JP2001046945A - Chemical supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the discharge defect of a resist liquid by automatically carrying out the closing work of a stop valve arranged between a pressure source and a chemical housing tank and the closing work of a drain valve for releasing air in the exchange work of a resist bottle. SOLUTION: This device is provided with the stop valve 25 for switching to a cut-off position A based on a nonworking signal from a residual quantity sensor working when the resist liquid in a trap tank 10 becomes equal to or below a prescribed quantity. Further, there is provided the drain valve 27 switched from a communicating position to the cut-off position by the elimination of the output pressure of the switching valve 28 to be switched to a nonworking position E by being connected to the pressure source 14 and synchronized with the stop valve 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical supply apparatus for a chemical processing unit which performs a predetermined process by supplying a chemical to a substrate to be processed.

[0002]

2. Description of the Related Art In a wafer process in semiconductor manufacturing, in a resist coating step of coating a resist solution on a wafer, for example, equipment as shown in FIG. 4 is used. This means that the supply unit 1, the buffer unit 2, the oven unit 3, the coater unit 4, the buffer unit 5, the oven unit 6,
A storage section 7 and a resist supply section 8 are provided. During the operation of the equipment, wafers to be processed are supplied one by one from the cassette set in the supply unit 1 to the buffer unit 2, and then the oven unit 3 is used to dry and remove moisture on the wafers.
At a predetermined temperature for a predetermined time. The processed wafers are transported one by one to the coater unit 4, and a photoresist is applied on the wafers. When the resist coating is completed, the wafer is transported to the oven unit 6 via the buffer unit 5 to dry the resist on the wafer. The oven section 6 has substantially the same configuration as the oven section 3 on the upstream side except for the temperature conditions. Thereafter, the wafer is stored in a cassette in the storage unit 7.

[0005] The resist coating apparatus disposed in the coater section 4 has a known configuration. For example, as shown in FIG.
A suction stage 43 for holding the wafer W by suction and a resist discharge tube 41 are provided. The resist discharge pipe 41 is rotatable in the direction indicated by A in the drawing, and after moving above the center of the wafer held on the suction stage 43, the discharge port 4
A predetermined amount of resist R is discharged from 2 (FIG. 5B). Thereafter, the suction stage is rotated at a predetermined rotation speed (for example, 1000 rpm) by driving a motor (not shown) to make the film thickness of the resist R uniform over the entire surface of the wafer W.

[0004] The supply of the resist solution to the coater unit 4 is as follows.
This is performed in the resist supply unit 8 shown in FIG. The resist solution is supplied from the resist bottle 9 to the trap tank 10 and the filter 1.
1. It is supplied to the coater unit 4 via the pump 12. The discharge of the resist R from the resist discharge pipe 41 to the wafer W is performed by the pump 12. When the resist solution in the resist bottle 9 becomes empty, the level of the resist solution in the trap tank 10 decreases, and the remaining amount sensor 13 for detecting the liquid level detects the empty space in the resist bottle 9 and displays it outside. And stop the operation of the equipment. When the equipment is restarted, the resist bottle 9 needs to be replaced anew.

[0005] The conventional operation of replacing the resist bottle 9 is performed by replacing the resist bottle 9 with a new resist bottle and then applying a pressurized source 14 for supplying a pressurized nitrogen gas.
Is connected to the supply port 16 of the new resist bottle 9, the on-off valve 17 is opened to supply pressurized nitrogen gas into the resist bottle 9, and the trap tank 1
By opening the drain valve 18 of 0, the resist in the resist bottle 9 is fed to the trap tank 10 under pressure. At the same time, the air from the resist bottle 9 to the trap tank 10 is vented. Thereafter, the opening / closing valve 17 and the drain valve 18 are closed, and the work of replacing the resist bottle 9 is completed.

[0006]

However, since the opening / closing operation of the on-off valve 17 and the drain valve 18 has conventionally been performed manually by an operator, there is a problem that a mistake in the operation causes a resist coating defect. There is.

[0007] Specifically, the drain valve 18 is closed and the on-off valve 1 is closed.
When the equipment is restarted with the tray 7 open, the resist bottle 9
Since the inside is pressurized by the pressurized nitrogen gas from the pressurizing source 14, the resist is discharged from the resist discharge pipe 41 even when the pump 12 is not operated. Hereafter,
Although it is expressed as liquid dripping, if the resist coating is performed in this state, the resist R drops on the wafer W even during the movement of the resist discharge pipe 41 as shown in FIG. Bad (resist coating unevenness)
Occurs. In such a case, exposure failure is caused even in the next exposure step, so that the wafer having coating unevenness is treated as a coating failure, and then the resist is peeled off with a resist peeling device, and again with the resist coating device. A rework operation to coat the resist must be performed. Therefore, if the liquid dripping frequently occurs, this regenerating operation increases and the amount of resist used increases.

Further, if the drain valve 18 is kept open, the resist discharge pressure by the pump 12 decreases, so that a predetermined amount of resist cannot be discharged onto the wafer, and the above-described coating failure occurs. Would.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a chemical solution capable of preventing defective discharge of a resist liquid by automatically opening and closing the above-mentioned on-off valve and drain valve accompanying a replacement operation of a resist bottle. It is an object to provide a supply device.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides communication or interruption between a pressurizing source and a chemical solution storage tank, and moves to a shut-off position based on a non-operation signal of a remaining amount sensor. A switching valve is provided, and a drain valve is provided for communicating or blocking between the chemical solution storage tank and the outside and switching to a blocking position based on a non-operation signal of the remaining amount sensor. That is, the opening / closing operation of the opening / closing valve and the drain valve is automatically performed based on the non-operation signal of the remaining amount sensor, thereby preventing defective discharge of a chemical such as a resist in the chemical processing unit.

[0011]

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

FIG. 1 shows a resist supply unit 20 according to an embodiment of the present invention. Parts corresponding to those of the conventional resist supply unit 8 described with reference to FIG. . The arrangement of other processing units (supply unit, buffer unit, oven unit, coater unit, storage unit) other than the resist supply unit 20 is the same as that of the related art, and a description thereof will be omitted.

The resist supply unit 20 includes a resist bottle 9 and a trap tank 10 serving as a chemical solution storage tank for temporarily storing the resist solution in the resist bottle 9 as in the prior art.
The trap tank 10 provided in the trap tank 10
A residual quantity sensor 13 which is activated when the resist liquid in the tank falls below a predetermined level, a pump 12 for supplying the resist liquid in the trap tank 10 to a coater unit 4 (not shown) as a chemical liquid processing unit, a trap tank 10 and a pump 12 And a filter 11 disposed between them.

In this embodiment, communication or interruption between a pressurized nitrogen gas supply source (hereinafter, referred to as a pressurized source) 14 and a resist bottle 9 and a resist waste liquid tank disposed outside the trap tank 10 and the trap tank 10 29 (see FIG. 2) is controlled by the pressurized nitrogen gas (N ₂ ) automatic exhaust mechanism 21 according to the present invention. The pressurized nitrogen gas automatic exhaust mechanism 21 is provided with a residual amount sensor 13 as described later.
The communication between the pressurizing source 14 and the resist bottle 9 is cut off and the communication between the trap tank 10 and the waste liquid tank 29 is cut off based on the non-operation signal.

FIG. 2 shows an example of a piping configuration inside the pressurized nitrogen gas automatic exhaust mechanism 21. The pressurized nitrogen gas automatic exhaust mechanism 21 has an on-off valve 25, a drain valve 27, and a switching valve 28. The on-off valve 25 and the switching valve 28 are brought into the non-operating positions A, E shown in the figure by excitation of the solenoids 25a, 28a.
This is a solenoid valve that is simultaneously switched to operating positions B and F from. When the switching valve 28 is switched to the F position, the drain valve 27 uses the output pressure as a pilot pressure as a detection unit 27a.
Is a pneumatic valve that switches from a non-operating position C to an operating position D as shown in FIG. Further, between the pressurizing source 14 and the on-off valve 25 and between the on-off valve 25 and the resist bottle 9, pressure reducing valves 24 and 26 and pressure gauges 30 and 3 are provided, respectively.
1 is provided.

Next, the operation of the present embodiment will be described. The resist solution in the resist bottle 9 is reduced by the supply of the resist to the coater unit 4 and finally becomes empty, the resist solution in the trap tank 10 is reduced. Decrease. At this time,
When the remaining amount of the resist solution becomes lower than a predetermined level, the remaining amount sensor 13 is activated, and the empty state of the resist bottle 9 is notified by a predetermined notifying means. At the same time, the operation of the equipment stops. The replacement operation of the resist bottle 9 is performed in the following procedure.

After replacing the empty resist bottle with a new resist bottle 9 filled with a resist solution, the coupler 15 of the connecting pipe connected to the pressure source 14 is connected to the supply port 19 of the resist bottle 9. Next, an automatic pressurizing switch 22 provided in the pressurized nitrogen gas automatic exhaust mechanism 21 is pressed. This switch 2
2 is pressed, so that the on-off valve 25 is turned on with reference to FIG.
Of the solenoid portion 25a and the solenoid 2 of the switching valve 28
8a are excited, respectively, and are switched from the inoperative positions A and E shown to the operating positions B and F.

The pressurized nitrogen gas from the pressurizing source 14 is reduced in pressure from 0.6 to 0.7 MPa (gauge pressure, the same applies hereinafter) to 0.4 to 0.5 MPa by the pressure reducing valve 24 and then opened and closed. 25 and a switching valve 28. As described above, since the open / close valve 25 is in the communicating position (position B), the pressurized nitrogen gas is further reduced to 0.05 MPa by the pressure reducing valve 26 and supplied to the resist bottle 9. The switching valve 28 is also F
Since the position is set, the output pressure is supplied to the detecting portion 27a of the drain valve 27, whereby the drain valve 27 is switched from the illustrated shut-off position (C position) to the communication position (D position).

As a result, the resist solution in the resist bottle 9 is pumped into the trap tank 10 and the resist solution containing air in the trap tank 10 is drained from the drain valve 27.
Is discharged to the resist waste liquid tank 29 through the path, and the air bleeding action of the path from the resist bottle 9 to the trap tank 10 is performed.

When the resist solution in the trap tank 10 reaches a predetermined amount (full), the remaining amount sensor 13 outputs a non-operation signal (ie, stops outputting the operation signal). Based on this, the solenoids 25a, 28a of the on-off valve 25 and the switching valve 28 in the pressurized nitrogen gas automatic exhaust mechanism 21
a is demagnetized, and is switched to the inoperative positions A and E shown in the figure by the urging forces of the springs 25b and 28b. This also allows the switching valve 2 to be input to the detection portion 27a of the drain valve 27.
When the output pressure at 8 disappears, the drain valve 27 is also switched to the inoperative position C shown in FIG. The pressurized nitrogen gas between the on-off valve 25 and the resist bottle 9 is exhausted from the on-off valve 25 at the position A, and the pressurized nitrogen gas between the switching valve 28 and the detection unit 27a of the drain valve 27 is , E from the switching valve 28.

As described above, the pressurization in the resist bottle 9 is released, and the drain valve 27 is switched to the shut-off position, so that the condition for proper restart of the equipment is established. Thereafter, the operation of the facility is restarted by operating a predetermined switch.

Therefore, according to the present embodiment, the switching between the open / close valve 25 and the drain valve 28 after the replacement of the resist bottle 9 is automatically performed. Discharge failure can be prevented and wafer coating failure can be reduced. In addition, this makes it possible to reduce the wafer reclamation work and reduce the amount of resist used. Further, it is possible to contribute to shortening of the replacement time of the resist bottle 9 and to improve the equipment operation rate.

The automatic pressurized nitrogen gas exhaust mechanism 21 according to the present embodiment is provided with a manual pressurizing switch 23, which operates regardless of whether the remaining amount sensor 13 is inactive or not. 28 are used to maintain the respective operating positions, and are mainly used for equipment maintenance.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited thereto, and various modifications can be made based on the technical concept of the present invention.

For example, in the above embodiment, the coater unit 4
Although the description has been given of the apparatus for supplying the resist solution to the developing apparatus, the present invention is not limited to this.
The present invention is applicable to the supply of a cleaning liquid to a wafer cleaning apparatus.

The piping configuration of the pressurized nitrogen gas automatic exhaust mechanism 21 is not limited to that shown in FIG. 2, but may be configured as shown in FIG. In the configuration example of FIG.
Is switched by the output pressure of the on-off valve 25. When the remaining amount sensor 13 is not operated, the on-off valve 2
When the output pressure of No. 5 disappears, the communication position is switched to the cutoff position. Therefore, as compared with the configuration example shown in FIG.
As a result, the cost of the apparatus and the piping configuration can be simplified. Note that, in FIG. 3, the same reference numerals are given to portions corresponding to FIG.

[0027]

As described above, according to the chemical liquid supply apparatus of the present invention, it is possible to prevent the chemical liquid discharge failure in the chemical liquid processing unit, to reduce the amount of the chemical liquid used and to reduce the amount of the chemical liquid used. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a resist supply unit in a chemical solution supply device according to an embodiment of the present invention.

FIG. 2 is a piping system diagram of a main part of the chemical solution supply device.

FIG. 3 is a piping diagram showing a modification of the configuration of FIG. 2;

FIG. 4 is a schematic configuration diagram of a conventional chemical liquid supply device.

FIG. 5 is a schematic view for explaining the operation of a resist discharge pipe in the resist coating apparatus, wherein A shows a movement form of the discharge pipe with respect to a wafer chuck, and B shows a resist discharge form with respect to a wafer on the wafer chuck. ing.

FIG. 6 is a schematic view showing a liquid dripping from a resist discharge pipe for explaining a problem of the related art.

[Explanation of symbols]

4 ... Coater part, 9 ... Resist tank, 10 ... Trap tank, 12 ... Pump, 13 ... Remaining amount sensor, 14 ... Pressure source, 20 ... Register supply part, 21 ... Pressurized nitrogen gas automatic exhaust mechanism, 25 ... Open / close Valve 27: Drain valve 28: Switching valve 29: Waste liquid tank 41: Resist discharge pipe

Claims (3)

[Claims] 1. A chemical storage tank for storing a chemical, a pump for supplying the chemical in the chemical storage tank to a chemical processing unit, and a residual quantity sensor that operates when the chemical in the chemical storage tank is below a predetermined level. And a pressurizing source for pressurizing the medicinal solution into the medicinal solution storage tank, wherein the communication between the pressurizing source and the medicinal solution storage tank is interrupted or interrupted. An on-off valve that switches to a shut-off position based on an operation signal; and a drain valve that communicates or shuts off between the chemical solution storage tank and the outside and switches to a shut-off position based on a non-operation signal of the remaining amount sensor. A chemical solution supply device characterized by the above-mentioned. 2. The drain valve is connected to the pressurizing source when the remaining amount sensor is not operated, and is switched from a communication position to a shut-off position due to a loss of output pressure of a switching valve switched in synchronization with the on-off valve. 2. The chemical solution supply device according to claim 1, wherein the device is a pneumatic valve that can be replaced. 3. The drain valve according to claim 1, wherein the drain valve is a pneumatic valve that switches from a communicating position to a shut-off position when the output pressure of the on-off valve is lost when the remaining amount sensor is not operated. Chemical supply device.