JPH11354487A - Method and equipment for drying substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dry a substrate well without leaving any stain on the surface. SOLUTION: A liquid cutting/drying section 3 for removing water drops from the surface of a substrate S after being cleaned at a water cleaning section 2 comprises air knife units 31, 32, and a high output infrared (IR) heater 33. The high output infrared IR heater 33 heats up the surface of the substrate S immediately after water drops are removed therefrom by the air knife unit 31 to evaporate residual moisture quickly. Downflow 38 is formed in a processing chamber 35 containing the air knife units 31, 32 and the high output infrared IR heater 33. Consequently, vapor produced on the upper surface of the substrate S is carried away quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a substrate drying apparatus and a substrate drying method for processing various substrates to be processed such as a semiconductor wafer and a glass substrate for a liquid crystal display.

[0002]

2. Description of the Related Art In a manufacturing process of a liquid crystal display device, a fine thin film pattern is repeatedly formed on a glass substrate. In order to perform such fine processing precisely, the glass substrate is cleaned as necessary.

[0003] A substrate cleaning apparatus for cleaning a glass substrate includes, for example, a chemical cleaning section for supplying a chemical such as an etching solution to the substrate surface, a water cleaning section for cleaning the substrate after processing in the chemical cleaning section, and a water cleaning section. And a drying section for drying the substrate after the water washing process in the section.
Further, a transport roller is provided so as to form a substrate transport path that penetrates the chemical cleaning section, the rinsing section and the drying section, and the transport roller transports the substrate from the chemical processing section to the drying section through the rinsing section. Will be done.

[0004] An air knife device as a liquid draining device is arranged between the water washing unit and the drying unit. This air knife device is disposed above and below a substrate transport path, and has a slot-shaped gas outlet along a direction orthogonal to the substrate transport direction. In addition, the structure is such that moisture is removed from the upper and lower surfaces of the substrate by injecting gas from a gas outlet onto the upper and lower surfaces of the substrate being transported by the transport rollers.

[0005] The drying section is provided with, for example, an IR (infrared) oven for evaporating the water on the substrate surface after the liquid draining process. This drying section is intended for precise drying at the molecular level, and the heating temperature is 130 ° C. to 1 ° C.
50 ° C.

[0006]

For example, it is assumed that a thin film pattern 100 is formed on the surface of a substrate S as schematically shown in FIG. The supply of the gas from the air knife device to the upper surface of the substrate S is performed in a direction inclined in a direction opposite to the transport direction TD of the substrate S. This is to prevent moisture from flowing into the surface after the liquid removal processing.

In this case, in the thin film pattern 100, it is inevitable that some water droplets 105 remain on the edge bottom portion 101 on the upstream side in the transport direction TD even after the liquid removal process by the air knife device. This water drop 1
05 is naturally dried slowly while being transported to the drying section.

However, during this time, the gas in the atmosphere, particularly oxygen, dissolves in the water, and a reaction product with the material of the substrate S is generated in the water droplet 105. Further, there is a possibility that impurities in the glass of the material of the substrate S may be dissolved in the water droplets 105 as ion elutes. Furthermore, while being dried naturally,
Particles in the atmosphere may dissolve into the water droplets 105. Due to these factors, after the moisture 105 is dried, "spots" called watermarks are generated at corresponding locations on the substrate S, and the precise cleaning of the substrate S is hindered.

An object of the present invention is to solve the above-mentioned technical problems and to provide a substrate drying apparatus and a substrate drying method capable of satisfactorily drying a substrate.

[0010]

Means for Solving the Problems and Effects of the Invention According to the first aspect of the present invention, there is provided a transfer means for transferring a substrate, and a liquid on the surface of the substrate being transferred by the transfer means. A liquid ejecting mechanism for ejecting the gas toward the surface of the substrate being transported by the transporting means, and immediately after receiving the gas ejection by the gas ejecting means. A heating means for heating the substrate surface and evaporating a liquid component remaining on the substrate surface.

[0011] According to the above arrangement, the substrate surface is heated immediately after receiving the gas injection from the gas injection means, and the liquid component that cannot be eliminated by the gas injection is removed. Evaporated quickly. As a result, the droplets do not remain on the substrate surface for a long time, so that the substrate surface can be satisfactorily dried without causing stains on the substrate surface.

[0012] A precision drying means for performing a molecular-level precision drying process on the surface of the substrate on which the liquid removal process has been performed by the liquid draining mechanism may be further provided.

According to a second aspect of the present invention, there is provided the substrate drying apparatus according to the first aspect, wherein the liquid draining mechanism further includes a processing chamber accommodating the gas injection means and the heating means.

According to this configuration, since the gas injection unit and the heating unit are housed in one processing chamber, the substrate surface can be heated immediately after receiving the gas injection. Thereby, drying of the substrate can be performed more favorably. The invention according to claim 3 is the substrate drying apparatus according to claim 1 or 2, wherein the heating unit is disposed above a path of the substrate conveyed by the conveyance unit.

When both sides of the substrate are transported after being cleaned,
The possibility that droplets remain is high on the upper surface side of the substrate. Therefore, by arranging the heating means above the path of the substrate and performing heating from the upper surface of the substrate, the droplets on the substrate surface can be effectively evaporated.

According to a fourth aspect of the present invention, the substrate drying apparatus further includes gas supply means for feeding gas from above a transfer path of the substrate transferred by the transfer means toward the transfer path. The substrate drying apparatus according to any one of claims 1 to 3, wherein:

According to this structure, the gas is supplied toward the upper surface of the substrate where the droplets to be evaporated are likely to be present, so that the replacement of the atmosphere on the upper surface of the substrate proceeds promptly. Therefore, the droplet can be heated while removing the vapor in the atmosphere, so that the evaporation of the droplet can be promoted.

According to a fifth aspect of the present invention, the method includes a step of transporting the substrate, and a draining step of draining the liquid on the surface of the substrate being transported. A substrate drying method immediately after the gas is injected, and an evaporation heating step of evaporating a liquid component remaining on the substrate surface by evaporating a liquid component remaining on the substrate surface. It is.

According to this method, the same effect as that of the first aspect can be obtained.

This method may further include a precision drying step of performing a precision drying treatment at the molecular level on the surface of the substrate, following the liquid removal step.

[0021]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view schematically showing the configuration of a part of a substrate cleaning apparatus to which a substrate drying apparatus according to an embodiment of the present invention is applied. This substrate cleaning apparatus is an apparatus for cleaning and drying the surface of a substrate S such as a glass substrate for a liquid crystal display. The apparatus includes a rinsing unit 2 for supplying pure water to the surface of the substrate S to rinse the substrate S, and a liquid for draining moisture on the upper and lower surfaces of the substrate S after the rinsing process by the rinsing unit 2. A drier / dryer 3 and a drier 4 (precision drying means) for precisely drying the substrate that has been drained in the drier / dryer 3 (drainer mechanism).
And these are connected in series.

A transport path 10 is formed so as to pass through the rinsing section 2, the draining section 3 and the drying section 4. The substrate S is moved from the rinsing section 2 to the drain section 3 by the action of a plurality of transport rollers 5 (transport means) arranged substantially parallel to each other along a horizontal direction substantially orthogonal to the transport path 10. It is sequentially sent to the drying unit 4 along the transport direction TD. Then, the water washing process, the draining drying process, and the precision drying process are sequentially performed on the substrate S which is transported while being held substantially horizontally by the transport roller 5.

The rinsing section 2 includes pure water nozzles 21 and 22 for supplying pure water to the upper and lower surfaces of the substrate S transported by the transport roller 5, respectively.

The drying section 4 exposes the substrate S to a high temperature (for example, 130 ° C. to 150 ° C.) for a certain period of time to perform a molecular-level precision drying process on the moisture on the surface of the substrate S. , For example, IR
An oven 41 is provided.

The draining / drying section 3 includes a pair of air knife devices 31 and 32 (gas injection means) and a high-output IR heater 33.
(Heating means) are housed in the processing chamber 35. The pair of air knife devices 31 and 32 respectively have upper and lower surfaces of the substrate S transported by the transport roller 5 and have slot-shaped openings 31a and 32a extending in a direction substantially orthogonal to the substrate transport direction TD. ing. Then, the air knife device 31 moves the transfer direction TD over the entire width of the substrate S with respect to the upper surface of the substrate S.
A gas (for example, air) is injected from the slot-shaped opening 31a in a direction inclined obliquely downward toward the opposite direction. Similarly, the air knife device 32 moves the gas (from the slot-like opening 32a in the direction inclined obliquely upward toward the direction opposite to the transport direction TD over the entire width of the substrate S with respect to the lower surface of the substrate S. For example, air) is injected.

The substrate S is transported by the transport roller 5 in the transport direction T.
By being transported to D, the position where the air current is supplied from the air knife devices 31 and 32 on the upper and lower surfaces of the substrate S changes every moment. Thereby, the water on the upper and lower surfaces of the substrate S is pushed to the upstream side in the transport direction TD, and the substrate S
At the time when the trailing edge passes through the air knife devices 31 and 32, almost all the water on the substrate S has been removed.

The high-output IR heater 33 heats the upper surface of the substrate S immediately after the liquid cutting process by the air knife device 31. That is, the high-output IR heater 33 transports the gas ejected from the air knife device 31 downstream of the position Pa where the gas reaches the upper surface of the substrate S in the transport direction TD and very near the position Pa. It is arranged slightly above the upper surface of the substrate S transported by the rollers 5. In this case, the distance between the position Pa and the substrate heating position Pb by the high-output IR heater 33 is preferably 300 mm or less. Also, a high output IR heater 33,
The distance between the upper surface of the substrate S and the upper surface of the substrate S being transported by the transport roller 5 is preferably 200 mm or less.

With this configuration, a small amount of moisture remaining on the surface of the substrate S after the liquid removal processing by the air knife device 31 is instantaneously evaporated by heating by the high output IR heater 33. Thus, the liquid is removed by the airflow from the air knife devices 31 and 32, and the high-power IR immediately after that is removed.
Due to the instantaneous evaporation by the heater 33, the liquid draining process on the surface of the substrate S can be favorably performed. Therefore, even when a thin film pattern is formed on the surface of the substrate S, the water does not remain on the surface of the substrate S after the draining process for a long time, so that a watermark is formed. And a good cleaning process can be performed.

Further, in the present embodiment, as shown in FIG.
An opening 35 </ b> A is formed in the top surface of No. 5. The opening 35A is provided with a clean gas supply device 37 (gas supply means) for purifying the air in the clean room and sending it under pressure into the processing chamber 35. This clean gas supply device 3
Reference numeral 7 denotes a blower 371 and a planar filter 372 which is disposed closer to the internal space of the processing chamber 35 than the blower 371 and which purifies air from the blower 371 and passes the air to the processing chamber 35.

The bottom surface of the processing chamber 35 has a substantially horn shape, and an exhaust port 3 formed at the lower end thereof.
5B is connected to an appropriate exhaust facility such as an exhaust utility pipe or a blower in the factory via an exhaust pipe 36. Accordingly, the down flow 38 can be formed in the processing chamber 35, so that air can be supplied to the upper surface of the substrate S. Thereby, the atmosphere on the upper surface side of the substrate S containing the vapor generated by the heating by the high-output IR heater 33 can be promptly replaced with the dried air, so that the heating and evaporating process by the high-output IR heater 33 can be effectively performed. I can do it.

An entrance sensor 61 for detecting the substrate S is provided near the entrance 51 into which the substrate S from the washing section 2 is introduced. An exit sensor 62 for detecting the substrate S is also provided near the exit 52 from which the substrate S is discharged to the drying unit 4.

FIG. 2 is a block diagram showing an electrical configuration related to the liquid drainage drying unit 3. A pair of air knife devices 3
Compressed air is supplied to 1 and 32 via a valve 71. The opening and closing of this valve 71 is controlled by a control unit 70 having a microcomputer, whereby the execution / stop of the injection of air from the air knife devices 31 and 32 is controlled.

The control unit 70 further includes a heater switch 7 for turning on / off the energization of the high-output IR heater 33.
2 is opened and closed, an inverter circuit 73 for energizing the blower 371 is controlled, and a drive circuit 74 for driving the transport roller 5 is controlled. This control unit 70
, The output signals of the entrance sensor 61 and the exit sensor 62 are input. These sensors 61,
Based on the output signal of 62, the control unit 70
1. Control the heater switch 72, the inverter circuit 73, and the drive circuit 74.

FIG. 3 is a flowchart for explaining the control operation by the control unit 70. After controlling the drive circuit 74 to start the transfer of the substrate S by the transfer roller 5 (step S1), the control unit 70 monitors the output signal of the entrance sensor 61 (step S2). When the entrance sensor 61 detects the substrate S and is turned on, the control unit 70 conducts the heater switch 72 to energize the high-output IR heater 33 (step S3). Further, the valve 71 is opened to start the injection of air from the air knife devices 31, 32 (step S4).

Further, at this time, the control unit 70 controls the inverter circuit 73 to reduce the amount of air blown by the blower 371, thereby reducing the amount of downflow air in the processing chamber 35 (see FIG. 1) (step S1). S5). This is to prevent the substrate S from being cooled by the downflow, and to effectively heat the surface of the substrate S by the high-output IR heater 33. If the downflow is stopped, the replacement of the atmosphere containing the vapor generated by the heating of the substrate S is hindered, particles may increase, and when the downflow is formed again, a stable downflow may occur. It may take some time before the flow is obtained.

Next, the control unit 70 waits for a fixed time longer than the time required for the leading edge of the substrate S to reach the position where the outlet sensor 62 is provided (step S6). It is monitored whether or not the board 62 has been turned off so as not to detect the substrate S (step S7). When the outlet sensor 62 is turned off, the control unit 70 further
Next, it is determined whether or not the entrance sensor 61 detects the transported substrate S (step S8). If the entrance sensor 61 has not detected the next substrate S, the valve 71 is closed, the injection of air by the air knife devices 31 and 32 is stopped (step S9), the heater switch 72 is shut off, and the high output IR The power supply to the heater 33 is stopped (step S10), and the blower 371 is controlled by controlling the inverter circuit 73.
Is returned to the original air volume, and the downflow air volume is increased to the normal air volume before being reduced in step S5 (step S11). Thereafter, the processing from step S2 is repeated.

If it is determined in step S8 that the entrance sensor 61 has detected the next substrate S, the flow advances to step S8.
6 are repeated, and the air knife devices 31 and 32 are repeated.
And the heating of the substrate S by the high-output IR heater 33 are performed under the reduced downflow air volume.

As described above, since the control unit 70 operates the air knife devices 31, 32 and the high-output IR heater 33 only when necessary, power consumption can be reduced.

Although one embodiment of the present invention has been described above, the present invention can be implemented in other embodiments. For example, the processing chamber 35 has a first exhaust port for exhausting a large amount of water generated in the first half of the liquid draining process on one substrate, and a second exhaust port for exhaust including a heated atmosphere generated in the second half of the processing. It is also possible to provide two exhaust ports with the exhaust port to separate the exhaust gas.

In the above-described embodiment, the clean gas supply device 37 for feeding clean air into the processing chamber 35 is used. However, the downflow in the clean room is directly taken into the processing chamber 35 from the opening 35A. You may. In this case, a downflow can be formed in the processing chamber 35 by the forced exhaust through the exhaust pipe 36.

For heating the substrate surface immediately after the gas is injected from the air knife device, other high-output heaters such as a halogen heater and a far-infrared heater can be applied in addition to a high-output IR heater.

In the transport path of the substrate drying apparatus of the above embodiment, the substrate is transported while being held substantially horizontally.
The substrate may be transported while holding the substrate in an inclined state with one end of the transport roller in the processing chamber positioned above or below. In this case, since the liquid on the substrate surface is guided by the inclination, the liquid can be drained efficiently.

Further, the present invention can be applied not only to the drying of the glass substrate for a liquid crystal display device, but also to the drying of other substrates to be processed such as a semiconductor wafer and a glass substrate for a plasma display.

Further, for example, the steps shown in Table 1 can be exemplified as a substrate cleaning step in which an air knife apparatus to which the present invention is applied can be used. These cleaning steps are the first
Steps, second steps,... Are executed in this order.

[0046]

[Table 1] The “pure water shower” is a step of cleaning the substrate by supplying pure water to the surface of the substrate in a shower shape. Also,
“Air knife” refers to a liquid draining process using an air knife device, and the present invention is applicable to this process. That is, in the air knife process, a gas such as air is injected onto the substrate surface, and the substrate surface is heated immediately after the injection is performed, thereby evaporating the liquid component.

Further, the "detergent brush shower" is a step of scrub-cleaning the surface of the substrate with a cleaning brush while supplying a cleaning solution to the surface of the substrate in a shower.
The “pure water high mega shower” is a step of supplying pure water to which ultrasonic vibration has been applied to the substrate surface in a shower shape. In addition, "Pure Water Mid Sonic Dip"
This is a step of washing the substrate by immersing the substrate in a water tank storing pure water and applying ultrasonic vibration to the pure water in the water tank.

In addition to these cleaning steps, as shown in Table 2 below, the air knife step in the resist film peeling processing and the developing processing, and the substrate cleaning processing before applying the material for the resist film and the alignment film, The present invention is applicable.
In Table 2, each process is a first step, a second step,
... Are performed in this order.

[0049]

[Table 2] In Table 2, the “processing solution shower” is a process of supplying a processing solution such as a resist film stripping solution or a developing solution to the substrate in a shower shape. The “rinse liquid shower” is a step of supplying a rinse liquid such as pure water, ozone water, or electrolytic ionic water to the substrate surface in a shower.

Further, "spray cleaning" is a step of supplying a cleaning liquid to the substrate surface in a spray form, and "roll brush cleaning" is a step of scrub cleaning the substrate surface with a roll brush. The “cleaning” is a step of cleaning the substrate by supplying pure water to which ultrasonic waves have been applied to the surface of the substrate. The “spray rinsing” is a step of supplying pure water to the surface of the substrate in a spray form, and the “IR oven” is a drying step of drying the surface of the substrate with an IR oven precisely at a molecular level.
Further, the “UV oven” is a step of irradiating ultraviolet rays to the substrate surface by the UV oven to decompose organic contamination on the substrate surface.

As is clear from Tables 1 and 2, the liquid draining process by the air knife process is generally performed after the water washing process.

As can be understood from Table 2, an IR oven may be used in a step after the air knife step. In this case, if the air knife process is performed by the substrate drying apparatus according to the present invention, I
Since the substrate is carried into the R oven, the amount of particles brought into the IR oven can be significantly reduced.

Note that the substrate drying apparatus of the present invention is configured to perform heat treatment as well as liquid drainage. The heat treatment in this substrate drying apparatus is performed by an IR oven intended for precision drying at a molecular level. The heat treatment is basically a different treatment. Therefore, even when the substrate drying apparatus of the present invention is applied, the IR oven process after the air knife process cannot be eliminated.

In addition to the above, various design changes can be made within the technical scope described in the claims.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating a configuration of a part of a substrate cleaning apparatus to which a substrate drying apparatus according to an embodiment of the present invention is applied.

FIG. 2 is a block diagram showing an electrical configuration related to a liquid drainage drying unit.

FIG. 3 is a flowchart illustrating a control operation performed by a control unit.

FIG. 4 is a cross-sectional view illustrating a state after performing a conventional air knife drying process on a substrate having a thin film pattern formed on a surface thereof.

[Explanation of symbols]

 2 Rinse processing part 3 Drain drying part 4 Drying part 5 Conveyance roller 31, 32 Air knife device 33 High output IR heater 35 Processing chamber 37 Clean gas supply device 61 Inlet sensor 62 Outlet sensor 70 Control unit 71 Valve 72 Heater switch 73 Inverter circuit 74 drive circuit

Claims (5)

[Claims] 1. A transporting means for transporting a substrate, and a draining mechanism for removing liquid on the surface of the substrate being transported by the transporting means, wherein the draining mechanism comprises a substrate transported by the transporting means. Gas injection means for injecting gas toward the surface of the
A heating means for heating the substrate surface immediately after receiving the gas injection by the gas injection means and evaporating a liquid component remaining on the substrate surface. 2. A substrate drying apparatus according to claim 1, wherein said liquid draining mechanism further includes a processing chamber containing said gas injection means and said heating means. 3. The substrate drying apparatus according to claim 1, wherein said heating means is disposed above a path of the substrate carried by said carrying means. 4. The substrate drying apparatus according to claim 1, further comprising gas supply means for feeding gas from above the transfer path of the substrate transferred by the transfer means toward the transfer path. 4. The apparatus for drying a substrate according to any one of items 3 to 3. 5. The method according to claim 1, further comprising the steps of: transporting the substrate; and draining the substrate by removing a liquid on the surface of the substrate being transported. And evaporating and heating a substrate surface immediately after the gas is injected to evaporate a liquid component remaining on the substrate surface.