JP3846873B2 - Vacuum drying apparatus and vacuum drying method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reduced-pressure drying apparatus and a reduced-pressure drying method for drying a coating liquid on a substrate to be processed by subjecting the substrate to be processed to which a coating solution such as a resist solution has been applied to a reduced-pressure drying process.
[0002]
[Prior art]
In the manufacturing process of semiconductor devices and LCDs, a resist process is performed on a substrate to be processed by a technique called photolithography. In this resist processing, a reticle substrate having a predetermined mask pattern formed on the surface is used.
In general, a mask pattern is formed on this type of reticle substrate by applying a predetermined coating solution on the surface of the reticle substrate, and then developing the film after exposure.
Here, in the coating liquid coating method, the coating liquid supply nozzle is reciprocated in one direction, and the reticle substrate is intermittently fed in a direction intersecting the reciprocating direction, and the coating liquid is supplied from the nozzle to the surface of the reticle substrate. There is a method in which a coating liquid is applied in the manner of so-called “one-stroke writing” by discharging the liquid onto the surface.
[0003]
In carrying out such a coating method, a solvent having low volatility is used as the solvent contained in the coating solution, or the solvent is quickly removed from the substrate surface to ensure the coating film thickness uniformity. For these reasons, it is considered that it is preferable to carry the reticle substrate into a reduced pressure drying apparatus and dry under reduced pressure immediately after the coating liquid is applied onto the reticle substrate.
[0004]
Conventionally, as this type of vacuum drying apparatus, for example, one configured as shown in FIG. 11 is known.
This apparatus will be described with reference to FIG. 11. In FIG. 11, a vacuum drying apparatus denoted by reference numeral 101 includes an airtight container 102 and a vacuum pump 103. The airtight container 102 includes a lid 104 and a mounting table 105. The lid body 104 is formed of a headed cylindrical body that opens downward as a whole. An opening 104 a is provided in the ceiling portion of the lid body 104. The mounting table 105 is disposed below the lid body 104 and is configured to mount the reticle substrate R thereon. On the other hand, the vacuum pump 103 is connected to the opening 104a via an exhaust pipe 106, and is configured to depressurize the airtight container 102.
[0005]
In such a reduced pressure drying apparatus, in order to dry the reticle substrate R under reduced pressure, the reticle substrate R coated with the coating liquid is placed on the placing table 105 by a substrate delivery pin (not shown), and then In addition, the temperature of the reticle substrate R is adjusted by a temperature adjusting means (not shown), and the vacuum pump 103 is driven to depressurize the inside of the hermetic container 102.
[0006]
By the way, as shown in FIG. 12A, the state of the coating liquid (before vacuum drying) on the surface of the reticle substrate R transported to the above-described vacuum drying apparatus is the peripheral region (for example, 20 mm from the peripheral edge) of the reticle substrate R. In the region on the inner side, the corners are rounded by the surface tension of the coating liquid 108 itself.
For this reason, as shown in FIG. 12B, a rectifying plate 107 (shown by a broken line in FIG. 11) is provided above the reticle substrate R placed on the mounting table 105 (shown in FIG. 11), and rectification is performed. A method is being studied in which the coating liquid 108 in the peripheral region is not rounded by the air current spreading between the plate 107 and the reticle substrate R.
[0007]
[Problems to be solved by the invention]
However, in the conventional vacuum drying apparatus, when the surface processing applied to the rectifying plate is insufficient, that is, when a minute uneven portion (a scratch having a depth of 50 μm or more) is formed on the surface of the rectifying plate. As a result, a temperature difference occurred in the plane of the reticle substrate facing the concave and convex portions. This temperature difference is considered to be due to the non-uniformity of the gap between the reticle substrate and the rectifying plate due to the concavo-convex portion, or the non-uniformity of the airflow flowing through the gap between the reticle substrate and the rectifying plate due to the concavo-convex portion. Moreover, due to this temperature difference, unevenness corresponding to the uneven portions of the rectifying plate is formed on the application surface of the reticle substrate, which causes a so-called transfer phenomenon, and a coating film having a certain film thickness cannot be obtained. There was a technical problem.
[0008]
Further, in the airtight container (mounting table), an insertion hole through which the substrate delivery pin is inserted is disposed in the pattern forming surface of the reticle substrate.
Therefore, when the inside of the hermetic container is evacuated under reduced pressure, a gas flow flowing into the hermetic container from the insertion hole is generated, and this gas flow causes the in-plane temperature of the reticle substrate to be non-uniform, and the coating having a certain film thickness. There was a technical problem that a film could not be obtained.
[0009]
The present invention has been made to solve such a technical problem, and is a reduced-pressure drying apparatus that improves the uniformity of the film thickness by improving the uniformity of the in-plane temperature of the substrate to be processed at the time of drying under reduced pressure. An object is to provide a vacuum drying method.
[0010]
[Means for Solving the Problems]
The reduced-pressure drying apparatus according to the present invention made to achieve the above object is a reduced-pressure drying apparatus for drying a substrate to be processed coated with a coating liquid under reduced pressure, and a mounting table on which the substrate to be processed is mounted The airtight container provided in the interior, the substrate to be processed placed on the mounting table, the rectifying plate provided to face the substrate with a predetermined gap, and the front mounting table are inserted in a freely movable manner. A substrate delivery member for placing the substrate to be processed on a mounting table, a vacuum exhaust means for decompressing the inside of the hermetic container and evaporating a solvent component contained in the coating liquid, and the substrate delivery member are inserted. And a vacuum exhaust means connected to the insertion hole.
[0016]
As described above, since the reduced pressure exhaust means is provided in the insertion hole through which the substrate delivery member is inserted, the differential pressure between the insertion hole and the airtight container can be suppressed, and the gas flows into the airtight container from the insertion hole. This can prevent the temperature drop around the insertion hole of the substrate to be processed. As a result, the uniformity of the in-plane temperature of the substrate to be processed can be improved during drying under reduced pressure, and a uniform film thickness can be obtained.
[0017]
Here, it is desirable that the decompression rate of the decompression exhaust means connected to the insertion hole and the decompression rate of the decompression exhaust means for decompressing the inside of the hermetic container are set to the same rate. Since it is comprised in this way, it can prevent that gas flows in into an airtight container from an insertion hole, and can suppress more the temperature fall around the insertion hole of a to-be-processed substrate.
[0018]
Further, it is desirable that the substrate transfer member is disposed so as to support a non-application region of the coating liquid on the substrate to be processed, and a surface of the rectifying plate facing the substrate to be processed is mirror-finished. .
Thus, since the substrate transfer member is arranged to support the non-application area of the coating liquid on the substrate to be processed, the influence of the substrate transfer member can be suppressed as much as possible, and the application of the coating liquid on the substrate to be processed can be performed. Uniformity of the in-plane temperature of the region can be ensured.
Moreover, since the surface of the rectifying plate facing the substrate to be processed is mirror-finished, the gap between the rectifying plate and the substrate to be processed is kept constant, and the airflow between the rectifying plate and the substrate to be processed Is rectified, and a temperature difference due to heat transfer in the surface of the substrate to be processed is prevented.
As a result, the uniformity of the in-plane temperature of the substrate to be processed can be improved during drying under reduced pressure, and a uniform film thickness can be obtained.
[0019]
In addition, the substrate delivery member includes a horizontal portion that supports the substrate to be processed on one end side, and a vertical portion that passes through the mounting table attached to the lower surface on the other end side of the horizontal portion. In addition, it is desirable that the mounting table is provided with a space for accommodating the horizontal portion below the mounting surface when the substrate to be processed is mounted. Moreover, it is desirable that the surface roughness Ra of the surface of the rectifying plate facing the substrate to be processed is 0.025 μm or less.
Further, it is desirable that temperature adjusting means for adjusting the temperature of the substrate to be processed is embedded in the current plate, and temperature adjusting means for adjusting the temperature of the substrate to be processed is embedded in the mounting table. It is desirable.
[0020]
Further, the reduced-pressure drying method according to the present invention made to achieve the above object is the reduced-pressure drying method in the reduced-pressure drying apparatus, wherein the substrate to be processed is mounted on the mounting table of the hermetic container by a substrate transfer member. And a step of decompressing the inside of the hermetic container by a decompression means in a state where the substrate to be processed on the placing table is opposed to the mirror-finished surface of the rectifying plate. It is said.
Thus, in order to dry under reduced pressure with the substrate to be processed facing the mirror-finished surface of the rectifying plate, the gap between the rectifying plate and the substrate to be processed is kept constant, and the rectifying plate and The airflow between the substrate to be processed is rectified, and a temperature difference due to heat transfer in the surface of the substrate to be processed is prevented.
As a result, the uniformity of the in-plane temperature of the substrate to be processed can be improved during drying under reduced pressure, and a uniform film thickness can be obtained.
[0021]
Further, the reduced-pressure drying method according to the present invention made to achieve the above object is the reduced-pressure drying method in the reduced-pressure drying apparatus, wherein the substrate to be processed is mounted on the mounting table of the hermetic container by a substrate transfer member. And a step of depressurizing the inside of the hermetic container by a decompression exhaust means in a state where the substrate to be processed on the mounting table is opposed to the current plate, The depressurizing means connected to the insertion hole of the substrate transfer member provided on the mounting table evacuates at a rate equal to the depressurization rate of the depressurizing means for depressurizing the inside of the hermetic container.
In this way, the reduced pressure exhaust means connected to the insertion hole of the substrate delivery member exhausts the reduced pressure at the same rate as the reduced pressure exhaust means for reducing the pressure in the hermetic container. The inflow of gas can be prevented, and the temperature drop around the insertion hole of the substrate to be processed can be suppressed. As a result, the uniformity of the in-plane temperature of the substrate to be processed can be improved, and a uniform film thickness can be obtained.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a vacuum drying apparatus and a vacuum drying method according to the present invention will be described based on the embodiments shown in the drawings. First, before explaining the reduced-pressure drying apparatus and the reduced-pressure drying method, an example of a coating apparatus incorporating the reduced-pressure drying apparatus will be described with reference to FIG. FIG. 1 is a perspective view showing a coating apparatus incorporating a vacuum drying apparatus to which the present invention is applied.
In FIG. 1, what is indicated by reference numeral 21 is a cassette station for carrying in / out a cassette C in which a plurality of reticle substrates are stored, for example.
The cassette station 21 is provided with a placement portion 21a on which the cassette C can be placed. On the back side of the cassette station 21, an application unit 22 and shelf units 23 to 25 are arranged in order from the left side to the right side as viewed from the cassette station side. The cassette station 21 is provided with a transport mechanism 26 having an arm 26a for transferring the reticle substrate between the units.
[0023]
The coating unit 22 is provided with a coating apparatus capable of performing a coating method described later. In addition to the heating unit 201 and the cooling unit 202, the shelf units 23 to 25 are provided with a reduced-pressure drying unit 203 which is a reduced-pressure drying apparatus according to the present invention, and a hydrophobic treatment unit 204 and the like in the vertical direction.
[0024]
A pattern forming method for the reticle substrate by the coating apparatus of the coating unit 22 will be described.
First, when the cassette C containing the reticle substrate is placed on the placement portion 21a from outside the apparatus, the reticle substrate is taken out from the cassette C by the transport mechanism 26.
Next, after the hydrophobic treatment is performed in the treatment unit in the hydrophobic treatment unit 204, the cooling unit 202 cools to a predetermined temperature, and the coating unit 22 applies a resist solution as a coating solution.
Subsequently, the reticle substrate is conveyed to the reduced pressure drying unit 203, and a resist film is formed by a reduced pressure drying process.
[0025]
The reticle substrate on which the resist film is formed is heated to a predetermined temperature in the heating unit 201, then cooled to a predetermined temperature in the cooling unit 202, and returned to the cassette C on the mounting portion 21a.
Thereafter, the reticle substrate stored in the cassette C is transported to an exposure apparatus (not shown). After the exposure process is performed by the exposure apparatus, the development process is performed by the developing apparatus to form a desired mask pattern. Is done.
[0026]
Here, a method of applying a coating solution (resist solution) obtained by mixing a resist component and a solvent to the surface of the reticle substrate in the coating unit described above will be described with reference to FIGS. FIG. 2 is a perspective view schematically showing a main part of the coating unit. FIG. 3 is a perspective view showing a coating state of the coating liquid.
In the substrate processing space of the coating unit, as shown in FIG. 2, the coating liquid supply nozzle 30 is moved in one direction (in the drawing) with respect to the surface of the reticle substrate R held horizontally by a substrate holder (not shown). The coating liquid (resist liquid RE) is supplied while reciprocating in the X direction. In this case, a plate 31 with a slit is used so as not to be supplied outside the application region.
[0027]
Next, when the coating liquid supply nozzle 30 moves from one edge of the reticle substrate R to the other edge, it moves in the direction intersecting with this moving direction (the arrow direction (Y direction) shown in FIG. 3) in accordance with the timing. The reticle substrate R is intermittently fed by a mechanism (not shown).
By repeating such an operation, the coating liquid is applied to the reticle substrate R in a so-called “one-stroke writing” manner.
[0028]
Next, a vacuum drying apparatus to which the present invention is applied will be described with reference to FIGS. FIG. 4 is a cross-sectional view showing the vacuum drying apparatus according to the first embodiment of the present invention. FIG. 5 is a perspective view showing a substrate support state of the vacuum drying apparatus according to the first embodiment of the present invention. FIG. 6 is an enlarged cross-sectional view showing the substrate support state of the vacuum drying apparatus according to the first embodiment of the present invention.
In FIG. 4, the vacuum drying apparatus denoted by reference numeral 1 includes an airtight container 2 and a substrate delivery member 3.
The airtight container 2 includes a mounting table 4 on which a reticle substrate R coated with a coating liquid is mounted, and a lid 5 positioned above the mounting table 4, and is formed in a cylindrical shape as a whole. ing.
[0029]
Embedded in the mounting table 4 is a temperature adjusting means 41 (for example, a temperature adjusting unit made of a Peltier element) for adjusting the temperature of the reticle substrate R. Thereby, the mounting table 4 is configured to function as a temperature control plate.
In the central portion of the mounting table 4, a concave portion 4 b for storing a substrate that is slightly larger than the size of the reticle substrate R is provided. Further, as shown in FIGS. 5 and 6, the mounting table 4 is provided with a protrusion 43 for holding the substrate that protrudes from the bottom surface of the recess 4 b. Thus, the reticle substrate R is configured to be held on the bottom surface in the recess 4b via a slight gap. Furthermore, the mounting table 4 is provided with four insertion holes 4a (only two are shown in FIG. 4) that open to the bottom surface and the periphery of the opening of the recess 4b.
[0030]
The lid body 5 is a headed cylindrical body that opens downward, and is disposed above and below the mounting table 4 so as to be movable up and down by an elevating mechanism (not shown). The airtight container 2 is raised when the reticle substrate R is carried in and out, and the hermetic container 2 is opened.
An exhaust port 51 connected to the vacuum pump 54 via a pipe 55 is provided at a substantially central portion of the lid 5. A rectifying plate 6 having a surface (lower surface) opposite to the surface (upper surface) of the reticle substrate R on the mounting table 4 is fixed in the lid 5. In the figure, reference numeral 52 denotes an on-off valve, and reference numeral 53 denotes a pressure adjusting unit.
[0031]
The rectifying plate 6 is disposed below the exhaust port 51 and is formed of a circular plate such as stainless steel having an area larger than the area of the upper surface of the reticle substrate R.
At least the lower surface of the current plate 6 is mirror-finished so that the surface roughness Ra is about 0.025 μm.
Thereby, there are no minute (about 50 μm) uneven portions such as scratches on the rectifying plate 6, and transfer to the surface (film formation surface) of the reticle substrate R by the uneven portions is prevented. That is, as described above, since the surface of the rectifying plate facing the reticle substrate R is formed smoothly, non-uniformity in the gap between the reticle substrate R and the rectifying plate, and the gap between the reticle substrate R and the rectifying plate are reduced. The non-uniformity of the flowing airflow can be suppressed, the in-plane temperature of the reticle substrate R can be made uniform, and a coating film having a constant film thickness can be obtained.
In addition, a temperature adjusting means 42 (for example, a heating unit including a heater) for adjusting the temperature of the reticle substrate R is embedded in the rectifying plate 6. Thereby, the said rectifying plate 6 is comprised so that it may function as a temperature control plate, and the uniformity of the in-plane temperature of the reticle board | substrate R can be ensured. Further, as shown in FIG. 4, the rectifying plate 6 is provided with a height adjusting mechanism 6A for adjusting the height of the rectifying plate 6 by rotating a support rod by a motor. The height adjusting mechanism 6A is configured to adjust the distance between the rectifying plate 6 and the reticle substrate R.
[0032]
On the other hand, the board transfer member 3 is composed of four support members, and as shown in FIG. 4, is erected on the elevating base 63 and can be raised and lowered by the elevating mechanism 64 in each insertion hole 4 a of the mounting table 4. It is inserted.
Then, as shown in FIG. 6, each of the substrate transfer members 3 has a support surface 3a that is inclined corresponding to the chamfered portion 44 (pattern non-formation region) of the reticle substrate R, and the chamfered portion is formed by these support surfaces 3a. 44 is supported.
[0033]
The elevating mechanism 64 has a ball screw 66 that rotates by driving of the motor M and a mover 65 that advances and retreats on the ball screw 66, and is disposed below the elevating base 63. The ball screw 66 is rotatably held on a fixed base 70, and the rotation from the motor M is transmitted through a transmission belt 71 and a pulley 67. The moving element 65 is connected to the central part of the elevating base 63 via a rocker 68 and is configured to elevate the elevating base 63 by advancing and retreating by the rotation of the ball screw 66.
[0034]
Reference numeral 69 in the figure is a bellows for maintaining a decompressed state in the hermetic container 2, which is disposed around the substrate delivery member 3, and has an opening periphery of the insertion hole 4 a and the lift base 63. It is interposed between the upper surface.
Further, the motor M, the temperature adjusting means 41 and 42, and the pressure adjusting unit 53 are connected to the controller 7, and the operation thereof is controlled when the decompression drying process of the reticle substrate R is performed. .
[0035]
With the above configuration, the reticle substrate R is dried under reduced pressure as follows.
First, in a state where the lid 5 is raised, the reticle substrate R coated with the coating liquid by the above-described method is delivered to the substrate delivery member 3 by a transfer arm (not shown).
Next, while the non-application area of the reticle substrate R is supported by the substrate transfer member 3, the reticle substrate R is placed on the mounting table 4 so as to be accommodated in the recess 4b.
Thus, since the substrate transfer member 3 supports the non-application area of the coating liquid on the reticle substrate R, the influence of the substrate transfer member 3 can be suppressed as much as possible, and the surface of the application area of the application liquid on the reticle substrate R can be reduced. Uniformity of the internal temperature can be ensured.
When the reticle substrate R is placed on the mounting table 4, the non-application area of the reticle substrate R is disposed above the insertion hole 4 a of the substrate delivery member 3.
Thereafter, the lid 5 is lowered and comes into contact with the mounting table 4 to form the hermetic container 2 surrounding the reticle substrate R. In this case, the upper surface of the reticle substrate R and the lower surface of the rectifying plate 6 face each other.
[0036]
Then, the on-off valve 52 is opened, and the vacuum pump 54 starts depressurization of the hermetic container 2.
In this case, when the decompression of the hermetic container 2 is started, evaporation of the solvent contained in the coating liquid (resist liquid RE) on the surface of the reticle substrate R starts, and the gas flows into the gap between the reticle substrate R and the rectifying plate 6. Is formed. At this time, the gas flow between the reticle substrate R and the rectifying plate 6 is rectified by the rectifying plate. By this rectification, occurrence of a temperature difference due to heat transfer in the plane of the reticle substrate R is prevented, and uniformity of the in-plane temperature is ensured. In addition, since the surface of the current plate is smoothly formed as described above, the gap between the reticle substrate R and the current plate is uniform, and the in-plane temperature of the reticle substrate R can be made uniform. Further, since the non-application area of the reticle substrate R is disposed above the insertion hole 4a, the application area of the reticle substrate R is not easily affected by the heat caused by the gas flowing from the insertion hole 4a.
In this way, the reticle substrate R is dried under reduced pressure, and a coating film having a certain film thickness can be obtained.
[0037]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a perspective view showing a support state of the substrate to be processed by the substrate transfer member in the vacuum drying apparatus according to the second embodiment of the present invention. FIG. 8 is an enlarged cross-sectional view showing a main part of the vacuum drying apparatus according to the second embodiment of the present invention. In these drawings, the same or equivalent members as in FIGS. 4 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted.
As shown in FIGS. 7 and 8, the reduced-pressure drying apparatus according to the present embodiment includes a horizontal portion 73a for supporting the reticle substrate R and a vertical portion 73b through which the insertion hole 4a of the mounting table 4 is inserted. It is characterized in that it is formed by a saddle-shaped support member having the shape. In addition, the code | symbol 74 in a figure is the temperature control plate part formed on the mounting base 4 mentioned above.
[0038]
The horizontal portion 73a is held by the vertical portion 73b at a position about 10 mm away from the substrate support side end, and is entirely formed by a square bar. A support surface 73A that is inclined corresponding to the chamfered portion 44 (non-application region) of the reticle substrate R is provided at the tip of the horizontal portion 73a.
The vertical portion 73b is erected on the elevating base 63 and is entirely formed by a round bar. The bellows 69 (shown in FIG. 4) is disposed around the vertical portion 73b.
[0039]
As described above, since the substrate transfer member 73 is formed by the bowl-shaped support member having the horizontal portion 73a and the vertical portion 73b, the insertion hole 4a is disposed at a position sufficiently separated from the application region of the reticle substrate R. The Thereby, the temperature change of the reticle substrate R due to the gas flowing into the airtight container from the insertion hole 4a can be suppressed, and uniform film formation can be performed.
In addition, since the space 4 for housing the horizontal portion 73a is provided in the mounting table 4 below the mounting surface (temperature control plate portion 74) in the mounting state of the reticle substrate R, the reticle substrate R and the insertion hole 4a. The space portion A is interposed between them and the influence of the gas flow from the insertion hole 4a on the reticle substrate R can be suppressed.
[0040]
Further, as in the case of the first embodiment, since the rectifying plate 6 is disposed above the mounting table 4 (in the lid 5), the lower surface of the rectifying plate 6 and the upper surface of the reticle substrate R are arranged. The gas flow between them is rectified, and the temperature difference due to heat transfer in the plane of the reticle substrate R is suppressed.
[0041]
Accordingly, in this embodiment as well, as in the first embodiment, the uniformity of the in-plane temperature of the reticle substrate R and the uniformity of the airflow are maintained, so that a coating film having a uniform film thickness can be obtained. .
[0042]
Next, a third embodiment of the present invention will be described with reference to FIG. 9 and FIG. FIG. 9 is a cross-sectional view showing a main part of a vacuum drying apparatus according to the third embodiment of the present invention. FIG. 10 is a circuit diagram for explaining the pressure reduction / exhaust line of the vacuum drying apparatus according to the third embodiment of the present invention. In these drawings, the same or equivalent members as in FIGS. 4 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0043]
As shown in FIG. 10, the reduced pressure drying apparatus 80 (shown in FIG. 9) in this embodiment connects four pipes 82a to 82d whose exhaust pressure can be adjusted by a controller 81 to the insertion holes 4a. The exhaust pressure rate of 82a to 82d and the exhaust pressure rate of the pipe 55 are set to the same pressure reduction rate.
The controller 81 is connected to flow meters 83a to 83e and solenoid valves 84a to 84d, 52. The flow meters 83a to 83d are installed in the pipes 82a to 82d connected to the insertion holes 4a. The flow meter 83e is installed in the pipe 55 connected to the exhaust port 51.
[0044]
The electromagnetic valves 84 a to 84 d are installed in a pipe 82 between the flow meters 83 a to 83 d and the manifold 85. The solenoid valve (open / close valve) 52 is installed in a pipe 55 between the exhaust port 51 and the flow meter 83e. The manifold 85 is connected to the vacuum pump 54.
[0045]
The controller 81 controls opening and closing of the electromagnetic valve 52 during drying under reduced pressure, and controls the degree of opening and closing of the electromagnetic valves 84a to 84d based on the flow rate values of the flow meters 83a to 83e, thereby reducing the pressure of the pipes 82a to 82d. The rate and the decompression rate of the pipe 55 are set to the same rate.
[0046]
With the above configuration, the reticle substrate R is dried under reduced pressure as follows.
First, in a state where the lid 5 is raised, the reticle substrate R coated with the coating liquid by the above-described method is delivered to the substrate delivery member 3 by a transfer arm (not shown).
Next, while the non-application area of the reticle substrate R is supported by the substrate transfer member 3, the reticle substrate R is placed on the mounting table 4 so as to be accommodated in the recess 4b. Thereafter, the lid 5 is lowered and comes into contact with the mounting table 4 to form the hermetic container 2 surrounding the reticle substrate R. In this case, the reticle substrate R and the current plate 6 face each other.
[0047]
Then, the electromagnetic valves 84a to 84d, 52 are opened, and the vacuum pump 54 starts to depressurize the airtight container 2. At this time, the controller 81 controls the degree of opening and closing of the electromagnetic valves 84a to 84d, and the decompression rate of the pipes 82a to 82d and the decompression rate of the pipe 55 are set to the same rate.
Accordingly, since the pressure of the pipes 82a to 82d matches the pressure of the pipe 55 (because the differential pressure in each insertion hole 4a and the airtight container 2 can be suppressed), gas flows into the airtight container from each insertion hole 4a. The temperature drop around the insertion hole of the reticle substrate R is suppressed. As a result, the uniformity of the in-plane temperature of the reticle substrate R can be improved.
[0048]
When the pressure reduction of the hermetic container 2 is started, evaporation of the solvent contained in the coating liquid (resist liquid RE) on the surface of the reticle substrate R starts, and a gas flow is generated in the gap between the reticle substrate R and the rectifying plate 6. It is formed. For this reason, the gas flow between the reticle substrate R and the rectifying plate 6 is rectified, and the temperature difference due to heat transfer in the surface of the reticle substrate R is suppressed.
In this way, the reticle substrate R is dried under reduced pressure while the uniformity of the in-plane temperature of the reticle substrate R is maintained, and a coating film having a uniform film thickness as in the first and second embodiments. Can be obtained.
[0049]
In each embodiment, the case where the substrate to be processed is the reticle substrate R has been described. However, the present invention is not limited to this, and other substrates to be processed, such as a semiconductor wafer, an LCD substrate, and a CD, for example. Of course.
[0050]
【The invention's effect】
As is apparent from the above description, according to the reduced pressure drying apparatus and the reduced pressure drying method of the present invention, the uniformity of the film thickness can be increased by improving the uniformity of the in-plane temperature of the substrate to be processed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a coating apparatus incorporating a reduced-pressure drying apparatus to which the present invention is applied.
FIG. 2 is a perspective view schematically showing a main part of a coating unit.
FIG. 3 is a perspective view showing a coating state of a coating solution.
FIG. 4 is a cross-sectional view showing a vacuum drying apparatus according to the first embodiment of the present invention.
FIG. 5 is a perspective view showing a substrate support state of the vacuum drying apparatus according to the first embodiment of the present invention.
FIG. 6 is an enlarged cross-sectional view showing a substrate support state of the vacuum drying apparatus according to the first embodiment of the present invention.
FIG. 7 is a perspective view showing a support state of a substrate to be processed by a substrate transfer member in a vacuum drying apparatus according to a second embodiment of the present invention.
FIG. 8 is an enlarged cross-sectional view showing a main part of a vacuum drying apparatus according to a second embodiment of the present invention.
FIG. 9 is a cross-sectional view showing a main part of a vacuum drying apparatus according to a third embodiment of the present invention.
FIG. 10 is a circuit diagram for explaining a decompression / exhaust line of the decompression drying apparatus according to the third embodiment of the present invention.
FIG. 11 is a cross-sectional view showing a conventional vacuum drying apparatus.
12 (a) and 12 (b) are cross-sectional views showing a coating state when a conventional reduced pressure drying apparatus is used.
[Explanation of symbols]
1 Vacuum drying equipment
2 Airtight container
3 Board delivery material
3a Support surface
4 mounting table
4a Insertion hole
4b recess
5 lid
6 Current plate
7 Controller
21 cassette station
21a Placement part
22 Application unit
23-25 Shelf unit
26 Transport mechanism
26a arm
30 Coating liquid supply nozzle
31 plates
41, 42 Temperature adjusting means
44 Chamfer
51 Exhaust port
52 On-off valve
53 Pressure adjustment part
63 Lifting base
64 Lifting mechanism
65 mover
66 Ball screw
67 pulley
68 Oscillator
69 Bellows
70 fixed base
71 Transmission belt
201 Heating unit
202 Cooling unit
203 Vacuum drying unit
204 Hydrophobic treatment unit
A space part
C cassette
M motor
R reticle substrate
RE resist solution

Claims (9)

A vacuum drying apparatus for drying a substrate to be processed coated with a coating liquid under reduced pressure,
An airtight container provided with a mounting table on which the substrate to be processed is mounted;
A current plate provided to face the substrate to be processed placed on the mounting table via a predetermined gap;
A substrate delivery member that is inserted into the mounting table so as to be movable up and down, and places the substrate to be processed on the mounting table;
Reduced pressure exhaust means for reducing the pressure in the airtight container and evaporating the solvent component contained in the coating solution;
A vacuum drying apparatus comprising: a vacuum exhaust means connected to an insertion hole through which the substrate transfer member is inserted. 2. The decompression rate according to claim 1, wherein the decompression rate of the decompression means connected to the insertion hole and the decompression rate of the decompression means for decompressing the inside of the hermetic container are set to the same rate. Drying equipment. Wherein the substrate transfer member is said while being arranged to support the non-application region of the coating solution of the substrate, the surface of the current plate facing the substrate to be processed is characterized in that it is mirror-finished Item 2. The vacuum drying apparatus according to Item 1 . The substrate delivery member is
The support member includes a horizontal portion that supports the substrate to be processed on one end side, and a vertical portion that passes through the mounting table attached to the lower surface on the other end side of the horizontal portion. The reduced-pressure drying apparatus according to claim 1 . 5. The reduced-pressure drying according to claim 3 , wherein the mounting table is provided with a space for accommodating the horizontal portion below a mounting surface in a mounting state of the substrate to be processed. apparatus. 2. The reduced-pressure drying apparatus according to claim 1, wherein a surface roughness Ra of a surface of the rectifying plate facing the substrate to be processed is 0.025 μm or less. 2. The reduced-pressure drying apparatus according to claim 1 , wherein a temperature adjusting means for adjusting a temperature of the substrate to be processed is embedded in the rectifying plate. The reduced-pressure drying apparatus according to claim 1 , wherein a temperature adjusting unit that adjusts the temperature of the substrate to be processed is embedded in the mounting table. In the vacuum drying method in the vacuum drying apparatus according to claim 1 ,
Placing the substrate to be processed by a substrate delivery member on a mounting table of the hermetic container;
A step of depressurizing the inside of the hermetic container by a depressurization exhaust means in a state where the substrate to be processed on the mounting table is opposed to the rectifying plate,
In depressurizing the inside of the hermetic container, the depressurization means connected to the insertion hole of the substrate delivery member provided on the mounting table is at the same rate as the depressurization rate of the depressurization means for depressurizing the inside of the hermetic container. A vacuum drying method characterized by exhausting under reduced pressure.

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