JP2001319852A - Method and device for drying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve throughput by greatly shortening the time necessary for drying a coating liquid on a substrate. SOLUTION: First, a substrate B is put into a first chamber 10. When the substrate B is placed on a base 18, the evacuation (vacuuming) of the first chamber 10 is started. By placing the substrate BV in the space in the first chamber 10 whose pressure is gradually reduced from a normal pressure to a set pressure of a considerably low vacuum level for a predetermined period, solvent in the coating liquid on the substrate B is gradually and moderately evaporated and the evaporated solvent is discharged to the outside of the chamber. When pressure-reduced drying in the first chamber 10 is finished, a carrying unit 24, is operated to transfer the substrate B from the first chamber 10 to a second chamber 12 through a substrate transfer opening 28 in the open state. In the second chamber 12, the substrate B subjected to drying of a predetermined step by reducing the pressure in the first chamber 10 is continuously subjected to pressure-reduced drying in the space whose pressure is reduced to a higher vacuum level and is heated at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a technique for drying a coating solution applied on a substrate to be processed, and more particularly to a method and an apparatus for performing a drying process in a reduced-pressure space.

[0002]

2. Description of the Related Art A vacuum drying process of this kind is performed, for example, in a photolithography process for manufacturing a liquid crystal display (LCD) or a semiconductor device.
This is performed to dry a resist solution applied on a semiconductor wafer). Usually, a substrate coated with a resist solution by a spin coating method or the like is carried into a sealable chamber, and the chamber is evacuated or evacuated at room temperature to a reduced pressure state. The resist solution is dried. In addition, for example, an interlayer insulating film in a multilayer wiring structure of a semiconductor device is formed by SOG.
(Spin On Glass) In the step of forming by the coating method, a similar reduced-pressure drying method can be used to dry the SOG solution applied on the substrate.

[0003] According to such a reduced-pressure drying method, since the solvent in the coating liquid gradually evaporates, distortion, voids and the like hardly occur in the coating film, and good film quality can be obtained.

[0004]

However, in the conventional vacuum drying method, it takes a considerable time (evacuation time) from the loading of the substrate into the chamber to the formation of a reduced pressure space of a required pressure. The processing time is long and it is difficult to increase the throughput. Further, it is difficult to obtain sufficient adhesion between the substrate and the coating film only by drying under reduced pressure. Therefore, after the drying under reduced pressure, the substrate is transferred to a heating device (oven), where the substrate is subjected to a heating process (baking) to further dry the coating liquid and improve the adhesion to the substrate. After all, in order to obtain a desired coating film on the substrate, drying under reduced pressure is not enough, and a drying process by baking is required as a post-process.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and provides a drying method and a drying apparatus capable of greatly shortening a time required for a drying process for a coating solution on a substrate to improve throughput. The purpose is to provide.

Another object of the present invention is to provide a drying method and a drying apparatus capable of drying a coating solution applied on a substrate to be processed stably and satisfactorily in a short time to form a high quality coating film. The purpose is to do.

[0007]

Means for Solving the Problems To achieve the above object, a drying method of the present invention is a drying method for drying a coating solution containing a volatile solvent applied on a substrate to be processed, A first step of placing the substrate in a first depressurized space and volatilizing a predetermined amount of a solvent in the coating solution; and after the first step, substantially removing the solvent from the first depressurized space. A second step of placing the substrate in an independent second reduced-pressure space and heating the same to further volatilize a predetermined amount of the solvent in the coating solution.

In the present invention, in the first step,
By subjecting the substrate to a drying treatment only under reduced pressure, the solvent is gently volatilized from the coating solution on the substrate. Therefore, the degree of vacuum of the first decompression space may be relatively low, and
May be started from normal pressure.

[0009] In the next second step, the substrate is substantially independent of the first reduced-pressure space and preferably on the substrate in the second reduced-pressure space having a lower pressure (higher degree of vacuum) than the first reduced-pressure space. By applying reduced pressure drying to the coating solution and heating at the same time,
The volatilization of the solvent from the coating liquid is immediately accelerated, and the coating liquid is dried in a short time, and a coating film having good adhesion to the substrate is formed. At this time, the coating liquid on the substrate has already been dried to a certain stage by the reduced pressure drying in the first step, and the second step is also subjected to the reduced pressure drying. However, distortion, voids, movement of the coating liquid, and the like hardly occur in the coating film, and good film quality can be obtained. In the second decompression space, a decompression state with a predetermined degree of vacuum can be prepared before the substrate is loaded.

[0010] In the present invention, in order to ensure the continuity or continuity of the reduced pressure drying treatment in the first and second steps, normal pressure or positive pressure is applied between the first reduced pressure space and the second reduced pressure space. Preferably, no pressure space is interposed.

One aspect of the apparatus configuration for satisfying the requirement of the continuity of the decompression space is to make the first and second decompression spaces adjacent to each other via a gate mechanism and to pass through the gate mechanism in an open state. In this configuration, a substrate transfer unit for transferring a substrate is provided in the first or second reduced pressure space. In such a configuration, after the first step is completed, it is possible to open the gate mechanism and move the substrate from the first reduced pressure space to the second reduced pressure space through the gate mechanism. The transition time from the process to the second process can be shortened.

Another aspect of the device configuration for satisfying the requirement of the continuity of the decompression space is that the device is adjacent to the first decompression space via the first gate mechanism and is connected to the second via the second gate mechanism. A third chamber capable of decompression is provided adjacent to the decompression space, and the substrate is carried out of the first decompression space through the first gate mechanism in an open state into the third chamber, and a second chamber in an open state is provided. This is a configuration in which a substrate transfer unit that carries the substrate into the second reduced-pressure space through the gate mechanism is provided. In such a configuration,
After the first step, the first gate mechanism is opened to transfer the substrate from the first reduced-pressure space to the third reduced-pressure space through the first gate mechanism, and then the second gate mechanism is opened. Then, the substrate can be transferred from the third reduced-pressure space to the second reduced-pressure space through the second gate mechanism.

In this aspect, since the two processing spaces (the first and second decompressed spaces) can be always separated by the third decompressed space, the space between the two process spaces (usually from the first decompressed space to the second depressurized space) The flow of particles and contamination into the decompression space can be reliably prevented. Further, the substrate is carried into the first reduced-pressure space via the third reduced-pressure space before the start of the first step, and is transferred from the second reduced-pressure space via the third reduced-pressure space after completion of the second step. The substrate can be unloaded.

In the present invention, the first and second reduced-pressure spaces do not necessarily need to be present at the same time. While one reduced-pressure space acts on the substrate, the other reduced-pressure space does not exist. Is also good. In addition, the first and second reduced-pressure spaces do not necessarily need to be spatially separated or blocked, and thus need not necessarily be formed in separate processing chambers or chambers. For example, the first and second reduced pressure spaces can be formed in different locations in the same chamber.

[0015]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows a configuration of a drying apparatus according to an embodiment of the present invention. The drying device comprises two process chambers or chambers 10, 1 which can be closed or decompressed.
2 is attached. Both chambers 10 and 12 have side walls 14.
And a gate valve 16 adjacent to each other.

In the first chamber 10, a substrate support or a support plate 18 is provided. On the support 18, a substrate (for example, an LCD substrate or a semiconductor wafer) B
Is to be placed. Normally, a large number of support pins 20 are discretely mounted on the surface or upper surface of the support base 18, and the substrate B is placed so as to be carried by these support pins 20. The support base 18 is also provided with a plurality of, for example, four lift pins 22 that can carry the substrate B and move up and down. An elevating drive unit (not shown) provided inside or below the support base 18 drives these lift pins 22 up and down.

In the first chamber 10, a support 18
A substrate transfer device 24 is provided between the side wall 14 and the side wall 14. The transfer arm 26 of the transfer device 24 is configured to be able to move up, down, rotate, and expand and contract, and can access a substrate transfer position set above the support table 18 in the chamber 10 for transfer of the substrate B. When the gate valve 16 is open, the second chamber 12 passes through a substrate loading / unloading opening (opening) 28 formed in the side wall 14.
It can access to the substrate transfer position in the inside.

In the first chamber 10, a substrate carrying inlet (opening) 32 and a gate valve 34 for opening and closing the same are provided on a side wall 30 different from the side wall 14 on the second chamber 12 side. With the gate valve 34 open, a transfer arm (not shown) of an external substrate transfer device loads the substrate B into the chamber 10 through the substrate transfer port 32.

The first chamber 10 is provided with an exhaust port 36 connected to or connected to a first vacuum exhaust system (not shown), for example, on the bottom surface. In addition, a pressure sensor 38 for measuring the indoor air pressure is provided.
The output signal (pressure measurement signal) S1 of the sensor 38 is sent to a controller (not shown). Under the control of the controller, the first evacuation system evacuates the chamber 10 to a predetermined degree of vacuum to form a decompression space in the room.

A gas supply pipe 40 for supplying an inert gas into the chamber is connected to the first chamber 10.
When the inside of the chamber 10 is returned to the normal pressure, an inert gas such as N2 gas from an inert gas supply unit (not shown) is supplied into the room through the gas supply pipe 40 as a purging gas. .

A support table or a support member 42 is provided in the second chamber 12, and the hot plate 4 is placed on the support table 42.
4 are installed. The heating plate 44 is made of a material having a high thermal conductivity, for example, aluminum, and incorporates a heating element, for example, a resistance heating element (not shown) made of molybdenum, tungsten, or the like, and a utility unit 46 inside or below the support base 42. Is supplied with power from a power supply unit (not shown) provided in the power supply unit and generates heat at a set temperature. In order to control the heat generation temperature of the heating plate 44 in a feedback manner, a temperature sensor (not shown) for detecting the temperature of the heating plate 44 or a temperature in the vicinity thereof may be provided.

The hot plate 44 has a plurality of through holes (not shown).
Are formed discretely at predetermined intervals so that the lift pins 48 can be moved up and down through the respective through holes. The lower end of the lift pin 48 is connected or connected to and supported by an elevating drive unit (not shown) provided in the utility unit 46 inside or below the support base 42. By the lifting drive and support of the lifting drive unit, the lift pins 48 can be moved to arbitrary heights within predetermined upper and lower limits (ranges) set above the hot plate 44 with the substrate B held substantially horizontally on the pins. And can be moved up and down, and can be stopped at any height.

As described above, in the second chamber 12, the height position of the substrate B just above the hot plate 44 that generates heat at a constant temperature,
That is, the heating temperature for the substrate B can be variably controlled by variably controlling the distance h between the hot plate 44 and the substrate B by the lift pins 48 and the elevation drive unit.

In the second chamber 12, a substrate outlet (opening) 52 and a gate valve 54 for opening and closing the substrate outlet 52 are provided on a side wall 50 different from the side wall 14 on the first chamber 10 side. With the gate valve 54 opened, the transfer arm (not shown) of the external transfer device is moved to the substrate transfer port 5.
2, the substrate B is carried out of the chamber 12.

The second chamber 12 is also provided, for example, on the bottom surface with an exhaust port 56 connected or connected to a second vacuum exhaust system (not shown). A pressure sensor 58 for measuring the indoor air pressure is also provided, and the sensor output (pressure measurement signal) S2 is sent to the controller. Under the control of the controller, the second evacuation system evacuates the second chamber 12 to a predetermined degree of vacuum to form a decompression space in the room.

Normally, the pressure in the reduced pressure space in the second chamber 12 where the next drying step is performed is lower (higher) than the pressure in the reduced pressure space in the first chamber 10 where the first drying step is performed. (Degree of vacuum). For example, when a resist solution is dried as a coating solution, the pressure in the reduced pressure space in the first chamber 10 is set to about ¹ Torr, and the pressure in the reduced pressure space in the second chamber 12 is set to about 10 ^-1 Torr. May do it. When the coating liquid is an SOG solution, for example, the pressure in the reduced pressure space in the first chamber 10 is set to several Torr.
The pressure in the reduced pressure space in the second chamber 12 may be set to around 10 ⁻³ Torr.

The second chamber 12 is also connected to a gas supply pipe 60 for supplying an inert gas into the chamber.
When the inside of the chamber 10 is returned to normal pressure after the processing, or during the processing, an inert gas such as an N 2 gas from an inert gas supply unit (not shown) is supplied into the chamber 12 through the gas supply pipe 60. It has become. Also, the second chamber 12
In addition to the heating of the substrate B, a reactive gas such as O2 gas or H2 gas can be supplied from another reactive gas supply pipe 61 as needed.

The controller cooperates with the operation of an external processing device or a transfer device, and controls various parts in the drying device, particularly, the respective components of the transfer system (gate valves 16, 34, 54, transfer device 24, lift pins 22, 48, and Components such as the elevation drive unit), pressure system components (first and second evacuation systems, inert gas supply units, reactive gas supply units, etc.), and heating system components (heat generation unit of the hot plate 44, lift pins 48 and its lifting drive).

Next, the operation of the drying apparatus will be described.

First, the substrate B to be processed is placed in the first chamber 10.
It is carried in. Immediately before this substrate B to be carried in, a coating liquid is applied to the entire surface of the substrate by a coating apparatus (not shown) to a constant thickness by, for example, an ordinary coating process, for example, a spin coating method.

When the substrate B is loaded, the interior of the first chamber 10 is filled with an inert gas (purging gas) and maintained at normal pressure. The gate valve 34 is opened, and the transfer arm of the external transfer device holds the substrate B while the chamber 10 is held.
And the substrate B is set above the support base 18. Then, the lift pins 22 move up to receive the substrate B from the transfer arm. After the transfer arm exits, the lift pins 22 descend to place the substrate B on the support base 18. On the other hand, the gate valve 34 is closed, and the inside of the first chamber 10 becomes a closed space.

When the substrate B has been placed on the support 18, the first vacuum pumping system starts pumping (evacuating) the first chamber 10 under the control of the controller. In this evacuation, the pressure in the chamber may be continuously or monotonously reduced from a normal pressure to a set value, or may be gradually reduced.

Thus, the solvent in the coating liquid on the substrate B is gradually placed in the first chamber 10 by placing the substrate B in the space where the pressure is gradually reduced from the normal pressure state to a relatively low set pressure. And volatilizes gently, and the evaporated solvent is discharged outside the room. Here, in the initial stage of the drying under reduced pressure, gas is released from the surface of the substrate B. In the initial stage of evacuation, gas is also released from the inner wall of the first chamber 10 and the like. These outgasses are also discharged outside the room by the first evacuation system.

When a predetermined time t1 has elapsed since the start of evacuation, the reduced-pressure drying process in the first chamber 10 ends. At this point, the coating solution on the substrate B has been dried to a certain stage. The degree of drying or the volatilization amount of the solvent in the reduced-pressure drying treatment depends on the type of the resist solution, but can be adjusted by parameters such as the treatment time t1 and pressure. 3
It may be dried to the extent of 0%.

When the reduced-pressure drying process in the first chamber 10 is completed as described above, the lift pins 22 are lifted to lift the substrate B to a predetermined height while maintaining the horizontal posture. Immediately after this, the transfer device 24 in the same room operates,
The transfer arm 26 is extended below the substrate B supported by the lift pins 22, and receives the substrate B from the lift pins 22. On the other hand, the gate valve 16 opens.

The transfer arm 26 carries the substrate B into the second chamber 12 through the substrate entrance 28 in the open state.
The substrate B is set directly above the hot plate 44 at a predetermined height position. Immediately thereafter, the lift pins 48 move up to receive the substrate B from the transfer arm 26. The transfer arm 26 having passed the substrate B withdraws from the second chamber 12, and immediately after that, the gate valve 16 closes. After the gate valve 16 is closed,
In the first chamber 10, the evacuation by the first evacuation system is stopped, and purging gas (inert gas) is supplied from the gas supply pipe 40 into the room. As a result, the inside of the chamber of the chamber 10 is released from the reduced pressure state, and is changed to the normal pressure space.

The interior of the second chamber 12 is maintained at a predetermined degree of vacuum, for example, around 10 ⁻² Torr before the substrate B is loaded. When the substrate B is carried in, the gate valve 16 is opened as described above and the first chamber 10 is temporarily stopped.
Therefore, the pressure in the second chamber 12 increases. This change in pressure is detected by the pressure sensor 58 and is immediately corrected by the second evacuation system under control of the controller. Thus, in the second chamber 12, the drying under reduced pressure can be started at a predetermined degree of vacuum immediately after the substrate B is loaded.

On the other hand, in the second chamber 12, the substrate B
The heating plate 44 maintains a heat-generating state at a predetermined temperature before the carry-in. Therefore, thermal energy can be supplied to the substrate B immediately after the loading.

The lift pins 48 can move up and down as described above, and can support the substrate B at an arbitrary height within a predetermined range while maintaining the substrate B in a horizontal posture. Normally, a height position at which the substrate B is received from the transfer arm 26 or another predetermined height position may be set as the initial position. At this initial position, the temperature at which the substrate B is heated by the hot plate 44 immediately below is the initial heating temperature. Becomes

The lift drive unit in the second chamber 12 continuously (monotonously) or stepwise with the passage of time under the control of the controller while holding the substrate B in a horizontal position on the lift pins 48. Is lowered. As the lift pins 48 move down, the height position of the substrate B on the lift pins 48 decreases continuously (monotonically) or stepwise with the lapse of time, so that the distance h between the substrate B and the hot plate 44 decreases. The heating temperature for the substrate B increases.

Thus, in the second chamber 12,
With respect to the substrate B that has been subjected to the reduced-pressure drying process to a certain stage in the first chamber 12, the reduced-pressure drying process is continued in a reduced-pressure space with a higher degree of vacuum, and at the same time, the heating process is performed. As a result, the solvent volatilized in earnest from the coating liquid on the substrate B, and the coating liquid dries in a short time,
A coating film (coating) is formed.

At this time, the coating solution on the substrate B has been dried to a certain stage by the reduced pressure drying process in the first chamber 10, and the reduced pressure drying process is continued in the second chamber 12. Therefore, even if thermal stress due to heating acts on the coating film, distortion, voids, movement of the coating solution, and the like in the film hardly occur.

Further, if the coating liquid on the substrate B is heated immediately without drying under reduced pressure, there is a problem that marks such as lift pins and support pins are formed on the dried coating film. However, according to the present invention, since the reduced pressure drying processing without heating is performed in the first chamber 10 as the first processing for the coating liquid, it is possible to prevent the generation of such pin marks.

The outgassing from the surface of the substrate B is performed in the first
The decompression drying in the second chamber 12 is almost exhausted, and degassing in the second chamber 12 under reduced pressure drying is scarce or not at all. In addition, since the inside of the second chamber 12 has been evacuated (evacuated) before the loading of the substrate B, degassing hardly occurs from the inner wall surface and each part of the room during the processing. Therefore, the substrate B can be subjected to a reduced pressure and a heat drying process in a clean reduced pressure space with few particles and contamination.

A predetermined time t2 after the loading of the substrate B is completed.
After this, the drying process in the second chamber 12 ends. At this point, the coating solution on the substrate B has been further dried to a predetermined stage. In addition, since it is heated and dried, it adheres well to the substrate B. The degree of drying or the volatilization amount of the solvent in the drying under reduced pressure and the heat treatment depends on the type of the coating liquid and the arrival of the drying in the first chamber 10 and the like. And may be dried, for example, to a desired ultimate dryness. In that case, a further drying process (baking) with a dedicated heating device can be made unnecessary. However, it is also possible to finish the drying process in the chamber 10 during the drying (for example, about 80% of the ultimate dryness) and then dry the chamber 10 to the ultimate dryness by baking in a dedicated heating device.

In addition, depending on the type of the coating film, for example, in the case of SOG made of a silanol compound, the drying process in the second chamber 12 does not always evaporate the solvent, but also under a predetermined temperature condition. It is also possible to condense or polymerize the coating film. In such a condensation or polymerization reaction, the reduced pressure space in the chamber 12 may be filled with an inert gas in order to prevent an undesired reaction such as an oxidation reaction on the surface of the coating film.

Alternatively, in the case of a silica-based film used as an interlayer insulating film or the like, a predetermined temperature, for example, 300 ° C.
Thus, an atmosphere can be formed with oxygen or water vapor supplied from the reactive gas supply pipe 16, and a coating film on the substrate B can be oxidized to obtain a desired film.

When the drying under reduced pressure and the heat treatment in the second chamber 12 are completed, the substrate B is carried out of the room.
When a decompression space, for example, a third chamber (or chamber) is provided next to (outside) the side wall 50, the gate valve 54 is opened immediately, and an external transfer device (not shown) is inserted into the chamber 12. The substrate B may be accessed to receive the substrate B from the lift pins 48 and carry it out to the third chamber. When the space next to (outside) the side wall 50 is a space of normal pressure, the evacuation by the second evacuation system is stopped, and the inert gas is supplied from the inert gas supply pipe 60 into the chamber 12 as a purging gas. And the gate valve 54 is opened after the decompression state in the room is released, and an external transfer device may carry the substrate B out of the room. After the substrate B is taken out of the room, the gate valve 54 is closed, the evacuation by the second evacuation system is restarted, and the reduced pressure space in the chamber 12 is regenerated.

However, as shown in FIG. 2, an apparatus may be provided in which a third chamber 62 is provided between the first and second chambers 10 and 12. In this device configuration, the third chamber 6
The substrate transfer device 64 may be installed in the two processing chambers 1.
There is no need to place a transport system in 0,12. Third room 62
Is adjacent to the first and second chambers 10 and 12 via gate valves 68 and 70, respectively, and is adjacent to another processing chamber or transfer space (not shown) via the gate valve 72. The exhaust port 74 of the third chamber 62 is connected to a third evacuation system, and the inside of the chamber 62 is depressurized to a predetermined degree of vacuum separately from the chambers 10 and 12. Also,
In the third chamber 62, a purging gas for adjusting the pressure of the chamber to normal pressure is supplied from a gas supply pipe 76 as necessary.

In this apparatus configuration, first, the substrate B is passed from the outside through the gate valve 72 in the open state to the third chamber 62.
It is carried in. Next, the gate valve 68 is opened and the third
The transfer device 64 installed in the chamber 62 carries the substrate B into the first chamber 10. In the first chamber 10, the same reduced-pressure drying process as described above is performed. When the drying process is completed, the gate valve 68 is opened, and the transfer device 64 in the third chamber 62 unloads the substrate B from the chamber 10. After the substrate B is carried into the third chamber 62, the gate valve 68
At the same time (preferably immediately after) the gate valve 7 is closed.
0 is opened, and the transfer device 64 transfers the substrate B to the second chamber 12.
Carry in. In the second chamber 12, the same vacuum drying and heating as described above are performed. After the completion of the drying process, the gate valve 70 is opened, and the transfer device 64 unloads the substrate B from the chamber 12. Thereafter, the gate valve 72 is opened, and the substrate B is carried out of the third chamber 62 to the outside. The gate valves 68, 70, 72 in the third chamber 62 need not be open at the same time, and all of the other gate valves may be closed when one of them is open.

Thus, the first and second chambers 1
In the apparatus configuration in which the third chamber 62 is provided between 0 and 12, both chambers 10 and 1 are provided by the reduced pressure space of the third chamber 62.
2 can always be separated from each other, so that both chambers 1
0,12 (usually from chamber 10 to chamber 12
) Can be reliably prevented from flowing particles and contamination. Further, the substrate B before the drying process is carried into the first chamber 10 via the third chamber 62,
The processed substrate B is transferred from the second chamber 12 to the third chamber 6.
2 can be carried out via both chambers 1
It is also possible to always maintain the decompressed state in the rooms 0 and 12.

Since the substrate B is placed in the reduced pressure space while the substrate B is transferred from the first chamber 10 to the second chamber 12 through the third chamber 62, strictly speaking, the first chamber 1
The vacuum drying process at 0 is continued or extended during the transfer. Therefore, the pressure in the third chamber 62 is, for example, an intermediate value between the pressures in the two chambers, that is, a value lower than the pressure in the depressurized space of the first chamber 10 and higher than the pressure in the depressurized space of the second chamber 12. May be set to

Next, a coating and developing system to which a coating apparatus according to an embodiment of the present invention is applied will be described with reference to FIGS.

FIG. 3 shows the configuration of the coating and developing system. This coating and developing system is, for example, an LCD
The substrate is a substrate to be processed, and cleaning, resist coating, drying, development, and post-baking are performed in a photolithography step in an LCD manufacturing process. The exposure processing is performed by an external exposure apparatus (not shown) installed adjacent to this system.

This coating and developing system is roughly composed of a cassette station (C / S) 100, a process station (P / S) 102, and an interface unit (I / F) 104.

A cassette station (C / S) 100 installed at one end of the system includes a cassette stage 106 on which a predetermined number of, for example, four cassettes C accommodating a plurality of LCD substrates B can be placed, and this stage 106 And a sub-arm mechanism 108 for loading and unloading the substrate B with respect to the upper cassette C. This sub arm mechanism 108
Has a transfer arm capable of holding the substrate B, and has X, Y,
It can operate on four axes of Z and θ, and a transfer device 132 and a substrate B on the process station (P / S) 102 side described later.
Can be delivered.

Process station (P / S) 102
Are a cleaning process unit 110 and a coating process unit 112 in order from the cassette station (C / S) 100 side.
And a developing process unit 114 are provided in a horizontal line (sandwiching) via a substrate relay unit 116, a chemical solution supply unit 118 and a space 120.

The cleaning process unit 110 includes two scrubber cleaning units (SCR) 122, upper and lower ultraviolet irradiation / cooling units (UV / COL) 124, a heating unit (HP) 126, and a cooling unit (COL). 128
And

The coating unit 112 includes a resist coating unit (CT) 134 and a drying unit (VD) 136.
, An edge remover unit (ER) 138, and an upper / lower two-stage adhesion / cooling unit (AD / COL)
140, a cooling unit (COL) 142, and a heating unit (HP) 144. Drying unit (V
D) 136 is a drying device according to an embodiment of the present invention, the details of which will be described later.

The development processing section 114 includes three development units (DEV) 150, two upper and lower two-stage heating / cooling units (HP / COL) 152, and a heating unit (H
P) 154.

At the center of each of the process units 110, 112, and 114, transport paths 130, 146, and 156 are provided in the longitudinal direction, and the main transport units 132, 148, and 158 move along the transport paths and Each unit in the unit is accessed to carry in / out or carry in the substrate B. In this system, each process unit 11
At 0, 112, 114, the transport paths 130, 146,
156 has a spinner-based unit (SCR, C
T, DEV, etc.) and a heat treatment system unit (HP, COL, etc.) is arranged on the other side.

The interface unit (I / F) 104 installed at the other end of the system includes a process station (P)
An extension (substrate transfer section) 159 and a buffer stage 160 are provided on the side adjacent to the (/ S) 102, and a transport mechanism 162 is provided on the side adjacent to the exposure apparatus.

FIG. 4 shows a processing procedure in this coating and developing system. First, the cassette station (C
/ S) 100, the sub arm mechanism 108 selects one substrate B from the predetermined cassette C on the stage 106.
Is taken out and transferred to the main transfer device 132 of the cleaning process section 110 of the process station (P / S) 102 (step S1).

In the cleaning process section 110, the substrate B
First, an ultraviolet irradiation / cooling unit (UV / COL) 1
24, and the first ultraviolet irradiation unit (U
In V), dry cleaning is performed by ultraviolet irradiation, and the next cooling unit (COL) cools to a predetermined temperature (step S2). This ultraviolet cleaning mainly removes organic substances on the substrate surface.

Next, the substrate B is placed in the scrubber cleaning unit (S
(CR) 122 is subjected to a scrubbing cleaning process to remove particulate dirt from the substrate surface (step S).
3). After the scrubbing cleaning, the substrate B undergoes a dehydration process by heating in the heating unit (HP) 126 (step S4), and is then cooled to a constant substrate temperature in the cooling unit (COL) 128 (step S5). This completes the pretreatment in the cleaning process unit 110, and the substrate B is
The main transfer device 132 transfers the substrate to the coating process unit 112 via the substrate transfer unit 116.

In the coating process section 112, the substrate B
First, the adhesion / cooling unit (AD / CO
L), the first adhesion unit (AD) undergoes a hydrophobizing treatment (HMDS) (step S6), and is cooled to a constant substrate temperature in the next cooling unit (COL) (step S7). ).

Thereafter, the substrate B is coated with a resist solution in a resist coating unit (CT) 134 and then subjected to a drying process according to the present invention in a drying unit (VD) 136.
Next, an unnecessary (unnecessary) resist on the periphery of the substrate is removed by the edge remover unit (ER) 138 (step S8).

Next, the substrate B is provided with a cooling unit (HP / C
(OL) 142, where it is cooled to a certain substrate temperature (step S9). However, if necessary,
Baking can be performed by the heating unit 144 before the cooling process.

After the above coating process, the substrate B is transferred to the main transfer device 148 of the coating process unit 112 and the developing process unit 114.
Interface unit (I /
F) The wafer is conveyed to 104, from which it is transferred to the exposure apparatus (step S10). In the exposure apparatus, a predetermined circuit pattern is exposed on the resist on the substrate B. Then, the substrate B that has been subjected to the pattern exposure is returned to the interface unit (I / F) 104 from the exposure apparatus. Interface (I /
The transport mechanism 162 of F) 104 transfers the substrate B received from the exposure apparatus to the development processing unit 112 of the process station (P / S) 102 via the extension 158 (step S10).

In the developing process section 114, the substrate B
Is subjected to a developing process in one of the developing units (DEV) 150 (step S11), and then is sequentially carried into one of the heating / cooling units (HP / COL) 152. In the first heating unit (HP), Post-baking is performed (step S12), and then the substrate is cooled to a constant substrate temperature by a cooling unit (COL) (step S13). A heating unit (HP) 154 can be used for this post-baking.

The substrate B that has undergone a series of processes in the developing process section 114 is processed by a process station (P / S) 102.
It is returned to the cassette station (C / S) 100 by the main transfer devices 158, 148, and 132 therein, where it is accommodated in any one of the cassettes C by the sub arm mechanism 108 (step S1).

FIG. 5 shows a resist coating unit (CT) 134 and a drying unit (V) in the coating process section 112.
D) 136 and Edge Remover Unit (ER) 1
38 shows the configuration of the main part of the system. Drying unit (VD) 136
1 is basically the same as the configuration in FIG. 1, and thus, portions having the same configuration or function as those in FIG. 1 are denoted by the same reference numerals.

The drying unit (VD) 136 is different from the apparatus configuration of FIG. 1 in that the gate valve 54 for carrying out the substrate on the side wall 52 of the second chamber 12 is omitted, and the A gate valve 170 for carrying out the substrate is provided on the side wall 168, and a support table or stage 172 for temporarily holding the processed substrate B in the first chamber 10 when passing the same to the main transfer device 148 is provided. That is, it is provided in one chamber 10.

The resist coating unit (CT) 134
A spin chuck 174 that holds the substrate B in a substantially horizontal posture and rotates together or integrally;
4 and a rotatable bottomed cylindrical rotating cup 176 surrounding the periphery of the substrate B on the chuck, and a lid (not shown) capable of closing the upper end opening of the rotating cup 176
A fixed installation type drain cup 178 surrounding the outer periphery of the rotating cup 176; and a resist supply mechanism 180 for discharging and supplying a resist liquid to the surface (upper surface) of the substrate B.
And a transport device (not shown) that transports the substrate B after the coating process to the drying unit (VD) 136 via the gate valve 34.

Edge remover unit (ER) 138
A stage 182 for mounting and supporting the substrate B, alignment means 184 for positioning the substrate B at a pair of corners, and removing excess resist from the four sides of the substrate B (edges). Four remover heads 186 and the like are provided.

The processing units 134, 136, 1
The series of processing at 38 is as follows. FIG.
, Reference numerals B, 1 representing a substrate and a main transfer device.
A number or number (n) in parentheses attached after 48 indicates the order of movement of each position in this series of processing.

First, the main transfer device 148 (1) unloads the substrate B (1) subjected to the hydrophobic treatment from the adhesion / cooling unit (AD / COL) 46 (FIG. 3), and the transfer path 146 side Then, the substrate B (1) is carried into the resist coating unit (CT) 134 as shown by the arrow.

In the resist coating unit (CT) 134, the spin chuck 174 rotates at a predetermined speed while holding the substrate B (2) in a horizontal state, and the lid is first retracted, and the rotary cup 176 is opened. The nozzle unit 182 of the resist supply mechanism 180 moves to a position directly above the substrate B (2) in a state where the resist liquid is ejected (drops) on the upper surface of the substrate B (2). After retreating from the top of B (2), the rotating cup 176 also rotates with the lid closing the top opening of the cup, and the resist solution spreads evenly over the entire surface of the substrate B (2) by centrifugal force. .

When the resist coating step by the spin coating method as described above is completed in the resist coating unit (CT) 134, the gate valve 34 is opened, and the transfer device in the unit (CT) 134 is opened as shown by the arrow. Substrate B that has been coated through gate valve 34
(2) First chamber 1 of drying unit (VD) 136
Carry in 0.

In the first chamber 10, the substrate B (3) may be subjected to the same reduced pressure drying process as in the apparatus configuration of FIG. When the drying process in the first chamber 10 is completed, as in the case of the apparatus configuration in FIG.
The transfer device 24 in the first chamber 10 carries the substrate B (3) into the adjacent second chamber 12 through the gate valve 16 in the open state as shown by the arrow.

In the second chamber 12, the substrate B (4)
The same vacuum drying and heat treatment as in the apparatus configuration of FIG. 1 may be performed. Processing conditions (pressure, temperature, time, supply gas, etc.) may be set to appropriate values according to the type of the resist solution and the like. When the baking (pre-bake) in the heating unit (HP) 144 is omitted, the coating liquid on the substrate B (4) may be dried in the second chamber 12 to a desired ultimate dryness. In this case, since the heating in the second chamber 12 is performed simultaneously with the drying under reduced pressure, the heating temperature can be set lower than the heating temperature when baking is performed by the dedicated heating device (144). Thereby, it is also possible to reduce the striation (a kind of wrinkle) on the resist surface due to the heat treatment, and it is possible to improve the distortion of the pattern shape after the exposure / development process due to such striation. .

When the drying process in the second chamber 12 is completed, the gate valve 16 is opened, and the transfer device 24 in the first chamber 10 is opened from the second chamber 12 as shown by the arrow. Substrate B through
(4) is picked up, and the substrate B (5) is placed on the support 172 in the chamber 10.

Thereafter, the gate valve 170 facing the transport path 146 is opened, and the main transport device 14 is opened from the transport path 146 side.
8 (2) draws the substrate B (5) from the support 172 through the gate valve 170 in the open state as indicated by the arrow. Then, the main transfer device 148 (2) moves to the right side of FIG. 5 on the transfer path 146 as indicated by an arrow while supporting the picked-up substrate B (6) in a horizontal state, and moves to the adjacent edge remover unit ( ER) 138 and the unit (ER) 138 from the side of the transport path 146 as shown by the arrow.
The substrate B (7) is carried into the inside.

Edge remover unit (ER) 138
In the state where the alignment means 184 positions the substrate B (8) on the stage 182, each remover head 18
While the substrate 6 moves along each side of the substrate B (8), excess resist adhering to the peripheral edge of each side of the substrate is dissolved and removed with a thinner.

Edge remover unit (ER) 138
When the resist removal process in the step
The main transfer device 148 (3) on the side transfers the substrate B (8) to the unit (E
R) Unload from 138. Next, the main transfer device 148
(3) transports the substrate B (8) to the cooling unit (COL) 142 on the opposite side.

As described above, the substrate B coated with the resist solution by the resist coating unit (CT) 134 is subjected to two-stage and substantial processing in the two chambers 10 and 12 of the drying unit (VD) 136 according to the present invention. Subject to continuous drying. More specifically, the coating liquid on the substrate B is dried in a reduced pressure space having a relatively low degree of vacuum in the first stage of the drying process in the first chamber 10, and is dried in the second stage 10 in the second stage 10. In the drying process, drying or heating is performed in a reduced pressure space having a relatively high degree of vacuum. As a result, the resist solution adheres well to the substrate B and dries without causing distortion, voids, pin marks, contamination, etc., and a high-quality resist film is obtained.

In addition, the two-stage drying process according to the present invention can efficiently obtain the required drying result (the amount of solvent volatilized) in a shorter time than the drying process in which only vacuum drying is performed at all times. In addition, by appropriately selecting the conditions (pressure, temperature, time, etc.) of the pressure reduction and the heat treatment in the second chamber 10, the coating liquid on the substrate B is thoroughly dried, and the baking by the dedicated heating unit is performed. It is also possible to make it unnecessary.

As a result, the time required for the drying process on the resist solution applied on the substrate B can be greatly reduced, and the throughput can be improved. Further, the resist solution applied on the substrate B can be dried stably and satisfactorily in a short time, and a high-quality resist film can be formed.

The above-described coating and developing system uses an LCD substrate as a substrate to be processed. However, it can be modified to a system using a semiconductor wafer as a substrate to be processed. The same operation and effect as described above can be obtained for drying.

The present invention is also applicable to a system in which another coating liquid, for example, an SOG solution is coated on a substrate (typically a semiconductor wafer) and dried. In this case, the processing conditions (pressure, temperature, time, and pressure) of the SOG solution on the semiconductor wafer in the first and second chambers 10 and 12 are determined.
The supply gas or the like may be appropriately selected according to the material of the SOG or the like. For example, for SOG before metal wiring formation,
The pressure in the first chamber 10 is several Torr, and the pressure and the heating temperature in the second chamber 10 are 1 to 1 respectively.
It may be 0 ^-3 Torr, 700 to 850 ° C. In addition, the SOG after the formation of the metal wiring is in the first chamber 1
The pressure at 0 is several Torr, the pressure and heating temperature in the second chamber 10 are 1 to 10 ^-3 Torr and 35, respectively.
The temperature may be 0 to 400 ° C.

The configuration of each part in the first and second chambers 10 and 12 can be variously modified. For example, the heating plate 44 of the heating mechanism in the second chamber 12
Can be replaced by another heating means such as a lamp.

The present invention is applicable to a technique for drying an arbitrary coating solution containing a volatile solvent applied on a substrate, in addition to a resist and SOG. The substrate to be processed in the present invention is not limited to an LCD substrate or a semiconductor wafer, but may be a CD substrate, a glass substrate, a photomask, a printed substrate, or the like.

[0094]

As described above, according to the present invention, the time required for the drying treatment of the coating solution on the substrate can be greatly reduced, and the throughput can be improved. In addition, the coating liquid on the substrate can be dried stably and satisfactorily in a short time to obtain a high-quality coating film.

[Brief description of the drawings]

FIG. 1 is a schematic side view schematically showing a configuration of a drying apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic side view schematically showing a configuration of a drying apparatus according to a modification.

FIG. 3 is a plan view showing a configuration of a coating and developing processing system to which an embodiment of the present invention is applied.

FIG. 4 is a flowchart illustrating a processing procedure in the coating and developing processing system according to the embodiment.

FIG. 5 is a diagram illustrating a resist coating unit, a drying unit, and an edge remover in the coating and developing processing system according to the embodiment.
FIG. 3 is a schematic plan view illustrating a main configuration of a unit.

[Explanation of symbols]

 Reference Signs List 10 first chamber (processing chamber) 12 second chamber (processing chamber) 16 gate valve 18 support base 24 substrate transfer device 34 gate valve 36 exhaust port 44 hot plate 48 lift pin 56 exhaust port 40, 60 inert gas supply pipe 61 Reactive gas supply pipe 62 Third chamber 64 Transfer device 68, 70 Gate valve 76 Inert gas supply pipe 134 Resist coating unit 136 Drying unit 138 Edge remover unit 148 Main transfer device 170 Gate valve

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) H01L 21/31 H01L 21/30 567 F term (Reference) 2H025 EA10 3L113 AA01 AB02 AB10 AC01 AC20 AC23 AC67 AC73 AC75 BA34 DA10 5F045 AB32 AE01 BB08 BB15 BB17 CA15 EB09 EB20 EN02 EN04 HA16 HA25 5F046 KA04 KA07 KA10

Claims (12)

[Claims] 1. A drying method for drying a coating solution containing a volatile solvent applied on a substrate to be processed, comprising: placing the substrate in a first reduced-pressure space, and removing the solvent in the coating solution. A first step of volatilizing by a predetermined amount, and after the first drying step, placing the substrate in a second reduced-pressure space substantially independent of the first reduced-pressure space and heating the substrate, A second step of further evaporating the solvent in the coating solution by a predetermined amount. 2. The drying method according to claim 1, wherein the pressure in the second reduced pressure space is set to a value lower than the pressure in the first reduced pressure space. 3. The drying method according to claim 1, further comprising a step of variably controlling a heating temperature of the substrate during the second step. 4. The first and second reduced-pressure spaces are adjacent to each other via a gate mechanism, and after the first step, the gate mechanism is opened to move the substrate from the first reduced-pressure space. The drying method according to any one of claims 1 to 3, wherein the drying method is transferred to the second reduced-pressure space through the gate mechanism. 5. A third depressurized space substantially independent of said first and second depressurized spaces is respectively adjacent to said first and second depressurized spaces via first and second gate mechanisms. After the completion of the first step, the first gate mechanism is opened to move the substrate from the first reduced pressure space to the third reduced pressure space through the first gate mechanism, The drying method according to any one of claims 1 to 3, wherein a second gate mechanism is opened to transfer the substrate from the third reduced pressure space to the second reduced pressure space through the second gate mechanism. . 6. The method according to claim 6, wherein the first gate mechanism is opened before the first step, and the substrate is moved from the third reduced pressure space through the first gate mechanism to the first reduced pressure space. And after the completion of the second step, the second
6. The drying method according to claim 5, further comprising the step of: opening the gate mechanism, and carrying out the substrate from the second reduced-pressure space to the third reduced-pressure space through the second gate mechanism. 7. The drying method according to claim 1, further comprising a step of filling the second reduced-pressure space with an inert gas during the second step. 8. The drying method according to claim 1, further comprising a step of filling the second reduced-pressure space with a reactive gas during the second step. 9. A drying apparatus for drying a coating liquid containing a volatile solvent applied on a substrate to be processed, comprising: a first depressurized space, wherein the substrate is placed in the first depressurized space. A first processing unit for volatilizing a solvent in the coating liquid by a predetermined amount, and a second reduced pressure space substantially independent of the first reduced pressure space, wherein the second reduced pressure space is provided. A second processing unit for placing the substrate therein and heating it to further volatilize a predetermined amount of the solvent in the coating solution. 10. The first and second depressurized spaces are made adjacent to each other via a gate mechanism, and a substrate transport means for transporting the substrate through the gate mechanism in an open state is provided by the first or the second. The drying device according to claim 9, wherein the drying device is provided in the reduced pressure space. 11. A decompressible third chamber adjacent to the first depressurized space via a first gate mechanism and adjacent to the second depressurized space via a second gate mechanism; The substrate is disposed in a third chamber, is carried out of the first depressurized space through the first gate mechanism in an open state, and is unloaded through the second gate mechanism in an open state. The drying apparatus according to claim 9, further comprising: a substrate transfer unit that loads the substrate into a space. 12. A heating means disposed at a predetermined position in the second decompression space and having a heating element for heating the substrate, wherein the heating means is provided at an interval variably controllable with respect to the heating means. The drying apparatus according to any one of claims 9 to 11, further comprising: a substrate supporting member that supports the substrate;