JPH11238716A - Substrate treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain an adequate pollution level for a treatment solution in a substrate treatment apparatus. SOLUTION: A treatment apparatus includes a rinsing chamber 4, a reservoir container 61 for reserving pure water, a pump 71, a drain pipe 81, a waste pipe 82, a return pipe 83, a pH meter 92, and a three-way valve 91. In the rinsing chamber 4, the substrate (W) is put in contact with pure water and cleaned. The pure water is fed by the pump 71 from the reservoir container 61 to the rinsing chamber 4. The pure water discharged from the rinsing chamber 4 is conducted through the drain pipe 81, the waste pipe 82, and the return pipe 83. The pure water from the washing chamber 4 is discharged to the waste pipe 82 or returned to the reservoir container 61 by the three-way valve 91 according to the pollution level detected by the pH meter 92.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for processing various substrates, and in particular, to an FPD (Flat PDP) such as a substrate for a liquid crystal display.
The present invention relates to a substrate processing apparatus for processing a substrate for an anel display, a photomask substrate, a printed circuit board, and a semiconductor substrate with a processing liquid.

[0002]

2. Description of the Related Art A substrate processing apparatus used in a manufacturing process of a liquid crystal display, a color filter, a photomask and the like generally includes a plurality of chambers such as a chemical processing chamber, a washing (washing) chamber, and a drying chamber. Further, a transport means for transporting the substrate to each chamber is provided.

In the rinsing chamber, a rinsing liquid such as pure water is supplied to the substrate that has been treated with the chemical solution, and a rinsing process is performed to wash away the chemical solution attached to the substrate. A rinsing liquid, which is a processing liquid for the rinsing process, is supplied to the rinsing chamber from a storage tank by a supply unit. Also, a discharge path for discharging the rinse liquid used in the washing chamber,
And a switching valve connected to the discharge path outlet side, one branch downstream of the switching valve is connected to a waste path outside the device, and the other branch downstream of the switching valve is connected to a storage tank. ing.

[0004] When the substrate having the chemical liquid attached thereto is carried into the washing chamber, the substrate starts to be washed by the rinsing liquid supplied from the storage tank. For a while after the start of the cleaning, the rinse liquid (hereinafter, referred to as high-concentration drainage) having a relatively high degree of chemical solution mixing (chemical solution mixing degree) due to the cleaning of the substrate flows out to the discharge path. At this time, the switching valve establishes communication between the discharge path and the waste path (a state in which the rinse liquid does not flow from the discharge path to the storage tank), and the high-concentration drainage is guided to the waste path. Then, the cleaning of the substrate proceeds to some extent,
When a rinsing liquid (hereinafter, referred to as low-concentration drainage) having a relatively low degree of chemical solution flow into the discharge path, the switching valve is switched, and the low-concentration drainage flows from the discharge path to the storage tank. By returning the low-concentration wastewater to the storage tank in this way, the amount of the rinsing liquid to be used can be saved, and the amount of the waste liquid (rinse liquid to be discarded) is reduced, so that the waste liquid treatment cost is suppressed. In addition, since the high-concentration wastewater is prevented from returning to the storage tank by operating the switching valve, the degree of mixing of the chemical into the rinse liquid in the storage tank is maintained at a level suitable for cleaning.

[0005]

Conventionally, the operation (switching operation) of the switching valve is manually performed by an operator, or a predetermined time has elapsed after the start of cleaning of the substrate. It is automatically controlled by a timer or the like. However, with such a switching operation, it is difficult to accurately and appropriately maintain the degree of mixing of the chemical solution into the rinsing liquid in the storage tank. In other words, it is difficult to make the switching time appropriate, and the high-concentration wastewater flows into the storage tank, and the rinsing liquid in the storage tank is contaminated beyond an allowable range, and the cleaning treatment capacity is reduced. There is a problem that the wastewater is discarded to a waste path and sufficient reuse cannot be achieved. In particular, when the timer control is performed, the appropriate switching time is set because the degree of mixing of the chemical with the rinse liquid to be discharged varies greatly depending on the size of the substrate to be processed, and the amount of the chemical attached varies depending on the surface state of the substrate. It is not constant, and the above-mentioned problems are likely to occur. Further, manual control based on the experience of the operator is disadvantageous in terms of work efficiency and cost.

An object of the present invention is to solve the problem of the contamination degree (concentration) of the processing solution.
The object of the present invention is to provide a substrate processing apparatus in which is more appropriately held.

[0007]

A substrate processing apparatus according to claim 1 is an apparatus for processing a substrate with a processing liquid,
A processing unit, a storage unit, a supply unit, a discharge unit, a detection unit, and a switching unit are provided. In the processing unit, the processing is performed on the substrate by bringing the processing liquid into contact with the substrate. The storage unit stores the processing liquid. The supply means carries the processing liquid from the storage unit to the processing unit. The discharge unit flows the processing liquid discharged from the processing unit. The detecting means detects the degree of contamination of the processing liquid. The switching unit switches between disposal of the processing liquid discharged from the processing unit and return of the processing liquid discharged from the processing unit to the storage unit according to the degree of contamination detected by the detection unit.

In this substrate processing apparatus, processing is performed by bringing a processing liquid supplied from a storage section into contact with a substrate in a processing section. The processing liquid that has processed the substrate by contact with the substrate flows to the discharge unit while being contaminated by the processing. The processing liquid is discarded or returned to the storage unit by the switching unit. The switching of the switching unit is performed according to the degree of contamination of the processing liquid detected by the detecting unit.

Here, a detecting means is provided to monitor the degree of contamination of the processing liquid. Then, it is determined whether to discard the processing liquid that has processed the substrate or return the processing liquid to the storage unit again based on the degree of contamination of the processing liquid. For this reason, the degree of contamination of the processing liquid in the storage unit for processing the substrate can be accurately maintained at a predetermined value. Further, wasteful disposal of the processing liquid having a low degree of contamination is reduced, and the cost for disposal is reduced.

According to a second aspect of the present invention, there is provided a substrate processing apparatus having a function of processing a chemical solution on a substrate and a cleaning processing function of cleaning a chemical solution adhered to the substrate after the processing of the chemical solution.
The storage device includes a storage unit, a supply unit, a discharge unit, a detection unit, and a switching unit. The processing unit accommodates the substrate that has been subjected to the chemical treatment, and rinses the chemical from the substrate by bringing the rinse liquid into contact with the substrate. The storage stores the rinse liquid.
The supply means carries the rinsing liquid from the storage section to the processing section. The discharge unit flows the rinse liquid discharged from the processing unit. The detecting means detects the degree of contamination of the rinsing liquid discharged from the processing section. The switching unit switches between rinsing the rinsing liquid discharged from the processing unit and returning the rinsing liquid discharged from the processing unit to the storage unit in accordance with the degree of contamination detected by the detection unit.

In this substrate processing apparatus, a cleaning process is performed on the substrate that has been subjected to the chemical liquid treatment, in the processing unit, by contacting the rinse liquid supplied from the storage unit to wash out the chemical liquid. The rinse liquid that has cleaned the substrate by contact with the substrate flows to the discharge section in a state in which the cleaning liquid is contaminated by mixing with a chemical liquid. This rinsing liquid is
Discarded or returned to storage. The switching of the switching unit is performed according to the degree of contamination of the rinsing liquid detected by the detecting unit.

Here, a detecting means is provided to monitor the degree of contamination of the rinse liquid discharged from the processing section. And
Whether to discard the rinse solution after washing the substrate or to return the rinse solution to the storage unit is determined based on the degree of contamination of the rinse solution. Therefore, the degree of contamination of the rinsing liquid in the storage section for cleaning the substrate can be accurately maintained at a predetermined value. In addition, wasteful disposal of the low-contamination rinse liquid is reduced, and the cost for disposal is reduced.

According to a third aspect of the present invention, there is provided a substrate processing apparatus.
The detecting means is a pH meter that detects the pH of the rinsing liquid. The chemical for treating the substrate is usually acidic or alkaline. Therefore, the pH of the rinsing liquid after cleaning the chemical liquid adhered to the substrate in the processing unit changes as compared with the rinsing liquid before cleaning.

Here, the degree of contamination of the rinsing liquid discharged from the processing section is monitored by detecting the pH of the rinsing liquid discharged from the processing section with a pH meter. According to a fourth aspect of the present invention, in the apparatus of the second or third aspect, the discharge unit includes a discharge pipe, a waste pipe, and a return pipe. The discharge pipe extends from the processing section. The waste pipe is connected to a waste path outside the substrate processing apparatus. The return pipe is connected to the reservoir. These discharge pipe, waste pipe, and return pipe are connected by switching means. The switching means is a switching valve that connects the discharge pipe, the waste pipe, and the return pipe, and flows the rinse liquid flowing through the discharge pipe to the waste pipe or the return pipe.

Here, the rinsing liquid that has washed the substrate by contact with the substrate flows to the discharge pipe of the discharge section while being contaminated by the cleaning. The rinse liquid flowing through the discharge pipe
By the switching means, it flows to the waste pipe and is discarded in the waste path, or is returned to the storage part through the return pipe. According to a fifth aspect of the present invention, in the apparatus of the fourth aspect, the detecting means detects a degree of contamination of a waste pipe of the discharge section or a rinse liquid flowing through the discharge pipe.

If the degree of contamination of the rinsing liquid discharged from the processing section is monitored by detecting the degree of contamination of the rinsing liquid flowing through the return pipe, the rinsing liquid with a high degree of contamination is detected immediately by the return pipe. Even if the flow of the rinsing liquid from the discharge pipe to the return pipe is stopped by the switching means, at this time, the highly-contaminated rinse liquid already inside the return pipe flows into the storage section. This may increase the degree of contamination of the rinsing liquid stored in the storage unit. In particular, when a highly-contaminated rinsing liquid flows into the return pipe, the degree of contamination of the rinsing liquid in the storage section jumps at a stretch, and a large amount of new rinsing liquid is required to dilute the rinsing liquid to an allowable level.

Here, since the contamination degree of the rinsing liquid flowing through the waste pipe or the discharge pipe of the discharge section is monitored, when the contamination degree of the rinsing liquid in these pipes becomes low, the return means returns to the discharge pipe by the switching means. What is necessary is just to let a pipe | tube communicate.
Normally, as the cleaning of the substrate proceeds, the degree of contamination of the rinsing liquid discharged from the processing unit becomes lower, so when the discharge pipe and the return pipe are connected, the degree of contamination of the rinsing liquid flowing through the discharge pipe is lower than when the detection is performed. Has become. Therefore, the degree of contamination of the rinsing liquid in the storage part rarely becomes higher than the allowable value.

According to a sixth aspect of the present invention, there is provided a substrate processing apparatus.
In the apparatus according to any one of Items 1 to 5, the storage section is a storage tank having an overflow section. The rinsing liquid flowing into the overflow section is discarded in a waste path outside the substrate processing apparatus. Here, for example, even when the amount of the chemical liquid attached to the substrate is small and the rinsing liquid returning to the storage tank is increased, the overflow section is provided in the storage tank,
It is possible to prevent the rinsing liquid from overflowing from the storage tank and leaking out around the device.

When the substrate is washed and the rinsing liquid mixed with the chemical leaks to the periphery of the apparatus, the chemical mixed in the rinsing liquid directly affects the apparatus, evaporates or becomes mist-like. The applied chemical liquid has an adverse effect on the substrate. Therefore, when the rinsing liquid is reused, it is important to prevent the rinsing liquid from leaking out of the storage tank as in the present invention.

According to a seventh aspect of the present invention, there is provided a substrate processing apparatus according to the sixth aspect.
The apparatus according to the above item, further comprising a new liquid replenishing means. The storage tank is divided into a first section and a second section by a partition member, and has a communication portion for communicating the first section and the second section. The overflow section is provided in the second section. The supply unit supplies the rinsing liquid from the first section to the processing unit. The rinsing liquid returning from the discharge unit to the storage tank is returned to the second section of the storage tank. The new liquid replenishing means replenishes the first section with a new rinse liquid.

Here, the storage tank is divided into two sections,
The degree of contamination of the rinsing liquid in the first section is lower than that of the rinsing liquid in the second section. That is, a new rinsing liquid is supplied to the first section by the new liquid supply means, and a rinsing liquid containing a chemical liquid and having a relatively high degree of contamination is returned from the discharge section to the second section. However, since the first and second sections communicate with each other through the communication portion, the liquid level heights of both sections are substantially equal, and the degree of contamination of the rinsing liquid in both sections becomes closer as time passes.

Since the overflow section is provided in the second section, the rinsing liquid in the second section flows out to the overflow section preferentially. As described above, since the rinsing liquid in the second compartment, which has a higher degree of contamination than the rinsing liquid in the first compartment, overflows first, the degree of contamination of the rinsing liquid in the storage tank is kept low.

[0023]

FIG. 1 shows a substrate processing apparatus 1 according to an embodiment of the present invention. The substrate processing apparatus 1 is an apparatus that performs an etching process on a thin film formed on a glass substrate W for a liquid crystal display, and mainly includes a series of chambers (an introduction chamber 2, an etching chamber 3, a washing chamber 4, and a drying / unloading chamber). Chamber 5) and a transport roller 6 penetrating each chamber.

When a substrate W having a thin film formed on its surface is carried to the substrate processing apparatus 1, the substrate W is first carried into the introduction chamber 2. After that, the substrate W is moved to the etching chamber 3 by the transport roller 6. In the etching chamber 3, a chemical solution for etching is sprayed on the substrate W, and a thin film on the substrate surface is etched by a predetermined thickness. The substrate W thus etched is then sent to the rinsing chamber 4, where the chemical solution attached to the substrate W is washed away. Then, the substrate W that has been subjected to the water washing process is carried out after the drying process by air blowing is performed in the drying / unloading chamber 5.

The etching chamber 3 has an upper spray 31 and a lower spray 32 for injecting a chemical solution onto the substrate W, position sensors 33 and 34 used when the substrate W is rocked back and forth by the transport roller 6, and an etching end point. An EPS (end point sensor) 35 of an optical reflection type for detecting the In the etching chamber 3, the end of the etching is automatically detected by the EPS 35. Until then, the substrate W is repeatedly swung back and forth between the position sensors 33 and 34 and the sprays 31 and 32 are repeated. Receives injection of chemicals from In addition,
The etching chemical sprayed onto the substrate W from the sprays 31 and 32 is acidic.

The drying / unloading chamber 5 is provided with upper and lower air knives 51 and 52 for injecting dry air onto the substrate W, and a mist prevention cover 53. In the drying / unloading chamber 5, pure water adhering to the substrate W is blown off by dry air jetted from the air knives 51 and 52 in the water washing process in the water washing chamber 4 described later, and the substrate W is dried. The mist prevention cover 53 is a member similar to a mist prevention cover 45 described later, and prevents mist of pure water generated in the washing chamber 4 from entering the adjacent drying / unloading chamber 5.

Next, the flow of the pure water which is a rinsing liquid used in the rinsing process of the substrate W in the rinsing chamber (processing section) 4 and the rinsing chamber 4 will be described in detail. As shown in FIGS. 1 and 2, an upper cleaning spray 41, a lower cleaning spray 42, and a position sensor 4 are provided in the washing chamber 4.
3, 44, mist prevention cover 45, inlet liquid curtain 46
Is arranged. A partition wall 49 is provided between the washing chamber 4 and the drying / unloading chamber 5, and a damper 47 is provided on a ceiling wall of the washing chamber 4. The damper 47 adjusts the pressure inside the washing chamber 4.

The upper and lower cleaning sprays 41, 42 are:
It has spray nozzles 41a and 42a directed to the substrate W, and injects pure water (rinse liquid) as a cleaning treatment liquid to the substrate W. The inlet liquid curtain 46 is provided upstream of the cleaning sprays 41 and 42 in the transport direction of the substrate W (a direction from the left side to the right side in FIGS. 1 and 2) as shown in FIG. Pure water is sprayed on the substrate W transferred to the
Wet evenly. Further, the spray position of the pure water by the inlet liquid curtain 46 is on the upstream side of the position sensor 43 in the substrate transport direction.

Pure water is supplied to both of the cleaning sprays 41 and 42 and the inlet liquid curtain 46 from a storage tank 61 shown in FIG. The storage tank 61 is divided into a first section 61a and a second section 61b by a partition member 62 (see FIGS. 2 and 3). In the upper part of the first section 61a,
By opening the valve 60a, new pure water flows from the pure water supply source 60. Further, a pipe extends from the lowermost part of the first section 61a toward the pump (supply means) 71. If the valve 71 between the storage tank 61 and the pump 71 is opened to drive the pump 71, the supply is started. From the main pipe 73 through the first supply branch pipe 74 and the second supply branch pipe 75 to the inlet liquid curtain 46 and both cleaning sprays 41 and 42, the first section 61a.
Pure water is supplied.

Inlet liquid curtain 46 and both cleaning sprays 4
The pure water sprayed or sprayed from 1, 42 contacts the surface of the substrate W to wash away the chemical solution attached to the substrate W, and then flows to the lower part of the washing chamber 4. Then, the pure water containing the chemical solution removed from the substrate W flows into the discharge pipe 81 connected to the bottom of the washing chamber 4. At the downstream end of the discharge pipe 81, there is an electromagnetic three-way switching valve (switching means) 91. In addition to the discharge pipe 81, a waste pipe 82 and a return pipe 83 are connected to the three-way switching valve 91 (see FIG. 2). The waste pipe 82 is connected to a waste path 99 outside the substrate processing apparatus 1, and a return pipe 83 is provided.
Is connected to the second section 61b of the storage tank 61. The discharge pipe 81, the waste pipe 82, and the return pipe 83 (discharge section) are connected by switching means. By switching the three-way switching valve 91, the discharge pipe 81 and the waste pipe 8 are switched.
2 and the discharge pipe 81 and the return pipe 83 are not in communication, or the discharge pipe 81 and the return pipe 83 are in communication and the discharge pipe 81 and the waste pipe 82 are not in communication. . The three-way switching valve 91 is switched by a signal from a control unit (not shown).

At the start of the cleaning process of the substrate W, the three-way switching valve 91 is switched so that the discharge pipe 81 and the waste pipe 82 are in communication with each other, and the cleaning is performed from the discharge pipe 81 to the waste pipe 82. Pure water after treatment (hereinafter referred to as waste water) flows. Thereafter, the waste water is discarded from the waste pipe 82 to the waste path 99. The waste water to be discarded is supplied to a waste pipe 8
During the flow through 2, the pH is measured by a pH meter 92 attached to a measurement hole provided in the waste pipe 82. The pH value measured by the pH meter 92 is monitored by the control unit. When it is determined that the pH of the wastewater in the waste pipe 82 is higher than a predetermined value and the pollution degree of the wastewater which is acidic and contaminated by the chemical liquid is lower than an allowable value, the control unit sends the three-way switching valve 91 a signal. A signal is sent, and the three-way switching valve 91 is connected to the discharge pipe 81 and the return pipe 83 so that the discharge pipe 8
1 and the waste pipe 82 are switched to a state where they do not communicate with each other. In other words, when the cleaning of the substrate W progresses and the degree of contamination of the wastewater used for the cleaning treatment with the chemical solution becomes lower than a predetermined value,
The wastewater (hereinafter referred to as low-contamination wastewater. Further, wastewater having a higher degree of contamination than the low-contamination wastewater is referred to as high-contamination wastewater) is provided as return water 83 as pure water that can be used for washing again. Then, it is returned to the storage tank 61.

The low-contamination wastewater returned from the discharge pipe 81 to the storage tank 61 through the return pipe 83 is supplied to the second compartment 6 of the storage tank 61.
1b. The second section 61b includes the partition member 6
2, and communicates with the first section 61a at a lower portion as described later (see FIGS. 2 and 3).
reference). As shown in FIG. 3, the partition member 62 includes pentagonal side portions 62a and 62b, a vertical portion 62c, and an inclined portion 62.
The side portions 62a and 62b are joined to both ends of the vertical portion 62c and the inclined portion 62d which are adjacent to each other with an inclination so as to be orthogonal to the vertical portion 62c and the inclined portion 62d.
One side of the side portions 62a, 62b is fixed to a side plate of the storage tank 61. Then, the side plate of the storage tank 61 and the partition member 6
2 is a second section 61b. As shown in FIG. 3, an opening (communication portion) 62e is formed between the side plate of the storage tank 61 and the inclined portion 62d.
e, the pure water in the second section 61b and the first section 61a
The pure water inside can come and go.

An overflow pipe (overflow section) 63 provided on the side plate of the storage tank 61 is connected to the upper part of the second section 61b. When the liquid level of the pure water in the storage tank 61 rises and reaches the level of the overflow pipe 63 in the second section 61b, the pure water in the second section 61b flows into the overflow pipe 63. . The overflow pipe 63 is connected to the above-mentioned waste pipe 82, and the pure water flowing into the overflow pipe 63 passes through the waste pipe 82 and is discarded in the waste path 99.

At the time of maintenance or the like, the storage tank 61
The pure water in the storage tank 61 can be discharged by opening a valve 64 shown in FIG. Further, the water level gauge 65 monitors the water level of the storage tank 61, and when the water level falls, new pure water is supplied from the pure water supply source 60 to the storage tank 61. The mist prevention cover 45 shown in FIGS. 1, 2, 4, and 5 is provided to prevent mist from entering the drying / unloading chamber 5 from the washing chamber 4 and is attached to and detached from the partition wall 49. It is freely fixed. The configuration of the mist prevention cover 45 is shown in FIGS. The mist prevention cover 45 is
An elongated sheet metal member, comprising a fixed portion 45a, an inclined portion 45,
b and an intrusion prevention part 45c,
The fixed part 45a and the intrusion prevention part 45c, which are parallel to each other, are connected by an inclined part 45b. The fixing portion 45a is provided with a plurality of long holes 45e, and the fixing portion 45a is fixed to the partition wall 49 by bolts passing through the long holes 45e. The intrusion prevention portion 45c is provided with an opening 45d slightly larger than a cross section of the substrate W orthogonal to the substrate transport direction. The height h2 of the opening 45d is larger than the thickness of the substrate W, but the height of the opening 49a of the partition wall 49 provided so that the largest substrate that can be processed by the present apparatus 1 can pass through. Smaller than the dimension h1 (FIG. 4)
reference). Therefore, the mist from the washing chamber 4 can be prevented from passing through the opening 49a of the partition wall 49 and entering the drying / unloading chamber 5, so that drying in the drying / unloading chamber 5 can be performed efficiently.

The mist prevention cover 45 is attached after the transport mechanism such as the transport roller 6 is adjusted to determine the height at which the substrate is transported (hereinafter referred to as the substrate transport height). At this time, since the long hole 45e is a vertically long hole, the mist prevention cover 45 can be moved up and down so that the opening 45d can be attached to correspond to the substrate transfer height. Therefore, when adjusting the transfer mechanism, the transfer mechanism can be easily adjusted because the substrate transfer height may be anywhere as long as the opening 49a exists.

If the mist is to be prevented from entering without using the mist prevention cover 45, the opening 49a must be narrowed. However, if the opening 49a is narrowed, the transfer mechanism can be adjusted only within a range where the substrate transfer height can be accommodated in the opening 49a, so that the adjustment becomes difficult. The position sensors 43 and 44 shown in FIGS.
This is an optical fiber sensor that detects the position of the substrate W in the substrate transport direction in the washing chamber 4.

Next, the cleaning of the substrate W in the washing chamber 4 will be described. The substrate W, which has been subjected to the etching treatment with the chemical solution in the etching chamber 3 and has the chemical solution attached thereto, is sent to the washing chamber 4 by the transport roller 6. At this time, pure water is first sprayed from the inlet liquid curtain 46 onto the substrate W, and the substrate W is carried between the position sensors 43 and 44 while being uniformly wet with the pure water. Thereafter, the substrate W is moved by the position sensors 43, 4 for a predetermined time.
The swinging back and forth between steps 4 is repeated. At this time, pure water is sprayed onto the substrate W from the upper and lower cleaning sprays 41 and 42. The pure water comes into contact with and collides with the substrate W, and the chemical solution attached to the substrate W is washed away from the substrate W.
Pure water (drainage) that has been washed and mixed with a chemical solution and contaminated flows into the lower portion of the washing chamber 4 and flows into the discharge pipe 81. The wastewater flowing into the discharge pipe 81 is discarded or returned to the storage tank 61 for reuse as described above.

In the substrate processing apparatus 1 of this embodiment, a pH meter 92 is provided to monitor the degree of contamination of the waste water. And
Based on the degree of contamination, it is determined whether the waste water obtained by cleaning the substrate W is discarded or returned to the storage tank 61 again. For this reason,
The degree of contamination of the pure water in the storage tank 61 can be accurately maintained at a predetermined value or less. In addition, wasteful disposal of low-contamination wastewater is reduced, and the cost for disposal is reduced.

If a pH meter is provided in the return pipe 83, even if the flow from the discharge pipe 81 to the return pipe 83 is stopped immediately after the detection of highly contaminated wastewater, the return pipe 83 Is discharged into the storage tank 61. In such a case, the degree of contamination of the pure water in the storage tank 61 jumps up, and a large amount of new pure water must be supplied from the pure water supply source 60 in order to dilute this to an allowable level. Until the degree of contamination of the pure water in the storage tank 61 decreases, the substrate W is cleaned with pure water having no sufficient cleaning ability.

However, since the pH meter is provided in the waste pipe 82 here, the flow from the discharge pipe 81 is switched from the waste pipe 82 to the return pipe 83 after the degree of contamination of the waste water in the waste pipe 82 becomes low. Normally, as the cleaning of the substrate W proceeds, the degree of contamination of the wastewater discharged from the washing chamber 4 decreases, so that the flow from the discharge pipe 81 is returned from the waste pipe 82 to the return pipe 8.
After the switch to 3, the pollution degree of the wastewater will decrease. Therefore, the degree of contamination of the pure water in the storage tank 61 hardly becomes higher than the allowable value. Although a pH meter is provided in the waste pipe 82 here, even if a pH meter is provided in the discharge pipe 81, the degree of contamination of pure water in the storage tank 61 hardly becomes higher than the allowable value. . Further, a pH meter may be provided in the washing chamber 4 to wash the substrate W and detect the contamination degree of pure water mixed with the chemical solution. At the stage where the cleaning of one substrate W is completed and the injection of pure water from both cleaning sprays to the substrate W is stopped, the three-way switching valve 9
1 is switched, the discharge pipe 81 and the waste pipe 82 communicate with each other, and the discharge pipe 81 and the return pipe 83 do not communicate with each other to prepare for the next processing of the substrate W.

Further, since the overflow pipe 63 is provided here, even when the amount of the chemical liquid attached to the substrate W is small and the low-contamination drainage returning to the storage tank 61 increases, for example,
Pure water is prevented from overflowing from the storage tank 61 and leaking to the surroundings. Here, the storage tank 61 is divided into two sections, and the first section 61 is compared with the pure water in the second section 61b.
The degree of contamination of the pure water in a is reduced. That is, new pure water is supplied to the first section 61a, and low-contamination wastewater having a higher degree of contamination than the pure water in the storage tank 61 is returned to the second section 61b. (However, since the first and second sections 61a and 61b communicate with each other through the opening 62e, the liquid level heights of the two sections 61a and 61b are substantially equal, and if time passes, the contamination of pure water in both sections 61a and 61b will occur. The degree approaches.)
Then, since the overflow pipe 63 is provided in the second section 61b, the pure water in the second section 61b overflows preferentially. As described above, since the pure water in the second section 61b, which has a higher degree of contamination than the pure water in the first section 61a, overflows first, the degree of contamination of the pure water in the storage tank 61 is kept low.

Here, by utilizing the fact that the acidic etching chemical is mixed into the pure water after the cleaning treatment, the drainage water is removed.
By monitoring H, the three-way switching valve 91 is switched. The method of monitoring the pH of the wastewater is not limited to the above-described combination of the etching process and the washing process, but may be employed in a combination of a developing process using an alkaline chemical solution or a combination of a stripping process and a washing process.

[0043]

According to the substrate processing apparatus of the present invention, a detecting means is provided to monitor the degree of contamination of the processing liquid, and whether the processing liquid obtained by processing the substrate is discarded or returned to the storage tank according to the degree of contamination of the processing liquid. Since the determination is made, the degree of contamination of the processing liquid in the storage unit for processing the substrate is more appropriately maintained.

[Brief description of the drawings]

FIG. 1 is a schematic view of a substrate processing apparatus according to an embodiment of the present invention.

FIG. 2 is a flow diagram of pure water used in a washing chamber.

FIG. 3 is a perspective view of a partition member.

FIG. 4 is an enlarged sectional view near a mist prevention cover.

FIG. 5 is a front view of a mist prevention cover.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 3 Etching chamber 4 Rinse chamber (processing part) 60 Pure water supply source 61 Storage tank 61a 1st section 61b 2nd section 62 Partition member 62e Opening (communication part) 71 Pump (supply means) 81 Discharge pipe 82 Disposal Pipe 83 Return pipe 91 Three-way switching valve (switching means) 92 pH meter (detection means) 99 Waste path

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C02F 1/00 C02F 1/00 V

Claims (7)

[Claims] 1. A substrate processing apparatus for processing a substrate with a processing liquid, comprising: a processing unit for performing processing on the substrate by bringing the processing liquid into contact with the substrate; a storage unit for storing the processing liquid; A supply unit that carries the processing liquid to the processing unit; a discharge unit that flows the processing liquid discharged from the processing unit; a detection unit that detects the degree of contamination of the processing liquid; and a contamination unit that is detected by the detection unit. A substrate processing apparatus comprising: switching means for switching between discarding the processing liquid discharged from the processing unit and returning the processing liquid discharged from the processing unit to the storage unit. 2. A substrate processing apparatus having a function of processing a chemical solution on a substrate and a cleaning function of cleaning a chemical solution adhered to the substrate after the processing of the chemical solution, wherein the substrate that has been processed by the chemical solution is accommodated, and a rinsing liquid is brought into contact with the substrate A processing unit for flushing a chemical solution from the substrate, a storage unit for storing a rinse liquid, a supply unit for conveying a rinse liquid from the storage unit to the processing unit, and a discharge unit for flowing a rinse liquid discharged from the processing unit. Detecting means for detecting the degree of contamination of the rinsing liquid discharged from the processing unit; disposing of the rinsing liquid discharged from the processing unit in accordance with the degree of contamination detected by the detecting means; A switching means for switching between returning the rinse liquid discharged from the storage section to the storage section. 3. The substrate processing apparatus according to claim 2, wherein said detecting means is a pH meter for detecting a pH of the rinsing liquid. 4. The discharge section has a discharge pipe extending from the processing section, a waste pipe connected to a waste path outside the substrate processing apparatus, and a return pipe connected to the storage section. 4. The substrate processing apparatus according to claim 2, wherein the switching valve connects the discharge pipe, the waste pipe, and the return pipe, and the rinse liquid flowing through the discharge pipe flows through the waste pipe or the return pipe. 5. . 5. The substrate processing apparatus according to claim 4, wherein said detecting means detects a degree of contamination of a rinsing liquid flowing through a waste pipe or a discharge pipe of said discharge section. 6. The storage device according to claim 2, wherein the storage portion is a storage tank having an overflow portion, and the rinsing liquid flowing out of the overflow portion is disposed in a waste path outside the substrate processing apparatus. Substrate processing equipment. 7. The storage tank is divided into a first section and a second section by a partition member, and has a communication portion that communicates the first section and the second section. The supply means is provided in the second section, and the supply means supplies a rinsing liquid from the first section to the processing section, and a rinsing liquid returned from the discharge section is returned to the second section of the storage tank. 7. The substrate processing apparatus according to claim 6, further comprising a new liquid replenishing unit that replenishes the first section with a new rinse liquid.