JPH10172943A - Substrate treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely detect the breakage of a bellows pump which sends a treatment liquid through application of a pressure. SOLUTION: A bellows pump 25 sends a chemical by application of a pressure toward a nozzle 22 from a chemical tank 23 through a chemical supplying route 24. In the chemical supplying route 24, a trap tank 26 is provided. If bubbles are produced in the chemical supplying tank 24, the liquid level in the trap tank 26 lowers. If the liquid level goes down to that of a liquid level sensor S1, an air valve 42 for bleeding air is opened. As a result, the liquid level in the trap tank 26 rises again. But, if a compressed air gets mixed in the chemical supplying route 24 by the breakage of the bellows pump 25, lowering of the liquid level does not stop even by the opening of the air valve 42. Consequently, it is judged that the bellows pump 25 is broken, if the liquid level becomes lower than the liquid level sensor S2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus for performing processing on various substrates to be processed such as a semiconductor wafer, a glass substrate for a liquid crystal display device, and a glass substrate for a PDP (plasma display panel).

[0002]

2. Description of the Related Art In a process of manufacturing an VLSI (Large Scale Integrated Circuit), a cleaning process and a wet etching process of a semiconductor wafer (hereinafter simply referred to as "wafer") are important processes. In these steps, for example, the surface of the wafer held by the spin chuck and / or
Alternatively, a substrate processing apparatus that supplies a chemical solution such as hydrofluoric acid to the back surface is used.

FIG. 9 shows a configuration related to the supply of a chemical solution in such a substrate processing apparatus. In this substrate processing apparatus, the wafer W is processed by supplying a chemical solution from the nozzle 2 to the wafer W held by the spin chuck 1. The chemical to be supplied to the nozzle 2 is guided from the chemical tank 3 via the chemical supply path 4. A bellows pump 5 is interposed in the chemical solution supply path 4 for pressure feeding of the chemical solution. Further, in the chemical supply path 4, a flow meter 6 for measuring the flow rate of the chemical, a filter 7 for removing foreign substances in the chemical, a flow control valve 8 for adjusting the flow of the chemical, and the supply of the chemical are started. / Air valve 9 for stopping
Is interposed. A pressure sensor 10 is provided between the air valve 9 and the nozzle 2 to detect the pressure of the chemical passing through the chemical supply path 4. This pressure sensor 1
By monitoring the output of 0, it is possible to monitor the start / stop state of the supply of the chemical liquid by the air valve 9.

From the position between the filter 7 and the flow control valve 8 in the chemical supply path 4, a circulation path 11 for returning the chemical to the chemical tank 3 when the air valve 9 is closed is provided. It has branched. An air valve 12, which is controlled to be closed when the air valve 9 is in an open state and is controlled to be open when the air valve 9 is in a closed state, is provided at an intermediate portion of the circulation path 11. . The circulation path 11 is also provided with a flow control valve 13 for adjusting the flow rate of the chemical solution returned to the chemical solution tank 3. In the chemical supply path 4 between the bellows pump 5 and the flow meter 6, a heat exchanger 15 is attached as temperature adjusting means for maintaining the temperature of the chemical at a constant level. When the chemical is not discharged from the nozzle 2, the chemical is returned to the chemical tank 3 via the circulation path 11, whereby the chemical can be circulated through the heat exchanger 15. The temperature of the chemical in the chemical supply path 4 up to the vicinity of 9 can be maintained at the optimum value.

[0005] The bellows pump 5 is employed for the purpose of achieving the pumping of the chemical solution while stirring the chemical solution as little as possible. The bellows pump 5 is normally driven by compressed air. The bellows of the bellows pump are made of, for example, a fluororesin and have a service life of one to three years. Therefore, the bellows are usually replaced regularly before the service life reaches its useful life. However, in some cases, the bellows may break before its useful life.

When the bellows of the bellows pump 5 is damaged, the compressed air for driving enters the chemical solution supply path 4 and the flow rate of the chemical solution becomes unstable, which may cause a problem in processing the wafer. Therefore, it is necessary to detect the breakage of the bellows pump 5, stop the processing of the wafer immediately, and prevent the wafer having the processing failure from being sent to the subsequent process.

Therefore, conventionally, the output of the pressure sensor 10 during the opening period of the air valve 9 is monitored to detect a decrease in the hydraulic pressure, thereby detecting breakage of the bellows.

[0008]

However, it is not always possible to determine that the bellows has been damaged simply by lowering the hydraulic pressure. For example, immediately after the start of the discharge of the chemical solution, the fluid pressure may decrease due to the characteristics of the bellows pump 5. Further, if gas dissolved in the chemical liquid foams, a pressure drop occurs. An example of a chemical solution that easily foams is sulfuric acid peroxide. Further, gas may accumulate in the filter 7 to cause a pressure drop. Therefore, the pressure drop has various causes other than the damage of the bellows, and there is a disadvantage that the detection of the damage of the bellows based on the output of the pressure sensor 10 lacks certainty.

In some cases, even though the bellows is damaged, the pressure drop is very small. In such a case, the damage of the bellows cannot be detected, and the discharge state of the chemical solution remains unstable. Wafer processing is continued. Therefore, an object of the present invention is to solve the above-described technical problem and to provide a substrate processing apparatus capable of reliably detecting breakage of a pumping unit for pumping a processing liquid.

[0010]

Means for Solving the Problems and Effects of the Invention According to the first aspect of the present invention, there is provided a processing liquid supply path for supplying a processing liquid for processing a substrate to the substrate. A pumping means for pumping the processing liquid through the processing liquid supply path, a container interposed in the processing liquid supply path and capable of storing a predetermined amount of the processing liquid, and a gas discharge connected to the container. A gas discharge valve that is provided in the passage, permits discharge of gas in the container by opening a valve, and restricts discharge of gas in the container by closing the valve; Detecting the amount of the treatment liquid in one of three liquid amount ranges, a first liquid amount range, a second liquid amount range, and a third liquid amount range, in descending order; The amount of the processing liquid in the A processing liquid amount detection unit that outputs a processing liquid amount detection signal indicating whether the processing liquid is present in the container, and the amount of the processing liquid in the container is within the first liquid amount range based on the processing liquid amount detection signal. In this case, the gas discharge valve is closed, and when the gas is in the second liquid amount range, the gas discharge valve is opened. And a control unit for outputting a damage detection signal indicating that the detection has been performed.

According to the above arrangement, air bubbles generated in the processing liquid supply path are captured by the container provided in the processing liquid supply path. When the amount of liquid in the container decreases due to the accumulation of the bubbles in the container, the amount of liquid in the container decreases from the first liquid amount range to the second liquid amount range. In response, the gas discharge valve is opened and discharged from the liquid gas discharge passage in the container. In this way, even if bubbles are generated in the processing liquid supply path, the bubbles can be captured and quickly eliminated.

On the other hand, when the accumulation of air bubbles in the container progresses rapidly and the decrease in the amount of liquid in the container cannot be prevented even by exhausting gas by opening the gas discharge valve, the amount of liquid in the container falls within the third range. Leads to. In response, the control unit outputs a damage detection signal indicating that the pumping means has been damaged. That is, for example, when the pumping means is driven by compressed air, if a large amount of air bubbles are generated at once in the processing liquid supply path, it is considered that the pumping means is damaged. Therefore, in the present invention, the breakage of the pressure feeding means is detected based on a sudden decrease in the amount of the processing liquid in the container.

In this way, since the breakage of the pumping means can be detected without relying on the output of the pressure sensor as in the prior art, the breakage of the pumping means can be reliably and quickly detected. Thereby, it is possible to prevent the occurrence of a defect in the processing of the substrate. According to a second aspect of the present invention, the processing liquid amount detection means detects the amount of the processing liquid in three liquid amount ranges by detecting the level of the processing liquid in the container. A substrate processing apparatus characterized in that the substrate processing apparatus is a surface detection unit.

According to this configuration, since the detection of the liquid amount is performed by detecting the liquid level, the liquid amount in the container can be accurately detected. Thus, the discharge of the gas in the container and the detection of the breakage of the pumping means can be performed more accurately. Claim 3
The invention described in claim 2, wherein the area of the horizontal cross section of the container is smaller in the upper part than in the lower part.
It is a substrate processing apparatus of a statement.

According to this configuration, since the horizontal cross section of the upper portion of the container is formed relatively small, it is possible to quickly detect a change in the liquid level due to the start of the accumulation of bubbles. Thereby, the gas accumulated in the container can be quickly eliminated.

[0016]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a system diagram showing a configuration related to a chemical solution supply of a substrate processing apparatus according to an embodiment of the present invention. This substrate processing equipment
A spin chuck 21 capable of rotating at high speed around a vertical axis passing through the center of the wafer W while holding the wafer W (substrate) is provided. In connection with the spin chuck 21, a nozzle 22 for supplying a chemical solution to the front surface and / or the back surface of the wafer W held by the spin chuck 21 is provided. The chemical to be supplied to the nozzle 22 is stored in a chemical tank 23, and the chemical in the chemical tank 23 is supplied to the nozzle 2 via a chemical supply path 24.
2 is supplied.

A chemical solution is supplied to the nozzle 22
Pump 25 as a pumping means for pumping the liquid toward the container, a trap tank 26 as a container capable of storing a predetermined amount of the chemical liquid and collecting gas generated in the chemical liquid supply path 24, a chemical liquid supply path 24 Flow meter 27 for measuring the flow rate of the chemical solution passing through, a filter 28 for removing foreign substances in the chemical solution, a flow rate adjusting valve 29 for adjusting the flow rate of the chemical solution, and start / stop of the supply of the chemical solution to the wafer W An air valve 30 is provided. Air valve 30
And the chemical supply path 24 between the nozzle 22 and
A pressure sensor 31 for detecting the liquid pressure of the chemical in the chemical supply path 24 is provided. This pressure sensor 3
By monitoring the output of No. 1, it is possible to detect whether the air valve 30 is normally opened and closed.

From the chemical supply path 24 between the filter 28 and the flow control valve 29, a circulation path 32 for returning the pressure-fed chemical to the chemical tank 23 when the air valve 30 is closed. Are formed by branching. An air valve 33, which is closed when the air valve 30 is in the open state and opened when the air valve 30 is in the closed state, is interposed in the middle of the circulation path 32, and is further circulated. A flow control valve 34 for adjusting the flow rate of the chemical is provided. In order to maintain the temperature of the chemical solution at an optimum temperature for processing the wafer W, the bellows pump 25 and the trap tank 2
A heat exchanger 35 as a temperature adjusting means is provided in the chemical solution supply path 24 between the chemical solution supply path 6 and the chemical solution supply path 24. The temperature of the chemical in the supply path 24 is
It can be kept at the optimum value. That is, in this embodiment, during operation of the substrate processing apparatus, the bellows pump 25 is in a driven state throughout.

An air vent pipe 41 forming a gas discharge passage is connected to the upper part of the trap tank 26. The air vent pipe 41 guides the gas stored in the trap tank 26 to the chemical liquid tank 23. An air valve 42 as a gas discharge valve and a flow control valve 43 are interposed in the middle of the air vent pipe 41. On the other hand, the trap tank 26
Are provided with two liquid level sensors S1 and S2 for detecting the liquid level of the liquid in the trap tank 26.

The output signals of these sensors S1 and S2 are given to a control unit 50 for controlling each unit of the apparatus. The output signal of the pressure sensor 31 is also supplied to the control unit 50. The control unit 50 controls the air valves 30, 33, 4 based on the outputs of these sensors.
2 and the operation of the bellows pump 25 is controlled. A display unit 51 such as a liquid crystal display device is also connected to the control unit 50. Under the control of the control unit 50, an abnormal message and the like are displayed on the display unit 51.

FIG. 2 is a diagram for explaining a mode of liquid level detection by the liquid level sensors S1 and S2. The liquid level sensors S1 and S2 are, for example, capacitance type sensors that detect a change in capacitance due to the presence or absence of liquid, and are attached to the outer surface of the trap tank 26. The liquid level sensor S1 detects a chemical solution in the trap tank 26 slightly below the upper surface 26a of the trap tank 26. Further, the liquid level sensor S2 detects the chemical solution in the trap tank 26 further below the liquid level sensor S1.
With these two liquid level sensors S1 and S2, the liquid level of the chemical in the trap tank 26 is higher than the detection height of the liquid level sensor S1 in a first range R1 (corresponding to a first liquid amount range), A second range R2 (corresponding to a second liquid volume range) between the detection heights of the liquid level sensors S1 and S2, and a third range R3 lower than the detection height of the liquid level sensor S2.
(Corresponding to the third liquid amount range), it is possible to distinguish and detect which height range exists. That is, the output signals of the liquid amount sensors S1 and S2 indicate that the amount of the chemical in the trap tank 26 is in three liquid amount ranges of a first liquid amount range, a second liquid amount range, and a third liquid amount range. The processing liquid amount detection signal indicates which of the ranges is within.

In the chemical supply path 24, various gases dissolved in the chemical are changed into bubbles to accumulate in the trap tank 26 due to pressure fluctuations. In this case, a void 45 is formed. Another cause of accumulation of air bubbles in the trap tank 26 is that the bellows of the bellows pump 25 is damaged. In this embodiment, the speed at which the gas dissolved in the chemical solution becomes bubbles and accumulates in the trap tank 26 is different from the speed at which bubbles accumulate in the trap tank 26 due to breakage of the bellows of the bellows pump 25. Attention has been paid to achieving accurate detection of bellows breakage as described below.

FIG. 3 is an illustrative view showing a basic structure of the bellows pump 25. The bellows pump 25 has a pair of cylinders 61 and 62 disposed opposite to each other.
64 are arranged respectively. Compressed air is alternately supplied to the internal space of the cylinders 61 and 62 via an electromagnetic valve mechanism 65, and air in the internal space of the cylinders 61 and 62 is alternately exhausted via the electromagnetic valve mechanism 65. It has become. That is, when compressed air is supplied to one of the cylinders 61 and 62, the air in the other cylinder is exhausted. Flange 63 of bellows 63, 64
a and 64a are connected by a connecting member 66 so that the extension of one bellows and the contraction of the other bellows are synchronized.

The internal space of the bellows 63, 64 is a chemical solution chamber, and this chemical solution chamber communicates with chemical solution supply passages 67, 68 through which the chemical solution from the chemical solution tank 23 is led. Check valves 69 and 70 for preventing backflow to the chemical tank 23 are interposed in the chemical supply paths 67 and 68, respectively. The chemical chambers formed by the inner spaces of the bellows 63 and 62 communicate with chemical outflow passages 71 and 72 for guiding the chemical to the trap tank 26, respectively. Non-return valves 73 and 74 that allow only the outflow of the chemical solution to the trap tank 26 side are interposed in the chemical solution outflow passages 71 and 72, respectively.

With this configuration, if compressed air is supplied from the solenoid valve mechanism 65 to the cylinder 62 and the air in the cylinder 61 is exhausted through the solenoid valve mechanism 65, the bellows 64 contracts and the inside of the bellows 64 The chemical is supplied to the chemical discharge passage 72
And the pressure is sent to the trap tank 26 through the check valve 74. At this time, the bellows 63 extends, and a chemical solution from the chemical solution tank 23 is supplied to the inside thereof through the check valve 69 and the chemical solution supply path 67. Conversely, if compressed air is supplied from the electromagnetic valve mechanism 65 to the cylinder 61 and the air in the cylinder 62 is exhausted through the electromagnetic valve mechanism 65, the bellows 63 contracts and the bellows 64 expands. Therefore, in this case, the chemical from the chemical tank 23 is introduced into the chemical chamber inside the bellows 64, and the chemical in the chemical chamber inside the bellows 63 is pressure-fed to the trap tank 26 side. Thus, the bellows 63 and 64 alternately expand and contract, so that the chemical solution can be supplied almost continuously.

In the bellows pump 25 having such a configuration, if the bellows 63 or 64 is damaged, the compressed air supplied through the solenoid valve mechanism 65 is supplied to the trap tank via the chemical discharge passages 71 and 72. It is sent to the 26 side. If the chemical solution containing the bubbles of the compressed air is supplied to the wafer W, the processing of the wafer W becomes defective.

FIG. 4 is a flowchart for explaining the operation of the control unit 50, and shows processing related to detection of a malfunction in the bellows pump 25. Control unit 5
In the case of 0, first, the output of the liquid level sensor S1 is checked (step n1). If the liquid level sensor S1 detects the chemical, and the liquid level of the chemical in the trap tank 26 is within the first range R1, the air valve 42 is closed (step n2). ).

On the other hand, when the liquid level sensor S1 has not detected the chemical, the output of the liquid level sensor S2 is further checked (step n3). When the liquid level sensor S2 detects the chemical, and the liquid level of the chemical in the trap tank 26 is in the second range R2, the air valve 42 is opened (step n4). As a result, air is vented, and the gas stored in the trap tank 26 is exhausted at a flow rate adjusted by the flow adjustment valve 43. Thereby, when the liquid level rises and reaches the liquid level sensor S1 (step n1), the air valve 42 is closed (step n2).

In this way, the opening / closing control of the air valve 42 based on the outputs of the sensors S1 and S2 allows the trap tank 2
The liquid level in 6 usually rises and falls within a range not lower than the second range R2. If the gas level in the trap tank 26 rapidly increases and the liquid level continues to decrease even when the air valve 42 is opened, the liquid level sensor S2 does not detect the chemical, and the liquid level becomes It falls to the third range R3. At this time, the control unit 50 stops the operation of the device (step n5), further detects the damage of the bellows pump 25, and outputs a damage detection signal. As a result, a message notifying that the bellows pump 25 has been damaged is displayed on the display unit 51 (step n6).

The opening of the flow control valve 43 interposed in the air bleed path 41 allows the air to be bleed faster than the increase in the air bubbles in the trap tank 26 when the bellows pump 25 is normal, and the bellows It is preferable that the air is evacuated much later than the increase of bubbles inside the trap tank 26 due to the damage of the pump 25. Thus, when the bellows pump 25 is normal, the liquid level in the trap tank 26 does not fall below the second range R2, and when the bellows pump 25 is damaged, the liquid level in the trap tank 26 does not fall. Quickly falls to the third range R3.

As described above, in this embodiment, air bubbles are stored in the trap tank 26 interposed in the chemical solution supply path 24, and the air bubbles are exhausted.
Bubbles in the chemical solution can be satisfactorily removed. In addition, since the breakage of the bellows pump 25 is detected based on the rapid increase of the air bubbles in the trap tank 26,
Compared with the conventional technology that relies on the output of the pressure sensor, it is possible to detect the damage of the bellows pump 25 quickly and reliably. Then, in response to the liquid level in the trap tank 26 having dropped to the third range R3, the operation of the apparatus is stopped immediately, and a message indicating that the bellows pump 25 has been damaged is output. Accordingly, it is possible to prevent the wafer W from being processed by the chemical solution containing a large amount of air bubbles, and to promptly notify the user of the apparatus of the failure.

FIG. 5 is a view for explaining the structure of the second embodiment of the present invention. A trap tank 126 to be used instead of the trap tank 26 shown in FIG.
Is shown. The trap tank 26 shown in FIG. 2 has the same horizontal cross section at any height, whereas the trap tank 26 shown in FIG.
In 26, the horizontal section near the detection range of the upper liquid level sensor S1 is formed to be smaller than the horizontal section near the detection range of the lower liquid level sensor S2.

According to this configuration, the trap tank 126
When gas accumulates in the liquid, the liquid level quickly drops. Therefore, the accumulation of gas is promptly detected by the liquid level sensor S1, so that the air can be quickly removed. Although two embodiments of the present invention have been described, the present invention is not limited to the above embodiments. For example, in the above embodiment, the trap tank 2
As a liquid level sensor for detecting the liquid level in 6 or 126,
Although a capacitance type sensor is used, it goes without saying that another form of liquid level sensor may be used. For example, an optical fiber sensor, a photo micro sensor, an ultrasonic sensor, or the like can be applied.

As shown in FIG. 6, the optical fiber type sensor detects the presence or absence of light reflection at the tip portion 81a of a fiber portion 81 made of, for example, a fluororesin. The tip portion 81a is formed to have an inverted conical surface shape. When the tip portion 81a is in the liquid 82, most of the light guided by the fiber portion 81 is radiated into the liquid 82 because the difference in the refractive index between the fiber portion 81 and the liquid 82 is small (see FIG. 6 (a)). On the other hand, when the distal end portion 81a is in the air, most of the light guided to the distal end portion 81a by the fiber portion 81 due to a large refractive index difference between the fiber portion 81 and the air. The light is reflected by the inverted conical surface 81a (FIG. 6 (b)). Therefore, if the light returning from the distal end portion 81a is detected by the light receiving element at the base end portion of the fiber portion 81, the presence or absence of the liquid 82 at the position of the distal end portion 81a can be detected based on the output of the light receiving element.

The photomicrosensor includes a pair of a light emitting element and a light receiving element, so that light emitted from the light emitting element can be received by the light receiving element. Since the amount of light received by the light receiving element changes depending on whether or not the chemical is present in the optical path between the light emitting element and the light receiving element, the presence or absence of the chemical can be detected based on this. In the case of using such a photomicrosensor, for example, as shown in FIG. 7, it is preferable to provide a transparent bypass pipe 85 disposed along the vertical direction on the side surface of the trap tank 26. If photomicrosensors 86 and 87 are provided on the outer surface of the bypass pipe 85 at intervals in the vertical direction, these photomicrosensors 86 and 87 can function as the above-described liquid level sensors S1 and S2. .

Further, the ultrasonic sensor comprises ultrasonic wave generating means and ultrasonic wave receiving means for receiving ultrasonic waves reflected from any object. When such an ultrasonic sensor is attached to the side wall of the trap tank and emits ultrasonic waves toward the internal space of the trap tank, the amount of reflected ultrasonic waves is large when a chemical solution is present, but if the chemical solution does not exist, The amount of ultrasonic reflection is small. Therefore, if the ultrasonic sensors are arranged on the side wall of the trap tank at an interval in the vertical direction, the function as the liquid level sensors S1 and S2 can be achieved.

For detecting the amount of liquid in the trap tank, a weight sensor 90 for detecting the weight of the trap tank 26 can be used as shown in FIG. . Furthermore, in the above embodiment, the trap tank 26 is disposed between the bellows pump 25 and the flow meter 27. However, if the trap tank 26 is closer to the nozzle 22 than the bellows pump 25, It may be arranged at any position on the path 24. However, when the filter 28 has a property that air bubbles are difficult to pass through, it is preferable that the trap tank is disposed closer to the bellows pump 25 than the filter 28 is.

In the above embodiment, when the bellows pump 25 is operated all the time and the chemical liquid is not discharged from the nozzle 22, the chemical liquid tank 2 is connected via the circulation path 32.
Although the chemical solution is returned to 3, the circulation path 32 need not be provided when temperature control of the chemical solution is not important. However, in this case, it is necessary to stop the bellows pump 25 at the same time when the supply of the chemical solution is stopped by closing the air valve 30.

Further, in the above-described embodiment, an example has been described in which the bellows pump is used as the pressure-feeding means for pressure-feeding the processing liquid. However, in the present invention, compressed air may be mixed into the processing liquid due to breakage. The present invention can be widely applied to a substrate processing apparatus using a certain type of pressure feeding means. Further, in the above embodiment, the configuration related to the supply of the chemical solution has been described,
A similar configuration may be adopted for a supply system of another processing liquid such as pure water, for example, in addition to the chemical liquid.

Further, in the above-described embodiment, an example in which the present invention is applied to an apparatus for processing a wafer has been described. However, the present invention relates to another substrate to be processed such as a glass substrate for a liquid crystal display device. Can be widely applied. In addition, various changes can be made within the scope described in the claims.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a configuration related to a chemical solution supply of a substrate processing apparatus according to an embodiment of the present invention.

FIG. 2 is an illustrative view showing a configuration of a portion related to a trap tank of the substrate processing apparatus.

FIG. 3 is an illustrative view for explaining a configuration of a bellows pump;

FIG. 4 is a flowchart for explaining an operation of a control unit related to detection of breakage of the bellows pump.

FIG. 5 is an illustrative view showing another configuration example of the trap tank;

FIG. 6 is a diagram illustrating an example of a liquid level sensor.

FIG. 7 is a diagram showing another example of the liquid level sensor.

FIG. 8 is an illustrative view showing another configuration example for detecting the amount of the chemical solution in the trap tank;

FIG. 9 is a system diagram showing a configuration related to chemical supply of a conventional substrate processing apparatus.

[Explanation of symbols]

 22 Nozzle 23 Chemical liquid tank 24 Chemical liquid supply path 25 Bellows pump 26 Trap tank 41 Air vent pipe 42 Air valve S1, S2 Liquid level sensor

Claims (3)

[Claims] 1. A processing liquid supply path for supplying a processing liquid for processing a substrate to a substrate, a pumping means for pumping the processing liquid through the processing liquid supply path, and a processing liquid supply path. A container that is interposed and is capable of storing a predetermined amount of the processing liquid, and is provided in a gas discharge path connected to the container, and allows discharge of gas in the container by opening a valve,
A gas discharge valve for restricting discharge of gas in the container by closing a valve; and a first liquid amount range and a second liquid amount range in descending order of the amount of the processing liquid in the container. , And a third liquid volume range, and detects which one of the three liquid volume ranges the volume of the processing liquid in the container is in. A processing liquid amount detection unit that outputs a processing liquid amount detection signal representing the processing liquid amount, and based on the processing liquid amount detection signal, when the amount of the processing liquid in the container is within the first liquid amount range, The gas discharge valve is closed, and when it is in the second liquid amount range, the gas discharge valve is opened, and when it is in the third liquid amount range, it is detected that the pressure feeding means is damaged. And a control unit for outputting a breakage detection signal as shown in the figure. 2. The liquid level detecting means for detecting the amount of the processing liquid in three ranges by detecting the position of the liquid level of the processing liquid in the container. A substrate processing apparatus, characterized in that: 3. The substrate processing apparatus according to claim 2, wherein the area of the horizontal section of the container is smaller at the upper part than at the lower part.