JP2023176416A - Substrate processing device and substrate processing method - Google Patents

Abstract

To provide a substrate processing device and a substrate processing method in which a problem does not occur in an explosion protection manner even when a solvent is mixed with sealing water.SOLUTION: A control unit 111 decompresses the inside of a chamber 3 by actuating a water sealing type vacuum pump 45, and supplies water repellency agent gas from a third nozzle 19 to perform processing on a substrate W, and discharges a portion of sealing water in a drain tank 57 by opening an on-off valve 73 when the decompression in the chamber 3 by the water sealing type vacuum pump 45 is complete. Therefore, the density of the water repellency agent in the sealing water in the drain tank 57 can be prevented from increasing to a fixed level or higher. Consequently, a problem does not occur in an explosion protection manner even when a solvent is mixed with sealing water.SELECTED DRAWING: Figure 1

Description

The present invention relates to a substrate processing apparatus and a substrate processing method. Examples of the substrate include semiconductor wafers, liquid crystal display substrates, organic EL (Electroluminescence) substrates, FPD (Flat Panel Display) substrates, optical display substrates, magnetic disk substrates, optical disk substrates, magneto-optical disk substrates, These are photomask substrates and solar cell substrates.

Conventionally, as this type of apparatus, there is an apparatus for processing a substrate (see, for example, Patent Document 1). This device includes a chuck table, a water ring vacuum pump, a drainage tank, a circulation path, and a heat exchanger.

A substrate to be processed is placed on the chuck table, and processing water is supplied to the chuck table. A portion of the processing water and air supplied to the chuck table are collected in a drainage tank through a suction path by suction by a water ring vacuum pump. One end of the circulation path is connected to the drainage tank, and the other end is connected to the water seal water supply port of the water ring vacuum pump via a heat exchanger. Processing water stored in the drainage tank passes through a circulation path and is cooled by a heat exchanger. Thereby, there is no need to replenish the water ring type vacuum pump with new cooled water seal water, and a complete circulation type can be constructed. The drainage tank separates the processed water and sealed water from air and releases the air to the atmosphere. The drain tank is configured such that a discharge pipe equipped with an on-off valve is connected to the lower part thereof, and water can be drained by operating the on-off valve.

Patent No. 4608074

However, the conventional example having such a configuration has the following problems.
That is, in the conventional device, a mixture of processed water, sealed water, and air is stored in a drainage tank. By the way, depending on the semiconductor processing process, a solvent may be mixed into the water sealing water. Therefore, if the solvent continues to be mixed into the water seal water, the concentration of the solvent in the water seal water will increase, and the solvent will volatilize in the drainage tank, causing a problem in terms of explosion protection.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a substrate processing apparatus and a substrate processing method that do not cause explosion-proof problems even when a solvent is mixed into water sealing water. purpose.

In order to achieve such an object, the present invention has the following configuration.
That is, the invention according to claim 1 provides a substrate processing apparatus that performs predetermined processing on a substrate, including a chamber that accommodates a substrate and performs processing on the substrate, and a chamber that contains a solvent insoluble in pure water. A solvent gas supply means for supplying the solvent gas into the chamber, a suction port for sucking the gas in the chamber, a discharge port for discharging the gas, and a water seal to which water is supplied. a water ring type vacuum pump having a water seal water supply port; a pressure reducing pipe having one end connected to the chamber and the other end connected to the suction port; and a water ring vacuum pump having a water seal water supply port; a drainage tank for storing the gas and water seal in the chamber containing the water seal, a circulation piping that communicates and connects the drainage tank and the water seal water supply port of the water ring vacuum pump, and provided in the circulation piping, a heat exchanger that cools the liquid flowing in the circulation pipe; an exhaust pipe connected to the upper part of the drainage tank; a drain pipe connected to the lower part of the drainage tank; An on-off valve is provided to control the flow of liquid in the drain pipe, and the water ring vacuum pump is operated to reduce the pressure in the chamber, and a solvent gas is supplied from the solvent gas supply means to supply the substrate. a control unit that opens the on-off valve and discharges a part of the liquid in the drainage tank when the pressure reduction in the chamber by the water ring vacuum pump is completed after the treatment; It is characterized by the fact that

[Operation/Effect] According to the invention described in claim 1, the control unit operates the water ring vacuum pump to reduce the pressure in the chamber, and supplies the solvent gas from the solvent gas supply means to process the substrate. conduct. Thereafter, when the pressure reduction in the chamber by the water ring vacuum pump is completed, the on-off valve is opened to discharge a portion of the liquid in the drainage tank. Therefore, it is possible to prevent the concentration of the solvent in the liquid in the drainage tank from becoming higher than a certain level. As a result, even if the solvent is mixed into the water sealing water, there will be no explosion-proof problem.

Further, in the present invention, it is preferable that the control unit opens the on-off valve immediately after activating the water ring vacuum pump to circulate the liquid in the drainage tank through the circulation pipe. 2).

Since the solvent is insoluble in pure water, the solvent separates from the liquid stored in the drain tank. Therefore, by circulating the liquid in the drainage tank through the circulation piping, the solvent and pure water are stirred, and the solvent is mixed with the pure water. Since the on-off valve is opened immediately after that, the solvent component can be reliably discharged from the drainage tank.

Further, in the present invention, the invention further includes a first inert gas supply means for supplying an inert gas into the chamber, and the control unit controls the first inert gas supply means when performing the circulation. It is preferable that the inert gas is supplied from (Claim 3).

When the gas in the chamber is exhausted and circulated through the circulation piping, inert gas is supplied from the first inert gas supply means. Therefore, the liquid in the drain tank can be circulated without reducing the pressure inside the chamber.

Further, in the present invention, a pressure reduction on/off valve is provided in the pressure reduction pipe and controls gas flow in the pressure reduction pipe, and a pressure reduction on/off valve is arranged in the chamber to accommodate the substrate and immerse the substrate in the processing liquid to perform the processing. A processing tank, one end of which is connected to the bottom of the chamber, and a chamber drain pipe that discharges the processing liquid stored at the bottom of the chamber, and the other end of the chamber drain pipe, which is connected to the bottom of the chamber. a lower tank disposed below, a second inert gas supply means for supplying inert gas to the lower tank, a sub-reducing pipe that communicates with the lower tank and the reducing pipe, and the sub-reducing pipe. further comprising: a sub-reducing on-off valve that is provided in the sub-reducing pipe to control gas flow in the sub-reducing pipe; the control unit closes the on-off valve when performing the circulation; It is preferable that the inert gas is supplied from the second inert gas supply means with the valve open (Claim 4).

When performing the circulation, the control unit closes the pressure reduction on-off valve, opens the auxiliary pressure reduction on-off valve, and supplies inert gas from the second inert gas supply means. Therefore, the liquid in the drainage tank can be circulated by operating the water ring vacuum pump without affecting the inside of the chamber. Therefore, the timing for loading the next substrate into the chamber can be brought forward, and throughput can be improved.

Further, in the present invention, it is preferable that the drainage tank is arranged at a higher position than the water seal water supply port (Claim 5).

The liquid in the drain tank moves by gravity to the water seal water supply port. Therefore, power such as a pump is not required for the circulation piping. As a result, it is possible to simplify the configuration and reduce costs, as well as to save power.

Further, in the present invention, the control unit further includes a liquid level sensor that detects a predetermined height position of the liquid level in the drainage tank, and after opening the on-off valve, when the liquid level sensor is activated, the control unit controls the on-off valve. It is preferable to close the (Claim 6).

It is possible to prevent the liquid in the drainage tank from falling below a predetermined height. Therefore, it is possible to prevent the operation of the water ring vacuum pump from being adversely affected due to a shortage of water in the water ring vacuum pump. The predetermined height position here is a height position corresponding to the capacity of water seal water required for operation of the water ring vacuum pump.

Further, in the present invention, it is preferable that the control unit closes the on-off valve before the next substrate is carried into the chamber and the pressure inside the chamber is reduced (Claim 7).

As soon as the next substrate is loaded into the chamber, vacuuming can begin. Therefore, the next process can be performed smoothly.

Further, in the present invention, a water sealing water supply pipe that supplies water sealing water to the drainage tank, and a water sealing water opening/closing valve provided in the water sealing water supply pipe and controlling the flow of water sealing water are further provided. It is preferable that the control unit replenishes the drainage tank with water sealing water by controlling the water sealing water on/off valve based on the liquid level of the drainage tank (claim 8).

The control unit replenishes the drainage tank with water sealing water by controlling the water sealing water on/off valve based on the liquid level of the drainage tank. Therefore, since there is no shortage of water seal water, the pressure reduction operation by the water ring vacuum pump can be performed stably over a long period of time.

In addition, the invention according to claim 9 provides a substrate processing method for performing a predetermined process on a substrate, including a step of reducing the pressure in the chamber using a water ring type vacuum pump after accommodating the substrate in the chamber; After the supply step of supplying a solvent insoluble in pure water as a solvent gas into the chamber while maintaining the reduced pressure, and the depressurization of the chamber by the water ring vacuum pump, the water ring vacuum pump and a discharge step of discharging a part of the liquid in a drainage tank that is connected to the discharge port of the chamber and stores gas and water sealed in the chamber containing the solvent. .

[Operation/Effect] According to the invention described in claim 9, after the pressure reduction step and the supply step, in the discharge step, after the pressure reduction of the chamber by the water ring vacuum pump is completed, all of the liquid in the drainage tank is removed. drain the portion. Therefore, it is possible to prevent the concentration of the solvent in the liquid in the drainage tank from becoming higher than a certain level. As a result, even if the solvent is mixed into the water sealing water, there will be no explosion-proof problem.

According to the substrate processing apparatus according to the present invention, the control section operates the water ring vacuum pump to reduce the pressure in the chamber, and supplies the solvent gas from the solvent gas supply means to process the substrate. Thereafter, when the pressure reduction in the chamber by the water ring vacuum pump is completed, the on-off valve is opened to discharge a portion of the liquid in the drainage tank. Therefore, it is possible to prevent the concentration of the solvent in the liquid in the drainage tank from becoming higher than a certain level. As a result, even if the solvent is mixed into the water sealing water, there will be no explosion-proof problem.

1 is a diagram showing the overall configuration of a substrate processing apparatus according to Example 1. FIG. 5 is a time chart illustrating an example of processing according to the first embodiment. 3 is a schematic diagram showing a circulation step according to Example 1. FIG. 7 is a time chart illustrating an example of processing according to the second embodiment. 3 is a schematic diagram showing a circulation step according to Example 2. FIG.

Examples of the present invention will be described below.

Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing the overall configuration of a substrate processing apparatus according to a first embodiment.

<1. Device configuration>

The substrate processing apparatus 1 performs predetermined processing on the substrate W. For example, the substrate W has a substantially circular shape. The substrate processing apparatus 1 can perform the same processing on a plurality of substrates W at the same time. The substrate processing apparatus 1 can also process one substrate W. The substrate processing apparatus 1 is a so-called batch type apparatus.

The substrate processing apparatus 1 includes a chamber 3 . The chamber 3 is provided with a loading/unloading port 5 at the top for loading/unloading the substrate W. The loading/unloading exit 5 is opened and closed by a shutter (not shown). The chamber 3 can be hermetically sealed from the outside.

The chamber 3 includes a processing tank 7 therein. The processing tank 7 is arranged at the bottom of the chamber 3. The processing tank 7 is spaced apart from the bottom surface of the chamber 3 . The bottom surface of the processing tank 7 is spaced apart from the upper surface of the lower part of the chamber 3. The processing tank 7 is equipped with ejection pipes 9 on both sides of the lower part. The spout pipe 9 supplies the processing liquid to the processing tank 7 . The processing liquid is, for example, pure water or an organic solvent. The processing tank 7 is equipped with a quick drain valve 11 on the bottom surface. The rapid drain valve 11 drains the processing liquid stored in the processing tank 7 to the bottom of the chamber 3 in a short time.

The substrate processing apparatus 1 includes a lifter 13. The lifter 13 can place a plurality of substrates W on its lower portion. The lifter 13 can place a plurality of substrates W in alignment in the front-rear direction of the paper. The lifter 13 can place even one substrate W. The lifter 13 can be raised and lowered to a first height H1, a second height H2, and a second height H3. The first height H1 is outside the chamber 3 and is a position where the substrate W is transferred to and from a transport mechanism (not shown). The second height H2 is a position inside the chamber 3 and above the processing tank 7. The second height H2 is the position at which the substrate W is dried. The third height H3 is a position inside the chamber 3 and inside the processing tank 7. The third height H3 is the position at which the substrate W is processed with the processing liquid in the processing tank 7.

The chamber 3 includes a first nozzle 15, a second nozzle 17, and a third nozzle 19. The first nozzle 15, the second nozzle 17, and the third nozzle 19 are each configured as a pair of nozzles in the left-right direction. The first nozzle 15, the second nozzle 17, and the third nozzle 19 have long axes in the direction in which the plurality of substrates W are aligned. The first nozzle 15 is provided at the highest position in the chamber 3. The second nozzle 17 is provided below the first nozzle 15 and above the third nozzle 19. The third nozzle 19 is provided below the second nozzle 17 and above the upper edge of the processing tank 7 .

The first nozzle 15 is connected to one end of the supply pipe 21 . A nitrogen gas supply source 23 is connected to the other end of the supply pipe 21 . The supply pipe 21 is equipped with an on-off valve 25. The nitrogen gas supply source 23 supplies nitrogen gas (dry N ₂ gas). The on-off valve 25 controls the flow of nitrogen gas in the supply pipe 21 .

The first nozzle 15 described above corresponds to the "first inert gas supply means" in the present invention.

The second nozzle 17 is connected to one end of the supply pipe 27 . A water-soluble solvent supply source 29 is connected to the other end of the supply pipe 27 . The supply pipe 27 is equipped with an on-off valve 31. The water-soluble solvent supply source 29 supplies a solvent soluble in pure water in the form of steam. The water-soluble solvent is, for example, IPA (isopropyl alcohol). The on-off valve 31 controls the flow of water-soluble solvent vapor in the supply pipe 27 . In order to supply the water-soluble solvent vapor from the second nozzle 17 at a high concentration, it is preferable to use a method that does not use a so-called carrier gas. However, if there is no problem in processing even if the concentration is low, a carrier gas may be used for supply.

The third nozzle 19 is connected to one end of the supply pipe 33 . A water repellent supply source 35 is connected to the other end of the supply pipe 33 . The supply pipe 33 is equipped with an on-off valve 37. The water repellent supply source 35 supplies water repellent vapor. Water repellents are also called silylating agents. The water repellent contains a solvent that is insoluble in pure water. Examples of the insoluble solvent include propylene glycol monomethyl ether acetate (also called PGMEA). The water repellent supply source 35 supplies a treatment liquid containing an insoluble solvent as water repellent vapor. The water repellent removes the processing liquid adhering to the surface of the substrate W by its water repellent action and promotes drying of the substrate W.

The chamber 3 includes a first liquid level sensor 39 and a second liquid level sensor 41. The first liquid level sensor 39 and the second liquid level sensor 41 are arranged at the lower part of the chamber 3. The first liquid level sensor 39 and the second liquid level sensor 41 detect a predetermined height position of the liquid level of the processing liquid discharged from the processing tank 7 into the chamber 3 . The first liquid level sensor 39 detects the upper limit height position at which the processing liquid can be stored. The second liquid level sensor 41 detects the lower limit height position of the liquid level of the processing liquid.

One end of a pressure reducing pipe 43 is connected to the chamber 3 in communication. One end of a pressure reducing pipe 43 is connected to the inside of the chamber 3 through its side wall. A water ring vacuum pump 45 is connected to the other end of the pressure reducing pipe 43 . The water ring type vacuum pump 45 is a pump that creates a vacuum state inside by filling water called seal water inside and generating a ring of water by the centrifugal force of an impeller (not shown). A pressure reducing valve 47 is attached to the pressure reducing pipe 43 . The pressure reducing pipe 43 exhausts the gas inside the chamber 3 and reduces the pressure inside the chamber 3 . The pressure reduction on/off valve 47 can adjust the flow rate of fluid flowing through the pressure reduction pipe 43. The pressure reduction on/off valve 47 can allow or block fluid flow at a regulated flow rate.

The water ring vacuum pump 45 includes a suction port 49, a discharge port 51, and a water seal water supply port 53. The water ring type vacuum pump 45 exhausts the gas in the chamber 3 including the vapor of water-soluble solvent and insoluble solvent through the pressure reducing pipe 43 to reduce the pressure in the chamber 3 . The suction port 49 sucks gas. The discharge port 51 discharges the gas sucked from the suction port 49 together with the water seal. The water sealing water supply port 53 is supplied with water sealing water.

One end side of a discharge pipe 55 is connected to the discharge port 51 . A drainage tank 57 is connected to the other end of the discharge pipe 55 . The discharge pipe 55 is always open. In other words, the discharge pipe 55 does not include an on-off valve or the like for controlling the flow of internal fluid. The drain tank 57 is arranged at a higher position than the water seal water supply port 53. Therefore, the liquid in the drain tank 57 moves to the water seal water supply port by gravity. Therefore, power such as a pump is not required for the circulation piping 75, which will be described later. As a result, the configuration can be simplified and costs can be reduced, and power consumption can also be reduced.

The drain tank 57 stores the gas and liquid in the chamber 3 discharged by the water ring vacuum pump 45. The gas in the chamber 3 includes gases such as air and nitrogen gas, and vapors of water-soluble solvents and insoluble solvents supplied to the chamber 3. The liquid includes a liquefied water-soluble solvent or an insoluble solvent (water repellent) supplied to the chamber 3, and water sealed from the water-sealed vacuum pump 45.

The drain tank 57 is connected to one end of a water seal water supply pipe 59 for communication. A pure water supply source 61 is connected to the other end of the water seal supply pipe 59 . The water sealing water supply pipe 59 is equipped with a water sealing water on-off valve 61. The water seal water on/off valve 61 controls the flow of pure water in the water seal water supply pipe 59 . The drain tank 57 is equipped with a liquid level sensor 63. The liquid level sensor 63 detects the height position of the liquid level in the drain tank 57. The liquid level sensor 63 can detect a predetermined height position of the liquid level in the drain tank 57. The liquid level sensor 63 can detect a predetermined upper limit position and a predetermined lower limit position among the height positions of the liquid level in the drain tank 57 . The upper limit position defines, for example, a suitable timing for draining the liquid in the drain tank 57. The lower limit position defines, for example, a suitable timing for stopping the discharge when the liquid in the drain tank 57 is discharged. The lower limit position is a height position corresponding to the minimum capacity of the water ring necessary for the operation of the water ring vacuum pump 45.

The drainage tank 57 is equipped with an exhaust pipe 65. Specifically, one end side of an exhaust pipe 65 is connected to the upper part of the drain tank 57 . The other end of the exhaust pipe 65 is connected to exhaust equipment 67 . The exhaust equipment 67 processes the solvent contained in the gas exhausted from the exhaust pipe 65.

The drain tank 57 is equipped with a drain pipe 69. Specifically, the drain tank 57 has one end side of a drain pipe 69 connected to the lower part thereof. The other end of the drain pipe 69 is connected to a drain facility 71 . The drain equipment 71 processes pure water and solvent contained in the liquid discharged from the drain pipe 69. The drain pipe 69 is equipped with an on-off valve 73. The on-off valve 73 controls the flow of liquid in the drain pipe 69.

The drainage tank 57 is connected to one end of the circulation pipe 75 . The drainage tank 57 is equipped with a circulation pipe 75 at its lower part. The other end of the circulation pipe 75 is connected to a water seal water supply port 53 of the water seal vacuum pump 45 . The circulation pipe 75 communicates and connects the drainage tank 57 and the water sealing water supply port 53 of the water sealing type vacuum pump 45 . The circulation pipe 75 is equipped with a heat exchanger 77. The heat exchanger 77 exchanges heat with the liquid flowing through the circulation pipe 75. The heat exchanger 77 cools the liquid flowing through the circulation pipe 75. Specifically, the heat exchanger 77 cools water seal water made of pure water containing a solvent and the like and flowing through the circulation pipe 75.

A lower tank 79 is arranged below the chamber 3 . The lower tank 79 has a smaller volume than the chamber 3. In other words, the chamber 3 has a larger volume than the lower tank 79. The processing liquid stored in the lower part of the chamber 3 is discharged from the lower tank 79 . The chamber 3 has one end side of a chamber drain pipe 81 connected to the bottom thereof. The other end of the chamber drain pipe 81 is connected to the lower tank 79 . The chamber drain pipe 81 is equipped with an on-off valve 83 . The on-off valve 83 controls the flow of the processing liquid in the chamber drain pipe 81 .

One end side of a branch pressure reducing pipe 85 is connected to the pressure reducing pipe 43 in communication. Specifically, one end of the branch pressure reduction pipe 85 is connected to the pressure reduction pipe 43 closer to the chamber 3 than the pressure reduction on/off valve 47 . The other end of the branch pressure reducing pipe 85 is connected to the lower tank 79 . The branch pressure reducing pipe 85 is equipped with an on-off valve 87. The on-off valve 87 controls the flow of gas in the branch pressure reducing pipe 85 . The branch pressure reducing pipe 85 is used to reduce the pressure in the chamber 3 and the lower tank 79 .

The lower tank 79 includes a pressure sensor 89, an upper limit sensor 91, and a lower limit sensor 93. Pressure sensor 89 detects the pressure inside lower tank 79. The pressure sensor 89 is used to detect that the pressure in the lower tank 79 has become lower than the pressure inside the chamber 3. The upper limit sensor 91 and the lower limit sensor 93 detect a predetermined height position of the processing liquid level in the lower tank 79 . Specifically, the upper limit sensor 91 detects that the liquid level of the processing liquid has reached a predetermined upper limit height position. The lower limit sensor 93 detects that the liquid level of the processing liquid has reached a predetermined lower limit height position.

One end side of a sub-pressure reducing pipe 95 is connected to the pressure reducing pipe 43 in communication. Specifically, one end side of the auxiliary pressure reducing pipe 95 is connected between the pressure reducing valve 47 of the pressure reducing pipe 43 and the suction port 49 of the water seal vacuum pump 45 . The other end of the sub pressure reducing pipe 95 is connected to the lower tank 79 . The sub pressure reducing pipe 95 is equipped with a sub pressure reducing on/off valve 97. The auxiliary pressure reducing valve 97 can adjust the flow rate of gas in the auxiliary pressure reducing pipe 95. The auxiliary pressure reduction on/off valve 97 can allow or block gas flow at a regulated flow rate.

The lower tank 79 has one end side of a drain pipe 99 connected to the lower part thereof. The other end of the drain pipe 99 is connected to a drain facility 101 . The drain pipe 99 is equipped with an on-off valve 103. The on-off valve 103 controls the flow of liquid in the drain pipe 99 . The drain pipe 99 discharges the liquid stored in the lower tank 79. The liquid includes pure water, a solvent, and a water repellent.

One end of the supply pipe 105 is connected to the upper part of the lower tank 79 for communication. The other end of the supply pipe 105 is connected to a nitrogen gas supply source 107 . A nitrogen gas supply source 107 supplies nitrogen gas. The supply pipe 105 is equipped with a flow rate regulating valve 109 . The flow rate adjustment valve 109 can adjust the flow rate of nitrogen gas in the supply pipe 105. The flow rate adjustment valve 109 can allow or block the flow of nitrogen gas at a regulated flow rate.

Note that the above-mentioned supply pipe 105 corresponds to the "second inert gas supply means" in the present invention.

The control unit 111 includes a CPU and memory. The control unit 111 operates each unit based on a recipe according to a processing procedure for processing the substrate W (or lot). The control unit 111 controls the water sealing water on-off valve 61 based on the liquid level measured by the liquid level sensor 63 of the drainage tank 57 to replenish the water sealing water to the drainage tank 57 . Therefore, since there is no shortage of water seal water, the pressure reduction operation by the water ring vacuum pump 45 can be performed stably over a long period of time.

The above-mentioned rapid drain valve 11, lifter 13, on-off valve 25, on-off valve 31, on-off valve 37, water-seal vacuum pump 45, pressure reduction on-off valve 47, water-seal water on-off valve 61, The on-off valve 73, the on-off valve 83, the on-off valve 87, the auxiliary pressure reducing on-off valve 97, the on-off valve 103, and the flow rate adjustment valve 109 are operated by the control unit 111. The control unit 111 receives outputs from the first liquid level sensor 39 , the second liquid level sensor 41 , the liquid level sensor 63 , the pressure sensor 89 , the upper limit sensor 91 , and the lower limit sensor 93 . In order to simplify the illustration, in FIG. 1, only some of the above-mentioned configurations are drawn with dotted lines as signal lines between them and the control unit 111.

<2. Specific example of processing>

Here, the processing of the substrate W will be specifically explained with reference to FIGS. 2 and 3. FIG. 2 is a time chart showing an example of processing according to the first embodiment. FIG. 3 is a schematic diagram showing a circulation step according to the first embodiment. Although the following description will be made assuming that a substrate W is processed, the same applies even if one substrate W, a plurality of substrates W, or these are referred to as a lot. In addition, in the following description, matters other than the drainage control in the drainage tank 57 are simplified and described. In FIG. 2, the symbol O means open and represents an open state, and the symbol C means close and represents a closed state.

In the initial state, it is assumed that pure water is stored in the processing tank 7. Pure water is supplied to the processing tank 7 upward from the jet pipe 7 . From time 0 to t1, the lifter 13 on which the substrate W is placed is located at a first height H1 corresponding to the outside of the chamber 3. Further, the on-off valve 25 is opened, and nitrogen gas is supplied into the chamber 3 from the first nozzle 15.

The control unit 111 lowers the lifter 13 to the third height position H3 at time t1. As a result, the substrate W placed on the lifter 13 is cleaned with pure water. This state is maintained until time t6, and the pure water cleaning process is performed. Particles and processing liquid adhering to the substrate W are removed from the substrate W by the pure water cleaning process.

The control unit 111 closes the on-off valve 25 at time t2 and stops supplying nitrogen gas. Furthermore, the control unit 111 opens the pressure reducing on-off valve 47 at the first flow rate at time t2. The control unit 111 simultaneously operates the water ring vacuum pump 45. The control unit 111 maintains this state until time t11. As a result, the pressure inside the chamber 3 is reduced to a predetermined processing pressure. At this time, nitrogen gas and water seal water are discharged from the discharge pipe 55 to the drainage tank 57 . The water seal in the drainage tank 57 passes through the circulation pipe 75, is cooled by the heat exchanger 77, and is supplied again to the water seal vacuum pump 45 as water seal.

The control unit 111 opens the on-off valve 31 at time t3, when the pressure inside the chamber 3 is reduced to some extent. When the on-off valve 31 is opened, IPA vapor is supplied into the chamber 3 from the second nozzle 17. This state continues until time t7.

For example, at time t4, the control unit 111 opens the auxiliary pressure reducing on-off valve 97 at the second flow rate. This state is maintained until time t5. That is, the control unit 111 closes the auxiliary pressure reducing on-off valve 97 at time t5. The second flow rate is larger than the first flow rate that reduces the pressure in the chamber 3. As a result, the pressure inside the lower tank 79 is reduced. Since the second flow rate is higher than the first flow rate, the lower tank 79 is depressurized to a lower pressure than the chamber 3.

The control unit 111 raises the lifter 13 to the second height H2 at time t6. As a result, the substrate W held by the lifter 13 is lifted above the pure water level in the processing tank 7 of the chamber 3 . The control unit 111 maintains the lifter 13 at the second height H2 until time t10. Thereby, the replacement process is performed on the substrate W. Specifically, the pure water adhering to the substrate W is replaced with IPA vapor, which is a water-soluble solvent. Even during the replacement process, the water ring vacuum pump 45 continues to reduce the pressure. Therefore, water sealed with IPA dissolved therein is discharged from the discharge pipe 55 into the drainage tank 57 .

At time t6, the control unit 111 raises the lifter 13 to the second height H2 and opens the rapid drain valve 11. Thereby, the pure water in the processing tank 7 is discharged to the lower part of the chamber 3 in a short time.

The control unit 111 opens the on-off valve 37 at time t6. As a result, water repellent vapor is supplied into the chamber 3 from the third nozzle 19, and water repellent treatment is performed. As a result, the front and back surfaces and end surfaces of the substrate W held by the lifter 13 are rendered hydrophobic. That is, the water repellent agent adheres to the entire substrate W in which pure water has been replaced with IPA, and the entire substrate W is made hydrophobic. This allows the pure water and water-soluble solvent remaining on the substrate W to be easily removed from the substrate W.

The control unit 111 closes the on-off valve 31 at time t7. As a result, IPA vapor from the second nozzle 17 into the chamber 3 is blocked.

The control unit 111 opens the on-off valve 83 from time t8 to time t9. As a result, the pure water containing IPA and water repellent, which has been stored in the lower part of the chamber 3, is discharged to the lower tank 79. The lower tank 79 is depressurized to a lower pressure than the chamber 3 from t4 to t5. Therefore, even if the chamber 3 is in a reduced pressure state, the stored pure water is smoothly discharged to the lower tank 79.

The pure water thus stored in the lower part of the chamber 3 is discharged to the lower tank 79. Therefore, it is possible to avoid the problem that moisture evaporates from the lower part of the chamber 3 under reduced pressure and adheres to the substrate W, which hinders drying.

The control unit 111 closes the on-off valve 37 at time t10. As a result, the supply of the water repellent into the chamber 3 is stopped. Therefore, the water repellent treatment for the substrate W is completed.

At time t10, the control unit 111 opens the on-off valve 25 and supplies nitrogen gas into the chamber 3 from the first nozzle 15. This supply of nitrogen gas is continued until the next substrate W is carried in at time t13. The flow rate of nitrogen gas at this time is approximately the same as the flow rate of exhaust by the water ring vacuum pump 45. Therefore, the pressure inside the chamber 3 is returned to approximately atmospheric pressure without being pressurized or depressurized. In other words, the inside of the chamber 3 is opened to atmospheric pressure. However, the evacuation operation of the chamber 3 by the water ring vacuum pump 45 continues. The control unit 111 raises the lifter 13 to a first height H1. Thereby, the processed substrate W is carried out to the outside of the chamber 3.

Note that even after the substrate W is unloaded, the water ring vacuum pump 45 continues to operate until time t11. At this time, as shown in FIG. 3, nitrogen gas is supplied to the chamber 3 from the first nozzle 15, and the water ring vacuum pump 45 exhausts the gas inside the chamber 3. Therefore, the water sealed in the drain tank 57 can be circulated without reducing the pressure inside the chamber 3. As a result, as shown in FIG. 3, the water seal containing IPA and water repellent is circulated to the drainage tank 57 via the circulation pipe 75. At this time, the water seal water is cooled by the heat exchanger 77, so that the water seal water whose temperature has increased due to the operation of the water ring vacuum pump 45 is cooled. Therefore, even if the water ring water is circulated, the operation of the water ring vacuum pump 45 is not adversely affected. In addition, Suifengui contains IPA and water repellent. Therefore, the water-soluble solvent and water repellent are efficiently concentrated by cooling.

The control unit 111 stops the water ring vacuum pump 45 at time t11 immediately after circulating the water seal water as described above. The control unit 111 opens the on-off valve 73 from time t11 to time t12. As a result, a part of the water seal water stored in the drainage tank 57 is discharged to the drainage equipment 71. In this water seal, the water-soluble solvent and water repellent are concentrated and circulated, so that the water repellent, which is insoluble in pure water, is also mixed into the pure water by stirring. Therefore, even if the water seal is discharged from the drain pipe 69 provided at the lower part of the drain tank 57, the water repellent can be appropriately discharged.

The control unit 111 closes the on-off valve 73 at time t12, which is before time t13 when the next substrate W is carried in. Thereby, as soon as the next substrate W is carried into the chamber 3, the water-sealing vacuum pump 45 can be operated to start depressurizing the inside of the chamber 3. Therefore, the next process can be performed smoothly.

Although the control unit 111 closes the on-off valve 73 at time t12, the on-off valve 73 may be closed when a predetermined liquid level detected by the liquid level sensor 63 is reached. Thereby, it is possible to avoid an adverse effect on the operation of the water ring type vacuum pump 45 due to insufficient water seal water being discharged too much.

Note that the water repellent is lighter than pure water. Therefore, if the water is not circulated and stirred through the circulation pipe 75, the water repellent will form a layer on top of the pure water and will be in a separated state. Therefore, if water is drained from the lower part of the drain tank 57 in this state, the water repellent will not be discharged. If such discharge continues, the concentration of the water repellent in the drain tank 57 will increase, causing a problem in terms of explosion protection. According to this embodiment, since the water repellent is properly discharged, the explosion-proof problem can be solved. Furthermore, the drainage equipment 71 performs processing assuming that the concentration of the water repellent agent is equal to or higher than a predetermined value. Therefore, if the concentration of the water repellent agent is too low, there is a possibility that drainage treatment cannot be performed appropriately. According to this embodiment, drainage treatment can be performed appropriately by stirring.

By the way, a concentration meter is provided to measure the concentration of the water repellent in the water seal water stored in the drainage tank 57, and when the concentration exceeds the concentration and the processing of the substrate W is completed, the water seal vacuum pump 45 Alternatively, the on-off valve 73 may be opened by stopping the on-off valve 73. Thereby, the circulation time from t10 to t11 can be suppressed. As a result, the operating time of the water ring vacuum pump 45 required for stirring can be shortened, so power consumption can be suppressed. To measure the concentration of the water repellent, a concentration meter may be provided at the top of the drainage tank 57 to measure the concentration of the water repellent. That is, the concentration of the water repellent agent volatilized from the water sealed in the water tank 57 is measured.

Note that the T1 period from t2 to t10 described above corresponds to the "depressurization step" in the present invention. The T2 period from t6 to t10 described above corresponds to the "supply step" in the present invention. The T3 period from t10 to t11 described above corresponds to the "circulation step" in the present invention. The T4 period from t11 to t12 described above corresponds to the "discharge step" in the present invention.

According to the present embodiment, the control unit 111 operates the water ring vacuum pump 45 to reduce the pressure in the chamber 3, supplies the water repellent from the third nozzle 19, and processes the substrate W. Thereafter, when the pressure reduction in the chamber 3 by the water ring type vacuum pump 45 is completed, the on-off valve 73 is opened to discharge a portion of the water seal water in the drainage tank 57. Therefore, it is possible to prevent the concentration of the water repellent agent in the water seal in the drainage tank 57 from becoming higher than a certain level. As a result, even if the water repellent is mixed into the sealed water, there will be no explosion-proof problem.

Next, a second embodiment of the present invention will be described with reference to the drawings. Note that the configuration of the substrate processing apparatus 1 is the same as that of the first embodiment described above. The difference between the second embodiment and the first embodiment is the control by the control unit 111. Therefore, only an example of the process will be described with reference to FIGS. 4 and 5.

FIG. 4 is a time chart showing an example of processing according to the second embodiment. FIG. 5 is a schematic diagram showing a circulation step according to the second embodiment.

The second embodiment is different from the first embodiment described above in the control performed by the control unit 111 during the T3 period from t10 to t11. The control unit 111 closes the pressure reduction on/off valve 47 at time t10 when the pressure reduction in the chamber 3 is completed. Furthermore, the control unit 111 opens the auxiliary pressure reduction on/off valve 97 and the flow rate adjustment valve 109 at time t10 when the pressure reduction in the chamber 3 is completed. As a result, the lower tank 79 is first opened to atmospheric pressure. The control unit 111 closes the auxiliary pressure reduction on/off valve 97 and the flow rate adjustment valve 109 at time t11 when the circulation is completed.

During the T3 period, the sealed vacuum pump 45 discharges the nitrogen gas in the lower tank 79 to the drain tank 57. During this time, as shown in FIG. 5, the water seal is circulated through the circulation pipe 75. Immediately thereafter, at time t11 to t12, the on-off valve 73 is opened, and a portion of the water seal water stored in the drainage tank 57 is discharged to the drainage equipment 71.

According to this embodiment, the same effects as in the first embodiment described above are achieved. Furthermore, according to the present embodiment, when performing circulation, the control unit 111 supplies inert gas from the nitrogen gas supply source 107 while closing the pressure reduction on-off valve 47 and opening the auxiliary pressure reduction on-off valve 97. let Therefore, the water ring type vacuum pump 45 can be operated to circulate the water seal water in the drain tank 57 without affecting the inside of the chamber 3. Therefore, for example, as shown by the dotted line in FIG. 4, the substrate W can be carried into the chamber 3 at time t10a, and the timing at which the next substrate W is carried into the chamber 3 can be brought forward. Therefore, improvement in throughput can be expected.

The present invention is not limited to the above embodiments, and can be modified as described below.

(1) In each of the first and second embodiments described above, immediately after the liquid in the drainage tank 57 is circulated through the circulation pipe 75, the on-off valve 73 is opened to discharge the liquid. However, the invention is not limited to such embodiments. For example, the on-off valve 73 may be opened after a predetermined time (several minutes) instead of immediately.

(2) In the first embodiment described above, nitrogen gas is supplied to the chamber 3 during circulation. However, the present invention is not limited to this form. For example, the inside of the chamber 3 may be made to have a negative pressure without supplying nitrogen gas to the chamber 3.

(3) In the second embodiment described above, the auxiliary pressure reducing pipe 95 and the lower tank 79 are evacuated to circulate the water seal. However, the present invention is not limited to this form. For example, the pressure reducing pipe 43 is provided with a three-way valve so that it can be switched between a state in which it communicates with the chamber 3 and a state in which it communicates with the atmosphere. When circulating the water seal, the three-way valve may be switched to a state where it communicates with the atmosphere. According to this, it is possible to circulate without affecting the chamber 3 or the lower tank 79. Therefore, it is possible to move forward the loading of the substrate W into the chamber 3, and also to advance the timing of reducing the pressure in the lower tank 79. As a result, throughput can be expected to improve.

(4) In each of the first and second embodiments described above, the drainage tank 57 is arranged at a higher position than the water seal water supply port 53 of the water ring vacuum pump 45. However, the present invention is not limited to this configuration. For example, the drain tank 57 may be arranged at a lower position than the water seal water supply port 53 of the water seal vacuum pump 45. In this case, a pump is disposed in the circulation pipe 75 to actively circulate the water seal with the pump.

(5) In each of Examples 1 and 2 described above, a water repellent containing pegmia (PGMEA) was used as an example of a solvent insoluble in pure water. However, the present invention is not limited to water repellents containing pegmia.

W ... Substrate 1 ... Substrate processing device 3 ... Chamber 7 ... Processing tank 11 ... Rapid drain valve 13 ... Lifter 15 ... First nozzle 17 ... Second nozzle 19 ... Third nozzle 35 ... Water repellent supply source 43 ... Pressure reducing pipe 45 ... Water seal vacuum pump 47 ... Pressure reducing valve 49 ... Suction port 51 ... Discharge port 53 ... Water seal water supply port 55 ... Discharge pipe 57 ... Drainage tank 59 ... Water seal water supply pipe 61 ... Water seal water On-off valve 63... Liquid level sensor 65... Exhaust pipe 69... Drain pipe 73... On-off valve 75... Circulation piping 77... Heat exchanger 79... Lower tank 81... Chamber drain pipe 95... Sub-pressure reducing pipe 97... Sub-pressure reducing on-off valve 105... Supply pipe 109... Flow rate adjustment valve 111... Control section

Claims (10)

In a substrate processing apparatus that performs predetermined processing on a substrate,
a chamber that accommodates the substrate and performs processing on the substrate;
a solvent gas supply means for supplying a solvent insoluble in pure water into the chamber as a solvent gas;
A water ring vacuum pump that sucks gas in the chamber, and includes a suction port for sucking the gas, an outlet for discharging the gas, and a water seal supply port for supplying water. and,
a decompression tube having one end connected to the chamber and the other end connected to the suction port;
a drainage tank that is connected to the discharge port and stores the gas and water contained in the chamber containing the solvent;
circulation piping that communicates and connects the drainage tank and the water seal water supply port of the water ring vacuum pump;
a heat exchanger that is provided in the circulation piping and cools the liquid flowing in the circulation piping;
an exhaust pipe connected to the upper part of the drainage tank;
a drain pipe connected to the lower part of the drain tank;
an on-off valve that is provided in the drain pipe and controls the flow of liquid in the drain pipe;
The water ring type vacuum pump is operated to reduce the pressure in the chamber, and after processing the substrate by supplying a solvent gas from the solvent gas supply means, the pressure in the chamber is reduced by the water ring type vacuum pump. a control unit that opens the on-off valve and discharges a portion of the liquid in the drainage tank when the process is completed;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 1,
The substrate processing apparatus is characterized in that the control unit opens the on-off valve immediately after activating the water ring vacuum pump to circulate the liquid in the drainage tank through the circulation piping. The substrate processing apparatus according to claim 1 or 2,
further comprising a first inert gas supply means for supplying an inert gas into the chamber,
The substrate processing apparatus is characterized in that the control section causes the first inert gas supply means to supply an inert gas when performing the circulation. The substrate processing apparatus according to claim 1 or 2,
a pressure reduction on/off valve provided in the pressure reduction pipe and controlling gas flow in the pressure reduction pipe;
a processing tank disposed in the chamber, accommodating a substrate, and performing processing by immersing the substrate in a processing liquid;
a chamber drain pipe, one end of which is communicatively connected to the bottom of the chamber, and which discharges the processing liquid stored in the bottom of the chamber;
a lower tank disposed below the chamber, the other end of the chamber drain pipe being connected in communication;
a second inert gas supply means for supplying inert gas to the lower tank;
an auxiliary pressure reducing pipe that communicates and connects the lower tank and the pressure reducing pipe;
a sub-pressure reducing on-off valve provided in the sub-pressure reducing pipe and controlling gas flow in the sub-pressure reducing pipe;
Furthermore,
When performing the circulation, the control unit closes the pressure reduction on-off valve and causes the second inert gas supply means to supply inert gas with the auxiliary pressure reduction on-off valve opened. Features of substrate processing equipment. The substrate processing apparatus according to claim 1 or 2,
The substrate processing apparatus is characterized in that the drainage tank is arranged at a higher position than the water sealing water supply port. The substrate processing apparatus according to claim 1 or 2,
further comprising a liquid level sensor that detects a predetermined height position of the liquid level in the drainage tank,
The substrate processing apparatus is characterized in that the control unit closes the on-off valve when the liquid level sensor is activated after opening the on-off valve. The substrate processing apparatus according to claim 1 or 2,
The substrate processing apparatus is characterized in that the control unit closes the on-off valve until the next substrate is carried into the chamber and the pressure inside the chamber is reduced. The substrate processing apparatus according to claim 1 or 2,
a water-sealing water supply pipe that supplies water-sealing water to the drainage tank;
a water sealing water on-off valve that is provided in the water sealing water supply pipe and controlling the flow of the water sealing water;
Furthermore,
The substrate processing apparatus is characterized in that the control unit controls the water sealing water on/off valve based on the liquid level of the drainage tank to replenish the water sealing water to the drainage tank. In a substrate processing method in which a predetermined process is performed on a substrate,
After accommodating the substrate in the chamber, a depressurizing step of reducing the pressure in the chamber using a water ring vacuum pump;
supplying a solvent insoluble in pure water as a solvent gas into the chamber while maintaining the reduced pressure;
After the pressure reduction of the chamber by the water-ring vacuum pump is completed, a drainage tank in a drainage tank is connected to the discharge port of the water-ring vacuum pump and stores the gas in the chamber containing the solvent and the water-sealed water. a draining step for draining a portion of the liquid;
A substrate processing method characterized by carrying out the following. The substrate processing method according to claim 9,
After the pressure reduction of the chamber by the water-ring vacuum pump is completed, the inside of the drainage tank is connected via a circulation pipe whose one end is connected to the drainage tank and whose other end is connected to the water-ring vacuum pump. further carrying out a circulation step of circulating the liquid;
A substrate processing method characterized in that the discharge step is performed immediately after the circulation step.

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