JP5503057B2 - Vacuum drying apparatus and vacuum drying method - Google Patents

Description

  The present invention relates to a reduced-pressure drying apparatus and a reduced-pressure drying method for performing a drying process in a reduced-pressure environment on a substrate to be processed on which a processing liquid is applied in order to form a coating film in a photolithography process.

For example, in the manufacture of an FPD (flat panel display), after a predetermined film is formed on a substrate to be processed such as a glass substrate, a photoresist (hereinafter referred to as a resist) as a processing liquid is applied to form a resist film. The circuit pattern is formed by a so-called photolithography process in which the resist film is exposed corresponding to the circuit pattern and developed.
In the resist film forming step, after applying the resist to the substrate, a reduced pressure drying process is performed in which the applied film is dried under reduced pressure.
Conventionally, as an apparatus for performing such a vacuum drying process, for example, there is a vacuum drying unit disclosed in Patent Document 1 shown in a cross-sectional view of FIG.

In the reduced-pressure drying processing unit shown in FIG. 26, the lower chamber 151 and the upper chamber 152 are in close contact with each other to form a processing space therein. A stage 153 for placing a substrate to be processed is provided in the processing space. The stage 153 is provided with a plurality of fixing pins 156 for placing the substrate G thereon.
In this reduced-pressure drying processing unit, when the substrate G coated with resist on the surface to be processed is loaded, the substrate G is placed on the stage 153 via the fixing pins 156.
Next, the upper chamber 152 is brought into close contact with the lower chamber 151, and the substrate G is placed in an airtight processing space.

  Next, the atmosphere in the processing space is exhausted from the exhaust port 154 to be a predetermined reduced pressure atmosphere. By maintaining this reduced pressure state for a predetermined time, the solvent such as thinner in the resist solution is evaporated to some extent, the solvent in the resist solution is gradually released, and the drying of the resist is promoted without adversely affecting the resist. The

JP 2000-181079 A

By the way, in recent years, glass substrates used for FPDs and the like have become larger, and chambers for accommodating glass substrates have also become larger in vacuum drying processing units.
For this reason, the volume in the chamber is increased, and it takes time to reduce the pressure to a predetermined pressure. Furthermore, since the amount of the resist solution applied on the substrate increases, it takes a long time until the resist solution is uniformly dried over the entire surface of the substrate, resulting in a problem that the production efficiency is lowered.

  The present invention has been made under the circumstances as described above, and in a reduced-pressure drying apparatus that forms a coating film by performing a drying treatment of the treatment liquid on a substrate to be treated coated with the treatment liquid. There are provided a reduced pressure drying apparatus and a reduced pressure drying method capable of reducing the drying time and obtaining a uniform film thickness.

In order to solve the above-described problems, a reduced-pressure drying apparatus according to the present invention is a reduced-pressure drying apparatus that performs a reduced-pressure drying process of the processing liquid on a substrate to be processed applied with a processing liquid to form a coating film. A chamber that accommodates the substrate to be processed and forms a processing space; a holding unit that is provided in the chamber and holds the substrate to be processed; an exhaust port formed in the chamber; and a chamber from the exhaust port to the chamber An exhaust means for exhausting the atmosphere inside, an air supply port formed on the upstream side of the airflow formed by the operation of the exhaust means in the chamber and on the side of the substrate, and the air supply opening Supplying air to the processing space in the chamber, and rectifying means provided in the chamber to form a flow path of airflow flowing in one direction on the upper surface of the substrate by the exhaust operation of the exhaust means And with The rectifying means is a rectifying member that fills at least the space below the periphery of the substrate to be processed held by the holding portion .
With this configuration, an airflow flowing in one direction can be formed in the vicinity of the upper surface of the substrate during the vacuum drying process. For this reason, drying of the processing liquid applied to the substrate is promoted, and a uniform drying process can be performed on the substrate processing surface in a shorter time.

Further, in order to solve the above-described problems, the reduced-pressure drying method according to the present invention is the reduced-pressure drying apparatus that performs a reduced-pressure drying treatment of the treatment liquid on the substrate to be treated on which the treatment liquid has been applied, A reduced-pressure drying method to be formed, the step of holding a substrate to be processed in the holding unit, the processing space in the chamber being depressurized by the exhaust unit, and the inert gas being introduced into the chamber by the air supply unit And a step of supplying air.
By carrying out such a method, an air flow can be generated in the processing space in the chamber during the vacuum drying process, and drying of the processing liquid applied to the substrate can be promoted.

  According to the present invention, in a reduced-pressure drying apparatus that forms a coating film by drying the processing liquid on a substrate to be processed coated with the processing liquid, the drying time of the processing liquid is reduced and the film thickness is uniform. A vacuum drying apparatus and a vacuum drying method can be obtained.

FIG. 1 is a plan view of a coating and developing treatment system including a reduced pressure drying apparatus according to the present invention. FIG. 2 is a flowchart showing a substrate processing flow of the coating and developing processing system of FIG. FIG. 3 is a plan view showing the overall configuration of the coating process section. FIG. 4 is a side view of the coating process section. FIG. 5 is a plan view of a vacuum drying unit applied as the first embodiment of the vacuum drying apparatus according to the present invention. 6 is a cross-sectional view taken along the line CC in FIG. FIG. 7 is a plan view of a vacuum drying unit applied as the second embodiment of the vacuum drying apparatus according to the present invention. 8 is a cross-sectional view taken along the line CC in FIG. 9 is a cross-sectional view taken along line DD in FIG. FIG. 10 is a plan view of a reduced-pressure drying unit applied as a third embodiment of the reduced-pressure drying apparatus according to the present invention. 11 is a cross-sectional view taken along the line CC in FIG. FIG. 12 is a cross-sectional view showing another embodiment of the reduced pressure drying unit applied as the third embodiment of the reduced pressure drying apparatus according to the present invention. FIG. 13 is a plan view of a reduced-pressure drying unit applied as the fourth embodiment of the reduced-pressure drying apparatus according to the present invention. 14 is a cross-sectional view taken along the line CC of FIG. FIG. 15 is a cross-sectional view showing another embodiment of a reduced-pressure drying unit applied as the fourth embodiment of the reduced-pressure drying apparatus according to the present invention. FIG. 16 is a plan view of a reduced-pressure drying unit applied as the fifth embodiment of the reduced-pressure drying apparatus according to the present invention. FIG. 17 is a cross-sectional view taken along the line CC of FIG. 16 and shows a state in which the stage holding the substrate moves up and down. 18 is a cross-sectional view taken along the line CC of FIG. 16 and shows a state in which the stage holding the substrate is located in the upper part of the chamber. FIG. 19 is a cross-sectional view taken along the line CC of FIG. 16 and shows a state in which the stage holding the substrate is positioned below the chamber. FIG. 20 is a diagram illustrating a chamber structure of the vacuum drying unit used in the first embodiment. FIG. 21 is a diagram showing a chamber structure of the vacuum drying unit used in Comparative Example 1. FIG. 22 is a diagram showing a chamber structure of the vacuum drying unit used in Comparative Example 2. FIG. 23 is a diagram showing the results of Example 1. FIG. 24 is a diagram showing the results of Comparative Example 1. FIG. 25 is a diagram showing the results of Comparative Example 2. FIG. 26 is a cross-sectional view showing a schematic configuration of a conventional vacuum drying unit.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a coating and developing treatment system including a reduced pressure drying apparatus according to the present invention.
This coating / development processing system 10 is installed in a clean room. For example, a glass substrate for LCD is used as a substrate to be processed, and a series of cleaning, resist coating, pre-baking, developing, post-baking, and the like during a photolithography process in the LCD manufacturing process. The processing is performed. The exposure process is performed by an external exposure apparatus 12 installed adjacent to this system.

In the coating and developing system 10, a horizontally long process station (P / S) 16 is arranged at the center, and a cassette station (C / S) 14 and an interface station (I / F) are arranged at both ends in the longitudinal direction (X direction). 18 are arranged.
The cassette station (C / S) 14 is a port for loading and unloading a plurality of cassettes C in such a manner that the substrates G are stacked in multiple stages, and up to four can be placed side by side in a horizontal direction (Y direction). A cassette stage 20 and a transport mechanism 22 for taking the substrate G in and out of the cassette C on the stage 20 are provided. The transport mechanism 22 has a means for holding the substrate G, for example, a transport arm 22a, can be operated with four axes of X, Y, Z, and θ, and is adjacent to the adjacent process station (P / S) 16 side and the substrate G. Delivery is now possible.

In the process station (P / S) 16, the processing units are arranged in the order of the process flow or the process on a pair of parallel and opposite lines A and B extending in the horizontal system longitudinal direction (X direction).
That is, in the process line A from the cassette station (C / S) 14 side to the interface station (I / F) 18 side, a carry-in unit (IN PASS) 24, a cleaning process unit 26, and a first thermal processing unit 28 are provided. The coating process unit 30 and the second thermal processing unit 32 are arranged in a line in this order from the upstream side along the first flat flow path 34.

More specifically, the carry-in unit (IN PASS) 24 receives the unprocessed substrate G from the transfer mechanism 22 of the cassette station (C / S) 14 and inputs it into the first flat flow transfer path 34 at a predetermined tact. It is configured.
The cleaning process unit 26 is provided with an excimer UV irradiation unit (E-UV) 36 and a scrubber cleaning unit (SCR) 38 in order from the upstream side along the first flat flow path 34.

  The first thermal processing unit 28 is provided with an adhesion unit (AD) 40 and a cooling unit (COL) 42 in order from the upstream side. The coating process unit 30 is provided with a resist coating unit (COT) 44 and a vacuum drying unit (VD) 46 as a vacuum drying apparatus according to the present invention in order from the upstream side.

The second thermal processing unit 32 is provided with a pre-bake unit (PRE-BAKE) 48 and a cooling unit (COL) 50 from the upstream side.
A pass unit (PASS) 52 is provided at the end point of the first flat flow conveyance path 34 located adjacent to the downstream side of the second thermal processing unit 32.
The substrate G that has been transported in a flat flow on the first flat flow transport path 34 is transferred from the pass unit (PASS) 52 at the end point to the interface station (I / F) 18.

  On the other hand, in the downstream process line B from the interface station (I / F) 18 side to the cassette station (C / S) 14 side, a development unit (DEV) 54, a post-bake unit (POST-BAKE) 56, a cooling unit are provided. A unit (COL) 58, an inspection unit (AP) 60, and a carry-out unit (OUT PASS) 62 are arranged in a line in this order from the upstream side along the second flat flow path 64.

  Here, the post-bake unit (POST-BAKE) 56 and the cooling unit (COL) 58 constitute a third thermal processing unit 66. The carry-out unit (OUT PASS) 62 is configured to receive the processed substrates G one by one from the second flat flow transfer path 64 and pass them to the transfer mechanism 22 of the cassette station (C / S) 14. .

  Further, an auxiliary transfer space 68 is provided between the process lines A and B, and a shuttle 70 on which the substrate G can be horizontally placed in units of one sheet is processed in the process line direction (X direction) by a drive mechanism (not shown). You can move in both directions.

  Further, the interface station (I / F) 18 includes a transport device 72 for exchanging the substrate G with the first and second flat flow transport paths 34 and 64 and the adjacent exposure device 12. A rotary stage (R / S) 74 and a peripheral device 76 are arranged around the device 72. The rotary stage (R / S) 74 is a stage that rotates the substrate G in a horizontal plane, and is used to change the orientation of the rectangular substrate G when it is transferred to the exposure apparatus 12. The peripheral device 76 connects, for example, a titler (TITLER), a peripheral exposure device (EE), and the like to the second flat flow path 64.

  FIG. 2 shows a processing procedure of the entire process for one substrate G in this coating and developing processing system. First, in the cassette station (C / S) 14, the transport mechanism 22 takes out the substrate G from any one of the cassettes C on the stage 20, and uses the removed substrate G as a process line of the process station (P / S) 16. It carries in to the A side carrying-in unit (IN PASS) 24 (step S1 of FIG. 2). The substrate G is transferred or loaded onto the first flat flow path 34 from the carry-in unit (IN PASS) 24.

The substrate G put into the first flat transport path 34 is first subjected to an ultraviolet cleaning process and a scrubbing cleaning process by the excimer UV unit (E-UV) 36 and the scrubber cleaning unit (SCR) 38 in the cleaning process unit 26 in order. (Steps S2 and S3 in FIG. 2).
The scrubber cleaning unit (SCR) 38 removes particulate dirt from the substrate surface by performing brushing cleaning and blow cleaning on the substrate G that moves horizontally on the flat flow path 34, and then rinses. Finally, the substrate G is dried using an air knife or the like. When a series of cleaning processes in the scrubber cleaning unit (SCR) 38 is completed, the substrate G reaches the first thermal processing unit 28 as it is down the first flat flow path 34.

  In the first thermal processing unit 28, the substrate G is first subjected to an adhesion process using vapor HMDS in an adhesion unit (AD) 40, and the surface to be processed is hydrophobized (step of FIG. 2). S4). After the completion of the adhesion process, the substrate G is cooled to a predetermined substrate temperature by the cooling unit (COL) 42 (step S5 in FIG. 2). Thereafter, the substrate G is carried into the coating process unit 30 along the first flat flow path 34.

  In the coating process section 30, the substrate G is first coated with a resist solution on the upper surface (surface to be processed) by a spinless method using a slit nozzle while being flown flat in a resist coating unit (COT) 44, and immediately after that, adjacent to the downstream side. A vacuum drying unit (VD) 46 receives a drying process at room temperature using a reduced pressure (step S6 in FIG. 2).

  The substrate G that has left the coating process unit 30 reaches the second thermal processing unit 32 through the first flat flow path 34. In the second thermal processing section 32, the substrate G is first pre-baked by the pre-bake unit (PRE-BAKE) 48 as a heat treatment after resist coating or a heat treatment before exposure (step S7 in FIG. 2).

  By this pre-baking, the solvent remaining in the resist film on the substrate G is evaporated and removed, and the adhesion of the resist film to the substrate is enhanced. Next, the substrate G is cooled to a predetermined substrate temperature by the cooling unit (COL) 50 (step S8 in FIG. 2). Thereafter, the substrate G is taken from the pass unit (PASS) 52 at the end point of the first flat flow transport path 34 to the transport device 72 of the interface station (I / F) 18.

  In the interface station (I / F) 18, the substrate G undergoes a turn of 90 degrees, for example, by the rotary stage 74, and then is carried into the peripheral exposure device (EE) of the peripheral device 76, where it adheres to the peripheral portion of the substrate G. After receiving the exposure for removing the resist to be developed during development, the resist is sent to the adjacent exposure apparatus 12 (step S9 in FIG. 2).

In the exposure apparatus 12, a predetermined circuit pattern is exposed to the resist on the substrate G. Then, when the substrate G that has undergone pattern exposure is returned from the exposure apparatus 12 to the interface station (I / F) 18, first, it is carried into a titler (TITLER) of the peripheral device 76, where it is transferred to a predetermined portion on the substrate. Is recorded (step S10 in FIG. 2). Thereafter, the substrate G is carried from the transfer device 72 to the starting point of the developing unit (DEV) 54 of the second flat flow transfer path 64 laid on the process line B side of the process station (P / S) 16. .
In this way, the substrate G is now transported on the second flat transport path 64 toward the downstream side of the process line B. In the first development unit (DEV) 54, the substrate G is subjected to a series of development processes of development, rinsing, and drying while being conveyed in a flat flow (step S11 in FIG. 2).

  The substrate G that has undergone a series of development processes in the development unit (DEV) 54 is sequentially passed through the third thermal processing unit 66 and the inspection unit (AP) 60 while being put on the second flat flow path 64 as it is. To do. In the third thermal processing section 66, the substrate G is first subjected to post-baking as post-development heat treatment in the post-baking unit (POST-BAKE) 56 (step S12 in FIG. 2).

  By this post-baking, the developer and the cleaning solution remaining in the resist film on the substrate G are evaporated and removed, and the adhesion of the resist pattern to the substrate is enhanced. Next, the substrate G is cooled to a predetermined substrate temperature by the cooling unit (COL) 58 (step S13 in FIG. 2). In the inspection unit (AP) 60, non-contact line width inspection, film quality / film thickness inspection, and the like are performed on the resist pattern on the substrate G (step S14 in FIG. 2).

  The carry-out unit (OUT PASS) 62 receives the substrate G that has been processed in all steps from the second flat-carrying conveyance path 64 and transfers it to the conveyance mechanism 22 of the cassette station (C / S) 14. On the cassette station (C / S) 14 side, the transport mechanism 22 accommodates the processed substrate G received from the carry-out unit (OUT PASS) 62 in any one (usually the original) cassette C (FIG. 2). Step S15).

In the coating and developing treatment system 10, the vacuum drying apparatus of the present invention can be applied to the vacuum drying unit (VD) 46 in the coating process unit 30.
Next, a first embodiment of a reduced pressure drying unit (VD) 46 to which the reduced pressure drying apparatus of the present invention is applied will be described with reference to FIGS.
FIG. 3 is a plan view showing the overall configuration of the coating process unit 30. FIG. 4 is a side view of the coating process unit 30. 5 is a plan view of the vacuum drying unit (VD) 46, and FIG. 6 is a cross-sectional view taken along the line CC in FIG.

  As shown in FIGS. 3 and 4, the coating process unit 30 includes a resist coating unit (COT) 44 having a nozzle 84 and a vacuum drying unit (VD) 46 on a support base 80 according to the order of processing steps. It is arranged in a horizontal row. A pair of guide rails 81 are laid on both sides of the support base 80, and the substrate G is transferred from the resist coating unit (COT) 44 to the reduced pressure drying unit (VD) by a pair of transfer arms 82 that move parallel along the guide rails 81. ) 46 can be conveyed.

  The resist coating unit (COT) 44 has the nozzle 84 as described above, and this nozzle 84 is fixed in a suspended state from a gate 83 fixed on the support base 80. The nozzle 84 is supplied with a resist solution R, which is a processing solution, from a resist solution supply means (not shown). The resist solution R is supplied from one end to the other end of the substrate G that moves under the gate 83 by the transfer arm 82. It is made to apply.

Further, as shown in FIGS. 4 and 6, the reduced-pressure drying unit (VD) 46 is configured to be hermetically tightly attached to the bottom chamber 85 of the shallow container type whose upper surface is open and the upper surface of the lower chamber 85. And an upper chamber 86 having a lid shape.
As shown in FIGS. 3 and 5, the lower chamber 85 has a substantially square shape, and a plate-like stage 88 (holding portion) for horizontally holding and holding the substrate G is disposed at the center. The upper chamber 86 is disposed so as to be movable up and down above the stage 88 by an upper chamber moving means 87. During the drying under reduced pressure, the upper chamber 86 descends and comes into close contact with the lower chamber 85. The substrate G placed on the processing space is accommodated in the processing space.

  Exhaust ports 89 are provided below the stage 88 (below the substrate G held by the stage 88) and on the bottom surface of the lower chamber 85, and are connected to the exhaust ports 89. The exhaust pipe 90 thus communicated with the vacuum pump 91 (exhaust means). The processing space in the chamber can be depressurized to a predetermined degree of vacuum by the vacuum pump 91 with the lower chamber 85 covered with the upper chamber 86.

Further, an air supply port 92 for supplying an inert gas (for example, nitrogen gas) into the chamber and purging the atmosphere in the chamber is provided in the vicinity of one side of the bottom surface of the substantially rectangular lower chamber 85. Yes. As shown in FIG. 6, the air supply pipe 96 connected to the air supply port 92 is connected to an inert gas supply unit 97 (air supply means).
The supply of the inert gas from the air supply port 92 is started when the pressure in the chamber reaches a predetermined value (for example, 400 Pa or less), or after a predetermined time has elapsed since the start of pressure reduction in the chamber. This is to maintain the air flow in the chamber where the flow rate decreases due to the reduced pressure, thereby contributing to shortening the time of the reduced pressure drying process.
In addition, in order to always maintain a stable air flow during the reduced pressure drying process, the supply of the inert gas may be started before the start of the pressure reduction in the chamber or at the same time.

  Further, as shown in FIG. 5, a U-shaped rectifying plate 93 (first rectifying member) is provided between the bottom surface of the lower chamber 85 and the stage 88 and around the exhaust port 89 in a plan view. ing. By providing the rectifying plate 93, a side opening 93a and a communication passage 93b that communicates from the side opening 93a to the exhaust port 89 are formed. That is, when the atmosphere in the chamber flows below the stage 88 (substrate G), it flows from the side opening 93a of the rectifying plate 93 through the communication passage 93b and is exhausted from the exhaust port 89.

  As shown in FIG. 5, the rectifying plate 93 is installed with the side opening 93 a facing in the opposite direction to the air supply port 92 (with the stage 88 in between). For this reason, the inert gas supplied from the air supply port 92 flows in one direction above the substrate G placed on the stage 88 and passes therethrough, and is then exhausted from the exhaust port 89.

Further, a block member 95 (second rectifying member) for filling the lower space of the substrate G held on the stage 88 adjacent to the rectifying plate 93 on both the left and right sides of the communication passage 93b in the chamber. Are provided.
Furthermore, a substantially square bar-shaped side bar member 94 is provided on each of the left and right inner walls of the lower chamber 85 adjacent to the block member 95, and the left and right inner walls of the upper chamber 86 are respectively Side bar members 98 are provided corresponding to the side bar members 94 in the lower chamber 85. By providing these side bar members 94 and 98 (eight rectifying members) and closing the upper chamber 86 and the lower chamber 85, the space on the left and right sides of the substrate G is filled, and the exhaust port 89 is disposed in the processing space in the chamber. The gas flow path that flows to is restricted to the one that passes above the substrate G.

  In the coating process unit 30 configured as described above, when the substrate G is loaded and placed on the transfer arm 82, the transfer arm 82 moves on the rail 81 and the gate 83 of the resist coating unit (COT) 44. Move down through. At this time, the resist solution R is discharged from the nozzle 84 fixed to the gate 83 to the substrate G moving under the nozzle 84, and the resist solution R is applied from one side of the substrate G to the other side. Note that when the resist solution is applied over the entire surface of the substrate G (application end position), the substrate G is positioned below the upper chamber 86 of the reduced pressure drying unit (VD) 46, and the entire substrate G is covered by the upper chamber 86. It becomes a broken state.

  Next, the substrate G is placed on the stage 88 of the vacuum drying unit (VD) 46 and covered by the upper chamber 86 that moves downward from above by the upper chamber moving means 87. The substrate G is accommodated in a processing space formed by bringing the upper chamber 86 and the lower chamber 85 into close contact with each other.

Further, in this state, the vacuum pump 91 is operated, air in the processing space is sucked from the exhaust port 89 through the exhaust pipe 90, and the pressure in the processing space is reduced to a predetermined vacuum state. Thereby, the resist solution formed on the substrate G is dried under reduced pressure without being heated.
Here, when the atmospheric pressure in the chamber reaches a predetermined value (for example, 400 Pa or less), or when a predetermined time elapses from the start of pressure reduction, the inert gas supply unit 97 drives the inert gas at a predetermined flow rate from the air supply port 92. Supplied into the chamber. Thereby, the airflow in the chamber is maintained even under a reduced pressure environment.
The supply of the inert gas from the air supply port 92 may be controlled so as to be performed before the start of pressure reduction or simultaneously with the start of pressure reduction.

  In this vacuum drying treatment step, as described above, the rectifying plate 93, the block member 95, and the side bar members 94 and 98 are provided as the rectifying means, so that the airflow flowing in one direction on the upper surface of the substrate as shown in FIG. The flow path is formed. For this reason, the flow of the inert gas supplied from the air supply port 92 passes through the upper surface of the substrate and is restricted from being exhausted from the exhaust port 89 through the side opening 93a of the rectifying plate 93 through the communication passage 93b. Is done.

Accordingly, gas continues to flow at a uniform flow rate over the entire upper surface of the substrate G during the vacuum drying process. As a result, the drying speed of the resist solution R applied on the upper surface of the substrate is improved, and the reduced-pressure drying process is performed in a shorter time.
When the vacuum drying process is completed, the upper chamber 86 is moved upward by the upper chamber moving means 87, and the substrate G is unloaded from the vacuum drying unit (VD) 46 for the next processing step.

As described above, according to the first embodiment of the reduced pressure drying apparatus of the present invention, in the reduced pressure drying unit (VD) 46, by controlling the air flow in the chamber, the upper surface of the substrate G during the reduced pressure drying process. A gas having a uniform flow rate can be continuously supplied in one direction with respect to the whole.
Therefore, in the drying under reduced pressure, the evaporated material from the resist solution R applied to the substrate G can be efficiently exhausted, and the drying speed of the resist solution R can be improved.

  In the first embodiment, an example in which the air supply port 92 and the air supply means 97 are provided has been described. However, the present invention is not limited to this, and in FIGS. Even if it is the structure which does not comprise 92 and the air supply means 97, the effect of this invention can fully be acquired. That is, even if no air is supplied, only the exhaust process from the exhaust port 89 causes the gas in the chamber not to flow below (and to the side) of the substrate G. It flows to 89. Therefore, even in that case, the drying speed of the resist solution R applied to the upper surface of the substrate can be improved, and the reduced-pressure drying process can be performed in a shorter time.

  Next, a second embodiment of the reduced pressure drying unit (VD) 46 to which the reduced pressure drying apparatus of the present invention is applied will be described with reference to FIGS. In the second embodiment, common parts with the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Moreover, since the embodiment of the exhaust and supply air control is the same as the first embodiment, the description thereof is omitted.

7 is a plan view of a vacuum drying unit (VD) 46 according to the second embodiment, FIG. 8 is a cross-sectional view taken along the line CC in FIG. 7, and FIG. 9 is a cross-sectional view taken along the line DD in FIG. is there.
In the second embodiment, the reduced-pressure drying unit (VD) 46 includes a shallow container type lower chamber 85 whose upper surface is open and an upper surface of the lower chamber 85, as in the first embodiment. And a lid-like upper chamber 86 configured to be airtightly close.

  However, the chamber shown in the figure does not need to use the sidebar members 94 and 98 (eight rectifying members) shown in FIG. 5 in the first embodiment, that is, as shown in FIGS. The inner wall of the chamber (in the figure, inner walls 86a and 86b of the upper chamber 86) is in close proximity to one end of the substrate G. When the space on the side of the substrate G is large, it is preferable to use the side bar members 94 and 98 shown in FIG.

A stage 88 (holding portion) is arranged at the center of the lower chamber 85 as in the first embodiment, and a block member 102 (third rectifying member) as a rectifying means is provided so as to surround the stage 88. It has been. By providing this block member 102, at least the peripheral lower space of the substrate G is filled. In the figure, an example is shown in which the substrate G is held at a position higher than the lower chamber 85. However, the block member 102 is digged in the lower chamber 85 so that the substrate holding position is within the lower chamber 85. To). Further, the block member 102 may be integrally formed with the lower chamber 85 or may be a separate member.
In the first embodiment, the exhaust port 89 is provided below the substrate G. However, in the second embodiment, a plurality of (three in the figure) exhaust ports 101 are provided on the substrate as illustrated. It is provided side by side on the side of G. The plurality of exhaust ports 101 and the air supply ports 92 are provided below the substrate G with the substrate G interposed therebetween.

With this structure, the block member 102 functions as a weir that prevents the airflow from flowing under the substrate. That is, as shown in FIG. 9, the inert gas supplied from the air supply port 92 does not flow below (and to the side) of the substrate G, but passes all the way above the substrate in one direction, to the side of the substrate. It flows to the exhaust port 101.
Therefore, also in the second embodiment, the gas continues to flow at a uniform flow rate over the entire upper surface of the substrate G during the reduced-pressure drying process above the substrate, and as a result, the resist solution applied to the upper surface of the substrate. The drying rate of R is improved, and the reduced-pressure drying treatment can be performed in a shorter time.

  In the second embodiment, the example in which the air supply port 92 and the air supply means 97 are provided has been described. However, the present invention is not limited to this, and in FIGS. Even if it is the structure which does not comprise 92 and the air supply means 97, the effect of this invention can fully be acquired. That is, even without supplying air, only the exhaust process from the exhaust port 101 causes the gas in the chamber not to flow below (and to the side) of the substrate G, but to pass all the way above the substrate in one direction. It flows to 101. Therefore, even in that case, the drying speed of the resist solution R applied to the upper surface of the substrate can be improved, and the reduced-pressure drying process can be performed in a shorter time.

  Next, a third embodiment of a reduced pressure drying unit (VD) 46 to which the reduced pressure drying apparatus of the present invention is applied will be described with reference to FIGS. In the third embodiment, common parts with the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 10 is a plan view of a vacuum drying unit (VD) 46 according to the third embodiment, and FIG. 11 is a cross-sectional view taken along the line CC in FIG.
The configuration of the vacuum drying unit (VD) 46 illustrated in the third embodiment includes the air supply port 92 and the inert gas supply unit 97 (air supply means) shown in the second embodiment. In addition, the form of the rectifying means provided in the chamber is different.
That is, as a rectifying means, instead of the block member 102 shown in the second embodiment, as shown in FIG. 11, a block member 104 (fourth in the figure) in which a plurality of (three in the figure) exhaust ports 101 are formed. And a block member 103 (fourth rectification member) provided on the opposite side of the block member 104 with the substrate G interposed therebetween.

  More specifically, as shown in the figure, the exhaust port 101 is formed in the block member 104 in the vicinity of the edge of the held substrate G. The lower space of the substrate edge on the side where the exhaust port 101 is formed is filled with the block member 104, and the lower space of the substrate edge on the opposite side of the exhaust port 101 across the substrate G is the block. It is filled with the member 103. The block members 103 and 104 may be formed integrally with the lower chamber 85 or may be separate members.

With this structure, as shown in FIG. 11, the gas in the chamber does not flow below (and to the side) of the substrate G, but flows all the way above the substrate in one direction to the exhaust port 101.
Therefore, also in the third embodiment, the gas continues to flow at a uniform flow rate over the entire upper surface of the substrate G during the reduced-pressure drying process above the substrate, and as a result, the resist solution applied to the upper surface of the substrate. The drying rate of R is improved, and the reduced-pressure drying treatment can be performed in a shorter time.

In the third embodiment, the fourth rectifying member is divided into separate block members 103 and 104, and a space is formed below the stage 88. However, the block members 103 and 104 are divided into one. It may be formed of two block members (not shown) and fill the space below the stage 88.
Further, in the third embodiment, in the example shown in FIGS. 10 and 11, the air supply port 92 and the inert gas supply unit 97 (air supply means) as shown in the second embodiment. However, the air supply port 92 may be provided on the side of the substrate opposite to the exhaust port 101 with the substrate G interposed therebetween (such as near the outside of the block member 103 in FIG. 11).

  When the air supply port 92 and the inert gas supply unit 97 (air supply means) are provided, the exhaust port 101 and the air supply port 92 are formed in the block member 105 (fifth rectifying member) as shown in FIG. These may be arranged on the side of the substrate (near the substrate edge) with the substrate G interposed therebetween. FIG. 12 shows an example in which the fifth rectifying member is one block member 105 and the lower space of the stage 88 is filled, but the lower space of the substrate edge on the exhaust port 101 side and the air supply port 92 are shown. It suffices that at least the space below the side substrate edge is filled. That is, for example, the exhaust port 101 and the air supply port 92 may be formed in different block members (fifth rectifying members), and a space may be formed below the stage 88.

  Next, a fourth embodiment of a reduced pressure drying unit (VD) 46 to which the reduced pressure drying apparatus of the present invention is applied will be described with reference to FIGS. Note that in this fourth embodiment, common portions with the first to third embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 13 is a plan view of a vacuum drying unit (VD) 46 according to the fourth embodiment, and FIG. 14 is a cross-sectional view taken along the line CC in FIG.
In the fourth embodiment, the vacuum drying unit (VD) 46 is different from the second embodiment only in the rectifying means provided in the chamber.
That is, instead of the block member 102 shown in the second embodiment, as shown in FIGS. 13 and 14, at least the space below the substrate edge on the opposite side of the substrate G from the exhaust port 101 is filled. A block member 106 (sixth rectifying member) is provided as a rectifying means.
The block member 106 may be formed integrally with the lower chamber 85 or may be a separate member.

With this structure, as shown in FIG. 14, the inert gas supplied from the air supply port 92 does not flow below (and to the side) of the substrate G, but passes all over the substrate in one direction, and the exhaust port. It flows to 101.
Therefore, also in the fourth embodiment, the gas continues to flow at a uniform flow rate over the entire upper surface of the substrate G during the reduced-pressure drying process above the substrate, and as a result, the resist solution applied to the upper surface of the substrate. The drying rate of R is improved, and the reduced-pressure drying treatment can be performed in a shorter time.

  In the fourth embodiment, the example in which the air supply port 92 and the air supply means 97 are provided has been described. However, the present invention is not limited to this, and in FIGS. Even if it is the structure which does not comprise 92 and the air supply means 97, the effect of this invention can fully be acquired. That is, even without supplying air, only the exhaust process from the exhaust port 101 causes the gas in the chamber not to flow below (and to the side) of the substrate G, but to pass all the way above the substrate in one direction. It flows to 101. Therefore, even in that case, the drying speed of the resist solution R applied on the upper surface of the substrate can be improved, and the reduced-pressure drying process can be performed in a shorter time.

  Moreover, in the said 4th Embodiment, although the air supply port 92 showed the example provided in the bottom part of the lower chamber 85, in this invention, it is not limited to the structure. That is, it is only necessary to fill the space below the substrate edge on the air supply port 92 side. For example, the air supply port 92 is formed in the block member 106 (seventh rectifying member) as shown in FIG. The mouth 92 may be disposed in the vicinity of the substrate G.

Next, a fifth embodiment of a reduced pressure drying unit (VD) 46 to which the reduced pressure drying apparatus of the present invention is applied will be described with reference to FIGS.
The fifth embodiment is characterized in that, unlike the first to fourth embodiments described above, the stage holding the substrate G is configured to be able to move up and down. Portions common to the forms are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 16 is a plan view of a vacuum drying unit (VD) 46 according to the fifth embodiment. FIGS. 17 to 19 are cross-sectional views taken along the line CC of FIG. 16, respectively, and show a state in which the stage holding the substrate G is moved up and down to have different heights.
As shown in the figure, the lower chamber 85 of the vacuum drying unit (VD) 46 is provided with a plurality of exhaust ports 101 and one air supply port 92 below the substrate G with the substrate G sandwiched therebetween. ing.

Further, in order to supply a large amount of inert gas to the upper surface of the substrate G when supplying the inert gas from the air supply port 92, the stage 88 is disposed below the chamber as shown in FIG. In this state, the space below the substrate edge on the opposite side of the substrate G from the exhaust port 101 is filled with block members 107 and 108 (sixth rectifying members) as rectifying means.
Further, as shown in FIG. 16, side walls are formed on the left and right sides of the block members 107 and 108 on the left and right sides of the substrate G to suppress the flow of inert gas to the sides of the substrate. A member 109 (eighth rectifying member) is provided.
The side bar member 109 may be formed in a bar shape (or plate shape) as shown in the figure so as to block the space on the left and right sides of the substrate G, or on the left and right sides of the substrate G. It may be provided so as to fill the space.
Further, the side bar member 109 is formed to be longer than at least the length of the left and right sides of the substrate G in order to make it easy to form an air flow on the substrate G.
Here, as shown in the figure, the end portion (particularly the exhaust port 101 side) of the side bar member 109 may be provided without contacting the inner wall of the chamber. In this case, a part of the space on the left and right sides of the substrate G is blocked, but the flow of the inert gas to the sides of the substrate can be sufficiently suppressed.
Further, the configuration is not limited to the example shown in FIG. 16, and the side bar member 109 is formed in such a length that both end portions thereof are in contact with opposite chamber inner walls, and blocks (fills) all the left and right side spaces of the substrate G. It is good.

As shown in FIG. 17, the stage 88 that holds the substrate G can be moved up and down by an elevating device 99 (elevating means) configured by, for example, a ball screw mechanism using a motor as a drive source.
By providing the elevating device 99, when the substrate G is loaded / unloaded, the upper chamber 86 is raised and the chamber is opened, and the stage 88 is moved up to near the upper surface height of the lower chamber 85. In this state, the substrate G is loaded and unloaded from the stage 88 by the transfer arm 82, for example.

On the other hand, in the vacuum drying process, with the chamber closed, the stage 88 is first moved up to an upper position in the chamber by the drive of the lifting device 99 as shown in FIG.
Next, the vacuum pump 91 is operated, air in the processing space is sucked from the exhaust port 101, and the pressure in the processing space is reduced to a predetermined vacuum state. Here, the upper surface of the substrate G is close to the lower surface of the upper chamber 86, so that almost no atmosphere flows on the upper surface of the substrate G. As a result, the resist solution R formed on the substrate G is first naturally dried by decompression, and the generation of transfer marks and the like is suppressed.

Here, when the atmospheric pressure in the chamber reaches a predetermined value (for example, 400 Pa or less) or when a predetermined time elapses from the start of pressure reduction, the stage 88 is moved downward in the chamber as shown in FIG. Move down to the position and stop.
Next, an inert gas having a predetermined flow rate is supplied from the air supply port 92 into the chamber by driving the inert gas supply unit 97. Thereby, the airflow in the chamber is maintained even under a reduced pressure environment.

  Further, since the block members 107 and 108 and the side bar member 109 as the rectifying means are provided, the inert gas supplied from the air supply port 92 does not flow below and to the side of the substrate G, and the upper portion of the substrate. Flows in one direction to the exhaust port 101. As a result, the drying speed of the resist solution R applied on the upper surface of the substrate is improved, a reduced-pressure drying process is performed in a short time, and the drying state is made more uniform.

  As described above, according to the fifth embodiment, after the resist solution R on the substrate G is first naturally dried, the inert gas can be flowed at a uniform flow rate over the entire upper surface of the substrate G. Generation of transfer marks and the like in the film can be suppressed, and the dry state of the resist film can be made uniform.

  In the fifth embodiment, an example in which the air supply port 92 and the air supply means 97 are provided has been described. However, the present invention is not limited to this, and in FIGS. Even if it is the structure which does not comprise 92 and the air supply means 97, the effect of this invention can fully be acquired. That is, the gas in the chamber does not flow below (side) the substrate G, but passes through the substrate in one direction to the exhaust port 101 without performing the supply of air, only by the exhaust process from the exhaust port 101. And flow. Therefore, even in that case, the drying speed of the resist solution R applied on the upper surface of the substrate can be improved, and the reduced-pressure drying process can be performed in a shorter time.

In the first to fifth embodiments, as the exhaust ports, two exhaust ports 89 (first embodiment) or three exhaust ports 101 (second and third) below the substrate G are provided. The fourth and fifth embodiments are shown, but the number and arrangement (layout) are not limited.
Further, the exhaust port 101 is formed on the bottom surface of the processing space. However, the exhaust port 101 is not limited to this. The exhaust port 101 may be formed on the inner wall of the chamber, and the height of the substrate G on the side of the substrate G. If it is in the vicinity of the position, it may be formed slightly above the substrate G.
Furthermore, although the shape of the exhaust ports 89 and 101 has shown a perfect circle, it is not limited to this, Other shapes, such as a long hole and a square, may be sufficient.

In addition, although the example in which the air supply port 92 is formed on the bottom surface of the processing space is shown, the present invention is not limited thereto, and may be a height position below the substrate G (for example, the inner wall portion of the lower chamber 85). .
Alternatively, each of the exhaust ports 89 and 101 and the air supply port 92 may be a nozzle-type port instead of a hole provided in the chamber.

  In the first to fifth embodiments, the substrate G is carried in and out by the transport arm 82 with respect to the vacuum drying unit (VD) 46. However, the present invention is not limited to this. Thus, the reduced-pressure drying apparatus of the present invention can be applied to a structure for carrying in and out the substrate.

  Next, the vacuum drying apparatus according to the present invention will be further described based on examples. In this example, the effect was verified by actually performing an experiment using the reduced-pressure drying apparatus having the configuration shown in the above embodiment (first embodiment).

In this experiment, the reduced pressure drying unit (reduced pressure drying apparatus) having the configuration shown in FIG. 20 is used to perform the reduced pressure drying process, and the development process (90 sec) is performed. As a result, the flow rate of the gas formed on the substrate, The relationship between the vacuum drying time and the remaining film rate was verified (Example 1). Here, the remaining film ratio is a ratio (%) of the resist film thickness after development to the resist film thickness before development.
FIG. 20 shows a chamber structure of a vacuum drying unit provided with a U-shaped straightening plate, a block member, and a sidebar member, as in the above embodiment. Components corresponding to the members shown are denoted by the same reference numerals. 20A is a plan view of the lower chamber, and FIG. 20B is a cross-sectional view taken along the line DD. FIG. 20B also shows a chamber ceiling portion by the upper chamber.

  Further, as Comparative Example 1, as shown in the plan view of FIG. 21A and the cross-sectional view taken along the arrow D-D of FIG. Using a reduced-pressure drying unit supported by the pins 120 and having a gap between the substrate G and the stage, reduced-pressure drying treatment and development treatment were performed in the same manner as in Example 1. In this case, by supporting the substrate with the pins 120, the distance between the substrate and the chamber ceiling is 5 mm, which is smaller than in the case of Example 1 (15 mm).

  As Comparative Example 2, a U-shaped rectifying plate is provided as shown in the plan view of FIG. 22A and the DD arrow cross-sectional view of FIG. The reduced-pressure drying unit and the development processing were performed in the same manner as in Example 1 using a reduced-pressure drying unit having a structure in which the substrate G was placed on the stage. In Comparative Example 2, unlike the configuration of the reduced pressure drying unit of Example 1, the block member 95 and the side bar members 94 and 98 are not provided.

As a result of Example 1, a streamline trace of gas on the substrate at a pressure of 100 Pa and a flow rate of 11 L / min during vacuum drying is shown in the perspective sectional view of FIG. 23A, and the remaining film on the substrate after development processing The rate distribution is shown in FIG.
Further, as a result of Comparative Example 1, gas stream traces on the substrate at a pressure of 100 Pa and a flow rate of 11 L / min during vacuum drying are shown in the perspective sectional view of FIG. The distribution of the remaining film rate is shown in FIG.
Furthermore, as a result of Comparative Example 2, a streamline trace of gas on the substrate at a pressure of 100 Pa and a flow rate of 11 L / min during vacuum drying is shown in the perspective cross-sectional view of FIG. The distribution of the remaining film rate is shown in FIG.

  As shown in FIG. 23A, in Example 1, it was confirmed that a large amount of gas was flowing on the upper surface of the substrate. Further, as shown in FIG. 23 (b), the remaining film ratio after development was high evenly on the upper surface of the substrate. Further, the time required for the reduced-pressure drying treatment was as short as about 16 seconds.

  On the other hand, as shown in FIG. 24A, in Comparative Example 1, it was confirmed that the flow rate of the gas flowing on the upper surface of the substrate was small. This is because the substrate G is supported by the pins 120, the gap distance between the substrate G and the upper chamber 86 is small, a space is created below the substrate G, and the flow rate of the gas flowing under the substrate is large. It was. Moreover, many airflows were formed in the space on the left and right sides of the substrate G. Further, as shown in FIG. 24B, the remaining film ratio after development was low overall on the upper surface of the substrate and became non-uniform. Further, the time required for the reduced pressure drying treatment was about 28 seconds.

  Further, as shown in FIG. 25A, it was confirmed that in Comparative Example 2, the flow rate of the gas flowing on the upper surface of the substrate was increased as compared with Comparative Example 1. This is because there is no gap between the substrate G and the stage 88 and the space above the substrate G is widened. Moreover, many airflows were formed in the space on the left and right sides of the substrate G. For this reason, it was considered that the flow rate of the gas flowing on the substrate was smaller than that in Example 1. Further, as shown in FIG. 25B, the uniformity of the residual film ratio distribution after development was remarkably improved over the entire top surface of the substrate as compared with Comparative Example 1, but not as much as in Example 1. The time required for the drying under reduced pressure was about 21 seconds, which was about 7 seconds shorter than that of Comparative Example 1.

  As a result of the above examples, it was confirmed that according to the reduced pressure drying apparatus of the present invention, the drying time of the treatment liquid such as resist can be shortened and a uniform film thickness can be obtained.

Claims (8)

A reduced-pressure drying apparatus that performs a reduced-pressure drying process of the processing liquid on a substrate to be processed coated with a processing liquid to form a coating film,
A chamber for accommodating a substrate to be processed and forming a processing space;
A holding unit provided in the chamber and holding the substrate to be processed;
An exhaust port formed in the chamber;
Exhaust means for exhausting the atmosphere in the chamber from the exhaust port;
In the chamber, an air supply port formed on the upstream side of the airflow formed by the operation of the exhaust means and on the side of the substrate;
An air supply means for supplying an inert gas from the air supply port to a processing space in the chamber;
A rectifying unit provided in the chamber and forming a flow path of an airflow flowing in one direction on the upper surface of the substrate by an exhaust operation of the exhaust unit;
The reduced-pressure drying apparatus characterized in that the rectifying means is a rectifying member that fills at least the space below the periphery of the substrate to be processed held by the holding unit. The exhaust port is formed in the rectifying member,
The exhaust port is formed in the vicinity of the edge of the substrate to be processed held by the holding unit,
2. The rectifying member fills at least a space below the substrate edge on the exhaust port side and a space below the substrate edge on the opposite side of the exhaust port across the substrate. The vacuum drying apparatus described. The rectifying member is formed with the exhaust port and the air supply port,
The exhaust port and the air supply port are respectively formed in the vicinity of the periphery of the substrate across the substrate to be processed held by the holding unit,
2. The lower space of the substrate edge on the exhaust port side and the lower space of the substrate edge on the opposite side of the exhaust port with the substrate interposed therebetween are at least filled by the rectifying member. Reduced-pressure drying apparatus. The exhaust port is formed on a side of the substrate to be processed,
2. The reduced-pressure drying according to claim 1, wherein the flow straightening member fills at least a lower space of a substrate edge on the opposite side across the substrate to be processed held by the holding unit with respect to the exhaust port. apparatus. The exhaust port is formed on a side of the substrate to be processed,
The air supply port is formed in the rectifying member,
In the rectifying member, the air supply port is formed on the opposite side of the exhaust port across the substrate to be processed held by the holding unit,
The reduced-pressure drying apparatus according to claim 1, wherein at least a lower space of a substrate edge on the air supply port side is filled with the rectifying member. The reduced-pressure drying apparatus according to any one of claims 1 to 5, wherein a reduced-pressure drying method of forming a coating film by performing a reduced-pressure drying treatment of the treatment liquid on a substrate to be processed coated with the treatment liquid. There,
Holding the substrate to be processed in the holding unit;
A decompression drying method comprising: depressurizing a processing space in the chamber by the exhaust unit and supplying an inert gas into the chamber by the air supply unit. In the step of depressurizing the processing space in the chamber by the exhaust means and supplying an inert gas into the chamber by the air supply means,
The reduced-pressure drying method according to claim 6, wherein the supply of air into the chamber is started before or simultaneously with the start of the decompression in the chamber. In the step of depressurizing the processing space in the chamber by the exhaust means and supplying an inert gas into the chamber by the air supply means,
Starting to depressurize the processing space in the chamber;
Performing a step of supplying an inert gas into the chamber when the atmospheric pressure in the chamber is reduced and reaches a predetermined value, or when a predetermined time has elapsed from the start of pressure reduction in the chamber. The vacuum drying method according to claim 6.

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