JP2001310147A - Pre-delivering apparatus and pre-delivering method for slit coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pre-delivering apparatus adapted so as to inhibit adhesion of a cleaning fluid or adhesion of a coating fluid of a different concentration on the tip of a nozzle when the delivering nozzle is washed by immersing it in a cleaning fluid tank. SOLUTION: A pre-delivering apparatus P is used prior to coating in a standby period between coating operations and performs the motion of pre-delivering a coating fluid in a coating element 21 just prior to a coating operation while adhering an excessive coating fluid L2 to a rotating roller 33. The motion of pre-delivering consists of allowing the delivering port 22 of the element 21 to approach the periphery of the roller 33 to such an extent that the surface tension can be cancelled so as to allow the fluid L2 to adhere to the periphery of the roller 33; fetching the fluid L2 by the rotation of the roller 33; and washing the fluid L2 off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slit coater which applies a coating solution such as a resist solution, a developing solution or a color filter onto a surface of a plate-like workpiece such as a glass substrate or a semiconductor wafer by flowing it down from a slit-shaped opening. And a preliminary discharge method using the preliminary discharge device.

[0002]

2. Description of the Related Art When a coating liquid is continuously supplied to a large number of substrates using a slit coater, the coating liquid in a discharge nozzle is contacted with air during a standby time between coating operations. Some concentrations increase. Then, if the coating is continued on the next substrate in this state, vertical streaks or film breakage occurs due to the highly concentrated coating solution.

[0003] Conventionally, to solve the above disadvantages,
During standby, the discharge nozzle is immersed in a tank filled with a cleaning liquid or a coating liquid, or preliminary discharge is performed to discard the coating liquid accumulated in the discharge nozzle immediately before coating.

[0004]

In the above-described means for immersing the discharge nozzle in the bath filled with the cleaning liquid, the concentration of the coating liquid held in the nozzle is diluted, and the thickness of the coating film becomes uneven. Cannot be effectively eliminated. In addition, in the means of immersing in the coating solution, the thickness of the leading (coating start portion) is increased, and the uniformity is deteriorated.

[0005] In addition, when preliminary discharge is performed to discard the coating liquid accumulated in the discharge nozzle immediately before coating, the coating liquid adheres to a wide area at the tip of the discharge nozzle due to surface tension, and as a result, vertical stripes are formed. There are problems such as the occurrence of the problem and an increase in the thickness of the reading, and improvement is desired.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an apparatus for pre-discharging a slit coater having a slit-shaped discharge nozzle, a cleaning tank for holding a cleaning liquid, and a horizontal cleaning tank. And a rotating roller whose lower part is immersed in the cleaning liquid in the cleaning tank and whose upper end surface is exposed so that the discharge nozzle of the slit coater can approach, and a discharge roller attached to the surface of the rotary roller. A shower nozzle for removing the coating liquid was provided.

The preliminary discharge device can be provided with a circulation path for the cleaning liquid in the cleaning tank after taking out and purifying the cleaning liquid in the cleaning tank and returning the cleaning liquid to the cleaning tank again. With such a configuration, the usage amount of the cleaning liquid can be saved.

Further, by mounting a plate above the shower nozzle and along the longitudinal direction of the shower nozzle, volatilization of the cleaning liquid in the cleaning tank is suppressed, and the cleaning liquid ejected from the shower nozzle toward the rotating roller is removed. Scattering can be prevented.

Further, if a highly volatile organic solvent is used as a cleaning liquid, the solvent dries quickly and has no adverse effect upon the next preliminary discharge. Further, by providing an exhaust device above the cleaning tank and weakly exhausting the air, the surface of the rotating roller cleaned by the shower nozzle can be dried more quickly.

As a preliminary discharge method performed immediately before the application liquid is supplied to the substrate surface using the above preliminary discharge device, a discharge nozzle of a slit coater is brought close to the upper surface of a rotating roller of the preliminary discharge device, and discharge is performed in this state. By discharging the coating liquid from the nozzle toward the upper surface of the rotating roller,
The coating liquid inside the discharge nozzle is drawn out, and good preliminary discharge can be performed. Therefore, it is possible to obtain a coating film of the same quality even if continuous processing is performed.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a diagram showing a coating device provided with a preliminary ejection device according to the present invention, and FIG.
3 is an overall view in which a portion of a cleaning tank of the preliminary discharge device is sectioned, and FIG. 4 is a top view of the preliminary discharge device.

In FIG. 1, C is a coating device, and P is a preliminary ejection device.
Although a non-contact type using a linear motor is shown, the coating device is not limited to this.

First, a coating apparatus C is provided with a table 3 on the upper surface of a base 1 via a leg 2 provided with a height adjusting mechanism, and a vertical cylinder unit 4 is provided on an upper surface of the base 1. Horizontal plate 5 on rod 4
A pin 6 for lifting the substrate W to be processed from the table 3 is mounted on the horizontal plate 5 so that the pin 6 faces the through hole 7 of the table 3, and a rail extending in the left-right direction is provided on the upper surface of the base 1. Two parallel members 8, 8 are provided, and a moving member 9 is movably arranged along the rail 8. An air bearing 10 as a floating means that straddles the rail 8 is fixed to the lower surface of the moving member 9, and the moving member 9 is moved by the air bearing 10 to the rail 8 (base 1).
Ascend from Note that a linear scale 13 is provided at both lower ends of the air bearing 10.

A linear motor 14 is arranged outside each rail 8. The linear motor 14 is mounted on the rail 8
And a plate-like coil 1 that enters a space defined by the magnet rail 15.
6

Further, a column 17 is erected on the moving member 9, a vertical guide rail 18 is provided on the column 17, and a gate-shaped elevating frame 19 is engaged between the front and rear guide rails 18. An elevating frame 19 is provided inside the support 17.
Is mounted on the lower surface of the elevating frame 19, a coating element 21 having a slit-shaped nozzle hole is attached, and a liquid feed pump 23 is fixed to the upper surface of one end side of the elevating frame 19, The application liquid is supplied to the liquid supply pump 23 from the application liquid tank via a supply pipe 24a, and the application liquid is supplied to the application element 21 from the liquid supply pump 23 via a supply pipe 24b. Further, the waste liquid tank, the liquid feed pump 23 and the coating element 2
1 and air vent pipes 25a and 25b, respectively.
Air bleeding for filling the coating liquid into the pump 23 and the coating element 21 is performed. Also,
A gap sensor 26 is attached to the side surface of the application element 21, and the gap sensor 26 and the amplifier 27 are connected by a signal line.

In the above, in order to supply the coating liquid to the surface of the substrate W to be processed, air is blown out from an opening provided on the rail side of the air bearing 10 to move the moving member 9 from the rail 8 (base 1). In the state, the linear motor 14
The direction of the current is continuously switched in a very short cycle and the current is applied to the coil 16 to move the moving member 9 along the rail 8 (magnet rail 15) in a non-contact state with the rail 8 (base 1). The liquid pump 23 is driven to supply the coating liquid from the slit-shaped nozzle holes toward the surface of the substrate W to be processed.

Next, the preliminary ejection device P will be described with reference to FIGS. The preliminary discharge device P has a cleaning tank 30 including a storage section 31 for storing the cleaning liquid L1, and a side wall section 32 in which a lower peripheral section is joined to an upper peripheral section of the storing section 31.
And the cylindrical roller 33 constitute a main part. The roller 33 is formed of a metal such as stainless steel, aluminum, and titanium. The diameter of the roller 33 is, for example, 30.
The distance between the upper end surface of the roller 33 and the discharge port of the slit-shaped nozzle hole is 25 to 300 μm.

The cleaning liquid L1 has a boiling point of 65 to 120.
° C, a highly volatile organic solvent having a vapor pressure of 12 to 90 mmHg (20 ° C) or a boiling point of 65 to 120 ° C and a vapor pressure of 12
Use a mixed solvent prepared to ~ 90 mmHg (20 ° C).

In the cleaning tank 30, both ends of a cylindrical roller 33 are rotatably supported by both side walls 31a and 31b of the storage section 31 facing each other in the direction perpendicular to the paper surface.
Is rotatable in a vertical plane in the cleaning tank 30 as shown in FIG. At one end of the shaft 33a of the roller 33,
The pulley 34 is attached, and the pulley 34 and the motor 3
The rotation shafts 5 are connected by a belt 36, and the driving force of the motor 35 is transmitted to the rollers 33.

On the other hand, the storage section 31 of the cleaning tank 30 is filled with a cleaning liquid L1 such as an organic solvent, and the lower part of the roller 33 is immersed therein. A shower nozzle 37 is attached to one side wall of the side wall portion 32. The shower nozzle 37 is connected to the collection tank T via a manifold 38 and a pipe 39 provided with a valve 39a, and ejects the cleaning liquid L1 stored in the collection tank T by controlling the valve 39a. Further, the shower nozzle 37 may be a single nozzle or a plurality of short nozzles connected to each other. When a short nozzle is used, it is easy to cope with a change in the length of the discharge nozzle, and maintenance and the like can be easily performed.

At the upper end of the side wall to which the shower nozzle 37 is attached, an exhaust cover 40 that covers substantially the upper surface of the cleaning tank 30 (the left half in FIGS. 3 and 4) is attached. An exhaust port 41 protruding outside the cleaning tank 30 is formed by the exhaust cover 40, and the gas containing the cleaning liquid accumulated in the cleaning tank 30 is connected to the duct 4 connected to the exhaust port 41.
Exhausted through 2.

Further, a recovery hole 43 for the cleaning liquid L1 is provided on the bottom side wall of the storage section 31. A pipe 44 provided with a pump P and a filter F is connected to the collection hole 43,
The washing liquid L1 is collected in the collection tank T. The cleaning liquid L1 recovered in the recovery tank T is ejected from the shower nozzle 37 into the cleaning tank 30 again through the pipe 39, circulated and reused.

A roller 33 having a predetermined width is provided on the upper surface of the side wall at a position facing the mounting position of the shower nozzle 37.
An upper surface cover portion 45 that extends along the axis of is provided.
A liquid level sensor 46 is attached to the upper cover 45,
The storage of the cleaning liquid L1 is continued until the liquid level confirms the preset upper limit level. When the upper limit is detected by the liquid level sensor 46, the collection tank T is collected in the collection tank T if the collection tank T can be collected, and if the collection tank T cannot be collected, the liquid is sent to a waste tank (not shown) through the waste liquid pipe 47. I do.

In the above, the preliminary ejection by the preliminary ejection device P is performed prior to the application in a standby state between the application operations. That is, the operation of previously discharging the coating liquid in the coating element 21 immediately before the coating is performed while the excess coating liquid L2 adheres to the rotating roller 33. In this preliminary discharge operation, the discharge port 22 of the application element 21 is
The coating liquid L2 from the discharge port 22 is adhered to the peripheral surface of the roller 33 by bringing the coating liquid L2 from the discharge port 22 close to the peripheral surface of the roller 33 so that the surface tension is canceled. The liquid L2 is removed by washing.

Further, the cleaning liquid is jetted from the shower nozzle 37 to the peripheral surface of the roller 33, and the applied coating liquid L2 is cleaned. At this time, since the prevention plate 48 is attached above the shower nozzle 37 along the longitudinal direction of the shower nozzle 37 and so as to protrude toward the roller 25 from the tip of the shower nozzle 37, the roller 3
The scattering and volatilization of the cleaning liquid ejected toward 3 can be prevented.

By exhausting air from the exhaust port 41, the cleaning liquid, which is a highly volatile organic solvent, can be dried even more quickly from the surface of the roller 33, and does not hinder the next preliminary ejection.

[0027]

According to the present invention as described above,
A cleaning tank filled with a cleaning liquid was provided below the rotating roller, preliminary discharge was performed by bringing the opening of the slit-shaped discharge nozzle close to the roller, and the discharged application liquid was attached to the annular peripheral surface of the roller. Therefore, contamination of the tip of the discharge nozzle is prevented, and even though the cleaning liquid is contaminated by the application liquid discharged by the preliminary discharge, the cleaning liquid is circulated by filtering, so that the dirt of the cleaning liquid is recovered and the cleaning liquid is used. The amount can be greatly reduced.

Further, the roller adheres the coating liquid discharged from the opening of the slit-shaped discharge nozzle to the peripheral surface of the roller, and draws the coating liquid from the discharge port by the surface tension of the coating liquid. The nozzle can maintain a state where uniform coating is possible, and the slit coater can shift to the subsequent coating process in a good state.

[Brief description of the drawings]

FIG. 1 is a view showing a coating apparatus provided with a preliminary ejection device according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is an overall view showing a cross section of a portion of a cleaning tank of the preliminary discharge device.

FIG. 4 is a top view of the preliminary ejection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base, 2 ... Leg, 3 ... Table, 4 ... Cylinder unit, 5 ... Horizontal plate, 6 ... Pin, 7 ... Through-hole, 8 ...
Rail 9 moving member 10 air bearing 13
Linear scale, 14: Linear motor, 15: Magnet rail, 16: Coil, 17: Support, 18: Guide rail, 19: Elevating frame, 20: Servo motor, 21
... Coating element, 23 ... Liquid pump, 24 ... Supply pipe,
25: return pipe, 26: gap sensor, 27: amplifier,
Reference Signs List 30 cleaning tank, 31 storage part, 32 side wall part, 33 roller, 33a shaft, 34 pulley, 35 motor, 36
... belt, 37 ... shower nozzle, 38 ... manifold, 39 ... piping, 39a ... valve, 40 ... exhaust cover,
41 ... exhaust port, 42 ... duct, 43 ... recovery liquid collecting hole,
44 ... piping, 45 ... top cover part, 46 ... liquid level sensor,
47: waste liquid pipe, 48: prevention plate, C: coating device, P: preliminary discharge device, T: recovery tank, W: substrate, L1: cleaning liquid,
L2 ... Coating liquid.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B08B 3/08 B08B 3/08 Z F-term (Reference) 3B201 AA02 AB01 AB33 BB22 BB33 BB82 BB95 CB01 CD22 4D073 BB03 CC10 4D075 AC04 DA10 DC15 4F041 AA01 AB01 BA60 4F042 AA03 CC04 CC08

Claims (6)

[Claims] 1. An apparatus for performing preliminary discharge of a slit coater having a slit-shaped discharge nozzle formed therein, wherein the preliminary discharge device is provided with a cleaning tank for holding a cleaning liquid, and is disposed horizontally in the cleaning tank and has a lower part. A rotating roller immersed in a cleaning liquid in a cleaning tank and having at least an upper end surface exposed so that a discharge nozzle of the slit coater can approach thereto, and a rotary roller for removing a coating liquid from the discharge nozzle attached to the surface of the rotary roller. And a shower nozzle for jetting a cleaning liquid toward the surface of the slit coater. 2. The preliminary discharge device for a slit coater according to claim 1, wherein the preliminary discharge device has a cleaning liquid circulation path for taking out and purifying the cleaning liquid in the cleaning tank and returning the cleaning liquid to the cleaning tank again. Preliminary discharge device for slit coater. 3. The preliminary discharge device for a slit coater according to claim 1, wherein a prevention plate for preventing volatilization and scattering of the cleaning liquid is provided in the vicinity of a rotating roller and the shower nozzle. A preliminary discharge device for a slit coater, which is installed above. 4. A slit discharger according to claim 1, wherein an exhaust port is provided in a part of said cleaning tank for exhausting weak exhaust gas. Pre-discharge device of coater. 5. A preliminary discharge method performed immediately before a coating liquid is supplied to a substrate surface using a slit coater, wherein the preliminary discharge method is a rotary roller of a preliminary discharge device according to any one of claims 1 to 3. A discharge nozzle of a slit coater is brought close to the upper surface of the roller, and in this state, the application liquid is discharged from the discharge nozzle toward the upper surface of the rotating roller. 6. The preliminary discharge method for a slit coater according to claim 5, wherein a highly volatile organic solvent is used alone or as a mixture as the cleaning liquid.