate vacuum drying is performed in a state in which defoaming due to bumping is prevented by a gentle air flow from the center to the edge of the main surface of the substrate W. It becomes possible to execute.

  If a certain time has passed in this state (step S18), the driving of the exhaust pump 50 is switched to increase the exhaust amount from the exhaust port 31 (step S19). At this time, a relatively large air flow is generated on the main surface of the substrate W from the center toward the edge. When vacuum drying is performed with such a large displacement, drying is performed quickly over the entire main surface of the substrate W. However, since the thin film is dried to some extent in the above-described drying process using a small amount of exhaust air, defoaming due to bumping does not occur.

  In this state, if it is detected by a sensor (not shown) that the degree of vacuum in the chamber 10 has reached a preset value (step S20), the third on-off valve 43 is opened to supply nitrogen gas into the chamber 10. The inside of the chamber 10 is purged with nitrogen gas (step S21). At the same time, a valve switching operation for closing the first on-off valve 41 and opening the second on-off valve 42 is executed (step S22).

  In this state, a large amount of nitrogen gas flows into the exhaust pump 50 from the on-off valve 42 via the pipeline 52 and the pipeline 51. That is, the flow rate of nitrogen gas increases from zero to a predetermined amount. Thereby, the solvent component of the resist containing a color filter resist or an acrylic resin can be discharged toward the gas-liquid separation unit 56 together with the nitrogen gas. Therefore, it is possible to prevent the color filter resist or the resist component containing the acrylic resin from adhering to the exhaust pump 50. At this time, it is possible to remove the resist adhering to the pipe 51 at the same time as the resist adhering to the exhaust pump 50 is removed.

  Even when a large amount of nitrogen gas flows into the exhaust pump 50 in this way, the degree of vacuum in the chamber 10 reaches a preset value and the first on-off valve 41 is closed. Therefore, the substrate drying process can be performed satisfactorily without affecting the degree of vacuum in the chamber 10.

  In this embodiment, the opening / closing operations of the first, second, and third opening / closing valves 41, 42, 43 are simultaneously performed. As a result, a timer or the like for executing the opening / closing operation can be simplified, and the configuration for controlling the apparatus can be simplified.

  If the inside of the chamber 10 becomes atmospheric pressure by purging with the nitrogen gas from the third on-off valve 43 (step S23), the second on-off valve 42 is closed to stop the supply of the nitrogen gas to the exhaust pump 54, and 3 The on-off valve 43 is closed to stop the nitrogen gas purge to the chamber 10 (step S24). Also in this case, the opening and closing operations of the second and third opening / closing valves 42 and 43 are performed simultaneously. As a result, a timer or the like for executing the opening / closing operation can be simplified, and the configuration for controlling the apparatus can be simplified.

  Next, the lid portion 11 in the chamber 10 is raised by an elevator mechanism (not shown) to open the chamber 10 (step S25). Next, by driving the lifting mechanism 25, the lifting pins 21 are raised together with the support plate 22 to the delivery position of the substrate W (step S26).

  In this state, a transfer arm (not shown) enters the chamber 10 (step S27). And by the drive of the raising / lowering mechanism 25, the raising / lowering pin 21 falls with the support plate 22 (step S28). Thereby, the board | substrate W currently supported by the raising / lowering pin 21 is supported by the conveyance arm. Then, the transfer arm that supports the substrate W leaves the chamber 10 (step S29).

  Next, another embodiment of the drying operation by this vacuum drying apparatus will be described. 5 and 6 are flowcharts showing a drying operation by the reduced pressure drying apparatus according to the present invention.

  In the above-described embodiment, when the inside of the chamber 10 becomes atmospheric pressure by purging with the nitrogen gas from the third on-off valve 43 (step S23), the second on-off valve 42 is closed and the nitrogen gas to the exhaust pump 54 is closed. While stopping supply, the 3rd on-off valve 43 is closed, and the nitrogen gas purge to the chamber 10 is stopped (step S24), thereby simplifying a timer or the like for executing the opening / closing operation and controlling the apparatus The configuration is simplified.

  On the other hand, in this embodiment, after the preset time has elapsed after the second on-off valve 42 is opened and the supply to the exhaust pump 50 is started, the second on-off valve 42 is closed and the exhaust gas is exhausted. The supply of nitrogen gas to the pump 50 is stopped. Other operations are the same as those in the above-described embodiment.

  That is, in this embodiment, after the third on-off valve 43 is opened and nitrogen gas is supplied into the chamber 10 and the inside of the chamber 10 is purged with nitrogen gas (step S21), the inside of the chamber 10 becomes atmospheric pressure. If so (step S23a), the third on-off valve 43 is closed to stop the supply of nitrogen gas to the chamber 10 (step S24a). On the other hand, after opening the on-off valve 42 in parallel with this and starting the supply of nitrogen gas to the exhaust pump 50 (step S22), after a predetermined time has elapsed (step S23b), the second on-off valve 42 is closed and supply of nitrogen gas to the exhaust pump 54 is stopped (step S24b). According to this embodiment, the supply time of the nitrogen gas to the exhaust pump 50 is set to an optimal time for preventing adhesion of the color filter resist or the resist containing acrylic resin to the exhaust pump 50. It becomes possible.

  In each of the above-described embodiments, the pipe 51 connected to the exhaust pump 10 is connected to the pipe 52 connected to the nitrogen gas supply source so that a large amount of nitrogen gas is supplied to the exhaust pump 10. It is configured to supply. However, a flow rate adjusting valve is provided in the pipe line 54 for supplying the purge gas to the exhaust pump 50, and after the degree of vacuum in the chamber 10 reaches a preset value and the first on-off valve 41 is closed, the pipe line 54 is used. Alternatively, a configuration may be adopted in which a large amount of nitrogen gas is caused to flow into the exhaust pump 50 to prevent the color filter resist or the resist-containing resist component from adhering to the exhaust pump 50.

1 is a schematic diagram of a vacuum drying apparatus according to the present invention. It is a block diagram which shows the main electrical structures of the reduced pressure drying apparatus which concerns on this invention. It is a flowchart which shows drying operation. It is a flowchart which shows drying operation. It is a flowchart which shows drying operation. It is a flowchart which shows drying operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Chamber 11 Cover part 12 Packing 13 Base 14 Upper surface 15 Support pin 15 Recess 21 Lifting pin 22 Support plate 25 Lifting mechanism 31 Exhaust port 32 Nitrogen gas introduction hole 41 First on-off valve 42 Second on-off valve 43 Third on-off valve 50 Exhaust Pump 51 Pipe line 52 Pipe line 53 Pipe line 56 Gas-liquid separator 57 Pipe line W Substrate

Claims (6)

In a vacuum drying apparatus for drying the thin film formed on the main surface of the substrate under reduced pressure,
A chamber covering the periphery of the substrate;
An exhaust pump for exhausting the atmosphere in the chamber;
A first on-off valve disposed between the exhaust pump and the chamber;
The first on-off valve is opened and the inside of the chamber is evacuated to dry the thin film formed on the main surface of the substrate under reduced pressure. After the first on-off valve is closed and the exhaust of the chamber is stopped, A vacuum drying apparatus, wherein an inert gas is supplied into a pipe line connecting the first on-off valve and the exhaust pump. In a vacuum drying apparatus for vacuum drying a thin film formed on a main surface of a substrate,
A chamber covering the periphery of the substrate;
An exhaust pump for exhausting the atmosphere in the chamber;
A first on-off valve disposed between the exhaust pump and the chamber;
A second on-off valve connected to a pipe connecting the first on-off valve and the exhaust pump, and for introducing an inert gas into the pipe;
A third on-off valve for supplying an inert gas into the chamber;
The first on-off valve is opened and the inside of the chamber is evacuated to dry the thin film formed on the main surface of the substrate under reduced pressure. After the first on-off valve is closed and the exhaust of the chamber is stopped, An inert gas is supplied to a pipe line connecting the first on-off valve and the exhaust pump by opening the second on-off valve, and the inert gas is supplied into the chamber by opening the third on-off valve. Supply control means;
A reduced-pressure drying apparatus comprising: The reduced-pressure drying apparatus according to claim 2,
The controller is a vacuum drying apparatus that simultaneously opens the second on-off valve and the third on-off valve. In a vacuum drying apparatus for vacuum drying a thin film formed on a main surface of a substrate,
A chamber covering the periphery of the substrate;
An exhaust pump for exhausting the atmosphere in the chamber;
A first on-off valve disposed between the exhaust pump and the chamber;
An inert gas supply means for supplying an inert gas to the exhaust pump;
The first on-off valve is closed after the chamber reaches a preset degree of vacuum by exhausting from the exhaust pump, and the flow rate of the inert gas supplied to the exhaust pump by the inert gas supply means is increased. Control means to control,
A reduced-pressure drying apparatus comprising: The reduced-pressure drying apparatus according to any one of claims 1 to 4,
The said thin film is a reduced pressure drying apparatus which is a resist containing a color filter resist or an acrylic resin. The reduced-pressure drying apparatus according to any one of claims 1 to 4,
The exhaust pump is a vacuum drying apparatus that is a dry pump.

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